Childhood leukaemia and parental occupational exposure to pesticides: a systematic review and meta-analysis
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To conduct a systematic review and meta-analysis of published studies on the association between parental occupational exposure to pesticides and childhood leukaemia.
Studies were identified from a MEDLINE search through 31 July 2009 and from the reference lists of identified publications. Relative risk (RR) estimates were extracted from 25 studies published between 1985 and 2008. Meta-rate ratio estimates (mRR) were calculated according to fixed and random-effect meta-analysis models. Separate analyses were conducted after stratification for study design, definition of exposure (employment in a farm/agriculture assuming exposure to pesticides versus exposure to pesticides stipulated), exposed parent, window of exposure, type of leukaemia and biocide category.
No statistically significant association between childhood leukaemia and parental occupation as farmers/agricultural workers was observed. When exposure to pesticides was stipulated, positive associations were reported for maternal exposure for all studies combined (mRR: 1.62; 95% CI: 1.22–2.16), in all exposure windows considered and for acute non-lymphocytic leukaemia (ANLL). There was no association with paternal exposure when combining all studies (mRR: 1.14; 95% CI: 0.76–1.69). However, significant increased risks were seen for paternal exposure, in some exposure windows as well as for the biocide category.
The strongest evidence of an increased risk of childhood leukaemia comes from studies with maternal occupational exposure to pesticides. The associations with paternal exposure were weaker and less consistent. These results add to the evidence leading to recommend minimizing parental occupational exposure to pesticides. Our findings also support the need to rely more on studies that clearly stipulate exposure to pesticides rather than those that assume pesticide exposure because of farm/agriculture employment.
KeywordsChild Leukaemia Parental occupational exposure Pesticides Systematic review Meta-analysis
Acute lymphocytic leukaemia
Acute myelogenous leukaemia
Acute non-lymphocytic leukaemia
- 95% CI
95% Confidence interval
Chronic lymphocytic leukaemia
Chronic myeloid leukaemia
Meta-rate ratio estimate
Proportional mortality ratio
- 95% UI
95% Uncertainty interval
V.M.F.G. was supported by a grant from the Belgian Ministry of Health (Grant Number 95/15 (164)).
Conflict of interest statement
- 10.Clarke M, Oxman AD (eds) (2000) Cochrane reviewers’ handbook 4.1 (update June 2000). In: Review Manager (RevMan) (computer program). Version 4.1. The Cochrane Collaboration 2000, Oxford, EnglandGoogle Scholar
- 27.Alexander FE, Patheal SL, Biondi A, Brandalise S, Cabrera ME, Chan LC, Chen Z, Cimino G, Cordoba JC, Gu LJ, Hussein H, Ishii E, Kamel AM, Labra S, Magalhães IQ, Mizutani S, Petridou E, Pombo de Oliveira M, Yuen P, Wiemels JL, Greaves MF (2001) Transplacental chemical exposure and risk of infant leukemia with MLL gene fusion. Cancer Res 61(6):2542–2546PubMedGoogle Scholar
- 41.Heacock H, Hertzman C, Demers PA, Gallagher R, Hogg RS, Teschke K, Hershler R, Bajdik CD, Dimich-Ward H, Marion SA, Ostry A, Kelly S (2000) Childhood cancer in the offspring of male sawmill workers occupationally exposed to chlorophenate fungicides. Environ Health Perspect 108(6):499–503CrossRefPubMedGoogle Scholar
- 45.Buckley JD, Robison LL, Swotinsky R, Garabrant DH, LeBeau M, Manchester P, Nesbit ME, Odom L, Peters JM, Woods WG, Hammond GD (1989) Occupational exposures of parents of children with acute nonlymphocytic leukemia: a report from the Childrens Cancer Study Group. Cancer Res 49(14):4030–4037PubMedGoogle Scholar
- 57.Perez-Saldivar ML, Ortega-Alvarez MC, Fajardo-Gutierrez A, Bernaldez-Rios R, Del Campo-Martinez Mde L, Medina-Sanson A, Palomo-Colli MA, Paredes-Aguilera R, Martinez-Avalos A, Borja-Aburto VH, Rodriguez-Rivera Mde J, Vargas-Garcia VM, Zarco-Contreras J, Flores-Lujano J, Mejia-Arangure JM (2008) Father’s occupational exposure to carcinogenic agents and childhood acute leukemia: a new method to assess exposure (a case–control study). BMC Cancer 8:7CrossRefPubMedGoogle Scholar
- 59.Rudant J, Menegaux F, Leverger G, Baruchel A, Nelken B, Bertrand Y, Patte C, Pacquement H, Vérité C, Robert A, Michel G, Margueritte G, Gandemer V, Hémon D, Clavel J (2007) Household exposure to pesticides and risk of childhood hematopoietic malignancies: the ESCALE study (SFCE). Environ Health Perspect 115(12):1787–1793CrossRefPubMedGoogle Scholar
- 67.Danila RN (1989) An epidemiologic study of acute lymphocytic leukemia in children less than sixteen years—an evaluation of potential risk factors with emphasis on farm exposures. University of Minnesota, Minnesota (cited by Wigle et al. 2009)Google Scholar
- 68.Steinbuch M (1994) The role of environmental exposures in the etiology of childhood acute myeloid leukemia. Ohio State University, OH (cited by Wigle et al. 2009)Google Scholar
- 69.Dell DM (2004) Epidemiology of childhood leukemia: environmental and genetic determinants. ProQuest Information and Learning Company, Ann Arbor; University of Pittsburgh, Pittsburgh (cited by Wigle et al. 2009)Google Scholar
- 75.Kishi R, Katakura Y, Yuasa J, Miyake H (1993) Association of parents’ occupational exposure to cancer in children (Japanese). Jpn J Ind Health 35(6):515–529Google Scholar