Bioavailability and toxicity of trace metals (Cd, Cr, Cu, Ni, and Zn) in sediment cores from the Shima River, South China. (February 2018)

• Record Type: Journal Article
• Authors: Gao, Lei; Wang, Zhuowei; Li, Shaoheng; Chen, Jianyao
• Is Part Of: Chemosphere. Volume 192(2018)
• Page Start: 31
• Page End: 42
• Publication Date: 2018-02
• Subjects: Riverine sediment -- Trace metal -- Geochemical fraction -- Toxic effects -- Vibrio fischeri; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2017.10.110
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Five sediment cores (S1−S5) were collected from the Shima River to determine the bioavailability of trace metals (Cd, Cr, Cu, Ni, and Zn) using the modified European Community Bureau of Reference (BCR) procedure. The toxic effects of polluted sediment were assessed using the LUMISTox ® bioassay with Vibrio fischeri and chemical models such as the toxicity unit (TU) of each metal, sum of all TUs (∑TU), and toxic risk index (TRI). The results showed that Cd, Ni, and Zn were present mainly in the acid-soluble and residual fractions, and the residual fraction of Cr accounted for the majority of the metal content (44%), while Cu was present mainly in the reducible and residual fractions. Cd had a mean enrichment factor (EF) of 15.1 and was considered to be severely enriched, while there was a minor enrichment of Cr and moderately severe enrichment of Zn, Cu, and Ni. From the LUMISTox ® bioassay, an acute TU (TUa) value exceeding 0.4 was found at the upper and middle reach sites and was considered to represent slightly acute toxicity, whereas little acute toxicity was found at the lower reach site. The acid-soluble fraction of trace metals was the geochemical fraction mainly responsible for the acute toxicity of the sediment, and acid-soluble Zn and Ni were identified as important contributors to sediment toxicity. Highlights: Metals cause sediment toxicity at the upper and middle reach sites of the Shima river. ∑TU = 4 is a critical threshold to identify toxic effects related to sediment metals. Acid-soluble metal is the chemical fraction mainly responsible for sediment toxicity. Acid-soluble Zn and Ni contribute significantly to acute toxicity in sediments.