Terahertz Waves:  Scientific Breakthrough or Impending Health Meltdown?

There is a new technology that has scientists positively giddy with excitement. 

As one article states “Over the last century, scientists have progressively explored and conquered the electromagnetic spectrum. Starting with visible light, and developing techniques for generating and detecting radiation at both higher and lower frequencies. As each successive region of the spectrum has been colonized, new technology has been developed to exploit the newly discovered radiation. For example, X-rays are used to image unseen objects with the visible light. Near-infrared radiation is used in fiber-optic communications and in compact-disc players, microwaves are used to transmit signals from mobile phone, etc.

But there is one part of the electromagnetic spectrum that has steadfastly resisted our advances. This is the terahertz region, which ranges from frequencies of about 300 GHz to 10 THz (10 x 10¹² Hz).”  The excitement is generated by many potential uses in medicine and industry.  Our question is – are they safe? How does our DNA feel about being bombarded by terahertz waves? The Technology Review, published by MIT, has the very same question!

Friday, October 30, 2009

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 tumours 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 ionize 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 this kind of damage but nonlinear resonances can. These nonlinear instabilities are much less likely to form which explains why the character of THz genotoxic effects 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

Our comment in response 1/15/10

Are we surprised?

Really? Why do so many of us continue to believe that toxic waves and chemicals are safe? Is it simply that we don't want to have to give up the "benefits" of all the new goodies? But at what cost?
Many people believe that since the link between technology and illness hasn't been conclusively proven, that there is no reason for concern. Reminds me of the 60s and the smoking issue.

We’ve been one of the original trail blazers in EMF protection and have been getting the word out since 1990.
We are so glad to have more information out there so that hopefully more of us will start to question and take steps to lessen the amount of exposure.
Carolyn