Microplastics Pollution in Fish and Aquatic Ecosystems; Sources, Impacts and Human Health Risks

Abstract

Microplastic pollution has emerged as one of the most pressing environmental challenges of
the 21st century, particularly in aquatic ecosystems where it poses significant ecological and
human health risks. This paper reviews the sources, pathways, and impacts of microplastic
contamination with a focus on their occurrence in fish and aquatic environments such as the
Lagos and Epe Lagoons in Nigeria. Microplastics, defined as plastic particles smaller than 5
mm, originate from both primary sources (e.g., microbeads, textile fibers) and secondary
sources such as the degradation of larger plastic debris. Their persistence enables
bioaccumulation and trophic transfer within aquatic food webs. Ingested by fish and benthic
organisms, microplastics impair growth, reproduction, and immune responses while also acting
as vectors for toxic substances such as persistent organic pollutants (POPs), phthalates, and
heavy metals. The implications for human health are increasingly concerning as seafood
consumption and water quality are directly affected. Studies indicate potential links between
microplastic exposure and oxidative stress, inflammation, and carcinogenicity. Lagos Lagoon,
heavily impacted by poor waste management and urbanization, exemplifies the socio-economic
and ecological costs of microplastic pollution. This paper highlights emerging detection
technologies, regulatory gaps, and management strategies including improved waste
management, recycling, and public awareness. It concludes with recommendations for multisectoral
collaboration and research to mitigate risks and protect aquatic ecosystems and human
health.