Contributor: For water and mining policy near Salton Sea, keep in mind local children’s health

Southern California’s Salton Sea was once a tourist playground, with sunny beaches, celebrities and water-skiing enthusiasts on the vast inland lake in the 1950s and 1960s.

Today, these resorts are long gone, replaced by a dried-out and increasingly toxic landscape. As the lake shrinks, wind blowing across the exposed lake bed kicks toxic dust left from years of agricultural chemicals and metals into the lake. This dust enters the lungs of children in the Imperial Valley.

New research from our team of epidemiologists at USC and UC Irvine shows that wind dust hinders the lung growth of children in the region, especially those who live closest to the Salton Sea. In fact, the effects on lung function near the Salton Sea were greater than studies in California’s urban communities near busy roads reveal.

As the lake’s water sources decline due to water use agreements regarding the Colorado River and this region gains more industrial activity through proposed lithium extractionair pollution will likely only get worse.

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. Runoff from irrigation of agricultural fields helped maintain this situation. But over the past two decades, declining water flow has exposed 36,000 new acres of dry lake bed.

The Colorado River’s largest water consumer, the Imperial County Irrigation District, agreed in 2003 to forgo billions of gallons of water each 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, this change is expected to result in an increase in windblown dust of 40 to 80 tons per day. Satellite images show rapid expansion of the exposed lake bed as water recedes.

The predominantly low-income Latino communities living just south of the Salton Sea say they have long been overlooked in conversations about the fate of the sea. Yet these communities face real health consequences, directly linked to regional water policy choices and the lack of action to manage this emerging environmental crisis.

In 2017, we launched a cohort study with more than 700 primary school aged children in five towns in the northern Imperial Valley. We followed these children for several years, documenting respiratory health symptoms and lung function measurements, in addition to household, lifestyle, and behavioral factors.

Our initial findings match what local residents have been discussing for years:

• Nearly one in five children in the north Imperial Valley are thought to have asthma – a rate much higher than the national rate.
• Higher rates of air pollution were linked to poorer overall respiratory health, such as wheezing and coughing, in all children. This indicates that although children with asthma were more susceptible, children without asthma also experienced significant health effects.
• Higher levels of dust exposure, particularly in children living closer to the sea, are linked to lower lung function, as well as reduced lung growth in children over time.

These findings are concerning because lung damage, poor lung function, and respiratory diseases early in life can increase the risk of chronic health problems in adulthood.

Children’s lungs are still developing and their lung function continues to develop throughout adolescence, making children more susceptible than adults to the harmful effects of air pollution.

Children also have a higher respiratory rate than adults, as well as a larger lung surface area relative to their body size, leading to 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 be more exposed to outdoor air pollution.

For years, community members have been concerned about high rates of asthma and poor respiratory health among children and residents.

The new evidence is important as communities and organizations such as the Comito Civico del Valle push for projects that could reduce the amount of Salton Sea dust entering the air, expand education on asthma management and increase access to health care.

The children participating in the study were just starting primary school when they joined the study. Now in high school, this generation grew up near the Salton Sea. Many have suffered from asthma and may face chronic health problems.

After seeing these effects in children living along the Salton Sea, we believe that protecting local air quality is crucial to 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 developments 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 Conversation.