Aug 16 2010

Banning Wi-Fi From Schools

In the town just north of where I live the middle school was completely torn down and an entirely new middle school was built. The reason for this was concerns that mold in the old school was making children sick.

Apparently, Wi-Fi is the new mold. In central Ontario parents are lobbying the school to turn off the Wi-Fi due to fears that it is making their children sick. You can take the news report of the parents concerns, time-warp about ten years in the past, and substitute “mold” for “Wi-Fi” – the arguments are the same, and the evidence as weak, but the identified problem has just shifted.

The Evidence

Let’s start by reviewing what we currently know about the health risks of Wi-Fi – wireless signals used to connect computers to a network or the internet. From a basic science perspective, there is little plausibility to the notion that Wi-Fi radiation would have any health effects. The amount of energy that is absorbed by a person living in a Wi-Fi field is negligible – less than 1% of exposure from a typical cell phone and well below current safety levels.

I have written about the risk from cell phones recently also. To summarize, there is no compelling evidence at this time that there is a health risk. The evidence so far seems to rule out any significant risk for adults with up to 10-15 years of exposure, but not yet for children or for >15 years exposure. In short, if there is any adverse health effect it must be tiny to be so difficult to detect – and Wi-Fi causes only 1% of the energy exposure as cell phones.

Further, the hypothesized risks of non-ionizing radiation (insufficient energy to break chemical bonds) is considered by many to lack plausibility due to the fact that so little energy is transferred to tissue.For non-ionizing radiation, regulations have focused on the thermal effects – heating tissue – which can occur depending upon the specific frequencies used and how easily it is coupled or transferred to tissues. This is the same effect exploited by microwaves (a form of non-ionizing radiation) to heat food.

The current regulations are largely based upon the thermal effects of EMF exposures – exposures are low enough to prevent significant heating of tissues. Some argue that this is not enough, however, and that there may be non-thermal biological effects, and therefore safety limits should be lowered.

While I agree with those who argue that a significant non-ionizing, non-thermal effect is unproven and implausible, a biological effect is not impossible, and so epidemiological and clinical studies are reasonable. The first question is simply – what is the exposure from Wi-Fi networks? Such exposures to EMF are typically thousands of times less than current safety limits. In fact, one review found:

In all cases, the measured Wi-Fi signal levels were very far below international exposure limits (IEEE C95.1-2005 and ICNIRP) and in nearly all cases far below other RF signals in the same environments.

So not only are exposures from Wi-Fi access points thousands of times less than safety limits, they are also less than the background radio frequency (RF) radiation.

Is there evidence for biological effects on cells? An extensive review of this research concluded:

Overall, there is little evidence of cellular effects of RF fields of health significance below current safety limits.

While they argue for further research in some areas, they were also including cell-phone level exposure, which remember is 100 times that of Wi-Fi, which in turn is no higher than background radiation.

What about electromagnetic hypersensitivity – the reporting of common non-specific symptoms, such as headache, fatigue, dizziness, and confusion, while being exposed to EMF? Well, the same review also summarizes this research, which finds that under blinded conditions there is no such hypersensitivity syndrome. Even with people who consistently report symptoms with exposure to EMF, in blinded conditions they cannot reliably tell if they are being exposed to EMF.

Wi-Fi in Schools

With the research as background, let’s take a look at the current Wi-Fi in school hubbub. News reports indicate:

Some parents in the Barrie, Ont., area say their children are showing a host of symptoms ranging from headaches and dizziness to nausea and even racing heart rates.

The symptoms, which also include memory loss, trouble concentrating, skin rashes, hyperactivity, night sweats and insomnia, have been reported in 14 Ontario schools in Barrie, Bradford, Collingwood, Orillia and Wasaga Beach since the board decided to go wireless, said Palmer.

That is a familiar list of symptoms – non-specific, common and subjective. They are similar to the symptoms that people previously blamed on mold in schools. (But it should be noted that the analogy to mold is not perfect as there is evidence to support the conclusion that some people have a genuine mold allergy, and developed real allergic symptoms to measurable exposures to mold. At the same time, there are those with non-specific symptoms who blame it on mold as the available explanation.)

How do parents know their children are having symptoms secondary to Wi-Fi?

“These kids are getting sick at school but not at home,” he said.

“I’m not saying it’s because of the Wi-Fi because we don’t know yet, but I’ve pretty much eliminated every other possible source.”

I doubt “every other possible source” has been adequately eliminated. That is tough to do for environmental exposures. Further, it should first be determined if there is an actual medical phenomenon, before explanations are sought. One of the primary sources of disconnect between medical professionals and the public is that professionals know from history of published evidence that people can exhibit symptoms without there being a specific physical cause, while the public remains largely unconvinced of this fact. As stated above, even those who had dramatic and consistent symptoms to EMF could not reproduce them under blinded conditions.

Further, the parents are more compelled than they should be at the timing of the symptoms. It should not be that much of a surprise that students are exhibiting non-specific symptoms at school but not home. Stress alone is a sufficient explanation, but there may be others. For example, many students go to school sleep-deprived because they are staying up too late. This is not an issue on weekends and over the summer. Sleep deprivation is a good explanation for most of the symptoms being reported.

There likely is no one answer to what the children are reporting. Once a community has identified a culprit, then many people with non-specific symptoms from any cause are likely to latch onto the available explanation for their symptoms.


Often these issues are framed as a debate over what level of safety is appropriate. There always seem to be those arguing for “zero” risk, or an absolute guarantee of safety. Absolute safety does not exist in our world and is not a reasonable goal. Even with this extreme position aside, it is always easy to argue for greater safety limits than are currently in place. It may always seem reasonable to say that we should err on the side of safety, or wait for further research.

But I do not think this is always the reasonable position. It makes more sense to consider risk vs benefit. In the case of Wi-Fi we have very low biological plausibility given the low levels of exposure, a 1000 fold safety margin with current regulations, no compelling evidence from cell studies of a biological effect, and no clinical evidence of a real health effect.

Meanwhile, convenient internet connectivity is increasingly a vital aspect of our modern lives – certainly in the context of education.

I wonder if those parents arguing against Wi-Fi in the schools, based upon vague anecdotal evidence in the face of low scientific plausibility and lack of evidence of risk, use cell phones. Do they drive, use power tools, have a swimming pool, or snow ski? There are probably hundreds of things we take for granted in our daily lives that have greater risks than Wi-Fi.

These news stories also highlight the need for greater public education in critical thinking. These parents mean well, they are just falling victim to poor critical thinking skills. The news report also indicates that the school board has been largely ignoring them, which is not a good strategy. Professionals and regulators also need to learn how to deal with the public over such issues.

What we have here are the seeds of yet another grassroots movement that is disconnected from science and hostile to authority. This is a scenario we have seen played out many times before, and no doubt we will see it many times again.

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