California's Largest Lake Is Turning to Dust

The Salton Sea, California's largest lake, is slowly drying up. As it shrinks, the dry lakebed turns into dust that blows through nearby towns. For about 500,000 people living in the area, that dust is a serious health threat — and for some families, it has already been deadly.

Michelle Dugan-Delgado has had asthma her whole life. Every time she leaves her home in California's Coachella Valley, she carries an inhaler and a face mask. She worries that a sudden dust storm could trigger an asthma attack or expose her to harmful bacteria and fungal spores carried in the dust. "I know that it's not safe for me to go outside," she said. "It's like I live in a bubble. I have to really protect myself."

Her fears come from painful experience. Dugan-Delgado has been hospitalized many times because of her asthma. In 2009, her younger sister Marie died of an asthma attack at just 16 years old. Today, her own 13-year-old daughter has asthma, and her 11-year-old son has allergies.

The main source of this dangerous dust is the Salton Sea itself. The lake covers about 343 square miles, but it has been shrinking for decades. Over the last 30 years, it has lost about 20% of its water — roughly 70 square miles. When the wind blows across the dry lakebed, it picks up fine dust and toxic chemicals left behind by nearby farms.

Studies show that children near the lake are much more likely to have asthma than kids elsewhere. One study followed more than 700 school-age children and found that 24% had asthma — compared to about 7% for boys nationwide. More than 70% had allergies, which is more than three times the national average. "The majority of families that I know will have at least one child with respiratory illnesses," Dugan-Delgado said.

The Salton Sea was not always a troubled place. It was created by accident in 1905, when the Colorado River flooded the area after breaking through an irrigation canal. By the 1950s, it had become a popular vacation spot with lakeside resorts. But rising temperatures and water policies that sent water elsewhere caused the lake to shrink, and climate change has made things worse.

Dust storms are a worldwide problem, not just a local one. The World Meteorological Organization says they affect about 330 million people every year. Dust particles can get deep into people's lungs and are tied to breathing problems and heart disease, causing an estimated 721,000 deaths worldwide each year.

California officials are working to restore 30,000 acres of the lake's shoreline by 2028. They have placed hay bales along the shore to hold down dust and planted native plants to keep soil stable. They have also created artificial wetlands to bring water and wildlife back to the area, though experts warn these projects need a great deal of money, water, and time.

Scientists are also building an early warning system so communities know when a dust storm is coming. "Just like you get a weather forecast, you should be able to get a forecast for dust," said Professor Amato Evan of UC San Diego. Dugan-Delgado supports this idea and hopes more families will learn how to protect themselves. "One death is too many and we just got to find a way to stop that," she said.