Institute of Environmental Management and Quality Control
Permanent URI for this collectionhttps://dspace.njala.edu.sl/handle/20.500.144402/148
Browse
13 results
Filters
Advanced Search
Filter by
Settings
Search Results
Item Leapfrog diagnostics: Demonstration of a broad spectrum pathogen identification platform in a resource-limited setting(BioMed Central, 2012-07-04) Łęski, Tomasz A.BACKGROUND: Resource-limited tropical countries are home to numerous infectious pathogens of both human and zoonotic origin. A capability for early detection to allow rapid outbreak containment and prevent spread to non-endemic regions is severely impaired by inadequate diagnostic laboratory capacity, the absence of a "cold chain" and the lack of highly trained personnel. Building up detection capacity in these countries by direct replication of the systems existing in developed countries is not a feasible approach and instead requires "leapfrogging" to the deployment of the newest diagnostic systems that do not have the infrastructure requirements of systems used in developed countries. METHODS: A laboratory for molecular diagnostics of infectious agents was established in Bo, Sierra Leone with a hybrid solar/diesel/battery system to ensure stable power supply and a satellite modem to enable efficient communication. An array of room temperature stabilization and refrigeration technologies for reliable transport and storage of reagents and biological samples were also tested to ensure sustainable laboratory supplies for diagnostic assays. RESULTS: The laboratory demonstrated its operational proficiency by conducting an investigation of a suspected avian influenza outbreak at a commercial poultry farm at Bo using broad range resequencing microarrays and real time RT-PCR. The results of the investigation excluded influenza viruses as a possible cause of the outbreak and indicated a link between the outbreak and the presence of Klebsiella pneumoniae. CONCLUSIONS: This study demonstrated that by application of a carefully selected set of technologies and sufficient personnel training, it is feasible to deploy and effectively use a broad-range infectious pathogen detection technology in a severely resource-limited setting.Item Variation in stable isotope ratios of monthly rainfall in the Douala and Yaounde cities, Cameroon: local meteoric lines and relationship to regional precipitation cycle(Springer Nature, 2016-04-16) Wirmvem, Mengnjo JudeHydrogen (D) and oxygen (18O) stable isotopes in precipitation are useful tools in groundwater recharge and climatological investigations. This study investigated the isotopes in rainfall during the 2013 and 2014 hydrological years in the Douala and Yaounde urban cities. The objectives were to generate local meteoric water lines (LMWLs), define the spatial–temporal variations of the isotopes in rainwater and their relationship to the regional precipitation cycle, and determine the factors controlling the isotopic variation. The LWMLs in Douala and Yaounde were δD = 7.92δ18O + 12.99 and δD = 8.35δ18O + 15.29, respectively. The slopes indicate isotopic equilibrium conditions during rain formation and negligible evaporation effect during rainfall. Precipitation showed similar wide ranges in δ18O values from −5.26 to −0.75 ‰ in Douala and −5.8 to +1.81 ‰ in Yaounde suggesting a common moisture source from the Atlantic Ocean. Enriched weighted mean δ18O (wδ18O) values during the low pre- and post-monsoon showers coincided with low convective activity across the entire region. Enriched isotopic signatures also marked the West African monsoon transition phase during each hydrological year. Abrupt wδ18O depletion after the transition coincided with the monsoon onset in the region. Peak periods of monsoonal rainfall, associated with high convective activities, were characterised by the most depleted wδ18O values. Controls on isotopic variations are the amount effect and moisture recycling. The stable isotope data provide a tool for groundwater recharge studies while the isotopic correlation with regional rainfall cycle demonstrate their use as markers of moisture circulation and detecting climatic changes in precipitation.Item Emission of Combustible Gases at Traffic and Practising Waste Dumpsite in Freetown, Sierra Leone: A Pilot Study(Scientific Research Publishing, 2016-12-07) Williams, Bunting KayodeAn assessment of the emission of combustible gases in developing countries requires reliable analytical realtime monitors that can rapidly screen them with minimal handling. Considering the expensive nature of monitoring environmental pollutants, chemical sensors are expected to play a pivotal role in measuring and recording environmental data. The Drager X am 5000 was used to report emission levels of combustible gases in this study, namely; nitrogen dioxide (NO2), sulphur dioxide (SO2) and carbon monoxide (CO) at traffic and practising waste dumpsite in Freetown, the main city of Sierra Leone. Hourly average values for the three pollutants were recorded in the morning, afternoon and evening periods, respectively. The range of values were 18 - 76 ppb for NO2, 211 - 506 ppb for SO2 and 11 - 14 ppm for CO at traffic site; and 6 - 16 ppb for NO2, 118 - 276 ppb for SO2 and 8 - 15 ppm for CO at the dumpsite, respectively. There were significantly high hourly variations for NO2 and SO2 at the traffic site and for CO and SO2 at the dumpsite. Evidence of peak values showed emission levels that were considered dangerous for human exposure. This pilot study revealed that combustible gases released in certain areas of the capital city are a concern for both public health officials and environmental advocates.Item Comprehensive Assessment of Groundwater Quality around a Major Mining Company in Southern Sierra Leone(Scientific Research Publishing, 2017) Massally, Rex-Edwin M.Ensuring availability and sustainable management of water and sanitation for all by 2030 is Goal 6 of the Sustainable Development Goals (SDGs). Since developing countries especially in Africa would struggle to meet this target, this study was conceived. Hence, the study was designed to assess the water quality for physiochemical parameters around a mined out site in southern Sierra Leone with the view to determine their levels, determine related associations among indicators and explore environmental forensic options. A finite population correction factor was used to identify fifty (50) groundwater sources from one hundred and fifty two (152) in nine (9) sections of Moriba Town, in Moyamba District, Sierra Leone which constitute the sample size. The study assessed sixteen (16) physical and chemical indicators across the defined boundary of the sample size. Results indicated that almost 80% of all the indicators were in good agreement with water quality standards with the exception of three. Turbidity correlated strongly with , Al and and almost all other indicators did not show meaningful association. High values with significant variance of water quality indicators of physical to chemical ratio were observed for pH, temperature, electrical conductivity (EC) and total dissolved solids (TDS) but no such observation was noted for turbidity. On the whole, the water quality was judged to be good, although more pro active actions were encouraged by the local people and the mining company so as to reduce contamination in some areas.Item Investigation into the Impacts of Artisanal Gold Mining on the Livelihood Foundation of Baomahun Community in Southern Sierra Leone(Scientific Research Publishing, 2018) Sheriff, IshmailArtisanal gold mining has a long history in Sierra Leone. Mining is the most important economic activity in the communities endowed with minerals. Many people who are often disadvantaged in the labour market are engaged in this sector. The poor implementation of mining laws and regulations is fueling the rate of involvement in the sector. In-depth studies of the effect of artisanal mining activities on the livelihood strategy of non-miming population in Sierra Leone are rare. The overarching objective of this work is to bring to light the effect of artisanal gold mining on the environment and livelihood of local resident with a case study of Baomahun, Delenga Section of Valunia Chiefdom, Bo District, Southern Sierra Leone. The study population comprised of people residing at the study area as at 2015. The primary sampling units included elements from the Baomahun vicinity such as miners, mines monitors, conservation agents and local residents of the village. The sample frame employed in this study was the random selection of artisanal miners at each site where mining was being undertaken, mines monitoring officers, conservation agents and local residents. Sample size was 76 people. This was done to indicate proper representation of the study area. And also 76 questionnaires were administered to miners, mines monitors, conservation agents and local residents. Both primary data and secondary data were used in the study. Detailed explanation of the analyses was accomplished by both qualitative and quantitative methods. The study revealed that there are varied degrees of visible impacts of artisanal mining on the environments. They include soil depression; creation of water pools in abandoned unfilled mines and diversion, and turbidity of local streams. Artisanal mining as an economic activity has imparted both positively and negatively on the livelihood of resident. Significant gaps and disparities exist in the implementation of the current Mines and Minerals Act of 2009 on the artisanal mining sector.Item Utilizing Geospatial Tools to Assign Unique Identifiers to Water Bodies in a Low-Income Country(Scientific Research Publishing, 2021) Mansaray, Abubakarr SidiqueInland waters support the growth of several sectors including mining, agriculture, and health. This makes it crucial to have sustainable quantity and quality through conservation practices. Achieving sustainability requires information on the spatial distribution of water bodies. This requirement is particularly critical in low-income nations where dependence on natural resources is a key driver to economic growth. Unfortunately, these nations lack the resources to promote costly waterbody characterization. This study pre-sents a cost-effective approach in assigning Unique Identifiers (UIDs) that define locations and characteristics of rivers and streams. Our objective is to develop a scheme that can be used to identify and characterize rivers and streams in a nation. We utilized an open-source Digital Elevation Model (DEM) of NASA’s ASTER satellite and the hydrology tool in ArcGIS 10.7.1. The DEM was imported to ArcGIS followed by delineation of hydrologic regions, subregions, and stream orders. Each stream segment was given a UID based on its region and Strahler’s stream order system. We present a case study analysis for two regions within Sierra Leone using water quality data of selected rivers and streams. These will lay the foundation for a nationwide coding exercise and provide a useful reference for water resource practitioners.Item Assessment of the Healthcare Waste Infrastructure at Kambia Government Hospital, Sierra Leone(Science Publishing Group, 2024-11-26) Kamara, AbubakarrThis study assessed the healthcare waste management (HCWM) infrastructure at Kambia Government Hospital (KGH), Sierra Leone. We evaluated various aspects of HCWM, including waste segregation, storage, collection, transportation, and disposal. Our findings revealed critical deficiencies, such as inadequate storage facilities, insufficient waste bins, and a lack of dedicated transportation systems. These shortcomings pose significant risks to healthcare workers, the general public, and the environment, including the potential for the spread of infectious diseases and contamination of the environment. To improve HCWM practices at KGH, we recommend implementing several key strategies. These include investing in adequate storage facilities, providing appropriate waste bins, establishing a dedicated waste transportation system, and conducting comprehensive staff training on HCWM protocols. Regular training sessions should cover topics such as waste classification, segregation, storage, collection, transportation, and disposal techniques. By empowering healthcare workers with the necessary knowledge and skills, we can significantly enhance HCWM practices at KGH. Furthermore, it is crucial to establish a robust system for monitoring and evaluating the effectiveness of HCWM interventions. Regular inspections of storage areas, waste bins, and transportation vehicles can help identify and address potential issues. By implementing these recommendations, KGH can improve its HCWM practices and contribute to a healthier and safer environment for its community. Effective HCWM is essential to protect public health and the environment. Poor management of healthcare waste can lead to the spread of infectious diseases, contamination of water sources, and exposure to hazardous chemicals. By addressing the identified deficiencies and implementing best practices, KGH can significantly improve its HCWM performance and reduce the associated risks.Item Environmental and Socio-economic Impacts of Sand Mining in Selected Coastal Communities along the Western Rural-Freetown Peninsular in Sierra Leone(Science Publishing Group, 2025-06-17) Mabey, Prince TongorThis study examines the environmental and socio-economic impacts of sand mining in three selected coastal communities (Hamilton, John Obey and Laka) along the Western Area Rural-Freetown peninsula in Sierra Leone. Coastal sand mining poses significant environmental and social problems. It damages ecosystems, increases coastal erosion and vulnerability to storms, threatens biodiversity, and can lead to social issues like corruption and violence. The study employed a quantitative cross-sectional perception survey-based research design. A simple random sampling technique was used to representatively select 666 community respondents including heads of households, community leaders, sand miners, sellers, and transporters. A combination of Statistical Package for the Social Science (SPSS) and Excel Software Package were employed. A multinomial logistic regression (MNL) model was used to analyse the data. Findings reveal that the determinants of respondents’ perceived knowledge on the negative impacts of sand mining were mainly demographic attributes including age (p<0.001), marital status (p<0.001), family size (p<0.001), and monthly household income (p<0.001). The findings further revealed that accident (p<0.001), community conflicts (p<0.001), drug abuse (p<0.001), and knowledge of negative effects of sand mining (p<0.001), exhibited a negative significant impact of sand mining. The determinants of respondents’ perceived knowledge on the positive impacts of sand mining indicated that occupation has a positive and significant impact on sand mining. The benefits of utilizing sand in the communities (p<0.001) and benefits of sand mining (p<0.001) had a negative significant impact on sand mining. It is recommended that increased awareness on the negative impacts of coastal sand mining coupled with the implementation of environmental policies could help to mitigate some of the negative environmental impacts.Item Assessment of Public Drinking Water Quality and Hygienic Conditions in Selected Communities in Tonkolili District, Sierra Leone(2025-06-10) Mabey, Prince TongorThis study investigated the public drinking water quality parameters from different sources, streams, springs, wells, and reservoirs and the hygienic conditions of people living in six communities in Yoni Chiefdom, Tonkolili District. The study involved both laboratory analysis and a survey on the perceptions of respondents on the hygienic conditions of drinking water. A total of 75 questionnaires were administered to respondents that fetch water for household consumption. The results revealed that different levels of turbidity, pH, temperature, oxygen demand (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), magnesium, nitrate, and chloride from streams, springs, wells, and reservoir water obtained based on well-established procedures were within the world health organization (WHO) standard for drinking water. The findings also revealed that four communities (Mamancha, Dogbokarama, Mile 91, and Malenpeh) recorded the highest mean turbidity values of 7.34 NTU, DO of 6.5 mg/l, NO3- of 11.00 mg/l and NO3- of 12.00 mg/l respectively, which exceeded the World Health Organization (WHO) standard level for drinking water. Most (89.3%) of the respondents opined that they had easy access to drinking water throughout the year, and most of the respondents affirmed that the drinking water was odourless (81.3%) and tasteless (72.0%). However, the drinking water turns cloudy or milky during the dry season, as opined by 53.3% of the respondents. The majority (66.7%) of the respondents experience water-borne diseases in their communities, such as skin disease, typhoid, and cholera. Most (86.7%) of the drinking water sources are not treated and are 20 m away from the toilet and dustbin, as opined by 65.3% of the respondents. Findings indicate that the short distance and poor sanitary precautions are the probable causes of the contamination of the drinking water in these communities. The government should create an enabling policy environment regarding quality drinking water and hygienic conditions for adaptation as well as to implement routine monitoring to improve the health and sanitary conditions of the people.Item Effects of Land-Use Patterns and Land Cover Change on Freshwater Quality in the Guma Dam Catchment in Freetown, Sierra Leone(Scientific Research Publishing, 2026) Mabey, Prince TongorRapid land-use and land-cover (LULC) change poses significant threats to freshwater resources, particularly in rapidly urbanizing catchments in Sub-Saharan Africa. This study assessed the effects of LULC dynamics on freshwater quality in the Guma (Mile-13) Dam catchment, Freetown, Sierra Leone, between 2004 and 2023. Landsat 7 ETM+ and Landsat 8 OLI imagery from 2004, 2013, and 2023 were analyzed using post-classification change detection to quantify transitions among vegetation, agriculture, settlements, bare land, and water bodies. Water quality was evaluated through monthly sampling at upstream, midstream, and downstream locations from January to June 2023, covering key physicochemical and microbial parameters. To quantitatively link land-use change and water quality, normalized land-use pressure indices were developed, and Pearson correlation analysis was applied. Results indicate substantial urban expansion within the catchment, with vegetation-to-settlement conversion increasing by 39.40 km2 and total settlement gain reaching 55.47 km2 between 2013 and 2023. Water quality parameters were generally within World Health Organization (WHO) guideline limits for physicochemical variables; however, elevated turbidity (up to 5.0 NTU), episodic increases in nitrate and phosphate concentrations, and persistent detection of Escherichia coli indicate pollution risks. Pearson correlation analysis revealed strong positive relationships between settlement expansion and turbidity (r = 0.91), phosphate (r = 0.75), and nitrate (r = 0.59), while vegetation cover showed an inverse relationship with water quality degradation. These findings demonstrate that rapid urban expansion and vegetation loss are key drivers of declining water quality in the Guma Dam catchment. The study underscores the need for integrated land-use planning, protection of vegetated buffers, sustainable urban development, and continuous water-quality monitoring to safeguard Freetown’s primary water supply.