Southern California’s Salton Sea was once a resort playground, with sunny beaches, celebrities and people waterskiing on the vast inland lake in the 1950s and ’60s.
Today, those resorts are long gone, replaced by a drying and increasingly toxic landscape. As the lake shrinks, wind blowing across the exposed lakebed kicks up toxic dust left by years of agriculture chemicals and metals washing into the lake. That dust makes its way into the lungs of the children of the Imperial Valley.
New research from our team of epidemiologists at USC and UC Irvine, shows that blowing dust is impeding the lung growth of children in the region — especially those living closest to the Salton Sea. In fact, the effects on lung function close to the Salton Sea have been greater than what studies find in urban California communities near busy roadways.
As the lake’s water sources diminish because of water use agreements regarding the Colorado River, and as this region gains more industrial activity from proposed lithium extraction, air pollution is likely to only worsen.
The Salton Sea — California’s largest inland lake at more than 340 square miles — has been shrinking for decades. It was created by a break in a canal carrying water from the Colorado River in the early 1900s. Irrigation runoff from farm fields kept it going. But over the past two decades, decreasing water flow has exposed 36,000 new acres of dry lakebed.
The largest consumer of Colorado River water, Imperial County’s irrigation district, agreed in 2003 to forgo billions of gallons of water every year to support growing urban areas — a plan that went into full effect in 2018. That meant less runoff into the lake. By one estimate, the change was projected to increase windblown dust by 40 to 80 tons per day. Satellite images show rapid expansion of exposed lakebed as the water has receded.
The predominantly low-income Latino communities that live just south of the Salton Sea say they have long been overlooked in conversations about the Sea’s fate. Yet, these communities are facing real health consequences tied directly to regional water policy choices and lack of action to manage this emerging environmental crisis.
In 2017, we initiated a cohort study with more than 700 elementary-school-age children across five northern Imperial Valley towns. We followed these children over several years, documenting respiratory health symptoms and lung function measurements, in addition to household, lifestyle and behavioral factors.
Our initial findings aligned with what local residents have discussed for years:
- Nearly 1 in 5 children in the northern Imperial Valley are reported as having asthma — far higher than the national rate.
- Higher rates of air pollution were linked to overall poorer reported respiratory health, such as wheezing and coughing, among all children. That indicates that while asthmatic children were more sensitive, non-asthmatic children experienced significant health effects as well.
- Higher levels of dust exposure, especially among those children living closer to the sea, are linked to poorer lung function, as well as reductions in children’s lung growth over time.
These findings are concerning because lung damage, poor lung function and respiratory illness in early life may increase the risk of chronic health problems into adulthood.
Children’s lungs are still developing, and lung function continues to mature throughout adolescence, making children more susceptible than adults to the adverse effects of air pollution.
Children also have higher respiratory rates than adults, as well as larger lung surface area relative to their body size, resulting in higher doses of pollution per breath. And because children tend to spend more time outdoors than adults and engage in more physical activity, they may have higher exposure to outdoor air pollution.
For years, community members have raised concerns about the high rates of asthma and poor respiratory health among children and residents.
The new evidence matters as communities and organizations such as Comito Civico del Valle push for projects that can reduce the amount of Salton Sea dust that gets into the air, expand education on asthma management and increase access to healthcare.
The kids in the study were just starting elementary school when they joined. Now in high school, this generation has grown up near the Salton Sea. Many have dealt with asthma and may face chronic health problems.
Having seen these effects among children living along the Salton Sea, we believe the protection of local air quality is crucial for the health of children in the Imperial Valley. Their health should be at the forefront as the public and private sectors plan future water changes, extraction projects and other development near the Salton Sea.
Jill Johnston is an associate professor of environmental and occupational health at UC Irvine. Shohreh Farzan is an associate professor of population and public health at USC. This article was produced in partnership with the Conversation.
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