Airborne Microplastics in Atmospheric Environments: Sources, Physicochemical and Biological Interactions, and Implications for Pollutant Dynamics and Human Exposure

The presence of microplastics in the atmosphere is now well-established across environments ranging from megacities to remote mountain ranges and polar regions. Across atmospheric environments, airborne microplastics have emerged as a significant and numerically abundant component of total suspended particulate matter, with documented sources including road traffic abrasion, textile wear, construction and demolition activities, waste handling, synthetic surface degradation, and indoor human activities. Despite this growing evidence base, the scientific community has largely characterized airborne microplastics as passive tracers, inventorying their concentrations, polymer types, and size distributions, while their role as chemically and biologically active particles within atmospheric systems remains poorly resolved.A critical and underexplored dimension concerns the capacity of microplastic particles to interact with coexisting atmospheric constituents. Field and laboratory studies increasingly indicate that microplastic surfaces adsorb trace metals, polycyclic aromatic hydrocarbons (PAHs), volatile and semi-volatile organic compounds, and other co-pollutants under atmospherically relevant conditions. These interactions are governed by surface properties, including hydrophobicity, electrostatic charge, roughness, and the degree of photooxidative aging, which evolve continuously during atmospheric transport. The concept of the plastisphere, extensively documented in aquatic systems, is beginning to be extended to the atmosphere, with evidence of microbial colonization and bioaerosol associations on airborne microplastic surfaces. Collectively, these processes may modify the transport, reactivity, bioavailability, and toxicological profile of co-occurring pollutants in ways that conventional aerosol models do not capture.The timing of this Research Topic reflects a genuine inflection point in the field. Recent methodological advances, including high-throughput micro-Fourier transform infrared (micro-FTIR) spectroscopy, Raman microspectroscopy, and pyrolysis gas chromatography-mass spectrometry (Py-GC/MS), now enable the detection, quantification, and physicochemical characterization of microplastics at high spatial and temporal resolution. Concurrently, expanding monitoring programs and growing regulatory attention—including the WHO’s work on plastics and human health and the European Union’s restrictions on intentionally added microplastics—have heightened the urgency of mechanistic, interaction-focused research. Yet atmospheric-specific data on adsorption kinetics, transformation pathways, and interaction-driven changes to pollutant dynamics remain scarce, relying heavily on analogies drawn from aquatic environments that may not translate directly to the gas-particle interface of the atmosphere.This Research Topic aims to consolidate and advance mechanistic understanding of airborne microplastics as active components of atmospheric systems across outdoor and indoor environments. By bringing together field observational studies, controlled laboratory experiments, and atmospheric modeling approaches, it seeks to fill critical knowledge gaps regarding the sources, surface interactions, transformation processes, and downstream implications of airborne microplastics for both pollutant dynamics and human inhalation exposure. Contributions that draw on real-world atmospheric conditions, provide high spatial or temporal resolution data, or introduce novel analytical methodologies are especially encouraged.The scope of this Research Topic encompasses, but is not limited to, the following themes:• Occurrence, size distribution, polymer composition, and morphology of airborne microplastics across indoor and outdoor atmospheric environments• Atmospheric emission sources and release pathways, including traffic, construction, textiles, waste management, and indoor activities• Adsorption and co-transport of trace metals, PAHs, and other organic compounds on microplastic surfaces under atmospheric conditions• Physicochemical aging and surface transformation of microplastics during atmospheric transport, including photooxidation and fragmentation• Microbial colonization of airborne microplastics and the emerging concept of the atmospheric plastisphere• Interactions between microplastics and biological aerosol components, including pollens, fungal spores, and bacteria• Influence of microplastic–pollutant interactions on the fate, reactivity, and toxicological profile of co-occurring atmospheric constituents• Spatial gradients across urban, suburban, rural, indoor, and remote environments, including long-range transport and dry and wet deposition dynamics• Human inhalation exposure assessment, respiratory deposition modeling, and associated health implications• Advances in detection, characterization, and quantification techniques for airborne microplastics• Atmospheric and dispersion modeling of microplastic transport and interaction dynamicsWe invite submissions of Original Research Articles, Review Articles, Mini Reviews, Methods papers, Perspective pieces, and Hypothesis and Theory articles relevant to the themes outlined above. Contributions integrating multiple disciplinary perspectives—spanning atmospheric chemistry, aerosol physics, environmental microbiology, analytical chemistry, and exposure science—are particularly welcome. Topic editors: Richard Toro Araya, Gabriella Di Carlo, GIULIA SIMONETTI Source: https://www.frontiersin.org/research-topics/83503/airborne-microplastics-in-atmospheric-environments-sources-physicochemical-and-biological-interactions-and-implications-for-pollutant-dynamics-and-human-exposure