Rhinocrisy

A few weeks back I happened across a news story trumpeting a link between cell phones and brain tumors, containing the ominous warning that cell phones are “worse than cigarettes”. By coincidence my roommate had happened to ask me if I knew anything about the subject, and so I spent a portion of the previous day scouring PubMed to answer this very question, and had, of course, also compared against cigarettes as the outstanding example of a public-health disaster caused by personal foibles.

So my immediate reaction to the story (”Balls.”) was based on more than just a gut feeling.

But let’s start off by poisoning the well a little bit: the source for this story was an Australian neurosurgeon named Vini Khurana. Vini’s methodology in answering this question was exactly the same as mine: reading some papers on PubMed. We should be clear that reviews are an important part of scientific literature, and they are a great way to collect information and present a perspective on the field. They’re usually the product of specific solicitations by journal editors to respected members of a field - e.g., asking James Hansen to write a review on the global temperature record, or even asking someone like Carl Woese to write a review on the future directions for the entire field of biology. The idea is that someone with a demonstrated expertise in the field is surely best-positioned to report on its history and state-of-the-art.

But no one solicited Vini’s article. In fact, Vini has no history of publication in the field. In fact, Vini didn’t even publish this paper anywhere. It was published on the web and was completely unreviewed.^*

As I’ve suggested before, I think the manner of propagation of many news stories is purely viral: something happens to make it onto some wire service, and if it is interesting or sensational, it spreads. As its exposure increases, so do opportunities for further dissemination - another outlet picks it up, and the cycle continues. This process doesn’t seem to include anything like quality control or actual journalism (mayhap the journalists here can speak to why this might be the case), with the result that bad, bad science gets broadcast loudly around the globe.

At any rate, the question at hand remains to be answered: do cell phones cause brain tumors? After Vini’s own pathetic review, he recommends an actual review in the Journal of Radiation Biology, whose abstract tells us:

Biophysical considerations indicate that there is little theoretical basis for anticipating that RF energy would have significant biological effects at the power levels used by modern mobile phones and their base station antennas. The epidemiological evidence for a causal association between cancer and RF energy is weak and limited. Animal studies have provided no consistent evidence that exposure to RF energy at non-thermal intensities causes or promotes cancer. Extensive in vitro studies have found no consistent evidence of genotoxic potential, but in vitro studies assessing the epigenetic potential of RF energy are limited. Overall, a weight-of-evidence evaluation shows that the current evidence for a causal association between cancer and exposure to RF energy is weak and unconvincing.

That first sentence, by the way, is an important one: there’s little justification for the notion of non-ionizing radiation being a significant cause of DNA damage.

Meanwhile, a simple comparison of some epidemiological studies on the question is revealing. This study finds odds ratios of 1.22 and 0.70 for gliomas and menigiomas respectively. This one finds an odds ratio of 0.6 for gliomas, with a 95% confidence interval of 0.4-0.9. I.e., the study finds that regular cell phone use is slightly protective against gliomas! And finally, this study examines both long- and short-term users of cell phones and finds no increased odds of acquiring tumors through phone use in either group.

By now you are probably shivering in your boots^†, so let’s take you back down a little, with a sentence from this case-control study:

The odds ratio (OR) for lung cancer in current United States smokers relative to nonsmokers was 40.4.

The short version: As you were, lieutenant.

^* Yes, reviews are normally reviewed. The reviewers of reviews are called re-reviewers, and they are required to do their reviewing work between two facing mirrors to deepen their powers of meta-analysis.

^† You are wearing your boots, right?

This song is from the ending credits of Valve’s stellar first-person-puzzler game Portal, as sung by the mad AI GLaDOS. I find the lyrics very poignant, especially:

I’m doing science and I’m still alive.

Lately I’ve been interested in the Fusor, a device which achieves fusion by accelerating individual ions to high energies using electric fields (rather than creating a high-temperature plasma, the strategy employed by expensive and to date unsuccessful “tokomak”-based methods). It seems some guys at UC Irvine have done something similar. Check it out.

Note that this is NOT “cold fusion”, it is “hot fusion”, and the physics is relatively uncontroversial. Fusion power in a matter of years?

UPDATE: Apparently not.

One of our most popular posts, google-wise, is hedgehog’s missive about the health effects of bisphenol-A, a common ingredient in many plastics. I happened across a nice letter in PLoS Biology, written by Rebecca Roberts, describing her fears as a new mother on her child’s exposure to BPA. Included is a nice summary and references for some of the research supporting the need for tighter regulation (some say banning) of BPA in plastic products, especially with regards to kids, and a chronicle of the failed legislative efforts at removing it.

Many liberals are crowing happily about a new study in Nature Neuroscience that purports to prove (basically) that liberals are better at parsing input correctly than conservatives. The study authors are careful to be politically circumspect in their statements, saying that this is only one test, conservatives might do better at others, but it’s pretty clear what they want to say: liberals are smarter.

It’s hard to argue with their results. As you can see from the figure I stole from their paper, the correlation is quite strong. A regression like that is an experimentalist’s wet dream. The only question is, what are they measuring?

I’m deeply skeptical of studies like this. Political orientation is not plastic; people change their views all the time, especially during college (which I imagine is where the bulk of the study sample was drawn from). Case in point: me. When I started school in 1996 I was a Dole supporter, staunchly conservative. When I graduated at the end of 1999 I was an anarcho-communist. Furthermore, political orientation is a very ill-defined quantity. “Liberal” or “conservative” may be taken on many, many different bases, and I would strongly dispute the authors’ contention that there is a political “spectrum”. I do not believe in a holistic “liberal” worldview, any more than I believe in a holistic “conservative” worldview. These are constructions imposed on public discourse by a self-feeding party machinery, and I don’t think actual political viewpoints can be so neatly broken down. I therefore find it hard to believe that there should be fundamental neurological attributes correlating with political orientation. How, then, do I explain these results?

Just prior to performing the trials, the subjects are given a questionnaire on their political orientation. That is, the study primes them to think about politics before they enter the trial. The study methodology relies on the ability of the subject to distinguish between the letter ‘M’ and the letter ‘W’.

Liberals have spent the past eight years imbuing the symbol ‘W’ with a particularly strong sense of hatred. Since they are going into the study primed to think about politics, it stands to reason that those subjects self-identifying as liberals would not see the two alternatives as value-neutral. That is, conservatives are distinguishing between the letters “M” and “W”. Liberals are choosing between “Bush” and “Something Else”, and are therefore bringing different cognitive resources to bear on the task.

This is a conjecture, of course, and easily tested by using two other symbols (say, ‘b’ and ‘d’) that don’t have any political implications. But given the dubious nature of the proposition and the visceral nature of the reactions being measured, I suspect that the choice of letters goes a long way towards explaining this difference.