[1] Inst Med Res & Occupat Hlth, Zagreb 41000, Ksaverska, Croatia
[2] Univ Hosp, Zagreb 12, Kispaticeva, Croatia
[3] WHO, Reg Off Europe, DK-2100 Copenhagen 8, Scherfigsvej, Denmark
[4] Childrens Hosp Srebrnjak, Zagreb 100, Srebrnjak, Croatia
[5] NILU, Norwegian Inst Air Res, Kjeller, Norway
[6] Natl Inst Canc Res, Genoa, Italy