Integrative assessment of multiple pesticides as risk factors for non-Hodgkin’s lymphoma among men

Abstract

Background: An increased rate of non-Hodgkin's lymphoma (NHL) has been repeatedly observed among farmers, but identification of specific exposures that explain this observation has proven difficult. Methods: During the 1980s, the National Cancer Institute conducted three case-control studies of NHL in the midwestern United States. These pooled data were used to examine pesticide exposures in farming as risk factors for NHL in men. The large sample size (n = 3417) allowed analysis of 47 pesticides simultaneously, controlling for potential confounding by other pesticides in the model, and adjusting the estimates based on a prespecified variance to make them more stable. Results: Reported use of several individual pesticides was associated with increased NHL incidence, including organophosphate insecticides coumaphos, diazinon, and fonofos, insecticides chlordane, dieldrin, and copper acetoarsenite, and herbicides atrazine, glyphosate, and sodium chlorate. A subanalysis of these "potentially carcinogenic" pesticides suggested a positive trend of risk with exposure to increasing numbers. Conclusion: Consideration of multiple exposures is important in accurately estimating specific effects and in evaluating realistic exposure scenarios.

Pesticide exposure as risk factor for non‐Hodgkin lymphoma including histopathological subgroup analysis

“…In our study, only few subjects were exposed to different organophosphates, but we found a nonsignificant OR of 2.81 (95% CI 0.54-14.7) for malathion based on 5 exposed cases and 2 controls, not shown in Table. The organochlorine DDT has shown suggestive but rarely significant association with NHL in some studies. 8,19,[38][39][40] Our study showed a moderately but not significant increased OR for exposure to DDT.…”

“…In some other studies on the relation between pesticides and NHL, insecticides seem to be of some importance as causative agents. 27,37,38 Especially, different organophosphates were indicated as risk factors in those studies, with a Canadian study 37 showing statistical significant ORs for malathion and diazinon. In our study, only few subjects were exposed to different organophosphates, but we found a nonsignificant OR of 2.81 (95% CI 0.54-14.7) for malathion based on 5 exposed cases and 2 controls, not shown in Table. The organochlorine DDT has shown suggestive but rarely significant association with NHL in some studies.…”

“…36 Recent findings from other groups also associate glyphosate with different B-cell malignancies such as lymphomas and myeloma. 32,37,38 Glyphosate has succeeded MCPA as one of the most used herbicides in agriculture, and many individuals that used MCPA earlier are now also exposed to glyphosate. This probably explains why the multivariate analysis does not show any significant ORs for these compounds.…”

Dichlorvos exposure and human cancer risk: results from the Agricultural Health Study

“…A case-control study from the Midwest indicated a suggestive elevated risk [12] of non-Hodgkin lymphoma associated with DDVP use. However, a pooled analysis that included three case-control studies found no association [13]. Early case reports linked DDVP exposure with leukaemogenic consequences, including acute lymphoblastic leukemia, in children [14].…”

The non-Hodgkin lymphomas: A review of the epidemiologic literature

“…De Roos et al 55 examined use of 47 specific pesticides by pooling data from 3 case-control studies conducted in the Midwestern United States. There were no associations between the total number of pesticides, herbicides, or insecticides used and risk of NHL.…”