Characterization of Acrylonitrile Exposure in the United States based on Urinary N-Acetyl-S-(2-cyanoethyl)-L-cysteine (2CYEMA): NHANES 2011–2016

BACKGROUND: Acrylonitrile is a possible human carcinogen that is used in polymers and formed in tobacco smoke. We assessed acrylonitrile exposure in the US population by measuring its urinary metabolites N-acetyl-S-(4-hydroxy-2-methyl-2-buten-1-yl)-L-cysteine (2CYEMA) and N-acetyl-S-(1-cyano-2-hydroxyethyl)-L-cysteine (1CYHEMA) in participants from the 2011–2016 National Health and Nutrition Examination Survey. OBJECTIVE: To assessed acrylonitrile exposure using population-based biomonitoring data of the US civilian, non-institutionalized population. METHODS: Laboratory data for 8,057 participants were reported for 2CYEMA and 1CYHEMA using ultrahigh-performance liquid chromatography / tandem mass spectrometry. Exclusive tobacco smokers were distinguished from non-users using a combination of self-reporting and serum cotinine data. We used multiple linear regression models to fit 2CYEMA concentrations with sex, age, race/Hispanic origin, and tobacco user group as predictor variables. RESULTS: The median 2CYEMA level was higher for exclusive cigarette smokers (145 μg/g creatinine) than for non-users (1.38 μg/g creatinine). Compared to unexposed individuals (serum cotinine ≤ 0.015 ng/ml) and controlling for confounders, presumptive second-hand tobacco smoke exposure (serum cotinine > 0.015 – ≤ 10 ng/ml and 0 cigarettes per day, CPD) was significantly associated with 36% higher 2CYEMA levels (p <0.0001). Smoking 1–10 CPD was significantly associated with 6,720% higher 2CYEMA levels (p <0.0001). SIGNIFICANCE: We show that tobacco smoke is an important source of acrylonitrile exposure in the US population and provide important biomonitoring data on acrylonitrile exposure.