Windblown dust from the shrinking Salton Sea harms the respiratory health of children living nearby, triggering asthma, coughing, wheezing and disrupted sleep, USC research shows.

The findings also indicate that children living closest to the sea, who are exposed to more dust in the air, may be the most affected.

The study, published in Environmental Research, found that 24% of children in the area have asthma — far higher than the national rate of 8.4% for boys and 5.5% for girls. The abnormally high rate raises health experts’ concerns about the children’s health in this predominantly low-income community of color 150 miles southeast of Los Angeles.

Furthermore, experts say, the dust problem is likely to intensify in a hotter climate, with evaporation exposing more and more of the lake bed, or playa, leading to more dust events.

Salton sea and health: Conservation efforts making problem worse

Ironically, successful water conservation efforts are compounding the problem. As state conservationists reduce the agricultural runoff that flows into the Salton Sea, the lake is slowly disappearing. A combination of development and lithium mining may promise more economic opportunities — and an increase in truck traffic likely to kick up more dust and further aggravate respiratory health issues.

“These rural environmental justice communities are facing health consequences due to local dust events,” said first author Jill Johnston, an associate professor of environmental health at USC. “The agricultural industry in Imperial Valley has used excessive amounts of water, but one of the impacts of water conservation is the shrinking of the sea.”

The Salton Sea was created by accident in 1905 by a canal system breach. Until recently, the sea was sustained largely by irrigation runoff from adjacent farmland. Over the past two decades, however, the decreasing waterflow has exposed 16,000 new acres of playa — and a lot of dust. Saline lake beds typically contain various harmful particulates — sulfate, chloride, pesticides and toxic metals such as arsenic, lead and chromium.

To better understand the relationship between airborne dust and respiratory health, researchers recruited 722 school-age children from the predominantly Latino/Hispanic community between 2017 and 2019. Parents and guardians completed a 64-item survey about their child’s health history of the previous 12 months, including episodes of asthma, a daily cough for three months in a row, congestion or excess phlegm for three months in a row.

Researchers then used data from a network of regulatory air monitors to estimate exposures to “dust events” in which hourly concentrations of dust exceeded 150 micrograms per cubic meter. The monitors measure levels of particulate matter in the air, including PM2.5 particles (typically from traffic and combustion) and the larger PM10 particles (typically dust and soil).

How far away: Salton Sea and health

The researchers also calculated the distance from the child’s home and the edge of the Salton Sea. Participants living within 7 miles of the sea were considered “close” for the analysis.

The research showed that dust events had a greater impact on wheezing and sleep disturbances among children living closest to the sea. In addition, each deviation increase from the average, annual fine PM2.5 measure resulted in a 3.4 and 3.1 percentage point increase in wheezing and bronchitis symptoms, respectively.

“The community has long suspected that air pollution near the sea may be impacting children’s health,” Johnston said, “but this is the first scientific study to suggest that children living close to the receding shoreline may experience more severe direct health impacts. Protecting public health should be integrated into the mitigation plans.”

In addition to Johnston, other authors included Shohreh Farzan, Elizabeth Kamai, Dayane Dueñas Barahona and Sandrah Eckel, all of USC; Christopher Zuidema and Edmund Seto of the University of Washington; and Luis Olmedo, Esther Bejarano and Christian Torres of Comité Civico del Valle, an Imperial Valley community-based organization.

This work was supported in part by R01ES029598 and 5P30ES007048-21S1 grants from the National Institute of Environmental Health Sciences.

A recent Gallup poll showed public trust in the electoral process — a cornerstone of American democracy — is eroding as the rampant spread of misinformation and organized disinformation campaigns breed dangerous skepticism among voters. Now, with early voting underway and Election Day around the corner, the stakes are higher than ever.

USC News spoke with Kristina Lerman, a senior principal scientist at USC’s Information Sciences Institute and research professor at the USC Viterbi School of Engineering, for insights into why misinformation spreads so easily online and why fighting it with traditional fact-checking may miss the mark.

How does misinformation tap into human psychology, especially emotions like fear and outrage, and why do these emotional triggers make it harder to combat misinformation through traditional methods like fact-checking?

Lerman: Conventional wisdom holds that misinformation is a primary culprit in the divisive nature of social media. The common explanation is that false or misleading content spreads rapidly through digital networks, distorting public understanding and fueling societal rifts. This view has led to widespread calls for fact-checking initiatives and content moderation policies aimed at stemming the tide of inaccurate information.

However, this perspective misses the mark. Truth is often beside the point, and our current approaches to combating it may be fundamentally misaligned with its true nature and impact.

So, is truth really no match for misinformation?

Lerman: The power of misinformation lies not in its factual content, but in the emotional response it elicits. Content that provokes outrage, anger or a sense of injustice can spread rapidly and influence beliefs, regardless of its veracity. Misinformation that triggers fear is one of the most powerful rhetorical devices and has been used in propaganda for centuries.

Weeks after it first surfaced, the tale of immigrants eating people’s pets in Springfield, Ohio, refuses to die. Despite numerous fact checks, rebuttals and heightened public scrutiny, the now-debunked story continues to circulate. Worse still, the unwanted attention has led to bomb threats and a climate of fear and intimidation in the local community.

The story, born and nurtured online, embodies the now-familiar concerns about social media’s role in unraveling the fabric of society. As we scroll through our feeds and navigate digital landscapes, we find an increasingly fractured world marked by growing divides, widespread mistrust and extreme polarization.

What strategies can social platforms adopt to address the emotional and identity-based drivers behind misinformation?

Lerman: Rather than focusing solely on fact-checking, we should consider “vibe-checking” — explaining to the reader who benefits from the spread of this information and who is potentially harmed by it, and what emotional needs it fulfills for its audience.

Acknowledging that the true power of misinformation lies not in its factual inaccuracy, but in its emotional resonance and social function may help dilute its power to divide.

You’ve also said our concept of so-called echo chambers needs an update. What do you mean?

Lerman: Echo chambers in social media have long been cited as a potent driver of polarization. Conventional wisdom suggests that these digital enclaves, where users are exposed primarily to ideas and opinions that align with their own, lead to an inevitable hardening of beliefs and a growing intolerance for opposing viewpoints.

The true power of echo chambers lies not in their ability to isolate people from diverse viewpoints, but in their role in creating shared emotional experiences and collective identities. The echo chambers allow members to talk to each other relatively unchallenged. This emotional dynamic, called othering, allows for marginalizing, excluding or discriminating against the out-group based on arbitrary or perceived differences, such as race, religion or ethnicity.

Over time, this dynamic fosters the development of in-group language — a specialized jargon of inside jokes that become a hallmark of belonging. The combination of shared language and shared emotional experiences cultivates a robust collective identity, transforming the echo chamber from a mere information bubble into a powerful crucible of social cohesion.

On the sun-baked corner of West 67th Street and South Main Street, shade is hard to come by. The nearly 1,000 students enrolled at the adjacent Mary McLeod Bethune Middle School need relief from rising temperatures. Thanks to support from USC’s Urban Trees Initiative, a solution is on the way.

The area will eventually have more than 60 trees lining its streets as part of a $3 million urban greening project made possible with a grant to the city of Los Angeles from the U.S. Forest Service for Urban and Community Forestry. The grant is funded through the Inflation Reduction Act to increase equitable access to trees and nature. USC Trees — a partnership between the city and USC to guide a more equitable urban forest — identified Bethune Middle School as a priority location due to its pollution exposure and lack of shade.

USC Trees is a project of the USC Dornsife College of Letters, Arts and Sciences Public Exchange initiative, which connects academic researchers with policy, industry and nonprofit partners to tackle complex challenges.

Earlier this month, USC Dornsife Public Exchange, the city of L.A. and the L.A. Conservation Corps welcomed Brenda Mallory, chair of the White House Council on Environmental Quality, for a firsthand look at the work being done to combat urban heat, one of the city’s biggest issues, and how various institutions, community groups and levels of government can work together to solve it.

“I think this collaboration shows the value of research universities in dealing with these big social issues,” said Monica Dean, climate and sustainability practice director with the USC Dornsife Public Exchange.

Origins of USC’s Urban Trees Initiative

Dean says the Bethune Middle School project will begin early next year, but the studies that led to this moment were years in the making. USC Trees published its first strategic guide for tree-planting opportunities in 2021, identifying Eastside communities such as Lincoln Heights, El Sereno and Ramona Gardens as high-need areas.

Then, from August 2021 to December 2022, USC Trees began looking into the areas of Boyle Heights, University Park and City Terrace/East L.A. to identify places with the greatest need.

According to USC Trees, in the University Park and South L.A. zone, just over one-fifth of residents are ages 0-14 or 65 and up — two groups who face the highest risk of adverse effects from extreme heat and pollution.

“We’re in a very fortunate position to have faculty who care about the communities that we work in and live in — and who want to work in partnership with the city and nonprofits to help maximize their resources and energy and effort,” Dean said.

A visit from Washington

The visible evidence of the upcoming project is scant: just a few painted markers on the sidewalk that indicate where trees will be planted. But as representatives from the city and USC walked along West 67th Street with Mallory and saw students walking out of the school’s gates, the need for the trees was obvious.

Bethune Middle School lies just east of the 110 Freeway, so the hundreds of thousands of cars passing nearby are clearly visible from where students walk in and out of school. It’s an experience that you can’t get from simply looking at a map, which is why Mallory said visits like this are so important.

“You do get a much better sense of the nature of the challenge and what more may be needed in order to provide additional support,” Mallory said during the visit. “Planting trees is a valuable step, but from a policy perspective, if we’re really serious about expanding access to nature and the availability of nature to all communities, what are some of the other elements besides providing trees that are going to be needed?”

Mallory’s visit to L.A. also included a roundtable discussion at USC Village, where the presidential advisor met with researchers, local government representatives and nonprofit leaders to discuss challenges and current projects addressing urban greening efforts across the city.

USC Urban Trees Initiative: A community partnership

USC Trees is a collaborative effort between the USC Dornsife Public Exchange, the USC Dornsife Spatial Sciences Institute, the USC Dornsife Carbon Census network, the USC School of Architecture’s Landscape Architecture program, USC’s Office of Community and Local Government Partnerships, and the city of L.A.

The site outside Bethune Middle School is just one project of the U.S. Forest Service for Urban and Community Forestry’s grant awarded to the city. The grant will also support the planting of 2,500 street trees along the perimeters of schools and in surrounding neighborhoods, providing improved air quality and multiple health benefits for residents.

According to Amy Schulenberg, tree planting project coordinator for L.A. Sanitation and Environment, the area is emblematic of an “urban heat island” with high traffic and low shade. That’s why planting trees isn’t just for aesthetic purposes.

“If we can lower the ambient temperature in front of our schools and homes, we could save lives out there too,” Schulenberg said.