The Aeroplastic Exposome: Airborne Microplastics as Interfaces Among Bioaerosol Transport, Aeroallergen Exposure, and Respiratory Immune Response

Airborne microplastics and nanoplastics (MNPs) are increasingly reported in indoor, outdoor, and occupational air, but their aerobiological significance remains incompletely defined. This narrative review proposes the aeroplastic exposome as a cautious, testable framework for evaluating airborne MNPs as interfaces among aerosol transport, biological and chemical loading, aeroallergen co-exposure, inhalation, respiratory deposition, clearance, and airway immune response. Evidence from environmental monitoring, indoor and occupational exposure studies, and human respiratory-sample and lung-tissue detection studies supports the occurrence of airborne MNPs, the plausibility of inhalation exposure, reported detection in human respiratory samples, and experimental hazard under selected conditions. However, evidence that airborne plastic particles routinely carry bioaerosols or aeroallergens remains insufficient or model-dependent. The aeroplastic exposome is therefore not proposed as a disease entity, validated exposure metric, or established explanation for asthma, chronic obstructive pulmonary disease, fibrosis, infection, or cancer. Instead, it is a framework for organizing testable questions about polymer identity, aerodynamic fraction, morphology, aging state, biological loading, co-exposure context, deposition, clearance, epithelial–immune responses, and host susceptibility. Priority research needs to include standardized airborne sampling, same-particle polymer–bioaerosol–allergen characterization, exposure-relevant aerosol systems, factorial co-exposure experiments, and prospective human studies with repeated personal exposure assessment.