Dr. Mittleman responds to the DNA damage claim

I received permission to repost this email from Dr. Mittleman.

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I have seen that report about the idea of DNA damage by THz radiation. I remain skeptical. The experimental evidence for any kind of THz-induced damage (other than merely by heating) is so far not repeatable. This recent paper is purely theory, assuming a very specific and detailed model for the dynamics of a DNA chain which may not correspond to reality. The way that they include the solvent damping (i.e., the effects of all those water molecules lying around) is not clear. In fact there doesn't seem to be any accounting for the fact that the water is going to absorb most of the incident field, which might heat up the water but would have no other effect on the solvated DNA. I can't say that they're wrong, but being an experimentalist, I am going to need to see experimental results before I buy this mechanism.

The bottom line here is that the world is awash in THz radiation. Every room-temperature object is emitting THz radiation just by virtue of being at room temperature. In fact, the power (per unit bandwidth) in that ambient THz field is larger than the power in most (though not all) artificial THz sources. This makes it hard to imagine how a typical (weak) THz source could give rise to any biological effects. It could be that this mechanism is relevant to real-world situations, but I think the burden of proof remains in the camp of those who say there is a non-thermal effect.