Airport Body Scanners, New Generation
of Cameras Can Create Bubbles In Our DNA
Great things were expected of terahertz (THz) waves, the radiation
that fills the slot in the electromagnetic spectrum between microwaves
and the infrared. However, emerging evidence suggests 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.
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
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
Reference Source: Technology
November 1, 2009