A little-known warning from the manufacturer hidden within your cellphone manual advises you to keep the device at a certain distance from your body to ensure you don’t exceed federal safety limits for radiofrequency (RF) exposure.
… In the real world, most people carry their phones close to their bodies, usually in a pocket or bra. When popular cellphones were tested in direct contact with the body, they all exceeded the safety limit.
The specific absorption rate (SAR) is a measure of how much RF energy your body will absorb from the device when held at a specific distance from your body (ranging from 5 to 15 mm, depending on the manufacturer). It’s important to realize that the SAR value is not an indication of how safe your phone is.
SAR testing, which is modeled on a very large male head, was devised before cellphone usage became commonplace among toddlers and young children, whose skulls allow for far greater RF energy penetration.