Sunday, October 24, 2010

Cell Phones Can't Cause Cancer -- Why Did Anyone Think They Could?

How many times have you heard a TV newscaster quoting a scientific source that maybe cell phones cause cancer?  Here and here are examples. Here is one to keep your cell phone out of your bra to avoid cancer. Type "cell phone" cancer into Google News and see for yourself.  The reports often say that studies cannot rule out a risk; or studies suggest a link may exist. Sometimes they talk about vague language in the lawyerly small print of cell phone operating manuals.

Michael Shermer in October's Scientific American wrote that scientifically this can't be true. Why didn't someone point this out before? How many people have been worrying for no reason? Shermer point is that the radiation in cell phones is not great enough to cause a chemical reaction. Longer exposure to low energy radiation does not make a given photon stronger in energy; that is higher in frequency --  there are just more low energy photons. Radiation exposure is simply different than chemical exposure.

Cell phones operate between 380 MHz and 1990 MHz. These waves are in the range of 15 - 80 cm in length, and about as dangerous as old-style TV signals. Waves longer than visible light (about 0.5 mm) are not energetic enough to cause chemical reactions, though they might cause heating, as microwaves (about 1 cm) can cause heating. Visible light interacts with a few cell on our retina in a non-harmful way, and also with fresh photographic film, but the vast majority of objects are unaffected. Sunburn is called by more harmful and energetic ultraviolet light. Cell phone radio waves are at least 30 times less energetic and less harmful.

Obviously cell phones don't make your head warm, or you would feel that. Some people say that the energy from a cell phone can be measurable, but it is just a degree. You get as much heat from the battery discharging or the LED display.

There are curmudgeonly, (generally) old people who think every new thing is dangerous. The frightening talk about cell phone cancer is completely uninformed -- just compulsive worriers babbling.

See the follow-up post from 7-June 2011.