Geospatial environmental sources of inhaled microplastics: A case in Zhuhai, China

The impact of inhaled microplastics has emerged as a public health concern, however, the environmental sources contributing to the pulmonary microplastic burden remain unclear. This study aimed to investigate the associations between environmental sources and inhaled microplastics. A total of 454 participants undergoing fiberoptic bronchoscopy in Zhuhai, China, were recruited, and bronchoalveolar lavage fluid (BALF) samples were collected. Microplastics in BALF were analyzed using laser direct infrared imaging spectrometry, and geospatial data were used to assess the distance from each participant's residence to roads, coastlines, and industrial parks. Linear regression models were applied to quantify the associations between each environmental exposure source and inhaled microplastics. Of the 454 participants, microplastics were detected in 96.26 % of BALF samples, with polyethylene, polyurethane, and polyvinyl chloride being the most prevalent types. Each 10-unit increase in distance to the nearest branch road and coastline was associated with a 0.46 % (95 % confidence interval [CI]: -0.83 %, -0.08 %) and 27.57 % (95 % CI: -40.59 %, -11.69 %) decrease in total microplastics, respectively. These findings identify key environmental contributors to inhaled microplastics and underscore the need to address airborne microplastic exposure in environmental health policy and urban planning.