The latest ranking by the World Health Organization (WHO) and the International Agency for Research on Cancer (IARC) shows four Iranian cities are among the most polluted in the world: Ahvaz, Sanandaj, Kermanshah and Yasooj.

The Mehr news agency is reporting on the latest survey done by the WHO and the IARC, which have ranked the following as the 10 most polluted cities in the world:  Ahwaz, Iran,  Ulaanbaatar, Mongolia,  Sanandaj, Iran, Ludhiana, India, Quetta, Pakistan, Kermanshah, Iran, Peshawar, Pakistan, Gaborone, Botswana, Yasooj, Iran, Kanpur, India.

With regard to air pollution in Ahwaz and the Province of Khusistan, Parvin Ghaffari, a member of the science committee of the Oceanic Research, said: "Places with gas pollution such as Ahwaz face acid rain."

In terms of the increase in air pollution in other Iranian cities, she warned: "It is necessary to implement new measures to better forecast and combat pollution in cities across the country."

Severe air pollution and rain in the Province of Khuzistan in the recent weeks have sent thousands of people to the hospitals. Following the November 17 rainfall, more than 1,500 people accessed various Ahvaz health centres. A week earlier, the Ministry of Health reported that more than 6,000 Ahvaz residents required medical care and attention due to respiratory problems.