Ask An Environmental Scientist: What Air Pollutants Does DEQ Test For?

Graphic showing the air pollutants DEQ monitors

By DEQ Communications

You asked and our environmental scientists answered. For the curious and inquisitive minded, our Ask An Environmental Scientist series lets you submit the questions you’ve always wanted to know and have them answered with the most up to date facts and studies from the scientists at Utah’s Department of Environmental Quality. With more than 175 scientists in fields ranging from air quality to x-ray radiation, Utah DEQ’s staff is eager to share their knowledge with you.

Our first question, submitted by Ian Hong, is all about air quality, so we turned to Bo Call, Manager of DEQ’s Air Monitoring Section to answer his question.

QUESTION: How does DEQ decide what air pollutants to test for?
Are there air pollutants that DEQ would like to or could test for if there were additional funding? – Ian Hong

ANSWER: Great questions Ian! Starting with your first question, the simple answer is that we monitor based on the six criteria pollutants under the Clean Air Act.

Although not required, we also monitor for a few additional items that are precursors or indicators of these pollutants. These are much harder to monitor for and therefore we do it less.

Mixing Layer Height (MLH)

A measure for the vertical turbulent exchange within the boundary layer, which is one of the controlling factors for the dilution of pollutants emitted near the ground. Or more simply, this is where pollution mixes out of our valleys. So when we have an inversion the air is not mixing well and there is a cap on everything. The top of that cap is where the mixing height is, so the lower the mixing height the worse our pollution is.

Ozone Monitoring Compounds

Using gas chromatography we look for 54 specific compounds including ethane, propane, isoprene and benzene. Gas chromatography is a process where we separate, identify and quantify various compositional elements of a compound by measuring how each of the components react when converted from a liquid or solid into a gas.

Identify Particulates

In addition to measuring how many particulates are in our air, we identify what makes up those particulates. This is called the chemical speciation network and all data including flow rate, volume and ambient temperature are used to assess air quality trends and help develop effective emission control strategies.

Monitor Air Toxins

There are 187 hazardous air pollutants that are regulated under the Clean Air Act. As part of the National Air Toxics Trends Station (NATTS) program, we help monitor long-term air pollutants to track trends in ambient air toxics levels that will help facilitate emission reduction.

Studies and Additional Monitoring

When we can, we support studies such as the Three State Air Quality Study, the 2012 Utah Ozone Study and the Air Toxics Study. Also when feasible, we support other specific monitoring and research projects. We provide data and facilities to many university researchers that house their equipment at our stations or use our data as a baseline. We have also worked with companies testing new equipment and those trying to get their equipment to pass EPA’s requirements.

QUESTION: Are there air pollutants that DEQ would like to or could test for if there were additional funding?

ANSWER: If there were additional funding the first thing I would do is put in more monitoring sites throughout Utah. This would provide us with more accurate information for areas within Utah that are farther away from an operating air quality monitor such as towns within Summit County and many rural counties in Southern Utah. More monitoring sites would also create more accurate results because it would better account for weather patterns like wind.

Within the Division of Air Quality our scientists evaluate the data from our air monitoring stations and use models to determine strategies for what we can eliminate or decrease to make our air cleaner. If we had additional funding, another route I would look at would be to create more programs that utilize those strategies to help decrease air pollution.

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