Why did the study focus on organochlorine compounds and PAHs?
The study focused on organochlorine compounds because smaller epidemiologic studies had suggested that the pesticide DDT, which is an organochlorine compound that has been banned in the United States since 1972, might be associated with increased risk for breast cancer. In addition, DDT and its metabolites are known to cause liver cancer in rats. This early research prompted a variety of studies in different populations to further examine a link between cancer and organochlorine compounds. PAHs were another focus of the study because these compounds are known to cause breast cancer in rodents. In addition, a few small epidemiologic studies suggested a possible association between these chemical agents and increased risk for breast cancer. Another reason for studying organochlorine compounds and PAHs was that scientists can detect evidence in the body of past exposure to these chemicals. Organochlorine pesticides can persist in the body for more than a decade, while PAHs can persist for
