Iran’s black rain after strikes: a toxic mix of pollutants explained

Following U.S.–Israeli strikes on oil depots in Iran, reports of black, ‘acid’ rain reflect a rainout of heavily polluted air. An atmospheric scientist explains the rain likely contains hydrocarbons, PM2.5, PAHs, heavy metals, and other chemicals, with sulfur dioxide and nitrogen dioxide forming acids in droplets. Short-term health risks include headaches and breathing difficulties, especially for those with asthma, while long-term exposure could raise cancer risk; deposition on surfaces and waterways can spread pollutants. Protective actions include staying indoors, wearing masks, and cleaning surfaces where possible. The piece also notes that all smoke is toxic and that war-related air pollution can have lasting environmental and health impacts.