Madame Chairman, Senator Glenn, other members of the Subcommittee: I am
William Raub, Science Advisor to the Secretary of Health and Human Services. I
am pleased to be here today to discuss the perspective of the Department of
Health and Human Services on the conduct of two studies designed to examine
the effects of exposure to Iodine-131 following nuclear testing or accidents. My
colleagues and I appreciate the time and attention the Subcommittee staff has
devoted to its review of these studies. We share your desire that our research be
conducted both rigorously and efficiently and that outcomes be used to promote
national policies that are protective of the public health.
The studies selected for review by the Subcommittee involve attempts to
understand the effects of two major cases of radiation exposure: one, the program
of nuclear bomb atmospheric tests conducted at the Nevada Test Site by the
former Atomic Energy Commission; and two, the Chernobyl nuclear power plant
accident. In both cases, people were exposed to Iodine-131 and other
radionuclides for reasons beyond their control and, for many individuals, without
their knowledge. The Department recognizes as understandable and legitimate
the frequently expressed concern that the exposed populations in both cases may
be at higher risk of diseases of the thyroid, particularly cancer.
The National Cancer Institute is the appropriate organization to direct research
toward resolving this concern. It has the requisite expertise and experience. In
particular, its staff includes leading international authorities on radiation
epidemiology and radiation dosimetry.
You have raised important questions about our response to Public Law 97-414,
which directed the Department to "(1) conduct scientific research and prepare
analyses necessary to develop valid and credible assessments of the risks of
thyroid cancer that are associated with thyroid doses of Iodine 131; (2) conduct
scientific research and prepare analyses necessary to develop valid and credible
methods to estimate the thyroid doses of Iodine 131 that are received by
individuals from nuclear bomb fallout; and (3) conduct scientific research and
prepare analyses necessary to develop valid and credible assessments of the
exposure to Iodine 131 that the American people received from the Nevada
atmospheric nuclear bomb tests ....". NCI clearly took too long to complete the
study. We have learned important lessons about use of resources and the setting
of priorities as a result of our experience with the Iodine-131 study. The
Department will review its procedures for monitoring such major studies, and
where necessary, will institute reforms to ensure that we do not repeat the
experience of the Iodine-131 study.
As you know, the Institute of Medicine (IOM) reviewed the NCI study and
recently issued its own report. IOM assessed the soundness of NCI's analyses and
assumptions and its estimates of risk of thyroid disease from Iodine-131 fallout.
IOM also analyzed the issues associated with population-based screening for
thyroid cancer and the challenges associated with providing clear and useful
information about the risks of both radiation and screening to those who have
been exposed. We are currently studying IOM's report so that the Department
can be responsive to its findings.
I call your attention to the fact that IOM did not recommend population-based
screening for people exposed to radiation fallout. Testimony earlier today from
the Agency for Toxic Substances and Disease Registry (ATSDR), however,
indicates that it recommends medical monitoring for people exposed to radiation
from the Hanford nuclear reactor. In his testimony, Dr. Johnson of ATSDR
compared his agency's recommendation with the IOM findings. He correctly
noted that ATSDR and the NCI studies differ considerably with regard to
circumstances, methodology, outcomes, and requirements.
On their face, the ATSDR and IOM conclusions do not appear to be in conflict.
However, the Department will review policies and practices at the Centers for
Disease Control and Prevention (CDC), ATSDR, and NCI to identify significant
differences, if any, in their respective approaches to dose reconstruction and
determinations regarding the need for and feasibility of population-based
screening or medical monitoring. If we find any differences that we believe
jeopardize the Department's ability to be protective of the public health, we will
initiate corrective action.
The ongoing NCI study of the Chernobyl disaster is a unique opportunity to
examine the effects of radiation on people. We have confidence that the Institute
is on course toward identifying proper cohorts, estimating exposure, and assessing
risks of disease.
The Department is aware of the difficulties of conducting such research in
countries that had been part of the former Soviet Union. The science of
epidemiology is not as uniformly well developed there as here; in many cases,
resources and experience lag far behind those available in the United States; and
managing a major international study in an area of the world that is experiencing
significant political and economic instability is a difficult undertaking. As a
consequence, I do not think we should judge the progress of the Chernobyl study
using the same standards that we would apply to a study conducted in the United
States.
Nevertheless, the Subcommittee has raised several important management issues
related to the Chernobyl research. Because this research is so important and, we
hope, the only opportunity we ever have to study such exposure to human beings,
the Department wants to be certain that the Chernobyl work is done as effectively
and efficiently as possible. We recognize the concerns of the Subcommittee, and
we take them seriously. I will work with NCI staff to arrange for an independent
review of the Chernobyl project to identify any problems associated with the way
the work is planned, organized, conducted, and overseen.
Our plan to seek an independent review does not mean we lack confidence in
NCI. To the contrary, we believe NCI is the right place to conduct this research;
and we are intent upon doing everything reasonable toward ensuring that the
project remains appropriately oriented and proceeds as expeditiously as
circumstances allow. We will await the outcome of the independent review with
an open mind.
Thank you for the opportunity to testify today.
