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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."
Who cares if we turn into an entire country of genetically deformed freaks, at least we'll be a country of SAFE and FREE genetically deformed freaks, right? Just as envisioned by our Founding Fathers. God Bless America.
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.
continuity of the state and its power structures is far more important than petty things like individual freedoms or human lives.
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.
If you follow the link provided about the airport scanners you find that they are passive devices meaning they don't emit terahertz waves they only recieve the waves coming off of everything around us.
There are some devices out there that using terahertz radiation to inspect packages much like x-ray today.
that besides my geiger muller counter, my gas spectroscopy meter, and my decibel meter, I have to carry a terahertz microwave detector with me all the time?
If Pandora's box is destined to be opened, *I* want to be the one to open it.
I was at LAX with my family several months ago and there was a huge line to go through the metal detectors. Tempers were up, to say the least.
Ahead of me there was a group of Arabs, kaffiyeh, long beard, the works. Behind them was a little white haired lady apparently on her way back to "Mizzurah" after seeing her grandkids in LA. Sweet as can be old lady, the kind that talks to much to strangers on the airplane. Single serving friend, you know.
Guess who gets stopped by the TSA.
Needless to say, everyone in line was a bit pissed that the TSA was giving extra screening to the old lady when they just waved the Arab guys through without a second glance. That's when the guy behind me yelled out, "What the fuck are you morons searching her for? The towelheads are the ones flying shit into buildings!"
Turns out we were all on the same flight to Chicago. Real American guy boarded last, about 15 minutes late. TSA had a word with him, I suppose. Maybe scanned him a few extra times to make sure his DNA was totally fucked up.
The times I've encountered the terahertz scanners at airports, they've always been optional (although they don't make it clear to you that it is). If directed to one, I've always simply asked if I must use it or if I had a choice of a "normal" metal detector. EVERY time they've allowed me to choose (and I travel a LOT). Most times they take a note of it or ask me to sign a sheet to indicate my declination - I assume so they can figure out if people object or not.
Asking the quesiton never hurts. It also sends the message that this intrusion isn't accepted by the public. Don't surrender to these things willingly.
I used to have a sig, but I set it free and it never came back.
"This creates bubbles in the strands that can significantly interfere with processes such as gene expression and DNA replication." i.e. The birth of cancer cells. Terahertz waves are carcinogens.
"I disapprove of what you say, but I will defend to the death your right to say it." - historian Evelyn Beatrice Hall
You would deprive us of hundreds, if not thousands, of leaked nude photos of famous celebs just to save a little DNA?!?!? Are you insane, man????
SJW: Someone who has run out of real oppression, and has to fake it.
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
The summary mentions that the terahertz waves "tear apart" strands of DNA. For those who might not remember their undergraduate biology, DNA strands are held together by hydrogen bonds - not covalent bonds. So the total amount of force to "tear apart" two strands is not as great as you might imagine. For that matter, strands have to be "torn apart" in order to be replicated for cell division.
Damn_registrars has no butt-hole. Damn_registrars has no use for a butt-hole.
Actually, the article states that "THz-radiation can affect biological function, but only under specific conditions, viz. high power, or/and extended exposure, or/and specific THz frequency". At any rate resonant absorbance does not, as a common property, "build up from very small amplitudes" outside of Star Trek. It's a way of getting energy into particular modes of the system, which can ensure you put the energy in the place where it'll do the most good (or bad), not a way of boosting that energy.
No kidding!!! What do you say at this point?
That's odd. I get just one result, from someone named "visualight" on Slashdot!
i thought all DNA was double stranded. Is there single or triple stranded DNA? If all DNA is double stranded, why mention strandedness at all?
i'm not trolling, i'm asking a question. Yesterday some jerks with more mod points than sense labeled me as a troll for asking questions.
Utilizing the synergization of benchmark e-solutions to pre-workaround action items!
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.
They produce a 3-dimensional model of your body that is accurate down to the pores of your skin. They can also see a bit beyond the skin.
The publicly-released zoomed-out pictures of blue people only show one way of rendering the data that these machines gather. They could just as easily render a full-color image that looks like a photograph, with a fancy zoom feature that will give them intricate detail of any body part they choose to examine.
Single-stranded DNA has its information-encoding side exposed and flops around kind of pathetically. Double-stranded DNA sticks the two information-encoding sides together so that they're hidden and inactive, and helps you wind up and store the DNA. However the double strand can "unzip" along a small part of its length to expose two single strands which can go to work.
You can get triple-stranded DNA, but it's not traditionally been thought of as important. Normally the groove for the third strand would be occupied by proteins involved in the function and maintainence of the DNA instead. However it now seems that forming a triple strand in some regions might be important in DNA's control mechanisms too.
No kidding!!! What do you say at this point?
"break chemical bonds or ionize electrons"
Don't know about breaking apart DNA, but I'm pretty sure they can't ionize electrons.
Wait a moment, folk! We are talking about temporary separation of already uncoiled DNA (meaning, that it's probably under the process of being expressed, anyway) under very specific conditions as predicted by a computer model.
This is not even an empirical observation: we don't know that any of this happens in a cell free in vitro system and how significant the effect is (if any), we don't know if it happens in a cell culture in vitro system and how significant the effect is (if any) and we certainly don't know that anything like this happens in vivo.
Even assuming that you can create these precise conditions by an airport scanner (which seems rather doubtful), you certainly would not, in any way, be facilitating mutation in any appreciable sense*. All that you would be doing, theoretically, is to subtly alter patterns of gene expression for the few seconds it would take to walk through the scanner (basically, a very subtle regulatory effect). While you certainly can facilitate the development of cancer through such a mechanism (in fact, I'd argue that dysregulation of gene expression** at some points is simply required for carcinogenesis --yes, it can be caused by mutating proteins but these mutated proteins are almost invariably going to have direct or indirect regulatory functions***), such a dysregulation of gene expression would have be the prolonged, normal state of affairs of a cell for a cancer to actually happen. For this to be happening (in a worse case scenario) for as much as a few mere seconds can hardly even be called a dysregulation in any meaningful sense and much, much less have any effect, whatsoever, on carcinogenesis.
If, on the other hand, some government agency is monitoring you 24/7 with these scanners, then you might have reason to worry****.
* I would speculate that there's an infinitesimal chance that DNA might be more susceptible to mutations from not being as protected as it would be when paired but you have to realize that active regions of DNA get unzipped like this all the time so this effect, if it might be real, would be a drop in the bucket and utterly swamped by the background.
** For purposes of this discussion, what I mean by dysregulation of gene expression is the production of various protein products at inappropriate times or in the wrong amounts (either too much or too little of a protein).
*** Whether the function is to induce cell division or stop cell division, or to induce cell death (apoptosis) or to evade cell death (and whether it is a direct or indirect effect on the preceding --such as mechanisms sensing DNA damage, loss of contact inhibition, etc.). While other factors which may not always be strictly regulatory do exist such as invasiveness, angiogenesis, telomerase function, etc (which often will also be regulatory by involving over or under expression); these factors need to happen together with a regulatory dysfunction for an actual cancer to happen because, basically, cancer happens when a lot of different sorts of things get screwed up at the same time.
**** About adjusting your medication dose, that is.
That slashdotter must be very dense indeed.
So We Use Terahertz"
i'm sorry, but for the sake of just beautifully rhyming government supported advertising jingles, we just can't stop using these waves
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
As long as they don't subject all airport service personnel, like baggage handlers, to the same level of screening, then these games will provide no significant improvement in security.
When information is power, privacy is freedom.
But that's radiation from a natural source. Natural photons are much safer that artificial photons.
I read TFA and all I got was this lousy cookie
There's no particular reason a continuous input at a given frequency can't cause oscillations which increase until something breaks.
Yes, there is. It's called "dissipation".
As something wiggles, it tends to leak energy into its mounting points or the medium surrounding it. In some cases, like Tacoma Narrows, energy can't dissipate as quickly as it accumulates, and that's when you get structural failure. Engineers strive to predict these vibrational modes and design their structures so that dissipation will always exceed accumulation before the resonance causes damage.
How about no exposure?
It sounds like this is probably far safer and more controllable then X-Rays or Gamma Rays for the treatment of Cancer.
A big part of the idea with radiation treatments for cancer is to break the DNA of the cells such that they do not die instantly leaving a big hole, but instead are just prevented from successful reproduction. So as these cancer cells try to reproduce they die off instead. This happens slowly over time so that normal cells from healthy surrounding tissue can migrate over and fill in the treated cells as they die off.
These THz waves could target just the DNA, killing those cells in a region and unlike X-Rays may have a lower chance of creating a new cancer from the radiation itself or damaging surrounding tissues.
I am always doing that which I can not do, in order that I may learn how to do it. - Pablo Picasso
As a physician, I agree with you. Even sunlight can disrupt some of the bonds in your skin's DNA. And unless you are genetically susceptible due to lack of an enzyme (eg xeroderma pigmentosum , you should be fine if you lead a normal life. However there is a positive correlation between excessive sunlight exposure (and thus DNA damage), pale skin, and skin cancer. No biological system is perfect - that's why disease and aging exist. So if you play roulette with your enzymes, you will eventually cause a problem that they won't be able to fix, and end up with disease. The "repair mechanisms" are NOT flawless or foolproof. That's also why we have genetic mutation and evolution. Not being "foolproof" has a plus side, too. But if you end up with melanoma, you won't be too happy.
Now with a new technology it's hard to put the brakes on and say "stop! we need 20 years of testing!". Even regular ultrasound machines - which operate in the MHz range - have not been tested conclusively. We assume that they're safe, in theory. Often the benefits of using them FAR outweigh the risk - especially since they've been around for a while and no cases of harm have been reported or linked to the machines. But it's logical to try and limit exposure to what's absolutely necessary, so we don't repeat what we were doing with "harmless" x-ray machines and coincidentally were killing all our radiologists with leukemia...
Unleashing a "scanner" to be used on the general population, without their consent, possibly even covertly, and without any followup or documentation to ensure that there is really zero risk is a large gamble on the part of the government. Only if "frequent travelers" start developing strange tumors at significantly increased statistical rates will we know there's a problem. I'd hate to be one of those travelers, and I'd hate to be the owner of the company that makes these machines, if it ever happens. I hope it doesn't, but we simply don't know.
Seven puppies were harmed during the making of this post.