The Welsh Government has used this published data to assign a concentration of NO 2, PM 2.5 and PM 10 to each residential dwelling in Wales based on which square kilometre of Wales it sits in.
Mae Llywodraeth Cymru wedi defnyddio’r data cyhoeddedig hwn i neilltuo crynodiad o NO 2, PM 2.5 a PM 10 i bob annedd breswyl yng Nghymru ar sail y cilometr sgwâr o Gymru y mae wedi ei lleoli ynddo.