Mobile phones are safe or at least that's what the industry would like you to believe. However, a number of new research projects around the world are coming up with disturbing results every possibility from brain damage to asthma.
These studies are so worrying that an expert group headed by Dr Alastair McKinlay of the National Radiological Protection Board (NRPB), has concluded that a lb20m, five year research program is warranted.
Drs Henry Lai and Narendra Singh at Washington State University observed that exposure of the brain cells of rats to low level microwaves (such as those found in microwave ovens and mobile phones) produced single and double strand breaks in DNA. With both pulsed and continuous wave radiation, they found an increase in both types of DNA strand breaks after only four hours of exposure (Intern J Radiat Biology, 1996; 69: 513-21). In humans, cumulative DNA damage in cells has been associated with cancer, Alzheimer's disease, Huntington's disease and Parkinson's disease.
In Australia, Dr Peter French, one of Australia's top cell biologists and director of the Centre for Immunology at St Vincent's Hospital in Sydney, has found dramatic reduction in brain proteins after irradiation of certain brain cells at mobile phone frequencies. After irradiating lab culture dishes of brain cells with antenna radiating similar frequencies to that of a mobile phone for 10 minutes a day for a week, certain skeletal proteins were reduced by as much as 70 per cent.
Most significantly, the researchers report that when the damaged cells were then cultured, the damage was never repaired, even after many cell generations.
Extending his research to lung function, Dr French then observed the effects of irradiation of mast cells in the test tube. These are the cells which deal with inflammatory responses. Under attack from an antigen such as dust, pollen, etc, they produce histamine, which constricts the bronchial tube and can trigger an attack of asthma.
French found that when such cells were irradiated at mobile phone frequencies for 10 minutes over seven days, they were so irreversibly damaged that exposure to an antigen would produce double the level of histamine than normal.
Then there are the many complaints lodged by users. In the UK, at least 100 BT engineers have rung an information service after being issued with phones, reporting headaches, poor short term memory and concentration, tingling, burning or twitching skin on the side of their face nearest the phone, eye problems including "dry eye", causing skin irritation with blinking of the eyelid, and buzzing in their ears, not only while actually using the phone, but also on waking up during the night.
Mobile phone manufacturers are increasingly replacing the original analogue (continuous wave) phone with the digital (pulsed) variety, mainly for performance and security reasons.
Both operate at between 800-900 Megahertz (MHz), but the digital ones emit a series of pulses. Research has shown that pulsed microwaves are far more biologically active and penetrative than continuous wave radiation of the same frequency and power level. Certain digital phones (Global System Mobile GSM and Personal Communications Network PCN) can operate at twice that frequency.
The current UK guidance on the safety of mobile phones by the NRPB is based on the Specific Absorption Rate (SAR), purely related to the heating up effect of this radiation, and aiming to prevent a rise in temperature of more than 2 to 4 watts (W) per kilogram (Kg) of body weight. However, "hot spots" of increased absorption can occur in various parts of the body, notably the head, depending on how you hold your phone and how small your head is.
Although the NRPB claims that a safe level of 10W/Kg for any 10 g of head tissue for both workers and the public, this is five times higher than the standard adopted by the rest of Europe's CENELEC (the European Committee for Electrotechnical Standardization). Digital cellular phones can emit considerably more than 2W/Kg (CENELEC's upper limit) into head tissue during their output pulses, but they are still deemed to comply because of the way that the power pulses are averaged.
Dr John Dennis, former assistant director of the NRPB, has admitted that the maximum power transmitted by mobile phones may need to be reduced for smaller head sizes.
If you must use a mobile phone, there are a number of ways to protect yourself. WaveGard, produced by 21st Century Concepts (lb30), a membrane made of the same insulating material as that used inside most ordinary phones, fits over the face of your phone and cuts radiation without interfering with its use.
Simon Best is editor of Electromagnetics & VDU News (PO Box 25, Liphook, Hants GU30 7SE).
(Harald Gaier is on holiday)