Heavy metals and Pb isotopes in a marine sediment core record environmental changes and anthropogenic activities in the Pearl River Delta over a century.

Heavy metal accumulation in marine sediments is associated with changes in both the natural environment and human activities. This study used heavy metals and Pb isotopes in a precisely dated (by Pb and Cs) sediment core from the Macao Sea to reconstruct the historical changes in anthropogenic activities and the environment in the western Pearl River Estuary (PRE). The distribution of heavy metals in the sediment core could be divided into four stages (pre-1950, 1950-1976, 1976-2000, and post-2000), which corresponded to the changes in anthropogenic activities and environment of the Pearl River Delta during the past 100 years.

Distribution, sources and ecological risks of organochlorine compounds (DDTs, HCHs and PCBs) in surface sediments from the Pearl River Estuary, China.

The Pearl River Estuary is an important sink of organochlorine compounds (OCs), and OC pollution levels in surface sediments remain largely unknown at present. We collected and analysed residual DDTs, HCHs and PCBs of 45 surface sediments from the Pearl River Estuary in 2017. The values of DDTs (1.

Heavy Metals in Agricultural Soils of the Lihe River Watershed, East China: Spatial Distribution, Ecological Risk, and Pollution Source.

Concentrations of cadmium, chromium, copper, nickel, lead, and zinc in agricultural soils at 32 sites in the Lihe River Watershed of the Taihu region, East China, and their potential ecological risks and possible sources were investigated. Enrichment factor analysis demonstrated enrichment in the order Cd > Pb > Zn > Cu > Ni > Cr. The potential ecological risk index and risk assessment code analyses indicated that, of the metals studied, Cd posed the most significant ecological risk in the study area.