Public Health Wales have stated that poor air quality is probably the second greatest health concern after smoking and is the most significant environmental determinant of health.
Mae Iechyd Cyhoeddus Cymru wedi datgan mai ansawdd aer gwael yw’r ail bryder iechyd mwyaf ar ôl ysmygu a’r ffactor amgylcheddol pennaf mewn perthynas ag iechyd.