Fivefold Spike in SO2 Pollution in Tehran 

The burning of sulfur-containing fuels by industries located near or inside the capital Tehran has led to a three to five times surge in SO2 pollution, Abbas Shahsavani, head of the Health Ministry’s department for air quality and climate change, stated on Tuesday. 
“Over the past days, especially between Dec 13-16, we witnessed a 3-5 times rise in the pollutant SO2,” Shahsavani was quoted as saying by ISNA. 
The health official warned that air pollution was the fourth leading cause of premature death and that Iran’s policy had been to curb the exposure of vulnerable groups to the toxic smog instead of working out solutions. 
Tehran and other major cities across the country have been engulfed by thick smog for the past weeks as calm winds and cold temperatures trapped hazardous airborne pollutants near the ground. 
Average Air Quality Index rose to values between 150-200 last weekend, prompting Tehran local authorities to close down school and university classes for three days and switch to online learning. 
An emergency task force meeting on Tuesday decided to extend the closures to Wednesday as air pollution showed no sign of abating.