WiFi: Handy but Also Harmful?

WiFi: Handy but Also Harmful? Carousel: John Moore/Getty Images; Video: HowStuffWorks

From the coffee shop and public library to the workplace and your living room, WiFi is everywhere. But can it be harmful to your health?

As our host Lauren Vogelbaum explains in the video above, WiFi works by translating data into radio signals and then transmitting and receiving those signals via antennae. Wireless networks harness radio waves, a part of the broad range of frequencies that make up the electromagnetic spectrum.


If Marvel Comics has taught us anything, it's that some radiation on the spectrum can be harmful. Gamma rays, X-rays or high-frequency ultraviolet light are so high in energy that they can break apart atoms and damage DNA. These waves, known as ionizing radiation, are not part of an ordinary WiFi network.

WiFi networks comprise nonionizing radio wavelengths that are too low in energy to bust up atoms or molecules, or damage DNA. In fact, WiFi often is transmitted at a 2.4-gigahertz frequency, which is about the same as most microwave ovens.

What's more, WiFi networks have a greater broadcast distance than microwaves. Every time the distance of a radio wave is doubled, only a quarter of its energy is released, a formula that's known generally as the inverse square law of physics. In other words, WiFi's intensity will drop sharply the farther you are from the device emitting it.

Does this mean there is zero risk? Nope. The World Health Organization (WHO) recognizes several studies that demonstrate a preliminary connection between these types of radiation and human illness. They categorize a wireless internet connection as a class 2B carcinogen, which means it is possibly carcinogenic to humans at certain exposures and under certain conditions. Diesel, carbon, lead and chloroform also are listed as class 2B carcinogens.

However, WHO concludes that WiFi at the levels commonly experienced by most people don't cause cancer, stating "there is no risk from low level, long-term exposure to WiFi networks."


Frequently Answered Questions

Do Wi-Fi routers emit harmful radiation?
There is no definitive answer to this question as the research on the matter is inconclusive. Some studies suggest that Wi-Fi routers do emit harmful radiation, while other studies are not able to confirm this.