Farming and mortality from multiple myeloma: a case-control study with the use of death certificates.

A case-control study of multiple myeloma among males was conducted with the use of digitized mortality listings for 1968-76 from the State of Wisconsin. Age, year of death, race, county of usual residence, marital status, and usual occupation were available for the 411 male deaths due to multiple myeloma and for a matched series of deaths due to other causes. Farmers were at an elevated risk compared to nonfarmers [odds ratio (OR) = 1.4], with decedents 65 years of age or older having a stronger association (OR = 1.5) than younger farmers (OR = 1.1). County levels of selected agricultural characteristics were used as surrogate measures of exposure. Significantly elevated OR were observed for farmers residing in counties high in chicken inventory (OR = 1.6), fertilizer use (OR = 1.7), and acres treated with insecticides (OR = 1.9). Further investigation of multiple myeloma among farmers is warranted.