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June 9, 2000 VOL. 29 NO. 22 | SEARCH ASIAWEEK Controversy in the Air A series of mixed signals on cellphone risks By MARIA CHENG Until it became cool to walk around as if you were talking to yourself, William Tsang hated the strange looks he was getting when he was using his cellphone. But he has a greater aversion to getting a brain tumor. "That's why I put on this thing," says the 29-year-old Hong Kong lawyer, motioning to his hands-free set. "I heard that radiation from mobiles might cause cancer," he says, "so I thought I'd better be careful."
Is he over-reacting? Possibly. Plenty of mobile owners are perfectly happy to hold the latest nifty model to their ears. They add up to a growing army of about 500 million people worldwide, and some of its most aggressive battalions live in Asia (see chart). Out of this band has emerged a highly visible corps of hands-free devotees. To motorists, it's a useful accessory that allows them to talk without driving off the road. Niggling concerns that mobiles may dial up hidden dangers, however, have also propeled the switch. A Hong Kong University report released last month could add a few more converts. Radiation leaps to 20 times the normal level when calls are being connected on cellphones, says Professor Tso Man-yin, head of the science faculty's radioisotope unit, which conducted the study. Emissions during this power surge remain within prescribed global safety standards, she says, and there's nothing to suggest a direct link between mobiles and cancer. "But the possibility exists. We cannot say there is absolutely no relationship." That's why Tso advises consumers not to use mobiles excessively, and to hold the device away from their heads while calls are hooked up. So hands-free sets would be just the thing for doubters. Consider then their dismay when recent product tests conducted by the Consumers Association in Britain found that two popular devices tripled the amount of radiation to the brain compared to ordinary cellphones. The earpiece wire apparently acts as an aerial, which channels radiowaves to the head. Users should not rely on such add-ons to reduce radiation levels, warns Which?, the association's magazine. The finding is "very worrying" for users, says Antonia Chitty, who wrote the report in April. "People who have been using the hands-free kits aren't getting the protection they want." Chitty concedes: "The balance of evidence at the moment indicates that emissions aren't a health risk." Most known radiation dangers occur at the high end of the electromagnetic spectrum, and include X-rays and gamma rays. This is ionizing radiation, which damages genetic material and disrupts cell function. The type of electromagnetic waves used in ovens and radar, as well radio and TV signals, occupy the lower end of the spectrum. Most scientists believe this non-ionizing energy isn't powerful enough to cause any harm. Still, non-ionizing energy sometimes induces nausea, blurred vision and even heart strain. Experiments conducted in the U.S. have shown that it can also cause the DNA of mice to mutate. But that's from exposure to extremely intense levels of non-ionizing radiation. Mobile phones emit very weak energy -- far lower than that given off by satellite stations or ovens. But what are the warnings that have been giving consumers the jitters? In a number of countries, safety guidelines are based on the assumption that the only risk from microwave signals is that they might cause living tissue to heat up. Recent research suggests, however, that there may be non-thermal effects from radiofrequency radiation. Scientists, for example, have reported changes in blood pressure and the permeability of the blood-brain barrier -- a physiological hurdle that prevents certain molecules from entering the central nervous system. For some, cancer worries rose when transgenic mice prone to tumors showed an increase in lymphomas after exposure to microwave radiation. Other reports record changes in neurotransmitters, chemicals responsible for carrying information between nerve cells, in animal brains. A study carried out by the European Research Institute for Electronic Components in Bucharest suggests that low-level radiation from mobiles can cause red blood cells to leak hemoglobin, the protein which carries oxygen around the body. A build-up of hemoglobin, the scientists say, can bring on heart disease and kidney stones. Cellphone makers insist that health fears are unfounded. "Allegations of possible links to harmful health effects suggested by some researchers are inconclusive," says Suguna Madhavan, a marketing manager at Nokia. "All our products fulfill the safety standards and limits set by public health authorities." At Motorola Asia-Pacific, Ken Joyner, the director of electromagnetic-energy strategy, says: "Safety is and always has been a top priority. We invest considerable time and effort in assuring that our products are as safe in use as they are sound in design." And that includes sponsoring independent studies into a wide range of health concerns such as the link between radiation and tumor development as well as DNA changes. In all cases, Joyner says, results have backed the general view that using cellphones "poses no known health risk." Indeed, separate studies (one in Britain, the other in Finland) last year found that people exposed to radiofrequency signals of mobiles were just a teensy bit quicker (15 milliseconds) at answering simple questions. So radiowaves improve your reflexes. A good thing, you might say. But some scientists see more disturbing implications. The researchers believe the fact that the emissions can affect brain activity shows that they affect biological function in some way. Of course, damaging effects observed in cell cultures and lab animals don't necessarily translate into harm in the human body. Studies reporting an increase in damage to DNA of rats due to radiofrequency radiation have not been replicated by others. "The power of these phones is so low that biological effects are implausible," says John Moulder, a professor at the Medical College of Wisconsin, who has studied the possible hazards of handphones since 1995. "Extensive laboratory studies [of cell and animals] have found no consistent evidence of biological effects." All the same, governments are moving to address public concerns. On the advice of an expert group of 12 scientists, Britain is now calling on parents to limit children's use of mobiles as a precaution. Its report said: "Children may be more vulnerable because of their developing nervous systems, the greater absorption of energy in the tissues of the head, and a longer lifetime of exposure." Their thinner skulls mean that radiation is able to penetrate more deeply into the head. Though there is no clear proof of health risks, the panel noted "some preliminary evidence that exposure may cause subtle effects on biological functions, including that of the brain." Britain also plans to impose tough rules on marketing mobiles to children and on where radiofrequency transmitters may be built. In Japan, officials want to make it mandatory for manufacturers to keep emissions from mobiles to two watts or less for each kilogram of the average user's weight (the U.S. standard is 1.6 watts). "For any new technology, we have to balance its potential risks with its benefits," says Hong Kong University's Tso. "Mobiles are relatively new, and there hasn't been enough time to really study all the effects on the body." Cancer, she notes, generally takes 10 years or more to develop." At the very least, too much gabbing on a cellphone is likely to give users more headaches. Replying to an editorial in the British Medical Journal last month, Professor Chia Sin Eng of the National University of Singapore writes that a survey of about 800 people in the Lion City found that the more handphones were used, the more frequent the pains became. Though mobiles aren't associated with central nervous system symptoms other than headaches, Chia believes more research should be conducted before stating that "the only established risk is of using one while driving." In other words, the jury's still out on the possible hazards of cellphones. At least until the World Health Organization completes an international assessment of the evidence in 2005. For devotees like Tsang, who doesn't think he could live without his mobile, the choice is limited: "I try to only use it when there's no other option." Write to Asiaweek at mail@web.asiaweek.com Quick Scroll: More stories from Asiaweek, TIME and CNN |
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