Radiation from a mobile phone has disrupted the structure and biochemical characteristics of an important enzyme found in the central nervous system.

The increased use of mobile phones has raised the question of adverse health effects induced by exposure to their electromagnetic fields, especially among the young. But very little hard evidence supporting the perceived dangers has been presented. Now, Italian researchers have shown that the radiofrequency transmissions affect an enzyme key to the central nervous system.

Mario Barteri and colleagues from the University of Rome studied the response of acetylcholinesterase from the electric eel to dual-band irradiation from a commercial mobile phone in call-receiving mode. The phone antenna was positioned 5cm away from an aqueous solution of the enzyme during incoming phone calls of 1-50 minutes duration.

After 20 minutes exposure, gel permeation chromatography showed that much of the enzyme had been converted from its natural dimeric form into the corresponding monomer. This change was irreversible. The associated changes in enzyme activity, including a fourfold increase in the catalytic constant, were attributed to monomer formation, rather than any conformational changes. At the same time, the enzyme solution was converted to a soluble hydrogel.

Barteri claims the results are practically without experimental error because they were obtained by comparing native and irradiated samples of the same enzyme solution. The changes to the enzyme were observed in vitro and Barteri admits that they cannot be used for direct extrapolation to humans who use mobile phones, but they should help to verify these effects on other in vivo and in vitro systems.

Sakari Lang, who is responsible for electromagnetic field research at mobile phone company Nokia, is critical of the research. 'It is unfortunate that the authors have carried out such a large number of biochemical/physical-chemical measurements...with poorly designed exposure and missing dosimetry,' he said. He adds that more than 1500 peer-reviewed publications have reached the same conclusion: 'that there are no adverse effects established when radiofrequency energy exposures are below the internationally accepted guidelines.'

Steve Down