On September 26, 2025, the Swiss air quality technology company IQAir ranked Tehran as the most polluted city in the world. A day later, the Iranian capital—along with several other major cities—experienced their most polluted days of the year. Air quality indices in parts of Tehran surpassed the “very unhealthy” threshold, while Mashhad, Isfahan, Urmia, Tabriz, Qom, and several cities in Khuzestan also entered red or orange alert levels.
In Tabriz, citizens launched an online campaign to oppose the government’s authorization for power plants to burn mazut—the dirtiest fossil fuel once used by the Soviet Union but now banned by most country. Sulfur content in Iran’s domestically produced mazut stands at 3.5 percent, seven times higher than what is permitted for marine fuel. During the cold season, Iran burns roughly 40 million to 50 million liters of mazut per day in industrial facilities and power plants.
About 70 percent of Iranian energy supply comes from natural gas and nearly all the rest from oil products.
Despite holding the world’s second-largest gas reserves, Iran faces year-round gas shortages due to chronic underdevelopment of its gas sector and waste across both production and distribution. In winter, when household gas consumption peaks, mazut replaces a significant share of fuel needed for industry and power generation.
Iran’s oil minister recently announced that the country will face a daily gas deficit of 300 million cubic meters this winter—an enormous gap equivalent to the entire winter gas consumption of Turkey, a country with a similar population but an economy 4.5 times larger.
An imbalanced energy mix also aggravates Iran’s energy crisis: About 70 percent of Iranian energy supply comes from natural gas and nearly all the rest from oil products. Turkey, by contrast, has a diversified energy portfolio with a significant share of renewables. Iran is the world’s sixth-largest emitter of greenhouse gases from fossil fuels, releasing nearly 800 million tons of carbon dioxide-equivalent emissions annually.
Saviz Sehat-Kashani, head of Iran’s Clean Air Scientific Association, notes that air pollution causes 58,000 deaths annually and generates $12 billion in health care costs in Iran. He says more than 75 percent of Iran’s air pollution stems from the energy sector. Alireza Raeisi, deputy minister for health, also points to the extremely low efficiency and high fuel consumption of domestically manufactured vehicles as a major contributor to pollution.
Iran’s domestic automakers produce roughly one million vehicles each year, all destined for the domestic market. Experts say the energy efficiency of these cars is so poor that they consume twice as much fuel as global standards.
At the same time, due to the government’s failure to expand refinery capacity, an increasing volume of petrochemical additives is blended into gasoline to make up for fuel shortages. Documents from Iran’s Oil Ministry show that in 2018, only 5 percent of the gasoline consumed contained petrochemical additives, but that figure has now risen to 20 percent.
Three-quarters of Iran’s gasoline has an octane rating of eighty-seven, and Iran produces only limited amounts of Euro-4 and Euro-5 gasoline.
For years, Iran’s automotive lobby successfully pressured the government to ban the import of foreign cars. But over the past two years, amid rising public criticism of domestic vehicle quality, the government finally allowed car imports. Customs data show that in the first seven months of the current fiscal year, which began on March 21, around 42,000 imported vehicles entered the country—many of them turbocharged or hybrid models. These cars require 95-octane gasoline. Starting December 1, the government has set the price of 95-octane gas at $0.55 per liter, up from the previous $0.015–$0.03 per liter.
Although gasoline remains cheap in nominal terms, this is largely due to the collapse of the Iranian rial
Previously, car owners received up to 60 liters per month at the subsidized price of $0.015 per liter, and any additional amount cost $0.03. But since November 25, drivers consuming more than 160 liters per month must pay $0.044 per liter for the excess. Vehicles using 95-octane gasoline must pay $0.55 per liter regardless of monthly quotas. Effectively, those who purchased turbocharged or hybrid cars over the past two years now must use fuel priced at global market levels.
Although gasoline remains cheap in nominal terms, this is largely due to the collapse of the Iranian rial—a direct result of the Islamic Republic’s economic mismanagement. The rial has lost 98 percent of its value over the past decade. In 2019, the government sharply increased gasoline prices, triggering widespread protests and violent crackdowns. Reports indicate that security forces killed at least 324 protesters. The depreciation of the Iranian rial continues, and since 2019 the US dollar has risen ninefold against the rial.
What this suggests is that pollution is becoming an element in Iran’s “perfect storm.” What concerns the Iranian regime most are issues around which Iranians of all backgrounds, beliefs, and socioeconomic class might rally. Pollution does not discriminate between rich and poor nor bypass any particular ethnicity or sect. With Iranians increasingly dependent on highly polluting fuel and unable to acquire clean energy either for financial reasons or its very scarcity, pollution is likely to again become a rallying cry for Iranians and a visual testament to government failure.
