DEPARTMENT OF ENVIRONMENTAL MANAGEMENT AND TOXICOLOGY

Heavy metal contamination from mechanic workshops poses a major environmental challenge due to the continuous accumulation of toxic metals in soil, which can affect microbial activities, reduce soil fertility, and pose health risks to humans and other organisms. This study assessed the effectiveness of hydroxyapatite (HAp) and phosphate solubilising bacteria (PSB) (Pseudomonas sp.) in remediating heavy metal contaminated soil collected from a mechanic workshop. The research involved four treatments: soil only (control), soil + PSB, soil + HAp, and soil + PSB + HAp. Microbial counts and heavy metal concentrations (Fe, Cu, and As) were analyzed after incubation. The total heterotrophic bacterial count (THBC) increased from 2.5 × 10⁵ CFU/g in soil treated with PSB alone to 2.75 ± 0.71 × 10⁵ CFU/g in soil treated with both PSB and HAp, indicating enhanced microbial growth due to the combined amendment. The concentrations of iron (Fe) and copper (Cu) decreased significantly in all treated samples compared to the control. Fe reduced from 7561.97 mg/kg in the control to 6197.18 mg/kg in the combined treatment, while Cu decreased from 205.32 mg/kg to 150.19 mg/kg. Percentage reductions of 18.05% (Fe) and 26.85% (Cu) were recorded for the combined treatment, while arsenic (As) was not detected in any sample. These findings demonstrate that hydroxyapatite and Pseudomonas sp. act synergistically to immobilize and reduce heavy metal concentrations in contaminated soils. The combination improves microbial activity, enhances metal precipitation, and reduces the bioavailability of toxic metals. The study concludes that the combined use of hydroxyapatite and phosphate solubilising bacteria is an efficient, low-cost, and environmentally friendly method for remediating heavy metal–polluted soils from mechanic workshops in Nigeria.

Meteorological conditions play an important role in ambient air pollution by influencing the emissions, transport, formation, and deposition of air pollutants both directly and indirectly. The relationships between meteorological parameters and particulate matter concentrations were investigated in ten (10) randomly selected locations within the University of Benin, Benin City, Nigeria. The particulates (PM1.0, PM2.5, and PM10), relative humidity (RH), and temperature were quantified using Dienmern DM106A Air Quality Detector, while the wind speed (WS) was monitored using the Holdpeak 866B digital anemometer respectively for four weeks. The ambient temperature and relative humidity and the concentrations of PM2.5 and PM10 obtained in this study were 34.1 to 36.1℃; 62.9 to 38.1%; 0.;8 to 1.9m/s 25.9 and 30.5µg/m3 .and 57.0 to 62.2 µg/m3. The values obtained were all above the recommended allowable limits. There were generally weak associations between air pollutants and meteorological parameters (R=-0.261, - 0.282, and -0.271; p<0.001)). The air quality index assessment revealed that the particulate matter AQI status was primarily unhealthy. The high levels of particulate matter obtained in the study call for the urgent need for awareness of air pollution-related health effects and preventive measures to reduce the concentrations of Particulate matter pollution. within the University

Benny seasoning is a cooking powder that is commonly used in Africa for improving the taste, aroma and color of food. The potential health risk from the use of Benny seasoning powder remains unclear. Oxidative stress has been implicated in disease onset. Hence in this study, oxidative parameters were assessed in fruit flies (Drosophila melanogaster) exposed to Benny seasoning at various concentrations (Control, 0.025 g/mL, 0.05 g/mL and 0.1g/mL)for seven (7) days. A survival study and climbing assay was conducted and the observations obtained from the study showed that with increasing concentration, mortality rate increased and the climbing activity decreased. After homogenization, specific markers of oxidative stress response (Protein, Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase(GPx), and malondialdehyde (MDA)) were assessed. The results showed that there was no significant difference (p<0.05) when control was compared with the treatment groups. However there were alterations (increase and decrease) in all of the markers indicating a response to oxidative stress. Some genes involved in neurotoxicity were observed (SPITZ, WINGLESS, EIGER, FOXO HEDGEHOG, KEAP1) after exposure to Benny seasoning. There were significant differences with increasing concentrations in the expression of thesegenes indicative of neurotoxicity. Further studies may be needed to fully assess oxidativeeffect at the genetic level in order to completely understand the oxidative stress responses of Drosophila melanogaster to Benny seasoning powder

Industrial effluents are significant contributors to environmental pollution, especially in developing countries where waste treatment is inadequate. Ceramic industries generate wastewater that often contains toxic heavy metals capable of accumulating in the environment and posing serious health risks. This study assessed the concentration of heavy metals in effluents discharged from a ceramic industrylocated in Utesi, Ikpoba-Okha Local Government Area, Edo State, Nigeria, and evaluated the associated potential health risks. Nine effluent samples were collected from three points around the discharge pond over three months. The samples were analyzed for copper (Cu), chromium (Cr), nickel (Ni), lead (Pb), manganese (Mn),and cadmium (Cd) using the Atomic absorption spectrophotometer following standard procedures. Results showed that Mn had the highest concentration (1.07 3.00 mg/L) in July, while chromium was most abundant in June (0.97–1.00 mg/L). Lead and copper ranged between 0.10–0.47 mg/L and 0.10–0.57 mg/L, respectively, while cadmium reached 0.63 mg/L in August. Compared with the WHO and NESREA standards, Cr, Pb, Mn, and Cd exceeded permissible limits. The mean concentration trend was Mn (1.10 mg/L) > Cr (0.58 mg/L) > Pb (0.27 mg/L) > Cu (0.24 mg/L) > Cd (0.22 mg/L) > Ni (0.06 mg/L). Health risk assessment revealed that cadmium posed the highest non-carcinogenic (HQ = 0.43 for children) and carcinogenic risks (CR = 2.62 × 10⁻⁴ for children).

This study evaluated indoor air quality and examined major risk factors for respiratory symptoms among students who used University of Benin libraries and laboratories. The concentrations of particulate matter, carbon dioxide, and formaldehyde were measured during the morning and afternoon sampling periods, and a structured questionnaire was used to collect demographic, environmental, and health data. Statistical analyses included paired-samples t tests and chi- square tests, with significance set at p < 0.01. The mean pollutant concentrations range from 14.5 ± 0.6 to 24.1 ± 3.1 µg/m³ (PM₂.₅), 27.0 ± 1.5 to 43.2 ± 6.7 µg/m³ (PM₁₀), 399.5 ± 0.3 to 404.4 ± 4.7 ppm (CO₂), and 0.003 ± 0.000 to 0.026 ± 0.012 mg/m³ (HCOH), 24.6 ± 0.2 °C to 32.6 ± 3.7 °C (Temperature), and 69.1 ± 0.5% RH to 78.3 ± 0.6% RH (Relative Humidity).The mean pollutant concentrations did not differ significantly between the morning and afternoon samples, indicating temporal stability. In contrast, environmental factors were significantly associated with symptom prevalence. Notably, a highly significant but inverse relationship emerged for cleaning frequency: participants reporting daily cleaning reported the highest symptom prevalence compared with those reporting monthly cleaning. Demographic variables such as age and sex were not significant predictors of symptoms. These findings indicate that respiratory health risks in these indoor settings are driven less by short-term fluctuations in measured pollutants and more by shortcomings in building maintenance.

Access to safe drinking water remains a critical public health concern in many developing communities. This study assessed the quality of drinking water and associated human health risks among households in Uholor Community, located off Upper Ekehaun, Benin City, Edo State. Water samples were collected from multiple household sources, including boreholes, wells, and stored water, and analyzed for key physicochemical and microbiological parameters using standard methods.
The results revealed variations in water quality across sources, with several samples exceeding recommended limits for parameters such as pH, turbidity, total dissolved solids, and microbial contamination indicators, including total coliforms and Escherichia coli. The presence of these contaminants suggests potential pollution from environmental and anthropogenic activities, including poor sanitation practices and inadequate waste disposal systems. Health risk assessment indicated that residents may be exposed to waterborne diseases such as diarrhea, typhoid fever, and cholera, particularly among vulnerable populations such as children and the elderly.
Overall, the findings highlight significant concerns regarding the safety of drinking water in the study area. The study recommends regular monitoring of water quality, improved sanitation infrastructure, public health education, and the implementation of appropriate water treatment methods at the household level. Ensuring access to clean and safe drinking water is essential to reducing health risks and improving the overall well-being of the Uholor Community.

Environmental pollution from heavy metals in mechanic workshop soils poses serious threat to soil fertility, microbial health and groundwater quality. This study evaluated the bioremediation potential of phosphate solubilizing bacteria (Pseudomonas sp.) and hydroxyapatite in reducing heavy metal concentrations in contaminated soil. The study was carried out in a mechanic workshop in Osasogie, Ugbowo, Benin city, Edo state, Nigeria with four treatments: soil only (O1), soil + phosphate solubilizing bacteria (O2), soil + hydroxyapatite (O3) and soil + phosphate solubilizing bacteria + hydroxyapatite (O4). Microbial count and heavy metal concentrations (iron, copper and arsenic) were tested after 14 days. According to results hydroxyapatite was most effective in increasing the growth of Pseudomonas sp. and in the remediation of soil contaminated with copper and iron while phosphate solubilizing bacteria was the least effective due to the short period of remediation. In conclusion, Pseudomonas sp. and hydroxyapatite showed great promise in cleaning up heavy metal contaminated soil from a mechanic workshop.

Access to safe drinking water remains one of the most critical public health challenges in Nigeria, where millions lack reliable sources. Rapid urbanization and inadequate waste management have contributed to the documented water quality challenges in Benin City. However, data on specific localities such as the Uholor community is scarce. In this study, an assessment of drinking water quality based on physicochemical and microbiological parameters was made. Observational checklists were also used to assess environmental conditions and hygiene practices at the household levels. Results have shown that sachet water is the main source of drinking water in the study area, at 52.5%, followed by boreholes at 41.6%. Another high-risk finding is that as many as 69.4% of the households do not treat water before drinking. Though a majority of the respondents, 89.1%, reported the use of flush toilets, environmental sanitation among households is poor 70.3%. The hygiene practices also showed a gap between knowledge and action, as while 91.9% of the respondents were "very" or "somewhat" aware of WASH importance, only 17% reported always using soap to wash their hands. Additionally, 24.6% of households "rarely" clean their water storage containers, entailing a risk of re-contamination. 31.7% of those reporting health issues cited poor taste of water, while 35.4% of households reported illness related to water in the last six months, predominantly Typhoid, 74.3%. The study finds that the community of Uholor is highly exposed to health risks from contaminated drinking water due to widespread non-treatment, and inadequate hygiene practices.

Public health and illness prevention depend on having access to clean drinking water and practicing good hygiene. To determine their effects on community health, the Upper Mission community in Benin City's water quality and cleanliness practices were examined. One hundred households chosen by multistage sampling were included in the community-based cross-sectional design. To investigate water sources, storage procedures, treatment techniques, and hygiene practices, structured questionnaires were given out. Additionally, physicochemical and microbiological analyses were performed on 30 drinking water samples obtained from river sources, sachet water, and boreholes. 89% of households have access to water within 100 meters of their homes, with sachet water (52%) and borehole water (41%) serving as the main sources of drinking water. There is a significant gap between accessibility and safety practices, as 80% of individuals did not purify the water before drinking it. With pH values ranging from 4.6 to 8.0, total dissolved solids between 24 and 136 milligrams per liter, and electrical conductivity between 44 and 219 microsiemens per centimeter, the physicochemical parameters mostly satisfied WHO requirements. River water had the highest
contamination (mean: 202.4×10⁰ colony-forming units per milliliter), followed by borehole water (79.7×10⁰ colony-forming units per milliliter) and sachet water (43.2×10⁰ colony-forming units per milliliter), according to microbiological analysis, which found
heterotrophic bacterial counts ranging from 26×10⁰ to 235×10⁰ colony-forming units per milliliter). River water (mean: 42.6×10⁰ colony-forming units per milliliter) and some borehole samples (mean: 24.9×10⁰ colony-forming units per milliliter) had total coliforms, but sachet water did not. Only one sample of river water had Escherichia coli. Although the infrastructure is good, there are notable shortcomings in environmental hygiene, handwashing with soap (34%), and water treatment, with 38% of residences located close to waste disposal sites. There is an immediate need for improved waste management systems, borehole maintenance, targeted health education initiatives, and increased water quality monitoring

The rapid urbanization of the 21st century significantly alters local climates, manifesting in phenomena like the Urban Heat Island (UHI) effect and elevated concentrations of greenhouse gases (GHGs). The COVID-19 lockdown offered a rare natural experiment to evaluate the extent to which human activities influence urban thermal environments and atmospheric conditions. This study employed remote sensing and Geographic Information System (GIS) techniques to analyse the effects of the COVID-19 lockdown on Urban Heat Islands (UHIs), Land Surface Temperatures (LST), and Greenhouse Gases (GHGs) in Abuja, Nigeria. Landsat 8 satellite imagery was used to derive UHI and LST data, while Sentinel-5P provided atmospheric measurements for key GHGs including sulphur dioxide (SO2), aerosols, and ozone (O3). The analysis covered three temporal phases which are the pre-lockdown (2017–2018), lockdown (2019–2020), and post-lockdown (2021–2024) and data were processed using Google Earth Engine and ArcGIS environments to classify spatial variations and identify thermal patterns across the study area. The results revealed a significant decline in both UHI and LST intensity during the lockdown period, with mean UHI values dropping from 6.00°C in 2017– 2018 to 4.93°C in 2019–2020, before rising again to 6.72°C post-lockdown. LST followed a similar trend, decreasing from 6.96°C to 5.14°C during lockdown and increasing thereafter. A corresponding reduction was also observed in atmospheric pollutants, with sulphur dioxide, aerosols, and ozone concentrations all declining during the lockdown. Pearson correlation analysis showed a strong positive relationship between UHI and LST (r = 0.786–0.877), confirming their interdependence and direct link to anthropogenic activity. These findings underscore the dominant role of human activities in shaping urban climatic and atmospheric conditions. The temporary cooling and emission reduction during the lockdown illustrate the potential environmental benefits of reduced fossil fuel consumption and improved urban planning. The study highlights the critical importance of integrating green infrastructure, energy-efficient systems, and climate-responsive policies into Abuja’s urban development framework. It further demonstrates the value of remote sensing and GIS as essential tools for continuous environmental monitoring and policy formulation toward achieving Sustainable Development Goals 11 (Sustainable Cities and Communities) and 13 (Climate Action)