[1] Karolinska Inst, Dept Clin Sci & Educ, Sodersjukhuset, Stockholm, Sweden
[2] Karolinska Inst, Inst Environm Med, Stockholm, Sweden
[3] Sachs Children & Youth Hosp, Stockholm, Sweden
[4] Karolinska Inst, Dept Med Epidemiol & Biostat, Stockholm, Sweden
[5] Karolinska Univ Hosp, Paediat Allergy & Pulmonol Unit, Astrid Lindgrens Childrens Hosp, Stockholm, Sweden
[6] Uppsala Univ, Dept Med Sci Resp Allergy & Sleep Res, Uppsala, Sweden
[7] Reg Stockholm, Ctr Occupat & Environm Med, Stockholm, Sweden