Iran has closed government offices and schools in Tehran for two days because of wind-blown dust that has polluted the capital.
Government authorities have declared Tuesday and Wednesday a public holiday, and Iranian media say many domestic airline flights have been canceled.
Medical authorities are advising people with heart and respiratory problems to stay inside.
Iran's Press TV says Tehran's Air Quality Control Company has found the amount of potentially harmful particulate in the air has reached dangerous levels.
The dust has blown in from Saudi Arabia and neighboring Iraq, where a severe sandstorm recently blanketed the capital, Baghdad.
Sandstorms can be caused by heavy winds blowing across deserts, or across land that has lost its fertile top soil and greenery.
Many offices, businesses and education establishments in Iran have closed for two days because of high pollution levels caused by desert storms.
State television said air pollution in the capital, Tehran, had reached levels not seen for 30 years.
Visibility has been reduced to several hundred metres, while some domestic flights have been cancelled.
The elderly, children and people with heart and respiratory problems have been told to stay indoors in west Iran.
"All administrative offices are closed because of the atmospheric pollution which has soared several times higher than the normal threshold," said Tehran governor Morteza Tamadon on state television.
In neighbouring Iraq, officials described the last week of sandstorms as the worst in history. Hundreds of people were taken to hospital with respiratory problems.
Reports say a reduction in the flow of the once-mighty Tigris and Euphrates rivers - from drought and upriver damming - has aggravated the situation.
Iran declares public holiday in Tehran as sandstorm blankets heavily polluted capital.
TEHRAN - Iranian authorities have declared Tuesday and Wednesday a public holiday in the capital Tehran after a sandstorm blotted out the already heavily polluted city.
"All administrative offices are closed because of the atmospheric pollution which has soared several times higher than the normal threshold," Tehran governor Morteza Tamadon said on state television.
Local media said the authorities had warned parents to keep their children inside and told elderly and sick people not to go out. Emergency services have been put on alert during the two-day holiday.
The sky over Tehran and over many towns in the eastern half of the country have been filled with sand, blown in from neighbouring Arab countries, particularly Iraq. The heavy pollution has blacked out the sun.
Newspapers said that many Tehran residents have left the city for provinces suffering less from pollution.
Government authorities have declared Tuesday and Wednesday a public holiday, and Iranian media say many domestic airline flights have been canceled.
Medical authorities are advising people with heart and respiratory problems to stay inside.
Iran's Press TV says Tehran's Air Quality Control Company has found the amount of potentially harmful particulate in the air has reached dangerous levels.
The dust has blown in from Saudi Arabia and neighboring Iraq, where a severe sandstorm recently blanketed the capital, Baghdad.
Sandstorms can be caused by heavy winds blowing across deserts, or across land that has lost its fertile top soil and greenery.
Many offices, businesses and education establishments in Iran have closed for two days because of high pollution levels caused by desert storms.
State television said air pollution in the capital, Tehran, had reached levels not seen for 30 years.
Visibility has been reduced to several hundred metres, while some domestic flights have been cancelled.
The elderly, children and people with heart and respiratory problems have been told to stay indoors in west Iran.
"All administrative offices are closed because of the atmospheric pollution which has soared several times higher than the normal threshold," said Tehran governor Morteza Tamadon on state television.
In neighbouring Iraq, officials described the last week of sandstorms as the worst in history. Hundreds of people were taken to hospital with respiratory problems.
Reports say a reduction in the flow of the once-mighty Tigris and Euphrates rivers - from drought and upriver damming - has aggravated the situation.
Iran declares public holiday in Tehran as sandstorm blankets heavily polluted capital.
TEHRAN - Iranian authorities have declared Tuesday and Wednesday a public holiday in the capital Tehran after a sandstorm blotted out the already heavily polluted city.
"All administrative offices are closed because of the atmospheric pollution which has soared several times higher than the normal threshold," Tehran governor Morteza Tamadon said on state television.
Local media said the authorities had warned parents to keep their children inside and told elderly and sick people not to go out. Emergency services have been put on alert during the two-day holiday.
The sky over Tehran and over many towns in the eastern half of the country have been filled with sand, blown in from neighbouring Arab countries, particularly Iraq. The heavy pollution has blacked out the sun.
Newspapers said that many Tehran residents have left the city for provinces suffering less from pollution.