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 lake bed 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 University of Southern California and University of California, 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 with the region’s Colorado River water use agreements, and this region gains more industrial activity from proposed lithium extraction, air pollution is likely to only worsen.
Robyn Beck/AFP/Getty Images
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The problem with the Salton Sea
The Salton Sea – California’s largest inland lake at over 340 square miles – has been shrinking for decades due to drought, agricultural water diversion and climate change. Its 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 lake bed, which release large amounts of dust into the air.
The lake sits 235 feet below sea level in one of the hottest and driest parts of California, approximately 150 miles southeast of Los Angeles and at the northern border of the highly productive agricultural region known as the Imperial Valley.
Its water level has been maintained primarily by agriculture irrigation runoff, which carries with it fertilizers, pesticides, salt and toxic metals. Those chemicals, salts and metals have concentrated over time in the lake bed sediments, and they get stirred up into the air when the wind blows through.
As 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 lake bed 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 lake’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.
Lung damage and slower lung growth
In 2017, we initiated the Assessing Imperial Valley Respiratory Health and the Environment, or AIRE, cohort study with over 700 elementary school-age children across five northern Imperial Valley cities.
The study was built on a partnership with Comité Cívico del Valle, a local nonprofit that has been active in addressing community health and environmental concerns in the Imperial Valley region.
Our study followed these children over several years, documenting respiratory health symptoms and lung function measurements, in addition to household, lifestyle and behavioral factors to account for individual differences.
Our initial findings aligned with what local residents have discussed for years:
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Among children living in the northern Imperial Valley, nearly 1 in 5 are reported as having asthma – far higher than the national rate.
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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, nonasthmatic children experienced significant health impacts as well.
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Our work has also begun to show that 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. Reduced lung function increases the risk for chronic respiratory disease, such as COPD, or more frequent respiratory infections, such as pneumonia, as adults.
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 impacts 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 since children often spend more time outdoors than many adults and tend to engage in more physical activity, that may increase their exposure to outdoor air pollution.
Looking ahead
For years, community members have raised concerns about the high rates of asthma and poor respiratory health among children and residents.
While questions remain about the longer-term impacts of worsening air quality related to the drying Salton Sea, our study adds scientific backing to residents’ experiences. This evidence matters as communities and organizations like Comité Cívico 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 health care services.
The kids in the AIRE 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.
From everything we have seen in the results of our studies involving the children living in communities along the Salton Sea, we believe the protection of local air quality is critical for the health of children in the Imperial Valley, and their health should be in the forefront of planning for future water changes, extraction projects and other development near the Salton Sea.
