[1] Univ So Calif, Dept Prevent Med, Los Angeles, CA 90089 USA
[2] Natl Res Ctr Environm & Hlth, GSF, Inst Epidemiol, Neuherberg, Germany
[3] Inst Municipal Invest Med, Ctr Recerca Epidemiol Ambiental, E-08003 Barcelona, Catalonia, Spain
[4] ICREA, Barcelona, Spain
[5] Univ Pompeu Fabra, Barcelona, Spain