1. Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Japan
2. Department of Public Health, School of Medicine, Faculty of Health Science, Kobe University, Kobe, Japan
3. Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
4. Toga River Conservancy, Kobe, Japan
5. Center for Environmental Management, Kobe University, Kobe, Japan