Occupational epidemiology in the real world: Irving Selikoff, odds ratios, and asbestosis

Epidemiology represents one of the most important and historically significant subdisciplines of Environmental and Occupational Health (EOH). Whereas EOH issues can be traced to antiquity, it was not until the 18th century that some of the more well-known epidemiological studies were conducted in the workplace. Lind’s intervention with citrus fruits to prevent scurvy is often cited as one of history’s first clinical trials, whereas Percivall Pott’s study on cancer among British chimney sweeps is often regarded as an archetypal cohort study and the first to link a particular malignancy with a defined environmental exposure. Although it was still evolving, by the early 20th century occupational epidemiology had risen in importance as scholarly attention began to focus on diseases with a suspected occupational aetiology. Many intuitive links were drawn from individual case studies and anecdotal reports, which often led to medical hypotheses and related publications on various topics of interest. In some sense, the early investigation of EOH hazards was more straightforward than today, as occupational exposures of yesteryear tended to be less complicated in nature and relatively high in intensity. Asbestos, and more particularly, the study of industrial exposure to asbestos and its relationship with subsequent disease, represents an excellent example in this regard.