The Agricultural Health Study is a prospective cohort of about 90,000 commercial pesticide applicators, farmers and farmers' spouses from Iowa and North Carolina. It is a collaborative project involving the National Cancer Institute, the National Institute of Environmental Health Sciences, the U.S. Environmental Protection Agency and the National Institute for Occupational Safety and Health.
Since it began in 1993, the study has included three cohort-wide interviews to obtain information on agricultural practices and pesticide use, other occupational exposures, lifestyle factors diseases and medication use. Cancer incidence has been ascertained via linkage to population-based cancer registries in the study states, and mortality through linkage to state mortality registries and the National Death Index. Mouth rinse samples, including buccal cell DNA were collected from 39% of the cohort. In addition, there have been a number of targeted sub-studies, focused on specific scientific questions. These studies include information on pesticide exposure monitoring from a sample of farms and the collection of a variety of biologic tissues from selected samples of participants. Collaborative ventures with extramural investigators are encouraged.
Agricultural exposures including pesticides, diesel exhaust, endotoxins, and allergens have been associated with risk of various cancers, although the biological mechanisms underlying these associations are generally not well understood. In 2010, a major new effort entitled “Biomarkers of Exposure and Effect in Agriculture” (BEEA) was initiated within the Agricultural Health Study, a cohort of pesticide applicators. The goal of BEEA is to conduct molecular epidemiology studies that will provide insight into the biological plausibility and mechanisms of action underlying observed associations between agricultural exposures and health outcomes in the Agricultural Health Study and elsewhere. We are collecting specimens (blood, urine, and house dust) and updated information about pesticide use and other agricultural exposures from at least 1,600 farmer/applicators in the Agricultural Health Study. Within BEEA, we will investigate agricultural exposures that might influence risk of multiple myeloma and its precursor, monoclonal gammopathy of undetermined significance, which was previously shown to be in excess in the Agricultural Health Study. The BEEA study establishes a biorepository for future cross-sectional molecular epidemiologic investigations to elucidate the biological mechanisms underlying associations between agricultural exposures and risk of cancer and other chronic diseases.