In 1994, a Unocal refinery in the San Francisco Bay area accidentally released the chemical catacarb into the air, potentially exposing area residents to the toxic substance for 16 days. Now, more than two years later, some of the residents say they continue to suffer chronic health problems from the catacarb and other pollutants. To help them learn more about what they were exposed to and the resulting potential health implications, a UC Davis toxicologist is working with scientists from California State University, San Francisco, and the communities in a new outreach program. Initiated by the UC Davis Center for Environmental Health Sciences, the center is funded by the National Institutes of Environmental Health Sciences. Toxicologist Mohammed Al-Bayati, in his role as a toxicology information specialist for the center, has worked to prepare health-risk assessment reports for the catacarb incident that can be used by local residents and doctors to establish more effective health-monitoring procedures. In dealing with other issues, he can help to identify toxic substance exposure problems, work with medical providers to determine the right monitoring approach, help interpret the results and help work toward treatments. The center will provide expert toxicological assessment of health risks associated with different toxic substances to various communities, as requested.