RT Journal Article SR Electronic T1 Doubts about the adverse effects of air pollution on asthma? JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 1901900 DO 10.1183/13993003.01900-2019 VO 54 IS 4 A1 Isabella Annesi-Maesano A1 Francesco Forastiere YR 2019 UL http://erj.ersjournals.com/content/54/4/1901900.abstract AB