..Safety limits for exposure to radio waves..
TETRA is subject to the same safety guidelines as other mobile communications products and systems. These are set by independent expert organizations, like the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The guidelines, which are endorsed by the WHO and other authorities around the world, set limits for exposure based on extensive reviews of the scientific evidence. The guidelines incorporate a substantial margin of safety, designed to protect both users and the general public. Member
companies of the TETRA Industry Group rigorously design and test their products and systems to make sure they comply fully with the safety guidelines.
The transmitting power of a TETRA portable radio is comparable to that of a mobile phone, typically 1 Watt at peak power, with average power of 0.25 Watt. TETRA terminals also use a feature called Adaptive Power Control, which continually adjusts the power output to the lowest level needed to maintain reliable communication with the base station.
A study carried out by the UK Defense Science and Technology Laboratory (DSTL) looked at the impact of TETRA signals on calcium concentrations in neuronal cells. The results were published in the
International Journal of Radiation Biology in December 2005. As well as simulating the maximum exposure that can arise from TETRA handsets, several lower power levels were also used to see if there could be "power windows" where TETRA signals cause a reaction. No effects of TETRA on calcium responses were found at any of the power levels used in the measurement.