Mortality in the California Farmer Health Study cohort.

Western agriculture, in comparison with Midwestern and Eastern, is more diverse, with a drier climate, mild winters, and different exposures. This randomly selected cohort of 1947 Californian farmers confirmed the usual finding: a lower mortality rate than general population (by 50%). A low smoking prevalence and healthy worker effect are likely contributors. Although farmers were more likely to die from injuries and skin cancer, death was less likely from Alzheimer's and cerebrovascular diseases. Within the cohort, disability and persistent wheeze were associated with increased mortality. The 200 deaths were insufficient to determine the significance of rare diseases.