Wilson has lived in the west-side neighborhood for more than 17 years. But it wasn’t until 2010, when she lost a pregnancy, that she was confronted by the severity of the area’s pollution problem.

The pregnancy loss was recorded in the state’s database, “and then the University of Utah reached out,” she said, “because they were doing some kind of survey study to see if air quality contributed to pregnancy loss in the area because of where I lived.” (The U. of U. study, published in 2018, surveyed more than 1,300 women and found a 16% higher risk of miscarriage “following short-term exposure to elevated air pollution.” )

Wilson is one of dozens of west-siders The Salt Lake Tribune and KUER have interviewed during the past year, to hear — in their own voices — what it’s like to live where air pollution can reach dangerous, even deadly, levels.

[”Reaching for Air”: Hear the voices of west-side residents on our interactive presentation. And check out the west side’s air quality in real time on our map.]

Experts point to several reasons why air quality is worse on Salt Lake County’s west side than other places: The interstate highways that run through and past the area; the industries and rail lines within it; the jet engines revving at Salt Lake City International Airport; and the concentration of warehouses — and the heavy-duty diesel vehicles that operate in and around them.

And, as a University of Utah study has shown, many of those reasons were influenced by a broader issue: Redlining, the systemic placement of minority populations to the west side, around those polluting sources, for more than a century. The practice was made illegal in 1968, but the aftereffects linger in a part of mostly-white Utah where minorities often make up the majority.

For west-siders, like Wilson, the effects of bad air can be enormous.

Since the University of Utah reached out, Wilson said she has made changes to her life. She limits her kids’ outside playtime and avoids using her car to run errands. If she plans to go on a hike, she switches the route to something less strenuous. It’s hard as a stay-at-home mom, she said, because she feels stuck inside to avoid health repercussions.

She said it’s “disheartening” to see more projects — such as the Utah Inland Port and the possible widening of Interstate 15 — that, if created, likely would bring more pollution to their homes.

For now, Wilson said, “I feel like we’re healthy. … But, again, I do worry about what that is going to look like long term.”

The west side’s air-quality problems are a long-term issue, said Logan Mitchell, a climate scientist who has researched the history of Utah’s air pollution — because some of the decisions that led to them were made by Utahns in the 1890s.

Those decisions, made “130 years ago, are still impacting us today,” Mitchell said. “And [as] we’re thinking about another industrial facility, and infrastructure that’s going to be set up, an important way of looking at it is: What are going to be the impacts of that for the next 100, 150 years?”

Feeling like ‘human filters’

The Environmental Protection Agency released an environmental justice assessment for neighborhoods on Salt Lake City’s west side earlier this year, helping residents confirm what they already knew: Their air is worse, their health risks are higher, and their quality of life is poorer.

A look at a map of the west side, compared with the map of emission sources, helps demonstrate the extent of that disproportion, said Daniel Mendoza, a research assistant professor in atmospheric sciences at the University of Utah and an adjunct assistant professor in internal medicine (pulmonary division) and city and metropolitan planning at the U.

“You have concentrated emission sources,” Mendoza said. Those include the interstates — I-15 on the eastern edge, I-80 and I-215 running through it — as well as the airport, industry, rail lines and warehouses that use diesel vehicles.

Such emission sources, Mendoza said, “become more prominent during stagnant events, such as inversion.”

On days without inversions, those pollutants usually get dispersed. But some west-siders say they feel like human filters — as one respondent to the EPA assessment put it — to that concentration of pollutants because that’s the air they breathe with less buffers, such as trees, which help filter out particulate matter.

Salt Lake City is making an effort to add 1,000 trees to the west-side canopy every year and plans to build a regional park in Glendale. However, the west side still lags behind the east side, which has older, larger trees and established regional parks.

It’s one reason why pollution that hits all of Salt Lake Valley — like dust from the Great Salt Lake and smoke from wildfires in other states — affects the west side more.

“When we look at air pollution, we don’t necessarily just need to stop at highways, for example, or point sources,” Mendoza said. “We also need to be thinking about what’s coming from beyond, what’s regional.”

An industrial hub

Air quality has vastly improved compared to the 1880s, when energy originated from burning wood and coal. The smoke was so thick it needed to be cleaned from the walls with sponges.

Mitchell, the climate scientist, said a few years before Utah became a state in 1896, communities already were organizing to tackle the “smoke nuisance” belching from businesses that used a large amount of coal for their operations.

In 1891, Salt Lake City leaders made it illegal for anyone to emit dense smoke from chimneys. It was a misdemeanor, punishable by a fine ranging from $5 to $50 a day.

Decisions to make the valley’s west side an industrial hub happened, partially, because of a miscalculation.

In 1893, amid Salt Lake City’s growth, officials tried to determine where to place industrial facilities based on how meteorology and wind patterns affected the air quality.

There were objections to locate any factory in the mouths of the eastern canyons, as air flowed in and out of them and smoke could blow over the entire city.

Many of the experts consulted were from the East Coast, who were used to the presence of big rivers, which often provide a thermal barrier. That “is not true in Salt Lake Valley, as we know, but these guys didn’t know that,” Mitchell said, “and the place to locate all the factories is west of the Jordan River. So they thought the current of the water would carry the smoke with it.”

Since the experts assumed the Jordan River would protect the city’s east side from air pollution, and there was no such buffer west of the river, Mitchell said, the west side was considered to have some of the valley’s worst air quality.

‘Walking through a ball of cotton’

Gary Sapp has called West Valley City home longer than it has been a city. He voted yes when residents approved a 1980 ballot measure to incorporate.

Sapp said he loves Utah’s second most-populous city but has complaints about the air.

A 1973 graduate of Granger High School, Sapp said he remembers periods in the dead of winter when the air quality was so bad that “you couldn’t see five feet in front of you.”

The summer haze was no different, he said. “It’s like you’re walking through a ball of cotton.”

Poor air quality isn’t a new phenomenon on the west side. Decades ago, when his kids were growing up, Sapp said, he remembers seeing ads for tourism in southern Utah, promoting an escape to fresher air.

“Back in those days,” he recalled, “St. George used to make a lot bigger deal about ‘get out of the fog and come down to where the sun is, come to Utah’s Dixie.’”

Sapp, having watched conditions evolve over the decades, said he believes air quality has improved in West Valley City in the past seven or eight years. But, he added, the problem hasn’t been erased.

Mendoza, the atmospheric scientist, said there has been a trade off in pollution.

“While anthropogenic [human-caused] emissions have generally declined, biogenic emissions, including wildfires and dust events, have increased over the years,” Mendoza said.

How Utah sees the issue

The Utah Division of Air Quality has installed monitors in the Rose Park neighborhood that have captured the worst annual ratings in the state’s monitoring network for wintertime fine particulates called PM2.5.

The reasons for the accumulation of PM2.5 include different emissions sources, such as freeways, rail and airport industries, said Bryce Bird, the division’s director. West-side communities also are in the lowest part of the valley, so they become hosts to the concentrated stagnant pollution caused by inversions.

A DAQ map shows the west side also houses a disproportionate amount of point source emissions — industries that require a permit from the state — compared to other parts of the county. West-side neighborhoods are closer to power plants and hazardous waste. Homes and businesses also add to the mix.

Though DAQ can regulate industries, there’s little it can do to prevent individual emissions, Bird said. “We can encourage the incentive programs to change our equipment, but we don’t have the ability to shut down transportation.”

Warehouses, for example, have direct emissions associated with their operations, Bird added, but they also spur indirect pollution, such as the trucks that transport goods to the warehouses. The Utah Legislature has worked to identify strategies to reduce those indirect impacts, by looking into cleaner technologies, encouraging better transportation planning, and placing caps for vehicle emissions.

Salt Lake City has exceeded the national ambient air quality standards for concentrations of ozone (over an 8-hour period), PM2.5 and sulfur dioxide, according to the 2023 EPA Environmental Justice Assessment.

When areas aren’t meeting EPA standards, the state is required to develop a plan to drive down emissions. But that process often drags on for years, especially if standards change or are not met repeatedly.

There are penalties for that excess pollution, Bird said. If companies take longer to lower their levels of pollution to reach the federal standards, the state requires them to put more costly controls in place.

If the state continuously fails to meet air quality standards, Bird said the federal government can place sanctions on Utah. Under the sanctions, Bird said, Utah could lose “hundreds of millions of dollars” from the federal government in highway funding. Bird added Utah has been placed on sanction watch before, but “were able to to meet the requirements and avoid the actual sanctions.”

It’s comparatively easy for the state to study PM2.5 in depth, but other pollutants, such as ozone, are underestimated in current models. Bird said DAQ is seeking money to further that research.

With the EPA study proving what was widely known — that being close to pollution sources was having bad effects — many west-siders have asked what solutions might be coming.

“It’s something that we are focused on,” Bird said, “and we really are focused on attaining the standards at the most compromised monitors.”

Bird said DAQ, using different strategies and controls, has seen a reduction in the 24-hour concentrations of PM2.5 — from nearly 60 micrograms per cubic meter of air in 2002, to an average of 35 micrograms per cubic meter in 2022.

“We’re certainly not done yet,” Bird said, “and our overall goal has been and will continue to be that all the people in Utah have air quality that is protective of their health.”

The legacy of redlining

There’s another, historical, reason why the west side has both the most diverse population in Utah and a high concentration of hazards: redlining.

As far back as the early 1900s, federal housing policies encouraged racial segregation by rating neighborhoods’ security and ability to pay loans back. White neighborhoods were marked as desirable. Areas with people of color were classified as “hazardous.”

According to a University of Utah study, such redlining not only made it nearly impossible for people in “hazardous” neighborhoods to buy homes, but it also harmed those neighborhoods’ school funding, home prices, access to food and green spaces.

Most of Salt Lake City’s west side was marked with that red ink. The practice was formally banned in 1968, but the aftereffects remain.

“In Salt Lake City, there is a link between redlining, lower access to hospitals on the west side, and a higher presence of industry,” the U. study states. “This industry presence can prove harmful to west-siders’ health and can be explained by zoning policies that allow for heavy manufacturing and industrial uses. These areas are now home to many residents but continue to be the site of industrial use.”

Examples, according to the study, include the amount of wastewater discharge and the proximity to Superfund sites on the west side.

Salt Lake County’s east side has much older trees and a larger urban canopy, and the west side has much more built spaces, said Mendoza, the atmospheric sciences researcher. Wealthier communities are associated with higher levels of vegetation. Minority populations are associated with higher amounts of built space, according to census data.

It takes resources to grow and keep nonnative vegetation alive in a desert, Mendoza said, and it takes an important investment to not build anything where these urban forests are.

“It’s almost really a straight-line relationship,” Mendoza said, “between income or race and amount of green space.” Utah’s population, according to 2020 census data, is 75% white. On Salt Lake County’s west side, minorities often make up the majority. About 56% of West Valley City’s residents are members of ethnicities other than white (39% are Hispanic; the largest group). Other west-side communities may not be officially minority-majority, but many have similar demographic compositions.

Historically, west-side neighborhoods have been identified as some of the hardest for census takers to count in the country, because a number of undocumented residents fear responding due to the threat of deportation; some refugees don’t speak English well; and low-income people often cannot find the time to respond to surveys.

West-siders also have some of the lowest voter turnouts. In the 2022 general elections, neighborhood precincts such as Poplar Grove and Glendale had, around 55% of registered voters cast ballots, while just a few miles east, communities like Liberty Wells had around 70% to 80% voter turnout.

There are many reasons why west-siders say they don’t engage with their elected officials, including busy schedules and an expectation that no structural changes occur.

Growing up around smokestacks

Daniel Hernandez has moved around a few times but home was almost always within Rose Park.

“I grew up around smokestacks,” he said. “I don’t have to drive too far in any direction and I see industrial areas.”

When his eldest son was born premature and caught respiratory syncytial virus twice before his first birthday, Hernandez and his partner started watching their environment. Not just air but also water and food — what was available, what wasn’t.

“The west side has a lot of other factors that are compounded, like water, air, food. What food do we have access to here?” he said. “I mean, there’s no Whole Foods that I know of in my neighborhood. I don’t know if I could afford it anyway. But there are 7-Elevens all over the place.”

Hernandez knew about KN95 masks before the COVID-19 pandemic happened. With breathing issues and lung concerns, his family kept a reserve on hand to wear on bad air days.

Now that he sees how many resources in the state are used to support big farming and other industries, with little thought about sustainability, he can’t help but wonder if Utah is experiencing what he called a “cultural crisis” and “an unwillingness to radically transform the way we live in order to live in a better way.”

“I drive a car, but it would be nice if public transport was free. It’d be nice if it was everywhere and so convenient that it was better to take that than to drive,” Hernandez said. “And I know that that can be done. I have been to other places in the world and I’ve seen it, I’ve experienced it.”

Editor’s note • This story is part of Reaching for Air — a collaboration of The Salt Lake Tribune, KUER and the Brown Institute for Media Innovation, which explores air quality along the Salt Lake Valley’s west side. If you would like to share your story, please complete this survey or leave a voice message at 385-419-2470.

Alixel Cabrera is a Report for America corps member and writes about the status of communities on the west side of the Salt Lake Valley for The Salt Lake Tribune. Your donation to match our RFA grant helps keep her writing stories like this one; please consider making a tax-deductible gift of any amount today by clicking here.

Saige Miller is a political reporter for KUER, NPR Utah and co-host of KUER’s politics podcast “State Street.” She previously worked as a reporter and producer for The Tribune’s Innovation Lab.