State Senate Advances Legislation Mandating Stricter Air Standards to Better Protect Residents Near Tijuana River
SACRAMENTO – This week, the California State Senate approved Senate Bill 58 by Senator Steve Padilla (D-San Diego), which will update California’s air quality standard for hydrogen sulfide (H2S), a gas that is found at high concentrations in the Tijuana River Valley and the Salton Sea region. California’s hydrogen sulfide standard has not been updated since 1969.
H2S is a colorless gas that smells of rotten eggs. It is commonly found in natural gas and oil extraction and is a natural emission from geothermal fields. It is also present during bacterial decomposition of human and animal waste. Exposure to H2S can cause headaches, nausea, eye and respiratory irritation and current evidence indicates that chronic exposure can contribute to persistent respiratory and neurological impacts, with heightened susceptibility among children, older adults, and individuals with preexisting health conditions. The gas is found in exceptionally high quantities in the Tijuana River Valley and the Salton Sea region.
The California Ambient Air Quality Standard (CCAAQS) for H2S was established by the California Air Resources Board (CARB) in 1969, at 0.03 parts per million (30ppb), averaged over one hour. This standard was developed to control odor nuisance, not to protect public health. The last review of the standard occurred in 1984, when the California Department of Public Health concluded that the existing standard was adequate. It concluded that tightening the standard would have only a “disappointingly small effect” on reducing odor intensity. The 1984 review focused on odor detectability and annoyance thresholds, not toxicological or epidemiologic data. No comprehensive review has been conducted in over four decades, despite advances in understanding chronic and low-level H2S health risks.
“Our communities suffer from the effects of overexposure to this gas every day,” said Senator Padilla. “This update is long overdue and needs to happen quickly.”
SB 58 would require the California Air Resources Board to conduct a comprehensive review of the current Hydrogen Sulfide standard and adopt an updated standard if necessary. In conducting the review, the board shall conduct at least three public workshops, including at least one in the TJRV region, one in the Salton Sea region, and a third in another overburdened community.
SB 58 is supported by the leading scientists studying the impacts of the pollution in the Tijuana River Valley.
“SB 58 addresses a critical gap: California's hydrogen sulfide standard hasn't been updated since 1969 and was designed for odor nuisance, not chronic health protection,” said Dr. Paula Stigler Granados, Division Head – Environmental Health, School of Public Health at San Diego State University. “Modern science shows long-term, low-level exposure causes persistent health impacts. Communities exposed to toxic air deserve protections grounded in evidence on long-term health effects, not outdated data. I urge the Assembly to support this legislation.”
“SB 58 positions California as both a national and global leader in addressing how poor water quality can directly degrade air quality and harm public health,” said Dr. Kimberly Prather, Distinguished Chair in Atmospheric Chemistry and a Distinguished Professor at UC San Diego, with joint appointments at Scripps Institution of Oceanography and the Department of Chemistry and Biochemistry. “By grounding policy in modern science and real-world exposures, this bill takes an essential step toward protecting communities affected by pollution at the water–air interface.”
“As SB 58 moves through the Assembly, the proposed changes are an important first step toward protecting communities,” said Isabella B. Arzeno-Soltero, Assistant Professor in Civil and Environmental Engineering at UCLA. “We must take a closer look at the hydrogen sulfide standard and what levels are truly dangerous. It’s deeply concerning that we still rely on outdated limits, especially as new research and community members’ experiences continue to show how this gas affects their health and quality of life. It is evident that the current standard isn’t enough. Passing this bill is critical to moving our work forward.”
Senator Padilla has authored several measures to address the public health crisis at California’s Southern Border. To read more about Senator Padilla’s previous efforts to address the pollution in the Tijuana River Valley, click here, here and here.
SB 58 passed the Senate with bipartisan support 39-0 and passed the Senate Environmental Quality Committee 7-0. The bill now heads to the Assembly.
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Steve Padilla represents the 18th Senate District, which includes the communities of Chula Vista, the Coachella Valley, Imperial Beach, the Imperial Valley, National City, and San Diego. Prior to his election to the Senate in 2022, Senator Padilla was the first person of color ever elected to city office in Chula Vista, the first Latino Mayor, and the first openly LGBT person to serve or be elected to city office. Website of Senator Steve Padilla: https://sd18.senate.ca.gov/