Are Chernobyl Birds Really Small Brained, Or is The Claim Part of the 25th Anniversary Promotion?
I just read a BBC Science News article titled Chernobyl birds are small brained. The headline writer succeeded in his job – he attracted me to click on the link and read the article. The person who shared the link on Twitter also succeeded, by copying the link and headline into a tweet, he pointed me to a though provoking article. However, neither of those people have succeeded in convincing me that radiation at the levels known to exist in the exclusion zone of Chernobyl nearly 25 years after the accident are harmful to plant, animal, or human life.
You see, I did not just see the headline and accept it on face value as one more scary bit of evidence that should make be fearful. I did not just glance and say to myself that Chernobyl was a huge disaster whose recurrence must be prevented by working to eliminate all nuclear energy facilities. Instead, I read the article to find out what the researchers were actually able to measure. Here is a quote from the article:
Birds living around the site of the Chernobyl nuclear accident have 5% smaller brains, an effect directly linked to lingering background radiation.
The finding comes from a study of 550 birds belonging to 48 different species living in the region, published in the journal PLoS One.
Brain size was significantly smaller in yearlings compared to older birds.
That summary of information was far less than convincing for the following reasons:
- How precisely do scientists know what the size of a yearling bird should be? A 5% difference is not very much; is it within expected variations?
- Why did the scientists announce their results on such a small sample? Though 550 birds is a pretty fair sample size, if they are from 48 different species and vary in age from very young to mature, the sample size of each category is vanishingly small for statistical analysis. The margin of error with those sample sizes is well above 5%.
- How does brain size between yearlings and older birds compare in populations that are not in an exclusion zone?
The results of the recently announced study also conflicts with the descriptions of vibrant life that are available in such works as Mary Mycio’s Wormwood Forest. It also seems to contradict many existing studies of the effects on flora and fauna in the area. Perhaps the new studies are right and the existing body of knowledge is wrong, but there is not enough information in the article to make that determination.
The final thing that makes me question whether or not the birds around Chernobyl really are small brained is my knowledge of the calendar. You should expect to see a drumbeat of stories over the next few months reminding people about the Chernobyl accident. They are part of a planned publicity effort timed to come to a crescendo by April 26th to commemorate the 25th anniversary of the accident.
In fact, the drumbeat started last fall with the publication of a controversial book that claimed that the number of deaths from the accident has been grossly underestimated by all of the studies conducted by credible and responsible organizations since 1986.
There is a well worn cliche in politics – never let a good crisis go to waste. The analogous phrase in the antinuclear industry is never let an anniversary pass without taking full fund and fear raising advantage and marketing the heck out of it. I know I am contributing to the attention gathering cause by providing links to efforts like those of the Huffington Post, which published a special section titled Chernobyl: 25 Years After The Nuclear Disaster (PHOTOS), but there is no way to hide from the onslaught. Instead, good information needs to be made just as widely available.
Chernobyl was a tragedy caused by the actions taken by lightly trained operators who were forced by a political appointee to continue a poorly planned experiment AFTER becoming nervous about their indications. It happened at a plant that would never have been allowed to be licensed and constructed in any country outside of the Soviet Union. The technology as implemented at the time was unstable and done for reasons of expediency and short term cost savings. (I said it that way because there were significant improvements made in later years that allowed several plants with similar designs to operate safely for decades.)
However, even though the tragic accident happened and a good portion of the radioactive core was released into the surrounding area, there were few impacts on the general public in areas around the plant except for the ones that were caused by the incredibly poor response effort and permanent evacuation orders.
There are excellent sources of information about the effects of the ionizing radiation released by the Chernobyl accident on both human health and on the environment. Arm yourself with understanding and recognize that there will always be people who have motives for spreading as much fear, uncertainty and doubt about the use of nuclear energy as they possibly can.
Some of the people are motivated by sincere, but unfounded fears reinforced by snippets of incomplete science reporting. Some of the people have political reasons for emphasizing the effects of the accident and demanding continued efforts at compensation and restitution. Some of the people are genuinely afraid that if people recognize the unique aspects of the Chernobyl accident and realize that it happened a quarter of a century ago without any similar recurrence that we just might determine that nuclear energy is worth aggressive pursuit. Those people fear not for their lives or for the health of future generations, but for the loss of income they would suffer as nuclear energy began capturing market share from their favorite fuels.
I can’t stand studies that try correlate event A with effect B, but don’t include any reasonable explanation of causality. This bird brain study smells of the “Tooth Fairy Project,” just another effort by some concerned scientist to make his contribution to the fight to stop nuclear weapons (because we all know that nuclear power equals nuclear weapons). Interesting that there hasn’t been a similar effect noticed in and around the Nevada National Security Site (formerly Nevada Test Site).
Chernobyl radiation is different then Nevada radiation. Chernobyl radiation is naturally worse for living creatures since it comes directly from a nuclear reactor accident. (End of sarcasm.)
I know it’s not related to the bird brain discussion (aren’t all bird brains small), but here’s the latest DOE/EIA estimated levelized cost of new generation. There’s a significant change in the Solar PV estimate, however the report includes regional variation in table 2.
http://www.eia.gov/forecasts/aeo/pdf/2016levelized_costs_aeo2011.pdf
Great info. Thanks.
My one critical comment about the EIA info is that they show wind at 34% capacity factor. It is my understanding this table is the national average. I have yet to see any wind industrial facility reach even a 25% average capacity factor. If the tables reflected running historical data instead of AWEA wishful thinking then wind power’s estimated levelized cost woud be even higher.
Two of the authors, M
Rod – Your link is broken. The article can be found here.
By the way, this is just more nonsense from M
Brian – thanks for the back up. The link is now fixed.
@Brian – is it time for another article about gullible journalists working for major news outlets that supposedly retain some amount of credibility and ethics?
@Brian – what is the best way to prove that these two researchers are outliers in the field? How can one point to a topic and show that the only publications reaching similar results repeatedly come from the same sources?
I am reaching for some assistance from someone who has done more science research and publication than I have. I want to try to effectively challenge the BBC EarthNews, but I have to get the facts and references straight first.
I would probably start by looking at the following source (an edited collection of studies in this area): “Chernobyl: Consequences of the Catastrophe for People and the Environment” (Alexey V. Yablokov, Vassily B. Nesterenko, Alexey V. Nesterenko, Janette D. Sherman-Nevinger). It probably summaries this research pretty well (and presumably has an extensive bibliography).
Some of these articles may have appeared elsewhere, such as this one by Yablokov (“Chernobyl’s radioactive impact on fauna,” in New York Academy of Sciences). Article cautions against using rare and infrequent species in Chernobyl exclusion zone as basis for claims of low or “healthful” effects: “Despite reports of a “healthy” environment in proximity to Chernobyl for rare species of birds and mammals, the presence of such wildlife is likely the result of immigration and not from locally sustained populations.” Related citations appear in the sidebar. This field may also be dominated by russian language sources, which may not show up in conventional english language literature reviews.
When I do a search (on Web of Science
Here’s a list of 100 or so studies on PubMed (biomedical literature reference site), for environment, chernobyl, radiotoxic or genetic impacts, etc. Not all are relevant, but it shows a pretty extensive list of some dozens or more researchers working in this field (not just two: M
EL – Rod has already covered this so-called “source.” Personally, I would file it under “fiction.”
Yes, the epidemiological studies on human impacts are quite extensive, and aside from an increase in thyroid cancer, these extensive studies have failed to find any clear effect of the ionizing radiation from the accident on cancer rates.
Well, Rod, you can’t prove that these two are outliers, because they’re pretty much the only people who are currently doing research in this area (i.e., on birds). They are certainly the only researchers who reach the conclusions that they do.
The best you can do is to point out that this is only one set of studies from only one set of researchers, and thus, the results of these studies should be taken with a grain of salt. In science, conclusions are not considered valid unless they can be confirmed or replicated by other researchers.
In this particular case, caution is even more warranted, because the lead author is a very prolific researcher who has a reputation of doing sloppy work, particularly on studies that support one of his pet theories. If you’re interested in reading more about this story, you can find it in an article published in The Scientist four years ago. Note that the article mentions that M
One way to find out if someone is an outlier is to see if other researchers are citing their work. This is also an important basis in many tenure review hearings (depending on whether original research is given a high priority, teaching, or other factors). Web of Science (currently called ISI Web of Knowledge) is good for this.
I looked up AP Moller
Rod – The factors that led to the Chernobyl disaster were unique to that time, place and circumstance, but it is the rare journalist who devotes the time and thought needed to realize this.
Thank you for modeling reserve as you explore these issues and try to build reality-based and science-based understandings to counter the reflex that leads many so many journalists to hype and highlight anything that demonizes nuclear power.
Even if the world experienced a Chernobyl every year, the resulting horror would not measure up to the deaths that result from the by-products of using fossil fuels in ways that are accepted and legal. And routine. And routinely ignored.
As the last 25 years have demonstrated, another Chernobyl becomes ever more implausible. New nuclear power technologies – – already the safest source of electricity on earth, from a deaths-per-kWh perspective (another thing that is far beyond most journalists) – – continue to advance and accomplish ever-higher levels of safety in operation.
All the same, alarming news makes for a more vibrant news cycle. Triggering fear is useful for getting attention, but it does not help with making rational decisions, or developing reality-based understandings.
Thanks for your blog, your work, and your service.
This is a piece of juink science from Mousseau and Moller. One glance at figure 2 in their report tells me that any “correlation” they have found after extreme data massaging is entirely fictional.
A second failure is that they do not take into account that they looked at three different charactreristics seeking a problem to report; this shifts the confidence levels they should have used, because random correlation becomes more likely.
I’m disappointed in the BBC; the “previous entries” against this story on their site all point to previous scare attempts from the same authors.
I recently started graduate coursework in Public Affairs and have been surprised that a primary method used by policy makers to analyze scientific information is Correlation. When Causation cannot be proved, Correlation is considered an acceptable alternative, even if there is no data that directly supports a connection.
As Rod stated, a 5% change is well within the margin of error for such a small study. If these results could be replicated in multiple, larger studies, then many factors other than radiation should also be considered before any direct link could be established. Correlation is not the same thing as proof. It is pretty bad that policy makers don’t always understand this distinction, but even worse when “scientists” make leaps in logic and present them as facts.
@Susy – excellent points. I glanced through the actual study – the authors themselves include an interesting statement that should cause anyone with a questioning attitude to take the reported results with some skepticism.
“Measurements have repeatabilities above 94%.” That sounds impressive until you compare it to the now well publicized result of smaller brains that are only smaller by 5%. That means that the 5% variation could be just measurement noise – notwithstanding the potential for noise in individual bird variations due to the small sample size.
The problem with all research done on the Chernobyl aftermath, is that so much of it is tainted with politics and ideology that it is impossible to sort the wheat from the chaff. However if one takes a global view, several things become clear: The number of deaths that can be attributed to the events is small in comparison to the predictions, and remains so, despite claims that it would rise due to latent effects; the number of cancers have not risen anywhere near the projected numbers; the area has not turned into a barren wasteland; and finally any review of the body of work done on the subject of the Chernobyl aftermath shows that any effect are so small that efforts to see any require making conclusions on observations that are down in the statistical noise.
Most of the studies, overestimating health consequences of Chernobyl accident, come from the former Soviet Union, and the motives are quite clear. At first, heated interest in Chernobyl guaranteed foreign help and international scientific cooperation. Now, puffing up Chernobyl hysteria has helped hinder the advancement of nuclear power in Europe, thus contributing to higher use of Russian natural gas.
I am almost sure that all of the birds studied are less than 25 years year old, thus all have been hatched and have lived in the post-accident environment around Chernobyl. If one accepts the “measurements” from the study, a valid conclusion would be: the smaller brain size of the yearling birds has been caused by the reduction of radiation as the radiation levels decrease around Chernobyl due to radioactive decay. After all, the older birds have been exposed to higher levels of radiation for a longer period of time than the yearling birds.
If brain size is an indication of health, then the yearling birds that have been exposed to less radiation are less healthy.
This is an excellent article by Zbigniew Jaworowski that puts Chernobyl and radiation in perspective:
“Observations on Chernobyl
After 25 Years of Radiophobia”
http://www.21stcenturysciencetech.com/Articles_2010/Summer_2010/Observations_Chernobyl.pdf
@Marje – You beat me to it! Thanks for posting the link. There is also a series of videos on YouTube about repopulating the flora and fauna around Chernobyl.