Heavy Metals Pollution of Soil Around Solid Waste Dumpsites in Abuja Metropolis

Abstract

There has been an increase in solid waste generation due to urbanization and improper dumping of wastes in developing countries like Nigeria causing severe adverse effect and impact on human health and the environment. This study was conducted to determine the level and associated risk of heavy metals (Cr, Mn, Pb, Cu, Fe, Cd, Zn) pollution of soils around solid waste dumpsites in Abuja Metropolis using standard methods. Soil samples were collected from ten municipal solid waste dumpsites within Abuja metropolis and a control sample was also collected and studied. From the results, the mean concentration of all the studied metals in the dumpsite soils were higher compared to local background values and international threshold except for Fe and Mn in sites DS3 and DS10 respectively. Further, the differences in the levels of heavy metals in soils of different dumpsites were not statistically significant (  <0.05). The values of the single pollution index (Pi) showed that the study area is most considerably polluted by Cd, Cu and Pb. Based on the Nemerow pollution index (PN), over 70.2% of soil sampling sites had moderate contamination levels. According to the results of the pollution load index (PLI), it was revealed that the PLI was greater than unity showing that there was minimum pollution in the studied dumpsite soils. However, the results of potential ecological risk evaluation indicated that the soil samples were at low risk with the studied heavy metals. This study suggested that the dumpsites contributed to soil metal loads and due to the toxicity of heavy metals, there is need for government to establish a monitoring program that addresses indiscriminate dumping of waste in the FCT.