The Agricultural Health Study (AHS) cohort consists of approximately 52,000 private pesticide applicators (primarily farmers) and 32,000 spouses of private applicators from Iowa and North Carolina, as well as approximately 5,000 commercial pesticide applicators from Iowa. The pesticide applicators were recruited between 1993-1997 (during Phase I of the AHS) when they obtained or renewed their license to apply restricted use pesticides; spouses were recruited largely by questionnaires brought home by the pesticide applicator (81%). In addition to the extensive information on lifetime use of pesticides, demographic and other lifestyle factors were collected from all participants at enrollment using self-administered questionnaires (during Phase I of the AHS). Two follow-up telephone interviews have been conducted since enrollment. The first follow-up interview was conducted from 1999 to 2003 (during Phase II of AHS), and the second follow-up interview was conducted from 2005-2009 (during Phase III of the AHS). Cancer incidence has been ascertained by annual linkage to the cancer registries in each state and mortality through linkage to the National Death Index since the inception of the study field work in 1993. The AHS began field work for Phase I of the study with three contracts in 1993. One contract was for a coordinating center (SRA Technology) which was primarily responsible for overall coordination of the study, developing questionnaires, and providing a secure computer system to store the vast amount of questionnaire and other research data coming from the field stations in Iowa and North Carolina. The other two contracts were for a field station in Iowa (University of Iowa) and a second field station in North Carolina (Battelle Memorial Institute). Field Stations were primarily responsible for managing the distribution and retrieval of self-administered questionnaires to eligible study subjects. The coordinating center contract was awarded, via a full and open competition, to SRA Technologies for Phase II of the study and to Westat Inc. for Phase III of the study; Westat assumed the coordinating center contract during Phase II when SRA Technologies went out of business. The field station contracts were awarded again, via a full and open competition, to the University of Iowa in Iowa and Battelle Memorial Institute in North Carolina for Phases II and III of the study. In the Phase IV contract, the contractor will be responsible for overall coordination and day-to-day management of the study, maintaining and updating a secure data base containing all study research and administrative records, provide liaison with appropriate state and federal offices necessary to conduct this research, appropriately communicate research findings to the cohort through a website and annual newsletter, and to collect specified biospecimens from selected study subjects. In Phase IV of the AHS, one contractor will perform all study related activities as there will be no cohort-wide interview conducted as part of this contract. The coordinating center will continue to be responsible for day-to-day study operations, managing and maintaining study data files, and coordinating National Advisory Panel meetings. In addition, the coordinating center will now assume responsibility for maintaining and securing the personal identifying information for cohort members; conducting annual linkages to the state cancer registries, state and federal mortality files, IRS address data bases; and facilitating add-on studies. New responsibilities under this contract will be the conduct of the Biomarker Study (BEEA: protocol attached in appendix) which will involve the collection of blood and urine samples from a subset of the cohort.
