In the studies, the researchers looked at a whole slew of health outcomes (like offspring survival, bodyweight changes, and body temperature changes), but importantly, they also looked at brain tumors, including gliomas. They exposed the animals to radio frequency radiation for up to nine hours a day over two years, and then examined more than 40 tissues in each animal. And they had a control group that wasn’t exposed to radiation for comparison.
When we think of harmful radiation, things like X-rays or gamma rays usually come to mind, but these types of radiation are different from mobile phone radiation in important ways. Radiation on the ultraviolet side of visible light, like those types just mentioned, has a wavelength that is short enough to alter some of the chemical properties of the objects it interacts with. It is referred to as ionizing radiation, for this reason. Non-ionizing radiation, which includes visible light, microwaves and radio waves, is typically regarded as harmless. Large amounts of it can produce a heating effect, like in a microwave oven, but no short-term damage has been linked to exposure to non-ionizing radiation.
For example, cellphone manufacturers currently test these devices for compliance with FCC standards by placing them against the head, and near the torso with some separation. Just check out Apple’s iPhone manual: The company tests the specific absorption rate at a 5mm separation from the body. But if you wear your device in your pocket, you’re probably not going to have that 5mm separation, meaning you may be exposed to more radiation — perhaps enough to exceed current standards.
Exposure to ionizing radiation, such as from x-rays, is known to increase the risk of cancer. However, although many studies have examined the potential health effects of non-ionizing radiation from radar, microwave ovens, cell phones, and other sources, there is currently no consistent evidence that non-ionizing radiation increases cancer risk in humans (2).