Limited to rats only, the Ramazzini study tested three doses expressed as the amount of radiation striking the animal’s bodies: either 5, 25 or 50 volts per meter. The exposure measures therefore differed from the absorbed doses calculated during the NTP study. But the Ramazzini scientists also converted their measures to W/kg, to show how the doses compared with RF limits for cell phones and cell towers set by the FCC and the International Commission on Non-Ionizing Radiation Protection; they ranged down to a 1,000 times lower. The exposures began when the rats were fetuses and continued for 19 hours a day until the animals died from natural causes.
The three most common brain tumor types — and the ones most cellphone and human health studies focused on — are gliomas (malignant tumors of the brain and spinal cord), meningiomas (mostly noncancerous tumors of the membranes surrounding the brain and spinal cord, though a small percentage are cancerous), and acoustic neuromas (noncancerous tumors on the main nerve that leads from the inner ear to the brain). Note that of these, gliomas are the main concern — they generally have more severe outcomes than meningiomas and acoustic neuromas.
The first one is easy, cellular frequencies vary between 450–2000MHz, but 800 or 900 MHz is the most common. The power emitted by a cell phone varies over the course of the call (higher when making initial contact, which lasts a few seconds). It can go up to 2 Watts at the start of a call, and can go down to .02 Watts during optimal operation [2]. Of course, most people barely use cell phones for calls, but I am using this example as a worst case scenario, because the phone is not right by your head when you are browsing Tinder.
The frequency of radiofrequency electromagnetic radiation ranges from 30 kilohertz (30 kHz, or 30,000 Hz) to 300 gigahertz (300 GHz, or 300 billion Hz). Electromagnetic fields in the radiofrequency range are used for telecommunications applications, including cell phones, televisions, and radio transmissions. The human body absorbs energy from devices that emit radiofrequency electromagnetic radiation. The dose of the absorbed energy is estimated using a measure called the specific absorption rate (SAR), which is expressed in watts per kilogram of body weight.