Newly-published research suggests that mobile phones can reduce the mineral content of the bones they hang out around.
Researchers at the the National University of Cuyo, in Mendoza, Argentina, looked at that strange breed - men who wear mobile phones on their hip. They discovered evidence to suggest that the proximity of the mobile phone caused a reduction in bone mineral content (BMC) and bone mineral density (BMD) in the men who wore the phones over a 12-month period, compared to a control group that didn't.
According to an abstract from the study to be published in the Journal of Craniofacial Surgery, wearers of a mobile phone had "significantly lower right BMD at the trochanter and significantly lower right BMC at both trochanter and total hip".
None of these differences were found in non users, the study notes.
Non users had a higher BMC at the right femoral neck (at the top of the thigh). The right-left difference in femoral neck BMD of non users was marginally non-significant. In users, there was no femoral neck right-left difference of BMC at the femoral neck. Right-left asymmetries in femoral neck BMC were significantly different between both groups, the study notes.
Study leader Dr Fernando D Sravi writes: "The different patterns of right-left asymmetry in femoral bone mineral found in mobile cell phone users and non users are consistent with a non-thermal effect of electromagnetic radio-frequency waves not previously described."
The study measured BMC and BMD in the left and right hips of two groups of healthy men - 24 who did not use cell phones and 24 who carried their cell phone on their right hip, for at least 12 months.
According to the researchers, few studies have looked at whether electromagnetic fields emitted by cell phones could affect bone mineralisation. They suggest that with rapid uptake of mobile phones, any significant effect on BMD could have a substantial effect on the osteoporosis rate in the population.
Osteoporosis is a systemic skeletal disease characterised by low bone mass and microarchitectural deterioration that leads to increased bone fragility and increased risk of fracture .
Dr Sravi says more research is needed to follow up his study, particularly in women, who generally have higher rates of osteoporosis, and children, who may have a long life of mobile phone use ahead of them.
Sravi writes that, while the actual energy emission by modern mobile cell phones is well below the limits set by current standards, precluding significant thermal effects, a growing body of evidence suggests that non-ionizing electromagnetic radiation in the frequency range of mobile cell phones may cause non-thermal biologic effects. Many of these non-thermal biologic effects "might be relevant for human health," the study notes.