Heavy metal contamination status in seven fish species from reservoirs of Polonnaruwa district, Sri Lanka

A concerning level of heavy metal contamination has been identified in seven fish species from the reservoirs of Polonnaruwa, Sri Lanka. The study found that lead (Pb) and cadmium (Cd) were significantly concentrated in the head regions of these fish, with Pb reaching up to 22.44 mg/Kg in Heteropneustes fossilis from Minneriya reservoir and Cd at 4.98 mg/Kg in Oreochromis niloticus from Kaudulla reservoir. Chromium (Cr) concentrations peaked at 30.87 mg/Kg, while zinc (Zn) was the most abundant metal detected across all sampled regions, with a notable concentration of 118.93 mg/Kg in Oligolepsis acutipennis from Minneriya. Copper (Cu) levels were highest in H. fossilis at 2.92 mg/Kg. Critically, concentrations of these metals in the head parts of popular edible species like Oreochromis mossambicus and Etroplus suratensis exceeded the FAO/WHO provisional tolerable weekly intake limits for Pb, Cd, Cr, Cu, and Zn. This suggests potential health risks from long-term consumption, particularly concerning for local populations relying on these fish as a dietary staple.

Wijesinghe, H., Idroos, F. S., & Manage, P. M. (2018). Heavy metal contamination status in seven fish species from reservoirs of Polonnaruwa district, Sri Lanka. Sri Lanka Journal of Aquatic Sciences, 23(1), 95–104. https://doi.org/10.4038/sljas.v23i1.7550