Smog to Persist Until Monday in Tehran, Karaj 

The capital Tehran and the nearby metropolitan city of Karaj have been blanketed by a cloud of toxic smog and the adverse conditions are likely to persist until Monday, a senior official with the Iran Meteorological Organization, Sadeq Ziayian, said on Saturday. 
“Tehran and Karaj’s air quality is ‘unhealthy’ for all groups today,” Ziayian was quoted as saying by IRNA.
The official added that wind blows could temporarily decrease concentration levels of airborne pollutants in the evenings. 
All nursery schools and schools in Tehran and Alborz provinces have been instructed to hold classes online on Saturday and Sunday, excluding the cities of Damavand and Firuzkuh. 
Entry of private cars into Tehran’s city center has also been banned and sand factories near the capital have been ordered to shut down in an attempt to minimize pollution. 
Citizens have been told to refrain from outdoor physical activity until further notice and to wear N95 masks to filter hazardous particles in the air. They were also encouraged to use the public transport system.
Tehran has experienced 113 “unhealthy” days in the past nine months, which translates into Air Quality Index values between 151 and 200.