title: HCHs and DDTs in Yellow River of Henan section-a typical agricultural area in China: levels, distributions and risks.
abstract: The levels, potential sources and ecological risks of hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) in Yellow River of Henan section, a typical agricultural area in China, were investigated. Surface water samples and suspended particulate matters (SPMs) were collected from 23 sites during two seasons. In wet season, the residues of ∑HCHs (α-HCH, β-HCH, γ-HCH and δ-HCH) and ∑DDTs (p,p'-DDT, o,p'-DDT, p,p'-DDE, p,p'-DDD) ranged from 41.7 to 290 and 4.42 to 269 ng/L in surface water, while those varied from 0.86 to 157 and 1.79 to 96.1 ng/g dw in SPM, respectively. Moreover, in surface water, the levels of HCHs and DDTs in wet season were much higher than those in dry season. The reverse was true for residues of HCHs and DDTs in SPM. Compared with the large rivers in other regions, the levels of HCHs and DDTs in the studied area ranked at high levels and the residual concentrations might cause adverse biological risk, especially for ∑HCHs during wet season. Distributions of HCHs and DDTs delineated that the input of tributaries made a significant effect on the residue of HCHs and DDTs in the mainstream. ∑HCHs in surface water were consist of 26.7 % α-HCH, 30.0 % β-HCH, 37.9 % γ-HCH and 5.45 % δ-HCH and those in SPM contained 5.16 % α-HCH, 22.1 % β-HCH, 60.5 % γ-HCH and 12.2 % δ-HCH on average. Combined with ratios of α-HCH/γ-HCH in surface water (0.70) and in SPM (0.09), the results strongly indicated that lindane was recently used or discharged in the studied area. The mean percentage of DDTs' isomers were 28.7 % p,p'-DDT, 29.8 % o,p'-DDT, 28.1 % p,p'-DDE and 13.4 % p,p'-DDD in surface water, while those were 12.5 % p,p'-DDT, 31.8 % o,p'-DDT, 30.5 % p,p'-DDE and 25.1 % p,p'-DDD in SPM. The ratios of (DDE + DDD)/∑DDTs and o,p'-DDT/p,p'-DDT revealed that the DDTs in the studied area mainly derived from long-term weathering of technical DDTs residue and the input of dicofol.
authors.affiliation: School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, 453007, Henan, People's Republic of China. fengjinglan@163.com.
authors.forename: Jinglan
authors.initials: J
authors.lastname: Feng
authors.affiliation: School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, 453007, Henan, People's Republic of China.
authors.forename: Pengtuan
authors.initials: P
authors.lastname: Hu
authors.affiliation: School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, 453007, Henan, People's Republic of China.
authors.forename: Fei
authors.initials: F
authors.lastname: Zhang
authors.affiliation: School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, 453007, Henan, People's Republic of China. sunjhhj@163.com.
authors.forename: Jianhui
authors.initials: J
authors.lastname: Sun
mesh_terms: D000383:Agriculture; D002681:China; D003634:DDT / Q000032:analysis*; D004010:Dicofol; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000032:analysis; D001556:Hexachlorocyclohexane / Q000032:analysis*; D007306:Insecticides; D010573:Pesticide Residues; D045483:Rivers; D012621:Seasons; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D007306:Insecticides; D010573:Pesticide Residues; D014874:Water Pollutants, Chemical; D001556:Hexachlorocyclohexane; D003634:DDT; D004010:Dicofol
keywords: DDTs; Ecological risk; HCHs; SPM; Surface water; Yellow River of Henan section