Urinary levels of PAH metabolites in pregnant women and their correlation with sociodemographic factors and PM2.5 exposure in an urban and a suburban area

Abstract

Exposure to PAHs during pregnancy is associated with adverse birth outcomes. The objectives of this study were to determine the urinary levels of PAH metabolites in pregnant women and to evaluate their association with sociodemographic and lifestyle variables and exposure to atmospheric PM2.5. Subjects of 80 non-smoking pregnant women from three regions in an urban area (Isfahan city) and one region of suburb area (Mobarakeh town) were recruited to the study. The urine samples of women were collected during their first (spring) and third (autumn) trimester of pregnancy. Urinary PAHs’ metabolites including 1-naphthol (1-NAP), 2-naphthol (2-NAP), 9-phenanthrol (9-PHN), and 1-hydroxypyrene (1-OHP) were analysed by a GC/MS after their extraction and derivatization. Ambient PM2.5 data for the study period were collected from air pollution monitoring stations. The mean urinary concentrations of 1-NAP, 2-NAP, 9-PHN and 1-HOP in spring were 3.3, 2.2, 0.9 and 8.8 μg g−1 creatinine, and those in autumn accounted for 5.2, 3.0, 11.2 and 11.3 μg g−1 creatinine, respectively. Coincidently, the mean atmospheric PM2.5 concentrations of 23.2 μg m−3 in spring and 37.3 μg m−3 in autumn were attained. The concentration of the metabolites in the urban area was higher than that in the suburban area in both seasons which was following the ambient levels of PM2.5. A significant positive correlation between the metabolites and ambient PM2.5 was observed (p value < 0.05). Although the socio-demographic factors affected the level of exposure, the difference was not statistically significant (p value < 0.05). Residents of the urban area were exposed to a higher level of PAHs due to air pollution especially in the cold season.