| Due to their carcinogenicity,mutagenicity and teratogenicity,as well as persistence and bioaccumulation,the persistent organic pollutants(POPs) have gained utmost attention as contaminants of threat to human health.In this study,using isotope dilution mass spectrometry with high resolution gas chromatography and high resolution mass spectra(HRGC/HRMS) to study organochlorine pesticides(OCPs),7 indicator polychlorinated biphenyls(PCBs),polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs),co-planar polychlorinated biphenyls(co-PCBs),and polychlorinated naphthalenes(PCNs) in sediments,soils,fish,duck,yak,rivers,snow and ice collected from coastal waters of Qingdao,Chongming Wetland in Yangtze River Estuary of the East China Sea and Wolong high mountain area.The aiming was to fulfill the POPs international joint pledge for our country,provide the scientific basis and the effective data support for our country organic chlorine pollutant model establishment.It may be background basis for control strategy of the organic chlorine pollutant contamination,for the elimination pollution measure and for the correlation laws.The contamination levels,possible sources,deposition fluxes,toxic equivalent quantity fluxes,temporal and spatial distribution characteristics were studied in sediment cores collected from Qingdao and Chongming Island.The gradient distribution,transportation and possible regional sources of POPs in in soils,rivers, snow and ice with altitude from Woolong high mountain area were preliminarily discussed.Based on the toxic equivalent quantity(TEQ) and assumption,potential exposure risk to consumers with edible fish,duck and yak were also evaluated.The main conclusions were summarized as follows:Sediment cores taken from Dongtan Wetland in Yangtze River Estuary of the East China Sea and a tidal flat in the north Chongming Island were measured.The vertical distribution characteristics of OCPs concentration with the depth and possible influence by climate changes were preliminarily discussed.HCHs,DDTs,and HCB were found in all sediment layers.The total OCPs concentrations ranged from 0.94 to 4.83 ng g-1 dw and from 3.04 to7.70 ng g-1 dw,with the average of 2.68 ng g-1 dw and 4.85 ng g-1 dw for Dongtan Wetland and northern Chongming tidal flat,respectively, showing a low pollution level.The total concentrations of the 7 indicator PCB isomers (Σ7PCBs) in each layers of the core were in the range of 0.14～0.40 ng g-1 dw,with an average of 0.23 ng g-1 dw.The vertical distributions of HCHs,HCB,and PCB isomers in the cores showed significant periodic variations while the vertical distributions of DDTs showing less periodicity were affected by the redox conditions down the core. Using time-series analysis,the long-term trends and frequency spectrum of OCPs and PCBs in the sediment core of Dongtan wetland during the last 60 years were discussed. The long-term trends of OCPs and PCBs in the wetlands showed that these chemicals began to rise in early 1950s with the maxima during 1960s to 1970s.Some isomers did not show significant declining trends after their productions being banned.The time-series generally show an 8-year periodicity,suggesting an influence of ENSO.PCDD/Fs,co-PCBs and PCNs were studied in seven surface sediments and two sediment cores near the costal sea of Qingdao.The total concentrations of PCDD/Fs, co-PCBs and PCNs ranged from 4.1～232.4,46.1～1057.7 and 212～1209 pg g-1 dw, with the highest concentrations in station J06 near the Haibo River mouth.Sediments core J37 and J94 showed a low pollution level.The depth profiles of total concentrations PCDD/Fs,co-PCBs,and PCNs were similar in J37 sediment core inside Jiaozhou bay,while difference occurred in J94 sediment core outside Jiaozhou bay due to the effluence of regions and countries surrounding the Yellow Sea.PCDD/F-TEQ in sediments core were lower than that of background values(＜3 pg TEQ g-1 dw) in America and Japan.Co-PCB-TEQ with the highest 0.14 pg TEQ g-1 dw showed lower levels than some reports in China and PCN-TEQ was less than 0.05 pg TEQ g-1 dw. The relative contribution toΣTEQ mainly comes from PCDD/Fs with average 92%. From 1950s to 1980s,the fluxes of 2,3,7,8-PCDD/Fs kept at stable levels,then significantly decreased in the middle of 1980s and exceeded all the levels in the beginning of 1990s.The fluxes of co-PCBs have been decreased steadily since 1950s reflecting the reduction of manufacture and use of PCBs in the world and showing no obvious contamination sources in Qingdao area.The fluxes peak of PCNs occurred in the middle of 1970s(J94) and the end of 1990s(J37).The congener profiles of the pollutant and PCA showed that sewage sludges,atmospheric deposition and the frame of current circulations were the mostly major sources.The congener profiles of dioxins indicated that pentachlorophenol(PCP) and PCP-Na did not play an important role and the indirect effluence of regions and countries surrounding the Yellow Sea may be taken into account.The concentration of PCB 118 was very high in J94 sediment core outside the bay and had different sources with the end of 1990s,showing the products of Kanechlor 300 and Kanechlor 400 from Japan were one of the possible sources.The congener profiles of PCNs in sediments core indicated that the incineration of municipal solid waste contributed greatly in the early dated periods,while highly input of Halowaxe 1013 and 1014 occurred in the beginning of 1990s.Two food categories(fish and duck) were collected from farms and in Chongming Island,Shanghai and coastal waters of Qingdao,Shandong Peninisular in 2007. Concentrations of PCDD/Fs,co-PCBs and PCNs were measured and potential heath risk for consumption of the fish and duck were preliminarily discussed.The mean concentrations of total 2,3,7,8-PCDD/Fs,co-PCBs and PCNs in fish were 33.2 and 54.5 pg g-1 lipid,3318 and 4041 pg g-1 lipid,225 and 640 pg g-1 lipid,and in duck meat were 12.6,966 640 and 60.6 pg g-1 lipid.The total 2,3,7,8-TCDD equivalents were ranged from 0.39 to 13 pg WHO-TEQ g-1 lipid for the fish and duck meat.The congener profiles of 2,3,7,8-PCDD/Fs and co-PCBs in fish and duck from Chongming Island were similar,suggesting common sources,while the homologue profiles of PCNs for fish from Qingdao and Chongming Island were quite different..Based on the food consumption patterns of the local populations,the average daily intake values of dioxin-like compounds by consumption of the fish and duck were estimated to be less than the tolerable daily intake(TDI) 1～4 pg WHO-TEQ kg-1 body weight,suggesting low health risk for the local people.Concentrations of OCPs and PCBs in soils,rivers,snow and ice with altitude from Wolong high mountain area were analyzed with HRGC-HRMS.The total average concentrations of HCHs and DDTs showed higher levels in winter(0.52 and 0.56 ng g-1 dw,respectively) soils than that in summer(0.29 and 0.32 ng g-1 dw,respectively) at stations above 2800 m,which suggesting the inverse correlations with altitudes. Similar concentrations levels of PCBs occurred in both summer and winter soil samples and also showed the inverse relationship with altitudes.Concentrations of HCHs and DDTs in rivers,snow and ice were under the required limitation of national standard and positive correlations with altitudes have been identified,showing the cold condensation roles.The effluence of long-range transportation and deposition of OCPs and PCBs should not be ignored.The total PCDD/Fs concentrations in the surface soils ranged between 2.48～4.30 pg g-1 dw,averaging 3.50 pg g-1 dw with the highest concentration at 3927 m altitude.The total co-PCB concentrations averaged 9.14 pg g dw with the highest concentration at 4487 m.The total 2,3,7,8-PCDD/Fs and total co-PCB concentrations showed positive co-relationships with altitude.The congener profiles of both 2,3,7,8-PCDD/Fs and total co-PCB at different altitudes showed similar patterns,suggesting common sources.The total PCNs,averaging 21.4 pg g-1 dw,showed a negative co-relationship with altitude,with the highest concentration at 3345 m altitude.The total PCNs was dominated by tri-Cl-CNs.Compared with soils in other areas in China and abroad,the contaminations of these compounds are less.The atmospheric transportation is likely the sources for them.TEQ in the soils were in the range of 0.29～0.43 pg g-1 dw.The total concentrations of PCDD/Fs in the yak meat and tissue were 27.5 and 23.6 pg g-1 lipid,respectively,while the total TEQ in the yak meat and tissue were 4.04 and 4.06 pg TEQ g-1 lipid,respectively,which is unlikely to cause adverse health effect to the yak meat consuming people.The cold-trapping effect of these compounds found in Wolong high altitude area soils suggested that the area with both limited space scale and climate scale could provide necessary conditions for observation of fractionation of semi-volatile organic pollutants.
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