ASSESSMENT OF HEAVY METAL LEVELS IN UNIVERSITY OF BENIN (UNIBEN) FARMLAND SOIL

ABSTRACT

This study assessed the levels of heavy metals in three soil samples (A, B, and C) and compared them to the reference standards set by the World Health Organization (WHO). The presence of lead (Pb) was found to have very low levels of contamination, with an average value of 1.00 mg/kg, which is far below the standard set by the World Health Organization (WHO) of 85 mg/kg. Cadmium (Cd) was not detectable (below detection limit, BDL) in any samples. The concentration of Zinc (Zn) was found to have a mean value of 79.67 mg/kg, which is above the standard set by the World Health Organization (WHO) of 50 mg/kg. Also, there was a large standard deviation of 81.57 mg/kg, indicating significant variance. Sample B surpassed the standard, indicating the possibility of concentrated enrichment in a specific area. The average concentration of Chromium (Cr) was 26.00 mg/kg, well below the WHO standard of 100 mg/kg. Although there was substantial variance in Cr levels (standard deviation = 20.67 mg/kg), all results were below the reference threshold. These findings indicate a low degree of Lead and Cadmium pollution, although there are certain regions where Zinc levels are higher than normal. For a more thorough assessment of heavy metal concerns, more research with a bigger sample size and consideration of soil conditions and land use are advised.