Microplastic Exposure and Human Health: An Emerging Challenge in Preventive Medicine

Microplastics, defined as plastic particles smaller than 5 mm, have emerged as ubiquitous environmental contaminants with significant implications for human health. These particles originate from the breakdown of larger plastic debris, synthetic textiles, personal care products, and industrial processes. Recent evidence demonstrates that microplastics have infiltrated the human body through multiple exposure pathways including ingestion, inhalation, and dermal contact. Studies have detected microplastics in human blood, lungs, placenta, and gastrointestinal tract, raising concerns about their potential health effects. The physicochemical properties of microplastics enable them to act as vectors for toxic chemicals and pathogenic microorganisms, while their presence in tissues may trigger inflammatory responses and oxidative stress. Epidemiological investigations suggest associations between microplastic exposure and cardiovascular disease, respiratory disorders, reproductive health issues, and potential carcinogenic effects, although causality remains to be definitively established. This narrative review synthesizes the current knowledge on microplastic sources, human exposure routes, biodistribution patterns, and documented health impacts. We examine the challenges in exposure assessment, discuss proposed mechanisms of toxicity, and evaluate the evidence linking microplastic exposure to specific disease outcomes. Given the pervasive nature of microplastic contamination and the impossibility of complete avoidance, preventive strategies must focus on reducing exposure through policy interventions, consumer behavior modification, and improvements in waste management systems. Understanding microplastic-related health risks represents a critical frontier in preventive medicine and environmental health.