DEPARTMENT OF ENVIRONMENTAL MANAGEMENT AND TOXICOLOGY

The hazards that microplastic pollution have incurred ecologically has made it a key environmental concern. This study determined the occurrences of microplastics in the surface water taken from Ikpoba River in Benin City, Nigeria. A total of thirty (N=30) water samples were obtained from the period of August to September 2025. The samples were collected in glass bottles from both upstream and downstream areas of the river and then tested in the laboratory using standard methods. Eight different polymer types were identified from Station 1, 2, and 3 including, Polyethylene Terephthalate (PET), Polyethylene (PE), Polypropylene (PP) and Polyvincyl Chloride (PVC) materials known for their potential toxic effects. The polymer composition of microplastics was confirmed using the Fourier-Transform Infrared Spectroscopy (FTIR). The result showed that microplastics were abundant in station 3, (40.35%) and was relatively low in station 1 (26.07%). The mean and standard error (S.E) indicated low concentrations of microplastics in the upstream (13.00 ± 1.58) and high concentrations in the downstream (20.12 ± 1.70). The findings indicate that microplastics pollution in the Ikpoba River may have potential ecological and human health implications due to long-term exposure and bioaccumulation in the aquatic environment. Consequently, it is important for government agencies and environmental regulators to improve waste management practices, adopt stricter regulations for plastic disposal, and scale up public awareness campaigns to mitigate plastic pollution and protect aquatic ecosystems and human populations.

This study evaluated the genotoxic risk associated with chronic exposure to petrol fumes among petrol station attendants in Benin City using the micronucleus (MN) assay on exfoliated buccal epithelial cells. A cross-sectional design was employed, comparing 25 exposed attendants with 10 unexposed controls. Buccal cell samples were collected with sterile tongue depressors, fixed in Carnoy’s fixative, and stained with May–Grünwald and Giemsa. A total of 3,400 cells were microscopically examined and scored for nuclear abnormalities according to established cytogenetic criteria. Results showed highly significant increases (p < 0.001) in all nuclear anomalies among the exposed group. Mean frequencies of micronucleate (10.76 ± 3.36 vs. 1.3 ± 0.82 per 1000 cells), binucleated (6.28 ± 2.55 vs. 0.5 ± 0.70), karyorrhexis (7.52 ± 2.47 vs. 1.0 ± 1.15), and anucleate (7.60 ± 2.54 vs. 0.7 ± 0.82) cells were markedly elevated in the exposed group, representing 8.3-, 12.6-, 7.5-, and 10.9-fold increases respectively, with p-values ranging from 2.17E-07 to 7.43E-10. These findings provide compelling evidence of substantial cytogenetic damage indicative of chromosomal instability and cytotoxic effects resulting from petrol fume exposure. The study concludes that occupational exposure to petrol fumes poses a significant genotoxic hazard and recommends strict enforcement of safety protocols, use of personal protective equipment, regular biomonitoring, and improved environmental controls at petrol stations to reduce health risks and safeguard workers.

This study examined the concentration trends and spatial distribution of tropospheric formaldehyde (HCHO) and ozone (O₃) across Lagos State, Southwestern Nigeria, from 2019 to 2024 using Sentinel-5P data processed on the Google Earth Engine (GEE) platform. These pollutants were selected due to their relevance to urban photochemical processes and respiratory health risks in rapidly developing megacities. Formaldehyde exhibited a marked seasonal cycle, with elevated concentrations during the dry Harmattan season (January–March) and lower values during the rainy months (June–September). High HCHO levels were consistently observed in dense and industrialized local government areas (LGAs) such as Ikeja, Kosofe, Shomolu, Oshodi-Isolo, and Lagos Island. Ozone demonstrated an opposite seasonal pattern, peaking in mid-year months (July–August), particularly across coastal LGAs including Eti-Osa, Ibeju-Lekki, and Epe, due to increased solar radiation and marine airflow dynamics favourable for photochemical ozone formation. Paired sample t-test results revealed no statistically significant differences in formaldehyde concentrations across all consecutive years (p > 0.05), indicating emission stability during the study period. Conversely, ozone concentrations showed a highly significant increase between 2021 and 2022 (p < 0.01), suggesting enhanced photochemical activity or intensified precursor emissions during that period. Overall findings highlight the role of anthropogenic emissions, seasonal meteorology, and policy interventions in shaping Lagos air quality. The study recommends strengthened emission controls, improved transportation systems, and continuous satellite-based air-quality monitoring to mitigate pollution impact.

Noise pollution is an increasingly recognized occupational hazard within healthcare environments, where the continuous operation of medical equipment, alarms, and human activity often generates sound levels exceeding recommended limits. This study investigated noise exposure levels and the prevalence of hearing impairment among hospital workers in Benin City, Edo State, Nigeria. A comparative cross-sectional approach was employed in two hospitals, the University of Benin Teaching Hospital (public) and Faith Mediplex Hospital (private). Noise measurements were conducted in selected wards via a calibrated AR824 sound level meter, while structured questionnaires and the Hearing Health Quick Test (HHQT®) were administered to 152 staff members to assess auditory and nonauditory effects. The findings revealed that average noise levels ranged between 63.1 dB and 77.7 dB, exceeding the permissible limit of the National Environmental Standards and Regulations Enforcement Agency (NESREA). The Pediatrics, Emergency, and COPD wards recorded the highest noise intensities. Statistical analysis revealed significant variation across hospital departments (p < 0.05) but no significant difference between public and private hospitals. Among the respondents, 86.2% exhibited signs of potential hearing problems, 21.7% reported hearing difficulty, and 20.4% reported tinnitus. Nonauditory symptoms such as tiredness (52.6%), poor sleep quality (31.6%), and lack of concentration (38.8%) were also prevalent. The study concluded that hospital workers in Benin city are consistently exposed to hazardous noise levels capable of inducing hearing impairment and related health effects. It recommends regular noise monitoring, staff education, and the enforcement of hearing conservation programs within healthcare facilities.

This study assessed the quality of drinking water in households within Utagban Community, Benin City, Nigeria, an area largely inhabited by artisans and small business owners who depend on sachet, borehole, and well water for domestic use. The aim of the study was to evaluate the drinking water quality and household water management and hygiene practices, in Utagban community. The study examined physicochemical characteristics, and determined the levels of total heterotrophic bacteria, coliforms, and Escherichia coli across various water sources. A structured questionnaire was used to assess the various household hygiene practices. Water samples (25) were aseptically collected from household for laboratory analysis. Physicochemical parameters such as pH, temperature, total dissolved solids (TDS), electrical conductivity (EC), and salinity were measured using a digital water quality meter, while microbiological analysis was conducted using the spread plate technique on Nutrient Agar and Chromogenic Coliform Agar to quantify bacterial loads. Data were analyzed using SPSS version 22.0 and Microsoft Excel. Results showed that sachet water was the most consumed (67%), followed by borehole water (30%) and well water (2%). Physicochemical parameters were generally within WHO limits, with pH ranging from 6.2 to 7.7. Mean heterotrophic bacterial counts varied from 0 to 82×10² CFU/mL, highest in well water. Coliforms were detected in borehole and sachet water but absent in bottled water, and E. coli was not found in any sample. The findings highlight moderate microbiological contamination in some water sources, underscoring the need for regular monitoring and improved household hygiene practices to ensure safe drinking water.

This study assessed DNA damage in commercial drivers exposed to vehicular emissions at the University of Benin (UNIBEN) Main Gate, Benin City, using the micronucleus assay of buccal cells. Vehicular emissions are a major source of air pollution containing genotoxic substances such as polycyclic aromatic hydrocarbons, nitrogen oxides, and particulate matter, which can induce chromosomal damage. A comparative cross-sectional design was used, involving 25 exposed drivers and 9 non-exposed controls. Buccal epithelial cells were collected using sterile wooden spatulas, fixed in Carnoy’s reagent, and stained with May-Grünwald–Giemsa for microscopic analysis. One hundred cells per participant were scored for nuclear abnormalities including micronuclei (MN), binucleated cells (BN), and nuclear buds (NB). Statistical analysis was carried out using SPSS v25, with p < 0.05 as the significance threshold. Results showed that the exposed drivers had markedly higher frequencies of nuclear anomalies compared to controls. The mean micronucleus frequency in the exposed group (8.00 ± 0.05 per 100 cells) was about 80 times higher than in the control group (0.10 ± 0.01), while BN and NB frequencies were increased 12-fold and 23-fold respectively. The total nuclear abnormality frequency was 165.00 ± 0.36 in exposed drivers versus 10.20 ± 0.94 in controls. Although the differences were not statistically significant, the biological trend suggests cumulative genotoxic stress from chronic exposure to vehicular pollutants. Routine biomonitoring and stricter air-quality measures are recommended to protect occupationally exposed populations.

Heavy metal contamination of food crops is a major environmental and public health hazard, especially in poorer countries with poor waste management procedures. This study looked at the bioaccumulation of selected heavy metals—Cadmium (Cd), Lead (Pb), Zinc (Zn), Nickel (Ni), and Copper (Cu)—in commonly consumed fruit samples (pawpaw, orange, pear, and garden egg) collected from areas with improper waste disposal in Obazogbe Community, Orhiomwon Local Government Area, Edo State, Nigeria. Following regular digestion processes, samples were analysed using Atomic Absorption Spectrophotometry (AAS). The observed metal concentrations were compared to the allowed limits defined by the World Health Organisation (WHO) and the Food and Agriculture Organisation (FAO). The results showed that Pb and Cd levels in most fruit samples surpassed suggested safety criteria, whereas Zn, Ni, and Cu were within or slightly above permissible ranges. The increased levels of Pb and Cd suggest contamination from local dumpsites, open garbage burning, and polluted irrigation water. Continuous use of such tainted fruits may pose major health hazards, including neurotoxicity, renal damage, and carcinogenic effects. The study emphasises the critical need for better waste management techniques, regular environmental monitoring, and public health awareness in order to limit heavy metal exposure through fruit intake. It also advocates for the implementation of sustainable agriculture and waste disposal techniques in rural communities to protect food safety and human health.

Air pollution in market environments poses significant public health risks, particularly in urban areas with high commercial activities. This study aims to determine the concentrations and health risks associated with ambient air pollutants in the Uwelu Spare Parts Market, Benin city, Nigeria. Air quality monitoring was carried out weekly from October to December 2024 at morning and evening intervals. Carbon monoxide (CO), PM2.5, and PM10 concentrations were measured via a Smart Sensor Model AS8700A, whereas temperature and relative humidity were recorded via an anemometer (BTMETER BT-100). A structured questionnaire was used to assess the respiratory health status of market users. The results revealed that CO concentrations ranged from 2.5–3.6 ppm in the morning and 2.3–3.2 ppm in the evening, remaining within the WHO (2021) limits. However, the PM2.5 and PM10 levels exceeded the WHO guidelines in the evening, indicating increased pollution due to commercial activities, generator use, and waste burning. Statistical analysis revealed significant variations (p<0.01) in the PM10 concentrations in the morning and in the PM2.5 and PM10 levels in the evening. Common respiratory symptoms reported among the respondents included cough (67%), phlegm (36%), and chest pain (20%). This study recommends improved waste management, regulated generator use, enhanced ventilation, and routine air quality monitoring to mitigate risks and protect public health. Implementing these measures can contribute to a safer market environment.

Climate change is part of the most pressing environmental challenges of the 21st century, with its adverse effects felt across the globe through increase in temperatures, altered rainfall patterns, and increasing incidences of extreme weather events. These changes pose serious threats to food security, livelihoods, and sustainable development. In regions like Benin City (Edo State, Nigeria), climate-induced flooding and other extreme events have undermined food availability and lead to food security. This study examines determinants of adopting climate change adaptation strategies for food security in Benin City. A structured Likert-scale questionnaire was distributed to one hundred and fifty (150) respondents using google form and the data collected was subjected to descriptive and correlation statistics using statistical package for social scientists (SPSS) . The results showed low awareness of climate change impacts on food security. Correlation analysis revealed moderate positive relationships between awareness to climate change and socio-demographic factors which is statistically significant (r = 0.373, p = 0.000<0.05) and between awareness to climate change and socio-cultural influences which is also statistically significant (r = 0.380, p = 0.000<0.05). However, the study also identified barriers such as inadequate institutional support, limited access to finance, and weak infrastructural capacity as key challenges limiting effective responses. It was concluded that although local communities in Benin City demonstrate resilience through livelihood diversification, their capacity to adapt remains constrained without coordinated government intervention and broader policy support. The study recommends the introduction of climate change awareness into educational and extension programmes, the promotion of renewable energy and sustainable agricultural practices, improved access to climate information, investment in sustainable agricultural practices, and stronger collaboration between government agencies, private actors, and civil society in order to enhance adaptive capacity and safeguard livelihoods.

Access to clean and safe water is fundamental to sustaining public health and ensuring community well-being. This study assessed the water quality and hygiene practices of households in Ogbelaka, Benin City, Edo State, Nigeria. The research aimed to determine the microbiological quality of household water, evaluate hygiene practices, and identify householdlevel factors contributing to contamination. A cross-sectional design was employed, combining field sampling and survey methods. Water samples from selected households were analyzed for thermotolerant coliforms and Escherichia coli using standard microbiological procedures. Data on hygiene, sanitation, and water handling practices were collected through structured questionnaires. Results indicated that a significant proportion of water samples showed microbial contamination exceeding WHO permissible limits, highlighting risks of waterborne diseases. Many households relied on untreated or poorly treated water sources such as boreholes and wells, with inadequate storage and handling practices contributing to contamination. Hygiene practices, particularly handwashing with soap at critical times, were suboptimal, and household water treatment methods were inconsistently applied. The findings underscore the urgent need for public health interventions that promote community- based water treatment, improved sanitation, and sustained hygiene education. The study concludes that strengthening local water management, behavioral change communication, and enforcement of water quality standards are crucial steps toward achieving Sustainable Development Goal 6 (Clean Water and Sanitation) in Ogbelaka and similar semi-urban communities.