Atomic Absorption Spectrophotometry

The contamination of soils with heavy metals from anthropogenic activities like automobile repair poses a significant threat to ecosystem and human health. This study investigated the effectiveness of hydroxyapatite (HAp) and phosphate-solubilizing bacteria (PSB) for the remediation of heavy metals in a contaminated mechanic workshop soil in Ekosodin, Benin City, Nigeria. Soil samples were collected and subjected to four treatments: untreated soil (control), soil amended with PSB only, soil amended with HAp only, and a combined treatment of soil with both HAp and PSB. Hydroxyapatite was synthesized from cow bones via thermal calcination, and indigenous PSB were isolated from the contaminated soil. The concentrations of Chromium (Cr), Lead (Pb), and Nickel (Ni) were analyzed using Atomic Absorption Spectrophotometry, and microbial counts were monitored over the experimental period.The results demonstrated that the combined application of HAp and PSB was the most effective treatment, achieving the highest percentage removal efficiencies: 38.65% for Cr, 29.05% for Pb, and 33.12% for Ni. Individual applications of PSB or HAP showed significantly lower remediation effects. Furthermore, the combined treatment (Soil+PSB+HAp) supported a higher total heterotrophic bacterial count (2.75 ± 0.71 × 10⁶ CFU/g) compared to the PSB-only treatment (2.50 ± 0.00 × 10⁶ CFU/g), indicating improved soil microbial activity. The study concludes that the synergy between hydroxyapatite and phosphate-solubilizing bacteria enhances the immobilization of heavy metals and promotes a healthier soil microbiome, presenting a promising, eco-friendly strategy for remediating soils co-contaminated with heavy metals

This study investigated the levels of cadmium (Cd) and zinc (Zn) in cow offal (shaki, liver and kidney) consumed within Benin City to assess potential human health risks associated with its exposure. Samples of liver, kidney, and intestine were collected from three different abattoirs (University of Benin abattoir, University of Benin Teaching Hospital (UBTH) abattoir and Ekosodin abattoir) and analyzed using an Atomic Absorption Spectrophotometer (AAS) to determine the heavy metal concentrations. Results showed cadmium levels ranging below detectable limits to 1.00 mg/kg was obtained for the duration of the sampling campaign with the highest concentration obtained in Ekosodin market and University of Benin abattoir. Also noteworthy is that cadmium was detected in 25% of all the samples collected. The concentration obtained in this study was found to exceed the Codex Alimentarius limits of 0.5 mg/kg in liver and 1.0 mg/kg in kidney. Zinc concentrations, though essential, were also found in higher than recommended amounts, suggesting contamination from feed or environmental sources. A zinc concentration range of 47 to 197 mg/kg was obtained with the highest concentration obtained in kidney sample from Ekosodin market with a concentration of 197mg/kg while the lowest concentration of 47 mg/kg was obtained in intestine sample from University of Benin Teaching Hospital abattoir. The elevated metal content reported poses potential health risks, especially for vulnerable groups such as pregnant women, children, and the elderly. The findings highlight the need for continuous monitoring of slaughterhouse practices, feed sources, and environmental pollution. Increased public awareness and enforcement of food safety regulations are essential to minimize exposure and protect public health