Ecological risk assessment of heavy metal concentrations in sediment and fish of a shallow lake: a case study of Baiyangdian Lake, North China

The pollution levels of lakes vary in quantity and type of contaminants accumulated in their sediment and water. The second Chinese capital city will be built around Baiyangdian Lake in the near future, and thus, it is important to monitor pollution status of Baiyangdian Lake. This study mainly focused on the accumulated heavy metal concentrations in the surface sediment and in variety of fish bodies. Sediment pollution status and ecological risk were evaluated through geo-accumulation (I-geo), contamination factor (CF), pollution load index (PLI), potential ecological risk (\( {E}_r^i \)), and mean probable effect concentration quotient (mPEC-Q). In addition, human health risks via fish consumption were also evaluated. Based on the results, the average sediment trace As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn concentrations were 9.53, 0.35, 56.37, 32.33, 617.05, 30.18, 19.17, and 84.24 mg/kg dry wt, respectively. Both I-geo and \( {E}_r^i \) inferred low pollution levels and low ecological risks from all assessed trace metals except Cd. Cd posed moderate to high ecological risks. Based on sediment quality guidelines (SQGs), average Ni and Cr concentrations exceeded the threshold effect concentrations (TEC), but their \( {E}_r^i \) are low as their average concentrations is below Hebei province pre-contaminations (30.8 mg/kg for Ni and 68.3 mg/kg for Cr). There is no cumulative toxicity from all the metals through mPEC-Q. Omnivorous fish accumulated statistically insignificantly higher amounts of metals than carnivorous fish, except for Hg. The intake of 12.22 g/person/day fish muscle for the entire life is safe from noncarcinogenic human health problems.