Heavy Metal Pollution in Soil Samples Obtained from some Communities around a Cement Factory in Obajana, Kogi State, Nigeria

Abstract
This study assessed the levels of heavy metals in the soils of three communities (Lokoja, Osara, and Kabba) within forty kilometers from a Cement factory situated in Obajana, Kogi State of Nigeria. Soil pH values ranged from 6.0 - 7.3, organic matter ranged from 2.5±0.5-4.03±0.3 %, Electrical Conductivity ranged from 104.1±31.5-188.5±75.5 µS/Cm, carbonates ranged from 2.8±0.8-3.7±0.5 mg/kg. The order of pollution of the locations under study was Lokoja > Osara > Kabba > Control based on the Pollution Load Index calculation. The elements’ dominance was in the order: Zn >Pb >Cu> Ni > Cd in general. Lokoja: Zn-31.32, Pb-30.78, Cu-28.12, Ni- 22.723, and Cd-1.63 mgkg-1 Osara: Cu-22.32, Zn-21.56, Pb-16.31, Ni- 3.61, and Cd-1.16 mgkg-1 Kabba: Zn-17.98, Cu-6.05, Pb-5.89, Ni- 4.70, and Cd-1.105 mgkg-1. Higher elemental concentrations were observed in Lokoja and Osara. The I-geo results indicated that the Cu and Ni were moderately to strongly polluted metals in Lokoja with I-geo 4.15 and 3.84 respectively, while Cu I-geo= 1.85), and Ni (I-geo=1.59) in Kabba and Cd (I-geo=1.93), Ni (I-geo=1.18) and Pb (I-geo=1.67) were moderately polluted. However Zn was, according to the I-geo values, unpolluted both in Kabba and Osara but moderately polluted in Lokoja. The PLI values ranged from 2.04 to 6.3 indicating that some of the studied metals exceeded the background (Control) metal concentration. The mathematical models revealed that the source of pollution was anthropogenic, the cement facility together with the attendant vehicular traffic and emissions were implicated as responsible for metal pollution in these areas.