HEAVY METALS IN UNTREATED WASTEWATER AND SOIL FOR IRRIGATION: A PUBLIC HEALTH CONCERN IN JERE LGA, BORNO STATE NIGERIA

Heavy metals constitute one of the major causes of contamination in the environment resulting from natural geological events and human activities. Most heavy metals have very long residence time. The presence of heavy metals in untreated wastewater and soil used for crop production could constitute serious public health risk as the heavy metals are readily absorbed by vegetables. Irrigation farming is a major preoccupation in the study area, hence the study. Fifty samples each of untreated wastewater and soil were collected from ten (10) locations in the study area by convenient sampling. The samples were analyzed for heavy metals by digestion and atomic absorption spectrophotometric (AAS) techniques. Result obtained indicates that the overall mean concentrations of Cu, Fe, Cr, Pb, Zn, Ni and Mn detected in the wastewater samples were 1.44±0.44, 1.59±0.32, 0.28±0.08, 1.58±0.82, 1.19±0.29, 0.63±0.12 and 1.02±0.22 mg/L respectively, and all these values are significantly higher (p<0.05) than the WHO permissible levels. Similarly, the overall mean levels of Cu, Cr, Zn and Ni in soil samples were significantly above (p<0.05) the permissible limits while Fe and Mn were normal. The study revealed the presence of heavy metals in both the wastewater and soil samples at levels above the WHO permissible limits. The high levels portend a serious environmental and health risk which requires urgent attention and interventions by relevant stakeholders.