“…Worker safety and health laws are being established or medical examination data are being utilized for prevention (Cho and Jeong, 2013;Pyo and Jeong, 2010;Jeon and Jeong, 2013), along with data of approved convalescence Yoo et al, 2011) and approaches in risk assessment (Jeong et al, 2012;Shin, 2013) in work places. In particular, researches on the effects of work time (ILO, 1990;Kim et al, 2012;Yoo et al, 2011) or shift work (Folkard, 2005;Jeon and Jeong, 2010;Jung et al, 2007;Kim et al, 2006;Park, 2012, Seo et al, 2003 on CVD have shown influence.…”