Influence of Municipal Solid Waste Dumpsite on Soil Physicochemical Properties and Vertical Distribution of Heavy Metals

The management of municipal solid waste (MSW) through open dumping or open burning has been a very common practice in Nigeria. The work investigated the impact of these practices on soil physicochemical properties and the vertical distribution of heavy metals at two dumpsites at Obollo-Afor and Nsukka in Southeastern Nigeria. Soil samples were collected at 10 m apart at depths of 0-20, 20-40, 40-60 cm from the dumpsite and at 100 m away from the dumpsite for the determination of soil physicochemical properties. A profile pit was dug at the centre of each dumpsite while soil sample collection was done from 0-100 cm for heavy metal determination. Soil chemical properties (TN, Av. P, OM, TEB, CEC, H+, Al3+, Ca2+, Mg2+, Na+, K+) and some soil physical properties e.g. aggregate stability (AS) and available water capacity (AWC) differed significantly (P \u3c 0.05) across locations and depths. Municipal solid wastes significantly (P \u3c 0.05) influence all soil chemical and some physical properties such as mean weight diameter (MWD), AS, clay, and sand contents. The impact of MSW was more pronounced at the surface soil (0-20 cm) and decreased with increasing depth. In addition, significant (P \u3c 0.05) interaction effects of MSW on soil chemical and physical properties were recorded across locations and depth zones. In both locations, heavy metal concentrations were higher in MSW dumpsites relative to the control. However, the heavy metal concentrations were too low to cause any ecological or health risk when compared to the heavy metal permissible limit in agricultural soils as recommended by WHO