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The Health Impacts of Ingested Microplastics: A Systematic Meta-Narrative Review
48 Pages Posted: 13 May 2025
More...Abstract
Introduction: Micro-nanoplastics (MNP) production has grown exponentially, with the majority entering landfill or unregulated waste, causing significant environmental accumulation.With environmental degradation of larger plastics items or direct emission - microplastics as a result are ubiquitous environmental particulates, resulting in human exposure. Yet determination of the potential human health implications of microplastic exposure is an unmet research area.
Methods: This systematic review used meta-narrative, Cochrane, and Navigation Guide frameworks to evaluate the health impacts of ingested microplastics. Searches across four databases identified studies published before 31st December 2022, screened by two investigators against predefined criteria. Blinded studies underwent thematic analysis, and conflicts of interest were assessed to ensure robust synthesis.
Results: Results of thematic analysis identified a wide range of cellular and tissue impacts from microplastic exposure - notably accumulation, gene expression, oxidative stress, and cytotoxicity albeit at high concentrations. There were potential health consequences across all biological systems, including exacerbation of gastrointestinal inflammation, behavioural change, reproductive dysfunction with impacts on offspring, significant impact on male reproductive system including testicular atrophy and reduction in sperm count and viability. There was evidence of both dose and size dependency. However, there was variability within results, representing the complex interactions between microplastics and biological systems.
Discussion and Conclusion: MNPs pose a significant public health challenge if environmental concentrations reach levels linked to inflammation, oxidative stress, and chronic diseases observed in toxicological studies. This review highlights critical gaps in research, including realistic exposure models and genetic impacts, and emphasises the need for standardised research and policy actions to reduce exposure, particularly among vulnerable populations. Comprehensive risk assessments, global regulations, and targeted interventions are critical to addressing this escalating health crisis and protecting future generations.
Keywords: Microplastics, Nanoplastics, Plastic, Micronanoplastic, Health Impacts, Toxicity, Fertility, Reproduction, Plastic Waste, Plastic Ingestion, Microplastic Ingestion, Human Health, Polymers, Micro-Nanoplastics, Environmental Accumulation, Human Health Implications, Systematic Review, Ingested Micropla
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