Brain tumors and exposure to pesticides: a case-control study in southwestern France

Abstract

Objectives: Brain tumors are often disabling and rapidly lethal; their etiology is largely unknown. Among potential risk factors, pesticides are suspected. We examined the relationship between exposure to pesticides and brain tumors in adults in a population-based case-control study in southwestern France. Methods: Between May 1999 and April 2001, 221 incident cases of brain tumors and 442 individually matched controls selected from the general population were enrolled. Histories of occupational and environmental exposures, medical and lifestyle information were collected. A cumulative index of occupational exposure to pesticides was created, based on expert review of life-long jobs and tasks. Separate analyses were performed for gliomas and meningiomas. Results: A non statistically significant increase in risk was found for brain tumors when considering all types of occupational exposure to pesticides (OR=1.29, 95% Confidence Interval=0.87-1.91) and slightly higher but still non statistically significant when considering gliomas separately (OR=1.47, 95%CI=0.81-2.66). In the highest quartile of the cumulative index, a significant association was observed for brain tumors (OR=2.16, 95%CI=1.10-4.23), and for gliomas (OR=3.21, 95%CI=1.13-9.11), but not for meningiomas. Concerning environmental exposure to pesticides, a significant increase in risk was also observed with treatment of home plants (OR=2.24, 95%CI=1.16-4.30). Conclusions: These data suggest that a high level of occupational exposure to pesticides might be associated with an excess in risk of brain tumors, and especially of gliomas.