Gill-tissue bioaccumulation of heavy metals in oreochromis niloticus and labeo coubie and associated drinking-water health risk in the lower river Niger, Lokoja, Kogi state, Nigeria

Bioaccumulation of aquatic pollutants by fish in the lower River Niger at Lokoja can expose those who consume them to elevated risk, yet species specific bioaccumulation and consumption risk data are lacking for these fish communities. Samples of Oreochromis niloticus and Labeo coubie were collected monthly over six months spanning the dry season from January to March and the onset of the rains from June to August, and concentrations of cadmium, lead, chromium, zinc, mercury and nickel were