Skip directly to searchSkip directly to the site navigationSkip directly to the page's main content

PHOM Indicator Profile Report of Air Quality: Ozone

Why Is This Important?

Ozone is a naturally occurring component of the earth's atmosphere at ground level and in the upper regions of the atmosphere. While upper atmospheric ozone protects the earth from the sun's harmful rays, ground-level ozone can be detrimental to the health of plants, animals, and human beings. Molecules of ozone are made up of three oxygen atoms (O3) and are chemically identical in the upper atmosphere and at ground level. The lungs of animals and humans have a thin liquid lining that protects lung tissue from normal amounts of ozone. However, sunlight and heat can create new ground-level ozone molecules from nitrogen oxides and volatile organic chemicals that are found naturally at the earth's surface, as well as in emissions from industrial facilities, electric utilities, motor vehicle exhaust, gasoline vapors, and chemical solvents in urbanized regions. Ozone is a principle component of urban smog and is measured in parts per million (ppm). Ozone can cause several adverse health effects in anyone, but especially in sensitive populations such as children, older adults, people with pre-existing lung diseases such as asthma, and people who are physically active outdoors. Some of these health problems include painful breathing, chest tightness, headache, coughing, increased asthma symptoms, lung inflammation, and temporary reduction in lung capacity. Over time, ozone is associated with chronic lung problems and respiratory infections. Adverse health effects from ozone are more likely to occur when ozone levels exceed the EPA standard, but are possible when ozone levels are below the standard, especially in sensitive populations. Ground-level ozone, not to be confused with the atmosphere's protective ozone layer, is created by reactions between environmental pollutants, light, and heat. Ozone is the main component of smog and is dangerous to health and the environment. The creation of ozone is facilitated by warm weather and sunshine; therefore, ozone levels are usually higher in the summer and in the mid-afternoon. Climate change may play a part in the creation of more ground-level ozone pollution. As temperatures increase, it is expected that the number of high ozone days will increase, since heat accelerates the nitrogen oxide and volatile organic compound reaction.^1^ Researchers have found that a combination of higher temperatures, sunlight, emissions, and air stagnation events (i.e., inversions) may result in an increase of ozone levels. However, more research is needed to accurately gauge what portion of ozone is actually increasing solely due to climate change.[[br]] [[br]] ---- 1. National Aeronautics and Space Administration (2004). The good, the bad and the ozone. Retrieved March 21, 2012 from the National Aeronautics and Space Administration: []

Maximum 8-hour Average Ozone Concentrations Above the National Ambient Air Quality Standard (NAAQS), Number of Days by County, Utah, 2018

::chart - missing::

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 2018

Data Notes

These data include "exceptional events", such as high winds, fires, construction, fireworks, etc.   [[br]] [[br]] These values represent days when at least one air monitoring station showed a reading over the National Ambient Air Quality Standard (NAAQS) for ozone within a county.

How Are We Doing?

The most urban counties in Utah often have days that do not comply with the new ozone standard of 0.070 ppm. The Utah Department of Environmental Quality (DEQ) is working to decrease the number of days over the ozone standard.

What Is Being Done?

In response to the new EPA ozone standard of 0.070 ppm, DEQ has begun fitting school buses with cleaner technology, and state office buildings have begun adopting more energy-efficient policies and practices. The DEQ 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 and safe. A green day informs the public that pollution levels are low, and they can safely drive and spend time outside. A yellow day informs the public that they should consider limiting 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, the air quality for Utah citizens is dependent upon each individual taking steps to reduce the amount of energy used and pollution emitted.

Date Indicator Content Last Updated: 09/11/2019

Other Views

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 Mon, 06 July 2020 6:55:42 from Department of Health, Center for Health Data, Indicator-Based Information System for Public Health Web site: ".

Content updated: Wed, 13 Nov 2019 14:29:32 MST