Exposure to atrazine and selected non-persistent pesticides among corn farmers during a growing season

Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, Rockville, Maryland 20852-7240, USA.
Journal of Exposure Science and Environmental Epidemiology (Impact Factor: 3.19). 09/2009; 19(6):544-54. DOI: 10.1038/jes.2008.53
Source: PubMed


The aim was to develop quantitative estimates of farmers' pesticide exposure to atrazine and to provide an overview of background levels of selected non-persistent pesticides among corn farmers in a longitudinal molecular epidemiologic study. The study population consisted of 30 Agricultural Health Study farmers from Iowa and 10 non-farming controls. Farmers completed daily and weekly diaries from March to November in 2002 and 2003 on pesticide use and other exposure determinants. Urine samples were collected at 10 time points relative to atrazine application and other farming activities. Pesticide exposure was assessed using urinary metabolites and diaries. The analytical limit of detection (LOD) ranged between 0.1 and 0.2 microg/l for all pesticide analytes except for isazaphos (1.5 microg/l) and diazinon (0.7 microg/l). Farmers had higher geometric mean urinary atrazine mercapturate (AZM) values than controls during planting (1.1 vs <LOD microg/g creatinine; P<0.05). AZM levels among farmers were significantly related to the amount of atrazine applied (P=0.015). Interestingly, farmers had a larger proportion of samples above the LOD than controls even after exclusion of observations with an atrazine application within 7 days before urine collection (38% vs 6%, P<0.0001). A similar pattern was observed for 2,4-D and acetochlor (92% vs 47%, P<0.0001 and 45% vs 4%, P<0.0001, respectively). Urinary AZM levels in farmers were largely driven by recent application of atrazine. Therefore, the amount of atrazine applied is likely to provide valid surrogates of atrazine exposure in epidemiologic studies. Elevated background levels of non-persistent pesticides, especially 2,4-D, indicate importance in epidemiologic studies of capturing pesticide exposures that might not be directly related to the actual application.

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    • "observed urinary traces of atrazine mercapturate similar to our study (6% of detectable levels, with an LOD below 0.2 µg/L) (Bakke et al. 2009). As Barr et al. (2007) "
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    • "Several studies have found non significant associations between atrazine exposure and NHL; for example, a study of 36,513 atrazine-exposed pesticide applicators in the U.S. Agricultural Health Study (AHS) demon strated non significant excesses of lung cancer, bladder cancer, NHL, and multiple myeloma (Rusiecki et al. 2004). Follow-up of the AHS cohort through 2006 is now under way and, along with analysis of biomarkers among corn farmers and similar studies in atrazine-exposed women (Bakke et al. 2008; Vermeulen et al. 2005), could shed light on the effects of atrazine. "
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