Air Quality Is Worse Than What Your Phone Reports Amid LA Fires, Officials Say

LOS ANGELES, CA — Officials on Tuesday warned that toxic ash from ongoing wildfires could pose health hazards to people across Southern California — and that the threat may not be reflected in Air Quality Index levels.

The South Coast Air Quality Management District has issued a windblown dust and ash advisory for large portions of Los Angeles, Orange, Riverside and San Bernardino counties. It's in effect from 4:30 p.m. Monday until 7 p.m. Wednesday.

The warning was issued because high winds — which are expected to pick up Tuesday — can disperse ash from the ongoing Palisades and Eaton fires, as well as from burn scars of earlier fires, such as the Hurst and Kenneth fires in LA County, Airport Fire in Orange and Riverside counties and Bridge Fire in LA and San Bernardino Counties, officials said.

Ash impacts are possible in all areas to the south and west of the burned areas, officials said.

"Ash is not just dirt — it's hazardous, fine dust that can irritate or harm your respiratory system and other parts of your body where it lands," Dr. Anish Mahajan, chief deputy director of LA County Department of Public Health, said at a Tuesday morning news conference.

Ash from burned structures "may contain higher air toxic levels," the SCAQMD said.

The ash particles "may be too large to be detected by air quality instrumentation and will not influence Air Quality Index (AQI) levels," air quality regulators wrote in the advisory. The AQI number is the most commonly cited way to measure the level of air pollution; it's widely used in phone apps and in weather reports on TV.

“People may think, ‘Well, I don’t see or smell smoke anymore, and it looks sunny like it normally does in Southern California,’ and be lulled into thinking everything is fine,” Dr. Jeremy Falk, associate professor of medicine at Cedars-Sinai, said in a release. “But much of what can harm us in situations like this doesn’t have an odor."

Falk added "the Air Quality Index system was developed for everyday pollution, and not necessarily to warn us about particles that are not typically in the air because of wildfires.”

The AQMD did note, however, that "ash particles are typically visible to the naked eye either in the air or on outdoor surfaces."

Mahajan said those who see ash should take precautions to reduce their exposure.

"If you're in the area that's impacted by the ash, you should wear proper respiratory masks, such as an N95 or a P100 mask to help protect you," he said. "These masks are specifically designed to reduce the exposure to harmful fine particles found in the ash and smoke which can penetrate deep into your lungs and cause serious health problems."

Cloth masks, medical masks and bananas do not provide adequate protection against ash or fine particles, he said.

"You really need to wear an N95 or P100 if you're seeing the ash in your area," he said.

Meantime, the SCAQMD warned that windy conditions may stir up non-fire-related dust, resulting in AQI levels that are Unhealthy for Sensitive Groups or worse.

Here's a look at the wind forecast, according to AQMD:

• Tuesday day: Winds are expected to decrease slightly in the afternoon, leading to slight improvements in windblown ash and dust levels
• Tuesday evening: High winds will likely lead to unhealthful levels of windblown ash and dust
• Wednesday: Winds will decrease throughout the day, leading to improved air quality

Air regulators said those in an area impacted by windblown dust or ash should:

• Remain indoors with windows and doors closed as much as possible.
• Avoid vigorous physical activity.
• Run air conditioning and/or an air purifier.
• Do not use swamp coolers or whole-house fans that bring in outside air.
• Minimize dust pollution by stabilizing loose soil and slowing down while driving on dirt roads.
• Wear personal protective equipment while working around ash. Wash off any ash you may get on your skin.
• Do not use leaf blowers, sweep or take any other action that will push ash into the air
• Use vacuums with HEPA filters to clean up ash.

N95 masks are available at all Los Angeles city libraries, recreation centers and senior centers, officials said.