How Terahertz Waves Tear Apart DNA

A new model of the way the THz waves interact with DNA explains how the damage is done and why evidence has been so hard to gather

Great things are expected of terahertz waves, the radiation that fills the slot in the electromagnetic spectrum between microwaves and the infrared. Terahertz waves pass through non-conducting materials such as clothes , paper, wood and brick and so cameras sensitive to them can peer inside envelopes, into living rooms and "frisk" people at distance.
The way terahertz waves are absorbed and emitted can also be used to determine the chemical composition of a material. And even though they don't travel far inside the body, there is great hope that the waves can be used to spot tumors near the surface of the skin. With all that potential, it's no wonder that research on terahertz waves has exploded in the last ten years or so.
But what of the health effects of terahertz waves? At first glance, it's easy to dismiss any notion that they can be damaging. Terahertz photons are not energetic enough to break chemical bonds or ionise atoms or molecules, the chief reasons why higher energy photons such as x-rays and UV rays are so bad for us. But could there be another mechanism at work?
The evidence that terahertz radiation damages biological systems is mixed.
"Some studies reported significant genetic damage while others, although similar, showed none," say Boian Alexandrov at the Center for Nonlinear Studies at Los Alamos National Laboratory in New Mexico and a few buddies.
Now these guys think they know why.
Alexandrov and co have created a model to investigate how THz fields interact with double-stranded DNA and what they've found is remarkable. They say that although the forces generated are tiny, resonant effects allow THz waves to unzip double-stranded DNA, creating bubbles in the double strand that could significantly interfere with processes such as gene expression and DNA replication. That's a jaw dropping conclusion.
And it also explains why the evidence has been so hard to garner. Ordinary resonant effects are not powerful enough to do do this kind of damage but nonlinear resonances can. These nonlinear instabilities are much less likely to form which explains why the character of THz genotoxiceffects are probabilistic rather than deterministic, say the team.
This should set the cat among the pigeons. Of course, terahertz waves are a natural part of environment, just like visible and infrared light. But a new generation of cameras are set to appear that not only record terahertz waves but also bombard us with them. And if our exposure is set to increase, the question that urgently needs answering is what level of terahertz exposure is safe.

Ref: arxiv.org/abs/0910.5294: DNA Breathing Dynamics in the Presence of a Terahertz Field
<a href="http://www.technologyreview.com/blog/arxiv/24331/">
http://www.technologyreview.com/blog/arxiv/24331/</a>

Hmmm That's pretty darned interesting!! Thanks for the article. Gets me wondering about something I had not thought about at all!!!

oh crap now I have to go read up on non-linear resonance and thz protons




I could see it.

microwaves are gigahertz down the spectrum and they will cook food

I thought all such processes were statistical in nature; and that even having something sit at room temperature will cause a few bonds to break, etc... so making a blanket statement that a photons of a certain energy simply can't (not energetic enough) to do the above seems a bit suspicious to me.

Further, these waves can penetrate a short distance into the body, but don't pass through the body? Wouldn't that mean that all of the waves energy would (temporarily) be transfered to tissue? On the other hand an space heater will transfer energy to tissue with IR, and I like that!

if it destroys dna then you should never get a breast check . the new scan puts a lot smaller wave threw you so it should be way safer than any other scan you already have gone threw .
what makes you think it doen't pass threw you . I mean electric is already in you makes you move you know .

There are some who believe the push for mammograms has increased the numbers of breast cancer...

You have to weigh the good with the bad.

X-rays are bad for us but in order to diagnose certain things they are needed. For scanning tests not only do they inject you with radioactive stuff but then the scanner does whatever damage it does but they are needed.

I think that in high risk situations the scanner is going to be needed.

I really feel for those people who travel for a living though. They will probably have health problems from the airports they have to go through.

I have no opinion on the actual safety of this scan. I do believe that in all cases like this (including cell phones and flu shots), there will be (1) reactive science-illiterate wingnuts who declare it 'unsafe' and make a mockery of reason while trying to convince others and (2) some parties who have a vested interest (financial and political) in pushing the device/technology/whatever without proving its safety, and are unconcerned about personal liberty.

These two groups will both spout BS, making it difficult sometimes to get to the truth.



I read the article. "And even though they don't travel far inside the body, there is great hope that the waves can be used to spot tumors near the surface of the skin. "

If they do not travel far inside the body, then they cannot pass through the body (except maybe for the narrow regions, like fingers).




I'm well aware of many electrical phenomena in human physiology, yet I have no idea what your point is, nor how this relates to the notion of 'penetration depth' of the radiation.

People who constantly have to fly..or choose to fly, possibly problems then.

another reason I don't like to fly

In Canada you can opt for a frisk, a body search, or a full body cavity search, instead of the teraherz machine. For a frisk you pay $20, for a body search, $50, and the body cavity, $200. You cannot request the procedure to be done more than five times in a row at any one boarding.