Heavy metal profiles and pollution indices of top soil sampled from six metallic material scrapyards located in Benin city, Mid Western Nigeria

Abstract

Heavy metal levels and other parameters which included organic carbon content of topsoil samples collected from six metallic material scrapyards and a control sites all located in Benin city were determined using routine techniques. The locations of the visited municipal scrapyards were; Aduwawa, St Savior street, 1st and 2nd Ibiwe, Waterboard at Iyaro (Idia college), and Uwelu. The control soil samples was collected from the premises of the Botanical Garden located within the premises of the Faculty of Life Sciences, University of Benin, Benin City. Duplicate soil samples were collected from the various study locations once every month during the months of February and March, 2022. The pH and EC values of soils collected in February ranged from 6.71 – 7.47 and 606.5 – 2541µS/cm respectively. Soil borne Fe and Pb readings varied from 763.5-2034.5mg/kg and 548.5-1881.5mg/kg as well as 24.50 – 50.35 and 24.75 – 50.60 for samples obtained in February and March respectively. Findings in this study revealed that soil samples obtained from the various scrapyard dumpsites where contaminated with high levels of heavy metals such as Iron, Lead, Chromium and Cadmium. Furthermore, it was observed that the levels of heavy metals analyzed in soil samples from the various scrapyard dumpsites were generally higher in values compared to control sites. Continuous monitoring and further studies on the prevailing soil borne levels of these trace metals should be conducted at regular intervals to ascertain long-term effects on the surrounding environment.

Keywords

• benin city
• contamination factor
• degree of contamination
• index of geoaccumulation
• metallic material scrapyards
• pollution load index
• trace metals