The study analyses the health risk assessment of the concentration of Iron, Lead, Copper, Chromium, and Cadmium heavy metals in vegetables grown near dumpsites of Jimeta and Ngurore areas of Adamawa State, Nigeria. Vegetables mainly Spinach (Spinacia oleracea) and lettuce (Lactuca sativa) were collected in triplicates and analyzed using Atomic Absorption Spectrophotometer Buck 210VGP (AAS). The result revealed that heavy metals detected in spinach at Jimeta dumpsite decreased in the following order: Fe (3.7 mg/kg) > Pb (0.18 mg/kg) > Cu (0.12 mg/kg) > Cr (0.07 mg/kg) > Cd (below limit of detection), compared to the metal concentration in spinach at Ngorure dumpsite with lower concentration of heavy metal which decreased in the order of: Fe (2.5 mg/kg) > Pb (0.16 mg/kg) > Cu (0.14 mg/kg) > Cr (0.02 mg/kg) > Cd (below limit of detection). Other result for Spinach in Jimeta decreased in the order Fe (3.31mg/kg) > Pb (0.2mg/kg) > Cu (0.11mg/kg) > Cr (0.05mg/kg) > Cd (ND) beyond the limit of detection while Lettuce decreased in the order Fe (22.54mg/kg) > Cu (0.31mg/kg) > Pb (0.12mg/kg) > Cr (0.07mg/kg) > Cd (ND) beyond the limit of detection. Fe is the most abundant element in the vegetables with a mean value of 21 mg/kg followed by Pb (0.177 mg/kg). The analyses of paired T-test for vegetables in Ngurore and Jimeta at 0.05 level of significant confirmed that Cu and Cr showed no statistically significant difference in their concentration level while Fe and Pb confirmed that there was statistically significant difference in their concentration level. However, the detection of heavy metals in these vegetables calls for close environmental monitoring and adequate public awareness. This is necessary to discourage further pollution which could lead to high metal concentration and metal poisoning in vegetables and invariably humans that consume them. Keywords: Spinacia oleracea, Lactuca sativa, Heavy metal, Atomic Absorption Spectrophotometer

Rapid urbanization and industrialization in developing countries have been associated with production and deposition of hazardous wastes in the soil environments. Heavy metals are major components of these wastes and have been implicated in several metal-related diseases and food poisoning in man. This study examined the concentration of Iron (Fe), Lead (Pb), Copper (Cu), Chromium (Cr), and Cadmium (Cd) heavy metals in soil near dumpsites of Jimeta and Ngurore, Yola North Local Government Areas (LGAs), Adamawa State. Soil samples from 0-20cm layer depth were collected in triplicates and analyzed using atomic absorption spectrophotometer (AAS). Results reveal that Fe, Pb, Cu and Chromium were detected, while Cadmium was found to be below the limit of detection. The mean concentration of the exchangeable cation in mg/kg in soil at Jimeta sites were: Fe (31.4 mg/kg) >Pb (0.92 mg/kg) > Cu (0.34 mg/kg) > Cr (0.11 mg/kg) >Cd (below limit of detection), while the mean concentration of the heavy metals in soil at Ngurore sites were: Fe (32 mg/kg) >Pb (0.83 mg/kg) > Cu (0.28 mg/kg) > Cr (0.07 mg/kg) >Cd (below limit of detection), respectively. Iron (Fe) was the most abundant element in both sites, followed by Pb. Heavy metal concentrations in soil followed the order of Fe>Pb>Cu>Cr>Cd, respectively. The paired T-test analyses for concentration of Cr, Fe, and Pb in soil nearthe two dumpsites show that there were statistically significant differences in the concentration levels of Cr, Fe, and Pb, while Cu showed no statistically significant difference between the two dumpsites. However, all the metals detected were below the permissible limit of WHO international standard with the exception of Pb whose concentration was above maximum permissible concentration (MPC). Persistent heavy metals accumulation in soils near these dumpsites may lead to increase uptake by vegetables grown near the dumpsites and this may pose a threat to its quality and safety and ultimately human health. The need to replace open dumpsites with well-designed landfills is advised.