Most of the fires, which began 40 miles west of Santiago, are under control, but smoke in the capital is not forecast to dissipate until Wednesday, the Santiago Times reported Monday.
The fires began in the province of Melipilla and have burned nearly 30,000 acres, said Manuel Plaza, commander of the Melipilla Fire Brigade. Although the fire has been contained in several areas, it was still active in a mountainous area around the town of Maria Pinto. Single-engine planes are being used to fight the blaze from the air, said Francisco Meneses, commander of the local fire service. Fire officials said the wind was in their favor.
No firefighters have been injured and no residential areas in either Melipilla or Maria Pinto had been affected, officials said.
Smoke from the fires has been trapped over Santiago, which sits in a valley, by winds off the coast and a thermal inversion, said Luis Salazar from the Institute of Meteorology. He predicted the smoke would diminish Wednesday after humidity levels rose and caused particles in the smoke to fall.
Until then, Santiago residents were cautioned by health officials to avoid exercising. Health officials emphasized people with chronic respiratory disease face increased danger.
Some 20 percent of the city's hospital beds have been reserved for people affected by the smoke.