It is an open question whether cellphones can cause cancer. This is a very large open question in a world with 4.6 billion cellphone users. The answer to such uncertainty is caution about extensive use, especially among children.
Panic is not, as doctors like to say, indicated. But neither is denial. Cellphone use in cancer patients was studied in 13 countries, including Canada, and the results were published this week in the International Journal of Epidemiology. The cancer patients were divided into 10 groups, by time of use. In the group that used cellphones the most – more than 1,640 hours over 10 years, or 30 minutes a day – the risk of developing the rare form of brain cancer known as glioma was elevated by 40 per cent. In the other nine groups, there was no extra risk; in fact, there were fewer cases overall in these nine groups than in control groups.
The study’s authors, led by Elisabeth Cardis, formerly of the University of Ottawa, say the findings are inconclusive. The elevated risk could have been caused by flaws in the study. No one is saying moderate cellphone use protects against brain cancer.
But these cellphone users are not representative of today’s world. Thirty minutes a day hardly constitutes the top 10 per cent any more. And some of those who use them more than that in Canada, and elsewhere, are children as young as eight or nine.
There’s another cause for concern, too. Cellphone users were studied only over the short term. “If it turns out that cellphones cause brain cancer, but in a 15- to 20-year time period before the tumours manifest themselves clinically, we would not have been able to pick this up,” says Jack Siemiatycki, the Canada Chair in Environmental Epidemiology at the University of Montreal.
The difficulty is that it’s hard to ensure safety before the evidence is in; and it’s hard to get the evidence before many people are exposed. “There are innumerable conceivable dangers to society, from genetically modified foods to pesticides to traffic problems and urban air pollution and global warming,” he says. Society doesn’t insist on halting progress until the dangers can be confirmed.
Our world is one of innumerable subtle dangers. Cellphone use may be one of them.
“Who would argue against being cautious with kids?” Dr. Siemiatycki says. “But you could say that about kids eating apples with pesticide residue or kids playing in parks where strangers might wander.” (We could and would say that.) “There are any number of things where parents should be cautious. I would be concerned if my 12-year-old son was using a cellphone for two hours a day every day by his head.”
It will be years until more conclusive research is available. Until then, add cellphones to the list of things to be cautious about, particularly in the hands, and near the developing brains, of children.
