Organochlorine contaminants in human adipose tissues from China: mass balance approach for estimating historical Chinese exposure to DDTs.

Concentrations of persistent organochlorines (OCs), such as DDTs, hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs), and chlordane compounds (CHLs) were determined in 34 human adipose tissues collected from Guizhou Province, southern China, during 2002. DDT was the predominant contaminant among OCs analyzed; concentrations ranged from 420 to 20 000 ng/g on a lipid wt basis (average +/- sd: 5700 +/- 4100 ng/g). Concentrations of DDTs and the ratio of p,p'-DDT/ sigmaDDT in humans in China were significantly higher than those reported for developed countries. DDT levels in humans in Guizhou Province were comparable to those from Shanghai City, implying the presence of significant sources of DDTs in inland and coastal areas in China. Age-dependent accumulation of HCH concentration was found in this study, possibly because of the considerable reduction in average dairy intake (ADI) of HCHs by Chinese during the recent two decades. On the basis of the information of the ADI rates, half-lives, and body burdens of DDTs, the magnitude of historical DDT exposures by Chinese was estimated. This suggested that approximately 80% of DDTs deposited in Chinese adipose tissues was accumulated before the 1990s. The monitoring of OC levels and epidemiological studies are needed in China to understand the status of contamination and the risks to humans.

Concentrations and compositions of organochlorine contaminants in sediments, soils, crustaceans, fishes and birds collected from Lake Tai, Hangzhou Bay and Shanghai city region, China.

Contamination by persistent organochlorines (OCs), such as DDTs, hexachlorocyclohexane isomers (HCHs), chlordane compounds (CHLs), hexachlorobenzene (HCB) and polychlorinated biphenyls (PCBs) were examined in sediments, soils, fishes, crustaceans, birds, and aquaculture feed from Lake Tai, Hangzhou Bay, and in the vicinity of Shanghai city in China during 2000 and 2001. OCs were detected in all samples analyzed, and DDT and its metabolites were the predominant contaminants in most sediments, soils and biota. Concentrations of p,p'-DDT and ratio of p,p'-DDT to SigmaDDTs were significantly higher in marine fishes than those in freshwater fishes. While the use of DDTs has been officially banned in China since 1983, these results indicate a recent input of technical DDTs into the marine environment around Hangzhou Bay. Comparison of organochlorine concentrations in fishes collected from Lake Tai and Hangzhou Bay suggests the presence of local sources of HCHs, chlordanes and PCBs at Lake Tai. Higher proportions of penta- and hexa-PCB congeners in fishes at Lake Tai may suggest the use of highly chlorinated PCB product, such as PCB(5), around this lake. To our knowledge, this is a first comprehensive study to examine the present status of organochlorine contamination in various environmental media, such as sediments, soils and wildlife, in China.