Microplastics in the Volta Lake: Occurrence, distribution, and human health implications

Charles Mario Boateng; Samuel Addo; Collins Prah Duodu; Harriet Danso-Abbeam; Prince Chapman Agyeman; Kofi Ferni Anyan; Eunice Konadu Asamoah; Emmanuel Robert Blankson; Elvis Nyarko; Atsushi Matsuoka

doi:10.1016/j.heliyon.2024.e29041

Microplastics in the Volta Lake: Occurrence, distribution, and human health implications

Heliyon. 2024 Apr 3;10(7):e29041. doi: 10.1016/j.heliyon.2024.e29041. eCollection 2024 Apr 15.

Affiliations

¹ Department of Marine and Fisheries Sciences, University of Ghana, Accra, Ghana.
² School of Marine Science and Ocean Engineering, University of New Hampshire, USA.
³ Environmental Research Resource Centre, Ghana Atomic Energy Commission, P.O Box LG 80, Accra, Ghana.
⁴ Division of Plant Sciences and Technology, University of Missouri, USA.
⁵ Department of Animal Biology and Conservation Science, University of Ghana, Accra, Ghana.
⁶ Regional Maritime University, Post Office Box GP 1115, Accra, Ghana.
⁷ Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA.

Abstract

Pollution of plastic waste in aquatic ecosystems in Ghana is of significant concern with potential adverse effects on food safety and ecosystem function. This study examined the abundance and distribution of microplastics (MPs) in freshwater biota samples namely: the African river prawn (Macrobrachium vollenhovenii), the Volta clam (Galatea paradoxa), Nile tilapia (Oreochromis niloticus), and sediment from the Volta Lake. Both biota and sediment samples were subjected to microscopic identification and FTIR analysis. In biota samples, the highest mean microplastic abundance of 4.7 ± 2.1 items per individual was found in the prawn, while the Nile tilapia recorded the least (2.8 ± 0.6 items per individual). A total of 398 microplastic particles were observed in sediment samples from the Volta Lake. Microfibers were the major plastic shapes identified in biota and sediment samples. We examined the relationship between microplastic abundance, biota size, and sediment properties. Despite the lack of statistical significance, microplastic shape, size, and polymer composition in assessed organisms mirrored those in the benthic sediment. Polyethylene, polypropylene, polyester, and polystyrene were the four dominant polymer types identified in the organisms and sediments. Although the estimated human exposure was relatively low compared with studies from other regions of the world, the presence of microplastics raises concern for the safety of fisheries products consumed by the general populace in the country. This research is essential for developing effective mitigation measures and tackling the wider effects of microplastic contamination on Ghana's freshwater ecosystems, particularly the Volta Lake.

Keywords: Human exposure; Microfiber; Microplastics; Polymer; Sediment; Volta lake.