California’s largest and most polluted lake, Salton Sea, is emitting hydrogen sulfide, a harmful gas that is far faster than the state’s air quality standards. Shockingly, a new study found that California’s air quality monitoring system may have severely underestimated the toxic pollution of people living near the lake.
Hydrogen sulfide smells like rotten eggs and is associated with many respiratory and neurological symptoms. The new study, published in the Journal of Journal, highlights the risks of the Salton Sea emissions pose to nearby communities, many of whom are primarily Latino or Torres Martinez Martinez Desert Kavaira Indians.
“The communities around the Salton Sea are on the frontline of a deteriorating environmental health crisis,” said Mara Freilich, co-author of Brown University’s assistant professor, in a statement. “Our research shows that hydrosulfide emissions are not only stronger than previously captured monitoring, but also systematically reported them, especially when sensors are away from lakes or aligned with prevailing winds.”
The Salton Sea is located about 160 miles (258 km) east of Los Angeles, Palm Springs and the Coachella Valley. It was initially formed by chance in 1905, when the Colorado River violated the irrigation canal. It has no natural inflow or outflow, and is supported primarily by agricultural runoff rich in fertilizers and pesticides, under state law. Since then, the lake has become an environmental disaster. Over the past two decades, climate change, drought and reduced water flows have caused the Salton Sea to lower the water level, increasing the hydrogen sulfide production of the lake and kicking out toxic dust.
To conduct the study, researchers at Brown University, UCLA, Los Angeles, Loma Linda University and UC Berkeley worked with local community organization Alianza Coachella Valley to study the causes of hydrogen sulfide emissions in the lake.
To measure emissions, the researchers used data captured by the South Coast Air Quality Management Area (SCAQMD) monitor installed in three locations by local agencies and placed other sensors in the lake. The study found that between 2013 and 2024, SCAQMD sensors in all three locations consistently exceeded California’s air quality standards. Readings peaked in the summer months, with Torres Martinez, who is closest to the lake, averaged over 250 hours, exceeding state standards every August from 2013 to 2024.
But these fearsome measurements may also be underestimated, the authors wrote. Air quality sensors deployed in shallow water of the lake detected significantly higher concentrations of hydrogen sulfide, especially when winds blow through exposed sediments and shallow water. This suggests that there may be a huge and neglected source of hydrogen sulfide that blows into nearby communities.
“Our results show that a large proportion of them [hydrogen-sulfide] The researchers wrote:
Among many communities in the Salton Sea, only three have air quality monitoring sites.
The problem may get worse. The Salton Sea relief efforts did not keep up with the recovery of water levels, resulting in “severe health effects” in areas already suffering from high levels of asthma and other lung diseases, the study authors wrote.
