Impacts of Anthropogenic Activities on Heavy Metal Levels in Surface Water of Nun River around Gbarantoru and Tombia Towns, Bayelsa State, Nigeria

This study assessed the impacts of anthropogenic activities on level of heavy metals in surface water of lower Nun River at Gbarantoru and Tombia town in Yenagoa local Government Area of Bayelsa state, Nigeria. Triplicate samples of surface water were collected from three locations (viz: Location A around oil and gas installations, B- Gbarantoru and C- Tombia town). The samples were processed and analyzed using atomic adsorption spectrophotometer. Results of the surface water were 0.002 – 0.011mg/l cadmium, 0.000 – 0.002mg/l chromium, 0.001 – 0.002mg/l cobalt, 0.001 – 0.002mg/l nickel, 0.011 – 0.013mg/l lead, 0.112 – 0.205mg/l zinc and 0.122 – 0.159 mg/l iron. There was significant variation (P<0.05) among the various locations for each of the heavy metals. Correlation showed positive significant relationship (P<0.05) for majority of the heavy metals. This suggests that heavy metals in the water and sediment are from similar source. The heavy metals concentration was within the standard for drinking water except for cadmium and lead as specified by World Health Organization, European Union and Standard Organization of Nigeria. Higher concentration of cadmium and lead in the water suggested that they could bioaccumulate in aquatic organisms such as fisheries. As such, caution should be exercised in the drinking of surface around the study area because of possible cadmium and lead toxicity over a prolong period of time.

Keywords: Contaminants, Health risk, Runoff, surface water, Toxicity.