Is THz radiation safe?
The real question here is: “safer than what?” At the microscopic level, THz radiation interacts with groups of molecules (e.g. cells in human tissue) but does not have sufficient energy to break up the molecules that make up the tissue. Thus, as far as we can judge, THz radiation is safe. So far, only a handful of safety studies have been reported, exposing cells to THz radiation emitted by equipment that can be bought for use in laboratories or clinics. There is, as yet, no official standard regarding exposure to THz radiation: standards are given for near-infrared and for millimetre-wave radiation (on either side of the THz band) but not, so far, for the THz band itself. Despite the above comments, it is important to remember that there may be other, more subtle, effects taking place and we are not yet fully aware of these. For example, it may be possible to stimulate “coherent” effects (when cells move together) with THz radiation: this has been predicted theoretically, but not yet
