Investigation and evaluation of contamination in dredged reclaimed land in China

Large-scale reclamation projects have been developing rapidly in China’s coastal lands since 2000. In this study, the scale and pollutant contents of reclaimed lands were collected from published data and field surveys. Over 80% of the gross area was formed using hydraulic reclaimed technology. The pollution index, geoaccumulation index, and Nemerow integrated pollution index (NIPI) of 13 pollutant types were calculated based on the collected data. The potential pollution within major newly reclaimed lands was evaluated with valid pollutant data from sediments of the neighboring water. All reclaimed lands larger than 30?km² were slightly to seriously polluted with Cu, Pb, Zn, Cd, Cr, Hg, As, and Ni according to NIPI. The reclaimed fields in Hengsha Island, Binhai Tower, and Lingang New City of Shanghai were selected as verification sites for the pollution evaluations. The Cu, Pb, Zn, Cd, Cr, As, and Ni concentrations in dredged soils determined through inductively coupled plasma mass spectrometry showed a generally good soil quality within the typical reclaimed fields. Principal component and hierarchical clustering analyses indicated that the relatively high As content in the reclaimed soils was due to the internal pollutants of dredging fills and originated from anthropogenic sources.