ATSDR Public Health Assessment
Page originally published 6/25/2025.
The Centers for Disease Control and Prevention (CDC)/Agency for Toxic Substances and Disease Registry (ATSDR) will conduct a public health assessment (PHA) to evaluate whether exposure to chemicals in the Tijuana River Valley could harm the health of community members.
ATSDR will:
- Analyze environmental data collected by government agencies and researchers to evaluate past, current, and future chemical exposures.
- Review air, surface water, sediment, soil, fish tissue, and odor complaint data.
- Identify information gaps and uncertainties where there is not enough data to determine health risks.
- Make recommendations to agencies, community members, and others to prevent and minimize harmful exposures.
On this page:
What is a Public Health Assessment (PHA)?
A PHA determines whether community members near a site:
- Are being exposed to toxic substances;
- Whether that exposure is harmful, and
- What should be done to stop or reduce exposure.
ATSDR’s mandate is specific to health risks from chemical exposures. ATSDR is not able to evaluate bacteria or other biological contaminants in this public health assessment.
What Information Will be Collected?
ATSDR does not collect individual health information from residents during this process. Instead, ATSDR will estimate exposures to chemicals, assess health risks, and recommend ways to reduce or stop exposures to protect people’s health.
- ATSDR will use health information and community concerns from Tijuana River Valley health surveys that the Centers for Disease Control and Prevention (CDC) and ATSDR conducted in San Diego County in 2024.
How Will Findings be Released?
Findings from the public health assessment will be released in two reports:
- The first report will focus on potential exposures to contaminants in the air.
- The second report will address other potential exposure sources, like surface water (any body of water above the ground, such as streams, rivers, lakes), sediment (materials, such as stones and sand, deposited by water), soil, and fish tissue.
Sign up to receive email updates about ATSDR’s public health assessment process, findings, and recommendations by contacting Ben Gerhardstein (bgerhardstein@cdc.gov) in the ATSDR Region 9 office.
County News Center:
- CDC Health Survey (CASPER)
- ATSDR Exposures Survey (ACE)
- Tijuana River Valley Sewage Crisis Environmental Dashboard
- Public Health Data
Centers for Disease Control and Prevention:
- ATSDR Will Evaluate Potential Health Risks in the Tijuana River Valley | Español (Spanish) (June 2025).
- Public Health Assessments
Send an e-mail to the Epidemiology Unit for more information.
