If you spend any time on a University campus, in an office building, or in some cities, you are probably being blanketed with a constant wireless internet signal.
Recent reports of sickness among children at Toronto-area schools were blamed on the installation of Wi-Fi routers and created a local uproar — but is there any scientific evidence backing the symptoms? Here's what we know about the science of Wi-Fi signals, and the phenomenon of "electromagnetic hypersensitivity."
The waves behind your Wi-Fi signal
Your wireless internet signal works by sending out radio waves with 2.4 GHz frequency. This is the same frequency used by many other devices, like your microwave oven, your cordless phone, and some motion-based security systems.
During the course of a day, you're exposed to radio frequencies in the range of 75 MHz to 3 GHz. Radio stations transmit on a frequency near 100 Mhz, and television stations transmit in the 300-400 Mhz range.
In the UK and North America, frequencies around 2.4 GHz are popular for use in wireless devices due to their unlicensed nature. Other frequencies in the spectrum are retained for license to communication companies, as a source of government revenue.
Radio Waves and electromagnetic radiation
Electromagnetic radiation isn't nearly as scary as it sounds — it's just a form of energy emitted by moving charged particles, and it forms an electromagnetic field. The radio waves used to transmit wireless signals are a non-ionizing type of radiation — unlike gamma radiation and Röntgen radiation (x-rays!), the radio waves do not have the strength to break chemical bonds within the body.
Two to three people per one million claim to exhibit electromagnetic hypersensitivity, a series of non-specific symptoms resulting from exposure to Wi-Fi and other signals in our environment.
Symptoms of electromagnetic hypersensitivity vary widely from allergy-like symptoms to tinnitus, memory deficits, and skin rashes. With little redundancy in symptoms between individuals, arguments persist over whether the phenomenon of electromagnetic field sensitivity is real or not.
725 people claiming to be sensitive to electromagnetic fields took part in a double-blind sensitive study performed by King's College London. The results of this enormous thirty-one experiment study showed that none of the purportedly hypersensitive individuals noticed electromagnetic fields any more than a non-sensitive individual.
A theoretical model exists that explains the symptoms of hypersensitivity as a side effect of increased histamine released from mast cells in the presence of electromagnetic fields. Electromagnetic hypersensitivity, however, could also be merely a psychosomatic response — which is what the lack of experimental evidence suggests.
Although heightened sensitivity may not be scientifically observed, claims of negative impacts from electromagnetic fields, particularly those emanating from Wi-Fi sources, continue. Parents of children at fourteen schools in Ontario, Canada became concerned when their children started exhibiting insomnia, skin rashes, and night sweats after the installation of wireless routers throughout elementary schools.
Parents supporting this possibility believe the thinner skulls of children allow for increased exposure to electromagnetic radiation. In response to ongoing concerns about the health effects of wireless signals, Ontario's Lakehead University decided to remove Wi-Fi hotspots on campus for a short period of time.
Spending an entire year within the radius of a Wi-Fi hotspot exposes your body to roughly the same amount of as a 20 minute call on your iPhone. Wi-Fi signals follow an inverse square law — as you move two feet away from the source, you receive one-forth of the exposure and one-sixteenth of the exposure when you are four feet away.
The strength of the electromagnetic signal emitted via Wi-Fi communication is also much lower than common household appliances. Your microwave, which uses the same 2.4 GHz frequency to vibrate the molecules in our food, exposes an individual to 100,000 times that of the typical background Wi-Fi signal.
The World Health Organization thinks you are safe when surfing
One point of contention at the moment is the amount of exposure from wireless signals while sitting at a laptop, or with a wireless beacon in your pocket throughout the day. The World Health Organization's official stance is that Wi-Fi use is safe for humans. The WHO also does not recognize electromagnetic hypersensitivity as a syndrome due to the lack of essential characteristics and symptoms.
Radio and television signals saw worldwide use, beginning in the early 20th Century, with no known adverse effects. And if you are becoming sick due to electromagnetic radiation, it's probably not due to your Wi-Fi signal. Keep your laptop, but quit acting on your voyeuristic temptation to watch your frozen food rotate as it heats.
The top image is a modified version of an image by Beautiful-Fantasies on DeviantArt. Images of a Mountain View, Colorado wireless transmitter owned and operated by Google courtesy of Nial Kennedy. Sources linked within the article.