Urinary monohydroxylated polycyclic aromatic hydrocarbons in the general population from 26 provincial capital cities in China: Levels, influencing factors, and health risks

• Large-scale PAH biomonitoring in the general population of China was conducted. • Regional differences of urinary OH-PAHs among the cities were analyzed. • Smoking is important factor led the association of OH-PAHs with other demographics. • Inhalation may be the main route of human exposure to PAHs, especially for smokers. • The Chinese general population exposed to PAHs had potential carcinogenic risk. Polycyclic aromatic hydrocarbons (PAHs) derived from the incomplete combustion of organic materials are associated with adverse health effects. However, little is known about PAH exposure levels and their influencing factors on a large scale in developing countries. In this study, urinary monohydroxylated metabolites of PAHs (OH-PAHs), including the metabolites of naphthalene, fluorene, phenanthrene, pyrene, chrysene, and benzo[a]pyrene, were measured in 1154 samples in the general population nationwide from 26 provincial capitals in China. Concentrations of OH-PAHs ranged from 1.39 to 228 μg/L. OH-Nap, metabolite of naphthalene, was the predominant compound, accounting for 65.1% of totals. People in eastern, southwest and northeast China, such as Shanghai, Kunming, Nanning, and Changchun, suffered more PAH exposure than other regions which might associate with sampling time, living habits of the subjects, and the imbalance of economic development and energy consumption across regions. Urinary OH-PAH concentrations were associated with body mass index, gender, and age, and smoking was the main correlating factor. Inhalation and diet might be the main exposure route of human exposure to PAHs, especially for smokers by inhalation. Hazard indices showed that no subject was exposed to PAHs with potential non-carcinogenic risk. Furthermore, the carcinogenic risk was the most significant health effects, with almost all subjects having carcinogenic risk values higher than the acceptable level of 10 −6 . Naphthalene and phenanthrene were the main contributors. The results also suggested a possible relationship between PAH exposure and lung cancer in the Chinese population. This first nationwide study on human internal exposure to PAHs provides a large body of scientific information for governmental decision-making about associated human health and the prevention of human exposure to PAHs.