Toxicity and bioavailability of chromium in contaminated sediments in the foshan waterway, China

Although the influence of acid volatile sulfide (AVS) on the bioavailability of divalent metals has been recognized, it was unable to predict the potential toxicity of Chromium (Cr). An 'AVS hypothesis' has been proposed to make up for the shortcoming The hypothesis will potentially extend the utility of AVS measurements as a tool of sedimentary heavy metal assessment but should be further tested under various conditions. Samples were taken and analyzed in the Foshan Waterway (China) to explore the relationship between AVS and the bioavailability of Cr in contaminated sediments under anaerobic conditions with a view to providing a field evaluation of the AVS hypothesis in a heavily polluted river rich in sulfur. In general, the results prove that the hypothesis works even in a highly contaminated area: while the value of AVS is high, porewater Cr is low and it positively correlates with bioaccumulation. Bioaccumulation has a significantly positive correlation with SEMCr, which hence may also be an appropriate indicator of Cr bioavailability.