Impacts of human activities and sampling strategies on soil heavy metal distribution in a rapidly developing region of China.

The impacts of industrial and agricultural activities on soil Cd, Hg, Pb, and Cu in Zhangjiagang City, a rapidly developing region in China, were evaluated using two sampling strategies. The soil Cu, Cd, and Pb concentrations near industrial locations were greater than those measured away from industrial locations. The converse was true for Hg. The top enrichment factor (TEF) values, calculated as the ratio of metal concentrations between the topsoil and subsoil, were greater near industrial location than away from industrial locations and were further related to the industry type. Thus, the TEF is an effective index to distinguish sources of toxic elements not only between anthropogenic and geogenic but also among different industry types. Target soil sampling near industrial locations resulted in a greater estimation in high levels of soil heavy metals. This study revealed that the soil heavy metal contamination was primarily limited to local areas near industrial locations, despite rapid development over the last 20 years. The prevention and remediation of the soil heavy metal pollution should focus on these high-risk areas in the future.

Distribution, sources and potential risk of HCH and DDT in soils from a typical alluvial plain of the Yangtze River Delta region, China.

Spatial distribution, sources and potential health risks of organochlorine pesticides (OCPs), including hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT), in surface soils (n = 544) collected from a typical alluvial plain of the Yangtze River Delta region, China, were elucidated. Concentrations of ΣHCH and ΣDDT in soils ranged from less than the limit of detection (

Organochlorine pesticides in soils from a typical alluvial plain of the Yangtze River Delta region, China.

Residues of organochlorine pesticides (OCPs), dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH), their risks and affecting factors in 544 representative soils collected from a typical alluvial plain of the Yangtze River Delta region, China, were investigated. Mean concentrations of ΣDDT and ΣHCH in soils were 88.8 and 99 ng/g, respectively. Historical application of DDT and HCH were the major sources of their residues in soils. Concentrations of DDT in soils had relative greater levels of contamination, while concentrations of HCH were almost at safe levels. Residues of DDT and HCH in soils were affected by soil types as well as soil textures.