Radiation From Cell Phones And Wireless Devices Harms Your Baby’s Brain Development. Cell phones and tablets use different signals to connect to phone and Wi-Fi networks. Extended exposures to cell phone signals have been linked to a risk of brain cancer, and the younger a person is the more vulnerable they are. Tablet computers can access both cellular networks and much weaker Wi-Fi signals, and this access can be turned off. The safest approach is to keep cell phones away from children. They’re not necessary for kids so this shouldn’t be a hardship.