Occupational exposure to pesticides and lymphoid neoplasms among men: results of a French case-control study

Laurent ORSI ^1*, Laurene Delabre ², Alain Monnereau ³, Philippe Delval ⁴, Christian Berthou ⁵, Pierre Fenaux ⁶, Gerald Marit ⁷, Pierre Soubeyran ⁸, Francoise Huguet ⁹, Noel Milpied ⁷, Michel Leporrier ¹⁰, Denis Hemon ¹, Xavier Troussard ¹¹ and Jacqueline Clavel ¹

¹ Inserm U754, France
² INVS, France
³ INSERM, France
⁴ ACTA, France
⁵ Morvan hospital, France
⁶ Avicenne hospital, France
⁷ Haut-Leveque hospital, France
⁸ Bergonie Institute, France
⁹ Purpan hospital, France
¹⁰ Clemenceau hospital, France
¹¹ Cote de Nacre hospital, France

^* To whom correspondence should be addressed. E-mail: laurent.orsi{at}inserm.fr.

Accepted 24 October 2008

Abstract

Objectives: Investigating the relationship between occupational exposure to pesticides and the risk of lymphoid neoplasms (LN) in men.

Methods: A hospital-based case-control study was conducted in six centres in France between 2000 and 2004. The cases were incident cases with a diagnosis of lymphoid neoplasm aged 18 to 75 years. During the same period, controls of the same age and gender as the cases were recruited in the same hospital, mainly in the orthopaedic and rheumatological departments. Exposures to pesticides were evaluated through specific interviews and case-by-case expert reviews. Four hundred and ninety-one cases (244 cases of non-Hodgkin's lymphoma (NHL), 87 of Hodgkin's lymphoma (HL), 104 of lymphoproliferative syndromes (LPS) and 56 of multiple myeloma (MM) cases) and 456 controls were included in the analyses. The odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using unconditional logistic regressions.

Results: Positive associations between HL and occupational exposure to triazole fungicides and urea herbicides were observed (OR=8.4 [2.2-32.4], 10.8 [2.4-48.1] respectively). Exposure to insecticides, fungicides and herbicides were linked to a three-fold increases in MM risk (OR=2.8 [1.2-6.5], 3.2 [1.4-7.2], 2.9 [1.3-6.5]). For LPS subtypes, associations restricted to hairy-cell leukaemia (HCL) were evidenced for exposure to organochlorine insecticides, phenoxy herbicides and triazine herbicides (OR=4.9 [1.1-21.2], 4.1 [1.1-15.5], 5.1 [1.4-19.3], although based on small numbers. Lastly, despite the increased odds ratios for organochlorine and organophosphate insecticides, carbamate fungicides and triazine herbicides, no significant associations were evidenced for NHL.

Conclusions: The results, based on case-by-case expert review of occupation-specific questionnaires, support the hypothesis that occupational pesticide exposures may be involved in HL, MM and HCL and do not rule out a role in NHL. The analyses identified specific pesticides that deserve further investigation and the findings were consistent with those of previous studies.