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Given the tie-ups between the NYT and the nuclear industry, I'd
think we'd at least want a second opinion...<br>
<br>
The author of this piece is a long-time Timesman who's written on
and perhaps contributed to US science propaganda. In the run-up to
the invasion of Iraq he published "Germs: Biological Weapons and
America's Secret War" (2001), and in 2007 he did a "Discovery
Channel" program called "Nuclear Jihad: Can Terrorists Get the
Bomb?"<br>
<br>
<br>
On 3/12/11 5:17 PM, Brussel Morton K. wrote:
<blockquote
cite="mid:8C3D1AD0-B18E-44EB-A915-1E2F1E5B6BED@comcast.net"
type="cite">A fair report by William Broad on the dangers of
radioactivity from the severely damaged Japanese reactor. We
don't yet know the intensity of its radiations, and so we don't
know if they are a serious problem. We are constantly exposed to
nuclear radiations, and the safety limits imposed by the
responsible agencies are considered super safe; there could be
very high multiples of those limits and yet have no observed
effects on human health (despite the claims of someone like
Wasserman).
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<div><a moz-do-not-send="true"
href="http://www.nytimes.com/2011/03/13/science/13radiation.html?hp">http://www.nytimes.com/2011/03/13/science/13radiation.html?hp</a></div>
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<div class="articleBody"><nyt_text>
<p> The different forms of radioactivity being reported at
the nuclear accidents in <a moz-do-not-send="true"
href="http://topics.nytimes.com/top/news/international/countriesandterritories/japan/index.html?inline=nyt-geo"
title="More news and information about Japan."
class="meta-loc">Japan</a> range from relatively benign
to extremely worrisome.</p>
</nyt_text></div>
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<div class="doubleRule">
<h3 class="sectionHeader"><span class="Apple-style-span"
style="font-weight: normal; font-size: medium;">The
central problem in assessing the degree of danger is
that the amounts of various radioactive releases into
the environment are now unknown, as are the winds and
other atmospheric factors that determine how
radioactivity will disperse around the stricken plants.</span></h3>
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<div class="articleBody">
<p>
Still, the properties of the materials and their typical
interactions with the human body give some indication of the
threat. </p>
<p>
“The situation is pretty bad,” said Frank N. von Hippel, a
nuclear physicist who advised the Clinton White House and
now teaches international affairs at Princeton. “But it
could get a lot worse.” </p>
<p>
In Vienna on Saturday, the <a moz-do-not-send="true"
href="http://www.iaea.org/">International Atomic Energy
Agency</a> said Japanese authorities had informed it that
iodine pills would be distributed to residents around the
Fukushima Daiichi and Daini plants in northeast Japan. Both
have experienced multiple failures in the wake of the huge
earthquake and tsunami that struck Friday. </p>
<p>
In the types of reactors involved, water is used to cool the
reactor core and produce steam to turn the turbines that
make electricity. The water contains two of the least
dangerous forms of radioactivity now in the news —
radioactive nitrogen and tritium. Normal plant operations
produce both of them in the cooling water, and they are even
released routinely in small amounts into the environment,
usually through tall chimneys. </p>
<p>
Nitrogen is the most common gas in the earth’s atmosphere,
and at a nuclear plant the main radioactive form is known as
nitrogen-16. It is made when speeding neutrons from the
reactor’s core hit oxygen in the surrounding cooling water.
This radioactive form of nitrogen does not occur in nature.
</p>
<p>
The danger of nitrogen-16 is an issue only for plant workers
and operators because its half-life is only seven seconds,
after which it decays back into natural oxygen. A half-life
is the time it takes half the atoms of a radioactive
substance to disintegrate. </p>
<p>
The other form of radioactivity often in the cooling water
of a nuclear reactor is tritium. It is a naturally occurring
radioactive form of hydrogen, sometimes known as heavy
hydrogen. It is found in trace amounts in groundwater
throughout the world. Tritium emits a weak form of radiation
that does not travel very far in the air and cannot
penetrate the skin. </p>
<p>
It accumulates in the cooling water of nuclear reactors and
is often vented in small amounts to the environment. Its
half-life is 12 years. </p>
<p>
The big worries on the reported radiation releases in Japan
center on radioactive iodine and cesium. </p>
<p>
“They imply some kind of core problem,” said Thomas B.
Cochran, a senior scientist in the nuclear program of the <a
moz-do-not-send="true" href="http://www.nrdc.org/">Natural
Resources Defense Council</a>, a private group in
Washington. </p>
<p>
The active core of a nuclear reactor splits atoms in two to
produce bursts of energy and, as a byproduct, large masses
of highly radioactive particles. The many safety mechanisms
of a nuclear plant focus mainly on keeping these so-called
fission products out of the environment. </p>
<p>
Iodine-131 has a half-life of eight days and is quite
dangerous to human health. If absorbed through contaminated
food, especially milk and milk products, it will accumulate
in the thyroid and cause cancer. Located near the base of
the neck, the thyroid is a large endocrine gland that
produces hormones that help control growth and metabolism. </p>
<p>
Dr. von Hippel of Princeton said the thyroid danger was
gravest in children. “The thyroid is more sensitive to
damage when the cells are dividing and the gland is
growing,” he said. </p>
<p>
Fortunately, an easy form of protection is potassium iodide,
a simple compound typically added to table salt to prevent
goiter and a form of mental retardation caused by a dietary
lack of iodine. </p>
<p>
If ingested promptly after a nuclear accident, potassium
iodide, in concentrated form, can help reduce the dose of
radiation to the thyroid and thus the risk of cancer. In the
United States, the <a moz-do-not-send="true"
href="http://topics.nytimes.com/top/reference/timestopics/organizations/n/nuclear_regulatory_commission/index.html?inline=nyt-org"
title="More articles about Nuclear Regulatory Commission"
class="meta-org">Nuclear Regulatory Commission</a>
recommends that people living within a 10-mile emergency
planning zone around a nuclear plant have access to
potassium iodide tablets. </p>
<p>
Over the long term, the big threat to human health is
cesium-137, which has a half-life of 30 years. </p>
<p>
At that rate of disintegration, John Emsley wrote in
“Nature’s Building Blocks” (Oxford, 2001), “it takes over
200 years to reduce it to 1 percent of its former level.” </p>
<p>
It is cesium-137 that still contaminates much land in
Ukraine around the Chernobyl reactor. In 1986, the plant
suffered what is considered the worst nuclear power plant
accident in history. </p>
<p>
Cesium-137 mixes easily with water and is chemically similar
to potassium. It thus mimics how potassium gets metabolized
in the body and can enter through many foods, including
milk. After entering, cesium gets widely distributed, its
concentrations said to be higher in muscle tissues and lower
in bones. </p>
<p>
The radiation from cesium-137 can throw cellular machinery
out of order, including the chromosomes, leading to an
increased risk of cancer. </p>
<p>
The <a moz-do-not-send="true"
href="http://topics.nytimes.com/top/reference/timestopics/organizations/e/environmental_protection_agency/index.html?inline=nyt-org"
title="More articles about the Environmental Protection
Agency." class="meta-org">Environmental Protection Agency</a>
says that everyone in the United States is exposed to very
small amounts of cesium-137 in soil and water because of
atmospheric fallout from the nuclear detonations of the cold
war. </p>
<p>
The agency says that very high exposures can result in
serious burns and even death, but that such cases are
extremely rare. Once dispersed in the environment, it says,
cesium-137 “is impossible to avoid.” </p>
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