Since the beginning of the year, multiple wildfires have devastated the state of California. The California Department of Forestry and Fire Protection reports that as of October 1, more than 8,100 wildfires have burned over 3.9 million acres in the state, and more than 96,000 residents across the state have been evacuated.
Experts suspect that the fires could continue for several more weeks. The state's peak wildfire season typically lasts from May to October, but reduced snowpack, earlier spring snowmelt, and warmer summer temperatures have increased the length of fire season.
Smoke from the fires has drifted over much of the U.S., affecting the air quality as far away as Washington, D.C. Even if you don't live on the West Coast, it's a good idea to pay attention to air quality warnings where you live. Air pollution is associated with numerous health issues, including heart attacks, worsened asthma symptoms, and an increase in COVID-19 deaths.
How Is Air Quality Measured?
Air quality is measured using the Air Quality Index (AQI), which runs from 0 to 500. The higher the number, the worse the air quality. An AQI value of 0 to 50 is considered good. Some people can experience health effects when the AQI value is between 100 and 200. An AQI value over 200 increases health risks for everyone.
Another important metric is particulate matter (PM) pollution or particle pollution. PM refers to the solid particles and liquid droplets in the air, which can be inhaled and cause serious health effects.
PM is typically classified into two categories. Particles that measure 10 micrometers in diameter are labeled as PM10; dust, pollen, or mold fall into this category, as does wood smoke. PM2.5, or fine particulate matter, comprises minute, inhalable particles that measure 2.5 micrometers in diameter or less. These very small particles pose the greatest health risk and are responsible for reduced visibility or haze. Not only do these small particles remain suspended in the air, but they can also be inhaled deep into the lungs and cause systemic health problems. The higher the PM2.5 level in an area, the greater the health risks.
Short-Term Effects of High PM2.5 Levels
Anyone exposed to high PM2.5 levels will notice immediate effects. Common symptoms include a dry cough, sore throat, and itchy eyes. The small particles can also irritate the lungs, causing inflammation and oxidative stress. Not only does this worsen existing lung conditions, but the inflammation and oxidative stress can also spread to other parts of the body, increasing the risk for heart problems. One study found that exposure to wildfire smoke increases the number of cardiac deaths that occur outside the hospital.
During active wildfires, asthma hospitalizations increase, as do visits to the emergency room for respiratory problems. Ambulance calls for cardiovascular, respiratory, and diabetic conditions rise within one hour of PM2.5 levels increasing, according to a Canadian study published earlier this year.
The risk for stroke increases within a few days of wildfire smoke exposure as well, especially for those with preexisting conditions who are over the age of 65.
A recent Harvard study also found that even a small increase in PM2.5 exposure is associated with an 8% increase in the COVID-19 death rate.
Long-Term Effects of High PM2.5 Levels
Less research has been conducted on the long-term effects of wildfire smoke exposure, but it does have an impact on the body's health. Systemic inflammation can persist for weeks or months, even after the air quality has improved. This could lead to higher rates of cardiovascular problems, respiratory issues, and other health conditions, such as diabetes and dementia.
One study found that wildfire season PM is associated with increased influenza rates, even months after the fires subsided.
What Can You Do?
If you're in an area affected by wildfires, the best thing you can do is stay indoors with the doors and windows closed as much as possible. Not all buildings are well sealed, however. Older buildings especially tend to be draftier and allow more air pollution to enter. Sealing off doors and windows with weather stripping can help.
If you have air conditioning, set it to recirculate the air that's already in your home, rather than bringing in new air from outside.
You may also want to purchase a high-efficiency particulate air (HEPA) filter, which can improve indoor air quality by removing PM. HEPA filters can be expensive, so consider buying a size appropriate for the room in which your family spends the most time. Other less expensive filters may not be as effective but will still offer some protection.
No matter where you live, make a habit of checking the air quality level when you're planning on spending time outdoors, especially if you have underlying health conditions such as asthma or heart disease.
Karen Eisenbraun is a Certified Holistic Nutrition Consultant. She holds an English degree from Knox College and has written extensively about topics related to holistic health, clinical nutrition, and weight management.