One environmental variable many do not consider when working with their trip weather planner is air quality. However, for many of us, being aware of the air quality is a matter of our own well being.
In this blog, we will cover who is most at risk in poor quality and what types of health problems it can cause. Then we will dig into some of the pollutants found in the air, how they get there and how to get air quality information.
WHO IS AT RISK
Air pollution is the greatest threat to people with breathing sensitivities such as asthma, the elderly or small children because of their smaller, still developing lungs. Those active or working outdoors should also monitor air quality.
HEALTH PROBLEMS
According to the EPA, higher ozone concentrations can:
Cause coughing and sore or scratchy throat.
Make it more difficult to breathe deeply and vigorously and cause pain when taking a deep breath.
Inflame and damage the airways.
Make the lungs more susceptible to infection.
Aggravate lung diseases such as asthma, emphysema, and chronic bronchitis.
Increase the frequency of asthma attacks.
While even healthy people can suffer from these symptoms, they are more severe in people with lung disease such as asthma. Consistent or recurring exposure to ozone is linked to the development of asthma and studies in locations with higher concentrations show an increased trend in respiratory deaths.
POLLUTANTS
In addition to the two primary natural gasses that make up our atmosphere—oxygen and nitrogen—the air also contains many other (some harmful) particles and pollutants. The five big ones are:
Ground level ozone*
Airborne particles*
Carbon monoxide
Sulfur dioxide
Nitrogen dioxide
*Pose the greatest threat to human health
WHAT CONDITIONS CAUSE POOR AIR QUALITY
To address the causes of poor air quality, we first need to clear up some confusion about ozone. “I thought the ozone layer was good?” You are correct! Ozone is a layer of gas high into the atmosphere that helps to block harmful radiation from the sun. Ground level ozone forms due to human created chemical emissions, and this is harmful for us to breathe.
Credit: National Oceanic & Atmospheric Administration (NOAA)
Dangerous airborne particles come from polluting factories, but not exclusively. Natural causes such as volcanoes and wildfires can send large plumes of particles into the air as well.
The weather plays a huge role in determining levels of ozone and airborne particles. Sun, rain, temperatures and winds all affect pollutant concentrations.
The poorest air quality tends to occur during sunny, hot, calm weather. Sunlight reacts with chemicals resulting in the development of smog. Higher air temperatures speed up the chemical reactions. Weaker winds cause the pollutants to settle toward the ground and stay in place.
On the other hand, less desirable weather tends to result in better air quality. Rain washes away and dissolves many pollutants. Stronger winds mix up and spread out the adverse particles.
HOW DO WE KEEP TRACK OF AIR QUALITY
From ground instruments to space satellites, we are able to collect information about possible pollutants in the atmosphere. For instance, in addition to detecting clouds, satellites can find particles from wildfire smoke, dust from sandstorms, ash from volcanoes and even pollutants from industry. Some
measurements come in as quickly as every five minutes while high resolution satellite pictures of the entire planet come in once a day. This is helpful in not only detecting levels, but the movement of pollutants as well.
All of this data is condensed into an Air Quality Index, or AQI. The levels represent the amount of pollution in the air from 0 (low) to 500 (high). Any AQI under 50 means it is safe to be outside with very little risk to health from air pollution. Even beyond this level, it is safe to be outside for the vast majority of people up to 100. Starting at 101, multiple groups with breathing sensitivities need to consider limiting time outside.
One common misperception: an air quality alert means pollen or allergens are high. It does not. The AQI deals strictly with the five major pollutants (listed above) identified by the EPA in the Clean Air Act.
The National Weather Service (NWS) will issue an Air Quality Alert when the AQI reaches those code orange levels (101-150). During an air quality alert, you should choose less strenuous activity than usual; reschedule outdoor activity for morning, evening or another day. If you cannot move plans around, than take more breaks during outdoor activity.
We can actually help reduce air pollution. On Air Quality Alert days especially, all of these steps help:
Don’t burn candles, leaves, garbage, plastic or rubber
Use HEPA air filters and air cleaners designed to reduce particles
Drive less: carpool, use public transportation, bike or walk
Keep car, boat and other engines tuned
Inflate tires to the recommended pressure
When refueling: avoid spills and tighten the gas cap
Choose energy saving appliances
Set thermostats higher in summer and lower in winter
Turn off lights you are not using
A long term weather outlook is not able to provide date specific guidance on air quality because the many factors that affect it, such as weather, are always changing. However, you and your weather planners can access this tool from the EPA to compare the number of unhealthy air quality index (AQI) days in one place versus another.
Bottom line: before a large outdoor event or travel, check in with your local NWS to be sure there are no air quality alerts. Better yet, you can go straight to the source, airnow.gov, and check out the national map, zoom in to the area of interest or get a location forecast by entering a zip code!