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Silk Industry

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Adapted from 3rd edition, Encyclopaedia of Occupational Health and Safety.

Silk is a lustrous, tough, elastic fibre produced by the larvae of silkworms; the term also covers the thread or cloth made from this fibre. The silk industry originated in China, as early as 2640 BC according to tradition. Towards the 3rd century AD, knowledge of the silkworm and its product reached Japan through Korea; it probably spread to India a little later. From there silk production was slowly carried westward through Europe to the New World.

The production process involves a sequence of steps not necessarily carried out in a single enterprise or plant. They include:

  • Sericulture. The production of cocoons for their raw silk filament is known as sericulture, a term which covers feeding, cocoon formation and so on. The first essential is a stock of mulberry trees adequate to feed the worms in their larval state. The trays on which the worms are reared have to be kept in a room with a constant temperature of 25 °C; this involves artificial heating in colder countries and seasons. The cocoons are spun after about 42 days of feeding.
  • Spinning or filature. The distinctive process in silk spinning is called reeling, in which the filaments from the cocoon are formed into a continuous, uniform and regular strand. First, the natural gum (sericin) is softened in scalding water. Then, in a bath or basin of hot water, the ends of the filaments from several cocoons are caught together, drawn up, attached to a reeling wheel and wound to form raw silk.
  • Throwing. In this process, the threads are twisted and doubled into more substantial yarns.
  • Degumming. In this phase, the raw silk is boiled in a solution of soap and water at approximately 95 °C.
  • Bleaching. The raw or boiled silk is then bleached in hydrogen peroxide or sodium peroxide.
  • Weaving. The silk thread is next woven into fabric; this usually takes place in separate factories.
  • Dyeing. Silk may be dyed while in the filament or thread form, or it may be dyed as a fabric.

 

Health and Safety Hazards

Carbon monoxide

Symptoms of carbon monoxide toxicity consisting of headache, vertigo and sometimes nausea and vomiting, usually not severe, have been reported in Japan, where sericulture is a common home industry, as a result of the use of charcoal fires in poorly ventilated rearing rooms.

Dermatitis

Mal des bassines, a dermatitis of the hands of female workers reeling raw silk, was quite common, particularly in Japan, where, in the 1920s, a morbidity rate of 30 to 50% among reeling workers was reported. Fourteen per cent of the affected workers lost an average of three working days each year. The skin lesions, localized mainly on fingers, wrists and forearms, were characterized by erythema covered with small vesicles which became chronic, pustular or eczematous and extremely painful. The cause of this condition was usually attributed to the decomposition products of the dead chrysalis and to a parasite in the cocoon.

More recently, however, Japanese observations have showed that it is probably related to the temperature of the reeling bath: until 1960 almost all reeling baths were kept at 65 °C, but, since the introduction of new installations with a bath temperature of 30 to 45 °C, there have been no reports of the typical skin lesions among reel workers.

The handling of raw silk may produce allergic skin reactions in some reel workers. Facial swelling and ocular inflammation have been observed where there was no direct local contact with the reeling bath. Similarly, dermatitis has been found among silk throwers.

Respiratory tract problems

In the former Soviet Union, an unusual outbreak of tonsillitis among silk spinners was traced to bacteria in the water of reeling basins and in the ambient air of the cocoon department. Disinfection and frequent replacement of reel bath water, combined with exhaust ventilation at the cocoon reels, brought about a swift improvement.

Extensive long-term epidemiological observations also carried out in the former USSR have shown that workers in the natural silk industry may develop respiratory allergy featuring bronchial asthma, asthmatiform bronchitis and/or allergic rhinitis. It appears that natural silk can cause sensitization during all stages of production.

A situation causing respiratory distress among spinning-frame workers when packaging or repackaging silk on a spinning or winding frame has also been reported. Depending upon the speed of the machinery, it is possible to aerosolize the proteinaceous substance surrounding the silk filament. This aerosol, when respirable in size, will cause a lung reaction very similar to that of the byssinotic reaction to cotton dust.

Noise

Noise exposure can reach harmful levels for workers at machines spinning and winding the silk threads, and at looms where fabric is woven. Adequate lubrication of the equipment and the interposition of sound baffles may reduce the noise level somewhat, but the continuing exposure throughout the working day can have a cumulative effect. If effective abatement is not obtained, resort will have to be made to personal protective devices. As with all workers exposed to noise, a hearing protection programme featuring periodic audiograms is desirable.

Safety and Health Measures

Control of temperature, humidity and ventilation are important at all stages of the silk industry. Home workers should not escape supervision. Adequate ventilation of rearing rooms should be ensured, and charcoal or kerosene stoves should be replaced by electric heaters or other warming devices.

Lowering the temperature of reeling baths may be effective in preventing dermatitis. The water should be replaced frequently, and exhaust ventilation is desirable. Direct skin contact with raw silk immersed in reeling baths should be avoided as far as possible.

The provision of good sanitary facilities and attention to personal hygiene are essential. Hand washing with a 3% acetic acid solution has been found effective in Japan.

The medical examination of new entrants and medical supervision thereafter are desirable.

The hazards from machinery in silk manufacture are similar to those in the textile industry in general. Accident prevention is best achieved by good housekeeping, adequate guarding of moving parts, continuing worker training and effective supervision. Power looms should be provided with guards to prevent accidents from flying shuttles. Very good lighting is required for the yarn preparation and weaving processes.

 

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Contents

Textile Goods Industry References

American Textile Reporter. 1969. (10 July).

Anthony, HM and GM Thomas. 1970. Tumors of the urinary bladder. J Natl Cancer Inst 45:879–95.

Arlidge, JT. 1892. The Hygiene, Diseases and Mortality of Occupations. London: Percival and Co.

Beck, GJ, CA Doyle, and EN Schachter. 1981. Smoking and lung function. Am Rev Resp Dis 123:149–155.

—. 1982. A longitudinal study of respiratory health in a rural community. Am Rev Resp Dis 125:375–381.

Beck, GJ, LR Maunder, and EN Schachter. 1984. Cotton dust and smoking effects on lung function in cotton textile workers. Am J Epidemiol 119:33–43.

Beck, GJ, EN Schachter, L Maunder, and A Bouhuys. 1981. The relation of lung function to subsequent employment and mortality in cotton textile workers. Chest suppl 79:26S–29S.

Bouhuys, A. 1974. Breathing. New York: Grune & Stratton.

Bouhuys, A, GJ Beck, and J Schoenberg. 1979. Epidemiology of environmental lung disease. Yale J Biol Med 52:191–210.

Bouhuys, A, CA Mitchell, RSF Schilling, and E Zuskin. 1973. A physiological study of byssinosis in colonial America. Trans New York Acad Sciences 35:537–546.

Bouhuys, A, JB Schoenberg, GJ Beck, and RSF Schilling. 1977. Epidemiology of chronic lung disease in a cotton mill community. Lung 154:167–186.

Britten, RH, JJ Bloomfield, and JC Goddard. 1933. Health of Workers in Textile Plants. Bulletin No. 207. Washington, DC: US Public Health Service.

Buiatti, E, A Barchielli, M Geddes, L Natasi, D Kriebel, M Franchini, and G Scarselli. 1984. Risk factors in male infertility. Arch Environ Health 39:266–270.

Doig, AT. 1949. Other lung diseases due to dust. Postgrad Med J 25:639–649.

Department of Labor (DOL). 1945. Special Bulletin No. 18. Washington, DC: DOL, Labor Standards Division.

Dubrow, R and DM Gute. 1988. Cause-specific mortality among male textile workers in Rhode Island. Am J Ind Med 13: 439–454.

Edwards, C, J Macartney, G Rooke, and F Ward. 1975. The pathology of the lung in byssinotics. Thorax 30:612–623.

Estlander, T. 1988. Allergic dermatoses and respiratory diseases from reactive dyes. Contact Dermat 18:290–297.

Eyeland, GM, GA Burkhart, TM Schnorr, FW Hornung, JM Fajen, and ST Lee. 1992. Effects of exposure to carbon disulphide on low density lipoprotein cholesterol concentration and diastolic blood pressure. Brit J Ind Med 49:287–293.

Fishwick, D, AM Fletcher, AC Pickering, R McNiven, and EB Faragher. 1996. Lung function in Lancashire cotton and man-made fibre spinning mill operatives. Occup Environ Med 53:46–50.

Forst, L and D Hryhorczuk. 1988. Occupational tarsal tunnel syndrome. Brit J Ind Med 45:277–278.

Fox, AJ, JBL Tombleson, A Watt, and AG Wilkie. 1973a. A survey of respiratory disease in cotton operatives: Part I. Symptoms and ventilation test results. Brit J Ind Med 30:42-47.

—. 1973b. A survey of respiratory disease in cotton operatives: Part II. Symptoms, dust estimation, and the effect of smoking habit. Brit J Ind Med 30:48-53.

Glindmeyer, HW, JJ Lefante, RN Jones, RJ Rando, HMA Kader, and H Weill. 1991. Exposure-related declines in the lung function of cotton textile workers. Am Rev Respir Dis 144:675–683.

Glindmeyer, HW, JJ Lefante, RN Jones, RJ Rando, and H Weill. 1994. Cotton dust and across-shift change in FEV1 Am J Respir Crit Care Med 149:584–590.

Goldberg, MS and G Theriault. 1994a. Retrospective cohort study of workers of a synthetic textiles plant in Quebec II. Am J Ind Med 25:909–922.

—. 1994b. Retrospective cohort study of workers of a synthetic textiles plant in Quebec I. Am J Ind Med 25:889–907.

Grund, N. 1995. Environmental considerations for textile printing products. Journal of the Society of Dyers and Colourists 111 (1/2):7–10.

Harris, TR, JA Merchant, KH Kilburn, and JD Hamilton. 1972. Byssinosis and respiratory diseases in cotton mill workers. J Occup Med 14: 199–206.

Henderson, V and PE Enterline. 1973. An unusual mortality experience in cotton textile workers. J Occup Med 15: 717–719.

Hernberg, S, T Partanen, and CH Nordman. 1970. Coronary heart disease among workers exposed to carbon disulphide. Brit J Ind Med 27:313–325.

McKerrow, CB and RSF Schilling. 1961. A pilot enquiry into byssinosis in two cotton mills in the United States. JAMA 177:850–853.

McKerrow, CB, SA Roach, JC Gilson, and RSF Schilling. 1962. The size of cotton dust particles causing byssinosis: An environmental and physiological study. Brit J Ind Med 19:1–8.

Merchant, JA and C Ortmeyer. 1981. Mortality of employees of two cotton mills in North Carolina. Chest suppl 79: 6S–11S.

Merchant, JA, JC Lumsdun, KH Kilburn, WM O’Fallon, JR Ujda, VH Germino, and JD Hamilton. 1973. Dose-response studies in cotton textile workers. J Occup Med 15:222–230.

Ministry of International Trade and Industry (Japan). 1996. Asia-Pacific Textile and Clothing Industry Form, June 3-4, 1996. Tokyo: Ministry of International Trade and Industry.

Molyneux, MKB and JBL Tombleson. 1970. An epidemiological study of respiratory symptoms in Lancashire mills, 1963–1966. Brit J Ind Med 27:225–234.

Moran, TJ. 1983. Emphysema and other chronic lung disease in textile workers: An 18-year autopsy study. Arch Environ Health 38:267–276.

Murray, R, J Dingwall-Fordyce, and RE Lane. 1957. An outbreak of weaver’s cough associated with tamarind seed powder. Brit J Ind Med 14:105–110.

Mustafa, KY, W Bos, and AS Lakha. 1979. Byssinosis in Tanzanian textile workers. Lung 157:39–44.

Myles, SM and AH Roberts. 1985. Hand injuries in the textile industry. J Hand Surg 10:293–296.

Neal, PA, R Schneiter, and BH Caminita. 1942. Report on acute illness among rural mattress makers using low grade, stained cotton. JAMA 119:1074–1082.

Occupational Safety and Health Administration (OSHA). 1985. Final Rule for Occupational Exposure to Cotton Dust. Federal Register 50, 51120-51179 (13 Dec. 1985). 29 CFR 1910.1043. Washington, DC: OSHA.

Parikh, JR. 1992. Byssinosis in developing countries. Brit J Ind Med 49:217–219.
Rachootin, P and J Olsen. 1983. The risk of infertility and delayed conception associated with exposures in the Danish workplace. J Occup Med 25:394–402.

Ramazzini, B. 1964. Diseases of Workers [De morbis artificum, 1713], translated by WC Wright. New York: Hafner Publishing Co.

Redlich, CA, WS Beckett, J Sparer, KW Barwick, CA Riely, H Miller, SL Sigal, SL Shalat, and MR Cullen. 1988. Liver disease associated with occupational exposure to the solvent dimethylformamide. Ann Int Med 108:680–686.

Riihimaki, V, H Kivisto, K Peltonen, E Helpio, and A Aitio. 1992. Assessment of exposures to carbon disulfide in viscose production workers from urinary 2-thiothiazolidine-4-carboxylic acid determinations. Am J Ind Med 22:85–97.

Roach, SA and RSF Schilling. 1960. A clinical and environmental study of byssinosis in the Lancashire cotton industry. Brit J Ind Med 17:1–9.

Rooke, GB. 1981a. The pathology of byssinosis. Chest suppl 79:67S–71S.

—. 1981b. Compensation for byssinosis in Great Britain. Chest suppl 79:124S–127S.

Sadhro, S, P Duhra, and IS Foulds. 1989. Occupational dermatitis from Synocril Red 3b liquid (CI Basic Red 22). Contact Dermat 21:316–320.

Schachter, EN, MC Kapp, GJ Beck, LR Maunder, and TJ Witek. 1989. Smoking and cotton dust effects in cotton textile workers. Chest 95: 997–1003.

Schilling, RSF. 1956. Byssinosis in cotton and other textile workers. Lancet 1:261–267, 319–324.

—. 1981. Worldwide problems of byssinosis. Chest suppl 79:3S–5S.

Schilling, RSF and N Goodman. 1951. Cardiovascular disease in cotton workers. Brit J Ind Med 8:77–87.

Seidenari, S, BM Mauzini, and P Danese. 1991. Contact sensitization to textile dyes: Description of 100 subjects. Contact Dermat 24:253–258.

Siemiatycki, J, R Dewar, L Nadon, and M Gerin. 1994. Occupational risk factors for bladder cancer. Am J Epidemiol 140:1061–1080.

Silverman, DJ, LI Levin, RN Hoover, and P Hartge. 1989. Occupational risks of bladder cancer in the United States. I. White men. J Natl Cancer Inst 81:1472–1480.

Steenland, K, C Burnett, and AM Osorio. 1987. A case control study of bladder cancer using city directories as a source of occupational data. Am J Epidemiol 126:247–257.

Sweetnam, PM, SWS Taylor, and PC Elwood. 1986. Exposure to carbon disulphide and ischemic heart disease in a viscose rayon factory. Brit J Ind Med 44:220–227.

Thomas, RE. 1991. Report on a multidisciplinary conference on control and prevention of cumulative trauma disorders (CDT) or repetitive motion trauma (RMT) in the textile, apparel and fiber industries. Am Ind Hyg Assoc J 52:A562.

Uragoda, CG. 1977. An investigation into the health of kapok workers. Brit J Ind Med 34:181–185.
Vigliani, EC, L Parmeggiani, and C Sassi. 1954. Studio de un epidemio di bronchite asmatica fra gli operi di una tessiture di cotone. Med Lau 45:349–378.

Vobecky, J, G Devroede, and J Caro. 1984. Risk of large-bowel cancer in synthetic fiber manufacture. Cancer 54:2537–2542.

Vobecky, J, G Devroede, J La Caille, and A Waiter. 1979. An occupational group with a high risk of large bowel cancer. Gastroenterology 76:657.

Wood, CH and SA Roach. 1964. Dust in cardrooms: A continuing problem in the cotton spinning industry. Brit J Ind Med 21:180–186.

Zuskin, E, D Ivankovic, EN Schachter, and TJ Witek. 1991. A ten year follow-up study of cotton textile workers. Am Rev Respir Dis 143:301–305.