Evaluation of Heavy metals pollution around Kano municipal solid waste Dumpsites, Kano state, Nigeria

Abstract

The research was conducted to assess the level of heavy metals contamination using single and integrated pollution indices in soils around municipal solid waste dumpsites of Kano Metropolis, Kano State, Nigeria. Forty-two soil samples were collected from seven municipal solid waste dumpsites of Kano metropolis using the circular plot method. A stainless hand auger at a depth of (0 to 15) top soils and sub-surface soils (15-30cm) depth were collected and analyzed with a Flame atomic absorption spectrophotometer to determine the heavy metal concentration. The mean concentration (mg/kg) of heavy metals from the depth of (15-30 cm) were observed to follow a decreasing order Pb (7.71) > Zn (0.50) > Ni (0.45) > Cr (0.31) > Cd (0.025), while for surface soils (0-15 cm) the mean concentrations were in the following order: Pb (1.77) > Ni (0.49) > Zn (0.30) > Cr (0.27) > Cd (0.012). The results showed that calculated CF and Er recorded that investigated soil samples are uncontaminated with Zn, Pb, Cd, Cr, and Pb and Ni. The pollution load index (PLI) was less than unity, showing that there was minimal pollution in the studied dumpsite. The potential ecological risk showed that soil samples were in the class of low contamination with the studied heavy metals. The results showed that concentrations of heavy metals of soil samples from dumpsites located at waste dumpsites of Kano Metropolis were within the limits of European Union (2002) standards.