NEUROPSYCHOLOGY UPDATE - CELL PHONES AND CANCER: THE NEED FOR BASIC RESEARCH (2010)
Recent data suggests that extended use of cell phones may pose a risk for certain kinds of brain tumors. According to the World Health Organization, use of cell phones for 30 minutes a day over a period of 10 years may increase the likelihood of gliomas.
The conclusion was reached on the basis of the review of several studies. However, it has been commented (Parker-Pope, New York Times, 2011) that the primary study referenced by the WHO depended upon recall of cancer patients regarding their cell phone use over the previous 10 years. Obviously, this dependence on subjective recall may present problems. Hopefully, future studies can be done in which exact cell phone use by subjects is noted and recorded.
Very significantly, recent studies however have demonstrated that brain activity was increased by just 50 minutes exposure to cell phone radiation. This increased activity was measured by PET (Positron Emission Tomography) scan which measures glucose metabolism.
Most worrisome are recent reviews indicating that the increased brain activity in response to non-ionizing radiation will penetrate much further in the brains of children because their skulls are smaller and thinner (Dr. Black, a neurosurgeon at Cedars-Sinai in Los Angeles has commented on this). Brain scans suggest that the brains of 5-year-olds may be affected two to three times more extensively than those of adults. Clearly, even the possible risk of childhood leukemia suggests that children’s use of cell phones should be carefully monitored or eliminated.
Ionizing Versus Non-ionizing Radiation:
Ionizing radiation is radiation that has enough energy to remove an electron from an atom or molecule. This includes radiation from x-rays, CT scans, nuclear radiation and so forth. Non-ionizing radiation does not have enough energy to produce this effect, but it is capable of exciting the molecule.
Sometimes it has been suggested that because the effects of ionizing radiation on cancer are well-documented and well-known, it is not necessary to even consider the effects of non-ionizing radiation.
However, this is not the case. Many studies on non-ionizing radiation which were done 30 to 40 years ago pointed to the possible biological effects of this radiation (Frey, A., Thomas, J., Gavalas-Medici, R., Adey, W.R., Bawin, S., and Kaczmarek, L.). The government actively supported this research through DoD, ARPA, ONR, et al. However, by about 1980, the funding began to slow down and eventually almost came to a halt. There was a significant lobby against this research from the microwave industry and from the military-industrial complex. Neither of them wanted to acknowledge even the possibility of non-ionizing effects. Paul Brodeur summarized much of this in his New Yorker articles in 1989. This in turn elicited a huge outcry from engineers such as Susskind (Annals of the New York Academy of Science, 1979). Many engineers and physicists were convinced that biological effects were impossible because a “mechanism” had not yet been found. Presenting a paper on non-ionizing radiation effects in the 70’s was akin to lighting a match in the trenches during World War II. The outcry was huge.
The Russians were also pursuing studies on non-ionizing radiation at that time. Some of them visited our laboratory at UCLA and seemed convinced that we had found dramatic ELF effects on mind control. They thought that we were dissembling and hiding these effects from them. The “zapping” of the American Embassy in Moscow set off another flurry of charges and counter-charges and increased research activity. Fortunately, to my knowledge, no indications of non‑ionizing radiation exposure were found in the embassy.
Between the antagonism of some industries and the sometimes comic interchanges with the Russians, it was, at least, an exciting time to be a scientific investigator in this area.
Basic Research on Non-Ionizing Radiation:
Clearly, the question of cancer is important. However, the basic question of non‑ ionizing radiation effects on brain and behavior is also important.
Epidemiological studies such as those done on cell phones and brain tumors, are long-term, difficult and broad in their scope, but sometimes are not convincing. Consequences for other brain-behavioral effects need to be evaluated and studies of basic brain research done.
As early as 1976, an article was published in Nature (Gavalas-Medici and Day‑ Magdaleno, Volume 261, Number 0557, pages 256 to 259) on the effects of extremely low frequency, weak, non-ionizing electric fields on behavior of monkeys. A number of research decisions were made to ensure the possibility that effects of these mild fields could be observed. A subtle measure of behavior (inter-response times) was chosen, along with long exposure (4 hours) and a carefully controlled study balancing “no field” versus “field” conditions over 300 four-hour trials. The experimental room itself was shielded from ambient fields.
Because it seemed likely that the effects of the fields would be subtle (voltage levels were 1 to 56 volts, p-p, and frequencies were set at 7-60 Hz), measures of behavior that were known to be sensitive to low doses of drugs along with long exposure times were selected for the study.
The results of the Nature study indicated that there was a dose-dependent response with stronger fields producing larger behavioral effects for the 7 Hz and 45 Hz conditions, but not for the 60 Hz condition.
The results for the 7 Hz condition, which is a brainwave frequency, were quite systematic across voltage levels and suggested possible frequency sensitivity to ELF.
A later experiment at the UCLA laboratory (Adey, R., Bawin, S., and Kaczmarek, L.) pointed out the possible role of calcium efflux across the cell membrane in producing these behavioral effects.
Behavioral studies that followed the Nature publication sometimes used insensitive measures of behavior (e.g., defecation by mice in an open field). These studies were more or less doomed to failure (see Medici, R., “Where Has All the Science Gone?” in Steneck, N.H., editor, Risk/Benefit Analysis …, 1982).
More recently, Anastassiou, et al. (2011) based at Caltech, have published an article on electric field effects in Nature Neuroscience. In an in vitro study, these investigators were able to use microelectrodes in rat cortical pyramidal neurons that could detect the effect of mini-extracellular electric fields. These effects were especially evident at low frequencies (8 Hz). This again, of course, suggests sensitivity at biologically important frequencies. These fields could modify action potentials even at strengths as low as less than 0.5 μV. They described these phenomena as ephaptically-mediated changes in brain action potentials caused by the fields “lightly touching” the neurons.
This research – after an approximately 35-year hiatus- with new measuring techniques suggests that there are many broader questions that need to be answered vis-à-vis non-ionizing radiation. The fact that these results occur among neurons and may be frequency-sensitive raises questions about a whole new range of possible biological effects. Hopefully, in the rush to explicate the effects of cell phones on cancer, the basic research itself will not be neglected.