Air Pollution Assessment and Metals Bioaccumulation Studies in the vicinity of Umuoghara and Amoffia-Ngbo Quarry Sites

This study focused on the assessment of particulate matter emission, dust composition, and heavy-metal accumulation in guinea pigs exposed to quarry environments of Umuoghara (UMR) and Ammofia-Ngbo (UMR), Ebonyi State, Nigeria. Measurements of TSPM, PM₁₀, and PM₂.₅ conducted quarterly at three distances (0 m, 5 m, and 10 m away from the perimeter) revealed significantly higher (p<0.05) concentrations in both quarry sites relative to the control site, with emissions consistently highest in Ammofia-Ngbo and also followed a seasonal trend January > April > July > October. The chemical analysis showed that all dust samples contained elevated levels of heavy metals (Fe, Pb, Cd, Cu, Zn, Mn, Ni, Cr, As, and Hg) and physicochemical parameters compared to the control, with some metals totally absent in the control samples. The PAH concentration was significantly higher in ‘UMR’ when compared to site ‘AMN’. These could be due to the intensive use of diesel-powered generators for quarry operations in site ‘UMR’. Sixty male guinea pigs exposed for 3–12 months exhibited significant (p<0.05) time-dependent increases in blood concentrations of Pb, Cd, Cu, Zn, Fe, Mn, As, Cr, and Ni, thus confirming systemic accumulation associated with quarry dust exposure. The presence of toxic metals and PAHs above the recommended air-quality standards indicated considerable risk to the environment and human health, which may lead to respiratory, hepatic, neurological, and carcinogenic effects. The findings highlight the urgent need for governmental enforcement of dust-emission standards and improved occupational and community health protection measures in quarrying areas of Ebonyi State