After years of opacity on the subject, the administration has admitted that the main source of the smog is sub-standard gasoline

This winter, as the smoke of around 4.2 million car exhausts settled over the city, pension-age Ali wheeled his pushcart onto a congested roundabout in south Tehran’s Shoosh Square and pulled a blackened surgical mask over his face. Braving the endless roar of aging engines, he stood all day inside a dense fog of cancer-causing toxins that blocked out the sun, stung his eyes and clogged his airways. By noontime, he developed a headache. On particularly smoggy days, he vomited.

Sixteen kilometers northwest, a similar concoction of carcinogens settled over the luxury apartment buildings of Tehransar, one of the city’s oldest and most polluted quarters. From there, the winds carried them across the city center toward the new housing communities in the east, where it hovered close to the ground for days, trapped by the mountains and inversion-causing winter temperatures.

Unlike many aspects of the international sanctions, the air pollution in one of the world’s smoggiest capitals does not discriminate among social classes. For more than six months out of the year, Tehran’s 8.3 million residents inhale a deadly mix of rubber particles, asbestos, sulfur dioxide, nitrogen oxide, carbon monoxide, and partially unburnt hydrocarbons.

According to city officials, some 270 people die each day from blood cancer, heart and respiratory diseases, and other pollution-related illnesses. The government, struggling to allay an environmental crisis after years of neglect by the previous administration, has urged young families to move out of large cities to protect their children from the adverse effects of the toxic air. Those lining up in emergency rooms are not just laborers like Ali, but also influential clerics, affluent businessmen and renowned filmmakers. According to one Tehran-based environmentalist, “Air pollution is reaching a point where it is noticeable as a social or political demand. If people were crying ‘where is my vote’ in 2009, their demand in 2014 will be, ‘where is my breathable air?”

Poor air quality has been a daily source of government criticism throughout the winter months, when pollution is typically at its peak. Among the world’s top ten most polluted cities, four are in Iran, according to data based on a 2013 World Health Organization index. President Hassan Rouhani repeatedly urged his reformist cabinet to improve the situation, while Iran’s environment agency head Massoumeh Ebtekar visited afflicted regions, assuring residents of their “right to live in unpolluted cities.”

Still, large population centers like Tehran, Tabriz and Isfahan suffocated in a yellow-tinged fog for the better part of the winter, leading to school closings, traffic restrictions and public health warnings. In the overpopulated capital, lawmakers renewed a debate about moving the country’s administrative centers out of the city to alleviate traffic. Clerics urged mosque goers to wear surgical masks when they went outdoors. A prominent filmmaker, Dariush Mehrjui, publicly lambasted policymakers for being “all talk” on environmental issues after his sister passed away prematurely due to pollution-related health complications.

But as the warming weather brings fresh gusts of wind and clearer skies, the government’s actions indicate its resolve to tackle pollution goes beyond rhetoric. After years of government opacity on the subject, oil minister Bijan Zanganeh has admitted that the the main source of the smog is sub-standard gasoline - an allegation officials had denied as recently as January. Fuel quality had been a touchy political topic since Iran began to convert petrochemical plants for gasoline production under the previous administration. When trade sanctions squeezed Iran’s access to fuel imports, this campaign to decrease dependence on foreign refineries was touted as a hallmark achievement of Mahmoud Ahmadinejad’s “resistance economy.” But when environmentalists began to record suspicious particles in air quality tests, officials provided elusive answers to public concerns that the domestically produced fuel was palpably dirty, despite expert estimates that such gasoline is responsible for some 88% of the pollution in Tehran.

As Iran’s relations with the west thaw amid ongoing nuclear negotiations, a lift on petrochemical industry sanctions promises to ease Iran’s access to cleaner gasoline. Last week, Zanganeh announced plans to triple high-standard (EURO 4-grade) gasoline imports in the next year, substituting the 8-10 million gallons of fuel produced in Iranian petrochemical plants, which are to be discontinued. In addition, Zanganeh pledged to introduce a domestic emissions trading scheme to regulate local industries, as well as long-term strategies to reduce energy consumption. The government also plans to renew the construction of a oil refinery in the Persian Gulf region, a project which had been halted due to corruption allegations during the Ahmadinejad era.

While these steps may help clean up the fumes emitted by private vehicles, this policy will not be enough to resolve matters in the long run. In Tehran, automobile use has doubled in the past eight years according to transportation ministry estimates, and around one million of the cars on the road each day are more than 20 years old. Aside from restricting gasoline imports, the sanctions also limited Iran’s ability to equip domestically produced cars with catalytic converters, a standard engine feature that reduces the emissions of harmful gases. While Iran has had some success in making its own clean air technology, local industry still lacks the capacity to supply the growing car market, the Tehran-based environmentalist said.

Iranian lawmakers have also been inconsistent in enforcing clean air acts and low industry standards. “Heavy energy subsidies...have contributed to inordinately high fuel use, and consequently higher levels of pollution from fuel emissions,” says David Michel, director of environmental security at the Washington, DC-based Stimson Center. The growth in fuel consumption, which at its peak reached five times the global average, was partially stymied by the subsidy reforms introduced by Ahmadinejad in 2010, but the progress stopped two years later, when the reform scheme was halted due to inflation and other economic concerns.

Aside from the ongoing subsidy reforms, Iran’s policymakers have a host of existing environmental legislation at their disposal, Michel says.

“Insufficient funds and inadequate coordination have delayed Tehran’s Master Plan for Air Pollution Control and prevented the city form reaching its emission reduction targets. Similarly, the 1995 Clean Air Act requires motor vehicle inspections...but enforcement is lax and typically waxes and wanes with the severity of the pollution.”

Another, longer-term challenge is education. After decades of uncontrolled energy consumption, Iranians lack the environmental awareness to conserve resources and reduce their personal carbon imprints. Standard practices like recycling and electricity saving is rare and not easily done in most households. Recently, however, the government has begun to plant seeds of awareness through televised advertisements, billboards and speeches. On 6 March, both the Supreme Leader and President Rouhani attended annual public ceremonies marking Iran’s annual “Tree-planting week,” using the occasion to draw attention to environmental issues. “Nowadays, trees act like the lungs which help the cities breathe,” Rouhani said.