An explanation of backscatter scan radiation as opposed to other forms of radiation.

[FaithManor]

There is great concern about this from two different groups of radiation experts from UC San Diego and one from (okay that uni escapes me but I will try to look it up) that the type of ray travelers are being exposed to and how the machine operates is exposing travelers to far more radiation than even a typical x-ray and as it is focused directly to the skin instead of dispersing throughout the body. The radiation experienced on the plane and from appliances is gamma radiation but the backscatter scans emit beta radiation which is far more likely to cause genetic mutations. Anyone one carrying the BRAC 1 gene is in danger especially because this gene is heavily influenced by beta radiation.

 

Also, the National Institutes of Health estimates that 1 out of every 20 people is especially susceptible (again, having to do with genetics) to rapidly progressing mutations due to direct beta radiation exposure. Cellular damage is accomplished at a blazingly fast rate because beta particles are much, much tinier than alpha particles and gamma waves. The very, very few medical scanning devices that ever utilized beta imaging were HEAVILY regulated. Yet, these scanners emit exactly that radiation. Inhalation of beta particles is the worst type of exposure there is and one has to question the quality of the air in any security checkpoint after even a few of these scans have been run. Currently, there is no radiation recapturing device with the scanner.

 

Beta particles will eventually recombine with another element due to an unstable electron shell. But, it takes far, far less exposure to beta radiation to cause cellular damage than it does to alpha or gamma radiation. That's the big concern. Not the, on appearance, low dose of radiation, but the type and the fact that it is administered directly to the skin at VERY close proximity to the emitter...you can go out to the EPA website and look up specifics on beta radiation and exposure to it in industrial devices. By their own definitions, these scanners are not safe and for some people, deadly.

 

Additionally, anyone who has already had a radioactive iodine uptake test, cancer, radiation treatment for cancer, etc. is at an even higher risk of being affected by the scanners.

 

For a person who flies only once every five years, it may not be such a big deal as long as that person does not carry one of the BRAC genes...there is no safe level of direct beta exposure to beta particles for someone with this genetic predisposition and certainly when one considers that in the the screening area it is possible for beta particles to accumulate after several scans and not dissipate fast enough to react with other atoms in the environment. Beta particles will not react with just any element and therefore recombine into a harmless, non-radioactive molecule. Inhalation is an almost guarantee when something like this is so heavily used in one area of a building. As a matter of fact, the government is really showing no care at all for the employees that are going to be exposed to so much beta radiation at work. This type of instrument comes with all kinds of radiation warnings from the EPA but "we the people" have been "assured" it is all good and fine.

 

For those that travel frequently and have several of these scans in a lifetime, it's scary. For airport workers, pilots, etc. it could very well be quite lethal.

 

Just to clarify: Alpha radiation is a large particle and very damaging. However, because of the large size of the particle it is literally deflected by air/rips air molecules apart as it bombards them which causes the alpha particle to disintegrate before it can even reach the skin. Our atmosphere does an excellent job of protecting us from alpha radiation. This is why smoke detectors pose no threat to human tissue. The element Americium which is highly sensitive to smoke particles is encased in gold...one grain of it...and placed inside the smoke alarm.

 

We can safely use a grain of Americium with our 4-H club just by keeping it in a steel tube and letting them use a geiger counter to get a reading. One end of the steel tube is covered with mesh so that the radiation escapes in only one direction as the particles "fall apart" when it encounters the steel. We then handle the substance with pliers and wear gloves....any kind of glove, even ones made of paper, will cause the alpha particles to be deflected. Don't get me wrong, alpha particles are theoretically the strongest and give off the most energy, but like a cannonball rolled on a gravel driveway, they don't make it far before their energy is destroyed. One reason radon poisoning is so dangerous is that radon gives off these high energy alpha particles which normally would be deflected in our environment but can build up inside an air tight home over a long period of time to the place that there aren't enough air particles to protect the person and alpha particles are then inhaled. So, alpha is dangerous but only under very limited circumstances.

 

Beta radiation would not be dangerous, since it is a weaker form of radiation (energy wise) than gamma and alpha, if it weren't concentrated. But, because of the itty bitty size of the particles, in a concentrated form, it is worse than gamma which is the kind of radiation we are more routinely exposed to. Beta especially affects cells at the time of cell division...this is when it is most dangerous.

 

Gamma radiation is not a particle but an electromagnetic wave. As such, though powerful, it emits radiation across a wider path. It also has a short wavelength, making it a bit more controllable. Because it is emitted as a wave, it disperses throughout the body instead of delivering a focused dose directly to a any cell. Therefore, it is still less likely, as an x-ray, to cause cancer than beta particles are when delivered in close proximity to the skin.

 

I hope that helps people better understand the concern over the scanners. We've been teaching some nuclear science to our 4-H club and will be helping them build a new geiger counter. Our research in anticipation of this, has caused us to be very leery of the new scanners.

 

Faith

[mazakaal]

This is very interesting. Thanks so much for sharing.

[Sophia]

Thanks for taking the time to write this out.

[Harriet Vane]

Thank you for sharing this. Do you mind if I pass this on to a friend or two? I have been in dialogue with a couple friends about my concerns with the TSA screening, and I think your explanation would help.

[Trish]

Faith, is there a link to some of that info? I'd like to share it with others who have concerns on this issue. Between invasive pat-downs and radiation, it seems like a lot of people are stuck between a rock and an unhealthy place.

[Parrothead]

 

Additionally, anyone who has already had a radioactive iodine uptake test, cancer, radiation treatment for cancer, etc. is at an even higher risk of being affected by the scanners.

 

I've had that test. I'm so glad that I've made the decision not to fly.

[Giraffe]

Thank you so much for writing this all out. I knew parts, but not the whole, and was having a hard time explaining to my family why I was opting out of the scanners (we fly frequently).

 

Can't wait for tomorrow's flight (she says sarcastically)....

[coffeegal]

Additionally, anyone who has already had a radioactive iodine uptake test, cancer, radiation treatment for cancer, etc. is at an even higher risk of being affected by the scanners.

Faith

 

Faith,

 

Would you happen to have any links to articles discussing the link between cancer and the scanners?

 

Thank you.

[Mrs Mungo]

Not everyone is agreed on how dangerous the risk is with the backscatter x-ray. However, the millimeter wave machines (the ones that whirl around you) pose no known health risk, whatsoever.

 

http://edition.cnn.com/2010/TRAVEL/11/12/body.scanning.radiation/?hpt=Sbin

 

The risk of harmful radiation exposure from backscatter scans is very small, according to David Brenner, director of the Center for Radiological Research at Columbia University and a professor of radiation biophysics.

Brenner said the risk to an individual is "very small indeed" for a single scan. He said he is most concerned about frequent fliers, pilots and young people, because children are more sensitive to radiation.

The American College of Radiology, an organization of more than 34,000 professionals, including radiologists, oncologists and medical physicists, said it believes backscatter technology is safe.

"The ACR is not aware of any evidence that either of the scanning technologies that the TSA is considering would present significant biological effects for passengers screened," the organization said in a statement.

The organization referenced a report from the National Council on Radiation Protection and Measurements, citing that a traveler would need to receive 100 doses of backscatter radiation per year to reach what it calls a "Negligible Individual Dose."

"By these measurements, a traveler would require more than 1,000 such scans in a year to reach the effective dose equal to one standard chest X-ray," the group's statement said.

http://www.npr.org/2010/11/19/131447056/are-airport-scanners-safe?ft=1&f=1007

 

Dr. BRENNER: That's correct. As far as we know - one can never say something is safe - but as far as we know, there is no health hazard associated with the millimeter wave scanners. So the concern is more about the X-ray scanners.

Edited November 22, 2010 by Mrs Mungo

[FaithManor]

Hi, you can share it with anyone you like. The info comes from a myriad of sites and from conversations with DH's cousin, a nuclear physicist. So, I don't really have it all compiled in one place. The EPA does have an explanation on the their website of beta radiation, their concerns about industrial devices that emit beta radiation, etc. I'll list a few of the sites with basic information but then I have to run because I am accompanying a vocal group at church that has a special practice tonight. This will be some of the basic information about types of radiation.

 

http://www.epa.gov/rpdweb00/understand/beta.html

 

http://www.furryelephant.com/content/radioactivity/alpha-beta-gamma-radiation/

 

http://www.npr.org/assets/news/2010/05/17/concern.pdf

 

http://orise.orau.gov/reacts/guide/beta.htm

 

There were many more sites and of course, conversations with a nuclear physicist. His big concern was a. not the level of radiation in terms of rads but the method of delivery and type of radiation and b. that the only tests conducted on these scanners was done by the company selling them. Citing posible "patent concerns" no independent labs have actually gotten their hands on these to examine the technology.

 

So, when the FDA says, NO concerns, I want to say, "Oh, you mean like Baycol, Darvocet, etc. when you approved those drugs based on the the manufacturers research because you HAVE NEVER required their findings to be verified by a testing agency that does not have a vested interest in the MONEY???? Oh yeah, I SOOOOOOOOOOOOO BELIEVE YOU!" That's what Mr. Nuclear Physicist thinks. I agree. These things might not be a health hazard but no one will ever know until a. they've been used for thirty years and the data compiled by an independent research group...so if the news is bad, well, ooops we've been frying people for quite some time or b. We get Chertoff's grubby mitts off the things and get them put through a rigorous testing from independent nuclear researchers backed by a congress with a backbone...a congress with a spine not having been seen naturally occuring in the wilds of America in the last 50 years or more!

 

I object on moral grounds. But, I also object on scientific grounds because they refuse to disclose the distance from the emitter, the possibility of inhalation which is sooooo much more deadly than the mrem/rads delivered, and have not allowed for any verification of the manufacturers findings. Anytime there is arrogance towards or fear of independent testing in the world of science, one should be cautious.

 

Faith

[Sara R]

However, the millimeter wave machines (the ones that whirl around you) pose no known health risk, whatsoever.

 

as far as we know

 

If you don't know, then you study it until you find out for certain. You don't just take the word of the company selling the machines; you make sure independent research agrees. You want long term studies before you foist it on the public for non-medical reasons.

 

If you look over the last 100 years of medicine, there have been plenty of things that science thought was "safe," and then changed their mind about. Most of those things (DES, fluoroscopes, rotavirus vaccine, just to name a few) were likely studied more than these machines have been.

[elegantlion]

Thanks, I appreciate the information. We're not planning on flying anytime soon, but I had 6 week of radiation tx for cancer several years ago. I didn't know if there was any more risk for me.

[Mrs Mungo]

However, the millimeter wave machines (the ones that whirl around you) pose no known health risk, whatsoever.

 

 

 

If you don't know, then you study it until you find out for certain. You don't just take the word of the company selling the machines; you make sure independent research agrees. You want long term studies before you foist it on the public for non-medical reasons.

 

If you look over the last 100 years of medicine, there have been plenty of things that science thought was "safe," and then changed their mind about. Most of those things (DES, fluoroscopes, rotavirus vaccine, just to name a few) were likely studied more than these machines have been.

 

Did you read the link? These waves are emitted by televisions, radios and cell phones in greater amounts than the scan exposes you to.

 

The Millimeter wave technology uses non-ionizing radio frequency energy in the millimeter wave spectrum to generate an image based on energy reflected from the body. The energy projected by the system is 100,000 times less than a cell phone transmission (.00000597 mW/cm2 for millimeter wave technology compared to 37.5 mW/cm2 for a cell phone)

[Murphy101]

Wha? Wait? OMgoodness! Isn't gamma radiation what cause Dr Banner to change into the hulk? A year from now we could have hulks every where!?

It's science fiction come to reality!

:svengo::willy_nilly::eek:

 

 

 

 

 

 

 

 

 

 

 

Sorry I'm against the scanners, but couldn't resist.:tongue_smilie:

[elizabeth]

http://www.acr.org/SecondaryMainMenuCategories/NewsPublications/FeaturedCategories/CurrentHealthCareNews/More/TheScan/TheScanSpring2010.aspx

 

I think I will take their word for it. Pop was a member of this organization, I wish he were still here to explain this to his non mathy daughter.

[Imprimis]

http://www.acr.org/SecondaryMainMenuCategories/NewsPublications/FeaturedCategories/CurrentHealthCareNews/More/TheScan/TheScanSpring2010.aspx

 

I think I will take their word for it. Pop was a member of this organization, I wish he were still here to explain this to his non mathy daughter.

 

Thanks for the link. I think it's important for all of us to be as informed as possible regarding the medical risks or lack thereof.

 

Thanks to the op, as well.

Edited November 23, 2010 by Imprimis

[Sara R]

Did you read the link? These waves are emitted by televisions, radios and cell phones in greater amounts than the scan exposes you to.

 

Even if that is true, radiation exposure is cumulative (as stated in the article). These scans are in addition to the radiation everywhere else. Some people (like me) already got plenty of radiation for good medical reasons, and I don't need any extra justfortheheckofit, thankyouverymuch.

 

And if the source of information about the safety of the radiation is solely TSA and the companies who created the scanner, I don't trust that the information is the whole truth. I want independent research, and I want more time for the scientific community to come to a consensus.

 

FLATOW: Have independent labs verified that these scanning machines are giving the low-level radiation that the TSA says they are?

 

Dr. BRENNER: Well, the answer is no.

[kalanamak]

Don't forget the radiation one is exposed to while flying. Here is a web site that talks about the excess radiation one receives while flying various routes.

 

http://www.hps.org/publicinformation/ate/faqs/commercialflights.html

[Sara R]

Read the quote carefully:

 

The American College of Radiology says it is not aware of any evidence that either of the technologies TSA is considering present any significant biological risk to passengers.

 

It's not saying they are safe; it is saying there is no evidence. That's a big difference. There is no evidence because they have not been studied by anyone other than the manufacturer. These machines aren't ready for prime time until there have been independent research studies that show no risk over the long term.

[Mrs Mungo]

Even if that is true, radiation exposure is cumulative (as stated in the article). These scans are in addition to the radiation everywhere else. Some people (like me) already got plenty of radiation for good medical reasons, and I don't need any extra justfortheheckofit, thankyouverymuch.

 

I'm sorry, but I think you are confused. One machine works by using very low x-rays. The other works via sound waves. One results in radiation, one does not. Here is yet another link explaining.

 

quote:

The new type of device being tested, called a "millimeter wave" machine, doesn't use radiation, Golden said Wednesday during a demonstration for reporters at the agency's headquarters in Arlington, Va. Instead, it uses electromagnetic waves to create an image based on energy reflected from the body.

[eternalknot]

These waves are emitted by televisions, radios and cell phones in greater amounts than the scan exposes you to.

 

The wavelength AMOUNTS may be greater than those emitted by televisions, radios and cell phones, but the wavelenth TRANSMISSIONS themselves are considerably smaller than any of those. That's an important consideration.

 

1. Unlike many people around me, I severely restrict cell phone use (and actually, many electronics) for myself and my children. I'm not convinced there aren't cumulative and long-term health concerns at risk. I actually am a bit weird in the sense that I feel this way WRT most electronics (except, obviously, my computer ;)). We don't keep any non-essential electronics in the home (alarm clocks, kitchen gadgets). We keep none in our bedrooms or living areas, where we spend 90% of our time at home - everything is pretty much in the one gameroom and the laundry room (charging area). That so many other remain unaware or unconcerned, doesn't do anything to make me feel less at risk. I'm secure in my paranoia LOL and fly my freak flag high on this one. I know most aren't like me, and that's who your comment is more likely directed towards. Still -

 

2. The TSA hasn't been forthcoming about what frequency the MMW operates on - that alone is disconcerting. We're* guessing it has to be between about 30Ghz and 100Ghz, based on what we know between us (just under 30 is minimum to penetrate most articles of clothing and - wait, your DH is military right? so he should be familiar with V-MADS, which emits 95Ghz. That's a wavelength of 3.2mm) The MMW could emit less, but it's a reasonable guess that it doesn't, if much, because that would affect resolution yada yada yada, gov't gov't gov't.

 

American cell phones operate in the 800Mhz range; for the sake of discussion let's just take 850Mhz, which is 353mm. Compare the 3.2mm from the V-MADS to the 353mm of the cell phone. Pretty considerable difference. Shorter wavelengths = more concentrated energy, even given equal electromagnetic exposure and time. That could be more than a 100x difference in wavelength between the two, all things considered. Again, the TSA hasn't shared it's operating frequency so this is all hypothetical. But for a hypothetical, it sure looks pretty plausible. Enough to err on the side of caution IMO.

 

To that, I concede that it's definitely the lesser of the two scanning evils and perhaps the least offensive of the three options (backscatter, pat-down, millimeter). But that's not necessarily the same as being without or with minimal risk or concern.

 

 

*In the room with me now are my husband, two brothers, a SIL, my two parents, my grandmother, and five kids. Both brothers are doctors, one is also a scientist. My SIL is a scientist. My dad runs the security department of a major international airline. My husband, former Army AD. I'm a flight attendant. My mom and grandma just have an opinion to share about everything LOL. We've been discussing this issue for months, but more relevantly - almost nonstop for the past several days as it affects two of us on a professional level and all of us on a personal level (we travel extensively as a family).

 

 

[ColoradoMom]

The new type of device being tested, called a "millimeter wave" machine, doesn't use radiation, Golden said Wednesday during a demonstration for reporters at the agency's headquarters in Arlington, Va. Instead, it uses electromagnetic waves to create an image based on energy reflected from the body.

quote:

 

So here's the thing - if they want to use electromagnetic waves and "not radiation" in the same sentence, then they should be called out on it. I don't know who Golden is, but this person obviously thinks the scientific explanation is far too complicated for us little people - but electromagnetic radiation and electromagnetic waves are the same thing. Radiation does not mean radioactive - it describes the movement of waves through a medium.

 

Furthermore - if you are saying they are sound waves then they are not electromagnetic waves. Which confuses people even more because he/she states in the "article" and I use the term loosely, that it IS electromagnetic waves. So which is it? Sound or electromagnetic waves? Radio waves are not sound waves.

 

If the **** people in charge would get their story straight maybe the entire country would not be so freaking confused, but as it stands now they did a pretty crappy job selling us on the necessity and the safety so they deserve every single bit of backlash they are getting.

 

In addition, terahertz waves, the type used in the scanners, do have a potential DNA effect - including the unzipping of double stranded DNA. That is no small finding.

 

Now, whether or not it turns out to be true is another story but you can read the paper here yourself: http://arxiv.org/PS_cache/arxiv/pdf/0910/0910.5294v1.pdf

[ColoradoMom]

And just to add - since the OP was about backscatter - it is still IONIZING radiation. Who cares that they are telling you it's a small dose. "Small" is relative to each individual person's past history with all other cumulative forms of ionizing radiation and that is not something they are even mentioning to the terrorist suspects - errr - airline customers.