How Terahertz Waves Tear Apart DNA

[joeblow]

How Terahertz Waves Tear Apart DNA

http://arxiv.org/abs/0910.5294

Friday, October 30, 2009

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 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 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: DNA Breathing Dynamics in the Presence of a Terahertz Field

[joeblow]

Terahertz are a subset of microwave radiation. They are also employing the use of hard X-rays at the airport for intestinal and stomach searches.



Terahertz Radiation Effects and Biological Applications

http://www.springerlink.com/content/u23v3006ku7572h9/

Abstract We present a brief overview of the literature on biological applications and experimental data on the effects of THz radiation. The region of the electromagnetic spectrum from 0.1 to 10 THz is a frontier area for research in physics, chemistry, biology, materials science and medicine. This area has recently begun to be filled by a variety of sources of high quality radiation with a wide range of new technologies related to it. New sources have led to new science in many areas, as scientists begin to become aware of the opportunities for research progress in their fields using THz radiation. Therefore the opportunities for THz science in chemistry and biology are wide ranging. Some of them will extend the range of already established work, many others have not yet been realized but show great promise, and the rest fall somewhere in between.

Based on the findings from the original paper combined with the whitewash of the health effects it received in the latest study it seems that further study is required to fully understand how THz disrupts DNA through resonance - although it is confirmed that it does under certain conditions. Prolonged exposures[1] and higher seem to exacerbate this effect especially when proteins are bonding and during replication. Lower frequency zaps yield no change on DNA itself initially. IMO they seem much safer than CT scans at first glance but the study was directed by the US Dept. of Energy[2] so I'd proceed on the side of caution until further independent study is conducted.

[1] The paper mention 6 hours but fail to plot any other metrics could have results in 30 seconds they used the term long period of exposure
[2] Part of (1/13) project DE-AC52-06NA25396 with a DoE grant of $230,835,000 for LOS ALAMOS NATIONAL SECURITY, LLC:

http://www.recovery.gov/Transparency/Re ... =Contracts

[Reboot]

Ever heard of 3G phones? iPones? Heard about 4G communications? That's terahertz. On December 14, 2009, the first commercial deployment was in the Scandinavian capitals Stockholm and Oslo by the Swedish-Finnish network operator TeliaSonera and its Norweigan brandname NetCom (Norway). TeliaSonera branded the network "4G". The aim of a 4G network is to provide data transfers of up to 1 Gbit/s. Samsung is currently the only manufacturer of compatible devices.

[sullivan]

Ever heard of 3G phones? iPones? Heard about 4G communications? That's terahertz.

No, it's not. 3G operates in the range 1.9-2.1 gigahertz.