Cellphones are safe to use, so long as you have a relatively new, that is digital, phone (not the old, clunky analog devices) and you stay at least three feet away from from patients and medical devices such as pacemakers, ventilators, and electrocardiogram machines that may be near them.
In the bad old days, — like five years ago — researchers at the mayo Clinic in Rochester, Minn. found that with older phones and older medical equipment, there was a troubling 7.4 percent rate of :clinically significant interference.” The radio frequency energy emitted by the old phones was picked up as electromagnetic interference by the machines, sometimes skewing readings, said, Jeffery L. Tri, a Mayo Clinic electrical engineer.
But a new Mayo study published in October found that, with newer phones and equipment, the rate had dropped to 1.2 percent. “What’s gotten better is that the phones themselves have changed and medical devices have been ‘hardened’ so there is less chance of radio frequency energy causing interference at these power levels.
Dr. John Halamka, chief information officer for the Harvard Medical School and Beth Israel Deaconess Medical Center, noted that older cellphones were 3-watt devices, “so they generated a lot of power.” The new, digital ones put out only “a small fraction” of that — 50 milliwatts.
In other words, Halamka said. “we believe the use of cellphones in hospitals in 2005 is safe as long as you understand the guideline of three feet.”
But some hospitals, like Newton-Wellesley, still keep the warning signs up. “It’s safe to use some cellphones in some parts of the hospital,” said spokesman Brian O’ Day, “But we’d rather err on the side of caution when it comes to someone’s health.