Smoke from wildfires is a mixture of water vapor, gases and microscopic particles called particulate matter. The smallest of these particles, known as PM2.5 because they are less than 2.5 micrometers in diameter, pose the greatest threat to human health. They can lodge deep in the lungs and sometimes enter the bloodstream. Earlier this week, PM2.5 levels in the Los Angeles area rose to “hazardous” levels, the highest warning ever US Air Quality Index.
“Wildfire smoke is dangerous to everyone, especially when the particulate matter released occurs in large quantities over long periods of time, as is currently the case in California,” says Zachary Rubin, a pediatric allergist in Chicago and spokesman for the American College of Allergy, Asthma and Immunology.
Inhaling fine particulate matter can cause inflammation in the body. Symptoms can be gentle, such as burning or itchy eyes, runny nose, scratchy throat and headache, to stern breathing problems including difficulty breathing, wheezing, cough, fatigue and chest pain. It may take several hours to several days after exposure for symptoms to appear. In the most stern cases, it increases the risk of premature death.
Children, older adults, pregnant women, and people with heart or lung disease or weakened immune systems are at greater risk of stern side effects. Rubin, however, says anyone can experience respiratory effects from exposure to wildfire smoke, regardless of health status.
“Any level of air pollution, including from wildfires, can be hazardous to health,” says Laura Corlin, an environmental epidemiologist at Tufts University School of Medicine. The level of risk depends on many factors, including your current health condition, distance from the fire and duration of exposure. “A good rule of thumb is that the more exposure, the worse it gets,” he says.
The composition of a fire can also affect human health. As wildfires in California burn homes and businesses, smoke in the region likely carries chemicals released from synthetic building materials that are more toxic than those emitted by burning vegetation.
Residents of Los Angeles County and other parts of the United States can check it out airnow.gov to learn more about the current air quality in your area. Because air quality can change rapidly throughout the day, you should monitor your readings regularly if there is a fire in your area and try to limit your exposure to outdoor air when its quality is indigent. The Watch Duty the app is a good source of information about whether there are fires burning near where you live.
How to protect yourself and others
“The lungs clean the air we breathe in and send it to the heart, and the heart pumps it to the rest of the body,” says Shazia Jamil, a pulmonologist and professor of medicine at Scripps Clinic and the University of California, San Diego. Jamil helped develop guide for the American Thoracic Society on how to stay fit during wildfires.
He says if someone is miniature of breath, wheezes or has an increased respiratory rate as a result of inhaling smoke, it causes the heart to beat faster and can exacerbate pre-existing heart problems. Even fit people can experience chest pain and shortness of breath from inhaling smoke.