While U.S. tests focus narrowly on whether phones heat tissue, some experts argue they fail to show the whole picture.

"The way they're tested is to see whether or not they heat you up, and not for the chronic long-term effects that have been demonstrated," Devra Davis, a cancer epidemiologist who holds a doctorate in science studies and a master's in public health in epidemiology, told The Epoch Times. "Particularly the effects on sperm and lower testosterone, among others."

Cellphone Radiation Tests Are 'Rigged': Expert

According to Ms. Davis, the biggest problem with U.S. testing is that it's not conducted with the phone against the body. She compared it to the "Dieselgate" scandal involving Volkswagen, where the company rigged its tests to show lower exhaust emissions than the vehicle actually produced.