TEHRAN — Air quality in Tehran has improved in the current [Iranian calendar] year (started on March 21) so far compared to the last year, Masoud Zandi, head of the national center for air quality and climate change affiliated with the Department of Environment, has said.

while this year only 28 days were reported to be polluted, IRIB quoted Zandi as saying on Tuesday.  

Out of the 28 days reported to be slightly polluted for sensitive groups, ozone pollution were to blame for messy air for 15 days, he added. 

In the Earth's lower atmosphere, near ground level, ozone is formed when pollutants emitted by cars, power plants, industrial boilers, refineries, chemical plants, and other sources react chemically in the presence of sunlight. Ozone at ground level is a harmful air pollutant.

Zandi further explained that measures taken to reduce air pollution and also recent rainfalls have played a role in the mitigation of air pollution in the metropolis of Tehran.

According to World Health Organization, 4.2 million deaths every year as a result of exposure to ambient (outdoor) air pollution and 91% of the world’s population lives in places where air quality exceeds WHO guideline limits.

MQ/MG