From 1990
to 1996, I worked with Northern Medical Services in Saskatchewan. In 1991, our clinic diagnosed three miners with Systemic Lupus Erythematosus,
a disease rarely found in men and, at that time, unknown among the Dene. We
were told by specialists that there was no connection between the disease and
the exposure of these men to uranium. The dearth of research on environmental
contamination from mining and the lack of baseline health information on
Northerners left me with questions.
The Process of Mining, Milling and Refining:
Wherever
mining occurs, the earth’s mantle is disrupted and mining waste (tailings)
remain on the surface or placed back into the mines in its pulverized form. On
the surface, to prevent wind erosion and spread of toxicity, they are usually
covered with water creating tailings ponds. Placed back into the mines, the
previously bound material is now loose aggregate.
What does
the ore contain? Besides uranium, a host of common elements are found including
arsenic, iron, magnesium, titanium, calcium, sodium, potassium, sulfur and
silicon. The heavy metal and toxic content is the real concern; the tailings
contain all the progeny of uranium’s radioactive decay - thorium, protactinium,
radium, radon, polonium, bismuth, francium, astatine, thallium and lead. 85% of
the radioactivity remains in the tailings and, over time, the waste actually
becomes more radioactive as the elements with very long half-lives[1]
decay[2]
into the elements with shorter half-lives.
Of special
concern is radon, a gas considered responsible for 20% of the lung cancers in
Canada. It is heavier than air and can be spread over 1000 km by a stiff wind. Furthermore,
as it decays in its 3.8 day half-life, it becomes polonium, a solid which eventually
settles out of the air and may be taken up by plants and lichens. Polonium is the
most toxic substance known to human kind. An alpha emitter and therefore
undetectable by normal Geiger counters, the amount of polonium equivalent to
the ink in a period in this sentence is 200 times a lethal dose for humans.
(That amount was used to kill the double Russian spy, Litvinenko, in 2006 in
the U.K.)
Milling
occurs close to the mine sites. The ore is pulverized into a dust, the uranium
oxide extracted using ammonia or sodium bicarbonate. The resulting “yellowcake”
which is 70% uranium, is trucked to a refinery at Blind River in Ontario where
it is further purified to uranium trioxide. Further processing occurs at a
conversion plant in Port Hope which changes the trioxide into either a dioxide
powder for CANDU-type reactors or to uranium hexafluoride. The uranium
hexafluoride is transported to enrichment plants in the United States. Both refinement
and conversion leave waste products with radioactive content.
Environmental Effects:
Uranium has
been mined in Canada for over seventy years. Little research has been done on
the direct effect of the mines and their tailings upon the environment. Mining, processing,
and reclamation have the potential to affect soils, air quality, and biota
through surface water quality and groundwater quality and quantity[3].
Any mine is
physically disruptive to the environment, displacing plant and wild life
kilometers away, separating animals from their food sources and affecting
migration patterns. In Ontario, the mining act permits a company to clear-cut
and surface-strip removing up to 1000 tonnes of rock without any restoration. Open
Pit mines may occupy hectares of land surface, release radon and other
elemental dust particles to the atmosphere; underground and leach mining
continue the same releases during the milling process. The tailings from both
mining and milling remain toxic for thousands of years.
The
potential to affect surface and ground water quality is evident in Nero Lake, a
small lake west of Uranium City used as a dump for tailings prior to the
closure of the Lorado mine site in 1961. When assessed in 2013, 52 years later,
Nero Lake had very little biological activity in its waters or rocky bed. “Even
if the entire set of mine sites are cleaned-up around Uranium City, four
watersheds will have levels of selenium and uranium in excess of Saskatchewan
Surface Water Quality Objectives.”[4]
The
potential to affect much wider areas was realized when the Church Rock Dam in
New Mexico was breached by its tailing pond in 1979. The amount of radiation
released to the water and the atmosphere was three times that of the Three Mile
Island power plant disaster. A swath of land following the overflowed creek
continues to be heavily contaminated, its water unsafe for cattle. Clean-up, 38
years later, continues to await resolution of federal/facility law suits.[5]
In summary,
to date there have been little substantive research upon the exact impact to
the environment of uranium mining. With the known toxicity of both the ore
mined and the tailings remaining exposed or remediated, the potential for
environmental contamination exists for millennia. Tailings ponds (as at Elliot Lake) may dry up
and the protected toxins lifted into the atmosphere by the wind; wastes buried
in mine pits (as in Cluff Lake) can be absorbed by plants which in turn are
ingested by animals.[6]
Long term risks are poorly defined.
It is human
hubris to assume that any attempt at restoration can stand the test of time for
these wastes.
Human Health Effects:
Studies of
workers at all of the mining and processing stages has established some of the
human health effects of uranium. Uranium and its progeny are heavy metals and
would be expected to have effects on human growth and development similar to
the two most extensively studied heavy metals, mercury and lead. These include
renal failure and brain damage, DNA damage and fertility problems, high blood
pressure and atherosclerosis, muscle and joint pain without arthritic changes,
behavioural and developmental challenges in children and hearing damage.
New
data is arising as more and more researchers focus on uranium as a chemically
reactive heavy metal. Besides its effect as a heavy metal, it mimics estrogen.
Rat studies indicate fertility problems but while this conclusion requires
human studies to confirm the effect on human populations, the estrogenic
effects may be responsible for the increase in a female-dominated disease,
Systemic Lupus Erythematosis.[8]
The radioactivity
cannot be discounted; the increase in cancer deaths amongst Eldorado miners who
worked unprotected from 1930’s to 1960 is never contested but attributed solely
to radon exposure by the CNSC; the SENES study reviewed the health of miners
from 1975 onwards and concluded that miners would experience 1:100 increase
lung cancer over non-miners[9].
Because it is an alpha-particle producer, uranium has the potential to be
extremely carcinogenic and genotoxic but it might take generations to document
the effect in humans.
As
Brugge and Buchner point out in their review paper of 2011, “As much damage is
irreversible, and possibly cumulative, present efforts must be vigorous to
limit environmental uranium contamination and exposure[10].”
Conclusion:
Uranium
has two uses, nuclear bombs and nuclear power.
Nuclear Bombs are an indiscriminate weapon. The
Non-Proliferation Treaty was established in 1967 to disarm the nuclear powers
and prevent the spread of nuclear bombs to other countries. It has failed on
both counts so a Nuclear Weapons Ban Treaty has been proposed by 122 countries.
Clearly, the majority global citizenry want disarmament.
Nuclear power was developed initially in order to provide material for nuclear weapons. It has created enormous amounts of waste for which, after 70 years and billions of dollars, no long-term storage
facility has been found. In addition to the failure to deal with its waste, the industry has priced
itself out of the market. It cannot compete with solar, wind or other sustainable energy technology. Currently
responsible for only 3% of the worlds energy, it is unlikely that there is a
future for nuclear power.
Since
there is no other purpose for uranium, a moratorium on the mining of uranium
(as exists in the provinces of British Columbia and Quebec) should become
global.
[1] A “half-life is the
length of time that a radioactive element takes to change one half of its atoms
into another element. Half-lives of uranium-238 and uranium-235 are 4.5 billion
and 703.8 million years while those of thallium-206 and polonium-210 (at the
other end of the series of decaying elements) are 4.2 minutes and 138.3 days.
[2] “Decay” occurs when
the element releases energy in the form of an alpha or beta particle and
changes into the next element of its decay chain. This length of time required
for a decay is specific to each element – it cannot be stopped.
[3] https://www.nap.edu/read/13266/chapter/9
[4] Ann Coxworth, PhD, The Environmental Resource, Saskatchewan
Environmental Society, Jan-Feb 2014, p13.
[5] Dale Dewar &
Florian Oelck, From Hiroshima to
Fukushima You, Between the Lines, Toronto, 2014
[6] Local hunters claim
that moose have already disturbed the overlaying protection in search of salt.
(Personal communication).
[7] CNSC Synopsis
Report, April, 2009. “Understanding Health Studies and Risk Assessments
Conducted in the Port Hope Community from the 1950’s to the Present”
[8] Lu-Fritts, et al,
“Systemi Lupus Erythematosus is Associationed with Uranium Exposure in a
Community Living Near a Uranium Processing Plant: A Nested Case-Control Study”,
Arthritis Rheummatol, 2014 Novemember, 66(11): 3105-3112
[9] Jointly reviewed by
CNSC in this paper: http://nuclearsafety.gc.ca/eng/pdfs/health-studies/Opportunity-North-Vol13-Issue4-P21-The-Health-of-Uranium-Miners_e.pdf. It is interesting
to compare the jump to conclusions reported here with the quandary where the
entire nuclear industry tried to discount the findings of the KiKK study, a
Germany study which concluded that there was a distance-related increase in
leukemia in children living close to nuclear power plants.
[10] Brugge D, Buchner V,
“Health Effects of uranium: new research findings”, Rev Environ Health. 2011;26(4):231-49
