Scientific Publications by FDA Staff

Cancer Epidemiol Biomarkers Prev 2020 Jan;29(1):103-11

Evaluation of tobacco smoke and diet as sources of exposure to two heterocyclic aromatic amines for the U.S. population: NHANES 2013-2014.

Zhang L, Wang L, Li Y, Xia Y, Chang CM, Xia B, Sosnoff CS, Pine BN, deCastro BR, Blount BC

BACKGROUND: Heterocyclic aromatic amines (HAAs) are a group of hazardous substances produced during combustion of tobacco or high-temperature cooking of meats. 2-Amino-9H-pyrido[2,3-b]indole (AalphaC) is a major carcinogenic HAAs in tobacco smoke. METHODS: Urinary AalphaC, used as a marker of AalphaC exposure, was analyzed on spot urine samples from adult participants of the 2013-2014 cycle of the National Health and Nutrition Examination Survey (NHANES; N=1,792). AalphaC was measured using isotope-dilution liquid chromatography-tandem mass spectrometry. Exclusive combusted tobacco smokers were differentiated from non-users of tobacco products through both self-report and serum cotinine data. RESULTS: Among exclusive smokers, sample-weighted median urinary AalphaC was 40 times higher than non-users. Sample-weighted regression models showed that urinary AalphaC increased significantly with serum cotinine among both exclusive tobacco users and non-users with second-hand smoke exposure. Among non-users, eating beef cooked at high temperature was associated with a significant increase in urinary AalphaC, while consuming vegetables was associated with decreased AalphaC. In addition, smoking one-half pack of cigarettes per day was associated with a significant increase of 23.6 pg AalphaC/mL calculated at geometric mean of AalphaC, controlling for potential confounders. In comparison, increase in AalphaC attributable to consuming the 99th percentile of beef cooked at high temperature was 0.99 pg AalphaC/mL. CONCLUSIONS: Both exclusive smokers and non-users of tobacco in the general U.S. population are exposed to AalphaC from tobacco smoke, with additional, lesser contributions from certain dietary components. IMPACT: AalphaC is an important biomarker that is associated with tobacco smoke exposure.