Definition: Occupational epidemiology involves the application of epidemiologic methods to populations of workers. Occupational epidemiologic studies may involve looking at workers exposed to a variety of chemical, biological or physical (e.g., noise, heat, radiation) agents to determine if the exposures result in the risk of adverse health outcomes. Alternatively, epidemiologic studies may involve the evaluation of workers with a common adverse health outcome to determine if an agent or set of agents may explain their disease. (Source: Occupational Safety and Health Administration)
Occupational studies show increased risk for breast cancer across three broad categories: (a) those who work with toxic chemicals – especially organic solvents – and ionizing radiation, such as chemists, dental hygienists, radiology technicians (Bhatti, 2007; Morin-Doody, 2006; Simon, 2006), agricultural workers, paper mill workers, autoworkers, and plastics and microelectronics manufacturing workers (Band, 2000; Bernstein, 2002; Brophy, 2006; Brophy 2012; Gardner, 2002; Labreche, 2010; Oddone, 2012; Petralia, 1998; Thompson, 2005); (b) professionals in higher socioeconomic groups such as school teachers, librarians, social workers and journalists (Teitelbaum, 2003; Zheng, 2002); and (c) women who work evening, especially overnight, shifts in careers such as nursing and flight attendants (Grundy, 2013; Jia, 2013;Kolstad, 2008; Megdal, 2005).
A 2012 study (Brophy, et al., 2012) found that women who work in plastics manufacturing and food canning have a fivefold increase in pre-menopausal breast cancer. Researchers conducted in-depth interviews andsurveys and took exhaustive 10-year work histories to determine which chemicals the women were exposed to on the job.
Occupational studies provide a strong source of data on potential exposures of concern. Workers may have their own questions about health and safety and therefore have strong interest in being part of research studies. Workplaces can also provide rich data for initial research, because of the relatively controlled setting of workplaces and government requirements to track certain individual exposures and pollutant levels in factories.
The relationship between toxic environments in the workplace and breast cancer has been difficult to establish in large part because until recently occupational studies have not included women in sufficient numbers to evaluate relationships between environments and female-specific cancers like breast cancer (Thompson, 2005). Most occupational research that has been conducted about women reports risk by type of job rather than by specific exposures, making it difficult to draw direct connections between particular environmental factors and health outcomes (Brody, 2007).