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A major study into the safety of
mobile phones has concluded that they may affect the health of people who use them. Research carried out
by scientists in Finland suggests that microwaves from cellphone handsets damage cells in the blood-brain
barrier -- the vital membrane that protects our brain from poisons.
The two-year study, by the
respected Radiation and Nuclear Safety Authority in Finland, is the first to show that mobile phone microwaves
can damage human tissue.
The research found that blood
vessel cells cultured in the laboratory behave abnormally when bombarded with emissions, even when they are
within safety guidelines for cellphones.
The Helsinki team, led by Professor
Darius Leszcynski, exposed human endothelial cells -- which line blood vessels -- to radiation at 2 watts per
kilogram, the maximum level permitted under international safety standards for mobile phones. After an
hour’s exposure Leszczynski identified changes in about 400 proteins inside the cells, brought on by a
response to stress known as phosphorylation. One of the altered proteins was HSP27, which is crucial to
the blood-brain barrier and may make it more permeable when damaged. |
The blood-brain barrier is the vast
array of minute capillaries which deliver oxygen and nutrients such as glucose and amino acids, and remove
carbon dioxide and waste from the brain tissue.
Drugs, including alcohol, can
also sneak through the barrier, causing intoxication. Exchange takes place in the capillaries because
their walls are composed of only one layer of very tightly-packed porous endothelial cells, which allow solutes,
but not larger molecules such as proteins, to pass through. HSP27 may cause the endothelial cells to
shrink, loosening the barrier. It may also interfere with the cycle by which cells “commit suicide” at
the end of their natural lives. In theory, that could promote cancer. |
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Speaking to journalists Leszcynski said: “The blood-brain
barrier has been shown to be affected by radiation in animal studies. There is a lot of uncertainty about
whether this happens in humans. We have shown some biological effects.”
He stressed that modern mobile phones emit much lower levels of
radiation than that involved in the experiment, and any effects would be less pronounced: “At the moment,
there is no scientific support for introducing any sort of limitation either on use of mobile phones or setting
new safety limits. There is no need because we don’t have any science to support it. All the
guidelines in place at the moment are fine.”
The findings which is published in the current issue of the journal
Differentiation will be presented at a conference in Quebec, Canada, next week.
ENDS
Sources: Differentiation, Finnish Radiation and Nuclear Safety
Authority |
