In a March 16, 2011 column in Townhall, conservative pundit Ann Coulter wrote an article about radiation entitled “A Glowing Report on Radiation,” in which she argues that radiation is not as dangerous as the media makes it out to be, and that low levels of radiation can actually have positive health effects. Even doses of radiation that are above the minimum safety levels, says Coulter, can actually do wonderful things for people, such as decrease cancer rates. Her clear implication is that the only people fear-mongering about radiation are the crazy liberal environmentalists.
Here is the major problem: Ann Coulter has no idea what she is talking about, and she is an idiot to boot. Of course, as those of us in the skeptical community have recognized for a long time, when politicians and political writers start writing about subjects that are not political and wander into subjects like science, they tend to get so far out of their element that they absolutely discredit themselves in the long run, if not right off the bat. Such damaging hits to their credibility come as a result of a combination of being insufficiently literate in science and holding political views that are very definitive (some might say extreme political views, in the case of Coulter). The simple fact that people like Coulter have a strong ideological position staked out to defend means that they are inevitably going to be interested in defending such positions with science, despite being scientifically illiterate.
While what I am describing is a general tendency characteristic of politicians and political writers who wander out of their field, one thing should be made clear: Ann Coulter never had any credibility to begin with, one reason being that a large portion of her 2007 book Godless: The Church of Liberalism (which I have reviewed here) is devoted to attacking the science of evolution as a “myth.” It is not as if Coulter randomly waltzed her way into the scientific field for the first time with this one article. She is in fact constantly exposing her scientific ignorance to the world (and has been for many years now), and the pride with which she does so makes it all the more embarrassing for her. Someone needs to remind Coulter that she is a lawyer; she studied law at the University of Michigan Law School in the 1980s. If she had her own best interests in mind, she would do what she should do and stick to law and only make comments within that field.
Coulter’s Scientific Errors
As an aspiring journalist with an interest in science, I want to do my part to improve the dismal state of science journalism in this country, and this rebuttal is a result of that interest. Upon my own investigation, I found the actual scientific backdrop to Ann Coulter’s fallacious claims very interesting and worth sharing.
The phenomenon of low levels of radiation having positive health effects is generally known as hormesis, where something that is either toxic or harmful can, at lower doses, actually be helpful in some way (but not necessarily in an proportionately inverse way to its harmful effects). Radiation hormesis is the subject at hand in Coulter’s article. The theory underlying hormesis is itself somewhat controversial; interestingly enough, hormesis is a term used by homeopaths as a way of justifying the pseudoscience of homeopathy, especially with regard to the “like cures like” notion. Of course, homeopaths do not treat their patients with small doses at all. They treat people with nonexistent doses, so their usage of the term “hormesis” is inappropriate (the sheer insanity of homeopathy is too wearying to explain here).
Moreover, even if hormesis does exist, it operates according to a very specific mechanism. It is not a generic principle of biology, as Coulter makes it out to be. The hormesis effect would be produced only in certain specific substances. At low doses, substances open to the hormesis process may display more of a positive than a negative effect, but toxicity does at some point kick in nevertheless. This is true of every single drug we have ever used. It is even true of water! While there is a dose range at which drugs have some effect that can be exploited for benefit, the fact remains that virtually everything becomes toxic given a dose that is high enough.
The specific notion of hormesis applies to the way in which toxicity versus dose is extrapolated and graphed. It is very easy to document a large toxic effect in studies of any kind, whether they are animal studies, experimental studies, or observational studies. Thus, our most reliable data concerning the dose response effect of toxins is that the higher the dose, the higher is the toxicity end of the spectrum. By definition, it is difficult to detect tiny amounts of toxicity; by virtue of being smaller, it wreaks less of an effect that is hard to detect against the background of noise. This means that the closer one approaches zero while attempting to extrapolate a graph downward, the less reliable the data becomes. When studying possible hormesis effects, scientists will often take the objective, clearly-measurable and high-toxic effects and then extrapolate downward, watching carefully to take note of the point at which the said toxic effects become essentially zero.
Whence the hormesis controversy? The controversy surrounds how that line should be extrapolated. Should we assume that it is linear all the way down to zero? This particular approach, which is the one favored by most government agencies when calculating safe limits, is called the linear non-threshold approach. Toxicity is extrapolated as a straight line and it is assumed that there is no threshold of toxicity, meaning that below a certain dose, there is zero toxicity. In other words, the toxicity does not kick in until some point. It is not as if anyone thinks that this approach is a universally useful one describes how every toxin works. But the threshold concept does make sense of many things. The majority of physicians and scientists would likely say that most substances probably really do contain a minimum threshold of toxicity. The only issue here is that it is very difficult to prove this empirically via experimentation. Taking the linear non-threshold approach is simply a way of building in a safety buffer; it represents the assumption of a worse-case scenario (or at least close to a worse-case scenario). Safety limits are then developed based on this method, regardless of the fact that the assumptions underlying the approach may not be literally true. They are simply the most cautious assumptions one can make.
There are a number of other possible models. One is a super-linear curve in which toxicity rises at a faster rate at the low-end of dose and then levels off slightly. Another possible model is the sub-linear curve in which toxicity slowly picks up and then grows greater and greater at a faster pace as dose is increased. Another is the hormesis curve, which actually dips below zero, meaning that not only is there no toxicity, but there is actually a benefit for a certain period of time before the toxicity kicks in. Again, none of these models need be universally true for all toxins. Different toxins can have different curves. For example, antibiotics kill off bacteria at low doses but at high doses will kill people, making antibiotics an example of a substance with which a hormesis-like effect can be present.
What about radiation? The available data for radiation hormesis (in which small doses of radiation might yield some health benefits, which is Coulter’s main argument) is very ambiguous and controversial. Ann Coulter’s approach was to cherry-pick and grossly misinterpret the data; she presents a number of cherry-picked studies and then proceeds to misrepresent those studies. She relies upon very outdated information and fails to provide the reader with any updated information.
Examples of the outdated studies Coulter cites include:
But it is worse than all this, because Coulter staked out her position long beforehand, then subsequently cherry-picked the data to fit that preconceived position. This is a classic, textbook case of pseudoscience in action. When one takes a far more objective look at this than Coulter has done, it is not at all clear that there even exists a hormesis effect for low doses of radiation. It is not impossible; radiation may have certain biological effects that lean ever so slightly on the positive side. But it is well established that ionizing radiation is powerful enough to break chemical bonds, which causes damage in a person’s cells by the breaking of DNA bonds. This causes mutations as well as the release of free radicals, which are well known to cause extensive cell damage. This is the damage caused by radiation, and it only makes sense that this damage can occur at any dose. Even a single cosmic ray, if it just happens to strike a DNA molecule, can cause a mutation which can then become a cancer cell. The takeaway point here is that there does not appear to be even a threshold for radiation. There is certainly a dose response: the more radiation one is exposed to, the more damage is caused. And the more mutations result, the likelihood the mutations will be harmful goes up. The fact that even a single particle of radiation could potentially cause major problems, even if we dismiss such a potentiality as a case of very bad luck, is what indicates a lack of any viable threshold. This is the fact of the matter notwithstanding the possibility that, at low doses, the effect that radiation has on cells can conceivably cause the cell to respond with protective mechanisms that may have more benefits than we would normally expect from the radioactivity that induced them.
In conclusion, radiation hormesis is not necessarily a crazy and outlandish idea (which is more than we can say for most of Ann Coulter’s views). It is just that no evidence for the phenomena currently exists. The “evidence” we have gathered so far is preliminary and ambiguous at best, and we are not at the point where we can positively affirm, as Coulter aggressively does, the radiation hormesis as a real phenomenon. Still, it is a highly interesting scientific concept that scientists should pursue further with careful research. Unfortunately, Coulter completely butchers the concept in the interests of her own ideological agenda.