Determination of potentially toxic elements in soil, pumpkin leaves (telfairia occidentalis) and maize (zea mays) around artisanal refining sites in Odagwa Etche

Abstract

Potentially toxic element (PTEs) pollution of the soil is an important issue because of deity intake, the negative impact of the potentially toxic elements causes myriad to health through the ecosystem. This study was undertaken to determine the potentially toxic elements in soil, telferia occidentalis and zea mays around illegal refining sites in Odagwa Etche. The soil, vegetable and maize samples were taken from different farmland close to where illegal refining activity takes place, the samples were digested and filtration by gravity was used to collect the filtrate. Analyses were done using Atomic Absorption Spectrophotometer, the results of analysis for potentially toxic elements in soil ranged from lead (Pb); 16.00 to 9.46(mg/kg), Cd; 5.485 to 3.505mg/kg, Zn; 13.09 to 8.14mg/kg, As; 9.375 to 6.2mg/kg, Cr; 0.62 to 0.34mg/kg and Ni; 10.324 to 9.149mg/kg. for vegetable samples the value varied from 1.755 to 0.025mg/kg for lead (Pb); 0.61 to 1.51 mg/kg for Cd; 6.3 to 3.16mg/kg for Zn and 0.915, to 0.105mg/kg for Cr, 5.24, to 2.225 mg/kg for As and 7.032, to 6.404 for Ni and for maize the mean value varied from 1.69, to 0.07mg/kg for Pb, 0.54, to 0.65 mg/kg for Cd, 4.63 to 3.355mg/kg for Zn, 1.12, to 0.04mg/kg for Cr, 1.135 to 0.135 for As and 1.457, to 2.012mg/kg for Ni respectively. The result of the analysis was further compared with the national and international standard and this revealed that some of the PTEs were above the DPR and WHO while maize was below the acceptable limit. The pollution load index was used to ascertain the levels of pollution by PTEs which indicate that the soil and vegetable samples were highly polluted while the maize samples were unpolluted.