For the second day in a row, air quality monitoring officials have issued a four-county smoke advisory because of accumulations of soot and noxious particles from the wildfire, the San Gabriel Valley Tribune reported Saturday.
White smoke from the fire was caught up in the Los Angeles air basin, a meteorologist said Friday.
"It went off the coast and then came back in on the sea breeze today. We saw regional levels of particulates go up," said Joe Cassmassi, a pollution forecaster with the South Coast Air Quality Management District.
The dirty air may have increased the number of people going to hospitals, said Dr. James E. Baker, an emergency physician at a hospital in the San Gabriel Valley of Los Angeles County.
Baker said he had seen "a mild to moderate increase" in the number of people reporting shortness of breath, sore throats and irritated eyes since the fire began Thursday.
The blaze has scorched nearly 1,900 acres and destroyed at least five homes. About 4,000 people evacuated from their homes in Glendora and Azusa have been allowed to return home, but the 300 residents in the upscale community of Mountain Cove are still under evacuation orders, said Azusa police Lt. Paul Dennis.
Four of the burned homes were in one block of the Glendora Mountain neighborhood, the Pasadena Star-News reported. Several others were damaged by smoke.
While the fire is only 30 percent contained, fire officials were upbeat, the Los Angeles Times reported.
"Things are looking good on the fire," said Mike Wakowski, commander of an incident team. "It's not moving like it sure did."
Cooler onshore winds were expected in the area by Sunday, said Kathy Hoxsie, a National Weather Service meteorologist.