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How Terahertz Waves Tear Apart DNA

Posted by kdawson on from the tear-a-cell dept.

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."

10 of 279 comments (clear)

  1. Shoe-Fitting Flouroscope by eldavojohn · · Score: 5, Interesting
    Reminds me of the time I was at the Science Museum in Minnesota and they had an exhibit from the Museum of Bad Science (or something like that). Anyway they had a shoe-fitting flouroscope which was a device that shoe stores bought. Basically you would put shoes on your child's feet but to see how well they fit you would jam their leg in this thing and see the bones of the toes up to the tip of the shoe and see how well it fit. See the problem yet?

    Although store clerks were frequently exposed to the radiation from the machines, the radiation was more dangerous to children who placed their feet directly into the radiation. The exposure rate is thought to have been approximately 0.005 Gy to 0.058 Gy per second. If children tried on several pairs of shoes per visit it was posited that they could be exposed to as much as 0.1 Gy to 1.16 Gy. In fact, experiments indicated that radiation could exceed 1 microGy per hour as far as 10 feet away from the machine.

    This device should be a warning (and I think it has been if you look at how cautious people are of new technologies like cell phones). Hopefully my sperm aren't being fried when I walk through a scanner in an airport--at least the parents of the 30s were using X-rays for their convenience and not the invasion of their privacy!

    --
    My work here is dung.
    1. Re:Shoe-Fitting Flouroscope by nitehawk214 · · Score: 3, Interesting

      This is exactly what I thought of when I read the summary. In fact I just saw the episode of Modern Marvels: Engineering Disasters that covers this topic last night.

      My favorite: the Revigator!

      --
      I'm a good cook. I'm a fantastic eater. - Steven Brust
  2. Ethical use of panic... by h4rm0ny · · Score: 4, Interesting


    So if there's a hysterical OMGCancer panic amongst the scientific illiterate, is it ethical to take advantage of that to protect ourselves against the privacy abuses of these things at train stations and airports and on the street?

    --

    Aide-toi, le Ciel t'aidera - Jeanne D'Arc.
    1. Re:Ethical use of panic... by AioKits · · Score: 4, Interesting

      With my assorted body jewelry I find it less hassle to actually be patted down. The scanners (last time I flew it was a millimeter waves scanner) always detect something 'on me'. The last time I went through they pulled me aside and asked, "Do you have anything on your chest sir?" I thought they were asking if I had something I wanted to tell them so I said no. They had to clarify, "Do you have any foreign objects on your chest?" I have one ring in that area, but it is only 12 gauge and not big enough to be mistken for anything really. So... I was escorted to a lil clear box, patted down, and sent on my way.

      I have little to no shame, so it didn't really bother me he was patting me down. In fact he seemed to grimace at the fact he had to do it, which made it all the more enjoyable to me.

      So now I just skip any of the scanners and opt for a pat down. It slows down security, it appears to make them uncomfortable, and if I'm lucky it'll be someone attractive patting me down.

      --
      "Quote me as saying I was mis-quoted." -Groucho Marx
  3. Doesn't worry me by Dolphinzilla · · Score: 3, Interesting

    If you read the story this conjecture is the results of a computer model ...NOT real measurements of actual damage to DNA - since no previous actual experiments have turned up any damage then I'd say the model is not quite right - at any rate its all theoretical and not proven with experiment

    1. Re:Doesn't worry me by radtea · · Score: 3, Interesting

      Actually, it's a theoretical explanation for some difficult experimental results.

      Which itself needs to be experimentally verified. The model they are using is fairly simple. In particular, they introduce the terahertz driving force into the model by hand. That's ok to suggest that under reasonable assumptions it is plausible that terahertz radiation can drive non-linear breathing-mode resonances that can create localized "bubbles" in double-stranded DNA, where the linking bonds between the two strands are broken. But it's a long, long way from a solid empirical result.

      Of course, if you believe GCM's are a sound basis for public policy, you would have to argue that there is no need to do any experimental follow-up on this: simply use the computer model to determine the safe limits. There should be no problem with that because this model is orders of magnitude more realistic than the best GCM.

      --
      Blasphemy is a human right. Blasphemophobia kills.
  4. Re:Who cares... by Xest · · Score: 3, Interesting

    Yeah exactly, so what if I have to have my arm amputated because of an agressive cancer caused by these scanners, at least it means I wont have to lose my arm to a terrorist!

  5. Re:In most cases, airport scanners are still optio by MadCow42 · · Score: 3, Interesting

    Actually, when I decline, they've always walked me to the front of the line for the other detectors. It's saved me time in the end, strangely enough.

    A few other times, when it was my turn, I simply walked to the standard detector myself, and had no issues.

    (they have two normal lanes and one terahertz scanner lane at my departure airport, but I've run into them in many other places recently too)

    --
    I used to have a sig, but I set it free and it never came back.
  6. Re:Translation by put_the_cat_out · · Score: 3, Interesting

    But what if Terahertz waves can also be used to kill a cancerous tumor? Think about this ... take to sources of focused EM energy beams, neither in the Terahertz range, and aim both energy beams at a cancerous tumor. When the two energy beams coincide at the tumor, through constructive interference, localized Terahertz waves are generated that disrupt the DNA of the cancer cells to the extent that those cells can no longer replicate. Since the energy is localized, damage to the surrounding body tissue is minimal and can be repaired by the body in a short time. As a result though, the cancer is gone.

  7. Re:Who cares... by postbigbang · · Score: 3, Interesting

    We agree. I'm not trying to go all tin-foil hat, but there are gigawatts in major cities floating around, nudging things in your body. You tell me which ones are ok [add your own citations, and I'll add mine] and everything will be fine. They'll stop the ones that have a higher statistical possibility of blowing apart DNA, RNA, or otherwise wreaking havoc, right? And everyone will follow the rule, right?

    My citation is admittedly anecdotal. But her surgeries weren't. They were damn painful.

    --
    ---- Teach Peace. It's Cheaper Than War.