Residues, Distribution And Chiralsignatures Of Organochlorine Pesticides In Sediments From Arctic Area

organochlorinated pesticides (OCPs) have the characteristics of environmental persistence, semi-volatility, long-distance transport all the world; trend in bio-accumulation in adipose tissue and bio-magnification via food chain. Furthermore, most OCPs have the effects of carcinogenicity, teratogenesis, mutagenesis and endocrine disruption. For adverse effects on humans and other animals, OCPs have now represented a global environmental problem and received great attention around the world.The paper concerned with the Arctic Ocean area. Based on the survey methods of organochlorine pesticides in sediments which accord with international criterion, the concentrations, spatial distribution and pollution source of OCPs in Arctic Ocean area were completely analyzed for the first time, and the composition characteristics of OCPs were discussed. The Enantiomeric fractions (EF) value of chiral OCPs were determined and ecological risks of OCPs in sediments were assessed. All the investigation would gain pollution status of OCPs in the Arctic area, provide a scientific basis to implement the stockholm joint pledge for our country, and have great significance for protecting people's health and safety. The main conclusions in the paper were as follows:(1)The spatial distribution and source of OCPs in surface sediments of Bering Sea, Chukchi Sea and Arctic Ocean were surveyed. Total OCPs concentrations ranged from 1.01ng/g to 2.86 ng/g (mean 1.69 ng/g), 0.99 ng/g to 3.00 ng/g (mean 1.77 ng/g) and 1.01 ng/g to 3.74ng/g (mean 1.92 ng/g) in Bering Sea, Chukchi Sea and Arctic Ocean, respectively. It was found that the values of OCPs tend to increase northward, the highest value of OCPs was found at site 35 (3.74 ng/g) in Arctic Ocean and the lowest value of OCPs occurred at site 19 (0.99 ng/g) in Chukchi Sea. According to the compositional patterns, the residues of HCHs were mainly originated from the historical input of technical HCH. The ratios of (DDE+DDD)/DDT were 0.42 in Bering Sea and Chukchi Sea, related to input of new pollution sources in near term, and the residues of DDTs in Arctic Ocean were originated from the historical input. Ratio of TC/CC was greater than 1.17, implying fresh input pattern.(2)The Enantiomeric fractions value of chiral OCPs were determined. The result showed that the degradation ofα-HCH and o,p'-DDT were enantioselective in most of the samples, However, the degradation of o,p'-DDD, TC and CC were not show enantioselective in all the samples.(3)According to the sediment ecotoxicological assessment criteria, the concentration of p,p'-DDT,p,p'-DDD,p,p'-DDE and∑Chlordane were all below the ERL value, However, for∑DDTs, 23% were between the ERL value and ERM value, indicating pernicious effects would be rarely observed for the compounds. Pollution of OCPs in the study areas are of great concern due to they resist degradation by physical, chemical, and biological pathways; trend in bioaccumulate through the food web; the two poles area was the global destination for persistent organic pollutants.