Kuwahara, Keisuke
Honda, Toru
Nakagawa, Tohru
Yamamoto, Shuichiro
Hayashi, Takeshi
Mizoue, Tetsuya
Article History
Received: 26 July 2016
Accepted: 25 January 2017
First Online: 7 March 2017
Competing interests
: T.H., T.N., S.Y., T.H. are occupational physician in the participating company. No other potential conflicts of interest relevant to this article were reported.