Just as we watch the forecast for rain, cold, and wind, air quality is now part of planning a VBC ride. During fire season especially, smoke can make outdoor exercise unpleasant or unhealthy even when the sky looks clear. This page explains the Air Quality Index (AQI), how the club uses it, and where to check conditions before a ride.

The Air Quality Index is the EPA's scale for reporting daily air quality, from 0 (cleanest) to 500. The pollutant most relevant to cyclists is PM2.5: fine particles from wildfire smoke and vehicle exhaust that are small enough to reach deep into the lungs. Cyclists are more exposed than most because we breathe hard, through the mouth, for hours at a time. Exercise multiplies the dose: a rider working hard can inhale many times more air, and with it more pollution, than someone at rest — by some estimates up to 18 times more. Those particles trigger inflammation and limit oxygen delivery to working muscles.

The standard AQI categories, as defined by the EPA and the Washington Department of Ecology:

For more background, see AirNow's AQI basics.

Ride postings include this line:

These are considerations, not rules. The club is not defining medical safety thresholds; we are providing a common reference so leaders and riders can make informed, personal decisions. Canceling is not the only response, either: any time the AQI is above 100, consider shortening the route or easing the pace — a shorter, easier ride simply moves less air through your lungs.

These tiers are consistent with EPA guidance, which calls for reducing prolonged or heavy exertion at AQI 151–200 and avoiding it above 200. Cycling is exactly that: prolonged, often heavy exertion, sustained for hours. Health organizations that address exercise specifically, including the American Lung Association, note that people with heart or lung conditions may be affected at lower levels. If that describes you, a lower personal threshold is entirely reasonable.

A ride leader's decision to proceed means the ride is on. It does not mean the ride is right for everyone registered. Sensitive groups are not a small minority in a club like ours: they include adults over 65, people with chronic heart or lung disease, people who are pregnant, and people with diabetes. Many riders who fit these categories think of themselves as low-risk; for air quality purposes, they are not. If you have any questions about the AQI level at which you should avoid outdoor activity, and cycling in particular, talk with your healthcare provider. They know your health history; the club and your ride leader do not. If conditions concern you, dropping out is always a legitimate choice, on any ride, at any number.

Use IQAir's Vancouver, WA page for current readings and forecasts. The forecast is the reason we recommend this source: it lets you plan a day ahead, not just react at the start line.

During active smoke events, the EPA/USFS Fire and Smoke Map is a useful second source. It incorporates local low-cost sensors and shows smoke plumes, but reports current conditions only.

• Washington Department of Ecology: Air Quality Index
• EPA Air Quality Guide for Particle Pollution (PDF)
• American Lung Association: Air Quality and Exercising Outdoors