M. O. Akharame

Heavy metal contamination of freshwater bodies poses a significant environmental and public health concern, particularly in urban regions with increasing anthropogenic activities. This study aimed to evaluate the concentrations and health risks of selected heavy metals in the Ogba River, Benin City, Nigeria. Water samples were collected across three locations (upstream, midstream, and downstream) over three months to assess both spatial and temporal variations. The samples were analyzed for copper (Cu), chromium (Cr), nickel (Ni), lead (Pb), manganese (Mn), and cadmium (Cd) using an atomic absorption spectrophotometer. The data were analysed using SPSS version 22, and descriptive statistics and one-way ANOVA were employed to assess variations, with p < 0.05 considered statistically significant. Results revealed that Ogba River water showed elevated levels of Cr, Ni, Pb, Mn, and Cd, often exceeding WHO and, in some cases, NESREA permissible limits, while Cu remained within safe limits. Children had higher Chronic Daily Intake (CDI) values than adults. Hazard Quotient (HQ) indicated low risk for Cu, Ni, and Mn, but potential non-carcinogenic risk from Cr, Cd, and Pb. Combined Hazard Index (HI) exceeded 1 at all stations, with children more vulnerable. Incremental Lifetime Cancer Risk (ILCR) for Cr, Cd, and Pb surpassed USEPA limits, with Cr posing the highest cancer risk. In conclusion, Ogba River is contaminated with heavy metals exceeding safe limits and posing health risks, particularly to children. Immediate monitoring and pollution control are needed to protect human health and the river ecosystem

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).

Air pollution in motor parks has become an increasing public health concern in many urban areas. This study assessed the concentrations of key air pollutants—Carbon Monoxide, Carbon Dioxide, PM2.5, and PM10—and their associated Air Quality Index levels in selected motor parks in Benin City. The study was conducted between September and November 2024 across four randomly selected motor parks in Oredo Local Government Area.

Air quality measurements were obtained at three different sampling points within each motor park using a handheld multigas detector. Meteorological parameters such as temperature, humidity, and wind speed were also recorded during the sampling period. The collected data were analyzed using descriptive and inferential statistical methods to determine pollutant concentrations and their implications for public health.

The results revealed that carbon monoxide concentrations ranged from 1.2 to 5.8 ppm, while PM2.5 values ranged from 20.3 to 74.6 µg/m³ and PM10 levels ranged from 45.2 to 112.4 µg/m³. Analysis of the Air Quality Index indicated that air quality in some areas ranged from “Moderate” to “Unhealthy for Sensitive Groups,” suggesting potential health risks for commuters, drivers, and traders operating within these motor parks.

The study highlights the urgent need for improved traffic management, stricter vehicle emission regulations, and increased public awareness to reduce air pollution levels in motor parks. It recommends strengthening air quality monitoring systems, enforcing pollution control policies, and promoting cleaner transportation technologies to mitigate the adverse health effects associated with urban air pollution.

This dissertation focused on the effects of zinc oxide nanoparticles (ZnO NPs) on the African
catfish (Clarias gariepinus) embryotoxicity. The total protein levels in the embryos of Clarias
gariepinus were determined following a standard method after exposure to different
concentrations (0.0, 0.5, 1.0, 5.0, and 10.0 µg/L) of ZnO NP for 96 hours. The results showed
that there was a minor increment in the total protein levels at the exposure of Clarias gariepinus
embryos to 0.5 µg/L ZnO NPs and a significant increase in NP concentration at 1 µg/L. The
highest level of the total protein was recorded at the 10.0 µg/L concentration exposure of the
ZnO NP to the embryos. The effect of ZnO NP increases with increasing concentration of the
ZnO NP in a dose-dependent manner. Elevated total protein levels imply that there is a possible
inflammation or infection, and this could lead to adverse developmental challenges for the fish
embryos.