distribution and health risk assessment of metal species and physicochemical parameters of water and sediments of river sasa, ife north local government area, nigeria

This study determined extent of contamination and total concentration of some potentially toxic elements in sediment and water samples obtained from river sasa. sequential extraction protocol was used to fractionate mn, cr, cu, zn, and fe to specific phases in sediment and water samples. atomic absorption spectrophotometry was used to quantify the metals while physicochemical parameters were determined using standard techniques. overall mean concentrations of anthropogenic-related metals in sediments for the dry season was highest for cr (66.7 ± 3.34 µgg-1) and lowest for zn (39.6 ± 1.30 µgg-1), while for the wet season, the mean concentration was highest for cr (82.3 ± 6.34 µgg-1) and lowest for zn (43.1 ± 4.33 µgg-1). generally, the metal levels followed the order: fe > cr > cu > zn > mn.  physicochemical parameters of the water samples for dry and wet seasons were within the stipulated limit set by regulatory agencies. speciation results indicated high bioavailability for cr, cu, and zn in water samples while relatively low bioavailability was indicated for all the studied metals in sediment samples. health risk assessment indicated that water quality was unsuitable for drinking in its present status without further treatment. results of the pollution load index (pli) indicated a deterioration level that called for concern in the quality of the river sediments. the results of this study showed that river sasa was polluted with high bioavailable metals such as cr, zn, and cu in the water which could pose threatening toxicity concerns to plants and animals.