International Science and Technology Journal of Namibia

Radioactivity concentrations in anthill soils used for building construction: A case study of Oshikoto region, Namibia

2024-11-19T10:16:44+02:00

The level of background radioactivity concentration is gradually increasing worldwide due to anthropogenic activities. Humans are exposed to radiation either from terrestrial sources emanating from these activities or cosmological sources. The main aim of the study was to measure the radioactivity concentrations in anthill soils used for building residential dwellings in the northern region. The study was conducted along the B1 road of the Oshikoto region to determine the natural activity concentration of terrestrial radionuclides of ²³⁸U (²²⁶Ra), ²³²Th and ⁴⁰K by using a high-purity germanium detector and to assess the radiological health parameters associated with the anthill building material. The average activity concentrations for (²²⁶Ra), ²³²Th and ⁴⁰K were found to be 8.01 ± 0.43, 11.75 ± 0.48 and 159.33 ± 5.19 Bq/kg, respectively. All measured average activity concentrations of the radionuclides were below the world safety limits. The corresponding radiological parameters of interest of the study (absorbed dose rate, annual effective dose equivalence, radium activity, external hazard index, and internal hazard index) were estimated. The averages for the absorbed dose rate and annual effective dose equivalent were found to be 17.02 ± 0.42 nGy/h and 0.02 ± 0.00 mSv/y, respectively, whilst the averages for radium equivalent activity, external hazard index and internal hazard index were 36.08 ± 0.92 Bq/kg, 0.10 ± 0.00 and 0.12 ± 0.00, respectively. The absorbed dose rate for soil was approximately three times (x3) lower than that of the world average. The spread of data from the mean value was 5.94 nGy/h for the absorbed dose rate, 6.29 mSv/y for annual effective dose, 11.02 Bq/kg for radium equivalent activity, 0.03 for the external hazard index and 0.04 for the internal hazard index. The average values for the external and internal hazard indices were below unity, implying that the external exposure of humans to radiation is negligible and therefore, the soil materials are safe for building constructions of human shelters

Determination of some selected heavy metals in catfish samples collected from some dams in Katsina state, Nigeria.

2024-10-08T14:01:26+02:00

This study was conducted to determine the concentrations of Cadmium, Cobalt, Copper, Nickel, Lead and Zinc in the Gill, Muscle and Tails of African catfish collected from Gwaigwaye, maska and Zobe dams in Katsina state, Nigeria across the dry and wet seasons. The collected tissues of African catfish were digested and analyzed for the toxic metals using microwave plasma atomic emission spectroscopy (MPAES). The levels of the metals obtained were compared with acceptable limits of world health organization(WHO) and Standard organization of Nigeria(SON).The metal levels were found in the following ranges, 0.0132±0.01 to 0.057±0.02 mg/kg for Cd, 0.00±0.00 to 0.887±0.01 mg/kg for Co, 0.090±0.00 to 0.26±0.00 mg/kg for Cu, 0.00±0.00 to 0.138±0.01 mg/kg for Ni, 0.00±0.00 to0.003±0.00 mg/kg for Pb and 0.133±0.04 to 0.855±0.01mg/kg for Zn for catfish gill in dry and wet seasons. Likewise, the concentration levels of the metals in catfish muscle in the following ranges were as follows 0.01±0.00 to 0.076±0.01 mg/kg for Cd, 0.00±0.00 to 0.048±0.01 mg/kg for Co, 0.066±0.04 to 0.108±0.03 mg/kg for Cu, 0.01±0.00 to 0.096±0.03 mg/kg for Ni, 0.00±0.00 to 0.01±0.00 mg/kg for Pb and 0.036±0.05 to 0.411±0.04 mg/kg for Zn . Similarly, 0.019±0.01 to 0.029±0.03 mg/kg for Cd, 0.00±0.00 to 0.091±0.01 mg/kg for Co, 0.079±0.01 to 0.133±0.03 mg/kg for Cu, 0.016±0.03 to 0.116±0.01 mg/kg for Ni, 0.00±0.00 to 0.023±0.03 mg/kg for Pb and 0.323±0.03 to1.08±0.01 mg/kg for Zn in catfish tail in both dry and wet seasons. The levels of the metals were found to be below the safe limits set by both WHO and SON. African catfish from gwaigwaye, maska and zobe dams are therefore safe for human consumption. The results of statistical analysis and P values<0.05 indicated no significant difference between the tissues of African catfish analyzed across all the dams in both seasons.

Microbial load and mycotoxins from malted pearl millet and sorghum

2024-12-06T12:42:57+02:00

Microbial contamination of pearl millet and sorghum grains during the process of malting can compromise the safety of their resulting products. In Namibia, malts of pearl millet and sorghum are used in making oshikundu/ontaku, omalovu (opaque beer) and exclusively sorghum malts for other alcoholic traditional brews. There is limited research on microbial load and mycotoxins from malts of pearl millet intended for making oshikundu and possibly omalovu. Varieties of pearl millet (Okashana2, Kantana, and Kangara) and sorghum (Macia and Red sorghum) grains were germinated at 30°C for 4 days before drying at 50–55°C for 24 hours. Results showed that malts total microbial load was above the South African recommended limit 6.3 Log cfu/g (2 ×10⁷ cfu/g). However, cereal malts showed no contamination by Salmonella spp., Shigella and coliforms. Regulated mycotoxins aflatoxin, deoxynivalenol, fumonisin and zearalenone were detected from malts irrespective of the cereal. However, detected mycotoxins were below the legal limit set by the European Commission. These suggests that malts may potentially not be of safety concern when it comes to coliforms. Nonetheless, aerobic bacterial load, fungal load and mycotoxins need to be further reduced should the malt be used for oshikundu, omalovu and other low alcoholic brews.

Covid-19 COVID-19 AND NATURAL HERBS: A WAY FORWARD

2025-02-06T12:51:15+02:00

The emergence of COVID-19 caused by the SARS-Coronavirus-2 (SARS-CoV-2) in late 2019 has caused dramatic downfall of economies, health and social mobilization of people all over the world. Up to date, there is no widely accepted drug for the treatment of COVID-19, necessitating the exploration of medicinal plants or plant components as therapeutic agents. To make matters worse there is massive Covid -19 vaccination hesitancy in the public and even in medical staff. Medicinal plants, according to various studies have shown varying efficacy in clearing signs and symptoms of COVID-19 which includes dry cough, loss of appetite, fever, tiredness, sore throat and diarrhea, as well as complications like chest pain, shortness of breath and loss of speech and movement. This review explores the extensive flora of Africa and other parts of the world for information on medicinal herbs with potentials for the treatment of COVID-19. Africa is in pole position because of her rich history, practice and knowledge of medicinal plants to treat varying number of infections to find the perfect herb for the cure of COVID-19. Bioactive phytochemicals such as alkaloids, flavonoids, polyphenols, terpenes and so on with varying mechanism of action could target the virus architecture such as the structural protein (Spike protein), the virus genome (RNA), and the non-structural proteins of the virus which are responsible for replication, transcription and host cell recognition. The indiscriminate use of medicinal plants in the treatment of various infections, should be avoided against COVID-19 and thus strict regulations and education of such implications should be highlighted to the public

Physico-chemical characteristics of soils at selected water-points in the Etosha National Pan, Namibia

2024-12-12T10:34:16+02:00

National parks are important systems for protecting biodiversity and ecosystems around the world. In Namibia, approximately 19% of the country’s land surface is proclaimed for protected areas including Etosha National Park (ENP). Managing the protected areas effectively and sustainably requires a great understanding of various components of the park, including the soils. This study aimed to understand the soil properties at different water-points in ENP (at Mushara, Rietfontein and Ombika water-points). Ten plots from each site were sampled, at different soil depths. Soil parameters such as soil texture, pH, electronic conductivity (EC), Cation Exchange Capacity (CEC), phosphorus (P), potassium (K) and organic matter content (OM) were measured and analysed. The results show that soils were poorer at Mushara than at Rietfontein and Ombika, in terms of OM, Zinc (Zn), EC, Iron (Fe), and CEC. Furthermore, Mushara had significantly more sand content than both Ombika and Rietfontein. However, there were no significant differences between Rietfontein and Ombika in terms of CEC, Zn, Calcium (Ca), pH, OM, iron, manganese, sodium (Na) and soil texture. All sites were largely dominated by sandy soil. However, Mushara had significantly more sand than both Ombika and Rietfontein, and significantly lower clay and silt content than Ombika and Rietfontein. The study concludes that the soil properties at assessed water-points might be influenced by vegetation communities, soil type and the total annual precipitation. Therefore, the results of this study can be used to refine conservation strategies and develop long-term monitoring programs. We recommend that future studies focus on the link between vegetation composition, above and below ground biomass and soil properties in ENP.

Towards safer roads: A study on road safety knowledge and practices among public transport users in Namibia

2025-02-26T16:33:20+02:00

Road crashes pose a significant burden on the social and economic growth of developing countries, where over 90 % of the world’s road traffic fatalities and injuries are recorded. The increasing vehicle population has subsequently led to an increasing number of road traffic crashes, which has brought to the fore the importance of investigating road safety awareness, attitudes and perceptions to combat the issue of road safety. A cross-sectional survey was carried out on respondents in six Namibian regions identified to have the most hazardous national rural road sections, to assess their knowledge, attitudes and road safety practices. Public transport (long distance busses) was observed as the most common mode of transport on the national rural roads. The study identified an inadequate level of road safety knowledge and poor road safety practices among the teenager and young adult population (15 to 29 years) using and operating public transport modes. These poor practices predispose the young road user population to higher crash risk. The poor practices were attributed to an inadequate level of road safety knowledge, which was reported by most of the respondents. Despite teenagers and young adults exhibiting poor road safety qualities, the statistical odds ratios found that the level of desirable road safety knowledge and practices increased with age. The study found that the poor road safety status quo is exacerbated by a low regularity of road safety campaigns, traffic rules enforcement and poor road safety practices by public transport operators. The study identified possible shortcomings in existing road safety programmes and recognised areas that need attention to effectively promote proactive road safety reforms. Furthermore, the study established baseline measures for the levels of awareness, attitudes and perceptions on national rural roads. The baseline measures developed in the study can be used as a base comparison tool for future studies, to guide the development of pro-active safety measures as advances and transformations take effect in road safety.

Exploring Methodologies for Assessing Land Degradation: A Comprehensive Review with Insights from Namibia

2024-11-19T08:54:10+02:00

Land degradation represents a significant global environmental challenge, posing threats to ecosystem integrity, food security, and sustainable development. In this comprehensive review, we examine the methodologies employed for assessing land degradation, drawing insights from studies conducted in various regions, with a particular focus on Namibia. The study conducted a systematic literature search to gather information on land degradation assessment methods applied, 159 publications were reviewed. Utilizing the Mann-Kendall trend test, the study discerns notable trends in the publication landscape, providing valuable insights into the evolving research trajectories within this field. A prominent finding of this review is the dominance of remote sensing as the primary method utilized for assessing land degradation. In conclusion, this review underscores the imperative for future research endeavours to prioritize an in-depth exploration of land degradation processes, mechanisms, impacts as well as advocates for the adoption of innovative technologies and monitoring methods, the advancement of theoretical frameworks, and the promotion of multidisciplinary integrated system research. By embracing these recommendations, stakeholders can effectively address the multifaceted challenges posed by land degradation and advance towards sustainable land management practices.

A systematic literature review on blockchain-based titles registries for transparent land administration

2024-10-22T11:10:25+02:00

Traditional land registration processes in many countries are vulnerable and lack transparency, resulting in fraud, delays, and costs, especially in developing countries, and blockchain integration has been proposed as a potential solution in land administration systems. This paper addresses the challenges of the conventional system in its examination of this integration. Sweden stands out for its successful implementation of blockchain in land registry, owing to its advanced digital landscape. In contrast, developing countries such as Namibia face limited internet access, particularly in rural areas, which can hinder blockchain adoption. Georgia, Honduras, and Ghana have had success combating corruption through blockchain in land titling, while Kenya, Dubai, and several other countries are all actively exploring various blockchain applications in land administration. Despite its potential, this systematic literature review identifies a few challenges, such as identity verification, contract legality, co-ownership management, and adaptation to legal frameworks, that must be addressed before widespread blockchain implementation. The successes of Sweden, Georgia, Honduras, and Ghana illustrate both the potential and limitations of utilizing blockchain technology for land registry purposes. This study concludes that while blockchain's potential in land administration is evident, its realization requires careful consideration of legal, technological, and governmental complexities.