Diazinon, a common organophosphate insecticide with genotoxic properties, was previously associated with lung cancer in the Agricultural Health Study (AHS) cohort, but few other epidemiologic studies have examined diazinon-associated cancer risk. We used updated diazinon exposure and cancer incidence information to evaluate solid tumor risk in the AHS.
Male pesticide applicators in Iowa (IA) and North Carolina (NC) reported lifetime diazinon use at enrollment (1993–1997) and follow-up (1998–2005); cancer incidence was assessed through 2010(NC)/2011(IA). Among applicators with usage information sufficient to evaluate exposure-response patterns, we used Poisson regression to estimate adjusted rate ratios (RRs) and 95% confidence intervals (95% CI) for cancer sites with ≥10 exposed cases for both lifetime (LT) exposure days and intensity-weighted (IW) lifetime exposure days (accounting for factors impacting exposure).
We observed elevated lung cancer risks (N=283) among applicators with the greatest number of LT (RR=1.60; 95%CI:1.11,2.31; P trend=0.02) and IW days of diazinon use (RR=1.41; 95%CI:0.98,2.04; P trend=0.08). Kidney cancer (N=94) risks were non-significantly elevated (RR LT days=1.77; 95%CI:0.90,3.51; P trend=0.09; RR IW days=1.37; 95%CI:0.64,2.92; P trend=0.50), as were risks for aggressive prostate cancer (N=656) .