The changes in trace metal contamination over the last decade in surface sediments of the Pearl River Estuary, South China

• Published in: The Science of the total environment 2012-11, Vol.439, p.141-149
• Main Authors: Chen, Baowei, Liang, Ximei, Xu, Weihai, Huang, Xiaoping, Li, Xiangdong
• Format: Article
• Language: English
• Subjects: Applied sciences; Brackish; China; Copper; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental Monitoring; Estuaries; Estuarine environments; Exact sciences and technology; Freshwater; Geologic Sediments - analysis; Geologic Sediments - chemistry; Lead (metal); Metals, Heavy - analysis; Nickel; Particle Size; Pearl River Estuary; Pollution; Pollution sources. Measurement results; Pollution, environment geology; Rivers; Sedimentation; Sediments; Soil and sediments pollution; Spatial distribution; Statistical analysis; Time Factors; Trace Elements - analysis; Trace metals; Water Pollutants, Chemical - analysis
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2012.09.025

Surface sediments can provide useful information on the recent pollution status of an estuary. One recent field survey was carried out in the Pearl River Estuary (PRE), South China in 2011. The comparisons with previous surveys demonstrated that the concentrations of Ni and Pb in the PRE declined over the last decade, but the concentration of Cu increased in the same time frame. The significant decreases in the concentrations of Ni and Pb were probably due to a reduction of anthropogenic inputs, such as industrial wastewater, into the PRE environment, and the ban imposed on leaded gasoline. Statistical analyses have consistently demonstrated that the process of the sedimentation of fine particles was the dominant factor in controlling the transport and distribution of trace metals in the PRE. The riverine trace metals generally displayed a pattern of diffusion from the northwest to the southeast in the estuary. However, the riparian industrial activities at the east bank of the inner PRE caused significant metal contamination in sediments. In general, effective pollution control measures in the PRD region have decreased the levels of some trace metals in the entire PRE over the last decade with the exception of Cu. ► Ni and Pb in sediment of the Pearl River Estuary declined over the last decade. ► Cu increased significantly in the same time. ► Levels and spatial distribution of metals reflect the shift of pollutant inputs. ► The east bank of the inner PRE had significant metal contamination in recent years.