Interphone, cell phones, EP2, glioma, acoustic neuroma, brain tumor, cancer

Do Cell Phones Increase the Risk of Brain Tumors?

Do Cell Phones Increase the Risk of Brain Tumors?

© 2010 Dale H. Peterson, M.D.

In mid-June a news brief on the radio caught my attention. According to the report, the largest cell phone study ever conducted had proven that there is no relationship between cell phone use and brain tumors. My immediate thought was that something was amiss. Either I had not heard the report correctly, or something was terribly wrong with the study. Before I had an opportunity to investigate, a FDA Consumer Health Information article was released confirming that I had not misunderstood the report. In tall, bold headlines the FDA article proclaimed, “No Evidence Linking Cell Phone Use to Risk of Brain Tumors.” I was appalled. I had to look beyond the headlines; I needed to examine the study upon which the reports were based.

The study behind the reassuring headlines turned out to be the Interphone Study, which collected data on brain tumors and cell phone use between 2000 and 2004. Under the auspices of the World Health Organization, thirteen countries participated. Each collected its own data, but a common protocol was followed. After the individual studies were concluded the data was pooled to analyze the overall experience.

Amazingly, the data not only failed to show a link between cell phone use and the risk of brain tumors, it indicated that regular cell phone use actually protected the user from brain tumors. According to the Interphone study, regular cell phone users were twenty percent less likely to develop a brain tumor than non-users. The official conclusion read, “Overall, no increase in risk of glioma or meningioma was observed with use of mobile phones. There were suggestions of an increased risk of glioma at the highest exposure levels, but biases and error prevent a causal interpretation. The possible effects of long-term heavy use of mobile phones require further investigation.”

For a study in which data collection was completed in 2004 to await publication until 2010 is unusual. It suggests that there was difficulty interpreting the data and drawing acceptable conclusions from it. That very much appears to have been the case with Interphone. It has been reported that at least five drafts were circulated among the study authors before a consensus could be achieved. When the report was finally published, only a part of the findings were included in the analysis. Clearly, the data was not as conclusive as the FDA article and other news reports suggest.

The outcome of the Interphone study has been challenged by many scientists around the world. Many of them endorsed an International EMF Collaborative Report that was issued in August 2009. The report was called Cell phones and Brain Tumors: 15 Reasons for Concern. Science, Spin and the Truth Behind Interphone.

While many people were prepared and hoping for a report that would find that there is little or no increased risk of brain tumors from using cellular telephones no one expected the study to show a protective effect. To suggest that regular cell phone usage provides protection from brain tumors is so outrageous that the entire study was immediately called into question. It was quickly discovered that the study was accidentally or intentionally designed to demonstrate cell phone safety. The design was so effective in discounting cell phone tumor risk that it generated data suggesting that regular cell phone use protects people from brain tumors.

The results of the Interphone study are not consistent with what is known about the effects of radiation in the cellular telephone frequency range. In 1995 Doctors Henry Lai and N.P. Singh of the University of Washington demonstrated that a single 2 hour exposure to microwave radiation lower than the government’s “safe” level caused breaks in DNA. Their work was confirmed by Dr. Jerry Phillips. Nevertheless, their work failed to gain general acceptance.

Finally, in 2004, twelve research institutions located in seven European countries reported that they had proven conclusively that low level exposure to radiofrequency/microwave radiation causes genetic damage. In what is referred to as the REFLEX study, DNA damage and a change in the action of numerous genes and proteins were shown to occur with great certainty. In September 2005, Dr. Zhengping Xu of the Zhejiang University School of Medicine reported that his laboratory had also found a significant increase in DNA damage in cells exposed to RF/MW radiation.

The fact that radiation in the range generated by cellular telephones and cordless phones causes DNA damage is highly significant because DNA damage predisposes to cancer development.

Non-industry funded studies have, in fact, shown an increased risk of tumors on the side of the head that is exposed to cell phone radiation. The tumors generally begin to appear after ten years of cell phone use.

Since cell phone radiation has been shown to cause DNA damage and independent studies have found an increase in the number of brain tumors appearing after ten years of exposure, one must conclude that the Interphone study is fundamentally flawed. It is not possible for a technology that causes breaks in DNA to provide protection from tumor development.

To understand how the Interphone study led to the conclusion that cell phone use provides protection from brain tumors one must first consider the study design. The study did not compare cell phone users to non-cell phone users. It did not seek to identify the number of brain tumors appearing in cell phone users as opposed to the number of brain tumors developing in non-users.

Interphone was an interview-based, case-control study. A number of people with confirmed brain tumors were asked about their prior cell phone use. A similar number of people without brain tumors were also asked about their cell phone use. If someone with a brain tumor reported having used a cell phone it was a positive association, suggesting that cell phone use may contribute to the development of brain tumors. If someone without a brain tumor reported having used a cell phone it was a negative association, suggesting that cell phone use is safe and does not increase the risk of developing brain tumors.

This design resulted in what is perhaps the most glaring flaw in the Interphone study – a biased control group. When people without a known brain tumor were invited to participate in the study a whopping 41 % declined. Under normal circumstances the study would not have proceeded. With such a high percentage of potential control subjects refusing to participate the chance of the control group being random and unbiased is very low. There is good reason to believe that the control group was biased in favor of cell phone use since nearly 2/3 of those declining in one country stated that they did not use a cell phone.

At the outset the Interphone study consisted of two disparate groups: a tumor group with a random history of cell phone use and a control group that consisted primarily of cell phone users. Since the tumor-free control group contained a higher percentage of cell phone users than the tumor group, cell phone use appeared to provide immediate protection from brain tumors. This, of course, was not the case. The researchers had simply selected a “control group” highly biased in favor of cell phone safety.

A second flaw in the Interphone study was a short latency time, meaning that most people in the study had not been using a cell phone long enough for a tumor to appear. Studies that have demonstrated an increased number of brain tumors in cell phone users generally involve individuals who have been using a cell phone for ten years or longer. In contrast, 85 % of the people participating in the United Kingdom arm of the study had been using a cell phone for less than 5 years and 98 % had been using a cell phone for less than 10 years. Numbers of people with ten or more years of cell phone use were similarly low in other countries. While Denmark found two tumor cases after ten years of use, the number of people involved was too small for the results to be significant. Sweden, with a larger number of long-term users, found that twelve tumors were present in those with a ten year history of cell phone use. That number was highly significant, but since the numbers were diluted when the Swedish data was pooled with that of other countries the finding was not reflected in the final report.

Incredibly, the Interphone protocol did not consider the use of other electronic devices by people with brain tumors. Users of cordless telephones, walkie talkies, and ham radio sets were classified as “non-users” in the study. Since use of such devices conveys a risk similar to cell phone use the number of “non-users” with brain tumors was artificially inflated.

Another challenge with the Interphone study was the definition of an “average user.” Average cell phone use was defined as 2 – 2 ½ hours per month! An average cell phone user today spends at least 20 minutes per day on the phone, which translates into 10 hours/month. Many people spend significantly more time on their phones.

Perhaps the most diabolical aspect of the Interphone design was the requirement that participants be between the ages of 30 and 59. I say diabolical because teens and young adults are among the heaviest users of cellular devices. Research has shown that children and young adults are much more susceptible to radiation-induced tumors than older adults. A 2004 German study, for example, found a 35 % increased risk of brain tumor with analog cellular or portable phone use in all adults, but a 717% increase in adults aged 20 – 29. A 2006 Japanese study found a 217% increased risk in young adults compared to a 26 % increase in older adults.

Children are particularly susceptible to damage from cell phone radiation. Because their skulls are thinner and less dense and because their brains have a higher water content the radiation penetrates much more deeply and exposes a far greater percentage of the brain than in adults. By failing to point out that those most at risk for tumor development were excluded from the study the FDA and other news outlets have unjustifiably reassured parents that their children and teenagers are not at risk of developing brain tumors from cell phone use. They have led young adults to believe that it is perfectly safe to use cell phones on a regular basis, even though people in their age group were excluded from the study.

The Interphone study contained a built-in geographic bias. Only urban cell phone users were interviewed. This is significant because cell phones must increase their power output to access signals as they move farther away from a tower. Since towers are more widely spaced and signals are weaker in rural areas, rural users are exposed to greater radiation levels than those in urban areas where towers are closely spaced and signals are strong.

Inexplicably, only three tumor types were considered in the Interphone study and data regarding one of them was not included in the official report. Gliomas, meningiomas, and acoustic neuromas were considered in the study, but other tumor types were ignored. This is significant because a study released in 2009 reported a 2.1 fold increased risk of neuro-epithelial tumors in cell phone users. Although no human study has been completed to date, mice exposed to cell phone radiation are more likely to develop lymphomas.

Incredibly, the data regarding acoustic neuromas did not appear in the report; it was not even noted that acoustic neuromas had been investigated. Acoustic neuromas are benign tumors of the nerve that carries signals from the ear to the brain. Because the acoustic nerve receives the greatest radiation exposure when a cell phone is used it is the part of the nervous system that is most susceptible to tumor development. It is particularly interesting to note that five Northern European countries pooled their Interphone acoustic neuroma data in 2005 and reported an 80% increase in acoustic neuromas after ten years of cell phone use.

Interphone design flaws are seemingly endless. Tumors outside of the radiation field were classified as “exposed.” If only tumors on the side exposed to the cell phone had been considered the risk would have been much greater than that reported. 23 % of glioma cases were excluded because the participant had died or was “too ill to be interviewed”. This is inexcusable. A 2002 study found an association between cell phones and high grade gliomas, which are the most deadly, but not for less deadly low-grade gliomas. Therefore many of the tumors most likely to be associated with cell phone use were treated as though they did not exist.

Interview studies are among the least reliable because they rely upon the ability of subjects to recall past activities. Fortunately, billing records were available to document cell phone usage, at least in some countries. When compared to billing records, subject recall of cell phone use was found to be inaccurate. Light users tended to underestimate and heavy users tended to overestimate their cell phone use. Unfortunately, Interphone researchers chose to use subject recall rather than billing records when recording hours of cell phone use.

Given the incredible number of flaws in the study design and the outrageous finding that cell phones protect users from brain tumors the source of funding for the study is worthy of consideration. Mobile communications industry funding was critical to the study. It is hardly surprising that industry funded studies almost always find no evidence of cell phone related health risks, while independently funded studies almost always find evidence of health risks.

The Interphone study is perhaps more revealing when one looks at what wasn’t reported than when one considers the report itself. In an attempt to compensate for the bias toward cell phone use in the control group investigators chose to compare participants who had used a cell phone for two or more years with participants with less than two years of regular use. When this approach was used the results suggested that a glioma was 168 – 218 % more likely to develop in the longer-term users.

The data also suggested that exposure is cumulative over time, in the same manner that x-ray risk accumulates over one’s lifetime. When total exposure was considered, 1640 lifetime hours of use appeared to double the risk of a glioma on the side of the head to which the phone was routinely held. This goes far to explain the lack of risk found in the Interphone study. Since average users were exposed for less than 2 ½ hours per month it would have taken them 54 years to accumulate 1640 hours of cell phone use.

Someone using a cell phone 20 minutes daily, however, would accumulate 10 hours of use monthly and would reach 1640 total hours of exposure in approximately 13 years. A particularly alarming practice has emerged in recent years. Many teenagers are putting their cell phones on vibrate and placing them on or under their pillows so that they will be awakened should a friend call or text them in the middle of the night. Since a cell phone is always producing radiation while looking for signals someone sleeping on the phone can easily be receiving 8 or more hours of exposure every day. That level of usage would result in 1640 cumulative hours of use in less than seven months! It is true that the intensity of radiation is less when a phone is on stand-by rather than actively receiving signals, but this must be considered in the context of a teenager’s increased susceptibility to that radiation.

Contrary to the reassuring headlines issued by the FDA and others, the Interphone study did not conclusively prove that there is no link between cell phone use and brain tumor risk. Many chapters remain to be written before the full extent of the challenge becomes clear. Current attempts to downplay cell phone radiation risks were put into perspective by Chris Woollams M.A. Biochemistry (Oxon). Editor Integrated Cancer and Oncology News and CEO of CANCERactive, one of the endorsers of the EMF Collaborative report. He wrote:

“In a world where a drug cannot be launched without proof that it is safe, where the use of herbs and natural compounds available to all since early Egyptian times are now questioned, their safety subjected to the deepest scrutiny, where a new food cannot be launched without prior approval, the idea that we can use mobile telephony, including masts, and introduce WiFi and mobile phones without restrictions around our 5 year olds is double-standards gone mad. I speak, not just as an editor and scientist that has looked in depth at all the research, but as a father that lost his beloved daughter to a brain tumour.”

Cell phone technology is a fact of twenty-first century life. People will continue to take advantage of it, but it is irresponsible to ignore the risks inherent in its use. Precautions should be taken.

Use cell and cordless phones on the speaker setting whenever possible. Although few people are aware of the recommendation, most cell phone manuals warn against holding the phone within 5/8 – 1 “ of the body. Severely restrict the use of cell phones in children and limit their use in teenagers and young adults. Texting is advantageous, but cannot be said to be risk free because the phone is still being held. Under no circumstances should anyone keep a cell phone near their body while sleeping.

Finally, use protective devices. The current state-of-the-art is the E-Dot, which effectively manages all six of the primary cell phone frequencies. When the E-Dot is combined with a personal protective device, such as the EP2 pendant, safety of cell phone use can be dramatically increased. Don’t be misled by reassuring messages based upon flawed research. Take steps to protect yourself now rather than waiting for governmental agencies to determine that a risk exists. Given the FDA’s endorsement of the Interphone study it is unlikely to sound a warning about cell phone use for quite some time.