Friday, March 13, 2009

Short exposure to mobile phone radiation kills brain cells in rats

Short exposure to Mobile phone radiation - two hours - has been reported in 2003 to destroy cells in parts of the brain important for memory, movement and learning, and could possibly conceivably premature onset of illnesses such as Alzheimers - although we have no evidence of a similar effect in humans. Lund University Hospital Professor Leif Salford says mobile radiation allows harmful proteins and toxins through the brain barrier in rats. He also has found significant degree of damage to brain neurons in adolescent rats.

He said: "If this effect was to transfer to young mobile users, the effects could be terrifying. We can see reduced brain reserve capacity, meaning those who might normally have got Alzheimer's or dementia in old age could get it much earlier." He used rats aged 12-26 weeks because their brain cells were still developing in a similar way to teenagers and younger children. They were exposed for just 120 minutes to radiation equivalent to typical intensive mobile phone use. Sections of rat brains were examined 50 days after exposure. Animals exposed to medium and high level radiation had many dead neurons in their brains - totally different from rats which were not exposed to radiation. (published Feb 2003).

The trouble is that similar studies cannot be carried out in humans because mobile phone radiation exposure would have to be followed by brain biopsy which can cause epilepsy later, permanent brain damage, stroke or even death. We can only get the answer in humans by doing studies on brain tissue of teenagers killed in accidents, and comparing brain tissue of heavy, medium, light and non-users of mobile phones. In addition, we have yet to see other centres replicate his work.

Dr Kjell Hansson Mild in Sweden studied radiation risk in 11,000 mobile telephone users. Symptoms such as fatigue, headaches, burning sensations on the skin were more common among those who made longer mobile phone calls. At the same time there are a growing number of unconfirmed reports of individuals whose health has been affected after chronic, frequent use of mobile phones, presumably from radiation effects on cells. See below for SAR data on mobile phone radiation levels. Once again, for every study with a positive finding of effect on cells, there is another that has found nothing.

As I say, from a physician's point of view this is all rather difficult to interpret. The truth is that no one knows for sure, but it looks as though the health risks for an individual person with normal patterns of use are extremely low, almost non-existent. I still use a mobile phone, as do our teenage children, and my home has a wireless network as well as hands-free local handsets for landlines. The only steps we have taken are to mount the wireless LAN connection a few feet from where anyone sits, and to encourage our younger children not to spend their entire lives chatting away on mobiles - there are other reasons for that too such as homework and of course cost.

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As long ago as June 1998 the Lancet reported that radiation from mobiles caused an increase of blood pressure. Dr Braune and colleagues in Freiburg, Germany, attached mobiles to the right side of the heads of ten volunteers. The phones were switched on and off by remote control without the volunteers knowing - so that any radiation effect could be separated from the psychological effect of holding a mobile phone. Their blood pressure rose each time by between 5-10mm Hg, probably from an electromagnetic radiation induced constrictive effect on blood vessels from the mobile phones.

This level of increase would be more than enough to trigger a stroke or heart attack in someone at severe risk, but is harmless in the vast majority of people. This was the first firm evidence that mobile phone radiation could directly alter cell function in the human body. But what about longer term radiation effects of using mobile phones? Could mobile phone exposure trigger cancer? Birth defects? What about the health risks not just from mobile phones but the transmitter masts?

This work on human subjects follows other ealier mobile phone studies in animals suggesting that electromagnetic radiation from mobiles may cause brain tumours, cancer, anxiety, memory loss and serious birth defects. But different studies have contradicted many of these findings. As in so much of cutting edge science, there are real uncertainties about mobile phone radiation. Remember it has taken 30 years to work out the side-effects of oral contraceptives and even that is still debated. Here are some of the more negative reports.

An Australian study found that mice exposed to pulsed digital mobile phone radiation over 18 months had twice the risk of developing cancers. An American study found that learning and short term memory were impaired after 45 minutes exposure to electromagnetic radiation from mobile phones in rats. And other studies of electromagnetic radiation on pregnant mice suggest that high exposure to mobile phones can affect intra-uterine development, confirmed recently in chicks (double birth defects, see below). The effects of mobile phone radiation in human embryo development are unknown.

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