[1] MRC, Biostat Unit, Cambridge, England
[2] Univ Sheffield, Sheffield S10 2TN, S Yorkshire, England
[3] De Montfort Univ, Leicester LE1 9BH, Leics, England
[4] London Sch Hyg & Trop Med, London, England
[5] Inst Natl Sante & Rech Med, Villejuif, France
[6] Napier Univ, Edinburgh EH14 1DJ, Midlothian, Scotland
[7] Off Natl Stat, London, England
[8] Univ London Imperial Coll Sci Technol & Med, London SW7 2AZ, England
[9] Univ London St Georges Hosp, Sch Med, London, England
[10] Radcliffe Infirm, Natl Perinatal Epidemiol Unit, Oxford OX2 6HE, England
[11] Univ Nottingham, Nottingham NG7 2RD, England
[12] Inst Terr Ecol, Penicuik EH26 0QB, Midlothian, Scotland
[13] Univ So Calif, Los Angeles, CA USA
[14] Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA
[15] Univ Sains Malaysia, Pulan Pinang, Malaysia
[16] Harvard Sch Publ Hlth, Boston, MA USA
[17] Dana Farber Canc Inst, Boston, MA 02115 USA
[18] Univ Iowa, Iowa City, IA USA
[19] Univ Rochester, Med Ctr, Rochester, NY 14642 USA
[20] US EPA, Res Triangle Pk, NC 27711 USA
[21] No Illinois Univ, De Kalb, IL 60115 USA
[22] King Edward Mem Hosp, Perth, WA, Australia
[23] Queensland Univ Technol, Brisbane, Qld, Australia
[24] Univ Girona, Girona, Spain
[25] Univ Washington, Seattle, WA 98195 USA