Agricultural use of organophosphate pesticides and the risk of non-Hodgkin's lymphoma among male farmers (United States)

Objective: Data from three population-based case-control studies conducted in Kansas, Nebraska, Iowa, and Minnesota were pooled to evaluate the relati onship between the use of organophosphate pesticides and non-Hodgkin's lymp homa (NHL) among white male farmers. Methods: The data set included 748 cases of non-Hodgkin's lymphoma and 2236 population-based controls. Telephone or in-person interviews were utilized to obtain information on the use of pesticides. Odds ratios (OR) adjusted for age, state of residence, and respondent status, as well as other pestic ide use where appropriate, were estimated by logistic regression. Results: Use of organophosphate pesticides was associated with a statistica lly significant 50% increased risk of NHL, but direct interviews showed a s ignificantly lower risk (OR = 1.2) than proxy interviews (OR = 3.0). Among direct interviews the risk of small lymphocytic lymphoma increased with dia zinon use (OR = 2.8), after adjustment for other pesticide exposures. Conclusions: Although we found associations between the risk of NHL and sev eral groupings and specific organophosphate pesticides, larger risks from p roxy respondents complicate interpretation. Associations, however, between reported use of diazinon and NHL, particularly diffuse and small lymphocyti c lymphoma, among subjects providing direct interviews are not easily disco unted.