How Terahertz Waves Tear Apart DNA

KentuckyFC writes "Great things are expected of terahertz waves, the radiation 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. That's not to mention the great potential they have in medical imaging. Because terahertz photons are not energetic enough to break chemical bonds or ionize electrons, it's easy to dismiss fears over their health effects. And yet the evidence is mixed: some studies have reported significant genetic damage while others, although similar, have reported none. Now a team led by Los Alamos National Labs thinks it knows why. They say that although the forces that terahertz waves exert on double-stranded DNA are tiny, in certain circumstances resonant effects can unzip the DNA strands, tearing them apart. This creates bubbles in the strands that can significantly interfere with processes such as gene expression and DNA replication. With terahertz scanners already appearing in airports and hospitals, the question that now urgently needs answering is what level of exposure is safe."

Comments

Re:Doesn't worry me

[Sockatume]

Actually, it's a theoretical explanation for some difficult experimental results. The issue was that some studies suggested that THz radiation would be harmful at any frequency/power range, while others pegged it as only being significant at particular resonant amplitudes or frequencies. It transpires that in the presence of thermal perturbations, you do indeed get some non-specific disruption of the base pairing, which would only be an issue if you had a long enough exposure to actually get a significant thermal perturbation and thus cause a very significant disruption. However there is also a resonant mechanism, at a particular frequency with a critical minimum amplitude, that can immediately cause a significant disruption, without the need to wait for a particularly big thermal perturbation. That's my reading, anyway.