Air pollution in association with mental and self-rated health and the mediating effect of physical activity , Hautekiet, Pauline, Saenen Nelly D., Demarest Stefaan, Keune Hans, Pelgrims Ingrid, Van der Heyden Johan, De Clercq Eva M., and Nawrot Tim S. , Environmental Health, Jan-12-2022, Volume 21, Issue 1, (2022)