Tehran was blanketed in a surreal and dangerous mix of black smoke and rain on March 8, following Israeli drone strikes on massive oil depots and refineries just outside the city. The attacks set fuel ablaze, sending thick columns of soot and toxic chemicals into the sky that later fell with the rain, creating a rare but highly hazardous phenomenon reminiscent of events from the Gulf War more than three decades ago. Nejat Rahmanian, an Iranian researcher at the University of Bradford, recalled similar black rain falling over Tehran in 1988, caused by oil fields set on fire in Kuwait during the conflict. “It was surreal,” he said. “Clothes hanging out to dry got stained and the air felt heavy. No one knew why.”
The latest strikes are releasing pollutants far closer to the urban center, putting the city’s 18.5 million residents at risk. Experts warn that the proximity of burning oil facilities to a major metropolis is rare and particularly dangerous. “We always see oil facilities being attacked in conflicts,” said Doug Weir, CEO of the Conflict and Environment Observatory, “but it’s extremely rare for them to be close to a large city like Tehran.” The strikes have unleashed toxic emissions including soot, hydrocarbons, sulphur dioxide, and other pollutants that can linger in the air, soil, and water for decades, causing long-term health problems and complicating clean-up efforts.
According to reports from CEOBS, more than 300 incidents with environmental risk have already been documented in the ongoing conflict. Missiles and bombs release heavy metals and chemical pollutants upon detonation, creating a legacy of contamination for local populations. “A lot of people are exposed to pollution and will continue to be,” Weir said, highlighting the Iranian oil depot strikes as the most severe pollution incident of the current war. David J.X. Gonzalez, assistant professor at the University of California, Berkeley, warned that young children and pregnant women are especially vulnerable to respiratory issues caused by these airborne toxins.
Iranian authorities initially advised residents to remain indoors due to the danger of acidic rain, which could cause chemical burns and respiratory harm. The UN’s World Health Organization echoed these warnings. Yet, in a conflicting message, state television and senior officials later encouraged citizens to participate in public events, including the annual pro-Palestine march in central Tehran. Some residents opted to flee to the northern regions of the country to avoid exposure, while others remained in the capital despite the mounting health risks.
Environmental scientists emphasize that Tehran’s geography worsens the situation. The city sits at the base of the Alborz Mountains, which trap pollutants and create thermal inversions that can prolong episodes of poor air quality for weeks or even months. Even before the strikes, Tehran faced dangerously high levels of particulate matter and heavy metals like lead, cadmium, chromium, and nickel, largely from vehicle emissions and industrial activity. Sulphur dioxide and other compounds released from burning fossil fuels and waste already posed serious health risks, and the recent strikes have compounded these hazards.
Rain, which usually helps cleanse the city’s air, may have exacerbated the contamination. Dimitris Kaskaoutis, a physicist at the National Observatory of Athens, explained that the combination of oil fires and precipitation makes the pollutants more easily absorbed by the human body, affecting organs such as the liver, kidneys, and nervous system. “These pollutants diluted in the water are much more toxic and can easily be absorbed in our bodies,” he said.
Communication blackouts across Iran since the start of the US and Israeli military campaign on February 28 have made it difficult to assess the full scale of the contamination. Sampling and monitoring are limited, leaving authorities and researchers with incomplete data. Senior adviser Nazanine Moshiri stressed the importance of documenting the environmental damage for accountability and future clean-up once hostilities end.
The conflict’s ongoing nature raises fears of additional attacks on Iran’s vast network of refineries, depots, oil platforms, and other strategic infrastructure, including nuclear and desalination facilities. “It’s stressful,” Rahmanian said, speaking of the uncertainty facing his relatives in Tehran. “We just don’t know what’s going to happen.” Experts warn that continued targeting of these sites could have catastrophic consequences for public health, the environment, and regional stability, compounding the already severe human and ecological costs of the war.