Heavy metal contamination of surficial tidal flat sediments in the Yangtze River Estuary, China.

摘要

The purpose of this research was to determine controls of onshore-offshore variations in heavy metal concentrations within surficial sediments of the Yangtze Estuary tidal flats. In order to accomplish this, two sampling transects were established along the eastern shores of Chongming and Hengsha Islands. Results showed that, while raw metals increased with distance seaward, no significant relations exist between normalized metals and distance within transects and that proximity to the turbidity maximum is not a significant control on metal distributions.;Statistical analysis using Spearman's Rank, Mann-Whitney and PCA all established grain-size as the primary control on the spatial distribution of metals within the Estuary. Furthermore, metal concentrations are consistent with Grade A soils and represent a relatively pristine environment. This lack of evidence in support of sediment contamination from domestic and industrial discharge is likely the result of dilution by high fluvial sediment loads.