A study conducted by the Health Effects Institute (HEI) in the US has stated that the gap between least and most polluted areas is increasing each year.
Daraasad uu sameeyay mac'hadka caafimaadka adduunka (HEIC) ee dalka Mareykanka, ayaa lagu sheegay in gaabka u dheexa dowladaha ugu wasakhowga yar iyo kuwa ugu wasakhowga badan uu sanad walba sii kordhayo.