[1] NIOSH, Ctr Dis Control & Prevent, Div Safety Res, Morgantown, WV 26505 USA
[2] Corp Hlth Serv, BJC Hlth Care, St Louis, MO 63110 USA
[3] Finnish Inst Occupat Hlth, Helsinki 00250, Finland
[4] Liberty Mutual Res Inst Safety, Hopkinton, MA 01748 USA
[5] Johns Hopkins Univ, Sch Publ Hlth, Baltimore, MD 21205 USA
[6] Washington Univ, Sch Med, St Louis, MO 63110 USA