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Organochlorine pesticides were used extensively in the Yangtze River Delta, China. However, knowledge about their residual levels and environmental fates in soils of this area is limited. This paper presents the residue isomers and spatial pattern of dichlorodiphenyltrichloroethane (DDT) in soils across 17 main cities in the Yangtze River Delta. Forty-three soil surface (0-15 cm) samples were collected during a field campaign conducted in October 2003 in the Delta. Six DDT isomers (1-[2-chlorophenyl]- 1-[4-chlorophenyl]-2,2-dichloroethane [o,p'-DDD], 1-[2-chlorophenyl]-1-[4-chlorophenyl]-2,2-dichloroethylene [o,p-'DDE], 1,1,1- trichloro-2-[p-chlorophenyl]-2-[o-chlorophenyl]ethane [o,p'-DDT], p,p'-dichlorodiphenyldichloroethane [p,p'-DDD], p,p'-dichlorodiphenyldichloroethylene [p,p'-DDE], p,p'-dichlorodiphenyltrichloroethane [p,p'-DDT]) were detected using gas chromatography. The results show that p,p'-DDE was the dominant isomer in the soil samples. The levels of DDT are generally low in soils of this area and are comparable to DDT levels in other cities in China and in soils from developed countries such as the United States and Germany. The isomer ratios of o,p'-DDT to p,p'-DDT and DDT to (DDD + DDE) were employed to identify the source of DDT. The computed ratios implied that the source of DDT might be related to the application of dicofol, an acaricide manufactured from technical DDTs and mainly used on cotton fields to treat mites. [ABSTRACT FROM AUTHOR]

Based on the datum line survey in August 2005 and June and August of 2006, water samples were collected in 30 sites to examine the trend of spatial distribution and temporal change of dissolved metals in seawater of Jinzhou Bay, China. The results showed that copper (Cu), lead (Pb), zinc (Zn), and cadmium (Cd) concentrations ranged from 1.71 to 3.49, 0.38 to 1.19, 21.77 to 39.16, and 1.65 to 2.01 μg/L, respectively. Except for Zn, the dissolved metal concentrations in August 2006 were much higher than those in August 2005. The concentrations in June 2006 were also higher than those in August 2006. The highest concentrations of dissolved metal were determined in samples collected from southwest of the Bay near sewage outfalls of Huludao Zinc Plant and Bohai Shipyard and the mouths of Wuli and Cishan rivers. The concentrations of dissolved metals increased inshore as compared with offshore. The principal contaminated factors were Zn, Cd, and Pb in the Jinzhou Bay. Significant positive correlations existed between the concentrations of Cu and Cd (0.016), as well as Zn and Cd (0.000). The overall results revealed that the Bohai Sea was one of the most contaminated areas by dissolved metals compared to other coastal areas in China. [ABSTRACT FROM AUTHOR]