I'm sad to say that my home country is not doing a very good job of keeping its air clean. Neglect combined with ecological and environmental protection issues have placed Serbia about a decade and a half or about 15 years behind the EU's regulations for ecological standards. However after the recent UN convention on climate change in November of 2016. Serbia has been doing more to meet the EU standards, but they still need to speed up the pace. For example Serbia has begun to introduce automatic measuring units that display air quality at any time, which enables them to intervene as soon as possible. However the fact that Serbia is not an EU state means they technically have no obligation to the EU standards for emission of hazardous gases. So only time will tell how much the Serbs will do to lower their emission.
link with more info: http://www.b92.net/eng/news/society.php?yyyy=2007&mm=03&dd=01&nav_id=39885