TEHRAN, Jan. 19 (Xinhua) — An Iranian health official said on Thursday that 20,800 people in Iran die of air pollution-caused diseases per year, the semi-official Tasnim news agency reported.

The figure was estimated according to the results of research and studies conducted in 27 Iranian cities with a total population of 35 million, Abbas Shahsavani, head of the Air Health and Climate Change Department of Iran’s Health Ministry, told Tasnim.

Nearly 12.6 percent of the annual fatalities in the country are due to diseases caused by air pollution, he said, adding air pollution annually incurs a cost of 8.2 billion U.S. dollars on the country.

Commenting on the situation in Tehran, the Iranian official said air pollution killed 6,400 people in the Iranian capital in the Iranian calendar year ending March 20, 2022.

Shahsavani blamed Tehran’s air pollution on old cars and diesel motorcycles, saying 90 percent of the country’s motorcycles and 50 percent of Tehran’s transport fleet are old and worn out.

With the arrival of the cold season, the air pollution in major Iranian cities, including Tehran, reaches alarming levels, which is hazardous for the health of local residents.

Domestic and foreign experts said under the years-long U.S. sanctions, the forced use of old vehicles, which should have been scrapped long ago, is the cause of the terrible air quality in Tehran.

“It is no surprise that Tehran is one of the world’s most polluted cities. U.S. sanctions force people to prolong the use of older vehicles that burn fuel less efficiently while making it impossible for Iran to obtain equipment and technology to reduce vehicle emissions,” a group of UN human rights experts announced on Dec. 20, 2022.

The sanctions also prevent Iranian scientists from engaging in joint environmental research projects abroad, and prevent Iranians from accessing online databases and courses about environmental issues and sustainability, they pointed out.