title: Co-exposure to polycyclic aromatic hydrocarbons, benzene and toluene and their dose-effects on oxidative stress damage in kindergarten-aged children in Guangzhou, China.
abstract: Polycyclic aromatic hydrocarbons (PAHs), benzene and toluene (BT) are ubiquitous toxic pollutants in the environment. Children are sensitive and susceptible to exposure to these contaminants. To investigate the potential oxidative DNA damage from the co-exposure of PAHs and BT in children, 87 children (aged 3-6) from a kindergarten in Guangzhou, China, were recruited. Ten urinary PAHs and four BT metabolites, as well as 8-hydroxy-2'-deoxyguanosine (8-OHdG, a biomarker of oxidative DNA damage)in urine, were determined using a liquid chromatography tandem mass spectrometer. The results demonstrated that the levels of PAHs and BT in children from Guangzhou were 2-30 times higher than those in children from the other countries based on a comparison with recent data from the literature. In particular, the difference is more substantial for pyrene and volatile BT. Co-exposure to PAHs and BT could lead to additive oxidative DNA damage. Significant dose-effects were observed between the sum concentration of urinary monohydroxylated metabolites of PAHs (∑OH-PAHs), the sum concentration of the metabolites of BT (∑BT) and 8-OHdG levels. Every one percent increase in urinary PAHs and BT generated 0.33% and 0.02% increases in urinary 8-OHdG, respectively. We also determined that the urinary levels of PAHs and BT were negatively associated with the age of the children. Moreover, significant differences in the levels of ∑OH-PAHs and ∑BT were determined between 3- and 6-year-old children (p<0.05), which may be caused by different metabolism capabilities or inhalation frequencies. In conclusion, exposure to PAHs or BT could lead to oxidative DNA damage, and 8-OHdG is a good biomarker for indicating the presence of DNA damage. There exists a significant dose-effect relationship between PAH exposure, BT exposure and the concentration of 8-OHdG in urine. Toddlers (3-4 years old) face a higher burden of PAH and BT exposure compared with older children.
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: Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China.
authors.forename: Shaoyou
authors.initials: S
authors.lastname: Lu
authors.affiliation: Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China.
authors.forename: Guihua
authors.initials: G
authors.lastname: Liu
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: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou 510631, China.
authors.forename: Yanshan
authors.initials: Y
authors.lastname: Lv
authors.affiliation: Environmental Health Laboratory Branch, California Department of Public Health, 850 Marina Bay Parkway, Richmond, CA 94804, United States.
authors.forename: Jianwen
authors.initials: J
authors.lastname: She
authors.affiliation: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou 510631, China. Electronic address: 20001047@m.scnu.edu.cn.
authors.forename: Ruifang
authors.initials: R
authors.lastname: Fan
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000393:Air Pollutants / Q000032:analysis* / Q000633:toxicity; D001554:Benzene / Q000032:analysis* / Q000633:toxicity; D015415:Biomarkers / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D002681:China; D004249:DNA Damage; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004781:Environmental Exposure / Q000032:analysis* / Q000706:statistics & numerical data; D006801:Humans; D018384:Oxidative Stress / Q000502:physiology; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis* / Q000633:toxicity; D014050:Toluene / Q000032:analysis* / Q000633:toxicity
chemical_list: D000393:Air Pollutants; D015415:Biomarkers; D011084:Polycyclic Aromatic Hydrocarbons; D014050:Toluene; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine; D001554:Benzene
keywords: Age; Benzene and toluene; Co-exposure; Oxidative DNA damage; Polycyclic aromatic hydrocarbons; Urinary metabolites