pesticide-induced carcinogenesis

Although pesticides are subject to extensive carcinogenicity testing before regulatory approval, pesticide exposure has repeatedly been associated with various cancers. This suggests that pesticides may cause cancer via non-mutagenicity mechanisms.

Pesticides may modify gene promoter DNA methylation levels, suggesting that epigenetic mechanisms may contribute to pesticide-induced carcinogenesis.

Pesticides are widely used in our environment [Weichenthal et al. 2010]. Although pesticides sold in the US have passed the Environmental Protection Agency’s (EPA) screening procedures for carcinogenicity (i.e, genotoxicity and mutagenicity tests [EPH 1997]), animal studies have shown that some of these pesticides are carcinogenic [Reuber 1981; Gupta et al. 2007; Wong and Matsumura 2007; Yu et al. 2008].

A number of pesticides have been repeatedly associated with various cancers in epidemiological investigations of farmers and pesticide manufacturing workers [Alavanja and Bonner 2005; Alavanja et al. 2007; Bassil et al. 2007; Koutros et al. 2010; Weichenthal et al. 2010; Waggoner et al. 2011].

The elevated cancer risk following exposure to pesticides indicates a gap in the current knowledge of pesticide carcinogenicity, and provides evidence that pesticides may cause cancer through alternative mechanisms, such as epigenetic changes [Skinner and Anway 2007; Alavanja 2009].

 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3753688/#R12

References

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 Alavanja MC, Ward MH, Reynolds P. Carcinogenicity of agricultural pesticides in adults and children. J Agromedicine. 2007;12(1):39–56. [PubMed]

 Bassil KL, Vakil C, Sanborn M, Cole DC, Kaur JS, Kerr KJ. Cancer health effects of pesticides: systematic review. Can Fam Physician. 2007;53(10):1704–1711. [PMC free article] [PubMed]

 Koutros S, Alavanja MC, Lubin JH, Sandler DP, Hoppin JA, Lynch CF, Knott C, Blair A, Freeman LE. An update of cancer incidence in the Agricultural Health Study. J Occup Environ Med. 2010;52(11):1098–1105. [PMC free article] [PubMed]

 Weichenthal S, Moase C, Chan P. A review of pesticide exposure and cancer incidence in the Agricultural Health Study cohort. Environ Health Perspect. 2010;118(8):1117–1125. [PMC free article] [PubMed]

 Waggoner JK, Kullman GJ, Henneberger PK, Umbach DM, Blair A, Alavanja MC, Kamel F, Lynch CF, Knott C, London SJ, Hines CJ, Thomas KW, Sandler DP, Lubin JH, Beane Freeman LE, Hoppin JA. Mortality in the agricultural health study, 1993-2007. Am J Epidemiol. 2011;173(1):71–83. [PMC free article] [PubMed]