Breathless Cities: Toxic Air as a National Crisis
Iran’s lethal air pollution is a nationwide crisis driven by dirty fuels, weak enforcement and sanctions, imposing a hidden economic tax and deepening social and spatial inequalities.
In recent weeks, thick, toxic air has wrapped not only Tehran but many Iranian cities in a persistent health emergency. In the capital alone, the head of Tehran’s emergency services reports that over the past eight days, 31 percent of all missions were directly linked to air pollution, and 357 deaths were recorded in that period – a number to which pollution is believed to have contributed.
But this is just the tip of a national iceberg. According to the Ministry of Health, in the Persian year 1402 (March 2023–March 2024) air pollution caused 30,692 premature deaths in 57 cities with a combined population of around 48 million. Of these, about 6,939 occurred in Tehran. This is no longer a series of local “bad air days”; it is a systemic, country-wide crisis of breath, health and livelihood.
Why the current wave is so intense
Several short-term factors have combined across different regions:
• Stable autumn weather and temperature inversions that trap pollutants over basins like Tehran, Karaj and Qazvin.
• Lack of effective rainfall in many provinces.
• A seasonal spike in energy demand, colliding with chronic gas shortages and pushing power plants toward the dirtiest possible fuels: heavy fuel oil (mazut) and highly contaminated diesel.
• The simultaneous spread of seasonal influenza, which makes lungs more vulnerable to the same toxic mix.
The result is a map of cities in red and orange: in Khuzestan, for example, at least seven cities – including Ahvaz, Susangerd, Hoveyzeh and Mahshahr – have recently been classified as “unhealthy for all groups”, with eight more in the “unhealthy for sensitive groups” range. In large parts of the country, closing schools and universities, going online and issuing fragmented alerts have become almost a routine.
Behind the smog: a dirty energy regime and uneven protection
The depth of the crisis is not meteorological; it is political and infrastructural. Official data show how extreme the fuel problem has become:
• At Rey power plant, south of Tehran, a recent fuel sample showed sulfur content in diesel more than 120 times the standard (6,012 mg/kg).
• At Rajaee power plant near Qazvin, mazut with 29,612 mg/kg sulfur has been burned – 592 times the standard.
• At Montazere-Ghaem near Karaj, both mazut and diesel with 6,752 mg/kg sulfur have been used – around 135 times above the limit.
• Power plants in Parand and Pakdasht have also burned diesel with sulfur levels 10 to 133 times higher than allowed.
Authorities insist “power plants around Tehran do not burn mazut”, but the Environment Department’s own measurements show that even what is officially labelled “diesel” is, in practice, a high-sulfur, highly toxic fuel whose effect on air quality rivals that of mazut.
This is part of a broader national pattern. At least 15 power plants across Iran can burn mazut, and recent reports show daily mazut consumption surpassing 21 million litres – with capacity to rise toward 43 million. Industrial belts around cities like Arak, Qazvin, Karaj, Rey and parts of Khuzestan form hyper-polluted corridors where refineries, cement plants, petrochemical units and old power stations sit next to residential neighbourhoods. In some places, such as Kahrizak, located south of Tehran, there is not even a single monitoring station to record what residents are forced to breathe.
On paper, the 2017 Clean Air Act was meant to stop exactly this. In practice, a parliamentary review found 22 of its clauses poorly implemented, 17 partially, and only 17 at an acceptable level – in open contradiction to Article 50 of the Constitution, which calls environmental protection a public duty.
The “hidden tax” on cities and people
Air pollution is not just an environmental issue; it is a multi-layered economic, social and political crisis. Combining national and international estimates, Iran loses at least 5.3 percent of its GDP to air pollution every year – roughly 23 billion dollars. This “hidden tax” is collected in several ways:
• Premature deaths: tens of thousands of people die earlier than they should, cutting short their productive years and tearing holes in families and communities.
• Reduced labour productivity: in hubs like Tehran, Karaj, Isfahan or Ahvaz, chronic smog means more sick leave, fatigue, lower concentration and more errors in sectors that are meant to drive growth.
• Erosion of future human capital: children in low-income districts, often located closest to industrial zones and highways, grow up exposed to toxic particles at home and school. This affects lung development, cognitive performance and learning outcomes, entrenching inequalities across generations.
• A hostile business environment and brain drain: cities where breathing is a daily health risk become less attractive for investment and long-term life plans, pushing skilled workers and capital away.
International sanctions have amplified this vicious circle by delaying refinery upgrades, pushing the state toward petrochemical gasoline and high-sulfur fuels, and blocking the normal renewal of the vehicle fleet. But sanctions do not explain why the dirtiest options are chosen and kept in place, or why laws are not enforced. Those are domestic policy choices.
What a responsible state would do
* Immediate national emergency measures
• Suspend the use of high-sulfur fuels (mazut and ultra-dirty diesel) in power plants and large industries located in or near urban areas, beginning with hotspots in Tehran–Rey, Karaj, Qazvin, Arak and Khuzestan.
• Make plant-level fuel quality and emissions data public, updated daily.
• Implement targeted, time-limited closures of schools, offices and large polluters on days rated “unhealthy for all”, coupled with real support for distance work and education.
• Expand and redistribute emergency health services toward the most polluted and underserved zones – including informal settlements on city fringes – rather than only central districts.
• Install air-quality monitoring stations in “invisible” sacrifice zones like Kahrizak and polluted industrial peripheries, so their reality cannot be erased from official statistics.
* Structural shifts across cities, not only in the capital
• Enforce the Clean Air Act nationwide: phase out mazut, standardise fuel quality, upgrade refineries and vehicle emission norms, and stop the production and circulation of obsolete, high-consumption vehicles and carburetor motorcycles.
• Invest massively in clean, affordable public transport in all major urban regions, not only Tehran – from metro and BRT to electric buses and suburban rail.
• Plan a gradual relocation and technological upgrade of the dirtiest industries away from dense residential areas, with binding guarantees that workers will not pay the price of transition.
• Use humanitarian exemptions in sanctions to secure international technical cooperation and financing for air-quality improvement through UN and green development mechanisms.
* From individual coping to collective pressure
Masks, air purifiers and staying at home have become survival strategies for those who can afford them, but they cannot replace structural change. What can begin to break the cycle is treating clean air as a central political and social demand in all affected cities:
• Demanding full transparency and accountability from power plants, refineries and industrial complexes – from Rey and Arak to Qazvin and Ahvaz.
• Connecting fragmented experiences – parents of sick children, workers in polluting plants, residents of industrial suburbs – into sustained campaigns against mazut burning and toxic fuels.
• Refusing the narrative that air pollution is a “natural” seasonal problem or a mere by-product of sanctions and “development”, and insisting that it is the result of concrete, reversible decisions.
The current wave of smog shows that Iran’s air-pollution crisis is not “a Tehran problem” but a national regime of toxic inequality: some breathe and move more safely, others pay with their lungs, hearts and futures. To fight for clean air in Tehran, Ahvaz, Qazvin, Karaj or Mashhad is to challenge an energy and urban model that has made the simple act of breathing a stratified and deeply political question.