‘Black rain’: Iran war’s toxic pollution will spread and last for years

News of black rain falling on Tehran felt all too familiar to Nejat Rahmanian as he scrolled through alerts on social media feeds and tried to contact relatives on March 8.

Israeli drone strikes hit giant oil depots and refineries on the outskirts of the Iranian capital a few hours earlier, setting fuel on fire and releasing columns of black smoke, which mixed with rain clouds that poured toxic chemicals onto the city later in the day.

The descriptions reminded the Iranian researcher of a similar event he experienced in the city 35 years ago.

It was surreal, recalled Rahmanian, a professor of chemical and petroleum engineering at the UK’s University of Bradford. Clothes hanging out to dry got stained and the air felt heavy. No one knew why.

Later, they learned that around 1,290km (801 miles) away in Kuwait, Iraqi forces battling US and allied forces in the Gulf War had set hundreds of oilfields ablaze.

Plumes of soot, hydrocarbons and sulphur dioxide blew over Iran, polluting everything in their path, and accelerating the melting of glaciers in the Himalayas, according to a 2018 study led by Jiamao Zhou at the Chinese Academy of Sciences.