1. Department of Community Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
2. Department of Physics and Material Science, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
3. School of Health Sciences Research, Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand
4. Toxicology Unit, Department of Forensic Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand