Monitoring of microplastics in road dust samples from Myanmar and Taiwan

Microplastics (MPs) are ubiquitous pollutants in various environmental matrices. In this study, 82 road dust samples collected from Myanmar and Taiwan between 2014 and 2018 were analyzed to investigate the status of MPs pollution and distribution. In Myanmar, the mean abundances of MPs in road dust were high in cities, such as Nay Pyi Taw (285 pieces/kg dry weight), Mandalay (79 pieces/kg), and Yangon (63 pieces/kg). Alternatively, no MPs were found in samples from the rural areas, Wundwin and Bagan. The mean MP abundance was 555 pieces/kg in road dust from Taiwan, which was two to nine times that of road dust from Myanmar. Polyethylene and polypropylene were the dominant polymers detected in road dust from Myanmar, whereas polyvinyl chloride was a major component in road dust from Taiwan. These results suggest that differences in economic and industrial activities and population densities are related to MP profiles in road dust. The plastic additives butylated hydroxytoluene, diethyl phthalate, and di-n-octyl phthalate were identified in a polyvinyl chloride MP in the road dust. These MPs originate from plastic products in the environment and lead to extensive pollution with hazardous chemicals. To our knowledge, this is the first study to report the occurrence of MPs in road dust from Myanmar.