Low-level air pollution and incidence of asthma among adults: pooled analysis of 2 European cohorts in the ELAPSE project. (October 2019) - S, Liu; M, Strak; S, Rodopolou; P, Ljungman; U, Hvidtfeldt; K, Hoogh; G, Hoek; K, Katsouyanni; K, Wolf; Z, Andersen