“What About Chernobyl?” Ranking World’s Deadliest Energy Accidents

When nuclear power comes up, more often than not someone declares that all anyone needs to know can be said with one word: Chernobyl.

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May 16, 2019

This name evokes a chilling reaction in most of us, and the idea is that this should conclude the conversation. There can be no argument heavier than “What about Chernobyl?” — Can there?

This piece was published originally in April 11, 2019 on Thoughtscapism.

A ‘radioactive’ sign hangs on barbed wire outside a café in the ghost-town of Pripyat near Chernobyl.

I’ve spent a lot of time trying to understand the impacts of Chernobyl nuclear disaster, as well as the overall effects of different energy forms on human health and the environment. I often try to make the argument that we should look at the big picture, the totality of the effects, at first hand.

But the big picture is vague, grey, and complex. The name of that place — Chernobyl — and the accident it’s irrevocably linked with, burns with a bright red focus in people’s minds. Chernobyl disaster might be the most famous accident in the world. It would definitely be wrong to sweep its effects aside — the tragedy of lives and homes lost is real, painful, and unforgettable.

But here we arrive at an odds. Do the lives of the people affected by the Chernobyl accident weigh more than the lives of people struck by man-made disasters elsewhere? Should we respect the memory of the victims of Chernobyl more than those who died as the result of the failures of other energy forms?

That does not seem to make sense. What about workers and their families who were killed and whose homes were destroyed by gas explosions or coal mine fires, or the tens of thousands who have drowned after dam breakages? And what about the millions who die every year, in the non-accident that is the steady production of particulate air pollution?

Pictured: Banqiao dam failure, the Great London Smog, San Juanico gas explosion, and Soma coal mine fire. Soma photo is a black and white version of the original by Mustafa Karaman, used according to licence CC BY 3.0.

It may be difficult for people to look away from the dramatic, swift, and deadly events that large energy accidents are. It may feel cold and detached to contrast such tragedies with the constant trickle of lives lost to the business-as-usual burning of fossil fuels, even if those lives are not any less real.

If we were to argue that these were two distinct classes of effects, and we wanted to look at impacts of energy accidents separately, the question remains: how can we justify only using certain accidents as dire warning examples, as end-all type of arguments, while ignoring others?

Let’s look at whether Chernobyl should weigh heaviest out of all energy accidents because of its death toll. (Note: I look at Chernobyl’s impacts on nature in the next piece, and put world’s worst energy accidents in environmental perspective in the final article.)

Chernobyl in context

Chernobyl accident directly cost 31 lives, and caused some 106 injuries among the cleanup-workers and firemen. Further injuries include thousands of cases of thyroid cancer. UNSCEAR report, summary on page 64:

To date, some 6,000 thyroid cancers have been seen […] of which a substantial fraction is likely to have been due to radiation exposure.

Most of the cases are easily treatable and fatalities are expected to stay low — so far, 15 deaths from thyroid cancer have been connected to exposure from the accident. This figure may eventually reach 160 by the time the cohort has reached the end of their lifespan. That brings the eventual sum to near 200 deaths.

Direct deaths and injuries of Banqiao dam failure, the Great London Smog, Machchhu dam failure, Benxihu coal mine fire, Courrieres coal dust explosion, San Juanico gas explosion, Ufa gas explosion, Guadalajara gas explosion, and Chernobyl. (Note injury count not available for Banqiao, Machchhu, Benxihu, or Courrieres.)

If we compare direct death tolls of the largest energy accidents (graph), we quickly notice that there is one accident above others: the massive flood after the dam failure in Banqiao, China, in 1975.

Most people may not have heard of the accident, disturbingly enough, because the Chinese government did their best to contain all information about the disaster. It first became public knowledge after 30 years when the documents were declassified.

Banqiao flood is in a class of its own, with estimated death toll of 170,000–250,000 thousand. About 100,000 drowned directly (pictured in the chart), and as much or more died in the resulting epidemics and famine.

Dams harness formidable forces. Pictured: the biggest dam in the world, Itaipu in Brazil. Not an accident site.

There is no data easily available on the number of injuries, but 11 million people were left homeless as towns and villages were destroyed.

To get an idea about the relative sizes of the rest of the grave accidents, let’s remove Banqiao from the chart — its toll is so staggering it leaves everything else in its shadow.

The second-worst event took place in London — it was the Great Smog of 1952. Air pollution pooled over the city under problematic weather-conditions. Over ten thousand people died directly, and twice that number developed serious ill health-effects due to the smog.

Chernobyl is still not much more than one datapoint among others in this chart — a tragic, horrendous datapoint, to be sure, but by no means unique.

But pictured here are the more direct effects of the accident — the radiation poisonings and the thyroid cancer deaths so far, which scientists connect to the accident with good certainty. What about the more indirect, long-term effects of Chernobyl?

Realistic effects vs worst case scenarios

After the established 50 or so direct deaths and thousands of thyroid cases, the long-term effects on overall cancer risk become more speculative. As the risk consultant David Ropeik writes, in Fear of Radiation Is More Dangerous than the Radiation Itself:

Much of what we understand about the actual biological danger of ionising radiation is based on the joint Japan-US research programme called the Life Span Study (LSS) of survivors of Hiroshima and Nagasaki, now underway for 70 years. Within 10 kilometres of the explosions, there were 86,600 survivors — known in Japan as the hibakusha — and they have been followed and compared with 20,000 non-exposed Japanese. Only 563 of these atomic-bomb survivors have died prematurely of cancer caused by radiation, an increased mortality of less than 1 per cent.
I’ve written more about what we know about radiation exposures here

The doses resulting from the Chernobyl accident were much lower. The extrapolation of effects on cancer incidence with such low doses is no longer considered scientifically justified, which is why the estimates of the other long-term effects from Chernobyl remain hypothetical. The hypothesis is that over the course of their natural lives, the populations who received an increased radiation dose near Chernobyl may have about 0.66 % added to their normal life-time cancer incidence of 40% — an increase on par with what we know about the effects of a couple of drinks of alcohol per week.

In 2005, based on this kind of extrapolation, the WHO and IAEA suggested that excess cancer fatalities could eventually number 4000. UNSCEAR has later refrained from quoting a figure, citing “unacceptable uncertainties in the predictions,” and underlined this extrapolation as a way of finding the theoretical worst case scenario, not a realistic one.

Not many energy accidents have these kind of thorough hypothetical analyses of the long-term effects exerted over the lives of those exposed (from exposures like smoke or poisonous gases from fires or explosions). But for the sake of the argument, let’s also look at the eventual and hypothetical death-toll of Chernobyl by the time the entire cohort has reached the end of their lifespan (still excluding Banqiao in this chart for resolution’s sake).

The worst possible outcome measured in health effects is that Chernobyl could qualify as the fourth gravest energy accident in history. Banqiao, 1975, the Great London Smog 1952, and Machchhu dam failure in Morbi, India, 1979, still caused thousands more direct deaths (no injury data or increase in eventual disease incidences available). The direct injuries of San Juanico gas explosion are also more numerous than the eventual ones from Chernobyl.

Update: a reader informed me of another large hydro accident in Italy, the Vajont Dam in 1963, leading to “1,910 deaths and the complete destruction of several villages and towns.”

If we were looking at single accidents as the end all, be all arguments, and the hypothetical death-toll of Chernobyl was the threshold of absolute opposition to an energy form, it appears that at least hydropower and coal, and possibly gas power, would also be out of the question.

These four together, by the way, at the moment represent about 60 % of the world’s energy sources.

What about repeat offenders?

Of course, here we run into the next problem — does it have to be a single large accident, or should we take into account how often such accidents occur? Looking at nuclear, the picture is not very complicated. There is only one nuclear accident that has claimed human lives over the history of the energy form.

What about Fukushima, you may ask? Well, while the tsunami killed almost 20,000 thousand people, radiation from the failed nuclear plant did not cause any casualties. The UNSCEAR conludes:

No discernible increased incidence of radiation-related health effects are expected among exposed members of the public or their descendants.

The evacuation, however, of the remaining Fukushima district was tragic. It was performed so hastily that many of the elderly and sick died — approximately 1600 people all in all. The decision was not based on the realistic risk from radiation, but on an inflated fear of it — sadly, Fear of Radiation Is More Dangerous than the Radiation Itself.

The picture is different for other energy forms. It is easy to find information about at least 26 grave gas explosions and 13 coal mine accidents that have occurred since the 1970s, resulting in 1492 and 1391 deaths, respectively. If we go further back, merely adding two of the largest coal mine accidents, those of Courrières, France in 1906, and Benxihu, China 1942, the toll climbs up to 4039 direct deaths for coal (and I don’t claim this list to be conclusive). How far back in the history of energy accidents should we go to make judgements for or against energy forms?

Comparing the lists of severe gas explosionsand coal mining accidents to the nuclear accident since year 1900, the situation looks like this (chart). About 40 coal mining accidents have taken twice as many lives directly than the one nuclear accident ever will.

If we include the estimate of about 100,000–250,000 deaths from Banqiao, also adding Machchhu dam failure with its 10,000 victims, and compare them to the toll of coal mining, gas explosions, and the eventual nuclear fatalities all put together, they comprise but a modest piece of the tragic pie.

Why talk about accidents at all?

I have two major motives for bringing up these energy accidents. Firstly, it seems disrespectful to the victims that only some of these tragedies are looked upon with the austerity and respect they deserve. We should put names and images to these events, remember them, acknowledge that accidents come in many forms, and look for ways to reduce their number and impact.

Energy is, by nature, energetic: it makes things happen. When we loose control of these formidable forces, the things that happen are sudden and violent. We should have respect for energy in all its forms — the potential energy packed into vast masses of water, the chemical energy stored in combustible carbon compounds, as well as the nuclear forces within atoms themselves. None of these energy forms are without risk. I hope I’ve been able to show why fixating on Chernobyl alone is not warranted — that even the picture of energy accidents is complex and multifaceted.

The second reason, sneakily enough, is an attempt to bring us back to the argument I made in the beginning. Is a death more tragic if it happens violently, in one big flash together with hundreds or thousands of others — or whether it happens in hundreds of thousands of beds, hospitals, streets, or workplaces all over the world, day after day?

Environmental Progress’ Michael Shellenberger’s presentation of the findings of the 2007 study Are passive smoking, air pollution and obesity a greater mortality risk than major radiation incidents?

Is it ethically defensible to insist on focusing on hundred victims of a decades old disaster, while ignoring the millions who died this year because of the simple fact that they needed to breath air, which slowly damages their lungs with particulate pollution from burning stuff for energy?

Including the toll of the Chernobyl disaster, nuclear power has so far saved 1.8 million lives that would have been lost to air pollution from fossil fuels. If we value human lives, then all lives should matter — and if so, then we should move away from energy forms with the highest death-toll all in all. The data service Statista reports on energy forms in descending order of fatalities for year 2018 as follows: highest toll for coal, then oil, natural gas, hydro, rooftop solar, wind, and lowest toll, nuclear.

Considering that no energy form exists in a vacuum, climate scientist James Hansen and his colleague P.A. Kharecha published a paper in 2013, outlining the effects of nuclear power in Prevented Mortality and Greenhouse Gas Emissions from Historical and Projected Nuclear Power, concluding that nuclear power has saved a net total of two million lives by replacing energy that would have been produced by coal. Nuclear power continues to save about 80 000 lives per year, at current rate.

What about Chernobyl, you ask? Well what about Banqiao, London, Machchhu, San Juanico, Benxihu, Courrieres, Ufa, Soma, and Guadalajara? More importantly: what about the millions of human lives lost because our fears have stopped us from looking beyond that question?

For more in this series: “What about Radioactive Wastelands?” A Look at Chernobyl’s Effects on Nature — didn’t Chernobyl turn a huge swath of land uninhabitable? And in the final piece, I put World’s Worst Energy Accidents in Environmental Perspective.

About the author: I’m Iida Ruishalme, Finnish Cell Biologist, writer, parent, and a science communicator. I want to understand the world, which makes me passionate about science. I’m an environmentalist, a member of Finnish and German ecomodernists, and a Mother for Nuclear.

For more articles on nuclear power and radiation, I write a lot about Climate and Energy on my blog. My largest worry used to be “What about the waste?” More on that in: Nuclear Waste: Ideas vs Reality.



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