Qualitative assessment of the impact of waste littering and dumping on surface water quality in Nigeria
Received date: 2024-05-02
Accepted date: 2025-02-27
Online published: 2025-03-13
Copyright
Water resources are vital for all living beings and should be managed properly to ensure the safety and well-being of humankind. Surface water bodies are constantly faced with serious contamination risks generated primarily by human activities and urbanization. The problem of waste littering and dumping in developing countries like Nigeria is increasingly affecting environmental resources such as air and water. Several studies have revealed alarming levels of heavy metals that exceed the World Health Organization (WHO) standards. Plastic waste represents a substantial portion of litter, affecting water quality. Pollution results in the depletion of aquatic ecosystems and an increase in water-related diseases. This review aims to assess the impact of waste littering and dumping on surface water quality in Nigeria. In this review, the findings of various studies on surface water bodies in Nigeria, particularly those under the influence of urbanization and waste disposal, were compiled. This review compared numerous physical and chemical parameters like pH, dissolved oxygen, and heavy metals, and microbiological properties such as total coliforms. The water quality index (WQI) was also computed in these studies to ascertain the suitability of the water samples for human consumption. Review results showed that numerous water bodies in Nigeria have significantly diverse water quality levels, with some samples meeting or exceeding the WHO guidelines for microbiological, chemical, and physical characteristics. Notably, levels of heavy metals, turbidity, and pH frequently exceeded permissible limits, pointing to contamination from agricultural and industrial sources. The WQI results for multiple locations revealed that the majority of surface water sources were classified as “bad” to “very bad”, meaning they were unfit for human consumption. The results emphasized the critical need for immediate action to prevent further harm and deterioration of surface water bodies in Nigeria. Recommendations include strengthening waste management policies, promoting recycling initiatives, fostering collaborations among stakeholders, developing littering penalties and enforcing fines to curb the challenge, and raising educational awareness from the primary level. This review emphasizes the need for proactive measures to protect the environment and surface water quality in Nigeria.
Gloria FAYOMI , Ednah ONYARI , Onyeka NKWONTA . Qualitative assessment of the impact of waste littering and dumping on surface water quality in Nigeria[J]. Regional Sustainability, 2025 , 6(1) : 100194 . DOI: 10.1016/j.regsus.2025.100194
| [1] | Abubakar Y., 2021. An assessment of the awareness level of coastal and upland communities in Nigeria on the impacts of marine litter on the ocean and its ecosystem services. MSc Thesis. Malm?: World Maritime University, 23-40. |
| [2] | Abui Y.M., Ezra V., Bonet R.A., et al., 2017. Assessment of heavy metals level of River Kaduna at Kaduna metropolis, Nigeria. Journal of Applied Sciences & Environmental Management. 21(2), 347-352. |
| [3] | Abulude F.O., Akinnusotu A., Adeoya E.A., et al., 2023. Quality of surface and ground water in three states of Nigeria: Assessment of physicochemical characteristics and selected contamination patterns. Environmental Sciences Proceedings. 25(1), 48, doi: 10.3390/ECWS-7-14258. |
| [4] | Acholonu C., Bridget E.D., Somtochukwu N.R., et al., 2023. Solid waste disposal: A potential threat to aquatic environment. Archives of Current Research International. 23(6), 22-32. |
| [5] | Adelagun R.O.A., Etim E.E., Godwin O.E., 2021. Application of water quality index for the assessment of water from different sources in Nigeria. IntechOpen. doi: 10.5772/intechopen.98696. |
| [6] | Adeola A.O., Akingboye A.S., Ore O.T., 2022. Crude oil exploration in Africa: Socio-economic implications, environmental impacts, and mitigation strategies. Environment Systems & Decisions. 42(1), 26-50. |
| [7] | Afolayan O.S., Ogundele F.O., Odewumi S.G., 2012. Hydrological implication of solid waste disposal on groundwater quality in urbanized area of Lagos state, Nigeria. International Journal of Applied Science and Technology. 2(5), 74-76. |
| [8] | Ahmed A., Obanore S., Paul P., 2022. Waste management regulations enforcement: Lead way to a healthy environment in Nigeria. Trends in Civil Engineering and its Architecture. 4(3), 673-677. |
| [9] | Aigberua A., Tarawou T., 2019. Water quality index (WQI) assessment along inland fresh waters of Taylor Creek in Bayelsa State, Nigeria. Journal of Environmental Treatment Techniques. 7(3), 260-269. |
| [10] | Akpan V.E., Olukanni D.O., 2020. Hazardous waste management: An African overview. Recycling-Basel. 5(3), 15, doi: 10.3390/recycling5030015. |
| [11] | Ali H., Khan E., Ilahi I., 2019. Environmental chemistry and ecotoxicology of hazardous heavy metals: Environmental persistence, toxicity, and bioaccumulation. J. Chem. 2019(1), 6730305, doi: 10.1155/2019/6730305. |
| [12] | Aljamali N.M., Alfatlawi I.O., Husien N.S.M., et al., 2020. Review on effect of chemical waste on the environment. International Journal of Green Chemistry. 6(1), 1-9. |
| [13] | Amusan L., Akintaro H., Osawaru F., et al., 2018. Information on state of challenges of waste management system in Nigeria urban housing system. International Journal of Mechanical and Production Engineering Research and Development. 8(2), 75-86. |
| [14] | Apinhapath C., 2014. Community mapping and theory of planned behavior as study tools for solid waste management. Journal Waste Manage. 2014(1), 934372, doi: 10.1155/2014/934372. |
| [15] | Aragaw T.A., 2021. Microplastic pollution in African countries’ water systems: A review on findings, applied methods, characteristics, impacts, and managements. SN Appl. Sci. 3(6), 629, doi: s42452-021-04619-z. |
| [16] | Ariza Restrepo J.L., Rodriguez Diaz Y.J., Onate Barraza H.C., 2023. Water quality indices (WQI) and contamination indices (WPI): A bibliographic review. Tecnura. 27(77), 121-140. |
| [17] | Avio C.G., Gorbi S., Regoli F., 2017. Plastics and microplastics in the oceans: From emerging pollutants to emerged threat. Mar. Environ. Res. 128, 2-11. |
| [18] | Awunor N.S., Okhimamhe A.F., Alenoghena I.O., et al., 2021. Determinants of street littering in an urban setting in South-South Nigeria. Western Journal of Medical & Biomedical Sciences. 2(2), 93-101. |
| [19] | Ayesha S., Hahladakis J.N., Al-Attiya W.A.K., 2022. An overview of the environmental pollution and health effects associated with waste landfilling and open dumping. Environ. Sci. Pollut. Res. 29(39), 58514-58536. |
| [20] | Ayodeji A.N., Afolalu S.A., Yusuf O.O., et al., 2021. Impact assessment of the current waste management practices in Nigeria. IOP Conference Series: Materials Science and Engineering. 1107(1), 012172, doi: 10.1088/1757-899X/1107/1/012172. |
| [21] | Bawa-Allah K.A., 2023. Assessment of heavy metal pollution in Nigerian surface freshwaters and sediment: A meta-analysis using ecological and human health risk indices. J. Contam. Hydrol. 256, 104199, doi: 10.1016/j.jconhyd.2023.104199. |
| [22] | Chaudhary A.H., Polonsky M.J., McClaren N., 2021. Littering behaviour: A systematic review. Int. J. Consum. Stud. 45(4), 478-510. |
| [23] | Coker J.O., Alausa S.K., Odunaike R.K., et al., 2019. The impact assessment of solid waste on groundwater quality in Olusosun dumpsite, Lagos Nigeria. Journal Nigerian Geophysical Society. 2(1), 1-12. |
| [24] | Dahunsi S.O., Owamah H.I., Ayandiran T.A., et al., 2014. Drinking water quality and public health of selected towns in Southwestern Nigeria. Water Quality, Exposure and Health. 6(1), 143-153. |
| [25] | Deswal M., Deswal P., Duhan S.S., et al., 2019. An assessment of anticipated pollution index of some common plants and trees of Rohtak city of Haryana (India). Rasayan Journal of Chemistry. 12, 1627-1640. |
| [26] | Diez S.M., Patil P.G., Morton J., et al., 2019. Marine Pollution in the Caribbean: Not a Minute to Waste. [2024-04-14]. https://documents1.worldbank.org/curated/en/482391554225185720/pdf/Marine-Pollution-in-the-Caribbean-Not-a-Minute-to-Waste.pdf. |
| [27] | Dzuro T., Králiková R., 2016. Effective patented method in the process of eutrophication of surface waters. Environmental Policy Tools. 1(1), 36-42. |
| [28] | EADP (Environmental Affairs and Development Planning), 2021. Waste collection and transportation status quo report 2021. In: Western Cape Government. EADP Report. Cape Town, South Africa. |
| [29] | Ebere E.C., Wirnkor V.A., Ngozi V.E., et al., 2019. Macrodebris and microplastics pollution in Nigeria: First report on abundance, distribution and composition. Environmental Analysis, Health and Toxicology. 34(4), e2019012-0, doi: 10.5620/eaht.e2019012. |
| [30] | Edmund N.E., Okeoma I.O., 2009. Street littering in Nigerian towns: Towards framework for sustainable urban cleanliness. African Research Review. 3(5), 147-164. |
| [31] | Egun N.K., Oboh I.P., 2023. Assessment of water quality for suitability and human health risk: A study of the Owan River, Edo State, Nigeria. Afr. J. Aquat. Sci. 48(1), 19-27. |
| [32] | Emeka C., Nweke B., Osere J., et al., 2020. Water quality index for the assessment of selected borehole water quality in Rivers State. European Journal of Environment and Earth Sciences. 1(6), doi: 10.24018/ejgeo.2020.1.6.101. |
| [33] | Engwa G.A., Tagbo R.N., Iyala C.P., et al., 2015. Physicochemical and microbial analysis of portable water sources in Enugu Metropolis. Journal of Public Health and Epidemiology. 7(3), 65-70. |
| [34] | Ewuzie U., Aku N.O., Nwankpa S.U., 2021. An appraisal of data collection, analysis, and reporting adopted for water quality assessment: case of Nigeria water quality research. Heliyon. 7(9), e07950, doi: 10.1016/j.heliyon.2021.e07950. |
| [35] | Federal Ministry of Environment, 2020. National Policy on Solid Waste Management. [2024-04-15]. https://www.environment.gov.ng/download/national-policy-on-solid-waste-management/. |
| [36] | Franca O.E., Ahmadu J., Hanis B., 2019. Effects of solid waste on the surface water quality of Usuma River, Phase IV, Kubwa-Abuja, Nigeria. International Journal of Environmental Protection and Policy. 7(6), 150-160. |
| [37] | Franz B., Freitas M.A.V., 2012. Generation and impacts of floating litter on urban canals and rivers: Rio de Janeiro megacity case study. Sustainability Today. 167(1), 321-332. |
| [38] | Freduah G., 2016. Climate change and fisheries in Ghana:Strategies for building adaptive capacity by small-scale fishers. PhD Dissertation. Brisbane: University of the Sunshine Coast. |
| [39] | Gikas G.D., Sylaios G.K., Tsihrintzis V.A., et al., 2020. Comparative evaluation of river chemical status based on WFD methodology and CCME water quality index. Sci. Total Environ. 745, 140849, doi: 10.1016/j.scitotenv.2020.140849. |
| [40] | Graham R.E.D., 2024. A study of illegal dumping near coastal zones and waterways in Grenada: Advancing waste management solutions and reducing marine litter. PLOS Water. 3(4), e0000175, doi: 10.1371/journal.pwat.0000175. |
| [41] | Hale R.C., Seeley M.E., La Guardia M.J., et al., 2020. A global perspective on microplastics. Journal of Geophysical Research: Oceans. 125(1), e2018JC014719, doi: 10.1029/2018JC014719. |
| [42] | Hammani B., Mohamed S.O., Mohammed K.A., et al., 2020. Evaluation of heavy metal contamination in surface and groundwater in Maiganga, Gombe State, Nigeria. Journal of Soil and Water Science. 52, 218-222. |
| [43] | Hansmann R., Steimer N., 2017. Subjective reasons for littering: A self-serving attribution bias as justification process in an environmental behaviour model. Environmental Research, Engineering and Management. 73(1), 8-19. |
| [44] | Haseena M., Malik M.F., Javed A., et al., 2017. Water pollution and human health. Environmental Risk Assessment and Remediation. 1(3), 16-19. |
| [45] | Hashan M.M., Moniruzzaman S.M., 2022. Seasonal variation and assessment of water quality: A study on Mayur River, Khulna. In:Proceedings of the 6th International Conference on Civil Engineering for Sustainable Development. Khulna, Bangladesh. |
| [46] | Henderson L., Dumbili E., 2021. Drinking and dropping: On interacting with plastic pollution and waste in South-Eastern Nigeria. Worldwide Waste. 4(3), 1-12. |
| [47] | Ibe P.I., Aigbedion I.P., Marcellinus M., et al., 2019. Assessment of water quality index for groundwater in Ado Ekiti, Nigeria. World News of Natural Sciences. 22(1), 93-101. |
| [48] | Ismail O.B., Samson O.J., Aina S.A., et al., 2023. Microbiological and physicochemical assessments of selected fish pond water sample in South-West, Nigeria. Journal of Biology and Applied Biology. 6(1), 1-13. |
| [49] | Kallenbach E.M.F., R?dland E.S., Buenaventura N.T., et al., 2021. Microplastics in terrestrial and freshwater environments. In: Bank, M.S., (ed.). Microplastic in the Environment:Pattern Process. Cham: Springer, 87-130. |
| [50] | Kanu I., Achi O.K., 2011. Industrial effluents and their impact on water quality of receiving rivers in Nigeria. Journal of Applied Technology in Environmental Sanitation. 1(1), 75-86. |
| [51] | Keep America Beautiful, 2020. 2020 National Litter Study. [2024-04-10]. https://kab.org/wp-content/uploads/2021/05/Litter-Study-Summary-Report-May-2021_final_05172021.pdf. |
| [52] | Kehinde O., Ramonu O.J., Babaremu K.O., et al., 2020. Plastic wastes: Environmental hazard and instrument for wealth creation in Nigeria. Heliyon. 6(10), e05131, doi: 10.1016/j.heliyon.2020.e05131. |
| [53] | Ken-Onukuba D.N., Okeke O.C., Amadi C.C., et al., 2021. Water quality assessment of Ekulu and Asata Rivers in Enugu Area, Southeastern Nigeria, using physico-chemical and bacteriological parameters. Journal of Environment and Earth Science. 11(4), 70-92. |
| [54] | Koda E., Miszkowska A., Sieczka A., 2017. Levels of organic pollution indicators in groundwater at the old landfill and waste management site. Appl. Sci.-Basel. 7(6), 638, doi: 10.3390/app7060638. |
| [55] | Krystosik A., Njoroge G., Odhiambo L., et al., 2020. Solid wastes provide breeding sites, burrows, and food for biological disease vectors, and urban zoonotic reservoirs: A call to action for solutions-based research. Front. Public Health. 7, 405, doi: 10.3389/fpubh.2019.00405. |
| [56] | Li J.N., Qu X.Y., Su L., et al., 2016. Microplastics in mussels along the coastal waters of China. Environ. Pollut. 214, 177-184. |
| [57] | Luvhimbi N., Tshitangano T.G., Mabunda J.T., et al., 2022. Water quality assessment and evaluation of human health risk of drinking water from source to point of use at Thulamela Municipality, Limpopo Province. Sci. Rep. 12(1), 6059, doi: 10.1038/s41598-022-10092-4. |
| [58] | Malik A., Katyal D., Narwal N., et al., 2023. Sources, distribution, associated health risks and remedial technologies for inorganic contamination in groundwater: A review in specific context of the state of Haryana, India. Environ. Res. 236, 116696, doi: 10.1016/j.envres.2023.116696. |
| [59] | Mbajiorgu C.C., 2020. Assessment of Surface Water Hydrology. Nsukka: University of Nigeria. |
| [60] | McAllister J., 2015. Factors influencing solid-waste management in the developing world. MSc Thesis. Logan: Utah State University. |
| [61] | Misman N.A., Sharif M.F., Chowdhury A.J.K., et al., 2023. Water pollution and the assessment of water quality parameters: A review. Desalin. Water Treat. 294, 79-88. |
| [62] | Moqbel S., El-tah Z., Haddad A., 2019. Littering in developing countries: The case of Jordan. Pol. J. Environ. Stud. 28(5), 3819-3827. |
| [63] | Nubi A.T., Nubi O.A., Laura F.G., et al., 2019. Effective solid waste management: A solution to the menace of marine litter in coastal communities of Lagos State, Nigeria. African Journal of Environmental Science and Technology. 13(3), 104-116. |
| [64] | Nwaezeigwe J., Babatunde T., 2023. Effect of solid waste disposal on chemical quality of groundwater in Ife North Local Government Area, Osun State, Nigeria: A GIS-based assessment. Ghana Journal of Geography. 15(2), 132-161. |
| [65] | Obi C.C., Adebusoye S.A., Ugoji E.O., et al., 2016. Microbial communities in sediments of Lagos Lagoon, Nigeria: elucidation of community structure and potential impacts of contamination by municipal and industrial wastes. Front. Microbiol. 7, 1213, doi: 10.3389/fmicb.2016.01213. |
| [66] | Ochuko U., Thaddeus O., Oghenero O.A., et al., 2014. A comparative assessment of water quality index (WQI) and suitability of River Ase for domestic water supply in urban and rural communities in Southern Nigeria. International Journal of Humanities and Social Science. 4(1), 234-245. |
| [67] | Okafor V.N., Omokpariola D.O., Obumselu O.F., et al., 2023. Exposure risk to heavy metals through surface and groundwater used for drinking and household activities in Ifite Ogwari, Southeastern Nigeria. Appl. Water Sci. 13(4), 105, doi: 10.1007/s13201-023-01908-3. |
| [68] | Olanrewaju O.O., Oyebade D., 2019. Environmental menace of plastic waste in Nigeria:Challenges, policies and technological efforts. In: Transition Pathways to Sustainable Development Goals: Integrated Landscape Approach, Economic Well Being and Inclusive Climate Resilience. Akure, Nigeria. |
| [69] | Ololade I.A., Adewunmi A., Ologundudu A., et al., 2009. Effects of household wastes on surface and underground waters. Int. J. Phys. Sci. 4(1), 22-29. |
| [70] | Omole D.O., Emenike C.P., Tenebe I.T., et al., 2015. An assessment of water related diseases in a Nigerian community. Research Journal of Applied Sciences, Engineering and Technology. 10(7), 776-781. |
| [71] | Omotayo A.E., Simeon O.M., Amund O.O., 2017. Microbial qualities of vegetables, water and soils from vegetable gardens in Lagos State, Nigeria. Nigerian Journal of Microbiology. 31(1), 3763-3767. |
| [72] | Osuagwu J.C., Nwachukwu A.N., Nwoke H.U., et al., 2014. Effects of soil erosion and sediment deposition on surface water quality: A case study of Otamiri River. Asian Journal of Engineering and Technology. 2(5), 438-442. |
| [73] | Pandit D.N., Kumari R., Shitanshu S.K., 2022. A comparative assessment of the status of Surajkund and Rani Pond, Aurangabad, Bihar, India using overall Index of Pollution and Water Quality Index. Acta Ecol. Sin. 42(3), 149-155. |
| [74] | Rana R., Ganguly R., 2020. Water quality indices: Challenges and applications-an overview. Arab. J. Geosci. 13(22), 1190, doi: 10.1007/s12517-020-06135-7. |
| [75] | Rangecroft S., Dextre R.M., Richter I., et al., 2023. Unravelling and understanding local perceptions of water quality in the Santa basin. Peru. J. Hydrol. 625, 129949, doi: 10.1016/j.jhydrol.2023.129949. |
| [76] | Rangel-Buitrago N., Mendoza A.V., Gracia A., et al., 2019. Litter impacts on cleanliness and environmental status of Atlantico department beaches, Colombian Caribbean coast. Ocean Coastal Manage. 179, 104835, doi: 10.1016/j.ocecoaman.2019.104835. |
| [77] | Sahoo D., Anandhi A., 2023. Conceptualizing turbidity for aquatic ecosystems in the context of sustainable development goals. Environ. Sci.-Adv. 2(9), 1220-1234. |
| [78] | Samuel O.O., Oyewole N.O., Abiola B., et al., 2019. Water quality assessment of surface and groundwater sources using a water quality index method: A case study of a peri-urban town in Southwest, Nigeria. Environments. 6(2), 23, doi: 10.3390/environments6020023. |
| [79] | Sawyerr H.O., Adeolu A.T., Afolabi A.S., et al., 2017. Impact of dumpsites on the quality of soil and groundwater in satellite towns of the Federal Capital Territory, Abuja, Nigeria. J. Health Pollut. 7(14), 15-22. |
| [80] | Schenck C.J., Nell C.M., Grobler L., et al., 2022. Clean cities and towns: Understanding societal behaviour in order to reduce and divert waste going to landfills. Waste Research Development and Innovation Roadmap. 1(1), 32-37. |
| [81] | Schultz P.W., Bator R.J., Large L.B., et al., 2013. Littering in context: Personal and environmental predictors of littering behavior. Environ. Behav. 45(1), 35-59. |
| [82] | Sharma V., Sharma M., Pandita S., et al., 2021. Assessment of water quality using different pollution indices and multivariate statistical techniques. In: Kumar, V., Sharma, A., Cerdà, A., (eds.). Heavy Metals in the Environment. Amsterdam: Elsevier. |
| [83] | Shultana S., Khan R.A., 2022. Water quality assessment, reasons of river water pollution, impact on human health and remediation of polluted river water. GSC Advanced Research and Reviews. 10(2), 107-115. |
| [84] | Solomon O.O., Palanisami T., 2016. Microplastics in the marine environment: Current status, assessment methodologies, impacts and solutions. Journal of Pollution Effects & Control. 4(2), 161, doi: 10.4172/2375-4397.1000161. |
| [85] | Taiwo A.M., Ogunsola D.O., Babawale M.K., 2023. Assessment of Water Quality Index and the probable human health implications of consuming packaged groundwater from Abeokuta and Sagamu, Southwestern Nigeria. Sustainability. 15(4), 3566, doi: 10.3390/su15043566. |
| [86] | Uddin M.G., Nash S., Olbert A.I., 2021. A review of water quality index models and their use for assessing surface water quality. Ecol. Indic. 122, 107218, doi: 10.1016/j.ecolind.2020.107218. |
| [87] | Umar M., Aziz H.A., Yusoff M.S., 2010. Variability of parameters involved in leachate pollution index and determination of LPI from four landfills in Malaysia. Int. J. Chem. Eng. 2010, 747953, doi: 10.1155/2010/747953. |
| [88] | United Nations Environment Programme, 2019. Styrofoam and Plastic Bag Bans in the Caribbean - Interactive Map. [2024-04-17]. https://www.unep.org/cep/news/blogpost/styrofoam-and-plastic-bag-bans-caribbean-interactive-map#:-:text=UN%20Environment%20CEP%20created%20an%20interactive%20map%20on,status%20of%20bans%20that%20can%20be%20updated%20periodically. |
| [89] | Urooj A., Ilyas R., Humayun N.H., 2019. Effects of dumping solid waste on water quality of surface water bodies. J. Plant Environ. 1(1), 21-24. |
| [90] | Usali N., Ismail M.H., 2010. Use of remote sensing and GIS in monitoring water quality. Journal of Sustainable Development. 3(3), 228-230. |
| [91] | Ustao?lu F., Tepe Y., Ta? B., 2020. Assessment of stream quality and health risk in a subtropical Turkey river system: A combined approach using statistical analysis and water quality index. Ecol. Indic. 113, 105815, doi: 10.1016/j.ecolind.2019.105815. |
| [92] | W?tor K., Zdechlik R., 2021. Application of water quality indices to the assessment of the effect of geothermal water discharge on river water quality - case study from the Podhale region (Southern Poland). Ecol. Indic. 121, 107098, doi: 10.1016/j.ecolind.2020.107098. |
| [93] | World Bank, 2021. From City to Sea: Integrated Management of Litter and Plastics in Urban Areas-A Guide for Municipalities. [2024-04-20]. https://openknowledge.worldbank.org/entities/publication/25086ea7-bacc-56c7-814b-554b4e33e683/full. |
| [94] | Wright S.L., Kelly F.J., 2017. Plastic and human health: A micro issue? Environ. Sci. Technol. 51(12), 6634-6647. |
| [95] | Yusuf M., Pamungkas A., Hudatwi M., et al., 2021. Distribution of turbidity values, total suspended solids and heavy metals Pb, Cu in Tanah Merah Beach waters and Semujur Island waters, Bangka Tengah Regency. IOP Conference Series. Earth and Environmental Science. 750, 012038, doi: 10.1088/1755-1315/750/1/012038. |
| [96] | Zangina A.S., Ali A.F., 2021. An overview of hazardous waste management in Nigeria. Dutse Journal of Pure and Applied Sciences. 7(4b), 214-221. |
/
| 〈 |
|
〉 |
REGSUS Wechat
新公网安备 65010402001202号