Iran faces serious and persistent air pollution challenges, particularly in major urban centres such as Tehran, Esfahan, Mashhad, and Tabriz. Tehran, the capital, frequently experiences hazardous or very unhealthy air quality levels, driven by factors including inadequate public transportation, an aging vehicle fleet, and a heavy reliance on fossil fuels, which account for 98% of the country’s energy production. This pollution poses a significant public health burden, with average annual exposure to fine particulate matter (PM2.5) reaching 32.3 µg/m³—more than six times the World Health Organization’s guideline. In 2019, air pollution was linked to an estimated 74 deaths per 100,000 people, totalling nearly 49,000 premature deaths nationwide. Fine particulate pollution is a major contributor to several diseases, accounting for 24% of chronic obstructive pulmonary disease deaths, 23% of strokes, 22% of both type 2 diabetes and lung cancer deaths, and 21% of ischemic heart disease fatalities. It also contributes to 19% of deaths from lower respiratory infections and 12% of neonatal disorder deaths.
Iran operates an extensive air quality monitoring network comprising 219 stations, with 171 currently active, that track key pollutants including NO₂, SO₂, O₃, CO, PM2.5, and PM10. This network supports data-driven policy and operational decisions. A central data system, the Tehran Emission Inventory, identifies pollution sources and informs targeted interventions in the capital city. To support effective implementation and oversight, Iran utilizes the Action Plan Progress Monitoring Platform, a digital tool that tracks 172 tasks across 11 national and 88 local stakeholders using defined Key Performance Indicators (KPIs). These monitoring and management tools are essential for coordinating efforts, assessing progress, and adapting policies to improve air quality outcomes.
A significant environmental concern in Iran is the impact of transboundary dust storms, particularly in western and southern regions. These natural events, combined with urban emissions and weak enforcement of vehicle and industrial standards, have made consistent air quality improvement difficult. Looking ahead, Iran is positioning itself for greater International Solar Investment Cooperation, aiming to accelerate its clean energy transition and reduce long-term emissions. It also seeks Regional Collaboration on Dust Storms, especially to address transboundary air pollution affecting western and southern provinces.
Yearly PM2.5 levels in major cities of Iran reveal consistently high air pollution across the country, with all monitored cities far exceeding the WHO’s 2021 standard. Tehran shows the highest concentrations, frequently surpassing 30 µg/m³ and occasionally nearing 37 µg/m³, especially in the early 2000s. Mashhad, Shiraz, and Tabriz also report elevated levels, fluctuating between 25–35 µg/m³ over the years. Isfahan, while consistently lower than the others, still records PM2.5 values between 15–25 µg/m³. Although there is some year-to-year variability, no clear downward trend is observed, highlighting persistent air quality concerns likely driven by industrial activity, vehicular emissions, and regional atmospheric conditions.
Iran has developed a layered and evolving policy framework to address its severe air pollution challenges. This journey began with the Environmental Protection and Enhancement Act (1974), which established the legal foundation for national environmental governance. The Air Pollution Prevention Act (1995) followed as the country’s first legislation specifically targeting urban air quality and industrial emissions. A significant milestone was the Clean Air Act (2017)—a comprehensive law mandating air quality monitoring, emission reductions, promotion of clean energy, urban transport reform, and public awareness initiatives. To implement this law, Iran launched the National Clean Air Action Plan, which outlines 24 coordinated policy areas including scrapping old vehicles, standardizing fuels, regulating industrial emissions, managing traffic, expanding public transport, and incentivizing clean energy adoption such as electric motorcycles. The plan also emphasizes public engagement and employs structured decision-making tools like the Analytic Hierarchy Process (AHP) to prioritize interventions based on their impact and feasibility. Notable progress under this framework includes scrapping over 100,000 old vehicles and adding 2,000 MW of clean energy capacity within the first year. Additionally, the country has adopted Euro 4 or higher Vehicle Emission Standards to reduce pollutants from transportation sources.