Theses and Dissertations

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Assessing the Namibian government's policy on improving national food production: A case study of the agronomic sector.
(2013) Ekondo, Fanuel Eita
The third National Development Plan, extending from 2007-12, seeks amongst other things to boost agricultural production at household and national levels in order to increase food security and create opportunities for employment. Government has indicated that Green Scheme initiative is hampered by low incentives for engaging in agricultural product ion and processing, and by unfavourable responses to manufacturing by food processors, manifested by the apparent low level of investment in agriculture and the food-processing sector. We conducted a questionnaire-based study focusing on the operators of eight major irrigation projects in northern and southern Namibia to determine the challenges faced in the economic, political and legal environment , aimed at understanding the underlying constraints to large-scale food production under irrigation. The main objective of the study is to understand the effective mechanisms necessary to boost agricultural production through sound investments into the sector. Data was collected through semi - structured interview quest ions and answers recorded on the questionnaire sheet. Respondents indicated that no incentives for investing in agriculture and food product ion were provided. Private operators of agroirrigation projects bemoaned the unreasonable limited lease period (5-10 years) , making it difficult to recoup any large-scale investment. Technical problems included lack of expertise to operate and service recently acquired modern technologies. Respondents suggested the introduction of longer leases, enabl ing investors to recoup their costs and realize profits from their investments. Project operators called for the training of competent personnel to provide technical services and know-how on the projects as well as the acquisition of new technologies to replace the obsolete equipment current ly in use.
Highlighting the importance of incorporating indigenous knowledge into new product development and commercial production processes through a study on the attitudes and preferences of mahangu flour consumers in Northern Namibia.
(2013) Denk, Steven William
Incorporating indigenous knowledge into new product development and by extension commercial production processes is critical for the successful commercialisation of traditional products. Traditionally, mahangu grain goes through a process referred to as the lactic acid fermentation process. The mahangu grain is exposed to a chemical reaction causing the taste, colour and texture of mahangu porridge to be altered. The results from the discrete choice experiment shows that mahangu consumers prefer the attributes emanating from the lactic acid fermentation process. However due to the lack of exposure to the lactic acid fermentation process, Meme Mahangu flour do not possess any of the attributes the choice data revealed to be the most preferred mahangu flour attributes. Attitudes were measured based on Fishbein’s multi-attribute model. The results showed a negative attitude towards Meme Mahangu. This could be attributed to the fact that the attributes preferred by mahangu consumers (i.e. light coloured porridge) are not present in Meme Mahangu. The results from the choice data collected from the discrete choice experiment shows that the most preferred mahangu flour attributes are those attributes emanating from the lactic acid fermentation process and that the least preferred mahangu flour attributes being those attributes present in mahangu flour that have not been fermented. A sour taste, light colour and soft texture are the attributes most preferred and those emanating from the lactic acid fermentation process. The colour of mahangu porridge has the highest relative importance (52%) with the maximum share of preference falling on light coloured mahangu porridge. Three main recommendations are proposed. These recommendations can significantly enhance the commercial value of mahangu flour and contribute to the improvement of the livelihood of small scale farmers in northern Namibia.
Evaluation of the efficiency of Moringa products as natural adsorbents of heavy metals in contaminated wastewater
(Namibia University of Science Technology, 2015-10) Sika, Franklin Obeng
Communal cattle husbandry practices and their impact on market participation: a case study of FSP farmers from Zambezi region in Namibia
(Namibia University of Science and Technology, 2016) Akashambatwa, Clifford Lubinda
Cattle play an important socio-economic role in the livelihood of communal farmers in Namibia. This study examines the socio-economic determinants of adoption of improved livestock management practices among communal livestock farmers in Zambezi region, Namibia. The main objective of the study was to explore the effect adoption of GIZ introduced livestock management practices on cattle production in the Zambezi region, the specific objectives were to conduct situational analysis of the livestock management practices in Zambezi region and examine factors influencing adoption of the newly introduced livestock management practices. Data for the study were obtained from a survey of a sample of 86 communal livestock farmers who are benefiting from the Farmer Support Project (FSP) in the Zambezi region. Descriptive statistics and a multi-logistic regression model were employed to analyse the data. Most respondents (48%) had secondary education, which is a significant factor in determining probability of adoption of improved agricultural management practices. 35% of the respondent‟s herd sizes ranged between 11 to 30 cattle, which was the highest and herd composition were mainly consisting of cows (34%), heifers (22%) and oxen (26%). The results revealed that about eight out of thirteen livestock management practices disseminated to farmers were adopted and in practice. Castration, tick control, branding and vaccination were the most adopted technologies. Multi-logistic regression model analysis indicated that probability of adoption of livestock management technologies increased with education, financial assistance, advice, total cattle owned, total cattle sales and experience. The study presented a very low off-take rate of 1.5%. Oxen older than 36 months were the most sold and the second most sold were cows 56% and 29% respectively. The findings imply that in order to increase adoption of improved technologies, access to education, financial assistance, and training in animal management practices should be enhanced. The empirical results showed that education, financial assistance, advice and total cattle owned were significant at 5%, 5%, 10%, and 10% respectively.
Investigating the Isotopic composition of water bodiesin the Kuiseb and Cuvelai-Etosha basin,namibia
(Namibia University of Science Technology, 2016-04) Uugwanga, Martha Ndeapo
HOME RANGE AND THERMAL ANALYSES OF TWO SYMPATRIC TORTOISE SPECIES, STIGMOCHELYS PARDALIS AND PSAMMOBATES OCULIFER IN THE THORNBUSH SAVANNA OF CENTRAL NAMIBIA.
(Namibia University of Science and Technology, 2016-04) Amutenya, Klaudia, K
Southern Africa harbors one-third of the world's Testudinid species, many of which inhabit arid or semi-arid areas. Namibia has the second highest tortoise diversity after South Africa with six species and five of the recognized genera of modem Testudinidae in the world. Detailed ecological information on the Namibian species is generally lacking. This study analyzed the home ranges and thermal activities of two sympatric tortoise species, the Leopard tortoise, Stigmochlelys pardalis (previously known as Geochelone pardalis) and the poorly studied Kalahari tent tortoise, Psammobates oculifer. The study was conducted at the Hohewarte Farm, situated in the thorn-bush savanna southwest of Windhoek, Namibia. All encountered tortoises from both species were equipped with radio transmitters and temperature loggers (iButtons) which allowed for continuous monitoring of individuals throughout the study period. Data was collected for 17 months from December 2013 to April 2015 to determine the average annual and seasonal difference in thermally driven activity patterns and home range of these tortoises. Results from the study suggest that the smaller P. oculifer (with one dramatic exception of a wandering male) had a larger average annual home range ( 64 ha) compared to the much larger and common S. pardalis (20 ha). Exclusion of the wandering male from data analysis yielded a reduction in the annual home range size of P. oculifer to 32 ha. There was however great variation within individual home range sizes; the largest annual home range size (299 ha) was for a male P. oculifer while the smallest annual average home range was 5 ha recorded for two (2) female P. oculifer. For S. pardalis, 58 ha was the largest annual average home range size recorded for a medium sized male while two (2) juvenile S. pardalis had the smallest annual average home ranges of 1 ha. The study also found that home ranges were larger during the wet seasons for both species and that there was evident intraspecific and interspecific home range overlaps between the two species and even between sexes of the same species. There was no significant difference found between the different temperatures recorded for the tortoises ( shell, iButton, ambient and surface). On the orientation aspect of the study, tortoise rear orientation directions differed and were not uniform. Results from Rayleigh's Z statistical test (Rayleigh Z7.075, P < 0.001) have shown that there was no mean direction for the species orientation. It was however found that during the dry season, the northerly directions (NE and NW) were the dominant rear directions for S. pardalis while N, NE, and easterly direction (E) were the dominant rear directions for P. oculifer. Observations during the wet seasons have indicated that s. pardalis tortoises mostly oriented their rear end towards the NE and N directions while the westerly directions (NW, W, and SW) were the dominant directions for P. oculifer. The NE direction was observed to be the mean direction that tortoises from both species oriented the rear ends towards.
Effects of the effluent from the new ujams wastewater treatment plant on the quality of the Klein Windhoek river
(Namibia University of Science Technology, 2016-10) Wapoteka, Sarafina
Production frontier of small scale pearl millet farmers under conservation agriculture in northern Namibia
(Namibia University of Science and Technology, 2016-10) Montle, Bonolo Pontsho
Pearl millet is a major staple food crop of Northern Namibia dominantly produced by small scale farmers. This paper examines technical efficiency of smallholder pearl millet farmers under Conservation and Traditional Agriculture as well as their willingness to pay for extension services. The data was collected using a structured questionnaire administrated to 100 randomly selected small-scale pearl millet farmers in Omusati, Ohangwena, Oshikoto, Oshana and Kavango regions. Data was analysed by descriptive statistics, stochastic frontier production function approach as well as the probit regression model. The estimated stochastic frontier Cobb- Douglas production function showed that land availability, the level of fertilizer use and tractor power explains variations in the production of pearl millet. The efficiency analysis results show that farm level technical efficiency for Conservation Agriculture and Traditional Agriculture were 32% and 33% respectively. This indicates that overall, there is a potential to improve efficiency in pearl millet production among smallholder farmers in the study area by 68% through the efficient use of Conservation Agriculture. Furthermore, on Traditional Agriculture, there is a potential to improve efficiency by about 67% utilising existing farm resources better and adopting improved technology and techniques. Based on this result, the study recommends that Conservation Agriculture should be continued and over a long period of time so that the impact can be felt. The results of the inefficiency model indicate that under Conservation Agriculture, farming experience has a significant positive effect on efficiency. While on Traditional Agriculture, farm experience, farm size, training had a significant and positive effect on efficiency. The policy implications with regards to the technical efficiency are that to improve farm efficiency, efforts should focus on capacity building, training, extension services, information on agronomic practices and farmer’s education. On farmer’s willingness to pay for extension services, the predicted probability of getting farmers willing to pay is 60%. The model showed that farm size, Income < 2000, cooperative membership and household size are significant determinants of farmers’ willingness to pay. The study recommends that these key parameters are given proper policy consideration in the design and the implementation of a workable policy, for example, improving extension services through privatization.
Evaluating the effectiveness of ''biosprite technology'' in reducing microbial contamination at the Windhoek Airport water scheme
(Namibia University of Science Technology, 2017-10) Nakale, Shiwa A.
The distribution of escherichia coli in pregnant women and antimicrobial susceptibility patterns of the isolates in selected rural areas in Namibia
(Namibia University of Science and Technology, 2018-11) Nangolo, Lea
BACKGROUND: Escherichia coli (E. coli) is a bacterium that can asymptomatically colonize a woman’s vagina and up to 31% of pregnant women are colonized worldwide. Furthermore, vaginal colonization with E. coli is associated with adverse pregnancy outcomes, such as preterm birth and stillbirth. It is also associated with neonatal sepsis or meningitis when transmitted to the foetus through amniotic fluid or to the neonate during delivery. To date in Namibia data on the colonization and the antibiotic susceptibility patterns of E. coli in pregnant women is sparse. This study aimed at determining the prevalence of E. coli, antimicrobial susceptibility patterns and genetic based resistance of the isolates from pregnant women at 35 weeks of gestation and above, who attended antenatal screening at Eenhana, Okongo, Onandjokwe state hospitals.
The distribution of Escherichia coli in pregnant women and antimicrobial susceptibility patterns of the isolates in selected rural areas in Namibia
(Namibia University of Science and Technology, 2018-11) Nangolo, Lea
Escherichia coli (E. coli) is a bacterium that can asymptomatically colonize a woman’s vagina and up to 31% of pregnant women are colonized worldwide. Furthermore, vaginal colonization with E. coli is associated with adverse pregnancy outcomes, such as preterm birth and stillbirth. It is also associated with neonatal sepsis or meningitis when transmitted to the foetus through amniotic fluid or to the neonate during delivery. To date in Namibia data on the colonization and the antibiotic susceptibility patterns of E. coli in pregnant women is sparse. This study aimed at determining the prevalence of E. coli, antimicrobial susceptibility patterns and genetic based resistance of the isolates from pregnant women at 35 weeks of gestation and above, who attended antenatal screening at Eenhana, Okongo, Onandjokwe state hospitals.
Assessing the roles of community based service providers and healthcare workers in the prevention of relapse among TB infected patients in Namibia.
(Namibia University of Science and Technology, 2019-01) Musuuo, Milka
Mycobacterium Tuberculosis commonly referred to as (TB) is still one of the major health concerns, with high prevalence globally as well as in Namibia. While significant progress has been achieved in the prevention and treatment services of TB in the country, including use of community-based service providers and community-based health workers, the number of relapse cases remained high. The study aimed at assessing the role of Community Based Service Providers in the prevention of relapse among TB infected patients in Namibia.
Prevalence and molecular characterisation of group B streptococcus in pregnant women from hospitals in ohangwena and oshikoto regions of namibia.
(Namibia University of Science and Technology, 2019-03) Haimbodi, Erastus Lafimana
Group B streptococcus (GBS) naturally colonises the lower gastrointestinal and female genitourinary tract. It poses a great risk of morbidity and mortality to infants born to colonised mothers. It is highly implicated in maternal infections such as endometritis and chorioamnionitis as well as neonatal infections such as pneumonia, meningitis and septicaemia. It also causes stillbirths and miscarriages in colonised women. Group B streptococcus infection in neonates is classified in two clinical syndromes, which are Early Onset Disease (EOD) and Late Onset Disease (LOD). Early Onset Disease presents between day zero and day seven, and LOD between day eight and day ninetieth (third month) of the infant’s life. GBS is classified into capsular types Ia, Ib and II – IX, based on the polysaccharide capsular antigens of the bacterium. This study aimed at determining the prevalence rate, antimicrobial susceptibility patterns and molecular characteristics of Streptococcus agalactiae isolated from pregnant women at 35 weeks of gestation and above, who attended antenatal screening at selected hospitals in Ohangwena and Oshikoto regions of Namibia.
Assessment of dust exposure and risk of chronic respiratory diseases among stone corrie quarry workers in Namibia, 2018.
(Namibia University of Science and Technology, 2019-04) Shihepo, Saima
Quarry mining produces substantial dust amounts bearing an adverse effect on human health in several ways, mainly the respiratory system. Even though employers are obligated to protect their employees from occupational hazards, the quarry mining industry in Namibia has failed to honour that obligation. This study investigated quarry workers and the surrounding community’s exposure to dust as well as their risk of getting chronic respiratory diseases in the Erongo region of Namibia. Objectively the study assessed the amount of silica emitted in quarry dust emissions from selected Namibian quarry mines in compliance with national and WHO Air Quality Standards. Secondly, this study made an evaluation of health risks connected to dust exposure amid quarry workers and surrounding communities of 1km radius to selected quarry sites. Lastly, this study established appropriate interventions to deter dust exposure effects on quarry workers and the surrounding community. A cross-sectional descriptive study was done with 233 quarry workers and community members from selected quarry mines around Karibib. Self-administered interview questionnaires were used to both quarry workers and community members. Respirable dust levels were evaluated in different work stations using Spirometry. Binominal logistic regression analysis was used to predictable the overall outcome of quarry dust exposure on respiratory outcomes, while linear regression predicted the exposure-related effect on lung function. Workers were stratified according to the cumulative dust exposure category. The highest mean dust level, by quarry site, was 1.13 mg/m³ (SD: 0.58) recorded among workers from Site A and the lowest was 0.63 mg/m³ (SD=0.38) at Site B. In relation to job types, excavation had the highest mean dust level of 1.20 mg/m³ (SD: 0.65) and wire saw the lowest at 0.54 mg/m³ (SD=0.42). The most prevalent of the respiratory symptoms reported by the quarry workers were coughing (57%) and the corresponding percentage among the community members was lower (14%). There were more respondents with 10 or more years in quarrying (78%) who reported coughing compared to 58% or less among workers with less than 10 years in the job. Statistical links between the lung function assessments and quarry site, job specification, or years in quarrying among the quarry workers (p>0.05) were not established. Lung function outcomes between the quarry workers and community members (p>0.05) did not also show a substantive difference. However, a significant statistically difference between quarry workers and community members, with 13 of the 120 of quarry 8 workers (11%) diagnosed with obstructive or restrictive lung functioning compared to none of the 96 community members. There were statistically significant associations between smoking history and the lung function assessments FVC1 Pred% and FEV1 Pred%. Workers with 6-10 years of smoking history had significantly lower mean scores on both these measures compared to non-smokers. The study found that there were no medical examinations records at any of the studied sites. The study recommended that routine occupational medical check-up is performed for each and every worker of the quarry mines. Environmental administration systems, such as dust management plan, can be used in quarries to minimise the generation of dust. Regular environmental audit and monitoring of quarrying activities should be enforced in order to ensure adherence to the standards and limits of the concentrations of the dust generated from the different stages of their operations.
An evaluation of the Namibian Government - Garage Transport Service Provision
(2019-04) Black, Anneline F. V.
Governments, are entrusted to actively promote and maintain the welfare of their people, and the Namibian Government is no exception. Governments go about promoting the well-being of their people by using many policies within their many respective arms of governance. It can be argued that in order for Governments to carry out their work, they need to move from point to point. According to Sperling and Salon (2002) ‘Enhanced mobility has many positive effects on economic development and social welfare, including more efficient movement of goods and improved access to jobs, health services, and education’. The Government-Garage is the custodian of Government road transport services; tasked with the responsibility of the acquisition of fleets; parts of or any fleet component, taxing, licencing, fuelling, repairs and maintenance of all Government fleets, on behalf of the Offices, Ministries and Agencies (OMA) centrally and reclaiming all funds spent on public entities transport needs from the respective OMA. The purpose of the study was to evaluate the general operational performance of Government-Garage. The study focused on the service level given to its customers in terms of fleet provision - capacities, cost implications and fleet specification, as well as to make appropriate recommendations for improvement. It was found that Government-Garage transport service provision is effective as their objective of providing vehicles to the OMA were met. In fact, they provided more vehicles to OMA than needed. However, the study showed that Government-Garages are not operating efficiently; the study confirmed that on many grounds, there was a wastage of resources and complex procedures. A few recommendations are a) to appoint council members, to implement and regulate policies b) A ‘Fleet Management Task Force’, to review the utilization data to specifically examine the use for each day of the week, and to review the number of vehicles needed per OMA with the purpose of eliminating waste.
The association of Epstein-bar virus and acute leukaemias in Namibia.
(Namibia University of Science and Technology, 2019-04) Naude, Marien
ABSTRACT There are two viruses found to be direct aetiological agents of leukaemia, namely Epstein-Barr virus (EBV) and Human T-cell leukaemia virus. Viral infections were estimated to cause 15 – 20 % of all human cancers, by its capability to release virus-encoded proteins into its host. These proteins reprogram host cell signalling pathways within deoxyribonucleic acid (DNA), which are responsible for differentiation and proliferation. Furthermore, 90% of the world’s population is infected with EBV as a life-long and dormant infection of B lymphocytes. EBV is a considerably known an etiological factor in various tumours, but very little is known of the relationship between EBV and Acute Leukaemia (AL), taking into consideration any type of AL, gender or age. AL is a serious disease and the actual cause of cancer remains unknown. This study, therefore, aimed to establish the presence of Epstein-Barr virus in patients with Acute Leukaemias. The patients who were previously diagnosed with AL and who visited the Oncology ward (Windhoek Central Hospital) within the specified time frame (01 March 2017 – 31 July 2018), were screened for the presence of EBV IgG and IgM antibodies, by the use of the Enzyme-linked Immunosorbent Assay (ELISA) method. The same Ethylene Diamine Tetra Acetic Acid (EDTA) samples, which were sent to Namibian Institute of Pathology (NIP) for routine AL check-up screening, were used for this study. Controls were randomly selected among non-AL patients of different ages. The AL patients which relapsed within the period of interest were screened for the presence of EBV DNA. The same amount of patients were picked as a control and also screened for EBV DNA by Real-Time Polymerase Chain Reaction (PCR). All variables were compared between cases and controls to determine any significant association of EBV with AL. Statistical differences between the AL patients and controls were determined by the use of Chi-square testing. The AL patient group presented with the following results: 66 out of 95 (69%) were Acute Lymphoblastic Leukaemia (ALL) patients and 29 out of the 95 (31%) were Acute Myeloid Leukaemia (AML) patients. Additionally, 8 out of 95 (8%) relapsed within the period of interest. EBV IgG was the most common marker among the AL patients of which 95 out of the 95 (100%) patients were positive for EBV IgG following, EBV IgM of which 0 out of the 95 were positive for EBV IgM (0%). In the control group, 54 out of the 95 patients were positive for EBV IgG (57%) and 41 out of the 95 were negative for EBV IgG (43%). Furthermore, 17 out of the 95 were positive for EBV IgM (18%) and 78 patients out of the 95 were negative for EBV IgM (82%). Positive results were considered for titer concentrations of more than and equal to 1.2 for EBV IgG, and, more than and equal to 1.24 for EBV IgM. EBV DNA was based on qualitative measures. Chi-square results: EBV IgG p=0.0002*** for AL. EBV IgG vii p=0.0002*** for ALL. EBV IgG p=0.0002*** for AML. EBV DNA p=0.03* for the relapsed AL cases. A P- value less than or equal to 0.05 was considered statistically significant. Overall it can be concluded that EBV is common amongst AL patients of Namibia, as a lifelong latent infection, which could have contributed to the development of AL regardless of the type of AL (ALL or AML), neither the age affected nor the gender. Furthermore, it’s concluded that there is also an association between EBV and relapsing AL. These conclusions broaden the knowledge that EBV can initially infect anyone and the consequences in the long term may be fatal. Prevention interventions considering EBV should already be taken at newborn infancy period. For those previously infected with EBV should maintain a strong immunity to prevent the EBV from going viral.
Relationship between the location and causes of motor vehicle accidents on the B1 road, Windhoek to Rehoboth, Namibia.
(Namibia University of Science and Technology, 2019-04) Cloete, Carolie
Motor Vehicle Accidents (MVAs) are fast becoming the leading cause of death globally. In 2010, one person died every 25 seconds due to an MVA. Namibia was highlighted in 2008 as the country with the highest accident‐related fatality rate in the world (45 deaths per 100 000) and in 2010, ranked 9th overall for fatality rate in Africa. The B1 road in the Hardap region (Rehoboth and its surrounding areas) was identified in 2009 as one of the top ten locations for MVAs and in 2014 as an area with high MVA associated fatality. Despite the identifiable causes of MVAs, accident rates continue to rise and have been recognised as a neglected epidemic due to poor data capturing and reporting. Despite the availability of data in Namibia there has been very little research performed to investigate the causes of these statistics and no research linking the cause to the location. Filling in these research gaps is important in beginning to remedy the high number of accidents and fatalities associated with MVAs in Namibia. The study aimed to map the causes of MVAs in relation to the location (at 20km intervals) on the B1 road between Windhoek and Rehoboth. The objectives of the study were to identify clusters of causes per location interval and determine and describe the relationship between the causes and location of MVAs. The final objective is to formulate and propose endorsements for the erection of cause‐specific features at identified locations as a prevention strategy.
ASSESSMENT OF PHENOTYPIC PROPERTIES OF THE RHESUS AND KELL BLOOD GROUP SYSTEMS AMONG BLOOD DONORS AND PREGNANT WOMEN IN NAMIBIA
(Namibia University of Science and Technology, 2019-04) MATARANYIKA, MARY NYARADZAYI
A determination of the phenotypic frequencies of blood group systems C, c, E, e and Kell among the Namibian blood donors and pregnant women and the prevalence of these antigens in Namibia was carried out. Two thousand nine hundred and eight six blood donor specimens and four hundred and eighty-four specimens from pregnant women were randomly selected for antigen characterisation. Donated specimens that were processed for grouping and Transfusion Transmissible Infections (TTIs) by NaMBTS and ready for discard were collected by the researcher for testing. The main aim was to determine the prevalence of C, c, E, e and Kell antigens among the Namibia blood donors and pregnant women and advice NaMBTS and the Ministry of Health and Social Services (MoHSS) on the findings in order to improve the outcome of patients who will be receiving donated blood and the pregnant women. This was to lay the foundation for further studies to establish a database for typed donors in Namibia and then store blood that is antigen negative and reduce the risks of Haemolytic Disease of the Foetus and the New-born (HDFN) and Haemolytic Transfusion Reaction (HTR). In some cases, the survival of the red blood cells that will have been transfused is shortened by the effect of transfused antigens. This is the first time this research has been carried out in Namibia.
Prevalence and associated risk factors of respiratory diseases among residents of Tsumeb locality of Namibia.
(Namibia University of Science and Technology, 2019-04) Nangolo, Rosalia Pendukeni
Respiratory infections represent a major global health problem, and occurrences of respiratory diseases have been increasing in Southern Africa countries including Namibia due to anthropogenic activities. This study was conducted in Tsumeb, a municipal township located in the Northern part of Namibia. It aimed at determining the prevalence of respiratory ailments among the residents, identify risk factors associated with the prevalence and recommend appropriate measures to prevent exposure of residents to identified risk factors. A combination of experimental and descriptive cross-sectional quantitative approach was adopted in the data collection process. Interviewer-administered questionnaires were presented to respondents for the purpose of data collection on exposure, prevalence and health impacts of respirable dusts on their health. Analysis of heavy metals in collected respirable dust from twelve (12) households was also carried out. Heavy metals were extracted from the dust samples using mineral acid digestion protocol. Qualitative and quantitative analysis of the metals was done by use of the Inductively-Coupled Plasma Optical Emission Spectroscopy (ICP-OES). From the results obtained, 66% of respondents indicated that the roads that passes by their houses were tarred, 91% reside in single storey dwellings while 78% indicated that the windows of their houses were not protected from the passage of respirable dusts. The 65% of responders confirmed that they noticed changes in the quality of air. About 25.5% of respondents affirmed that reduced air quality may affect their health and possibly lead to other respiratory ailments such as difficulty in breathing, nasal congestion and running nose. Severe coughing was reported to be experienced by 79.5% of respondents. From the heavy metal analyses, metallic values in the analysed respirable dust samples ranged from 72 – 713.4, 0 – 18.0,1.66 – 15.8,14.15– 2338.3,68.9– 1616.6 and 6.86– 897.9 mg/kg for Mn, Cd, Ni, Cu, Zn and Pb respectively. Zinc (Zn) recorded the highest metallic value while Ni recorded the lowest value. Most of the analysed heavy metals were above the acceptable limit with the exception of Ni. Identification of respiratory risk factors is important for the prevention of exposure and development of health problems. Research findings have clearly showed that residents are exposed to respiratory disease risk factors such as poor air quality, air-borne respirable dust that are laden with toxic heavy metals and residual cigarette smoke. Regular monitoring of air quality in the locality, prevention of the release of heavy metals as a result of anthropogenic activities and sensitization of residents of the need to install appropriate air net on windows and doors of their residences in order to prevent the passage of respirable dust are recommended.
Distribution and Dynamics of toxic heavy metals in cultivated farm produce from Tsumeb, Grootfontein and Otavi localities of, Namibia
(Namibia University of Science and Technology, 2019-07) Hidinwa, Joshua Kaviyu
ABSTRACT The presence of toxic heavy metals such as Cr, Pb, Ni, As and Hg in foods constitute serious threat to the health of consumers, particularly humans. Continual consumption of foods with high level of toxic metals can lead to bioconcentration and bioaccumulation with long-term health implications. This study was carried out in Tsumeb, Grootfontein and Otavi local municipal areas in the Oshikoto region of Namibia. The focus was to assess the level, distribution and chemical mobility of selected toxic heavy metals in soil and farm produce from agricultural farmlands from these local municipalities. An experimental research design was used in the process of data collection. Soil and food samples from farms were collected over a period of two years. Samples were pre-treated and heavy metals content extracted using mineral acid microwave assisted digestion protocol. Qualitative and quantitative analysis of the metals was by the Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). The mean concentration of heavy metals in soil samples across the period ranged from 0.8 mg/kg; 1513.72 mg/kg; 7.97 mg/kg; 1.21 mg/kg; 2.03 mg/kg 13.18 mg/kg and 9.36 mg/kg from Tsumeb. The level in Grootfontein varied from 0.12 mg/kg; 1317.07 mg/kg; 7.97 mg/kg; 0.08 mg/kg; 1.61 mg/kg and 1.35 mg/kg and 8.18 mg/kg, while the concentration from Otavi ranged from 0.41 mg/kg; 1082.9 mg/kg; 7.96 mg/kg; 0.53 mg/kg; 1.75 mg/kg 7.82mg/kg and 8.49 mg/kg for Cr, Mn, Hg, Ni, Cu, Zn and Pb respectively. The mean concentration of these toxic metals in food samples across the period also ranged from 5.8 mg/kg; 12.49 mg/kg; 0.68 mg/kg; 1.27 mg/kg; ND and ND from Tsumeb. The level in Grootfontein varied from 1.7 mg/kg; 153.5 mg/kg; 0.41 mg/kg; 1.42 mg/kg; 5.13 mg/kg and 13.22 mg/kg 2.06 mg/kg, while the concentration from Otavi ranged from 0.64 mg/kg; mg/kg; 62.3 mg/kg; 0.65 mg/kg; 0.61 mg/kg and 7.33 mg/kg 13.87 mg/kg 4.38 mg/kg for Cr, Mn, Hg, Ni, Cu, Zn and Pb respectively. Analyzed metals were widely distributed in both soil and food samples. Metallic accumulation factor (AF) of > 1 was obtained in Manganese, Copper, Nickel and Zinc food samples which revealed chemical mobility of metals from labile metals fractions obtained in soil samples. The mean concentrations of 77.7mg/kg, 60.0 mg/kg, 17.8 mg/kg and 50.4 mg/kg for Manganese, Copper, Nickel and Zinc respectively obtained in food samples were found to be higher than permissible levels in foods.

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