Can RF Protect Against Cancer?
Could cell phone radiation actually protect against brain cancer? Could it provide “vitamins for the brain”, as one irreverent epidemiologist suggested recently? Such a possibility, however improbable, is not as far fetched as it may sound.
This is not a new idea, but a new epidemiological , published yesterday in Neurology brings it back to mind. A team led by Chrisoffer Johansen of the Danish Cancer Society in Copenhagen was looking at whether cell phones could promote brain tumors. They did not see an increased risk but did find that users had fewer aggressive tumors than non-users and that, in general, the tumors that did develop were smaller among users. These so-called “regular users” had only a little more than half as many high-grade gliomas as expected. And the tumors were, overall, 25% smaller.
The Danish study is the second brain tumor study to appear from the project, which is being coordinated by IARC, the International Agency for Research on Cancer in Lyon, France. (In all, 13 countries are participating). Maria Feychting and coworkers at the Karolinska Institute in Stockholm published their results last month in the American Journal of Epidemiology (AJE). They also saw fewer gliomas among cell phone users, though this difference was not statistically significant. While the Danes observed the greatest protection for the high-grade gliomas, the Swedes found it for the low-grade, or less aggressive, gliomas.
Since the Karolinska appeared on March 15, there has been much talk among epidemiologists about the fact that practically all the observed risks were smaller than expected. Amazingly, in one table (Table 2) presenting approximately 50 different categories of cell phone use, the Swedes found only a single risk above unity. (A relative risk of one signifies no effect; without a protective or deleterious effect, one would expect to see the risks randomly distributed above and below one.)
Sam Milham, the well-known epidemiologist, was the first to spot the skewed distribution of observed risks in the Swedish paper and has pointed this out in a letter which will appear in the AJE. If cell phones are not protective, then there was some kind of bias in the way the Swedes collected their data. This could mean that the whole study is faulty, calling into questions their conclusion that cell phones are not linked to brain cancer. Indeed, Milham believes that the Karolinska study points to a brain tumor risk on the same side of the head as a phone is used.
What’s so tantalizing about these two sets of findings is that there is some experimental evidence to support a protective effect. More than 15 years ago, Steve Cleary of Virginia Commonwealth University in Richmond that microwaves could either stimulate or suppress the growth of human glioma cells exposed in a laboratory setting. The direction of the effect depended on the intensity of the radiation (see MWN, M/A90, p.5).
To be sure, Cleary used some relatively high power levels in his experiments, but Jerry Phillips, in some sponsored by Motorola, later showed a similar delicate balance between beneficial and deleterious effects in experiments on RF-induced DNA breaks. Phillips exposed human cancer cells at intensities that are common for users of cell phones (see MWN, J/F98, p.13).
A number of animal studies have also pointed to a protective effect The most notable of these was the run by the late Ross Adey for Motorola (see MWN, M/J96, p.8 and MWN, J/A96, p.11). In essentially all these cases, the protective effect has been due to digital or pulsed microwave signals. (For an overview of these studies, see MWN, S/O02, pp.12-13.).
The Danes and the Swedes who participated in the newly published epidemiological studies mostly used analog phones —at least in the early years. So one should be careful before jumping to any conclusions, but the results are provocative and should, we would hope, stimulate some interesting experiments. That is of course, if there is any money for follow-up work, always a dicey proposition.
The Danish group dismisses the possibility of a protective effect because of a lack of a “biologic plausibility.” But we would counter that many say that there is no biological plausibility for a detrimental effect.
Until we better understand what’s really going on, we are in uncharted waters and all possibilities should be considered. These two epidemiological studies and the others due from the Interphone project are only a preliminary picture of the long-term impact of cell phone use. So far at least, they have included only a small number of subjects who have used phones for ten or more years, with substantial air time over that period.
[It is worth noting that the definition of a “regular user” of a cell phone in all the Interphone studies is the use of a mobile phone on average once per week during at least six months.” Today, mobile phone companies routinely sell plans that allow thousands of minutes per month.]
The issues discussed here go far beyond hazard research. They raise fascinating questions about basic science that need to be answered. We shall see if anyone out there is interested in science or if this is really all about telling people that it’s okay to keep using their mobile phones.