S -Ethyl- N,N -dipropylthiocarbamate Exposure and Cancer Incidence among Male Pesticide Applicators in the Agricultural Health Study: A Prospective Cohort

Abstract

BackgroundThe Agricultural Health Study (AHS) is a prospective cohort study of licensed pesticide applicators from Iowa and North Carolina enrolled between 1993 and 1997. EPTC (S-ethyl-N,N-dipropylthiocarbamate) is a thiocarbamate herbicide used in every region of the United States. The U.S. Environmental Protection Agency reports that EPTC is most likely not a human carcinogen; however, the previous epidemiologic data on EPTC exposure and cancer risk were limited.ObjectivesThe purpose of this study was to examine cancer incidence and EPTC use in 48,378 male pesticide applicators enrolled in the AHS.MethodsWe estimated the rate ratio (RR) and 95% confidence intervals (CIs) for all cancers and selected cancer sites using Poisson regression. We assessed EPTC exposure using two quantitative metrics: lifetime exposure days and intensity-weighted lifetime exposure days, a measure that accounts for application factors that modify personal exposure likelihood.ResultsAmong the 9,878 applicators exposed to EPTC, 470 incident cancer cases were diagnosed during the follow-up period ending December 2004 compared with the 1,824 cases among individuals reporting no use. Although EPTC was associated with colon cancer in the highest tertile of both lifetime exposure days and intensity-weighted lifetime days (RR = 2.09; 95% CI, 1.26–3.47 and RR = 2.05; 95% CI, 1.34–3.14, respectively) and the trend test was < 0.01 for both, the pattern of RR was not monotonic with increasing use. There was a suggestion of an association with leukemia. No other associations were observed.ConclusionIn this analysis, EPTC use appeared to be associated with colon cancer and leukemia. However, given the relatively small number of cases in the highest exposure tertile, results should be interpreted with caution, and further investigations are needed.

The impact of exposure to pesticides on the risk of gastrointestinal cancer among pistachio farmers; a case-control study

“…The results of the present study showed increased risk of gastrointestinal cancers in people who were at the highest level of exposure to pesticides. These findings were consistent with the results of some studies on the effects of different levels of exposure to pesticides on gastrointestinal cancers (16)(17)(18)(19)(20)(21).…”

A review of pesticide exposure and cancer incidence in the agricultural health study cohort

“…Overall cancer incidence was increased among applicators in the highest exposure categories for diazinon (Beane Freeman et al 2005) and S-ethyl-N,N-dipropylthiocarbamate (EPTC) (van Bemmel et al 2008) relative to nonexposed applicators, and significant exposure-response trends were observed for both pesticides with both exposure measures. None of the other pesticides Alavanja et al (2003Alavanja et al ( , 2004, Andreotti et al (2009), and Lee et al (2007b); all others are RRs.…”

Increased cancer burden among pesticide applicators and others due to pesticide exposure

“…65 although the risk associated with both of these herbicides was limited to the highest exposure group and thus further follow-up will be necessary.…”

“…Recent epidemiological evidence linking specific pesticides to leukemia has established hypotheses that need to be evaluated in other studies (eg, the associations between leukemia overall and diazinon [an OP insecticide currently in widespread use] and several OC insecticides no longer in use in the United States or other developed countries are of particular interest). 65,66,[146][147][148][149][150][151] Linking leukemia to specific pesticides that are used at high levels occupationally should help to identify the chemical agents responsible for childhood cancers as well. The use of preclinical biomarkers (eg, monoclonal B-cell lymphocytosis) to study the etiology of CLL may be a powerful approach for this leukemia subtype.…”