Do Cellular Phones Cause Cancer?

When a man appeared on a national talk show in 1993 and claimed his wife had developed brain cancer from using a cell phone, the public reacted with fear. While extreme exposure to radiofrequency radiation can have serious health effects, there is no evidence that the low levels of radiofrequency radiation emitted by hand-held cellular phones cause cancer, according to a review of studies by a Medical College of Wisconsin researcher.

Studies with laboratory animals have sometimes indicated that even small levels of radiofrequency radiation exposure could be harmful, but all of these studies had major flaws, according to John E. Moulder, PhD, Professor of Radiation Oncology at the Medical College. Radiofrequency radiation and its relation to cancer is his specialty.

Dr. Moulder examined studies that claimed radiofrequency radiation exposure had genotoxic effects -- directly damaging DNA as most carcinogens do -- or epigenetic activity, which causes cancer rates to increase without directly damaging genetic material.

Dr. Moulder said: "The epidemiological evidence for an association between radiofrequency radiation and cancer is weak and inconsistent, the laboratory studies generally do not suggest that cell phone radiation has genotoxic or epigenetic activity, and the connection between a cell phone's radiofrequency radiation and cancer appears to be physically implausible."

High levels of radiofrequency radiation exposure are dangerous, but are not relevant to the general public. For example, a soldier who is directly exposed to an operating military attack radar, or a contractor who climbs a radio transmitter tower that has not been turned off, risk serious effects, including burns, heat stroke and cataracts.

Whole-body radiofrequency radiation exposure, including some magnetic resonance imaging (MRI) scans, might cause problems for pregnant women because the fetus could heat up.

But even in the long-term, there are no particular indicators that suggest that using a cell phone will cause cancer. Technically, it is impossible to prove something is absolutely safe because more studies are always possible (and it is not possible to prove a negative). Moreover, today's cell phones are getting less and less powerful. Original hand-held portable telephones emitted 600 milliwatts while today's new digital PCS versions emit about 125 milliwatts. In fact, some new long-range cordless phones are far more powerful than cell phones. But this does not mean they are dangerous either.

For those individuals who remain concerned, Dr. Moulder recommends simply not using cell or portable phones or using them with a headset. In addition, because a modern cell phone broadcasts a stronger signal in areas of bad reception, cell phone users could avoid using their phones in areas of poor reception.

"Overall," Dr. Moulder said, "the evidence for a causal relationship between radiofrequency radiation from cell phones and cancer is found to be weak or non-existent."

The true danger of using a cell phone is that it distracts the user from a potentially dangerous task, whether it be driving a car, riding a bike or rollerblading. Numerous studies, said Dr. Moulder, have proven the danger of using cell phones in these situations.

For more information about Dr. Moulder's work, visit the Medical College of Wisconsin General Clinical Research Center Web pages.

MCW Health News presents up-to-date information on patient care and medical research by the physicians of the Medical College of Wisconsin.