Airborne microplastics and human health in urban environments

Airborne microplastics (MPs) are emerging as significant urban atmospheric pollutants, with their potential risks demanding urgent attention. While most research initially focused on aquatic environments, evidence is increasingly showing that MPs are pervasive in urban air, originating from various sources. This review explores recent studies conducted in cities such as Paris, London, Shanghai, and Delhi, highlighting the spatial and temporal variability of airborne MPs in both outdoor and indoor environments. Additionally, the paper examines the health impacts associated with MPs, including respiratory inflammation, oxidative stress, and systemic toxicity. It also discusses the environmental fate of MPs and their interactions with other pollutants, which could further exacerbate urban air quality issues. Currently, airborne MPs are not included in international or national air quality frameworks, such as those of the WHO, CPCB, and USEPA. This study advocates for the development of standardized monitoring protocols, pointing out that existing methodologies and risk assessments are inconsistent. The paper calls for integrating microplastic indicators into urban sustainability efforts linked to the SDGs, recognizing airborne MPs as both an environmental burden and a public health threat.