[ RadSafe ] CBS News Report - NO safe radiation

[Dave Biela]

Study: No Radiation Level Safe
WASHINGTON, June 29, 2005
The preponderance of scientific evidence shows that even very low doses
of radiation pose a risk of cancer or other health
problems and there is no threshold below which exposure can be viewed
as harmless, a panel of prominent scientists concluded
Wednesday.
The finding by the National Academy of Sciences panel is viewed as
critical because it is likely to significantly influence what
radiation levels government agencies will allow at abandoned nuclear
power plants, nuclear weapons production facilities and
elsewhere.
The nuclear industry, as well as some independent scientists, have
argued that there is a threshold of very low level radiation
where exposure is not harmful, or possibly even beneficial. They said
current risk modeling may exaggerate the health impact.
The panel, after five years of study, rejected that claim.
"The scientific research base shows that there is no threshold of
exposure below which low levels of ionized radiation can be
demonstrated to be harmless or beneficial," said Richard R. Monson, the
panel chairman and a professor of epidemiology at
Harvard's School of Public Health.
The committee gave support to the so-called "linear, no threshold"
model that is currently the generally acceptable approach to
radiation risk assessment. This approach assumes that the health risks
from radiation exposure declines as the dose levels
decline, but that each unit of radiation ― no matter how small ―
still is assumed to cause cancer.
The panel, formally known as the Committee on Biological Effects of
Ionizing Radiaton, or BEIR, generally supported previous
cancer risk estimates ― the last one by an earlier BEIR group in
1990.
Contrary to assertions that risks from exposure from low-level
radiation may have been overstated, the panel said "the availability
of new and more extensive data have strengthened confidence in these
(earlier) estimates."
The committee examined doses of radiation of up to 100 millisievert, a
measurement of accumulated radiation to an individual
over a year. By comparison, a single chest X-ray accounts for 0.1
millisievert and average background radiation 3 millisievert.
The committee estimated that 1 out of 100 people would likely develop
solid cancer or leukemia from an exposure of 100
millisievert of radiation over a lifetime.
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