A review of preliminary results of the 20 year Keokuk County Rural Health Study, which was initiated in June 1994, was presented. Results from 106 initial environmental assessments, including 26 farms, were reviewed. Environmental assessments included a systematic examination of rural households to characterize the environmental exposures associated with residences and properties comparing farm, rural nonfarm, and town households in the area. Questionnaires and checklists were used to assess hazards in residences, local environments, occupations and daily practices of each family individual. Farm operations, facilities and equipment were described and occupational exposures associated with activities of individuals, specifically those related to farming and the rural environment, were characterized. Environmental measurements were used to assess exposure to potentially hazardous materials. Data from 196 households indicated that housing stock was old, with 51% of the homes being built before 1950. Sources of drinking water included public systems (68%), private wells (57%), bottled water (11%), cisterns (5%), and a spring (1%). Of the 57 wells, 29 were less than 50 feet deep and 18 were located close to septic tanks, manure, and chemical storage. Most homes were heated with liquid propane gas. Most depended on a furnace with forced air heating. Dangerously high levels of carbon-monoxide (630080) were detected in several homes during the winter. Smoke detectors were present in 80 homes, but only 77 of the 148 detectors actually functioned. A wide variety of chemicals were found stored in the home. Many different agricultural chemicals including pesticides were found. The authors conclude that there is a high prevalence of potentially hazardous exposures among this rural population.