Petridou, Eleni1; Panagiotopoulou, Kelly1; Katsournni, Klea1; Spanos, Evangelos2; Trichopoulos, Dimitrios3
1Department of Hygiene and Epidemiology, University of Athens Medical School, Athens 11527, Greece.
2Biomedicine Laboratories, Athens 11527, Greece.
3Department of Epidemiology, Harvard School of Public Health, 677 Huntington Ave, Boston, MA 02115.