Warshaw, Leon J.

Warshaw, Leon J.

Address: Institute of Environmental Medicine, 180 West End Avenue #6C, New York, New York 10023-4926

Country: United States

Phone: 1 (212) 877-1060

E-mail: 76451.333@compuserve.com

Past position(s): Executive Director, New York Business Group on Health; Deputy Director for Health Affairs, New York City Mayor's Office of Operations; Vice-President, Corporate Medical Director, Equitable Life Assurance Society of the US

Education: BA, 1938, Columbia College; MD, 1942, Columbia College of Physicians and Surgeons

Areas of interest: Organization of occupational health services; health promotion; stress; violence in the; workplace

Monday, 04 April 2011 15:09

Violence in Gasoline Stations

Gasoline station workers rank fourth among US occupations with the highest rates of occupational homicides, with almost all occurring during attempted armed robberies or other crimes (NIOSH 1993b). The recent trend to replace repair shops with convenience stores has made them even more of a target. Study of the circumstances involved has led to the delineation of the following risk factors for such criminal violence:

  • exchange of money with the public
  • working alone or in small numbers
  • working late night or early morning hours
  • working in high-crime areas
  • guarding valuable property or possessions
  • working in community settings.

 

An additional risk factor is being in locations that are readily accessible and particularly suited to quick getaways.

To defend themselves against attempted robberies, some gasoline station workers have provided themselves with baseball bats or other cudgels and even acquired firearms. Most police authorities oppose such measures, arguing that they are likely to provoke violent reactions on the part of the criminals. The following preventive measures are suggested as more effective deterrents of robbery attempts:

  • bright lighting of the gasoline pump and parking areas and of the interiors of stores and cashier’s areas
  • large, unobstructed, bullet-resistant windows to enhance the visibility of the interior of the store and enclosures of bullet-resistant glass for the cashier
  • separate outside entrances to any public rest rooms so that persons using them do not have to enter the store. (A separate, indoor, employee-only rest room would provide privacy for employees and obviate the need for them to go outside to use the public restroom.)
  • provision of drop-boxes and time-release safes to hold all but a very limited amount of cash, as well as highly visible signs indicating their use
  • establishing a policy of not making change for cash purchases during night and early morning hours
  • hiring an additional worker or a security guard so that the worker is never alone (operators of gasoline stations and convenience stores object to the additional cost)
  • installing an electrical or electronic alarm system (triggered by easily accessed “panic” buttons) that will provide audible and visual distress signals to attract police or other assistance—this can be combined with an alarm wired directly to a local police station
  • installing high-fidelity television monitors to assist in identifying and, ultimately, apprehending the perpetrator(s).

 

Consultation with local police authorities and crime-prevention experts will assist in the selection of the most appropriate and cost-effective deterrents. It must be remembered that the equipment should be properly installed and periodically tested and maintained, and that the workers must be trained in its use.

 

Back

Saturday, 02 April 2011 22:43

Health Effects and Disease Patterns

The health and safety problems in the forestry and lumber industries are covered elsewhere in this Encyclopaedia. This article will deal with wood as it arrives from the mill and is used in carpentry and the making of furniture and other articles. These activities are predominantly performed in small enterprises. Many workers in these industries are individual contractors and, therefore, not listed as employees, and large numbers of individuals are exposed in do-it-yourself projects and in-home workshops. This means that many of the workers involved are inadequately trained and are supervised poorly or not at all, while proper safeguards and protective equipment are often lacking.

Ahman and colleagues (1995a, 1995b, 1996) call attention to the exposure of teachers of industrial arts and woodworking in Sweden. In contrast to unexposed controls, these teachers had notable (but mainly reversible) nasal effects and complaints that increased with the number of classes from the beginning of the week and receded over the weekends, even though the dust concentrations were below the Swedish threshold limit of 2 mg/m3. In several establishments in the Netherlands, dust levels regularly exceeded that limit, and during sanding operations in a furniture factory, almost all exposures were over the local threshold limit of 5 mg/m3 (Scheeper, Kromhout and Boleij 1995).

Accidental Injuries

The most common health problem in the wood and woodworking industries is accidental injuries. These are more frequent among younger, inexperienced workers, and, for the most part, they are relatively minor. On occasion, however, they may involve long-term impairment or loss of an extremity. They include: splinters, which may become infected, and lacerations, gouges and amputations resulting from improperly used or inadequately guarded woodworking machinery (Ma, Wang and Chou 1991); sprains and strains from injudicious lifting or working in an awkward position (Nestor, Bobick and Pizatella 1990); repetitive motion injuries involving the hand or shoulder; and eye injuries. Many if not most of these can be prevented by proper training, the judicious application of machine guards and restraints and the use of personal protective equipment such as gloves and safety glasses. When they occur, prompt removal of splinters and prevention of infection by expeditious cleansing and first aid treatment of wounds will minimize disability.

Wood Dust

Wood dust exposure occurs whenever wood is sawed, chipped, planed, routed or sanded. The effects vary with the intensity and duration of the exposure and the size of the particles. Particles in the eyes may cause irritation, and wood dust gathering in skin folds may be aggravated by perspiration and chemicals and lead to irritation and infection. These effects may be reduced by vacuum removal of the dust, protective masks and clothing and good personal hygiene practices.

Nasopharyngeal and respiratory passages

Wood dust in the nasal passages may diminish mucociliary clearance and impair olfactory sensitivity (Andersen, Solgaard and Andersen 1976; Ahman et al. 1996). These may lead to irritation, frequent sneezing, nosebleeds and infection of the sinuses (Imbus 1994).

Exposures in a furniture factory (Whitehead, Ashikaga and Vacek 1981) and in sawmill workers (Hessel et al. 1995) were shown to be accompanied by decreases in both 1-second forced expiratory volume (FEV1) and forced vital capacity (FVC), adjusted for age, height and smoking. These were accompanied by significant increases in shortness of breath and wheeze with chest tightness and the occurrence of bronchitis and asthma. There is, however, no convincing evidence of other lung disease due to wood dust exposures (Imbus 1994). In a 6-year prospective follow-up study of approximately 350,000 males in the United States, the 11,541 individuals who reported having been employed in wood-related occupations had a lower relative risk of mortality due to non-malignant respiratory disease than those who did not report exposure to wood dust (Demers et al. 1996).

Allergy and Asthma

Some woods, notably teak, mansonia and radiata pine, contain chemicals that are irritants (see table 1 for an extended list of wood species, their geographic origins, and their health effects). Some species may cause allergic contact dermatitis (e.g., Douglas fir, western red cedar, poplar, rosewood, teak, African mahogany and other “exotic” woods). Western red cedar, rosewood, mahogany and other exotic woods have been shown to cause asthma (Imbus 1994).

Cancer

An unusually high incidence of nasal cancer has been described among woodworkers in Australia, Canada, Denmark, Finland, France, Italy, the Netherlands, the United Kingdom and the United States (Imbus 1994). A recent pooled re-analysis of 12 case-control cohort studies conducted in seven countries confirmed a high risk of nasopharyngeal cancer among woodworkers (Demers et al. 1995). The cause of these excesses of nasal cancer is not known, but, according to recent reports from the United Kingdom and the United States, the risk of nasal cancer among furniture workers has declined since the Second World War, presumably reflecting changes in the manufacturing process (Imbus 1994). No excess risk of sino-nasal cancer was found among the 45,399 men exposed to wood dust included among the 362,823 men enrolled in the American Cancer Society’s 6-year Cancer Prevention Study, but, the researchers note, the number of cases was small. They did, however, find an especially high increase in lung cancer mortality among woodworkers who also reported exposure to asbestos or formaldehyde, and suggested that exposure to these known carcinogens was responsible for the observed increased risk (Stellman et al., in press).

Chemical Exposures

Wood may contain biological contaminants. Moulds and fungi, which often grow on the bark of trees, may cause allergic reactions. Inhalation of fungal spores found on maple, redwood and cork trees has been shown to cause maple bark disease, sequoiosis and suberosis (Imbus 1994).

Wood often contains exogenous chemicals applied in the course of its processing. These include adhesives, solvents, resin binders, insecticides and fungicides, waterproofing compounds, paints and pigments, lacquers and varnishes. Many of these are volatile and may be emitted when the wood is treated, heated or incinerated; they are also conveyed as elements in wood dust. The most important of these include: toluene, methanol, xylene, methyl ethyl ketone, n-butyl alcohol, 1, 1,1-trichlorethane and dichloromethane (EPA 1995).

Conclusion

Health hazards of the wood and woodworking industries may be controlled by installation of engineering controls (e.g., proper placement and guarding of power machinery, ventilation systems to control wood dust and chemical emissions) and personal protective equipment (e.g., gloves, safety glasses, respirators), coupled with periodic inspections to ensure that these are properly maintained and used. Perhaps most important is appropriate education and training of the workers and their supervisors.

Table 1. Poisonous, allergenic and biologically active wood varieties

Scientific names Selected commercial names Family Health Impairment
Abies alba Mill (A. pectinata D.C.) Silver fir Pinaceae Dermatitis; conjunctivitis-rhinitis; asthma
Acacia spp.
A. harpophylla
F. Muell.
A. melanoxylon
R. Br.
A. seyal
Del.
A. shirley
Maiden
Australian blackwood Mimosaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Acer spp.
A. platanoides
L.
Maple Aceraceae Dermatitis
Afrormosia elata Harms.
(Pericopsis elata
Van Meeuwen)
Afrormosia, kokrodua, asamala, obang, oleo pardo, bohele, mohole Papilionaceae Dermatitis; conjunctivitis-rhinitis; asthma
Afzelia africana Smith
A. bijuga
A. Chev. (Intsia bijuga A. Cunn.
A. palembanica
Bak. (Intsia palembanica Bak.)
Doussié, afzelia, aligua, apa, chanfuta, lingue merbau, intsia, hintsy Caesalpinaceae Dermatitis; conjunctivitis-rhinitis; asthma
Agonandra brasiliensis Miers Pao, marfim, granadillo Olacaceae Dermatitis
Ailanthus altissima Mill Chinese sumac Simaroubaceae Dermatitis
Albizzia falcata Backer 
A. ferruginea Benth.
A. lebbek Benth 
A. toona F.M. Bail
Iatandza
Kokko, siris
Mimosaceae Dermatitis; conjunctivitis-rhinitis; asthma; 
toxic effects
Alnus spp.
A. glutinosa
Gaertn.
Common alder
Black alder
Betulaceae Dermatitis; conjunctivitis-rhinitis; asthma
Amyris spp.
A. balsamifera
L.
A. toxifera
Willd.
Venezuelan or West Indian sandalwood Rutaceae Dermatitis; toxic effects
Anacardium occidentale L.
A. excelsum
Skels.
Cashew Anacardiaceae Dermatitis
Andira araroba Aguiar. (Vataireopsis araroba Ducke)
A. coriacea
Pulle
A. inermis
H.B.K. 
Red cabbage tree Partridge wood Papilionaceae Dermatitis; conjunctivitis-rhinitis; asthma
Aningeria spp.
A. robusta
Aubr. and Pell.
A. altissima
Aubr. and Pell.
Antiaris africana
Engl.
A. welwitschi
Engl.
Aningeria Antiaris, ako, chen chen Sapotaceae Moraceae Conjunctivitis-rhinitis; asthma Toxic effects
Apuleia molaris spruce (A. leiocarpa MacBride)
(A. ferrea
Mart.)
Redwood Caesalpinaceae Dermatitis; toxic effects
Araucaria angustifolia O. Ktze
A. brasiliana
A. Rich.
Parana pine, araucaria Araucariaceae Toxic effects
Aspidosperma spp.
A. peroba
Fr. All.
A. vargasii
A. DC.
Red peroba Pau marfim, pau amarello, pequia marfim, guatambu, amarilla, pequia Apocynaceae Dermatitis; conjunctivitis-
rhinitis; asthma; toxic effects
Astrocaryum spp. Palm Palmaceae Dermatitis; toxic effects
Aucoumea klaineana Pierre  Gabon mahogany Burseraceae Dermatitis; conjunctivitis-rhinitis; asthma; allergic extrinsic alveolitis
Autranella congolensis
A. Chev. (Mimusops congolensis
De Wild.)
Mukulungu, autracon, elang, bouanga, kulungu Sapotaceae Dermatitis
Bactris spp. (Astrocaryum spp.) Palm Palmaceae Dermatitis; toxic effects
Balfourodendron riedelianum Engl. Guatambu, gutambu blanco Rutaceae Dermatitis
Batesia floribunda Benth. Acapu rana Caesalpinaceae Toxic effects
Berberis vulgaris L. Barberry Berberidaceae Toxic effects
Betula spp.
B. alba
L. (B. pendula Roth.)
Birch Betulaceae Dermatitis
Blepharocarva involucrigera F. Muell.  Rosebutternut Anacardiaceae Dermatitis; conjunctivitis-rhinitis; asthma
Bombax brevicuspe Sprague
B. chevalieri
Pell
Kondroti, alone Bombacaceae Dermatitis
Bowdichia spp.
B. nitida
Benth.
B. guianensis
Ducke (Diplotropis guianensis Benth.) 
(Diplotropis purpurea
Amsh.)
Black sucupira Papilionaceae Dermatitis
Brachylaena hutchinsii Hutch. Muhuhu Compositae Dermatitis
Breonia spp. Molompangady Rubiaceae Dermatitis
Brosimum spp.
B. guianense
Hub. (Piratinera guianensis Aubl.)
Snakewood, letterwood, tigerwood Moraceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Brya ebenus DC. (Amerimnum ebenus Sw.)
Brya buxifolia
Urb.
Brown ebony, green ebony, Jamaican ebony, tropical American ebony Papilionaceae Dermatitis
Buxus sempervirens L.
B. macowani
Oliv.
European boxwood, East London b., Cape b. Buxaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Caesalpinia echinata Lam. (Guilandina echinata Spreng.) Brasilwood Caesalpinaceae Dermatitis; toxic effects
Callitris columellaris F. Muell. White cypress pine Cupressaceae Dermatitis; conjunctivitis-rhinitis; asthma
Calophyllum spp.
C. brasiliense
Camb.
Santa maria, jacareuba, kurahura, galba Guttiferae Dermatitis; toxic effects
Campsiandra laurifolia Benth. Acapu rana Caesalpinaceae Toxic effects
Carpinus betulus Hornbeam Betulaceae Dermatitis
Cassia siamea Lamk. Tagayasan, muong ten, djohar Caesalpinaceae Dermatitis; conjunctivitis-rhinitis; asthma
Castanea dentata Borkh
C. sativa
Mill.
C. pumila
Mill.
Chestnut, sweet chestnut Fagaceae Dermatitis; conjunctivitis-rhinitis; asthma
Castanospermum australe A. Cunn. Black bean, Australian or Moreton Bay chestnut Papilionaceae Dermatitis
Cedrela spp. (Toona spp.) Red cedar, Australian cedar Meliaceae Dermatitis; conjunctivitis-rhinitis; asthma
Cedrus deodara (Roxb. ex. Lamb.) G. Don
(C. libani
Barrel. lc)
Deodar Pinaceae Dermatitis; conjunctivitis-rhinitis; asthma
Celtis brieyi De Wild.
C. cinnamomea
Ldl.
Diania
Gurenda
Ulmaceae Dermatitis
Chlorophora excelsa Benth. and Hook I.
C. regia
A. Chev.
C. tinctoria
(L.) Daub.
Iroko, gelbholz, yellowood, kambala, mvule, odum, moule, African teak, abang, tatajuba, fustic, mora Moraceae Dermatitis; conjunctivitis-rhinitis; asthma; allergic extrinsic alveolitis
Chloroxylon spp.
C. swietenia
A.DC.
Ceylon satinwood Rutaceae Dermatitis; toxic effects
Chrysophyllum spp. Najara Sapotaceae Dermatitis
Cinnamomum camphora Nees and Ebeim Asian camphorwood, cinnamon Lauraceae Toxic effects
Cryptocarya pleurosperma White and Francis Poison walnut Lauraceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Dacrycarpus dacryoides (A. Rich.) de Laub. New Zealand white pine Podocarpaceae Dermatitis; conjunctivitis-rhinitis; asthma
Dacrydium cupressinum Soland Sempilor, rimu Podocarpaceae conjunctivitis-rhinitis; asthma
Dactylocladus stenostachys Oliv. Jong kong, merebong, medang tabak Melastomaceae Toxic effects
Dalbergia spp.
D. amerimnon
Benth.
D. granadillo
Pitt.
D. hypoleuca
Standl.
D. latifolia
Roxb.
D. melanoxylon
Guill. and Perr.
D. nigra
Fr. All.
D. oliveri
Gamble
D. retusa
Hemsl.
D. sissoo
Roxb.
D. stevensonii
Standl.
Ebony Red foxwood Indian rosewood, Bombay blackwood, African blackwood, pallisander, riopalissandro, Brasilian rosewood, jacaranda Burma rosewood
Red foxwood
Nagaed wood, Honduras rosewood
Papilionaceae Dermatitis; conjunctivitis-rhinitis; asthma;
toxic effects
Dialium spp.
D. dinklangeri
Harms.
Eyoum, eyum Caesalpinaceae Dermatitis; conjunctivitis-rhinitis; asthma
Diospyros spp.
D. celebica
Bakh.
D. crassiflora
Hiern
D. ebenum
Koenig
Ebony, African ebony Macassar ebony, African ebony, Ceylon ebony Ebenaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Dipterocarpus spp.
D. alatus
Roxb.
Keruing, gurjum, yang, keruing Dipterocarpaceae Dermatitis
Distemonanthus benthamianus Baill. Movingui, ayan, anyaran, Nigerian satinwood Caesalpinaceae Dermatitis
Dysoxylum spp.
D. fraseranum
Benth.
Mahogany, stavewood, red bean Meliaceae dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
D. muelleri Benth. Rose mahogany    
Echirospermum balthazarii Fr. All. (Plathymenia reticulataBenth.) Vinhatico Mimosaceae Dermatitis; conjunctivitis-rhinitis; asthma
Entandophragma spp.
E. angolense
C.D.C.
E. candollei
Harms.
E. cylindricum
Sprague
E. utile
Sprague
Tiama
Kosipo, omo
Sapelli, sapele, aboudikro
Sipo, utile, assié,
kalungi, mufumbi
Meliaceae Dermatitis;
allergic extrinsic alveolitis
Erythrophloeum guineense G. Don
E. ivorense
A. Chev.
Tali, missanda, eloun, massanda, sasswood, erun, redwater tree Caesalpinaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Esenbeckia leiocarpa Engl. Guaranta Rutaceae Dermatitis
Eucalyptus spp.
E. delegatensis
R.T. Back
E. hemiphloia
F. Muell.
E. leucoxylon
Maiden
E. maculata
Hook.
E. marginata
Donn ex Sm.
E. microtheca
F. Muell.
E. obliqua
L. Herit.
E. regnans
F. Muell.
E. saligna
Sm.

Alpine ash
Grey box
Yellow gum
Spotted gum Mountain ash
Myrtaceae Dermatitis; conjunctivitis-rhinitis; asthma
Euxylophora paraensis Hub. Boxwood Rutaceae Dermatitis; conjunctivitis-rhinitis; asthma
Excoecaria africana M. Arg. (Spirostachys africana Sand)
E. agallocha
L.
African sandalwood, tabootie, geor, aloewood, blind-your-eye Euphorbiaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Fagara spp.
F. flava
Krug and Urb. (Zanthoxylum flavum Vahl.)
F. heitzii
Aubr. and Pell.
F. macrophylla
Engl.
Yellow sanders, West Indian satinwood, atlaswood, olon, bongo, mbanza Rutaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Fagus spp. (Nothofagus spp.) 
F. sylvatica
L.
Beech Fagaceae Dermatitis; conjunctivitis-rhinitis; asthma
Fitzroya cupressoides (Molina) Johnston
(
F. patagonica Hook. f.)
Alerce Cupressaceae Dermatitis
Flindersia australis R. Br.
F. brayleyana
F. Muell.
F. pimenteliana
F. Muell.
Australian teak, Queensland maple, maple
Silkwood, Australian maple
Rutaceae Dermatitis
Fraxinus spp.
F. excelsior
L.
Ash Oleaceae Dermatitis
Gluta spp.
G. rhengas
L. (Melanorrhoea spp.)
M. curtisii
Pierre
M. laccifera wallichii
Hook.
Rengas, gluta
Renga wood
Rhengas
Anacardiaceae Dermatitis; toxic effects
Gonioma kamassi E. Mey. Knysna boxwood, kamassi Apocynaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Gonystylus bancanus Baill. Ramin, melawis, akenia Gonystylaceae Dermatitis; conjunctivitis-rhinitis; asthma; allergic extrinsic alveolitis
Gossweilerodendron balsamiferum (Verm.) Harms. Nigerian cedar Caesalpinaceae Dermatitis; conjunctivitis-rhinitis; asthma
Grevillea robusta A. Cunn. Silky oak Proteaceae Dermatitis
Guaiacum officinale L. Gaiac, lignum vitae Zygophyllaceae Dermatitis; conjunctivitis-rhinitis; asthma
Guarea spp.
G. cedrata
Pell. G. laurentii De Wild.
G. thompsonii
Sprague
Bossé
Nigerian pearwood Cedar mahogany
Scented guarea
Black guarea
Meliaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Halfordia scleroxyla F. Muell.
H. papuana
Lauterb.
Saffron-heart Polygonaceae Dermatitis; allergic extrinsic alveolitis
Hernandia spp.
H. sonora
L. (H. guianensis Aubl.)
Mirobolan, topolite Hernandiaceae Dermatitis
Hippomane mancinella L. Beach apple Euphorbiaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Illipe latifolia F. Muell.
I. longifolia
F. Muell. (Bassia latifolia Roxb.) (B. longifoliaRoxb.)
Moak, edel teak Sapotaceae Dermatitis
Jacaranda spp.
J. brasiliana
Pers. Syn. (Bignonia brasiliana Lam.)
J. coerulea
(I.) Gris.
Jacaranda Caroba, boxwood Bignoniaceae Dermatitis
Juglans spp.
J. nigra
L.
J. regia
L.
Walnut Juglandaceae Dermatitis; conjunctivitis-rhinitis; asthma
Juniperus sabina L.
J. phoenicea
L.
J. virginiana
L.
Virginian pencil cedar, Eastern red cedar Cupressaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Khaya antotheca C. DC. K. ivorensis A. Chev.
K. senegalensis
A. Juss.
Ogwango, African mahogany, krala Dry-zone mahogany Meliaceae Dermatitis; allergic extrinsic alveolitis
Laburnum anagyroides Medic. (Cytisus laburnum L.)
L. vulgare
Gris
Laburnum Papilionaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Larix spp.
L. decidua
Mill.
L. europea
D.C.
Larch
European larch
Pinaceae Dermatitis; conjunctivitis-rhinitis; asthma
Liquidambar styracifolia L. Amberbaum, satin-nussbaum Hamamelidaceae Dermatitis
Liriodendron tulipifera L. American whitewood, tulip tree Magnoliaceae Dermatitis
Lovoa trichilioides Harms. (L. klaineana Pierre) Dibetou, African walnut, apopo, tigerwood, side Meliaceae dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Lucuma spp. (Pouteria spp.)
L. procera
Guapeva, abiurana
Massaranduba
Sapotaceae Dermatitis; conjunctivitis-rhinitis; asthma
Maba ebenus Wight. Makassar-ebenholz Ebenaceae Dermatitis
Machaerium pedicellatum Vog.
M. scleroxylon
Tul.
M. violaceum
Vog.
Kingswood Papilionaceae Dermatitis
Mansonia altissima A. Chev. Nigerian walnut Sterculiaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Melanoxylon brauna Schott Brauna, grauna Caesalpinaceae Dermatitis
Microberlinia brazzavillensis A. Chev.
M. bisulcata
A. Chev.
African zebrawood Caesalpinaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Millettia laurentii De Wild.
M. stuhlmannii
Taub.
Wenge
Panga-panga
Papilionaceae Dermatitis; conjunctivitis-rhinitis; asthma;
toxic effects
Mimusops spp. (Manilkara spp.)
Mimusops
spp. (Dumoria spp.) (Tieghemella spp.)
M. congolensis
De Wild. (Autranella congolensis A. Chev.)
M. djave
Engl. (Baillonella toxisperma Pierre)
M. heckelii
Hutch. et Dalz. (Tieghemella heckelii Pierre)  
(Dumoria heckelii
A. Chev.)
Muirapiranga
Makoré
Mukulungu, autracon Moabi
Cherry mahogany
Sapotaceae Dermatitis; conjunctivitis-rhinitis; asthma;
allergic
extrinsic alveolitis; toxic effects
Mitragyna ciliata Aubr. and Pell.
M. stipulosa
O. Ktze
Vuku, African poplar
Abura
Rubiaceae Dermatitis; conjunctivitis-rhinitis; asthma;
toxic effects
Nauclea diderrichii Merrill (Sarcocephalus diderrichii De Wild.)
Nauclea trillessi
Merrill
Bilinga, opepe, kussia, badi, West African boxwood Rubiaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Nesogordonia papaverifera R. Capuron Kotibé, danta, epro, otutu, ovové, aborbora Tiliaceae Toxic effects
Ocotea spp.
O. bullata
E. Mey
O. porosa
L. Barr. (Phoebe porosa Mez.)
O. rodiaei
Mez. (Nectandra rodiaei Schomb.)
O. rubra
Mez.
O. usambarensis
Engl.
Stinkwood Laurel Brazilian walnut
Greenheart
Louro vermelho
East African camphorwood
Lauraceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Paratecoma spp.
P. alba
P. peroba
Kuhlm.

Brazilian white peroba
Peroba white. p.
Bignoniaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Parinarium spp.
P. guianense (Parinari
spp.) (Brosimum spp.)
P. variegatum

Guyana-satinholz
Antillen-satinholz
Rosaceae Dermatitis
Peltogyne spp.
P. densiflora
Spruce
Blue wood, purpleheart Caesalpinaceae Toxic effects
Phyllanthus ferdinandi F.v.M. Lignum vitae, chow way, tow war Euphorbiaceae Dermatitis; conjunctivitis-rhinitis; asthma
Picea spp.
P. abies
Karst.
P. excelsa
Link.
P. mariana
B.S.P.
P. polita
Carr.
European spruce, whitewood
Black spruce
Pinaceae Dermatitis; conjunctivitis-rhinitis; asthma; allergic extrinsic alveolitis
Pinus spp.
P. radiata
D. Don
Pine Pinaceae Dermatitis; conjunctivitis-rhinitis; asthma
Piptadenia africana Hook f.
Piptadeniastrum africanum
Brenan
Dabema, dahoma, ekhimi
agobin, mpewere, bukundu
Mimosaceae Dermatitis; conjunctivitis-rhinitis; asthma
Platanus spp. Plane Platanaceae Dermatitis
Pometia spp.
P. pinnata
Forst.
Taun
Kasai
Sapindaceae Dermatitis; conjunctivitis-rhinitis; asthma
Populus spp. Poplar Salicaceae Dermatitis; conjunctivitis-rhinitis; asthma
Prosopis juliflora D.C. Cashaw Mimosaceae Dermatitis
Prunus spp.
P. serotina
Ehrl.
Cherry
Blackcherry
Rosaceae dermatitis; conjunctivitis-rhinitis; asthma
Pseudomorus brunoniana Bureau White handlewood Moraceae Dermatitis; toxic effects
Pseudotsuga douglasii Carr. (P. menziesii Franco) Douglas fir, red fir, Douglas spruce Pinaceae Dermatitis; conjunctivitis-rhinitis; asthma
Pterocarpus spp.
P. angolensis
D.C.
P. indicus
Willd.
P. santalinus
L.f. (Vatairea guianensis Aubl.)
African padauk, New Guinea rosewood, red sandalwood, red sanders, quassia wood Papilionaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Pycnanthus angolensis Warb. (P. kombo Warb.) Ilomba Myristicaceae Toxic effects
Quercus spp. Oak Fagaceae Dermatitis; conjunctivitis-rhinitis; asthma
Raputia alba Engl.
R. magnifica
Engl.
Arapoca branca, arapoca Rutaceae Dermatitis
Rauwolfia pentaphylla Stapf. O. Peroba Apocynaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Sandoricum spp.
S. indicum
Cav.
Sentul, katon, kra-ton, ketjapi, thitto Meliaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Schinopsis lorentzii Engl.
S. balansae
Engl.
Quebracho colorado, red q., San Juan, pau mulato Anacardiaceae Dermatitis; toxic effects
Semercarpus australiensis Engl.
S. anacardium
L.
Marking nut Anacardiaceae Dermatitis; toxic effects
Sequoia sempervirens Endl. Sequoia, California
redwood
Taxodiaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Shorea spp. Alan, almon, red balau
White heavy, red lauan, white L., yellow L., mayapis, meranti bakau, dark red M., light red M., red M., white M., yellow M., red seraya, white seraya
Dipterocarpaceae Dermatitis
S. assamica Dyer Yellow lauan, white meranti    
Staudtia stipitata Warb. (S. gabonensis Warb.) Niové Myristicaceae Dermatitis
Swietenia spp.
S. macrophylla
King
S. mahogany
Jacq.
Mahogany, Honduras mahogany, Tabasco m., baywood, American mahogany,
Cuban mahogany
Meliaceae Dermatitis; conjunctivitis-rhinitis; asthma; allergic extrinsic alveolitis; toxic effects
Swintonia spicifera Hook.
S. floribunda
Griff.
Merpauh Anacardiaceae Dermatitis
Tabebuia spp.
T. ipe
Standl. (T. avellanedae Lor. ex Gris.)
T. guayacan Hensl. (T. lapacho
K. Schum)
Araguan, ipé preto, lapacho Bignoniaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Taxus baccata L. Yew Taxaceae Dermatitis; conjunctivitis-rhinitis; asthma; allergic extrinsic alveolitis; toxic effects
Tecoma spp.
T. araliacea
D.C.
T. lapacho
Green heart
Lapacho
Bignoniaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Tectona grandis L. Teak, djati, kyun, teck Verbenaceae Dermatitis; conjunctivitis-rhinitis; asthma; allergic extrinsic alveolitis
Terminalia alata Roth.
T. superba
Engl. and Diels.
Indian laurel
limba, afara, ofram, fraké, korina, akom
Combretaceae Dermatitis; conjunctivitis-rhinitis; asthma
Thuja occidentalis L.
T. plicata
D. Don
T. standishii
Carr.
White cedar
Western red cedar
Cupressaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Tieghemella africana A. Chev. (Dumoria spp.)
T. heckelii
Pierre
Makoré, douka, okola, ukola, makoré, abacu, baku, African cherry Sapotaceae Dermatitis; conjunctivitis-rhinitis; asthma; toxic effects
Triplochiton scleroxylon K. Schum Obeche, samba, wawa, abachi, African whitewood, arere Sterculiaceae Dermatitis; conjunctivitis-rhinitis; asthma
Tsuga heterophylla Sarg. Tsuga, Western hemlock Pinaceae Dermatitis
Turraeanthus africana Pell. Avodiré
Lusamba
Meliaceae Dermatitis; allergic extrinsic alveolitis
Ulmus spp. Elm Ulmaceae Dermatitis
Vitex ciliata Pell.   Verbenaceae Dermatitis
V. congolensis De Wild. and Th. Dur Difundu    
V. pachyphylla Bak. Evino    
Xylia dolabriformis Benth.   Mimosaceae Conjunctivitis-rhinitis;
X. xylocarpa Taub. Pyinkado   asthma
Zollernia paraensis Huber Santo wood Caesalpinaceae Dermatitis; toxic effects

Source: Istituto del Legno, Florence, Italy.

 

Back

Saturday, 02 April 2011 18:56

Health Effects and Disease Patterns

As an emerging industry, semiconductor manufacturing often has been viewed as the epitome of the high-technology workplace. Because of stringent manufacturing requirements associated with producing multiple layers of micron dimensional electronic circuitry on silicon wafers, the cleanroom environment has become synonymous with the workplace for this industry. Since certain of the hydride gases used in semiconductor manufacturing (e.g., arsine, phosphine) were recognized early as highly toxic chemicals, inhalation exposure control technology has always been an important component of wafer fabrication. Semiconductor workers are further isolated from the production process by wearing special clothing covering the whole body (e.g., gowns), hair covers, shoe covers and, frequently, facial masks (or even air-supplied breathing devices). From a practical standpoint, employer concerns for product purity have resulted, also, in worker exposure protection.

In addition to personal protective clothing, highly sophisticated systems of ventilation and chemical/gas air monitoring are used throughout the semiconductor industry to detect leaks of toxic chemical solvent vapours, acids and hydride gases at parts per million (ppm) or less. Although, from the historic viewpoint, the industry has experienced frequent worker evacuations from wafer fabrication rooms, based on real or suspected leaks of gases or solvents, such evacuation episodes have become rare events because of the lessons learned in design of ventilation systems, toxic gas/chemical handling and increasingly sophisticated air-monitoring systems with continuous air sampling. However, the increasing monetary value of individual silicon wafers (together with increasing wafer diameters), which can contain scores of individual microprocessors or memory devices, can place mental stress on workers who must manually manipulate containers of these wafers during manufacturing processes. Evidence of such stress was obtained during a study of semiconductor workers (Hammond et al. 1995; Hines et al. 1995; McCurdy et al. 1995).

The semiconductor industry had its beginnings in the United States, which has the highest number of semiconductor industry workers (approximately 225,000 in 1994) of any country (BLS 1995). However, obtaining valid international employment estimates for this industry is difficult because of the inclusion of semiconductor workers with “electrical/electronic equipment manufacturing” workers in most nations’ statistics. Because of the highly stringent engineering controls required for semiconductor device manufacturing, it is most probable that semiconductor workplaces (i.e., cleanrooms) are comparable, in most respects, throughout the world. This understanding, coupled with US government requirements for recording all significant work-related injuries and illnesses among US workers, makes the work injury and illness experience of US semiconductor workers a highly relevant issue on both a national and international scale. Simply stated, at this time there are few international sources of relevant information and data concerning semiconductor worker safety and health experience, other than those from the Annual Survey of Occupational Injuries and Illnesses by the US Bureau of Labor Statistics (BLS).

In the United States, which has collected work injury and illness data on all industries since 1972, the frequency of work-related injuries and illnesses among semiconductor workers has been among the lowest of all manufacturing industries. However, concerns have been voiced that more subtle health effects may be present among semiconductor workers (LaDou 1986), although such effects have not been documented.

Several symposia have been held concerning control technology assessment in the semiconductor industry, with several of the symposia papers dealing with environmental and worker safety and health issues (ACGIH 1989, 1993).

A limited quantity of work injury and illness data for the international semiconductor manufacturing community was derived via a special survey performed in 1995, involving cases reported for the years 1993 and 1994. These survey data are summarized below.

Work Injuries and Illness among Semiconductor Workers

With respect to international statistical data associated with work injuries and illnesses among semiconductor workers, the only comparable data appear to be those derived from a survey of multi-national semiconductor manufacturing operations performed in 1995 (Lassiter 1996). The data collected in this survey involved the international operations of US-based semiconductor manufacturers for the years 1993-94. Some of the data from the survey included operations other than semiconductor manufacturing (e.g., computer and disk drive manufacturing), although all participating companies were involved in the electronics industry. The results of this survey are presented in figure 1 and figure 2, which include data from the Asia-Pacific region, Europe, Latin America and the United States. Each case involved a work-related injury or illness which required medical treatment or work loss or restriction. All incidence rates in the figures have been calculated as numbers of cases (or lost workdays) per 200,000 worker-hours per year. If total worker-hours was not available, average annual employment estimates were used. The 200,000 worker-hours denominator is equal to 100 full-time equivalent workers per year (assuming 2,000 work hours per worker per year).

Figure 1. Distribution of incidence rates for work injuries and illnesses by world sector, 1993 and 1994.

MIC060F6

Figure 2. Distribution of incidence rates for Injuries and illnesses with days off from work by world sector 1993 and 1994

MIC060F7

Figure 1 depicts work injury and illness incidence rates for the various world regions in the 1993-94 survey. Individual country rates have not been included to ensure confidentiality of those participating companies which were the sole sources of data for certain countries. Hence, for certain countries in the survey, data were reported for only a single facility. In several instances, companies combined all international data into a single statistic. These latter data are listed in figure 1 and figure 2 as “Combined”.

The annual incidence of work injuries and illnesses among all workers in the international survey was 3.3 cases per 100 employees (200,000 worker-hours) in 1993 and 2.7 in 1994. There were 12,615 cases reported for 1993 and 12,368 for 1994. The great majority of cases (12,130 in 1993) were derived from US companies. These cases were associated with approximately 387,000 workers in 1993 and 458,000 in 1994.

Figure 2 presents incidence rates for lost workday cases involving days away from work. The 1993 and 1994 incidence rates were based on approximately 4,000 lost workday cases for each of the 2 years in the international survey. The international/regional range in incidence rates for this statistic was the most narrow of those measured. The incidence of lost workday cases may represent the most comparable international statistics with respect to worker safety and health experience. The incidence rate for lost workdays (days away from work) was approximately 15.4 days away from work per 100 workers for each of the 2 years.

The only detailed data known to exist concerning case characteristics of semiconductor worker injuries and illnesses are those compiled annually in the US by the BLS, involving cases with lost workdays. The cases discussed here were identified by the BLS in their annual survey for the year 1993. Data obtained from these cases appear in figure 3, figure 4, figure 5 and figure 6. Each figure compares the lost workday case experience for the private sector, all manufacturing and semiconductor manufacturing.

Figure 3. Comparative incidence of lost workdays cases1 by type of event or exposure, 1993

MIC060F2

Figure 4. Comparative incidence of lost workday cases1 by source of injury or illness, 1993.

MIC060F3

Figure 5. Comparative incidence of lost workday cases1 by nature of injury or illness, 1993.

MIC060F4

Figure 6. Comparative incidence of lost workday cases by part of body affected, 1993

MIC060F5

Figure 3 compares the lost workday case experience of US semiconductor workers in 1993 with the private sector and with all manufacturing with respect to type of event or exposure. The incidence rates for most categories in this figure were much less for semiconductor industry workers than for the private sector or all manufacturing. Cases involving overexertions among semiconductor workers were less than half the rate for all workers in the manufacturing sector. The harmful exposure category (primarily associated with exposures to chemical substances) was equivalent among all three groups.

Comparative distributions of lost workday cases according to source of injury or illness are presented in figure 4. Lost workday case incidence rates for semiconductor workers were less than those for the private sector and all manufacturing in all source categories except for cases associated with exposures to chemical substances.

Figure 5 compares lost workday case incidence rates associated with nature of injury or illness among the three groups. The rates for semiconductor workers were less than half of the rates for both the private sector and for all manufacturing in 1993. The incidence of chemical burns was slightly higher for semiconductor workers, but was very low for all three comparison groups. The incidence of carpal tunnel syndrome (CTS) among US semiconductor workers was less than half the rate for all manufacturing.

In figure 6, the distribution and incidence of cases involving days away from work is illustrated according to part of body affected. Although the incidence of cases involving body systems was low for all comparison groups, the rate for semiconductor workers was slightly elevated. All other body parts affected were much lower for semiconductor workers than for the other two comparison groups.

Epidemiological Studies of Semiconductor Workers

Concern for possible reproductive health consequences associated with employment in the semiconductor surfaced in 1983 when a female employee at the Digital Equipment Corporation’s semiconductor facility in Hudson, Massachusetts, indicated that she believed that an excess of miscarriages had occurred among employees in the facility’s cleanrooms. This allegation, coupled with an absence of internal data at the facility, led to an epidemiological study by the University of Massachusetts School of Public Health in Amherst (UMass). The study was begun in May of 1984 and completed in 1985 (Pastides et al. 1988).

An elevated risk of miscarriage was observed in both the photolithographic area and the diffusion area when compared to non-exposed workers in other areas of the facility. A relative risk of 1.75 was considered to be not statistically significant (p <0.05), although a 2.18 relative risk observed among workers in diffusion areas was significant. Publication of the UMass study led to concern throughout the semiconductor industry that a larger study was warranted to validate the observed findings and to determine their extent and possible causation.

The Semiconductor Industry Association (SIA) of the United States sponsored a larger study performed by the University of California at Davis (UC Davis) beginning in 1989. The UC Davis study was designed to test the hypothesis that semiconductor manufacturing was associated with an increased risk of miscarriage for female wafer fabrication employees. The study’s population was selected from among 14 companies which represented 42 production sites in 17 states. The highest number of sites (representing almost half of the employees in the study) was in California.

The UC Davis study consisted of three different components: a cross-sectional component (McCurdy et al. 1995; Pocekay et al. 1995); an historical cohort component (Schenker et al. 1995); and a prospective component (Eskenazi et al. 1995). Central to each of these studies was an exposure assessment (Hines et al. 1995; Hammond et al. 1995). The exposure assessment component assigned employees to a relative exposure group (i.e., high exposure, low exposure and so on).

In the historical component of the study, it was determined that the relative risk of fabrication workers, compared with non-fabrication workers, was 1.45 (i.e., 45% excess risk of miscarriage). The highest risk group identified in the historical component of the study were women who worked in photolithography or etching operations. Women performing etching operations experienced a relative risk of 2.15 (RR=2.15). In addition, a dose-response relationship was observed among women who worked with any photoresist or developer with respect to increased risk of miscarriage. These data supported a dose-response association for ethylene glycol ethers (EGE) but not for propylene glycol ethers (PGE).

Although an increased risk of miscarriage was observed among female wafer fabrication workers in the prospective component of the UC Davis study, the results were not statistically significant (p less than 0.05). A small number of pregnancies significantly reduced the power of the prospective component of the study. Analysis by exposure to chemical agent indicated an increased risk for those women who worked with ethylene glycol monoethyl ether, but was based on only 3 pregnancies. One important finding was the general support for, and not contradiction of, the findings of the historical component.

The cross-sectional component of the study noted an increase in upper respiratory symptoms primarily in the diffusion furnace and thin film groups of workers. An interesting finding was the apparent protective effects of various engineering controls related to ergonomics (e.g., footrests and the use of an adjustable chair to reduce back injuries).

Air measurements made in the wafer fabs found most solvent exposures were less than 1% of the permissible exposure limits (PEL) established by the US government.

A separate epidemiological study (Correa et al. 1996) was performed by the Johns Hopkins University (JHU), involving a group of IBM Corporation semiconductor employees in 1989. The overall miscarriage rate observed in the JHU study involving female cleanroom workers was 16.6%. The relative risk for miscarriage among female cleanroom workers with the highest potential exposure to ethylene glycol ethers was 2.8 (95% C.I. = 1.4-5.6).

Discussion of Reproductive Epidemiological Studies Involving Semiconductor Workers

The epidemiological studies were remarkable in the scope and similarity of results. These studies all produced similar findings. Each study documented an excess risk of spontaneous abortion (miscarriage) for female semiconductor wafer fabrication workers. Two of the studies (JHU and UC Davis) may indicate a causal association with exposures to ethylene-based glycol ethers. The UMass study found that the photo group (those exposed to glycol ether) had less risk than the diffusion group, which had no documented glycol ether exposure. While these studies indicate an increased risk of spontaneous abortions among wafer fabrication workers, the cause of such excess risk is unclear. The JHU study failed to document a significant role for glycol ethers, and the UC Davis study only marginally linked glycol ethers (through modelling of exposures and self-reported work practices) to reproductive effects. Little if any monitoring was performed in either study to determine exposures to glycol ethers. Following completion of these studies the semiconductor industry began switching from ethylene series glycol ethers to substitutes such as ethyl lactate and propylene series glycol ethers.

Conclusion

Based on the best available data concerning the annual incidence of work-related injuries and illnesses, semiconductor workers are at less risk than workers in other manufacturing sectors or throughout the private sector (including many non-manufacturing industries). On an international basis, it appears that work injury and illness statistical data associated with lost workday cases may be a fairly reliable indicator of the worldwide safety and health experience of semiconductor workers. The industry has sponsored several independent epidemiological studies in an attempt to find answers to questions of reproductive health consequences related to employment in the industry. Although a definitive association between observed miscarriages and exposures to ethylene-based glycol ethers was not established, the industry has begun to use alternative photoresist solvents.

 

Back

The Textile Industry

The term textile industry (from the Latin texere, to weave) was originally applied to the weaving of fabrics from fibres, but now it includes a broad range of other processes such as knitting, tufting, felting and so on. It has also been extended to include the making of yarn from natural or synthetic fibres as well as the finishing and dyeing of fabrics.

Yarn making

In prehistoric eras, animal hair, plants and seeds were used to make fibres. Silk was introduced in China around 2600 BC, and in the middle of the 18th century AD, the first synthetic fibres were created. While synthetic fibres made from cellulose or petrochemicals, either alone or in varied combinations with other synthetic and/or natural fibres, have seen increasingly widening use, they have not been able to totally eclipse fabrics made of natural fibres such as wool, cotton, flax and silk.

Silk is the only natural fibre formed in filaments which can be twisted together to make yarn. The other natural fibres must first be straightened, made parallel by combing and then drawn into a continuous yarn by spinning. The spindle is the earliest spinning tool; it was first mechanized in Europe around 1400 AD by the invention of the spinning wheel. The late 17th century saw the invention of the spinning jenny, which could operate a number of spindles simultaneously. Then, thanks to Richard Arkwright’s invention of the spinning frame in 1769 and Samuel Crompton’s introduction of the mule, which allowed one worker to operate 1,000 spindles at one time, yarn-making moved from being a cottage industry into the mills.

Making of fabric

The making of fabric had a similar history. Ever since its origins in antiquity, the hand loom has been the basic weaving machine. Mechanical improvements began in ancient times with the development of the heddle, to which alternate warp threads are tied; in the 13th century AD, the foot treadle, which could operate several sets of heddles, was introduced. With the addition of the frame-mounted batten, which beats the weft or filling yarns into place, the “mechanized” loom became the predominant weaving instrument in Europe and, except for traditional cultures where the original hand looms persisted, around the world.

John Kay’s invention of the flying shuttle in 1733, which allowed the weaver to send the shuttle across the width of the loom automatically, was the first step in mechanization of weaving. Edmund Cartwright developed the steam-powered loom and in 1788, with James Watt, built the first steam-driven textile mill in England. This freed the mills from their dependence on water-driven machinery and allowed them to be constructed anywhere. Another significant development was the punch-card system, developed in France in 1801 by Joseph Marie Jacquard; this allowed automated weaving of patterns. The earlier power looms made of wood were gradually replaced by looms made of steel and other metals. Since then, technological changes have focused on making them larger, faster and more highly automated.

Dyeing and printing

Natural dyes were originally used to impart colour to yarns and fabrics, but with the 19th-century discovery of coal-tar dyes and the 20th-century development of synthetic fibres, dyeing processes have become more complicated. Block printing was originally used to colour fabrics (silk-screen printing of fabrics was developed in the mid-1800s), but it soon was replaced by roller printing. Engraved copper rollers were first used in England in 1785, followed by rapid improvements that allowed roller printing in six colours all in perfect register. Modern roller printing can produce over 180 m of fabric printed in 16 or more colours in 1 minute.

Finishing

Early on, fabrics were finished by brushing or shearing the nap of the fabric, filling or sizing the cloth, or passing it through calender rolls to produce a glazed effect. Today, fabrics are pre-shrunk, mercerized (cotton yarns and fabrics are treated with caustic solutions to improve their strength and lustre) and treated by a variety of finishing processes that, for example, increase crease resistance, crease holding and resistance to water, flame and mildew.

Special treatments produce high-performance fibres, so called because of their extraordinary strength and extremely high temperature resistance. Thus, Aramid, a fibre similar to nylon, is stronger than steel, and Kevlar, a fibre made from Aramid, is used to make bullet-proof fabrics and clothing that is resistant both to heat and chemicals. Other synthetic fibres combined with carbon, boron, silicon, aluminium and other materials are used to produce the lightweight, superstrong structural materials used in airplanes, spacecraft, chemical resistant filters and membranes, and protective sports gear.

From hand craft to industry

Textile manufacture was originally a hand craft practised by cottage spinners and weavers and small groups of skilled artisans. With the technological developments, large and economically important textile enterprises emerged, primarily in the United Kingdom and the Western European countries. Early settlers in North America brought cloth mills to New England (Samuel Slater, who had been a mill supervisor in England, constructed from memory a spinning frame in Providence, Rhode Island, in 1790), and the invention of Eli Whitney’s cotton gin, which could clean harvested cotton with great speed, created a new demand for cotton fabrics.

This was accelerated by the commercialization of the sewing machine. In the early 18th century, a number of inventors produced machines that would stitch cloth. In France in 1830, Barthelemy Thimonnier received a patent for his sewing machine; in 1841, when 80 of his machines were busy sewing uniforms for the French army, his factory was destroyed by tailors who saw his machines as a threat to their livelihood. At about that time in England, Walter Hunt devised an improved machine but abandoned the project because he felt that it would throw poor seamstresses out of work. In 1848, Elias Howe received a US patent for a machine much like Hunt’s, but became embroiled in legal battles, which he ultimately won, charging many manufacturers with infringement of his patent. The invention of the modern sewing machine is credited to Isaac Merritt Singer, who devised the overhanging arm, the presser foot to hold down the cloth, a wheel to feed the fabric to the needle and a foot treadle instead of a hand crank, leaving both hands free to manoeuvre the fabric. In addition to designing and manufacturing the machine, he created the first large-scale consumer-appliance enterprise, which featured such innovations as an advertising campaign, selling the machines on the installment plan, and providing a service contract.

Thus, the technological advances during the 18th century were not only the impetus for the modern textile industry but they can be credited with the creation of the factory system and the profound changes in family and community life that have been labelled the Industrial Revolution. The changes continue today as large textile establishments move from the old industrialized areas to new regions that promise cheaper labour and sources of energy, while competition fosters continuing technological developments such as computer-controlled automation to reduce labour needs and improve quality. Meanwhile, politicians debate quotas, tariffs and other economic barriers to provide and/or retain competitive advantages for their countries. Thus, the textile industry not only provides products essential for the world’s growing population; it also has a profound influence on international trade and the economies of nations.

Safety and Health Concerns

As machines became larger, speedier and more complicated, they also introduced new potential hazards. As materials and processes became more complex, they infused the workplace with potential health hazards. And as workers had to cope with mechanization and the demand for increasing productivity, work stress, largely unrecognized or ignored, exerted an increasing influence on their well-being. Perhaps the greatest effect of the Industrial Revolution was on community life, as workers moved from the country to cities, where they had to contend with all of the ills of urbanization. These effects are being seen today as the textile and other industries move to developing countries and regions, except that the changes are more rapid.

The hazards encountered in different segments of the industry are summarized in the other articles in this chapter. They emphasize the importance of good housekeeping and proper maintenance of machines and equipment, the installation of effective guards and fences to prevent contact with moving parts, the use of local exhaust ventilation (LEV) as a supplement to good general ventilation and temperature control, and the provision of appropriate personal protective equipment (PPE) and clothing whenever a hazard cannot be completely controlled or prevented by design engineering and/or substitution of less hazardous materials. Repeated education and training of workers on all levels and effective supervision are recurrent themes.

Environmental Concerns

Environmental concerns raised by the textile industry stem from two sources: the processes involved in textile manufacture and hazards associated with the way the products are used.

Textile manufacture

The chief environmental problems created by textile manufacturing plants are toxic substances released into the atmosphere and into wastewater. In addition to potentially toxic agents, unpleasant odours are often a problem, especially where dyeing and printing plants are located near residential areas. Ventilation exhausts may contain vapours of solvents, formaldehyde, hydrocarbons, hydrogen sulphide and metallic compounds. Solvents may sometimes be captured and distilled for reuse. Particulates may be removed by filtration. Scrubbing is effective for water-soluble volatile compounds such as methanol, but it does not work in pigment printing, where hydrocarbons make up most of the emissions. Flammables may be burned off, although this is relatively expensive. The ultimate solution, however, is the use of materials that are as close to being emission-free as possible. This refers not only to the dyes, binders and cross-linking agents used in the printing, but also to the formaldehyde and residual monomer content of fabrics.

Contamination of wastewater by unfixed dyes is a serious environmental problem not only because of the potential health hazards to human and animal life, but also because of the discolouration that makes it highly visible. In ordinary dyeing, fixation of over 90% of the dyestuff can be achieved, but fixation levels of only 60% or less are common in printing with reactive dyes. This means that more than one-third of the reactive dye enters the wastewater during the washing-off of the printed fabric. Additional amounts of dyes are introduced into the wastewater during the washing of screens, printing blankets and drums.

Limits on wastewater discolouration have been set in a number of countries, but it is often very difficult to heed them without an expensive wastewater purification system. A solution is found in the use of dyestuffs with a lesser contaminating effect and the development of dyes and synthetic thickening agents that increase the degree of dye fixation, thereby reducing the amounts of the excess to be washed away (Grund 1995).

Environmental concerns in textile use

Residues of formaldehyde and some heavy-metal complexes (most of these are inert) may be sufficient to cause skin irritation and sensitization in persons wearing the dyed fabrics.

Formaldehyde and residual solvents in carpets and fabrics used for upholstery and curtains will continue to vaporize gradually for some time. In buildings that are sealed, where the air-conditioning system recirculates most of the air rather than exhausting it to the outside environment, these substances may reach levels high enough to produce symptoms in the occupants of the building, as discussed elsewhere in this Encyclopaedia.

To ensure the safety of fabrics, Marks and Spencer, the British/Canadian clothing retailer, led the way by setting limits for formaldehyde in garments they would purchase. Since then, other garment manufacturers, notably Levi Strauss in the United States, have followed suit. In a number of countries, these limits have been formalized in laws (e.g., Denmark, Finland, Germany and Japan), and, in response to consumer education, fabric manufacturers have been voluntarily adhering to such limits in order to be able to use eco labels (see figure 1).

Figure 1. Ecological labels used for textiles

TEX005F1

Conclusion

Technological developments are continuing to enhance the range of fabrics produced by the textile industry and to increase its productivity. It is most important, however, that these developments be guided also by the imperative of enhancing the health, safety and well-being of the workers. But even then, there is the problem of implementing these developments in older enterprises that are marginally financially viable and unable to make the necessary investments, as well as in developing areas eager to have new industries even at the expense of the health and safety of the workers. Even under these circumstances, however, much can be achieved by education and training of the workers to minimize the risks to which they may be exposed.

 

Back

Tuesday, 29 March 2011 20:05

Health Effects and Disease Patterns

Leather Tanning

The major International Standard Industrial Classification (ISIC) group for the leather and fur processing is 323. In the United States, the Standard Industrial Classification (SIC) group for leather and leather manufacturing products industry is SIC 311 (OMB 1987). This group includes establishments engaged in tanning, currying and finishing hides and skins, as well as establishments manufacturing finished leather and artificial leather products and some similar products made of other materials. Leather converter, belting and chamois leather are also included in SIC 311. In addition, parts of SIC 23 (i.e., SIC 2371 and 2386) include establishments involved in the manufacturing of coats, garments, accessories and trimmings made of fur and establishments involved in sheep-lined clothing.

There are many varieties of leather with different characteristics depending upon the animal species and the specific part of the body of the animal from which the hide is obtained. Hides are made from cattle or horse skins; fancy leather from the skin of the calf, pig, goat, sheep and so on; and reptile leather from crocodile, lizard, chameleon and so on.

Employment in the leather and leather manufacturing products industry has been associated with various diseases caused by biological, toxicological and carcinogenic agents. The specific disease associated with exposure in the leather industry depends upon the extent to which the worker is exposed to the agent(s), which is dependent upon the occupation and work area within the industry.

For the tanning process, the epidermis of the hide is first removed and only the dermis transformed into leather. During this process, infection is a constant hazard, since the hide serves as a medium for numerous micro-organisms. Colonies of fungi may develop, specifically Aspergillus niger and Penicillus glaucum (Martignone 1964). To avoid the development of fungi, chlorinated phenols, specifically pentachlorophenol, have been widely used; unfortunately, such chemicals have been found to be toxic to the worker. Yeasts of three genera (Rhodotorula, Cladosporium and Torulopsis) have also been found (Kallenberger 1978). Tetanus, anthrax, leptospirosis, epizootic aphtha, Q fever and brucellosis are examples of diseases that workers could contract during the tanning process due to infected hides (Valsecchi and Fiorio 1978).

Skin disorders such as eczema and contact (allergic) dermatitis have also been diagnosed among leather tanners exposed to preservatives applied to the hides (Abrams and Warr 1951). The leather tanning and finishing process has been shown to have the highest incidence of dermatoses of any working group in the United States (Stevens 1979). Irritations of the mucous membranes of the throat and nose and perforations of the nasal septum may also occur after inhaling chromic acid fumes liberated during the chrome-tanning process.

Tannery workers have the potential for exposure to numerous known or suspected occupational carcinogens, including hexavalent chromium salts, benzidine-based azo dyes, organic solvents (e.g., benzene and formaldehyde), pentachlorophenol, N-nitroso compounds, arsenic, dimethylformamide and airborne leather dusts. These exposures may result in the development of various site-specific cancers. An excess of lung cancer has been observed in studies carried out in Italy (Seniori, Merler and Saracci 1990; Bonassi et al. 1990) and in a case-control study carried out in the United States (Garabrant and Wegman 1984), but this result is not always supported by other studies (Mikoczy, Schutz and Hagmar 1994; Stern et al. 1987; Pippard and Acheson 1985). Chromium and arsenicals were mentioned as possible contributors to the lung cancer excess. A significantly increased risk of soft tissue sarcoma has been observed in at least two separate tannery studies, one in Italy and one in the United Kingdom; the investigators of both studies suggest that the chlorophenols used at the tanneries may have produced these malignancies (Seniori et al. 1989; Mikoczy, Schutz and Hagmar 1994).

A threefold statistically significant excess in pancreatic cancer mortality was noted in a Swedish case control study (Erdling et al. 1986); a 50% increase in pancreatic cancer was also noted in another study examining three Swedish tanneries (Mikoczy, Schutz and Hagmar 1994) and in a study of an Italian tannery (Seniori et al. 1989). Despite the excess risk of pancreatic cancer, no specific environmental agent was identified, and dietary factors were considered a possibility. An excess risk of testicular cancer was observed among leather tanners from the finishing department of one tannery; all three workers with testicular cancer had worked during the same time period and were exposed to dimethylformamide (Levin et al. 1987; Calvert et al. 1990). An excess risk of sinonasal cancer among leather tannery workers was observed in a case-control study in Italy; chromium, leather dust and tannins were indicated as possible aetiological agents (Comba et al. 1992; Battista et al. 1995). However, IARC research in the early 1980s found no evidence of an association between leather tanning and nasal cancer (IARC 1981). The results of a study of the Chinese leather tanning industry showed a statistically significant excess morbidity from bladder cancer among those tanners ever exposed to benzidine-based dyes, which increased with duration of exposure (Chen 1990).

Accidents are also a leading cause of disability in leather tannery workers. Slips and falls on wet and greasy floors are common, as are knife cuts from the trimming of hides. In addition, the machines used to process the hides are capable of crushing and inflicting bruises, abrasions and amputations. For example, United States Bureau of Labor Statistics (BLS) data for 1994 have shown an incidence rate in SIC 311 for injuries and illnesses combined of 19.1 per 100 full-time workers and an incidence rate for injuries alone of 16.4. These results are over 50% higher than the all-manufacturing incidence for illnesses and injuries combined, 12.2 per 100 full-time workers, and the incidence of 10.4 for injuries alone (BLS 1995).

Footwear

The handling and processing of leather in the manufacturing of shoes and boots may entail exposures to some of the same chemicals used in the tanning and finishing processes as cited above, giving rise to similar diseases. Furthermore, different chemicals used may also produce other diseases. Exposures to the toxic solvents used in adhesives and cleaners and to airborne leather dusts are of particular concern. One solvent of specific concern is benzene, which can produce thrombocytopenia; depression of the red blood cell, platelet and white cell counts; and pancytopenia. Benzene has largely been eliminated from the footwear industry. Peripheral neuropathy has also been found among workers in shoemaking factories due to n-hexane in the adhesives. This, too, has largely been substituted for by less toxic solvents. Electroencephalographic changes, liver damage and behavioural alterations have also been reported in connection with exposure to solvents in shoeworkers.

Benzene has been judged to be a human carcinogen (IARC 1982), and various investigators have observed excess leukaemias among workers exposed to benzene in the shoe industry. One study included the largest shoe manufacturing facility in Florence, Italy, consisting of over 2,000 employees. The study results revealed a fourfold excess risk of leukaemia, and benzene was cited as the most likely exposure (Paci et al. 1989). A follow-up to this study showed an over fivefold risk for those shoe workers employed in jobs where benzene exposure was substantial (Fu et al. 1996). A study in the United Kingdom examining mortality among males employed in shoe manufacturing found an elevated risk for leukaemia among workers handling glues and solvents which contained benzene (Pippard and Acheson 1985). Various studies of shoe industry workers in Istanbul, Turkey, have reported an excess risk of leukaemia from exposure to benzene. When benzene was later replaced by petrol, the absolute number of cases and risk of leukaemia dropped considerably (Aksoy, Erdem and DinCol 1974; 1976; Aksoy and Erdem 1978).

Various types of nasal cancer (adenocarcinoma, squamous-cell carcinoma and transitional-cell carcinoma) have been associated with employment in shoe manufacture and repair. Relative risks in excess of tenfold have been reported from studies in Italy and the United Kingdom (Fu et al. 1996; Comba et al. 1992; Merler et al. 1986; Pippard and Acheson 1985; Acheson 1972, 1976; Cecchi et al. 1980) but not in the United States (DeCoufle and Walrath 1987; Walker et al. 1993). The elevated nasal cancer risks were almost entirely accounted for by employees “heavily” exposed to leather dust in the preparation and finishing rooms. The mechanism by which exposure to leather dust may increase the risk of nasal cancer is not known.

Excesses of digestive and urinary tract cancers, such as bladder (Malker et al. 1984; Morrison et al. 1985), kidney (Walker et al. 1993; Malker et al. 1984), stomach (Walrath, DeCoufle and Thomas 1987) and rectal (DeCoufle and Walrath 1983; Walrath, DeCoufle and Thomas 1987) cancers, have been found in other studies of shoe workers but have not been consistently reported and have not been linked with particular exposures in the industry.

Ergonomic hazards causing work-related musculoskeletal disorders (WRMDs) are major problems in the shoe manufacturing industry. These hazards are due to the specialized equipment used and hands-on work requiring repetitive movements, forceful exertions and awkward body postures. BLS data show men’s footwear to be one of the “industries with the highest rates of nonfatal illness disorders associated with repeated trauma” (BLS 1995). The incidence rate for the total footwear industry for illnesses and injuries combined was found to be 11.9 per 100 workers, with 8.6 being the incidence rate for injuries alone. These rates are slightly less than the incidence rates for all manufacturing. WRMDs in the shoe manufacturing industry include conditions such as tendinitis, synovitis, tenosynovitis, bursitis, ganglionic cysts, strains, carpal tunnel syndrome, low-back pain and cervical spine injuries.

Fur Workers

Fur processing involves the activities of three categories of workers. Fur dressers flesh and tan skins; fur dyers then colour or tint the skins with natural or synthetic dyes; and finally fur service workers grade, match and bale dressed furs. Dressers and dyers are exposed to potential carcinogens including tannins, oxidative dyes, chromium and formaldehyde, whereas fur service workers are potentially exposed to residual tanning materials while handling previous dressed furs. Very few epidemiological studies have been conducted on fur workers. The only comprehensive study among these workers revealed statistically elevated risks of colo-rectal and liver cancer among the dyers, lung cancer among the dressers and cardiovascular diseases among the service workers as compared to overall rates in the United States (Sweeney, Walrath and Waxweiler 1985).

 

Back

Tuesday, 29 March 2011 18:58

Health Effects and Disease Patterns

Health effects found in food processing are similar to those found in other manufacturing operations. Respiratory disorders, skin diseases and contact allergies, hearing impairment and musculoskeletal disorders are among the most common occupational health problems in the food and beverage industry (Tomoda 1993; BLS 1991; Caisse nationale d’assurance maladie des travailleurs salariés 1990). Thermal extremes are also a concern. Table 1 shows rankings of the three most common occupational diseases in this industry in selected countries.

Table 1. Most common occupational diseases in the food and drink industries in selected countries

Country

Year

Occupational diseases

     
   

Most common

Second most common

Third most common

Other

Austria

1989

Bronchitis, asthma

Hearing impairment

Skin diseases

Infections transmitted by animals

Belgium (food)

1988

Diseases induced by inhalation of substances

Diseases induced by physical agents

Skin diseases

Infections or parasites from animals

Belgium (drink)

1988

Diseases induced by physical agents

Diseases induced by chemical agents

Diseases induced by inhalation of substances

Colombia

1989

Hearing impairment

Respiratory disorders (asthma)

Musculoskeletal disorders

Skin diseases

Czechoslovakia

1988

Respiratory disorders

Musculoskeletal disorders

Digestive disorders

Circulatory disorders, skin diseases

Denmark

1988

Physical coordination disorders

Skin diseases

Hearing impairment

Infections, allergies

France

1988

Asthma and other respiratory disorders

Strains in various parts of body (knees, elbows)

Septicemia (blood poisoning) and other infections

Hearing impairment

Poland

1989

Respiratory disorders

Skin diseases

Infections

Hearing impairment

Sweden

1989

Musculoskeletal disorders

Allergies (contact with chemical agents)

Hearing impairment

Infections

United States

1989

Disorders associated with repeated trauma

Skin diseases

Diseases due to physical agents

Respiratory conditions associated with toxic agents

Source: Tomoda 1993.

Respiratory System

Respiratory problems can largely be classified as rhinitis, which affects the nasal passages; broncho-constriction in the major airways; and pneumonitis, which consists of damage to the fine structures of the lung. Exposure to airborne dust from various foodstuffs, as well as chemicals, may lead to emphysema and asthma. A Finnish study found chronic rhinitis common among slaughterhouse and pre-cooked foods workers (30%), mill and bakery workers (26%) and food processing workers (23%). Also, food processing workers (14%) and slaughterhouse/pre-cooked foods workers (11%) suffered from chronic coughs. The causative agent is flour dust in bakery workers, while temperature variations and various kinds of dust (spices) are believed to cause disease in other branches.

Two studies in the former Yugoslavia found a much higher prevalence of chronic respiratory symptoms than in a control group. In a study of spice workers the most common complaint (57.6%) was dyspnea or breathing difficulty, followed by nasal catarrh (37.0%), sinusitis (27.2%), chronic cough (22.8%) and chronic phlegm and bronchitis (19.6%). A study of animal food processing workers found that in addition to the animal food processing ingredients, exposure included powdered coriander, garlic dust, cinnamon dust, red paprika dust and dust from other spices. Non-smokers studied showed a significantly higher prevalence of chronic phlegm and chest tightness. Smokers had a significantly higher prevalence of chronic coughs; chronic phlegm, chronic bronchitis and chest tightness were also observed. The frequency of acute respiratory symptoms associated with the working day was high for the exposed group, and respiratory ventilatory capacity of smokers was significantly lower than predicted. The study therefore concluded an association exists between exposure to animal food dust and the development of respiratory disorders.

Industrial injury compensation in the United Kingdom recognizes occupational asthma from the handling of enzymes, animals, grains and flour. Exposure to cinnamic aldehyde from tree bark and sulphur dioxide, a bleaching agent and fumigant, cause a high prevalence of asthma in cinnamon workers in Sri Lanka. Dust exposure is minimal for the workers who peel the bark, but workers in the local buyers’ stores are exposed to high levels of dust and sulphur dioxide. A study found 35 of 40 cinnamon workers complained of chronic coughs (37.5%) or suffered from asthma (22.5%). Other abnormalities included weight loss (65%), skin irritation (50%), hair loss (37.5%), eye irritation (22.5%) and rashes (12.5%). For workers who work under similar high concentrations of airborne dust of vegetable origin, asthma is highest in cinnamon workers (22.5%, compared with 6.4% in tea workers and 2.5% in kapok workers). Smoking is not believed to be directly related to the coughs, since similar symptoms occurred in 8 non-smoking women and 5 men who smoked about 7 cigarettes a day. Irritation of the respiratory mucosa by cinnamon dust causes the coughing.

Other studies examined the relationship between respiratory disorders and the allergens and antigens originating in foodstuffs, such as egg protein and seafood products. While no specific workplace dust could be linked to the various acute and chronic respiratory disorders among the exposed workers, the results of the studies indicate a strong association between the disorders and the work environment.

Use of microbiology has long been a part of food production. In general, most of the micro-organisms used in the food and drink industries are considered to be harmless. Wine, cheese, yogurt and sour dough all use a microbial process to yield a usable product. Production of proteins and enzymes increasingly use biotechnological techniques. Certain species of aspergillus and bacillus produce amylases that convert starches into sugar. Yeasts turn starch into acetone. Tricoderma and Penicillium produce cellulases that break down cellulose. As a result, spores of fungi and actinomycetes are widely found in food processing. Aspergillus and Penicillium are frequently present in the air in bakeries. Penicillium is also found in dairy and meat processing plants; during the maturation of cheeses and sausages, there can be abundant surface growth. Cleaning steps, prior to sale, disperse them into the air, and workers may develop allergic alveolitis. Occupational asthma cases have association with many of these organisms, while some are suspected of causing infection or carrying mycotoxins. The enzymes trypsin, chymotrypsin and protease are associated with hypersensitivity and respiratory disease, particularly among laboratory workers.

In addition to the airborne particulate originating from foodstuffs and microbial agents, inhalation of hazardous chemical substances used as reagents, refrigerants, fumigants and sanitizers may cause respiratory and other disorders. These substances are found in solid, liquid or gaseous form. Exposure at or above recognized limits often results in skin or eye irritation and respiratory disorders. Headaches, salivation, burning of the throat, perspiration, nausea and vomiting are symptoms of intoxication due to overexposure.

Ammonia is a colourless gas refrigerant, cleaning agent and fumigant for foodstuffs. Exposure to ammonia can result in corrosive burns or blistering of skin. Excessive and prolonged exposure can produce bronchitis and pneumonia.

Trichloroethylene, hexane, benzene, carbon monoxide (CO), carbon dioxide (CO2) and polyvinyl chloride (PVC) are frequently found in food and beverage plants. Trichloroethylene and hexane are used for olive oil extraction.

CO, a colourless, odourless gas, is difficult to detect. Exposure occurs in smokehouses that are poorly ventilated or while working in grain silos, wine fermentation cellars or where fish are stored. Dry-ice freezing or chilling, CO2-freeze tunnels and combustion processes expose workers to CO2. Intoxication symptoms of overexposure to CO and CO2 include headache, dizziness, drowsiness, nausea, vomiting and, in extreme cases, even death. CO also can aggravate heart and respiratory symptoms. The acceptable exposure limits, set by several governments, permit 100 times greater exposure to CO2 than CO to trigger the same response.

PVC is used for packaging and food-wrap materials. When PVC film is heated, thermal degradation products cause irritation to the eyes, nose and throat. Workers also report symptoms of wheezing, chest pains, breathing difficulties, nausea, muscle pains, chills and fever.

Hypochlorites, acids (phosphoric, nitric and sulphuric), caustics and quaternary ammonium compounds are frequently used in wet cleaning. Microbiology labs use mercury compounds and formaldehyde (gas and formalin solution). Disinfection in the lab uses phenolics, hypochlorites and glutaraldehyde. Irritation and corrosion to eyes, skin and lungs occur with excessive exposure and contact. Improper handling can release highly toxic substances, like chlorine and sulphur oxides.

The National Institute for Occupational Safety and Health (NIOSH) in the United States reported worker breathing difficulties during washing of poultry with super-chlorinated water. The symptoms included headaches, sore throat, tightness in the chest and difficulty breathing. Chloramine is the suspected agent. Chloromines can form when ammonia-treated water or amine-treated boiler water contacts hypochlorite solutions used in sanitation. Cities have added ammonia to water to prevent the formation of halomethanes. Air sample methods are not available for chloramines. Chlorine and ammonia levels are not predictive as indicators of exposure, as testing found their levels to be well below their limits.

Fumigants prevent infestation during storage and transport of food raw materials. Some fumigants include anhydrous ammonia, phostoxin (phosphine) and methyl bromide. The short duration of this process makes respiratory protection the cost-effective strategy. Proper respiratory protection practices should be observed when handling these items until air measurements of the area are below applicable limits.

Employers should take steps to assess the level of toxic contamination at the workplace and ensure that exposure levels do not exceed limits found in safety and health codes. Contamination levels should be measured frequently, especially following changes in processing methods or the chemicals used.

Engineering controls to minimize the risk of intoxication or infection have two approaches. First, eliminate the use of such materials or substitute a less hazardous material. This may involve replacing a powdered substance with a liquid or slurry. Second, control the exposure through reducing the level of air contamination. Workplace designs include the following: total or partial enclosure of the process, suitable ventilation systems and restricted access (to reduce exposed population). An appropriate ventilation system is instrumental in preventing the dispersal of spores or aerosols throughout the workplace. Substitution of vacuum cleaning or wet cleaning for compressed-air blow-out of equipment is critical for dry materials that could become airborne during cleaning.

Administrative controls include worker rotation (to reduce exposure period) and off-shift/weekend hazardous task work (to reduce exposed population). Personal protective equipment (PPE) is the least favoured exposure control method due to high maintenance, availability issues in developing countries and the fact that the worker must remember to wear it.

PPE consists of splash goggles, face shields and respirators for workers mixing hazardous chemicals. Worker training on use and limitations, plus equipment fitting, must occur for the equipment to adequately serve its purpose. Different types of respirators (masks) are worn depending on the nature of the work and the level of the hazard. These respirators range from the simple half facepiece for dust and mist, through chemical air purifying of various facepiece types, up to self-contained breathing apparatus (SCBA). Proper selection (based on hazard, face-fit and maintenance) and training assure effectiveness of the respirator in reducing exposure and the incidence of respiratory disorders.

Skin

Skin problems found in the food and drink industries are skin disease (dermatitis) and contact allergies (e.g., eczema). Due to sanitation requirements, workers are constantly washing their hands with soap and using hand-dip stations that contain quaternary ammonium solutions. This constant wetting of the hands can reduce the lipid content of the skin and lead to dermatitis. Dermatitis is an inflammation of the skin as a result of contact-exposure to chemicals and food additives. Work with fats and oils can clog the pores of the skin and lead to acne-like symptoms. These primary irritants account for 80% of all occupational dermatitis seen.

There is growing concern that workers may become highly sensitized to microbial proteins and peptides generated by fermentation and extraction, which can lead to eczema and other allergies. An allergy is a hypersensitive response of any type that is greater than that which normally occurs in response to antigens (not-self) in the environment. Allergic contact dermatitis is rarely seen before the fifth or seventh day after exposure is initiated. Hypersensitivity occupational dermatitis is also reported for work with enzymes, such as trypsin, chymotrypsin and protease.

Chlorinated solvents (see “Respiratory system” section above) stimulate the epidermal cells to undertake peculiar growth patterns. This keratin stimulation may lead to tumour formation. Other chlorinated compounds found in soaps for antibacterial purposes can lead to photosensitivity dermatitis.

Reduction of exposure to causative agents is the principle preventive method for dermatitis and contact allergies. Adequately drying foodstuffs prior to storage and clean-condition storage can control airborne spores. PPE such as gloves, masks and uniforms keep workers from direct contact and minimize the risk of dermatitis and other allergies. Latex glove materials can cause allergic skin reactions and should be avoided. Proper application of barrier creams, where permitted, can also minimize contact with the skin irritant.

Infectious and parasitic diseases of animal origin are the occupational diseases most specific to the food and drink industries. The diseases are most common among meat-packing and dairy workers as a result of direct contact with infected animals. Agricultural workers and others are also at risk due to their contact with these animals. Prevention is particularly difficult since the animals may not give any overt signs of disease. Table 2 lists the types of infections reported.

Table 2. Types of infections reported in food and drink industries

Infections

Exposure

Symptoms

Brucellosis (Brucella melitensis)

Contact with infected cattle, goats and sheep (Northern and Central Europe and North America)

Constant and recurring fever, headaches, weakness, joint pain, night sweats and loss of appetite; can also give rise to symptoms of arthritis, influenza, asthenia and spondylitis

Erysipeloid

Contact of open wounds with infected pigs and fish (Czechoslovakia)

Localized redness, irritation, a burning sensation, pain in the infected area. It can spread to the bloodstream and lymph nodes.

Leptospirosis

Direct contact with infected animals or their urine

Headaches, aching muscles, eye infections, fever, vomiting and chills; in more serious cases, kidney and liver damage, plus cardiovascular and neurological complications

Epidermycosis

Caused by a parasitic fungus on the skin of animals

Erythema and blistering of skin

Dematophytosis (ringworm)

Fungal disease through contact with skin and hair of infected animals

Localized hair loss and small crusts on the scalp

Toxoplasmosis

Contact with infected sheep, goats, cattle, pigs and poultry

Acute stage: fever, muscle pain, sore throats, headaches, swollen lymph nodes and enlarged spleen. Chronic infection leads to development of cysts in the brain and muscle cells. Foetal transmission causes still- and premature births. Full-term babies can have brain and heart defects and may die.

Papilloma viral lung cancers

Regular contact with live animals or animal flesh coupled with exposure to polycyclic aromatic hydrocarbons and nitrites

Lung cancers in butchers and slaughterhouse workers studied in England, Wales, Denmark and Sweden

 

The fundamental principle for preventing the contraction and spread of infectious and parasitic skin diseases is personal hygiene. Clean washrooms, toilets and shower facilities should be provided. Uniforms, PPE and hand towels need to be washed and in some cases sterilized frequently. All wounds should be sterilized and dressed, regardless of how slight, and covered with protective gear until healed. Keeping the workplace clean and healthy is just as important. This includes the thorough washing of all equipment and surfaces that contact animal flesh after each workday, the control and extermination of rodents and the exclusion of dogs, cats and other animals from the workplace.

Vaccination of animals and inoculation of workers are measures many countries take to prevent infectious and parasitic diseases. Early detection and treatment of diseases with antibacterial/anti-parasitic drugs is essential to contain and even eradicate them. Workers should be examined as soon as any symptoms, such as recurring coughs, fever, headaches, sore throats and intestinal disorders, appear. In any case, workers should undergo medical examinations at established frequencies, including pre-placement/post-offer baseline exams. In some countries, authorities must be notified when examination detects work-related infection in the workers.

Noise and Hearing

Hearing impairment occurs as a result of continuous and prolonged exposure to noise above recognized threshold levels. This impairment is an incurable illness causing communication disorders and is stressful if the work demands concentration. As a result, psychological and physiological performance can deteriorate. There is also an association between high noise level exposure and abnormal blood pressure, heartbeat, respiration rate/volume, stomach and intestinal spasms and nervous disorders. Individual susceptibility, exposure duration and noise frequency plus intensity are factors that determine the exposure risk.

Safety and health codes vary from country to country, but worker exposure to noise is usually limited to 85 to 90 dBA for 8 continuous hours, followed by a 16-hour recovery time below 80 dBA. Ear protection should be made available at 85 dBA and is required for workers with a confirmed loss and for 8-hour exposures at or above 90 dBA. Annual audiometric testing is recommended, and in some countries required, for this exposed population. Noise measurements with a meter such as the American National Standards Institute (ANSI) Type II sound meter should be taken at least every 2 years. Readings should be repeated whenever equipment or process changes could increase the ambient noise levels.

Ensuring that noise exposure levels are not hazardous is the primary strategy for noise controls. Good manufacturing practices (GMPs) dictate that control devices and their exposed surfaces be cleanable, do not harbour pests and have necessary approvals to contact food or be ancillary to food production. The methods adopted also depend on the availability of financial resources, equipment, materials and trained staff. One of the most important factors in noise reduction is the design of the workplace. Equipment should be designed for low noise and low vibration. Replacing metal parts with softer materials, like rubber, can reduce noise.

When new or replacement equipment is purchased a low-noise type should be selected. Silencers should be installed at air valves and exhaust pipes. Noise-producing machines and processes should be enclosed to reduce to a minimum the number of workers exposed to high noise levels. Where permitted, noise-proof partitions and noise-absorbing ceilings should be installed. Removal and cleaning of these partitions and ceiling tiles need to be included in the maintenance costs. The optimum solution is usually a combination of these measures, adapted to the needs of each workplace.

When engineering controls are not feasible or when it is impossible to reduce noise below harmful levels, PPE should be used to protect the ears. Protective equipment availability and worker awareness is important to prevent hearing impairment. In general, a selection of plugs and earmuffs will lead to greater acceptance and wearing.

Musculoskeletal System

Musculoskeletal disorders were also reported in the 1988–89 data (see table 1]). Data in the early 1990s noted more and more workers reporting occupational musculoskeletal disorders. Plant automation and work whose pacing is regulated by a machine or conveyor belt occurs today for more workers in the food industry than ever before. Tasks in automated plants tend to be monotonous, with workers performing the same movement all day long.

A Finnish study found that nearly 40% of survey participants reported performing repetitive work all day. Of those performing repetitive work, 60% used their hands, 37% used more than one part of the body and 3% used their feet. Workers in the following occupational groups perform repetitive work for two-thirds or more of their working hours: 70% of cleaners; 67% of slaughterhouse, pre-cooked food and packaging workers; 56% of warehouse and transport workers; and 54% of dairy workers.

Ergonomic stresses arise because most food products come from natural sources and are not uniform. Meat handling requires workers to handle carcasses of varying sizes. With the introduction of poultry sold in parts in the 1960s, more birds (40%, up from less than 20%) were cut into parts. Workers must make many cuts using sharp tools. Changes in US Department of Agriculture (USDA) inspection procedures now permit average line speeds to increase from 56 to 90 birds per minute. Packaging operations may involve repetitive hand and wrist motions to place finished items undamaged into trays or packs. This is especially true for new products, as the market may not justify high-volume operations. Special promotions, including recipes and coupons, may require that an item be manually inserted into the package. Ingredient packaging and workplace layout may require lifting beyond the action limits recommended by occupational health agencies.

Repetitive strain injuries (RSIs) include inflammation of the tendon (tendinitis) and inflammation of the tendon sheath (tenosynovitis). These are prevalent among workers whose jobs require repetitive hand movements, like meatpacking workers. Tasks that repeatedly combine the bending of the wrist with gripping, squeezing and twisting motion can cause carpal tunnel syndrome (CTS). CTS, characterized by a tingling sensation in the thumb and first three index fingers, is caused by inflammation in the wrist joint creating pressure on the nerve system in the wrist. Misdiagnosis of CTS as arthritis can result in permanent numbness and severe pain in the hands, elbows and shoulders.

Vibration disorders also accompany an increased level of mechanization. Food workers are no exception, although the problem may not be as serious as for certain other industries. Food workers using machines such as band saws, mixers and cutters are exposed to vibration. Cold temperatures also increase the probability of vibration disorders to the fingers of the hand. Five per cent of the participants in the Finnish study noted above were exposed to a fairly high level of vibration, while 9% were exposed to some level of vibration.

Excessive exposure to vibration leads, among other problems, to musculoskeletal disorders in the wrists, elbows and shoulders. The type and degree of disorder depend on the type of machine, how it is used and the level of oscillation involved. High levels of exposure can result in growth of a protuberance on the bone or the gradual destruction of the bone in the joint, resulting in severe pain and/or limited mobility.

Rotation of workers with a view to avoiding repetitive motions may reduce the risk by sharing the critical task across the team. Teamwork by task rotation or two-person handling of awkward/heavy ingredient bags can reduce the stress on a single worker in material handling. Tool maintenance, especially knife sharpening, also plays an important role. An ergonomic team of management and production workers can best address these issues as they arise.

Engineering controls focus on reduction or elimination of the 3 primary causes of musculoskeletal problems—force, position and repetition. The workplace should be analysed to identify needed changes, including workstation design (favouring adjustability), working methods, task automation/mechanical assists and ergonomically sound hand tools.

Adequate training should be provided to workers using knives on keeping the knife sharp to minimize force. Also, plants must provide adequate knife-sharpening facilities and avoid the cutting of frozen meat. Training encourages workers to understand the cause and prevention of musculoskeletal disorders. It reinforces the need to use correctly the tools and machines specified for the task. It should also encourage workers to report medical symptoms as soon as possible. Elimination of more invasive medical intervention by restriction of duties and other conservative care, is effective treatment of these disorders.

Heat and Cold

Thermal extremes exist in the food work area. People must work in freezers with temperatures of –18 °C or below. Freezer clothing helps insulate the worker from the cold, but warm break rooms with access to warm liquids must be provided. Meat-processing plants must be kept at 7 to 10 °C. This is below the comfort zone and workers may need to wear additional clothing layers.

Ovens and steam cookers have radiant and moist heat. Heat stress can occur during season changes and heat waves. Copious amounts of fluids and salting of foods may relieve the symptoms until the worker can acclimatize, usually after 5 to 10 days. Salt tablets are not recommended due to complications of hypertension or gastrointestinal upset.

 

Back

Friday, 25 March 2011 06:15

Health Effects and Disease Patterns

Hotels and restaurants constitute a large, diversified, labour-intensive service industry made up predominantly of small enterprises. While there are a number of giant corporations, some of which attempt to standardize procedures and working rules, their hotels and restaurants are usually operated individually, often on a franchise rather than a directly owned basis. Frequently, the eating and drinking establishments in hotels are leased to franchise operators.

There is a high degree of failure among the enterprises in this industry, with many being very close to the edge of financial insolvency for some time before closing their doors. This often dictates economies in staffing, in the purchase and maintenance of equipment and in the provision of necessary supplies. It also often forces neglect of employee training programmes and a reluctance to spend scarce resources on measures to promote and protect employee safety and health.

The majority of the jobs are unskilled and provide low or minimal wages (in some of the jobs, these may be supplemented by gratuities that depend on the largesse of the patrons). Consequently, they attract only workers with minimal education and experience, and because minimal language and literacy skills are required, many of the jobs are filled by immigrants and ethnic minorities. Many are entry-level positions with little or no opportunities for advancement. Shift work is required in hotels because they operate around the clock; in restaurants, the flurries of activity at meal times are often covered by part-time workers. Because their patronage is seasonal, many establishments curtail their operations or shut down entirely during the off-season, and, as a result, there may be little or no job security. The end result of all of this is a high rate of turnover in the workforce.

Job Stress

Because of the periods of intense activity and the necessity of pleasing the patrons on whose gratuities their livelihoods often depend, many of the workers in this industry are subject to high levels of job stress. They must often comply with seemingly unreasonable or even impossible requests and may be subjected to abusive behaviour on the part of supervisors as well as customers. Many of the jobs, particularly those in kitchens and laundries, must be carried out in stressful environments featuring high heat and humidity, poor ventilation, poor lighting and noise (Ulfvarson, Janbell and Rosen 1976).

Violence

Hotels and restaurants rank high on the lists of workplaces with the greatest incidence of occupational violent crime. According to one survey, over 50% of such incidents involving hotel and restaurant workers resulted in death (Hales et al. 1988). These workers are exposed to many of the risk factors for workplace homicide: exchange of money with the public, working alone or in small numbers, working late night or early morning hours and guarding valuable property or possessions (Warshaw and Messite 1996).

Types of Injuries and Diseases

According to the US Bureau of Labor Statistics, food and beverage preparation and housekeeping departments accounted for 76% of all work injuries and accidents in hotels (US Bureau of Labor Statistics 1967), while a Danish survey found that these were predominantly skin and musculoskeletal problems (Direktoratet for Arbejdstilsynet 1993). Most of the skin problems may be traced to exposure to soap and hot water, to the chemicals in detergents and other cleaning/polishing materials and, in some instances, to pesticides. Except for the special problems noted below, the majority of musculoskeletal injuries result from slips and falls and from lifting and handling heavy and/or bulky objects.

Sprains, strains and repetitive motion injuries

Back injuries and other sprains and strains commonly occur among doormen, porters and bellmen lifting and carrying luggage (a particular problem when large tour groups arrive and depart); kitchen workers and others receiving and storing bulk supplies; and housekeeping workers lifting mattresses, making beds and handling bundles of laundry. A unique type of injury is carpal tunnel syndrome among food service workers who use scoops to prepare servings of hard ice cream and other frozen desserts.

Cuts and lacerations

Cuts and lacerations are common among restaurant workers and dishwashers who deal with broken glass and crockery, and who handle or clean sharp knives and slicing machines. They are also common among chambermaids who encounter broken glasses and discarded razor blades in cleaning out waste baskets; they may be protected by lining the baskets with plastic bags which can be removed en masse.

Burns and scalds

Burns and scalds are common among chefs, dishwashers and other kitchen workers and laundry workers. Grease burns occur from splatters during cooking or as food is dropped into deep-fat fryers, when hot grease is added, filtered or removed, and when grills and fryers are cleaned while hot. Many result when workers slip on wet or slippery floors and fall on or against hot grills and open flames. A unique type of burn occurs in restaurants where flaming desserts, entrees and drinks are served (Achauer, Bartlett and Allyn 1982).

Industrial chemicals

Hotel and restaurant establishments share with other small enterprises a propensity for improper storage, handling and disposal of industrial chemicals. All too frequently cleaning supplies, disinfectants, pesticides and other “household” poisons are stored in unlabelled containers, are placed above open food containers or food preparation areas or, when used in spray form, are excessively inhaled.

The fast food industry

The fast food industry, one of the most rapidly growing in the United States and becoming increasingly popular in other countries, is one of the largest employers of young people. Lacerations and burns are common hazards in these establishments. It has also been noted that the home delivery of pizzas and other prepared food is often extremely hazardous because of policies which encourage reckless driving on bicycles as well as in motor vehicles (Landrigan et al. 1992).

Preventive Measures

Standardized work processes, adequate training and proper supervision are key elements in the prevention of work-related injuries and illnesses among workers in the hotel and restaurant industry. It is essential that, because of their generally low educational levels and language difficulties, the educational materials and training exercises be readily understood (they may have to be conducted in several languages). Also, because of the high turnover, training must be repeated at frequent intervals. The training exercises should be supplemented by frequent inspections to assure that the basic principles of good housekeeping and elimination of accident hazards are observed.

Emergency drills

In addition to regular inspections to verify that firefighting equipment (e.g., smoke alarms, sprinkler systems, fire extinguishers and hoses and emergency lighting equipment) is in good working order and that emergency exits are clearly marked and not blocked, frequent drills are necessary to train the workers in how to prevent themselves and the patrons from being trapped and overcome in the event of a fire or an explosion. It is desirable to hold at least some of these drills in concert with the community fire, rescue and police organizations.

Conclusion

Apropriately designed and diligently practised preventive measures will do much to lower the frequency of occupational injuries and illnesses among hotel and restaurant workers. Language barriers and relatively low educational levels often represent formidable challenges to the effectiveness of training and indoctrination programmes, while the high rate of turnover dictates the frequent repetition of these programmes. It is important to remember that the health and safety of the workers in this industry is an essential element in the enjoyment and satisfaction of the patrons, upon whose good will the success - and even the survival - of the enterprise depends.

 

Back

Friday, 25 March 2011 05:02

Violence in the Workplace

Violence is pervasive in modern society and appears to be escalating. Entirely apart from repression, wars and terrorist activities, the media daily report in banner headlines on the mayhem inflicted by humans upon each other in “civilized” as well as more primitive communities. Whether there has been a real increase or this simply represents more thorough reporting is arguable. After all, violence has been a feature of human interaction since prehistoric ages. Nevertheless, violence has become one of the leading causes of death in modern industrial societies—in some segments of the community it is the leading cause of death—and it is increasingly being recognized as a public health problem.

Inescapably, it finds its way into the workplace. From 1980 to 1989, homicide was the third leading cause of death from injury in North American workplaces, according to data compiled by the National Traumatic Occupational Facilities Surveillance System (NIOSH 1993a). During this period, occupational homicides accounted for 12% of deaths from injury in the workplace; only motor vehicles and machines accounted for more. By 1993, that figure had risen to 17%, a rate of 0.9 per 100,000 workers, now second only to motor vehicle deaths (Toscano and Windau 1994). For  women  workers,  it  remained  the  leading  cause  of  work-related death, although the rate (0.4 deaths per 100,000) was lower than that for men (1.2 deaths per 100,000) (Jenkins 1995).

These deaths, however, represent only the “tip of the iceberg”. For example, in 1992, about 22,400 American workers were injured seriously enough in non-fatal assaults in the workplace to require days away from work to recuperate (Toscano and Windau 1994). Reliable and complete data are lacking, but it is estimated that for every death there have been many thousands—perhaps, even hundreds of thousands—of instances of violence in the workplace.

In its newsletter, Unison, the large British union of health care and governmental service workers, has labelled violence as “the most threatening risk faced by members at work. It is the risk which is most likely to lead to injury. It can bring unmanageable levels of occupational stress which damages personal esteem and threatens people’s ability to continue on the job” (Unison 1992).

This article will summarize the characteristics of violence in the workplace, the kinds of people involved, its effects on them and their employers, and the steps that may be taken to prevent or control such effects.

Definition of Violence

There is no consensus on the definition of violence. For example, Rosenberg and Mercy (1991) include in the definition both fatal and nonfatal interpersonal violence where physical force or other means is used by one person with the intent of causing harm, injury or death to another. The Panel on the Understanding and Control of Violent Behavior convened by the US National Academy of Sciences adopted the definition of violence as: behaviours by individuals that intentionally threaten, attempt or inflict physical harm on others (Reiss and Roth 1993).

These definitions focus on threatening or causing physical harm. However, they exclude instances in which verbal abuse, harassment or humiliation and other forms of psychological trauma may be the sole harm to the victim and which may be no less devastating. They also exclude sexual harassment, which may be physical but which is usually entirely non-physical. In the national survey of American workers conducted by the Northwestern National Life Insurance Company, the researchers separated violent acts into: harassment (the act of creating a hostile environment through unwelcome words, actions or physical contacts not resulting in physical harm), threats (expressions of an intent to cause physical harm), and physical attacks (aggression resulting in a physical assault with or without the use of a weapon) (Lawless, 1993).

In the UK, the Health and Safety Executive’s working definition of workplace violence is: any incident in which an employee is abused, threatened or assaulted by a member of the public in circumstances arising out of the course of his or her employment. Assailants may be patients, clients or co-workers (MSF 1993).

In this article, the term violence will be used in its broadest sense to include all forms of aggressive or abusive behaviour that may cause physical or psychological harm or discomfort to its victims, whether they be intentional targets or innocent bystanders involved only impersonally or incidentally. While workplaces may be targets of terrorist attacks or may become involved in riots and mob violence, such instances will not be discussed.

Prevalence of Violence in the Workplace

Accurate information on the prevalence of violence in the workplace is lacking. Most of the literature focuses on cases that are formally reported: homicides which get tallied in the obligatory death registries, cases that get enmeshed in the criminal justice system, or cases involving time off the job that generate workers’ compensation claims. Yet, for every one of these, there is an untold number of instances in which workers are victims of aggressive, abusive behaviour. For example, according to a survey conducted by the Bureau of Justice Statistics in the US Department of Justice, over half the victimizations sustained at work were not reported to the police. About 40% of the respondents said they did not report the incident because they considered it to be a minor or a personal matter, while another 27% said they did report it to a manager or a company security officer but, apparently, the report was not relayed to the police (Bachman 1994). In addition to the lack of a consensus on a taxonomy of violence, other reasons for under-reporting include:

  • Cultural acceptance of violence. There is in many communities a widespread tolerance for violence among or against certain groups (Rosenberg and Mercy 1991). Although frowned upon by many, violence is often rationalized and tolerated as a “normal” response to competition. Violence among minority and ethnic groups is often condoned as a righteous response to discrimination, poverty and lack of access to social or economic equity resulting in low self-esteem and low valuations of human life. As a result, the assault is seen as a consequence of living in a violent society rather than working in an unsafe workplace. Finally, there is the “on-the-job syndrome”, in which workers in certain jobs are expected to put up with verbal abuse, threats and, even, physical attacks (SEIU 1995; Unison 1992).
  • Lack of a reporting system. Only a small proportion of organizations have articulated an explicit policy on violence or have designed procedures for reporting and investigating instances of alleged violence in the workplace. Even where such a system has been installed, the trouble of obtaining, completing and filing the required report form is a deterrent to reporting all but the most outrageous incidents.
  • Fear of blame or reprisal. Workers may fear being held responsible when they have been attacked by a client or a patient. Fear of reprisal by the assailant is also a potent deterrent to reporting, especially when that person is the worker’s superior and in a position to affect his or her job status.
  • Lack of interest on the part of the employer. The employer’s lack of interest in investigating and reacting to prior incidents will certainly discourage reporting. Also, supervisors, concerned that workplace violence might reflect unfavourably on their managerial capabilities may actually discourage or even block the filing of reports by workers in their units.

 

To determine the prevalence of violence in the workplace in the absence of reliable data, attempts have been made to extrapolate both from available statistics (e.g., death certificates, crime reports and workers’ compensation systems) and from specially designed surveys. Thus, the US National Crime Victimization Survey estimated that about 1 million American workers (out of a workforce of 110 million) are assaulted at work each year (Bachman 1994). And, a 1993 telephone survey of a national sample of 600 American full-time workers (excluding self-employed and military personnel) found that one in four said that he or she had been a victim of workplace violence during the study year: 19%ere harassed, 7% were threatened, and 3% were attacked physically. The researchers reported further that 68%of the harassment victims, 43% of the threat victims and 24% of the attack victims had not reported the incident (Lawless 1993).

A similar survey of workers in the UK employed by the National Health Service revealed that, during the previous year, 0.5% had required medical treatment following an on-the-job physical assault; 11% had suffered a minor injury requiring only first aid, 4 to 6% had been threatened by persons wielding a deadly weapon, and 17% had received verbal threats. Violence was a special problem for emergency staff in ambulances and accident departments, nurses, and workers involved in the care of psychologically disturbed patients (Health Services Advisory Committee 1987). The risk of health workers being confronted by violence has been labelled a feature of everyday work in primary care and in accident/emergency departments (Shepherd 1994).

Homicide in the Workplace

Although workplace homicides are only a small proportion of all homicides, their substantial contribution to work-related deaths, at least in the United States, their unique features, and the possibility of preventive interventions by employers earn them special attention. For example, while most homicides in the community involve people who know each other, many of them close relatives, and only 13% were reported to have been associated with another felony, these proportions were reversed in the workplace, where more than three-fourths of the homicides were committed in the course of a robbery (NIOSH 1992). Further, while persons aged 65 and older in the general population have the lowest rates of being victims of homicide, this age group has the highest rates of such involvement in workplace homicides (Castillo and Jenkins 1994).

American workplaces with the highest rates of homicide are listed in table 1. Over 50% are accounted for by only two industries: retail trade and services. The latter includes taxi driving, which has nearly 40 times the average workplace homicide rate, followed by liquor/convenience stores and gas stations, prime targets for robberies, and by detective/protective services (Castillo and Jenkins 1994).

Table 1. US workplaces with the highest rates of occupational homicide, 1980-1989

Workplaces

No. of homicides

Rate1

Taxicab establishments

287

26.9

Liquor stores

115

8.0

Gas stations

304

5.6

Detective/protective services

152

5.0

Justice/public order establishments

640

3.4

Grocery stores

806

3.2

Jewellery stores

56

3.2

Hotels/motels

153

3.2

Eating/drinking places

754

1.5

1 Number per 100,000 workers per year.

Source: NIOSH 1993b.

 

Table 2 lists the occupations with the highest rates of workplace homicides. Again, reflecting the likelihood of involvement in attempted felonies, taxi drivers head the list, followed by law-enforcement personnel, hotel clerks and workers in various types of retail establishments. Commenting on similar data from the UK, Drever (1995) noted that most of the occupations with the highest mortality from homicides had high rates of drug dependence (scaffolders, literary and artistic occupations, painters and decorators) or alcohol abuse (cooks and kitchen porters, publicans, bartenders and caterers).

Table 2. US occupations with the highest rates of occupational homicide, 1980-1989

Occupations

No. of homicides

Rate1

Taxicab drivers/chauffeurs

289

15.1

Law enforcement officers

520

9.3

Hotel clerks

40

5.1

Gas station workers

164

4.5

Security guards

253

3.6

Stock handlers/baggers

260

3.1

Store owners/managers

1,065

2.8

Bartenders

84

2.1

1 Number per 100,000 workers per year.

Source: NIOSH 1993b.

 

As noted above, the vast majority of work-related homicides occur during the course of a robbery or other crime committed by a person or persons usually not known to the victim. Risk factors associated with such incidents are listed in table 3.

 


Table 3. Risk factors for workplace homicides

 

Working alone or in small numbers

Exchange of money with the public

Working late night or early morning hours

Working in high crime areas

Guarding valuable property or possessions

Working in community settings (e.g. taxi drivers and police)

Source: NIOSH 1993b.


 

About 4% of workplace homicides occur during confrontations with family members or acquaintances who have followed the victim into the workplace. About 21% arise out of a confrontation related to the workplace: about two-thirds of these are perpetrated by workers or former employees with a grudge against a manager or a co-worker, while angry customers or clients account for the rest (Toscano and Windau 1994). In these cases, the target may be the particular manager or worker whose actions provoked the assault or, where there is a grudge against the organization, the target may be the workplace itself, and any employees and visitors who just happen to be in it at the critical moment. Sometimes, the assailant may be emotionally disturbed, as in the case of Joseph T. Weisbecker, an employee on long-term disability leave from his employer in Louisville, Kentucky, because of mental illness, who killed eight co-workers and injured 12 others before taking his own life (Kuzmits 1990).

Causes of Violence

Current understanding of the causes and risk factors for assaultive violence is very rudimentary (Rosenberg and Mercy 1991). Clearly, it is a multifactorial problem in which each incident is shaped by the characteristics of the assailant, the characteristics of the victim(s) and the nature of the interplay between them. Reflecting such complexity, a number of theories of causation have been developed. Biological theories, for example, focus on such factors as gender (most of the assailants are male), age (involvement in violence in the community diminishes with age but, as noted above, this is not so in the workplace), and the influence of hormones such as testosterone, neurotransmitters such as serotonin, and other such biological agents. The psychological approach focuses on personality, holding that violence is engendered by deprivation of love during childhood, and childhood abuse, and is learned from role models, reinforced by rewards and punishments in early life. Sociological theories emphasize as breeders of violence such cultural and subcultural factors as poverty, discrimination and lack of economic and social equity. Finally, interactional theories converge on a sequence of actions and reactions that ultimately escalate into violence (Rosenberg and Mercy 1991).

A number of risk factors have been associated with violence. They include:

Mental illness

The vast majority of people who are violent are not mentally ill, and the vast proportion of individuals with mental illness are not violent (American Psychiatric Association 1994). However, mentally disordered individuals are sometimes frightened, irritable, suspicious, excitable, or angry, or a combination of these (Bullard 1994). The resultant behaviour poses a particular risk of violence to the physicians, nurses and staff members involved in their care in ambulances, emergency departments and both inpatient and outpatient psychiatric facilities.

Certain types of mental illness are associated with a greater propensity for violence. Persons with psychopathic personalities tend to have a low threshold for anger and frustration, which often generate violent behaviour (Marks 1992), while individuals with paranoia are suspicious and prone to attack individuals or entire organizations whom they blame when things do not go as they would wish. However, violence may be exhibited by persons with other forms of mental illness. Furthermore, some mentally ill individuals are prone to episodes of acute dementia in which they may inflict violence on themselves as well as on those trying to restrain them.

Alcohol and drug abuse

Alcohol abuse has a strong association with aggressive and violent behaviour. While drunkenness on the part of either assailants or victims, or both, often results in violence, there is disagreement as to whether alcohol is the cause of the violence or merely one of a number of factors involved in its causation (Pernanen 1993). Fagan (1993) emphasized that while alcohol affects neurobiological functions, perception and cognition, it is the immediate setting in which the drinking takes place that channels the disinhibiting responses to alcohol. This was confirmed by a study in Los Angeles County which found that violent incidents were much more frequent in some bars and relatively uncommon in others where just as much drinking was taking place, and concluded that violent behaviour was not related to the amount of alcohol being consumed but, rather, to the kinds of individuals attracted to a particular drinking establishment and the kinds of unwritten rules in effect there (Scribner, MacKinnon and Dwyer 1995).

Much the same may be said for abuse of illicit drugs. Except perhaps for crack cocaine and the amphetamines, drug use is more likely to be associated with sedation and withdrawal rather than aggressive, violent behaviour. Most of the violence associated with illegal drugs seems to be associated not with the drugs, but with the effort to obtain them or the wherewithal to purchase them, and from involvement in the illegal drug traffic.

Violence in the community

Violence in the community not only spills over into workplaces but is a particular risk factor for workers such as police and firefighters,  and  for  postal  workers  and  other  government employees, repair and service personnel, social workers and others whose jobs take them into neighbourhoods in which violence and crime are indigenous. Important factors in the frequency of violence, particularly in the United States, is the prevalence of firearms in the hands of the general public and, especially for young people, the amount of violence depicted in films and on television.

Work-Related Factors Associated with Violence

Instances of violence may occur in any and all workplaces. There are, however, certain jobs and work-related circumstances that are particularly associated with a risk of generating or being subjected to violence. They include:

Criminal activities

Perhaps the least complex of episodes of work-related violence are those associated with criminal violence, the major cause of worksite homicides. These fall into two categories: those involved with attempts at robbery or other felonies, and those related to traffic in illicit drugs. Police, security guards and other personnel with law-enforcement responsibilities face a constant risk of attack by felons attempting to enter the workplace and those resisting detection and arrest. Those working alone and field workers whose duties take them into high-crime neighbourhoods are frequent targets of robbery attempts. Health professionals making home visits to such areas are particularly at risk because they often carry drugs and drug paraphernalia such as hypodermic syringes and needles.

Dealing with the public

Workers in government and private community service agencies, banks and other institutions serving the public are frequently confronted by attacks from individuals who have been kept waiting unduly, have been greeted with disinterest and indifference (whether real or perceived), or were thwarted in obtaining the information or services they desired because of complicated bureaucratic procedures or technicalities that made them ineligible. Clerks in retail establishments receiving items being returned, workers staffing airport ticket counters when flights are overbooked, delayed or cancelled, urban bus or trolley drivers and conductors, and others who must deal with customers or clients whose wants cannot immediately be satisfied are often targets for verbal and sometimes even physical abuse. Then, there are also those who must contend with impatient and unruly crowds, such as police officers, security guards, ticket takers and ushers at popular sporting and entertainment events.

Violent attacks on government workers, particularly those in uniform, and on government buildings and offices in which workers and visitors may be indiscriminately injured or killed, may result from resentment and anger at laws and official policies which the perpetrators will not accept.

Work stress

High levels of work stress may precipitate violent behaviour, while violence in the workplace can, in turn, be a potent stressor. The elements of work stress are well known (see chapter Psychosocial and Organizational Factors). Their common denominator is a devaluation of the individual and/or the work he or she performs, resulting in fatigue, frustration and anger directed at managers and co-workers perceived to be inconsiderate, unfair and abusive. Several recent population studies have demonstrated an association  between  violence  and  job  loss,  one  of  the  most  potent job-related stressors (Catalano et al. 1993; Yancey et al. 1994).

Interpersonal environment in the workplace

The interpersonal environment in the workplace may be a breeding ground for violence. Discrimination and harassment, forms of violence in themselves as defined in this article, may provoke violent retaliation. For example, MSF, the British union of workers in management, science and finance, calls attention to workplace bullying (defined as persistent offensive, abusive, intimidating, malicious or insulting behaviour, abuse of power or unfair penal sanctions), as a characteristic of the management style in some organizations (MSF 1995).

Sexual harassment has been branded a form of assault on the job (SEIU 1995). It may involve unwelcome touching or patting, physical assault, suggestive remarks or other verbal abuse, staring or leering, requests for sexual favours, compromising invitations, or a work environment made offensive by pornography. It is illegal in the United States, having been declared a form of sexual discrimination under Title VII of the Civil Rights Act of 1964 when the worker feels that his or her job status depends on tolerating the advances or if the harassment creates an intimidating, hostile or offensive workplace environment.

Although women are the usual targets, men have also been sexually harassed, albeit much less frequently. In a 1980 survey of US federal employees, 42% of female respondents and 15% of males said that they had been sexually harassed on the job, and a follow-up survey in 1987 yielded similar results (SEIU 1995). In the United States, extensive media coverage of the harassment of women who had “intruded” into jobs and workplaces traditionally filled by males, and the notoriety given to the involvement of prominent political and public figures in alleged harassment, have resulted in an increase in the number of complaints received by state and federal anti-discrimination agencies and the number of civil law suits filed.

Working in health care and social services

In addition to the attempted robberies as noted above, health care staff are often targets of violence from anxious and disturbed patients, especially in emergency and outpatient departments, where long waits and impersonal procedures are not uncommon and where anxiety and anger may boil over into verbal or physical assaults. They may also be victims of assault by family members or friends of patients who had unfavourable outcomes which they rightly or wrongfully attribute to denials, delays or errors in treatment. In such instances they may attack the particular health worker(s) whom they hold responsible, or the violence may be aimed randomly at any staff member(s) of the medical facility.

Effects of Violence on the Victim

The trauma caused by physical assault varies with the nature of the attack and the weapons employed. Bruises and cuts on the hands and forearms are common when the victim has tried to defend himself or herself. Since the face and head are frequent targets, bruises and fractures of the facial bones are common; these can be traumatic psychologically because the swelling and ecchymoses are so visible and may take weeks to disappear (Mezey and Shepherd 1994).

The psychological effects may be more troublesome than the physical trauma, especially when a health worker has been assaulted by a patient. The victims may experience a loss of composure and self-confidence in their professional competence accompanied by a sense of guilt at having provoked the attack or having failed to detect that it was coming. Unfocused or directed anger may persist at the apparent rejection of their well-intended professional efforts, and there may be a persistent loss of confidence in themselves as well as a lack of trust in their co-workers and supervisors that can interfere with work performance. All this may be accompanied by insomnia, nightmares, diminished or increased appetite, increased consumption of tobacco, alcohol and/or drugs, social withdrawal and absenteeism from the job (Mezey and Shepherd 1994).

Post-traumatic stress disorder is a specific psychological syndrome (PTSD) that may develop after major disasters and instances of violent assault, not only in those directly involved in the incident but also in those who have witnessed it. While usually associated with life-threatening or fatal incidents, PTSD may occur after relatively trivial attacks that are perceived as life-threatening (Foa and Rothbaum 1992). The symptoms include: re-experiencing the incident through recurrent and intrusive recollections (“flashbacks”) and nightmares, persistent feelings of arousal and anxiety including muscular tension, autonomic hyperactivity, loss of concentration, and exaggerated reactivity. There is often conscious or unconscious avoidance of circumstances that recall the incident. There may be a long period of disability but the symptoms usually respond to supportive psychotherapy. They can often be prevented by a post-incident debriefing conducted as soon as possible after the incident, followed, when needed, by short-term counselling (Foa and Rothbaum 1992).

After the Incident

Interventive measures to be taken immediately after the incident include:

Care of the victim

Appropriate first-aid and medical care should be provided as quickly as possible to all injured individuals. For possible medico-legal purposes (e.g., criminal or civil actions against the assailant) the injuries should be described in detail and, if possible, photographed.

Clean-up of the workplace

Any damage or debris in the workplace should be cleaned up, and any equipment that was involved should be checked to make sure that the safety and cleanliness of the workplace have been fully restored (SEIU 1995).

Post-incident debriefing

As soon as possible, all those involved in or witnessing the incident should participate in a post-incident debriefing or a “trauma-crisis counselling” session conducted by an appropriately qualified staff member or an outside consultant. This will not only provide emotional support and identify those for whom referral for one-on-one counselling may be advisable, but also enable the collection of details of exactly what has happened. Where necessary, the counselling may be supplemented by the formation of a peer support group (CAL/OSHA 1995).

Reporting

A standardized report form should be completed and submitted to the proper individual in the organization and, when appropriate, to the police in the community. A number of sample forms that may be adapted to the needs of a particular organization have been designed and published (Unison 1991, MSF 1993, SEIU 1995). Aggregating and analysing incident report forms will provide epidemiological information that may identify risk factors for violence in the particular workplace and point the way to suitable preventive interventions.

Investigating the incident

Each reported incident of alleged violence, however trivial it may seem, should be investigated by a designated properly trained individual. (Assignment for such investigations may be made by the joint labour/management safety and health committee, where one exists.) The investigation should be aimed at identifying the cause(s) of the incident, the person(s) involved, what, if any, disciplinary measures should be invoked, and what may be done to prevent recurrences. Failure to conduct an impartial and effective investigation is a signal of management’s disinterest and a lack of concern for employees’ health and welfare.

Employer support

Victims and observers of the incident should be assured that they will not be subject to discrimination or any other form of reprisal for reporting it. This is especially important when the alleged assailant is the worker’s superior.

Depending on the regulations extant in the particular jurisdiction, the nature and extent of any injuries, and the duration of any absence from work, the employee may be eligible for workers’ compensation benefits. In such cases, the appropriate claim forms should be filed promptly.

When appropriate, a report should be filed with the local law enforcement agency. When needed, the victim may be provided with legal advice on pressing charges against the assailant, and assistance in dealing with the media.

Union Involvement

A number of unions have been playing a prominent role in dealing with workplace violence, most notably those representing workers in the health care and service industries, such as the Service Employees International Union (SEIU) in the United States, and Management, Science and Finance (MSF) and Unison in the UK. Through the development of guidelines and the publication of fact sheets, bulletins and pamphlets, they have focused on the education of workers, their representatives and their employers about the importance of violence in the workplace, how to deal with it, and how to prevent it. They have acted as advocates for members who have been victims to ensure that their complaints and allegations of violence are given appropriate consideration without threats of reprisal, and that they receive all of the benefits to which they may be entitled. Unions also advocate with employers’ and trade associations and government agencies on behalf of policies, rules and regulations intended to reduce the prevalence of violence in the workplace.

Threats of Violence

All threats of violence should be taken seriously, whether aimed at particular individuals or at the organization as a whole. First, steps must be taken to protect the targeted individual(s). Then, where possible, the assailant should be identified. If that person is not in the workforce, the local law enforcement agencies should be notified. If he or she is in the organization, it may be desirable to consult a qualified mental health professional to guide the handling of the situation and/or deal directly with the assailant.

Preventive Strategies

Preventing violence in the workplace is fundamentally the employer’s responsibility. Ideally, a formal policy and programme will have been developed and implemented before victimization occurs. This is a process that should involve not only the appropriate individuals in human resources/personnel, security, legal affairs, and employee health and safety departments, but also line managers and shop stewards or other employee representatives. A number of guides for such an exercise have been published (see  table 4). They are generic and are intended to be tailored to the circumstances of a particular workplace or industry. Their common denominators include:

Table 4. Guides for programmes to prevent workplace violence

Date

Title

Source

1991

Violence in the Workplace:
NUPE Guidelines

Unison Health Care
1 Marbledon Place
London WC1H 9AJ, UK

1993

CAL/OSHA Guidelines for Security
and Safety of Health Care and
Community Service Workers

Division of Occupational Safety and Health
Department of Industrial Relations
45 Fremont Street
San Francisco, CA 94105, USA

1993

Prevention of Violence at Work:
An MSF Guide with Model
Agreement and Violence at Work
Questionnaire (MSF Health and
Safety Information No. 37)

MSF Health and Safety Office
Dane O’Coys Road
Bishops Stortford
Herts, CM23 2JN, UK

1995

Assault on the Job: We Can Do
Something About Workplace
Violence (2nd Edition)

Service Employees International Union
1313 L Street, NW
Washington, DC 20005, USA

1995

CAL/OSHA: Model Injury and
Illness Prevention Program for
Workplace Security

Division of Occupational Safety and Health
Department of Industrial Relations
45 Fremont Street
San Francisco, CA 94105, USA

1996

Guidelines for Preventing Work-
place Violence for Health Care
and Social Service Workers
(OSHA 3148)

OSHA Publications Office
P.O. Box 37535
Washington, DC 20013-7535, USA

 

Establishing a policy

A policy explicitly outlawing discriminatory and abusive behaviour and the use of violence for dispute resolution, accompanied by specified disciplinary measures for infractions (up to and including dismissal), should be formulated and published.

Risk assessment

An inspection of the workplace, supplemented by analysis of prior incidents and/or information from employee surveys, will enable an expert to assess risk factors for violence and suggest preventive interventions. Examination of the prevailing style of management and supervision and the organization of work may disclose high levels of work stress that may precipitate violence. Study of interactions with clients, customers or patients may reveal features that may generate needless anxiety, frustration and anger, and precipitate violent reactions.

Workplace modifications to reduce crime

Guidance from police or private security experts may suggest changes in work procedures and in the layout and furnishing of the workplace that will make it a less attractive target for robbery attempts. In the United States, the Virginia Department of Criminal Justice has been using Crime Prevention Through Environmental Design (CPTED), a model approach developed by a consortium of the schools of architecture in the state that includes: changes in interior and exterior lighting and landscaping with particular attention to parking areas, stairwells and restrooms; making sales and waiting areas visible from the street; use of drop safes or time-release safes to hold cash; alarm systems, television monitors and other security equipment (Malcan 1993). CPTED has been successfully applied in convenience stores, banks (particularly in relation to automatic teller machines which may be accessed around the clock), schools and universities, and in the Washington, DC, Metro subway system.

In New York City, where robbery and killing of taxi drivers is relatively frequent compared to other large cities, the Taxi and Limousine Commission issued regulations that mandated the insertion of a transparent, bullet-resistant partition between the driver and passengers in the rear seat, a bullet-proof plate in the back of the driver’s seat, and an external distress signal light that could be turned on by the driver while remaining invisible to those inside the cab (NYC/TLC 1994). (There has been a spate of head and facial injuries among rear seat passengers who were not wearing seat belts and were thrown forward against the partition when the cab stopped suddenly.)

Where work involves interaction with customers or patients, employee safety may be enhanced by interposing barriers such as counters, desks or tables, transparent, shatter-proof partitions, and locked doors with shatter-proof windows (CAL/OSHA 1993). Furniture and equipment can be arranged to avoid entrapment of the employee and, where privacy is important, it should not be maintained at the expense of isolating the employee with a potentially aggressive or violent individual in a closed or secluded area.

Security systems

Every workplace should have a well-designed security system. Intrusion of strangers may be reduced by limiting entry to a designated reception area where visitors may have an identity check and receive ID badges indicating the areas to be visited. In some situations, it may be advisable to use metal detectors to identify visitors carrying concealed weapons.

Electronic alarm systems triggered by strategically located “panic buttons” can provide audible and/or visual signals that can alert co-workers to danger and summon help from a nearby security station. Such alarm systems may also be rigged to summon local police. However, they are of little use if guards and co-workers have not been trained to respond promptly and properly. Television monitors can not only provide protective surveillance but also record any incidents as they occur, and may help identify the perpetrator. Needless to say, such electronic systems are of little use unless they are maintained properly and tested at frequent intervals to ensure that they are in working order.

Two-way radios and cellular telephones can provide a measure of security for field personnel and those who are working alone. They also provide a means of reporting their location and, when necessary, summoning medical and other forms of assistance.

Work practice controls

Work practices should be reviewed periodically and modified to minimize the build-up of work stress. This involves attention to work schedules, work load, job content, and monitoring of work performance. Adequate staffing levels should be maintained in high-risk work areas both to discourage violent behaviour and to deal with it when it occurs. Adjustment of staffing levels to cope with peak flows of clients or patients will help to minimize irritating delays and crowding of work areas.

Staff training

Workers and supervisors should be trained to recognize rising tension and anger and in non-violent methods of defusing them. Training involving role-playing exercises will help employees to cope with overly aggressive or abusive individuals without being confrontational. In  some  situations,  training  employees  in  self-defence may be indicated, but there is the danger that this will breed a level of self-confidence that will lead them to delay or entirely neglect calling for available help.

Security guards, staff in psychiatric or penal institutions, and others likely to be involved with physically violent individuals should be trained to subdue and restrain them with minimal risk of injury to others or to themselves (SEIU 1995). However, according to Unison (1991), training can never be a substitute for good work organization and the provision of adequate security.

Employee assistance programmes

Employee assistance programmes (EAPs—also known as member assistance programmes, or MAPs, when provided by a union) can be particularly helpful in crisis situations by providing counselling and support to victims and witnesses of violent incidents, referring them to outside mental health professionals when needed, monitoring their progress and overseeing any protective arrangements intended to facilitate their return to work.

EAPs can also counsel employees whose frustration and anger might culminate in violent behaviour because they are overburdened by work-related problems or those arising from life in the family and/or in the community, whose frustration and anger might culminate in violent behaviour. When they have several such clients from a particular area of the workplace, they can (without breaching the confidentiality of personal information essential to their operation) guide managers to making desirable work modifications that will defuse the potential “powder keg” before violence erupts.

Research

Because of the seriousness and complexity of the problem and the paucity of reliable information, research is needed in the epidemiology, causation, prevention and control of violence in society in general and in the workplace. This requires a multidisciplinary effort involving (in addition to experts in occupational safety and health), mental health professionals, social workers, architects and engineers, experts in management science, lawyers, judges and experts in the criminal justice system, authorities on public policy, and others. Urgently needed are expanded and improved systems for the collection and analysis of the relevant data and the development of a consensus on a taxonomy of violence so that information and ideas can be more easily transposed from one discipline to others.

Conclusion

Violence is endemic in the workplace. Homicides are a major cause of work-related deaths, but their impact and cost are considerably outweighed by the prevalence of near misses, non-fatal physical assaults, threats, harassment, aggressive behaviour and abuse, much of which remains undocumented and unreported. Although most of the homicides and many of the assaults occur in conjunction with criminal activities, workplace violence is not just a criminal justice problem. Nor is it solely a problem for mental health professionals and specialists in addictions, although much of it is associated with mental illness, alcoholism and drug abuse. It requires a coordinated effort by experts in a broad variety of disciplines, led by occupational health and safety professionals, and aimed at developing, validating and implementing a coherent set of strategies for intervention and prevention, keeping in mind that the diversity in workers, jobs and industries dictates an ability to tailor them to the unique characteristics of a particular workforce and the organization that employs it.

 

Back

Wednesday, 02 March 2011 16:27

Health Care Workers and Latex Allergy

With the advent of the universal precautions against bloodborne infections which dictate the use of gloves whenever HCWs are exposed to patients or materials that might be infected with hepatitis B or HIV, the frequency and severity of allergic reactions to natural rubber latex (NRL) have zoomed upward. For example, the Department of Dermatology at the Erlangen-Nuremberg University in Germany reported a 12-fold increase in the number of patients with latex allergy between 1989 and 1995. More serious systemic manifestations increased from 10.7% in 1989 to 44% in 1994-1995 (Hesse et al. 1996).

It seems ironic that so much difficulty is attributable to rubber gloves when they were intended to protect the hands of nurses and other HCWs when they were originally introduced toward the end of the nineteenth century. This was the era of antiseptic surgery in which instruments and operative sites were bathed in caustic solutions of carbolic acid and bichloride of mercury. These not only killed germs but they also macerated the hands of the surgical team. According to what has become a romantic legend, William Stewart Halsted, one of the surgical “giants” of the time who is credited with a host of contributions to the techniques of surgery, is said to have “invented” rubber gloves around 1890 to make it more pleasant to hold hands with Caroline Hampton, his scrub nurse, whom he later married (Townsend 1994). Although Halsted may be credited with introducing and popularizing the use of rubber surgical gloves in the United States, many others had a hand in it, according to Miller (1982) who cited a report of their use in the United Kingdom published a half century earlier (Acton 1848).

Latex Allergy

Allergy to NRL is succinctly described by Taylor and Leow (see the article “Rubber contact dermatitis and latex allergy” in the chapter Rubber industry) as “an immunoglobulin E-mediated, immediate, Type I allergic reaction, most always due to NRL proteins present in medical and non-medical latex devices. The spectrum of clinical signs ranges from contact urticaria, generalized urticaria, allergic rhinitis, allergic conjunctivitis, angioedema (severe swelling) and asthma (wheezing) to anaphylaxis (severe, life-threatening allergic reaction)”. Symptoms may result from direct contact of normal or inflamed skin with gloves or other latex-containing materials or indirectly by mucosal contact with or inhalation of aerosolized NRL proteins or talcum powder particles to which NRL proteins have adhered. Such indirect contact can cause a Type IV reaction to the rubber accelerators. (Approximately 80% of “latex glove allergy” is actually a Type IV reaction to the accelerators.) The diagnosis is confirmed by patch, prick, scratch or other skin sensitivity tests or by serological studies for the immune globulin. In some individuals, the latex allergy is associated with allergy to certain foods (e.g., banana, chestnuts, avocado, kiwi and papaya).

While most common among health care workers, latex allergy is also found among employees in rubber manufacturing plants, other workers who habitually use rubber gloves (e.g., greenhouse workers (Carillo et al. 1995)) and in patients with a history of multiple surgical procedures (e.g., spina bifida, congenital urogenital abnormalities, etc.) (Blaycock 1995). Cases of allergic reactions after the use of latex condoms have been reported (Jonasson, Holm and Leegard 1993), and in one case, a potential reaction was averted by eliciting a history of an allergic reaction to a rubber swimming cap (Burke, Wilson and McCord 1995). Reactions have occurred in sensitive patients when hypodermic needles used to prepare doses of parenteral medications picked up NRL protein as they were pushed through the rubber caps on the vials.

According to a recent study of 63 patients with NRL allergy, it took an average of 5 years of working with latex products for the first symptoms, usually a contact urticaria, to develop. Some also had rhinitis or dyspnoea. It took, on average, an additional 2 years for the appearance of lower respiratory tract symptoms (Allmeers et al. 1996).

Frequency of latex allergy

To determine the frequency of NRL allergy, allergy tests were performed on 224 employees at the University of Cincinnati College of Medicine, including nurses, laboratory technicians, physicians, respiratory therapists, housekeeping and clerical workers (Yassin et al. 1994). Of these, 38 (17%) tested positive to latex extracts; the incidence ranged from 0% among housekeeping workers to 38% among dental staff. Exposure of these sensitized individuals to latex caused itching in 84%, a skin rash in 68%, urticaria in 55%, lachrymation and ocular itching in 45%, nasal congestion in 39% and sneezing in 34%. Anaphylaxis occurred in 10.5%.

In a similar study at the University of Oulo in Finland, 56% of 534 hospital employees who used protective latex or vinyl gloves on a daily basis had skin disorders related to the usage of the gloves (Kujala and Reilula 1995). Rhinorrhoea or nasal congestion was present in 13% of workers who used powdered gloves. The prevalence of both skin and respiratory symptoms was significantly higher among those who used the gloves for more than 2 hours a day.

Valentino and colleagues (1994) reported latex induced asthma in four health care workers in an Italian regional hospital, and the Mayo Medical Center in Rochester Minnesota, where 342 employees who reported symptoms suggestive of latex allergy were evaluated, recorded 16 episodes of latex-related anaphylaxis in 12 subjects (six episodes occurred after skin testing) (Hunt et al. 1995). The Mayo researchers also reported respiratory symptoms in workers who did not wear gloves but worked in areas where large numbers of gloves were being used, presumably due to air-borne talcum powder/latex protein particles.

Control and Prevention

The most effective preventive measure is modification of standard procedures to replace the use of gloves and equipment made with NRL with similar items made of vinyl or other non-rubber materials. This requires involvement of the purchasing and supply departments, which should also mandate the labelling of all latex-containing items so that they may be avoided by individuals with latex sensitivity. This is important not only to the staff but also to patients who may have a history suggestive of latex allergy. Aerosolized latex, from latex powder, is also problematic. HCWs who are allergic to latex and who do not use latex gloves may still be affected by the powdered latex gloves used by co-workers. A significant problem is presented by the wide variation in content of latex allergen among gloves from different manufacturers and, indeed, among different lots of gloves from the same manufacturer.

Glove manufacturers are experimenting with gloves using formulations with smaller amounts of NRL as well as coatings that will obviate the need for talcum powder to make the gloves easy to put on and take off. The goal is to provide comfortable, easy to wear, non-allergenic gloves that still provide effective barriers to the transmission of the hepatitis B virus, HIV and other pathogens.

A careful medical history with a particular emphasis on prior latex exposures should be elicited from all health care workers who present symptoms suggestive of latex allergy. In suspect cases, evidence of latex sensitivity may be confirmed by skin or serological testing. Since there is evidently a risk of provoking an anaphylactic reaction, the skin testing should only be performed by experienced medical personnel.

At the present time, allergens for desensitization are not available so that the only remedy is avoidance of exposure to products containing NRL. In some instances, this may require a change of job. Weido and Sim (1995) at the University of Texas Medical Branch at Galveston suggest advising individuals in high-risk groups to carry self-injectable epinephrine to use in the event of a systemic reaction.

Following the appearance of several clusters of latex allergy cases in 1990, the Mayo Medical Center in Rochester, Minnesota, formed a multidisciplinary work group to address the problem (Hunt et al. 1996). Subsequently, this was formalized in a Latex Allergy Task Force with members from the departments of allergy, preventive medicine, dermatology and surgery as well as the Director of Purchasing, the Surgical Nursing Clinical Director and the Director of Employee Health. Articles on latex allergy were published in staff newsletters and information bulletins to educate the 20,000 member workforce to the problem and to encourage those with suggestive symptoms to seek medical consultation. A standardized approach to testing for latex sensitivity and techniques for quantifying the amount of latex allergen in manufactured products and the amount and particle size of air-borne latex allergen were developed. The latter proved to be sufficiently sensitive to measure the exposure of individual workers while performing particular high-risk tasks. Steps were initiated to monitor a gradual transition to low-allergen gloves (an incidental effect was a lowering of their cost by concentrating glove purchases among the fewer vendors who could meet the low allergen requirements) and to minimize exposures of staff and patients with known sensitivity to NLR.

To alert the public to the risks of NLR allergy, a consumer group, the Delaware Valley Latex Allergy Support Network has been formed. This group has created an Internet website (http://www.latex.org) and maintains a toll-free telephone line (1-800 LATEXNO) to provide up-to-date factual information about latex allergy to persons with this problem and those who care for them. This organization, which has a Medical Advisory Group, maintains a Literature Library and a Product Center and encourages the exchange of experiences among those who have had allergic reactions.

Conclusion

Latex allergies are becoming an increasingly important problem among health care workers. The solution lies in minimizing contact with latex allergen in their work environment, especially by substituting non-latex surgical gloves and appliances.

 

Back

Wednesday, 02 March 2011 15:50

Case Study: Treatment of Back Pain

Most episodes of acute back pain respond promptly to several days of rest followed by the gradual resumption of activities within the limits of pain. Non-narcotic analgesics and non-steroidal anti-inflammatory drugs may be helpful in relieving pain but do not shorten the course. (Since some of these drugs affect alertness and reaction time, they should be used with caution by individuals who drive vehicles or have assignments where momentary lapses may result in harm to patients.) A variety of forms of physiotherapy (e.g., local applications of heat or cold, diathermy, massage, manipulation, etc.) often provide short periods of transient relief; they are particularly useful as a prelude to graded exercises that will promote the restoration of muscle strength and relaxation as well as flexibility. Prolonged bed rest, traction and the use of lumbar corsets tend to delay recovery and often lengthen the period of disability (Blow and Jayson 1988).

Chronic, recurrent back pain is best treated by a secondary prevention regimen. Getting enough rest, sleeping on a firm mattress, sitting in straight chairs, wearing comfortable, well-fitted shoes, maintaining good posture and avoiding long periods of standing in one position are important adjuncts. Excessive or prolonged use of medications increase the risk of side effects and should be avoided. Some cases are helped by the injection of “trigger points”, localized tender nodules in muscles and ligaments, as originally advocated in the seminal report by Lange (1931).

Exercise of key postural muscles (upper and lower abdominal, back, gluteal and thigh muscles) is the mainstay of both chronic care and prevention of back pain. Kraus (1970) has formulated a regimen that features strengthening exercises to correct muscle weakness, relaxing exercises to relief tension, spasticity and rigidity, stretching exercises to minimize contractures and exercises to improve balance and coordination. These exercises, he cautions, should be individualized on the basis of examination of the patient and functional tests of muscle strength, holding power and elasticity (e.g., the Kraus-Weber tests (Kraus 1970)). To avoid adverse effects of exercise, each session should include warm-up and cool-down exercises as well as limbering and relaxing exercises, and the number, duration and intensity of the exercises should be increased gradually as conditioning improves. Simply giving the patient a printed exercise sheet or booklet is not enough; initially, he or she should be given individual instruction and observed to be sure that the exercises are being done correctly.

In 1974, the YMCA in New York introduced the “Y’s Way to a Healthy Back Program”, a low-cost course of exercise training based on the Kraus exercises; in 1976 it became a national programme in the US and, later, it was established in Australia and in several European countries (Melleby 1988). The twice-a-week, six week programme is given by specially-trained YMCA exercise instructors and volunteers, mainly in urban YMCAs (arrangements for courses at the worksite have been made by a number of employers), and it emphasizes the indefinite continuation of the exercises at home. Approximately 80% of the thousands of individuals with chronic or recurrent back pain who have participated in this program have reported elimination or improvement in their pain.

 

Back

Page 1 of 2

" DISCLAIMER: The ILO does not take responsibility for content presented on this web portal that is presented in any language other than English, which is the language used for the initial production and peer-review of original content. Certain statistics have not been updated since the production of the 4th edition of the Encyclopaedia (1998)."

Contents

Preface
Part I. The Body
Part II. Health Care
Part III. Management & Policy
Part IV. Tools and Approaches
Part V. Psychosocial and Organizational Factors
Part VI. General Hazards
Part VII. The Environment
Part VIII. Accidents and Safety Management
Part IX. Chemicals
Part X. Industries Based on Biological Resources
Part XI. Industries Based on Natural Resources
Part XII. Chemical Industries
Part XIII. Manufacturing Industries
Part XIV. Textile and Apparel Industries
Part XV. Transport Industries
Part XVI. Construction
Part XVII. Services and Trade
Part XVIII. Guides