Field Survey of Indoor Microplastic in Four Regions of Japan Eunsu Lim, Yifan Bai, Yuan Ni, Jinya Takeuchi, Takeshi Ogasawra, Akihisa Takemura, Hoon Kim and Kazuhide Ito E3S Web of Conf., 396 (2023) 01120 Published online: 16 June 2023 DOI: 10.1051/e3sconf/202339601120