Assessment of environmental risk to Vladimir Bay, Sea of Japan, exposed to heavy metal pollution

Abstract

The present paper provides an assessment of the environmental risk to Vladimir Bay, Sea of Japan, where the components of the environment and biota are exposed to heavy metals (Pb, Cd, Zn, Cu, and Ni). The abundance of metal-resistant forms of bacteria in the surface waters of the bay is quantified. The content and spatial distribution of heavy metals (HM) in bottom sediments are assessed. HM concentrations in sea urchin gonads are estimated. The Cd contamination of the waters in the bay has been found to be significant (more than 3 maximum allowable concentrations). Exceedance of background concentrations and Clarke numbers in bottom sediments were recorded for several HM. The contamination factor Cf is calculated. On the basis of this factor, the level of Zn contamination of bottom sediments is categorized as high, and the Cd and Cu contamination as very high. The total contamination degree Cd indicates a high level of bottom sediment contamination with the HM under study. Environmental risk indices are calculated. On the basis of the SQG-Q value, sediments of the bay are categorized as moderately toxic. It has been found that, according to the Technical Regulations of the Customs Union standards on Safety of Food Products (TR CU 021/2011), the Cd and Pb concentrations in gonads of sea urchins from Vladimir Bay do not exceed the allowable values. Nevertheless, the calculated incremental lifetime cancer risk (ILCR) values predict the existence of cancer risk from eating gonads.