----- Original Message -----
Sent: Monday, December 17, 2001 2:42
PM
Subject: French Academy denounces LNT and
use of collective dose [FW]
Anyone know
whether the French Academy of Medicine’s statement, entitled "Medical
Irradiation, Radioactive Waste, and Disinformation," is available on the
internet somewhere ?
Thanks
Jaro
NUCLEONICS WEEK - December 13, 2001
FRENCH ACADEMY DENOUNCES
NEW
LIMITS, RADIATION
MISINFORMATION
France’s Academy of Medicine has renewed its opposition
to a 20-milliSievert (2 rem) annual dose limit for professional
exposures, saying such a regulation would "bring no
health benefit while hampering operation of medical radiology
departments by making it more difficult to develop new techniques."
The Academy, in a new opinion issued Dec. 4, said
France should adopt without modification the Euratom radiation
protection directive, which sets a professional dose limit
of 100 mSv averaged over five years and doesn’t change the
current annual exposure limit of 50 mSv.
The French administration is in the final throes of drafting
decrees to enact the 1996 Euratom general directive, as well
as a 1997 directive covering rad protection in medical practices.
The French nuclear industry, too, has railed against the
current draft which stipulates a strict 12-month dose limit of
20 mSv (see related story, page 11).
The Academy also "denounces" the use of the
linear nonthreshold
(LNT) theory to estimate the health effect of
doses
below a few milliSieverts, the order of
magnitude of the variation
in natural background radiation among French
regions.
It also condemns the use of the collective
dose concept to
estimate health effects, saying "these
procedures have no
scientific validity, even if they appear
convenient for administrative reasons."
The Academy’s statement, entitled "Medical
Irradiation,
Radioactive Waste, and Disinformation," was signed by
Guy de The,
chairman of its public health commission, and Maurice
Tubiana,
a renowned cancer specialist. Other drafters were
Andre Aurengo,
another well-known radiotherapist, and Roland Masse,
a former director of rad protection agency OPRI.
They are in the forefront of French scientists combating
what they see as the misuse of international radiation
protection recommendations to fan public concern about the health effects
of low doses.
Within the French system, the Academy scientists are
often considered to represent an extreme view and they have
clashed on occasion with radiation protection
professionals
who appreciate the current system, including the use of the
LNT hypothesis and collective dose, because it simplifies their
lives.
The full Academy adopted the opinion in a
unanimous vote Dec. 4.
The statement supplements one issued in October 2000
and goes into more detail on medical irradiation. In particular,
the Academy says that radiation protection efforts should be
increased for medical X-rays to reduce doses for certain exams,
such as scans for young people, and recommends further
measures, such as more training for radiology personnel. The
scientists say it is "unacceptable" that while medical irradiation
represents 95% of artificial irradiation received by a
typical Frenchman, "so few resources" are devoted to reducing
medical doses compared to the "high funding" given to
rad protection in power industry.
X-rays represent an effective dose of about 1 mSv/year in
France, compared to 2-4 mSv from natural sources. The
Academy makes several recommendations about how to optimize
medical doses and how to justify them, two principles
required under the Euratom directive 97/43 that will be enacted
into national regulations next year.
‘Disinformation’
But the Academy goes further to address what
it considers
"disinformation" that has been circulating
recently about the
radiological risks from nuclear waste and the
health effects of
the Chernobyl accident.
Concerning radwaste, the Academy says that risk
studies
should give priority to isotopes not on the basis of
collective
dose, but on the basis of potential individual doses,
"since
collective doses calculated from individual
doses below a few
microSieverts can have no health
significance." Besides supporting
more epidemiological studies of people living in naturally
high-radiation areas like India’s Kerala state and of ex-USSR
populations exposed to relatively high doses of nuclear
and other contaminants over long periods, the doctors call for
a "significant national effort" in France, similar to that underway
in the U.S., to study biological mechanisms implicated in
cellular response below 100 mSv.
The Academy scientists assert that it is "legitimate" to
evaluate risks from nuclear plant dismantling and waste transport,
storage and disposal programs on the basis of what is
known about millions of people living in high-background
areas, since the dose levels are lower in the case of industrial
activities and there’s no difference in biological impact of
natural or artificial radiation. They noted that no adverse
health effects have been detected in Kerala or other
high-background
areas in studies so far.
The doctors also say the LNT theory of
dose-effect relation
is disproven by numerous experimental and
epidemiological data.
No increase in cancer has been shown in Hiroshima
and Nagasaki survivors at doses below 200 mSv for adults
and 100 mSv for children, they asserted, the only "doubt"
being for in-utero exposure where 10 mSv could be the limit.
The Academy railed in particular against the use of the
LNT hypothesis to evaluate risks from Chernobyl fallout
outside the ex-USSR. It said high doses to thyroids of children
in areas near Chernobyl (1-3 Gray average in the most-exposed
regions) have led to about 2,000 cancers, with about
10 deaths so far. But "no increase in thyroid affections that
can be attributed to Chernobyl fallout has been shown outside
of the USSR, for example in Poland or other adjacent states," it
says.
France has been plunged for the past several months in
a controversy over the role of Chernobyl fallout in an increase
of thyroid cancer, among all age groups, since the 1986 accident.
The dispute is complicated by disagreement over the
extent of Chernobyl fallout in France and charges that authorities
of the time hid the truth about the contamination from the
French public and failed to take necessary countermeasures.
Some 100 people who suffer from thyroid cancer have now
filed suit in Paris court seeking to establish authorities’
responsibility
for their plight, and the matter has received broad publicity.
Doctors who work with radiation say that the incidence of
thyroid cancer has risen everywhere over the past 15 years
thanks to widespread screening, including in areas not affected
by Chernobyl (NW, 12 April, 1). The Academy’s latest
opinion is designed to press the point that the doses from
Chernobyl fallout in France could only have been very low,
given the distance from the Ukrainian reactor, and because
such low doses haven’t been shown to cause any negative
health impacts elsewhere, they can’t be held responsible for a
perceived increase in thyroid problems in France.
—Ann MacLachlan, Paris