As the Salton Sea shrinks, is enough being done to protect public health?

Mothers located around southern California’s Salton Sea don’t just have the usual worries about broken bones or bullies. Many have additional concerns that childhood nosebleeds, skin rashes, and asthma attacks could carry long-lasting impacts.

The Salton Sea is shrinking. By 2030, up to 11,000 acres of playa, the salty sediments left when the sea recedes, will be exposed. Fed by the Colorado River, agricultural runoff from Coachella Valley to the north, and Imperial Valley to the south has made the lake a repository for decades worth of pesticides, heavy metals and microorganisms. And now these potential toxins are blowing in the wind. Dwindling inland lakes — including the Salton Sea, Owens Lake, and the Great Salt Lake — are among the top dust sources harming public health across the Western United States.

Salton Sea communities are home to large populations of farmworkers. On the Northwest side of the lake, the Coachella Valley is better known for its glamorous music festival than the 70,000 acres of veggies and orchard crops. To the Southeast lies Imperial Valley’s 500,000 acres of lettuces, melons, broccoli, carrots, spinach and onions. Most of Imperial workers live in Mexicali, across the border. More than a fifth of Imperial residents live in poverty; a third lack air conditioning despite the heat. 

Not only is the air quality decreasing, the number of extreme heat events is on the rise. Imperial County experienced 117 days above 100 degrees in 2022. One of the biggest concerns is that scorching temperatures increase the toxicity of pesticides, which in turn may exacerbate respiratory distress in the region. 

The best existing estimates are that roughly 20-22% of the population closest to the Salton Sea exhibits asthma-like symptoms — compared to the California state average of 14.5%. The region also has double the rate of child emergency room visits for asthma compared to the rest of the state, and eight-fold higher tuberculosis rates than the rest of the nation. But the asthma data are likely an underestimate since many of the farmworkers are undocumented immigrants who seek medical treatment across the border in Mexicali, according to medical anthropologists studying public health in disadvantaged, rural communities. And there is new evidence that air pollution is fueling rising tuberculosis rates in Mexicali as well as Imperial Valley. 

Partnering with a group of community health care advisors, or promotoras de salud, I will detail the conditions that farmworkers face — from abysmal air quality, brutal temperatures, skyrocketing rates of asthma, and pesticide exposures — as they harvest the nation’s winter vegetables in the dust-ridden Coachella and Imperial Valleys. I will also report on efforts by the local authorities tasked with improving air quality in eastern Coachella Valley. Assembly Bill 617 requires the California Air Resources Board and air districts to develop and implement emissions reporting, monitoring, reduction plans and measures in an effort to reduce air pollution exposure in disadvantaged communities. But is it enough — especially this year?

As Colorado River water cuts threaten to further dwindle the flows that ultimately feed agriculture as well as the Salton Sea, this year promises to reveal what continued aridification will mean to public health in the region. My project for the 2023 Health Equity Impact Fund will not only highlight the experiences of impacted communities, but will also document whether the steps that have been taken to improve air quality and protect public health have had meaningful impact.

These vulnerable, neglected communities are eager for information about the air pollution they endure, any efforts to mitigate the dust and its impacts, and the science uncovering the health risks they face.