Climate change and wildfires
Climate change is making wildfires worse. Greenhouse gases from the combustion of fossil fuels are making much of our planet hotter, which contributes to the severity and duration of many wildfires.1 This trend is projected to increase in the coming decades.2,3
Wildfires across the country are burning more intensely than ever before, and what used to be a set wildfire season now stretches into most of the year.4 Until recently, wildfires have largely been considered a West Coast concern, but no one is immune. Depending on shifts in weather, East Coasters now sometimes inhale more wildfire pollution than West Coasters. We share air and wind connects us all, which is why fires in Canada can result in hazardous air quality in New York City. Wherever they burn, wildfires can have a significant impact on our health.5
What’s in wildfire smoke?
Wildfire smoke is made up of ash, tiny particles, liquid droplets, and gases. The most harmful component of wildfire smoke is fine particle pollution, also known as PM2.5 or soot—a dangerous air pollutant. Each individual bit of solid or liquid in soot pollution is less than 2.5 microns in diameter—smaller than one twentieth the width of a human hair. These tiny particles can become embedded in the lungs and bloodstream.6 Soot is also released from car and truck tailpipes, power plants, and factories.
In the US, wildfire smoke contributes to 15–30% of the soot pollution in the air we breathe.7
Wildfire smoke can also contain toxic air pollutants such as polycyclic aromatic hydrocarbons, benzene, and formaldehyde.8,9 When wildfires reach homes and towns, the smoke can also contain toxic chemicals released from burning flame retardants in furniture and fabrics and other chemicals in building materials.
How does wildfire smoke affect our health?
Immediate health impacts of smoke inhalation can include coughing, difficulty breathing, eye irritation, scratchy throat, runny nose, chest pain, headaches, and asthma attacks. Smoke inhalation can also exacerbate preexisting conditions, like heart disease.10
Wildfires affect people in the immediate area of a fire, but they also send vast amounts of dangerous pollution into communities near and far. Sixty percent of American wildfire pollution happens outside the state where the fire is burning. We currently know less about the health effects of wildfire pollution that travels from a distance than we do about health effects at the site of the fire.11
Wildfire smoke can linger. Cleaning up from fires also exposes people to potentially hazardous conditions, heavy metals in ash and dust, and risk of injury from unstable buildings and debris.
Wildfires can also take a toll on mental health. Living through a wildfire can make people more vulnerable to depression and post-traumatic stress disorder,12 and exposure to soot pollution may be associated with anxiety and depression.13
What are the environmental justice concerns around wildfire smoke?
The impacts of air pollution are not distributed evenly. Communities already impacted by environmental racism are disproportionately burdened by unhealthy air. And other vulnerable communities—including children, older adults, pregnant people, outdoor workers, and firefighters—are also hit harder when wildfires burn.14,15
How to stay safe in wildfires
Make an emergency evacuation plan. Familiarize yourself with your community’s plans,16 and identify public buildings where you live with smoke-reducing air filtration. These may include schools and libraries.
Heed air quality alerts. Rely on phone weather apps to track air quality and act accordingly. You can also access air quality and wildfire information at AirNow.gov.
Prepare a basic emergency supply kit. Gather supplies ahead of time using a checklist like this one from Ready.gov. Make sure to include smoke-protecting face masks. Choose an N95 or better mask to filter fine particles. Regular surgical masks, bandanas, and single-strap masks don’t create a tight enough seal. Make sure to cover your nose and mouth.17
Know the warning signs of smoke inhalation. Early signs of trouble include wheezing, stinging in eyeballs and throat, a feeling of mucous membrane “burn,” chest tightness, and a chronic need to cough. If you have any of these symptoms, get away from the smoke as soon as you can.
Minimize smoke exposure. To keep smoke outdoors, choose a room that can be closed off from outside air, and if possible, set up a portable air cleaner or filter. Follow these instructions from EPA on creating a "clean room" during wildfires.
Keep children safe
Children breathe faster than adults and their small lungs are still developing, making them uniquely at risk. Children with allergies, asthma, or chronic health issues may have more trouble breathing during wildfires. Bookmark these tips from the CDC on protecting kids in wildfires.
Use your voice for healthier air
Use your voice to advocate for strong clean air and climate policy at the local, state, and federal levels. Everything we do to reduce global greenhouse gas emissions now can help reduce the impact of wildfires in the future.
Join Moms Clean Air Force to learn more about the health impacts of wildfires and how you can take action.
Updated: June 2023