Study of Surface Morphology, Elemental Composition and Sources of Airborne Fine Particulate Matter in Agbara Industrial Estate, Nigeria

Ambient atmospheric fine particle emission contribution to industrial pollution load is hard to quantify due to absence of air quality monitoring stations and difficulties in assessing suitable analytical instruments. Therefore, to keep abreast of air quality information, the use of physicochemical signatures to assess the sources of elements associated with fine particulate matter in Agabra Industrial Estate was explored with Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X-ray (EDX) and Principal Component Analysis (PCA). A greater proportion of Si and C were observed in the particles amongst other detected elements by EDX. Morphology results by SEM confirmed soot, alumino silicate and irregular shape mineral particles as the most common inhalable particles. Prominent among emission sources identified are industries, automobile exhaust, fugitive dust and solid waste combustion. The research suggests that adequate public awareness, industrial compliance, vehicle emission control, smooth operation of municipal solid waste incineration and government regulation will significantly reduce fine particulate pollution

Chemical Speciation and Health Risk Assessment of Fine Particulate Bound Trace Metals Emitted from Ota Industrial Estate, Nigeria

In this study carcinogenic and non-carcinogenic health risk due to exposure to PM2.5-bound trace metals from an industrial area in Southwestern Nigeria was estimated. A four-step chemical sequential extraction procedure was employed for the chemical extraction of arsenic (As), cadmium (Cd), chromium (Cr) copper (Cu), manganese (Mn), nickel (Ni), and zinc (Zn). Samples were analyzed using inductively coupled plasma mass spectrometry (ICPMS). Results reveal Cr and Cu as the most dominant exchangeable fraction metals, indicating possibility of their being readily soluble once PM2.5 is inhaled. Cd and Cr record the highest bioavailability index of 0.7. The cumulative lifetime cancer risks due to inhalation exposure for adults (4.25×10-2), children 1-6 years old (4.87×10-3), and children 6-18 years old (1.46×10-2) were found above Environmental Protection Agency’s acceptable range of 1×10-6 to 1×10-4. The hazard index values for all studied trace metals suggest significant potential for noncarcinogenic health risks to adults and children. The choice of chemical speciation as an essential tool in facilitating a better predictive insight on metal bioavailability and toxicity for immediate remediation action has been highlighted

Assessment of Noise and Associated Health Impacts at Selected Secondary Schools in Ibadan, Nigeria

Background. Most schools in Ibadan, Nigeria, are located near major roads (mobile line sources). We conducted an initial assessment of noise levels and adverse noise-related health and learning effects. Methods. For this descriptive, cross-sectional study, four schools were selected randomly from eight participating in overall project. We administered 200 questionnaires, 50 per school, assessing health and learning-related outcomes. Noise levels (A-weighted decibels, dBA) were measured with calibrated sound level meters. Traffic density was assessed for school with the highest measured dBA. Observational checklists assessed noise control parameters and building physical attributes. Results. Short-term, cross-sectional school-day noise levels ranged 68.3–84.7 dBA. Over 60% of respondents reported that vehicular traffic was major source of noise, and over 70% complained being disturbed by noise. Three schools reported tiredness, and one school lack of concentration, as the most prevalent noise-related health problems. Conclusion. Secondary school occupants in Ibadan, Nigeria were potentially affected by exposure to noise from mobile line sources

Characterization of Airborne Fine Particulate Matter (PM2.5) and Its Air Quality Implications in Ogun State, Nigeria

Atmospheric aerosols pose a serious threat to environmental quality and health of the public. Several studies in Nigeria have documented the pollution levels from coarse particles but very few have elucidated the nature of the fine particles in the context of air quality index. Our investigation therefore focused on air quality index in relation to ambient fine particulate and composition of PM2.5 collected from an industrial area (IA) and a university community (UC) in Ogun State, Nigeria. The PM2.5 samples were collected using Environtech gravimetric sampler according to standard methods. The morphology and elemental composition of PM2.5 were assessed by scanning electron microscope (SEM) coupled with an energy dispersive X-ray (EDX). The SEM images of fine particles indicated the following clustered groups: soot particles, alumino silicates, and mixture of alumino silicate with soot. Energy dispersive X-ray spectra showed nine most abundant elemental composition in all samples. Possible source emissions of elements identified by principal component analysis are industrial processes, vehicle emissions, crustal dust, fuel-oil and biomass burning. Air quality index (AQI), for particulate pollution was calculated for each location. Fine particle pollution indices scaled from 51 to 500, reflecting six out of the seven AQI categories in varying proportions. The absence of 0 to 50 gradation representing the good AQI category is conspicuously highlighted. Results indicate that most AQI values were above 100. Possible adverse health concerns mostly for the vulnerable populations are indicated considering the unhealthy air quality state of studied locations

FINE PARTICULATE MATTER-BASED AIR QUALITY INDEX: A CASE STUDY

The impact of air pollution on human health can be communicated through the application of air quality index (AQI). This has been underutilized in the developing countries due to inadequate technology. In this study, ambient fine particulate matter (PM2.5)-AQI in selected industrial areas in Ogun State, Nigeria was evaluated during weekends of wet season. PM2.5 samples were collected on Teflon filters using Environtech gravimetric sampler. AQIs were further computed following the United States Environmental Protection Agency (US EPA) formulae. The result showed that for the major part of the wet season, the weekend air quality was categorized as “unhealthy” in all the industrial sites. An indication of possible adverse health concerns especially for the sensitive group. In addition, gradations of 0 to 50, representing the good AQI category was not observed. Therefore, synergy from Engineers, Scientist and Policy makers is required towards the availability of sensitive and low cost instruments. A permanent network of air quality monitoring stations and reporting system for on-time information on air pollutants should be established by the government. Also, a community project on greenbelts development programme is strongly recommended

EMERGENCE OF NEW STRAINS OF SARS-COV-2: AFRICA’S FATE AND ITS PREPAREDNESS AGAINST COVID-19 INFECTION WAVES

Background: Severe acute respiratory syndrome coronavirus-2(SARS-CoV-2) has infected over 100million individuals worldwide with diverse impacts on nations. The rising cases of new strains and resultant infection waves create an urgent need to assess the readiness of countries especially in Africa to mitigate the impact on community transmission. This paper delivers a brief synopsis of the novel SARS-CoV-2, emerging cases of new variants reported worldwide, and implications for genetic surveillance of disease transmission in low-and middle-income countries (LMICs) especially Africa. Materials and Methods: Literature search used keywords like SARS-CoV-2; COVID-19 epidemiology; pandemic waves; corona outbreak, clinical syndromes, treatments, prevention and control. Cross-sectional and observational studies published on COVID-19 from 2019 till date of study provided main information sources. Databases such as Web of Science, Embase, PubMed and Google Scholar were utilised. Main findings: Over 220 countries have documented COVID-19 cases with varied severity till date. Before the spikes in resurgence, a highly virulent mutated (>90% fatality rate) novel strain of COVID-19 had been documented. There is very little data to ascertain the impact of the COVID-19 infection waves in LMICs. Discussion: LMICs especially African countries still grapple with significant challenges like inefficient surveillance mechanisms, inadequate vaccination coverage, inadequate enforcement of environmental health strategies, poor health systems etc. Hence, Africa’s fate remains dicey in the face of the dynamic evolution of the SARS-CoV-2 and other identified challenges. Conclusion:  The adoption of a multidisciplinary approach to mitigate the impact of emergence of mutant SARS-CoV-2 variants and resurgence of infection spike is recommende

Seasonal methane emission from municipal solid waste disposal sites in Lagos, Nigeria

The Municipal Solid Waste (MSW) Sector is a major source of Methane ( CH4) emission, a Greenhouse Gas (GHG) that contributes to Climate Change. However, governments of developing countries have not been able to address the challenges posed by this sector due to inadequate funding and technical requirement. The objective of this study was to determine how seasonal variation influences the CH4 gas emission. The First Order Decay (FOD) Tier 1 Model was used to estimate CH4 emission from four Solid Waste Disposal Sites (SWDS) in Lagos namely: Ewu-Elepe (Ewu), Abule-Egba (A/E), Soluos (Sol), and Olushosun (Olu) covering the dry and wet seasons, respectively for the inventory year 2020. A known weight of the wet waste deposited was characterized. The study revealed that the Degradable Organic Carbon (DOC) for the dry season was 12.897 GgC/kgWaste while that of the wet season was 12.547 GgC/kgWaste. But, the methane gas generated during the wet season was 0.331 Gg higher than that of the dry season which was 0.134 Gg for the study period. This is an appreciable quantity of methane that can contribute to the global Climate Change impact if not addressed. Therefore, these waste types should be segregated from other recyclables and processed into compost or energy resource

Air Quality Indexing, Mapping and Principal Components Analysis of Ambient Air Pollutants around Farm Settlements across Ogun State, Nigeria

The focus of this study was to portray the spatial pattern of air quality across seasons in the eight sampled farm settlements using air quality indexes and assess the clusters of monitored air pollutants. The concentrations of air pollutants were determined using in-situ portable gas detectors and particulate counter. The AQI for each criteria pollutants (CO, O3, TSP, PM10, SO2, and PM2.5) was calculated using AQI formulae of the United States Environmental Protection Agency and mapped using the Inverse distance weighting (IDW) interpolation method in the Geographic information systems (GIS) environment. Principal component analysis (PCA) was used to group the parameters and estimate the interrelationships between the loadings of the parameters in each component. The AQI ranges of pollutants which deviated from the acceptable good status are CO (71.98 – 238 and 88.85 – 220.93), NO2 (10.14 – 107.07 and 10.84 – 72.88) and PM2.5 (12.90 – 70.85 and 12.56 – 54.02) for the dry and wet seasons, respectively. There were five and four PCs with eigenvalues > 1, accounting for 69.75% and 61.73% of the total variance during the wet and dry season, respectively. The parameters in each component are as follows; PC1 - TSP, PM10, PM2.5, Bacteria and fungi; PC2 - CO and Temperature; PC3 - relative humidity and O3; PC4 - CO2; PC5 - NO2 and SO2 for the wet season and PC1 - TSP, PM10, PM2.5, Bacteria and fungi; PC2 - NH3 and NO2; PC3 - CO2 and O3; PC4 - Temperature and relative humidity during the dry season. Biomass burning, engine exhausts and fine-particulate related activities are sources of air pollution and such may pose negative implication to human health and environment. Therefore, the use of alternative biomass disposal, regular servicing of processing engines and the wearing of protective wears against dust are recommended