Prof Sylvanus Onjefu

PUBLICATIONS:

E.H. Agba, S.A. Onjefu, G. Agbo, T. Sombo (2001). The Effect of X – Rays on the electrical conductivity of invitro Bovine Tissues. Nigerian Journal of pure and Applied Science: Vol; 2 (1) 107 – 112.

E.H Agba, S.A. Onjefu, J.U Ugwuanyi, (2006). Preliminary Investigation of the Ambient Radiation Levels of Mining sites in Benue State, Nigeria. Nigerian Journal of Physics, Vol. 18 (2) 219 – 222.

E.A Anyebe S.A Onjefu (2008). Beyond Credentialism: Empowering Nigerian Undergraduates for Self-Reliance. International Journal of Social and Policy Issues. Vol 5 (2) 1 – 12.

J. Abah, P Mashebe, S.A. Onjefu (2014). Survey of the level of some Heavy Metals in Roadside Dusts along Katima Mulilo urban road construction, Namibia. American Journal of Environmental Protection. Vol 3(1) 19-27

J. Abah, P Mashebe, S.A. Onjefu (2014). Some Trace Metals Content of Atmospheric Deposited Dust in Katima Mulilo metropolis, Namibia. IOSR Journal of Environmental Science, Toxicology and Food Technology. Vol 8, Issue Ver. 1 (Mar-Apr. 2014).

J. Abah, P Mashebe, S.A. Onjefu (2015). Assessment of Consumer’ Exposure to Vegetable Dietary Nitrate in Katima Mulilo, Namibia. IOSR Journal of Applied Chemistry. e-ISSN: 2278-5736. Vol 8, Issue 2 Ver. 11.

J. Abah, P Mashebe, S.A. Onjefu, S.P. Malu (2015). Assessment of the In-situ Concentrations of Some Heavy Metals in surface soil dusts at the Katima Mulilo Urban Waste dumpsite, Namibia. International Journal of Advanced Scientific and Technical Research. Vol 4, Issue 5, 88-100.

J. Abah, P Mashebe, S.A. Onjefu (2016). Preliminary Assessment of some Heavy Metals Pollution Status of Lisikili River Water in Zambezi Region, Namibia. International Journal of Environmental and Pollution Research. Vol. 4, No. 2, 13-30.

S.A. Onjefu, N.A Kgabi, S.H Taole, O.P.L Mtambo, C. Grant, J. Antoine (2016). Occupancy factor Model for Exposure to Natural Radionuclides along the Coastline of Erongo, Namibia. Journal of Geoscience and Environment Protection. Vol. 4, 117-126.

S.A. Onjefu, N.A Kgabi, S.H Taole (2016). Heavy metal Seasonal Distribution in Shore Sediment Samples along the Coastline of Erongo Region, Western Namibia. European Journal of Scientific Research, Vol. 139 (1): 49-63.

S.A. Onjefu, N. Hamatui, J.Abah (2016). Measurement of the Level of Some Heavy Metals in Fall-out Dusts at Rehoboth Town, Hardap Reegion, Namibia. British Journal of Applied Science and Technology, Vol. 17 (3): 1-11.

N. Hamatui, S.A Onjefu, I. Maposa, J.Abah (2016). Particulate pollution, house location, gravel road, and associated respiratory health effects among the residents of Rehoboth metropolis, Namibia. International Research Journal of Public and Environmental Health, Vol. 3 (10): 224-233. 

K.W Endjambi, S.A. Onjefu, N.A Kgabi, I. Maposa, N. Hamatui (2016). Particulate Matter Concentrations in the vicinity of an Incinerator. Journal of Geoscience and Environment Protection. Vol. 4, 88-100.

J. Abah, P Mashebe, S.A. Onjefu (2017). Assessment of Heavy Metals Pollution Status of the Pasture Grass around Katima Mulilo Municipal Solid Waste Dumpsite, Namibia. International Journal of Environmental Science and Development. Vol. 8, No. 5, 372-377.

J. Abah, P Mashebe, S.A. Onjefu (2017). Heavy metals Content of the Grassland soil around Katima Mulilo Municipal Solid Waste Dumpsite, Namibia. American Journal of Environmental Sciences. Vol. 13, No. 2, 128-137.

S.A Onjefu, N.A Kgabi, S.H Taole, C. Grant, J. Antoine (2017). Assessment of Natural Radionuclide Distribution in Shore Sediment Samples Collected from the North Dune Beach, Henties Bay, Namibia. Journal of Radiation Research and Applied Sciences. Vol 10, 301-306.

S.A Onjefu, J.Abah, B. Nambundunga (2017). Some Heavy Metals’ Concentrations in Roadside Dusts at Monte Christo, Windhoek Namibia. International Journal of Environmental Science and Development. Vol. 8, No. 9, 647-652.

Maria N.N. Amwaalanga, Sylvanus A. Onjefu, Munyaradzi Zivuku, Roswita H. Hamunyela (2019). Assessment of natural radioactivity levels and radiation hazards in shore sediments from the Zambezi River, Namibia. Int. Sci. Technol. J. Namibia. 13:59-67.

Onjefu Sylvanus Ameh, Ejembi Emmanuel, Onjefu Agbo Leonard (2019).Measurement of Noise Pollution in Northern Industrial Areas of Windhoek, Namibia. Journal of Environmental Protection 10(09): 1144-1154.

Abah James, Mashebe Percy, Onjefu Sylavnus Ameh (2020). Heavy Metals Pollution Status of Katima Mulilo Urban open land Wastewater disposal centre and immediate vicinity.  Cogent Environmental Science Vol. 6: 1726093.

Onjefu Sylvanus Ameh, Ejembi Emmanuel, Onjefu Agbo Leonard (2020). Investigating urban Traffic noise pollution carried out at three Institutions of Higher Learning in Windhoek, Namibia. Nigerian Annals of Pure and Applied Sciences Vol.3: (1), 122-128. 

Sylvanus Ameh Onjefu, Fatima Shaningwa, Julien Lusilao, James Abah, Euodia Hess & Habauka Majority Kwaambwa (2020) Assessment of heavy metals pollution in sediment at the Omaruru River basin in Erongo region, Namibia, Environmental Pollutants and Bioavailability, Vol. 32, N0. 1, 187–193, https://doi.org/10.1080/26395940.2020.1842251

Onjefu SA, Hitila M, Katangolo H, Zivuku M, Abah J, Mutorwa MK, (2020).Measuring Natural Radioactivity Concentration in Various Types of Rice Consumed in Windhoek, Namibia. Nigerian Journal of Physics 28 (2): 124-128. 

Sylvanus Ameh Onjefu, Mpingana Laimi Iyambo, James Abah & Sindila Mwiya (2021) Radiological analysis of the suitability of Erongo granite for building material, Geomatics, Natural Hazards and Risk, 12:1, 181-197, DOI: 10.1080/19475705.2020.1863270.

Onjefu Sylvanus Ameh, Caspah Kamunda, Abah James (2021) Health Risk Assessment of Natural Radioactivity in Wasteland Soils in Okakarara, Namibia, Arab Journal of Nuclear Sciences and Applications, 54(2): 143-150.

Onjefu S.A, Kafidi N.N., Kamunda C., Uloko P.I, Hitila M., Ejembi E & Kennedy J. (2021) Activity concentrations of 226Ra, 232Th, and 40K in common maize meal consumed in Namibia and their potential radiation hazards. Nigerian Annals of Pure and Applied Sciences Vol.4: (1), 146-152. 

Onjefu Leonard A, Abubakar Idris, Amana Ocholi, Onjefu S.A, Kiangi Geoffrey (2021) Reliability-Based Analysis For Failure Modes of Mansard Roof Truss According To Euro Code 3. International Journal of Engineering Research & Technology 10 (11), 136-146.

Markus Vaefeni Hitila. Sylvanus Ameh Onjefu (2022)Radiological Risk Assessment of Technologically Enhanced Naturally Occurring Radioactive Materials in coal wastes from Van Eck Coal-Fired thermal Power Plant, Namibia. Namibia Journal for Research, Science and Technology. 3(1): 21-29. 

Onjefu Sylvanus Ameh, Hamukotoh Tuwilika, Caspah Kamunda, Abah James, Hitila Markus, and Jeya Kennedy (2022) Annual effective dose and radiological risk assessment from selected salt pans from the lagoon of Erongo region, Namibia. International Journal of Applied Science and Engineering. https://doi.org/10.6703/IJASE.202202 19 (1).009.

S.A. Onjefu, N.N. Johannes, J. Abah, L.A. Onjefu S. Mwiya (2022)Natural radioactivity levels and evaluation of radiological hazards in Usakos marble, Erongo region, Namibia. International Journal of Radiation Research 20 (20): 403-409.

Markus Vaefeni Hitila. Sylvanus Ameh Onjefu (2022)Natural radioactivity & associated radiological health hazards in soil around Van Eck Power plant, Windhoek, Namibia. Proceedings of the African Conference on Fundamental and Applied Physics Second Edition, ACP2021, March 7{11, 2022}.

Sylvanus Ameh Onjefu, Aina Nancy Iyaloo Kauluma, Munyaradzi Zivuku, Emmanuel Ejembi, Roswita Hambeleleni Hamunyela, Bismark Mzubanzi Tyobeka (2022) Assessment of radioactivity levels in shore sediments along the coastline of the Orange River, Oranjemund, Namibia. Heliyon 8, https://doi.org/10.1016/j.heliyon.2022e10579

Onjefu SA, Wilika NP, Hitila M, Kamunda C, Hamunyela RH, Asuquo SO, Ejembi E, Mutorwa MK, Euodia HH (2022) Determination of natural radioactivity in nuts and seeds and their radiological implications in the human body. Nig Annals of Pure and Appl. Sci. 5(1): 221-228.

Lawrence Sawunyama, Opeyemi A. Oyewo, Naledi Seheri, Sylvanus A. Onjefu, Damian C. Onwudiwe (2023) Metal oxide functionalized ceramic membranes for the removal of pharmaceuticals in wastewater. Surfaces and Interfaces 38, http://doi.org/10.1016/j.surfin.2023.102787

Martha Hweka, Jude Osakwe, Sylvanus Onjefu, Ujakpa martin (2023) Business intelligence strategic approach for decision support tool in business organisation. SSRN. Proceedings of International Conference on Information Systems and Emerging Technology, Https://ssrn.com/abstract=4674985.

James Abah, Evans Kamwi Simasiku, Sylvanus Ameh Onjefu (2023) Assessment of heavy metals pollution status of surface soil dusts at the Katima Mulilo urban motor park, Namibia, Geomatics, Natural Hazards and Risk, 14:1, 2204181, DOI: 10.1080/19475705.2023.2204181

Oghenevovwero E. Esi, Gregory O. Avwiri, Onjefu A. Sylvanus, Damian C. Onwudiwe (2024)Radiometric Survey of Sediments and Health Risk Assessments from the southern coastal area of Delta State, Nigeria, Heliyon, Volume 10, Issue 5, doi.org/10.1016/j.heliyon.2024.e26805.

Sylvanus Ameh Sylvanus, Biere Peter Ebibuloami, Caspah Kamunda, Markus Hitila, Marius Kudumo Mutorwa, Jeya Kudi Kennedy, Euodia Hess, Damian C. Onwudiwe (2025). Natural radioactivity assessments and radiological hazards in agricultural soils around mining activities in Karibib, Namibia. Nuclear Analysis, https://doi.org/10.1016/j.nucana.2025.100155

J. Abah, E.k. Simasiku, S.A, Onjefu, & K. Hove (2025) Preliminary assessment of heavy metals contamination of sediments in Lake Liambezi, Namibia. Journal of Environmental Protection and Ecology, 26, No 5, 1641–1656.

VU Nwagbara, E Naomab, MB Tyobeka, SA Onjefu, J Abah, N Kgabi, (2025). Assessment of heavy metal pollution of the stream sediment from the Omaruru Basin, Erongo Region of western central Namibia, All Earth 37 (1), 1-13.

Onjefu Sylvanus Ameh, Nandjovo Maria Ndeshipanda, Hitila Markus, Indongo Vaino, Zivuku Munyaradzi, Ejembi Emmanuel, Hamunyela Roswita Hambeleleni (2025). Health Risk Assessment of Natural Radioactivity in soil from Helao Nafidi dumpsite, Omafo, Namibia. International Science and Technology Journal of Namibia 18:39-56

CONFERENCE PAPERS (Oral)

Onjefu SA. Monitoring Air pollution of Co and SO₂ Resulting from Bye products of Biomass Fuel in Otukpo and Environ., 29^th Annual Conference of the Nigerian Institute of Physics (UNN, 2006).

Onjefu SA. Ambient Radiation Levels in Guma Salt Mine, Benue State, Nigeria; 29^th Annual Conference of the Nigerian Institute of Physics (UNN, 2006).

Onjefu SA. Preliminary investigation of the Ambient Radiation Levels of Mine Sites in Benue State, Nigeria; 29^th Annual Conference of the Nigerian Institute of Physics (UNN, 2006).

Onjefu SA. Mining Activity, Ionizing Radiation and the Environmental Question, 4^th National Conference of the School of Science, College of Education Oju, Benue State (2006).

Onjefu SA. Measurement of the Colour vision deficiency in Benue state University, Makurdi, Nigeria, 30^th Annual Conference of the Nigerian Institute of Physics (LASU, 2007).

Onjefu SA. Measurement of Alpha Particle, Beta Particle and Gama Radiation in Mine Site in Jos Metropolis, 30^th Annual Conference of the Nigerian Institute of Physics (LASU, 2007).

Onjefu SA. Variation of Noise Pollution Levels with time of the day in residential, commercial and industrial Areas in Otukpo Benue State, 30^th Annual Conference of the Nigerian Institute of Physics (LASU, 2007). 

Onjefu SA. Assessment of NORMs from salt mine along the coast of Erongo Region Namibia (FHAS 2015).

Onjefu SA. Assessment of desalinating efficiency of renewable and non-renewable energy operated desalination plants in Namibia (WaterNet Swakopmund 2017).

Onjefu SA. Health Risk Assessment of Natural Occurring Radionuclides in Shore Sediment Collected from Ovambo Beach, Walvis Bay, Namibia (African Conference on Fundamental Physics; ACP 2018).

Onjefu SA. Heath risk assessment of natural radioactivity in wasteland soils of Rundu dumpsite, Kavango region, Namibia (Nuclear Science and Technology Conference; Swakopmund, 2024).

POSTER PRESENTATION

Onjefu SA. Studies on Natural Radioactivity in Shore Sediments of Swakopmund Beach, Erongo Region, Namibia (African Conference on Fundamental Physics; ACP 2018). 

Onjefu SA. Assessment of Heavy Metals Pollution in Sediment at the Omaruru River Basin in Erongo Region, Namibia (WaterNet Livingstone, Zambia 2018).

Onjefu SA. Measuring Natural Radioactivity Concentration in Various Types of Rice Consumed in Windhoek Namibia (Nigerian Institute of Physics NIP-FUTO 2019).

Onjefu SA. Natural radionuclides and radiological risk assessment of granite samples from Ariskop quarry, Windhoek, Namibia (African Conference on Fundamental Physics; ACP 2021; {March 7-11, 2022}.). 

PLENARY OR KEYNOTE PRESENTATIONS

Beyond Credentialism: Empowering Namibian Youths for Self-Reliance Through Innovative Research (Key Presenter at the Research and Innovation Day of the University of Namibia Katima Mulilo Campus Windhoek 12 October 2016).