According to the announcement of Tehran Air Quality Control Company, the air pollution index of the capital, Saturday (November 23, 1405), is in an unhealthy condition with a number of 126 “pm2”, according to the display of weather stations, the pollution in region 19 with a number of 172 is higher than all other places. Tehran’s air quality index is measured by numbers that range from 0 to 50 in clean or green conditions, 51 to 100 in acceptable or yellow conditions, 101 to 150 in unhealthy conditions for the sensitive or orange group, 151 to 200 in unhealthy conditions for all or red, 201 to 300 in very unhealthy or purple conditions, and 301 to 500 in dangerous or purple conditions.
