Nuclear radiation

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What is nuclear radiation and how dangerous is it?

Nuclear radiation involves protons and neutrons and electrons and gamma rays, and is addressed here.

How dangerous is it?

Short answer: it's like sunlight; if it's very intense it can cause burns and cancers and can kill. (At Chernobyl, where radiation was so intense that some victims got immediate radiation "sunburn", 28 of the workers at the power plant, firefighters, and "liquidators" who tackled the accident, and who were most heavily exposed, subsequently died of Acute Radiation Syndrome (ARS).)

What happens at lower levels - including within the Fukushima and Chernobyl exclusion zones?

We now have vast amount of data on the risks to health of exposure to ionising radiation. These include long-term follow up studies of exposure following atomic bomb explosions, accidents at nuclear plants, and accidents involving medical isotopes. From these we know that risks are very low compared to common risks such as exposure to air pollution, or eating red meat. The regulatory criteria that we apply to ionising radiation are at least 100-fold more stringent that the criteria applied to air pollution; for example air pollution in a city like London shortens inhabitants lives more than living in the Fukushima exclusion zone would do. This discrepancy has resulted in failure to expand nuclear energy, and even shutting down working reactors, which have caused millions of avoidable deaths from burning fossil fuels for electricity generation instead of using nuclear energy, and resulted in increased CO
emissions which threaten us through climate change. Being over-protective against nuclear risks can actually result in greater harm from other causes, just as avoiding sunlight due to fear of skin cancers may result in harm from lack of exercise and other benefits of being outdoors in the sunshine.

What the exact effects are of low intensity radiation, especially the very low levels generally classified as "background radiation", is still a matter of scientific uncertainty and discussion. This is because at low levels — including those at most of the areas surrounding Chernobyl and Fukushima — any health effects are so low that they are masked by the effects of countless other things in our lifestyles and environment that affect our health, from second-hand smoking to stress[1].

Radiation risk models (OxMartin).png

The differing schools of thought are:

  • Linear No Threshold (LNT)
    harm (such as cancers) caused by radiation is proportional to dose at all levels, even the low levels of background radiation,
  • Linear with Threshold
    no harm at levels below a certain threshold,
  • Non-Linear
    disproportionately more harm (concave down in picture), or disproportionately less harm (concave up), at low levels compared to higher levels,
  • Hormesis
    that at low levels radiation has a positive effect on health.

The Non-linear/Threshold and Hormesis models have a theoretical basis in the repair mechanisms which cells had to evolve billions of years ago in order for life to survive on a planet that was much more radioactive than it is now.

A paper summarising the scientific evidence on the health effects of low-level radiation from the Oxford Martin school presents a review of the scientific evidence by a group of experts and describes in which areas there is a scientific consensus, an emerging consensus, no consensus, or uncertainty[2].

Of particular interest to discussions on nuclear energy are the paper's findings on Chernobyl and Fukushima:

The Chernobyl nuclear power plant accident

A number of early emergency workers at the accident at the Chernobyl nuclear power plant received high doses which produced tissue reactions and 28 early deaths. The long-term health impacts are contested. There is consensus on two major health impacts: thyroid cancers caused by high levels of exposure of children to radioactive iodine, and ill-effects to mental health caused by widespread fear of potential risks and social disruption. There is emerging evidence on the risk of leukaemia among recovery workers and those risks are broadly in line with what is expected from the LSS. At present, there is little convincing evidence of other radiation-associated effects in recovery workers or the wider public.

The Fukushima Dai-ichi nuclear power plant accident

The Fukushima Dai-ichi nuclear power plant accident has caused substantial ill-health through the effects of the evacuations, continued displacement and fear of radiation. It is unclear if there will be a detectable excess in thyroid cancer in the coming years. No other discernible increase in ill-health attributable to radiation exposure is expected in either emergency workers or members of the public.

The paper also notes:


Compared with other common health risks (obesity, tobacco smoking, exposure to ambient particulate air pollution), the number of years of life lost owing to radiation exposure is small.

Further reading: links and resources

CNSC radiation site.png

Health Physics Society

The Health Physics Society advises against estimating health risks to people from exposures to ionizing radiation that are near or less than natural background levels because statistical uncertainties at these low levels are great. [...] below levels of about 100 mSv above background from all sources combined, the observed radiation effects in people are not statistically different from zero.

The International Atomic Energy Agency (IAEA) publishes Radiation, People and the Environment, "a broad overview of ionizing radiation, its effects and uses, as well as the measures in place to use it safely". This document is a fairly comprehensive lay-person's introduction to atoms, types of radiation, interactions between radiation and matter, effects in living tissues and doses, sources and effects of ionising radiation, cancers and hereditary disease risks, radiological protection principles and practice, international safety standards, natural radiation, medical uses, environmental pollution including Chernobyl, nuclear power reactors, decommissioning and waste, accidents, transport of radioactive materials, and more.

The United Nations Scientific Committee on the Effects of Atomic Radiation publishes a FAQ (answers to Frequently Asked Questions):

  • What is radiation?
  • How is radiation measured?
  • How are people exposed to radiation?
  • What levels of radiation exposure do people receive?
  • What are the effects of exposure to radiation?

The Canadian Nuclear Safety Commission has a web page Types and sources of radiation describing clearly what non-ionizing and ionizing radiation are, and discussing natural and artificial sources of the latter, how much occurs naturally in foodstuffs and our bodies, etc. (Image at right is a screenshot of the CNSC page.)


Radiation doses

Ionising radiation: dose comparisons Public Health England; 18 Mar 2011

Radiation Dose Chart Randall Munroe; xkcd Xkcd radiation.png

Radiation in Perspective Nuclear Energy Institute; Facebook; 13 Apr 2015

Facebook-Nuclear Energy Institute-IDigUMining-radiation chart.png

Infographic of the Day: The Best Radiation Chart We've Seen So Far MORGAN CLENDANIEL; fastcodesign; 29 Nov 2011

Radiation levels outside the Fukushima power plant remain mostly safe, but just how close are they to being dangerous?

Information is Beautiful -- radiation chart 3.jpg

A banana contains naturally occurring radioactive potassium-40

Banana equivalent dose (BED) is an informal measurement of ionizing radiation exposure, intended as a general educational example to compare a dose of radioactivity to the dose one is exposed to by eating one average-sized banana. Bananas contain naturally occurring radioactive isotopes, particularly potassium-40, one of several naturally-occurring isotopes of potassium. One BED is often correlated to 10−7 sievert (0.1 μSv); however, in practice, this dose is not cumulative, as the principal radioactive component is excreted to maintain metabolic equilibrium. The BED is only meant to inform the public about the existence of very low levels of natural radioactivity within a natural food and is not a formally adopted dose measurement. -- from Wikipedia

Viewpoint: We should stop running away from radiation Wade Allison; BBC; 26 Mar 2011

More than 10,000 people have died in the Japanese tsunami and the survivors are cold and hungry. But the media concentrate on nuclear radiation from which no-one has died - and is unlikely to.

Nuclear radiation at very high levels is dangerous, but the scale of concern that it evokes is misplaced. Nuclear technology cures countless cancer patients every day - and a radiation dose given for radiotherapy in hospital is no different in principle to a similar dose received in the environment.

What of Three Mile Island? There were no known deaths there.

And Chernobyl? The latest UN report published on 28 February confirms the known death toll - 28 fatalities among emergency workers, plus 15 fatal cases of child thyroid cancer - which would have been avoided if iodine tablets had been taken (as they have now in Japan). And in each case the numbers are minute compared with the 3,800 at Bhopal in 1984, who died as a result of a leak of chemicals from the Union Carbide pesticide plant.

So what of the radioactivity released at Fukushima? How does it compare with that at Chernobyl? Let's look at the measured count rates. The highest rate reported, at 1900 on 22 March, for any Japanese prefecture was 12 kBq per sq m (for the radioactive isotope of caesium, caesium-137).

A map of Chernobyl in the UN report shows regions shaded according to rate, up to 3,700 kBq per sq m - areas with less than 37 kBq per sq m are not shaded at all. In round terms, this suggests that the radioactive fallout at Fukushima is less than 1% of that at Chernobyl.

Radioactive Isotopes

Iodine-131 Wikipedia

(8 days)

Iodine-131 (131I), is an important radioisotope of iodine discovered by Glenn Seaborg and John Livingood in 1938 at the University of California, Berkeley.[1] It has a radioactive decay half-life of about eight days. It is associated with nuclear energy, medical diagnostic and treatment procedures, and natural gas production. It also plays a major role as a radioactive isotope present in nuclear fission products, and was a significant contributor to the health hazards from open-air atomic bomb testing in the 1950s, and from the Chernobyl disaster, as well as being a large fraction of the contamination hazard in the first weeks in the Fukushima nuclear crisis. This is because I-131 is a major uranium, plutonium fission product, comprising nearly 3% of the total products of fission (by weight). I-131 is also a major fission product of uranium-233, produced from thorium.

Due to its mode of beta decay, iodine-131 is notable for causing mutation and death in cells that it penetrates, and other cells up to several millimeters away. For this reason, high doses of the isotope are sometimes less dangerous than low doses, since they tend to kill thyroid tissues that would otherwise become cancerous as a result of the radiation. For example, children treated with moderate dose of I-131 for thyroid adenomas had a detectable increase in thyroid cancer, but children treated with a much higher dose did not. Likewise, most studies of very-high-dose I-131 for treatment of Graves disease have failed to find any increase in thyroid cancer, even though there is linear increase in thyroid cancer risk with I-131 absorption at moderate doses.[2] Thus, iodine-131 is increasingly less employed in small doses in medical use (especially in children), but increasingly is used only in large and maximal treatment doses, as a way of killing targeted tissues. This is known as "therapeutic use."

Caesium-137 Wikipedia

(30 years)

Caesium-137 (Cs-137), cesium-137, or radiocaesium, is a radioactive isotope of caesium which is formed as one of the more common fission products by the nuclear fission of uranium-235 and other fissionable isotopes in nuclear reactors and nuclear weapons. It is among the most problematic of the short-to-medium-lifetime fission products because it easily moves and spreads in nature due to the high water solubility of caesium's most common chemical compounds, which are salts.

Strontium-90 Wikipedia

(28.8 years)

Radiation effects

X-rays don’t cause cancer: study safety and health magazine

US Low dose radiation research program US Department of Energy, Office of Biological and Environmental Research; 13-15 Mar 2012

DOE’s Low Dose Program: Is unique within the U.S. government in focusing on low dose iological research aimed at informing current and future national radiation risk policy for the public and the workplace

A restatement of the natural science evidence base concerning the health effects of low-level ionizing radiation Angela R. McLean, Ella K. Adlen, Elisabeth Cardis, Alex Elliott, Dudley T. Goodhead, Mats Harms-Ringdahl, Jolyon H. Hendry, Peter Hoskin, Penny A. Jeggo, David J. C. Mackay, Colin R. Muirhead, John Shepherd, Roy E. Shore, Geraldine A. Thomas, Richard Wakeford, H. Charles J. Godfray; Proceedings of the Royal Society - Biological Sciences; 13 Sep 2017

Exposure to ionizing radiation is ubiquitous, and it is well established that moderate and high doses cause ill-health and can be lethal. The health effects of low doses or low dose-rates of ionizing radiation are not so clear. This paper describes a project which sets out to summarize, as a restatement, the natural science evidence base concerning the human health effects of exposure to low-level ionizing radiation. A novel feature, compared to other reviews, is that a series of statements are listed and categorized according to the nature and strength of the evidence that underpins them. The purpose of this restatement is to provide a concise entrée into this vibrant field, pointing the interested reader deeper into the literature when more detail is needed. It is not our purpose to reach conclusions on whether the legal limits on radiation exposures are too high, too low or just right. Our aim is to provide an introduction so that non-specialist individuals in this area (be they policy-makers, disputers of policy, health professionals or students) have a straightforward place to start. The summary restatement of the evidence and an extensively annotated bibliography are provided as appendices in the electronic supplementary material.

Radiation burns

Radiation burns - Beta burns Wikipedia

"Beta burns" are shallow surface burns, usually of skin and less often of lungs or gastrointestinal tract, caused by beta particles, typically from hot particles or dissolved radionuclides that came to direct contact with or close proximity to the body. They can appear similar to sunburn. Unlike gamma rays, beta emissions are stopped much more effectively by materials and therefore deposit all their energy in only a shallow layer of tissue, causing more intense but more localized damage. On cellular level, the changes in skin are similar to radiodermatitis.

Radiation and cancers

Cancer Mortality Among People Living in Areas With Various Levels of Natural Background Radiation Ludwik Dobrzynski, Krzysztof W. Fornalski, Ludwig E. Feinendegen; Dose-response; Jul-Sep 2015

There are many places on the earth, where natural background radiation exposures are elevated significantly above about 2.5 mSv/year. The studies of health effects on populations living in such places are crucially important for understanding the impact of low doses of ionizing radiation. This article critically reviews some recent representative literature that addresses the likelihood of radiation-induced cancer and early childhood death in regions with high natural background radiation. The comparative and Bayesian analysis of the published data shows that the linear no-threshold hypothesis does not likely explain the results of these recent studies, whereas they favor the model of threshold or hormesis. Neither cancers nor early childhood deaths positively correlate with dose rates in regions with elevated natural background radiation.

Comment On: NRC-2015-0057-0086 Linear No-Threshold Model and Standards for Protection Against Radiation; Extension of Comment Period Mohan Doss, Ph.D., MCCPM, Medical Physicist, Associate Professor, Diagnostic Imaging, Fox Chase Cancer Center, 333 Cottman Avenue Philadelphia, PA 19111; 17 Nov 2015

I am responding to comments received from many members of the public who have raised major concerns regarding the recent petitions to discontinue the use of the linear no-threshold (LNT) model for establishing radiation safety regulations, and the proposed higher radiation dose limits for the public. These concerns are based on a misunderstanding that exists regarding cancer and radiation effects in our society.

Linear No-Threshold Model and Standards for Protection Against Radiation Nukes Pretty Please; 8 Mar 2016

This is a, sort of, re-blog of Mohan Doss' submission to the U.S. Nuclear Regulatory Commission, NRC, on radiation protection standards (link is above). Don't let that put you off reading it. It is a well-written summary of what we currently know about the harms of radiation and actual causes of cancer.

Radiation and Cancer Risk – What Do We Know? Iida Ruishalme; Thoughscapism; 1 Mar 2018

After my visit to the nuclear waste facility ZWILAG, I set out to answer one question: How dangerous is their “high radiation area?”

I found that regulatory limits on radiation are set very cautiously, that effects of low level radiation are really hard to pin down, and that there are people naturally living with radiation levels far beyond what are the legal limits for nuclear plant workers. Some of those areas I visit every year.

I conclude that I could camp in the dry cask hall without being likely to have an increased cancer risk, but I should probably think twice about living there.

Linear No Threshold model

Why was H. J. Muller an effective tool in effort to exaggerate danger of radiation? Rod Adams; Atomic Insights; 7 Apr 2019

Methods used to create the “no safe dose” myth about radiation supports immediate transition to a better model Rod Adams; Atomic Insights; 24 Aug 2018

Hormesis *

atomic bomb survivors

Genetic studies at the Atomic Bomb Casualty Commission–Radiation Effects Research Foundation: 1946–1997 James V. Neel; PNAS; 12 May 1998

Background radiation

Background Radiation Wikipedia

Hot Spots: Earth’s 5 Most Naturally Radioactive Places Steve; Web Ecoist;

  • Guarapari, Brazil
  • Ramsar, Iran
  • Paralana Hot Springs, Arkaroola, Australia
  • Yangjiang, China
  • Karunagappally, Kerala, India

The Most Radioactive Places on Earth (Veritasium; YouTube; 17 Dec 2014)

Who on Earth is exposed to the most ionizing radiation? I'm filming a documentary for TV about how Uranium and radioactivity have shaped the modern world. It will be broadcast in mid-2015, details to come. The filming took me to the most radioactive places on Earth (and some places, which surprisingly aren't as radioactive as you'd think). Chernobyl and Fukushima were incredible to see as they present post-apocalyptic landscapes. I also visited nuclear power plants, research reactors, Marie Curie's institute, Einstein's apartment, nuclear medicine areas of hospitals, uranium mines, nuclear bomb sites, and interviewed numerous experts.

with sources

Here's Why Every Glass Of Wine You Drink Is Radioactive -- Yes, Really (Quora; Forbes; 2 Feb 2016)

Human exposure to high natural background radiation: what can it teach us about radiation risks? Jolyon H Hendry, Steven L Simon, Andrzej Wojcik, Mehdi Sohrabi, Werner Burkart, Elisabeth Cardis, Dominique Laurier, Margot Tirmarche, and Isamu Hayata

Natural radiation is the major source of human exposure to ionising radiation, and its largest contributing component to effective dose arises from inhalation of 222Rn and its radioactive progeny. However, despite extensive knowledge of radiation risks gained through epidemiologic investigations and mechanistic considerations, the health effects of chronic low-level radiation exposure are still poorly understood. The present paper reviews the possible contribution of studies of populations living in high natural background radiation (HNBR) areas (Guarapari, Brazil; Kerala, India; Ramsar, Iran; Yangjiang, China), including radon-prone areas, to low dose risk estimation. Much of the direct information about risk related to HNBR comes from case–control studies of radon and lung cancer, which provide convincing evidence of an association between long-term protracted radiation exposures in the general population and disease incidence. The success of these studies is mainly due to the careful organ dose reconstruction (with relatively high doses to the lung), and to the fact that large-scale collaborative studies have been conducted to maximise the statistical power and to ensure the systematic collection of information on potential confounding factors. In contrast, studies in other (non-radon) HNBR areas have provided little information, relying mainly on ecological designs and very rough effective dose categorisations. Recent steps taken in China and India to establish cohorts for follow-up and to conduct nested case–control studies may provide useful information about risks in the future, provided that careful organ dose reconstruction is possible and information is collected on potential confounding factors.

Childhood cancers

Childhood leukaemia incidence around UK nuclear power plants Department of Health / Committee on Medical Aspects of Radiation in the Environment (COMARE); 6 May 2011

The aim of this report by the Committee on Medical Aspects of Radiation in the Environment (COMARE) is to undertake a further review of the incidence of childhood leukaemia in the vicinity of nuclear power plants (NPPs) in Great Britain, with particular reference to recent publications, including the German ‘Kinderkrebs in der Umgebung von Kernkraftwerken’ study and studies from other countries (for example France and Finland), and in relation to the conclusions in the tenth and eleventh COMARE reports. This review considers England, Scotland and Wales, because there are no NPPS in Northern Ireland.

Nuclear power 'not source of leukaemia' NHS choices; 9 May 2011

commentary on COMARE 14th report, and Guardian article quoting it.

Case–control study on childhood cancer in the vicinity of nuclear power plants in Germany 1980–2003 Claudia Spix, Sven Schmiedel, Peter Kaatsch, Renate Schulze-Rath, Maria Blettner; European Journal of Cancer; 2007

The 1984 Windscale study raised concern about a possible association between living in the vicinity of nuclear power plants and childhood cancer. No such effect for all cancers was seen in ecological studies in Germany (1980–1995). Results from exploratory analyses led to a new study.

Pre-selected areas around all 16 major nuclear power plants in Germany formed the study area. The design is a matched case–control study; cases are all cancers under five years diagnosed in 1980–2003: 1592 cases, and 4735 controls. Inverse distance of place of residence to the nearest nuclear power plant at the time of diagnosis was used as the independent variable in a conditional logistic regression model.

Results show an increased risk for childhood cancer under five years when living near nuclear power plants in Germany. The inner 5-km zone shows an increased risk (odds ratio 1.47; lower one-sided 95% confidence limit 1.16). The effect was largely restricted to leukaemia.

The results are compatible with the corresponding subgroups in the previous German ecological studies, with which this study shares most of the cases. They contrast with the lack of an effect observed or expected from other studies due to low doses from routine nuclear power plant operation.

Leukaemia in young children in the vicinity of British nuclear power plants: a case–control study J F Bithell, M F G Murphy, C A Stiller, E Toumpakari, T Vincent, R Wakeford; British Journal of Cancer; 12 Sep 2013

  • background: Concern about the risk of leukaemia in children living near nuclear power plants (NPPs) persists. Previous British analyses have been area based and consequently thought to be less effective than case–control studies.
  • methods: Cases of childhood leukaemia and non-Hodgkin lymphoma (LNHL) born and diagnosed in Great Britain between 1962 and 2007, with matched cancer-free controls, were analysed by logistic regression to estimate the risk of residential proximity at birth and diagnosis to the nearest NPP, adjusting for relevant variables.
  • results: For 9821 children with LNHL under the age of 5 years, the estimated extra risk associated with residential proximity to an NPP at birth was negative—interpolated Odds Ratio (OR) at 5 km was 0.86 (0.49–1.52). The comparison of 10 618 children with LNHL under five with 16 760 similarly aged children with other cancers also gave a negative estimate of the extra risk of residential proximity at diagnosis—interpolated OR at 5 km was 0.86 (0.62–1.18).
  • conclusion: Our results show little evidence of an increase in risk of LNHL to children aged under 5 years from living in the vicinity of an NPP. Risk estimates are incompatible with comparable ones published in a recent German case–control study.

'No link' between nuclear plants and child cancer NHS choices; 13 Sep 2013

article based on the Bithell et al study

Philip Thomas / NREFS

Professor Philip Thomas

The J-value Risk Assessment Tool and its application to big nuclear accidents

NREFS: Management of Nuclear Risk Issues: Environmental, Financial and Safety

Geraldine Thomas

Professor Geraldine Thomas wikipedia

video of lecture (with Q&A) at the CDT Festival of Science 2015 at Imperial College London

Look at the science – smoking and obesity are more harmful than radiation Geraldine Thomas; Guardian; 26 Apr 2011

Chernobyl and the WW2 bombs should have taught us about how dangerous nuclear really is, but it continues to be hyped up

radiation released from nuclear v. coal

Coal Ash Is More Radioactive Than Nuclear Waste Mara Hvistendahl; Scientific American; 13 Dec 2007

By burning away all the pesky carbon and other impurities, coal power plants produce heaps of radiation
based on 1978 paper for Science, J. P. McBride at Oak Ridge National Laboratory (ORNL)

Radiological Impact of Airborne Effluents of Coal-Fired and Nuclear Power Plants J. P. McBride, R. E. Moore, J. P. Witherspoon, R. E. Blanco; ORNL Chemical Technology Division; Aug 1977

Nuclear proliferation through coal burning Gordon J. Aubrecht, II; Physics Education Research Group, Department of Physics, Ohio State University; 25 May 2003

page 8

The EPA found slightly higher average coal concentrations than used by McBride et al. of 1.3 ppm and 3.2 ppm, respectively. Gabbard (A. Gabbard, “Coal combustion: nuclear resource or danger?,” ORNL Review 26, finds that American releases from each typical 1 GWe coal plant in 1982 were 4.7 tonnes of uranium and 11.6 tonnes of thorium, for a total national release of 727 tonnes of uranium and 1788 tonnes of thorium. The total release of radioactivity from coal-fired fossil fuel was 97.3 TBq (9.73 x 1013 Bq) that year. This compares to the total release of 0.63 TBq (6.3 x 1011 Bq) from the notorious TMI accident, 155 times smaller.

The National Council on Radiation Protection and Measurements (NCRP) similarly found that population exposure from operation of comparable (1 GWe) nuclear and coal-fired power plants was 4.9 personSv/yr for coal plants and 4.8 x 10-2 person-Sv/yr for nuclear plants, a factor of ~100 greater for the coal-fired plants.

A single 1 GWe coal-fired plant causes 25 fatalities, 60,000 cases of respiratory disease, and $12 million in property damage, as well as emitting an amount of NOx equivalent to 20,000 cars per year. It also produces ashes and sludge.


There's no Thyroid cancer epidemic in Fukushima

The Linear No Threshold hypothesis is extremely difficult to test below levels quite a bit above typical background levels because it predicts effects in terms of rates of cancers so much lower than occur naturally anyway that rates of radiation-induced cancers down in the "noise" of normal variability and confounding effects, such as especially inaccuracies in reported levels of smoking earlier in subjects' lives.


What I Learned from an Ocean Radioactivity Testing Project Ken Buesseler; Scientific American; 12 Dec 2018

We live in a radioactive world. That simple fact about our planet kept coming to me in the weeks and months after March 11, 2011, when the Fukushima Dai-ichi Nuclear Power plant overheated, exploded and began releasing radioactivity into the ocean and atmosphere. It was a fact that I also learned after Chernobyl in 1986, when I was a graduate student in chemical oceanography studying plutonium in the ocean produced during nuclear weapons testing.

In the days and years after Fukushima, I would find myself responding to audiences up and down the West Coast who expressed concern about reports of a radioactive “blob” making its way across the Pacific or dead birds found on a beach or decomposing starfish. I kept hearing the same questions from worried parents, fisherman and surfers: Is it safe? Should I stay out of the water? Can I eat seafood? Is the Pacific dying?

I am a scientist, so my first response after the accident was to head to Japan, collect samples and assess the situation. Near the reactors, where we were not allowed to sample, levels of radioactivity in the ocean spiked to more than 10 million times the pre-accident background in early April. By the time we arrived in June, levels had thankfully had fallen thousands of times, but it was still easy to detect this new source of radioactivity as it mixed into the ocean and began moving inexorably east.

To my surprise, as radioactivity levels near Japan decreased, public concern in the United States increased. Maps pinpointing the spread and dilution of radioactive cesium-134 and -137—the principal markers of radioactivity from Fukushima—did little to allay public concerns. But because no federal agency claims oversight for radioactivity in ocean water, there was no place I could apply for funding to respond to these concerns in a comprehensive way. And since there was also no way I could take everyone in California on a research cruise to see what I was seeing, I decided to get people to see for themselves how much radiation there was.

The result was Our Radioactive Ocean (ORO), a crowd-funded campaign to measure the levels of radioactive cesium along the West Coast of North America and around Hawaii. Our goal was to empower individuals and groups to collect water at their favorite beach with our simple kit, then send the sample to my lab for analysis. In the process, they would take ownership of the information we returned to them and hopefully become ambassadors for the scientific process and the knowledge that we assembled, one sample at a time.

What started out as a blank map of the eastern North Pacific, is now dotted with well over 300 sample locations. More importantly, we have photos of families, surfing groups, and classrooms, all wading into the ocean to collect a sample—their sample. The results we have assembled show that radioactivity levels in the ocean off the West Coast are lower today than they were in the 1960s when similar radioactive contaminants were first released as fallout from nuclear weapons testing.

Study of workers in nuclear industry

Researchers pin down risks of low-dose radiation Alison Abbott; Nature News; 8 Jul 2015

"Large study of nuclear workers shows that even tiny doses slightly boost risk of leukaemia

"A landmark international study has now provided the strongest support yet for the idea that long-term exposure to low-dose radiation increases the risk of leukaemia, although the rise is only minuscule"

study of workers in the nuclear industry whose exposure (at work) is monitored by dosimeters, claims increased risks of leukaemia, but as the comments to the article point out there are possible flaws in these findings.


Plutonium and Health: How great is the risk? George L. Voelz; Los Alamos Science; 2000

Because it is radioactive, plutonium is dangerous when it finds its way into the human body. Driven by knowledge of the possible harmful health effects of plutonium, scientists carefully warned the public about them and established procedures to protect the workers in plutonium-processing facilities. In fact, their care was so extreme that many believe it was the scientists themselves who promoted an overstated idea that became well known at the end of the 1940s: “Plutonium is the most toxic substance known to man.”

In this article, we will give a realistic assessment of the health risks of plutonium.

Genetic factors in radiation susceptibility

There is evidence that individuals' susceptibility to cancer from low-dose radiation depends on genetic factors.

New Clues About the Risk of Cancer From Low-dose Radiation: Berkeley Lab research could lead to ways to ID people particularly susceptible to cancer


Identification of genetic loci that control mammary tumor susceptibility through the host microenvironment Pengju Zhang et al; Scientific Reports; 9 Mar 2015

Treatment for radiation exposure

Pectin "cure"


Comparison of Prussian blue and apple-pectin efficacy on 137Cs decorporation in rats. Le Gall B, Taran F, Renault D, Wilk JC, Ansoborlo E.; Biochimie; Nov 2006

Cesium-137 (137Cs) is one of the most important nuclear fission elements that contaminated the environment after the explosion of the Chernobyl nuclear power plant in Ukraine (1986). The aim of the study was to compare the efficacy of two chelating agent, Prussian blue and apple-pectin on 137cesium decorporation in rats. Rats were intravenously injected with a solution of 137cesium (5 kBq per rat). Chelating agents, Prussian blue or apple-pectin were given immediately after Cs contamination and during 11 days by addition of each chelating agent in drinking water at a concentration corresponding to 400 mg kg(-1) day(-1). Efficiency was evaluated 11 days after contamination (at the end of treatment) through their ability to promote Cs excretion and to reduce the radionuclide accumulation in some retention compartments (blood, liver, kidneys, spleen, skeleton and in the remaining carcass). In these conditions after treatment with Prussian blue a fivefold increase in fecal excretion of Cs was observed and was associated with a reduction in the radionuclide retention in the main organs measured. In contrast, no significant differences were observed between untreated rats and rats treated with apple-pectin. These observations were discussed in terms of ability of pectins to bind Cs and compared to recently published results obtained after treatment of Cs-contaminated children with this chelate.


Radiophobia: Long-Term Psychological Consequences of Chernobyl Ross H. Pastel; Military Medicine; 2002

The primary health effect of Chernobyl has been widespread psychological distress in liquidators (workers brought In for cleanup), evacuees, residents of contaminated areas, and residents of adjacent noncontaminated areas. Several psychoneurological syndromes characterized by multiple unexplained physical symptoms including fatigue, sleep and mood disturbances, impaired memory and concentration, and muscle and/or joint pain have been reported in the Russian literature.

These syndromes, which resemble chronic fatigue syndrome and fibromyalgia, are probably not due to direct effects of radiation because they do not appear to be dose related to radiation exposure and because they occur in areas of both high and low contamination.

Footnotes and References

  1. The scientific body comprising professionals who specialise in radiation safety advises against estimating health risks to people from exposures to radiation at natural background levels because of the statistical uncertainties at such low levels; see "Radiation Risk In Perspective"; Health Physics Society
  2. A restatement of the natural science evidence base concerning the health effects of low-level ionizing radiation Angela R. McLean, Ella K. Adlen, Elisabeth Cardis, Alex Elliott, Dudley T. Goodhead, Mats Harms-Ringdahl, Jolyon H. Hendry, Peter Hoskin, Penny A. Jeggo, David J. C. Mackay, Colin R. Muirhead, John Shepherd, Roy E. Shore, Geraldine A. Thomas, Richard Wakeford, H. Charles J. Godfray; Proceedings of The Royal Society B, Biological Sciences; 13 Sept 2017 (also available from the Oxford Martin School (pdf))