Source Apportionment and Health Risk of Heavy Metals in Contaminated Agricultural Soil from Egi, Rivers State, Nigeria

The study was to identify the source and evaluate the health risk of heavy metals in contaminated agricultural soil from Egi community (Oboburu, Obagi and Ogbogu), Niger Delta, Nigeria. Multivariate and health risk equations were employed to achieve this. The mean of heavy metals in samples of Oboburu indicated high levels for Fe (271.0±156.6 mg/kg), Pb (111.2±94.97 mg/kg), and Mn (27.92±23.80 mg/kg), Obagi was high for Fe (248.4±175.9 mg/kg), Mn (80.46±12.40 mg/kg), and Co (116.3±193.7 mg/kg), and Ogbogu was high for Fe (160.9±150.3 mg/kg), Co (240.1±412.1 mg/kg), and Mn (42.90±16.82 mg/kg) respectively. Geo-accumulation index indicated that Pb, Cd and Co was of high contamination and the enrichment factor showed that metals were of anthropogenic sources. The Principle component analysis revealed three (3) components accounting for 88.448%, which revealed that the contamination in the sample was more of anthropogenic than biogenic. The Cancer Risk estimate for children population was of high risk for Ni, Cr, Cd and Pb (10-5 to 10-6) while adult population was 10-6 and lower. The non-carcinogenic risk indicated highest value for children in Co (2.75), Pb (1.70E-1) and Fe (1.32E-1), while adult in Co (1.007) and Fe (3.29E-2). The findings suggest human activities have contributed greatly to the contamination of the agricultural soil and usage of such may be of risk to the users.