Tag Archives: nuclear

Nuclear Fishin?

by Peggy Olive

The July 19, 2012 issue of Georgia Straight featured a full-page cover graphic showing a cartoon of three-eyed mutant fish cleverly entitled, Nuclear Fishin’. According to the article, high radiation levels in some Pacific Ocean fish have created concern among doctors at B.C. universities. Should we be worried about the health effects of consuming fish from Japan or fish that migrate here from Japan?

Sixteen months after the Fukushima nuclear accident in March 2011, the average level of radioactive cesium in fish from Japan had risen from 5 becquerels per kilogram to 65 Bq/kg. We are told that Japan’s official limit for radioactive cesium in food is 100 Bq/kg. Radioactivity in about 10% of the fish species, some exported to Canada this spring, may have exceeded this limit.

The cesium action level is the level above which food is no longer considered safe for human consumption so that action must be taken to prevent consumption. This level is ten times higher in Canada and elsewhere than in Japan. Why the difference?

According to Yomiuri Online (Dec. 25, 2011), action levels were recently set much lower in Japan in order to ensure the public’s safety and provide reassurance. Do you feel reassured to know that fish considered safe to eat last year is now considered contaminated? This article also goes on to say that the planned tightening of the limits is puzzling local government officials who are charged with monitoring radioactive cesium in food.

There is a good reason behind the choice of 1000 Bq/kg cesium as the action level for our food set by Health Canada and most other international advisory and national regulatory bodies. The cesium action level of 1000 Bq/kg in foodstuffs translates, with a few reasonable assumptions, to a dose to a person of about 5 milli-Sieverts per year. There is international consensus that exposure to 5 mSv in a year is acceptable because we already receive a natural background dose of ionizing radiation of similar magnitude and because no actions have been recommended for avoiding exposure from other natural sources at doses of 5 mSv or less. Radiation workers have an exposure limit of 20 mSv per year, and medical diagnostic procedures like CT scans can produce exposures in excess of 10 mSv.

What can we expect from exposure to 5 mSv? There are recognized limitations in trying to predict health effects from chronic radiation exposures below about 50 mSv (Brenner et al.,Proc. Nat’l. Acad. Sci, 2003). However, acceptable estimates can be made by extrapolating information on cancer risks observed after higher doses. If a population of 10,000 individuals receives 5 mSv, this would be expected to result in an additional two cancer deaths on top of a background of about 2000 cancer deaths in that population. Should we worry if we consume fish that contains 65 Bq/kg cesium radiation? Based on the above numbers, we could expect perhaps one additional cancer in 100,000 people who consume this fish. In my view, the protection afforded by avoiding food with more than1000 Bq/kg cesium is adequate.

Recently, small but measurable levels of radioactivity were found in endangered bluefin tuna that migrated from Japan to the California coast last summer (Madigan et al., Proc. Nat’l Acad. Sci. 2012). The World Health Organization had previously reported that there was no reason for concern about seafood safety outside of Japan. Even though levels of radioactive cesium in the California tuna were 200 times below our action level, the presence of even trace amounts of radioactivity still stimulated concern about whether the tuna was safe to consume. Increasing the risk of developing a radiation-induced cancer by 5% would require eating over 40 tons of this tuna!

In spite of the lack of health concerns with the current action levels in place, fear of eating radioactive fish is widespread and disproportionate to risk. An article in Forbes quotes one of the PNAS study’s coauthors as saying, “My first thought was this will do more for the conservation of this endangered animal (bluefin tuna) than nearly anything else could.” I hope he’s right because this would be the small silver lining in a radioactive cloud.

The pros and cons of nuclear power versus coal

by Peggy Olive

In an ideal world, inexpensive, reliable, and safe sources of green energy would abound, and we could avoid using energy derived from either nuclear fission or coal burning. But we’re not there yet, and with climate change already affecting life on our planet, most of us believe that we need to move quickly to using clean energy sources to limit the rise in global temperature caused by greenhouse gas emissions.

In a talk on energy and climate entitled, “Innovating to Zero”, Microsoft’s Bill Gates gives a compelling argument for why we need nuclear power in an age of increasing levels of atmospheric CO2 [1]. Using a simple equation, he argues that CO2 is a product of the number of people on the planet, the services delivered per person, the energy needed per service, and the amount of CO2 produced by each unit of energy. The first two are heading up and are unlikely to be stopped. The cost of energy is decreasing, but not enough. So that leaves the fourth factor. We must use energy that does not produce greenhouse gases, but we need reliable energy – energy that’s available when the sun doesn’t shine and the wind doesn’t blow. Gates believes that nuclear power offers this promise and should be part of the mix, especially if improved (safer) technology is employed. Energy conservation should be a viable way to transition from dirty to clean energy, but increases in services delivered per person along with a growing population would quickly eat up conservation savings.

Like coal power, nuclear power is economical and does not fluctuate as much as wind or solar power. Unlike coal, it is considered clean in terms of the amount of greenhouse gas emissions produced by the power plant itself, although uranium mining and processing are not without risks and environmental impact. But the public is overly fearful of nuclear power, seeing it as an accident waiting to happen and, when it does, likely to adversely affect millions. Of equal concern, radioactive wastes from power plants accumulate and represent a threat by terrorists willing to handle the material, but this has not yet occurred. Accidents at nuclear power plants have the potential to be dangerous to the local population and environment as we’ve recently appreciated with the Fukushima disaster, and once long-lived radioactive elements like cesium-137 and strontium-90 are released, they can contaminate the surrounding land for decades. A case in point, the a 30 km exclusion zone surrounding Chernobyl remains empty of people twenty-five years after that disaster.

Fortunately, nuclear power plant “accidents” that spread deadly isotopes are rare, and the planet has suffered only two (avoidable) serious events that rank at the top of the International Nuclear Event Scale. As serious as these events were, there were few immediate deaths. At Chernobyl, the nuclear core of a poorly designed and operated reactor exploded and was cast outside the facility. Thirty-two radiation workers died shortly after radiation exposure at Chernobyl. At Fukushima Daiichi, in spite of IAEA concerns, an older reactor was operating without adequate safety precautions to ensure reactor coolant in the event of an earthquake and tsunami. No one has died from acute radiation poisoning at Fukushima. Other than thyroid cancers (which are mitigated by potassium iodide tablets and easily treated) increases in the incidence of other types of cancer have not been conclusively linked to radiation from the Chernobyl accident [2]. Cardis and colleagues [3] estimated that “of all the cancer cases expected to occur in Europe between 1986 and 2065, around 0.01% may be related to radiation from the Chernobyl accident”. Although a tiny percentage, this still represents a large number of excess cancer cases, more than 5000 to date. However, air pollution is estimated to end life prematurely in at least 17,000 US citizens per year [4] and up to 850,000 globally [5]. A 2002 analysis by the International Energy Association concluded that nuclear power ranked much lower than coal in terms of impact on biodiversity, accidents, and health risks, and only ranked higher on risk perception [6].

When seen in comparison to the risks of deriving energy from burning coal, the evidence that deriving energy from nuclear power is dangerous remains relatively weak. It is the perceived threat that is strong, and this threat recently caused Germany to close eight of their nuclear power plants and to begin to phase out the remaining nine by 2022. Although the intent is to generate energy cleanly, almost half of the energy in Germany currently comes from coal, and it is difficult to believe that this percentage will not rise in the next few decades, thus contributing further to global warming.

Coal-derived power, in addition to being a major contributor to greenhouse gas emissions and acid rain, is hardly safe. Thousands of coal miners die in accidents each year, and the public is susceptible to lung and heart effects from air-borne pollutants. In 2000, the Ontario Medical Association declared air pollution “a public health crisis” [7] and coal-fired power plants as the single largest industrial contributors to this crisis, producing carbon dioxide, fine particulates, and cancerous heavy metals including mercury. In 2005, the Ontario Medical Association estimated that air pollution costs the province more than six hundred million dollars per year in health care costs, as well as causing the premature deaths of thousands of Ontarians each year [8]. Although of little health consequence, it is worth noting that burning coal produces fly ash that concentrates natural radioactive isotopes in excess of levels produced by nuclear power plants under normal operating conditions [9]. Disposal of toxic coal combustion wastes, orders of magnitude larger in volume than nuclear wastes, has also come under scrutiny [10].

We constantly accept risks in our lives without giving it much thought. A person who smokes twenty cigarettes a day over their lifetime would shorten their life, on average, by six years. A person currently living 50 km from Fukushima who is exposed to an extra 3 mSv per year over their lifetime (the average background exposure is now greater than 3 mSv per year thanks to medical imaging) would shorten their life by 15 days [11]. What cannot be easily evaluated, and is therefore ignored in these risk assessments, is the psychological trauma to evacuees and to those who fear the consequences of minimal radiation exposure because they do not comprehend the risks. Wild animals, ignorant of continuing radioactive decay, are now thriving in the Chernobyl exclusion zone [12].

Economic arguments favour the use of coal over nuclear power when waste management and decommissioning are taken into account. Nuclear plants are very expensive to build (and dismantle) although estimated capital costs for advanced coal plants with carbon control and sequestration appear to be on par with costs to build nuclear power plants [13]. The cost to run and maintain coal plants can be higher than nuclear power plants, in part because of the transportation costs of coal. A major concern with both nuclear and coal power plants is that once the plants are built, they are likely to be around for a long time because the infrastructure is so costly to develop. Public pressure will be needed to ensure that these plants are closed as soon as clean energy sources become available.

In summary, although recent events at Fukushima warn us that safety standards and compliance must be improved, nuclear power plants operating normally produce less greenhouse gas and toxic emissions, less global environmental damage, and fewer health issues than coal-burning power plants. Neither represents a safe, sustainable, energy choice, but given a choice between these two, nuclear power comes out on top. According to Walter Keyes, a proponent of nuclear power who has worked as an energy consultant for the Saskatchewan and Federal governments, “If climate change really is the serious global issue that most scientists believe it is, there is a very limited amount of time to fix the problem and we should not be wasting valuable time debating which non GHG (green house gas) generation source is the best – we need them all, desperately!” [14].


1. Bill Gates on Energy: Innovating to Zero! TED talks, February, 2010. http://www.ted.com/talks/bill_gates.html

2. UN Summary of the Chernobyl Forum, Chernobyl’s Legacy: Health, Environmental and Socio-Economic Impacts, IAEA, 2006. http://www.iaea.org/Publications/Booklets/Chernobyl/chernobyl.pdf

3. Cardis E, Krewski D, Boniol M, Drozdovitch V, Darby SC, Gilbert ES, et al. 2006. Estimates of the cancer burden in Europe from radioactive fallout from the Chernobyl accident Inter. J Cancer 119, 1224–1235 (2006).

4. US Environmental Protection Agency, Power plant, mercury and air toxics standards, March, 2011. http://www.epa.gov/airquality/powerplanttoxics/pdfs/overviewfactsheet.pdf

5. World Health Organization. Estimated deaths and DALYs linked to environmental risk factors. http://www.who.int/quantifying_ehimpacts/countryprofilesebd.xls

6. International Energy Agency, Environmental and health impacts of electricity generation, June 2002 (Table 9.9) http://www.ieahydro.org/reports/ST3-020613b.pdf

7. Canadian Medical Association, June 27, 2000. http://www.collectionscanada.gc.ca/eppp-archive/100/201/300/cdn_medical_association/cmaj/cmaj_today/2000/06_27.htm

8. Ontario Medical Association Illness Costs of Air Pollution (ICAP) – Regional Data for 2005. https://www.oma.org/Resources/Documents/d2005IllnessCostsOfAirPollution.pdf

9. McBride JP, Moore RE, Witherspoon JP, Blanco, RE. Radiological impact of airborne effluents of coal and nuclear plants. Science, 202: 1045-1050, 1978.

10. Dellantonio A, Fitz WJ, Repmann F, Wenzel WW. Disposal of coal combustion residues in terrestrial systems: contamination and risk management. J Environ Qual. 39:761-75, 2010

11. U.S. Nuclear Regulatory Commission, Instruction concerning risks from occupational radiation exposure. Regulatory Guide 8.29, Feb. 1996. http://www.nrc.gov/reading-rm/doc-collections/reg-guides/occupational-health/rg/8-29/08-029.pdf

12. Hinton TG, Alexakhim R, Balonov, M., Gentner N, Hendry J, Prister B, Strand P, Woodhead D. Radiation-induced effects on plants and animals: Finds of the United Nations Chernobyl Forum. Health Physics 93: 427-440, 2007.

13. US Department of Energy/Energy Information Administration, Levelized cost of new generation resources in the annual energy outlook 2011. http://www.eia.gov/oiaf/aeo/electricity_generation.html

14. Howell, G and Keyes W, Green (renewable) energy versus nuclear energy. Part five of an eight part written debate regarding nuclear power generation. Mile Zero News and Banner Post, March 17, 2010. http://www.computare.org/Support%20documents/Guests/MZN%20Nuclear%20Debate/5%20of%208%20Green%20Energy%20Howell-Keyes.pdf