Air quality tells us how much pollution is in the air.
Air we breathe is often contaminated by a variety of gaseous chemicals and tiny solid and liquid particles that either shouldn’t be there at all, or are present at higher concentrations than they should be. We generally call this air pollution. The fewer pollutants there are in the air, the better the air quality.

• The average adult breathes about 3,400 gallons of air each day.
• Air pollution also damages the environment. Acid rain and ground level ozone can harm trees, crops, streams, lakes, and animals as well as buildings, monuments and statues.
• Pollutants can easily move from one area to another as the wind blows, so air quality concerns everyone.

Air quality affects human health in a variety of ways. It can:

• Irritate the eyes, nose and throat
• Cause coughing, chest tightness and shortness of breath
• Increase the severity of lung conditions such as asthma, bronchitis and emphysema
• Increase the risk of heart attacks and strokes
• Contribute to low birth weight

Anyone can suffer health problems due to air pollution, but the most vulnerable groups are:

• Children
• Older adults
• People who already have lung or heart disease

The health effects of air pollution depend on how much pollution a person is exposed to. This is determined by:

• The amount of pollution in the air
• How much air a person breathes in (for example, a runner breathes in more air than someone walking)

Air pollution tends to be a more severe problem in cities, but high levels of air pollution can be found anywhere.

• Keep track of the air quality in your area. Avoid strenuous outdoor exercise or stay inside if the air quality index (AQI) indicates that the air is unhealthy or hazardous.
• Don’t exercise near areas that tend to have poor air quality. For example, don’t go running next to a busy road.
• Do what you can to help reduce air pollution:
  
  • Drive less: walk or bike to work, carpool, take mass transit
  • Make sure your car is properly maintained to reduce pollution.
  • Use less electricity. Power plants can produce a lot of pollution, so using less energy helps reduce air pollution.
  • Recycle. It conserves energy and helps reduce air pollution.

Air monitoring stations around the state measure the levels of different pollutants.
Currently, Colorado is reporting real-time measurements of carbon monoxide, nitrogen oxides, sulfur dioxide, ground level ozone and particulate matter (PM), both PM10 (particles 10 micrometers and smaller) and PM_2.5 (particles 2.5 micrometers and smaller).

The two air pollutants that cause the most problems in Colorado are ground level ozone and PM2.5.
Those are the measures of air quality that are currently included in the Tracking network.

• Ground level ozone is the major component in what we usually call smog. It is measured continuously by air monitoring stations.
• Particulate matter 2.5 (called PM2.5) includes very small particles of dust, dirt, smoke, soot and even tiny drops of liquid. It is called PM2.5 because these particles are between 0.01 and 2.5 micrometers in size. The small size of these particles allows them to get deep into the lungs, which is a health hazard. Air monitors measure PM2.5 hourly in some areas, and either daily or once every third day in other areas.

Urban areas tend to have higher levels of air pollution due to more traffic, power plants and factories.
Because of this, many of the air pollution monitors in Colorado are located along the Front Range corridor from Colorado Springs to Fort Collins, the most densely populated area of the state.
Data from remote monitoring sites is automatically uploaded to the Air Pollution Control Division website every hour, 365 days per year. You can view this data in near real-time to help you make decisions about how to reduce your risk of health problems due to air pollution.

Site locations:
PM_2.5 sites are, as of November 2010, located in all the major Front Range cities from Pueblo to Fort Collins and in Greeley, Cortez, Elbert, Grand Junction, Platteville, and Rifle. There are 19 sites monitoring PM2.5. Of these, eight locations collect only filter samples, two locations collect only continuous hourly data, and nine locations collect both filter sample data and continuous hourly data. Ozone sites are, as of November 2010, located all along the Front Range and in Cortez, Grand Junction, and Rifle. There are 21 monitoring locations for ozone. All of these sites are continuous monitors.

Measurement at filter sites:
Clean filters are equilibrated at a known temperature and humidity, precisely weighed by a microbalance in a laboratory clean-room, shipped to the sites under “chain of custody”, and sampled for 24 hours from midnight to midnight. The filters are collected and sent back to the lab, with associated data, for equilibration and post-weighing analyses. The pre-weight is subtracted from the post-weight to get a net weight. Sampler data, including the volume of air that flowed through the filter for 24 hours, is matched to the lab data using a unique filter ID to get a concentration of the particles in the air. The mass of particles per volume of air is calculated to get micrograms per cubic meter (ug/m3).

Measurement at continuous monitoring sites:
Continuous air monitors use a variety of methods to measure levels of different pollutants in the air. They produce measurements every hour of every day. These measurements are sent by computer to the CDPHE Air Pollution Control Division. You can view this data to help you make decisions to reduce your risk of health problems due to air pollution.