Paul Matthews, IITP Chief Executive. 30 December 2013, 10:24 pm

I wouldn't normally comment on issues such as the safety or otherwise of wifi gear, however I have to make an exception in light of the latest round of well-intentioned paranoia around the use of wifi in schools, especially given how it's been reported.



This is not a new issue: whether low level electromagnetic fields (EMFs) such as those emitted by wifi, cellphones, lightbulbs, TV, FM radio, power lines and more or less any other electrical appliances - as well as nature - are harmful to humans. So does the science suggest that prolonged exposure to very low levels of EMFs is harmful? And should schools get rid of wifi around kids as Te Horo School on the Kapiti Coast has just done?

Electromagnetic strength in wifi

In terms of Electromagnetic Fields (EMFs), the debate is actually around intensity; the evidence is clear that high strength EMFs - massively higher than wifi signal strength - can be harmful to people. But what is high and low, and can prolonged exposure to very low levels of EMFs also be harmful?

This low vs high intensity question is the same in many other radiation contexts as well. For example, exposure to sunlight in moderation is not considered harmful, however too much of it can cause burning and lead to skin cancer. So where does wifi sit on that spectrum?

Let's first consider just how strong a signal we're talking about here. Jonathan Brewer's Inside Telecommunications blog has a great summary of EMFs and electromagnetic radiation, including the following table (Hat tip @shiftygeek):

Type of Radiation Power Level Potential to be Harmful (heat can be felt) 200W/kg Maximum Permitted in New Zealand 4.00W/kg Highest Radiation Cell Phones (Avg of 20) 1.43W/kg 50 Watt Cell Phone Transmitter at 10m distance 0.365W/kg Lowest Radiation Cell Phones (Avg of 20) 0.32W/kg Wi-Fi Device Average between 0.5 and 2m distance 0.0057W/kg

So going by this table, wifi would have to be 35,000x as strong as its current average to be potentially harmful to humans.

Interestingly, Jonathan also makes the point that banning wifi actually increases electromagnetic radiation, given the vast number of devices that would thus drop back to 3G (which emits considerably greater levels of radiation - although still well under the level considered harmful).

Recent developments

The issue of wifi and cellphone fields has reared its head again this month with the news that a parent has successfully convinced a school community to deny their kids the educational benefits of technology by turning off wifi in their junior school, amid concerns about EMFs from wifi.

Interestingly, the school's Board of Trustees apparently made it clear that they agreed with the evidence that wifi wasn't harmful to kids but were buckling to the pressure and canning it anyway, which is a little odd. They've also retained wifi throughout much of the rest of the school.

Adding to the increased noise recently is the fact that the National Environmental Society Incorporated, a mostly inactive non-profit (with total revenue of $186 in 2012 according to Societies Register records) changed its name to "Safer Wireless Technology NZ Inc" in September 2013. Those behind this group (a board of four individuals who NBR reports are united by opposition to cellphone towers) are now calling on the Government to spend millions re-researching the issue despite the considerable historic and ongoing research overseas.

What's more concerning is how this issue is being reported in some media. For example, apparent unsubstantiated claims that wired internet was "safer" than wifi going unchallenged and a lack of coverage of independent evidence that contradicts this.

What the science says

In response to growing concerns the World Health Organisation (WHO) launched the International EMF Project in 1996 to provide scientifically sound and objective answers to public concerns about possible hazards of low level electromagnetic fields. Following review of over 25,000 scientific articles and research projects, the EMF Project has concluded that:

Despite extensive research, to date there is no evidence to conclude that exposure to low level electromagnetic fields is harmful to human health.

In relation to cellphones, which emit far higher levels of electromagnetic fields:

The long-term health effects of mobile telephone use is another topic of much current research. No obvious adverse effect of exposure to low level radiofrequency fields has been discovered.

Not convinced? How about the US National Cancer Institute:

Although there have been some concerns that radiofrequency energy from cell phones held closely to the head may affect the brain and other tissues, to date there is no evidence from studies of cells, animals, or humans that radiofrequency energy can cause cancer.

It is generally accepted that damage to DNA is necessary for cancer to develop. However, radiofrequency energy, unlike ionizing radiation, does not cause DNA damage in cells, and it has not been found to cause cancer in animals or to enhance the cancer-causing effects of known chemical carcinogens in animals.

In the UK, Public Health England has this to say:

There is no consistent evidence to date that exposure to radio signals from Wi-Fi and WLANs adversely affects the health of the general population. The signals are very low power, typically 0.1 watt (100 milliwatts) in both the computer and the router (access point), and the results so far show exposures are well within the internationally-accepted guidelines from the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Based on current knowledge and experience, radio frequency (RF) exposures from Wi-Fi are likely to be lower than those from mobile phones. Also, the frequencies used in Wi-Fi are broadly the same as those from other RF applications such as FM radio, TV and mobile phones.

And back home in New Zealand, manager of the Royal Society's Science Media Centre Peter Griffin considers both of the above developments in detail, considers the research, then concludes:

The Te Horo school example is a legitimate news story for the media. A school is seriously considering switching of its wireless internet coverage. I don't need to throw any studies at you to show how important wireless access is to education.

Many of the devices kids are using at school can't even be plugged into a wired internet connection. If you turn off the wireless network, you make it harder for kids to go online to find the learning resources they need. ... Without an evidence base to justify it, turning off the Wifi is therefore a regressive move that could hurt the development of children.

Damon Wyman may think he is doing the students of Te Horo School a favour. In fact, he is helping to generate the sort of hysteria that could lead to wifi networks going dark in schools across the country. That would be a disaster.

If you're interested in this topic I strongly recommend you read Peter's full post. And there's far more global evidence to boot.



What does that all mean?

In short, the science is clear and credible. Following very comprehensive and ongoing research, there is absolutely no evidence of a link between exposure to wifi transmission and adverse health effects. It would appear to make no more sense banning wifi in schools as banning electricity, and neither is supported by the evidence.

Te Horo School's board is acting on a call from their community and you certainly can't begrudge them for that. However we do live in the 21st century: decisions such as this should have an evidential basis and unfortunately that simply doesn't appear to be the case here.

Hopefully other communities around New Zealand will consider the science first and foremost rather than letting emotion override fact - to the detriment of their kid's education.

Paul Matthews is Chief executive of the Institute of IT Professionals NZ.