Monitoring air quality is often far from the minds of coaches and athletic administrators while preparing for the school year. However, smoke from wildfires has been increasingly disruptive the past few years to athletic practices and competitions throughout the western United States. This past spring, Hawaii experienced poor air quality as a result of volcanic activity!
Athletes are at special risk of inhaling air pollutants during exercise for several reasons. The increased respiratory rate during exercise results in the intake of 10 to 20 times the normal volume of air every minute. A larger fraction of air is inhaled through the mouth during exercise, bypassing nasal filtration, and the increased velocity of respirations forces air (and particulate matter) deeper into the lungs.
Air pollution has long been known to worsen the symptoms of asthma and other respiratory diseases. In athletes without asthma, the effects of air pollution upon athletic performance and the long-term consequences of exercising in air pollution are not well understood. There is some evidence to indicate that chronic exposure may adversely affect blood vessels throughout the body, but more studies are needed before making definitive statements.
There are two key sources of air pollution that may exacerbate asthma or potentially affect the lungs in other ways: ozone and particle pollution. Ozone is found in smog and is often at its worst in the late afternoon and early evening on hot summer days. It forms through a variety of complex chemical interactions, all of which require sunlight as a catalyst. Ozone can travel significant distances and, contrary to conventional wisdom, is more predominantly a pollutant in rural areas.
While ozone is important, our focus is on particle pollution. This type of air pollution may arise at any time of the year, and can be especially bad when the air is still. Particle pollutants can be at high levels near busy roads, pollutant-emitting factories and, at times, when there is smoke in the air from wood stoves, fireplaces or wildfires. Smoke from late summer forest and grass fires may cause severe air pollution coinciding with the beginning of the fall sports season. Other potentially harmful air pollutants include carbon monoxide, nitrogen oxides and sulfur dioxide.
The Air Quality Index (AQI) is a system developed by U.S. Environmental Protection Agency to help the public determine if air quality levels in a specific location are good, moderate, unhealthy or hazardous. The AQI describes the general health effects associated with different pollution levels, as well as whatever precautionary steps may need to be taken if air pollution levels rise into the unhealthful range. During times of suspected high air pollution, the AQI should be checked prior to all practices and contests. A particular location’s AQI can be found at https://www.airnow.gov/.
The AQI measures five separate air pollutants (particulate matter, sulfur dioxide, carbon monoxide, nitrogen dioxide and ozone), and converts the measured pollutant concentrations in a community’s air to a number on a scale of 0 to 500. The intervals on the AQI scale relate to the potential health effects of the daily concentrations of each pollutant. The most important number on this scale is 100, as this number corresponds to the National Ambient Air Quality Standard established under the Clean Air Act. An AQI level greater than 100 indicates that a pollutant is in the unhealthful range whereas an AQI level at or less than 100 indicates that a pollutant is in the satisfactory range.
Most western states have additional online resources to track air quality. These websites may use the AQI or a PM2.5 concentration. PM2.5 describes fine inhalable particulate matter with diameters that are generally 2.5 micrometers and smaller. There also may be variation on recommendations as to whether you should use 24-hour, 8-hour or 1-hour measures.
The important thing to note is that the health effect category (color coding) is generally consistent across these different tools. A red “unhealthy” day will be the same whether it is reported as an AQI or a PM2.5 value. You can always contact your state or local health department to learn more about how this data is reported.
Putting an air quality policy into practice is the next step. First, locate the nearest air monitor to your practice and competition venues. Go online to https://www.airnow.gov. Enter your zip code to get the readings at your closest monitor.
Not all schools and venues will have a nearby monitor, and weather variation (wind) and geographic features (hills and valleys) can account for large differences between relatively close locations. While the DEQ has increased the number of monitoring stations across the state, not all schools or athletic facilities will have a nearby monitoring station. Therefore, you must be familiar with the 5-3-1 Visibility Index Method. Based on previous air pollution research, we know that there is a correlation between air quality and visibility. While this method does allow some room for error, remember student, staff and spectator health is more important than completing a practice or competition.
On a clear day, use Google maps to locate three landmarks that you can see from your venue. If you use multiple venues, you will need to do this for each separate location. The landmarks you choose should be 1 mile away, 3 miles away and 5 miles away. When using this method, make sure the sun is behind you. When the outline of the landmark can no longer be seen, then the visibility range is less than the mile marker.
For example, if you have a cell tower that is located 5 miles from your stadium and you cannot see it, the visibility range is less than 5 miles. This estimate puts you in the Orange Category. When the air is smoky and hazy, monitoring the AQI or the Visibility Index should be done at least hourly during competitions and practices as conditions can change quickly.
Some students will be more susceptible to the health effects of poor air quality. The Preparticipation Physical Examination will identify at-risk students. At-risk conditions include asthma, respiratory infections and chronic heart or lung disease. Students diagnosed with asthma should have an Asthma Action Plan that they follow if symptoms occur during or after exercise. All schools must have an Emergency Action Plan in place for every practice and competition venue in case of respiratory or other medical emergencies. If poor air quality persists over several days, those who are susceptible may have symptoms triggered more easily, and those without pre-existing conditions may start to notice effects of the sustained poor air quality.
If the health effect category is in a zone where your state health department does not allow outdoor activity, all practices and games must be moved indoors or cancelled. Please check with your maintenance staff to ensure proper HVAC systems are in place to provide properly filtered indoor air. If this is not in place, indoor air quality may be worse than the outdoor air and, therefore, it is not appropriate to practice or work out indoors.
Also, when moving indoors, heat and hydration guidelines must be followed as temperatures may be hotter inside a gymnasium on a hot summer day than outside. If indoor practices are not an option, practices may be held earlier in the day to avoid warmer temperatures, or moved to a location with better air quality. Please note that all of the above principles should also be followed for physical education classes and other outdoor activities involving physical activity for students and staff.
The graphic – “Public Health Guidance: School Outdoor Activities During Wildfire Events” – was produced by the Oregon Health Authority and reprinted with permission of the OHA. The document is available through the following link: https://apps.state.or.us/forms/served/le8815H.pdf
Additional Resources for Western States:
Corrie Arnold, MS, ATC, is a certified athletic trainer at Willamette High School in Eugene, Oregon. Brian Michelotti is assistant director of the Montana High School Association in Helena, Montana. Brad Garrett is assistant executive director of the Oregon School Activities Association in Wilsonville, Oregon. Michael Koester, M.D. is a pediatric sports medicine specialist at the Slocum Center for Orthopedics and Sports Medicine in Eugene, Oregon where he also directs the Slocum Sports Concussion Program. He is the chair of the NFHS Sports Medicine Advisory Committee (SMAC).