Chile has issued environmental alert for its capital because of air pollution. Santiago is bordered by the Andes mountains where smog from cars and factories is often bottled up.
City officials have now placed limits on industries and the circulation of cars.
4200 people die in Chile each year from causes directly linked to smog and other kinds of pollution.
It is the first environmental alert for Santiago this year.
The official State of the Environment Report 2011, released this week found that the limits set for ambient fine particulate matter PM2.5 was exceeded in 30 cities for Chile.
What does PM stand for?