Pollution Profile and Ecological Risk Assessment of Heavy Metals from Dumpsites in Onne, Rivers State, Nigeria

Abstract

The present study quantified and characterized the pollution status and ecological risk as well as sources of heavy metals in soil samples collected from active dumpsites in Onne, Rivers State Nigeria. Soil samples were collected from four designated points in the study areas and heavy metals concentrations, namely; lead (Pb), cobalt (Co), cadmium (Cd), zinc (Zn), nickel (Ni), copper (Cu), and manganese (Mn) were measured using flame atomic absorption spectrophotometer. The pollution status assessment, sources of heavy metals pollution and ecological risk parameters were determined using standard models, namely; Contamination Factor (CF), Pollution Load Index (PLI), Geoaccumulation Index (Igeo), Enrichment Factor (EF), Potential Ecological Risk Factor (PERF) and Potential Ecological Risk Index (PERI). The results showed that the heavy metals concentrations (mg/kg) in soil samples from the active dumpsites were Pb: 2.54 ± 1.00, Co: 8.17 ± 1.96, Cd: 7.54 ± 4.40, Zn: 16.46 ± 2.81, Ni: 12 ± 1.35, Cu: 14.79 ± 1.19, Mn: 13.95 ± 3.57, which was in the order; Zn > Cu > Mn > Ni > Co > Cd > Pb. The standard models showed that the study areas were highly contaminated and polluted with Cd. Furthermore, the sources of the Cd pollution in soil samples from active dumpsites in Onne, Rivers State Nigeria were more of anthropogenic activities than natural causes. Urgent steps should be taken by the government and other regulatory bodies to control human activities in the study areas that promote the release of Cd into the environment.