Pollution levels of banned and non-banned pesticides in surface sediments from the East China Sea.

In this paper, 65 pesticides, including banned ones of DDTs, etc. and non-banned ones of iprobenfos, etc. have been detected in 31 surface sediment samples from the East China Sea (ECS) to study their pollution levels, sources, and risks. There were 8 banned pesticides (90-97%) and 10 non-banned pesticides (26-100%) presenting higher detection frequencies. For the 18 pesticides detected, their total contents ranged from 183.49 to 1363.77 ng/g dry weight (d.w.) and presented a seaward decreasing trend. Higher contents of banned pesticides were concentrated in the inner shelf close to Zhoushan Island. Iprobenfos, one of non-banned pesticides, showed the highest detection frequency (100%) and pollution level (79.14-1169.18 ng/g d.w.), indicating its continuous input in recent years. The pesticides concentrations in water calculated by the equilibrium partitioning (EqP) method were lower than the toxicological endpoint for tested aquatic invertebrates and fish, indicating ecological risks of these pesticides were at low levels.