Funding for this research was provided by:
Ministry of the Environment (NA)
Received: 13 April 2020
Accepted: 23 July 2020
First Online: 6 August 2020
Ethics approval and consent to participate
: The JECS comprehensive protocol was approved by the Review Board on Epidemiological Studies of the Ministry of the Environment of Japan (100910001) and by the ethics committees of all participating institutions. This specific study was also approved by the Ethics Committee of the University of Toyama (R2015094). JECS is conducted in accordance with the Helsinki Declaration and other national regulations, and written informed consent was provided by all participants.
: Not applicable.
: The authors declare that they have no competing interests.