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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."
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.
Hasn't it always been the case that you have the option to decline to use "the machine" and be hand-searched instead?
Until this issue gets resolved, that's what I plan to do anyhow.
If libertarians are so opposed to effective government, why don't they all move to Somalia?
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
out to be one of the biggest spies for the soviet union during the cold war.
dont mess with little old ladies.
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.
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?
continuity of the state and its power structures is far more important than petty things like individual freedoms or human lives.
Yep, and things like the Universal Declaration of Human Rights are only for people like us, not sub-human towelheads, Jews, Christians, Arabs, Catholics, Scots, Buddhists, dissidents or other noisemakers.
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I'm not sure which airports you go to, but the ones I go to, about half the people searched opt not to use the scanner, and the TSA agents clearly don't give a damn which route you take.
My citation is admittedly anecdotal. But her surgeries weren't. They were damn painful.
Anecdotal, yet really painful. Well, that clinches it!
Just like that guy accused of being a child rapist and murderer, it was a horrible fate for the kid, therefore that slimeball is guilty as sin.
When information is power, privacy is freedom.
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.
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.
To put this into context, the Gy (gray), is the amount of absorbed radiation. One gray is typically the point where physical effects are felt, usually in a burn to the skin. 5 Gy over the entire body is considered a lethal dose.
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.