High levels of fine particulate matter (PM2.5) air pollution mostly caused by car fumes are again causing havoc in Tehran with schools closed across the Iranian capital, Young Journalists Club reported on November 13.

In the past 24 hours alone, the winter smog has reportedly sent 2,863 people with suspected heart and lung conditions to accident and emergency departments, ISNA said.

The majority of kindergartens and elementary schools in the southern and central areas of the Iranian capital have reportedly been shut down on official orders until the pollution, seen as a particular threat to children, pregnant women and the elderly, subsides.

According to Iranian law, whenever the average air pollution index reaches 133, the government must be notified by city officials so that schools can be shut and vulnerable groups warned. The acceptable index level in most cities is under 50.

Index readings as high as 169 have been recorded in Tehran’s Grand Bazaar area and southern workshop districts in the latest pollution outbreak.

The areas of the capital with the best air quality remain the northern hilly districts—which boast the priciest property in the city—while the eastern Tehranpars area also does well. It is scoring under 100 on the index.

Tehran Mayor Pirouz Hanachi said that, apart from waiting for it to rain to cleanse the air, car users should stop using their vehicles until the pollution subsides.

Hanachi said that 80% of the air-borne pollutants in Iran stem from vehicles.

"[As this is the case] we decided to reduce public transport costs by 50% and increase the cost of entering the congestion zone," he said. “We also have restrictions on heavy-duty vehicles. Citizens should also make less personal car journeys with a single occupant,” he added.