Determination Of Heavy Metals And Environmental Health Status Of Agro Soils In Ikot Abasi, Niger Delta, Nigeria

Heavy metal pollution of soils is a worldwide concern due to the security of the agricultural products derivable from the heavy metal contaminated soils. The toxic metals enter the soil-agro ecosystem through natural processes derived from anthropogenic activities and geological weathered materials. This study is aimed at investigating the contamination status of soils from Ikot Abasi, Akwa Ibom State, being an area of intense agricultural and industrial activities. Twelve locations were demarcated for soil sampling, whereby top (0- 15 cm ) and sub-surface ( 15 – 30cm ) soil samples were obtained. The soil samples were air-dried and subjected to heavy metal determination (iron, Fe; cadmium, Cd; lead, Pb; zinc, Zn; copper, Cu; vanadium, V; nickel , Ni; chromium, Cr ; mercury, Hg ) by inductively coupled plasma– optical emission spectrometer (AGILENT 720 ICP-OES). The mean concentrations of heavy metals during the dry and wet seasons followed the order: Fe > Zn > Cu > Cr > Ni > Pb > V > Cd > Hg. The geo-accumulation index (Igeo) determined for all the metals studied were less than one , which falls in the Class zero , implying that the soils of the study area is practically unpolluted ; the potential ecological risk ( RI) were less than one , which was in the class of no potential ecological risk : modified degree of contamination ( mCd) calculated for both seasons falls in the category of less than 1.5 , which is nil to very low degree of contamination of the soils of the study area; pollution load index ( PLI), falls in the category of PLI of zero, which is excellence with no metal pollutant contamination. The public concern in respect of the security of the agricultural products derivable from the heavy metal contaminated soil, seem not to be applicable in the soils of Ikot Abasi, however, regular monitoring, is recommended to check possible future contamination.