Contamination level and ecological risk assessment of particulate trace metals in Southwestern Mediterranean Sea

Abstract

In an effort to assess the coastal water quality in an Algerian Bay, suspended particulate matter (SPM) was analyzed for trace metals and various environmental parameters in Bou Ismail Bay. The trace metal concentrations analyzed by absorption atomic spectrometry followed the decreasing order Al > Fe > Zn > Mn > Ni > Cu > Pb > Co > Cr > Cd > Hg > As (p<0.001). To assess risk, a multiple risk assessment approach was used. The enrichment of particulate metals followed a descending order of Cd > Zn > Ni > Fe > Cu > Co > Hg > Pb > Cr > As. Cadmium and nickel, may enter the bay from anthropogenic non-point sources, had the highest potential ecological risk and biological effect. Nickel contributes 46% to the potential acute toxicity (ΣTUi) of the SPM. The combined metals Pb, Cd, Cu, Zn, Cr, Ni, Hg and As had 25%–30% probability of biotoxicity but did not indicate a likelihood of any significant toxic effects based on results from previous amphipod toxicity tests. Generally, the SPM was categorized as being slightly toxic (ΣTUi<4).