Europe bans backscatter X-ray machines
- Thread starter Cap'n Jack
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denverpilot
Tied Down
Nice that someone has a brain. Too bad it's not here.
n20junkie
Pre-takeoff checklist
You mean bombarding our bodies with radiation is bad?
If you are afraid of radiation, stay away from flying (on) jets for a living.
Cap'n Jack
Final Approach
So you're Ok with some security agency dosing you with more?
No. But I am equally suspect of hysteria.
The cancers that have been 'linked' to backscatter scanners are purely theoretical numbers based on aggressive assumptions not supported by much evidence.
The radiation exposures from regular flight at altitude are real, measurable and fall into a range where long term occupational exposure can indeed increase ones odds of suffering a number of cancers.
My objection to those scanners is that their false positive rate is huge and that otoh they are easily defeated.
Cap'n Jack
Final Approach
The radiation exposures from the back scatter machines are real and measurable, just as real and measurable as that from high altitude flight.
I agree with these. Radiation damage is cumulative. One could add to your list that these machines add to cumulative radiation exposure with out much, if any, benefit from improving air safety.
Reams of file cabinets have been filled with the arguments at the ICRP and NCRP level on whether radiation damage at low levels is cumulative.
I believe that it is not, if it was, we would all be dead.
Cap'n Jack
Final Approach
I hold it might be, but that's not really the point here?
Your comment about them being easily defeated is more pertinent to the thread.
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Bob Noel
huh? Aren't you assuming how quickly radiation damage can be detected?
Quite pertinent.
If a threshold exist (which is the hotly debated issue), then very low level exposures like the backscatter scanner or a single transatlantic flight are inconsequential. If we believe that the experience of populations who were exposed to millions of times the doses and dose rates in the atomic bomb explosions and the experience of displaced war refugees radiated for head-lice can be linearly scaled down to that level of a backscatter scanner, then we have to worry about 1, 10 or maybe 30 additional cases of cancer in a country of 300million.
'damage' in the sense of free radicals or chromosome breaks can be detected within seconds.
'damage' as in a clinically significant risk of developing cancer takes a number of years.
Dont move to Denver, Leadville or any of the other mining towns in the rockies. People are falling over in the streets from all the radiation they are exposed to from space and the minerals below their feet.
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Bob Noel
What makes you think that your criteria is valid? That is, because certain people aren't "falling over in the streets" that is proof that low level radiation damage isn't cumulative?
It is my educated opinion derived from dealing with this issue for the past 10 years in a professional capacity that very low level radiation exposures are not cumulative.
Doses of background radiation accross the US are quite variable. Some of this variation is based on the rocks we live on, some of it is based on how much atmosphere we have above ourselves to stop the stuff that hits us from space. It is difficult to impossible to show any difference in the numbers or types of cancers when comparing high radiation and low radiation locales (there is some evidence that radon does bad stuff, but that acts a bit different from external radiation in that you actually take it up into your lungs where it does direct damage through alpha particles).
Palmpilot
Touchdown! Greaser!
I've seen some discussion about the wavelength distribution of the backscatter machines not being the same as the natural background radiation to which it is being compared, thus making the comparison invalid. What's your opinion on that issue?
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denverpilot
Tied Down
I know you said this jokingly, but we do have some diseases with elevated rates that no one has tied a cause to. MS for one. Much higher incidence of it here than most other places.
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Bob Noel
I'm going to assume that your educated opinion is based on more than just whether or not people are falling over in the street.
See? Isn't that a more compelling rationale for believing that low level radiation doses are not cumulative (albeit not conclusive)?
Of course, on the other hand there are the precautions taken in hospitals and with dentists. Why is the technician hiding in a safe location when taking x-rays?
More seriously, I was primarily reacting to your "falling over in the street" criteria being offered as proof. I realize that with a mobile society, the vast numbers of things that produce radiation, and the body's amazing ability to heal or not, it can be extremely difficult to show correlation between exposures and damage. Even more so if the time frames of exposure span years or decades.
Anytime you are shielded from a higher energy radiation, e.g. by sitting underneath the metal roof of a car or by wearing a tinfoil hat, you will be exposed to those lower energy derivatives that are generated when higher energy radiation is dissipated in the shield. The effects of this type of radiation have been pretty well studied as they play a role during radiation therapy and in diagnostic imaging. They can cause effects on the skin, similar to what UV light will do.
Very odd disease, at this point the thinking is that there is a genetic predisposition in combination with some environmental factor. Viral infection, bacterial infection, I have never seen radiation implicated.
Most of the time, you can predict your incidence of MS pretty well by knowing how many germans, brits, scottish and swedes you have in a population.
Yes.
To make himself and the patient feel better.
Occupational radiation protection is based on the most conservative interpretation of the data and assumes a cumulative effect.
And that is why anytime someone tells you that this and that 'causes' x number of cases of cancer, you have to look at how they arrived at that number. The reality is, we live in a radioactive world with much of the radiation being from natural sources (including some of the potassium within your own cells). Other radiation is from man-made sources, the colleague of yours who got treated for thyroid disease last week, the CT scan you get for medical reasons, leftover fallout from 1960s atomic testing etc.
The natural background levels are variable and existed before the first x-ray was ever taken and before Marie Curie ever isolated radium (Marie Curie btw. died from aplastic anemia, probably related to her experiments, Pierre Curie otoh got run over by a horsedrawn carriage which somewhat illustrates my approach to radiation: Yes, it'll kill you, but so will a lot of other things). I am not terribly worried about anything that falls within the range of variability of natural background radiation.
n20junkie
Pre-takeoff checklist
So because my job has me around radiation, means I need even more?
Maybe because i am already exposed, i should be the LAST one getting more.
Soon we will all need to carry dosimeters to see if we can withstand any more radiation scans before my kids come out with 12 toes and an extra eyeball.
Well, the way cellular repair mechanisms work, by routinely being exposed to radiation, your ability to deal with just a little bit more may actually be better.
There have been dosimetric studies of airline crews that fly long haul routes accross the noth pole. They are basically radiation workers. Nobody really wants to touch this because it could mean that those lucrative routes that are handed out by seniority would have to be rotated among staff to manage the risk. Nobody would want that, right ?
mantakos
Final Approach
http://www.scientificamerican.com/article.cfm?id=graphic-science-radiation-exposure
...
Natural background (U.S.) per year: 3.1
...
Airport scanner (backscatter method): 0.0001
...
Dental x-ray: 0.005
Domestic airline flight (five hours): 0.017
Smoking one pack of cigarettes per day for a year: 0.36
Mammogram: 0.4
...
-harry...
Natural background (U.S.) per year: 3.1
...
Airport scanner (backscatter method): 0.0001
...
Dental x-ray: 0.005
Domestic airline flight (five hours): 0.017
Smoking one pack of cigarettes per day for a year: 0.36
Mammogram: 0.4
...
p1l0t
Line Up and Wait
Exactly. 300 people per year die from terrorist attacks. The cancer number is in the 6-7 figure range. Let's get real here. There is no security benefit. There are better ways that are more effective and less radioactive.
<---<^>--->
Gary F
Final Approach
I am solidly behind Weilke in this thread. I am not convinced that backscatter devices are useful for screening passengers but the fear of radiation is way overblown. I am exposed to both nuclear tracer (gamma) and conventional x-ray radiation on a regular basis. I have not even heard of anybody in my line of work getting any type of cancer or MS or any unusual diseases even though some of my older colleagues have very impressive cumulative film badge totals.
Ditch the backscatter machines and start profiling....
All Muslims are not terrorists but......
All terrorists ARE muslims
...
All Muslims are not terrorists but......
All terrorists ARE muslims
...
SkyHog
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Everything Offends Me
Ditch the backscatter machines and start profiling....
All Muslims are not terrorists but......
All terrorists ARE muslims
Except the terrorists that aren't...
Gary F
Final Approach
I think that profiling can be useful but the idea that only Muslims are a threat is ridiculous. A good examople of the failure of profiling is the Mennonite drug smugglers. That's Mennonite, like the Amish, only slightly more hip.Ditch the backscatter machines and start profiling....
All Muslims are not terrorists but......
All terrorists ARE muslims
For US police forces, the entry point into the labyrinth of today’s Mennonite drug network came via a grandfather named Cornelius Banman. It was November 23, 1989, and the Old Colony Mennonite sat in an aging pickup truck that inched towards a busy US border crossing in El Paso, Texas. Banman had pocketed several thousand dollars to deliver a load of Mennonite-made furniture from Cuauhtemoc to Winkler, Man. He had made the long, monotonous journey often. This time, however, he was in for a surprise.
A drug-sniffing dog was in another lineup when it suddenly charged towards Banman’s vehicle, barking hysterically and furiously pawing the ground beneath his truck. When startled agents tore into the furniture, they discovered over 100 kilograms of marijuana ‘bricks’ hidden in the false bottoms of a few couches. The estimated street value of the haul was $1.5 million. A 52-year old farmer who attended church regularly with his wife and children in Winkler, Banman was a ‘mule’ paid to courier drugs.
Soon, a trickle of Mennonite mules holding dual Canadian-Mexican citizenship would be detained by US border agents who realized they were encountering an unlikely new breed of drug smuggler.
By the late 1990′s, a fifth of the marijuana sold on the streets of Canada could be traced back to Mennonite drug kingpins holed up in Mexico. The slew of arrests did little to deter a steady strean of willing new recruits from teenagers to the elderly. And as confidence in the smuggling apparatus grew, so did the quantity and size of shipments. Source: Mexico
Symposium
http://mexfiles.net/2006/10/27/the-mennonites-in-mexico/
Good thing you live where you live so even if you stick your head under the c-arm you are not going to catch up with folks in Nevada.
http://energy.cr.usgs.gov/radon/usagamma.gif
Well, there is some data on posterior subcapsular cataracts in some of your colleagues. There has also be some concern about clusters of CNS tumors and hematological issues, none of it ever borne out in larger studies. But again, those doses are so many orders of magnitude higher than what a backscatter scanner will do, can't even get it on the same sheet of milimeter paper.
Interestingly, most of the radiation you (and I) are exposed to is the type of low energy scatter that is in the same energy range as the backscatter machines. Except that we get it minutes at a time instead of miliseconds.
Most of the problem is the secrecy TSA is cloaking around this. Rather than stating 'this is the energy, this is the air-kerma, this is the filter' they say 'it's a matter of national security and trust us it's safe'. The official explanation of course is that if they give up the technical details, it would be easier for the evildoers to subvert the scanners. Well, maybe it is, but I would expect an adversary that is sophisticated enough to devise a method to defeat the scanner would also be sophisticated enough to conduct a dosimetry study to detect the energy range of the radiation used.
Gary F
Final Approach
I guess that natural radiation is ok but the man made stuff is bad.
A bigger concern is the back problems you can get from wearing a lead apron for long periods of time. I use leaded glasses so hopefully cataracts are less of an issue.
The worst kind is if it's prescribed by the goverment. Who cares about the 0.1mSv you are going to get during the upcoming transcontinental flight or the 3000mSv you are exposed to just by living in an industrialized country if you can get upset about the 0.0001mSv you are exposed to duing the security screen.
Your odds of being killed during the resulting back surgery is a real one.
Consider getting protective gear made from DEMRON™ . I believe it is a Barium salt integrated in nylon fibers and woven into a fabric. Very light. Not cheap.
Care to name even one terrorist that was involved in a ( AVIATION ) related act that was not muslim ? Remember, we are discussing TSA actions at airports.
Palmpilot
Touchdown! Greaser!
Ditch the backscatter machines and start profiling....
All Muslims are not terrorists but......
All terrorists ARE muslims
Tomothy McVeigh?
n20junkie
Pre-takeoff checklist
What happens if i wear demron through a scanner?
The topic is ( aviation)... Unless he flew that Ryder rental truck to the scene of the crime.
Palmpilot
Touchdown! Greaser!
Can you explain how that relates to my question? Thanks.
Palmpilot
Touchdown! Greaser!
The topic is ( aviation)... Unless he flew that Ryder rental truck to the scene of the crime.
Ah, so ground-based terrorists can be any religion, but all aviation terrorists are Muslim. Oooookay.
That you are constantly exposed to the same types of lower energy x-rays as part of terrestial and cosmic radiation.
While the energy of the photons that hit us from space and below is in a higher energy band, if those photons hit objects in your vicinity and get slowed down or stopped, that process will create lower energy secondary x-rays. Most of those lower energy x-rays get absorbed in your clothing, objects in your pockets, or oh-wait cause backscatter from your skin....
Iow just because we are exposed to high energy radiation from space doesn't mean we are not also exposed to lower energy radiation in our environment.
You will look a bit silly
https://radshield.com/products_showmedia.asp?fName=Picture&ProductID=991
It would shield you from most of the radiation emitted by the scanner. The immediate result would probably be a pat-down.