Joan Fortuny1
, Manolis Kogevinas1
, Michael S Zens2
, Alan Schned3
, Angeline S Andrew2
, John Heaney4
, Karl T Kelsey5
and Margaret R Karagas2 
1Respiratory and Environmental Health Research Unit. Municipal Institute of Medical Research (IMIM), 08003 Barcelona, Catalonia, Spain
2Department of Community and Family Medicine, Section of Biostatistics and Epidemiology, Dartmouth Medical School, Hanover, NH 03756, USA
3Department of Pathology, Dartmouth Medical School, Hanover, NH 03756, USA
4Department of Surgery, Dartmouth Medical School, Hanover, NH 03756, USA
5Departments of Community Health and Laboratory Medicine and Pathology, Brown University, PRovidence, RI 02912, USA