This was reported by tehrantimes.com website.

It is stated that schools in the Iranian capital were closed on Tuesday and Wednesday due to the high levels of harmful substances in the air. In recent weeks, air pollution has sharply intensified in Tehran and several other cities, forcing educational institutions to change to remote learning.

According to the Tehran Air Quality Control Company, the capital recorded "clean air" on only six days in total during the current Iranian year. Meanwhile, more than half of the days throughout the year were assessed as "unhealthy" for sensitive groups of citizens.