Study Approach

The Aliso Canyon Disaster Health Research Study will assess short- and long-term effects of the disaster and routine emissions on the health of communities living and working in proximity to the blowout. Following the disaster, a settlement between the State and County with Southern California Gas Company established the parameters and funding for this study.* In December 2022, UCLA was contracted to lead the research. It is a comprehensive assessment comprised of multiple studies that together will form a full picture of the impact of exposure to the emissions on people’s health.

These include:

1) studies of environmental exposures; and

2) studies of health and well-being.

UCLA will collect, use, and analyze multiple data sources. The overall assessment is further informed by the experiences of the communities impacted by the Aliso Canyon disaster and expertise from an independent scientific oversight committee (SOC). UCLA will meet regularly with the SOC to solicit their technical expertise and guidance. UCLA will share the findings with these groups and distribute broadly to illustrate the outcomes of this disaster.

To read more about the main study elements, click on the boxes below:

Environmental Exposure

Environmental Exposures:

  • Assess the composition and amount of emissions released from the facility
  • Examine how emissions traveled through the air
  • Understand where emissions landed and who may have been exposed

Environmental Exposures

UCLA will use various methods to collect and analyze environmental data to document the health risks of living in communities near the Aliso Canyon facility during and after the disaster. The results will provide a clear understanding of the community’s exposure to specific air toxins in specific locations. Knowing the specific exposures helps understand what types of health outcomes could be expected.

UCLA will:

  • Compile and review existing environmental data from the disaster and collect new data on current conditions including measurement of air toxins and particles of interest in homes and outdoors.
  • Develop detailed maps and models that show where the methane plume and other airborne materials flowed during the disaster.
  • Estimate risk of exposure using state-of-the art atmospheric chemistry and statistical models in conjunction with health data, similar to analysis used in other major disaster studies.

Health and Well-Being

Health and Well-Being

  • Search for evidence of emissions exposure in blood samples
  • Ask residents about their physical and mental health experiences and well-being
  • Conduct clinical assessment of residents
  • Examine changes in health and mental health status over time
  • Examine changes in patterns of health care use over time
  • Study prevalence and incidence of cancer

Health and Well-Being

UCLA and its partners will examine how exposure to air toxins impacted the physical health, mental health, and well-being of the residents of communities near the Aliso Canyon facility, using existing and newly gathered data. We will:

  • Examine historic birth records and blood spots collected from infants at birth and conduct clinical exams for traces of methane and other air toxins, which can remain in the body for various lengths of time after exposure.
  • Analyze vital statistics, health care utilization records, and third-party surveys to assess the impact of exposure on general health and trends in health and mental health use before and after the disaster.
  • Conduct surveys and focus groups to understand the impact of the disaster on the community’s physical health, mental health, and quality of life at the time of and following the exposure.
  • Study the cancer registry data to measure changes in incidence and prevalence of specific cancers.
  • Use all data sources to assess the health impact of the disaster on affected communities, including those who are susceptible to worse outcomes such as pregnant women, children and older adults.


Highlighted Methods

The details below are provided in response to community requests for more information on specific study methods.

*Consent Decree
The consent decree following the settlement noted: “The broad goals of the Health Study shall be to contribute to the understanding of the potential short and long-term health impacts of exposure to natural gas and/or the constituents of natural gas.”

Statement of Independence
The conduct of this research and the findings solely represent the views of the UCLA study team and its partners.

Funding Acknowledgment
Funding was provided in full by the Los Angeles County Department of Public Health and secured through a consent decree agreement between the County of Los Angeles, County Counsel for the County of Los Angeles, the Los Angeles City Attorney, the California Attorney General, and the California Air Resources Board with SoCal Gas. The contents do not represent the official views or policies of the State, County, or City.