If you have been concerned about wildfires and the smoke they create lately, you are not alone. California and the western United States are experiencing an increasing number of smoky days each year and this year’s wildfires have even caused smoky pollution on the east coast — a disturbing trend that makes good air quality seem more and more like a luxury. Wildfire smoke is a public health hazard because it can impact both outdoor and indoor air quality. Read on for a breakdown of why wildfire smoke is such a concern and what steps you can take to protect yourself and your loved ones from exposure.
What is in wildfire smoke and why is it dangerous?
Wildfire smoke contains two types of air pollution: particulate matter (PM) and gaseous pollutants. Gases found in wildfire smoke can include carbon monoxide, ozone and volatile organic compounds (VOCs). While larger particles are certainly the most visible, tinier particles and gases may travel further from the fire (Black et al., 2017; Kinney, 2008; Prospero et al., 2003; Sapotka, 2005) and can have more significant health effects.
Particle pollution includes both solid particles and liquid droplets, most of which are too small to be seen by the naked eye. These particles come in all shapes and sizes, and their potential to cause health problems increases as they get smaller. Particle size is measured in microns (which is one ten-thousandth of a centimeter). The majority of PM in wildfire smoke falls into the category of “fine particles” measuring 2.5 microns or less.
Fine particles and ultrafine particles (PM smaller than 0.1 micron across) are small enough to get deep into your respiratory system. They can travel through your lungs and into your bloodstream, reaching your internal tissues and organs. Short-term exposure to the PM in wildfire smoke can cause irritation as your body tries to protect you from the pollutants. Symptoms can include runny nose, burning eyes, coughing, wheezing and respiratory illnesses such as bronchitis. Exposure to wildfire smoke has also been linked to increased risk of cardiovascular and respiratory health effects, including allergies and asthma. The PM in smoke can also worsen symptoms of existing heart and lung conditions, especially as the density of the smoke increases.
While the majority of wildfire smoke is from burning trees, everything else in the wildfire’s path (think: cars, homes, etc.) and all the chemicals contained in them also burn, producing more VOCs and toxic gases than you’d find from familiar BBQ or campfire smoke. Communities experiencing wildfires nearby may be at greater risk of exposure to toxic VOCs and ozone, which are far more likely to be absorbed by the lungs and end up in the blood than larger particles which are filtered out by the body’s natural defenses.
According to the Environmental Protection Agency (EPA), people at the greatest risk of health effects from wildfire smoke include:
- Anyone with cardiovascular or respiratory disease;
- Older adults;
- Children under 18 years old;
- Pregnant women;
- People who work outdoors.
Tip #1: Monitor the air quality in your area
If you live in a region where wildfires are common, checking the air quality in your area should be a part of your daily routine. Even if a wildfire is hundreds of miles away, it still has the potential to impact your local air quality. By staying current on the level of smoke and other pollution in your region, you can make informed choices to decrease your exposure to harmful pollutants.
- You can find information on the air quality in your area on AirNow.gov, a free resource provided by the EPA that assigns Air Quality Index (AQI) numbers to describe the current level of air pollution.
- The real-time air quality map from PurpleAir can also help you determine the current level of air pollution where you live.
- Fire.AirNow.gov combines the data from AirNow and PurpleAir sensors to create a map of fire and smoke conditions throughout the United States.
- You can also find air quality information from the National Weather Service, as well as many local news outlets.
Bear in mind that sites that report on air quality may not always agree. Different organizations may use different kinds of sensors to collect their air quality information. Additionally, some sites provide real-time data, while others use a rolling average of air quality measurements over time.
Note: The sensors used by the above organizations only measure PM. They cannot detect VOCs, which can make the air smell like smoke even on a “good” air quality day. If you think it is smoky outside — even if the sites say it is not — trust your gut and take steps to reduce your exposure.
Tip #2: Reduce your smoke exposure outdoors
On days when smoke affects your outdoor air quality, it is best to limit the amount of time you spend outside. You should be especially careful about performing any strenuous outdoor activity, such as running or mowing the lawn, which can make you breathe harder and increase the amount of smoke you inhale.
In addition to avoiding outdoor activities on bad air quality days, you can also use the following tips to help decrease your exposure to smoke outdoors.
- Reduce the number of times you leave the house by keeping enough food and medicine on hand to last you a few days. That way, you can avoid going out when the air quality outdoors is especially bad.
- Pay attention to how the air quality changes throughout the day. When the air quality gets better, try to run any necessary errands as soon as possible before it gets worse again.
- If you cannot avoid going out, make sure to keep the windows rolled up in your car. You can also set your car air conditioner on recirculate mode to decrease the amount of outdoor air entering your vehicle.
- Stay alert for any public service announcements, air quality advisories, or health advisories from local authorities. These can help you decide when and if you should leave the house on smoky days.
Tip #3: Wear a mask when you go outside
If you cannot avoid going outside during smoky conditions, you can wear a mask to help reduce the smoke that you inhale. However, not all masks can effectively filter out the particulate matter in smoke. The cloth masks, bandanas and surgical masks that you collected to help protect yourself and others from COVID-19 will not be able to protect you from exposure to air pollution from wildfire smoke.
Respirator masks, on the other hand, can filter out particle pollution from the air you breathe. These masks work by forming a seal around your mouth and forcing you to breathe through filtered vents in the mask. Look for N95 respirator masks, which can filter out 95% of particles sized 0.3 microns.
Note: Masks that are stamped with “NIOSH” have been approved by the National Institute for Occupational Safety and Health.
Respirator masks may not work as well if you have facial hair, as it can keep them from forming a full seal around your mouth. If you are concerned about smoke exposure, you may want to consider trimming your facial hair to get the most use of your N95 respirator.
Additionally, respirator masks are typically not made to fit children or pets (although there are options for purchase online). If possible, try to keep them from exposure to smoke. If you cannot avoid that, you should look for specially fitted respirator masks for them to wear.
Tip #4: Protect your home from smoke
On this blog, we often talk about increasing the indoor-outdoor air exchange in your home to improve your indoor air quality and keep pollutants from building up to dangerous levels. However, this practice only works if the air outdoors is cleaner than your indoor air (according to the EPA, indoor air is often more polluted than outdoor air, even in large industrialized cities).
During wildfire season, outdoor air can frequently reach levels that are dangerous to breathe. In those cases, it is best to decrease the amount of outdoor air that enters your home in an effort to minimize the presence of wildfire smoke in the house. You can do this by refitting windows, installing new weather stripping around door frames, or even using tape to cover any cracks where outdoor air may enter your home. You should also ensure that whatever measures you take will not make it difficult to leave your home quickly in emergencies.
If securing your entire home against smoke is not practical, you can create a clean air room instead. To do this, choose a room in your home that is big and comfortable enough for everyone in your household to spend the day there together ( a bedroom with an attached bathroom is a great choice). Remember to close all windows and doors to keep smoke from entering the room. Use fans, window air conditioners, or central air conditioning to stay cool while you are in the room. Finally, you should set an air purifier (if you have one) up in this room and run it on its highest setting.
Note: When you are sealing your home against polluted outdoor air, it will also seal in any pollutants you may have inside. To minimize the concentration of pollutants in your indoor air, you should avoid activities that cause pollution, such as:
- Burning candles;
- Frying food;
- Cooking on a gas stove;
- Spraying aerosol products;
Tip #5: Monitor and maintain your indoor air quality
Even if you have sealed your home to keep out smoky air, it is still possible for smoke to make its way indoors. You will also have everyday sources of indoor air pollution affecting your indoor air quality during this time. To keep track of the current state of the air in your home, you can buy an indoor air quality sensor. There are a variety of options available online that can tell you the AQI inside your home.
To keep wildfire pollutants from building up to unhealthy levels, you can use an HVAC filter and air purifier to remove some of the pollution present in your indoor air. If you get a filter for your HVAC system, we recommend getting one with a Minimum Efficiency Reporting Value (MERV) 13 rating, or the highest rating that your system can accommodate. You may need to talk to a technician to ensure that the filter you choose will not keep your HVAC from pushing air through the system efficiently.
If you use an air purifier to help clean the air in your home, look for one rated to handle your specific room size. It’s also worth noting that only certain filters can handle both the particulate matter and certain gaseous pollutants (such as VOCs) present in wildfire smoke. For example, the PECO technology found in Molekule air purifiers can trap and destroy organic pollutants, including both particulate matter and VOCs.
Note: If you live in an area prone to wildfires, you may want to stock up on extra air purifier and HVAC filters before a fire breaks out.
Wildfire smoke contains a mixture of different types of pollution, including particulate matter and toxic gases, and it is important to consider all the airborne pollutants that are ever-present during wildfire season. By taking steps to minimize your smoke exposure and seal your home from outdoor air, you can help protect your health during wildfire season.