Distribution and sources of organochlorine pesticides in sediments of the Xiangjiang River, south-central China

Environ Monit Assess. 2013 Nov;185(11):8861-71. doi: 10.1007/s10661-013-3218-z. Epub 2013 May 1.

Abstract

The Xiangjiang River (XR), the second largest tributary of the Yangtze River, is mainly located in Hunan province in south-central China. Nineteen surface sediment samples (the top 3-cm layer) collected from XR were analyzed to determine the concentrations, distribution, sources, and ecological risk of organochlorine pesticides (OCPs). The concentrations of OCPs were 3.0-29.8 ng/g (dry weight) with a mean of 12.6 ± 7.7 ng/g. The widely detected compounds included HCHs, DDTs, HCB, and dieldrin. Overall, the dominant OCPs in the sediments were mainly composed of residual and degradation products, e.g., β-HCH with a mean of 42.2% in HCHs and p,p'-DDE with a mean of 43.5% in DDTs, implying that OCPs in the sediments had suffered from long-term aging without fresh inputs in XR. However, there was a high proportion of p,p'-DDT to DDTs in three sites, suggesting that there was use of technical DDT from their surrounding areas at present. The ratios of α-HCH/γ-HCH and p,p'-DDD + p,p'-DDE/DDTs increase from the upper reaches to the lower reaches of XR, suggesting sediments enriched with α-HCH and metabolites DDD and DDE during sediment transport process and could be attributed to the transformation of γ-HCH to α-HCH and DDT to DDE or DDD. The assessment of the ecological risk indicates that the OCPs in the sediments of XR have a moderate adverse biological effect on organisms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • China
  • Environmental Monitoring*
  • Geologic Sediments / chemistry*
  • Hydrocarbons, Chlorinated / analysis*
  • Pesticides / analysis*
  • Rivers / chemistry*
  • Water Pollutants, Chemical / analysis*
  • Water Pollution, Chemical / statistics & numerical data

Substances

  • Hydrocarbons, Chlorinated
  • Pesticides
  • Water Pollutants, Chemical