No, Wi-Fi exposure is not killing your kids

Last week a blog post at Forbes on Wi-Fi devices went viral. That post, by fellow Forbes contributor Robert Szczerba, claimed that Wi-Fi exposures from cell phones, iPads, microwave ovens, and other mobile devices are "more dangerous to kids than previously thought."

Szczerba claimed that Wi-Fi devices might be causing cancer, especially in children." It was illustrated with a photo of a toddler playing with a tablet PC, possibly an iPad.

Well, that got some attention.

The problem is, it's all wrong. Even the premise is wrong: there was no "previous" evidence of danger from Wi-Fi devices, except from conspiracy theorists. Let's start where Szczerba started: he based his article on a newpaper published in the Journal of Microscopy and Ultrastructure, titled "Why children absorb more microwave radiation than adults: The consequences."

I read the article, painful though it was, to see what it actually claims. The first red flag is that it appeared in a very obscure journal that does not focus on radiation or environmental health. The second red flag is that two of the authors, Lloyd Morgan and Devra Davis, work for a private organization whose sole purpose seems to be to promote claims that cellphones and other wi-fi devices cause cancer. The remaining author, Santosh Kesari, seems to be a respectable neuroscientist at UC San Diego. I wrote to Kesari to ask for comment, but he did not respond.

Now to the article itself I have to say that this is perhaps the worst scientific paper I have read in years–and I read a lot. It purports to be a review of some sort on microwave radiation (MWR) exposure in children. It is nothing of the sort. It's not even written like a scientific paper.

Essentially, the article is a series of claims, most of them unrelated to one another, about the effects of MWR and other topics. The authors have cherry-picked several dozen studies that they believe support their hypothesis, which they cite without any explanatory details, while ignoring hundreds of studies that contradict their claims. For example, they write:

"In 2008 Joe Wiart, a senior researcher for French telecom and Orange reported that the brain tissue of children absorbed about two times more MWR than adults' brain tissue."

That's it: just one sentence, with no explanation of what the study was about (nor of what "Orange" is here). It turns out to be a simulation study with little or no relevance to the health risks of MWR on actual people.

Other cherry-picked examples in this so-called review include a 1972 study of myelin degeneration in guinea pigs and a 1977 study in rats, neither of which tell us anything about the risks of wi-fi devices. This paper is a dreadful mess.

The paper also includes many stunning non sequiturs, such as this:

"The Australian study reported, "an overall significant increase in primary malignant brain tumors was observed over the study period from 2000 to 2008." 

This study does indeed exist, but it has nothing to do with wi-fi or microwaves! It's a study of changing cancer rates in Australia, and the authors don't even mention wi-fi, much less suggest that it causes cancer. In a real journal, peer reviewers would have insisted that the studies cited have some relevance to the main topic of the paper. Not here, apparently.

I don't have time to debunk all the nonsense in this truly awful paper - nor should you want to read about it. My guess is that the Journal of Microscopy and Ultrastructure will publish anything as long as the authors pay the publication fees. In its entire history, the journal has only published 6 issues.

So what is the evidence for Wi-Fi and cancer? Just a few months ago I wrote an article explaining that high-voltage power lines do not cause cancer. But how about Wi-Fi devices like cell phones and iPads? It only took me a few minutes to find a recent review of the literature, published just a year ago in the journal Health Physics. Note that this is a journal that's actually about human health, unlike the microscopy journal that Szczerba relied upon. That study concluded:

"The overwhelming consensus of health agencies around the world is that RF [radio frequency] exposures below international exposure limits have not been shown to produce any health hazard (Verschaeve 2012). That conclusion would not be changed by the Wi-Fi–related studies reviewed here, some of which indeed were already considered in these expert reviews."

Or to put it in simpler terms: Wi-Fi is not more dangerous than previously thought, and your iPad is not going to give your kids cancer. That's what Robert Szczerba should have written, if he'd looked at the real science instead of one really bad paper.

But that wouldn't have gone viral, would it?

Do high voltage power lines cause cancer?

This could be a very short article. I could just write “no, power lines don’t cause cancer"—but that wouldn't explain why so many people believe otherwise. And it won’t help people who are thinking about buying a home that has power lines nearby. So let’s look at this question a bit more closely.

For the past century or more, humans have been surrounding ourselves with an ever-growing array of electrical devices. All of these devices create electrical or magnetic fields, often called EMFs. There’s no doubt that our exposure to EMFs has increased dramatically in modern times. Not surprisingly, many people have worried that this is a bad thing. The belief is so pervasive that NIH has at least two websites devoted to this topic, one by NIEHS and one by NCI, as does the Medical College of Wisconsin. Realtors have created webpages to inform home buyers about how power lines might affect the value of their home. Not surprisingly, you can easily find companies on the Internet that will sell you devices (such as SafeSpace and EMFshield) to protect your body from the supposed perils of EMF.

People worry especially about high-voltage power lines, probably because they are carried by very large, highly visible structures that look vaguely threatening. This fear seems to have started with a 1979 study in which Nancy Wertheimer and Ed Leeper reported a correlation between high-voltage power lines and childhood leukemia in the area around Denver, Colorado. Wertheimer's results spurred numerous studies in the years since. A review of the evidence in 1995 pointed out that

“There is no known mechanism by which magnetic fields of the type generated by high voltage power lines can play a role in cancer development. Nevertheless, epidemiologic research has rather consistently found associations between residential magnetic field exposure and cancer.”

Scientifically, the question at the time was, were these associations real or coincidental?  If they were real, what’s the mechanism? Clearly, further studies were needed. Well, twenty years later, the data are in: power lines do not cause cancer.

In 2002, the WHO commissioned a huge (339 pages) and very thorough report on all the types of electrical and magnetic fields on the planet and how these EMFs might effect our health. Among its findings were:

“There is little experimental or theoretical evidence that mutations could be directly caused by ELF [extremely low frequency] magnetic fields…. There is little evidence that ELF electric or magnetic fields can cause malignant transformation of cells in culture.”

The final conclusion of the WHO commission was that

“Static electric and magnetic fields and extremely low-frequency electric fields are not classifiable as to their carcinogenicity to humans (Group 3).”

Group 3 means we don’t have any positive evidence that EMFs cause cancer. The only lower category, Group 4, would mean we have evidence that electromagnetic fields do NOT cause cancer, but such evidence is very difficult to produce. In other words, they concluded that the evidence didn't support a link, but more studies might yet find something.

After the 2002 report by the WHO, a study in 2005 raised the alarm again. In that study, Gerald Draper and colleagues claimed to find an association between the distance to the nearest high voltage power line and childhood leukemia. Draper found that living less than 200 meters from these power lines (in England and Wales) raised the risk of leukemia significantly compared to living at least 600 meters away.

The scientific reaction to the Draper study immediate and highly critical. Hepworth and colleagues pointed out that the results did not support a causal role for electromagnetic fields (which were not measured), but at best a geographic correlation. Kheifets and colleagues demonstrated out that the effect disappeared when the control groups were analyzed differently. Other critiques quickly emerged as well: a sign that science was working to self-correct, as it often does. But Draper’s study was widely reported, while the criticisms were not. The critiques, though, paint a compelling picture that Draper’s work was seriously flawed.

One of the most recent studies is from 2013 by Elliott et al. who looked at over 50,000 cases of cancer, including leukemia, brain cancer, breast cancer, skin cancer, and others. They found no increased risk for any of these cancer types and concluded

“Our results do not support an epidemiologic association of adult cancers with residential magnetic fields in proximity to high-voltage overhead power lines.”

This debate sounds very familiar. Many false hypotheses, such as the notion that vaccines cause autism, or that acupuncture can reduce pain, show the same pattern: a few small studies produce weak positive evidence, but then larger, better studies fail to back them up. Proponents always call for more studies, but if the effect is real, it doesn't disappear when you do a bigger study. If anything, the effect should appear stronger.

A major problem that the EMF alarmists have, which none of the proponents have ever answered, is one of mechanism: how is the very weak EMF from a power line supposed to cause cancer? Multiple theories have been suggested: maybe EMFs affect the movement of magnetic particles within cells, or alter the voltages across cell membranes—but as the editor of BMJ, Geoff Watts, put it in his response to the 2005 Draper study:

“Evidence to support these and other ideas is at best thin and at worst non-existent.”

So no, electrical power lines do not cause cancer. But they're still ugly. We should bury them all underground.