Air Pollution Grips Tehran 

Alarming levels of air pollution in the capital Tehran and the prospect of worsening air quality over the next few days prompted authorities to advise against outdoor activities and place the province on alert. 
With the air quality index (AQI) reaching 112, the emergency committee for Tehran air quality convened on Sunday to discuss measures, ISNA reported. 
AQI readings between100-150 are labeled as “unhealthy” for sensitive groups. Cold, heavy air traps vehicle emissions and construction dusts near the ground every year, increasing levels of PM2.5 (particles of less than 2.5 microns in diameter) which can enter the bloodstream through the lungs and severely impact health. 
Abed Maleki, a senior official with Tehran’s governor-general office, said air quality is likely to remain unhealthy for the time being and citizens should take care of themselves by wearing N95 facemasks.
Hamed Yazdimehdr, head of Tehran Province’s Crisis Management said calmer winds had led to dangerous levels of pollutants in the air. 
“Considering the warnings, air quality isn’t currently healthy for people, especially the elderly, children and those with existing respiratory or heart problems,” he added. 
Citizens have been told to avoid going outside as much as possible.