DEPARTMENT OF SCIENCE LABORATORY TECHNOLOGY

This study assessed the human health risks associated with heavy metals in groundwater from Oluku, Edo State, Nigeria, with a focus on dermal exposure. Groundwater, a primary domestic water source, is vulnerable to contamination by both natural and anthropogenic activities, including industrial discharge, agricultural runoff, and improper waste disposal. Key heavy metals analyzed included zinc (Zn), cadmium (Cd), manganese (Mn), iron (Fe), and Lead (Pb). Fifteen groundwater samples were collected and analyzed using atomic absorption spectrometry (AAS) following standard procedures. Concentrations were compared against World Health Organization (WHO, 2017) and Nigerian Standard for Drinking Water Quality (NSDWQ, 2007) limits, while potential human health risks were estimated using the United States Environmental Protection Agency (USEPA, 2004) Human Health Risk Assessment (HHRA) framework. Results indicated that zinc (Zn) and iron (Fe) were present at relatively higher levels, with mean concentrations of 3.05 mg/L and 1.53 mg/L, respectively, while lead (Pb) and cadmium (Cd) recorded concentrations of 0.604 mg/L and 0.462 mg/L, exceeding WHO and NSDWQ limits. Chronic Daily Intake (CDI) and Hazard Quotient (HQ) analyses revealed that non-carcinogenic risks from Zn, Fe, and Mn were minimal. However, Pb and Cd posed significant health risks, particularly for children, who exhibited higher exposure levels due to lower body weight and greater dermal contact. Carcinogenic risk assessment further indicated that both Pb and Cd exceeded acceptable USEPA limits, with cadmium presenting the highest lifetime cancer risk. The study concluded that Fe and Zn likely originated from natural geogenic sources within the Benin Formation, while Pb and Cd contamination was predominantly anthropogenic, linked to industrial, domestic, and agricultural activities. The uneven spatial distribution of metals highlighted the influence of proximity to pollution sources. These findings underscore the urgent need for continuous groundwater monitoring, effective waste management, and public health interventions to mitigate exposure risks in Oluku, ensuring the safety of groundwater resources for domestic use.

Polyherbal formulations have long been utilized in traditional medicine for their synergistic therapeutic benefits. This study evaluated the comparative antimicrobial activities of Macedar a polyherbal formulation composed of Carica papaya leaves, Veronica amygdalina leaves, and Croton hirtus leaves and Carica papaya leaves alone. Methanol extracts were prepared using cold maceration and tested against selected Gram-positive (Staphylococcus aureus, Bacillus cereus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria through agar well diffusion at varying concentrations (62.5–500 mg/ml). The results revealed that both extracts exhibited significant, dose-dependent antibacterial activity, with Macedar demonstrating stronger inhibitory effects across all test organisms. The highest inhibition zones were observed at 500 mg/ml, with Staphylococcus aureus showing the greatest susceptibility. These findings indicate that the synergistic interaction of the three plants in Macedar enhances antimicrobial potency beyond that of single-plant extracts. The study provides scientific validation for the ethno medicinal use of these plants and highlights the potential of polyherbal formulations Macedar as effective alternatives in combating resistant bacterial infections.

Haemolytic anaemia is characterised by accelerated erythrocyte destruction and is often accompanied by oxidative damage and organ dysfunction. Medicinal plants used in traditional medicine may offer protective and regenerative benefits in anaemic conditions. This study evaluated the regenerative effects of a polyherbal aqueous leaf extract of Ipomoea batatas, Justicia carnea and Ficus sur on selected organs in phenylhydrazine-induced haemolytic anaemic rats. Anaemia was induced in Wistar rats using phenylhydrazine hydrochloride. Animals were treated with graded doses of the polyherbal extract, while control groups included normal and anaemia-induced untreated rats. Liver, spleen and thymus tissues were harvested and processed for histopathological examination using haematoxylin and eosin staining. Phenylhydrazine-induced anaemia caused marked histopathological alterations in the liver, spleen and thymus, including hepatocellular degeneration, splenic architectural distortion and thymic involution. Treatment with the polyherbal extract resulted in varying degrees of tissue protection and structural recovery across the organs examined. The polyherbal aqueous extract of I. batatas, J. carnea and F. sur demonstrated protective and regenerative effects against phenylhydrazine-induced organ damage, supporting its potential role in the management of haemolytic anaemia.

This study investigated the hydrogeological evaluation of borehole water contamination near a solid waste dumpsite in Iyowa, Benin City, Nigeria. The aim was to assess how dumpsite leachate affects groundwater quality by examining physicochemical, microbiological, and heavy metal parameters. Five borehole samples were collected at varying elevations and distances around the dumpsite (coordinates: 6°27′29″N–6°27′44″N, 5°36′10″E–5°36′37″E) using GPS mapping and WHO-recommended sampling procedures. Laboratory analyses covered pH, electrical conductivity (EC), total dissolved solids (TDS), turbidity, nitrate, sulphate, phosphate, and selected metals (Pb, Fe, Cr, Zn) determined by Atomic Absorption Spectrophotometry (AAS), alongside microbial tests for total coliforms and E. coli. The results (Tables 4.1–4.3, Figures 1–2) showed acidic groundwater (pH 5.19–6.14) below WHO limits (6.5–8.5), with low alkalinity (4–6 mg/L) and elevated metal concentrations: Pb (0.106–0.428 mg/L), Fe (2.98–7.51 mg/L), and Cr (0.37–3.87 mg/L), all exceeding the permissible limits of 0.01, 0.3, and 0.05 mg/L respectively. Potassium spiked at 55.8 mg/L in the borehole closest to the dumpsite (Sample 2), indicating direct leachate influence. Microbial tests showed absence of coliforms and E. coli, but minor heterotrophic bacteria (1 CFU/mL). Overall, the acidic and metal-enriched groundwater reveals significant leachate intrusion linked to dumpsite proximity, making the borehole water unsafe for domestic consumption without treatment. The findings highlight the need for controlled waste disposal, borehole siting regulation, and continuous groundwater monitoring in Iyowa.

This study was designed to assess the presence and levels of selected heavy metals, polycyclic aromatic hydrocarbons (PAHs), and microbes in bank note dust as well as their potential health risks. Two commercial banks (Location A, Ekehuan Road, located in Oredo Local Government Area, and Location B, Ugbowo, University of Benin Campus in Ovia North-East Local Government Area) were selected within Benin City metropolis and banknote dust from the counting rooms were collected. The samples were extracted using wet digestion for heavy metals concentrations and solvent (hexane) extraction for the PAHs. The extracted samples were cleaned up and the concentrations determined using an atomic absorption spectrophotometer, AAS (Buck Scientific, VGP210) and gas chromatograph fitted with flame ionization detector (GC-FID) were used to determine heavy metals and PAHs respectively. Particle size determination was carried out by using the dynamic light scattering (DLS) techniques based onBrownian movement principles. Results obtained revealed that the sizes of the dust particles were in the range of 36.57 nm and 48.48 nm which the nano range (0-100 nm). The results of heavy metal analysis revealed that the concentration of iron was the highest value for both locations A (2,055 ± 70.06 mg/kg) and B (1,934.53 ± 68.64 mg/kg). This result is below standard (10,000 mg/kg) set by WHO/USEPA. While cadmium was the lowest concentration of 1.82 ± 0.30 mg/kg and 0.95 ± 0.15 mg/kg for locations A and B respectively, exceeding the permissible limit of 0.8 mg/kg for cadmium as set by WHO. Copper for locations A and B were found to be 56.06 ± 2.53 mg/kg and 50.56 ± 4.42 mg/kg respectively exceeding limit of 36.0 mg/kg standard set by WHO. The concentrations of the heavy metals were found to follow the order: Fe ˃ Zn ˃ Mn ˃ Cr ˃ Cu ˃ Ni ˃ Pb ˃ Cd for location A and Fe ˃ Zn ˃ Mn ˃ Cu ˃ Cr ˃ Ni ˃ Pb ˃ Cd for location B with location A having higher concentration of Cr than location B. PAHs results revealed that all 16 EPA priority PAHs as specified by WHO/USEPA were detected in the banknote dust samples from the two locations. Location A had the highest PAHs summation of 4.278 µg/kg with pyrene alone contributing 3.084 µg/kg, while for location B, phenanthrene was the highest with a value of 1.167 µg/kg. The diagnostic ratio suggests multi-sources ranging from petrogenic to pyrogenic, traffic to non-traffic emissions, coal and wood combustion. Microbial analysis revealed significant loads of bacteria with 1.2 x 104 cfu and 1.1 x 104 cfu obtained from locations A and B respectively while the fungi load was found to be x 2.0 x 104 cfu and 1.1 x 104 cfu for locations A and B respectively. The bacteria identified was streptococcus spp while the fungi were aspergillus and penicillium. This study clearly indicated the potential health risk faced by bank staff especially those in the cash processing units due to long exposure to banknote dust and it is recommended that regulatory bodies monitor human exposure to these pollutants and adequate personal protective equipment (PPE) be made available to staff working in these sections of the banks.