Transcript Ingen bildrubrik - System and Instrumentation Physics

Some annoying cases in
radiation protection
Ulf Bäverstam
Three areas worth discussion
(there are more)
• Cancer incidence in Sweden after Chernobyl
• The EMF case
• Smokers and radon in dwellings
The Chernobyl cancer incidence
case
Physical measurements:
Deposition on ground of depositing nuclides with halflives
longer than say 24 hours.
Air concentration in cloud that has passed (filter
measurements)
Measurements of ground penetration and shielding
The Chernobyl cancer incidence
case
Commonly accepted: Epidemiological studies will not be
able to detect the increase of cancer cases in Sweden
after Chernobyl accident due to low power.
Alternative hypothesis: Risk figures, or measured deposition,
or both, are severely underestimated, so there is a
possibility to detect the increase.
The Chernobyl cancer incidence
case
A recently published Swedish study claims to have detected
the increase.
The study is discussed in international media during a few
days. SSI (defender of the generally accepted view) finds
the results odd in several respects, and authors agree.
The Chernobyl cancer incidence
case
So, what is the problem? Among other thing:
That you can never prove anything to be completely
harmless
That alarm reports will always awake the interest of mass
media
That there are political parties that take advantage of this
That not all scientists use the highest ethical standards
The EMF case
The EMF case
We are all exposed by EMF in a wide frequency range
Thermal health effects are known to exist.
Non-thermal health effects are much debated – some groups claim that
they have seen effects, other groups not.
Measurements can be made of intensity, frequency etc, but any good
”dose” concept does not exist.
A plausible interaction mechanism causing health effects is still lacking.
The EMF case
The strongest argument for the existence of health effects
seem to be ”why should there not be any effects?”
The EMF case
Since at least 30 years different sources of EMF have
been investigated in search of non thermal health
effects. So far very little is found.
Today cellular telephones are the suspects. In Sweden
there are today as many telephone subscriptioins as
inhabitants. And there are verly loud (but fairly small)
resistance groups acting with much help from mass
media.
The EMF case
”The precautionary principle” used in the debate, and
now claimed to be used by authorities involved, is a
very diffuse and unclear principle.
What is the real problem?
That we do not know, of course.
That some parties, based on very poor or no indication claims risks
to exist. That competent authorities don’t have logically based
stand points. That very poor scientific studies have been
performed and published
The smoker and radon case
Smoking is without any doubts a very unhealthy habit. It is
related to a number of diseases, one of the most severe
being lung cancer.
In Sweden we have around 3000 new lung cancer cases
every year, and a large fraction of these are connected to
smoking
The smoker and radon case
Radon in dwellings have also been shown to be a health
problem, but a much smaller risk than smoking.
The smoker and radon case
It has been shown in some large studies that a combination
of smoking and radon will increase the risk figures.
In fact, according to recent studies radon is probably more
than 10 times (perhaps even 20 times) more dangerous
for smokers than for non-smokers.
The smoker and radon case
And the problem?
Costly measures to reduce radon (often with a poor long
term efficiency) are recommended. Very little is said by
authorities about the great radon risk reduction reached
by stopping smoking. In fact, for non-smokers the radon
risk is almost always not a problem
Common traits?
There are some …