Occurrence,distribution and possible sources of organochlorine pesticides in peri-urban vegetable soils of Changchun,Northeast China

The characterizations of residue levels and sources of organochlorine pesticides (OCPs) in soils are necessary to evaluate the potential pollution and risks of OCPs to the ecosystems and human health. A total of 51 surface soil samples were collected from peri-urban vegetable fields of Changchun and 13 OCPs were analyzed to learn the composition, spatial distribution and sources. The concentrations were in the ranges of 0.94–107.8 ng g^?1 for DDTs, 0.89–98.3 ng g^?1 for HCHs, 0.22–18.20 ng g^?1 for Chlordanes, nd–4.49 ng g^?1 for aldrin and nd–9.66 ng g^?1 for dieldrin, respectively. The total OCPs concentrations ranged from 2.44 to 177.1 ng g^?1 and the higher residues were mainly distributed in northeast and southwest sites, as well as sites along the Yitong River. According to the concentrations and detection frequencies, DDTs and HCHs were the most dominant compounds. Compositional analysis and principal component analysis suggested that DDT, HCH and chlordane in most soil samples derived from historical application except the slight fresh introduction at some locations. There exist a variety of OCPs residues in peri-urban vegetable soils of Changchun, but it is still safe and suitable for agricultural production for the most part, and some specific locations with high OCPs residues ought to be a cause for concern.