How dust pollution from shrinking Great Salt Lake affects communities disproportionately
Research highlights social justice implications of restoring the Utah lake
UNIVERSITY OF UTAH
VIDEO:
THIS VIDEO, SHOT FROM UNIVERSITY OF UTAH CAMPUS, SHOWS A DUST STORM PASSING THROUGH SALT LAKE CITY ON MAY 17, 2023.
view moreCREDIT: DEREK MALLIA, UNIVERSITY OF UTAH
New research from the University of Utah demonstrates how wind-carried dust from the exposed bed of Great Salt Lake is disproportionately affecting disadvantaged communities in the Salt Lake metro area.
The findings suggest restoring the lake to a healthy water level would reduce disparities in harmful dust exposure experienced by different racial/ethnic and socioeconomic groups, along with delivering other ecological and economic benefits.
Exposure to particulate pollution arising from dry portions of the playa is highest among Pacific Islanders and Hispanics and lowest among white people compared to other racial/ethnic groups, according to the findings reported June 21 in the journal One Earth. It was also higher for individuals without a high school diploma.
This is likely because Salt Lake City’s lower-income neighborhoods are more likely to lie in the path of windblown dust from Great Salt Lake, which has shrunk to less than half its historical size, leaving about 800 square miles of lakebed exposed.
More than two decades of drought and unrelenting upstream diversions have contributed to the decline of the saline terminal lake located immediately west and north of Utah’s main population corridor along the Wasatch Front.
“People here in Utah are concerned about the lake for a variety of reasons—the ski industry, the brine shrimp, the migratory birds, recreation—and this study adds environmental justice and the equity implications of the drying lake to the conversation,” said lead author Sara Grineski, a professor of sociology and environmental studies.
Grineski led an interdisciplinary team of U faculty, largely associated with the Wilkes Center for Climate Science and Policy, from both the College of Social and Behavioral Science (CSBS) and the College of Science. Co-authors are Timothy Collins and Malcolm Araos (geography); John Lin, Derek Mallia and Kevin Perry (atmospheric sciences); and William Anderegg (biology).
The study analyzed data from the Utah Department of Environmental Quality’s air-quality monitoring network, which screens for fine particulate matter, or PM2.5. Comprised of ultra tiny particles that can penetrate lung tissue, this pollution is linked to myriad health problems, including cardiovascular disease and asthma.
During dust storms, current levels expose residents to 26 micrograms per cubic meter, or μg/m3, of PM2.5 on average, according to the study, significantly higher than the World Health Organization’s threshold of 15 μg/m3. Were the lake to dry up completely, exposure could rise to 32 μg/m3, while restoring the lake could reduce exposure to 24 μg/m3 during these wind events, according to the study.
The study examined four such events in 2022 on April 19, 20 and 21 and May 7, when spikes of recorded PM2.5 coincided with high winds.
For the study, which was funded by the National Science Foundation, researcher Derek Mallia developed a model for predicting exposure levels for the three counties abutting the lake’s east and south shores—Salt Lake, Davis and Weber, home to 1.8 million residents—under four different lake level scenarios. It uses a weather model that simulates wind direction and speed, and includes a wind-blown dust model, which measures how much dust is emitted from an erodible surface, such as the Great Salt Lake playa, and is primarily based on the wind speed and soil texture and characteristics.
“We have to use weather models, since we cannot physically go out to the lake and remove/add water to see how much more/less dust it would emit,” Mallia said. “Models like the one that I developed let us run these hypothetical scenarios.”
The study’s scenarios range from a totally dry lake, to very low lake level, to current lake, to ‘healthy’ lake level designated as 4,200 feet above sea level. The lake’s South Arm currently sits at 4,194.4 feet, almost 6 feet higher than the historic low of 4,188.7 registered at the end of 2022.
According to the model, neighborhood disparities in exposure levels would increase when the lake level drops.
“We frame it the converse. Lake levels rise, overall levels of dust go down during the dust events and the gap, especially between Hispanic and Pacific Islander people, narrows with respect to the level of dust exposure for non-Hispanic white people,” Grineski said. “So if we can take better care of the lake, the dust for everyone goes down and the gap in exposure between these groups goes down too.”
Her team’s prior research has previously documented disparities of PM2.5 exposure generally in the Salt Lake Valley
“There is a really strong pattern of inequality with respect to race and ethnicity,” she added. “It’s sort of a hopeful finding that if we can raise the lake to a ‘healthy’ level we can at least with respect to lake dust we can reduce some of that inequality.”
Most dust from the playa is PM10, pollution comprised of much larger particles that are only measured at a few of Utah’s air quality monitoring stations. Without a robust PM10 monitoring network, researchers and regulators are deprived of a key data source that could give a more complete assessment of the lakebed dust threat, according to co-author Kevin Perry. He said the study points to the need for Utah to expand its network of PM10 monitors since windblown lakebed dust contains about six times more PM10 than PM2.5.
“We have to use the PM2.5 data because that’s the network that we have available. It’s not what I would design and not what I would like to do,” he said. “Because of the network being so sparse, I can’t even answer a really basic question, like how many dust events do we have a year that are impacting these communities. And that’s super frustrating.”
A professor of atmospheric science, Perry is known as “Dr. Dust” thanks to his tireless bicycle forays across the vast lakebed gathering sediment samples. These sediments were found to be contaminated with heavy metals in some places.
He noted that potentially harmful dust events typically occur in the spring and fall when cold fronts pass through the Wasatch Front.
“Before a cold front gets here, we have really strong winds from the south that will last for 12 or 18 hours,” Perry said. “And where’s it pushing that dust? It’s pushing it to Layton, Syracuse, Ogden, Brigham City where we have almost no PM10 monitors at all, and then the wind reverses and we’ll get three to four or five hours of stuff coming into Salt Lake Valley where we do have monitors.”
Because of its ability to infiltrate living tissue, PM2.5 is considered more harmful to human health than PM10, which is also classified as a criteria pollutant under the federal Clean Air Act.
The exposed bed of Great Salt Lake, which has shrunk to about half its historic size over the past two decades, has become a source of dust pollution impacting Utah's population centers.
CREDIT
Michael Werner, University of Utah
JOURNAL
One Earth
METHOD OF RESEARCH
Computational simulation/modeling
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Harmful dust from drying lakes: Preserving Great Salt Lake (USA) water levels decreases ambient dust and racial disparities in population exposure
AMS science preview: Maui wildfire, Salt Lake drying, traffic and weather
Early online research from journals of the American Meteorological Society
AMERICAN METEOROLOGICAL SOCIETY
IMAGE:
“AN EAST-WEST VERTICAL CROSS SECTION INCLUDING LAHAINA AND THE EASTERN PORTION OF LANAI FROM A WRF FORECAST VALID 0300 9 AUGUST 2023." FIGURE 18, FROM Mass & Ovens (2024), “THE METEOROLOGY OF THE AUGUST 2023 MAUI WILDFIRE,” IN MONTHLY WEATHER REVIEW.
view moreCREDIT: MASS & OVENS (2024), “THE METEOROLOGY OF THE AUGUST 2023 MAUI WILDFIRE,” MONTHLY WEATHER REVIEW. HTTPS://DOI.ORG/10.1175/WAF-D-23-0210.1 © AMERICAN METEOROLOGICAL SOCIETY.
The American Meteorological Society continuously publishes research on climate, weather, and water in its 12 journals. Many of these articles are available for early online access–they are peer-reviewed, but not yet in their final published form.
Below is a selection of articles published early online recently. Some articles are open-access; to view others, members of the media can contact kpflaumer@ametsoc.org for press login credentials.
JOURNAL ARTICLES
Understanding Observed Precipitation Change and the New Climate Normal from the Perspective of Daily Weather Types in the Southeast U.S.
Journal of Climate
Wetter and drier in the U.S. Southeast. This study documents changes in precipitation in the U.S. Southeast from the 1960s to 2020, finding a drying of the inland Southeast and eastern Gulf Coast, and increased precipitation on the East Coast and southern Florida. The authors discuss the changes in atmospheric patterns that are responsible for these shifts.
Rising Extreme Meltwater Trends in Greenland Ice Sheet (1950–2022): surface energy balance and large-scale circulation changes
Journal of Climate
“Extreme summer melting” increasing significantly in the Greenland ice sheet. The authors’ analysis finds an upward trend in extreme, nearly unprecedented melting events in the Greenland ice sheet, especially in the north and along the coasts—substantially contributing to global sea level rise. These events correlate with large-scale atmospheric circulation changes and increased summer air and ice-surface temperatures, among other factors that fuel the breakdown of ice sheets.
Climate and Kidney Injury: A look at the impact of meteorological factors on kidney function within Colorado
Weather, Climate, and Society
Humidity predicts kidney injury in Colorado. Chronic kidney disease (CKD) appears to be increasing in the U.S., despite declines in traditional risk factors; many communities at highest risk for CKD are also the most vulnerable to climate change impacts. A 15-year study in Colorado’s agrarian San Luis Valley found a significant correlation between heat and acute kidney injury (AKI, which can be a precursor to CKD); however, unlike in warmer climates, the greatest AKI predictor was low relative humidity: dry air.
For a Pluralism of Climate Modelling Strategies
Bulletin of the American Meteorological Society
Is climate model funding strategy wrong? Currently, funding for climate models focuses on increasing the resolution and complexity of atmospheric General Circulation Models (GCMs) for more accurate predictions. The authors argue that funding should be distributed more equitably among different model types, some of which–for instance, statistical and machine learning models, and those simulating economic and ecosystem impacts–are both complementary and vital for informing policy and decision-making.
The Shrinking Great Salt Lake May Exacerbate Droughts by Reducing Local Precipitation: A Case Study
Journal of Hydrometeorology
Great Salt Lake drying causes feedback loop of drought. Utah’s Great Salt Lake has shrunk in recent years due to water diversions and drought–but this also means less lake water available to feed local rain patterns. A modeling study suggests that reducing the lake area dramatically reduces the amount of rain dropped by a specific storm; getting rid of the lake completely would halve the amount of precipitation dropped by the storm. This sheds light on how shrinking lakes feed regional droughts.
The Meteorology of the August 2023 Maui Wildfire
Weather and Forecasting
What caused the Maui wildfire? A meteorological analysis the 2023 Maui wildfire found that the event was well-forecast by meteorological models, and that the main meteorological contributors to the fire were stronger-than-normal northeast trade winds sweeping over the West Maui Mountains, accompanied by a stable atmospheric layer near the mountain crest forcing strong wind gusts down the mountains’ lee side (a downslope windstorm). The authors find no significant role for Hurricane Dora in the event, nor were the preceding months significantly drier than normal; the winter before the wildfire was wetter than normal.
The Role of Temperature and Rainfall in Traffic Congestion: Evidence from 98 Chinese cities
Weather, Climate, and Society
Heat decreases (and rain increases) traffic congestion across Chinese cities. A study of meteorological and traffic data from 98 Chinese cities found that when temperatures warm past 25°C, traffic congestion decreases by 6%, while rainfall increases congestion by 2%-5.6% when it happens on a workday. Cities with subways were buffered somewhat from the effects of heat, but not rain.
East Pacific ENSO Offers Early Predictive Signals for Harvest Yields
Journal of Applied Meteorology and Climatology
Predicting Kansas wheat yield via El Niño, seasons ahead. The climate of Kansas is variable and warming, with unknown consequences for this major wheat-producing state. A new analysis suggests that signals in the El Niño-Southern Oscillation pattern in the eastern Pacific are strongly correlated with Kansas’s wheat crop yield a year or so in advance, which could help farmers plan and adapt for optimal production.
Influences of Large Scale Circulation and Atmospheric Rivers on US Winter Precipitation Beyond ENSO
Journal of Climate
Western U.S. winter precipitation may be less affected by climate change. The authors’ analysis and modeling suggests that unlike some other facets of U.S. weather, the so-called 'West Mode' atmospheric pattern, responsible for 50% of western U.S. winter rainfall variability, has been relatively unresponsive to anthropogenic climate forcing thus far. Based on their model, the authors suggest that western winter rainfall "may possess some resilience to the effects of global warming in the coming decades.
You can view all research published in AMS Journals at journals.ametsoc.org.
About the American Meteorological Society
The American Meteorological Society advances the atmospheric and related sciences, technologies, applications, and services for the benefit of society. Founded in 1919, AMS has a membership of around 12,000 professionals, students, and weather enthusiasts. AMS publishes 12 atmospheric and related oceanic and hydrologic science journals; hosts more than 12 conferences annually; and offers numerous programs and services. Visit us at www.ametsoc.org/.
About AMS Journals
The American Meteorological Society continuously publishes research on climate, weather, and water in its 12 journals. Some AMS journals are open access. Media login credentials are available for subscription journals. Journals include the Bulletin of the American Meteorolocial Society, Weather, Climate, and Society, the Journal of Climate, and Monthly Weather Review.
JOURNAL
Journal of Climate
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