I can’t tell you the number of times over the years that someone has come up to me when I’m pulling cables and commented, “Some day everything will be wireless.” And it certainly seems to be going in that direction.
Bluetooth, invented in 1994, allowed short distance transmission of high speed data using the 2.4 GHz short-range radio frequency band, the same band that’s used for cordless phones and garage door openers.
Around the same time, Wi-Fi was invented to allow for wireless networking of computers. It, too, uses the 2.4 GHz range but with higher power. These technologies have made smart phones and electronic notebooks possible. But what was seen as a boon when first introduced is now being seen by some as a danger.
The concern is that we don’t know what the health effects of all this radiation are. With Wi-Fi hotspots being installed in public places throughout cities and schools, businesses and homes being equipped with Wi-Fi networks, the air is full of unseen vibrations.
In 2003, when Wi-Fi was just beginning to catch on globally, a group of parents in Oak Park, Illinois sued the local school, seeking to stop the installation of a wireless network in the school on the basis that the long term effects are unknown. They cited a study that indicated problems with rats exposed to cell phone radiation.
Cell phones emit more wattage than Wi-Fi and they operate in a different frequency range. While wireless networks emit radiation in spurts, cell phones emit constant radiation and you hold them right next to your brain,. Although evidence has been mounting that there may be a danger associated with cell phones, and particularly with their broadcasting towers, Wi-Fi is not exactly the same thing.
It’s not easy to get a clear picture of the potential health risks because there is no consistency in standards or testing.
Austria and Lichtenstein set the acceptable maximum level of microwave radiation at one tenth of a microwatt per square centimetre. Switzerland sets the threshold at ten times that amount, and Canada sets it 10,000 times higher.
Why the discrepancy? It’s because the Canadian guidelines are based on the ability of microwaves to raise the body temperature, leading to health risks.
The power output of Wi-Fi is so low that there is no danger of body tissue being heated. The danger, if there is one, is from long term, low level radiation filling the environment, particularly in schools with Wi-Fi networks where students would be exposed to it all day long.
The World Health Organization has stated that “there is no convincing scientific evidence that the weak RF signals from base stations and wireless networks cause adverse health effects”. The fact that the evidence isn’t there doesn’t mean that the danger doesn’t exist. It just means it hasn’t yet been proven.
Quoted in a London Times article in December of 2006, Dr. Michael Clark of the Health Protection Agency said, “When we have conducted measurements in schools, typical exposures from wi-fi are around 20 millionths of the international guideline levels of exposure to radiation. As a comparison, a child on a mobile phone receives up to 50 per cent of guideline levels. So a year sitting in a classroom near a wireless network is roughly equivalent to 20 minutes on a mobile. If wi-fi should be taken out of schools, then the mobile phone network should be shut down, too — and FM radio and TV, as the strength of their signals is similar to that from wi-fi in classrooms.”
Medical physics expert Professor Malcolm Sperrin, told the BBC in May of 2007 that “research is still proceeding in this area at leading centres in many countries but evidence points to wi-fi transmissions being well below any likely threshold for human effects."
While the levels may be low they are constant and a child in school is in that environment for fourteen years, like a burrito in a slow motion low intensity microwave oven.
In July of last year, Dr. Magda Havas, from Trent University sent an open letter to parents, teachers and school boards warning of the dangers of both cell towers near schools and Wi-Fi networks within them. She refers to a growing segment of the population affected by EHS, or Electro-Hyper-Sensitivity.
While the health risks of Wi-Fi in general are dismissed by the World Health Organization, they accept the existence of EHS, stating, “EHS is a real and sometimes a debilitating problem for the affected persons, while the level of EMF in their neighbourhood is no greater than is encountered in normal living environments.” Dr. Havas lists the symptoms of EHS as sleep disturbance, fatigue, pain, nausea, skin disorders, problems with eyes and ears (tinnitus), dizziness. And, more disturbing, she suggests that “prolonged exposure may be related to sensitivity and for this reason it is imperative that children’s exposure to microwave radiation (Wi-Fi and mobile phones) be minimized as much as possible.”
The world is full of dangers and people are going to differ greatly in their opinions about whether this is worth adding to our list of worries. But Dr. Havas makes a compelling point when she cites the “Precautionary Principle”, which states “Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost effective measures to prevent environmental degradation.” It was this principle that caused Lakehead University President Fred Gilbert to back off installation of a campus-wide Wi-Fi network last fall.
As the debate rages on, there is something to be said for a hardwired network. The 2.4 GHz band is already getting crowded and will become even more so as the years pass. Almost all signals now are digital rather than analog and when interference affects a digital signal, it doesn’t weaken, it disappears.
A hardwired system sends signals down dedicated cable pathways that are permanently connected and exclusive. That means it has a better chance of arriving intact. And it’s safe for children.
Bill Monahan is a “smart home” specialist who has been in the construction industry for thirty years, with the last twelve devoted exclusively to residential electronics. While he provides and installs products he sees his main mission as making homeowners comfortable with the new technologies.
