Integration of geophysical and radiological assessment of solid waste diposal impact on groundwater and human health in Southern Nigeria

Abstract

The solid waste contaminated leachate may cause radiological human risk when it comes in contact with the aquifer groundwater. To ascertain the radiological contamination level of research area, the electrical resistivity method was used to assess the depth of the aquifer of the groundwater and radiometric survey analytical method were used to assessed the radiological human risk. The electrical resistivity Dar-Zarrouk parameters longitudinal conductance (S), transverse resistance (Tr), longitudinal resistance (L) and aquifer properties such as transmissivity (T) and hydraulic conductivity (K) used to evaluate groundwater potential revealed that Aladja had higher values of Tr compared to other research sites. The values obtained from S also suggested that surface pollution of groundwater is a possibility. The research area's Effurun axis was the location of the highest value of ρ_L. Subsequent investigation indicated that high K values were found in the research area near the Ogunu and Warri axes. A total of 18 water samples were collected for a radiometric survey and mean measured results of ²³⁸U, ²³²Th and ⁴⁰K are 6.57 ± 2.89Bql^-1, 3.23 ± 1.25Bql^-1 and 53.21 ± 3.51Bql^-1 respectively. The obtained mean results exceeded the permissible limits of 1.0 Bql^-1, 0.1 Bql^-1, and 10 Bql^-1 respectively. The computed radiological parameter results are all slightly higher than standard. The results prove that the studied groundwater will be detrimental to human health with time. Deductions from the study revealed that groundwater quality should be monitored and that suitable treatment technologies should be used to filter the water before drinking.