Studies to examine whether devices are hazardous to your health
BY SYLVAIN COMEAU (The Thursday Report, November 1994)
More than a year after the "cellular phone scare " some people are still looking twice at those handy, portable devices that they hold close to their heads every day. The scare started in January 1993, when a Florida man claimed on CNN's Larry King Live that his wife's fatal brain cancer had been caused or worsened by cellular phones.
That interview touched off a wave of fear among cellular phone users, a drop in manufacturers' stock, and a new round of research into the health risks of using cellular phones - despite the fact that numerous studies had already concluded that they were safe. Two Concordia professors of Electrical Engineering were enlisted in the renewed effort. Stanley J. Kubina and Christopher Trueman, working in the EMC (Electromagnetic Compatibility) lab, are trying to provide a computer model for calculating the energy deposited in the head and hand from cellular phones.
"The goal of our project is to try to get a handle on both the external and internal electromagnetic fields (EMF) distribution when you use a portable hand set," said Kubina. The two professors received the contract from the Communications Research Centre in Ottawa, part of Industry Canada. The contract is a small part of a larger programme with Health and Welfare Canada, aimed at attempting to predict EMFs from a variety of portable transmitters.
Safe exposure levels to EMFs have already been quantified, and the fields pxoduced by cellular phones are well below this level. They radiate 0.6 watts, while a device radiating less than .74 W at the frequency of cellular phones is considered safe. But the biomedical community is trying to determine whether long term exposure, even to these lower levels, is likely to cause subtle effects which have not yet been identified. Although the energy emissions from cellular phones have been estimated fairly well, the distribution within the human head is not well known. Our job is to find out what model ling methodology should be used."
Working with undergraduate student Mina Danesh, the re searchers match cross-sections of the head obtained from anatomy texts with magnetic resonance images to map the electromagnetic properties of the head and neck: Using computer work-stations, they have come up with the electromagnetic profile of 22 anatomical cross- sections in a textbook.
"By knowing the electrical proper ties of the tissue types, we will be able to do a calculation that will tell us how much energy penetrates into your head when you use a cellular phone. A lot of work has been done at a variety of frequencies, but we are looking now at the specific frequency of various cellular phones," said Trueman.
Kubina and Trueman are loath to make predictions about their study, which is now in its second year, but all the published studies they have seen so far suggest that ceIlular phones are safe. Trueman says that their work may address many other concerns besides the rumoured tumour connection. A good example is the effect of cellular phones on hospital equipment.
"The radiated signal might interfere with the operation of a heart/lung machine, for example. We are able to predict field strengths associated with cellular phones. If we extend the work we're doing, we might be able to predict how those field strengths couple with other equipment. So the computational ability we are developing can be applied to broader problems as time goes by."