Cell Phones and Brain Cancer : Fear Factor

by Food and Drug Administration (FDA)

(Page 3 of 3)

The new studies may bolster current scientific knowledge, but they will never be able to prove cell phones to be absolutely safe. Proving that cell phones don't cause cancer presents the insurmountable scientific obstacle of trying to prove a negative, Moulder explains. "The closest thing to proving that something is safe — that it doesn't cause cancer — is to try to prove that it does, and fail, and fail enough times and in enough different ways."

Even when scientists are convinced of the safety of a technology — be it the technology of cell phones or of televisions, radios, computers, or microwave ovens — it doesn't necessarily follow that public fears will be put to rest. Lay people interpret scientific evidence differently from scientists, according to risk experts, and the general public may be more likely to be frightened when preliminary research shows a mere possibility of harm.

Scientist Moulder is already confident that cell phone use doesn't increase a person's chance of getting brain cancer — so confident, in fact, that he sees nothing wrong with using a cell phone for even hours each day. "Go right ahead," the cancer researcher says, "but please-please-please don't use it while driving. That's dangerous."

Steps To Take If You're Still Concerned

Earlier this year, the British government recommended that children's use of cell phones be limited to essential calls. The recommendation was not based on any scientific evidence that cell phones pose a special risk to children. Rather, it was a precautionary recommendation, the government explained, to protect a vulnerable population with still-developing nervous systems.

FDA has suggested some simple steps that American cell phone users can take if they remain concerned about potential health risks but don't want to give up their mobile phones.

First, people can of course consider reserving the use of mobile phones for shorter conversations or when a conventional phone is not available. Also, they can switch to a type of mobile phone with a headset to place more distance between the antenna and their bodies. And for the car, people can switch to a mobile phone with the antenna mounted outside the vehicle.

With the recent media spotlight on cell phones, cancer researcher John Moulder, Ph.D., warns that some marketers are preying on people's fear of radiation, selling fraudulent devices with claims that they are protective. Moulder has seen a variety of creative but useless items, mostly on the Internet, from pendants worn around the neck to so-called RF-proof lingerie. As to products sold as shields for the phone to cut your RF exposure while not interfering with the communication signal, Moulder says, "I have yet to see one that can do both of those things."

Studies So Far

Epidemiological and animal studies undertaken by the U.S. cell phone industry and others have yielded mixed results.

In a study published in 1999, investigators at the Orebro Medical Centre in Sweden compared the past mobile phone use of 209 Swedish brain tumor patients and 425 healthy people. Conclusion: The study found no mobile phone/brain cancer link "in virtually all respects," cancer researcher John E. Moulder, Ph.D., says in the August 2000 issue of IEEE Spectrum, the official magazine of the Institute of Electrical and Electronics Engineers. Investigators did find that mobile phone users who got certain types of brain tumors tended to report using the phone on the side of the head where they developed the tumor. The study's limitations, according to Moulder, include a weak association between cell phone use and tumor development, as well as a possibility that the cancer patients' recollections were biased by already knowing on which side of their head the brain cancer developed.

In a yet-unpublished study presented at a 1999 scientific meeting, researcher Joshua Muscat looked for an association between mobile phone use and a type of brain cancer called glioma. Muscat did not find evidence that cell phone use increased people's risk of this type of brain cancer generally. He did, however, observe an increase in one rare kind of glioma, which FDA scientists say might have occurred by chance. Interestingly, with increased hours of mobile phone use, the risk tended to decrease rather than increase as might be expected.

A few animal studies have suggested that low levels of RF exposure could speed up development of cancer in laboratory animals. In one recent Australian study, for example, mice genetically altered to be predisposed to developing lymphoma got more than twice as many of these cancers when exposed to RF energy compared to mice not exposed to the radiation.

A large number of laboratory tests have been conducted to assess RF's effects on genetic material, looking for mutations, chromosomal changes, DNA strand breaks, and structural changes in blood cells' genetic material. One kind of test, called a micronucleus assay, showed structural changes in genetic material after exposure to simulated cell phone radiation. The changes occurred only after 24 hours of continuous exposure, which experts say raises questions about this test's sensitivity to heating effects and whether that sensitivity could be solely responsible for the results.

In one study of brain function and RF exposure, two groups of 18 people were given cognitive function tests while being exposed to simulated mobile phone signals. No changes were seen in the ability to recall words, numbers, or pictures, or in spatial memory, but among the 20 variables compared, there was one standout observation: The participants were actually able to make choices more quickly in one visual test when they were exposed to the signals.

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.