HEAVY METAL CONTENT OF SOIL SAMPLES FROM TWO MAJOR DUMPSITES IN MINNA

Abstract

This study investigates the concentrations of some heavy metals in two major dumpsites in Minna located at Kpakungu and Gidan Kwanu road both along Minna –Bida road in Niger state. Soil samples from the dumpsites were collected and prepared using standard analytical procedures and analytical grade reagents were used for digestion. A flame type atomic absorption spectrophotometer (AAS) was used for the analysis of the heavy metal (Zn, Cu, Pb, Cd, As, Ni, Cr, Mn and Fe) content of the samples. The result of the analysis of the samples from Kpakungu gave the following mean concentrations: Zn, 9.28mg/kg; Cu, 2.08mg/kg; Pb, 17mg/kg; Ni, 21mg/kg; Mn, 3.07 mg/kg; Fe, 19.76 mg/kg. The mean concentrations for samples from Gidan Kwanu are: Zn, 23.21mg/kg; Cu, 4.57mg/kg; Pb, 12mg/kg; Ni, 52mg/kg; Cr, 72.90 mg/kg; Mn, 19.64 mg/kg; Fe, 47.29 mg/kg .These results showed that the concentrations of the metals are comparatively higher for samples from Gidan Kwanu road dumpsite than that from Kpakungu dumpsite with the exception of As which had higher concentration at Kpakungu dumpsite. The concentrations of Cadmium at both sites were below detection. The result obtained was attributed to the refuse constituent and their quantity in each site, since Gidan-Kwano was a larger dump site and enjoy more patron than Kpangungu. The concentrations of the investigated metals in the two sites were found to be within their natural range in soil and could be said to pose no immediate toxic threat to man through the environment or the crop that might be planted on the soil collected from these sites. Recommendations on the proper handling of wastes to reduce possible toxic metal loads at dumpsites have also been highlighted.