Oct. 27, 2009 -- Early research suggests that wearing a cell phone on your hip may weaken the area of the pelvis widely used for bone grafting.
Using an X-ray technique used in the diagnosis and monitoring of patients with osteoporosis, researchers from Turkey's Suleyman Demireli University measured pelvic bone density in 150 men who regularly carried their cell phones attached to their belts.
The men carried their phones for an average of 15 hours each day; they had used cell phones for an average of six years.
The researchers found that bone mineral density was slightly less on the side of the pelvis where the mobile phones were carried than on the side that was not in contact with the phones.
The difference was not statistically significant and fell far short of approaching bone density reductions seen in people with osteoporosis.
But the findings raise the possibility that bone density could be adversely affected by electromagnetic fields emitted by cell phones, researcher Tolga Atay, MD, and colleagues note in a news release.
The study appears in the September issue of the Journal of Craniofacial Surgery.
It is among the first to suggest that close-proximity, long-term exposure to mobile phones may weaken bones, and the researchers stress that their findings are preliminary.
Frank Barnes, PhD, who is a distinguished professor of electrical and computer engineering at the University of Colorado, Boulder, tells WebMD that he knows of no other research examining the impact of cell phone exposure on bone density.
Barnes chaired a National Research Council (NRC) committee asked by the FDA to report on the research evaluating cell phone safety.
He points out that electromagnetic waves have been used experimentally to promote bone growth in people with broken bones that would not heal.
Electromagnetic wave treatment has also been found to strengthen bone in research involving patients with osteoporosis.
But Atay and colleagues point out that these studies involved very low electromagnetic wave frequencies of 15 to 72 Hz, while cell phones typically have frequencies of between 900 to 1,800 MHz.
The NRC committee chaired by Barnes published its report in January 2008, concluding that more research is needed to determine if cell phone use is associated with any long-term health problems.
"It is clear that using a cell phone poses no immediate risk," Barnes tells WebMD. "But it may take many years to have the answers we are looking for with regard to long-term risk."
Barnes says there has been very little research aimed at determining whether radiofrequency waves emitted by cell phones pose a risk to specific groups, such as children, adolescents, and pregnant women and their fetuses.
More than 500 studies have been published examining the impact of cell phones on health, with the bulk of the studies exploring whether cell phones cause cancer. The results have been conflicting.
The publication of one of the largest studies ever to explore cell phone use and cancer is expected soon.
The Interphone study, which began over a decade ago and involved cell phone users in 13 countries, was designed to determine if cell phone use causes brain tumors.
But Barnes says this question may not be answered for several decades.
"People have only been using cell phones heavily for about 10 years," he says. "If the latency period [for cancer] is 30 or 40 years, the data we have now isn't going to tell us much."