title: Biomass fuels and coke plants are important sources of human exposure to polycyclic aromatic hydrocarbons, benzene and toluene.
abstract: Large amounts of carcinogenic polycyclic aromatic hydrocarbons (PAHs), benzene and toluene (BT) might be emitted from incomplete combustion reactions in both coal tar factories and biomass fuels in rural China. The health effects arising from exposure to PAHs and BT are a concern for residents of rural areas close to coal tar plants. To assess the environmental risk and major exposure sources, 100 coke plant workers and 25 farmers in Qujing, China were recruited. The levels of 10 mono-hydroxylated PAHs (OH-PAHs), four BT metabolites and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in the urine collected from the subjects were measured. The 8-OHdG levels in the urine were determined to evaluate the oxidative DNA damage induced by the PAHs and BT. The results showed that the levels of the OH-PAHs, particularly those of 1-hydroxynathalene and 1-hydroxypyrene, in the farmers were 1-7 times higher than those in the workers. The concentrations of the BT metabolites were comparable between the workers and farmers. Although the exact work location within a coke oven plant might affect the levels of the OH-PAHs, one-way ANOVA revealed no significant differences for either the OH-PAHs levels or the BT concentrations among the three groups working at different work sites. The geometric mean concentration (9.17 µg/g creatinine) of 8-OHdG was significantly higher in the farmers than in the plant workers (6.27 µg/g creatinine). The levels of 8-OHdG did not correlate with the total concentrations of OH-PAHs and the total levels of BT metabolites. Incompletely combusted biomass fuels might be the major exposure source, contributing more PAHs and BT to the local residents of Qujing. The estimated daily intakes (EDIs) of naphthalene and fluorene for all of the workers and most of the farmers were below the reference doses (RfDs) recommended by the U.S. Environmental Protection Agency (EPA), except for the pyrene levels in two farmers. However, the EDIs of benzene in the workers and local farmers ranged from 590 to 7239 µg/day, and these levels were 2- to 30-fold higher than the RfDs recommended by the EPA. Biomass fuel combustion and industrial activities related to coal tar were the major sources of the PAH and BT exposure in the local residents. Using biomass fuels for household cooking and heating explains the higher exposure levels observed in the farmers relative to the workers at the nearby coal tar-related industrial facility.
authors.affiliation: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou 510631, China.
authors.forename: Ruifang
authors.initials: R
authors.lastname: Fan
authors.affiliation: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou 510631, China.
authors.forename: Junnan
authors.initials: J
authors.lastname: Li
authors.affiliation: Urban Environment and Ecology Research Center, South China Institute of Environmental Sciences (SCIES), Ministry of Environmental Protection, Guangzhou 510655, China. Electronic address: chenlaiguo@scies.org.
authors.forename: Laiguo
authors.initials: L
authors.lastname: Chen
authors.affiliation: Urban Environment and Ecology Research Center, South China Institute of Environmental Sciences (SCIES), Ministry of Environmental Protection, Guangzhou 510655, China. Electronic address: xuzhencheng@scies.org.
authors.forename: Zhencheng
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Urban Environment and Ecology Research Center, South China Institute of Environmental Sciences (SCIES), Ministry of Environmental Protection, Guangzhou 510655, China.
authors.forename: Dechun
authors.initials: D
authors.lastname: He
authors.affiliation: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou 510631, China.
authors.forename: Yuanxiu
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: China National Environmental Monitoring Center, Beijing 100012, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: China National Environmental Monitoring Center, Beijing 100012, China.
authors.forename: Fusheng
authors.initials: F
authors.lastname: Wei
authors.affiliation: Qujing Center for Disease Control and Prevention, Yunan 655099, China.
authors.forename: Jihua
authors.initials: J
authors.lastname: Li
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000383:Agriculture; D000395:Air Pollutants, Occupational / Q000633:toxicity / Q000652:urine*; D000704:Analysis of Variance; D001554:Benzene / Q000032:analysis; D056804:Biofuels / Q000032:analysis*; D002681:China; D003033:Coal Tar / Q000737:chemistry*; D004249:DNA Damage / Q000187:drug effects*; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000652:urine; D004784:Environmental Monitoring / Q000706:statistics & numerical data; D006801:Humans; D016273:Occupational Exposure / Q000032:analysis*; D011084:Polycyclic Aromatic Hydrocarbons / Q000652:urine; D014050:Toluene / Q000652:urine
chemical_list: D000395:Air Pollutants, Occupational; D056804:Biofuels; D011084:Polycyclic Aromatic Hydrocarbons; D014050:Toluene; D003033:Coal Tar; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine; D001554:Benzene
keywords: 8-hydroxy-2′-deoxyguanosine; Benzene and toluene; Biomarker; Biomass fuel; Coke plant; Polycyclic aromatic hydrocarbons