Air pollution causes schools in Teheran to close
Huge increases in emissions from traffic and industry are the main causes of severe air pollution. In addition, the city of Teheran is burdened with an unfavourable topography that makes matters even worse.
There is no wind or rain and the dirty air is trapped on top of the city by the mountains surrounding it.
More than 1,600 people have been taken to hospitals in Tehran as pollution in the Iranian capital reaches critical levels, health officials have said.
Hospitals have reported increased cases of heart attacks and breathing problems, while many residents are complaining of fatigue and headaches.
Read more about the current situation in Teheran Here.
The Norwegian Institute for Air Research (NILU) has many years of experience in dealing with air pollution in megacities. Numerous projects have been, and are being undertaken in big cities in China, South East Asia, the Middle East and in Africa.
At the moment, NILU is tendering for an air quality management project in Iran.