Occupational safety research is the study of the incidence, characteristics, causes and prevention of workplace injury. Beginning with the pioneering work of John Gordon (1949) and William Haddon, Jr. (Haddon, Suchman and Klein 1964), and increasingly in the 1980s and 1990s, injury has been viewed as a public health problem to which the public health approach, historically successful against disease, could be applied. Epidemiology, the science of public health, has been applied to injury, including occupational injury. The epidemiological model describes the relationship between the agent (the environmental entity or phenomenon that is the necessary cause of the disease or injury), the host (the affected person) and the environment. Its adaptation to the study of workplace injury came largely through the insights of two seminal figures in injury research, James J. Gibson (1961) and later Haddon (Haddon, Suchman and Klein 1964). Haddon recognized that the various forms of energy—me-chanical, thermal, radiant, chemical or electrical—were the “agents” of injury, analogous to the micro-organisms that cause infectious illnesses. Researchers and practitioners from multiple disciplines—primarily epidemiology, engineering, ergonomics, biomechanics, behavioural psychology, safety management and industrial hygiene—are engaged in the study of the factors associated with the worker (the host); the environment; the type and source of energy involved (the agent); and the tools, machines and tasks (the vehicles) that combine to cause or contribute to workplace injury.

Two Complementary Approaches: Public Health and Safety Analysis

The public health approach is one model which provides a framework for occupational safety research. The public health approach involves:

• the identification, characterization and description of injury cases, hazards and exposures through surveillance

• the in-depth analysis of specified injury problems in specified worker populations in order to identify, quantify and compare risk and causal factors

• the identification and development of prevention strategies and interventions

• the evaluation of preventive strategies in laboratory and field experiments

• the communication of information on risk and the development of strategies and programmes for reducing risk and preventing injuries.

Ideally, workplace safety problems may be identified and solved systematically by means of this process.

Safety analysis is another relevant model for addressing workplace injury. Safety analysis has been defined as “a systematic examination of the structure and functions of a system aiming at identifying accident contributors, modelling potential accidents, and finding risk-reducing measures” (Suokas 1988). It is an engineering-oriented approach which involves the consideration of potential system failures (one outcome of which could be worker injury) during the design or evaluation of processes, equipment, tools, tasks and work environments. This model presupposes an ability to analyse and understand the interactions among components of workplace systems in order to predict possible modes of failure before the systems are implemented. Ideally, systems can be made safe at the design stage, rather than modified after injury or damage has already occurred.

The Public Health Approach to Occupational Safety Research

The field of occupational safety research is evolving as different approaches and perspectives, such as epidemiology and engineering, merge to create new methods for evaluating and documenting workplace hazards, and thereby identifying possible strategies for prevention This article discusses the public health approach to occupational safety research, and the areas where safety analysis fits into this approach in order to provide both a general overview of the field and some insight into future opportunities and challenges. A secondary intent is to discuss (1) the relationship of occupational safety research to safety management, regulation and technology transfer, and (2) the impact of advancing technology on occupational safety research and communication.

Surveillance

To solve occupational injury problems, specific problems faced by specific worker populations must be identified. Therefore, the public health approach to occupational safety research begins with epidemiological surveillance, which has been defined as “the ongoing systematic collection, analysis and the interpretation of health data in the process of describing and monitoring a health event” (CDC 1988). In safety research, this refers to the collection, analysis and interpretation of data on injuries, hazards, exposures, work processes and worker populations.

Surveillance answers the basic questions about occupational injury. Surveillance can provide information about injuries by various demographic categories, including the worker’s gender, ethnicity, age, occupation and industry, in addition to information relating to the time and place of injury and sometimes the circumstances surrounding the incident. With such basic case information and employment information to provide denominators for the calculation of rates, researchers have been able to describe risk in terms of (1) the frequency of injuries, which helps define the scope or extent of a problem, and (2) the rate of injury (expressed as the number of injuries or deaths per 100,000 workers), which helps define the relative risk faced by certain types of workers in certain circumstances. These analyses and comparisons are useful to researchers in identifying problems, including emerging or escalating problems; establishing priorities; formulating hypotheses for further research; and monitoring trends in order to evaluate the effectiveness of prevention programmes.Findings obtained from occupational injury and fatality surveillance have enabled researchers to plan and conduct in-depth research aimed at both identifying causes or contributing factors and ultimately developing preventive strategies. Additionally, the information gained from surveillance serves an important social function by raising awareness of risk among those at risk, risk managers, policy makers and the general public, and by pointing to problem areas in need of increased attention and resources for research and prevention.

Analytical Research

As major occupational injury problem areas become apparent through surveillance, researchers can devise studies to answer more detailed questions about the risks faced by target populations. Analytical epidemiology and engineering methods can be employed to look more closely at the circumstances and factors that may cause or contribute to injuries. Occupational injury surveillance generally does not provide data in sufficient detail to enable one to determine risk factors, those characteristics associated with workplace components (including workers) that can directly or indirectly cause injurious incidents. Without such detailed information, opportunities for prevention may not be discovered. This sort of information, which describes the circumstances surrounding an injurious event, is necessary to analyse the sequence of tasks; the interaction of factors associated with the victim, the coworkers, the tasks, the tools and the processes; the time phases of the event (from pre-event to post-event); the preventive strategies employed; and the organization and safety attitudes of the employer.

One method of collecting detailed information is through the investigation of occupational injuries or fatalities. Investigation generally relies on a formal methodology that combines information collection via interviewing, analysing case reports and other documentation, and onsite or laboratory-based engineering analysis and observation (i.e., forensic engineering) in the attempt to reconstruct the events and circumstances that led to the incident. Analytical epidemiological research techniques require various types of study designs such as case-control, prospective or retrospective designs to test hypotheses regarding specific risk factors and their relative contributions to specified outcomes. Safety analysis techniques such as hazard analysis, job/task analysis, fault-tree analysis and other systems safety engineering tools can also be used to define risks and causes, and to predict or assign probabilities to various failure modes that might eventuate in injury to workers. The future of occupational risk and causality research may well lie in a combination of these research modes that allows causation models based on analytical systems engineering methods to be validated by experience as documented through investigative and epidemiological research findings.

Developing Prevention Strategies and Interventions

As risk and causal factors are identified and characterized, and the relative importance of multiple risk factors are discerned, opportunities for prevention may become apparent. With insight into risk and causal factors, occupational safety researchers and practitioners can consider possible prevention strategies aimed at reducing risk, or consider interventions to interrupt the causal sequence of accidents. Currently, there are a wide range of protective technologies and strategies that have already been applied to worker protection, and might be more broadly applied with beneficial results. Similarly, technologies and strategies have been developed and applied in other fields which may have potential for worker protection. Finally, undiscovered technologies and strategies will be brought to light in the pursuit of improved worker protection. The goal of occupational safety research is the identification, development and implementation of effective preventive strategies to reduce the risk of injury to workers.

Haddon (1973) postulated ten basic, generalized strategies for reducing damage due to environmental or workplace hazards. The highest priority of occupational safety researchers studying preventive strategies is to identify, design and evaluate engineering controls that are well integrated into the workplace environment, equipment, tools or processes, and that provide protection automatically (“passive” controls), without any specific action or behaviour on the part of the worker. Of the three classes of prevention strategies—persuasion (via information and education), those that impose requirements (via laws and standards) (Robertson 1983) and those that provide automatic protection, it is the latter that is generally cited as the most effective and preferable. Examples of passive, or automatic, controls might include an interlock safety device on an electrical circuit that automatically de-energizes the circuit if safety barriers are removed or bypassed, or protective vehicle airbags that automatically deploy upon collision.

Evaluating and Demonstrating Prevention Strategies and Interventions

A crucial step that is often omitted from the safety research process is the formal evaluation of potential prevention strategies and interventions to ensure that they work in controlled laboratory settings and in actual workplace environments before they are widely or universally implemented. Sometimes, the well-intentioned introduction of a prevention strategy may have the effect of creating a new, unforeseen hazard. Even if there are compelling reasons to implement preventive strategies before they can be formally evaluated, evaluation should not be neglected altogether. Evaluation is important not just for engineering controls and modifications, but also for tasks, processes, procedures, regulations, training programmes and safety information products—that is, any strategy, intervention or modification aimed at eliminating or reducing risk.

Occupational Injury Risk and Prevention Information

When effective preventive strategies are identified or developed, they are the keys to implementing the strategies. Occupational safety research produces two types of information that are useful to individuals and organizations outside the research community: risk information and prevention information.

• Risk messages may include the notification that risk exists; information about the scope or nature of risk; information about the individuals or populations at risk; information about when, where, how and why the risk exists; and information about the factors that influence or contribute to risk and their relative importance. Risk information is a principal product of surveillance and analytical research.
• Prevention messages include information on methods of reducing risk and may cover a broad range of strategies and interventions.

The most important audiences for risk and prevention information are the populations at risk, and the various individuals and organizations that have the power to change or influence workplace risk through their decisions, programmes and policies. These audiences, which include the workers, employers, safety and health practitioners, regulators, insurers, legislators and policymakers, are targeted when researchers develop new information regarding the existence or scope of occupational injury problems, or recommendations aimed at reducing risk. Another key audience for both the methods and findings of research are peer scientists and scientists in government agencies, private sector organizations and academic institutions who are working to illuminate and solve the injury and illness problems besetting the workforce. Researchers must also cultivate the mass and regional media and continue to promote the ideas that occupational injuries and deaths constitute a significant public health problem and are preventable.

Communication

Research is needed into the diffusion and practical application of occupational safety research findings. The communication of safety information is rarely evaluated to determine what methods, messages, channels and formats are effective in given situations for specific groups. The growing need for communication of information related to health has given rise to several approaches applicable to the communication of safety information. Health education, health communication, health promotion, risk communication and social marketing are some of the areas where communication activities are being systematized and studied scientifically. Research into human behaviour, motivation, cognition and perception plays an obvious role in determining whether and how information and communication processes can produce safety awareness and safety behaviours in at-risk individuals and groups. Many of the customer-oriented techniques of commercial marketing have been adapted by “social” marketers to promote changes in behaviour and attitude that serve a social benefit, including those that can lead to improved safety, health and well-being among workers.

Relationship of Research Findings to Safety Management

Safety practitioners and managers must be aware of current research findings that have practical implications for workplace safety. New risk or prevention information may require review and modification of existing programmes and procedures. The following sections discuss the relationship of research to the regulation of workplaces and the transfer of technology—that is, the transferral of new, proven preventive strategies and technologies from their innovation sites to other, comparable workplaces where similar conditions and risks exist.

Research and regulation

Regulators—those who develop and enforce occupational safety standards—must be aware of current research findings that affect regulatory requirements. Regulatory safety requirements imposed on employers should be based on scientifically proven prevention strategies that have been sufficiently demonstrated to be effective in reducing the risk of injury. This requires a close relationship and effective communications between the occupational safety research and the regulatory communities. Whether the regulatory body is a government agency or a voluntary, industry-based organization, the safety standards that they promulgate should incorporate the best available research findings. It is incumbent on both the regulators and the researchers to ensure effective communications.

Research and technology transfer

Individual workers, supervisors, companies, safety specialists and researchers are solving safety problems every day through the development and implementation of prevention strategies and interventions. Unfortunately, however, there are too few mechanisms and incentives enabling and actuating individuals or companies to share effective prevention measures with others that may face similar safety problems. Industry and trade associations, labour unions, insurers and other organizations serve the function of collecting, organizing and distributing prevention information to their members and clients. However, a large potential benefit from the sharing of prevention information remains unrealized, particularly by small employers and underserved workers. Research findings in the diffusion of innovations, communications and information management may be useful in addressing this gap.

Research and technology

The advance of technology has expanded upon the ways in which research can be designed and conducted; harmful exposures can be detected, measured, recorded or displayed, and reduced; hazards can be controlled; and information can be presented and distributed. The most significant technologies for safety research are in the areas of sensors, materials and, perhaps most important, digital electronics; the processing power, storage capacity and networking of computers has set the stage for a new era of simulation, automation and global communications. The challenge for researchers and practitioners in the field of occupational safety is to utilize advanced technological tools for research and to improve the communication of hazard and hazard control information. Some technological tools can improve our ability to accomplish difficult or otherwise dangerous research—for example, through simulations that do not require destruction of costly equipment or tools, or exposure of human participants. Some tools can improve analysis or decision making—for example, through simulating human expertise—and thus command a scarce resource: knowledge of how to conduct occupational injury research and achieve injury prevention. Technological tools can improve our ability to distribute relevant hazard-related information to those who need it, and make it possible for them to actively seek out such information.

Research needs and trends

Occupational safety research should be prepared to take advantage of evolving technologies and expressions of increased social concern, to focus on areas where more research is needed, including the following:

• new scientific methods that incorporate and integrate epidemiology and engineering techniques and approaches in the study of occupational safety
• expanded and standardized surveillance to include systems for nonfatal injuries, “near miss” incidents, hazards and exposures
• increased attention to the role of organizational factors, as well as economic factors, in occupational safety; this would include study of the effects of management techniques and movements, such as the worldwide quality movement sparked by the work of W. Edwards Deming
• more emphasis on underserved, high-risk populations, including those in agriculture, logging, commercial fishing, construction and small businesses in all sectors; and on leading causes of death and serious injury that require more study, including those causes involved in work-related motor-vehicle transportation and violence (Veazie et al. 1994)
• evaluation and demonstration of engineering controls and other preventive strategies, including regulation, education and communications
• technology transfer: the use of technologies utilized for other purposes to address questions of occupational safety research and management, and the appropriate use of effective protective technologies or strategies implemented at one site or in a limited setting, to address similar risks in a wider area
• the role of psychosocial factors, including stress, on the incidence of occupational injury
• old and new technological approaches to passive methods of worker protection, including sensors, microprocessors, robotics, artificial intelligence, display and imaging technology, wireless telecommunications and interlocks.

Summary

Traditionally, public health researchers and practitioners have employed epidemiology, biostatistics, medicine, microbiology, toxicology, pharmacology, health education and other disciplines in the identification, evaluation and prevention of infectious and, more recently, chronic illnesses. Injuries and injury deaths, including those that occur at work, are serious public health problems too, and are often associated with specific causes and factors that contribute to their occurrence. Injuries and injury deaths are not random events, but result from cause-and-effect relationships, and are therefore predictable and preventable. These injury outcomes lend themselves to the same problem-solving approaches as have been used to identify, characterize and prevent illnesses.

One primary difference between the approaches to illness and injury outcomes lies in the nature of the preventive measures that can be taken. To prevent or reduce the risk of infectious and chronic diseases, health practitioners may recommend or use vaccines and pharmaceuticals, nutritional and lifestyle modifications, or environmental controls. To prevent or reduce the risk of occupational injuries, safety practitioners may recommend or use engineering controls, such as equipment guards, interlocks, and ergonomically designed tools and machines; or administrative controls, such as work practices, schedules and training; or personal protective equipment, such as respirators, hard hats or fall protective devices. This means that in injury prevention, epidemiologists, biostatisticians and health educators are joined by engineers, physicists, industrial hygienists and ergonomists. The problem-solving process is the same; some of the intervention approaches, and therefore the disciplines involved in identifying, developing and testing interventions, may be different.

The mechanism of occupational safety and health research is the public health approach, an integrated, multidisciplinary approach to identification through (1) surveillance and investigation, (2) epidemiological and safety analysis, (3) research and development leading to preventive technologies and strategies, (4) evaluation and demonstration to ensure that these technologies and strategies are effective, and (5) communication of risk information, research methods and findings, and effective technologies and strategies. The public health approach and the safety analysis approach are merging in the study of occupational safety. The principal disciplines of epidemiology and engineering are collaborating to bring new insight into injury causation and prevention. New and advancing technologies, particularly digital electronic computer technology, are being adapted to solve workplace safety problems.

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