Determination of pollutions in the surface of water samples from Ogbajarajara river, Nigeria by spectrophotometer and atomic absorption spectrometry before evaluation of health risk assessment

Determination of environmental pollution in the surface water is very important. So, in this study, determination, and health risk assessment were evaluated. The pollutions such as anions, cations, and heavy metals were analyzed in surface water by photometer spectrometry and atomic absorption spectrometry (AAS). Other parameters such as pH and TDS were determined. The results showed us, the electrical conductivity (EC) in this study falls between 100.68 ± 1.0 - 194.74 ±1.4 μs cm^-1 in the dry and wet season. The pH value in this study for the two seasons varied from 5.57±0.22 to 5.73±0.28 which shows a little acidity. In the current study, TDS for wet and dry seasons goes from 122.17±1.74 mg L^-1 to 63.80±0.86 mg L^-1. This may conceivably be a sign of typical pollution from the runoff of soils in the study area. The high phosphate levels in both wet and dry seasons are recorded from 60.74±0.61 to 60.27±0.38 mg L^-1 in both seasons. Iron values observed range from 8.42±0.06 to 6.28±0.11 mg L^-1 in the wet and dry season, Cu was recorded between 0.08±0.01 - 0.07±0.01 mg L^-1, Mn recorded from 0.07±0.01 to 0.06±0.01 mg L^-1, Zn recorded between 2.29±0.09 - 1.15±0.09 mg L^-1, and Pb recorded from 0.69±0.09 to 0.40±0.18 mg L^-1 while Cd and Ni were not detected in the study. Water quality index (WQI) values were determined as 549 for wet and 328 for the dry season, the hazard indices for both seasons are below one. The outcomes in this present study showed that the level of Pb in the surface water could present a carcinogenic risk to both adults and children. All heavy metals results were validated by electrothermal atomic absorption spectrometry (ET-AAS).