Acid rain falls on Ahvaz, in Iran’s south western Khuzestan province. Photo uploaded onto Facebook.
Patients suffering breathing problems have been filling up emergency rooms in Ahvaz in recent weeks as bouts of acid rain fall on the western Iranian city.
Images filmed in Ahvaz and Khuzestan province show villages blanketed in thick fog, residents clutching handkerchiefs to their mouths or wearing breathing masks. They are reminiscent of  pictures regularly seen in Beijing, but data from the World Health Organisation (WHO) show Khuzestan is three times more polluted than the Chinese capital. WHO figures also suggest that five out of the ten most polluted cities in the world are in Iran, with Ahwaz topping the list.
Local media reports say acid rain has caused 20,000 people to become ill in the past month. The number could be much higher: Farsnews website, which is quoted by the Ahwaz News Agency, claims the provincial governor has forbidden hospitals from revealing the number of people admitted for respiratory troubles.
According to the Iran Pulse news website, Khuzestan’s environmental protection officer blames acid rain on high concentrations of nitrates in the air. According to Sasan Mogahi from Jondi Shapour hospital, the local petroleum industry and post-harvest fires in sugarcane fields are the main culprits behind high atmospheric nitrate levels.
Photo uploaded to Flickr by GHAZALEH GHAZANFARI
The authorities have temporarily closed primary schools and nurseries in several cities in Khuzestan and recommended parents keep their children indoors. Meanwhile, the suspected industrial culprits activity has continued.

“It's like the city is cursed”

Ahad, 22 years old, is a shopkeeper in Ahvaz. 
The weather has always been awful in Ahvaz, for as long as I can remember. But it gets worse every year. This year, we had dust storms and, more recently, acid rain that has caused people to become sick.
Last time it fell, I had to go to hospital because I had trouble breathing. The people that took care of me didn’t really know what to do. The nurses just gave me medication and put me on respiratory support. It cost me 100,000 tomans (about 30 euros). There were many people, mainly children and older people, and the medical personnel looked overwhelmed. After an hour or two, I was able to go home.
Last Wednesday, a new round of acid rain caused many people to get sick. According to what I heard, thousands went to the hospital. Those people who protested against the dam on the Karun River now intend to protest against the pollution and the unbearable living conditions that cause Ahvaz to resemble a ghost town. Indeed, it looks like some kind of nuclear wasteland.
Business is bad, especially in the afternoons when the pollution is so strong that we have to close our stores. People are worried, and they feel miserable. Ahvaz suffered for 25 years from the horrors of war. It is one of the cities with the poorest urban infrastructure, even though it is situated in an oil-rich region. It’s like the city is cursed.
Ahvaz is not a unique case. In the WHO ranking of most polluted cities, three Iranian cities - Ahvaz, Sanandaj, and Yasouj - are among the top ten. In December 2012, an adviser to the Minister of Health, Assan Aghajani, told the Iranian announced 4,460 people had died because of pollution between March 2011 to March 2012.
Post written in collaboration with freelance journalist Omid Habibinia, and France 24 journalist François-Damien Bourgery (@FDBourgery).