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Wildfire smoke and air quality

Wildfire smoke from Canadian wildfires is polluting air across much of the northeastern US. Explore Stanford research about wildfire smoke, health impacts, and solutions.

Smoky New York skyline
Smoke from Canadian wildfires shrouds the New York City skyline on June 7, 2023. Image credit Kena Betancur Getty Images

Smoke from wildfires in Canada has descended on much of the northeastern United States, darkening skies and prompting warnings to avoid the unhealthy air.

Wildfire smoke contains high levels of the smallest and deadliest type of particle pollution, known as PM 2.5. These specks of toxic soot, or particulate matter, are so fine they can embed deep in the lungs and pass into the bloodstream, just like the oxygen molecules we need to survive.

Stanford-led research shows that wildfire smoke, predicted to be one of the most widely felt health impacts of climate change in the United States, is already unraveling decades of air quality gains. Other studies have shown that exposure to wildfire smoke during pregnancy increases the risk that a baby will be born too early, and when wildfire smoke pollutes the air in schoolyards and classrooms, it hurts not only children’s health but also their ability to learn and possibly their future earning power.

Research from Stanford also points to a range of solutions for individuals, communities, and governments to address wildfire smoke and its impacts, from ways to overcome barriers to controlled burns, to programs for establishing clean air shelters, to tips for setting up a clean air room at home. This collection features recent research and insights from Stanford experts on wildfire smoke, air quality, health impacts, and solutions.

Practical tips to mitigate harm from wildfire smoke

Woman closes window

Warnings of another severe wildfire season abound, as do efforts to reduce the risk of ignition. Yet few are taking precautions against the smoke. Stanford experts advise on contending with hazardous air quality.

July 7, 2021

Stanford News

The shifting burden of wildfires in the United States

San Francisco Bay smoke

Wildfire smoke will be one of the most widely felt health impacts of climate change throughout the country, but U.S. clean air regulations are not equipped to deal with it. Stanford experts discuss the causes and impacts of wildfire activity and its rapid acceleration in the American west.

January 12, 2021

Stanford News

Wildfire smoke is unraveling decades of air quality gains

Yellow wildfire smoke pollution over a residential neighborhood

Stanford researchers have developed an AI model for predicting dangerous particle pollution to help track the American West’s rapidly worsening wildfire smoke. The detailed results show millions of Americans are routinely exposed to pollution at levels rarely seen just a decade ago.

September 22, 2022

Stanford News

U.S. isn’t ready for the next wildfire smoke wave. Here’s what needs to change

parent and child reading on a couch in background, with air filter in foreground

Most government policies for mitigating public health risks from wildfire smoke aim to educate citizens to protect themselves by staying indoors, closing windows, and using air filters. Stanford research shows why that approach fails for Americans across all income groups and points to solutions.

July 7, 2022

Stanford Doerr School of Sustainability

Wildfire smoke exposure hurts learning outcomes

Young students sit at a table with a teacher in a classroom near sunlit windows

Pollution from wildfires is linked to lower test scores and possibly lower future earnings for kids growing up with more smoke days at school, a new study finds. Impacts of smoke exposure on earnings are disproportionately borne by economically disadvantaged communities of color.

September 29, 2022

Stanford Doerr School of Sustainability

Wildfires bring questions about health and climate

California wildfires have destroyed homes and communities, and even people hundreds of miles away are feeling the effects of smoke. Stanford faculty weigh in on the health effects and increasing frequency of fires.

November 15, 2018

Stanford News

California wildfires shrink partisan differences about climate strategies

Wildfire smoke over Sunnyvale

Survey findings suggest that wildfires tearing through the state may bring Democrats and Republicans closer together in support of climate resilience measures.

September 25, 2020

Stanford News

Wildfire smoke exposure during pregnancy increases preterm birth risk, Stanford study finds

Smoky San Francisco

Smoke from wildfires may have contributed to thousands of additional premature births in California between 2007 and 2012. The findings underscore the value of reducing the risk of big, extreme wildfires and suggest pregnant people should avoid very smoky air.

August 23, 2021

Stanford News

Stanford researchers discuss wildfires' health impacts

Wildland firefighters

Massive wildfires bring a host of health concerns for vulnerable populations, firefighters and others. Experts from Stanford’s Sean N. Parker Center for Allergy and Asthma Research discuss related threats, preparedness and ongoing research.

August 26, 2020

Stanford Woods Institute for the Environment

How do people respond to wildfire smoke?

Covid mask

Interviews with Northern California residents reveal that social norms and social support are essential for understanding protective health behaviors during wildfire smoke events – information that could be leveraged to improve public health outcomes.

August 30, 2021

Stanford Earth Matters

Wildfire smoke is worse for kids' health than smoke from controlled burns

Forestry worker observed a controlled burn

Immune markers and pollutant levels in the blood indicate wildfire smoke may be more harmful to children’s health than smoke from a controlled burn, Stanford researchers found.

May 30, 2019

Stanford Medicine

Smoke rising from wildfire on forested hill


New evidence on the health impacts of wildfire smoke

September 22, 2020

Expert panelists discussed health impacts of exposure to wildfire smoke and what individuals and policymakers can do to reduce impacts, now and in the future.

Stanford Woods Institute for the Environment

Wildfire and health: Impacts on the most vulnerable

November 4, 2021

Expert panelists discussed scientific findings highlighting the need for investment in infrastructure that decreases vulnerable populations' smoke exposure and increases wildfire prevention strategies.

Stanford Woods Institute for the Environment

Red sky

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Media Contacts

Josie Garthwaite
Stanford Doerr School of Sustainability
(650) 497-0947;

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