Exposed Lakebed On The Great Salt Lake | Stephanie Frohman
TAKEAWAY
Utah has achieved progress in cutting winter PM2.5. New studies and monitoring capacity will provide additional insights on how to improve summer PM10.
Terms to Know
Design Value: EPA’s calculated pollution level used to determine air quality compliance.
Airborne particulate matter, especially along the Wasatch Front and in Cache Valley, is one of Utah’s biggest air quality concerns. Regulators track two main types: PM10 (particles smaller than 10 microns) and PM2.5 (smaller than 2.5 microns). PM10 can be inhaled into the lungs, while PM2.5 is more dangerous because it reaches deep into the lungs and can harm long-term health.
Over the past two decades, Utah has made major progress in reducing PM2.5 during winter inversions. In the mid-2000s, parts of northern Utah were labeled “non-attainment” areas by the U.S. Environmental Protection Agency, meaning air quality did not meet federal standards. Since then, scientists, regulators, industries, and community members worked together to understand how weather, emissions, and chemistry combined to create Utah’s unique ammonium nitrate–based winter pollution. That collaboration led to new State Implementation Plans and a series of strategies to reduce emissions.
The results have been significant. Cache Valley reached compliance in 2021, and design values for the Wasatch Front continue to drop. Utah has now submitted documents to the EPA requesting that the Wasatch Front receive a “Clean Designation,” a decision expected in 2025. These gains came even as Utah’s economy and population grew.
Dust has become a newer concern. As the Great Salt Lake shrinks, exposed lakebed can release fine dust during strong wind events. Similar conditions also occur at Sevier Dry Lake and in the West Desert. Most of this dust is made of natural earth materials, but it can sometimes include small amounts of harmful metals such as arsenic or selenium. These episodes are usually short-lived, lasting a few hours, but they can create very high temporary PM10 levels. Even brief exposure to high dust concentrations can affect lung function. To better understand the risk, the Utah Division of Air Quality has plans to add monitors around the Great Salt Lake, and universities and state agencies have formed a working group to guide research and policy.
Dust episodes are usually short-lived, lasting a few hours, but they can create very high temporary PM10 levels.
Figure 3.B.1 PM2.5 Concentrations and Gross Domestic Product Change
Figure 3.B.2 May 2025 Hourly PM10
