Investigations of some heavy metals in soils around refuse dumpsites, Sagbama Local Government Area, Bayelsa State, Nigeria

Abstract

The concentrations of some heavy metals in dumpsite soil collected from eight different locations in the Sagbama Local Government Area of Bayelsa State, Nigeria, were ascertained through AAS and standard analytical methods. The heavy metal concentrations obtained in the samples were in the following pattern: nickel, chromium, zinc, copper, lead, and cadmium. The heavy metal concentration values in dumpsite soil samples ranged from 7.698 to 8.865 for Pb, from 6.154 to 8.154 for Cr, from 5.787 to 7.586 for Cu, from 1.053 to 1.528 for Cd, from 4.231 to 6.167 for Zn, and from 5.76 to 8.60 for Ni. The standards given by the World Health Organization (WHO) and the National Environmental Standard Regulation and Enforcement Agency (NESREA) were used in the comparison of these results and also with the work done by other researchers. These results were within or lower than the permissible limits of WHO and NESREA, except Cd. The result also indicated pollution with heavy metals in the soil in the following order: Chromium>Lead> Nickel>Cadmium. This research indicated that the environment is not at risk because the heavy metals studied had very low concentrations. It was suggested, amongst others, that the dumpsites should be put under strict supervision and public awareness made of the negative effects on health from exposure to heavy metal contamination in the soil. Also, the environment should be safeguarded for microorganisms and people living in the area who depend on it for their livelihood by curbing all anthropogenic activities that heighten the metal pollution of the soil.