I genuinely started research on this with a clean slate, knowing that Chernobyl needed to be addressed. And I was surprised at what I found. Here are results from a range of the largest studies- first in bullet point, and then explained below with links to the studies.
- Cumulative deaths: According to a comprehensive UN study, all cumulative deaths over twenty years after Chernobyl are 56 people- 47 emergency workers and 9 thyroid cancer deaths.
- Effects on pregnant women's babies: According to research from the U.S. National Cancer Institute, a study of over 2,500 people who were in utero at the time of the accident showed no significant increase in rate of thyroid carcinoma more than 20 years after Chernobyl.
- Adults not involved in cleanup efforts and risks of either leukemia or thyroid cancer: another National Cancer Institute study found that in contaminated areas including Russia, Belarus, and the Ukraine that "risks of thyroid cancer and leukemia for adults are not significantly elevated among residents of contaminated areas who were not involved in cleanup efforts."
- Total thyroid cancer incidence in Belarus: Using the data from another large study in Belarus compared with U.S. thyroid incidence data, the thyroid cancer incidence is significantly higher in the U.S., far away from the fallout of Chernobyl, than it is in Belarus-- both on average and for men and women separately.
- Total thyroid cancer incidence in the highest exposed areas of Belarus: even in the highest exposed areas of Belarus, the thyroid cancer incidence level for men is less than that of the men in the U.S. Only the incidence rate for women selected from highest exposed areas exceeds that of U.S. women.
- Overdiagnosis (the screening effect) and Biases: multiple NIH studies showed that there were biases in a majority of post-Chernobyl studies which led to overdiagnosis of thyroid nodules due to improper screening methods which both detected pre-existing nodules and associated nodules incorrectly with radiation exposure.
The most comprehensive study was done by the UN. It is titled Chernobyl’s Legacy: Health, Environmental and Socio-Economic Impacts. In this study, all cumulative deaths over the 20 years after Chernobyl, including cancer deaths through the year 2005, was 56 people- 47 emergency workers and only 9 thyroid cancer deaths.
Effects on pregnant women's babies
Babies are perhaps most sensitive to iodine exposure. Until recently, it was fairly unknown how babies in utero are affected by iodine fallout. The National Cancer Institute, a subset of the NIH, has a special set of studies centered around Chernobyl. One of their studies published in 2009 studied 2,582 mother-child pairs who were in utero in the Ukraine during Chernobyl accident and the two months after. Twenty years after Chernobyl, no statistically significant increase in rate of thyroid carcinoma was found for the adults who were babies in utero during the accident.
Adults not involved in cleanup efforts
For adults, another comprehensive study of contaminated areas in the Ukraine, Belarus, and Russia, done by the National Cancer Institute found that "risks of thyroid cancer and leukemia for adults are not significantly elevated among residents of contaminated areas who were not involved in cleanup efforts."
Total thyroid cancer incidence in Belarus
What are the estimated cancer increases for each segment of the population? Another large study (Thyroid Cancer Incidence Trends in Belarus: Studying the Impact of Chernobyl) compared the outcomes to natural outcomes of thyroid cancer per 100,000 people. With scary statistics like increases in thousands of percent between 1970 and the 2000s, the study looks grim. But here it is in perspective:
higher in the U.S., far away from the fallout of Chernobyl, than it is in Belarus--both for men and women. What this highlights is two things: 1) thyroid cancer occurs worldwide due to naturally occurring environmental factors and living habits and 2) that higher screening rates and better access to medical care gives higher visibility of thyroid cancer nodules. Think about what health care was like in the 3rd world situation in 1970 in Soviet Russia. They couldn't get bread, certainly not thyroid cancer screening. The difference in rates is most likely because the U.S. still has somewhat better screening and reporting for thyroid cancer incidence. So, the dramatic increase in thyroid cancer incidence in Belarus is also not surprising considering they had practically no care and no screening for thyroid nodules in the Soviet Belarus of 1970 paired with an onslaught of testing following Chernobyl (a significant amount of which did not distinguish already existing or naturally occuring nodules with those caused by radiation exposure- see "overdiagnosis and biases" below)
Total thyroid cancer incidence in the highest exposed areas of Belarus
Even those men in Belarus with the highest exposure had lower thyroid cancer rates than men in the U.S.! The rate for women in Belarus in the highest exposed areas is the only group that had higher cancer rates than the American equivalent- at roughly 27 per 100,000. The highest incidence rate is among people who were children during the accident. Unfortunately, due to malnutrition and iodine deficiency, these children in Soviet Russia had unusual susceptibility. However, their numbers still do not significantly change overall incidence rates or mortality.
These incidence rates indicate that no more than roughly 5,500 total cases of thyroid cancer could even be occurring in both the Ukraine and Belarus regardless of cause. It is obvious that not every case, or even the majority of cases, could be due to Chernobyl, if countries like the U.S. have similar rates and that thyroid cancer occurs normally. So even the number declared by the UN study of 4,000 cases of thyroid cancer being due to Chernobyl is probably a significant exaggeration.
Overdiagnosis (the screening effect) and Biases
On top of all of this, multiple published NIH studies have shown that due to radically increased screening rates along with biases toward attributing nodules to radiation exposure as opposed to pre-existing nodules or nodules not due to exposure, that there was a screening effect which unscientifically inflates the incidence rate reports and require caution in interpretation and evaluation. Two of these studies are here and here.
The combination of the facts in study after study on incidence rates over decades of research compounded with the evidenced screening effect clearly discredit the Union of Concerned Scientists' Lisbeth Gronlund's "study" claim of up to an absurd 108,000 thyroid cancer cases caused by Chernobyl as nothing but junk "science" by a biased society with an agenda of fear.
It's easy to find things that have killed more than 56 people or things that increase cancer risk- things which the majority of us are happy to use and accept the risk every day. Car accidents, plane accidents, cell phones, smoking, trans fats, obesity, tanning, sun exposure, pollution, and so many more things either kill far, far more people and/or increase the risk of cancer and disease by far greater margins. That will be a post for another day.
Chernobyl was a horrible example of what a terribly poor reactor design can do in the hands of an arrogant Soviet Russia with poor safety standards. No U.S. reactor is allowed to have the instability characteristics of the RBMK which caused the Chernobyl accident (a net positive void coefficient). There is no possibility for a U.S. reactor to become rapidly unstable in that way.
So, things worse than Chernobyl? Sadly, many, many things that we eat, drink, and use every day without even thinking twice. Is mitigating the innumerable--at least MILLIONS of deaths-- due to pollution, ozone, greenhouse gases, and their complications worth not disposing of emission-free nuclear for coal, oil, or natural gas to have a steady supply of energy?