See the Methods section of the Estimating the Mortality Burden of Air Pollution in Wales paper (Public Health Wales) for more information on methodology and quality.
Gweler adran Dulliau y papur Amcangyfrif Baich Marwolaethau Llygredd Aer yng Nghymru (Iechyd Cyhoeddus Cymru) i gael rhagor o wybodaeth am fethodoleg ac ansawdd.