Radio transmitters operate at different frequencies and powers depending on their application. Broadcast AM and FM radio and TV transmitters operate at comparatively high powers (several thousands of watts). Mobile phone base stations operate at moderate to low power. Microwave systems used for point to point communications and mobile phones operate at low power.
There are many radio sources in the community and exposures from mobile communications are comparable to broadcast radio and TV. The strength of the radio signals is greatest near the source and reduces rapidly with distance. Typical exposures in publicly accessible areas are usually thousands of times below international guidelines. As the radio signals are directed outwards from the antennas, exposures directly below the antennas are typically very low. The WHO says that recent surveys show that the RF exposures from base stations typically range from 0.002% to 2% of the levels of international exposure guidelines.
It is only in areas close to the antennas that the recommended limits may be exceeded. The network operator will take steps to prevent public access to these areas by placing the antennas near the top of the mast or high on a building.