Concern over health effects of air pollution is associated to NO2in seven European cities - Dons, E; Laeremans, M; Anaya-Boig, E; Avila-Palencia, I; Brand, C; de, Nazelle A; Gaupp-Berghausen, M; Götschi, T; Nieuwenhuijsen, M; Orjuela, JP; Raser, E; Standaert, A; et al. (Air Quality, Atmosphere and Health, 2018)