Electromagnetic field (EMF), electromagnetic radiation (EMR)
All known cancer-inducing agents, including radiation, certain chemicals and a few viruses act by breaking chemical bonds, producing mutant strands of DNA. Not until the ultraviolet region of the electromagnetic spectrum is reached, beyond visible light, beyond infrared and far, far beyond microwaves, do photons have sufficient energy to break chemical bonds. Microwave photons heat tissue, but they do not come close to the energy needed to break chemical bonds, no matter how intense the radiation. —Dr. Robert L. Park of the American Physical Society (New York Times Oct. 1, 2002)
An electromagnetic field (also called electromagnetic radiation) is a region in space through which energy passes that has been created by electrically charged particles. EMFs are produced by such things as power lines, electric appliances, radio waves, and microwaves.
Many people fear that EMFs cause cancer; however, a causal connection between EMFs and cancer has not been established. The National Research Council (NRC) spent more than three years reviewing more than 500 scientific studies that had been conducted over a 20-year period and found “no conclusive and consistent evidence” that electromagnetic fields harm humans. The chairman of the NRC panel, neurobiologist Dr. Charles F. Stevens, said that “Research has not shown in any convincing way that electromagnetic fields common in homes can cause health problems, and extensive laboratory tests have not shown that EMFs can damage the cell in a way that is harmful to human health.”*
Nevertheless, it is impossible to prove that no study will ever find a significant correlation between EMFs and cancer or any other disease or disorder. No product can be shown to be absolutely safe for everybody. For example, a 2004 British Medical Journal article claimed to have found an inexplicable increase in leukemia in children living near power lines in England and Wales. The researchers wrote: “There is no accepted biological mechanism to explain the epidemiological results; indeed, the relation may be due to chance or confounding.” On the other hand, a 2003 study of women on Long Island found no causal connection between living near power lines and developing breast cancer. A single study does not prove there is or there isn’t a causal link between EMFs and cancer. We have to look at what is indicated by the preponderance of the evidence from all the studies.
There is also a strong contingent of folks hell-bent on proving this link, so it is likely that studies will continue to be done that support a contrary viewpoint. For example, a research team in Sweden found an increased risk for brain tumors in people who used cellular or cordless phones (2006). The study was a small one and assessed exposure by self-administered questionnaires. On the other hand, a large Danish study (420,000 mobile phone users) found neither long nor short-term mobile phone use to be associated with an increased risk of cancer (2006). The Danish study did not use the memories of the subjects to assess exposure; they analyzed data from mobile phone company records. Another small Swedish study found no increased risk of acoustic neuroma related to short-term mobile phone use (2004). The researchers thought that their data suggest an increased risk of acoustic neuroma associated with mobile phone use of at least 10 years duration. They don’t say how they measured exposure, but they note that “detailed information about mobile phone use and other environmental exposures was collected.” Other studies on laboratory animals have found effects from microwave exposure (2003; 2006; 2007). Some studies have collected data suggestive of possible harmful effects from cell phone microwave exposure, but they are too small to have ruled out chance or other causal agents (2006) or they have not been tested on in vivo cells (2004; 2006a; 2006b).
Recently, the alarm has been raised by some who fear that damage might be done to our brains from being exposed to Wi-Fi. Despite the fact that modulated frequencies bringing radio and television transmissions into our homes are stronger and more pervasive than the radio waves used by wireless networks, there has been little call to reduce radio or TV transmission. (The power levels for Wi-Fi are lower than that for cell phones, by the way. Photons of visible light carry more energy than microwaves and bombard us much more frequently than microwaves from such things as cell phones or wireless networks.)
One university president has banned Wi-Fi on his campus, claiming:
microwave radiation in the frequency range of Wi-Fi has been shown to increase permeability of the blood-brain barrier, cause behavioural changes, alter cognitive functions, activate a stress response, interfere with brain waves, cell growth, cell communication, calcium ion balance, etc., and cause single and double strand DNA breaks.*
What compelling scientific evidence he has for making such claims is not known.
Another school banned Wi-Fi after a classics teacher complained that it was making him physically ill. The teacher said that after Wi-Fi was in place:
I felt a steadily widening range of unpleasant effects whenever I was in the classroom. First came a thick headache, then pains throughout the body, sudden flushes, pressure behind the eyes, sudden skin pains and burning sensations, along with bouts of nausea. Over the weekend, away from the classroom, I felt completely normal.*
That the teacher’s symptoms were caused by Wi-Fi is, however, pure speculation and unlikely. Wi-Fi goes through ordinary walls up to about 300 m, so the teacher should have felt symptoms long before entering and long after leaving the classroom. There is no compelling scientific evidence that these kinds of symptoms are caused by exposure to Wi-Fi. There have been a number of studies that have tried to establish that some people are hypersensitive to EMFs. Ben Goldacre of Bad Science writes:
There have been 31 studies looking at whether people who report being hypersensitive to electromagnetic fields can detect their presence, or whether their symptoms are worsened by them. A typical experiment would involve a mobile phone hidden in a bag, for example, with each subject reporting their symptoms, not knowing if the phone was on or off.
Thirty-one is a good number of studies, and 24 found that electromagnetic fields have no effect on the subjects. But seven did find a measurable effect…in two of those studies with positive findings, even the original authors have been unable to replicate the results; for the next three, the results seem to be statistical artifacts; and for the final two, the positive results are mutually inconsistent (one shows improved mood with provocation, and the other shows worsened mood).*
At this time, it looks as if hypersensitivity to EMFs (electrosensitivity or ES) is a psychosomatic disorder. (For example, a research team in Norway (2007) conducted tests using sixty-five pairs of sham and mobile phone radio frequency (RF) exposures. “The increase in pain or discomfort in RF sessions was 10.1 and in sham sessions 12.6 (P = 0.30). Changes in heart rate or blood pressure were not related to the type of exposure (P: 0.30?0.88). The study gave no evidence that RF fields from mobile phones may cause head pain or discomfort or influence physiological variables. The most likely reason for the symptoms is a nocebo effect.”)
(Warning: studies on this subject are published quite frequently. No study, no matter how large and well
designed can prove that any amount of EMF exposure is always safe for everybody under any circumstances. But the preponderance of the evidence as of spring 2008 is that there is no great danger to humans from using cell phones, Wi-Fi, or living near power lines.)
In 1997, The New England Journal of Medicine published the results of the largest, most detailed study of the relationship between EMFs and cancer ever done. Dr. Martha S. Linet, director of the study, said: “We found no evidence that magnetic field levels in the home increased the risk for childhood leukemia.” The study took eight years and involved measuring the exposure to magnetic fields generated by nearby power lines. A group of 638 children under age 15 with acute lymphoblastic leukemia were compared to a group of 620 healthy children. “The researchers measured magnetic fields in all the houses where the children had lived for five years before the discovery of their cancer, as well as in the homes where their mothers lived while pregnant.” The study was criticized because it is impossible to know exactly what the EMFs were at the times the mothers or their children were exposed. All measurements must be done after the exposure has taken place and assumptions must be made that the level of EMFs was not substantially different during exposure. It is unlikely, however, anyone except the intellectual descendants of Nazi doctor Joseph Mengele will ever do a control study on humans which systematically controls exposure to EMFs from the moment of conception through early childhood.
A report published in the Journal of the American Medical Association on a study of 891 adults who used their cell phones between 1994 and 1998 found that there was no increased risk of brain cancer associated with cell phone use (Muscat 2000).Yet, many people believe that living near power lines or using cellular phones causes cancer. Why? Some lawyers, the mass media and a scientifically illiterate public can take the credit here.
Robert Pool claims popular opinion has been aroused against EMFs by unscientific sources such as The New Yorker magazine (Pool 1990). Paul Brodeur, called “a scientifically-ignorant writer” by physicist Bob Park, wrote three fearmongering and scientifically inept articles for The New Yorker in the early 1990s and published them as a book in 1993. The fear that cell phones might be causing brain tumors was aroused by ABC’s “20/20” (October 1999) in a story focused on the claims of Dr. George Carlo, who, for the previous six years, ran the cell phone industry’s research program on the effects of radiation from cell phones. Gordon Bass also relied heavily on Carlo for his alarmist piece in PC Computing, “Is Your Cell Phone Killing You?” (November 30, 1999). Carlo contradicts the conclusions of most other researchers in the field and maintains that “we now have some direct evidence of possible harm from cellular phones (italics added).” (Carlo also claims there is a causal connection between Wi-Fi and autism.) Contrast Carlo’s view with the following:?
The epidemiological evidence for an association between RF radiation and cancer is found to be weak and inconsistent, the laboratory studies generally do not suggest that cell phone RF radiation has genotoxic or epigenetic activity, and a cell phone RF radiation-cancer connection is found to be physically implausible. Overall, the existing evidence for a causal relationship between RF radiation from cell phones and cancer is found to be weak to nonexistent (Moulder et al. 1999).
In a press release on October 20, 1999, the FCC responded to “20/20” and claimed that the “values of exposure reported by ABC were well within that safety margin, and, therefore, there is no indication of any immediate threat to human health from these phones.” Furthermore, the “20/20” story claimed that cell phone antennae emit radiation into the brain, which is misleading. You might also say that TVs and radios emit radiation into the brain if you put your head close enough to those devices.
Cellular phones operate at the radio frequency (RF) part of the electromagnetic spectrum. This is non-ionizing radiation. Other examples of the non-ionizing part of the electromagnetic spectrum include AM and FM radio waves, microwaves, and infrared waves from heat lamps. Unlike x-rays and gamma rays (which are examples of ionizing radiation), radio waves have too little energy to break the bonds that hold molecules (such as DNA) in cells together. Similarly, since RF of this frequency contains relatively low energy, it does not enter tissues. At very high levels of exposure, RF can cause warming of tissues, much as a heat lamp does. The wavelength of cell phone waves is about one foot and the frequency is approximately 800 to 900 MHz, although newer models may use higher frequencies up to 2,200 MHz.*
Similar arousal has been evoked by talk show hosts such as Larry King, who introduced the nation to a widower who claims that his wife’s fatal brain tumor was caused by the EMF emitted from her cellular phone. There is a lawsuit, of course. The evidence? The tumor was located near where she held the phone to her ear. The major networks reported the story about the lawsuit and the brain tumor and the cellular phone. Scientists were interviewed to give the story more ‘depth’ and credibility. However, no scientist has yet found a causal connection between EMF and cancer, much less between cellular phones and brain tumors. So, a scientist who has exposed existing tumors to EMF was interviewed. He reported that his research indicates that tumors grow faster when exposed to EMF. Sales of cellular phones dropped and stock in companies that manufacture them dropped. Because tumors exposed to EMF grow more rapidly than tumors not so exposed does not indicate that EMF causes tumors, cancerous or otherwise.
It is possible that cellular phones are causing brain tumors, but the likelihood is small. The phones emit very low EMF levels and exposure to them is intermittent. It is possible that a person with a brain tumor who uses a cellular phone is running a significant risk that the tumor will grow faster than it otherwise would. As yet, however, there is no evidence to support the view that there is a reasonable probability of either.
Lawyers representing claimants who blame their cancers on power lines cite a Swedish study that found leukemia rates were 400% higher among children living near power lines. Another study, done by the University of Southern California, found increased leukemia rates in children living near power lines. According to Robert Pool,
The study examined 232 leukemia patients under the age of 10, and a group of control subjects that were matched for age, sex, and race. The amount of EMF exposure for each child was determined in a number of ways. No correlation was found between the incidence of leukemia and the electric field exposure as measured by spot checking. An insignificant correlation was noted between incidence of leukemia and levels of exposure to magnetic fields, as measured by a continual measurement over a 24-hour period. A significant correlation was seen between the EMF exposure, as measured by wire coding, and an increased risk of leukemia. Those with the highest level of exposure had a 2.5-fold greater risk of developing leukemia. It is not understood how these differences in correlation depend on the way the EMFs are measured. It is possible that some types of EMF exposure may lead to an increased risk of leukemia. On the other hand, measurements taken by wire coding may be more sensitive. Further study is needed to see what factors are being measured by the wire coding and not by the other methods. Until that is understood, it is not clear if exposure to high levels of EMFs is related to an increased risk of leukemia (Pool, 1991).
Also, Pool reports, “there have been numerous scientific reports of elevated levels of leukemia in people who are exposed to high EMF levels on the job, such as power-line repairmen and workers in aluminum smelters.” Because there have been and probably will continue to be a few studies that find some sort of correlation between cancer and living by power lines,* lawyers will always be able to find some evidence, however weak, to justify filing a lawsuit. Over 201 challenges to utility projects were made in 1992 in which EMF was an issue. At least three suits have been filed in federal courts claiming exposure to utility lines caused cancer (Pool, 1991). Utility companies were scared. They? poured billions of dollars into efforts to cut EMF exposure from their power lines. Dr. Robert Adair, a physicist at Yale University, calls the reaction “electrophobia” and says that it would take EMF levels 150 times higher than those measured by the Swedish researchers to pose a hazard.
Lawyers can take their cases to court long before the scientific evidence is anywhere near conclusive. And the standards of proof in a court of law are appallingly much lower than those in science. “All it’s going to take is one or two good hits and the sharks will start circling,” says Tom Ward, a Baltimore attorney who is suing Northeast Utilities Co. and its Connecticut Light & Power Co. unit over an alleged EMF cancer (Pool, 1991). There is currently a great push to bury all power lines. Better safe than sorry? The cost goes up twenty-fold to bury the lines. Then what? Lawyers claiming their clients’ cancers were caused by EMFed water? It was bad enough trying to sell a house with power lines nearby when people cared about the ugliness of the view. But try to sell the same house when people are afraid of getting cancer from the ugly lines! In any case, we will have to bury our electrical wires even deeper than our power poles are high if we are to make a significant difference in shielding us from the magnetic fields of power lines.
It is not very likely that the average person has anything to worry about from power linesm cell phones, or Wi-Fi. Most of us do not get that close to power lines to be significantly affected by their EMFs. Our exposure to them, even if they are nearby, is not direct, up close, and constant. The energy emitted by our cell phones is pretty weak. There is more EMF exposure from radio and TV, and the wiring in our homes and the electrical appliances we use, than from our cell phones or Wi-Fi. No one can avoid electromagnetic radiation. It is everywhere. We are constantly exposed to it from light, commercial radio and television transmissions, police 2-way transmissions, walkie-talkies, etc. Furthermore, “while electrical fields are easily screened, magnetic fields make their way unimpeded through most substances” (Pool, 1990). In fact, it is curious that while fear of EMFs is on the rise so is magnet therapy as a panacea and source of positive energy for the healthful-minded New Ager.?
- “Cellular Telephones and Cancer: How Should Science Respond?” by Robert L. Park. Journal of the National Cancer Institute, Vol. 93, No. 3, 166-167, February 7, 2001.
- Electromagnetic Hypersensitivity: Real or Imagined? by Brian Dunning
- Death in Your Kitchen: Microwave Ovens (and the Microwave Militia) by Brian Dunning
- Mobiles ‘don’t raise cancer risk’ Jan. 20, 2006
- National Institute of Environmental Health Sciences report on Electrical and Magnetic Fields
- The Truth About My Cancer Studies by Robert Liburdy
- Study: no clear proof electromagnetic fields pose health risk
- Study: Leukemia risk no higher near power lines
- Power lines and Cancer – Nothing to Fear by John W. Farley, Ph.D.
- Power lines and Cancer FAQs (last updated Oct. 8, 2004, but still contains some valuable information)
- Rats Dive into Cell Phone Debate by Kristen Philipkoski?
- Mobile Phone (Cell Phone) Base Stations and Human Health (last updated June 2004 but still contains some valuable information)
- Mobile phone ‘brain risk’?
- EMF Link
- Microwave News
- Cell phone: A Convenience, a Hazard or Both? By JANE E. BRODY New York Times, Oct 1, 2002
- Wi-Fi & Autism?
Edwards, Diane D. “Cells Haywire in Electromagnetic Field?,” Science News, v. 133, n. 14 (April 2, 1988).
Moulder. J. E. et al. “Cell Phones and Cancer: What Is the Evidence for a Connection?” Radiation Research, Volume 151, Number 5, May 1999.
Muscat, Joshua E. et al. “Handheld Cellular Telephone Use and Risk of Brain Cancer,” JAMA / volume:284 (page: 3001) December 20, 2000.
Pool, Robert. “EMF-Cancer Link Still Murky,” Nature, v. 349, n. 6310 (Feb 14, 1991).
Pool, Robert. “Is there an EMF-cancer connection?,” Science, v. 249, n. 4973 (Sept 7, 1990), pp. 1096-1099.
Richards, Bill.? “Elusive Threat: Electric Utilities Brace for Cancer Lawsuits Through Risk is Unclear/ Companies Spend on Cutting Electromagnetic Fields as Lawyers Smell Blood,” The Wall Street Journal, February 5, 1993, p. 1.
Sagan, Leonard A. “EMF Danger: Fact or Fiction?,” Safety & Health, v. 145, n. 1 (Jan, 1992), pp. 46-49.