On November 14, Dr. Nicole Deziel joined PHC for a discussion on pesticide exposure and cancer. As an Assistant Professor of Epidemiology focusing on Environmental Health at the Yale School of Public Health, Dr. Deziel’s research is designed to enhance the understanding of the interface between exposure to environmental agents and human disease. Most of her research is focused on evaluating, improving, and developing exposure estimates for application in environmental epidemiological studies. Nicole Deziel explained that while many studies strongly suggest that the widespread use of certain organic and inorganic chemicals may increase the risk of certain cancers, more work needs to be done to convincingly validate these claims. To truly elucidate whether a certain environmental factor directly increases the risk of a certain disease, it is important for researchers to use rigorous methods of developing exposure estimates. For example, Nicole Deziel explained that simply surveying a population of individual homes to understand the correlation between the use of indoor pesticides and the incidence of cancer can lead to biased estimates. Particularly, if a parent’s child already has cancer at the time of the survey, the parent may retrospectively blame the use of indoor pesticides as the cause of their child’s diagnosis and, as a result, unjustifiably mark on the survey that their child had higher than normal rates of exposure to pesticides. Conversely, a parent whose children are all healthy may mark down lower estimates on indoor pesticide use than are accurate.
Therefore, Nicole Deziel’s research attempts to use more precise biological and environmental measurements to develop exposure estimates. Creatively, her research team enters homes and collects dust samples from age-old rugs, which both conveniently and dangerously serve as reservoirs for many chemicals that are used and tracked into the home, such as pesticides and other pollutants. By comparing the exposure estimates she obtained from dust in homes to those obtained from surveys of the people living in homes, she was able to prove that the survey is not perfect in its methodology in linking pesticide use to cancer incidence in homes. Interestingly, Nicole Deziel also noted that while farmers typically are some of the healthiest citizens in the U.S. because they have less exposure to pollution, exercise more, and smoke less, they also have some of the highest incidences of cancers that are linked to exposure to pesticides. During our discussion with Dr. Deziel, we also touched on many issues related to environmental health more broadly, including the paradox between DDT use and malaria prevention and the sustainability of organic food production. Dr. Deziel will be teaching EHS 510: Introduction to Environmental Health next semester at the Yale School of Public Health.