Analysis of polycyclic aromatic hydrocarbon intake in the US adult population from NHANES 2005-2014 identifies vulnerable subpopulations, suggests interaction between tobacco smoke exposure and sociodemographic factors.

Polycyclic aromatic hydrocarbons (PAHs) are a toxic and ubiquitous class of environmental chemicals, products of fuel combustion from human and natural sources. The objective of this study was to identify vulnerable populations for high PAH exposure and variability, to better understand where to target PAH exposure reduction initiatives. Urinary metabolite data were collected from 9517 individuals from the U.S. CDC National Health and Nutrition Examination Survey years 2005-2014 for four parental PAHs naphthalene, fluorene, phenanthrene, and pyrene. We utilized these urinary biomarkers to estimate PAH intake, and regression models were fit for multiple demographic and lifestyle variables, to determine variable effects, interactions, odds of high versus low PAH intake. Smoking and secondhand smoke exposure accounted for the largest PAH intake rate variability (25.62%), and there were strongest interactions between race/ethnicity and smoking or SHS exposure, reflected in a much greater contribution of smoking to PAH intake in non-Hispanic Whites as compared to other races/ethnicities. Increased odds of high PAH intake were seen in older age groups, obese persons, college graduates, midrange incomes, smokers, and those who were SHS exposed. Among the non-smoking population, effects of other demographic factors lessened, suggesting a highly interactive nature. Our results suggest that there are demographic subpopulations with high PAH intake as a result of different smoking behaviors and potentially other exposures. This has human health, environmental justice, and regulatory implications wherein smoking cessation programs, SHS exposure regulations, and public health initiatives could be better targeted towards vulnerable subpopulations to meaningfully reduce PAH exposures.