Hydrogen sulfide emissions, hypereutrophication, and environmental injustices linked in California’s shrinking lake
Salton Sea, CA — A newly published study reveals that hydrogen sulfide (H₂S), a toxic and foul-smelling gas, is being emitted from California’s Salton Sea at levels far higher and more frequently than previously reported — disproportionately impacting nearby communities already burdened by environmental and socioeconomic stressors.
The research, titled “Hypereutrophication, Hydrogen Sulfide, and Environmental Injustices: Mechanisms and Knowledge Gaps at the Salton Sea,” was authored by a diverse team of scientists and community advocates from institutions including Brown University, UCLA, Loma Linda University, UC Berkeley, and local nonprofit organization Alianza Coachella Valley.
“The communities around the Salton Sea are on the front lines of a worsening environmental health crisis,” said co-author Dr. Mara Freilich, assistant professor at Brown University. “Our study shows that hydrogen sulfide emissions are not only more intense than previous monitoring captured, but they are systematically underreported — especially when sensors are placed away from the lake or out of alignment with prevailing winds.”
Key Findings:
- Hydrogen sulfide emissions from the Salton Sea routinely exceed California’s air quality standards, especially during the hot summer months.
- Wind direction plays a critical role in whether toxic gases reach community air sensors — creating significant blind spots in public monitoring data.
- Community-deployed sensors located closer to or within the lake detected much higher H₂S concentrations, suggesting exposed sediment and shallow waters are major, overlooked sources.
- Impacted communities are primarily Latinx and Indigenous (Torres Martinez Desert Cahuilla Indians), and already face elevated rates of asthma and other respiratory illnesses — raising urgent environmental justice concerns.
The Salton Sea, California’s largest inland lake, is rapidly shrinking due to water diversion policies and climate change. The resulting drop in water levels has intensified hypoxic conditions that drive the formation of hydrogen sulfide — a compound known to cause headaches, nausea, fatigue, and long-term neurological and respiratory effects at even low levels of exposure.
“This is a textbook case of environmental injustice,” said Aydee Palomino, project manager for the Campaign for Thriving Salton Sea Communities at Alianza Coachella Valley. “People in the Coachella and Imperial Valleys are breathing in pollutants that are under the radar of traditional monitoring systems. Our work highlights the power of community science to expose these gaps and push for equitable solutions.”
Implications:
- The study calls for improved and more strategic air quality monitoring, especially in frontline communities.
- Researchers emphasize community-led initiatives as essential to both data collection and environmental advocacy.
- Findings may be relevant to other shrinking lakes and inland water bodies globally that are experiencing similar environmental and public health dynamics.
“Community residents exposed to hydrogen sulfide are affected not only in terms of their physical health—experiencing respiratory irritation, headaches, and fatigue—but also in their overall quality of life. As the Salton Sea’s shoreline continues to recede, exposing newly formed playa and increasing sulfate concentrations, there is growing concern that hydrogen sulfide emissions will become more frequent and more intense,” said Diego Centeno, PhD student at UCLA and researcher at Brown University.
This research adds to a growing body of evidence connecting water management, climate change, and air quality — urging policymakers to consider both environmental science and community voices in future planning.
Media Contacts:
Mara Freilich
Department of Earth, Environmental, and Planetary Sciences, Brown University
Email: mara_freilich@brown.edu
Braxton Kellogg
Director of Strategic Communications & Public Relations, Alianza Coachella Valley
Email: braxton@alianzacv.org
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