Airborne microplastics in indoor and outdoor environments of a coastal city in Eastern China

Microplastics (MPs) in marine and terrestrial environments have been intensively studied, but the dynamics of airborne MPs remains limited. Existing studies on atmospheric are mostly derived from collection deposition, whereas direct measurements scarce. However, abundance is more relevant for evaluating human inhalation exposure risk. Herein, indoor outdoor urban rural areas a coastal city eastern China were investigated. MP concentrations (mean±SD) air (1583 ± 1180 n/m 3 ) an order magnitude higher than (189 85 ), (224 70 (101 47 ). smaller 100 µm dominated MPs, predominant shape was fragments, as opposed to fibers. The larger size fractions contained proportion fibers, nearly exclusively composed fragments. health risk caused by ubiquitous should not be discounted maximum annual can reach 1 million/year, while may even due concentrations. • High found air. dominant both samples. Fragments compared fibers all Fibers dominate large fragments small MPs. Maximum million/year.