Persistent toxic substances in agricultural soils of Lishui County, Jiangsu Province, China.

The contamination status and distribution of PTS, including HCHs, DDTs, PCBs, and PAHs, were studied in the agricultural soil of Lishui County, one of China's nationally designated eco-demonstration region. The PTS was analyzed by GC, GC/MS, and HPLC coupled with microwave extraction. The concentrations of the sum of HCHs, DDTs, and PCBs ranged from <0.1 ng g(-1) to 133 ng g(-1), 93.8 ng g(-1), and 81.0 ng g(-1) (dry wieght), respectively; while the contents of the sum of PAHs ranged from 3.26 ng g(-1) to 91.0 ng g(-1) (dry wieght). The soil investigation revealed that there were no recent HCHs and DDTs pollution; none of the soil PCBs concentrations suggested a serious biological threat in the investigated area; the extent of pollution of PAHs was low compared to other investigations. In summary, levels of PTS contamination in the soil of the Lishui County were relatively low, but caution should be taken in industrial zone.