Sources of ambient PM2.{5|five} exposure in 96 {global|international|worldwide} cities
{To improve|To enhance} air {quality|high quality|top quality|good quality|excellent|high-quality}, {knowledge|understanding|information|expertise|know-how} {of the|from the|in the|on the|with the|of your} sources and {locations|places|areas} of air pollutant emissions is {critical|crucial|vital|essential|important}. {However|Nevertheless|Nonetheless|Even so|On the other hand|Having…