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Frequently Asked Questions

Can ground-level ozone rise up to plug the hole in the stratospheric ozone layer?
What can I do to reduce air pollution?
How can I check my local air quality?
How can I protect my health when ozone levels are high?
How can I protect my health when particle pollution levels are high?
How can smoke from fires affect my health?

Can ground-level ozone rise up to plug the hole in the stratospheric ozone layer?

No. The exchange processes between the troposphere and the stratosphere are extremely slow. In fact, usually the air in the troposphere and stratosphere don't mix. However, the air will mix when the tops of giant thunderstorms poke through into the stratosphere.

Ozone is an unstable molecule, and easily mixes with other substances, so when it's created in the troposphere, it doesn't last nearly long enough to get transported into the stratosphere. Chlorofluorocarbons (CFCs) and other ozone-depleting compounds last for hundreds of years, and therefore eventually some get into the stratosphere. At the stratospheric level the increased radiation causes them to break down, and they mix with the ozone. That's why there was a lag from when these gases were first used until the ozone hole was seen, and why there will be another lag before we see the ozone hole disappear. The long life of CFCs and other ozone-depleting compounds also means that even if we could add ozone to the stratosphere, it would be ineffective. A single ozone-depleting compound can react with many ozone particles, so we would have to replace ozone indefinitely, or as long as increased amounts of ozone-depleting compounds remained active in the stratosphere.

What can I do to reduce air pollution?

Keep the Air Cleaner Every Day

When ozone is expected to be high:

  • Conserve electricity and set your air conditioner at a higher temperature.
  • Choose a cleaner commute — share a ride to work or use public transportation. Bicycle or walk to errands when possible.
  • Refuel cars and trucks after dusk.
  • Combine errands and reduce trips.
  • Limit engine idling.
  • Use household, workshop and garden chemicals in ways that keep evaporation to a minimum, or try to delay using them when poor air quality is forecast.

Days when particle pollution is expected to be high.

  • Reduce or eliminate fireplace and wood stove use.
  • Avoid using gas-powered lawn and garden equipment.
  • Avoid burning leaves, trash and other materials.

How can I check my local air quality?

  1. Visit the AIRNOW.GOV
  2. Select "Local Conditions and Forecasts"
  3. Check the Air Quality Index (AQI)
  4. You can also check your local TV stations or newspapers. The AQI or air quality may be discussed with the weather.

How can I protect my health when ozone levels are high?

The brochure "Ozone and your Health" provides information on the health effects of ozone, and what you can do to protect yourself. Ozone and Your Health

How can I protect my health when particle pollution levels are high?

The brochure "Particle Pollution and your Health" provides information on the health effects of particle pollution, and what you can do to protect yourself. Particle Pollution and Your Health.

How can smoke from fires affect my health?

If you are healthy, you're usually not at a major risk from short-term exposures to smoke. Still, it's a good idea to avoid breathing smoke if you can help it. Smoke is made up of a complex mixture of gases and fine particles produced when wood and other organic matter burn. The biggest health threat from smoke comes from fine particles. These microscopic particles can get into your eyes and respiratory system, where they can cause health problems such as burning eyes, runny nose, and illnesses such as bronchitis. Fine particles also can aggravate chronic heart and lung diseases - and even are linked to premature deaths in people with these conditions. How to Protect Your Family from the Health Effects of Smoke

Air Quality Index - AQI
Good
Moderate
Unhealthy for
Sensitive Groups
Unhealthy
Very Unhealthy
Hazardous