Have several hundreds of thousands of people died because of the Chernobyl disaster?

Question

The Wikipedia article on this is littered with [citation needed] and a commenter on hacker news linked to it while stating:

Chernobyl cost several hundred thousand lives. Let's hope and pray Fukushima will not exact a similar cost.

However I read a recent article in the Guardian about a journalist that was seemingly desperately trying to figure out what research backs up such claims. In the link-bait titled article The unpalatable truth is that the anti-nuclear lobby has misled us all he states:

For the last 25 years anti-nuclear campaigners have been racking up the figures for deaths and diseases caused by the Chernobyl disaster, and parading deformed babies like a medieval circus. They now claim 985,000 people have been killed by Chernobyl, and that it will continue to slaughter people for generations to come. These claims are false.

The UN Scientific Committee on the Effects of Atomic Radiation (Unscear) is the equivalent of the Intergovernmental Panel on Climate Change. Like the IPCC, it calls on the world's leading scientists to assess thousands of papers and produce an overview. Here is what it says about the impacts of Chernobyl.

Of the workers who tried to contain the emergency at Chernobyl, 134 suffered acute radiation syndrome; 28 died soon afterwards. Nineteen others died later, but generally not from diseases associated with radiation. The remaining 87 have suffered other complications, including four cases of solid cancer and two of leukaemia.

In the rest of the population there have been 6,848 cases of thyroid cancer among young children – arising "almost entirely" from the Soviet Union's failure to prevent people from drinking milk contaminated with iodine 131. Otherwise "there has been no persuasive evidence of any other health effect in the general population that can be attributed to radiation exposure". People living in the countries affected today "need not live in fear of serious health consequences from the Chernobyl accident".

Is the probably widespread belief that Chernobyl disaster has caused hundreds of thousand, or even tens of thousand deaths true when examining the literature?

Answer 1

From the World Health Organisation (2005)

The total number of deaths already attributable to Chernobyl or expected in the future over the lifetime of emergency workers and local residents in the most contaminated areas is estimated to be about 4000. This includes some 50 emergency workers who died of acute radiation syndrome and nine children who died of thyroid cancer, and an estimated total of 3940 deaths from radiation-induced cancer and leukemia among the 200 000 emergency workers from 1986-1987, 116 000 evacuees and 270 000 residents of the most contaminated areas (total about 600 000). These three major cohorts were subjected to higher doses of radiation amongst all the people exposed to Chernobyl radiation.

The estimated 4000 casualties may occur during the lifetime of about 600 000 people under consideration. As about quarter of them will eventually die from spontaneous cancer not caused by Chernobyl radiation, the radiation-induced increase of about 3% will be difficult to observe. However, in the most highly exposed cohorts of emergency and recovery operation workers, some increase in particular cancers (e.g., leukemia) has already been observed.

Confusion about the impact has arisen owing to the fact that thousands of people in the affected areas have died of natural causes. Also, widespread expectations of ill health and a tendency to attribute all health problems to radiation exposure have led local residents to assume that Chernobyl related fatalities were much higher than they actually were.

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'Several hundred thousand' may not have died, but

More than 350 000 people have been relocated away from the most severely contaminated areas, 116 000 of them immediately after the accident. Even when people were compensated for losses, given free houses and a choice of resettlement location, the experience was traumatic and left many with no employment and a belief that they have no place in society.

Answer 2

Taken from here:

http://www.who.int/mediacentre/news/releases/2005/pr38/en/index.html

As of mid-2005, however, fewer than 50 deaths had been directly attributed to radiation from the disaster, almost all being highly exposed rescue workers, many who died within months of the accident but others who died as late as 2004.

About 4000 cases of thyroid cancer, mainly in children and adolescents at the time of the accident, have resulted from the accident’s contamination and at least nine children died of thyroid cancer; however the survival rate among such cancer victims, judging from experience in Belarus, has been almost 99%.

Most emergency workers and people living in contaminated areas received relatively low whole body radiation doses, comparable to natural background levels. As a consequence, no evidence or likelihood of decreased fertility among the affected population has been found, nor has there been any evidence of increases in congenital malformations that can be attributed to radiation exposure.

“This was a very serious accident with major health consequences, especially for thousands of workers exposed in the early days who received very high radiation doses, and for the thousands more stricken with thyroid cancer. By and large, however, we have not found profound negative health impacts to the rest of the population in surrounding areas, nor have we found widespread contamination that would continue to pose a substantial threat to human health, within a few exceptional, restricted areas.”

Generally speaking it would seem that the consequences of a nuclear disaster are drastically overestimated and the science in no way backs up the hysteria in the media whenever anything nuclear is mentioned.

Answer 3

Okay, now let's try another take with more numbers. I found a nice page with many references (NB: I haven't personally checked them all, but I've seen the Chernobyl Forum report and it lines up). Relevant quotes of the specific death numbers:

Apart from the initial 31 deaths (two from the explosions, one reportedly from coronary thrombosis (heart attack), and 28 firemen and plant personnel from acute radiation syndrome), the number of deaths resulting from the accident is unclear and a subject of considerable controversy. According to the 2006 report of the UN Chernobyl Forum's 'Health' Expert Group: "The actual number of deaths caused by this accident is unlikely ever to be precisely known."
On the number of deaths due to acute radiation syndrome (ARS), the Expert Group report states: "Among the 134 emergency workers involved in the immediate mitigation of the Chernobyl accident, severely exposed workers and fireman during the first days, 28 persons died in 1986 due to ARS, and 19 more persons died in 1987-2004 from different causes. Among the general population affected by the Chernobyl radioactive fallout, the much lower exposures meant that ARS cases did not occur.
[...]
Regarding the emergency workers with doses lower than those causing ARS symptoms, the Expert Group report referred to studies carried out on 61,000 emergency Russian workers where a total of 4995 deaths from this group were recorded during 1991-1998. "The number of deaths in Russian emergency workers attributable to radiation caused by solid neoplasms and circulatory system diseases can be estimated to be about 116 and 100 cases respectively." Furthermore, "the number of leukaemia cases attributable to radiation in this cohort can be estimated to be about 30." Thus, 4.6% of the number of deaths in this group are attributable to radiation-induced diseases. (The estimated average external dose for this group was 107 mSv.)
[...]
The picture is even more unclear for the populations of the areas affected by the Chernobyl fallout. However, the report does link the accident to an increase in thyroid cancer in children: "During 1992-2000, in Belarus, Russia and Ukraine, about 4000 cases of thyroid cancer were diagnosed in children and adolescents (0–18 years), of which about 3000 occurred in the age group of 0–14 years. For 1152 thyroid cancer patient cases diagnosed among Chernobyl children in Belarus during 1986-2002, the survival rate is 98.8%. Eight patients died due to progression of their thyroid cancer and six children died from other causes. One patient with thyroid cancer died in Russia."
[...]
"The predicted lifetime excess cancer and leukaemia deaths for 200,000 liquidators, 135,000 evacuees from the 30 km zone, 270,000 residents of the SCZs ['strict control zones'] were 2200 for liquidators, 160 for evacuees, and 1600 among residents of the SCZs. This total, about 4000 deaths projected over the lifetimes of the some 600,000 persons most affected by the accident, is a small proportion of the total cancer deaths from all causes that can be expected to occur in this population. It must be stressed that this estimate is bounded by large uncertainties."
Beyond this, "for the further population of more than 6,000,000 persons in other contaminated areas, the projected number of deaths was about 5000. This latter estimate is particularly uncertain, as it is based on an average dose of just 7 mSv, which differs very little from natural background radiation levels."

Answer 4

Nuclear power is a controversial topic and everyone is biased, especially IAEA, but even WHO. The author of the book that claims that 985,000 people have been killed by Chernobyl is also biased. I too am biased. However, I have no association with the nuclear industry and I don't personally know anyone that died because of the Chernobyl disaster.

That being said, I feel like all the answers up until this point has been very one-sided. The number 985,000 is based on a scientific study and I found it peculiar that no one addressed the study presented in this book. In order to be able to criticize a number you need to know what it's based on, right?

I did some digging and actually found the book freely available as pdf:

Chernobyl: Consequences of the Catastrophe for People and the Environment

It's 349 pages, so I didn't read all of it and I certainly don't have time to make a full review. I found this Wikipedia article about the book where they present the following quotes from reviews of the book:

"The introduction addresses the issue of why assessments of health effects from Chernobyl are so disparate. The authors disparage the approach favoured by the majority of the epidemiology community, which seeks a correlation of health effects with levels of contamination or dose. They believe this approach is ‘impossible’ due to lack of measurements in the first few days, lack of information on ‘hot spots’ and lack of information on all of the isotopes involved."

"They consider that the USSR authorities distorted links between health effects and radiation exposure and they prefer therefore to rely on what they consider are independent investigations of comparative health measures in various territories that they consider are identical in terms of ethnic, social and economic characteristics and differ only in the exposure to radiation."

George Monibot comments on that review:

A devastating review in the journal Radiation Protection Dosimetry points out that the book achieves this figure by the remarkable method of assuming that all increased deaths from a wide range of diseases – including many which have no known association with radiation – were caused by the Chernobyl accident. There is no basis for this assumption, not least because screening in many countries improved dramatically after the disaster and, since 1986, there have been massive changes in the former eastern bloc. The study makes no attempt to correlate exposure to radiation with the incidence of disease.

However, his comment is disputed:

The fact of deliberately choosing control groups which they judge not to have been exposed for the purpose of comparison appears to contradict Monbiot's assertion that Yablokov simply assumed all increased deaths were caused by the Chernobyl accident. The review states that excess deaths recorded in the unexposed areas cited in the book were not alleged by Yablokov to be caused by the Chernobyl accident.

Another Wikipedia article stated that:

Between 1986 and 1992, it is thought between 600,000 and one million people participated in works around Chernobyl and their health was endangered due to radiation. Because of the dissolution of the USSR in the 1990s, evaluations about liquidators' health are difficult, since they come from various countries (mostly Ukraine, Belarus and Russia, but also other former Soviet republics). Furthermore, the government of Russia has never been keen on giving the true figures for the disaster, or even on making serious estimates. However, according to a study by Belarusian physicians, rate of cancers among this population is about four times greater than the rest of the population. All the figures quoted by various agencies are controversial

I included the last quote just to point out that things like increased cancer rates in these areas are likely due to the Chernobyl disaster. However, it's hard to prove that a particular individual got cancer because of Chernobyl and not due to other causes.

I think the main difference between WHO's report and Yablokov's is that WHO only counts deaths that is proven to be directly caused by Chernobyl, while Yablokov includes deaths that are statistically likely to have been caused by Chernobyl.

My conclusion is that 985,000 is plausible, but so is 4000 and there is no way of knowing the actual number. I understand that it's in IAEA's best interest to have the public believe that nuclear power is safe and thus only include deaths confirmed to have been caused by radiation from Chernobyl. Likewise I understand that Yablokov has the opposite agenda and thus includes deaths that can't be directly linked to Chernobyl.

In the end I think it's all about the criteria for attributing deaths to the Chernobyl disaster. If you die from cancer two years before you otherwise would have because of Chernobyl, is your death to be attributed to Chernobyl?