Smog is a secondary pollutant that is composed of nitrogen oxides, sulfuroxides, ozone, smoke and otherparticulates, from things like coal burning and car emission
Smog
Cutting down on coal combustion emission, vehicular emissions, industrial emissions will cut down on man-made smog
Due to the possibility of Ground-level ozone, sulphur dioxide, nitrogen dioxide and carbon monoxide being present in smog can be seriously harmful to senior citizens, children, and people with heart and lung disease like emphysema, bronchitis, and asthma. this is the major concern for cutting down on smog
The Great Smog of London was a period in 1952 London where unusually cold weather mixed with an anticyclone, and windless conditions, collected airborne pollutants (mainly burning coal) formed a thick layer of smog which lasted 4 days killing around 4,000-12,000 roughly
Smog is most presentin these three cities, Beijing, Ahwaz and Ulan Bator, they all have problems like birth defects, lung diseases, Alzheimerrisk and cancer all due to the over exposure to smog and the items present in it.