[1] Eunice Kennedy Shriver Natl Inst Child Hlth & Hum, Div Intramural Populat Hlth Res, NIH, 6710B Rockledge Dr, Bethesda, MD 20829 USA
[2] Emory Univ, Rollins Sch Publ Hlth, Dept Environm Hlth, 1518 Clifton Rd, Atlanta, GA 30322 USA
[3] SUNY Albany, Sch Publ Hlth, New York State Dept Hlth, Wadsworth Ctr,Dept Environm Hlth Sci, Empire State Plaza,POB 509, Albany, NY 12201 USA
[4] Eunice Kennedy Shriver Natl Inst Child Hlth & Hum, Div Intramural Populat Hlth Res, Biostat & Bioinformat Branch, NIH, 6710B Rockledge Dr, Bethesda, MD 20829 USA
[5] NIH, NCI, Biostat Branch, Div Canc Epidemiol & Genet, 9609 Med Ctr Dr, Rockville, MD 20850 USA
[6] George Mason Univ, Coll Hlth & Human Serv, 4400 Univ Ave, Fairfax, VA 22030 USA