Distribution and mass inventories of polycyclic aromatic hydrocarbons and organochlorine pesticides in sediments of the Pearl River Estuary and the northern South China Sea.
Surface sediment (0-5 cm) samples were collected from the Pearl River Estuary (PRE) and the adjacent northern South China Sea (SCS) in July 2002 and analyzed for 25 polycyclic aromatic hydrocarbons (PAHs) and 8 organochlorine pesticides (OCPs) including dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), and heptachlor. The total PAHs and OCPs concentrations were 138-1100 and 0.18-3.57 ng/g dry weight, respectively. Compositional pattern analysis suggested that PAHs in the PRE were derived from both pyrogenic and petrogenic sources, whereas most PAHs in the northern SCS were pyrogenically originated. The concentrations of both PAHs and OCPs were higher in the PRE than in the northern SCS, and a decreasing trend with the distance from the estuary to the open sea was observed. In addition, perylene was a predominant component in all samples and clustered with PAH compounds with high log Kow values (from phenanthrene). These findings indicated that river outflows were the major source of contamination in the offshore sediments. A preliminary assessment suggested that atmospheric deposition contributed only a minor portion of PAHs or OCPs in the sediments of the northern SCS. The sediment (0-5 cm) mass inventories were 126 and 423 metric tons for PAHs and were 0.4 and 1.4 metric tons for OCPs in the PRE and the northern SCS, respectively. Clearly, contaminated sediments of the northern SCS may be a potential source of PAHs and OCPs to the global oceans.
Chen
She-Jun
SJ
State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Science, Guangzhou 510640, China.
Luo
Xiao-Jun
XJ
Mai
Bi-xian
BX
Sheng
Guo-Ying
GY
Fu
Jia-Mo
JM
Zeng
Eddy Y
EY
D000393:Air Pollutants; D002681:China; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry; D006843:Hydrocarbons, Chlorinated / Q000032:analysis*; D017745:Incineration; D010575:Pesticides / Q000032:analysis*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D012623:Seawater / Q000737:chemistry; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis*
D000393:Air Pollutants; D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical