Funding for this research was provided by:
Ministry of the Environment (N.A.)
Received: 5 September 2019
Accepted: 9 December 2019
First Online: 27 December 2019
Ethics approval and consent to participate
: The JECS protocol was approved by the Ministry of Environment’s Institutional Review Board for Epidemiological Studies (100910001) and by the Ethics Committees of all participating institutions. This study was also approved by the Ethics Committee of the University of Toyama (R2019035). The JECS was conducted in accordance with the Declaration of Helsinki and other nationally valid regulations, and written informed consent was obtained from all participants.
: Not applicable.
: The authors declare that they have no competing interests.