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.