Une "mer" toxique à Coachella ?!

While Coachella festival in the Californian desert presents an image of glamour, a severe environmental and health crisis is unfolding just tens of kilometers away. Videos circulating after each festival edition highlight health issues, particularly respiratory problems, which are significantly above the state average in areas less than 30 km from the festival grounds. These issues disproportionately affect Latino and indigenous communities, including many children, and are concentrated around the Salton Sea, California's largest lake. The Salton Sea, a landlocked body of water without sufficient natural river input, emerged suddenly in the early 1900s due to a massive infrastructure project. Entrepreneur Charles Rockwood envisioned transforming the desert-like Imperial Valley into an agricultural paradise by constructing a large irrigation canal from the Colorado River. Initial efforts in 1901 proved insufficient. In 1904, Rockwood ordered a new, wider trench to be dug. During significant Colorado River floods, a dike broke, and immense quantities of water flowed into a dry basin, the Salton Basin, forming the Salton Sea. This event was deemed a severe and criminal error. Nearly 400 members of the indigenous Cahuilla people, who had inhabited the region for centuries, were forced to flee, losing almost half of their land reserves. It took engineers two years, until 1907, to stop the water flow, by which time the desert had been replaced by a vast lake, the third largest in the United States, roughly five times the size of Marseille. In the subsequent years, the lake became a stopover for pelicans and other wildlife, attracting many birds to the desert. Historically, a lake had naturally formed and receded in this location multiple times over millennia, serving as a vital resource for the Cahuilla ancestors, providing fish, hunting grounds, and reeds. Some scientists believe the lake might have reformed naturally even without human intervention. Despite initial expectations that the lake would evaporate within years, it entered a golden age in the 1960s, becoming a popular destination for celebrities like Frank Sinatra and the Beach Boys. The region, dubbed the "California Riviera," boasted beaches, boating, waterskiing, sport fishing, and large parties, attracting 1.5 million visitors annually—more than Yosemite National Park at the time. However, this prosperity was short-lived. Today, around the Salton Sea, one in four children suffers from asthma, three times the national average. Emergency room admissions for childhood asthma attacks in the county are nearly twice as frequent as in the rest of California, and at least two children have died from asthma attacks in the last 20 years. Recent studies indicate the region is also affected by other respiratory issues, including nosebleeds, allergies, and sleep difficulties, with figures potentially underestimated due to population decline. Entire tourist areas are now abandoned, but many residents, like those in Bombay Beach where over 60% lived below the poverty line in 2021, cannot afford to leave. The area is now one of California's most polluted. As early as 1993, the Coachella Valley was classified as a severe non-attainment area for PM10 particles—suspended particles less than 10 micrometers in diameter that can deeply penetrate the respiratory system. Even finer PM2.5 particles, strongly linked to increased lung cancer risk, are also present, causing the Salton Sea valleys to "suffocate." Research, including that by biomedical scientist Kesia Israel, has established a link between Salton Sea dust and lung inflammation. The Imperial County consistently fails air pollution assessments by the American Lung Association and experiences frequent, impressive dust storms that cause road accidents and contribute to the "Coachella cough." These dust storms have been compared to the 1930s Dust Bowl, which devastated the Midwest, causing severe, often fatal, respiratory illnesses and displacing two million people. In September 2012, a strong rotten egg smell, hydrogen sulfide, emanating from the Salton Sea, traveled over 250 km to Los Angeles, irritating eyes, nose, and lungs. Local schools in the two valleys have implemented a color-coded flag system to indicate air pollution risk, requiring children to stay indoors on "red flag" days. Access to healthcare further exacerbates the problem; in 2010, eastern Coachella Valley had only one doctor per 8,400 residents, about eight times less than the California average, compounded by language barriers, fear of deportation, and lack of health insurance. Over the last 30 years, the Salton Sea’s surface area has shrunk by 180 km², nearly 20% of its total. As a landlocked lake, water only exits through evaporation, leading to increased salinity and concentration of pollutants. For a long time, the lake’s water level was maintained by agricultural runoff from the Imperial Valley, sourced from the Colorado River. However, a 2003 agreement, the largest agricultural water transfer in US history, diverted billions of liters of water annually from the lake to areas like San Diego County. This, along with other water transfers, conservation measures, droughts, and climate change, significantly reduced water flowing into the Salton Sea. Consequently, vast areas of exposed lakebed, known as "playa," have appeared. Between 2003 and 2022, nearly 145 km² of playa emerged, equivalent to about 20,000 football fields. The Salton Sea is now more than twice as salty as the ocean, making it uninhabitable for many fish species, such as perch and croaker. This evolution also leads to the death or departure of numerous birds. The agricultural runoff, rich in fertilizers, fuels algal blooms, which deplete oxygen and contribute to hydrogen sulfide production. In a region with strong winds, dust from the playa, laden with PM10 and PM2.5 particles, is easily lifted and dispersed, traveling over 160 km. A recent report indicates that the amount of particles from the lake is increasing, threatening the health of over 500,000 people, though other sources like desert dust, unpaved roads, and agricultural operations also contribute to air pollution, including ozone, pesticides, and other chemicals not directly linked to the lake. In 2014, scientists estimated that inaction would cost up to $70 billion, considering biodiversity loss, land value depreciation, and public health costs. Despite alerts since the 1960s, authorities have largely failed to prevent the lake's desiccation. California state and local actors are now addressing the existing playa by using straw, drip irrigation, and other measures to reduce dust and particle emissions. They are also creating new natural areas and wetlands to suppress dust, provide habitat for birds and fish, and reduce pollutant emissions. By 2024, approximately 40% of the 145 km² of playa that appeared since 2003 had been subject to dust reduction or wetland creation projects, costing tens of millions of dollars. A 2025 report acknowledges some benefits but states that these measures only address a small fraction of the region's total air pollution. It suggests it might be too late to tackle all root causes due to prohibitive costs, recommending instead to strengthen population adaptation measures, such as informing residents about dust storms, installing air filters, and improving home insulation. However, this approach raises questions about its effectiveness for outdoor workers and the long-term impact on wildlife and the environment if the lake is not maintained. Adaptation measures are also costly, with air filters and insulation for a home estimated at around $4,200, posing accessibility challenges for vulnerable populations. A new development emerged in late 2023: the US Department of Energy confirmed that approximately 18 million tons of lithium, valued at around $540 billion and representing one-third of global demand, are trapped 1 to 3 km beneath the Salton Basin. Companies are already planning to extract this "white gold," used in batteries for phones, computers, and electric cars. Some see this as a solution for the Salton Sea, bringing new jobs and revenue to address the region's problems. However, local associations fear additional pollution and negative consequences for residents, having filed a lawsuit to halt these projects. The juxtaposition of the Coachella Valley's luxury image with the harsh realities faced by workers and communities in the same region highlights a profound disparity.