Assessment of Geo-Accumulation Index (Igeo) In Soil Samples of Fika Agrarian Community of Yobe State, Nigeria, Using Mp-Aes Analytical Technique

Abstract

This study examined the concentration level and geo-accumulation index of trace element in composite soil samples in Fika local government area of Yobe, Nigeria. Soil samples from ten locations were collected at a depth of 0 to 20 cm using soil auger in the study area through purposive sampling technique and global Positioning System (GPS) device was used to mark the sample locations and elevations above sea level. Microwave Plasma Atomic Emission Spectrophotometer (MP-AES) was used to determine the concentrations of trace elements in the study area. From the data obtained elemental concentration (EC) and geo-accumulation index (I_geo) of each element was determined. Based on the result obtained, the mean elemental concentration in the study area was of the order of Pb(81.585 ± 25.591) > Fe(53.907 ± 4.593) > Al(3.941 ± 2.595) > Mn(2.311 ± 0.291) > Zn(0.500 ± 0.167) > Cr(0.151 ± 0.015) > Co(0.002 ± 0.000) > Cd(0.001 ± 0.00) in ppm respectively. Of all the trace elements detected, only Pb in FKA₁ was found to be above the International benchmark. Moreover, strong I_geo value correlations were obtained between (Zn – Pb) and (Al - Fe) at 0.5 significance level. The result further revealed that all the mean I_geo values of trace element were < 0 which imply that all the soil samples analyzed were uncontaminated and unpolluted. The study recommends that there is need to extend the scope of the study to cover radiological contaminants in soil, plants and river sediments in the study area so as to obtain a composite baseline data.