Solution by dilution?—A review on the pollution status of the Yangtze River

Abstract

The Yangtze River has been a source of life and prosperity for the Chinese people for centuries and is a habitat for a remarkable variety of aquatic species. But the river suffers from huge amounts of urban sewage, agricultural effluents, and industrial wastewater as well as ship navigation wastes along its course. With respect to the vast amounts of water and sediments discharged by the Yangtze River, it is reasonable to ask whether the pollution problem may be solved by simple dilution. This article reviews the past two decades of published research on organic pollutants in the Yangtze River and several adjacent water bodies connected to the main stream, according to a holistic approach. Organic pollutant levels and potential effects of water and sediments on wildlife and humans, measured in vitro, in vivo, and in situ, were critically reviewed. The contamination with organic pollutants, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans, polybrominated diphenyl ethers (PBDEs), perfluorinated compounds (PFCs), and others, of water and sediment along the river was described. Especially Wuhan section and the Yangtze Estuary exhibited stronger pollution than other sections. Bioassays, displaying predominantly the endpoints mutagenicity and endocrine disruption, applied at sediments, drinking water, and surface water indicated a potential health risk in several areas. Aquatic organisms exhibited detectable concentrations of toxic compounds like PCBs, OCPs, PBDEs, and PFCs. Genotoxic effects could also be assessed in situ in fish. To summarize, it can be stated that dilution reduces the ecotoxicological risk in the Yangtze River, but does not eliminate it. Keeping in mind an approximately 14 times greater water discharge compared to the major European river Rhine, the absolute pollution mass transfer of the Yangtze River is of severe concern for the environmental quality of its estuary and the East China Sea. Based on the review, further research needs have been identified.

PBDEs, PCBs and PCDD/Fs in the sediments from seven major river basins in China: Occurrence, congener profile and spatial tendency

“…Especially in Yangtze River Delta (S12), one of the most developed regions and important harbors in China, the levels of PBDEs, PCBs and PCDD/Fs were up to ten thousand times higher than the lowest values. The higher levels of POPs in the Lower Reaches were also reviewed by Floehr et al (2013). PCDD/F and PCB concentrations were generally comparable to the previous results in the lower reaches areas of Yangtze River (Nie et al, 2013;Shen et al, 2006;Sun et al, 2005;Yang et al, 2009).…”

Short-term transport of glyphosate with erosion in Chinese loess soil — A flume experiment

“…The risk of offsite transport glyphosate and AMPA should be particularly evaluated due to the heavy rain after glyphosate-based herbicides application (Hanke et al, 2010;Styczen et al, 2011). Admittedly, with the duration of rainfall and the distance of transport route, the dilution effect on pollutant has been considered a solution to reduce the risk based on the environmental load but it is also debated (Floehr et al, 2013). EPA (2003) reported that 1.1 μg L − 1 of glyphosate was detected which is ten times of the EU limit value (0.1 μg L −1 ) for this herbicide in groundwater while the level of glyphosate/AMPA in public water system is seldom reported comparing to the studies of them in soils, China (Zhao et al, 2009;Zhou et al, 2010).…”

Microplastics in Taihu Lake, China

“…Freshwater systems have several important functions, such as the use as providing sources of drinking water and fisheries. Some freshwater systems are surrounded by a high population density, and such intensive anthropogenic activity can introduce various contaminants, including microplastics, into the body of water (Floehr et al, 2013;Ismail et al, 2014;Driedger et al, 2015). In recent years, the occurrence of microplastics has been documented in several lakes and rivers (Eriksen et al, 2013;Castaneda et al, 2014;Yonkos et al, 2014).…”