Problem at its worse around Tehran where over half of Iran’s industry, including automobile manufactureing, electronics and arms production, to name but a few, is concentrated
Yogev Israeli|. 02.16.25
Iran is among the countries with the highest air pollution levels globally. For several years, the air in Tehran and other major metropolitan centers like Tabriz, Isfahan, and Mashhad has become nearly unbreathable, with pollution levels soaring to dangerous highs. Several key factors contribute to this phenomenon, posing significant challenges for city residents, especially in Tehran, which serves as the country’s political, economic, and social hub.
More than half of Iran’s industrial activity is concentrated around Tehran, including automobile manufacturing, electronics, electrical equipment, arms production, textiles, sugar production, cement, and chemicals. Additionally, a large oil refinery operates in the southern part of the city. Vehicle emissions combined with refinery pollution and weather conditions create hazardous air quality, frequently reaching extreme levels.
Tehran also relies on fossil fuels like mazut—a heavy, highly polluting oil derived from crude oil—and natural gas for electricity production. Despite its environmental risks, mazut continues to be used, even though it emits sulfur oxides at six times the rate of diesel and double the nitrogen oxides.
Iran’s air quality index (AQI) often fluctuates between the “red” level, indicating unhealthy conditions, and the “purple” level, which signals very unhealthy air. The primary sources of pollution include outdated vehicles, substandard public transportation infrastructure, and pollutant-heavy industrial operations.
In 2018, the World Health Organization (WHO) ranked Tehran among the most polluted cities worldwide, while the World Bank reported that year that the city accounted for a significant share of air pollution-related deaths in Iran. Estimates suggest dozens of people die each day from pollution-related illnesses, adding up to thousands annually. Experts warn that, without effective intervention, these numbers will continue to climb.
Historical Urban Development and Pollution Challenges
“Tehran became Iran’s capital in the late 18th century, though the country’s administrative centers shifted over the course of its 2,500-year history based on the ruling dynasty’s preferences—often without urban planning,” explained Prof. David Menashri, founding director of the Alliance Center for Iranian Studies at Tel Aviv University.
“In the early 20th century, Tehran had about 150,000 residents. By 1963, that number had grown to three million. With the 1979 Islamic Revolution, it rose to five million, and today it stands at nearly 9.5 million. The city was never designed to accommodate millions of people, and this unplanned urban and industrial growth has worsened pollution,” Menashri said.
He noted that pollution was already a noticeable issue half a century ago. “When I was conducting research in Iran 50 years ago, we could feel the pollution. We’d occasionally leave the city for a few days just to breathe cleaner air. The difference was evident even on the city’s outskirts.”
Despite proposals for stricter traffic regulations and partial lockdowns to address the issue, these measures have largely failed. Bureaucratic disarray, including a lack of coordination among government bodies like the health, oil, and energy ministries and Tehran’s municipality, has further hindered efforts.
While some advocate for temporarily halting activity in the city and improving public transportation and fuel quality, critics argue that high public transportation costs force many residents to continue using old, polluting vehicles.
The ongoing crisis has prompted Iran’s Health Ministry to issue public warnings, particularly to vulnerable populations such as the elderly, the chronically ill, and children, urging them to minimize time outdoors—especially when weather conditions heighten pollution risks.
Air pollution has led to repeated closures of schools and universities across Iran due to dust storms that worsen air quality. Government offices in Tehran and other cities have also been affected. In 2023, Jafar Jandak, head of the Iranian Health Ministry’s environmental center, told the state-run IRNA news agency that more than 38 million Iranians face serious health risks from airborne dust particles, which increase the likelihood of heart disease and disrupt daily life and transportation services.
Geographical and Climatic Factors
The name Tehran is believed to mean “warm slope,” a nod to its distinct climate. The city lies at the base of the Alborz Mountains, which stretch from Iran’s border with Armenia in the northwest, run south of the Caspian Sea, and end near Iran’s eastern borders with Turkmenistan and Afghanistan. Cold air descends from these mountains into the valley where Tehran is located, warming as it descends and contributing to the city’s dry conditions. The region receives only about 250 millimeters (roughly 10 inches) of rainfall annually, comparable to northern Israel’s Negev Desert.
Tehran’s elevation of 1,200 meters (3,937 feet) above sea level results in particularly harsh winters. Snow frequently blankets the peaks overlooking the city, including Mount Damavand, Iran’s highest point and one of Asia’s tallest volcanoes.
(Photo: Ebrahim Noroozi, AP)
“During winter, stable nighttime atmospheric conditions often trap pollutants within the valley,” explained Prof. Hadas Saaroni from Tel Aviv University’s Porter School of Environmental Studies. “The combination of long nights, late sunrises, early sunsets, and heavy traffic during peak atmospheric stability worsens pollution, particularly in the colder months.”
According to Saaroni, rain and strong winds occasionally help clear the air, but Tehran experiences these conditions infrequently. “Iran lies along the world’s desert belt and is therefore regularly exposed to dust storms originating in the Middle East’s deserts, the Sahara—the world’s largest dust source—and the Gobi Desert in East Asia. Tehran’s geographic location, arid climate, and man-made pollution make it one of the most polluted cities globally, with severe environmental and health consequences,” she said.
Looking Ahead: Relocating the Capital
Growing environmental awareness has led researchers and policymakers to consider drastic measures, including relocating the capital. Iran is not a global leader in environmental policy, but awareness of the issue has grown. “Proposals have surfaced to move the capital to a less polluted location—similar to what Brazil did when it established Brasília,” said Prof. Menashri.
“Iran has demonstrated its capacity to tackle large-scale challenges before—for example, reducing its birthrate despite religious restrictions. But as long as the country prioritizes regional influence, contends with heavy sanctions, and diverts resources to fund proxy forces, environmental reforms will be difficult to implement,” he added.
Iranian officials have confirmed the formation of two committees to assess the feasibility of relocating the capital due to Tehran’s population density and environmental struggle
Discussions about moving the capital have been ongoing since the Islamic Revolution in 1979. The idea gained traction during Mahmoud Ahmadinejad’s presidency due to concerns over potential earthquakes and resurfaced during Hassan Rouhani’s term. It remains a topic of interest under current President Masoud Pezeshkian.
Current proposals suggest establishing a new capital in the Makran region of Sistan and Baluchestan province or near the Gulf of Oman. Officials argue that this move could yield strategic and economic benefits, turning the area into a key commercial and maritime hub while easing pressure on Tehran. However, critics warn that the project’s high costs and logistical challenges could destabilize Iran’s already fragile economy and require decades to repair the damage.