The Danes, relatively inactive on the world scene since their conquest of Greenland and invention of that delightful pastry, have conducted one of the best health studies yet revealing that there's no apparent link between cancer and cell phones.
Researchers at the Danish Cancer Institute (who, remember, don't want you to get cancer) followed more than 420,000 cell phone users, nearly a tenth of the Danish population, and found that their cell phone habits did not increase their risk of any type of cancer. The results were published last week in the Journal of the National Cancer Institute.
Brain cancers can take many years to develop. The most reassuring aspect of the massive Danish study is that some of the cancer-free subjects have been using cell phones for more than 20 years.
Yet most scientists aren't surprised by the result. Study after study has been showing no evidence of cancer precisely because there's no plausible reason for cell phones to cause cancer.
Technology = worry
Cell phone users worried about brain cancer can call on history to ease their fears. Older readers might remember when microwave ovens were said to cause cancer. After this, it was power lines. After this, computer monitors.
Every new technology brings worry. Books are written each time—there are quite a few on cell phone dangers—attempting to reveal the truth and uncover the vast conspiracy of those villains forcing electricity and other useless products upon us. Lots of money is made selling the fear; lots of money is spent on studies to convince the public the technology is safe.
The fear isn't always groundless. Industry has pushed a lot of deadly products our way, such as asbestos and, well, a lot of processed junk food we heat up in our harmless microwaves.
One fear certainly worth investigating was the possible link between childhood leukemia, a blood cancer, and electric and magnetic fields from power lines. In the late 1970s researchers investigating a clustering of leukemia cases in Denver found that the sickened children lived in homes near power lines whose configurations could emit higher levels of magnetic fields. But subsequent studies over the next 20 years exceeding $20 billion, according to White House estimates, have found no elevated risk of cancer from daily exposure to electromagnetic fields from power supplies.
While excessive exposure to magnetic fields can cause illness, cell phone "radiation" has always been far too feeble to be of concern.
Speaking of (and with) radiation
Electromagnetic radiation can be divided into ionizing and non-ionizing radiation. Ionizing radiation can knock an electron loose, break a chemical bond, cause a DNA mutation, and cause cancer. Radiation isn't ionizing, however, until it reaches ultraviolet energies. UV causes skin cancer; X-rays and gamma rays are well-known carcinogens.
Visible light and lower-energy forms of radiation such as infrared and radio waves aren't ionizing. This is a basic property of quantum physics. Light particles, called photons, are like little balls. An X-ray is like a golf ball; it will break a window. Microwaves, the kind emitted by a cell phone, are like puff balls. You can throw a million at the window. It won't break.
This is your brain on microwaves
Microwaves can cook meals when concentrated in an oven by vibrating the water molecules in food, which creates heat [See: How microwave ovens work]. The omni-directional microwaves emitted by your cell phone are millions of times less concentrated. Your head, which does a good job protecting the brain from the heat of the sun, would start to cook before any brain tissue inside started to heat.
Yes, microwaves are penetrating your brain as you speak on a cell phone. If they do cause cancer, though, this would entail an entirely new process unlike any other cancer-inducing chemical, virus or ionizing photon.
The most prudent scientists don't entirely rule out the radiation dangers (heat, magnetic or ionizing) present in modern society. They do rely on scientific facts and findings to assess these dangers, such as a lack of biological mechanism at the given exposure and studies involving nearly a half-million Danes.
Scientists are more concerned about improper use of radiating devices—talking on a cell phone and driving, heating up Cheez Whiz in the microwave, or watching reruns of "Married with Children" on the telly. Now we're talking about true dangers.
Christopher Wanjek is the author of the books “Bad Medicine” and “Food At Work.” Got a question about Bad Medicine? Email Wanjek. If it’s really bad, he just might answer it in a future column. Bad Medicine appears each Tuesday on LIveScience.
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Christopher Wanjek is a Live Science contributor and a health and science writer. He is the author of three science books: Spacefarers (2020), Food at Work (2005) and Bad Medicine (2003). His "Food at Work" book and project, concerning workers' health, safety and productivity, was commissioned by the U.N.'s International Labor Organization. For Live Science, Christopher covers public health, nutrition and biology, and he has written extensively for The Washington Post and Sky & Telescope among others, as well as for the NASA Goddard Space Flight Center, where he was a senior writer. Christopher holds a Master of Health degree from Harvard School of Public Health and a degree in journalism from Temple University.