Detection Of Typical Organic Pollutants In Changjiang Estuary And Preliminary Study On Their Biological Effects

Typical persistent organic pollutants in water, including low molecular weight polycyclic aromatic hydrocarbons (LMW PAHs) and organchlorinate pesticides (OCPs), were detected in Changjiang Estuary, and their biological effects were investigated with zebrafish (Brachydamio rerio) as experimental object, such as phenanthrene (LMW PAH) and lindane (OCP).Water samples from Changjiang Estuary were collected from November, 2005 to July, 2006. The analytical results of water samples indicated that LMW PAHs and OCPs were detected in water samples at each sampling locations with different concentrations. The concentration of LMW PAHs (sum of concentrations of naphthalene, fluorine, phenanthrene and anthracene) was 53.3-417.6ng·L^-1 in water. Concentrations of BHCs and DDTs in water were N.D.-101.97ng·L^-1 and N.D.-85.40ng·L^-1 respectively; and those in surface sediments were 0.07-0.95 ng·g^-1 and 0.01-0.07 ng·g^-1. Sources of LMW PAHs in water from Changjiang Estuary were preliminarily discussed by analyzing a characteristic index (ratio of anthracene to phenanthrene plus anthracene), which ranged from 0.00 to 0.84. Results of the characteristic index showed that PAHs were from incomplete combustion of fuels and oil spill, and PAHs pollution at the location of Xuliujing and Shidongkou was mainly from incomplete combustion. As for source of OCPs, there were different sources in water and sediment. OCPs in water were from the OCPs in surface sediment, and those in surface sediment were from input of pesticides in agriculture produce many years ago. Seasonal variation of LMW PAHs and OCPs indicated that the concentration of pollutants in flood season were higher than that in normal and dry season. The seasonal variation at the locations near Nantong was more obviously than that near sea, which indicated the inflow of Changjiang River was the primary pollution source at the estuary. And OCPs' distribution was related to the distribution of farmland. In other words, the concentration of OCPs was a higher contamination level at the locations with a large number of farmland.