Plastic Chemicals in Wildfire Smoke and How to Protect Yourself

Wildfires themselves can be natural occurrences in dry forested areas, but the climate crisis coupled with plastic pollution is making these fires more dangerous, destructive, and frequent. Here’s what to know about plastic chemicals in wildfire smoke—and precautions you can take to stay safe.

Plastic Increases the Dangers of Already Toxic Wildfire Smoke

Breathing in wildfire smoke can cause immediate health issues, including asthma attacks, chest pain, coughing, difficulty breathing, fatigue, headaches, itchy throat, irritation in sinuses, rapid heartbeat, runny nose, stinging eyes, and wheezing. People at the greatest risk of experiencing these and other health problems from wildfire smoke include children and pregnant people, as well as people with chronic health conditions, such as asthma, COPD, diabetes, and heart or kidney disease. Responders such as firefighters are also at greater risk of harm. 

Wildfire smoke typically contains a mixture of gases, water vapor, particle pollution, and toxic compounds known as hazardous air pollutants. Hazardous air pollutants are known or suspected to cause cancer or other serious health effects, including birth defects and fertility and reproductive problems. While some hazardous air pollutants are created when natural materials, such as wood from trees or vegetation, are burned, many come from the burning of plastic.

Today, most modern buildings, homes, and furniture are made primarily from plastics. Plastic appliances, plastic foam mattresses, chairs, and couches covered in plastic fabric; plastic rugs, and other furnishings; to plastic flooring, paints, PVC pipes, roofing, siding, and other building materials are widely used. Both personal and public vehicles are largely made of plastics, and so are synthetic lawns and decking, patio furniture, pools, sheds, and other outdoor items like tools and equipment. The result is a landscape largely made of plastic. 

When wildfires burn through urban and suburban areas, all of these plastics are open-burned, releasing some of the most toxic chemicals into already dangerous wildfire smoke. Plastics contain any mixture of more than 16,000 chemicals, at least 4,200 of which are already known to be toxic to people and the environment. Many of these chemicals are known endocrine disruptors, meaning they interfere with the body’s normal hormone function and can cause serious health problems, especially in children and pregnant people. When burned, some of the most dangerous chemicals that plastics release include:

• Bisphenols: linked to cancer; developmental, learning, and behavior issues; heart disease; infertility and reproductive problems; metabolic disorders like diabetes and obesity
• Dioxins: linked to cancer, developmental problems, liver and other organ damage, skin irritation
• Furans: linked to birth defects, cancer, immune system disease, organ damage, neurological problems, 
• Heavy metals: heart problems, respiratory difficulties, and damage to the kidneys and other organs, and bones
• Nitrogen oxides: reactive compounds that can form fine particulate pollution that embeds itself deep in the lungs, causing severe respiratory diseases like emphysema and bronchitis; can aggravate pre-existing heart problems, leading to early death
• Phthalates: hormone-disrupting chemicals linked to cancer, early puberty, heart and respiratory problems, immune system diseases, infertility and poor birth outcomes, metabolic problems, neurological and behavioral problems
• Polyaromatic hydrocarbons (PAHs), such as benzo(a)pyrene: linked to cancer, and can cause respiratory and skin irritation
• Sulfur dioxide: severe irritant to eyes, nose, respiratory tract, skin, and throat
• Volatile organic chemicals (VOCs), such as benzene: linked to cancer; irritation of eyes, nose, throat; damage of liver, kidneys, central nervous system

What’s more, plastic containers holding cleaning agents, gasoline, pesticides, and other dangerous substances contribute even more toxic substances into the air, and can further fuel fires. Research has shown that microplastics are also released into the air when burned, along with wildfire ash and other particulate pollution. Microplastics have been found throughout the human body, and are known to cause respiratory health problems. Children, whose developing lungs are most sensitive to breathing in particulate matter in the air, are at the greatest risk of adverse health effects from toxic wildfire smoke.

What the Air Quality Index Measures—and What It Doesn’t

Wildfire smoke can travel for hundreds of miles, reducing air quality near and far away from burning fires. Officials often recommend that people living in areas affected by wildfire smoke check local air quality reports. The US Government’s AirNow Air Quality Index (AQI) measures particulate matter (PM) and shows local levels of PM 10—larger particles with a diameter of 10 micrometers or less—and PM 2.5—tiny particles with a diameter of less than 2.5 micrometers, which are the most dangerous because their small size allows them to penetrate deeper into the lungs. 

Home air quality monitors may or may not monitor other sources of air pollution in addition to ozone and PM, including VOCs, radon, and carbon monoxide—making them an imperfect tool to understand the full range of air pollutants present indoors. Wildfire smoke can get into your home, even when windows and doors are kept closed. 

While these measurements can be a useful way for some people to understand the levels of ozone and PM in local air, they do not indicate risks of the full range of wildfire smoke pollutants. Ozone and PM are considered everyday pollutants, while the pollutants in wildfire smoke include complex mixtures of chemicals. Further, wildfire conditions and smoke cover can change rapidly, and there can be a lag in real-time air quality data.

Wildfire ash and chemical residues can persist in the environment long after fires and smoke have cleared. High winds, rain, and other weather events can re-expose individuals in areas affected by fire to pollutants.

How to Protect Yourself

• Experts recommend that adults wear a fitted N-95 mask when outdoors to properly filter particles in polluted air. Note that experts say facial hair can affect the way N-95 masks fit, potentially making them less effective.
  • Check your local libraries and health centers for mask distribution.
  • Cloth masks are not recommended, since smoke particles collect in the material and are breathed in continuously.
  • Surgical masks are also not recommended, since their looser fit allows too much air to get in without being filtered.
• For children, because N-95 masks are not fitted to their smaller faces, it is important to keep young people indoors in “clean rooms” and avoid bringing them outside during and after wildfires.
• Consider wearing eyewear when outdoors (like safety goggles), gloves, and a change of clothes, including shoes.
  • It’s recommended to take off all clothes and shoes worn outside before coming indoors.
• Stay indoors as much as possible and keep all windows closed.
  • Seal gaps around windows and doors.
  • Use HEPA air filter purifiers when possible.
  • Do not exercise or perform strenuous activities, which can draw polluted air deeper into your lungs.

Take Action

All of us, even those who are not immediately impacted by wildfires, face increasing health risks from our increasingly plastic- and chemical-filled landscape and culture. It is crucial that our government representatives protect people and the planet by holding polluters accountable with better pollution monitoring and regulation, and by mandating a drastic reduction in plastic and chemical production globally. A strong UN Plastics Treaty would expedite this necessary systems shift. Urge the leaders of the world’s biggest plastic polluting country—the US Government—to support such an agreement to end plastic pollution today.