The new 5G cell-phone network promises to be the most powerful and fastest of all time. But with that extra speed comes extra risks. 

Because of the shorter length of 5G’s high-frequency waves and their inability to go through walls and trees, this new network will require building about 800,000 new wireless antenna structures, many of which will be located close to houses and schools in residential neighborhoods. To put that into perspective, there were about 300,000 antennas in 2015 and half as many in 2002. 

The new antennas will be able to emit 3G, 4G and 5G microwave ­radiation at the same time. The World Health Organization classifies this kind of radiation as a possible carcinogen, and there’s evidence that it can lead to some types of brain tumors both in animal studies by the US government and in humans that have used phones regularly for a decade or longer. Recently, Sprint stopped operating a cell tower in a California school yard after four students and three teachers there developed rare cancers in the 10 years since the tower was erected. With 5G, these risks may only worsen.

The US National Toxicology Program, considered the industry gold standard for this kind of testing, reported clear evidence of rare cancers and genetic damage in animals after prolonged exposure to 2G and 3G radiation. 5G radiation is very similar, but it operates at a higher frequency and shorter range, making it potentially more dangerous.

Self-defense: The good news is that there already is a way to eliminate the damage. Hardwired fiber-optic cable can be run from a 5G tower to a home—as is regularly done in ­South Korea—and that means the tower can be far away from your home. Share your concerns with your local leaders, who should consider hardwiring at least the last mile with fiber-optic cable, as they did in St. Louis and Chattanooga.