As fires rage in the Los Angeles area, the health risks from air pollution mount. Here’s what to know.
The fires burning across Los Angeles County have sent billowing plumes of black smoke into the air, posing a major health threat even as quick-moving flames have blowtorched homes, schools and other buildings.
As the fires rage and air quality worsens, the risk of health problems escalates. That’s because wildfire smoke contains fine particulates, known as PM2 .5, which are one-seventieth the width of a single human hair and can easily infiltrate the heart and lungs.
While the fires are currently concentrated on the West Coast, the threat isn’t limited to that region. Residents nationwide need to be cautious because wildfire smoke can travel, said Susan Anenberg, chair of the environmental and occupational health department at George Washington University.
“The smoke is not containable. The smoke goes where it goes,” Anenberg said.
Here’s what you need to know about the health effects of wildfire smoke and how to protect yourself.
What are the components of wildfire smoke?
PM2.5 from wildfire smoke is an invisible yet dangerous component of smoke and soot.
Wildfire smoke is particularly harmful because it includes other hazardous chemicals produced from burning common household products such as electronics, plastics and aerosols, Anenberg said. The mix of materials from homes, vehicles and buildings is enough to cause concerns about short- and long-term biological harm, she said.
What are the health risks of smoke exposure?
PM 2.5 particulates are so small that they can travel through your lungs and even enter the bloodstream. According to the Environmental Protection Agency, PM2.5 “is the air pollutant of greatest concern to public health from wildfire smoke.”
“Once [the particles are] in the bloodstream, they can affect every organ of the body,” Anenberg said.
And the harmful particles aren’t isolated to outdoor air: Even indoor air can be affected by air pollution and can cause health damage.
Exposure can trigger short-term respiratory problems such as coughing, wheezing, difficulty breathing and asthma exacerbation, according to the EPA. Breathing in smoke can also irritate your sinuses, throat and eyes, according to the Centers for Disease Control and Prevention. Anenberg said black particles in your nose also indicate exposure.
In more severe cases, exposure is linked to heart attacks and stroke, as well as lung cancer and damage to cognitive functions. A growing body of research also links wildfire smoke to long-term neurological effects such as dementia and Alzheimer’s disease.
“Whether or not those turn into some health outcome, some subset of people that have that exposure will experience effects and cardiovascular effects,” Anenberg said.
Is it safe to breathe wildfire smoke? And in what quantities?
The EPA strengthened its limits on fine particulate matter in February, lowering the annual soot standard to 9 micrograms per cubic meter of air, down 12 micrograms. But the maximum allowable concentration of PM2.5 in the air according to the National Ambient Air Quality Standards is still 35 micrograms per cubic meter over a 24-hour period.
During wildfires and smoky conditions, however, concentrations tend to get higher. Anenberg said health effects are possible even when concentrations are at or below the EPA threshold.
The Air Quality Index — a measure of outdoor air pollution — can also be a helpful tool in determining the safety of air. The index ranges from 0 to 500. An AQI below 50 is considered healthy, or Code Green. Code Orange indicates that the AQI is between 101 and 150, which can affect sensitive groups but is unlikely to affect the general public. Code Red, 151 to 200, means that the air is unhealthy for more members of the public. Code Purple, 201 to 300, means that everyone faces increased health effects. Code Maroon, 301 to 500, is considered hazardous for everyone and could trigger strong irritations and health effects for the general public.
To Irva Hertz-Picciotto, director of the University of California Davis Environmental Health Sciences Center, the more particulate matter people breathe, the higher their risk of respiratory issues and other adverse health outcomes.
“We know that the more particulate matter, the worse,” she said.
How deadly is air pollution?
PM2.5 smoke in general is associated with premature death, Anenberg said. “These fine particles are some of the worst offenders when it comes to global health risk factors,” she said.
The World Health Organization states that indoor and outdoor air pollution is associated with 7 million premature deaths annually. Research published by the Lancet Planetary Health journal found that air pollution continues to be the world’s largest environmental health threat and accounted for 6.7 million premature deaths in 2019.
Children, the elderly and those with preexisting conditions are most vulnerable to high levels of PM2.5, said Joel Kaufman, professor of environmental health and medicine at the University of Washington, and it can lead to death in some cases.
What you can do to protect yourself
Everyone is vulnerable to the risks posed by wildfire smoke — even healthy people, according to the CDC.
Here’s what experts suggest you do to keep yourself safe:
- Remove yourself from the threat. If you’re under an evacuation order and are able to evacuate, do it. Moving away from the flames could help reduce your level of exposure. While driving, put the air on the recirculate setting.
- Wear a mask. The type of mask matters. Because the particles from wildfire smoke are so fine, experts recommend wearing an N95 mask — which we are all familiar with from the pandemic — to block particles.
- Reduce your exposure. Close your windows and doors to protect the indoor environment. You can try to filter the particles before they enter your home by using an air filter or a heating, ventilation and air-conditioning (HVAC) system with good-quality air filters. A portable air purifier can also help. “You want to be trying to remove the particles from the outdoor air before it gets into the indoor environment or remove it from the air once it’s within the indoor environment,” Anenberg said.
- Be aware of your local air quality. Numerous apps and websites provide real-time data on air quality.