Initial Trials of Monochloramine Disinfection of Circulating Bathtub Water at Public Hot Spring Facilities and Determining its Efficacy - Yasunori MORI; Keita YANAGIMOTO; Tetsuji YAMAMOTO; Yuki NAGAI; Hideki YOSHIMURA; Shigehiro AKACHI; Takaya YAMAGAMI; Kosei UEMATSU; Yoshiko HISADA; Masaya Nisnio; Jyurina YAGI; Shinji IZUMIYAMA (Journal of Hot Spring Sciences, 2020)