[1] Ctr Dis Control & Prevent, Epidemiol & Hlth Serv Branch, Div Canc Prevent & Control, Natl Ctr Chron Dis Prevent & Hlth Promot, Atlanta, GA 30341 USA
[2] Emory Univ, Rollins Sch Publ Hlth, Dept Epidemiol, Atlanta, GA 30322 USA
[3] Emory Univ, Rollins Sch Publ Hlth, Dept Environm & Occupat Hlth, Atlanta, GA 30322 USA
[4] Ctr Dis Control & Prevent, Radiat Studies Branch, Div Environm Hazards & Hlth Effects, Natl Ctr Environm Hlth, Atlanta, GA 30341 USA