Concentrations of Airborne Microplastics during the Dry Season at Five Locations in Bangkok Metropolitan Region, Thailand

Information on airborne microplastics (AMPs) in Thailand is still not available. This study monitored and identified AMPs in Bangkok Metropolitan Region (BMR), Thailand. A high-volume air sampler was used to collect AMPs at five different locations in BMR. These five locations are university, roadside, urban park, dumpsite, and industrial estate. The results showed that AMPs concentration was averaged at 333.42 ± 142.99 per cubic meter (n/m3). The concentration of AMPs at the dumpsite was much higher than the concentration in the other areas. The relationship between AMPs and total suspended particles (TSP) was highly dependent on the locations and sources of microplastics nearby. Higher AMP with higher TSP were found at the university, dumpsite, and industrial estate. On the other hand, lower AMP with higher TSP were found at the roadside and urban park. Regarding the shape of the AMPs, the majority (97.22%) of the AMPs were in fragment form while only 2.78% were in fiber form. Polyethylene (PE) in the fragments and cellophane in the fibers were the major polymer types which were present in all locations.