Microplastics as an emerging threat to human health: An overview of potential health impacts

Microplastics have emerged as a pervasive environmental pollutant and can infiltrate the human body through ingestion via the digestive tract, inhalation via the respiratory system, and dermal contact, thereby posing significant implications for human health. Recent studies have confirmed the presence of microplastics in human tissues, including the placenta, blood, gastrointestinal tract, lungs, and reproductive organs, raising serious concerns about their potential toxicological effects. Due to the diverse sizes, types, shapes, and surface characteristics of microplastics, the pathways through which they reach various organs and their toxic effects on these organs can vary significantly. Despite growing evidence, the exposure pathways, toxic effects of microplastics on human health, and their underlying mechanisms have not been fully elucidated. This review provides a comprehensive overview of microplastic exposure pathways, their potential health risks, the emerging evidence linking microplastics to diseases, and existing research gaps. Additionally, the present review highlights the risks of microplastics to children's health. Children are particularly at risk due to their frequent hand-to-mouth behaviors, higher ventilation rates relative to body size, and immature biological barriers, all of which enhance their susceptibility to microplastic exposure and toxicity. By providing an integrated overview of microplastic exposure and its health risks, this review seeks to inform the pressing need for multidisciplinary research to elucidate the mechanisms of microplastic toxicity and to develop regulatory frameworks aimed at mitigating microplastic-related hazards.