Is There Asbestos in That Wildfire Smoke?
How Smoke From Recent Wildfires Can Carry Asbestos and Other Dangerous Contaminants from Burned Structures into Your Home
Wildfires have become increasingly frequent and destructive, especially in areas where human development meets natural landscapes, a region known as the wildland-urban interface (WUI). When wildfires occur in these areas, they don’t just burn trees and grasslands; they also consume homes, vehicles, and infrastructure, releasing a mix of hazardous pollutants into the air. Oftentimes, health authorities will issue an air quality warning, cautioning residents to stay indoors whenever possible and to use personal protective equipment (PPE) when out and about.
Asbestos is one of the most dangerous contaminants found in ashes from older homes and buildings.
These warnings are not something that should be taken lightly. Toxins tend to travel through the air as buildings burn, stirring up mass debris that can contain poisonous gases, chemicals, and other hazardous substances. Lead, mercury, arsenic, polycyclic aromatic hydrocarbons (PAHs), and even asbestos, a well-known carcinogen, can be easily breathed in by anyone nearby.
While asbestos is not the only contaminant in wildfire smoke, it has long been a very real and persistent environmental threat. Used extensively in industry during most of the 20th century, the mineral was added to everything from clothing and curtains to brake pads and construction materials, military artillery, and commonly used household goods. Asbestos was eventually banned in the U.S. in the 1980s; however, its legacy lives on aging infrastructure and vintage products, as well as in goods imported from regions where asbestos has yet to be regulated.
When structures and asbestos-containing products go up in flames, microscopic fibers enter the air. Invisible to the naked eye, these can be inadvertently inhaled or ingested, lodging themselves permanently to internal tissues. The fibers cause inflammation, which, over time, can lead to life-threatening diseases such as lung cancer, asbestosis or mesothelioma.
This article will take a closer look at asbestos and the other dangerous contaminants found in wildfire smoke, the health risks they pose, and the importance of safe handling and proper cleanup efforts in the aftermath.
The Presence of Asbestos in Wildfire Smoke
Asbestos is a naturally occurring fibrous mineral that was once widely used in construction, particularly during the 20th century, due to their fire resistance and durability. Asbestos-containing materials (ACMs) were commonly used in insulation, floor tiles, roofing materials, cement products, and pipe insulation. Though its use has since been restricted in many countries, as mentioned previously, older infrastructure can still contain asbestos, exposing those nearby as building age or fall victim to natural disasters like wildfires.
When a wildfire sweeps through an urban area, it can incinerate homes and structures built before asbestos bans and restrictions. The intense heat can break down ACMs, releasing microscopic fibers into the air. Once airborne, these fibers can travel long distances, mixing with smoke and ash. Inhalation of asbestos fibers is hazardous, as they can lodge in the lungs and lead to severe health conditions.
Health Risks of Exposure
Exposure to wildfire smoke laden with asbestos and other toxic compounds can have both immediate and long-term health consequences. Some of the immediate issues include:
Respiratory distress – Fine particulate matter can cause coughing, shortness of breath, and irritation of the eyes, nose, and throat.
Neurological effects – Exposure to heavy metals like lead and arsenic can result in headaches, dizziness, and cognitive impairments.
Skin and eye irritation – Contact with toxic ash can lead to rashes, burns, and eye damage.
Unfortunately, the health threats caused by contaminated smoke don’t end there, either. Over time, internalized toxins can lead to more significant consequences, including:
Mesothelioma – A rare and aggressive form of cancer, breathing in asbestos fibers can eventually lead to this deadly disease, which commonly impacts the lungs, abdomen, heart, or testes in men. Mesothelioma is both difficult to diagnose and difficult to treat, with proper diagnoses often arriving too late for treatments to be effective.
Lung cancer – One of the more lethal forms of cancer, asbestos exposure significantly increases a person’s chances of being diagnosed with lung cancer, particularly if they also smoke. In fact, smokers exposed to asbestos are up to 90 times more likely to develop this form of cancer at some point in their lifetime.
Chronic respiratory conditions – Prolonged inhalation of toxic particles can lead to, or make worse, respiratory conditions like asthma, emphysema, COPD, and fibrosis. Asbestos exposure can also lead to respiratory difficulties even in the absence of these diseases, including chest tightness and a chronic cough.
Cardiovascular disease – Already known as one of the leading causes of death in adults, studies have linked wildfire smoke exposure to an increased risk of cardiovascular events such as heart attacks and strokes.
How Asbestos Spreads in Wildfire Smoke
The spread of asbestos fibers in wildfire smoke depends on several factors, including wind conditions, fire intensity, and the composition of burned structures. When homes and commercial buildings are reduced to ash, asbestos fibers can become encapsulated in the smoke plume, traveling miles from the original site of the fire. This means that people far from the fire’s location may still be at risk of exposure, particularly if they breathe in contaminated air or come into contact with deposited ash.
Even after a wildfire is extinguished, asbestos contamination remains a persistent concern. Settled ash on rooftops, soil, and other surfaces can easily become airborne again through wind disturbance, cleanup activities, or rebuilding efforts. Without proper safety measures, individuals may unknowingly inhale hazardous fibers during post-fire recovery. Asbestos has also been known to contaminate soil and water supplies for a long time to come, presenting an ongoing environmental hazard that can be particularly detrimental to those who come into contact with this contamination in their food, drinks via other everyday activities like watering crops or showering.
Other Hazardous Substances Released in Urban Wildfires
A study published in PNAS Nexus highlights the significant health risks posed by urban wildfires, outlining the specific toxins that have been present in these plumes. In addition to asbestos fibers, the study identifies numerous toxic emissions from burning buildings, including all of the following:
Particulate Matter (PM)
PM2.5 and PM10 – Tiny airborne particles that can penetrate deep into the lungs and enter the bloodstream, leading to respiratory and cardiovascular issues.
Heavy Metals
Lead – Can cause neurological damage, particularly in children.
Arsenic – A carcinogen linked to lung, skin, and bladder cancers.
Cadmium – A toxic metal that can cause kidney damage and respiratory issues.
Chromium – Some forms, like hexavalent chromium, are highly carcinogenic.
Mercury – Can cause neurological and developmental issues, especially harmful to children and pregnant women.
Toxic Gases
Carbon Monoxide (CO) – Reduces oxygen delivery to organs and tissues, leading to dizziness, confusion, and even death at high concentrations.
Hydrogen Cyanide (HCN) – Released from burning plastics, it interferes with the body’s ability to use oxygen and can be fatal in high doses.
Hydrogen Fluoride (HF) and Hydrogen Chloride (HCl) – Corrosive gases that cause severe lung and respiratory irritation.
Sulfur Dioxide (SO₂) and Nitrogen Oxides (NOₓ) – Contribute to acid rain and can cause respiratory problems and aggravate asthma.
Volatile Organic Compounds (VOCs)
Benzene – A known carcinogen that can cause leukemia and other blood disorders.
Toluene, Xylene, and Styrene – Affect the nervous system and can cause headaches, dizziness, and long-term neurological damage.
Formaldehyde – A respiratory irritant and carcinogen.
Polycyclic Aromatic Hydrocarbons (PAHs)
Found in smoke from burning organic materials, these are carcinogenic compounds that can cause DNA damage and increase cancer risk.
Dioxins and Furans
Extremely toxic and persistent environmental pollutants released when materials like PVC plastic and treated wood burn.
Can cause immune system damage, reproductive issues, and cancer.
Isocyanates
Found in polyurethane products, these chemicals can cause severe asthma and other respiratory issues.
Pesticides and Herbicides
If stored chemicals or treated fields burn, they can release toxic fumes that are hazardous to both humans and animals
The research team pointed out that toxic species emitted from urban fires are present in concentrations several orders of magnitude higher than those from purely wildland fires, pointing to the profound health risks associated with WUI fires, specifically.
Persistence of Toxins in the Environment
The environmental persistence of these hazardous substances adds to their danger. Lead, arsenic, and cadmium can remain in the soil for years, making contaminated areas unsafe for habitation and agriculture. Additionally, PAHs and dioxins can infiltrate water supplies, affecting drinking water quality and aquatic ecosystems. The long-term impact of these toxins requires ongoing monitoring and remediation efforts.
Case Studies: Los Angeles and Maui Fires
Case studies from the recent Los Angeles and Maui fires have shown that executing even the most comprehensive cleanup efforts during and after these fires may not be enough to fully eliminate the long-term health risks that result..
The Los Angeles Fires
Los Angeles has seen numerous devastating wildfires over the years. The most recent Los Angeles wildfires, for example, burned through residential areas, raising concerns about toxic smoke exposure. As schools and public spaces reopened, parents worried about the lingering presence of toxic ash, which can contain asbestos and other hazardous materials. Despite extensive cleanup efforts, many residents remained concerned about the long-term health effects of exposure to fire-related toxins.
The Maui Lahaina Fire
The 2023 wildfire in Lahaina, Maui, was one of the deadliest in U.S. history. The fire destroyed thousands of homes and buildings, leaving behind a toxic layer of ash. Experts warned that the debris likely contained asbestos, arsenic, and heavy metals, posing severe health risks to returning residents. Local authorities advised residents to wear protective gear when sifting through the debris and to avoid disturbing ash piles.
While the risk of exposure to asbestos and other hazardous substances in the aftermath of wildfires can persist for a long time to come, taking measures to ensure proper cleanup protocols are followed can decrease this risk. Before rebuilding or reoccupying a burned site, it is essential to test for asbestos and other hazardous materials. Professional environmental testing companies can assess contamination levels and provide guidance on safe removal.
Testing should include air quality assessments, soil sampling, and water testing to ensure that toxic substances have not infiltrated the surrounding environment. Regular monitoring should also be conducted throughout the cleanup and rebuilding process to prevent prolonged exposure. Random sampling in the months and years to follow can also help health authorities determine whether additional precautions should be taken to protect the public from ongoing environmental risks.
If asbestos fibers are found, abatement must be handled by certified professionals who follow strict safety protocols. Improper removal can lead to further contamination. Property owners must comply with regulations concerning asbestos handling and disposal. Otherwise, they may face serious financial and legal liabilities.
Conclusion
Wildfire smoke in urban areas contains far more than just burnt wood and plant material—it can carry asbestos, heavy metals, and other toxic pollutants from destroyed buildings. As seen in the Los Angeles and Maui fires, the aftermath of urban wildfires poses long-term risks to both human health and the environment. Proper testing, professional abatement, and adherence to safety regulations are essential in minimizing these risks.
While it’s difficult to control when and where wildfires break out, by taking necessary precautions, communities can reduce exposure to hazardous substances and ensure safer rebuilding efforts in wildfire-prone regions. Future generations depend on this due diligence.