Cell Phones Are Safe, But Science May Never End the Debate
The impending move from 4G to 5G wireless networks represents a quantum jump that will make possible the transmission of the greatly increased volume of data necessary to keep self-driving cars separated and to power Virtual Reality and Augmented Reality applications, as well as the Internet of Things.
In the face of this seismic change, some members of Congress are demanding “proof” that the new technology will be “safe,” and some health advocates are calling for a moratorium on the rollout of 5G technology.
But science is unlikely to completely dispel concerns about 5G or to identify adverse effects, if there are any. Here’s why.
The question of the safety of exposure to radiofrequency (RF) emissions from cell phones has been marked by confusion and disputed science since this issue first arose in the mid-1990s.
The difficulty is due, first and foremost, to the fact that the type of radiation involved in wireless communications is in the range of radio waves, and these waves carry much less energy than ionizing radiation, such as X-rays and cosmic rays, that can break chemical bonds in DNA and lead to cancer.
Furthermore, there are limits, set by the Federal Communications Commission, on the amount of RF that cell phones can emit. The only known biological effect of RF at the power levels used in wireless technology is heating, and the FCC limits restrict heating. There are no known health effects below the level at which heating occurs.
Last week, Science Friday on NPR aired a segment on 5G and its possible health effects. The program’s host, Ira Flatow, interviewed two scientists who have done work in this area – John Bucher of National Toxicology Program (NTP) and Jonathan Samet, an epidemiologist and dean of the Colorado School of Public Health.
Bucher led the NTP’s large, ten-year study of 2G and 3G RF on rodents, the results of which were published last year. The study involved exposing thousands of rats and mice to RF for 18 hours a day (10 minutes on/10 minutes off) starting in utero and continuing throughout the course of their life. The power levels ranged from somewhat above to slightly below permitted levels. Unlike humans’ use of cell phones, the rodents’ entire bodies were exposed to RF.
Of the many tissues and organs that were examined when the rodents died or were sacrificed, the only observed tumor excesses were of glial cells in the heart and brain in male rats. No excess tumors were seen in female rats or in mice of either sex.
Some of the chief criticisms of the NTP results include the following:
· The small number of excess tumors could be due to chance;
· This possibility is increased due to the fact that excess tumors were only seen in male rats;
· The level and duration of exposure was much greater than what people experience even at the highest levels of cell phone use;
· Rodents exposed to RF actually lived longer than controls, who were not exposed
A fuller discussion of questions raised by the NTP can be found here.
In discussing the implications of the NTP results, neither Bucher nor Samet so much as considered the possibility that the positive results might be due to chance or to experimental error. Instead, when Flatow raised some of the criticisms, both scientists dismissed questions about the validity of the results, saying that “there are often inconsistencies” in animal studies and referring to the “usual quandary” of how to extend the findings of animal studies to humans.
According to Samet, the “bottom line” is that “effects were found.”
The lack of interest in looking critically at the findings is striking. Scientists shouldn’t just assume that their findings are meaningful and provide the basis for the next experiment. Findings must be probed, validated, and extended to see whether they stand up. In fact, the past ten years have witnessed a growing awareness that there is an epidemic of false research findings.
Contrast the uncurious “effects were found” position of Samet and Bucher with that of Kenneth Foster, a professor of bioelectrical engineering at the University of Pennsylvania, who studies the interactions of non-ionizing electromagnetic energy, including radiofrequency energy, with biological systems. In response to questions from me, Foster made two points about the NTP results.
First, he put the highlighted findings in perspective by underscoring the large number of analyses, “None of these results are corrected for multiple comparisons, …, and I am sure that correcting for that would yield a totally negative study.”
Second, he addressed the biological mechanism involved in subjecting test animals to RF energy, “Another consideration is that the increase [in tumors] occurred at the highest exposure levels (6 watts/kg whole body absorption). That is well above the level at which rats show behavioral thermoregulatory responses. The exposed rats maintained their core body temperatures (although some rats increased core temperature by a degree or so at 6 watts/kg exposure), but that does not preclude significant metabolic changes due to the imposed heat load. The metabolic rate of adult rats is about 6 watts/kg, i.e., comparable to the highest exposure levels used.”
Foster concluded, “So there are three possibilities: (a) a statistical fluke; (b) a real effect due to thermophysiological changes; or (c) a direct effect of RF energy. Occam's razor suggests that the first two are more likely.”
When asked how scientists can address the health effects of 4G and 5G exposure, Bucher mentioned a much smaller rodent study in the planning stages that would use a flexible design to explore the effects of the new technology and “clever observational studies” that would use “biological markers” to explore mechanisms in humans. However, he acknowledged that studying the effects of 4G and 5G would be difficult.
The idea that the unexplained NTP findings provide the basis for directing new studies of new generations of technology seems like blinkered thinking. In fact, for twenty-five years, the study of the effects of cell phones has been marked by giving much more weight to the occasional positive results, while ignoring the evidence that argues against the likelihood of adverse effects. This evidence includes: the weakness of the energy involved, and the lack of a known mechanism by which cell phone energy could induce or promote cancer; the lack of convincing associations in epidemiologic studies; the failure of animal experiments to show an effect; and, perhaps most important, the absence of any increase in the incidence of brain cancer in populations with high-quality cancer registration, such as the Nordic countries, over the past two decades, in spite of the dramatic growth of cell phone use.
One thing that’s certain is that “more studies” will be done. Foster told me, “The main effect of the NTP study is that it will trigger another $20M or so in added research. Already two Asian countries are talking about repeating the study.”
But, by the same token, there is little reason to believe that these new studies will resolve the fears and uncertainties surrounding the ever-evolving wireless technology.