A total number of 3200 million cars, which are already on Tehran streets, are the largest source of generating air pollutants, MNA quoted secretary of Air Pollution Committee as saying on Tuesday.
Motorcycles have also large share in polluting Tehran air, Mohammad-Baqer Saduq added.
Automobiles produce at least 4,400 tones of air pollutants a day and 1.6 million tones a year in Tehran, a new study by Tehran Controlling Air Quality co. showed.
Three main types of air pollutants are common smog-causing pollutants, air toxics, and greenhouse gases.
And vehicles are the largest source of generating carbon monoxide and nitrogen oxides emissions and a significant source of tiny particles within Tehran. In addition, vehicles are a significant and chronic source of 'air toxics' (toxic substances in the air).
According to Saduq, carbon monoxide is the main air pollutant in Tehran.
Drastic measures should be taken to improve air quality in the capital city. And it's not quite as simple as just turning off the pollution tap, reduction in car traffic also needed to conquer the filthy air conundrum.