Bradley Roth is a retired physicist and acknowledged expert in electromagnetism who co- authored the textbook Intermediate Physics for Medicine and Biology. In this new book, Are Electromagnetic Fields Making Me Ill?, he shares his knowledge and understanding with the general public. The book asks a number of questions about electricity, magnetism, and health claims, starting with unchanging static magnets and progressing through fields that change with increasing frequencies, from 60 Hz to fields that oscillate at up to trillions of times per second. Each chapter title is a question, and his answer is usually “probably not” or “no”. I’ll elaborate chapter by chapter, starting with Chapter 2, after the Introduction. His explanations are thorough and full of interesting facts that will help the reader decide if health claims are plausible and may help them win a trivia contest.
Chapter 2: Can Magnets Cure All Your Ills?
Magnetic fields are claimed to relieve pain; to cure arthritis, backache, and menstrual cramps; to heal sports injuries; and much more. Testimonials abound, but the evidence is iffy.
Roth does a great job of explaining the physics of magnets. Magnetic fields are measured in tesla. The earth has a magnetic field of 0.00005 tesla, refrigerator magnets have a field of about 0.001 tesla, and an MRI scanner has 1.5 tesla. For comparison, the magnetic fields recommended to relieve pain are around 0.1 tesla. The magnetic field produced by the brain is so feeble it can only be measured by a supercooled SQUID device. The magnetic fields of nerves are far too weak to affect nerve conduction; those claims are not true. Physiotherapist Isaac Goiz Durán claims that his biomagnetic therapy can cure cancer, diabetes, AIDS, and COVID-19. He believes the north and south poles of a magnet have dramatically different biologic effects. He is wrong: the only difference between the poles is the direction of the field.
Some bacteria are magnetotactic; they can react to the earth’s magnetic field because they contain magnetite. Homing pigeons have magnetite in their beaks. Isolated iron atoms, like those found in the blood’s hemoglobin, can’t sense a magnetic field; that requires densely packed iron atoms whose unpaired electrons tend to spin in the same direction. Magnetite has been found in the human brain. Is it possible that humans can detect magnetic fields? Roth says the evidence is tantalizing but inconclusive; he has his doubts. Free radicals also might detect magnetic fields, but the jury is still out.
Roth explains diamagnetism, which is exhibited by water and has been demonstrated by levitating a frog. (I wonder what the frog thought was happening. Did he think it was the Rapture?)
Biological effects could only occur if the magnetic energy is greater than the thermal energy of Brownian motion. Roth covers this in greater depth in subsequent chapters.
I was surprised to learn that the south magnetic pole of the earth is located near the north geographic pole.
Chapter 3: Can a 9 Volt Battery Make You Smarter?
A device that applies a weak electrical current to the head is said to improve “productivity, focus, and performance”.
“…when people are exposed to an electric field, charge accumulates on their skin but no electric field exists anywhere inside their body; their tissues are shielded from an external field”. Electrical fields are created when electrodes are used.
Electroreception. Some animals can detect small, static electrical fields, for instance by the ampullae of Lorenzini that can be seen as pores on the snouts of sharks. But does detection have any physiologic effect on the animals, or on humans?
Electricity is used to promote bone healing when there is non-union of a fracture, but “After decades of research and clinical use, we still are not sure if electric fields help bones heal.” Roth’s verdict: plausible but definitely not proven.
Transcranial direct current stimulation:
Three meta-analyses published from 2014 to 2016 concluded that the influence of tDCS on memory is either small, partial, or nonexistent.
There is much debate about tDCS. Roth’s conclusion: “First, science is difficult. Large effects are relatively easy to discover, but small ones tend to be buried in noise. Second, a single study or analysis does not decide an issue.”
There is “a slow slog ultimately leading to a consensus among scientists”. We will have to wait and see.
“The science behind transcranial direct current stimulation is unclear. There are enough positive studies that we cannot reject it out of hand, but there are enough questions that we cannot accept it as an established therapy.”
Chapter 4: Do Power Lines Cause Cancer?
Paul Brodeur’s 1989 book Currents of Death alleged that electromagnetic fields associated with power lines, electric blankets, and video display terminals cause cancer, and that people who denied it were engaged in a conspiracy to hide the truth from the public.
While radio stations and cell phones use frequencies in the millions and billions of Hz, power lines and the entire electrical grid operate at the extremely low frequency of 60 Hz (they alternate at 60 cycles per second).
The electrical field under the highest voltage power lines can be as high as 15,000 V/m; the magnetic field is less than 1/3 the magnetic field of the earth. Surface charge is very effective in shielding our bodies from electric fields. The magnetic field is not shielded; it can produce small electrical fields in the body through induction.
Roth points out that the electric fields induced in the body by power lines are smaller than the endogenous electric fields that always exist in our bodies.
Can humans detect a 60 Hz magnetic field? When an experiment in the 1970s showed that some “super perceivers” could, the experimenters did not trust their original results. Roth tells a fascinating story about the series of extraordinary measures they took to remove every possible confounder from the experimental setup. Their final determination was that no real perception had occurred.
He points out that “The thermal noise electric field experienced by a cell and the endogenous field produced by the heart are both larger than the electric field induced by a power line. Power line fields are swamped by thermal noise.” Numerous physicists and committees have reviewed the evidence and found no evidence that power lines can cause cancer. If they could, shouldn’t the incidence of childhood leukemia have risen? It hasn’t. The supposed association proved to be spurious when better studies were done.
Chapter 5: Will Electrical Stimulation Help Your Aching Back?
Electrical stimulation by Transcutaneous Electrical Nerve Stimulation (TENS) and other devices are often used to treat backaches. Electrical stimulation has proven effective for pacemakers and defibrillators, which operate at a frequency of around 1000 Hz. That’s higher than the 60 Hz of power lines but much lower than the frequencies of radio, TV, and cell phones.
Hodgkin and Hughes won a Nobel Prize for their studies of nerve conduction in the giant nerve axon of the squid. Nerve conduction in peripheral nerves is now well understood; electrical stimulation of the brain is not as well understood. “Heart pacemakers, neural prostheses, deep brain stimulation, and transcranial magnetic stimulation represent dramatic biomedical advances…but the success of TENS has been uninspiring.” The consensus of numerous meta-analyses is that “clinical studies to date are either inconclusive or mildly negative about the use of TENS.” Electroconvulsive therapy has received a lot of bad press, but it has been proven effective. Several randomized, controlled clinical trials have found that “electroconvulsive therapy is significantly better than a placebo for treating depression and is significantly better than antidepressant drugs.”
Electric eels stun their prey with a strong electric shock that acts like a taser, causing the fish’s muscles to go into tetanus. An electric fish called a ray was used in ancient Rome to treat headaches and gout.
Roth relates this interesting bit of trivia: “The Tennessee Aquarium’s electric eel, Miguel Wattson, has his own Twitter account (@EelectricMiguel) that sends out a tweet every time he delivers a shock.”
Chapter 6: Is Your Cell Phone Killing You?
In her book Disconnect (discussed on SBM), Devra Davis asks whether “the pervasive use of cell phones is causing a host of subtle, chronic health problems today, damaging our ability to have healthy children and creating long-term risks to our brains and bodies?” Vini Kurana even announced on the Larry King Live show that “cell phones are more dangerous than smoking”. One widespread fear has been that cell phones cause brain cancer. Roth shows how physics and epidemiology have essentially ruled out that possibility.
He explains Maxwell’s equations, which “brought electricity, magnetism, and optics together into a single unified theory” but did not account for quantum theory and wave-particle duality. Ionizing radiation can remove an electron from a molecule, damaging DNA and causing mutations that might develop into cancer. The radiation from cell phones is not ionizing; it is non-ionizing.
The new 5G cell phones will make use of frequencies up to nearly 1000 GHz, with a photon energy of 0.004 electron volts. This is less than the thermal energy of randomly moving molecules (Brownian motion), which is 0.02 electron volts.
Roth explains how diathermy, radio frequency ablation, and electroporation work by heating the tissues.
He reaches these conclusions:
- A photon from a cell phone is so weak that it cannot break bonds in a DNA molecule and cause cancer directly. If cell phones cause cancer the effect must be indirect.
- Cell phone radiation is not intense enough to heat tissue. Any mechanism by which cell phone radiation causes cancer must be nonthermal.
He covers the proposed non-thermal mechanisms for tissue damage from cell phones and explains how physics shows that those mechanisms are not plausible.
The evidence is questionable, and has been interpreted differently by different observers, but the clincher is that the incidence of brain cancer has not risen as the use of cell phones skyrocketed. Major health agencies like the FDA, CDC, and NCI have examined the evidence and concluded that cell phones do not cause cancer.
Chapter 7: Did 5G Cell Phone Radiation Cause COVID-19?
Roth calls this an “outlandish” conspiracy theory circulated on social media. He refuses to discuss the nonsense, but he examines the physics of 5G to see whether it might affect our health. Compared to 4G, 5G uses higher frequencies and offers higher download speeds (more bits per second), lower error rates, shorter delays between sending data and receiving a response, and greater connectivity (more devices can join a network). Roth explains that in some ways 5G is safer than 4G: the brain is shielded, and the greatest risk is to the skin and the cornea of the eye.
After evaluating the evidence, Roth concludes: “Dangers arising from cell phone radiation strike me as unlikely, but not inconceivable. However, the claims that there exists a vast plot, with scientists colluding to conceal the facts, are ridiculous. Scientific consensus arises when a diverse group of scientists openly scrutinizes claims and critically evaluates evidence. Science is the best way to debunk conspiracy theories and uncover the truth.”
Chapter 8: Did Cuba Attack America with Microwaves?
The Havana Syndrome refers to mysterious medical symptoms reported by personnel at the American and Canadian embassies in Cuba in 2016, including ringing in the ears, fatigue, and dizziness. Questionable studies blamed everything from crickets to acoustic or microwave weapons aimed at the embassies by enemy agents. Roth explains what physics has to say about the evidence and why the most likely explanation is mass psychogenic illness.
Chapter 9: Is That Airport Security Scanner Dangerous?
Airport scanners expose people to microwaves. A physician writing on the Scientific American blog refuses to be scanned “until there is proof that the machines … are 100 percent safe even with long-term chronic exposure.” That seems like excessive caution, since airport scanners only expose you for half a second.
A National Academies report concluded that “As a result of the short time of exposure, the weak intensity of the radiation, and the lack of penetration, millimeter wave scanners should be harmless. The relative risk is less than the risk from talking on your cell phone for a minute.”
A bonus: Explaining critical thinking
As he asks his questions about health claims, Roth has much to say about the principles of critical thinking. He points out that “You can find peer-reviewed scientific studies supporting all points of view. Hundreds of papers of varying quality have been published describing laboratory experiments, and generally dozens of these reports are consistent with your opinion regardless of what your opinion is.”
He explains how confounders can lead to false results and how meta-analyses can help sort out the truth from conflicting studies. He explains placebos, randomization, blinding, the need for large sample sizes, the meaning of “statistical significance,” the file drawer effect, publication bias, p-hacking, and HARKing (hypothesizing after results are known). A well-done meta-analysis concluded that in most cases the evidence is against static magnets for pain relief, although in the case of arthritis there is not enough evidence to decide.
Promoting placebos because they help patients deal with pain is counterproductive. Roth explains why.
…for almost any illness, some people get better and some do not. If you give patients just about any treatment, no matter how silly, some of them are bound to improve. You can then point to those people and tell their story to justify the effectiveness of the treatment. The main purpose of randomized, placebo-controlled, double-blind clinical trials is to go beyond anecdotes and determine if a treatment has a real effect.
Science does not proceed by proclaiming universal truths, but by accumulating evidence that allows us to be more or less confident in our hypotheses.
Conclusion: We needn’t worry
Roth says “Nobody is able to prove beyond a shadow of a doubt that power lines do not cause cancer, magnets fail to reduce pain, or those airport scanners are 100% safe, but to me the evidence supporting their safety is overwhelming.”
This book is an essential reference that would be a great addition to every skeptic’s bookshelf. It summarizes the evidence about the health effects of electromagnetism and provides ammunition for debunking pseudoscientific rumors. It’s short, inexpensive, well-written, and full of interesting facts. I was particularly intrigued to learn that an electric eel has its own Twitter account.