FACULTY OF LIFE SCIENCE

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.

Plants have long been used as medicine to cure a wide range of illnesses and humans have depended on nature to meet their basic needs. This study was aimed at determining the mineral content, proximate content, phytochemical composition and the antibacterial properties of the aqueous and ethanolic extract of citrus sinensis on some bacterial. The aqueous and ethanolic extracts were evaluated for mineral elemental analysis, proximate content and phytochemical properties using the method of A.O.A.C. Antibacterial activity was evaluated using an agar well dilution techniques against five bacterial isolates using the Mueller Hinton Agar (MHA) method. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract were determined using the MIC and MBC. The mineral element of Citrus sinensis of aqueous and ethanolic extract for Sodium (Na) was (250.333 ± 0.333 mg/kg) and (260.300 ± 0.3111 mg/kg), Potassium (K) (3415.667 ± 2.500 mg/kg) and (2215.060 ± 2.400) mg/kg, Calcium (Ca) (1.412.077± 1.400 mg/kg) and (1,521.047 ± 1.453 mg/kg), Phosphorus (P) (0.2100 ± 0.005 mg/kg) and (0.1900± 0.005 mg/kg), Iron (Fe) (1.1400 ± 0.004 mg/kg) and (1.2400 ± 0.009 mg/kg), Nitrogen (N) (0.1400 ± 0.001 mg/kg) and (1.2000 ± 0.009 mg/kg), Magnesium (Mg) (129.100± 0.700 mg/kg) and (131.000± 0.577 mg/kg). The result for proximate content of aqueous and ethanolic extract of Citrus sinensis showed varying composition of moisture content, ash content, crude fibre, crude fat, protein and carbohydrate. The qualitative phytochemical result revealed the presence of phenols, terpenoids, alkaloids, eugenols, flavonoids, tannins, and reducing sugars. The quantitative phytochemical result revealed the presence of alkaloid to be (5.4063 ± 0.2985) for aqueous and (6.3427±0.329) for ethanolic, total saponins, (5.9620 ± 3.6112) for aqueous and (7.0867±0.002) for ethanolic, total phenolic, (0.2077 ± 0.0012) for aqueous and (0.2140±0.001) for ethanolic, total tannins (10.1533 ± 0.0023) for aqueous and (12.7747±0.161) for ethanolic and for total flavonoids, (6.9993 ± 0.0127) for aqueous and (6.5827±0.031) for ethanolic. The antibacterial activity of the crude extract against selected bacterial isolates was also evaluated using the MHA method. It was demonstrated that at a concentration of 200 mg/kg of both the aqueous and ethanolic extract, the extract of Citrussinensis expressed bactericidal potential against the bacterial isolates. The result from this research shows the potency of the extract of Citrus sinensis being able to the utilized for drug formations with antibacterial effects

The scalp hair is composed of soft tissue layers that cover the cranium. This study focused on isolation, identification and antibiogram of bacteria isolates from scalp hair. With the aid of a sterile swab sticks, nine scalp hair of undergraduates’ students were swabbed and transported to the laboratory for bacteriological analysis. All the samples were analyzed within 24hrs of collection. Collected swabbed stick was submerged in a sterile test tubes label A – I contained Nutrient broth and incubated for 2hrs. 1ml was plated from each test tube. It was then incubated at 37 0 C for 24hours. The result of the bacteria isolated include; Staphylococcus epidermis 6 (15%), Staphylococcus aureus 6 (15%), Pseudomonas sp. 2(5%), Bacillus sp. 18(45%), Streptococcus spp. 5(12.5%) and Micrococcus spp. 3(7.5%). Haemolysin test on the strains of Staphylococcus auraeus Streptococcus sp. Staphylococcus epidermis, Micrococcus spp. and Psuedomonas sp. revealed they had β hemolytic activity and only strains of Bacillus spp. showed α hemolytic activity. While the gelatin test showed that all isolates produce gelatinase enzyme which breakdown gelatin. The antibiogram results revealed that All isolates were highly sensitive to ciprofloxacin, Ofloxacin and clindamycin 40(100%). Ciprofloxacin, Ofloxacin and clindamycin was proved to be the most effective against Gram positive and Gram-negative isolates studied in this work. Contamination of scalp hair from this research, could be from poor hand hygiene and environmental hygiene.

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 aimed to investigate the effects of graded doses of Hibiscus Sabdariffa aqueous extract on intraocular pressure (IOP) and blood pressure (BP) in normotensive individuals. A total of 40 university students (22 males, 18 females) aged 18-29 years (mean age: 24.3 ± 3.20 years) participated in this study. The participants were divided into four groups: three experimental groups (A, B, C) and a control group (D), each consisting of 10 normotensive subjects. Baseline IOP and BP measurements were obtained using an iCare TA01i Tonometer and a HEM-7124 blood pressure monitor, respectively. The experimental groups received graded doses of Hibiscus Sabdariffa aqueous extract, and IOP and BP measurements were taken at 30-, 60-, 90-, and 120-minutes post-ingestion. The results showed a significant decrease in IOP in the left eye, with a statistically significant effect observed (p < 0.05), and the most substantial reduction occurred at 120 minutes post-ingestion. Additionally, the effect of Hibiscus Sabdariffa on BP was found to be dose-dependent, with a statistically significant effect observed (p < 0.05). This study recommends that potential integration of Hibiscus sabdariffa leaf aqueous extract as a complementary therapy in the management of certain ocular conditions warrants further consideration. However, additional research is needed to fully elucidate its therapeutic potential and safety profile Keywords: Hibiscus Sabdariffa, Intraocular pressure, Blood pressure and Normotensives.

Lemongrass (Cymbopogon citratus) is widely known for its medicinal and antimicrobial properties, with its extracts being used in traditional and modern medicine. Due to the increasing resistance of bacteria to conventional antibiotics, plant-based antimicrobials have gained attention as alternative therapeutic agents. This study investigated the phytochemical composition and antibacterial activity of hot and cold water extracts of Lemongrass leaves against Staphylococcus aureus, Escherichia coli, and Pseudomonas sp. Phytochemical analysis revealed the presence of flavonoids, tannins, and glycosides in both extracts, with glycosides being more prominent in the hot extract. Saponins, steroids, and terpenoids were absent. Antibacterial activity was assessed using the agar well diffusion method, where the hot extract showed higher zones of inhibition at 100% concentration: S. aureus (13.00 ± 0.00 mm), E. coli (16.00 ± 0.00 mm), and Pseudomonas sp. (18.20 ± 0.00 mm), compared to the cold extract: S. aureus (9.0 ± 0.50 mm), E. coli (11.20 ± 0.20 mm), and Pseudomonas sp. (12.00 ± 0.00 mm). The Minimum Inhibitory Concentration (MIC) revealed that the hot extract inhibited E. coli at 25 mg/ml, Pseudomonas sp. at 50 mg/ml, and S. aureus at 25 mg/ml, while the cold extract only inhibited Pseudomonas sp. at 100 mg/ml and S. aureus at 25 mg/ml. Minimum Bactericidal Concentration (MBC) results showed that the hot extract was bactericidal against S. aureus and bacteriostatic against E. coli and Pseudomonas sp., while the cold extract was bactericidal against Pseudomonas sp. and bacteriostatic against the other isolates. Antibiotic susceptibility testing indicated that Gram-positive bacteria were highly susceptible to ciprofloxacin, while Gram-negative bacteria were sensitive to azithromycin. These results highlight the potential application of Cymbopogon citratus as an alternative treatment for bacterial infections, particularly in combating antibiotic-resistant pathogens.

This study focused on the green synthesis of copper chloride (CuCl2) nanoparticles using onion peel extract as an eco-friendly reducing and stabilizing agent, and evaluated their efficacy in the photocatalytic degradation of crude oil in contaminated wastewater. The synthesized nanoparticles were characterized Dynamic Light Scattering (DLS),X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Scanning electron microscopy (SEM) and Fourier- Transform Infrared (FTIR) spectroscopy. DLS confirmed the formation of nanoparticles with a primary size of 16.25 nm, XRD determined the crystalline phase of the nanoparticles, TGA measured the thermal stability and decomposition temperature, SEM visualized the particle size, shape, surface texture while FTIR analysis identified functional groups from the onion peel extract, verifying its role in capping and stabilizing the particles. The photocatalytic activity of the nanoparticles was assessed by studying the degradation of total petroleum hydrocarbons (TPH) under sunlight, investigating the effects of catalyst dose, pH, temperature, and initial pollutant concentration. Results demonstrated that the green-synthesized CuCl2 nanoparticles were effective in degrading crude oil components, with optimal performance observed under specific conditions. This indicates that onion peel-mediated CuCl2 nanoparticles present a sustainable, cost-effective, and promising photocatalyst for remediating crude oil-contaminated water, offering a potential solution for environmental cleanup, particularly in oil producing regions like the Niger Delta.

Wastewater drains within university hostels can serve as reservoirs for various microorganisms, including opportunistic pathogens that pose significant health and environmental risks. Among these microbes, Klebsiella species—especially Klebsiella oxytoca—are notable for their ability to survive in damp environments and their resistance to multiple antibiotics. This study aimed to isolate and identify Klebsiella spp. from wastewater drains in male hostels (Hall 3 and Hall 4) at the University of Benin, Edo State, Nigeria. Wastewater samples were aseptically collected from four designated drain points—two each from Hall 3 and Hall 4—using sterile 500 mL bottles. The samples were transported in ice-packed coolers to the Microbiology Laboratory, Faculty of Life Sciences, for bacteriological examination. Standard microbiological methods were used to enumerate, isolate, and identify bacterial species based on their cultural, morphological, and biochemical features. The total heterotrophic bacterial counts ranged from 4.82 to 4.87 Log₁₀ CFU/mL, reflecting high microbial loads in all the sampled drains. Total Klebsiella counts varied between 5.75 to 6.00 Log₁₀ CFU/mL, with the highest found at Hall 4 Point A and the lowest at Hall 3 Point A. The identified bacterial isolates included Escherichia coli, Klebsiella oxytoca, Bacillus subtilis, Staphylococcus aureus, and Pseudomonas aeruginosa. Notably, Klebsiella oxytoca appeared consistently across all sampling points, indicating its strong adaptability to wastewater environments. The findings underscore that hostel drainage systems can act as reservoirs and transmission routes for potentially pathogenic and environmentally persistent bacteria. Regular sanitation and effective wastewater management are therefore essential to minimize environmental contamination and associated public health risks.

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.

Medicinal plants have long been recognized for their therapeutic properties and remain an essential source of bioactive compounds with potential antimicrobial activity. The growing problem of antibiotic resistance has heightened global interest in exploring natural plant extracts as alternative or complementary agents against infectious diseases. This study evaluated the phytochemical composition and antimicrobial potential of lemongrass (Cymbopogon citratus) and uziza leaf (Piper guineense) extracts against selected bacterial and fungal pathogens. Fresh leaves of both plants were collected from local markets in Benin City, Edo State, Nigeria, authenticated, air-dried, pulverized, and extracted using ethanol and water. Phytochemical screening revealed the presence of alkaloids, flavonoids, tannins, terpenoids, and saponins in varying concentrations. Lemongrass contained high levels of alkaloid, flavonoids and tannins, while uziza exhibited moderate presence of these compounds. Saponin was present in lemongrass but absent in uziza. Antimicrobial testing showed that ethanolic extracts demonstrated superior activity compared to aqueous extracts. The ethanolic extract of lemongrass exhibited the highest inhibition zone of 20 mm against S. aureus and 15 mm against E. coli at 100% concentration, while the uziza ethanolic extract produced inhibition zones of 18 mm and 15 mm, respectively, against the same organisms. Pseudomonas sp. showed moderate sensitivity with inhibition zones of 12 mm, whereas fungal isolates Aspergillus sp., Penicillium sp. and Fusarium sp. recorded inhibition zones ranging from 10 to 15 mm. The minimum inhibitory concentration (MIC) for ethanolic extracts ranged from 50 mg/mL for S. aureus, E. coli and Pseudomonas sp. to 100 mg/mL (for fungal isolates), while minimum bactericidal concentrations (MBCs) were observed at 100 mg/mL. Aqueous extracts displayed weaker activity, requiring higher concentrations (100 mg/mL) for inhibition and showing little or no effect on fungal isolates. Overall, these findings highlight the significant antimicrobial potential of lemongrass and uziza leaf extracts, particularly their ethanolic forms, which exhibited notable inhibitory effects against common bacterial pathogens. The results support their traditional medicinal use and underscore their potential as natural sources of plant-based antimicrobial agents.