Benefits and risks associated with consumption of Great Lakes fish containing omega-3 fatty acids and polychlorinated biphenyls (PCBs)

Assessment of environmental health effects arising from exposure to multiple substances is often very challenging. This is particularly true when humans are exposed to a mixture that contains both beneficial and harmful substances. A good example relates to the risk and benefits of fish consumption. Fish contain a variety of essential nutrients, such as omega-3 fatty acids and proteins, which are beneficial to human health. Fish may also contain trace amounts of environmental contaminants, such as polychlorinated biphenyls (PCBs), which can disrupt endocrine function. How would environmental health studies confront the challenges of assessing the adverse and beneficial effects from food consumption? A recent study (Haslam et al., 2015) published in the Journal of Environmental Sciences demonstrates an example of an approach based onenvironmental epidemiology to tackle this complex problem. Focusing on a group of sport fishermen in New York, Haslam et al. (2015) examined the effects of estimated consumption of omega-3 fatty acids and PCBs on the risk of thyroid cancer over a 17-year span from 1991 to 2008. The study concluded that consumption of Great Lakes fish, with the concomitant PCBs, did not increase the risk of thyroid cancer in New York fishermen. The study results also suggest that long-term consumption of omega-3 fatty acids may protect against the development of thyroid cancer.