Frequently Asked Questions

We breathe over 3,000 gallons of air each day. Children breathe more per pound of body weight than adults. Poor air quality can cause immediate effects and also problems that don’t show up for years. Too many pollutants in the air we breathe has been found to cause low birth weight, heart attacks, reduced lung function, asthma and trigger asthma attacks. Some toxic air pollutants cause or are suspected of causing cancer, birth defects, reproduction problems, and damage to the immune system.

There are four general categories for sources of air pollution. These are mobile sources (cars, trucks, buses, planes, and trains), area sources (agricultural areas, cities, wood burning fireplaces), stationary sources (power plants, oil refineries, industrial facilities, factories), and natural sources (wildfires, volcanoes, wind-blown dust). Industrial activities and driving cars and trucks are the greatest sources of air pollution in Colorado. Sources of air pollution are diverse, change, and sometimes it’s not very clear exactly where the pollution comes from, especially for pollutants that are created in the atmosphere instead of directly emitted. Other sources of pollution can be small but because there are thousands of them, they collectively produce a lot of pollution. Each fireplace that emits smoke, each can of solvent in a garage that is not tightly capped, or each spill of a few drops of gasoline as we fill the tank of our car add up and contribute to poor air quality.

Knowledge and awareness of air quality and how it can affect you and your family is a great way to start reducing your exposure. This may be as simple as knowing when is best to exercise or play outdoors. Unfortunately, some pollutants can pose a health risk even when you’re indoors. If dealing with PM 2.5, a specialized filter can help reduce exposure risks. Be mindful of the AQI advisories and forecasts from the APCD or EPA and their health recommendations.

There are actions we can individually take to lower the amount of pollution getting into our air. Combining car trips to reduce the number of miles driven will reduce the exhaust that is produced by cars and trucks. If you’re able, consider walking, biking, or taking public transit to run those errands. On hot summer days, use gas-powered lawn equipment and pump gas after 5pm. Remember: each fireplace that emits smoke, each can of solvent in a garage that is not tightly capped, or each spill of a few drops of gasoline as we fill the tank of our car add up and contribute to poor air quality.

The Air Pollution Control Division posts air quality advisories and forecasts for Colorado at the Colorado Air Quality Summary page.The AirNow app provides real-time air quality information that you can use to protect your health while planning your day:AirNow mobile app.Air quality forecasts and real-time info can be found on EPA’s AirNow website.airnow.gov.Next day air quality forecasts for more than 400 cities across the US are posted daily by 4:40pm.

The CAA requires EPA to establish National Ambient Air Quality Standards (NAAQS) for six common air pollutants also known as “criteria” air pollutants.

In Colorado, an Action Day means that either current air quality is unhealthy or conditions are expected to worsen later in the day or on the next day. In the summer: an Action Day for ozone and/or PM2.5 triggers a ban on open burning. In the winter: an Action Day for Visibility leads to restrictions that limit indoor burning to approved devices only, voluntary driving reductions, and public health recommendations.  

An ozone design value (DV) is the metric the U.S. EPA uses for assessing compliance with the NAAQS. It is calculated as a three year average of the annual 4thhighest maximum daily 8-hour average concentration. For ozone, there are two NAAQS that Colorado must show to be in compliance: the 2008 NAAQS at 75 ppb and the 2015 NAAQS at 70 ppb.