California's Salton Sea Drying Up, Causing Dust Storms and Health Crises

Michelle Dugan-Delgado has had asthma for as long as she can remember. It's why she always takes an inhaler and face mask with her when she leaves the house — just in case the wind picks up and a dust storm hits.

"I know that it's not safe for me to go outside,” she told DW. "It's like I live in a bubble. I have to really protect myself.”

If dust enters her lungs, it could trigger an asthma attack. Invisible bacteria, fungal spores and viruses carried by dust could also cause a life-threatening infection.

"If I'm outside and a dust storm hits, there's a very high chance I'm going to catch something, which means I will end up in the hospital,” the 35-year-old said.

Dugan-Delgado knows the dangers well enough. She's been hospitalized multiple times. Asthma has also taken a deadly toll on her family. In 2009, her younger sister Marie died of an asthma attack at the age of 16.

"It wasn't anything that we thought would take her life away,” she said. "It's painful to talk about it because I have a lot of survivor's guilt.”

Dugan-Delgado lives in the Coachella Valley, an agricultural hub in California's far south that's surrounded by desert. She believes the poor air quality there is to blame for making her and Marie sick.

Dusty air near an evaporating lake

Dust storms are common in the region, which is home to around 500,000 people.

A major source of that dust is a huge lake that's steadily drying up. Spanning some 343 square miles (888 square kilometers), the Salton Sea is California's largest lake. But it's rapidly shrinking. When winds sweep over the exposed lakebed, they pick up the parched sediment, producing harmful dust storms.

Children living near the lake have been found to have disproportionately high rates of asthma. One study that followed more than 700 primary-school aged children over a number of years found that 24% reported having the condition — far higher than the national rate of about 7% for boys and 5.5% for girls. Over 70% had allergies — more than three times the national average.

"The majority of families that I know will have at least one child with respiratory illnesses,” said Dugan-Delgado. "That's really heartbreaking.”

Her own 13-year-old daughter has asthma, and her 11-year-old son has allergies.

From paradise to environmental crisis

The Salton Sea was formed by accident in 1905 when the Colorado River burst an irrigation canal gate and flooded the area. Since then, the waterbody has been maintained by continuous agricultural runoff/irrigation wastewaters and local rivers.

It became a popular holiday spot in the 1950s, with trendy lakeside resorts drawing tourists and celebrities. But then the water levels started to drop, partly due to a hotter climate and policies that diverted water away. In the last 30 years, the lake has shrunk by around 20%, or 70 square miles.

The exposed lakebed holds more than just dust, though. Pesticides and other toxic chemicals from farms are also left behind to be picked up by the wind, only worsening air quality in the region.

Climate change driven by the continued burning of fossil fuels is leading to hotter temperatures and prolonged drought that's making desert regions around the world more arid. That makes it considerably harder for plants to grow and stresses water resources, according to Amato Evan, a professor of climate science at the Scripps Institution of Oceanography at the University of California, San Diego.

"Dust storms are definitely becoming more frequent over time,” he said.

Globally, at least a quarter of the dust in the air comes from human activities, including off-roading, deforestation, and unsustainable agricultural practices like tilling and overgrazing.

Lakes that are drying up are also major producers of dust — from California's Salton Sea to Iran's Lake Urmia. The shrinking Aral Sea, for instance, has made Central Asia 7% dustier over the last 30 years.

Damaging for the economy and human health

More than half of the world's dust emissions come from the Sahara Desert in North Africa. If the wind is strong enough, that dust can rise up to 5 miles into the sky and travel over vast distances — across the Atlantic toward the Americas, or over the Mediterranean to Europe.

The World Meteorological Organization says sand and dust storms impact about 330 million people every year. They can engulf entire cities, ground flights, decimate crops and cause deadly traffic accidents.

And then there's the toll on human health.

"This is the number one adverse impact: it's humans breathing in dust,” Evan says.

Dust particulate matter can get lodged deep in the lungs and is linked to serious respiratory illnesses and heart disease. It accounts for about 721,000 deaths worldwide each year, with children, the elderly and people with lung conditions most at risk.

Living with dust

Dugan-Delgado says her lungs are continuing to deteriorate. Meanwhile, the Salton Sea is predicted to continue shrinking.

State and local authorities have launched a series of projects as part of a plan to restore 30,000 acres of the lake's dusty shoreline by 2028. Thousands of hay bales have been laid out along the shore to hold down dust. They've also planted native vegetation in an attempt to stabilize the soil and pumped in water to make artificial wetlands for wildlife.

Evan says initiatives such as planting native vegetation can work well at some sites to combat desertification. But he points out that it needs a lot of investment, water, and time.

"All of those things are resources that are not in infinite supply,” he says.He and his team are currently developing an early warning system to alert communities when a dust storm is approaching.

"Just like you get a weather forecast, you should be able to get a forecast for dust,” he says.

Dugan-Delgado says she'd welcome a warning system for dust storms. She'd also like to see more attempts to raise awareness about the risks of living with dust pollution, so that others know how to protect themselves and their kids.