Spatial and temporal distribution, fate, and potential health risks of microplastics in urban indoor air

Abstract

The growing awareness of microplastics (MPs) in indoor residential environments stems from their pervasive presence and potential health risks. MPs were collected from living rooms and bedrooms, and their accumulation in the lungs of residents in three urban cities during summer and winter was assessed. The abundance of MPs at ≤ 2.5 μm and ≤ 10 μm was determined (Changchun: 713 ± 477 and 4239 ± 2420, Xingtai: 1003 ± 726 and 3781 ± 2070, Guangzhou: 492 ± 479 and 2446 ± 903, item/m³/day). Nearly 50 % of the total abundance of MPs discovered in this study were ≤ 10 μm in size. Considerable differences in MPs abundance were observed between summer and winter (p < 0.01). The quantity of MPs in residential settings correlated with lifestyle choices and ventilation time (p < 0.05). Fragments represented the primary shape of MPs (45 % – 68 %), with polyamide (PA; 5 % – 35 %) and polycarbonate (PC; 5 % – 33 %) being the predominant polymers. Indoor uptake of MPs in lungs varied by age group. Adults had the highest intake, followed by teenagers and older individuals, while children had the lowest intake. Children and adults were estimated to intake 530 – 2060 and 1046 – 4068 items/day of MPs, respectively. Additionally, living rooms and bedrooms exhibited medium to extreme hazards according to the pollutant loading index (PLI) and polymer hazard index (PHI) assessments. This study deepens our understanding of MPs pollution in urban indoor air, raises awareness of the health risks to lungs associated with MPs exposure, and provides data to support these findings.