Tehran Named World's Most Polluted City

Tehran recorded the worst air quality among major global cities on Wednesday, according to real-time monitoring by the international platform IQAir.

The city’s Air Quality Index (AQI) reached approximately 233, placing it in the “Very Unhealthy” category and making it the most polluted urban center in the world at the time of measurement, The Caspian Post reports citing Iranian media.

Authorities and health experts report that the dangerous spike is primarily driven by elevated concentrations of PM2.5, ultrafine particulate matter small enough to penetrate deep into the lungs and enter the bloodstream.

Prolonged or repeated exposure to such particles is linked to increased risks of heart attacks, strokes, aggravated asthma, reduced lung function, and other serious health complications.

With pollution levels exceeding the threshold considered hazardous for the general population, officials are urging residents to limit outdoor activities.

People who must leave their homes are advised to wear well-fitted N95 or FFP2 masks to reduce inhalation of fine particles.