Computer Q&A: Can
You Die From Wi-Fi? Cell phones Likely
Worse
Post Gazette
Journalist: David Radin
March 04, 2004
Are we building an electronic oven for ourselves by surrounding ourselves with high tech devices? You might come to that conclusion by looking at three families in Oak Park, Ill., who are suing their school district alleging that it is exposing their children to serious health risks by using Wi-Fi wireless technology.
Wi-Fi allows computers, printers and other network devices to talk to one another without wires. In its basic form, Wi-Fi is a set of transmitters and receivers that send electronic waves at high frequency over short distances. They operate on the same frequency band as many cordless phones -- the 2.4 GHz range.
Are they dangerous?
John Brown, a physicist from Sunnyvale, Calif., says the health risk posed by Wi-Fi is minimal because of the way it is used and the frequency at which it operates.
According to Dr. Brown, the real danger is the proximity to the transmitter because the transmitter sends out the waves that could heat up human tissue if close enough to the antenna. Wi-Fi transmissions, just like TV, radio, light, microwave and other transmissions, are radiation. Radiation produces heat by causing electrons to move faster. That's generally not good for the human body, which operates best within a specific temperature range. The higher frequencies, such as X-Rays, can more easily penetrate your tissue. That's why your physician has used X-Rays for years to take pictures. Wi-Fi operates at a much lower frequency.
Think of your microwave oven. It penetrates food with high frequency waves to make molecules in the food move faster, thereby heating up. My wife and I won't let our children near our microwave oven for fear of exposure to stray rays -- even though there are interlocks to keep rays from seeping out.
But why worry about Wi-Fi gear? According to Dr. Brown, the power drops off by the square of the radius. In non-physicist language, it means the farther you are from the source of the wave, the weaker the signal. Moving from one inch away to only one foot away from the Wi-Fi antenna weakens the signal by a factor of 100. So unless you're hugging the antenna, or leaning against it, you're being exposed to very little radiation.
There are much bigger risks in your life. Your 2.4 GHz wireless phone has a transceiver (combination transmitter and receiver) to talk to its base station. And you put the device right next to your face, with the antenna almost touching.
Theoretically, cell phones cause even greater risk, although the statistical studies do not conclusively point to cell phones as major problems. But if you think of them as transmitters and receivers, you're placing the transmitter's antenna right next to your head -- and its signal has to be strong enough to reach the cell tower to enable you to talk to another person.
Don't forget CRT monitors, such as your TV and older computer monitors. Your mother may have been right about the dangers of staying too close, although she may not have known why. According to Dr. Brown, CRTs emit X-Rays as they excide the phosphors on your screen.
I hope that the families in Illinois don't encounter long-term problems due to their school environment. If I were as worried as they are, instead of suing the school system, I'd turn off my TV and replace my wireless phone with a traditional wired phone. I'd also teach my children to keep the cell phone away from their heads, which I have actually already done. Those actions will increase their safety factor, not just fatten their checkbook.