From Laptop.com. . .Article Comments Share Print by Peter M. Ferenczi on March 11, 2008
Most of us don’t consider our wireless gadgets a health risk. But while neo-Luddites and tinfoil-hat wearers have been sounding the alarm for decades, the safety of wireless signals is getting attention in circles that might make you take notice: The World Health Organization, the European Environmental Agency, and the British Health Protection Agency are all asking questions, not just about cell phones, but about lower-power signals such as Wi-Fi. Could the cloud of “weak” signals from Bluetooth, Wi-Fi, and Wireless USB radios really be the next asbestos? Where hard science, junk science, and politics come together, the signal gets choppy.
Signs and Symptoms
It’s a justified question. We’re all drenched in radio signals all the time, and people don’t seem to be keeling over, right? Well, kind of. Hundreds of thousands of people worldwide claim to suffer symptoms, ranging from itchy skin to fatigue and nausea, that they attribute to radio waves, including low-power emissions such as Wi-Fi. The condition is known as electrosensitivity, or electrohypersensitivity if the symptoms are particularly debilitating. “In Sweden, this is fully recognized as a functional impairment,” said Dr. Olle Johansson, associate professor in the department of Neuroscience at the Karolinska Institute in Stockholm. In a 2002 survey in California, 3.2 percent of respondents reported being “allergic or very sensitive” to being near electrical devices. According to Johansson, a Swedish survey reported electrohypersensitivity in 3.1 percent of Swedes. Johansson believes that radio frequency (RF) radiation may well be affecting us. “If you look at the research papers and boil down the knowledge, it says that very short exposures to very low levels, sometimes hundreds of thousands of times below the recommended exposure levels, still give effects that, from a human health point of view, could be devastating in the long term,” he said.
Johansson isn’t alone in his concern. He was among 31 researchers who drafted and signed the Benevento Resolution in 2006, calling on governments to take a number of precautionary steps to reduce RF exposures and inform the public on exposure levels from technologies like Wi-Fi and WiMax. He also contributed to the BioInitiative Report (along with the European Environmental Agency), a 600-page document proposing that conventional guidelines for RF exposure inadequately take into account the biological realities of how organisms are likely to react to RF radiation.
But don’t pull the plug on your Wi-Fi router just yet; the opinion of the scientific community is hardly unanimous. “We’ve all been exposed to TV and FM radio for quite some time,” said Dr. Michael Clark, science spokesman for the U.K. Health Protection Agency (HPA). “There isn’t hard evidence of adverse health effects.” That said, the HPA has launched an investigation to study Wi-Fi exposures in schools. Why? “I think it’s very similar to [the situation with] mobile phones ten years ago: When there’s a sudden increase in use, the proper thing to do is to get basic information about how much people are exposed to,” Clark said.
Yet for some, precautions are already warranted. Germany’s Federal Environmental Ministry has recommended that people minimize their exposure to Wi-Fi and other wireless signals by using wired technologies when possible. Proposed Wi-Fi deployments have raised controversies in schools. Canada’s Lakehead University has instituted a policy that restricts Wi-Fi in areas served by wired connections. “The only new deployment of Wi-Fi [since the decision] has been in student-controlled space. And students have the option of being exposed or not, as long as the location is appropriately posted and the radiation contained within the site,” said Fred Gilbert, president of the university.
Before trying to separate precaution from paranoia, a quick brush-up on what those wireless signals really are is in order. All radio waves are electromagnetic radiation—energy moving through space. Most of our short-distance data RF signals (Bluetooth and Wi-Fi) are in the microwave frequency band, the same range that microwave ovens use to heat food (this is why nuking a bag of Jiffy Pop can disrupt wireless networks in the vicinity).
But while an oven may blast food with 1,000 watts of microwave energy, a Wi-Fi access point transmits around 100 milliwatts, 10,000 times less.
Exposure guidelines such as those set by the International Commission on Non-Ionizing Radiation Protection are based largely on the assumption that cooking our heads is probably unhealthy, so human exposures should be kept below levels that create “thermal effects,” meaning heating up our tissues like a microwave oven would. Mobile gadgets don’t kick out enough energy to warm things up, so thermal effects aren’t a concern there.
“People have sat down and, based on thermal effects and model experiments not dealing with biology, concluded what’s safe,” said Johansson, who is critical of the guidelines. Researchers are also finding “non-thermal” biological effects, or effects in biological systems not caused by heating. These effects aren’t considered in the most widely applied guidelines, an omission that’s the focus of the BioInitiative report.
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