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URANIUM: The Deadliest Metal
Uranium: The Deadliest Metal
by Dr. Gordon Edwards, President of CCNR This article appeared in Perception
magazine, v. 10 n. 2, 1992
Bombs and Radioactive Waste
Dying for a Living
Radioactive Daughters
Irrefutable Evidence
Radioactive Homes
Acceptable Doses?
Boosting the Cancer Rate
Radioactive Smoke
Fallout from Uranium Mines
Unbounded in Time & Space
A Deadly Legacy
Bombs and Radioactive Waste Canada is the world's largest producer and exporter
of uranium, yet most Canadians are entirely unaware of our involvement with
this "deadliest of metals." There are only two commercially important
uses for uranium: nuclear weapons and nuclear reactors. The ultimate products
of the uranium industry are therefore bombs and radioactive wastes. For this
reason alone, uranium merits classification as a deadly metal.
But the lethal nature of uranium was manifested long before the first atomic
bombs were built or the first nuclear reactors were fuelled.
Dying for a Living
As early as 1546, and for centuries afterwards, it was reported that underground
miners in Schneeberg, Germany, suffered an unusually high incidence of fatal
lung disease. In 1879, it was demonstrated both clinically and anatomically
that about half of these miners were dying of lung cancer. This was a much higher
incidence of lung cancer than that found in the general population. The same
grim statistic -- 50 per cent mortality from lung cancer -- was later found
among the miners in Joachimsthal, Czechoslovakia. The ores in question were
particularly rich in uranium.
Similar excesses in lung cancer incidence have occurred among iron, lead and
zinc miners in Sweden, in fluorspar miners in Newfoundland, and especially among
uranium miners in all parts of the world. Scientific papers published in the
1930s, even before the outbreak of World War II, clearly indicated that airborne
radioactivity in the mines was the most likely cause of this lung cancer. The
principal culprits are radon gas and its solid by-products, the so-called "radon
daughters."
Radioactive Daughters
Uranium is a naturally-occurring radioactive substance, very widespread in
the earth's crust, but concentrated in certain hard rock formations. As the
uranium atoms slowly disintegrate over billions of years, a host of radioactive
by-products are formed: thorium-230, radium-226, radon-222 and the infamous
"radon daughters," including lead-210 and polonium-210.
As the miners dig the uranium-bearing ore, they inevitably release large quantities
of radioactive radon gas into the mine atmosphere. Radon has a relatively short
half-life (3.8 days); before long, the air in the mine is heavily contaminated
with radon daughters. Adhering to microscopic dust particles, these tiny, pernicious
particles are breathed into the miners' lungs where they lodge delivering a
massive dose of alpha radiation to the sensitive lung tissue. The result is
an extraordinarily high incidence of lung cancer, fibrosis of the lungs, and
other lung diseases, all of which take decades to become manifest.
Irrefutable Evidence
The carcinogenic effects of radon daughters have been studied for many years.
The medical evidence is overwhelming and indisputable: radon (with its daughters)
is one of the most potent carcinogens known. A 1982 study published by the Atomic
Energy Control Board (Ottawa) revealed that workers exposed to the present maximum
permissible levels in Canadian uranium mines for a 30-year period would experience
about four times as much lung cancer as non-miners. Instead of 54 out of every
thousand males dying of lung cancer (Ontario statistics for non-miners), we
would expect over 200 out of every thousand miners to die of lung cancer --
more than one in five!
In 1974, the Ontario Royal Commission on the Health and Safety of Workers in
Mines pointed out that the Elliot Lake uranium miners had already experienced
twice as many lung cancers as expected. In 1980, the British Columbia Medical
Association published a hard-hitting 470-page report entitled "The Health
Dangers of Uranium Mining." The BCMA Report warns of a "gradually
flowering crop of radiation-induced cancers" among Canadian uranium miners,
adding that "We are aware of no other carcinogen which is permitted at
levels close to the doubling dose for humans." A total of 81 Canadian uranium
miners had died of lung cancer by October 1974. At the end of 1977, the number
was 119; at the end of 1981, 174; at the end of 1984, 274.
Radioactive Homes
At Elliot Lake, about a ton of ore is required to extract two pounds of uranium.
Huge quantities of pulverized rock (called uranium tailings) are left over from
the milling process. The tailings contain 85 per cent of the original radioactivity
in the ore: they contain thorium-230, radium-226, and all the other uranium
by-products. The tailings also give off at least 10,000 times as much radon
gas as the undisturbed ore. (When radon gas is produced inside hard rock, it
has little chance to escape; but when the rock is pulverized, radon escapes
easily.)
In the Southwest U.S. and in Port Hope, Ontario, many homes and schools were
built using the sand-like uranium tailings as construction material. As a result,
some of the buildings ended up with levels of radon gas and radon daughters
even higher than those permitted in the mines. Similar (though less severe)
problems arose in Florida and Newfoundland when phosphate tailings were used
for construction, and in Oka and Varennes (just outside of Montreal) when other
mine tailings were used in construction. In each case, the original ore was
rich in uranium, so the tailings gave off high amounts of radon.
In 1975, St. Mary's School in Port Hope was evacuated because of extraordinarily
high radon levels. Radioactive fill had to be removed, at public expense, from
hundreds of homes and gardens. Even today, there are over 200,000 tons of radioactive
debris lying about the town of Port Hope in open ravines, easily accessible
to children and to pets. Eldorado Nuclear Limited, the crown corporation whose
radioactive wastes had been generously donated to the eager townsfolk for construction
purposes many years earlier, has recently promised -- under the prodding of
the Ontario Environment Department -- to finish cleaning up the mess sometime
during the next few years.
Acceptable Doses?
According to all scientific evidence, there is no such thing as a "safe
dose" of radiation. Every dose of radiation will cause a corresponding
increase in cancers and other diseases. Spreading a given dose out to a larger
number of people -- so that each individual dose is smaller -- does not reduce
the number of resulting illnesses. In fact, in the case of alpha radiation,
there is very strong evidence from many different quarters that spreading a
dose out among more people actually increases the total number of cancers and
other diseases. Uranium and most of its by-products, including thorium, radium,
radon and most of the radon daughters fall into this category of alpha-emitting
substances.
Since the town of Port Hope had been thoroughly contaminated with alpha- emitting
radioactive substances, the Canadian nuclear authorities had to make a political
decision back in 1975: What was an acceptable level for radioactive contamination
in a private residence?
And so a standard for an "acceptable level" of radon contamination
in a private home was set at about 20 times the normal background levels of
radon, to guide the cleanup operations at Port Hope. Before long, that same
standard was being used for the construction of whole subdivisions of new homes
in Elliot Lake in the late 1970s. Radon levels in these new homes were so unacceptably
high that fans had to be installed under the floorboards to blow the radon out
of the house. Sometimes two fans had to be installed to bring the contamination
levels down to the"acceptable" level.
Boosting the Cancer Rate
In testimony to the Elliot Lake Environmental Assessment Board in 1978, mortality
figures published by the Ontario government were used to show that even the
"acceptable" levels of radon contamination in homes would result in
an extra 17 lung cancer deaths per thousand people chronically exposed to such
levels. In other words, instead of 54 lung cancers per thousand, one would expect
71, a 31 per cent increase. In light of this evidence, the Board recommended
that the radon standard for homes be reassessed. But no such reassessment has
taken place.
Since 1980 the B.C. Medical Association has published a slightly higher risk
estimate and has condemned the radon standard for homes "as tantamount
to allowing an industrially induced epidemic of cancer." A 1982 report
published by the Atomic Energy Control Board concurs, estimating a 40 percent
increase in lung cancer among those living in homes contaminated to the "acceptable"
radon level.
Radioactive Smoke
Radon gas is also given off by phosphate fertilizers (since phosphate ores
are rich in uranium). When tobacco crops are so fertilized, radon gas accumulates
under the thick canopy of tobacco leaves, and tiny dust particles impregnated
with radon daughters adhere to the sticky, resinous hairs on the underside of
each leaf. When harvested, the tobacco contains high concentrations of radioactive
lead-210 and polonium-210. Cigarette smokers breathe these radon daughters into
their lungs with every inhalation.
Some of these radioactive particles lodge in the lungs of smokers, as confirmed
by autopsies. Others enter the bloodstream along with oxygen and carbon monoxide.
Radioactive deposits of this kind have been found in plaque removed from sclerotic
arteries. Many researchers now believe these excessive concentrations of radon
daughters are responsible for most of the 135,000 deaths each year in the U.S.
from lung cancer, strokes and heart disease which the American Medical Association
attributes to smoking.
Fallout from Uranium Mines
In addition to killing uranium miners and those living in contaminated homes,
each uranium mine is, in effect, a "slow bomb" -- spreading deadly
radioactive poisons over vast areas of the earth, as surely as the Chernobyl
disaster did, as surely as atmospheric tests of nuclear weapons have done, but
at an insidiously slower rate. Radon gas can travel a thousand miles in just
a few days, with a light breeze. As it travels low to the ground (it is much
heavier than air) it deposits its "daughters" -- solid radioactive
fallout -- on the vegetation, soil and water below; the resulting radioactive
materials enter the food chain, ending up in fruits and berries, the flesh of
fish and animals, and ultimately, in the bodies of human beings.
On February 25, 1986, the Wall Street Journal printed a front page story that
portrayed the 220 million tons of uranium tailings in the U.S. as an ecological
and financial time bomb. (In Canada, we have about 150 million tons of such
tailings.) Everyone agrees that these materials are too dangerously radioactive
to leave on the surface of the earth, yet no one has devised a satisfactory
method for permanently containing them. Even at a very modest rate, say $10
per ton, it will cost billions of dollars to dispose of these wastes.
Uncontained in Time and Space
The tailings will remain dangerously radioactive for millions of years. Thorium-
230, itself a by-product of uranium, is an alpha-emitter with a half-life of
almost 80,000 years. It continually replenishes all the other radioactive by-products
of uranium in the abandoned tailings piles. Radium-226, a bone-seeking alpha-emitting
carcinogen which is at least 20 times as harmful as strontium-90, is blown in
the wind, washed by the rain, and leached into the waterways from the tailings
piles, where it re-concentrates by factors of thousands in aquatic plants and
by factors of hundreds in land plants. It has a half-life of 1,600 years. When
the levels of radium increased in Canadian rivers as a result of uranium mining
activities, the nuclear establishment obligingly increased the standard for
an "acceptable level" of radium in drinking water by a factor of nine.
(The B.C. Medical Association refers to radium as a "superb carcinogen."
It is known to have killed many of the women who patriotically painted radium
on the dials of military instruments during World War II so that the readings
would glow in the darkness of a cockpit or battlefield.)
In addition, the radon gas emissions from abandoned tailings can cause radioactive
contamination on a continental and even on a global basis. The U.S. Nuclear
Regulatory Commission has estimated that radon emissions from uranium tailings
in the Southwest U.S. can be expected to cause over 3,000 cancer deaths per
century over the North American continent. Many researchers believe that this
death toll is underestimated by at least a factor of ten, even if we ignore
the fallout of solid radon daughters on leafy vegetation as the radon gas passes
overhead, and even if we assume that the tailings are not blown by the wind,
washed by the rain, or spread through the food chain, thereby distributing the
source of contamination over a much wider area.
A Deadly Legacy
The legacy of uranium is truly a devastating one. Miners and smokers dead and
dying, vast reservoirs of tailings releasing radioactive poisons into the biosphere,
radon daughters accumulating in buildings and in the food chain -- and all for
the sake of building more bombs and nuclear reactors. The radioactive fission
products that were released into the atmosphere from Chernobyl -- iodine-131,
strontium-90, cesium-137, and the rest -- are all the broken pieces or uranium
atoms left over from the fission process. Even the extraordinary toxicity of
plutonium can be rightfully attributed to uranium, since plutonium is created
by transmutation of uranium through the absorption of neutrons.
Because Canada is the world's largest uranium producer and exporter, Canadians
have an important role in halting the widespread use of uranium. If we do not
come to grips with the Pandora's box of problems which it spawns, and soon,
our children and grandchildren may find that we have left them with a burden
too great for them to bear.
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