What AQI is safe and what to do on bad air days
Dr. Grant Lipman
Grant S. Lipman, MD, is a clinical assistant professor of surgery in the division of emergency medicine at Stanford University and associate director of the wilderness medicine fellowship at Stanford University School of Medicine.
AQI is the Air Quality Index, a measurement that tells us how polluted the air is by calculating these five major pollutants:
- ground-level ozone
- carbon monoxide
- sulfur dioxide
- nitrogen dioxide
- particulate matter
Ranging from 0 to 500, the higher the AQI number is, the worse the associated health effects are. Safe outdoor exercise starts to decrease as the range of AQI increases above 100. As the climate becomes more extreme, wildfires and their resulting AQI hazards are also on the rise. Whether you live in the woods, the ‘burbs, or an urban city, we’ve all experienced by now how wildfires can impact our AQI from many states away.
Particle pollution from wildfires can hurt your airways
Wildfire smoke is a complex mixture of:
hazardous gasses + air pollutants + particle pollution
The particles can be a mixture of solid and liquid droplets suspended in the air and are very small (2.5 microns and smaller, about 30 times smaller than a strand of hair).
Particulate matter irritates the eyes and mucous membranes lining your throat. The tiny size means these particles can travel deep into your lungs. When inhaled, they can cause irritation, wheezing, shortness of breath, and flare underlying lung diseases, causing a dangerous breathing situation.
Learn about breathing problems
Is it safe to exercise in high AQI?
Is there a way to circumvent the poor AQI and still get your trail run in outdoors? Unfortunately, the short answer is no.
If you need to go outside, the only thing you can do is wear a mask. Since the particles specific to wildfires are so small, you need a special mask that blocks particles 3 microns and smaller. These are the N-95 masks, which are tight-fitting and block 95% of small particles all the way down to 0.3 micron in size.
Surgical masks will only block the larger particles. And cloth face coverings won’t block smaller particles.
These hikers might be staying COVID-safe, but their masks aren’t protecting them from particle pollution; only the N-95 mask will help filter out the small wildfire particles.
But even with the proper N-95 mask on, it won’t stop the smoke from irritating your eyes and skin. So on bad AQI days, it’s just best to stay indoors and try out that new workout video.
General tips for lowering risks from high AQI
If there are wildfires or poor AQI in your area, follow these tips to lower your health risks:
🏠 Stay inside on higher AQI days. Close windows and doors. Run any air purification devices if you have them.
🫁 Be extra cautious if you have any underlying lung disease. Follow local guidelines and instructions from your doctor. Make sure you have any medications you need.
💤 Get plenty of rest and avoid overexertion to help the immune system fight off viral infections.
📳 Turn on GOES push notifications to receive up-to-date alerts when the AQI is unsafe or if there are any wildfire threats nearby.
High AQI levels are here to stay
With drought, warming climate, and unpredictable weather patterns abound, wildfires and high AQI levels are more common than ever. Knowing what to do to take care of yourself in these conditions will come in handy if you’re planning an expedition, exercising outside, or are just sensitive to polluted air.
No matter where you are, stay on top of the AQI and other environmental health risks with GOES, your pocket guide to outdoor safety.
