Institutional Review Board Statement
All procedures performed in studies involving human participants were in accordance with the ethical standards of the Ministry of Health, Labor and Welfare and Ministry of Education, Culture, Sports, Science and Technology, and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The study was approved by the ethics committee of the Center for Environment, Health and Field Science, Chiba University (project identification number 49), and registered with the ICMJE by the UMIN (UMIN000042368).