Preliminary Assessment of Heavy Metals in Soil along the Vaisigano River in Samoa

Abstract

The contamination of heavy metals in various environmental matrices is a major concern to many researchers and requires attention due to their detrimental impacts on the environment and humans as well. This research was carried out to investigate heavy metal levels in soils of some selected sites along the Vaisigano river in Upolu, Samoa. The soil samples were also analysed for physicochemical parameters such as pH, Electrical Conductivity, Moisture Factor, Cation Exchange Capacity (CEC), Organic Carbon, Nitrogen, Phosphorus, and Soil texture. The mean concentrations of heavy metals at the Lelata site were 0.19 ± 0.05 mg/kg (Pb), 0.37 ± 0.45 mg/kg (Mn), 0.15 ± 0.02 mg/kg (Zn) and 0.56 ± 0.42 mg/kg (Cu). The mean concentrations of heavy metals at the Alaoa site were 0.13 ± 0.03 mg/kg (Pb), 0.42 ± 0.51 mg/kg (Mn), 0.16 ± 0.03 mg/kg (Zn) and 0.45 ± 0.43 mg/kg (Cu). The heavy metal concentrations from both sites were lower than the permissible levels given by the World Health Organization (WHO). The Geo-accumulation pollution index (I(geo)) of heavy metals in the Lelata site was Cu > Mn > Pb > Zn and from the Alaoa site was Cu > Pb > Zn > Mn.