Friday September 21 5:33 PM ET

Mobile Phones May Do Harm by Speeding Up Brain

By Lucas van Grinsven

LONDON (Reuters) - Mobile phones may cause damage to health by speeding up the brain's response times, a British scientist told a conference on Friday.

As consumer concerns mount that prolonged mobile phone use could lead to problems ranging from headaches to tumors, a recent study showing an alarming rate of brain cancer in some cell phone users is helping swing scientific opinion in Britain.

Dr. Alan Preece, head of biophysics at Bristol Oncology Center, is among a group of scientists becoming increasingly convinced that radiation from cell phones triggers chemical processes in the body that may be harmful.

Six separate studies now indicate that response times speed up when people are exposed to radio frequency (RF) signals from mobile phones. ``Perhaps we now have to accept there is an effect on the brain,'' Preece told a London conference on the health risks of mobile phones.

``The response time has improved because of stress proteins, which are switched on by a gene. This needs further research. The chronic exposure to radio frequency signals might well have a detrimental (health) effect.''

Stress proteins are produced when body temperature rises, but Preece and other scientists said they can also be released purely as a result of RF signals, when body temperature is normal.

Other research from Sweden and Switzerland has indicated that radiation from mobile phone calls disturbs sleep.

In a study not yet published in scientific literature, Swedish professors Lennart Hardell and Kjell Hansson Mild found that people who had used analog mobile phones for up to 10 years had a 26% higher risk of brain cancer than a ``control'' sample of patients.

The study has unsettled many scientists--even though it is based largely on a previous generation of mobile phones, many of which were installed in cars with aerials on the roof, and which emitted signals continuously, unlike the latest, digital phones.

``One can no longer go around saying there is no link (between cell phone use and health effects),'' Preece said.

``Without question, there is a biological threat,'' agreed James Lin, professor of Bioengineering and Electrical Engineering at the US University of Illinois. ``The question is how hazardous mobile phone use is.''

But Lin said there were as almost as many studies purporting to show a biological impact from mobile phone use as studies that indicated the opposite: ``Our understanding is still evolving. We need to have a much larger database.''

He noted that it takes nearly a decade for most brain cancers to develop--longer than the period of use covered by most studies.

The World Health Organization (news - web sites) (WHO) said last week that more research was needed before damage to health could be ruled out.

However, Elisabeth Cardis, chief of Radiation and Cancer at the WHO's International Agency for Research in Cancer, told a conference in Finland that any possible risk was small.

Last year, a British government-sponsored scientific inquiry concluded that while there was no evidence of a danger to health, it would be wise to discourage children from using mobile phones, because they were more susceptible to radiation.