[cdn-nucl-l] Nuclear Fallout: Is the Threat Real

["Adam McLean" <adam.mclean@utoronto.ca>]

Posted on MSNBC on November 24, 2001 and at:
http://www.msnbc.com/news/660257.asp?0si=-&cp1=1
The comments about increased disease occurrences in Hiroshima and Nagasaki
I'm not aware of and would like to see data on but an interesting read.

For more on radiation effects on health, see:
United Nations Scientific Committee on the Effects of Atomic Radiation
(UNSCEAR):
http://www.unscear.org/
and the Low Dose Radiation page at:
http://www.cns-snc.ca/branches/Toronto/radiation/radiation.html

Adam

Nuclear fallout:
Is the threat real?

How exposure to radiation can effect your health

       The release of nuclear radiation either through an attack on a
nuclear plant or waste site or by the dropping of a bomb is yet another real
concern that seemed unthinkable before Sept. 11. What can you do to prepare
for this possibility and what should you do if such an attack occurs? Edwin
Lyman, Ph.D, scientific director for the Nuclear Control Institute, answers
your questions.

If a nuclear weapon were detonated there is a tell-tale flash followed by a
shock wave blast; the bomb, if detonated near the ground, would cause a
crater, and material and earth within the crater would be sucked up as
fallout and then distributed over a wide area.

Question: The last time the nation seriously considered the threat of a
nuclear explosion, the advice was to “duck and cover.” Today we realize how
silly that advice was, but is there anything the average person can do to
prepare for the aftermath of a nuclear explosion or accident, if lucky
enough to survive?
       Edwin Lyman: When we look at “duck and cover” it seems silly today in
the context of an all-out nuclear war between the U.S. and the Soviet Union.
There was no protection in the case of such a war.
       But if we are talking about the possibility of a terrorist with a
small number of nuclear weapons, it does make sense to ask the question,
“Are there ways in which individuals can reduce their risk of injury in the
event of a terrorist nuclear attack?”
       The first question that is often asked is about potassium iodide — is
it something that individuals should stockpile? Potassium iodide can block
the uptake of radioactive iodine, an isotope that would be released in great
quantity if a nuclear power plant were to have an accident or if a nuclear
bomb were to be detonated.
       It is my judgment that it would be useful for individuals in the
vicinity of nuclear power plants to have ready access to potassium iodide in
the event of an attack on a nuclear plant, however, the limitations of
potassium iodide need to be explained.
       The evidence now is that it would be most effective only for people
under the age of twenty or for pregnant women. For adults it is less clear
whether potassium iodide would be a significant factor in preventing thyroid
cancer, but obviously for children it could be an important measure. This
said, one has to realize that radioactive iodine is only one element of an
enormous soup of different radioactive elements that would be released in a
nuclear terrorism incident. And potassium iodide can provide only limited
protection.

 Since Sept. 11, people who live near nuclear plants have been stocking up
on potassium iodide pills, which can help protect against cancer from a
radiation release.
          Question: Where do we obtain potassium iodide, and in what form
does it come? In a pill, a shot, a liquid?
       Edwin Lyman: After opposing the requirement to stockpile potassium
iodide near nuclear plants, the nuclear regulatory commission has recently
changed its position and has delegated the authority to state governments to
make that decision. I am unaware that any state government has made that
decision, but if that were the case, then people within the emergency
planning zones around nuclear plants would be able to obtain it from
emergency responders.
       It is also being sold over the Internet and I have seen a lot of
false and misleading claims about what it can do, so people should be aware
that there are cons out there with potassium iodide sales.

         Again, I don’t think it is necessary at this point for people to
obtain it unless in they are within 10 miles of a nuclear plant. The form is
a tablet, I believe, and it should be noted that it does have side effects.
       There are some sad stories in the aftermath of the Chernobyl
incident. Local governments attempted to distribute potassium iodide tablets
but were short of supply, so individuals went to pharmacies and bought it in
liquid form and fed it to their children and it caused injury to the
children. So it should be recognized that it is a drug and it has side
effects and people should not take it or give it to children in the absence
of a true emergency.
       Question: What long-term health effects could people expect who were
exposed but didn’t perish?
       Edwin Lyman: The primary health effect from ionizing radiation is
cancer. The type of cancer depends on the nature of the exposure. But
fundamentally, ionizing radiation can damage the DNA in our cells, and this
causes lesions that can affect the cell division process and ultimately lead
to cancer.
       Besides thyroid cancer, which we have discussed, leukemia is a very
well-established consequence of radiation overexposure as well as cancer of
the lungs, breast, and brain. The only cancer that is not linked to ionizing
radiation exposure is one of the chronic leukemias.
       It is also interesting that the study of the victims at Hiroshima and
Nagasaki is now revealing higher death rates than expected from diseases
other than cancer, including cardiovascular and respiratory diseases. And,
in fact, the full array and consequence of radiation exposures are still not
entirely known. There are also neurological effects of radiation, especially
for the developing fetus, and mental retardation has been observed in
higher-than-expected rates among children who were exposed in utero in
Japan.
       Question: What are the first physical signs of radiation exposure?
Could we see a radiation cloud, or is it invisible?
       Edwin Lyman: Again, it probably makes sense to go over a few basics
here. There are two distinct classes of effects of radiation exposure. There
are effects in which very high doses cause acute symptoms within hours to
days of exposure. These symptoms commonly include skin burns,
gastrointestinal symptoms, reduced white blood cell counts, and increased
susceptibility to infection, hair loss, and similar acute symptoms. There is
a range in very high radiation doses where it is unlikely someone would
survive, even with heroic measures.

       At lower doses the acute radiation syndrome can spontaneously
resolve. However, at doses below the threshold for acute effects there will
be no visible symptoms although the damage to DNA that could lead to later
cancers will have been done. In that case, tests may show chromosomal damage
and can help to calibrate exposures.
       In response to what radiation looks like — it is well known that
radiation is invisible and to detect elevated radiation levels in the
environment requires instrumentation. However, that said, we can think of
particular ways exposures might occur.
       If a nuclear weapon were detonated there is a tell-tale flash
followed by a shock wave blast; the bomb, if detonated near the ground,
would cause a crater, and material and earth within the crater would be
sucked up as fallout and then distributed over a wide area.
       This would be visible ash and would be extremely radioactive, so one
of the first measures that could be taken for individuals surviving the
initial blast would be to avoid contact with visible fallout. However, this
would not ensure a lack of exposure because there are other components that
would not be visible.
       In the case of a nuclear power plant accident, there may be some
debris, but I don’t believe the radioactive plume would be visible downwind
of the site; if the plant were on fire there would be smoke visible, once
dissipated there would be no way to detect this visually.
       Member Question: What are the levels of radiation risk at 10 miles,
100 miles, 100,000 miles from ground zero? How far can the radiation travel?
Is that based solely on wind direction?
       Edwin Lyman: Well, again one should distinguish between a nuclear
weapon attack and an attack on a nuclear plant.
       For a nuclear power plant accident, the acute effects I described —
acute radiation sickness with a high chance of death — would be limited to
within 10 miles or less of the accident. This is partly the basis for the
choice of 10 miles as the size of the emergency planning for U.S. plants.
However, the plume would be carried by the wind and depending on atmospheric
conditions could contaminate a large area and even hundreds of miles
downwind there would be some significant contamination. This was seen after
the Chernobyl accident, where large sections of Northern Europe did receive
significant contamination and the aftermath was detectable all around the
northern hemisphere.

          The range of effects from a nuclear weapon is very strongly
dependent on its yield and whether it was detonated on the ground or at some
height above the ground. If we take the example of a terrorist crude nuclear
device, let’s say one-tenth or one-fifteenth of the Hiroshima yield (which
would be about a 1,000 tons of TNT equivalent), the blast affects would be
fairly limited in range, probably to less than one mile.
       The direct radiation effects would be felt considerably farther and
fallout would travel hundreds of miles, and that would be directly related
to atmospheric conditions and wind direction. So, the extent does depend on
a lot of factors, but the ultimate effect could be felt tens or hundreds of
miles away. However, the farther one is from the site of detonation, the
more time there is to take countermeasures.
       Member question: What kind of countermeasures?
       Edwin Lyman: Well, this takes us back to “duck and cover.” If there
were a nuclear explosion of relatively small yield, such as I described
above, people who are maybe tens of miles away would have something like a
half an hour to shelter themselves. And such action could potentially mean
the difference between life and death. Actions as simple as taking cover in
a basement or reinforced concrete structure away from windows could
potentially reduce radiation exposure. But fallout even at large distances
would persist and people may have to remain in those locations for days or
even weeks.
       Does this mean that the U.S. should reactivate a system of fallout
shelters? I don’t know. I hope the office of Homeland Security is addressing
this issue in the context that I described — that is, in the event of a
small number of terrorist weapons. I still do not believe that civil defense
is an appropriate response to an all-out nuclear war, but hopefully the
threat of that kind of an exchange has been greatly reduced and will
continue to diminish.
       Member question: How real is this threat of nuclear terrorism in our
current situation?
       Edwin Lyman: You cannot assess whether the threat is a real one
without access to intelligence, but what one can do is point to
vulnerabilities that do exist today and ask is it plausible that these
vulnerabilities could be exploited?
       We know that Osama bin Laden has stated he has nuclear weapons. There
is skepticism on the part of the U.S. government, but not outright denial.
And the fact is that there are large amounts of nuclear-weapon capable
materials that are poorly secured, and inventories are not well established.
This is largely the case in the former Soviet Union. So it is difficult to
exclude the possibility that determined terrorists have been able to obtain
nuclear material.
       However, that leaves the challenges of assembling a workable nuclear
device and delivering it.
       It is believed that a crude nuclear device is within the capabilities
of terrorists. Such a device, if it has a low yield, would be more of a
threat from the radiation exposure than from the actual blast. In the case
of a nuclear reactor, there are plausible ways in which a group of
determined terrorists could attack a plant and cause a massive release of
radiation.
       Nuclear plants in the U.S. are required to have security forces and
other physical protection measures. But the sad truth is that the existing
requirements are not likely to be adequate to prevent a determined attack by
a large number of attackers. The issue of an aerial threat to a nuclear
plant as we saw on Sept. 11 still remains a real possibility.

       Question: Do you have any final comments for us?
       Edwin Lyman: I certainly don’t want people to panic. And I don’t
think there is any need to rush out and buy potassium iodide. But I think
the public needs to be aware of the issues, especially nuclear power plant
security. I would hope that people who live in the area of nuclear plants
would take a critical look at the level of security that is being applied
and pressure the authorities to increase that security. This can’t be left
up to the industry,

       The opinions expressed herein are the guest’s alone. If you have
questions about your health, you should consult your personal physician.
This event is meant for informational purposes only.

       WebMD content is provided to MSNBC by the editorial staff of WebMD.
The MSNBC editorial staff does not participate in the creation of WebMD
content and is not responsible for WebMD content. Remember that editorial
content is never a substitute for a visit to a health care professional.