Microplastics in aquatic ecosystems of Africa: A comprehensive review and meta-analysis.

Microplastic pollution is a global issue of great public concern. Africa is flagged to host some of the most polluted water bodies globally, but there is no enough information on the extent of microplastic contamination and the potential risks of microplastic pollution in African aquatic ecosystems. This meta-analysis has integrated data from published articles about microplastic pollution in African aquatic ecosystems. The data on the microplastic distribution and morphological characteristics in water, sediments and biota from African rivers, lakes, oceans and seas were extracted from 75 selected studies. Multivariate statistics were used to critically analyze the effects of sampling and detection methods, ecological risks, spatial distribution and similarity of microplastics in relation to the geographical distance between sampling sites. This study found that sampling methods have significant effect on abundance and morphological characteristics of microplastics and that African aquatic ecosystems are highly contaminated with microplastics compared to global data. The most prevalent colors were white, transparent and black, the most prevalent shapes were fibres and fragments, and the most available polymers were polypropylene (PP), polystyrene (PS) and polyethene terephthalate (PET). Microplastic polymers similarity decreased with an increase in geographical distance between sites. Risk levels of microplastics in African aquatic ecosystems were comparatively high, and more than 40 % of water and sediments showed highest level of ecological risk. This review provides recent information on the prevalence, distribution and risks of microplastics in African aquatic ecosystems.

The threat of micro/nanoplastic to aquatic plants: current knowledge, gaps, and future perspectives.

Plastics have been recognized as an emerging pollutant and have raised global concerns due to their widespread distribution in the environment and potential harm to living systems. However, research on the threat of micro/nanoplastics (MPs/NPs) to the unique group of aquatic plants is far behind, necessitating a comprehensive review to summarize current research progress and identify future research needs. This review explores the sources and distribution patterns of MPs/NPs in aquatic environments, highlighting their uptake by aquatic plants through roots and leaves, and subsequent translocation via the vascular system facilitated by the transpiration stream. Exposure to MPs/NPs elicits diverse effects on the growth, physiology, and ecological interactions of aquatic plants, with variations influenced by plastic properties, plant species, and experimental conditions. Furthermore, the presence of MPs/NPs can impact the toxicity and bioavailability of other associated toxicants to aquatic plants. This review shows critical knowledge gaps and emphasizes the need for future research to bridge the current understanding of the limitations and challenges posed by MPs/NPs in aquatic ecosystems.