Microplastics exposure levels based on building composition and usage in built environment

Indoor environment use various plastic materials, and during their usage and disposal, microplastics may become airborne. These airborne microplastics pose potential health risks through inhalation. Despite increasing interest, the levels of human exposure to airborne microplastics in indoor environment remain unclear. Given that plastic usage varies with building composition and usage, variations in microplastics exposure levels are expected. This study presents a quantitative and qualitative analysis of airborne microplastics in ten different indoor environment with varying building functions. This study finds that offices exhibited the highest microplastics concentration (25.8-155 particles/m^3). Microplastics were classified into six shape categories, with particles smaller than 10 μm were found to be the most dominant. Notably, fragment-type microplastics were more frequently detected than fibrous ones. We briefly discuss how our results can be used to potentially generate time-varying microplastics exposure for eventual use in simulation. The findings emphasize the necessity of assessing microplastics exposure across various indoor spaces and provide fundamental data for improving indoor air quality and mitigating microplastics pollution.