The concentration and distribution of three persistent organic pollutants （hexachlorocyclohexanes （HCHs）, dichlorodiphenyltrichloroethanes （DDTs） and polyehlorinated biphenyls （PCBs）） was assessed in tidal fia...The concentration and distribution of three persistent organic pollutants （hexachlorocyclohexanes （HCHs）, dichlorodiphenyltrichloroethanes （DDTs） and polyehlorinated biphenyls （PCBs）） was assessed in tidal fiat sediments collected from the south bank of Hangzhou Bay, China from 2009 to 2013. Gas chromatography coupled to triple quadrupole mass spectrometry （GC-MS/MS） was used for analysis, based on United States Environmental Protection Agency methods EPAS080A, EPA8081B, and EPA3550B. The results showed that the levels of HCHs, DDTs and PCBs decreased in the order of DDTs 〉 HCHs 〉 PCBs, and their mass fractions ranged from 0.29-32.91, 0.09-13.19 and 0.16-4.10 ktg/kg （dry mass）, respectively. The levels of HCHs, DDTs and PCBs decreased slowly from 2009 to 2013, with considerably greater concentrations in winter than in spring and summer. In this study area, the concentrations of DDTs and HCHs decreased gradually towards the mouth of Hangzhou Bay, while the concentrations of PCBs were related to changes in the local economy. In addition, the sources of HCHs and DDTs were identified as atmospheric precipitation and historical residues, Finally, we predicted that PCBs pollution primarily originated from Aroclor 1254（Lot A4）, which might root in the illegal demolition and stacking of abandoned paint, transformer or electronic equipment in the south bank of Hangzhou Bay.展开更多
A field survey was conducted in a contaminated industrial site of southern Beijing, China to investigate the contents and distribution of the organochlorine pesticides （α-, β-, y-, δ-HCH, p,p＇-DDT, p,p＇-DDE, p,p...A field survey was conducted in a contaminated industrial site of southern Beijing, China to investigate the contents and distribution of the organochlorine pesticides （α-, β-, y-, δ-HCH, p,p＇-DDT, p,p＇-DDE, p,p＇-DDD and o,p＇-DDT） in the profiles of soil, and a health risk assessment was carded out with CalTOX multimedia exposure model. Results showed that mean concentrations of total hexachlorocyclohexane isomers （HCHs） and total dichlorodiphenyltrichloroethane isomers （DDXs） in soils were in the range of 13.20- 148.71 mg/kg, and 3.02-67.43 mg/kg, respectively. Organochlorine pesticides （OCPs） content peaked in the surface and declined in soil profile with depth. The amounts of HCHs in three profiles of soil were larger than DDXs. Composition analysis indicated that there was a trend of degradation of OCPs in the site, but the mean of HCHs and DDXs concentration were over the state warning standard limit （HCHs, 0.50 mg/kg; DDXs, 0.50 mg/kg）. According to current land use development, health risk assessment with CalTOX and Monte Carlo analysis showed that health risks mainly came from two exposure pathways： dermal uptake and inhalation, and the total risk values all exceeded the general acceptable health risk value （10-6）. The sensitivity analysis indicated that five parameters significantly contributed to total risk.展开更多
基金Supported by the Medical and Health Science Research Foundation of Zhejiang Province(No.2011RCA031)the Agriculture and Social Development Funds of Ningbo,China(No.2012C0030)
文摘The concentration and distribution of three persistent organic pollutants （hexachlorocyclohexanes （HCHs）, dichlorodiphenyltrichloroethanes （DDTs） and polyehlorinated biphenyls （PCBs）） was assessed in tidal fiat sediments collected from the south bank of Hangzhou Bay, China from 2009 to 2013. Gas chromatography coupled to triple quadrupole mass spectrometry （GC-MS/MS） was used for analysis, based on United States Environmental Protection Agency methods EPAS080A, EPA8081B, and EPA3550B. The results showed that the levels of HCHs, DDTs and PCBs decreased in the order of DDTs 〉 HCHs 〉 PCBs, and their mass fractions ranged from 0.29-32.91, 0.09-13.19 and 0.16-4.10 ktg/kg （dry mass）, respectively. The levels of HCHs, DDTs and PCBs decreased slowly from 2009 to 2013, with considerably greater concentrations in winter than in spring and summer. In this study area, the concentrations of DDTs and HCHs decreased gradually towards the mouth of Hangzhou Bay, while the concentrations of PCBs were related to changes in the local economy. In addition, the sources of HCHs and DDTs were identified as atmospheric precipitation and historical residues, Finally, we predicted that PCBs pollution primarily originated from Aroclor 1254（Lot A4）, which might root in the illegal demolition and stacking of abandoned paint, transformer or electronic equipment in the south bank of Hangzhou Bay.
基金supported by the National Natural Sci-ence Foundation of China (No. 70433001)the Knowledge Innovation Project of the Chinese Academy of Sciences(No. KZCX2-YW-422, 324)
文摘A field survey was conducted in a contaminated industrial site of southern Beijing, China to investigate the contents and distribution of the organochlorine pesticides （α-, β-, y-, δ-HCH, p,p＇-DDT, p,p＇-DDE, p,p＇-DDD and o,p＇-DDT） in the profiles of soil, and a health risk assessment was carded out with CalTOX multimedia exposure model. Results showed that mean concentrations of total hexachlorocyclohexane isomers （HCHs） and total dichlorodiphenyltrichloroethane isomers （DDXs） in soils were in the range of 13.20- 148.71 mg/kg, and 3.02-67.43 mg/kg, respectively. Organochlorine pesticides （OCPs） content peaked in the surface and declined in soil profile with depth. The amounts of HCHs in three profiles of soil were larger than DDXs. Composition analysis indicated that there was a trend of degradation of OCPs in the site, but the mean of HCHs and DDXs concentration were over the state warning standard limit （HCHs, 0.50 mg/kg; DDXs, 0.50 mg/kg）. According to current land use development, health risk assessment with CalTOX and Monte Carlo analysis showed that health risks mainly came from two exposure pathways： dermal uptake and inhalation, and the total risk values all exceeded the general acceptable health risk value （10-6）. The sensitivity analysis indicated that five parameters significantly contributed to total risk.
