Metal Pollution and Bioaccumulation in the Nhue-Day River Basin, Vietnam: Potential Ecological and Human Health Risks.

Dinh Quoc Nguyen,Thao Thanh Le,Yue Gao,Lan Anh Thi Tran,Huong Thi Thuy Ngo,Tien Thi Hanh Nguyen

doi:10.3390/ijerph182413425

Abstract

(1) Background: Metal pollution in the Nhue-Day River basin has impacted approximately 12 million people. However, none of the previous studies considered the entire basin’s environmental and health risks. Thus, this research aims to fill knowledge gaps and reduce risks. (2) Methods: Sediment and fish samples from the basin were analyzed to determine the levels of Zn, Cu, Pb, and Cd pollution and their potential ecological (EF, modified Pollution Index—mPI, and expanded, modified potential ecological risk index—emRI) and human health risks (THQ, HI, and TR indices). (3) Results: Metal levels in sediment exceeded Canadian aquatic life protection guidelines, indicating moderate to severe contamination (EFs: 1.3–58.5 and mPIs: 4–39). Compared to the new proposed ecological risk threshold, all river sites and Site 1 for ponds had elevated metal levels; and these posed a very high ecological risk in spring (emRI > 4.5), with Cd being the most hazardous. Lead levels in all fish tissues surpassed Vietnamese and EU food regulations. In agreement with THQ, EWI (Zn, Cu) and EMI (Cd) were both less than 2.5% of the PTWI and PTMI, respectively. However, HI values of 0.67–1.26 suggested a moderate health risk. Carcinogenic risk (TR > 10−6; estimated for Pb) was detected in several localities for Common carp and Tilapia during the warm season. (4) Conclusions: Metals had a negative impact on the basin’s ecosystem, with Cd being the most dangerous. Because of lead, consumption of Common carp and Tilapia from the basin may pose both non-carcinogenic and carcinogenic health concerns.

Highlights

Metal pollution in the aquatic ecosystem, including the river basin, is unavoidable due to rapid industrialization and urbanization [1]; and it has a negative impact on the health of the ecosystem and, aquatic organisms such as fish
In terms of spatial variation, Zn and Cu in the rivers were higher at Site 1 (p < 0.05)
The authors are responsible for setting parameters for using target hazard quotient (THQ), hazard index (HI), and target cancer risk (TR) values in risk assessment studies, onof the of the study, region, country

Summary

Introduction

Metal pollution in the aquatic ecosystem, including the river basin, is unavoidable due to rapid industrialization and urbanization [1]; and it has a negative impact on the health of the ecosystem and, aquatic organisms such as fish. The agriculture and aquaculture sectors may be influenced because the polluted river water is used for crop irrigation and aquaculture ponds. Consuming potentially contaminated products puts human health at risk [2,3]. Under the pressure of economic development, Vietnam has entered a rapid industrialization and urbanization period, putting the environment at risk of extreme degradation. Metal contamination in water and sediments has become unavoidable and has been observed in several riverine ecosystems, including the Red River [4,5], the Nhue.

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Conclusion