Contamination and Source Identification of the Elemental Contents of Soil Samples from Municipal and Medical Waste Dumpsites in Ile-Ife, Nigeria

Contamination in soil samples collected from municipal and medical waste sites was assessed by employing four indices: contamination factor (Cf ), degree of contamination (Cdeg), pollution load index (PLI), and index of geoaccumulation (Igeo).  The sources of soil contaminants were identified by using Positive Matrix Factorization (PMF). Iron had the highest average concentrations of 46.47 ± 14.03 and 39.42 ± 2.54 µg/g in the municipal and medical waste dumpsites. Cf values were above 6 for both dumpsites, classifying the dumpsite soil as very high contamination with respect to Cr, Fe, Ni, Cu, Zn, As, Cd, and Pb. The overall Cdeg and PLI values are 176.9 and 170.4 and > 5 for both dumpsite implying very high degrees of contamination and progressive deterioration, respectively. The average Igeo values for Zn, Cd, and Pb of the two dumpsites were >3, indicating that the soil samples at both study areas were classified as highly to moderately polluted. The three identified sources resolved by PMF and their respective percentage contributions were crustal (32 %), scrap metals wastes (40 %), and electronic wastes (28 %)