Facilitated bioaccumulation of cadmium and copper in the oyster Crassostrea hongkongensis solely exposed to zinc

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

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Original languageEnglish
Pages (from-to)1670-1677
Journal / PublicationEnvironmental Science and Technology
Issue number3
Online published2 Jan 2013
Publication statusPublished - 5 Feb 2013
Externally publishedYes


Exposure to one metal might have significant effects on the bioaccumulation of other metals. In the present study, we examined the possible effects of Zn exposure on the bioaccumulation of Cd and Cu in three populations of the oyster Crassostrea hongkongensis. We found that Zn exposure significantly enhanced the tissue concentrations of Cd and Cu in all populations, and the tissue concentrations of Cd and Cu were highly and positively related to the tissue Zn concentration. Furthermore, the enhanced bioaccumulation of Cd and Cu resulted mainly from their increasing accumulation and distribution in two subcellular fractions (i.e., metallothionein-like proteins and metal-rich granules). Tissue concentrations of Cd and Cu in the natural Zn-contaminated oysters also covaried with tissue Zn concentration, and prediction analyses revealed that Zn exposure was a significant contributor to tissue Cd and Cu concentrations. Therefore, we concluded that the increased Zn bioavailability in ambient waters not only increased the tissue Zn concentration but also enhanced the overall bioaccumulation of Cd and Cu. This study strongly demonstrates that contamination of metals in oysters may result from concurrent exposure to other metals. Thus, environmental managers should consider the possible exposure to other metals such as Zn in order to interpret/predict the tissue concentrations of toxic metals in oysters. © 2013 American Chemical Society.