Air Quality Awareness Week: How do I make my air quality data count?

Some of the Air Quality Monitoring Team with a SensOR outside the Lab in Hillsboro (L to R): Luke Mattheis, Tom Roick, Dan Johnson and Anthony Barnack.

It’s Air Quality Awareness Week and the DEQ Laboratory and Environmental Assessment Division (You may know us as “The Lab”) thought it a great time to address one of the most common questions we receive: What is the difference between air quality data collected by DEQ and that collected by people with low-cost sensors? As scientists, we might frame the question as so: How do I collect data of known quality?

 (L to R): Natural Resource Specialists  Chris Modderman and Peter Husted record air quality data in the shed at a local monitoring site.

To determine “known quality,” DEQ follows methods and procedures established by the U.S. Environmental Protection Agency that ensure the accuracy of our measurements. In addition, we frequently maintain, repair and calibrate our more than 60 monitors across Oregon. The information shows up on our Air Quality Index.

The AQI records consistent data across the state so we can examine trends in smoke, ozone, nitrogen dioxide and more. We use it when working with other agencies to determine if we should call an air quality advisory, which warns people when the air is so bad they need to take precautions to protect themselves. Many homes, schools and businesses use the AQI to understand what the air quality will be so they can decide for themselves about participating in sports or other outdoor activities that day. This may be particularly important for those who are sensitive to poor air quality, such as people with asthma, emphysema, lung disease or other respiratory illnesses. Finally, the data provides important information about wildfire smoke and pollution we use to inform policy proposals.

Natural Resource Specialists (L to R) Chris Modderman and Peter Husted check and calibrate air quality monitors at a local site.

The network of commercial, low-cost air quality sensors continues to grow, with more than a thousand in Oregon. They can provide useful information on local conditions, but their pollutant level estimates are of unknown quality. For that reason, DEQ cannot guarantee their levels will match what our monitors indicate.

For individual and community projects, you can adopt practices to establish more confidence in your estimates. The key is to answer the important questions about the process: Who? What? Where? How? When? Why? You can find some great resources at the following:

Understanding the monitoring process can help your project deliver data that counts. For more information, contact DEQ’s Air Quality Monitoring Team at

— Dan Johnson, air monitoring specialist, DEQ LEAD

Published by Oregon Department of Environmental Quality

DEQ’s mission is to be a leader in restoring, maintaining and enhancing the quality of Oregon’s air, land and water.

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