|Back To Previous Page|
|Print This Page|
Australia's per capita ownership of mobile phones is one of the highest in the world, but just what are the risks, if any?
The jury is still out on this question, but there is growing scientific evidence to suggest that more research is needed before concerns about safety can be dismissed.
Australians are enthusiastic users of mobile phones. We have one of the highest take-up rates in the world on a per capita basis. There are 4.5 million mobile phones now in use in Australia, but the number of people using those phones is higher, as businesses and families often share one device.
Both digital and analogue mobile phones emit radiofrequency electromagnetic fields, although the digital fields are more powerful. It is these emissions, similar to those emitted by mobile phone towers but much stronger, that are being seen as a possible cancer risk.
Independent medical consultant and former Telstra chief medical officer, Dr Bruce Hocking, is concerned by the number of complaints he has received from mobile phone users. He presented the results of a study of neurological symptoms in 40 mobile phone users at an Auckland conference in May, noting that headaches radiating from the side of the head nearest the phone was the major complaint. Blurred vision and nausea were also reported.
Studies so far have only been able to cautiously conclude that more research is necessary before any substantive statements can be made regarding health risks to humans. The most recent and significant study into the risks of using digital mobile phones was conducted in Australia and published in the American journal Radiation Research in May. It takes the first steps towards finding out just what the potential risks are, and provides a model for future research, said its authors. It found an increased risk of lymphoma in mice after prolonged exposure to radiofrequency electromagnetic fields (RF fields).
The four-year, Telstra-funded study used 200 mice that were genetically predisposed to developing lymphomas. Half of these mice were exposed to radiofrequency electromagnetic fields, mimicking a digital phone's 900MHz emissions at a handspan distance. The other 100 were not exposed.
In 18 months, 43% of those exposed developed lymphoma, while 22% of those not exposed developed lymphoma. That is, exposure to RF fields increased the incidence of tumours from a spontaneous rate of 22% to 43%.
While the study itself should not be interpreted as meaning mobile phones are adverse to your health, it does prove that exposure to phone emissions could enhance the chances of lymphoma. The extent of this effect is still unclear, said researchers.
"Our study found strong evidence of some tumour-enhancing effect with radiofrequency exposure," said Alan Harris, one of the report's authors and senior research fellow at the Walter and Eliza Hall Institute of Medical Research. "The uncertainty relates to the energy dose absorbed by mice compared to the human head or other parts of the body."
While the study was designed as much as possible to mimic the fields emitted by a GSM handset, the 'tricky physics' of just how different biological objects absorb energy (how much, how deeply, and so on) remains a problem.
The scientists concluded that more research was necessary before any conclusions could be made about the possible risks associated with the use of mobile phones. "The study suggests such exposure can increase the frequency of tumours, but we don't know to what extent or at what exposure doses," said Harris. More focused research was needed to resolve the issue concerning human versus mouse absorption of energy.
So what's next?
"The first priority should be to get independent confirmation of our results and to test the effects of varying exposure doses," said Harris. "The second would be to test whether similar results can be obtained in experimental models involving other kinds of cancer."
Another of the scientists involved, Professor Tony Basten, executive director of the Centenary Institute of Cancer Medicine and Cell Biology, suggested that such research would take at least three years once it began. Then perhaps a decision could be made on changing emission standards if necessary.
Further research could be funded by the $4.5 million set aside by the federal government for research on low-frequency electromagnetic fields. However, Harris said this money, to be spent over five years and managed by the National Health and Medical Research Council, was insufficient. To undertake a dose-response curve professionally would cost well over $1 million alone, he said. He added that for it to be an internationally believable and responsible study, Australia would need to invest in a larger and more elaborate exposure facility.
Dr Hocking suggested anyone concerned about adverse symptoms from using a phone should see their local GP to discount any other causes. If the mobile phone were still under suspicion, he said users could use the phone less for calls, use it more as a pager and return calls on a normal phone or using a hands-free mobile phone.