Heavy Metal Speciation and Health Risk Assessment of Soil and Jute Mallow (Corchorus Olitorus) Collected From a Farm Settlement in Ikorodu, Lagos, Nigeria

There is an increasing global concern for adverse effects of inorganic fertilizer and pesticides applied to agricultural soils. This study investigated metal speciation in soil and health risk assessment of Jute mallow (Corchorus olitoriuos) from a farm settlement in Ikorodu, Lagos State. Soil samples were collected according to the set standard procedure, sequentially extracted and analyzed for selected heavy metals using standard methods. Results showed that chromium (Cr) was associated with reducible fraction (Fe-Mn) for top soil, while cadmium (Cd), manganese (Mn), and copper (Cu); lead (Pb) and nickel (Ni); and Cr were predominantly bound to carbonate, reducible and residual mineral components respectively for sub-soil. The results of Contamination Factor (CF), Contamination Degree (CD), Pollution Load Index (PLI) and Geoaccumulation Index (Igeo) showed that the soil samples were not polluted for all the investigated metals. The Cd level in the soil (13.54 ± 1.21 mg·kg﹣1) and vegetables (0.83 ± 0.05 mg·kg﹣1) were above the USEPA critical permissible limit of 3.0 mg·kg﹣1 and 0.1 - 1.2 mg·kg﹣1 respectively. The daily intake of estimated selected heavy metals from the vegetable ranged from 8.8 × 10﹣03 to 1.4 × 10﹣02 for adult and 3.8 × 10﹣03 to 1.1 × 10﹣02 for children while the Hazard Quotient (HQ) for adults ranged from 5.4 × 10﹣05 to 1.1 × 10﹣01 and that of children ranged from 8.3 × 10﹣03 to 1.4 × 10﹣02. The cancer risk (CR) values of heavy metals in the soil ranged from 1.02 × 10﹣11 to 9.90 ×