In early March, reports indicated that U.S.-Israeli airstrikes on Iranian targets set multiple oil storage facilities near Tehran ablaze. At least four depots were struck, creating a large plume of toxic gases and particulate matter.
Witnesses describe a city overwhelmed by the scent of burning petroleum, with thick black smoke obscuring daylight. The real concern lies in the inhalation of the hazardous compounds released during the fires.
The initial danger manifests as acid rain. Typically associated with smog‑laden cities, acid rain in Tehran is expected to be far more concentrated and damaging. Combustion releases sulfur dioxide, nitrogen oxides, and other pollutants that mix with cloud moisture, forming acidifying precipitation. When this rain falls, it can corrode infrastructure, damage crops, acidify waterways, and pose serious health risks to humans.
While acid rain does not directly harm the skin, the fine particulate matter it carries can penetrate the respiratory system, leading to cardiovascular problems and, in severe cases, fatal heart attacks. The Environmental Protection Agency (EPA) notes that "many scientific studies have shown a relationship between these particles and heart function, such as heart attacks and effects on lung function." EPA
It is difficult to determine the exact chemical profile of the emissions from Tehran’s burning depots without direct sampling, but experts warn that the concentration of toxins could be several orders of magnitude higher than the acid rain common in cities like New Delhi or Beijing. In some assessments, the plume has been labeled "black rain." The situation is comparable to a refinery explosion, which has historically left nearby communities with elevated cancer rates.
Even normal refinery operations emit pollutants that are linked to cancer, cardiovascular disease, neurological disorders, reproductive issues, and other health problems. Key carcinogens include benzene, nitrogen oxides, methylene chloride, toluene, and methylene. These same chemicals are likely present in the toxic cloud over Tehran.
Tehran’s topography, which resembles a basin, creates temperature inversions that trap polluted air near the surface. Consequently, the toxic cloud is forced downward, depositing carcinogenic chemicals into residents’ lungs and the city’s water cycle. Without timely cleanup, the population faces a growing risk of chronic illness and mortality.
