Introduction: Micro plastic and nanoplastic pollution has emerged as a pervasive global environmental health concern, with mounting evidence of ecological disruption and credible risks to human health. Once framed primarily as a marine litter problem, micro plastics are now recognized as complex contaminants capable of interacting with biological systems at molecular, cellular, and systemic levels. These concerns are particularly acute for Pacific Island nations, which experience disproportionate exposure despite contributing minimally to global plastic production.

Aim: This review synthesizes current evidence on environmental distribution, exposure pathways, and health-related effects of micro plastics, with specific emphasis on implications for ocean-dependent Pacific Island nations such as Fiji.

Method: A structured qualitative literature review was conducted, drawing on 38 peer-reviewed studies published between 2015 and 2024 and supplemented with additional high-impact literature across environmental science, toxicology, epidemiology, and public health.

Results: The evidence demonstrates that micro plastics are ubiquitous in marine environments, readily enter food webs, act as vectors for chemical and biological contaminants, and induce oxidative stress, inflammatory responses, immune dysregulation, and metabolic disruption in experimental systems. Pacific Island populations may face heightened vulnerability due to oceanographic convergence, high seafood consumption, climate-driven redistribution of debris, and limited waste management infrastructure.

Conclusion: Micro plastic pollution represents a significant and under-recognized public health challenge for Small Island Developing States (SIDS), underscoring the urgent need for targeted research, regionally appropriate monitoring, and policy interventions tailored to Pacific contexts.

Keywords: micro plastics; nanoplastics; human health; Pacific Islands; Fiji; marine pollution; Small Island Developing States