A new UCLA study published June 2026 finds Porter Ranch residents experienced 26 more emergency department visits per 1,000 people during the Aliso Canyon gas blowout, with spikes in respiratory, gastrointestinal, and anxiety-related conditions.
A new peer-reviewed study published this week reveals the scale of health damage suffered by residents during the . People living downwind of the natural gas storage facility experienced a significant spike in emergency department visits during and after the disaster, according to research from the .
The study, published June 16, 2026, in the journal Environment International, found that residents of the affected community had 26 more emergency department visits per 1,000 people during the blowout compared to a demographically similar comparison community. That surge remained similarly elevated a full year after the leak was sealed.
"Our study is the first one to examine the broad health impacts of exposure to hazardous air pollutants during the blowout on residents of the affected community," said Nadereh Pourat, director of the Health Economics and Evaluation Research Program at the UCLA Center for Health Policy Research and lead author of the study. "Visits to the emergency department reflect the urgency and intensity of residents' reactions to these pollutants."
The blowout released approximately 109,000 metric tons of methane along with hazardous air pollutants including benzene into the atmosphere over 112 days. Residents reported visible oily residue on buildings and vehicles.
The UCLA researchers broke down the increase in emergency visits by condition:
The spike was most severe in the coldest months. Emergency department visits for acute respiratory infections jumped 14.8 more per 1,000 residents in February 2016 compared to the same month in 2015 and the comparison community. Gastrointestinal symptom visits surged 8.9 more per 1,000 residents in January 2016.
Pourat said comparing the affected community with a demographically similar community allowed the researchers to isolate the disaster's health effects. The team used data from the California Department of Health Care Access and Information to track emergency department visits across three time periods:
The blowout itself ended on February 11, 2016, but the researchers extended the "during" period through April to capture visits after residents returned to homes where pollutants may have lingered on surfaces or in the air.
The UCLA-led Aliso Canyon Disaster Health Research Study operates under a five-year contract with the Los Angeles County Department of Public Health. It is studying both the short-term and long-term health effects of what the researchers call the largest uncontrolled release from an underground gas storage facility in U.S. history.
"Our findings provide important insights into the health consequences of high levels of exposure to hazardous and toxic air pollutants," Pourat said. "These findings highlight the importance of prioritizing the safety of communities living around natural gas storage facilities."
The Aliso Canyon facility remains active. A recent natural gas leak was reported at 10643 N Atlanta Avenue in Porter Ranch on May 30, 2026, according to LAIT911 dispatch records. The Porter Ranch Community Air Monitoring Project continues to operate local air quality stations to track ongoing conditions in the neighborhood.
This article was generated with AI assistance.