Light rainfall in Tehran has failed to ease the capital’s pollution crisis, with the city’s air quality remaining firmly in the “unhealthy for all” category for the tenth consecutive day.
The Tehran Air Quality Control Company reported that fine particulate matter smaller than 2.5 microns (PM2.5) reached an average Air Quality Index of 165 on Monday, following a reading of 158 over the previous 24 hours.
The AQI scale classifies air quality from “good” to “hazardous,” and Tehran’s current levels place it well into the unhealthy range. Such conditions are not unusual in colder months, when temperature inversion traps pollutants close to the ground, but this year the problem has arrived earlier and with greater intensity.
In a recent report, Iran’s Department of Environment has attributed the crisis to a combination of factors, including stagnant weather conditions, ageing diesel fleets, heavy traffic, industrial activity on the city’s outskirts, and the use of fuels with high sulphur content.
The report noted that PM2.5 concentrations have risen by 13% compared with the same period last year.
The persistent pollution has forced widespread closures. Since November 25, schools and universities have moved online, government offices have adopted remote work, and cultural venues such as cinemas, theatres, galleries and museums have shut their doors.
With unhealthy air continuing into December, authorities announced that restrictions would remain in place through Tuesday and Wednesday.
