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35461 | Death toll from Chernobyl and Fukushima | untitled-reusable-block-222 | wp_block | publish | <!-- wp:paragraph --> <p>Nuclear energy is an important source of low-carbon energy. But, there is <a href="https://ourworldindata.org/grapher/public-opposition-to-nuclear-energy-production">strong public opposition</a> to it, often because of concerns around safety.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>These concerns are often sparked by memories of two nuclear accidents: the Chernobyl disaster in Ukraine in 1986, and Fukushima in Japan in 2011.{ref}The third incident that often comes to mind was the Three Mile Island accident in the US in 1979. This was rated as a level five event (“Accident with Wider Consequences”) on the seven-point <em>International Nuclear Event Scale</em>.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>No one died directly from this incident, and follow-up epidemiological studies have not found a clear link between the incident and long-term health impacts.<br><br>Hatch, M. C., Beyea, J., Nieves, J. W., & Susser, M. (1990). <a href="https://academic.oup.com/aje/article-abstract/132/3/397/103678">Cancer near the Three Mile Island nuclear plant: radiation emissions</a>. <em>American Journal of Epidemiology</em>, 132(3), 397-412.<br><br>Hatch, M. C., Wallenstein, S., Beyea, J., Nieves, J. W., & Susser, M. (1991). <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1405170/">Cancer rates after the Three Mile Island nuclear accident and proximity of residence to the plant</a>. <em>American Journal of Public Healt</em>h, 81(6), 719-724.{/ref}</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>These two events were by far the largest nuclear accidents in history; the only disasters to receive a level 7 (the maximum classification) on the International Nuclear Event Scale.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>How many people died in these nuclear disasters, and what can we learn from them?</p> <!-- /wp:paragraph --> <!-- wp:heading {"level":3} --> <h3>How many died from the nuclear accident in Chernobyl?</h3> <!-- /wp:heading --> <!-- wp:paragraph --> <p>In April 1986, the core of one of the four reactors at Chernobyl nuclear plant, in Ukraine, melted down and exploded. It was the worst nuclear disaster in human history.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>There are several categories of deaths linked to the disaster – for some we have a good idea of how many died, for others we have a range of plausible deaths.</p> <!-- /wp:paragraph --> <!-- wp:heading {"level":4} --> <h4>Direct deaths from the accident</h4> <!-- /wp:heading --> <!-- wp:paragraph --> <p><strong>30 people died during or very soon after the incident. </strong></p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Two plant workers died almost immediately in the explosion from the reactor. Overall, 134 emergency workers, plant operators, and firemen were exposed to levels of radiation high enough to suffer from acute radiation syndrome (ARS). 28 of these 134 workers died in the weeks that followed, which takes the total to 30.{ref}UNSCEAR (2008). Sources and effects of Ionizing Radiation. UNSCEAR 2008 Report to the General Assembly with Scientific Annexes. Available <a href="https://www.unscear.org/unscear/en/publications/2008_1.html"><strong>online</strong></a>.{/ref} </p> <!-- /wp:paragraph --> <!-- wp:heading {"level":4} --> <h4>Later deaths of workers and firemen</h4> <!-- /wp:heading --> <!-- wp:paragraph --> <p>A point of dispute is whether any more of the 134 workers with ARS died as a result of radiation exposure. In 2008, several decades after the incident, the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) published a large synthesis of the latest scientific evidence.{ref}UNSCEAR (2008). Sources and effects of Ionizing Radiation. UNSCEAR 2008 Report to the General Assembly with Scientific Annexes. Available <a href="https://www.unscear.org/unscear/en/publications/2008_1.html"><strong>online</strong></a>.{/ref} It reported that a <strong>further 19 ARS survivors had died by 2006</strong>. But many of these deaths were not related to any condition caused by radiation exposure. Seven were related to diseases not related to cancers including tuberculosis, liver disease, and stroke; six were from heart attacks; one from a trauma incident; and five died from cancers.{ref}The UNSCEAR (2008) report lists the causes of death in each of these survivors in Table D4 of the appendix.{/ref} It’s difficult to say how many of these deaths could be attributed to the Chernobyl accident – it’s not implausible it played a role in at least some of them, especially the five cancer deaths.</p> <!-- /wp:paragraph --> <!-- wp:heading {"level":4} --> <h4>Thyroid cancer deaths in children through contaminated milk</h4> <!-- /wp:heading --> <!-- wp:paragraph --> <p>Most of the population was not exposed to levels of radiation that would put them at risk of negative health impacts. However, the slow response to the disaster meant that some individuals were exposed to the short-lived radionuclide Iodine-131 (<sup>131</sup>I) through the contamination of milk. Radioactive fallout settled on pasture grass across the region; this contaminated milk supplies and leafy vegetables that were consumed in the days immediately after the incident.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>This exposure to <sup>131</sup>I has not been linked to increased cancer risk in the <em>adult</em> population, but several studies have shown an increased incidence of thyroid cancer in those who were children and adolescents around this time. Figuring out how many cases of thyroid cancer in this young population were caused by the accident is not straightforward. This is because there was a large increase in screening efforts in the aftermath of the disaster. It’s not uncommon for thyroid cancer cases to go undetected – and have no negative impact on an individual’s life. Increased screening, particularly in child populations, would result in finding many cases of cancer that would normally go undetected.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>In 2018, UNSCEAR published its latest findings on thyroid cancers attributed to the Chernobyl disaster. Over the period from 1991 to 2015, there were 19,233 cases of thyroid cancer in patients who were younger than 18 at the time of the disaster across Ukraine, Belarus, and exposed regions of Russia. UNSCEAR concluded that around one-quarter of these cases <em>could</em> be linked to radiation exposure. That would mean 4,808 thyroid cancer cases.{ref}25% of 19,233 is 4808 cases.{/ref}</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>By 2005, it was reported that <strong>15 of these thyroid cancer cases had been fatal</strong>.{ref}This figure was included in the UNSCEAR’s 2008 report. I found no updated figure for fatalities in its 2018 report.{/ref} However, it was likely that this figure would increase: at least some of those still living with thyroid cancer will eventually die from it.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>It’s therefore not possible to give a definitive number, but we can look at survival rates and outcomes to get an estimate. Thankfully the prognosis for thyroid cancer in children is very good. Many patients that have undergone treatment have seen either a partial or complete remission.{ref}Reiners, C. (2011). Clinical experiences with radiation induced thyroid cancer after Chernobyl. Genes, 2(2), 374-383.{/ref} Large-scale studies report a 20-year survival rate of 92% for thyroid cancer.{ref}Hogan, A. R., Zhuge, Y., Perez, E. A., Koniaris, L. G., Lew, J. I., & Sola, J. E. (2009). Pediatric thyroid carcinoma: incidence and outcomes in 1753 patients. Journal of Surgical Research, 156(1), 167-172.{/ref}. Others show an even better prognosis, with a survival rate of 98% after 40 years.{ref}Hay, I. D., Gonzalez-Losada, T., Reinalda, M. S., Honetschlager, J. A., Richards, M. L., & Thompson, G. B. (2010). Long-term outcome in 215 children and adolescents with papillary thyroid cancer treated during 1940 through 2008. <a href="https://link.springer.com/article/10.1007/s00268-009-0364-0">World Journal of Surgery</a>, 34(6), 1192-1202.{/ref} </p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>If we combine standard survival rates with our number of radiation-induced cancer cases – 4,808 cases – we might estimate that the <strong>number of deaths could be in the range of 96 to 385</strong>. This comes from the assumption of a survival rate of 92% to 98% (or, to flip it, a mortality rate of 2% to 8%).{ref}2% of 4808 is 96, and 8% is 385.{/ref} This figure comes with significant uncertainty.</p> <!-- /wp:paragraph --> <!-- wp:heading {"level":4} --> <h4>Deaths in the general population</h4> <!-- /wp:heading --> <!-- wp:paragraph --> <p>Finally, there has been significant concern about cancer risks to the wider population across Ukraine, Belarus, Russia, and other parts of Europe. This topic remains controversial. Some reports in the early 2000s estimated much higher death tolls ranging from 16,000 to 60,000.{ref}Cardis et al. (2006). Estimates of the cancer burden in Europe from radioactive fallout from the Chernobyl accident. International Journal of Cancer. Available <a href="http://www.nature.com/nature/journal/v440/n7087/full/440982a.html?foxtrotcallback=true"><strong>online</strong></a>.<br><br>Fairlie and Sumner (2006). An independent scientific evaluation of health and environmental effects 20 years after the nuclear disaster providing critical analysis of a recent report by the International Atomic Energy Agency (IAEA) and the World Health Organisation (WHO). Available <a href="http://www.chernobylreport.org/?p=summary"><strong>online</strong></a>.{/ref} In its 2005 report, the WHO estimated a potential death toll of 4,000.{ref}IAEA, WHO (2005/06). <a href="http://www.who.int/mediacentre/news/releases/2005/pr38/en/">Chernobyl’s Legacy: Health, Environmental and Socio-Economic Impacts</a>.{/ref} These estimates were based on the assumption that a large number of people were exposed to elevated levels of radioactivity, and that radioactivity increases cancer risk, even at very low levels of exposure (the so-called ‘<a href="https://en.wikipedia.org/wiki/Linear_no-threshold_model">linear no-threshold model</a>’ of radiation exposure).</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>More recent studies suggest that these estimates were too high. In 2008, the UNSCEAR concluded that radioactive exposure to the general public was very low, and that it does not expect adverse health impacts in the countries affected by Chernobyl, or the rest of Europe.{ref}As it details in its report:<br>“The vast majority of the population were exposed to low levels of radiation comparable, at most, to a few times the annual natural background radiation levels and need not live in fear of serious health consequences. This is true for the populations of the three countries most affected by the Chernobyl accident, Belarus, the Russian Federation and Ukraine, and even more so for the populations of other European countries.”</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>“To date, there has been no persuasive evidence of any other health effect in the general population that can be attributed to radiation exposure”{/ref} In 2018 it published a follow-up report, which came to the same conclusion. </p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>If the health impacts of radiation were directly and linearly related to the level of exposure, we would expect to find that cancer rates were highest in regions closest to the Chernobyl site, and would decline with distance from the plant. But studies do not find this. Cancer rates in Ukraine, for example, were not higher in locations closer to the site{ref}Leung, K. M., Shabat, G., Lu, P., Fields, A. C., Lukashenko, A., Davids, J. S., & Melnitchouk, N. (2019). <a href="https://ascopubs.org/doi/full/10.1200/JGO.19.00099">Trends in solid tumor incidence in Ukraine 30 years after chernobyl</a>. <em>Journal of Global Oncology</em>, <em>5</em>, 1-10.{/ref} This suggests that there is a lower limit to the level at which radiation exposure has negative health impacts. And that most people were not exposed to doses higher than this.</p> <!-- /wp:paragraph --> <!-- wp:heading {"level":4} --> <h4>Combined death toll from Chernobyl</h4> <!-- /wp:heading --> <!-- wp:paragraph --> <p>To summarize the previous paragraphs: </p> <!-- /wp:paragraph --> <!-- wp:list --> <ul><li><strong>2 workers died in the blast.</strong></li><li><strong>28 workers and firemen died in the weeks that followed from acute radiation syndrome (ARS).</strong></li><li><strong>19 ARS survivors had died later, by 2006</strong>; most from causes not related to radiation, but it’s not possible to rule all of them out (especially five that were cancer-related).</li><li><strong>15 people died from thyroid cancer due to milk contamination</strong>. These deaths were among children who were exposed to <sup>131</sup>I from milk and food in the days after the disaster. This could increase to between 96 and 384 deaths, however, this figure is highly uncertain.</li><li><strong>There is currently no evidence of adverse health impacts in the general population across affected countries, or wider Europe</strong>.</li></ul> <!-- /wp:list --> <!-- wp:paragraph --> <p>Combined, the <em>confirmed</em> death toll from Chernobyl is less than 100. We still do not know the <em>true</em> death toll of the disaster. My best approximation is that the true death toll is in the range of 300 to 500 based on the available evidence.{ref}When we report on the safety of energy sources – in <a href="https://ourworldindata.org/safest-sources-of-energy"><strong>this article</strong></a> – I take the upper number of 433 deaths to be conservative.{/ref}</p> <!-- /wp:paragraph --> <!-- wp:heading {"level":3} --> <h3>How many died from the nuclear accident in Fukushima?</h3> <!-- /wp:heading --> <!-- wp:paragraph --> <p>In March 2011, there was an accident at the Fukushima Daiichi Nuclear Power Plant in Ōkuma, Fukushima, Japan. This accident was caused by the <a href="https://en.wikipedia.org/wiki/2011_T%C5%8Dhoku_earthquake_and_tsunami">2011 Tōhoku earthquake and tsunami</a> – the most powerful earthquake recorded in Japan’s history.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Despite it being such a large event, so far, only one death has been attributed to the disaster. This includes both the direct impact of the accident itself and the radiation exposure that followed. However, it’s estimated that several thousand died indirectly from the stress and disruption of evacuation.</p> <!-- /wp:paragraph --> <!-- wp:heading {"level":4} --> <h4>Direct and cancer deaths from the accident</h4> <!-- /wp:heading --> <!-- wp:paragraph --> <p><strong>No one died directly from the disaster. </strong>However, 40 to 50 people were injured as a result of physical injury from the blast, or radiation burns.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>In 2018, the Japanese government <a href="https://www.bbc.co.uk/news/world-asia-45423575">reported that</a> <strong>one worker has since died</strong> from lung cancer as a result of radiation exposure from the event.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Over the last decade, many studies have assessed whether there has been any increased cancer risk for local populations. <strong>There appears to be no increased risk of cancer or other radiation-related health impacts</strong>. </p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>In 2016, the World Health Organization noted that there was a very low risk of increased cancer deaths in Japan.{ref}World Health Organization (2016). FAQs: Fukushima Five Years On. Available online at: <a href="https://www.who.int/ionizing_radiation/a_e/fukushima/faqs-fukushima/en/.%7B/ref">https://www.who.int/ionizing_radiation/a_e/fukushima/faqs-fukushima/en/.{/ref</a>} Several reports from the UN Scientific Committee on the Effects of Atomic Radiation came to the same conclusion: they report that any increase in radiation exposure for local populations was very low and they do not expect any increase in radiation-related health impacts.{ref}To quote UNSCEAR directly: “The doses to the general public, both those incurred during the first year and estimated for their lifetimes, are generally low or very low. No discernible increased incidence of radiation-related health effects are expected among exposed members of the public or their descendants.”<br><br><a href="http://www.unscear.org/docs/GAreports/A-68-46_e_V1385727.pdf">Report of the United Nations Scientific Committee on the Effects of Atomic Radiation. General Assembly Official Records</a>, Sixty-eighth session, Supplement No. 46. New York: United Nations, Sixtieth session, May 27–31, 2013.{/ref} </p> <!-- /wp:paragraph --> <!-- wp:heading {"level":4} --> <h4>Deaths from evacuation</h4> <!-- /wp:heading --> <!-- wp:paragraph --> <p>A more difficult question is how many people died indirectly through the <em>response</em> and evacuation of locals from the area around Fukushima. Within a few weeks of the accident more than 160,000 people had moved away, either from official evacuation efforts or voluntarily from fear of further radioactive releases. Many were forced to stay in overcrowded gyms, schools, and public facilities for several months until more permanent emergency housing became available.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>The year after the 2011 disaster, the Japanese government estimated that 573 people had died indirectly as a result of the physical and mental stress of evacuation.{ref}The Yomiuri Shimbun, 573 deaths ‘related to nuclear crisis’, The Yomiuri Shimbun, 5 February 2012, <a href="https://wayback.archive-it.org/all/20120204190315/http://www.yomiuri.co.jp/dy/national/T120204003191.htm.%7B/ref">https://wayback.archive-it.org/all/20120204190315/http://www.yomiuri.co.jp/dy/national/T120204003191.htm.</a>{/ref} Since then, more rigorous assessments of increased mortality have been done, and this figure <a href="https://www.reconstruction.go.jp/topics/main-cat2/sub-cat2-6/20201225_kanrenshi.pdf">was revised</a> to 2,313 deaths in September 2020.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>These indirect deaths were attributed to the overall physical and mental stress of evacuation; being moved out of care settings; and disruption to healthcare facilities. </p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>It’s important to bear in mind that the region was also trying to deal with the aftermath of an earthquake and tsunami: this makes it difficult to completely separate the indirect deaths related to the nuclear disaster disruptions, and those of the tsunami itself.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Combined, the <em>confirmed</em> death toll from Fukushima is therefore 2,314.</p> <!-- /wp:paragraph --> <!-- wp:heading {"level":3} --> <h3>What can we learn from these nuclear disasters?</h3> <!-- /wp:heading --> <!-- wp:paragraph --> <p>The context and response to these disasters were very different, and this is reflected in what people died from in the aftermath.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Many more people died from Chernobyl than from Fukushima. There are several reasons for this.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>The first was <strong>reactor design</strong>. The nuclear reactors at Chernobyl were poorly designed to deal with this meltdown scenario. Its fatal RBMK reactor had no containment structure, allowing radioactive material to spill into the atmosphere. Fukushima’s reactors did have steel-and-concrete containment structures, although it’s likely that at least one of these was also breached. </p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Crucially, the cooling systems of both plants worked very differently; at Chernobyl, the loss of cooling water as steam actually served to accelerate reactivity levels in the reactor core, creating a positive feedback loop toward the fatal explosion. The opposite is true of Fukushima, where the reactivity reduced as temperatures rose, effectively operating as a self-shutdown measure.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>The second factor was <strong>government response</strong>. In the case of Fukushima, the Japanese government responded quickly to the crisis with evacuation efforts extending rapidly from a 3-kilometer (km), to a 10-km, to a 20-km radius whilst the incident at the site continued to unfold. In contrast, the response in the former Soviet Union was one of denial and secrecy.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>It’s reported that in the days which followed the Chernobyl disaster, residents in surrounding areas were uninformed of the radioactive material in the air around them. In fact, it took at least three days for the Soviet Union to admit an accident had taken place, and did so after radioactive sensors at a Swedish plant were triggered by dispersing radionuclides. As we saw above, it’s estimated that approximately 4,808 thyroid cancer cases in children and adolescents could be linked to radiation exposure from contaminated milk and foods. This could have been prevented by an earlier response.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Finally, while an early response from the Japanese government may have prevented a significant number of deaths, many <a href="https://www.ft.com/content/000f864e-22ba-11e8-add1-0e8958b189ea">have questioned</a> whether the scale of the evacuation effort – where more than 160,000 people were displaced – was necessary.{ref}Hayakawa, M. (2016). <a href="https://journals.sagepub.com/doi/pdf/10.1177/0146645316666707">Increase in disaster-related deaths: risks and social impacts of evacuation</a>. Annals of the ICRP, 45(2_suppl), 123-128.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Normile (2021). <a href="https://www.science.org/content/article/physician-has-studied-fukushima-disaster-decade-and-found-surprising-health-threat">Nuclear medicine: After 10 years advising survivors of the Fukushima disaster about radiation, Masaharu Tsubokura thinks the evacuations posed a far bigger health risk</a>. <em>Science</em>.{/ref} As we see from the figures above, evacuation stress and disruption are estimated to have contributed to several thousand early deaths. Only one death has been linked to the impact of radiation. We don’t know what the possible death toll would have been <em>without</em> any evacuation. That’s why a no-evacuation strategy, if a future accident was to occur, seems unlikely. However, many have called for governments to develop early assessments and protocols of radiation risks, the scale of evacuation needed, and infrastructure to make sure that the disruption to those that are displaced is kept to a minimum.{ref}Normile (2021). <a href="https://www.science.org/content/article/physician-has-studied-fukushima-disaster-decade-and-found-surprising-health-threat">Nuclear medicine: After 10 years advising survivors of the Fukushima disaster about radiation, Masaharu Tsubokura thinks the evacuations posed a far bigger health risk</a>. <em>Science</em>.{/ref}</p> <!-- /wp:paragraph --> <!-- wp:heading {"level":3} --> <h3>Nuclear is one of the safest energy sources</h3> <!-- /wp:heading --> <!-- wp:paragraph --> <p>No energy source comes with zero negative impact. We often think of nuclear energy as being more dangerous than other sources because these low-frequency but highly-visible events come to mind.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>However, when we <a href="https://ourworldindata.org/safest-sources-of-energy">compare the death rates</a> from nuclear energy to other sources, we see that it’s one of the safest. The numbers that have died from nuclear accidents are very small in comparison to the <a href="https://ourworldindata.org/data-review-air-pollution-deaths"><em>millions</em> that die</a> from air pollution from fossil fuels <em>every year</em>. As the linked post shows, the death rate from nuclear is roughly comparable with most renewable energy technologies.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Since nuclear is also a key source of low-carbon energy, it can play a key role in a sustainable energy mix alongside renewables.</p> <!-- /wp:paragraph --> | { "id": "wp-35461", "slug": "untitled-reusable-block-222", "content": { "toc": [], "body": [ { "type": "text", "value": [ { "text": "Nuclear energy is an important source of low-carbon energy. But, there is ", "spanType": "span-simple-text" }, { "url": "https://ourworldindata.org/grapher/public-opposition-to-nuclear-energy-production", "children": [ { "text": "strong public opposition", "spanType": "span-simple-text" } ], "spanType": "span-link" }, { "text": " to it, often because of concerns around safety.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "These concerns are often sparked by memories of two nuclear accidents: the Chernobyl disaster in Ukraine in 1986, and Fukushima in Japan in 2011.{ref}The third incident that often comes to mind was the Three Mile Island accident in the US in 1979. 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", "spanType": "span-simple-text" }, { "children": [ { "text": "American Journal of Public Healt", "spanType": "span-simple-text" } ], "spanType": "span-italic" }, { "text": "h, 81(6), 719-724.{/ref}", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "These two events were by far the largest nuclear accidents in history; the only disasters to receive a level 7 (the maximum classification) on the International Nuclear Event Scale.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "How many people died in these nuclear disasters, and what can we learn from them?", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "text": [ { "text": "How many died from the nuclear accident in Chernobyl?", "spanType": "span-simple-text" } ], "type": "heading", "level": 2, "parseErrors": [] }, { "type": "text", "value": [ { "text": "In April 1986, the core of one of the four reactors at Chernobyl nuclear plant, in Ukraine, melted down and exploded. It was the worst nuclear disaster in human history.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "There are several categories of deaths linked to the disaster \u2013 for some we have a good idea of how many died, for others we have a range of plausible deaths.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "text": [ { "text": "Direct deaths from the accident", "spanType": "span-simple-text" } ], "type": "heading", "level": 3, "parseErrors": [] }, { "type": "text", "value": [ { "children": [ { "text": "30 people died during or very soon after the incident.\u00a0", "spanType": "span-simple-text" } ], "spanType": "span-bold" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "Two plant workers died almost immediately in the explosion from the reactor. Overall, 134 emergency workers, plant operators, and firemen were exposed to levels of radiation high enough to suffer from acute radiation syndrome (ARS). 28 of these 134 workers died in the weeks that followed, which takes the total to 30.{ref}UNSCEAR (2008). Sources and effects of Ionizing Radiation. UNSCEAR 2008 Report to the General Assembly with Scientific Annexes. Available ", "spanType": "span-simple-text" }, { "url": "https://www.unscear.org/unscear/en/publications/2008_1.html", "children": [ { "children": [ { "text": "online", "spanType": "span-simple-text" } ], "spanType": "span-bold" } ], "spanType": "span-link" }, { "text": ".{/ref}\u00a0", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "text": [ { "text": "Later deaths of workers and firemen", "spanType": "span-simple-text" } ], "type": "heading", "level": 3, "parseErrors": [] }, { "type": "text", "value": [ { "text": "A point of dispute is whether any more of the 134 workers with ARS died as a result of radiation exposure. In 2008, several decades after the incident, the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) published a large synthesis of the latest scientific evidence.{ref}UNSCEAR (2008). Sources and effects of Ionizing Radiation. UNSCEAR 2008 Report to the General Assembly with Scientific Annexes. Available ", "spanType": "span-simple-text" }, { "url": "https://www.unscear.org/unscear/en/publications/2008_1.html", "children": [ { "children": [ { "text": "online", "spanType": "span-simple-text" } ], "spanType": "span-bold" } ], "spanType": "span-link" }, { "text": ".{/ref} It reported that a ", "spanType": "span-simple-text" }, { "children": [ { "text": "further 19 ARS survivors had died by 2006", "spanType": "span-simple-text" } ], "spanType": "span-bold" }, { "text": ". But many of these deaths were not related to any condition caused by radiation exposure. Seven were related to diseases not related to cancers including tuberculosis, liver disease, and stroke; six were from heart attacks; one from a trauma incident; and five died from cancers.{ref}The UNSCEAR (2008) report lists the causes of death in each of these survivors in Table D4 of the appendix.{/ref} It\u2019s difficult to say how many of these deaths could be attributed to the Chernobyl accident \u2013 it\u2019s not implausible it played a role in at least some of them, especially the five cancer deaths.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "text": [ { "text": "Thyroid cancer deaths in children through contaminated milk", "spanType": "span-simple-text" } ], "type": "heading", "level": 3, "parseErrors": [] }, { "type": "text", "value": [ { "text": "Most of the population was not exposed to levels of radiation that would put them at risk of negative health impacts. However, the slow response to the disaster meant that some individuals were exposed to the short-lived radionuclide Iodine-131 (", "spanType": "span-simple-text" }, { "children": [ { "text": "131", "spanType": "span-simple-text" } ], "spanType": "span-superscript" }, { "text": "I) through the contamination of milk. Radioactive fallout settled on pasture grass across the region; this contaminated milk supplies and leafy vegetables that were consumed in the days immediately after the incident.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "This exposure to ", "spanType": "span-simple-text" }, { "children": [ { "text": "131", "spanType": "span-simple-text" } ], "spanType": "span-superscript" }, { "text": "I has not been linked to increased cancer risk in the ", "spanType": "span-simple-text" }, { "children": [ { "text": "adult", "spanType": "span-simple-text" } ], "spanType": "span-italic" }, { "text": " population, but several studies have shown an increased incidence of thyroid cancer in those who were children and adolescents around this time. Figuring out how many cases of thyroid cancer in this young population were caused by the accident is not straightforward. This is because there was a large increase in screening efforts in the aftermath of the disaster. It\u2019s not uncommon for thyroid cancer cases to go undetected \u2013 and have no negative impact on an individual\u2019s life. Increased screening, particularly in child populations, would result in finding many cases of cancer that would normally go undetected.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "In 2018, UNSCEAR published its latest findings on thyroid cancers attributed to the Chernobyl disaster. Over the period from 1991 to 2015, there were 19,233 cases of thyroid cancer in patients who were younger than 18 at the time of the disaster across Ukraine, Belarus, and exposed regions of Russia. UNSCEAR concluded that around one-quarter of these cases ", "spanType": "span-simple-text" }, { "children": [ { "text": "could", "spanType": "span-simple-text" } ], "spanType": "span-italic" }, { "text": " be linked to radiation exposure. That would mean 4,808 thyroid cancer cases.{ref}25% of 19,233 is 4808 cases.{/ref}", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "By 2005, it was reported that ", "spanType": "span-simple-text" }, { "children": [ { "text": "15 of these thyroid cancer cases had been fatal", "spanType": "span-simple-text" } ], "spanType": "span-bold" }, { "text": ".{ref}This figure was included in the UNSCEAR\u2019s 2008 report. I found no updated figure for fatalities in its 2018 report.{/ref} However, it was likely that this figure would increase: at least some of those still living with thyroid cancer will eventually die from it.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "It\u2019s therefore not possible to give a definitive number, but we can look at survival rates and outcomes to get an estimate. Thankfully the prognosis for thyroid cancer in children is very good. Many patients that have undergone treatment have seen either a partial or complete remission.{ref}Reiners, C. (2011). Clinical experiences with radiation induced thyroid cancer after Chernobyl. Genes, 2(2), 374-383.{/ref} Large-scale studies report a 20-year survival rate of 92% for thyroid cancer.{ref}Hogan, A. R., Zhuge, Y., Perez, E. A., Koniaris, L. G., Lew, J. I., & Sola, J. E. (2009). Pediatric thyroid carcinoma: incidence and outcomes in 1753 patients. Journal of Surgical Research, 156(1), 167-172.{/ref}. Others show an even better prognosis, with a survival rate of 98% after 40 years.{ref}Hay, I. D., Gonzalez-Losada, T., Reinalda, M. S., Honetschlager, J. A., Richards, M. L., & Thompson, G. B. (2010). Long-term outcome in 215 children and adolescents with papillary thyroid cancer treated during 1940 through 2008. ", "spanType": "span-simple-text" }, { "url": "https://link.springer.com/article/10.1007/s00268-009-0364-0", "children": [ { "text": "World Journal of Surgery", "spanType": "span-simple-text" } ], "spanType": "span-link" }, { "text": ", 34(6), 1192-1202.{/ref}\u00a0\u00a0", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "If we combine standard survival rates with our number of radiation-induced cancer cases \u2013 4,808 cases \u2013 we might estimate that the ", "spanType": "span-simple-text" }, { "children": [ { "text": "number of deaths could be in the range of 96 to 385", "spanType": "span-simple-text" } ], "spanType": "span-bold" }, { "text": ". This comes from the assumption of a survival rate of 92% to 98% (or, to flip it, a mortality rate of 2% to 8%).{ref}2% of 4808 is 96, and 8% is 385.{/ref} This figure comes with significant uncertainty.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "text": [ { "text": "Deaths in the general population", "spanType": "span-simple-text" } ], "type": "heading", "level": 3, "parseErrors": [] }, { "type": "text", "value": [ { "text": "Finally, there has been significant concern about cancer risks to the wider population across Ukraine, Belarus, Russia, and other parts of Europe. This topic remains controversial. Some reports in the early 2000s estimated much higher death tolls ranging from 16,000 to 60,000.{ref}Cardis et al. (2006). Estimates of the cancer burden in Europe from radioactive fallout from the Chernobyl accident. International Journal of Cancer. Available ", "spanType": "span-simple-text" }, { "url": "http://www.nature.com/nature/journal/v440/n7087/full/440982a.html?foxtrotcallback=true", "children": [ { "children": [ { "text": "online", "spanType": "span-simple-text" } ], "spanType": "span-bold" } ], "spanType": "span-link" }, { "text": ".", "spanType": "span-simple-text" }, { "spanType": "span-newline" }, { "spanType": "span-newline" }, { "text": "Fairlie and Sumner (2006). An independent scientific evaluation of health and environmental effects 20 years after the nuclear disaster providing critical analysis of a recent report by the International Atomic Energy Agency (IAEA) and the World Health Organisation (WHO). Available ", "spanType": "span-simple-text" }, { "url": "http://www.chernobylreport.org/?p=summary", "children": [ { "children": [ { "text": "online", "spanType": "span-simple-text" } ], "spanType": "span-bold" } ], "spanType": "span-link" }, { "text": ".{/ref} In its 2005 report, the WHO estimated a potential death toll of 4,000.{ref}IAEA, WHO (2005/06). ", "spanType": "span-simple-text" }, { "url": "http://www.who.int/mediacentre/news/releases/2005/pr38/en/", "children": [ { "text": "Chernobyl\u2019s Legacy: Health, Environmental and Socio-Economic Impacts", "spanType": "span-simple-text" } ], "spanType": "span-link" }, { "text": ".{/ref} These estimates were based on the assumption that a large number of people were exposed to elevated levels of radioactivity, and that radioactivity increases cancer risk, even at very low levels of exposure (the so-called \u2018", "spanType": "span-simple-text" }, { "url": "https://en.wikipedia.org/wiki/Linear_no-threshold_model", "children": [ { "text": "linear no-threshold model", "spanType": "span-simple-text" } ], "spanType": "span-link" }, { "text": "\u2019 of radiation exposure).", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "More recent studies suggest that these estimates were too high. In 2008, the UNSCEAR concluded that radioactive exposure to the general public was very low, and that it does not expect adverse health impacts in the countries affected by Chernobyl, or the rest of Europe.{ref}As it details in its report:", "spanType": "span-simple-text" }, { "spanType": "span-newline" }, { "text": "\u201cThe vast majority of the population were exposed to low levels of radiation comparable, at most, to a few times the annual natural background radiation levels and need not live in fear of serious health consequences. This is true for the populations of the three countries most affected by the Chernobyl accident, Belarus, the Russian Federation and Ukraine, and even more so for the populations of other European countries.\u201d", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "\u201cTo date, there has been no persuasive evidence of any other health effect in the general population that can be attributed to radiation exposure\u201d{/ref} In 2018 it published a follow-up report, which came to the same conclusion.\u00a0", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "If the health impacts of radiation were directly and linearly related to the level of exposure, we would expect to find that cancer rates were highest in regions closest to the Chernobyl site, and would decline with distance from the plant. But studies do not find this. Cancer rates in Ukraine, for example, were not higher in locations closer to the site{ref}Leung, K. M., Shabat, G., Lu, P., Fields, A. C., Lukashenko, A., Davids, J. S., & Melnitchouk, N. (2019). ", "spanType": "span-simple-text" }, { "url": "https://ascopubs.org/doi/full/10.1200/JGO.19.00099", "children": [ { "text": "Trends in solid tumor incidence in Ukraine 30 years after chernobyl", "spanType": "span-simple-text" } ], "spanType": "span-link" }, { "text": ". ", "spanType": "span-simple-text" }, { "children": [ { "text": "Journal of Global Oncology", "spanType": "span-simple-text" } ], "spanType": "span-italic" }, { "text": ", ", "spanType": "span-simple-text" }, { "children": [ { "text": "5", "spanType": "span-simple-text" } ], "spanType": "span-italic" }, { "text": ", 1-10.{/ref} This suggests that there is a lower limit to the level at which radiation exposure has negative health impacts. And that most people were not exposed to doses higher than this.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "text": [ { "text": "Combined death toll from Chernobyl", "spanType": "span-simple-text" } ], "type": "heading", "level": 3, "parseErrors": [] }, { "type": "text", "value": [ { "text": "To summarize the previous paragraphs:\u00a0", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "list", "items": [ { "type": "text", "value": [ { "children": [ { "text": "2 workers died in the blast.", "spanType": "span-simple-text" } ], "spanType": "span-bold" } ], "parseErrors": [] }, { "type": "text", "value": [ { "children": [ { "text": "28 workers and firemen died in the weeks that followed from acute radiation syndrome (ARS).", "spanType": "span-simple-text" } ], "spanType": "span-bold" } ], "parseErrors": [] }, { "type": "text", "value": [ { "children": [ { "text": "19 ARS survivors had died later, by 2006", "spanType": "span-simple-text" } ], "spanType": "span-bold" }, { "text": "; most from causes not related to radiation, but it\u2019s not possible to rule all of them out (especially five that were cancer-related).", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "children": [ { "text": "15 people died from thyroid cancer due to milk contamination", "spanType": "span-simple-text" } ], "spanType": "span-bold" }, { "text": ". These deaths were among children who were exposed to ", "spanType": "span-simple-text" }, { "children": [ { "text": "131", "spanType": "span-simple-text" } ], "spanType": "span-superscript" }, { "text": "I from milk and food in the days after the disaster. This could increase to between 96 and 384 deaths, however, this figure is highly uncertain.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "children": [ { "text": "There is currently no evidence of adverse health impacts in the general population across affected countries, or wider Europe", "spanType": "span-simple-text" } ], "spanType": "span-bold" }, { "text": ".", "spanType": "span-simple-text" } ], "parseErrors": [] } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "Combined, the ", "spanType": "span-simple-text" }, { "children": [ { "text": "confirmed", "spanType": "span-simple-text" } ], "spanType": "span-italic" }, { "text": " death toll from Chernobyl is less than 100. We still do not know the ", "spanType": "span-simple-text" }, { "children": [ { "text": "true", "spanType": "span-simple-text" } ], "spanType": "span-italic" }, { "text": " death toll of the disaster. My best approximation is that the true death toll is in the range of 300 to 500 based on the available evidence.{ref}When we report on the safety of energy sources \u2013 in ", "spanType": "span-simple-text" }, { "url": "https://ourworldindata.org/safest-sources-of-energy", "children": [ { "children": [ { "text": "this article", "spanType": "span-simple-text" } ], "spanType": "span-bold" } ], "spanType": "span-link" }, { "text": " \u2013 I take the upper number of 433 deaths to be conservative.{/ref}", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "text": [ { "text": "How many died from the nuclear accident in Fukushima?", "spanType": "span-simple-text" } ], "type": "heading", "level": 2, "parseErrors": [] }, { "type": "text", "value": [ { "text": "In March 2011, there was an accident at the Fukushima Daiichi Nuclear Power Plant in \u014ckuma, Fukushima, Japan. This accident was caused by the ", "spanType": "span-simple-text" }, { "url": "https://en.wikipedia.org/wiki/2011_T%C5%8Dhoku_earthquake_and_tsunami", "children": [ { "text": "2011 T\u014dhoku earthquake and tsunami", "spanType": "span-simple-text" } ], "spanType": "span-link" }, { "text": " \u2013 the most powerful earthquake recorded in Japan\u2019s history.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "Despite it being such a large event, so far, only one death has been attributed to the disaster. This includes both the direct impact of the accident itself and the radiation exposure that followed. However, it\u2019s estimated that several thousand died indirectly from the stress and disruption of evacuation.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "text": [ { "text": "Direct and cancer deaths from the accident", "spanType": "span-simple-text" } ], "type": "heading", "level": 3, "parseErrors": [] }, { "type": "text", "value": [ { "children": [ { "text": "No one died directly from the disaster. ", "spanType": "span-simple-text" } ], "spanType": "span-bold" }, { "text": "However, 40 to 50 people were injured as a result of physical injury from the blast, or radiation burns.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "In 2018, the Japanese government ", "spanType": "span-simple-text" }, { "url": "https://www.bbc.co.uk/news/world-asia-45423575", "children": [ { "text": "reported that", "spanType": "span-simple-text" } ], "spanType": "span-link" }, { "children": [ { "text": "one worker has since died", "spanType": "span-simple-text" } ], "spanType": "span-bold" }, { "text": " from lung cancer as a result of radiation exposure from the event.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "Over the last decade, many studies have assessed whether there has been any increased cancer risk for local populations. ", "spanType": "span-simple-text" }, { "children": [ { "text": "There appears to be no increased risk of cancer or other radiation-related health impacts", "spanType": "span-simple-text" } ], "spanType": "span-bold" }, { "text": ".\u00a0", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "In 2016, the World Health Organization noted that there was a very low risk of increased cancer deaths in Japan.{ref}World Health Organization (2016). FAQs: Fukushima Five Years On. Available online at: ", "spanType": "span-simple-text" }, { "url": "https://www.who.int/ionizing_radiation/a_e/fukushima/faqs-fukushima/en/.%7B/ref", "children": [ { "text": "https://www.who.int/ionizing_radiation/a_e/fukushima/faqs-fukushima/en/.{/ref", "spanType": "span-simple-text" } ], "spanType": "span-link" }, { "text": "} Several reports from the UN Scientific Committee on the Effects of Atomic Radiation came to the same conclusion: they report that any increase in radiation exposure for local populations was very low and they do not expect any increase in radiation-related health impacts.{ref}To quote UNSCEAR directly: \u201cThe doses to the general public, both those incurred during the first year and estimated for their lifetimes, are generally low or very low. No discernible increased incidence of radiation-related health effects are expected among exposed members of the public or their descendants.\u201d", "spanType": "span-simple-text" }, { "spanType": "span-newline" }, { "spanType": "span-newline" }, { "url": "http://www.unscear.org/docs/GAreports/A-68-46_e_V1385727.pdf", "children": [ { "text": "Report of the United Nations Scientific Committee on the Effects of Atomic Radiation. General Assembly Official Records", "spanType": "span-simple-text" } ], "spanType": "span-link" }, { "text": ", Sixty-eighth session, Supplement No. 46. New York: United Nations, Sixtieth session, May 27\u201331, 2013.{/ref}\u00a0", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "text": [ { "text": "Deaths from evacuation", "spanType": "span-simple-text" } ], "type": "heading", "level": 3, "parseErrors": [] }, { "type": "text", "value": [ { "text": "A more difficult question is how many people died indirectly through the ", "spanType": "span-simple-text" }, { "children": [ { "text": "response", "spanType": "span-simple-text" } ], "spanType": "span-italic" }, { "text": " and evacuation of locals from the area around Fukushima. Within a few weeks of the accident more than 160,000 people had moved away, either from official evacuation efforts or voluntarily from fear of further radioactive releases. Many were forced to stay in overcrowded gyms, schools, and public facilities for several months until more permanent emergency housing became available.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "The year after the 2011 disaster, the Japanese government estimated that 573 people had died indirectly as a result of the physical and mental stress of evacuation.{ref}The Yomiuri Shimbun, 573 deaths \u2018related to nuclear crisis\u2019, The Yomiuri Shimbun, 5 February 2012, ", "spanType": "span-simple-text" }, { "url": "https://wayback.archive-it.org/all/20120204190315/http://www.yomiuri.co.jp/dy/national/T120204003191.htm.%7B/ref", "children": [ { "text": "https://wayback.archive-it.org/all/20120204190315/http://www.yomiuri.co.jp/dy/national/T120204003191.htm.", "spanType": "span-simple-text" } ], "spanType": "span-link" }, { "text": "{/ref} Since then, more rigorous assessments of increased mortality have been done, and this figure ", "spanType": "span-simple-text" }, { "url": "https://www.reconstruction.go.jp/topics/main-cat2/sub-cat2-6/20201225_kanrenshi.pdf", "children": [ { "text": "was revised", "spanType": "span-simple-text" } ], "spanType": "span-link" }, { "text": " to 2,313 deaths in September 2020.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "These indirect deaths were attributed to the overall physical and mental stress of evacuation; being moved out of care settings; and disruption to healthcare facilities.\u00a0", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "It\u2019s important to bear in mind that the region was also trying to deal with the aftermath of an earthquake and tsunami: this makes it difficult to completely separate the indirect deaths related to the nuclear disaster disruptions, and those of the tsunami itself.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "Combined, the ", "spanType": "span-simple-text" }, { "children": [ { "text": "confirmed", "spanType": "span-simple-text" } ], "spanType": "span-italic" }, { "text": " death toll from Fukushima is therefore 2,314.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "text": [ { "text": "What can we learn from these nuclear disasters?", "spanType": "span-simple-text" } ], "type": "heading", "level": 2, "parseErrors": [] }, { "type": "text", "value": [ { "text": "The context and response to these disasters were very different, and this is reflected in what people died from in the aftermath.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "Many more people died from Chernobyl than from Fukushima. There are several reasons for this.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "The first was ", "spanType": "span-simple-text" }, { "children": [ { "text": "reactor design", "spanType": "span-simple-text" } ], "spanType": "span-bold" }, { "text": ". The nuclear reactors at Chernobyl were poorly designed to deal with this meltdown scenario. Its fatal RBMK reactor had no containment structure, allowing radioactive material to spill into the atmosphere. Fukushima\u2019s reactors did have steel-and-concrete containment structures, although it\u2019s likely that at least one of these was also breached.\u00a0", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "Crucially, the cooling systems of both plants worked very differently; at Chernobyl, the loss of cooling water as steam actually served to accelerate reactivity levels in the reactor core, creating a positive feedback loop toward the fatal explosion. The opposite is true of Fukushima, where the reactivity reduced as temperatures rose, effectively operating as a self-shutdown measure.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "The second factor was ", "spanType": "span-simple-text" }, { "children": [ { "text": "government response", "spanType": "span-simple-text" } ], "spanType": "span-bold" }, { "text": ". In the case of Fukushima, the Japanese government responded quickly to the crisis with evacuation efforts extending rapidly from a 3-kilometer (km), to a 10-km, to a 20-km radius whilst the incident at the site continued to unfold. In contrast, the response in the former Soviet Union was one of denial and secrecy.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "It\u2019s reported that in the days which followed the Chernobyl disaster, residents in surrounding areas were uninformed of the radioactive material in the air around them. In fact, it took at least three days for the Soviet Union to admit an accident had taken place, and did so after radioactive sensors at a Swedish plant were triggered by dispersing radionuclides. As we saw above, it\u2019s estimated that approximately 4,808 thyroid cancer cases in children and adolescents could be linked to radiation exposure from contaminated milk and foods. This could have been prevented by an earlier response.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "Finally, while an early response from the Japanese government may have prevented a significant number of deaths, many ", "spanType": "span-simple-text" }, { "url": "https://www.ft.com/content/000f864e-22ba-11e8-add1-0e8958b189ea", "children": [ { "text": "have questioned", "spanType": "span-simple-text" } ], "spanType": "span-link" }, { "text": " whether the scale of the evacuation effort \u2013 where more than 160,000 people were displaced \u2013 was necessary.{ref}Hayakawa, M. (2016). ", "spanType": "span-simple-text" }, { "url": "https://journals.sagepub.com/doi/pdf/10.1177/0146645316666707", "children": [ { "text": "Increase in disaster-related deaths: risks and social impacts of evacuation", "spanType": "span-simple-text" } ], "spanType": "span-link" }, { "text": ". Annals of the ICRP, 45(2_suppl), 123-128.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "Normile (2021). ", "spanType": "span-simple-text" }, { "url": "https://www.science.org/content/article/physician-has-studied-fukushima-disaster-decade-and-found-surprising-health-threat", "children": [ { "text": "Nuclear medicine: After 10 years advising survivors of the Fukushima disaster about radiation, Masaharu Tsubokura thinks the evacuations posed a far bigger health risk", "spanType": "span-simple-text" } ], "spanType": "span-link" }, { "text": ". ", "spanType": "span-simple-text" }, { "children": [ { "text": "Science", "spanType": "span-simple-text" } ], "spanType": "span-italic" }, { "text": ".{/ref} As we see from the figures above, evacuation stress and disruption are estimated to have contributed to several thousand early deaths. Only one death has been linked to the impact of radiation. We don\u2019t know what the possible death toll would have been ", "spanType": "span-simple-text" }, { "children": [ { "text": "without", "spanType": "span-simple-text" } ], "spanType": "span-italic" }, { "text": " any evacuation. That\u2019s why a no-evacuation strategy, if a future accident was to occur, seems unlikely.\u00a0However, many have called for governments to develop early assessments and protocols of radiation risks, the scale of evacuation needed, and infrastructure to make sure that the disruption to those that are displaced is kept to a minimum.{ref}Normile (2021). ", "spanType": "span-simple-text" }, { "url": "https://www.science.org/content/article/physician-has-studied-fukushima-disaster-decade-and-found-surprising-health-threat", "children": [ { "text": "Nuclear medicine: After 10 years advising survivors of the Fukushima disaster about radiation, Masaharu Tsubokura thinks the evacuations posed a far bigger health risk", "spanType": "span-simple-text" } ], "spanType": "span-link" }, { "text": ". ", "spanType": "span-simple-text" }, { "children": [ { "text": "Science", "spanType": "span-simple-text" } ], "spanType": "span-italic" }, { "text": ".{/ref}", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "text": [ { "text": "Nuclear is one of the safest energy sources", "spanType": "span-simple-text" } ], "type": "heading", "level": 2, "parseErrors": [] }, { "type": "text", "value": [ { "text": "No energy source comes with zero negative impact. We often think of nuclear energy as being more dangerous than other sources because these low-frequency but highly-visible events come to mind.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "However, when we ", "spanType": "span-simple-text" }, { "url": "https://ourworldindata.org/safest-sources-of-energy", "children": [ { "text": "compare the death rates", "spanType": "span-simple-text" } ], "spanType": "span-link" }, { "text": " from nuclear energy to other sources, we see that it\u2019s one of the safest. The numbers that have died from nuclear accidents are very small in comparison to the ", "spanType": "span-simple-text" }, { "url": "https://ourworldindata.org/data-review-air-pollution-deaths", "children": [ { "children": [ { "text": "millions", "spanType": "span-simple-text" } ], "spanType": "span-italic" }, { "text": " that die", "spanType": "span-simple-text" } ], "spanType": "span-link" }, { "text": " from air pollution from fossil fuels ", "spanType": "span-simple-text" }, { "children": [ { "text": "every year", "spanType": "span-simple-text" } ], "spanType": "span-italic" }, { "text": ". As the linked post shows, the death rate from nuclear is roughly comparable with most renewable energy technologies.", "spanType": "span-simple-text" } ], "parseErrors": [] }, { "type": "text", "value": [ { "text": "Since nuclear is also a key source of low-carbon energy, it can play a key role in a sustainable energy mix alongside renewables.", "spanType": "span-simple-text" } ], "parseErrors": [] } ], "type": "article", "title": "Death toll from Chernobyl and Fukushima", "authors": [ null ], "dateline": "July 29, 2020", "sidebar-toc": false, "featured-image": "" }, "createdAt": "2020-07-29T17:48:57.000Z", "published": false, "updatedAt": "2022-11-11T10:09:57.000Z", "revisionId": null, "publishedAt": "2020-07-29T16:48:45.000Z", "relatedCharts": [], "publicationContext": "listed" } |
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Nuclear energy is an important source of low-carbon energy. But, there is [strong public opposition](https://ourworldindata.org/grapher/public-opposition-to-nuclear-energy-production) to it, often because of concerns around safety. These concerns are often sparked by memories of two nuclear accidents: the Chernobyl disaster in Ukraine in 1986, and Fukushima in Japan in 2011.{ref}The third incident that often comes to mind was the Three Mile Island accident in the US in 1979. This was rated as a level five event (“Accident with Wider Consequences”) on the seven-point _International Nuclear Event Scale_. No one died directly from this incident, and follow-up epidemiological studies have not found a clear link between the incident and long-term health impacts. Hatch, M. C., Beyea, J., Nieves, J. W., & Susser, M. (1990). [Cancer near the Three Mile Island nuclear plant: radiation emissions](https://academic.oup.com/aje/article-abstract/132/3/397/103678). _American Journal of Epidemiology_, 132(3), 397-412. Hatch, M. C., Wallenstein, S., Beyea, J., Nieves, J. W., & Susser, M. (1991). [Cancer rates after the Three Mile Island nuclear accident and proximity of residence to the plant](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1405170/). _American Journal of Public Healt_h, 81(6), 719-724.{/ref} These two events were by far the largest nuclear accidents in history; the only disasters to receive a level 7 (the maximum classification) on the International Nuclear Event Scale. How many people died in these nuclear disasters, and what can we learn from them? ## How many died from the nuclear accident in Chernobyl? In April 1986, the core of one of the four reactors at Chernobyl nuclear plant, in Ukraine, melted down and exploded. It was the worst nuclear disaster in human history. There are several categories of deaths linked to the disaster – for some we have a good idea of how many died, for others we have a range of plausible deaths. ### Direct deaths from the accident **30 people died during or very soon after the incident. ** Two plant workers died almost immediately in the explosion from the reactor. Overall, 134 emergency workers, plant operators, and firemen were exposed to levels of radiation high enough to suffer from acute radiation syndrome (ARS). 28 of these 134 workers died in the weeks that followed, which takes the total to 30.{ref}UNSCEAR (2008). Sources and effects of Ionizing Radiation. UNSCEAR 2008 Report to the General Assembly with Scientific Annexes. Available [**online**](https://www.unscear.org/unscear/en/publications/2008_1.html).{/ref} ### Later deaths of workers and firemen A point of dispute is whether any more of the 134 workers with ARS died as a result of radiation exposure. In 2008, several decades after the incident, the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) published a large synthesis of the latest scientific evidence.{ref}UNSCEAR (2008). Sources and effects of Ionizing Radiation. UNSCEAR 2008 Report to the General Assembly with Scientific Annexes. Available [**online**](https://www.unscear.org/unscear/en/publications/2008_1.html).{/ref} It reported that a **further 19 ARS survivors had died by 2006**. But many of these deaths were not related to any condition caused by radiation exposure. Seven were related to diseases not related to cancers including tuberculosis, liver disease, and stroke; six were from heart attacks; one from a trauma incident; and five died from cancers.{ref}The UNSCEAR (2008) report lists the causes of death in each of these survivors in Table D4 of the appendix.{/ref} It’s difficult to say how many of these deaths could be attributed to the Chernobyl accident – it’s not implausible it played a role in at least some of them, especially the five cancer deaths. ### Thyroid cancer deaths in children through contaminated milk Most of the population was not exposed to levels of radiation that would put them at risk of negative health impacts. However, the slow response to the disaster meant that some individuals were exposed to the short-lived radionuclide Iodine-131 (131I) through the contamination of milk. Radioactive fallout settled on pasture grass across the region; this contaminated milk supplies and leafy vegetables that were consumed in the days immediately after the incident. This exposure to 131I has not been linked to increased cancer risk in the _adult_ population, but several studies have shown an increased incidence of thyroid cancer in those who were children and adolescents around this time. Figuring out how many cases of thyroid cancer in this young population were caused by the accident is not straightforward. This is because there was a large increase in screening efforts in the aftermath of the disaster. It’s not uncommon for thyroid cancer cases to go undetected – and have no negative impact on an individual’s life. Increased screening, particularly in child populations, would result in finding many cases of cancer that would normally go undetected. In 2018, UNSCEAR published its latest findings on thyroid cancers attributed to the Chernobyl disaster. Over the period from 1991 to 2015, there were 19,233 cases of thyroid cancer in patients who were younger than 18 at the time of the disaster across Ukraine, Belarus, and exposed regions of Russia. UNSCEAR concluded that around one-quarter of these cases _could_ be linked to radiation exposure. That would mean 4,808 thyroid cancer cases.{ref}25% of 19,233 is 4808 cases.{/ref} By 2005, it was reported that **15 of these thyroid cancer cases had been fatal**.{ref}This figure was included in the UNSCEAR’s 2008 report. I found no updated figure for fatalities in its 2018 report.{/ref} However, it was likely that this figure would increase: at least some of those still living with thyroid cancer will eventually die from it. It’s therefore not possible to give a definitive number, but we can look at survival rates and outcomes to get an estimate. Thankfully the prognosis for thyroid cancer in children is very good. Many patients that have undergone treatment have seen either a partial or complete remission.{ref}Reiners, C. (2011). Clinical experiences with radiation induced thyroid cancer after Chernobyl. Genes, 2(2), 374-383.{/ref} Large-scale studies report a 20-year survival rate of 92% for thyroid cancer.{ref}Hogan, A. R., Zhuge, Y., Perez, E. A., Koniaris, L. G., Lew, J. I., & Sola, J. E. (2009). Pediatric thyroid carcinoma: incidence and outcomes in 1753 patients. Journal of Surgical Research, 156(1), 167-172.{/ref}. Others show an even better prognosis, with a survival rate of 98% after 40 years.{ref}Hay, I. D., Gonzalez-Losada, T., Reinalda, M. S., Honetschlager, J. A., Richards, M. L., & Thompson, G. B. (2010). Long-term outcome in 215 children and adolescents with papillary thyroid cancer treated during 1940 through 2008. [World Journal of Surgery](https://link.springer.com/article/10.1007/s00268-009-0364-0), 34(6), 1192-1202.{/ref} If we combine standard survival rates with our number of radiation-induced cancer cases – 4,808 cases – we might estimate that the **number of deaths could be in the range of 96 to 385**. This comes from the assumption of a survival rate of 92% to 98% (or, to flip it, a mortality rate of 2% to 8%).{ref}2% of 4808 is 96, and 8% is 385.{/ref} This figure comes with significant uncertainty. ### Deaths in the general population Finally, there has been significant concern about cancer risks to the wider population across Ukraine, Belarus, Russia, and other parts of Europe. This topic remains controversial. Some reports in the early 2000s estimated much higher death tolls ranging from 16,000 to 60,000.{ref}Cardis et al. (2006). Estimates of the cancer burden in Europe from radioactive fallout from the Chernobyl accident. International Journal of Cancer. Available [**online**](http://www.nature.com/nature/journal/v440/n7087/full/440982a.html?foxtrotcallback=true). Fairlie and Sumner (2006). An independent scientific evaluation of health and environmental effects 20 years after the nuclear disaster providing critical analysis of a recent report by the International Atomic Energy Agency (IAEA) and the World Health Organisation (WHO). Available [**online**](http://www.chernobylreport.org/?p=summary).{/ref} In its 2005 report, the WHO estimated a potential death toll of 4,000.{ref}IAEA, WHO (2005/06). [Chernobyl’s Legacy: Health, Environmental and Socio-Economic Impacts](http://www.who.int/mediacentre/news/releases/2005/pr38/en/).{/ref} These estimates were based on the assumption that a large number of people were exposed to elevated levels of radioactivity, and that radioactivity increases cancer risk, even at very low levels of exposure (the so-called ‘[linear no-threshold model](https://en.wikipedia.org/wiki/Linear_no-threshold_model)’ of radiation exposure). More recent studies suggest that these estimates were too high. In 2008, the UNSCEAR concluded that radioactive exposure to the general public was very low, and that it does not expect adverse health impacts in the countries affected by Chernobyl, or the rest of Europe.{ref}As it details in its report: “The vast majority of the population were exposed to low levels of radiation comparable, at most, to a few times the annual natural background radiation levels and need not live in fear of serious health consequences. This is true for the populations of the three countries most affected by the Chernobyl accident, Belarus, the Russian Federation and Ukraine, and even more so for the populations of other European countries.” “To date, there has been no persuasive evidence of any other health effect in the general population that can be attributed to radiation exposure”{/ref} In 2018 it published a follow-up report, which came to the same conclusion. If the health impacts of radiation were directly and linearly related to the level of exposure, we would expect to find that cancer rates were highest in regions closest to the Chernobyl site, and would decline with distance from the plant. But studies do not find this. Cancer rates in Ukraine, for example, were not higher in locations closer to the site{ref}Leung, K. M., Shabat, G., Lu, P., Fields, A. C., Lukashenko, A., Davids, J. S., & Melnitchouk, N. (2019). [Trends in solid tumor incidence in Ukraine 30 years after chernobyl](https://ascopubs.org/doi/full/10.1200/JGO.19.00099). _Journal of Global Oncology_, _5_, 1-10.{/ref} This suggests that there is a lower limit to the level at which radiation exposure has negative health impacts. And that most people were not exposed to doses higher than this. ### Combined death toll from Chernobyl To summarize the previous paragraphs: * **2 workers died in the blast.** * **28 workers and firemen died in the weeks that followed from acute radiation syndrome (ARS).** * **19 ARS survivors had died later, by 2006**; most from causes not related to radiation, but it’s not possible to rule all of them out (especially five that were cancer-related). * **15 people died from thyroid cancer due to milk contamination**. These deaths were among children who were exposed to 131I from milk and food in the days after the disaster. This could increase to between 96 and 384 deaths, however, this figure is highly uncertain. * **There is currently no evidence of adverse health impacts in the general population across affected countries, or wider Europe**. Combined, the _confirmed_ death toll from Chernobyl is less than 100. We still do not know the _true_ death toll of the disaster. My best approximation is that the true death toll is in the range of 300 to 500 based on the available evidence.{ref}When we report on the safety of energy sources – in [**this article**](https://ourworldindata.org/safest-sources-of-energy) – I take the upper number of 433 deaths to be conservative.{/ref} ## How many died from the nuclear accident in Fukushima? In March 2011, there was an accident at the Fukushima Daiichi Nuclear Power Plant in Ōkuma, Fukushima, Japan. This accident was caused by the [2011 Tōhoku earthquake and tsunami](https://en.wikipedia.org/wiki/2011_T%C5%8Dhoku_earthquake_and_tsunami) – the most powerful earthquake recorded in Japan’s history. Despite it being such a large event, so far, only one death has been attributed to the disaster. This includes both the direct impact of the accident itself and the radiation exposure that followed. However, it’s estimated that several thousand died indirectly from the stress and disruption of evacuation. ### Direct and cancer deaths from the accident **No one died directly from the disaster. **However, 40 to 50 people were injured as a result of physical injury from the blast, or radiation burns. In 2018, the Japanese government [reported that](https://www.bbc.co.uk/news/world-asia-45423575)**one worker has since died** from lung cancer as a result of radiation exposure from the event. Over the last decade, many studies have assessed whether there has been any increased cancer risk for local populations. **There appears to be no increased risk of cancer or other radiation-related health impacts**. In 2016, the World Health Organization noted that there was a very low risk of increased cancer deaths in Japan.{ref}World Health Organization (2016). FAQs: Fukushima Five Years On. Available online at: [https://www.who.int/ionizing_radiation/a_e/fukushima/faqs-fukushima/en/.{/ref](https://www.who.int/ionizing_radiation/a_e/fukushima/faqs-fukushima/en/.%7B/ref)} Several reports from the UN Scientific Committee on the Effects of Atomic Radiation came to the same conclusion: they report that any increase in radiation exposure for local populations was very low and they do not expect any increase in radiation-related health impacts.{ref}To quote UNSCEAR directly: “The doses to the general public, both those incurred during the first year and estimated for their lifetimes, are generally low or very low. No discernible increased incidence of radiation-related health effects are expected among exposed members of the public or their descendants.” [Report of the United Nations Scientific Committee on the Effects of Atomic Radiation. General Assembly Official Records](http://www.unscear.org/docs/GAreports/A-68-46_e_V1385727.pdf), Sixty-eighth session, Supplement No. 46. New York: United Nations, Sixtieth session, May 27–31, 2013.{/ref} ### Deaths from evacuation A more difficult question is how many people died indirectly through the _response_ and evacuation of locals from the area around Fukushima. Within a few weeks of the accident more than 160,000 people had moved away, either from official evacuation efforts or voluntarily from fear of further radioactive releases. Many were forced to stay in overcrowded gyms, schools, and public facilities for several months until more permanent emergency housing became available. The year after the 2011 disaster, the Japanese government estimated that 573 people had died indirectly as a result of the physical and mental stress of evacuation.{ref}The Yomiuri Shimbun, 573 deaths ‘related to nuclear crisis’, The Yomiuri Shimbun, 5 February 2012, [https://wayback.archive-it.org/all/20120204190315/http://www.yomiuri.co.jp/dy/national/T120204003191.htm.](https://wayback.archive-it.org/all/20120204190315/http://www.yomiuri.co.jp/dy/national/T120204003191.htm.%7B/ref){/ref} Since then, more rigorous assessments of increased mortality have been done, and this figure [was revised](https://www.reconstruction.go.jp/topics/main-cat2/sub-cat2-6/20201225_kanrenshi.pdf) to 2,313 deaths in September 2020. These indirect deaths were attributed to the overall physical and mental stress of evacuation; being moved out of care settings; and disruption to healthcare facilities. It’s important to bear in mind that the region was also trying to deal with the aftermath of an earthquake and tsunami: this makes it difficult to completely separate the indirect deaths related to the nuclear disaster disruptions, and those of the tsunami itself. Combined, the _confirmed_ death toll from Fukushima is therefore 2,314. ## What can we learn from these nuclear disasters? The context and response to these disasters were very different, and this is reflected in what people died from in the aftermath. Many more people died from Chernobyl than from Fukushima. There are several reasons for this. The first was **reactor design**. The nuclear reactors at Chernobyl were poorly designed to deal with this meltdown scenario. Its fatal RBMK reactor had no containment structure, allowing radioactive material to spill into the atmosphere. Fukushima’s reactors did have steel-and-concrete containment structures, although it’s likely that at least one of these was also breached. Crucially, the cooling systems of both plants worked very differently; at Chernobyl, the loss of cooling water as steam actually served to accelerate reactivity levels in the reactor core, creating a positive feedback loop toward the fatal explosion. The opposite is true of Fukushima, where the reactivity reduced as temperatures rose, effectively operating as a self-shutdown measure. The second factor was **government response**. In the case of Fukushima, the Japanese government responded quickly to the crisis with evacuation efforts extending rapidly from a 3-kilometer (km), to a 10-km, to a 20-km radius whilst the incident at the site continued to unfold. In contrast, the response in the former Soviet Union was one of denial and secrecy. It’s reported that in the days which followed the Chernobyl disaster, residents in surrounding areas were uninformed of the radioactive material in the air around them. In fact, it took at least three days for the Soviet Union to admit an accident had taken place, and did so after radioactive sensors at a Swedish plant were triggered by dispersing radionuclides. As we saw above, it’s estimated that approximately 4,808 thyroid cancer cases in children and adolescents could be linked to radiation exposure from contaminated milk and foods. This could have been prevented by an earlier response. Finally, while an early response from the Japanese government may have prevented a significant number of deaths, many [have questioned](https://www.ft.com/content/000f864e-22ba-11e8-add1-0e8958b189ea) whether the scale of the evacuation effort – where more than 160,000 people were displaced – was necessary.{ref}Hayakawa, M. (2016). [Increase in disaster-related deaths: risks and social impacts of evacuation](https://journals.sagepub.com/doi/pdf/10.1177/0146645316666707). Annals of the ICRP, 45(2_suppl), 123-128. Normile (2021). [Nuclear medicine: After 10 years advising survivors of the Fukushima disaster about radiation, Masaharu Tsubokura thinks the evacuations posed a far bigger health risk](https://www.science.org/content/article/physician-has-studied-fukushima-disaster-decade-and-found-surprising-health-threat). _Science_.{/ref} As we see from the figures above, evacuation stress and disruption are estimated to have contributed to several thousand early deaths. Only one death has been linked to the impact of radiation. We don’t know what the possible death toll would have been _without_ any evacuation. That’s why a no-evacuation strategy, if a future accident was to occur, seems unlikely. However, many have called for governments to develop early assessments and protocols of radiation risks, the scale of evacuation needed, and infrastructure to make sure that the disruption to those that are displaced is kept to a minimum.{ref}Normile (2021). [Nuclear medicine: After 10 years advising survivors of the Fukushima disaster about radiation, Masaharu Tsubokura thinks the evacuations posed a far bigger health risk](https://www.science.org/content/article/physician-has-studied-fukushima-disaster-decade-and-found-surprising-health-threat). _Science_.{/ref} ## Nuclear is one of the safest energy sources No energy source comes with zero negative impact. We often think of nuclear energy as being more dangerous than other sources because these low-frequency but highly-visible events come to mind. However, when we [compare the death rates](https://ourworldindata.org/safest-sources-of-energy) from nuclear energy to other sources, we see that it’s one of the safest. The numbers that have died from nuclear accidents are very small in comparison to the [_millions_ that die](https://ourworldindata.org/data-review-air-pollution-deaths) from air pollution from fossil fuels _every year_. As the linked post shows, the death rate from nuclear is roughly comparable with most renewable energy technologies. Since nuclear is also a key source of low-carbon energy, it can play a key role in a sustainable energy mix alongside renewables. | { "data": { "wpBlock": { "content": "\n<p>Nuclear energy is an important source of low-carbon energy. But, there is <a href=\"https://ourworldindata.org/grapher/public-opposition-to-nuclear-energy-production\">strong public opposition</a> to it, often because of concerns around safety.</p>\n\n\n\n<p>These concerns are often sparked by memories of two nuclear accidents: the Chernobyl disaster in Ukraine in 1986, and Fukushima in Japan in 2011.{ref}The third incident that often comes to mind was the Three Mile Island accident in the US in 1979. This was rated as a level five event (\u201cAccident with Wider Consequences\u201d) on the seven-point <em>International Nuclear Event Scale</em>.</p>\n\n\n\n<p>No one died directly from this incident, and follow-up epidemiological studies have not found a clear link between the incident and long-term health impacts.<br><br>Hatch, M. C., Beyea, J., Nieves, J. W., & Susser, M. (1990). <a href=\"https://academic.oup.com/aje/article-abstract/132/3/397/103678\">Cancer near the Three Mile Island nuclear plant: radiation emissions</a>. <em>American Journal of Epidemiology</em>, 132(3), 397-412.<br><br>Hatch, M. C., Wallenstein, S., Beyea, J., Nieves, J. W., & Susser, M. (1991). <a href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1405170/\">Cancer rates after the Three Mile Island nuclear accident and proximity of residence to the plant</a>. <em>American Journal of Public Healt</em>h, 81(6), 719-724.{/ref}</p>\n\n\n\n<p>These two events were by far the largest nuclear accidents in history; the only disasters to receive a level 7 (the maximum classification) on the International Nuclear Event Scale.</p>\n\n\n\n<p>How many people died in these nuclear disasters, and what can we learn from them?</p>\n\n\n\n<h3>How many died from the nuclear accident in Chernobyl?</h3>\n\n\n\n<p>In April 1986, the core of one of the four reactors at Chernobyl nuclear plant, in Ukraine, melted down and exploded. It was the worst nuclear disaster in human history.</p>\n\n\n\n<p>There are several categories of deaths linked to the disaster \u2013 for some we have a good idea of how many died, for others we have a range of plausible deaths.</p>\n\n\n\n<h4>Direct deaths from the accident</h4>\n\n\n\n<p><strong>30 people died during or very soon after the incident. </strong></p>\n\n\n\n<p>Two plant workers died almost immediately in the explosion from the reactor. Overall, 134 emergency workers, plant operators, and firemen were exposed to levels of radiation high enough to suffer from acute radiation syndrome (ARS). 28 of these 134 workers died in the weeks that followed, which takes the total to 30.{ref}UNSCEAR (2008). Sources and effects of Ionizing Radiation. UNSCEAR 2008 Report to the General Assembly with Scientific Annexes. Available <a href=\"https://www.unscear.org/unscear/en/publications/2008_1.html\"><strong>online</strong></a>.{/ref} </p>\n\n\n\n<h4>Later deaths of workers and firemen</h4>\n\n\n\n<p>A point of dispute is whether any more of the 134 workers with ARS died as a result of radiation exposure. In 2008, several decades after the incident, the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) published a large synthesis of the latest scientific evidence.{ref}UNSCEAR (2008). Sources and effects of Ionizing Radiation. UNSCEAR 2008 Report to the General Assembly with Scientific Annexes. Available <a href=\"https://www.unscear.org/unscear/en/publications/2008_1.html\"><strong>online</strong></a>.{/ref} It reported that a <strong>further 19 ARS survivors had died by 2006</strong>. But many of these deaths were not related to any condition caused by radiation exposure. Seven were related to diseases not related to cancers including tuberculosis, liver disease, and stroke; six were from heart attacks; one from a trauma incident; and five died from cancers.{ref}The UNSCEAR (2008) report lists the causes of death in each of these survivors in Table D4 of the appendix.{/ref} It\u2019s difficult to say how many of these deaths could be attributed to the Chernobyl accident \u2013 it\u2019s not implausible it played a role in at least some of them, especially the five cancer deaths.</p>\n\n\n\n<h4>Thyroid cancer deaths in children through contaminated milk</h4>\n\n\n\n<p>Most of the population was not exposed to levels of radiation that would put them at risk of negative health impacts. However, the slow response to the disaster meant that some individuals were exposed to the short-lived radionuclide Iodine-131 (<sup>131</sup>I) through the contamination of milk. Radioactive fallout settled on pasture grass across the region; this contaminated milk supplies and leafy vegetables that were consumed in the days immediately after the incident.</p>\n\n\n\n<p>This exposure to <sup>131</sup>I has not been linked to increased cancer risk in the <em>adult</em> population, but several studies have shown an increased incidence of thyroid cancer in those who were children and adolescents around this time. Figuring out how many cases of thyroid cancer in this young population were caused by the accident is not straightforward. This is because there was a large increase in screening efforts in the aftermath of the disaster. It\u2019s not uncommon for thyroid cancer cases to go undetected \u2013 and have no negative impact on an individual\u2019s life. Increased screening, particularly in child populations, would result in finding many cases of cancer that would normally go undetected.</p>\n\n\n\n<p>In 2018, UNSCEAR published its latest findings on thyroid cancers attributed to the Chernobyl disaster. Over the period from 1991 to 2015, there were 19,233 cases of thyroid cancer in patients who were younger than 18 at the time of the disaster across Ukraine, Belarus, and exposed regions of Russia. UNSCEAR concluded that around one-quarter of these cases <em>could</em> be linked to radiation exposure. That would mean 4,808 thyroid cancer cases.{ref}25% of 19,233 is 4808 cases.{/ref}</p>\n\n\n\n<p>By 2005, it was reported that <strong>15 of these thyroid cancer cases had been fatal</strong>.{ref}This figure was included in the UNSCEAR\u2019s 2008 report. I found no updated figure for fatalities in its 2018 report.{/ref} However, it was likely that this figure would increase: at least some of those still living with thyroid cancer will eventually die from it.</p>\n\n\n\n<p>It\u2019s therefore not possible to give a definitive number, but we can look at survival rates and outcomes to get an estimate. Thankfully the prognosis for thyroid cancer in children is very good. Many patients that have undergone treatment have seen either a partial or complete remission.{ref}Reiners, C. (2011). Clinical experiences with radiation induced thyroid cancer after Chernobyl. Genes, 2(2), 374-383.{/ref} Large-scale studies report a 20-year survival rate of 92% for thyroid cancer.{ref}Hogan, A. R., Zhuge, Y., Perez, E. A., Koniaris, L. G., Lew, J. I., & Sola, J. E. (2009). Pediatric thyroid carcinoma: incidence and outcomes in 1753 patients. Journal of Surgical Research, 156(1), 167-172.{/ref}. Others show an even better prognosis, with a survival rate of 98% after 40 years.{ref}Hay, I. D., Gonzalez-Losada, T., Reinalda, M. S., Honetschlager, J. A., Richards, M. L., & Thompson, G. B. (2010). Long-term outcome in 215 children and adolescents with papillary thyroid cancer treated during 1940 through 2008. <a href=\"https://link.springer.com/article/10.1007/s00268-009-0364-0\">World Journal of Surgery</a>, 34(6), 1192-1202.{/ref} </p>\n\n\n\n<p>If we combine standard survival rates with our number of radiation-induced cancer cases \u2013 4,808 cases \u2013 we might estimate that the <strong>number of deaths could be in the range of 96 to 385</strong>. This comes from the assumption of a survival rate of 92% to 98% (or, to flip it, a mortality rate of 2% to 8%).{ref}2% of 4808 is 96, and 8% is 385.{/ref} This figure comes with significant uncertainty.</p>\n\n\n\n<h4>Deaths in the general population</h4>\n\n\n\n<p>Finally, there has been significant concern about cancer risks to the wider population across Ukraine, Belarus, Russia, and other parts of Europe. This topic remains controversial. Some reports in the early 2000s estimated much higher death tolls ranging from 16,000 to 60,000.{ref}Cardis et al. (2006). Estimates of the cancer burden in Europe from radioactive fallout from the Chernobyl accident. International Journal of Cancer. Available <a href=\"http://www.nature.com/nature/journal/v440/n7087/full/440982a.html?foxtrotcallback=true\"><strong>online</strong></a>.<br><br>Fairlie and Sumner (2006). An independent scientific evaluation of health and environmental effects 20 years after the nuclear disaster providing critical analysis of a recent report by the International Atomic Energy Agency (IAEA) and the World Health Organisation (WHO). Available <a href=\"http://www.chernobylreport.org/?p=summary\"><strong>online</strong></a>.{/ref} In its 2005 report, the WHO estimated a potential death toll of 4,000.{ref}IAEA, WHO (2005/06). <a href=\"http://www.who.int/mediacentre/news/releases/2005/pr38/en/\">Chernobyl\u2019s Legacy: Health, Environmental and Socio-Economic Impacts</a>.{/ref} These estimates were based on the assumption that a large number of people were exposed to elevated levels of radioactivity, and that radioactivity increases cancer risk, even at very low levels of exposure (the so-called \u2018<a href=\"https://en.wikipedia.org/wiki/Linear_no-threshold_model\">linear no-threshold model</a>\u2019 of radiation exposure).</p>\n\n\n\n<p>More recent studies suggest that these estimates were too high. In 2008, the UNSCEAR concluded that radioactive exposure to the general public was very low, and that it does not expect adverse health impacts in the countries affected by Chernobyl, or the rest of Europe.{ref}As it details in its report:<br>\u201cThe vast majority of the population were exposed to low levels of radiation comparable, at most, to a few times the annual natural background radiation levels and need not live in fear of serious health consequences. This is true for the populations of the three countries most affected by the Chernobyl accident, Belarus, the Russian Federation and Ukraine, and even more so for the populations of other European countries.\u201d</p>\n\n\n\n<p>\u201cTo date, there has been no persuasive evidence of any other health effect in the general population that can be attributed to radiation exposure\u201d{/ref} In 2018 it published a follow-up report, which came to the same conclusion. </p>\n\n\n\n<p>If the health impacts of radiation were directly and linearly related to the level of exposure, we would expect to find that cancer rates were highest in regions closest to the Chernobyl site, and would decline with distance from the plant. But studies do not find this. Cancer rates in Ukraine, for example, were not higher in locations closer to the site{ref}Leung, K. M., Shabat, G., Lu, P., Fields, A. C., Lukashenko, A., Davids, J. S., & Melnitchouk, N. (2019). <a href=\"https://ascopubs.org/doi/full/10.1200/JGO.19.00099\">Trends in solid tumor incidence in Ukraine 30 years after chernobyl</a>. <em>Journal of Global Oncology</em>, <em>5</em>, 1-10.{/ref} This suggests that there is a lower limit to the level at which radiation exposure has negative health impacts. And that most people were not exposed to doses higher than this.</p>\n\n\n\n<h4>Combined death toll from Chernobyl</h4>\n\n\n\n<p>To summarize the previous paragraphs: </p>\n\n\n\n<ul><li><strong>2 workers died in the blast.</strong></li><li><strong>28 workers and firemen died in the weeks that followed from acute radiation syndrome (ARS).</strong></li><li><strong>19 ARS survivors had died later, by 2006</strong>; most from causes not related to radiation, but it\u2019s not possible to rule all of them out (especially five that were cancer-related).</li><li><strong>15 people died from thyroid cancer due to milk contamination</strong>. These deaths were among children who were exposed to <sup>131</sup>I from milk and food in the days after the disaster. This could increase to between 96 and 384 deaths, however, this figure is highly uncertain.</li><li><strong>There is currently no evidence of adverse health impacts in the general population across affected countries, or wider Europe</strong>.</li></ul>\n\n\n\n<p>Combined, the <em>confirmed</em> death toll from Chernobyl is less than 100. We still do not know the <em>true</em> death toll of the disaster. My best approximation is that the true death toll is in the range of 300 to 500 based on the available evidence.{ref}When we report on the safety of energy sources \u2013 in <a href=\"https://ourworldindata.org/safest-sources-of-energy\"><strong>this article</strong></a> \u2013 I take the upper number of 433 deaths to be conservative.{/ref}</p>\n\n\n\n<h3>How many died from the nuclear accident in Fukushima?</h3>\n\n\n\n<p>In March 2011, there was an accident at the Fukushima Daiichi Nuclear Power Plant in \u014ckuma, Fukushima, Japan. This accident was caused by the <a href=\"https://en.wikipedia.org/wiki/2011_T%C5%8Dhoku_earthquake_and_tsunami\">2011 T\u014dhoku earthquake and tsunami</a> \u2013 the most powerful earthquake recorded in Japan\u2019s history.</p>\n\n\n\n<p>Despite it being such a large event, so far, only one death has been attributed to the disaster. This includes both the direct impact of the accident itself and the radiation exposure that followed. However, it\u2019s estimated that several thousand died indirectly from the stress and disruption of evacuation.</p>\n\n\n\n<h4>Direct and cancer deaths from the accident</h4>\n\n\n\n<p><strong>No one died directly from the disaster. </strong>However, 40 to 50 people were injured as a result of physical injury from the blast, or radiation burns.</p>\n\n\n\n<p>In 2018, the Japanese government <a href=\"https://www.bbc.co.uk/news/world-asia-45423575\">reported that</a> <strong>one worker has since died</strong> from lung cancer as a result of radiation exposure from the event.</p>\n\n\n\n<p>Over the last decade, many studies have assessed whether there has been any increased cancer risk for local populations. <strong>There appears to be no increased risk of cancer or other radiation-related health impacts</strong>. </p>\n\n\n\n<p>In 2016, the World Health Organization noted that there was a very low risk of increased cancer deaths in Japan.{ref}World Health Organization (2016). FAQs: Fukushima Five Years On. Available online at: <a href=\"https://www.who.int/ionizing_radiation/a_e/fukushima/faqs-fukushima/en/.%7B/ref\">https://www.who.int/ionizing_radiation/a_e/fukushima/faqs-fukushima/en/.{/ref</a>} Several reports from the UN Scientific Committee on the Effects of Atomic Radiation came to the same conclusion: they report that any increase in radiation exposure for local populations was very low and they do not expect any increase in radiation-related health impacts.{ref}To quote UNSCEAR directly: \u201cThe doses to the general public, both those incurred during the first year and estimated for their lifetimes, are generally low or very low. No discernible increased incidence of radiation-related health effects are expected among exposed members of the public or their descendants.\u201d<br><br><a href=\"http://www.unscear.org/docs/GAreports/A-68-46_e_V1385727.pdf\">Report of the United Nations Scientific Committee on the Effects of Atomic Radiation. General Assembly Official Records</a>, Sixty-eighth session, Supplement No. 46. New York: United Nations, Sixtieth session, May 27\u201331, 2013.{/ref} </p>\n\n\n\n<h4>Deaths from evacuation</h4>\n\n\n\n<p>A more difficult question is how many people died indirectly through the <em>response</em> and evacuation of locals from the area around Fukushima. Within a few weeks of the accident more than 160,000 people had moved away, either from official evacuation efforts or voluntarily from fear of further radioactive releases. Many were forced to stay in overcrowded gyms, schools, and public facilities for several months until more permanent emergency housing became available.</p>\n\n\n\n<p>The year after the 2011 disaster, the Japanese government estimated that 573 people had died indirectly as a result of the physical and mental stress of evacuation.{ref}The Yomiuri Shimbun, 573 deaths \u2018related to nuclear crisis\u2019, The Yomiuri Shimbun, 5 February 2012, <a href=\"https://wayback.archive-it.org/all/20120204190315/http://www.yomiuri.co.jp/dy/national/T120204003191.htm.%7B/ref\">https://wayback.archive-it.org/all/20120204190315/http://www.yomiuri.co.jp/dy/national/T120204003191.htm.</a>{/ref} Since then, more rigorous assessments of increased mortality have been done, and this figure <a href=\"https://www.reconstruction.go.jp/topics/main-cat2/sub-cat2-6/20201225_kanrenshi.pdf\">was revised</a> to 2,313 deaths in September 2020.</p>\n\n\n\n<p>These indirect deaths were attributed to the overall physical and mental stress of evacuation; being moved out of care settings; and disruption to healthcare facilities. </p>\n\n\n\n<p>It\u2019s important to bear in mind that the region was also trying to deal with the aftermath of an earthquake and tsunami: this makes it difficult to completely separate the indirect deaths related to the nuclear disaster disruptions, and those of the tsunami itself.</p>\n\n\n\n<p>Combined, the <em>confirmed</em> death toll from Fukushima is therefore 2,314.</p>\n\n\n\n<h3>What can we learn from these nuclear disasters?</h3>\n\n\n\n<p>The context and response to these disasters were very different, and this is reflected in what people died from in the aftermath.</p>\n\n\n\n<p>Many more people died from Chernobyl than from Fukushima. There are several reasons for this.</p>\n\n\n\n<p>The first was <strong>reactor design</strong>. The nuclear reactors at Chernobyl were poorly designed to deal with this meltdown scenario. Its fatal RBMK reactor had no containment structure, allowing radioactive material to spill into the atmosphere. Fukushima\u2019s reactors did have steel-and-concrete containment structures, although it\u2019s likely that at least one of these was also breached. </p>\n\n\n\n<p>Crucially, the cooling systems of both plants worked very differently; at Chernobyl, the loss of cooling water as steam actually served to accelerate reactivity levels in the reactor core, creating a positive feedback loop toward the fatal explosion. The opposite is true of Fukushima, where the reactivity reduced as temperatures rose, effectively operating as a self-shutdown measure.</p>\n\n\n\n<p>The second factor was <strong>government response</strong>. In the case of Fukushima, the Japanese government responded quickly to the crisis with evacuation efforts extending rapidly from a 3-kilometer (km), to a 10-km, to a 20-km radius whilst the incident at the site continued to unfold. In contrast, the response in the former Soviet Union was one of denial and secrecy.</p>\n\n\n\n<p>It\u2019s reported that in the days which followed the Chernobyl disaster, residents in surrounding areas were uninformed of the radioactive material in the air around them. In fact, it took at least three days for the Soviet Union to admit an accident had taken place, and did so after radioactive sensors at a Swedish plant were triggered by dispersing radionuclides. As we saw above, it\u2019s estimated that approximately 4,808 thyroid cancer cases in children and adolescents could be linked to radiation exposure from contaminated milk and foods. This could have been prevented by an earlier response.</p>\n\n\n\n<p>Finally, while an early response from the Japanese government may have prevented a significant number of deaths, many <a href=\"https://www.ft.com/content/000f864e-22ba-11e8-add1-0e8958b189ea\">have questioned</a> whether the scale of the evacuation effort \u2013 where more than 160,000 people were displaced \u2013 was necessary.{ref}Hayakawa, M. (2016). <a href=\"https://journals.sagepub.com/doi/pdf/10.1177/0146645316666707\">Increase in disaster-related deaths: risks and social impacts of evacuation</a>. Annals of the ICRP, 45(2_suppl), 123-128.</p>\n\n\n\n<p>Normile (2021). <a href=\"https://www.science.org/content/article/physician-has-studied-fukushima-disaster-decade-and-found-surprising-health-threat\">Nuclear medicine: After 10 years advising survivors of the Fukushima disaster about radiation, Masaharu Tsubokura thinks the evacuations posed a far bigger health risk</a>. <em>Science</em>.{/ref} As we see from the figures above, evacuation stress and disruption are estimated to have contributed to several thousand early deaths. Only one death has been linked to the impact of radiation. We don\u2019t know what the possible death toll would have been <em>without</em> any evacuation. That\u2019s why a no-evacuation strategy, if a future accident was to occur, seems unlikely. However, many have called for governments to develop early assessments and protocols of radiation risks, the scale of evacuation needed, and infrastructure to make sure that the disruption to those that are displaced is kept to a minimum.{ref}Normile (2021). <a href=\"https://www.science.org/content/article/physician-has-studied-fukushima-disaster-decade-and-found-surprising-health-threat\">Nuclear medicine: After 10 years advising survivors of the Fukushima disaster about radiation, Masaharu Tsubokura thinks the evacuations posed a far bigger health risk</a>. <em>Science</em>.{/ref}</p>\n\n\n\n<h3>Nuclear is one of the safest energy sources</h3>\n\n\n\n<p>No energy source comes with zero negative impact. We often think of nuclear energy as being more dangerous than other sources because these low-frequency but highly-visible events come to mind.</p>\n\n\n\n<p>However, when we <a href=\"https://ourworldindata.org/safest-sources-of-energy\">compare the death rates</a> from nuclear energy to other sources, we see that it\u2019s one of the safest. The numbers that have died from nuclear accidents are very small in comparison to the <a href=\"https://ourworldindata.org/data-review-air-pollution-deaths\"><em>millions</em> that die</a> from air pollution from fossil fuels <em>every year</em>. As the linked post shows, the death rate from nuclear is roughly comparable with most renewable energy technologies.</p>\n\n\n\n<p>Since nuclear is also a key source of low-carbon energy, it can play a key role in a sustainable energy mix alongside renewables.</p>\n" } }, "extensions": { "debug": [ { "type": "DEBUG_LOGS_INACTIVE", "message": "GraphQL Debug logging is not active. 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