Occupational exposure to pesticides and risk of hematopoietic cancers: Meta-analysis of case-control studies

UMR 1089 Xénobiotiques, INRA, 180 Chemin de Tournefeuille, Toulouse 31931, France.
Cancer Causes and Control (Impact Factor: 2.74). 01/2008; 18(10):1209-26. DOI: 10.1007/s10552-007-9061-1
Source: PubMed


In this study we conducted a meta-analysis of 13 case-control studies that examined the occurrence of hematopoietic cancers in pesticide related occupations in order to undertake a qualitative and quantitative evaluation of a possible relationship.
Pubmed databases were searched for case-control studies published between 1990 and 2005 investigating the relation between hematopoietic cancers and occupational exposure to pesticides. Fixed and random effect meta-analysis models were used depending on the presence of heterogeneity between studies.
The overall meta-odds ratio obtained after pooling 44 ORs from 13 studies was 1.3 (95% CI: 1.3-1.5). We realized stratified analysis on three different types of hematopoietic cancers (non-Hodgkin lymphoma (NHL), leukemia and multiple myeloma). A significant increased risk of NHL was found (OR = 1.35; 95% CI = 1.2-1.5). Moreover, increased risks of Leukemia (OR = 1.35; 95% CI = 0.9-2) and multiple myeloma (OR = 1.16; 95% CI = 0.99-1.36) were also detected but these results were not statistically significant. Significant heterogeneity existed among the different studies and a publication bias was detected. Therefore, a meta-regression was carried out. Our results showed that a long period of exposure (more than 10 years) provided an increase in the risk of all hematopoietic cancers and for NHL by fractions of 2.18 (95% CI = 1.43-3.35) and 1.65 (95% CI = 1.08-2.51), respectively. Conclusions: The overall meta-odds ratio suggests that there is a significantly positive association between occupational exposure to pesticides and all hematopoietic cancers as well as NHL. A major limitation of our meta-analysis is the lack of sufficient data about exposure information and other risk factors for hematopoietic cancer (genetic predisposition, ethnic origin, immunodepression...). In addition, data concerning specific subtypes of hematopoietic cancers are often confusing. Thus, future epidemiological studies should undertake a major effort to assess the identity and the level of pesticides exposure and should control for the most likely potential confounders.

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Available from: Helen Raynal, Dec 18, 2013
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    • "Epidemiologic studies have reported a lower incidence of overall cancer among farmers. However, a higher incidence of certain types of cancers, particularly hematopoietic cancers (Merhi et al. 2007; Van Maele-Fabry et al. 2007), soft tissue sarcoma (Kogevinas et al. 1995), lung cancer (Veglia et al. 2007) and prostate cancer (Parent et al. 2009; Van Maele-Fabry and Willems 2004), has been described (for review Alavanja and Bonner 2012). There are several etiologic clues to farming-related pathologies such as ultraviolet light, zoonotic viruses and pesticides, all being clearly or potentially genotoxic. "
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    ABSTRACT: Purpose: The effect of one pesticide spraying season on DNA damage was measured on B and T lymphocytes among open-field farmers and controls. Methods: At least two peripheral blood samples were collected from each individual: one in a period without any pesticide application, several weeks after the last use (January, at period P0), and another in the intensive pesticide spraying period (May or June, at period P4). DNA damage was studied by alkaline comet assay on isolated B or T lymphocytes. Results: Longitudinal comparison of DNA damage observed at both P0 and P4 periods revealed a statistically significant genotoxic effect of the pesticide spraying season in both B (P = 0.02) and T lymphocytes (P = 0.02) in exposed farmers. In contrast, non-farmers did not show any significant modifications. DNA damage levels in B and T lymphocytes were significantly higher in farmers than in non-farmers during the P4 period (P = 0.003 and P = 0.001 for B and T lymphocytes, respectively) but not during the P0 period. The seasonal effect observed among farmers was not correlated with either total farm area, farm area devoted to crops or recent solar exposure. On average, farmers used pesticides for 21 days between P0 and P4. Between the two time points studied, there was a tendency for a potential effect of the number of days of fungicide treatments (r (2) = 0.43; P = 0.11) on T lymphocyte DNA damage. Conclusions: A genotoxic effect was found in lymphocytes of farmers exposed to pesticides, suggesting in particular the possible implication of fungicides.
    International Archives of Occupational and Environmental Health 02/2015; 88(7). DOI:10.1007/s00420-015-1024-3 · 2.20 Impact Factor
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    • "Although pesticides help control agricultural pests and organisms harming human activities, they may present a risk for human health. Severe pathologies such as cancers, neurodegenerative diseases or reproductive disorders are suspected of being connected to exposure to pesticides, particularly for specific populations such as farmers and their children (Bailey et al., 2011; Baldi et al., 2011; Inserm, 2013; Koutros et al., 2011; Merhi et al., 2008). In the general population, dietary intake is considered to be the main route of exposure to most pesticides (Cao et al., 2011; Lu et al., 2006; Nougadère et al., 2012). "
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    ABSTRACT: The French system for monitoring dietary exposure to pesticide residues and its scoring method are presented. This system aims both to assess acute and chronic risks to the general population and to identify food commodities and pesticides that need to be better monitored and/or regulated thanks to 6 priority levels. The method combines four chronic and acute dietary risk indicators based on the results of the most recent national monitoring programmes and maximum residue levels, in connection with individual and national food consumption data. The probability of exceeding the toxicological reference values was estimated for children and adults, for 522 pesticides and their metabolites. Food contributors were detailed and a minimum number of samples to be taken per food was proposed. The majority of the pesticides (87%) was scored at the lowest priority level 1. For pesticides classified in levels 2 to 5, there is a need to refine the assessment. The monitoring should also be extended to include newly authorised substances in levels 2 to 4. Carbendazim, dimethoate, dithiocarbamates and imazalil merit particular attention as they scored at level 6 and are frequently quantified in fruits and vegetables, meaning that risk managers should take corrective measures in order to ensure consumer safety.
    Food Control 07/2014; 41(1):32–48. DOI:10.1016/j.foodcont.2013.12.025 · 2.81 Impact Factor
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    • "In conclusion, previous studies have suggested that HL might be associated with exposure to pesticides, but it has generally been less compelling than for other lymphatic and hematopoietic cancers [34]. This study provides additional information on the relationship between HL and pesticide exposure. "
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    ABSTRACT: Purpose To determine the risk of Hodgkin lymphoma (HL) associated with exposures to multiple pesticides grouped by various classes, including carcinogenic classifications. Methods Data collected in the Cross-Canada Study of Pesticides and Health, a population-based incident case–control study in six provinces conducted between 1991 and 1994, were analyzed using unconditional logistic regression. Cases (n = 316) were identified through provincial cancer registries and hospital records. Controls (n = 1,506) were frequency-matched to cases by age (±2 years) within each province and were identified through provincial health records, telephone listings, or voter lists. The Cochran–Armitage test was used to check for trends within pesticide classes. Results Overall, there was an increase in the risk of HL among all subjects who reported use of five or more insecticides (OR 1.88, 95 % CI 0.92–3.87) and among subjects younger than 40 who reported use of two acetylcholinesterase inhibitors (OR 3.16, 95 % CI 1.02–9.29). There was an elevated odds ratio associated with reported use of three or more probably carcinogenic pesticides (OR 2.47, 95 % CI 1.06–5.75), but no increase in risk for use of possibly carcinogenic pesticides. The risk of HL from reported use of fungicides or any pesticides was greater for cases diagnosed before age 40 than for cases diagnosed at or after age 40. When analyses excluded proxy respondents, OR estimates strengthened in some circumstances. Conclusions This study found associations between HL and fungicides, insecticides, specifically acetylcholinesterase inhibitors, and pesticides previously identified as probable human carcinogens. These associations should be further evaluated, specifically in relation to age at diagnosis.
    Cancer Causes and Control 06/2013; 24(9). DOI:10.1007/s10552-013-0240-y · 2.74 Impact Factor
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