title: Diverse toxicological risks of PAHs in surface water with an impounding level of 175m in the Three Gorges Reservoir Area, China.
abstract: The impounding level of 175m for the Three Gorges Reservoir (TGR) is of vital importance for efficient flood control, power generation and convenient navigation in China. However, little is known about the spatial distribution and toxicological risks of major pollutants in the Three Gorges Reservoir Area (TGRA) at that stage. The aim of this study is to probe the ubiquitous polycyclic aromatic hydrocarbons (PAHs) contamination and toxicological impacts in the surface water of the TGRA at the highest water impoundment level of 175m. Our results showed that the ƩPAHs levels ranged from 83 to 1631ng/L in the upper reaches, 354 to 1159ng/L in the middle reaches, and 23 to 747ng/L in the lower reaches of the TGRA. Source apportionment of PAHs indicated that coal combustion, industrial emissions, heavy traffic, agriculture and shipping activities were the primary sources. Compositional pattern highlighted >85% dominancy of low molecular weight (LMW) PAHs in the reservoir. Risk assessment based on risk quotients (RQs) implied moderate to high ecological risks: the upper reaches>the middle reaches>the lower reaches. However, gene expression profiles portrayed contrary scenario because of the presence of relatively higher footprints of high molecular weight (HMW) PAHs in the middle and the lower reaches, which was confirmed by Cox hazard proportional model. Moreover, the transgenic zebrafish Tg(cyp1a:gfp) induced by PAHs also expressed stronger fluorescent signals in the middle and lower reaches. Taken together, different approaches were employed to firstly reveal the real status of ecological toxicity of PAHs and explore the underlying mechanisms at the highest impounding level of 175m in the TGRA.
authors.affiliation: Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Yu-Mei
authors.initials: YM
authors.lastname: Tang
authors.affiliation: Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Junaid
authors.affiliation: Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China.
authors.forename: Aping
authors.initials: A
authors.lastname: Niu
authors.affiliation: Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China.
authors.forename: Shun
authors.initials: S
authors.lastname: Deng
authors.affiliation: Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China. Electronic address: peids@cigit.ac.cn.
authors.forename: De-Sheng
authors.initials: DS
authors.lastname: Pei
mesh_terms: D002681:China; D004784:Environmental Monitoring; D019015:Geologic Sediments; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D018570:Risk Assessment; D045483:Rivers; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical
keywords: Gene expression; Polycyclic aromatic hydrocarbons (PAHs); TGRA; Tg(cyp1a:gfp) zebrafish; Toxicology