The smoke and ash from the two wildfire outbreaks was incredible.

In the foothills of the San Gabriel Mountains, the Eaton Fire engulfed homes and businesses, sending thick smoke billowing across the horizon and blocking out sunlight.

The wildfires have produced some of the worst smoke and ash the region has seen in recent years.

On Jan. 8, air monitors in Chinatown, about 10 miles downwind from the Eaton Fire, recorded 483.7 micrograms per cubic meter of fine particulate matter, according to preliminary data from the California Air Resources Board. This is the highest hourly reading from an air monitor approved by the Los Angeles County Department of Environmental Protection in more than four years, surpassed only by smoke from the 2020 Fourth of July fireworks display.

Near the coast, the Palisades Fire swept through the Santa Monica Mountains, burning the foundations of a dream home with Pacific views and sending a plume of smoke out to sea. As the fire spread to Pacific Palisades Elementary School, a low-cost air monitor in the Los Angeles Unified School District recorded fine particulate matter concentrations of 1,100 micrograms per cubic meter, the highest level recorded since the air monitors were installed in 2021.

At these levels, this microscopic contamination becomes dangerous. While the extent of this pollution's impact is not fully understood, studies have shown it is linked to an increased risk of heart disease, stroke and severe lung damage.

The exact number of deaths and hospitalizations related to wildfire smoke is often not known until months, if not years, after these natural disasters occur. Still, fire-related hospital visits in Los Angeles County jumped 16-fold during the region's recent wildfires, according to the Los Angeles County Department of Public Health. At the peak on January 8, at least 81 people went to the hospital with burns or smoke.

Experts say children are particularly vulnerable because their still-growing lungs require more breathing and are therefore more likely to be exposed to certain amounts of pollution. In 2018, 76 percent of children with asthma experienced an asthma attack or asthma attack within two weeks of the 2018 Camp Fire in Northern California, the worst and deadliest on record in the state. A study by Stanford University and data firm Komodo Health showed a 27% increase in asthma-related emergency room visits in the region during that period.

Latino children with asthma appear to be most severely affected. There has been a 95% increase in assaults and incidents among this specific group of people. Asian and black children also had significantly higher asthma attack rates compared with white children.

Mark Carmichael, currently a medical student at Stanford University, said similar disparities may be seen in the aftermath of wildfires in Los Angeles County. Some of the worst pollution from the Eaton fire wafted into Chinatown, Boyle Heights, Compton and Long Beach, historically disadvantaged communities that are largely Latino, Asian and Black and have long suffered the worst of the region's Impact of industrial pollution.

"Air quality standards don't play any role in these events," Carmichael said. "Because these are emergencies, you need to develop prevention strategies for those who you already know are more susceptible to adverse outcomes."

As of Wednesday afternoon, 25 people have been confirmed dead as a result of recent wildfires in Los Angeles County. But researchers suspect the ensuing smoke wave could have more consequences.

As many as five people may have died in Los Angeles County, according to an online tool that estimates wildfire smoke mortality rates across the county. The experimental model, which analyzes federal air quality data and satellite imagery, was created by Cornell University researchers who hope it will help us better understand how smog affects public health.

“It’s really hard to know, especially the mortality rate,” said Alistair Hayden, an assistant professor at Cornell University and former chief of the California Governor’s Office of Emergency Services. "We know it has (potentially fatal) effects, but it doesn't show up on people's death certificates."

"What people are really interested in when we see this is, is this just a nasty smoke wave, or could it be considered a real disaster?"

Other groups are also trying to answer this question. NASA, for example, uses its satellites to assess air pollution, both chronic and during acute events, such as what occurred in Los Angeles County. In addition to smoke and soot, the space agency has detected large amounts of harmful gases emitted by wildfires, including lung-irritating nitrogen dioxide and cancer-causing formaldehyde.

"My gut feeling, based on the numbers that I've seen, is that this is on par with other fires," NASA air quality expert Laura Judd said of the emissions issues plaguing Los Angeles County over the past few days. "There could be some. The difference is just the footprint - the density of people there."

Some potentially good news: While the smoke was intense at its peak, it was short-lived. Experts say other longer-lasting wildfires that produced smoke that lingered longer may have caused more premature deaths than they expected. Wildfire smoke thinned to a gray haze in Los Angeles County over the weekend, and strong winds have helped clear away much of the remaining smoke since Monday.

But that doesn't mean Los Angeles County residents are completely safe. Now, concerns about air quality are shifting from smog to ash. Experts say the vast amounts of wildfire ash and debris covering many neighborhoods across the county may contain high levels of toxic chemicals from fire-damaged homes and cars. Contaminants in burn scars can pose a threat for years.

The South Coast Air Quality Management District has issued a dust advisory since Sunday, warning that strong winds could blow wildfire ash. It encourages people in much of Los Angeles County and neighboring areas to keep their windows closed and continue to wear N95 masks outdoors to protect themselves.

Although recent air quality index readings appear to be safe, officials warn that some wildfire ash is too large to be detected by instruments and will not be captured by air monitors.

While it's unclear whether wildfires cause long-term contamination, NASA scientists are using sensors mounted on aircraft to assess fire damage and potentially detect toxic substances in burn scars. The same type of instrument was used to assess the World Trade Center disaster site after the 9/11 terrorist attacks.

"I hope to use the data we get from (these sensors) to understand toxicity in these environments and how toxic it is when volcanic ash is redistributed by wind and currents," said NASA terrestrial ecology scientist Michael Falkowski. change."

NASA's findings could inform cleanup and recovery efforts expected to last several years.

"We know from other fires, like the Marshall Fire in Colorado, that these environments are highly toxic long after the fire," Falkowski said. "But we still have a lot to learn."