Iran is turning to environmentally friendly Euro-4 emissions standard petrol in major cities to battle worsening air pollution which claims thousands of lives every year, media reports said Monday.

"Some eight million litres (two million gallons) of clean gasoline was distributed to 90 gas stations in Tehran on Saturday," the Ettelaat daily reported Morteza Abedini, head of Tehran's Oil Products Distribution Company, as saying.

"In order to reduce environmental pollution... all petrol stations are expected to distribute clean gasoline by February 20," he said.

Pollution is a constant woe for Tehran's more than eight million residents.

It is caused by bumper-to-bumper traffic and the city's location between two mountains, ensuring that fumes from both cars and factories blanket the city.

Since the last Iranian year began in March 2013, residents have endured polluted air for 143 days, media reports said.

The poor air quality is made worse by reliance on domestic production of lower quality and therefore more polluting petrol, blamed on Western sanctions against Iran's fuel imports.

Daily petrol consumption in Tehran is around nine million litres, according to official figures.

Iran currently produces 16 million litres of Euro-4 gasoline daily.

Euro-4 fuel has also been distributed in other major cities including Karaj west of Tehran and in the central province of Arak.

Other major cities such as Mashhad, Isfahan and Tabriz also suffer from air pollution caused by lower emissions standard Euro-2 fuel.

In 2012, air pollution contributed to nearly 4,400 premature deaths in Tehran alone and nearly 80,000 nationwide, according to health ministry figures.