LYMPHOID NEOPLASIA Pesticide exposure and risk of monoclonal gammopathy of undetermined significance in the Agricultural Health Study

Pesticides are associated with excess risk of multiple myeloma, albeit inconclu-sively. We included 678 men (30-94 years) from a well-characterized prospective co-hort of restricted-use pesticide applica-tors to assess the risk of monoclonal gammopathy of undetermined signifi-cance (MGUS). Serum samples from all subjects were analyzed by electrophore-sis performed on agarose gel; samples with a discrete or localized band were subjected to immunofixation. Age-adjusted prevalence estimates of MGUS were compared with MGUS prevalence in 9469 men from Minnesota. Associations between pesticide exposures and MGUS prevalence were assessed by logistic re-gression models adjusted for age and education level. Among study partici-pants older than 50 years (n 555), 38 were found to have MGUS, yielding a prevalence of 6.8 % (95 % CI, 5.0%-9.3%). Compared with men from Minnesota, the age-adjusted prevalence of MGUS was 1.9-fold (95 % CI, 1.3- to 2.7-fold) higher among male pesticide applicators. Among applicators, a 5.6-fold (95 % CI, 1.9- t