Utah study: Industrial pollution linked to intellectual disabilities in grandchildren​on October 4, 2025 at 12:00 pm

As Utah families welcomed children in the 1970s and ’80s, many were living just miles from smelters, refineries, mines and manufacturing plants — which were quietly releasing toxins into the air.

​As Utah families welcomed children in the 1970s and ’80s, many lived near refineries and manufacturers that were releasing toxins.  

As Utah families welcomed children in the 1970s and ’80s, many were living just miles from smelters, refineries, mines and manufacturing plants — which were quietly releasing toxins into the air.

Today, the grandchildren of those families are more likely to develop intellectual disabilities — a lingering impact of industrial pollution documented in a new University of Utah study.

The denser the industrial activity around the grandmother’s home, the greater the risk was to the grandchild’s brain development, according to U. research published in August in the journal Science of the Total Environment.

The risk was higher when the maternal grandmother had been exposed to pollution.

[Read more: See how many toxic chemicals were released in your Utah neighborhood last year]

Lead researcher Sara Grineski said the findings underscore the need for stronger regulation of industrial facilities.

“It’s really important, especially as you think about intergenerational equity — what do we need to do to protect our future children and grandchildren?” she asked in a news release about the findings.

Since there haven’t been dramatic changes to regulations about emissions since the 1990s, Grineski added in an interview, and many facilities are still emitting the same types of chemicals, she would expect harmful effects of pollution to continue showing up in future generations.

Grineski and her team analyzed 12,503 industrial facilities that operated in Utah between 1969 and 1995 — some for just one year, others for up to 25 years. For this time period, when the grandmothers and mothers would have been pregnant, they located the companies using Dun & Bradstreet business directories.

In 1987, the U.S. Environmental Protection Agency began recording and releasing emissions data in its Toxics Release Inventory (TRI) program.

Using the TRI data, the researchers examined facilities operating between 2000 and 2014,when the grandchildren were born.

They created a map showing the density of such businesses; those listed in both the directories and TRI data are marked with dual symbols.

Starting with 753 grandchildren diagnosed with intellectual disabilities, they mapped how close their grandmothers lived to these industrial sites during pregnancies with either parent.

They found a consistent pattern: Children were at greater risk of developing an intellectual disability if their grandmothers lived within 2 to 3 miles of industrial activity during pregnancy, Grineski said in an interview.

Industrial polluters still rooted in Utah’s urban centers

Most of the industrial facilities analyzed in the study are clustered near Utah’s largest cities and along major highways — with the highest concentration around Salt Lake City.

That pattern remains today.

In Utah, 220 facilities reported toxic chemical releases in 2024, according to the most recent TRI report, released this week.

That year, they released 243.2 million pounds of toxic chemicals into the environment — the third-highest total in the nation, trailing only Texas and Alaska.

The new TRI data shows an improvement from 2023, when Utah held the top spot in the nation for the number of releases per square mile. Releases had jumped by 103.1 million pounds, compared to 2022.

According to the 2024 report, Utah now ranks second in the nation for total toxic releases per square mile.

In Utah, 63 facilities in Salt Lake County were responsible for 86% of the state’s total toxic chemical releases in 2024 — emitting a combined 210 million pounds.

Most of these industrial sites are concentrated on the county’s west side, with 17 facilities located in a zip code that includes the Poplar Grove and Glendale neighborhoods. Another eight facilities are farther north, near Westpointe, Fairpark, Rose Park and Jordan Meadows.

These facilities, mostly in industries like manufacturing, metal mining, power generation and hazardous waste treatment, are required by law to report how they handle certain chemicals. Their reports must include details about how the chemicals are treated and released into the environment.

The EPA’s Toxic Release Inventory tracks these reports to show what chemicals facilities use in communities, how they manage waste and how the amounts of chemicals and releases change over time.

Communities of color face heaviest pollution burden

A previous environmental justice assessment found that residents on Salt Lake City’s west side are disproportionately affected by Utah’s air quality and pollution.

West side neighborhoods tend to face higher levels of pollution, greater health risks and socioeconomic factors that exacerbate those risks, according to a 2023 EPA assessment.

While Grineski’s study did not look at risk factors by neighborhood, it found that among the children with intellectual disabilities included in the study, most were people of color and more often had younger mothers with lower levels of education.

This aligns with broader research showing that communities of color in Utah are disproportionately impacted by pollution. A 2024 study led by Grineski found that Hispanic and Pacific Islander populations experience the highest exposure to particulate pollution from the Great Salt Lake.

Her work also showed that these groups — as well as people with lower education levels — tend to live in areas with greater exposure to toxic dust and pollutants.

Although regulations on industrial facilities have tightened over the years, Grineski believes the results would likely stay the same if the study focused on children born more recently, since many facilities continue to emit similar types of pollutants.

And industrial activity often produces concentrated toxic pollutants that can persist in soil, air and water for decades, said Roger Renteria, a doctoral candidate in the University of Utah’s Department of Sociology in a university news release.

Grineski, who in recent years has also led studies linking prenatal exposure to ozone, particulate matter and industrial pollution with intellectual disabilities, said she wanted to understand how those exposures might affect future generations, including those who were never directly exposed.

About 1% of Americans have an intellectual disability, according to the study, and prior research has shown that a child’s risk increases with direct exposure to toxins in the womb — such as when a mother accidentally ingests lead or mercury.

However, studies on the intergenerational impacts of industrial pollution exposure remain relatively rare, Grineski said.

She hopes to expand her research to include other health issues linked to air pollution, like asthma, and to explore new ways to measure exposure — such as pollution from traffic near homes.

While no health or environmental agencies have formally responded to the findings, Grineski said she hopes the research sparks stronger regulation of industrial facilities.

“The multigenerational impacts of toxins must be taken seriously by medical professionals, government agencies and anyone concerned with protecting future generations,” she wrote in the study.