Pesticide use and colorectal cancer risk in the agricultural health study

Abstract

We investigated the relationship between agricultural pesticides and colorectal cancer incidence in the Agricultural Health Study. A total of 56,813 pesticide applicators with no prior history of colorectal cancer were included in this analysis. Detailed pesticide exposure and other information were obtained from self-administered questionnaires completed at the time of enrollment (1993)(1994)(1995)(1996)(1997). Cancer incidence was determined through populationbased cancer registries from enrollment through December 31, 2002. A total of 305 incident colorectal cancers (212 colon, 93 rectum) were diagnosed during the study period, 1993-2002. Although most of the 50 pesticides studied were not associated with colorectal cancer risk, chlorpyrifos use showed significant exposure response trend (p for trend 5 0.008) for rectal cancer, rising to a 2.7-fold (95% confidence interval: 1.2-6.4) increased risk in the highest exposure category. Aldicarb was associated with a significantly increased risk of colon cancer (p for trend 5 0.001), based on a small number of exposed cases, with the highest exposure category resulting in a 4.1-fold increased risk (95% confidence interval: 1.3-12.8). In contrast, dichlorophenoxyacetic acid showed a significant inverse association with colon cancer but the association was not monotonic. Our findings should be interpreted cautiously since the literature suggesting that pesticides are related to colorectal cancer is limited. Nonetheless the possibility of an association between exposure to certain pesticides and incidence of colorectal cancer among pesticide applicators deserves further evaluation. ' 2007 Wiley-Liss, Inc.

Review of the Toxicology of Chlorpyrifos With an Emphasis on Human Exposure and Neurodevelopment

“…In a recent publication on the Agricultural Health study (study period from enrollment through 2002, i.e., 7.3 years) chlorpyrifos use showed a significant exposure response trend for rectal cancer, rising to a 2.5-and 2.7-fold increase in risk in the 2 highest exposure categories, while no increase was seen with colon cancer (Lee et al, 2007). These associations between chlorpyrifos and lung and rectal cancer were unexpected in view of the absence of an increased incidence of intestinal or other tumors in animal studies, and the authors conclude that their findings should therefore be interpreted cautiously.…”

“…These associations between chlorpyrifos and lung and rectal cancer were unexpected in view of the absence of an increased incidence of intestinal or other tumors in animal studies, and the authors conclude that their findings should therefore be interpreted cautiously. Indeed, the positive association is based on small numbers of cases, i.e., an excess of less than 10 cases in the 2 highest exposure groups in the study of Lee et al (2007). Additional uncertainty arises from the limitations in exposure assessment, which is estimated from information recalled by surrogate respondents.…”

Occupational Exposure to Terbufos and the Incidence of Cancer in the Agricultural Health Study

“…In previous epidemiologic reports from the Agricultural Health Study (AHS) of specific cancer sites, terbufos use was not associated with cancers of the prostate (7), lung (8), breast (9), colon and rectum (10) or pancreas (11); other cancer sites have not been examined. However, several OPs, including chlorpyrifos (12), diazinon (13), and fonofos (14), have been associated with select cancers in the AHS.…”

Remediation of Chlorpyrifos in Artificially Spiked Soil by Defined Microbial Consortium

“…It has been shown to be possessed genotoxicity and mutagenicity against Drosophila melanogaster (Gupta et al, 2010), rat tissues (Ojiha et al, 2011), mouse lymphocytes (Cui et al, 2011). Epidemiological studies have found some evidence of an association between chlorpyrifos exposure and some cancers (Karunanayake et al, 2012;Waddell et al, 2001;Lee et al, 2007). Immunotoxicity of chlorpyrifos has been shown by Thrasher et al (1993), Gotoh et al (2001), Galloway and Handy (2003).…”