California Wildfires: How Smoke Harms Your Body

Wildfires are ablaze across California and they pose a significant threat to residents—not just because of the fire, but also due to the health impacts of breathing in smoke. These can range from a runny nose and tickly throat all the way up to an increased risk of heart attacks and lung cancer. Wildfire smoke is a mixture of gases and tiny particles from burning plants, trees, buildings and anything else that catches fire. Some particulates—tiny pieces of burnt plant matter—are particularly harmful, especially when they measure 2.5 micrometers or less. Dubbed "PM2.5", these particles are more than 30 times smaller than the diameter of a human hair and are dangerous because they can easily travel deep into the lungs, pass into the bloodstream and move into other tissues and organs elsewhere. Apart from PM2.5, gases such as carbon monoxide can be dangerous, as can toxic compounds created from burning plastics and other non-natural materials.

Short-Term Effects of Inhaling Wildfire Smoke

Breathing smoke can cause irritation in the airways, with symptoms such as coughing, a sore or scratchy throat and wheezing. Individuals with existing lung conditions—like asthma, bronchitis or chronic obstructive pulmonary disease (COPD)—may find they experience worse symptoms, such as asthma attacks. The smoke can cause irritation to the eyes, skin, sinuses and nose, possibly resulting in stinging eyes and a runny nose. If the particles travel deep into the lungs or too much carbon monoxide is inhaled, this can reduce oxygen in the blood and may result in fatigue and headaches. Inhaling PM2.5 can increase inflammation in the body, worsening symptoms of people with inflammatory or autoimmune conditions, such as arthritis. Inflammation can make heart, blood vessel and lung health worse, increasing the risk of heart attacks and strokes—particularly among people already at risk, for instance from heart disease.

Long-Term Effects of Inhaling Wildfire Smoke

Inhaling a lot of wildfire smoke can cause permanent damage to lung tissue and increase the risk of conditions such as asthma, COPD, lung cancer and pneumonia. Exposure to wildfire smoke has been linked to an increased risk of heart problems, such as high blood pressure, heart attacks and heart disease. Some substances released when plastics and other materials are burnt may increase the risk of certain cancers when inhaled—such as benzene or formaldehyde. With heightened inflammation in the body, some studies have linked exposure to wildfire smoke with poorer immunity and individuals may find they are more susceptible to falling ill from coughs, colds and infections. Studies have found that people exposed to smoke from wildfires are more likely to experience mental health disorders afterwards, such as post-traumatic stress disorder (PTSD) and depression. Cognitive decline and dementia are also more prevalent among those affected by wildfire smoke. A 10-year study of 1.2 million Californians published in 2024 found that exposure to PM2.5 was strongly associated with future dementia diagnosis. Among pregnant people, studies show that wildfire smoke exposure may affect the baby's development and increase the chances of the baby being born early or underweight.

Who Is Most at Risk From Smoke Inhalation?

Children are more at risk of being affected by wildfire smoke, because their lungs are still developing and they breathe in more air relative to their body weight than do adults. Older adults are more likely to suffer from a heart attack or stroke linked to elevated inflammation levels from PM2.5, and they are more at risk of developing dementia than younger people. People with pre-existing conditions that affect lung or heart health, and smokers, may also suffer more after inhaling wildfire smoke.

What To Do To Avoid Inhaling Wildfire Smoke

Those who live in areas affected by wildfires are advised to stay indoors, keep windows closed, consider using air purifiers, limit outdoor exercise and wear medical-grade N95 masks when outside. Those who are particularly at risk may wish to consider evacuating for their safety. Is there a health problem that's worrying you? Do you have a question about smoke inhalation? Let us know via health@newsweek.com. We can ask experts for advice and your story could be featured in Newsweek.

References

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