In this section we provide a brief overview of the extent of occupational illness and injury. Much of our focus is on the United States, where conditions and production processes are comparable to those in developed industrialized nations worldwide. Both the nature of work, the distribution of jobs in various workplaces, the extent of exposure, and the lack of regulation make it clear that these conditions and exposures are much worse in developing nations, but few reliable or comparable statistics are available.
In 2005 in the United States, according to its Bureau of Labor Statistics (BLS), there were 4.2 million nonfatal injuries and illnesses in private industry (Bureau of Labor Statistics, 2006). These workplace injuries and illnesses occurred at a rate of 4.6 cases per 100 workers among private industry employers. Approximately 2.2 million of the reported injuries and illnesses were serious enough that the worker was unable to perform his or her normal duties; that is, they involved either days away from work, job transfer, or job restrictions. This injury rate corresponds to an incidence rate for cases with days away from work, job transfer, or restriction of 2.4 cases per 100 workers. These rate data are, by design, underestimates of the true injury and illness rate among workers because they exclude incidents diagnosed among retired or otherwise inactive workers. It is widely acknowledged these data do not include occupational illness arising from long-term exposure. Such conditions are simply neither counted nor, for the most part, even recognized as attributable to occupational exposures.
Despite the fact that these official survey data are widely thought to be undercounts (Rosenman et al., 2006) and largely represent only acute injuries diagnosed by the employers, they still result in substantial costs. In 2004, the workers’ compensation cost of occupational injuries in the United States was $87.4 billion, representing employer expenditures of about $1.76 per $100 of labor cost, with $1.13 per $100 going to actual wage replacement and medical care of workers. The balance of employer costs goes to administration. When a worker does receive benefits, the usual replacement in the United States is generally about half the pre-injury wages. Of the costs to the employer, only slightly more than half represents wage replacement, with the balance going to medical costs (Sengupta et al., 2006).
Other data sources provide a more reliable idea of the much larger impact of the working environment on health than is revealed by workers’ compensation and official occupational injury statistics. One such source is disability insurance. Disability insurance covers costs associated with incidents or illnesses that are not recognized as ‘related to’ workplace exposures or conditions, even if, in fact, workplace conditions either caused or exacerbated the condition. For example, a private insurance company reported an incidence of 9.1 short-term disability claims per 100 covered employees and concluded that of these, one-third were musculoskeletal conditions. A substantial fraction of these musculoskeletal conditions were likely to be of occupational origin. They also reported that long-term disability claims were filed at 0.36 per 100 covered employees, and of these, one-third, again, were musculoskeletal, with a substantial fraction of likely occupational origin (Leopold, 2004). Similarly, claims-based insurance data from an industrial employer revealed approximately a 20 per 100 incidence of claims, with approximately 50% for musculoskeletal or injury causes.
Although health insurance claims are a difficult data source to analyze for possible work-related disorders, some specific databases have been identified that could help elucidate the true work-related incidence of disease and disability (Park, 2001; Reeve et al., 2003). When evaluating general disability insurance data, it is important to keep in mind that the particular condition that has led to the disability may not be the work environment. Rather, it may be the case that the rigor of the work environment requires a worker to withdraw from or delay return to work after a non-occupational illness. Thus, occupational exposures result in lost time, even if the initial incident was not occupational in origin.
Some indications of the extent of chronic disease related to employment can also be gleaned from epidemiological studies, but often these are more difficult to generalize from and true rates are not as readily calculable as in claims-based data.