On Monday, air pollution levels in Tehran hit record levels as authorities issued a call for all of the city's 14 million residents to stay indoors.
The Air Quality Index, which monitors the levels of particulate matter in the city, has held a "red status" for the past day, indicating that the air quality is unsafe for everyone, not just sensitive populations such as the elderly and children.
"Today's air quality index was at 162 and Tehran's air conditions reached status red," an official at the Air Quality Control Company said to the media. "Breathing in such conditions is considered inadequate for all people."
The state affiliated Tasnim News Agency reported that the levels were seven times the maximum levels recommended by the World Health Organization — the second highest from the country since the year began in March.
Health authorities estimate that in 2012, pollution contributed to the premature deaths of 4,500 people in Tehran and about 80,000 nationwide.
The topography of Iran has served to compound the problem of air pollution in Tehran, according to Armin Sorooshian, an environmental engineer at the University of Arizona.
"The mountains suppress ventilation and wind that could come and clean the area, so pollutants accumulate, just like in a soup," Sorooshian said. Conditions are exacerbated in the winter, he explained, because of a temperature inversion that forms near the surface.
While the readings are well below those from Beijing last month — which hit 50 times recommended WHO standards — authorities have signaled that they will throw their administrative weight behind a solution to the problem.
Last month, Supreme Leader Ayatollah Ali Khamenei issued a 15-point list of policy suggestions related to the environment. Addressed to President Hassan Rouhani, the letter called for increased investment in clean energy and improved environmental diplomacy.
On her blog, the vice president of Iran and head of Environmental Protection Organization Masoumeh Ebtekar noted that these new policies represent "high level strategies" that will "define the outlines and content of the major policies we need for the environment in Iran."
Specifically, Khamenei recommended the development of public transportation systems that would not rely on fossil fuels, as vehicle emissions is the top contributor to air pollution.
While industry effluents and factory operations are major causes of air pollution, vehicle pollution contributes to estimated 80 percent of air pollution in the city of Tehran, as well as other major cities across the country.
According to David Michel, a non-resident fellow at the Stimson Center, vehicle pollution raises four primary concerns: the number of cars in Tehran, the age of these cars, the kind of fuel being burned, and the quantity of fuel being burned.
"The roadways in Tehran have the capacity for less than a million cars, but there are more are 3.5 to 4 million cars in the city now," Michel said. "And they're not Cuba, but the stock of cars is older and doesn't have the emission control technologies that you're find in the US or other western countries."
The quality of the fuel burned for transportation in Iran has suffered, by some accounts, because of sanctions that have limited the country's ability to refine its own gasoline. As an alternative, they have resorted to mixing petrochemicals into gasoline in order to increase overall supply.
In 2012, researchers at the University of Tehran estimated that all the cars on the city's roads emitted a combined average of more than 26 tons of carbon dioxide daily, while all urban transport operations consumed an estimated 178 million liters of diesel and 4 billion liters of gasoline per year.
The high amounts of fuel being burned in the city and throughout the country, Michel explained, is high due to subsidies offered by authorities. "Consumers only pay five or ten percent of what fuel would cost in absence of such a subsidy," he said.
According to the United Nations Development Programme (UNDP) deputy resident representative Balasubramaniam Murali, air pollution in Iran has greatly impacted development in the country, in Tehran and beyond.
"It has shut down schools, increased health costs, and reduced productivity among the working population," said Murali, who added that the entire UN system in Iran was working from home on Tuesday due to the air pollution.
And in his experience, the government is acting in good faith when it puts environmental goals like air pollution reduction in its public agenda.
For the first time ever, he said, the development framework that the UNDP developed alongside Iranian authorities will include non-communicable diseases as a focus area, and within that area, air pollution is listed as a priority.
"It is the government that is asking for it — there is absolutely no doubt," Murali added. "This is clearly an area that they see as a priority and we see that things are being done to address this problem."
An international shift towards renewable, sustainable energy might also offer a nudge in the right direction.
"Iran is part of the global visibility of these transitions, that are pushing many fossil fuel producing countries to take a close look at renewables and reduce their own use of fossil fuels," said Michel. That Iran would act on this issue now, he added, "has to do with the visibility of problems like air pollution, especially when schools close down and people don't go to work."
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