Characteristics of Electromagnetic Fields (EMFs)
Mobile phones use high frequency electromagnetic fields (EMFs) or radio waves within the frequency range of 300 MHz (megahertz) to 3 GHz (gigahertz)*. The radio waves in this frequency range propagate following straight lines, but also exhibit distortion and diffraction from barriers, such as buildings or mountains. As they can carry a large amount of information, radio waves are used in various mobile telecommunication systems other than mobile phones.
* Under the Radio Law of Japan electromagnetic waves in the frequency range from 10 kHz (kilohertz) to 3,000 GHz (gigahertz) are called radiowaves.
There is more detail information available on the Radio Use WEB site hosted by the Ministry of Internal Affairs and Communications (MIC) of Japan.
Adverse Health Effects
When exposed to the high frequency electromagnetic field (EMF) or radio wave, the human body or some part of its received an energy which could be converted to heat. As a result, the temperature of specific body parts could be elevated in case of exposure to a very strong high frequency EMF or radio wave.
Fortunately, the body's thermoregulatory* system prevents the elevation of temperature above the safety levels at exposure to an EMF at or below a certain strength of the acting factor.
Since the mobile phones operate at low level of energy (relying mostly on modulation) there is no possibility that in common living or working environment for exposure to strong EMF that can raise the body's temperature. Therefore, high frequency EMFs and radiowaves used in mobile phones and other types of wireless telecommunications are thought to have no adverse health effects.
* The human body has a system that maintains the body temperature within certain boundaries by regulation of perspiration and blood circulation.
The Ministry of Internal Affairs and Communications of Japan has publicized a brochure, Radio Waves and Safe Living Environments (Only in Japanese. 「電波と安心な暮らし」), that discusses the health effects of radio waves.
The Ministry of Internal Affairs and Communications (MIC) of Japan has set out the Radio Radiation Protection Guidelines for Human Exposure to Electromagnetic Fields that serves as a standard in the use of mobile phone, radio and TV waves. Under the Radio Law, Regulations for Enforcement of Radio Law and Radio Equipment Regulations of Japan, MIC has defined the standards for the frequency and strength of the radio waves that will prevent occurrence of harmful to human health effects.