Uranium Mining: Human and Environmental Health Effects

 Uranium is a common element in the earth’s crust, more abundant than gold, silver and mercury and found everywhere. Being chemically reactive, it is never found in its elemental form; most commonly it is bound as uranium oxide, U₃0₈. Mining can be cost effective wherever ore concentrations reach 0.02%. One of the highest concentrations was Saskatchewan’s mine at Key Lake at 15.9% U₃0₈. Saskatchewan also boasts the world’s largest mine at McArthur River (concentration of 9.6% U₃0₈₎.

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.

However, these potential risks have been very poorly researched. While the CNSC (Canadian Nuclear Safety Commission) Synopsis report[7]concluded that “no adverse health effects have occurred or are likely to occur in Port Hope as a result of the operations of the nuclear industry in the town” they actually ignored some the research they quoted in the paper. The same organization claimed that the report was “peer-reviewed” when, in fact, a single Harvard researcher was paid to review the document. The document itself admits to statistically higher incidences of circulatory disease, and pneumonia; some of the research quoted as non-significant showed increases in incidence of the target health concern up to the end of the period of time allotted to the study which leads to the question of why that particular “cut-off” date or why the need for longer term research was not recommended? Other objections to the quality of research include: an increase in Down’s syndrome amongst the children of male workers at the refinement plant in spite of the short length of time and small population studied, mixing rare and relatively common cancers so that the effect of the common cancer (leukemia) is lost in the data, excusing the elevated incidences of circulatory disease and pneumonia on poorly matched mortality data – all suggestive of CNSC’s collusion with the industry itself. 

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.

                                                                                   

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[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