Pa ge 1 Pa ge 15 5 American Journal of Environment and Climate (AJEC) Microplastics Pollution in Nigerian Aquatic Ecosystems: Sources, Pathways, Impacts, and Mitigation Strategies. A Review Terngu Paul Ugosor1*, Korom Terna2, Ornguga Terlumum Timothy3, Apeyuan Kparev-Wua David3, Asemave Kaana4 Volume 4 Issue 3, Year 2025 ISSN: 2832-403X (Online) DOI: https://doi.org/10.54536/ajec.v4i3.6354 https://journals.e-palli.com/home/index.php/ajec Article Information ABSTRACT Received: October 12, 2025 Accepted: November 15, 2025 Published: December 15, 2025 Microplastics, MPs (< 5mm) are ubiquitous plastic contaminants in freshwater and marine environments. MPs have been increasingly documented across Nigerian aquatic systems, including rivers, lagoons, estuaries, sediments, seafood, and drinking waters. They arise from multiple primary and secondary sources, undergo complex transport and transformation pathways, and affect organisms across trophic levels. Evidence indicates widespread contamination with fibers and fragments dominated by polyethylene, polypropylene, and polyester at urban drainage and estuarine sinks, and detectable particles in sachet/bottled water and commercially harvested fish. Reports showed that land-based inputs dominate marine microplastic loads, which are transported into subsurface and Polar Regions by currents with effects ranging from physiological stress in organisms to potential human exposure through seafood and drinking water. This review synthesizes recent findings on major sources and environmental pathways, ecological and human-health impacts, and mitigation strategies tailored to Nigeria’s socio-environmental context. The article recommended targeted source-reduction (including enforcement of single-use plastic restrictions and alternatives for sachet water), technological upgrades in wastewater and stormwater trash capture at drainage outfalls and treatment, coordinated upstream interventions (product design, waste management, extended producer responsibility), exposure and health risks studies for high- risks occupational and coastal communities, long-term toxicology for chronic low-dose exposures (including nanoplastics), and standardized national monitoring framework. These steps are urgent to protect aquatic ecosystem services and public health in Nigeria. Keywords Aquatic Environments, Ecological Impacts, Microplastics, Pollution Mitigation, Wastewater Treatment 1 Department of Chemistry, College of Education, Katsina-Ala, Benue State, Nigeria 2 Department of Geography, College of Education, Katsina-Ala, Benue State, Nigeria 3 Department of Biology, College of Education, Katsina-Ala, Benue State, Nigeria 4 Department of Chemistry, Rev. Fr. Moses Orshio Adasu University, Makurdi, Benue State, Nigeria * Corresponding author’s e-mail: paulugosor@gmail.com INTRODUCTION Microplastics (MPs), commonly defined as plastic particles <5 mm, are persistent environmental contaminants that pose ecological and human-exposure concerns worldwide (Huirong et al., 2021). According to Iviwe (2021), the increase in MPs pollution in the aquatic environments is attributed to the exponential rise in plastic production since the mid-20th century. Continuous fragmentation and direct release of small plastic particles have created an environmental problem recognized globally as microplastic contamination or pollution. Microplastics (MPs) pollution of aquatic ecosystems is a worldwide challenge because of its negative impacts on the aquatic ecosystem and human health). In Nigeria, rapid urbanization, extensive use of single-use plastics (notably sachet water and styrofaom), gaps in municipal waste collection, and informal waste economies have created conditions that favour plastic leakage to waterways. Recent field surveys and monitoring studies across multiple Nigerian states document MPs in surface waters, sediments, commercial fish, bottled/ sachet waters and drinking supplies, indicating both environmental and direct human exposure routes (Ebere, 2019; Akindele et al., 2019; Idowu et al., 2019; Apata et al., 2022a; Apata et al., 2022b). Similar, researches by Isaac et al., (2023), Akinhanmi et al. (2023), Aliyu et al. (2023), Akinhanmi (2024), Nduka et al. (2024), Obiakara- Amaech, 2025), Onyena (2025), and Kpikpi et al. (2025) collaborated similar findings. MPs are found in surface waters, sediments, organisms, sea ice, and drinking water sources, provoking concern about ecological damage and potential human health risks. The presence of microplastics in aquatic ecosystems such as sediments (Ahmad et al., 2025), sea beds/ocean floors (Hartz et al., 2025) and biota (Witczak et al., 2024) has been recorded worldwide. A review of related literature has shown that MPs pollution is increasing geometrically in aquatic ecosystems, threatening aquatic life, biodiversity, degradation, and human health. Aquatic organisms often mistake MPs as food and ingest them, resulting in altered metabolic functions and serious health challenges (Atiqur et al., 2025; Pal et al., 2025; Sunny et al., 2025). Microplastics are distributed and transported in an aquatic environment through various patterns and sources either as primary or secondary. Primary microplastics are manufactured in small sizes (e.g., pellets, microbeads) usually present in beauty care products and abrasives which enter the environment directly. Pa ge 15 6 https://journals.e-palli.com/home/index.php/ajec Am. J. Environ. Clim. 4(3) 155-165, 2025 Secondary microplastics result from the fragmentation of larger plastic items (e.g., packaging, fishing gear, tyres (Wu et al., 2023; Marcharla et al., 2024; Zhang et al., 2024). The impacts of MPs on biota and human health through food chain are also well documented (Rummel et al., 2017; Nelms et al., 2021; Ragusa et al., 2021, and Toussaint et al., 2023). The persistence and inability of Microplastics to biodegrade as well as serve as potential vectors of other toxic pollutants (Wei et al., 2023) have serious health implications to aquatic life and human health. According to estimates (UNDP, 2022; Atiqur et al., 2025), 80 million tonnes of plastics found their way into the aquatic environments in 2015 where Africa alone contributed 21 % of the figure. Available records showed that approximately 85 % of plastics wastes is unregulated in Africa, which is above the global average of 47% (Atiqur et al., 2025). According to a report by Safaa., (2024), Egypt, Nigeria, South Africa, and Algeria ranked 7th, 9th, 11th,and 13th respectively in global plastics wastes mismanagement. Most of these wastes eventually end up in the aquatic ecosystems with the attendant consequences. The level of microplastics pollution in aquatic ecosystems is expected to increase if deliberate measures are not taken to mitigate it. It is worthy of note that African freshwaters (especially Nigeria) are gradually dwindling due to plastics pollution and climate change. Accordingly, the presence of microplastics in fishes, crustaceans, amphibians, insects, freshwater birds, Jellyfish/sea jellies, turtles, seaweed/kelp, mollusks, coral/anemones, and marine worms are increasingly being documented by researchers Sun et al., 2022; Tiwari et al., 2023). Many communities in Nigeria depend on fishing and fish farming for their livelihood. Thus, microplastic pollution in these Nigerian aquatic ecosystems (dams, lakes, rivers, seas, and oceans) will no doubt result to devastating consequences on aquatic life, biodiversity, human health, and food insecurity. Again, Nigeria is home to a number of stunning beaches: Elegushi beach, La Campagna Tropicana Beach Resort, Bar Beach, Tarkwa Bay and Lekki beach (Lagos state); Ibeno beach (Akwa Ibom state); Calabar beach (Cross River state); Asaba beach (Delta state); Patigi beach (Kwara state); Finima and Ifoko beaches (Rivers state), and Ndibe sand beach (Ebonyi state) among others. These beaches are perfect for relaxation, recreation, and cultural experiences, offering a mixture of urban vibes, cultural heritage, and natural beauty. The beaches make Nigeria a great destination for beach lovers and also attract tourists all over the world, generating revenue for the government. Therefore, microplastics pollution or plastics washed up on beach sediments will render these aquatic ecosystems unattractive for tourist attraction, hindering economic development. It is therefore important to create awareness on the negative impacts of microplastics pollution on aquatic environments in Nigeria. Information on MPs pollution of Nigerian aquatic ecosystems will help to educate and provide a platform for legislations and regulations that will assist in curbing the menace of microplastics pollution in the country. Literature searches have revealed only a handful of researches on microplastics pollution in Nigerian aquatic environments, resulting to difficulty in appreciating the associated ecological consequences of microplastics pollution. This review summarizes up-to-date knowledge on the sources, and pathways of MPs into Nigerian aquatic systems, their observed impacts on aquatic organisms, human health, and ecosystems, and practical mitigation strategies supported by recent research and technological developments. MATERIALS AND METHODS This is a narrative systematic review of peer-reviewed literature and authoritative published reports from 2019 to 2025 that measured microplastics in Nigerian aquatic environments or food/water products. Both peer- reviewed articles and credible gray literature (university repositories, government notices, reputable news reporting on national policy) were included to reflect the rapidly evolving local evidence base. Priority was given to meta-analyses, systematic reviews, high-impact empirical studies, and authoritative reviews. The most relevant studies were extracted to produce a comparative table summarizing sampling location, year, compartment sampled, analytical methods, and key findings. RESULTS AND DISCUSSION Occurrence and Characteristics of Microplastics in Nigeria Surface Waters And Sediments Microplastics pollution in Nigerian aquatic environments is a pressing environmental issue, with several studies highlighting the severity of the problem. Idowu et al. (2019) conducted studies on River Osun (A UNESCO World Heritage site), focusing on microplastics pollution. They investigated the presence of microplastics in the river, specifically looking at the ingestion of microplastics by freshwater gastropods. The study found evidence of microplastics contamination in the river with concentrations reaching 22,079 particle/L, highlighting the impact of microplastic pollution on aquatic life. A research conducted on Rivers Dukku and Kalgo, Kebbi state by Tajudeen et al. (2024) on the impact of MPs pollution on aquatic life found significant concentrations of MPs in both rivers with the Dukku river showing concentrations ranging from 125.00 particles/L to 160.30 aprticles/L and Kalgo river ranging from 119.30particle/L to 134.70 particle/L. Similar researches conducted by Abdullahi et al. (2022) on the physocochemical properties and diversity of microalgae, in Dukku River, Birnin Kebbi, Nigeria and Yahaya et al.,(2024) on the abundance, characterization, and health risks evaluation of microplastics in borehole water in Birni Kebbi, Nigeria confirmed varying concentrations of microplastics in the water sources. Lagos Lagoon surveys and sediments sampling Pa ge 15 7 https://journals.e-palli.com/home/index.php/ajec Am. J. Environ. Clim. 4(3) 155-165, 2025 consistently found microplastics in surface water and sediments. Common morphologies included fibers, fragments and films, with polyethylene (PE), polypropylene (PP), and polyester frequently reported. Spatial hotspots typically coincide with densely populated landing sites and drainage outfalls (Akinhanmi et al., 2023; Akinhanmi, 2024). A research conducted by Aliyu et al (2023) on the assessment of MPs contamination on River water, sachet water, and branded table slat samples in Kaduna metropolis showed Mps ranged 25 to 36 particle/L in treated water, 153 particle/L in raw water, 1.4-3.7 particle/L for bottled water and 0.13 to 0.27 particles/L in salt samples. Water and salt samples contained five different types of polymers: polyethylene, polypropylene, polyester, polyvinyl chloride, and polyethylene terephthalate. The result also indicated that fragments were more prevalent in both raw and treated water, while fragments and fibres predominated in bottled water and table salt samples. Another research conducted by Isaac et al. (2024) on microplastic particles in river sediments of southwestern Nigeria showed abundance of microplastic in surface sediments and water samples across all locations, ranging from 12.82 particle/kg to 22.90 particle/kg dw and 6.71 particle/L to 17.12 particle/L during the dry season and 5.69 particle/kg to 14.38 particle/kg dw and 12.41 particle/L to 22.73 particle/L during the wet season respectively. The result revealed that on the average, fibre constituted the highest percentage of MPs in sediments (71 %) and water (67 %), while foam recorded the lowest value of 0.6 % and 1.7 % respectively, with polypropylene (PP) and polyethylene (PE) being the main MPs across all the locations. Similarly, riverine studies in Imo (Otammiri River) by Nduka et al. (2024) confirmed the presence of MPs in surface water samples and sediments, with spatial gradients indicating higher loads near urban drainage outlets and downstream estuarine zones. The results revealed that polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polystyrene (PS), and polyurethane were the predominant polymers found across the river. Kpikpi et al. (2025) confirmed microplastic contamination in the surface water of the lower Forcados River, Burutu, Delta State, Nigeria. The result revealed the abundance and composition in the surface water as 44 items/L and microfiber 14(31.81 %), microfragments 6 (13.63 %), microfilms 7 (15.90 %), microfilaments 12 (27.27 %), and microfoams 5 (11.36 %) which also accounted for densities ranging from microfilms (ρ = 0.00001) to microfragments (ρ = 6.6) and filament showing a similar blueprint to the microfilms in the study. A covenant University ePrint review, (2024) also confirmed progressive increase in MP detections and called for harmonized methods and monitoring to reduce the negative impacts of microplastics pollution in Nigerian surface waters(Reuters, 2024; OSGF, 2024; AP news, 2024). River systems (e.g., River Niger at Onitsha; Forcados River; Ogun River; Otuoke and Ovia rivers) document MPs in both water and sediments and, in some cases, in tissues of fish and benthic invertebrates sampled for human consumption. Concentrations vary by site and season, with higher loads near urban centers and river mouths (Kpikpi et al., 2025). According to researches, the major sources of microplastic in such environments came from single-use plastics such as carrier bags and Styrofoam; breakdown of larger plastic items; manufacturing processes generating plastic pellets and nurdles and domestic and industrial wastes. The patterns point to strong local sources and riverine transport to coastal sinks. These researches are significant as the water sources are vital in supporting various ecosystems and human activities. The research findings underscore the need for effective plastic waste management and conservation efforts to mitigate microplastics pollution in Nigerian aquatic environments so as to reduce aquatic ecosystems degradation, aquatic life and human exposures. Table 1: Compact table summarizing key Nigerian field studies on microplastics pollution in the Nigerian aquatic environments. S/N Study Location Sample Type Method Key Findings 1. Akinhami et al., 2023/2024 Lagos Lagoon (Epe, Mokoko, Sagbokoji, Badagry) Surface water & sediments: fish organs Composite sampling; visual sorting and FTIR/Raman polymer ID/ histology for fish Fibres and fragment dominant; PE/PP/ polyester common; hotspots near urban drain outlets; evidence of MPs in fish organs. 2. Kaduna assessment, 2023 Kaduna metropolis Raw river water, treated municipal water, sachet & bottled water, table salt Standard digestion, visual counting (size cutoff reported) MPs detected in raw water (up to 153 particles/L), treated water (25-36 Particle/L), bottled water/sachet water measurable. Pa ge 15 8 https://journals.e-palli.com/home/index.php/ajec Am. J. Environ. Clim. 4(3) 155-165, 2025 Biota and Fisheries Field sampling and analysis from Lagos coastal waters and lagoons, has detected MPs within the gastrointestinal tracts of commercially important fish species (Akinhanmi, 2024). Some studies also report associated histopathological signs in fish organs (Akindele et al., 2019; Atiqur et al., 2025; Ahmad et al., 2025; Ahmad & Siti Salami, 2025). These findings imply direct trophic exposure and potential food-safety concerns for consumers relying on locally caught fish. Biota contamination taken together, the Nigerian evidence base confirms widespread occurrence of MPs in multiple environmental compartments and in food/ water items consumed by people. Drinking Water and Food Products Analyses in Lagos, Kaduna, Imo, Delta, Osun and other urban centers report MP particles in raw river water, treated municipal water, sachet and bottled water, and market table salts, showing human exposure pathways via ingestion. Reported particle counts for treated water ranged from tens of particles per liter, depending on analytical cutoffs and methods. Methodological variability across studies (size limits, digestion procedures, polymer ID) complicates direct numerical comparisons but the repeated detection across product types is robust. Sources and Environmental Pathways of MPs Primary and Secondary Microplastics Microplastics (MPs) are classified based on their origin as primary or secondary. Primary microplastics are intentionally manufactured in small sizes, typically <5 mm, for specific industrial or commercial uses such as cosmetic microbeads, industrial abrasives, and pre- production plastic pellets (Sharma et al., 2023). They enter aquatic systems directly through wastewater effluents and stormwater discharges. Secondary microplastics, on the other hand, result from the fragmentation of larger plastic debris (e.g., packaging, fishing gear, tyres) through physical, chemical, and biological degradation processes, including UV radiation, wave action, and microbial activity (Koelmans et al., 2022). Common sources include degraded plastic bags, fishing nets, and bottles. Unlike primary MPs, secondary MPs vary widely in composition and morphology, influencing their persistence and interactions with aquatic organisms (Zhang et al., 2024).Recent surveys indicate that secondary MPs: fibres and fragments are the dominant shapes found in surface waters and sediments globally, reflecting widespread breakdown of macroplastics and textile fibre shedding (Allen et al., 2021). Dominant sources of microplastics in Nigerian aquatic ecosystems include widespread single-use plastics and sachet water packaging, informal dumping, poor municipal collection, and lost fishing gear. Once in the aquatic system, buoyant plastics disperse and concentrate at sheltered bays and estuarine mouths, while biofouling and aggregation with organic flocs encourage sinking to benthic sediments typical of Niger Delta mangrove and estuarine zones (Lesley, 2020; Nwabuisi & Ihenetu, 2022; Green Habitat Nigeria, 2024). Seasonal rains amplify transport (flood pulses) and resuspension of Mps inaquatic environments. 3. Otammiri River microplastics, 2024 Otammmiri River, Imo state Surface water NOAA trawling protocol; size range(0.3- 5 mm); density separation (NaCl); visual & spectroscopic ID MPs present across sites; fragments and fibres: recommended further monitoring. 4. Lower Forcado River, Burutu, 2022-2-23 sampling (published, 2025) Forcado River, Delta state Surfacewater (monthly for 12 months) Multi-site sampling,NOAA protocols; visual counts & polymer ID Seasonal trends; higher concentrations near downstream and urban zones; identified fragments, films 5. Convenant University ePrint review, 2024 Review/Lagos focus Synthesis of Lagos studies Literature synthesis Confirms progressive increase in MPs detections; calls for harmonized method sand monitoring 6. Akindele et al., (2019) Osun River, Osun state Invertebrates, Hand detaching, µFTIR MPs in the river 7. Ja’afar et al.,(2022) Dukku and Kalgo Rivers, Kebbi state surface and bottom water FTIR High levels of MPs 8. Idowu et al., (2019) Major Rivers, Southwestern Nigeria Sediments and surface water FTIR-ATR High MPs in samples Pa ge 15 9 https://journals.e-palli.com/home/index.php/ajec Am. J. Environ. Clim. 4(3) 155-165, 2025 Major Entry Routes Into Aquatic Systems Microplastics enter aquatic environments through direct and indirect pathways. Major entry routes are land- based sources (urban runoff, mismanaged waste, storm drains, wastewater treatment plant effluents, industrial discharges) account for the majority of microplastic inputs to freshwater and marine systems (Pal et al., 2025). Several country-specific drivers of MPs in aquatic systems include: Single-Use Plastic Proliferation and Informal Disposal Nigeria’s high reliance on low-cost single-use items (including the ubiquitous small water sachets) and limited formal waste collection infrastructure mean that large volumes of plastics escape capture and degrade in the environment. The federal government announced measures and phased bans on categories of single-use plastics in 2024–2025, aiming to reduce such inputs (Reutere, 2024; OSGF, 2024). Urban Runoff and Drainage Stormwater systems in major cities (Lagos, Port Harcourt, Onitsha, Kaduna) often discharge directly to rivers and lagoons without effective trash capture; road runoff and street litter transport fragmented plastics into waterways. Studies identify drainage mouths and landing sites as MPs hotspots. Wastewater and Informal Laundries Although centralized sewage coverage is limited, wastewater and effluents from industrial, commercial, and household sources (including laundromats) contribute synthetic fibers and primary microplastic particles to local waters; conventional water treatment and informal treatment systems vary widely in effectiveness. Maritime and Fishing Activities Lost or discarded fishing gear, nets, and aquaculture materials produce secondary MPs that accumulate near coasts and estuaries. Atmospheric Deposition and Agricultural Plastics Although less studied in Nigeria, airborne fibers and degraded agricultural plastics: mulch, greenhouse covers (Allen et al., 2021) are plausible supplementary inputs that merit investigation. Transport And Sinks The environmental fate of MPs in Nigeria broadly mirrors global patterns but is strongly modulated by local hydrology and seasonal rains. Once released, microplastics are distributed vertically and horizontally by currents, wind-driven mixing, and biophysical interactions. MPs undergo complex transport and transformation processes governed by size, density, and hydrodynamic conditions (Nelms et al., 2021). Lighter polymers particles (E.g. polyethylene and polypropylene) and fibers often remain suspended or float, moving with currents and accumulating at sheltered bays, lagoon inlets and around river mouths whereas denser polymers such as polyvinyl chloride (PVC) tend to sink and accumulate in sediments (Atiqur et al., 2025). Observed surface and shoreline accumulations in Lagos and Delta coastal zones reflect this behavior. Biofouling, aggregation with organic matter and flocculation during high-turbidity events encourage sinking of MPs into sediments, creating benthic sinks, especially in estuaries and mangrove sediments characteristic of the Niger Delta (Rummel et al., 2017). Seasonal resuspension during floods redistributes particles upstream and downstream. Small particles and fibers are readily ingested by zooplankton, bivalves and small fish, leading to trophic transfer and potential retention in tissues consumed by humans and predators (Tiwari et al., 2023). Field detections in fish from Lagos Lagoon and other coastal waters confirm trophic exposure pathways. Recent measurements reveal substantial subsurface and polar accumulations transported by subsurface currents and high-latitude circulation, meaning MPs are not confined to surface gyres but penetrate the water column and accumulate in remote regions. Sediments and coastal deposits act as long-term sinks. Although country-level toxicological field studies remain limited, the presence of MPs in key habitats and in commercial fish suggests likely ecological impacts similar to those documented globally: ingestion and physical harm to invertebrates and fish, vectors for hydrophobic contaminants and pathogens, and potential disruptions of benthic processes in sediment sinks. In the Niger Delta, the intersection of oil-related contaminants and MPs may compound ecological risk. Ecological and Human Health Impacts Field data from Nigeria on toxicological endpoints remain limited compared with laboratory studies, but a combination of field observations and regional lab work points to several concerns. Effects on Aquatic Organisms Microplastics can induce physical, chemical, and biological effects on aquatic life. Ingestion of MPs has been documented across taxa: zooplankton, bivalves, fish, seabirds, and megafauna. Physical effects of MPs have been reported to include reduced feeding efficiency, gut blockage, reduced growth, oxidative stress, altered behaviour, and impaired reproduction. Size, shape, polymer type, and associated sorbed chemicals modulate toxicity (Wang et al., 2022). Chemically, MPs adsorb hazardous pollutants such as polycyclic aromatic hydrocarbons (PAHs), heavy metals, and persistent organic pollutants (POPs), which can be transferred to organisms upon ingestion (Allen et al., 2021). Additionally, MPs can act as vectors for heavy metals, hydrophobic/persistent organic pollutants and pathogenic microbes, potentially altering exposure profiles for organisms (Wu et al., 2023). Laboratory studies have reported oxidative stress, inflammation, and Pa ge 16 0 https://journals.e-palli.com/home/index.php/ajec Am. J. Environ. Clim. 4(3) 155-165, 2025 Delta, where oil-related pollution coexists with plastic debris, combined stressors could amplify toxicity. A few Nigerian studies measure co-contaminant burdens associated with plastics, signaling compounded risks. Food-Web and Ecosystem-Level Concerns Microplastics infiltrate the aquatic food web through ingestion by lower trophic organisms such as zooplankton and bivalves (Nelms et al., 2021). MPs that are retained by lower trophic organisms can be transferred up food chains (trophic transfer), potentially altering energy flow and contaminant dynamics. Subtle sublethal effects (e.g., reduced fitness, immune impairment) could scale up to population-level consequences in sensitive species. Sediment and benthos-associated MPs may also alter benthic habitat functioning. This leads to bioaccumulation and biomagnification of plastics and associated contaminants across food chains. Consequently, top predators, including fish consumed by humans, often exhibit elevated MP concentrations (Witczak et al., 2024). Ecosystem-level impacts include alterations in nutrient cycling, primary productivity, and sediment structure due to the physical presence of MPs (Akinhanmi et al., 2023). Furthermore, microplastics may modify microbial communities essential for ecosystem functioning. These disruptions threaten ecological stability, fisheries productivity, and ecosystem services critical to human welfare. The sources, fate, and trophic level transfer of microplastics in aquatic environments are shown in figure 1. Figure 1: Sources, fate, and trophic level transfer of microplastics in aquatic environments (Osamah et al., 2025). Human Exposure and Health Uncertainties Human Exposure Humans are exposed to microplastics primarily through seafood consumption, drinking water, inhalation, food packaging contamination, and possibly dermal contact (Toussaint et al., 2024). Drinking Water (Sachet, Bottled, Treated Municipal) Detection of nano- and microplastics in bottled and tap water has raised concerns, but definitive evidence linking environmentally relevant exposures to specific human disease outcomes remains limited. Potential risks include inflammation, oxidative stress, and cytotoxicity arising from particle accumulation and chemical leaching (Wu et al., 2023; Toussaint et al., 2024). Studies in Kaduna (Aliyu et al., 2023) and other towns (Idowu et al., 2016; Apata et al., 2022a and b; Isaac et al., 2023; Kpikpi et al.,2025) report MPs in sachet and bottled waters and in treated drinking water at detectable levels, implying regular ingestion exposures across the population that consumes these products. Studies have confirmed the presence of MPs in human feces, placenta, and blood, suggesting systemic exposure ( Onyema, 2025). Methodological differences across studies Pa ge 16 1 https://journals.e-palli.com/home/index.php/ajec Am. J. Environ. Clim. 4(3) 155-165, 2025 (size cutoffs, digestion protocols) make cross-study comparisons challenging, but the repeated detection across independent studies strengthens the conclusion that exposure exists. Nano-sized plastics (<100 nm) can penetrate biological barriers, raising concerns about translocation into tissues and interference with cellular metabolism. Emerging toxicological studies indicate inflammatory responses and immunomodulation in animal models and cell systems, but long-term human epidemiological data are lacking. Although the extent of chronic health effects is still under investigation, the ubiquity of microplastics in the human environment underscores the need for precautionary measures and further toxicological research. Seafood Consumption Detection of MPs in fish species consumed locally suggests dietary exposure for coastal communities and urban consumers buying locally sourced fish. The fraction of plastics that translocate to edible tissues versus remaining in viscera is an active research question; existing Nigerian studies report MPs mainly in visceral tissues but also sometimes in edible parts. Inhalation And Occupational Exposure Urban dust, fibers released during handling of plastics, and emissions from informal recycling sites may create inhalation exposures for waste workers and residents near dumps, but robust exposure measurements in Nigeria are scarce. Health Uncertainties Globally, the toxicology of micro- and nano-plastics in humans is under development. Multiple studies detect MPs in drinking water (including sachet/bottled water) and in fish sold for consumption, indicating dietary exposure. However, critical uncertainties remain on exposure dose (numbers, sizes, polymers), translocation of MPs from gut to edible tissue, and long-term health effects in human populations. While systemic exposure (blood, placenta) has been reported in other countries, causal links to chronic disease remain unestablished. Although country-level toxicological field studies remain limited, the presence of MPs in key habitats and in commercial fish suggests likely ecological impacts similar to those documented globally: ingestion and physical harm to invertebrates and fish, vectors for hydrophobic contaminants and pathogens, and potential disruptions of benthic processes in sediment sinks. In the Niger Delta, the intersection of oil-related contaminants and MPs may compound ecological risk. For Nigeria, the urgent priorities are quantitative exposure assessment (how many particles, what sizes, which polymers), co-exposure to chemical contaminants (e.g., PAHs, heavy metals), and population health studies in high-exposure groups (fishers, waste workers, and communities dependent on local water supplies). Given the economic importance of small-scale fisheries (especially around Lagos, Benue, and the Niger Delta), contamination of commercial species has implications for marketability, consumer confidence, livelihoods, and food security if contamination becomes widespread or highly publicized. Existing Policies and Recent National Actions Single-Use Plastic Bans and National Policy In 2024, the federal government of Nigeria announced phased bans on certain single-use plastics (including, Styrofoam and sachet water in certain contexts), adopted measures limiting single-use plastics in federal government procurement and announced staggered national restrictions aimed at reducing single-use items, building on the 2020 National Policy on Plastic Waste Management and local actions (e.g., Lagos state bans) (The Punch, 2024, October 3; Blessing, 2024). This ban was part of measures by the state government to put in place policy guidelines for plastic utility in further ensuring a sustainable management of plastic wastes, healthy, safe, and sustainable environment. According to the report, plastic waste materials make up significant proportion of solid wastes (about 60 % of the monthly 13,000 tones) of wastes generated in Lagos, causing everything from ecosystem degradation to drainage clogs and flooding. The ban followed increasing prevalence of plastic wastes and its negative effects on the environment in recent years. Waste Management and Circular Economy Measures Strengthening municipal collection, formalizing waste- pickers and recycling value chains, and investment in material recovery facilities reduce environmental leakage (Magalhaes, 2025; Sun et al., 2022). For Nigeria, pragmatic interventions (community-level waste traps at drainage mouths, river cleanup campaigns, and plastic buy-back schemes) can have near-term benefits for microplastics pollution mitigation in hotspot areas. Water Treatment Upgrades and Point-of-Use Actions Improving treatment plant filtration, installing fine screens and membrane processes where feasible, and encouraging household-level filtration for drinking water can lower human exposure via drinking water. However, costs and maintenance challenges require adaptive locally appropriate approaches. Research, Monitoring and Standardization Nigeria needs a coordinated national monitoring framework for MPs (harmonized sampling and analysis protocols, reference labs, and data sharing) so that trends can be assessed and policy efficacy evaluated. Several recent regional studies provide a starting point for designing such a programme. Nigeria recently State-level actions complement national moves, but enforcement, affordable alternatives, and systemic waste-management investment remain key challenges to translating policy into reduced Pa ge 16 2 https://journals.e-palli.com/home/index.php/ajec Am. J. Environ. Clim. 4(3) 155-165, 2025 environmental MP loads. However, an effective response spans the full lifecycle of plastics: reduce production of harmful items, improve product design, optimize waste management, treat urban and industrial effluents, and remediate existing environmental loads. Mitigation Strategies Mitigating microplastics pollution requires integrated strategies encompassing prevention, removal, and policy interventions. At the source level, banning or restricting microbeads in personal care products, promoting biodegradable alternatives, and improving product design can significantly reduce primary MP generation (UNEP, 2022). The following mitigation strategies are key towards curbing Nigeria’s microplastic pollution in the aquatic ecosystems: Upstream Interventions (Source Reduction And Design) Policy Instruments Bans on unnecessary microbeads (successful in many jurisdictions), restrictions on single-use plastics (e.g. styrofoam), while supporting affordable alternatives for small businesses and sachet water distribution and product standards that mandate durability and recyclability. Product Redesign Reducing polymer shedding (textile innovations, tyre formulations), designing for recyclability, and substitution with low-emission materials. Extended Producer Responsibility (EPR) Shifting lifecycle waste costs to producers incentivizes design for reduced leakage. These upstream approaches are foundational and cost-effective compared with downstream cleanup. Waste Management and Circular Economy Improved collection, sorting, and recycling reduce plastic leakage to the environment. Informal-sector integration and investments in material recovery in low- and middle- income countries (LMICs) are critical because most mismanaged waste originates there. Avoiding open burning and leak-prone landfills reduces fragment generation. Strategic waste infrastructure deployment combined with behaviour-change campaigns reduces inputs to rivers and coasts. Wastewater and Stormwater Treatment Improvements Wastewater treatment optimization can significantly reduce MP loads via primary (screening, grit removal) and secondary (settling, filtration) processes, and advanced tertiary options (membrane filtration, dissolved air flotation, advanced oxidation) ( Magalhaes, 2025). Urban stormwater management, green infrastructure, and riverine clean-up programs are also critical. On a broader scale, extended producer responsibility (EPR) policies, plastic waste recycling, and public awareness campaigns can minimize plastic leakage into the environment. Emerging biotechnological approaches, such as enzymatic and microbial degradation of polymers, offer promising future solutions (Wei et al., 2023). International collaboration under frameworks like the UN Plastics Treaty (2024) is essential to harmonize monitoring, research, and policy implementation globally. However, no single technology is universally optimal: trade-offs include cost, energy, and concentrate/sludge management. Removing MPs from effluents concentrates them in sludge, which requires safe disposal or further treatment to prevent secondary release (e.g., via agricultural land application). Technologies such as membrane bioreactors, rapid sand filtration, advanced tertiary filters, and coagulation/ flocculation are promising when appropriately configured and maintained. Thus investment in drainage trash capture (screens/booms) at urban outfalls and pilot community buy-back, formalization programs for waste pickers will reduce leakage, and promote household point-of-use measures where appropriate. Innovative Remediation and Product-Level Solutions Recent advances include engineered absorbents and bio- based sponges that capture suspended MPs with high efficiency (laboratory/field-scale tests show promising removal rates) (Magalhaes, 2025). For example, composite sponges made from natural polysaccharides/chitin show high microplastic uptake in trials, suggesting potential for localized remediation and integration into filtration systems (e.g., washing machine filters). However, scalability, lifecycle impacts, and cost-effectiveness need thorough assessment. Behavioural and Societal Measures Consumer-level interventions (washable microfibre filters for laundry, promoting reusable items, improved public waste practices) combined with public education campaigns reduce microplastics generation. Industry transparency and labeling (e.g., microfibre shedding rates) may drive competition toward low-shedding products. Above all, there is the need to implement a standardized national MP monitoring network with harmonized sampling (size classes, digestion, polymer ID by FTIR/ Raman), sentinel sites (Lagos, Niger Delta, Anambra/ Onitsha, Kaduna) and prioritize exposure assessments for drinking water (treatment plant influent/effluent, sachet and bottled products) as well as dietary exposure through common fish species. Challenges, Research Gaps, and Priorities for Nigeria Key barriers to decisive action include methodological heterogeneity (sampling, size-class definitions, analytical detection limits), limited understanding of nanoplastics, sparse long-term ecotoxicology and epidemiology, and incomplete socio-economic evaluations of mitigation pathways. Based on the current evidence and the country’s socio- environmental context, the following priorities are recommended: Pa ge 16 3 https://journals.e-palli.com/home/index.php/ajec Am. J. Environ. Clim. 4(3) 155-165, 2025 Nationwide Baseline and Monitoring Network Standardize of sampling methods, extraction, and analytical protocols (especially for particles <100 µm and nanoplastics), digestion, polymer ID, and implement representative sampling across major river basins, estuaries, coastal zones and drinking water sources. Use sentinel sites in Lagos, Niger Delta, Anambra/Onitsha, Kaduna and coastal states. Exposure and Health Risk Assessments Quantify human exposures via diet and water (particle counts and polymer identification), and design epidemiological and long-term toxicological studies focusing on chronic low-dose exposures and mixture effects (MPs plus sorbed pollutants) for high-risk occupational groups. Source-Focused Interventions and Evaluation Pilot and evaluate interventions (sachet alternatives, extended producer responsibility pilots, stormwater trash traps) using measurable environmental endpoints (MP loads at drainage outfalls). Capacity Building and Stakeholder Engagement Strengthen laboratory capacity (FTIR/µ-FTIR, Raman) in universities and government labs; engage local communities, fisherfolk and informal waste sectors in co- designed mitigation. Integrated Monitoring and Policy Implementation Translate national bans into enforceable local regulations, incentivize alternatives, and combine regulatory actions with education and economic supports for affected workers and small businesses. There is urgent need for routine, comparable national monitoring programmes to track trends and measure policy effectiveness. Efficiency and Life-Cycle Analysis Efficacy and life-cycle analyses of mitigation technologies (WWTP upgrades, novel sorbents) to ensure solutions do not create secondary harms. Socio-Economic Interventions Scaling socio-economic interventions in LMIC contexts where waste leakage is highest. CONCLUSION Microplastic pollution is pervasive and persistent in aquatic environments. Evidence from aquatic ecosystems in Nigeria demonstrates widespread presence of microplastics across aquatic compartments and exposure pathways relevant to ecosystem integrity and public health. The evidence justifies a precautionary, multi- pronged mitigation approach that prioritizes upstream prevention and improved waste management while deploying targeted technological fixes (e.g., WWTP upgrades, filters) and encouraging innovation (bio-based sorbents). A coherent national strategy combining standardized monitoring and regulatory measure (bans, EPR), targeted source reduction (including practical alternatives to sachet plastics), improved waste infrastructure, investment in circular-economy infrastructure, water treatment efficacy or enhancements, and research into exposure and health outcomes is necessary to manage this emerging contaminant effectively. International collaboration will be important because microplastics cross political boundaries via rivers, oceans, and the atmosphere. Continued monitoring and adaptive management, informed by improved data on environmental distributions and effects are essential to manage and reduce risks. 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