title: Organochlorine pesticides (OCPs) in wetland soils under different land uses along a 100-year chronosequence of reclamation in a Chinese estuary.
abstract: Soil profiles were collected at a depth of 30 cm in ditch wetlands (DWs), riverine wetlands (RiWs) and reclaimed wetlands (ReWs) along a 100-year chronosequence of reclamation in the Pearl River Delta. In total, 16 OCPs were measured to investigate the effects of wetland reclamation and reclamation history on OCP levels. Our results showed that average ∑DDTs, HCB, MXC, and ∑OCPs were higher in surface soils of DWs compared to RiWs and ReWs. Both D30 and D20 soils contained the highest ∑OCP levels, followed by D40 and D100 soils; lower ∑OCP levels occurred in D10 soils. Higher ∑OCP levels were observed in the younger RiWs than in the older ones, and surface soils exhibited higher ∑OCP concentrations in the older ReWs compared with younger ReWs. The predominant percentages of γ-HCH in ∑HCHs (>42%) and aldrin in ∑DRINs (>46%) in most samples reflected the recent use of lindane and aldrin. The presence of dominant DDT isomers (p,p'-DDE and p,p'-DDD) indicated the historical input of DDT and significant aerobic degradation of the compound. Generally, DW soils had a higher ecotoxicological risk of OCPs than RiW and ReW soils, and the top 30 cm soils had higher ecotoxicological risks of HCHs than of DDTs.
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, P.R. China.
authors.forename: Junhong
authors.initials: J
authors.lastname: Bai
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, P.R. China.
authors.forename: Qiongqiong
authors.initials: Q
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, P.R. China.
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, P.R. China.
authors.forename: Junjing
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, P.R. China.
authors.forename: Zhaoqin
authors.initials: Z
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, P.R. China.
authors.forename: Guangliang
authors.initials: G
authors.lastname: Zhang
mesh_terms: D002681:China; D004784:Environmental Monitoring; D006801:Humans; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry / Q000633:toxicity*; D010575:Pesticides / Q000737:chemistry / Q000633:toxicity*; D045483:Rivers / Q000737:chemistry; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity; D053833:Wetlands
chemical_list: D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; D012987:Soil; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical