EghtesadOnline: Based on the average yearly PM2.5 concentration, Tehran is ranked as the 23rd most polluted capital in the world by the Swiss-based air quality monitoring company IQAir AirVisual.
IQAir AirVisual is a nonprofit firm trying to promote access to real-time air quality information, aggregate and validate real-time data from governments and monitors operated by individuals and organizations across continents.
According to the firm’s 2018 World Air Quality Report published on airvisual.com, the sprawling Iranian capital is ranked as the 23rd most polluted capital based on the average yearly PM2.5 concentration.
Average PM2.5 concentration in Tehran was 26.1 μg/m³ in 2018, significantly higher than the World Health Organization’s recommended threshold, according to Financial Tribune.
The WHO recommends an annual mean exposure threshold of 10 μg/m³ to PM2.5 to minimize the risk of health impact from particulate matters while advising that no level of exposure has been shown to be free of health impacts.
Top five polluted capitals in the world are Delhi, Dhaka, Kabul, Manama, and Ulaanbaatar.