Discriminating contaminant sources is crucial for pollution control. The study aimed at identifying the source(s) of heavy metals in active dumpsite soils from selected areas in Southeastern Nigeria using statistical tools. The dumpsites were Enyimba dumpsite Aba (dumpsite-1), Okpuno-Egbu dumpsite Nnewi (dumpsite-2), Rice mill dumpsite Abakaliki (dumpsite-3) and Nekede dumpsite Owerri (dumpsite-4) in Abia, Anambra, Ebonyi and Imo State respectively. After standard sampling, elemental analysis was carried out using an energy dispersive x-ray fluorescence spectrometer; Chromium (Cr), Manganese (Mn), Cobalt (Co), Iron (Fe), Nickel (Ni), Copper (Cu), Zinc (Zn), Arsenic (As), Lead (Pb) and Cadmium (Cd) were quantified and results showed they were present in high concentrations above control and standard values set by the National Environmental Standards and Regulations Enforcement Agency (NESREA) and the Food and Agriculture Organization of the United Nations (FAO) / World Health Organization (WHO). Metals investigated exhibited variable correlations among themselves suggesting potential multi-element contamination, while soil organic matter (OM) and pH displayed both significant positive and negative influence on the metal availability in the studied soils. Test of significance of the observed correlation were positive and significant (r > 0.9 at p < 0.05/0.01) for Cr/Co, Cr/Fe, Mn/Co, Co/Fe, Cu/Zn, Zn/Pb, Cu/As, Cu/Pb, Zn/As, As/Pb in dumpsite-1; in dumpsite-2, only Ni/Cu; in dumpsite-3, Fe/OM and Cd/OM while in dumpsite-4,Co/Fe, Cu/As, Cu/Pb, Zn/Cd, Ni/OM, and As/Pb. Hierarchical cluster analysis (HCA) and Principal component analysis (PCA) extracted two to three components/groups based on square Euclidean distance and eigenvalues > 1, confirming sources to be from organic pigments in plastics, scrap metals and incinerated biodegradable wastes. This study concludes that statistical methods can provide a scientific basis for monitoring heavy metals accumulation in dumpsite soils.

No abstract

This work was carried out in collaboration between all authors. Author VIO designed the study and wrote the protocol. Author LOA performed the sampling and managed the analyses of the study. Author MNM managed the literature searches and wrote the first draft of the manuscript. All authors read and approved the final manuscript.

The proximate, elemental and phytochemical compositions of the leaves of Pterocarpus soyauxii (Oha) were studied. The results obtained for the proximate composition showed the following: moisture content (17.2%), ash content (5.7%), crude fibre (17.2%), crude protein (29.5%), crude fat (4.15%) and carbohydrates (25.95%). The results of the mineral (elemental) analysis in mg/L showed the following to be present in the leaves: Ca (4.04), Cu (0.20), Zn (1.39), Mg (41.0), K (0.31), Mn (0.17), Na (32.0) and Fe (0.60) with Pb and Cr absent. The leaves also contained vitamin A (0.2044 mg/g) and vitamin C (0.4470 mg/g). The phytochemical analysis of different solvent extracts showed the presence of alkaloids, saponins, glycosides and tannins. Flavonoids, phenols and steroids were absent. These findings showed that the leaves of Pterocarpus soyauxii are good sources of beneficial micronutrients, mineral elements and secondary metabolites which are required for healthy growth, justifying the use of the leaves for the popular "Oha" soup of the Igbos of South East Nigeria.

The physico-chemical and metal analysis of five different borehole waters in Ovim Isuikwuato Local Government Area, Abia State were analysed to ascertain the quality of the water used in Ovim. Five different samples were collected from each borehole and a composite sample made. The parameters determined include