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Health Indicator Report of Air Quality: Particulate Matter (PM2.5)

PM2.5 can get deep inside the lungs and cause a variety of symptoms, such as painful breathing, chest tightness, headache, and coughing. PM2.5 can exacerbate respiratory infections, trigger asthma attacks and symptoms, and cause temporary reductions in lung capacity. Respiratory symptoms are more likely to occur when PM2.5 levels exceed the EPA's standard, but are possible when PM2.5 levels are below the standard, especially in sensitive populations. PM2.5 has been found in some studies to be associated with an increased risk of chronic lung disease [2]. In addition to these adverse outcomes, PM2.5 can influence the environment in ways that will eventually affect human health. Fine particles cause haze which reduces visibility. The long-term effects of PM2.5, which settles in the soil, natural water sources, forests, and agricultural areas, are still to be determined. Whether or not climate change has an effect on PM2.5 concentration has yet to be determined. However, as temperatures increase, PM2.5 concentration has been shown to increase in the United States, but this is not the general consensus of the scientific community. Researchers seem to agree that as precipitation increases, PM2.5 levels will decrease since it "clears" the air [3]. If precipitation events are seen to increase with climate change, it is reasonable to conclude that PM2.5 levels may decrease. PM2.5 concentrations could also be affected by air stagnation events (i.e., inversions). If air stagnation events increase in frequency with climate change, PM2.5 levels are likely to rise because these events trap the pollution at the Earth's surface [3]. More research is needed to accurately quantify to what extent PM2.5 levels will be affected by a changing climate.

PM2.5 Levels Over the National Ambient Air Quality Standard: Person-days by Year, Washington County, 2000-2014


Product of the total population of the county (estimate) and the number of days over the daily National Ambient Air Quality Standard for PM2.5.

Data Sources

  • U.S. Environmental Protection Agency, Air Quality System (AQS)
  • Population Estimates: National Center for Health Statistics (NCHS) through a collaborative agreement with the U.S. Census Bureau, IBIS Version 2013

Data Interpretation Issues

Data on PM2.5 levels are only available where air monitors exist. The Environmental Protection Agency (EPA) and Utah's Department of Environmental Quality (DEQ) have scientifically determined where in Utah PM2.5 is likely to exceed the standard. Geographies reported will vary based on measurement type. Data for this report represent ambient air, or outside air quality. The relationship between ambient concentrations and personal exposure can vary significantly depending upon the pollutant, activity patterns, and microenvironments. Data for this report came from the EPA and therefore, may differ slightly from data to other sources. One reason for a possible difference is that this data include exceptional events such as fireworks, construction, fires, etc.


Particulate matter that measures 2.5 micrometers in diameter or less is often called PM2.5. Particulate matter 10 (PM10) measures one-seventh the width of a strand of human hair, so one can imagine just how small PM2.5 really is. PM2.5 is composed of metals, allergens, nitrates, sulfates, organic chemicals, soil, and dust that are emitted from sources such as combustion products, soot from fireplaces, and blowing dust from construction sites and agricultural activities. PM2.5 levels are generally higher during the winter months due to weather, temperature, and inversions. The United States' Environmental Protection Agency (EPA) PM2.5 standard states that daily averaged PM2.5 levels should not exceed 35 micrograms per cubic meter, while annually averaged PM2.5 levels should not exceed 12 micrograms per cubic meter [1].


This indicator report contains the following views: 1. Percent of days above the National Ambient Air Quality Standards (NAAQS) 2. Number of person-days above the NAAQS 3. Average annual ambient concentrations of PM2.5 4. Percent of population living in counties exceeding NAAQS


Where applicable, population based on U.S. Census Bureau estimates for July 1 of each year.

Other Objectives

Physical exercise is essential to maintaining good health. In order to do this safely, refer to daily PM2.5 levels by checking them at If PM2.5 levels are high, consider exercising indoors. If outdoor exercise is unavoidable during high PM2.5 levels, consider light to moderate activity such as walking.

How Are We Doing?

Several of the most urban counties in Utah have days that do not comply with the PM2.5 standard. This may be due in part to Utah's unique geography and seasonal conditions. PM2.5 levels increase seasonally in the winter and often due to inversions. Utah's Department of Environmental Quality (DEQ) is working to decrease the number of days over the PM2.5 standard.

What Is Being Done?

The DEQ is working to decrease Utah's PM2.5 emissions to comply with national standards. Because the majority of particulate matter is caused by automobile emissions, DEQ encourages the public to use mass transit and to stay indoors on days with high pollution levels, which you can check at In addition, DEQ has studied the effects of high particulate matter levels on children playing outside at recess so that schools may make informed decisions about when to keep children indoors. The DEQ's 3-day air quality forecasting program uses a red, yellow, and green stoplight color code to inform the public about how they can help keep pollution levels low. A green day informs the public that pollution levels are low, and they can safely drive and spend time outside. A yellow day suggests citizens consider limiting their driving to reduce pollution levels. A red day strongly encourages the public to reduce driving and other polluting activities to prevent pollution levels from exceeding the health standard. Ultimately, Utah's air quality for depends on each individual taking steps to reduce the amount of energy being used and pollution being emitted.

Available Services

Find out about current air quality conditions in your county by going to This can help you make informed decisions about your health. Current air quality conditions are available at and The Department of Environmental Quality's 3-day air quality forecasting is available at This forecast helps the public make smart decisions under current air quality conditions. People can use this information to choose when to stay indoors and whether to use mass transit.
Page Content Updated On 04/10/2015, Published on 04/10/2015
The information provided above is from the Department of Health's Center for Health Data IBIS-PH web site ( The information published on this website may be reproduced without permission. Please use the following citation: " Retrieved Fri, 27 November 2015 13:50:22 from Department of Health, Center for Health Data, Indicator-Based Information System for Public Health Web site: ".

Content updated: Tue, 28 Jul 2015 19:46:04 MDT