Urinary concentrations of polycyclic aromatic hydrocarbons in Israeli adults: demographic and life-style predictors

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants associated with adverse health outcomes, including cancer, asthma, and reduced fertility. Because data on exposure to these contaminants in Israel and the Middle East are very limited this study was conducted to measure urinary levels of PAHs in the general adult population in Israel and to identify demographic and life-style predictors of exposure. We measured concentrations of five PAH metabolites: 1-hydroxypyrene (1OH_pyrene) and four different hydroxyphenanthrenes (1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, 4-hydroxyphenanthrene), as well as cotinine in urine samples collected from 243 Israeli adults from the general population. We interviewed participants using structured questionnaires to collect detailed demographic, smoking and dietary data. For over 99% of the study participants, urinary concentration of at least one of the PAHs was above both the limit of detection (LOD) and the limit of quantification (LOQ). All PAHs were significantly correlated (rho=0.67-0.92). Urinary concentration of hydroxyphenanthrenes, but not 1OH_pyrene, was significantly higher among Arabs and Druze study participants (N=56) compared to Jewish participants (N=183). For 4-hydroxyphenanthrene, concentration in Arabs and Druze was 1.95 (95% CI 1.50-2.52) that of Jews, after controlling for creatinine, age and cotinine levels. Urinary concentrations of all PAHs were significantly higher among current smokers or participants with higher cotinine levels and increased significantly with smoking frequency. While PAHs concentrations were not associated with cotinine concentrations in nonsmokers in the overall study population, PAHs concentration was significantly higher among nonsmoking Jews with cotinine ≥LOQ (1μg/L), which represents exposure to environmental tobacco smoking, compared to nonsmoking Jews with cotinine concentrations <LOQ, with the highest ratio for 1OH_pyrene (Ratio=2.38, 95% CI 1.47-3.85). Among nonsmoking Arabs and Druze, higher hydroxyphenanthrenes concentrations were found for those consuming grilled food once a month or more. For 3-hydroxyphenanthrene, concentration in those consuming grilled food once a month or more was 2.72 (95% CI 1.01-4.98) times that of those consuming grilled food less than once a month or not at all, after controlling for creatinine, age and cotinine levels. In conclusion, we found that the general adult population in Israel is widely exposed to PAHs. Exposure differed by ethnic sub-groups both in magnitude and sources of exposure. The finding of higher exposure among Arabs and Druze highlights disparities in environmental exposures across subpopulations and suggests that further research and preventive measure are warranted to reduce PAHs exposure and associated health outcomes, especially in the Arab population in the Middle East.

Keywords: Biomonitoring; Diet; Ethnicity; Polycyclic aromatic hydrocarbons; Smoking; Urinary metabolites.