Microplastic Contamination and Its Impact on Soil Properties Across Different Land Uses in Cross River State, Nigeria

References

[1] Adebayo, A. A., & Ojo, O. (2021). Soil characterization and agricultural productivity in southeastern Nigeria.

[2] Ajakaiye, D. E., & Ojo, S. B. (1988). Geology and mineral resources of the Benue Trough. Journal of African Earth Sciences, 7(3), 401-416.

[3] Ajayi, O., & Ojo, M. O. (2008). Geological diversity and ecosystem support in Cross River Basin. West African Journal of Applied Ecology, 14, 23-38.

[4] Akpan, V. E., Omole, D. O., & Bassey, D. E. (2021). Assessing the optimal plastic waste management mode for Nigeria. Journal of Material Cycles and Waste Management, 23, 2267-2280.

[5] Andrady, A. L. (2011). Microplastics in the marine environment. Marine Pollution Bulletin, 62(8), 1596-1605. Bouyoucos, G. J. (1962). Hydrometer method improved for making particle size analyses of soils. Agronomy Journal, 54(5), 464-465.

[6] Büks, F., & Kaupenjohann, M. (2020). Global concentrations of microplastics in soils a review. SOIL, 6, 649-662.

[7] Corradini, F., Meza, P., Eguiluz, R., Casado, F., Huerta-Lwanga, E., & Geissen, V. (2019). Evidence of microplastic accumulation in agricultural soils from sewage sludge disposal. Science of the Total Environment, 671, 411-420.

[8] Cross River National Park. (2021). Biodiversity Assessment Report 2020. Nigeria National Parks Service. Day, P. R. (1965). Particle fractionation and particle-size analysis. In C. A. Black (Ed.), Methods of Soil Analysis: Part 1 (pp. 545-567). American Society of Agronomy.

[9] Ekong, P. S. (2020). Land use patterns and agricultural sustainability in Cross River State. Nigerian Agricultural Journal, 51(3), 412-429.

[10] Environmental Science & Technology, 50(5), 2685-2691.

[11] Eze, J. N. (2020). Vegetation dynamics in the Cross River rainforest ecosystem. African Journal of Ecology, 58(2), 234-251.

[12] Horton, A. A., Walton, A., Spurgeon, D. J., Lahive, E., & Svendsen, C. (2017). Microplastics in freshwater and terrestrial environments: Evaluating the current understanding to identify the knowledge gaps and future research priorities. Science of the Total Environment, 586, 127-141.

[13] Huang, Y., Liu, Q., Jia, W., Yan, C., & Wang, J. (2020). Agricultural plastic mulching as a source of microplastics in the terrestrial environment. Environmental Pollution, 260, 114096.

[14] Huang, Y., Zhao, Y., Wang, J., Zhang, M., Jia, W., & Qin, X. (2021). LDPE microplastic films alter microbial community composition and enzymatic activities in soil. Environmental Pollution, 254, 112983.

[15] Huerta Lwanga, E., Gertsen, H., Gooren, H., Peters, P., Salánki, T., van der Ploeg, M., ... & Geissen, V. (2016).

[16] IUCN. (2021). The IUCN Red List of Threatened Species. Version 2021-3. https://www.iucnredlist.org Kochian, L. V., Hoekenga, O. A., & Piñeros,

[17] Microplastics in the terrestrial ecosystem: Implications for Lumbricus terrestris (Oligochaeta, Lumbricidae).

[18] M. A. (2004). How do crop plants tolerate acid soils? Mechanisms of aluminum tolerance and phosphorus efficiency. Annual Review of Plant Biology, 55, 459-493.

[19] Lehmann, A., Zheng, W., & Rillig, M. C. (2020). Soil biota contributions to soil aggregation. Nature Ecology & Evolution, 4, 1828-1835.

[20] Liu, H., Yang, X., Liu, G., Liang, C., Xue, S., Chen, H., ... & Yin, W. (2020). Response of soil dissolved organic matter to microplastic addition in Chinese loess soil. Chemosphere, 185, 907-917.

[21] Liu, M., Lu, S., Song, Y., Lei, L., Hu, J., Lv, W., ... & He, D. (2018). Microplastic and mesoplastic pollution in farmland soils in suburbs of Shanghai, China. Environmental Pollution, 242, 855-862.

[22] Machado, A. A. S., Kloas, W., Zarfl, C., Hempel, S., & Rillig, M. C. (2018). Microplastics as an emerging threat to terrestrial ecosystems. Global Change Biology, 24(4), 1405-1416.

[23] Nigerian Meteorological Agency. (2022). Annual Climate Report 2021: Cross River State. Abuja: NiMet Publications.

[24] Nizzetto, L., Futter, M., & Langaas, S. (2016). Are agricultural soils dumps for microplastics of urban origin? Environmental Science & Technology, 50(20), 10777-10779.

[25] Nwafor, O. E., Akinyemi, A. F., & Egbe, C. A. (2022). Ethnobotanical survey of medicinal plants in Cross River National Park, Nigeria. Journal of Medicinal Plants Research, 16(3), 89-104.

[26] Ofoegbu, C. O. (1990). Geological framework of Nigerian sedimentary basins. In S. O. Ako & A. O. Onuoha (Eds.), Geology of Nigeria (pp. 123-156). Lagos: Rock View Nigeria Limited.

[27] Ofoegbu, C. O. (1995). Basement complex rocks of southeastern Nigeria. Journal of African Earth Sciences, 21(2), 305-318.

[28] Okwakol, M. J. N. (2019). Soil classification and agricultural potential of Ultisols in humid tropical Africa. Tropical Soil Science Journal, 28(4), 234-251.

[29] Okwakpam, I. N. (2018). Rainfall patterns and agricultural implications in Cross River Basin, Nigeria. Nigerian Journal of Environmental Sciences, 12(2), 78-91.

[30] Parga Sánchez, M., Segura, C., García-Gaines, R. A., & Hernández, L. M. (2022). Microplastic contamination in urban soils of Mexico City. Science of the Total Environment, 812, 152463.

[31] Qi, R., Jones, D. L., Li, Z., Liu, Q., & Yan, C. (2020). Behavior of microplastics and plastic film residues in the soil environment: A critical review. Science of the Total Environment, 703, 134722.

[32] Qi, Y., Yang, X., Pelaez, A. M., Lwanga, E. H., Beriot, N., Gertsen, H., ... & Geissen, V. (2018). Macro- and micro- plastics in soil-plant system: Effects of plastic mulch film residues on wheat (Triticum aestivum) growth. Science of the Total Environment, 645, 1048-1056.

[33] Rillig, M. C. (2012). Microplastic in terrestrial ecosystems and the soil? Environmental Science & Technology, 46(12), 6453-6454.

[34] Rillig, M. C., Ingraffia, R., & de Souza Machado, A. A. (2017). Microplastic incorporation into soil in agroecosystems. Frontiers in Plant Science, 8, 1805.

[35] Rillig, M. C., Kim, S. W., Zhu, Y. G., & Lehmann, A. (2019). The soil plastisphere. Nature Reviews Microbiology, 17, 524-525.

[36] Rillig, M. C., & Lehmann, A. (2020). Microplastic in terrestrial ecosystems. Science, 368(6498), 1430-1431.

[37] Rodriguez-Seijo, A., Lourenço, J., Rocha-Santos, T. A. P., Da Costa, J., Duarte, A. C., Vala, H., & Pereira, R. (2017). Histopathological and molecular effects of microplastics in Eisenia andrei Bouché. Environmental Pollution, 220, 495-503.

[38] Sanchez, P. A. (1976). Properties and Management of Soils in the Tropics. New York: John Wiley & Sons.

[39] Udo, E. J., Ibia, T. O., Ogunwale, J. A., Ano, A. O., & Esu, I. E. (2019). Manual of Soil, Plant and Water Analysis (2nd ed.). Lagos: Sibon Books Limited.

[40] Wan, Y., Wu, C., Xue, Q., & Hui, X. (2019). Effects of plastic contamination on water evaporation and desiccation cracking in soil. Science of the Total Environment, 654, 576-582.

[41] Zhang, G. S., Zhang, F. X., & Li, X. T. (2019). Effects of polyester microfibers on soil physical properties: Perception from a field and a pot experiment. Science of the Total Environment, 670, 1-7.

[42] Zubris, K. A. V., & Richards, B. K. (2005). Synthetic fibers as an indicator of land application of sludge. Environmental Pollution, 138(2), 201-211.

@article{1713602,
      author = {Tangban, E. E., Nwamuo, L. O., Nnaji, G. U., Oguike, P. C.},
      title = {Microplastic Contamination and Its Impact on Soil Properties Across Different Land Uses in Cross River State, Nigeria},
      journal = {Iconic Research And Engineering Journals},
      year = {2026},
      volume = {9},
      number = {7},
      pages = {1584-1598},
      issn = {2456-8880},
      url = {https://www.irejournals.com/formatedpaper/1713602.pdf},
      abstract = {Background: Microplastic contamination in terrestrial ecosystems represents an emerging environmental threat, yet comprehensive assessments of its distribution and impact on soil properties in tropical African environments remain limited.
Objective: This study investigated the spatial distribution of microplastics across four land-use types (forest, agricultural, residential, and commercial) in Cross River State, southeastern Nigeria, and evaluated their effects on soil physical, chemical, and hydrological properties.
Methods: A factorial experimental design was employed across 12 locations in three Local Government Areas (Boki, Obubra, and Ikom). Soil samples were collected from 0-10 cm depth, and microplastics were extracted using density separation with saturated saline solution. Comprehensive soil analyses included particle size distribution, chemical properties (pH, organic matter, nutrients, cation exchange capacity), and hydrological characteristics.
Results: Microplastic concentrations varied significantly across land uses, with commercial areas exhibiting the highest contamination (12.12 g kg??; 150.87 tons ha??), followed by residential (5.40 g kg??; 70.08 tons ha??), agricultural (3.09 g kg??; 39.50 tons ha??), and forest (1.00 g kg??; 10.65 tons ha??) sites. Spatial variability was highest in commercial zones (CV = 48.07%). Soil texture was predominantly sandy loam, with pH ranging from moderately acidic to slightly acidic (5.47-5.57). Organic carbon content varied from 0.89% to 3.26%, with forest soils showing significantly higher values. Bulk density ranged from 1.05 to 1.32 g cm??, with commercial areas demonstrating higher compaction. Cation exchange capacity averaged 9.74 cmol kg?? across sites, with commercial areas showing elevated values (14.73 cmol kg??). Hydraulic conductivity exhibited substantial variation (15.69-41.57 mm hr??), with forest soils maintaining superior infiltration rates.
Conclusion: This study provides the first comprehensive assessment of microplastic distribution in Nigerian tropical soils, revealing critical land-use-dependent contamination patterns. Commercial areas represent microplastic hotspots with concentrations exceeding forest baselines by over 1,000%. The contamination correlates with alterations in soil physical structure, nutrient dynamics, and water retention properties, potentially threatening soil ecosystem services and agricultural productivity in the region.
},
      keywords = {Microplastics; Soil Contamination; Land Use; Tropical Soils; Soil Properties; Cross River State; Nigeria.},
      month = {January},
      doi = {https://doi.org/10.64388/IREV9I7-1713602}
  }