Deposition record of organochlorine pesticides in a sedimentary core in Macao Estuary, Pearl River, China

This paper present the concentration profiles of the organochlorine pestici des in a sediment core from Macao Estuary, Pearl River, China. Concentratio ns of organochlorine pesticides were determined by GC/ ECD and GC/MSD, and the core was dated by Pb-210 method in a content-activity model. The result s show that the concentrations of HCHs and DDTs in the core ranged from 0.4 8-26.3 and 1.92-39.1 mug/kg, respectively. Concentration of DDTs in the res earch area was above the Effects Range-Low value (ERL) for Marine and Estua rine sediments. The vertical distributing of organochlorine pesticides in t he core was influenced by the water flux of Pearl River and the pollutants are mainly attributed to the runoff of local agricultural soils.