Browsing by Author "Yusuf, R.O."
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Item Air quality impact of diesel back-up generators (BUGs) in Nigeria’s mobile telecommunication base transceiver stations (BTS)(Emerald Insight, UK, 2017) Adeniran, J.A.; Yusuf, R.O.; Amole, M.O.; Jimoda, L.A.; Sonibare, J.A.Purpose – The introduction of mobile telecommunication services in Nigeria led to the development of base transceiver stations (BTS) across the country. Inadequate power supply from the national grid has led to massive use of diesel-fueled back-up generators (BUGs). The purpose of this paper is to attempt to quantify and inform relevant stakeholders about air quality implications of BTS BUGs. Design/methodology/approach – Seven major telecommunication network operators were identified. Emission factor approach was used to estimate the quantity of important air pollutants such as NOx, CO, SO2, PM10, PM2.5, PAH and TVOC that are emitted from the use of the BUGs based on fuel consumption rate and generators’ capacity. Fuel-based emission inventory and emission factor from the United States Environmental Protection Agency AP-42 and National Pollution Inventory were used to estimate pollutants emission from diesel-powered generators used in the BTS sites and amount of diesel consumed. Land distribution and per capita dose of the estimated pollutants load were calculated. Findings – The study showed that the deployment of BUGs will lead to increase emissions of these air pollutants. The states that are most affected are Lagos, Kano and Oyo, Katsina and Akwa Ibom states with respective total air pollutants contribution of 9,539.61, 9,445.34, 8,276.46, 7,805.14 and 7,220.70 tonnes/yr. Originality/value – This study has estimated pollutant emissions from the use of diesel-fueled BUGs in mobile telecommunications BTS sites in Nigeria. The data obtained could assist in policy making.Item Analytical modeling of human exposure from short-term point source releases of aerosols from household spray products(Taylor and Francis, 2018) Adeniran, J.A.; Araromi, D.O.; Yusuf, R.O.; Oke, E.O.; Sonibare, J.A.Indoor air measurements of aerosols emitted from the use of household spray products are expensive and time-consuming. An analytical model was developed and incorporated into a graphical user interface to quantify exposure as a function of distance and time. The model considered point source dispersion with reflection from a wall and aerosol concentration decay due to air exchange rate and deposition. Aerosol concentration decreased with respect to increase in time and distance from the release point. There was no significant difference between the developed model and experimental results. The developed model could be used to adequately predict indoor human exposure to aerosols as a function of distance and time.Item Assessment of Stored Flour Types and Effectiveness of Freezing, Sun-Drying and Hermetic Storage in the Management of Red Flour Beetle, Triboliumcastaneum (Herbst) in Ilorin(School of Agriculture and Agricultural Technology, Federal University of Technology, Akure, Nigeria, 2020) Yusuf, R.O.; Ojumoola, A.O.; Uddin II, R.O.; Adesiyun, A.A.Infestation and contamination of flour by the red flour beetle, Tribolium castaneum (Herbst) is a major constraint to flour storage especially in many households of sub Saharan Africa region. Unlike grain protection, flour protection does not lend itself to the use of plant powders, ash, sand and other admixture-based materials often employed by householders in the region as innocuous and cheap alternatives to synthetic insecticides. Scanty information however exists on how effective the few methods used for stored grains insect pest management will be for stored flour. In this study, flour use and T. castaneum management practices of householders in Ilorin, Nigeria was investigated in a survey using questionnaires. Effects of different duration of freezing, sun-drying and hermetic storage treatments on adult and larval mortality of T. castaneum and on population growth in three commonly stored flour types identified during the survey were also evaluated in the laboratory at the Department of Crop Protection, University of Ilorin, Ilorin Nigeria. Furthermore, the effect of each physical method on organoleptic characteristics of treated flour types was assessed. Results showed that semolina, yam and wheat flours were most preferred by householders in the study area. In addition, 12 hours of freezing and 6 hours of sun-drying significantly (p<0.05) caused complete adult and larval mortalities (100.0%) while also preventing population increases in the three most preferred flour types even after 3 months of post-treatment storage. In contrast, hermetic storage treatment for 336 hours caused lower (p<0.05) mean percentage mortalities (6.0% - 16.0%; 7.0% - 12%) and higher post-treatment storage population changes (11.20 – 16.60; 160.60 – 189.80) of T. castaneum adults and larvae respectively in all the flour types. However, none of the treatments negatively affected the organoleptic characteristics of the flours at p=0.05. Information provided in this study will enhance utilization of locally available physical methods for effective management of T. castaneum in the stored flours.Item Exposure to coarse and fine particulate matter at and around major intra-urban traffic intersections of Ilorin metropolis, Nigeria(Elsevier, 2017) Adeniran, J.A.; Yusuf, R.O.; Olajire, A.A.This study aims to determine the seasonal variations and composition of suspended particulate matter in different sizes PM1.0, PM2.5, PM10 and the total suspended particles (TSP) emitted at major intra-urban traffic intersections (TIs) of Ilorin metropolis. The concentration levels of PM (PM1.0, PM2.5, PM10) obtained at the TIs during the rush hours (45.1, 77.9, and 513 mg/m3) are higher than the levels obtained for the non-rush hour periods (42.3, 62.7, and 390 mg/m3). The average on-road respiratory deposition dose (RDD) rates of PM1.0, PM2.5 and PM10 during the dry period at TIs types was found to be about 24%, 9% and 25% higher than those obtained during the wet period. Based on EF values calculated, Pb and Zn were anthropogenically-derived while Fe, Mn, Cr, Cu and Mg were of crustal source. Principal component analysis (PCA) has been applied to a set of PM data in order to determine the contribution of different sources. It was found that the main principal factors extracted from particulate emission data were related to exhaust and non-exhaust emissions such as tyre wears, oil and fuel combustion sources.Item Exposure to total volatile organic compounds from household spray products(Kaunas University of Technology, 2017) Adeniran, J.A.; Yusuf, R.O.; Mustapha, S.I.; Sonibare, J.A.Emission of volatile organic compounds from the use of household spray products has a negative impact on health and environment. Total volatile organic compound (TVOC) concentration levels emitted from 45 registered consumer spray products in Nigeria were measured using the MultiRAE TVOCs gas monitor. Human exposure to emitted TVOCs through inhalation, ingestion or through the dermal route was evaluated using the ConsExpo spray model. The average TVOCs emission from all the investigated samples was in the range of 1,664 and 560,994.7 μg m-3 with an average of 63,632.2 μg m-3. Generally for all the samples considered, the average released concentrations, the inhaled doses, the dermal doses, and the average deposition rates values obtained were in the ranges of 1.83E+04 – 1.00E+06 μg m-3; 1.47E+03 – 8.01E+04 μg; 3.41E+04 – 4.84E+05 μg; and 1.79E+01 – 1.01E+03 μg s-1, respectively. The results provide information that could be used to significantly improve human exposure and risk assessment to emitted aerosols from spray products.Item Ground level Concentration of some air pollutants from Nigeria thermal power plants(Taylor and Francis, 2016) Adesanmi, A.J.; Adeniran, J.A.; Fakinle, B.S.; Jimoda, L.A.; Yusuf, R.O.; Sonibare, J.A.Power sector in Nigeria is undergoing structural reforms aimed at improving and expanding the current generation capacity, using thermal power plants. Ground level concentrations of air pollutants emitted from natural gas-powered thermal power plants were estimated using the American Meteorological Society-Environmental Protection Agency Regulatory Model (AERMOD). The average 24-h ground level concentrations of CO, NOx, SO2, particulate matter (PM), and volatile organic compounds (VOCs) were 31.88–72.79; 61.33–104; 0.61–3.91; 0.21–1.52; and 0.19–1.09 ìg/m3, respectively. There is need for continuous monitoring of ground level concentration of pollutants around the thermal power plants to guarantee the safety of the environment in the host communities.Item Life cycle engineering case study: sulphuric acid production(Malaysian Technical Universities Network (MTUN), Malaysia, 2017) Adeniran, J.A.; Yusuf, R.O.; Adetoro, M.A.Sulphuric acid is an essential basic chemical in the world. This chemical is used in different industries, and is mainly sold as intermediates applied in a range of products. This study investigated the life cycle assessment of sulphuric acid production in commercial scale in Nigeria by identifying the processes that contribute significantly to the hotspots and the impact the product has on climate change. The data gathered for the study represents operations at a major plant in Nigeria. System boundaries were established using a cradle to gate approach, based on primary data from the plant. Secondary data was obtained from the US database. Sulphuric acid plant process simulation was done using Aspen HYSYS 2006-aspen ONE from ASPENTECH. GaBi life cycle assessment (LCA) software, (PE International) was used to evaluate the environmental impact of the process. The work was done in accordance with ISO 14040 series LCA standards. The weak point analysis identified the raw material stages as areas of weakness in the sulphuric acid model. The assessment in this study identified the raw material stage; elemental sulphur at plant as the main contributor to the carbon footprint with emission to air amounting to 4 x107kg. The total CO2 emission the sulphuric acid model is 1.24 x107 kg with approximately 0.66% direct emission from fuel combustion in the plant. The opportunity for improvement in terms of emission reduction is in reduction of energy consumed by replacing fossil based material with bio-based material. An advantage of this study is that the methodology applied can serve as a means for determining the carbon footprint of other sulphuric products. This study has shown that life cycle assessment has a potential to identify hotspots of a product to find strategies to sustain the environment.Item Nauclea Latifolia (African Peach) Attenuates Gastric Acid Secretion in Rats with Ethanol-Induced Ulceration(Faculty of Health Sciences, Al-Hikmah University, 2021) Balogun, M.E.,; Umahi, G.O.,; Ayinde, T.O.,; Oluwasola, A.,; Busari, A.O.,; Ajibola, K.A.,; Yusuf, R.O.; Ojulari, L.SItem Spatiotemporal distributions of polycyclic aromatic hydrocarbons close to a typical medical waste incinerator(Springer, 2018) Adesina, O.A.; Sonibare, J.A.; Diagboya, P.N.; Adeniran, J.A.; Yusuf, R.O.hydrocarbons (PAHs) especially from incinerators occur subtly, and PAH contribution from this source is underestimated. However, as environmental PAH concentrations build up, this may be a serious concern around the incinerator vicinity due to the potential consequences of PAHs on ecosystems and human health. Thus, the contribution of selected (12) PAHs from the Obafemi Awolowo University Teaching Hospital medical waste incinerator (or source, HWI_0) was determined by sampling stack gas and ambient air around incinerator vicinity from June 2014 to May 2015. Results showed that the 12 PAH source (HWI_0) concentrations were in the range of NA (for phenanthrene, pyrene, anthracene, benz[e]acephenanthrylene, and indeno[2,1- b]chromene) to 10.9 ng/m3 (pyrelene) and generally higher than the receptor points (hospital waste incinerators (HWIs)). The average total PAH concentrations per month at HWI_0 and the receptors—HWI_1, HWI_2, HWI_3,HWI_4 and HWI_5—were 73.0 ± 27.9, 60.4 ± 30.8, 42.5 ± 23.6, 38.7 ± 21.9, 35.0 ± 27.2, and 39.2 ± 22.9 ng/m3, respectively. These results and multivariate receptor model analysis indicated high correlations between source PAH contributions and the receptor points. The PAH concentrations in the dry season were higher than the wet season suggesting that hydrological condition affects ambient PAH concentrations. The average PAH concentrations in the HWIs as well as the cumulative exposure concentrations observed throughout the period are of major health concern because PAH concentrations detected are several times higher than both the European Union standard and the WHO guideline level.