The information below is aimed at FCC ride leaders, but it is useful for anyone trying to decide when to cycle (or exercise at all) when we are getting smoke from wildfires. This was last updated August 2022.
Cancellation Guidelines for FCC Rides during times of poor air quality
- Numbers below are from the AQI (Air Quality Index).
- If rides are to be canceled, that should be done by no later than 4 p.m.
- These guidelines are based on several sources, including local medical experts
Up to 100 AQI
Ride should go on as scheduled.
100 to 150 AQI
Ride leaders should consider canceling or modifying ride, depending on the length and difficulty of the scheduled ride. Slower, shorter, easier rides are better than longer, harder rides.
151 to 200 AQI
Ride leaders should consider canceling, especially as the readings get closer to 200. At minimum, reduce the length and difficulty of the ride.
Above 200 AQI
Ride should be canceled.
There are three maps from which to choose when looking for air quality readings. All take a bit of getting used to.
- Purple Air monitors are the most ubiquitous but are not as accurate as more expensive monitors, so the government maps apply a correction to them. In the government maps they are denoted differently (as squares).
- Monitors may update at different intervals. Some update every couple of minutes, while others update every 10 minutes or even hourly.
- The Purple Air map has many “data layers.” Make sure you are using the one titled “US EPA PM2.5 AQI Real Time.”
- Under “Apply conversion” use “US EPA” to apply the U.S. government conversion rate.
- Use your best judgement when referring to this map. Some individual monitors seem to show incorrect data (usually readings that are far too low for the rest of the area) and may be inside buildings. And monitors don’t cover all areas used by FCC rides.
What is PM2.5?
PM2.5 stands for particulate matter (also called particle pollution) around 2.5 micrometers and smaller. Particulate matter is the term for a mixture of solid particles and liquid droplets found in the air. These are so small are so small that they can be inhaled and cause serious health problems. For more see this EPA page.
Advice from Experts
The main concern for high levels of PM2.5 is for people with health issues such as asthma or heart disease, but the pollution can affect even healthy people.
According to Owen Q. Hanley, a retired Fairbanks chest medicine specialist:
“People often believe the harm from exposure comes primarily from long term exposure and any harm from short term exposure is small or quickly reversed, like washing dirt off your hands. This is NOT the case. Within 2 hours of exposure the risk of cardiac arrythmias, stroke and cardiac arrest are increased. This evidence comes from numerous studies on hour-by-hour cardiac arrest data based on PM2.5 levels, review of cardiac pacemaker monitors during spikes in PM2.5, even FMH admission rates for stroke based on daily PM2.5 Levels.”
Owen recommends not exercising if the air is “unhealthy,” when the AQI is above 100.
The government air quality advice is more lenient. (Though Owen says, “I strongly advise against weakening already weak guidelines.”)
Here is the government advice:
- It’s a great day to be active outside
- Unusually sensitive people: Consider reducing prolonged or heavy exertion. Watch for symptoms such as coughing or shortness of breath. These are signs to take it easier.
- Everyone else: It’s a good day to be active outside.
- 101-150 AQI:
- Sensitive groups: Reduce prolonged or heavy exertion. It’s OK to be active outside but take more breaks and do less intense activities. Watch for symptoms such as coughing or shortness of breath.
- 151-200 AQI:
- Sensitive groups: Avoid prolonged or heavy exertion. Consider moving activities indoors or rescheduling.
- Everyone else: Reduce prolonged or heavy exertion. Take more breaks during outdoor activities.
- 201-300 AQI:
- Sensitive groups: Avoid all physical activity outdoors. Move activities indoors or reschedule to a time when air quality is better.
- Everyone else: Avoid prolonged or heavy exertion. Consider moving activities indoors or rescheduling to a time when air quality is better.
See the government activity chart here.
It should be noted that the AQI numbers do not relate directly to parts-per-million of PM2.5. From Owen: “The AQI numbers do not linearly reflect PM2.5 levels: for example, a PM2.5 level of 35 (the EPA maximum) is an AQI of 100. But at an AQI of 200 the PM2.5 level is 150 (six times higher!).”
Unfortunately, studies are unclear on exactly how exposure to PM2.5 affects healthy people. It’s not like poison. You don’t inhale it and automatically become sick. It could affect you in the short term or the long term or both. That depends on length of exposure, intensity of exposure, and individual body chemistry.
According to a recent Fairbanks Daily News-Miner story, most local youth sports organizations cancel outdoor activities if air quality readings are above 150 AQI.
Environmental Protection Agency (EPA) pages