Assessment of the level of Heavy Metals in Ecosystem around Quarry site in Ogun State, Nigeria

Abstract

This study investigated the anthropogenic impacts of quarrying activities on the ecosystem. Soil, rock, water, and plant samples were collected at varying distances around a quarry site located in Ijebu North local government area of Ogun State, Nigeria. The physicochemical properties were determined using standard methods, and metal quantification was done using Inductively Coupled Optical Emission Spectrometry (ICP-OES). The results of physicochemical properties of the sampled soil include: pH (7.20–8.74), bulk density (0.922–1.198 g/cm³), and moisture content (26.3–34.1%). Turbidity is 56.3 higher than the WHO standard, while alkalinity is 144. The physicochemical properties of the water samples all fall within the permissible limits set by the WHO except for alkalinity, turbidity, hardness, suspended solids, and COD. The results of metal analysis (mg/kg) are as follows: ≤9.94, ≤ 3961.77, ≤ 11.07, ≤ 244.03, ≤ 111.77, ≤ 251.19, ≤ 262.84, ≤ 101.23, ≤ 3094.87, ≤ 2816.07, ≤ 235.78, ≤ 182.72 for Ag, Al, As, B, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, and Pb, respectively, in all the environmental samples. High levels above the WHO permissible standard of toxic metals under study were found in rock samples, and these are statistically similar to the levels recorded in soil samples close to the quarry site. Additionally, high levels of Al, Cd, Cr, Cu, Fe, and Mn above the WHO limit were recorded in plant and water samples close to the quarry site. Quarry activities in the study site have a negative impact on the soil, plant, and water body around the site, and this needs to be checked on time before it degenerates into an environmental catastrophe.