Frequently Asked Questions (FAQs)
The UCLA Team responses to community questions reflect the team’s current Study plans and understanding of the evidence available to date. These responses may be updated as new evidence and further discussions could lead to changes in Study methodology.
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Identifying Gas Components During the Blowout
UCLA is collecting all available data related to chemicals released during the blowout. While the Southern California Gas Company (SCG) is not required to disclose the various chemicals in its gas, UCLA will make every effort to obtain this information.
We will:
- Request data from Los Angeles (L.A.) County that was previously obtained from Southern California Gas (SCG) during legal proceedings. Los Angeles County has shared this information.
- Request comprehensive chemical composition data from emissions from the Aliso Canyon facility through agencies that have regulatory oversight over SCG.
- Seek permission from SCG’s legal counsel to access the relevant chemical data.
- Review other studies related to natural gas composition that have been shared with L.A. County.
- Review industry-reported emissions data, as required by South Coast Air Quality Management District (AQMD) regulations and California Air Resources Board (CARB) regulations.
- Submit public records requests, to acquire information that is not readily accessible to the public.
- Examine various reports from agencies, such as Office of Environmental Health Hazard Assessment (OEHHA), and consultants, such as Blade Energy, which have characterized the well kill fluids and muds in previously published public reports.
- Examine archived soil samples provided by L.A. County to detect potential contaminants near the wellhead site.
- Obtain current samples of gas delivered to homes in the community.
Determining the Impact Zone
The primary impact zone is a five- to six-mile radius south of the blowout site. The impact zone was determined based on:
- Remote sensing satellite retrievals of methane, which is the main part of natural gas and an indicator for associated air toxins;
- Self-reported symptom data from LACDPH;
- Local methane monitoring data collected during the blowout; and
- A sophisticated chemical transport model that modeled emissions.
For further discussion on the methodology used to arrive at the impact zone, please refer to Community Meeting #2.
Indoor and Outdoor Air Monitoring
We aim to assess the ambient air quality and potential emissions outdoors and at residences near the Aliso Canyon facility. This newly collected data will help us better characterize any potential ongoing emissions, how those emissions may travel through air, and where those emissions travel within the community.
The Study includes indoor air quality monitoring of emissions that could occur during natural gas appliance usage and from other pollution sources. Specifically, we aim to identify any potentially harmful chemicals present in the gas supplied to homes near the Aliso Canyon facility. In addition, we will collect gas samples directly from pipes that transport gas to residences to gain insight into gas composition before it is used.
These steps will afford a more holistic understanding of the potential sources of exposures associated with the natural gas facility.
Measuring Topographical/Canyon Effects
We will use exposure models and atmospheric chemistry and transport models that account for the presence of canyons and other topographical variations to accurately characterize potential exposure to the blowout. We will use “distance decay models,” which will further identify areas of highest exposure and can assess whether health effects are more severe in those areas.
We will also place air pollution monitors and collect air samples in areas affected by the canyon winds because air flow through the nearby canyons could influence where chemicals emitted from the facility are currently dispersed and where they may have been dispersed during the blowout.
Focus on Exposure vs. Health Impact Assessment
The Study encompasses a comprehensive cancer assessment. Our approach combines both risk assessment and an examination of actual cancer data. Data from the California Health Map and Cancer Registry will provide detailed insights into cancer diagnoses within the impact zone, spanning periods before, during, and after the disaster. This dual approach is paramount for comprehensive analysis and the ability to provide meaningful and plausible explanations for any elevated cancer rates we may encounter.
Analyzing cancers can be particularly challenging due to their long latency periods, which is the time between exposure to a carcinogen and the manifestation of the disease. Therefore, our approach focuses on cancers with shorter latency periods, including various blood cancers. We will also examine cancers known to have associations with contaminants emitted from the facility, such as blood cancers due to their known connection to benzene exposure and nasopharyngeal cancers linked to formaldehyde exposures. We are also studying if health care use patterns for patients with cancer change.
Clinical assessments and medical testing will be comprehensive. The Study involves the use of metabolomics, an approach that allows for the identification of thousands of chemicals and metabolites in participants’ blood, encompassing various pollutants that may remain in the body for many years. We will also examine health status, lung function, hematologic (i.e., blood) impact, and inflammation markers. In addition, data from the disaster period and a symptoms survey will be incorporated to address the lack of published medical data on chemical exposure effects.
The exposure and health impact assessments are essential elements of understanding the impact of the blowout. The Study approach balances evidence obtained from direct resident assessments, focus groups, and surveys; existing health care utilization, birth records, and blood samples; and environmental exposure data.
We will conduct clinical assessments to gather evidence of potential exposures during the blowout and current health status of residents. We will use exposure data to determine the likelihood of developing specific health conditions due to the exposure.
Measuring Short- and Long-Term Exposures and Outcomes
We are using various methods and sources to collect data from before, during, and after the disaster. Some of our data sources including the neonatal blood samples, health care utilization records, cancer registry, and the California Health Interview Survey (CHIS) were collected before, during, and after the blowout. Additionally, we are actively working to obtain data from legal settlements.
For exposure, we will estimate short-term exposures using available datasets collected during the blowout to model and characterize emissions, understand how they traveled, identify were they landed during the disaster, and develop a detailed risk assessment. We will measure long-term exposures by conducting indoor/outdoor air quality monitoring and by monitoring methane emissions from the facility using new remote sensing techniques during normal operations.
For the health impact assessment, we will measure short-term impact by analyzing existing data on birth outcomes of the blowout for pregnant women who were exposed during their third trimester; the neonatal blood samples to examine impact of the blowout on newborns; and rates of hospitalizations, emergency department visits, and doctor visits during the blowout.
We will measure the long-term impact by conducting clinical assessments, examining the rates of hospitalizations, emergency department visits, and doctor visits after the blowout; surveys and focus groups of current and past residents; and likelihood of developing cancers associated with exposure to gas. We will use statistical methods to distinguish between short- and long-term effects, particularly when assessing health impact.
Study Participation
While there’s a desire to include everyone, representativeness of the sample must be prioritized, which could mean not everyone who wants to participate can be included.
We will select 2,000 individuals (1,400 from the impacted community and 600 in comparison areas) to participate in the survey. To achieve a representative sample of the affected community, survey participants will be selected utilizing a rigorous address-based approach that takes into account factors such as race, ethnicity, socioeconomic status, and proximity to the wellhead within a 5 to 6-mile radius to the south.
The selected individuals will receive a letter requesting their participation in the survey. From the pool of 2,000 survey participants, we plan to select 600 individuals (400 from the impacted community and 200 in comparison areas) for the Study’s clinical assessments and medical testing with the goal of achieving a representative sample.
Identifying the Comparison Communities (Control Groups)
We created a set of standards to identify a comparison community similar to the impact zone. We considered income levels and racial and ethnic composition of the population as well as environmental conditions such as distance from possible sources of pollution like landfills and oil wells. We selected comparison communities that are in or near Los Angeles County and demographically similar to the impact zone. We did not use comparison communities in areas further away because that would introduce environmental, social, and contextual variations that are not quantifiable and would restrict our ability to draw meaningful conclusions.
Studying Specific Subpopulations in the Impact Zone
We will identify individuals who lived in the area during the blowout but have since left using multiple data sources and methods including mobility tracking and health utilization data. We are actively seeking legal settlement information and welcome the community’s input to comprehensively account for these changes. Individuals who have moved away or died since the blowout will be included in the analysis of the California Health Interview Survey and health care utilization data. Individuals who moved away since the blowout may also be eligible to participate in the focus groups.
The Study is primarily a population-based study, designed to determine if people living in the community closest to the natural gas facility experienced a higher level of health impact that can be attributed to the blowout or ongoing operations of the facility than those living far away. This approach will also help to answer questions about whether people in the community are at higher risk of developing certain medical conditions or diseases in the future, so that residents can take measures to screen for exposure and take preventative measures.
In addition, as part of the Study, we are developing a comprehensive list of the types of medical tests that communities that face these exposures can request from their own physicians. We have further provided the opportunity to hear directly from community members about their experiences in community meetings.
Sharing the Study Findings and Recommendations
Our objective is to provide a comprehensive assessment of exposure and health impacts of the blowout and the most robust and scientifically sound information possible to inform public health decisions.
Our findings can be used by regulatory agencies, policymakers, health care providers, and community organizations to inform local responses and/or actions that support the recovery and the health of the impacted communities. While we aim to supply valuable insights that can assist regulators and communities in establishing standards or limits related to natural gas health hazards, it is not within our purview to identify standards or regulations.
Similarly, while the UCLA Team excels in studying emissions and their potential health impacts, we may not possess the expertise needed to manage natural gas storage fields and thus to make regulatory recommendations. Therefore, while we can offer general guidance, we acknowledge that the specifics of implementation may require the involvement of regulatory authorities with the necessary expertise to ensure the safety and well-being of the community.
The Study is planned for five years and will come to completion at the end of October 2027, pending approval for continuation of the study by the Scientific Oversight Committee (SOC) by the end of the third year. We will share findings of the completed studies as soon as they become available, followed by publication in scientific journals. We will share findings prior to the end of the third year and through the end of the Study.
Community Engagement
We believe that effective community engagement is crucial to the success of the Study and appreciate suggestions for improving our efforts. We have developed a Community Stakeholder Communications Plan (CSCP) that provides a comprehensive guide to community engagement efforts during implementation of the Study. The CSCP is posted on the website.
We have held and plan to hold additional general community meetings to provide overall Study information and updates as well as focused meetings to address more specific topics. These focused meetings will allow for deeper discussion of those topics that are of greatest interest.
The CSCP also calls for the development of a Community Engagement Support and Advice Network (CESAN). This network aims to tap into the expertise of individuals who understand the community’s unique dynamics and preferences. It will include a diverse range of organizations and community groups to ensure that the advisory network encompasses a broad cross-section of community demographics and interests. We are committed to working closely with the CESAN to effectively engage and motivate residents to participate.