Occupational Exposure to Pesticides and Central Nervous System Tumors: Results from the CERENAT Case-control Study

Abstract

Background: The etiology of the central nervous system (CNS) tumors remains largely unknown. The role of pesticide exposure has been suggested by several epidemiological studies, but with no definitive conclusion. Objective: To analyze associations between occupational pesticide exposure and primary CNS tumors in adults in the CERENAT study. Methods: CERENAT is a multicenter case-control study conducted in France in 2004-2006. Data about occupational pesticide uses - in and outside agriculture - were collected during detailed face-to-face interviews and reviewed by experts for consistency and exposure assignment. Odds ratios (ORs) and 95% confidence intervals (95%CI) were estimated with conditional logistic regression. Results: A total of 596 cases (273 gliomas, 218 meningiomas, 105 others) and 1 192 age- and sex-matched controls selected in the general population were analyzed. Direct and indirect exposures to pesticides in agriculture were respectively assigned to 125 (7.0%) and 629 (35.2%) individuals and exposure outside agriculture to 146 (8.2%) individuals. For overall agricultural exposure, we observed no increase in risk for all brain tumors (OR=1.04, 0.69-1.57) and a slight increase for gliomas (OR=1.37, 0.79-2.39). Risks for gliomas were higher when considering agricultural exposure for more than 10 years (OR=2.22, 0.94-2.24) and significantly trebled in open field agriculture (OR=3.58, 1.20-0.70). Increases in risk were also observed in non-agricultural exposures, especially in green space workers who were directly exposed (OR=1.89, 0.82-4.39), and these were statistically significant for those exposed for over 10 years (OR=2.84, 1.15-6.99). Discussion: These data support some previous findings regarding the potential role of occupational exposures to pesticides in CNS tumors, both inside and outside agriculture.

Agricultural activities and risk of central nervous system tumors among French farm managers: Results from the TRACTOR project

“…One study reported a decreased risk of meningioma for open field farming in France (OR = 3.58 [1.20‐10.7]) 10 . Regarding crop farming, AGRICAN found a risk similar to ours (Figure 1).…”

“…However, our risk estimations had narrower 95% CIs, likely due to a larger number of exposed cases. Regarding viticulture, two studies found an increased risk 11,12 while one found a decreased risk but for harvesting (OR = 0.62 [0.46‐0.82]) 10 . Our results are closer to the two studies that found an increased risk, with a positive trend observed in viticulture (HR = 1.21 [0.98‐1.48]).…”

“…8,9,24 By contrast, one study found a decreased risk of gliomas for phenoxys exposure in the United States 25 and a French case-control study reported a decreased risk of gliomas and meningiomas for indirect pesticide exposures. 10 We found no studies reporting either a decreased or an increased risk of CNS tumors other than gliomas or meningiomas related to pesticide exposures.…”

“…Several studies have examined agricultural exposure and the risk of CNS tumors. Results from the literature are inconsistent, in particular for overall agriculture, with for instance several studies that found an increased risk of CNS tumors related to agriculture, 2,10 while others found a decreased risk 2 . Most studies focused on overall CNS tumors, without giving information on specific types such as gliomas or meningiomas.…”

“…Other French studies are also limited both geographically and in scope, and pertained only to a small proportion of the agricultural workforce. [10][11][12] It is therefore paramount to consolidate existing and recent evidences by studying the entire French agricultural workforce on the whole metropolitan territory.…”