Modulatory effect of magnesium hydroxide-nanoparticles on lead-induced toxicity in river Clarias gariepinus near mining site

Abstract

Effluents emerging from unprotected local mining activities pollute the nearby rivers containing aquatic lives. Advent of nanotechnology however, supposedly helps in removal of water contaminants and as well make waste water remediation possible. To this effect, Clarias gariepinus from rivers near mining site at Ijero-Ekiti, Ekiti-State, Nigeria were collected and exposed to 62.5, 125 and 250mg/L suspension of 10nm magnesium hydroxide nanoparticles (MgOHNPs) for 14-days under semi-static conditions. The suspected lead concentration in the river water was estimated using atomic absorption spectrophotometer while the quality of the river water was also examined. Clarias gariepinus collected were sacrificed and alterations in their biochemical and hematological indices were evaluated. The results showed that water sample from river I exhibit highest (0.033ppm) lead concentration while water sample from river III has the lowest (0.006ppm) lead concentration relative to their proximity to the mining site. Besides, the collected fishes demonstrated significant (P<0.05) concentration dependent increase in some biochemical indices and no observable significant alteration in hematologic state of the fishes at tested doses. Hence, results from this study suggest that toxic lead effluent from local mining activities may have elevated lead concentration levels in nearby rivers while exposure to MgOHNPs could evoke alterations in physiological system of the inhabiting aquatic lives.