Reassessment of heavy metal pollution in riverine sediments of Hainan Island, China: sources and risks.

Riverine sediment samples from Hainan Island were collected in 2013 to assess the heavy metal pollution levels, sources, and associated environmental risks. The concentrations of Cr, Ni, Cu, Zn, As, Cd, and Pb measured in this study were 31.6-128.8 mg kg-1, 9.8-70.3 mg kg-1, 18.3-210.8 mg kg-1, 49.3-314.2 mg kg-1, 2.3-69.2 mg kg-1, 0.3-1.5 mg kg-1, and 23.2-113.4 mg kg-1, respectively. The results indicate that the sediment quality of Hainan Island has been obviously influenced by heavy metals. Based on the effect range classification, the heavy metals in Hainan riverine sediments likely have adverse biological effects on local ecosystems. The enrichment factor (EF), geoaccumulation index (Igeo), contamination factor (CF), and pollution load index (PLI) clearly reflect significant metal pollution in this region. The most significant pollution was observed in the northern and eastern parts of Hainan Island. The pollution levels of the three largest rivers on Hainan Island (i.e., the Nandu, Changhua, and Wanquan Rivers) were notably high. The results of this research will be useful in assessing and managing environmental pollution in this region. In the future, greater attention and further investigation should focus on the metal sources linked to further economic development on Hainan Island.

Environmental background values of trace elements in sediments from the Jiaozhou Bay catchment, Qingdao, China.

Selected trace elements (As, Cr, Zn, Cu, Cd, Co, Pb and Ni) in 76 surface sediment samples collected from the rivers and the intertidal zone of Jiaozhou Bay (JZB) were evaluated to assess their environmental background values in the JZB catchment. Overall, the sediment quality in the area meets the China Marine Sediment Quality criteria. The background values (ranges) of the elements As, Cr, Zn, Cu, Cd, Co, Pb and Ni were, respectively, 8.28 (4.10-12.46), 67.96 (38.40-97.52), 56.80 (16.42-196.51), 19.13 (5.71-64.06), 0.10 (0.02-0.42), 6.51 (2.08-20.40), 17.97 (12.26-55.84) and 20.69 (10.43-30.95)mg/kg. The background values of most of the trace elements were lower than those in Chinese soil, the upper continental crust, global shales and global preindustrial sediments. The results may assist in defining future coastal and river management measures specifically targeted at monitoring trace element contamination in the JZB catchment.