Urinary Concentrations of Polycyclic Aromatic Hydrocarbon Metabolites in Smokers, Passive Smokers and Non-smokers in the United States

摘要

Polycylic aromatic hydrocarbons (PAHs) are a class of carcinogenic compounds found in tobacco smoke. In the United States, the National Health and Nutrition Examination Survey (NHANES), conducted in two-year cycles, provides an ongoing exposure assessment of the civilian, non-institutionalized population to a wide range of environmental chemicals, including PAHs. We report urinary concentrations of ten hydroxyl polycyclic aromatic hydrocarbon metabolites (OH-PAHs) from the latest NHANES cycles, for Americans aged 6 years and older and evaluated concentration trends. There were approximately 2700 participants with PAH measurements for each NHANES cycle. We used sample weights to account for the unequal probability of selection and log transformed the concentrations to compute all of the estimates. After excluding users of snuff or smokeless tobacco, we categorized NHANES participants as non-smoker (serum cotinine ＜0.015 ng/mL), exposed to second hand smoke (SHS) (serum cotinine 0.015-10 ng/mL), or active smoker (serum cotinine ＞10 ng/mL). We included age, sex, race/ethnicity, urinary creatinine and serum cotinine concentrations in multiple linear regression models. Smoking status was confounded by age; therefore, age was retained as a significant factor in the final model. The geometric mean (GM) concentrations of all OH-PAHs in active smokers were significantly higher than in non-smokers, after adjusting for age, sex, race/ethnicity and urine creatinine. For example, the adjusted GM of the naphthalene metabolites in heavy smokers (with serum cotinine ＞300 ng/mL) were approximately 8 times higher than in non-smokers. In active smokers, the fact that urinary OH-PAH concentrations correlated with serum cotinine concentrations suggested that smoking was their main source of PAH exposure. We will also demonstrate the usefulness of PAH NHANES data to track the US population exposure to tobacco smoke over time.