Levels and risk factors for urinary metabolites of polycyclic aromatic hydrocarbons in children living in Chongqing, China

Aims: Since childhood exposure to polycyclic aromatic hydrocarbons (PAHs) have been associated with a variety of adverse health outcomes, the aims of this study were tol) document PAH exposure levels among children in Chongqing, China by measuring urinary concentrations of four PAH metabolites, 1-hydroxypyrene (1-OHPyr), 2hydroxynaphthalene (2-OHNap), 2-hydroxyfluorine (2-OHFIu) and 9-hydroxyphenanthrene (9-OHPhe), and 2) assess the associations of urinary concentrations of these PAH metabolites with risk factors related to sources of PAHs inhalation and ingestion exposures and with personal attributes such as sex, age, and BMI. Methods: The present study is a cross-sectional analysis using data drawn from the third follow up of a longitudinal study. Purposive sampling was used with all students in grades one to four in four schools being eligible to participate. The baseline survey included a total of 1237 students 5.8 to 12.2 years of age. At the third follow up survey, 1.5 years after the baseline survey, 1230 of the children had a physical exam and provided urine samples. Their parents completed a questionnaire including social-demographic information and possible sources of children's exposure to PAHs. Urine samples were measured for the four OH-PAHs using an HPLC-MS/MS technique. Concentrations were corrected by specific gravity. Linear regression analysis was used to investigate factors related to sources of PAHs exposure. Results: The urinary concentrations were highest for 9-OHPhe (median at the range of 3661 ng/L), followed by 2-OHNap (3189 ng/L), 2-OHFlu (1116 ng/L), and 1-OHPyr (250 ng/L). In multiple linear regressions, being female (P = 0.04), school location near a thermal power plant (P = 0.02) and higher maternal age at birth (P < 0.01) were associated with increased concentrations of urinary 1-OHPyr; no significant associations were found for 2-OHNap; school location near a thermal power plant (P < 0.01) and lower family income (P < 0.01) were associated with increased concentrations of urinary 2-OHFIu; higher age (P < 0.01), school location near a thermal power plant (P = 0.01), frequent consumption of smoked foods (P = 0.04) and lower family income (P = 0.07) were all found to be associated with increased concentrations of 9-OHPhe. Conclusions: Urinary concentrations of OH-PAHs, especially 9-OHPhe, were elevated in Chongqing Children compared to children in other countries. Being female, older age, school location near an industrial site, frequent consumption of smoked foods and lower family income were all associated with higher OH-PAHs concentrations. Further cohort studies are needed to confirm the associations between potential exposure sources and children's exposure to PAHs, in order to provide recommendations to reduce exposure. (C) 2017 Elsevier B.V. All rights reserved.National Youth Science Fund Project [81502825]; Basic and Frontier Research Project of Chongqing Science and Technology Commission [cstc2013jcyjA10001]; China Scholarship Council [201508500021]SCI(E)ARTICLE553-56159