Department of Hygiene and Public Health, Nippon Medical School, Tokyo, Japan

Correspondence to Tomoyuki Kawada, Department of Hygiene and Public Health, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-Ku, Tokyo 113-8602, Japan E-mail: [email protected]

Received 16 May, 2023

Revised 10 July, 2023

Accepted 13 July, 2023