HEALTHWATCH
Mobile menace
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How safe is it to use mobile phones? Dr. U.S. SRINIVASAN tries to find out.
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BIJOY GHOSH
No Final Answer: Are mobile phones dangerous?
"DO mobile phones cause brain tumour? Are they harmful to health?" These questions are constantly being asked even as mobile phones revolutionise the concept of communication.
How do mobile phones work? They emit electromagnetic radiation called low intensity pulsed microwave radiation. Can this interfere with biological systems?
Specific Absorption Rate (SAR) measures the rate of radio energy absorption in the body tissue. The SAR limit recommended by the International Commission of Non-Ionising Radiation Protection is 2 Watts/kilogram (W/kg). Most mobile phones emit radio signals at SAR levels between 0.5 and 1 W/kg. Of late, third generation phones that emit higher rates of radiation are being marketed. (December 21, 2004 study by Britain's National Radiological Protection Board (NRPB), an independent advisory group).
Reactions
Initial reports said that mobile phone radiation had some minor effects on the human body and caused headaches and nausea. Later, it was said that they affected the brain and could cause memory impairment. But the experts failed to consider the negative biological effects of exposure to long-term low intensity pulsed microwave radiation that the phones emit. Our bodies, especially our brains, are extraordinarily sensitive receptors of EMF radiation. (Dr. Mercola in an article in the Lancet).
To find out if use of mobile phones causes tumours, researchers studied the medical records of 1600 patients who had used mobile phones for up to 10 years before being diagnosed. They found that the more mobile phones were used and the longer they were used, the higher the risk of brain tumours.
Researchers also found that spending more than an hour a day on the mobile phone increased the risk of a type of tumour called acoustic neurinoma by 30 per cent. This tumour arises in the nerve responsible for hearing in the brain and can lead to deafness in one ear. They also found that the tumour was on that side of the head to which the user held the phone.
Research
But this tumour has occurred earlier too, so how can we conclude that the tumour is caused by mobile phones? Researchers then found that the incidence had increased from one in 1,00,000 in 1980 (before the advent of mobile phones) to one in 80,000 today. (International Journal of Oncology, February 2003, The Times (London), December 28, 2000)
The Reflex study conducted by 12 research groups in seven European countries and coordinated by the German research group Verum looked at the effect of radiation on human and animal cells. They found that after being exposed to radiomagnetic fields between 0.3 and 2 W/kg, cells showed a significant increase in single and double strand DNA breaks i.e. the basic gene that contains the DNA itself is damaged. The cells could not always repair this. This implied that there was damage for the future generation of cells. The change led to a genetic mutation producing cells different from the normal existing cells. The conclusion was that radio waves from mobile phones could harm body cells and damage DNA in laboratory conditions but that did not prove that mobile phones were a risk to health. It was also stated that more research was needed to see if effects could be found outside labs.
Research groups also felt that children may be more vulnerable since, with a developing nervous system, they may have a greater absorption of energy and a longer lifetime exposure. (Britain's NRPB)
Where does that leave us? There is still no final answer to the million-dollar question "Do mobile phones cause brain tumour?" But we can take precautions: Use text messaging for communication and use low SARs phones for a short time. Also keep pace with the new technology and replace obsolete ones.
Acoustic neurinoma is amenable to surgical resection resulting in a complete cure if detected at an early stage and if the tumour size is small. However, even after the surgery there may be hearing impairment on that side. (Neurosurgery, editors Robert H. Wilkins, Setty Rengachary; published by McGrawHill)
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