NON-HODGKINS-LYMPHOMA AND AGRICULTURAL USE OF THE INSECTICIDE LINDANE

Data from population-based case-control studies of non-Hodgkin's lymph oma among white men from Kansas, Nebraska, Iowa, and Minnesota were po oled to evaluate potential risks from environmental exposures in more detail, while controlling for potential confounding factors. These dat a provided the opportunity to evaluate the risk of non-Hodgkin's lymph oma from potential exposures to lindane, a pesticide that causes cance r in laboratory animals and has been associated with human cancer in a few epidemiologic investigations. This pooled data set includes 987 i ndividuals with non-Hodgkin's lymphoma and 2,895 population-based cont rols. Information was obtained by telephone or in person interviews, w hich included detailed questions on farm practices and agricultural us e of chemicals. Logistic regression was used to calculate odds ratios (ORs) adjusted for age, state of residence, and subject or proxy inter views. Reported use of lindane significantly increased the risk of non -Hodgkin's's lymphoma by 50%. Some use characteristics were suggestive of an association. ORs were greater among persons who first used the pesticide 20 years before diagnosis (OR = 1.7) than more recently (OR = 1.3), among those who reported more frequent use (OR = 2.0 for use 5 or more days per year versus 1.6 for fewer than five days per year), and from use on crops (OR = 1.9), rather than from use on animals (OR = 1.3), although these differences were not statistically significant. On the other hand, ORs were lower when based on direct interviews (OR = 1.3) than on data from proxy respondents (OR = 2.1) and adjustment for potential confounding by use of 2,4-D and diazinon reduced the ORs associated with lindane use from 1.5 to 1.2 and 1.3, respectively. Li ndane does not appear to be a major etiologic factor in the developmen t of non-Hodgkin's's lymphoma, although a small role cannot be ruled o ut. (C) 1998 Wiley-Liss, Inc.