[1] Imperial Coll London, Natl Heart & Lung Inst, Resp Epidemiol Occupat Med & Publ Hlth Grp, Emmanuel Kaye Bldg,Manresa Rd, London SW3 6LR, England
[2] Univ Cagliari, Dept Med Sci M Aresu, Cagliari, Italy
[3] Univ Porto, Fac Med, Oporto, Portugal
[4] Hosp Sao Joao, Oporto, Portugal
[5] Sapienza Univ Rome, Lung Funct Unit, Dept Publ Hlth & Infect Dis, Rome, Italy
[6] Imperial Coll London, Natl Heart & Lung Inst, London, England
[7] Univ Helsinki, Cent Hosp, Skin & Allergy Hosp, Helsinki, Finland
[8] European Med Agcy, London, England
[9] Univ Naples 2, Rome, Italy
[10] IFT CNR, Rome, Italy
[11] Univ Oslo, Dept Med & Allergol, Oslo, Norway
[12] Transylvania Univ, Fac Med, Brasov, Romania
[13] Univ Manchester, Inst Human Dev, Manchester, Lancs, England
[14] Univ Athens, Dept Allergy, Paediat Clin 2, Athens, Greece
[15] Univ Porto, Fac Med, Immunol Lab, Oporto, Portugal
[16] Univ Porto, CINTESIS Ctr Hlth Technol & Serv Res, Oporto, Portugal