ASSESSMENT OF CONCENTRATION LEVEL OF SOME HEAVY METALS AND NON -METALLIC IONS IN DUMPSITE SOILS IN THE FEDERAL CAPITAL TERRITORY, NIGERIA

The concentration of heavy metals (Fe, Cd, Cr, Cu, Pb, Mn, Ni and Zn), pH and non-metallic ions (Cl-, NO3- and SO42-) in soil samples from dumpsites and soil samples from areas without dumpsites (control) in the study area were determined at depth 0-15cm, 45-60cm and 85-100cm.The digestion of samples was done using concentrated nitric acid. The Atomic Absorption Spectrophotometer (AAS) and titration methods were used to determine heavy metals and non-metallic ions respectively. At depth 0-15cm, heavy metal concentration in the dumpsite soil in both seasons were; Fe (19.8911 and 21.8488 mg/g), Cd (0.0012 and 0.0017 mg/g), Cr (0.7610 and 0.2285 mg/g), Cu (0.3657 and 0.1259 mg/g), Pb (0.5063 and 0.9991 mg/g), Mn (6.3547 and 3.446 mg/g), Ni (0.2549 and 0.1247 mg/g), Zn (1.2057 and 3.2462 mg/g). In both seasons control Fe (18.0275 and 14.5668 mg/g), Cd (0.0078 and 0.0000 mg/g), Cr (0.1768 and 0.2643 mg/g), Cu (0.0308 and 0.0528 mg/g), Pb (0.0201 and 0.3776 mg/g), Mn (0.0824 and 0.1163 mg/g), Ni (0.0256 and 0.0000 mg/g), Zn (0.0695 and 0.8055 mg/g). Heavy metal contents for soil samples across the profile depth at 0-15cm, 45-60cm and 85-100cm were also significantly higher at P