The 5G Health Hazard That Isn’t

Screenshot of the start of the article “The 5G Health Hazard That Isn’t” by William Broad in the New York Times.

A recent article by William Broad in the New York Times—titled “The 5G Health Hazard That Isn’t”—tells the sad story of how unfounded fears of radio-frequency radiation were stoked by one mistaken scientist. Broad begins

In 2000, the Broward County Public Schools in Florida received an alarming report. Like many affluent school districts at the time, Broward was considering laptops and wireless networks for its classrooms and 250,000 students. Were there any health risks to worry about?

The district asked Bill P. Curry, a consultant and physicist, to study the matter. The technology, he reported back, was “likely to be a serious health hazard.” He summarized his most troubling evidence in a large graph labeled “Microwave Absorption in Brain Tissue (Grey Matter).”

The chart showed the dose of radiation received by the brain as rising from left to right, with the increasing frequency of the wireless signal. The slope was gentle at first, but when the line reached the wireless frequencies associated with computer networking, it shot straight up, indicating a dangerous level of exposure.

“This graph shows why I am concerned,” Dr. Curry wrote. The body of his report detailed how the radio waves could sow brain cancer, a terrifying disease that kills most of its victims.

Over the years, Dr. Curry’s warning spread far, resonating with educators, consumers and entire cities as the frequencies of cellphones, cell towers and wireless local networks rose. To no small degree, the blossoming anxiety over the professed health risks of 5G technology can be traced to a single scientist and a single chart.

Except that Dr. Curry and his graph got it wrong.

Russ Hobbie and I describe the possible effects of weak electric and magnetic fields in Section 9.10 of Intermediate Physics for Medicine and Biology. We quote a review by Moulder et al. (2005) that concludes

Overall, a weight-of-evidence evaluation shows that the current evidence for a causal association between cancer and exposure to RF [radio frequency] energy is weak and unconvincing.

In his New York Times article, Broad goes on to describe how your “skin” blocks the radio waves. That’s not how I would say it. The waves can’t penetrate your body because of “skin depth” (to learn more about skin depth, do Problem 29 in Chapter 8 of IPMB). An electromagnetic wave penetrates a conductor to a distance on the order of the skin depth, which decreases as the frequency increases. A typical 5G frequency is 3 GHz, corresponding to a skin depth of about 30 mm (a little over an inch). Therefore, deep structures in your body are somewhat shielded from this radiation. It has nothing to do with skin itself; the effect works the same when the wave tries to penetrate the surface of the ocean. It depends on the electrical conductivity. Some planned 5G networks will operate at even higher frequencies (up to 300 GHz). In that case, the skin depth would be ten times smaller than for 3 GHz, or 3 mm, similar to the thickness of skin.

If the amplitude of the electromagnetic wave was high enough, it could burn you. Most people who object to radio frequency waves aren’t worried about heating. They’re concerned about hypothetical nonthermal effects, like causing cancer.

I can think of many reasons to ditch your fancy-schmancy 5G cell phone. Cancer isn’t one of them.