Dr. Ying Li, assistant professor in the department of environmental health for the East Tennessee State University College of Public Health, has co-authored an article on water quality in the Pearl River of China. The article, “Temporal variation and regional transfer of heavy metals in the Pearl (Zhujiang) River, China” was published in the January 2016 edition of Environmental Science and Pollution Research.
[Photo: Dr. Ying Li]
The Pearl River has a length of about 1,243 miles and is the third longest river in China. The region where the Pearl River flows into the South China Sea has seen rapid urban expansion over the past few decades – transforming what was mostly agricultural land into an area of significant manufacturing. Heavy metals are highly persistent in water and have a particular significance in ecotoxicology. Heavy metals loading from the Pearl River are likely to cause significant impacts on the environment in the South China Sea and the West Pacific.
In this study, using monthly monitoring data from a water quality monitoring campaign during 2006–2012, the temporal variation and spatial transfer of six heavy metals (lead, copper, cadmium, zinc, arsenic, and mercury) in the Pearl River were analyzed, and the heavy metal fluxes into the sea were calculated. The metal fluxes showed a seasonal variation with the maximum fluxes occurring from June to July. There is a close association between metal fluxes and runoff.
The analysis of the heavy metal transfer from the upstream to the downstream revealed that the transfer from the upstream accounted for a major portion of the heavy metals in the Pearl River Delta. Therefore, earlier industry relocation efforts in the Pearl River watershed may have limited effect on the water quality improvement in surrounding areas. It is suggested that watershed-based pollution control measures focusing on wastewater discharge in both upstream and downstream areas should be developed and implemented in the future.