[1] Sophiahemmet Univ, Dept Hlth Promoting Sci, POB 5605, S-11486 Stockholm, Sweden
[2] Swedish Red Cross Univ, POB 1059, S-14121 Huddinge, Sweden
[3] Karolinska Inst, Inst Environm Med, Unit Expt Asthma & Allergy Res, Stockholm, Sweden
[4] Ersta Skondal Bracke Univ Coll, Stigbergsgatan 30,POB 11189, SE-10061 Stockholm, Sweden
[5] Karolinska Inst, Danderyd Hosp, Dept Clin Sci, Stockholm, Sweden