Microplastics and Human Health: An Emerging Public Health Threat: A Narrative Review

Abstract

Microplastics, defined as plastic particles smaller than 5 mm, have emerged as pervasive environmental contaminants with growing implications for human health. Initially studied in marine ecosystems, microplastics are now detected across air, water, soil, and food chains, leading to continuous human exposure. This narrative review synthesises current evidence on sources, exposure pathways, biological mechanisms, and potential health impacts of microplastics from a public health perspective. Humans are exposed primarily through ingestion of contaminated food and drinking water, inhalation of airborne particles, and occupational contact in high-risk industries. Recent studies have demonstrated the presence of microplastics in human stool, placenta, and blood, indicating systemic exposure and raising concerns regarding bioaccumulation. Experimental findings suggest that microplastics may induce inflammation, oxidative stress, and endocrine disruption, either directly or through associated chemical contaminants. Although long-term epidemiological evidence remains limited, potential links with respiratory disorders, cardiometabolic diseases, and reproductive health effects are increasingly discussed. Significant research gaps persist, particularly in exposure assessment, dose–response relationships, and long-term health outcomes. Given their ubiquity and persistence, microplastics represent an emerging environmental health challenge. Strengthening surveillance, promoting plastic reduction strategies, and advancing interdisciplinary research are essential to address this evolving public health threat