February 18, 1997

Miriam Topel
President
Berkeley Board of Education
Berkeley Unified School District
2134 Martin Luther King, Jr. Way
Berkeley, CA 94704

Dear Ms. Topel:

Having served on a board of directors for my daughter’s day care and having been involved in my local school parents’ club, I appreciate your difficulty in trying to balance the importance of responding to public concern with the desire to utilize the wonderful educational opportunities at the Lawrence Hall of Science. To help perhaps put your mind at ease regarding the safe conditions at Lawrence Hall of Science I would like to offer to you my evaluation.

Let me assure you that all visitors to the Lawrence Hall of Science are not in any danger from exposure to the trace amounts of tritium from the Lawrence Berkeley National Laboratory (LBNL). My conclusion, as the radiation specialist involved with LBNL for 8 years, is based on LBNL's compliance with the EPA standard for tritium releases to the air. The EPA standard is 10 millirem / year. A person working at the Lawrence Hall of Science all year long, would receive less than 1 millirem / year. Visitors to the Hall of Science, since they are on the property briefly compared to a Hall of Science worker, would be exposed to much less than 1 millirem. For comparison purposes, one receives between 40-100 millirem from a chest or dental x-ray and about 100-300 millirem/year from background radiation, i.e. radiation from natural sources such as cosmic radiation and trace amounts of naturally occurring radioactive elements in soil and radon gas. People's exposure at the Hall of Science was determined by taking the known concentrated emissions from the tritium stack at LBNL and calculating the diluted levels down wind at the Hall of Science.

As small as the less than 1 millirem / year exposure from LBNL’s tritium stack is, exposures from other sources on the lab grounds such as emissions from the soil or from tritium transpired from trees and other plants, would be much smaller still. Therefore, reports of the presence of tritium in soil and in the transpired water from trees are not cause for warnings regarding visits to the Lawrence Hall of Science. Since the concentrated emissions from the stack itself are a fraction of our standard, parents of children visiting the Hall of Science should be assured that there is no danger and that the reports of emissions from the stack or from these other minor sources do not indicate a hazard to their children. As a father I am not worried about my daughter visiting the Hall of Science, and our family will continue to make visits and take advantage of the educational opportunities available there.

Comparisons of tritium levels in soil or water transpired from trees, to drinking water standards are irrelevant. The drinking water standard pertains to drinking 8 glasses of tritium-contaminated water daily. The public will not be exposed in the same manner as to drinking water. Thus, levels of tritium in soil above drinking water standards do not necessarily indicate a hazard. Reports to date by the lab, by researchers, and others, describing levels of tritium in soil or from plant-transpired water vapor, above standards designed for drinking water, do not indicate that the public is threatened by continued operation of the facility nor by visiting the Lawrence Hall of Science.

You may be aware that several scientists have expressed the opinion that EPA standards are not sufficiently protective. There is a spectrum of scientific opinion regarding the effects of radiation on health, with some scientists feeling it is more risky while others insist we greatly overestimate the risks. To insure that the public health is protected, EPA, DHS, and other regulatory agencies rely on the scientific consensus represented by national and international committees and the Science Advisory Board. Scientific consensus says that exposure to any amount of radiation carries some risk but that very small amounts of radiation have very small risk. Radiation exposure to the public from LBNL is very small.

To provide further reassurance we will be doing an independent evaluation of LBNL to review their monitoring and reports. This process will rely heavily on input from the public. We have received and will be reviewing materials provided to us by members of the community in order to determine if and what kind of additional monitoring might be useful to further insure that the environment and public health continue to be protected.

I would be pleased to make myself available to your Board if you want a more detailed discussion or if you would like to provide input for the independent evaluation. Please feel free to call me at (415) 744-1047.

Sincerely,

Shelly Rosenblum
Environmental Engineer
Office of Radiation & Compliance Assurance

cc:
James Keene, City Manager / Berkeley City Council
Ed Bailey / DHS
Jeffrey Wong / DHS
William Lew / DHS
Steve Hsu / DHS
Ron Pauer / LBNL
Iraj Javavdel / LBNL
Carl Schwab / DOE
Ken Rivera / DOE
Janis Thomas / CEAC
Jamie Case-Burr / CEAC
Poki Namkung, M.D. / City of Berkeley
Kris Surano / LLNL
Leroy Griffin / City of Oakland
Bernie Echada / DTSC
Sal Cirillo / DTSC
Periann Wood / USEPA
Vicky Semones / USEPA
Lois Grunwald / USEPA
Pamela Sihvola / CTMTW