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Near-road Monitor Installation Important Step in Reducing Air Pollution in Utah

WRA made the installation of Salt Lake City’s first-ever near-road air quality monitor a top priority. Learn why this was such an important step in protecting Utah communities from air pollution.

joro walker

Joro Walker

Senior Attorney


WRA made the installation of Salt Lake City’s first-ever near-road air quality monitor a top priority. WRA’s Utah experts understood that data from a monitor is a critical step to protecting people’s health from air pollution – which is almost always worst near congested highways – and to ensuring that the Salt Lake Valley meets national air quality standards.

Why is it important to reduce PM2.5 concentrations?

What is PM2.5?

Fine particulate matter (often called, “PM2.5”) is a type of air pollution that leads to a wide range of poor health outcomes, including premature death, heart attacks, strokes, cancer, susceptibility to infection and asthma and is linked to developmental harm, birth defects and infant mortality. Recently, studies have connected fine particle pollution with Alzheimer’s disease. Utah has the highest prevalence of Alzheimer’s disease in the nation.

Monitoring data shows that PM2.5 concentrations are higher near highways and that, as a result, low-income and minority populations are often disproportionately exposed to high PM2.5 concentrations, and bear a disproportionate risk of adverse health outcomes from PM2.5.

Why is it important to reduce concentrations of smog-forming NOX?

What is ozone?

Ozone – often called smog – develops in the atmosphere chiefly from nitrogen oxides (NOX) and volatile organic compounds (VOCs) that come from tailpipes, smokestacks and many other sources. When these gases are exposed to sunlight, they react and form ozone smog.

Like PM2.5, exposure to high concentrations of ozone cause premature death, heart attacks, stroke, respiratory disease, increased hospitalizations for asthma, and is linked to low birth weights and decreased lung function in newborns.

Utahns deserve air that meets federal standards for PM2.5 and ozone.


Federal law recognizes that Utahns are entitled to clean air and sets national standards for air quality that states must meet to protect public health. For the past decade, the Wasatch Front has experienced severe bouts of high concentrations of PM2.5 and has routinely exceeded the PM2.5 standard during wintertime inversions. Because it has missed deadlines to achieve good air quality, the Salt Lake Valley has been designated a serious nonattainment area. Recently, winter weather patterns in Northern Utah have meant cleaner air for Utah, but it is still evident that when inversions take hold, concentrations of PM2.5 increase rapidly.


In the summer, concentrations of ozone in the Salt Lake Valley have increasingly violated the ozone standard. This means that the Utah Division of Air Quality (DAQ) must develop a plan to reduce emissions, improve air quality, and bring the Salt Lake Valley into compliance. The plan should create regulations for all emissions sources, including rules that limit emissions from businesses and industrial operations, to ensure that the Salt Lake Valley will comply with the standard as soon as possible.

Why are near-road monitors important to protect people’s health?

To help ensure that all Salt Lake Valley communities are protected from air pollution and to inform efforts to meet the federal standards for PM2.5 and ozone, the Clean Air Act required Utah to have an operational near-road monitor – a monitor located close to a busy highway – in Salt Lake City. This monitor was to be collecting data for nitrogen dioxide (NO2) – a gas that leads to the formation of ozone – and PM2.5, at least by January 2017. However, it took more than two years for the state to install the near-road monitor. Throughout the process, WRA’s air quality attorney advocated repeatedly for the monitor to be installed, filing comments and meeting with DAQ and the U.S. Environmental Protection Agency, and making presentations to the Utah Air Quality Board. Finally, in January 2019, a monitor was installed close to I-15 in Murray, Utah, and began recording data for PM2.5 and NO2.

The installation of this monitor near I-15 will help Utah and the public better understand the degree to which communities living near highways are exposed to high concentrations of air pollutants.

Data from the near-road monitor will also help determine whether or not Utah is meeting federal standards for air quality throughout the Salt Lake Valley, including at locations near highways.

Already, data from the near-road monitor regularly shows higher concentrations of PM2.5 and NO2 than elsewhere in the Salt Lake Valley.

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