This study was carried out to investigate heavy metals concentrations: lead (Pb), cobalt (Co), cadmium (Cd), zinc (Zn), nickel (Ni), copper (Cu) and manganese (Mn) in Musa paradisiaca (plantain), Zea mays (maize), Cucumeropsis manii (melon), Manihot esculenta (cassava) and soil samples from dumpsites in Onne, Eleme Local Government Area, Rivers State, Nigeria. The plant leaf and soil samples were measured for heavy metals concentrations using atomic absorption spectrophotometer. The health risk index (HRI) of the heavy metals following the consumption of these plant materials by the populace was estimated using standard protocols. The heavy metals concentrations in the leaf samples ranged from 0.012-14.712 mg/kg, whereas those of the soil samples were within the range of 2.543-16.459 mg/kg. Cd concentrations in the soil and leaf samples were above the maximum permissible level according to the World Health Organization (WHO). The bioaccumulation of the heavy metals followed the trend: (M. paradisiaca) Zn > Pb > Co > Mn > Cu > Cd > Ni; (Z. mays) Mn > Pb > Co > Zn > Cu > Cd > Ni; (C. mannii) Mn > Co > Pb > Cu > Zn > Cd > Ni; (M. esculenta) Zn > Pb > Mn > Cu > Co > Ni > Cd. The highest bioaccumulation of the heavy metals occurred in M. esculenta. The estimated HRI of Pb in M. esculenta was greater than 1. HRI > 1 was indicative that the consumer population is not safe. Cassava-based meals from the dumpsites contained Pb at toxic level, whereas Co, Cd, Zn, Ni, Cu, and Mn concentrations in plantain-, maize-and melon-based meals were relatively within safe limits.

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

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