Trends in urinary metabolites of polycyclic aromatic hydrocarbons (PAHs) in the non-smoking US population, NHANES 2001-2014

Background: Recent studies indicate airborne PAH levels have decreased in the U.S., but it is unclear if this has resulted in PAH exposure changes in the U.S. population. Objective: Examine temporal trends in urinary metabolites of Naphthalene, Fluorene, Phenanthrene, and Pyrene in U.S. non-smokers, 6+ years old. Methods: We used biomonitoring data from the National Health and Nutrition Examination Survey (NHANES) program, 2001-2014, (N = 11,053) using survey weighted linear regression. Models were adjusted for age, sex, race/ethnicity, creatinine, BMI, income, diet, and seasonality. Stratified models evaluated the effect of age, sex, and race/ethnicity on trends. Results: Between 2001 and 2014, Naphthalene exposure increased 36% (p < 0.01); Pyrene exposure increased 106% (p < 0.01); Fluorene and Phenanthrene exposure decreased 55% (p < 0.01), and 37% (p < 0.01), respectively. Naphthalene was the most abundant urinary PAH, 20-fold higher than Fluorene and Phenanthrene, and over 50-fold higher than Pyrene compared to reference groups, effect modification was observed by age (Naphthalene, Pyrene), sex (Fluorene, Pyrene), and race/ethnicity (Naphthalene, Fluorene, Phenanthrene, Pyrene). Significance: This study shows exposure to Naphthalene and Pyrene increased, while exposure to Fluorene and Phenanthrene decreased among the non-smoking U.S. general population between 2001 and 2014, suggesting environmental sources of PAHs have changed over the time period. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This study found that exposure to Naphthalene and Pyrene increased, while exposure to Fluorene and Phenanthrene decreased among non-smoking U.S. population between 2001 and 2014, suggesting changes in environmental sources of PAHs over time.