Study On Residues Of Organochlorine Pesticides From Aerosol In Qingdao Region

Samples were collected in Qingdao University from summer 2003 to summer 2004 to determine the seasonal variations of chlorinated pesticides (e.g., HCHs, chlordanes, and DDTs) and in Jiaonan, Jimo, Cangkou in summer 2004 to estimate the spatial distribution together with the Qingdao University samples. The residual amount of OCPs were determined with gas chromatography-electron capture detector(GC-ECD). Results showed that the OCPs compounds in the sampling areas were mainly DDTs, HCHs and aldrin. DDTs in all samples comprised 24.7% to 93.0% of the total amount of OCPs, particulate DDTs in air ranged from 1.58 to 108.16 pg/m3. p,p'-DDE and p,p'-DDT were found in all samples. The contents of DDTs tended to be in the order of Cangkou > Jimo >Jiaonan >Qingdao University. Levels of DDTs in the spring were similar to those in the summer whereas levels od DDTs were similar as other couple of in the autumn and in the winter, but the concentrations were higher in the winter than in the summer. The low ratio(<1)of m(DDD+DDE)/m(DDT) possibly indicated that there were still flesh DDT emitted into the atmosphere except in the winter. Concentrations of HCHs ranged from 0.75 to 66.92 pg/m3. γ-HCH was not found in all samples. The distributions of HCHs in the air revealed no clear spatial diference. Elevated levels of HCHs in the air occurred in the winter and revealed clear seasonal trend. The seasonal trend and the spatial distributions of aldrin were similar to those of HCHs. Concentrations of p,p'-DDE in north China (Huhehaote urban, Beijing and Tianjin) air were 14-62 times higher than in the Qingdao region. This suggests that transport from north China is a continuing source of DDTs to the Qingdao region in the winter.