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Wildfire smoke poses serious health risks

Wildfire smoke poses serious health risks
Wildfire smoke poses serious health risks

Smoke containing noxious gases, particulates and other harmful substances is causing a pungent haze to blanket millions of people around the globe.

What you need to know about wildfire smoke.

What is contained in wildfire smoke?

Wildfire smoke is more toxic than regular air pollution and can linger for weeks in the air. It can also travel thousands of kilometers.

Wildfires are not limited to burning vegetation. They can also burn vehicles, buildings and their contents. Wildfire smoke contains not only soil particles and biological materials but also metals, plastics, and other synthetic materials.

What are the known health effects?

Kent Pinkerton is co-director of the Center for Health and the Environment, University of California Davis. He said that in laboratory experiments, wildfire smoke caused more tissue damage and inflammation than air pollution. Wildfire smoke has been linked to increased rates of heart attacks and strokes. It also increases emergency room visits due to asthma. In Maryland, a study conducted in 2023 found that wildfire smoke from up to 2,100 km away was responsible for a spike of heart and lung diseases.

Wildfires have also been associated with eye and skin conditions. Wildfire exposure during pregnancy is associated with miscarriage and low birth weight. Californian researchers found that wildfire exposure and placental cellular damage are linked. In a separate study, wildfire smoke inhalation during the third trimester was linked to an increased risk of autism. Exposure can have long-lasting effects. Heart disease rates in Australia remained high for more than two and a half years after the Hazelwood coal mine?fire of 2014. Respiratory illnesses remained high for another five years. In a study published in 2026, wildfire smoke was linked to increased risks of lung, colorectal and breast cancers, as well as blood and bladder cancers. The risks increased with the amount of pollution from the fires. Researchers in California found that exposure to the Camp Fire of 2018 in California led to changes in brain activity and cognition six to twelve months later. Multiple studies now link longer-term exposure to wildfire smoke with increased dementia risk. Californian data also shows an increase in fungus?infections following exposure to wildfire smoke, probably due to the spores present in the smoke.

Is there a safe level of inhaled particles?

Doug Brugge who chairs the Department of public health sciences at University of Connecticut School of Medicine said, "The bad news, there is no safe level" of wildfire smoke particles inhaled. The higher the exposure level, the greater the risk, but these particles can still make people sick even at levels lower than the national safety standard.

Inflammatory responses can be triggered by any amount of particles inhaled. The most vulnerable are children, the elderly, and those with chronic diseases.

Keith Bein, Air Quality Research Center, University of California Davis, says that even in healthy adults, certain effects of exposure, such as sore throats or excessive phlegm and coughing, headaches, and brain fog, can occur immediately and persist for a long time after the smoke plume has disappeared.

What can you do to mitigate the risks?

Experts recommend wearing N95 masks in the presence of wildfire smoke and limiting outdoor activity, particularly strenuous sports. Dr. Jasvinder Sing, a specialist in lung medicine at Medstar Franklin Square Medical Center Baltimore.

Indoor air purifiers capable of trapping particles smaller than 2.50 microns are also recommended by experts. Brugge stated that air purifiers reduced exposure to air pollution and, in studies, the blood pressure and cognitive effects of it. UC Davis provides'simple instructions' for those who can not afford to buy an air purifier. The EPA offers online instructions on how to reduce exposure to wildfire smoke.

Are people safe indoors?

Experts claim that the smoke from wildfires can enter buildings at high concentrations.

Singh stated that the average concentration of wildfire pollutants indoors is half what it is outside.

He said that if a building has poor sealing, it can have a concentration of up to 70% more than what is outside. Through drafty doors and windows, old buildings can expose people to higher levels of pollution. The EPA recommends that people refrain from indoor activities which can cause fine particles to be released into the air. This includes smoking cigarettes, frying food or broiling it, or burning incense or candles.

Bein compared the indoor exposure to wildfire smoke with second-hand smoke.

He said that "the particles... end up all over - on clothes, walls, surfaces and are still outgassing", i.e. being released into air, "after the plume has gone."

What is unknown?

Climate change will likely lead to more frequent wildfires, which means people will be exposed to them more frequently. The health effects of multiple seasons have not been determined.

Bein stated that it is difficult to predict the number of fires, the duration and the type of smoke from the fires.

Researchers are examining the effects of smoke particles on water supplies, crops or livestock. They also examine the effects of wildfire smoke in utero and the effects of extreme heat. Researchers warn that nutrients carried by wildfire smoke can contribute to algal blooms in the downwind area, which could have implications for drinking-water reservoirs and lake ecosystems. Reporting by Nancy Lapid, Editing by Mark Porter

(source: Reuters)