But how come when I tried to do a binomial distribution in Minitab, it became less probable with an increasing sample size? AM I JUST RETARDED
There's something wrong with your formula obviously, as the sample size gets larger the probability should approach 1.0. Like, very large, orders of magnitude larger than the base odds (so if 1 in 30 million, try a sample size of 300 million or 3 billion).
The exact probability of a positive result using a sample size of only 30 million is not going to be a very meaningful number, because that's simply not a large enough sample size, given those odds. It would be like taking a dice, which has a chance to come up any given number 1 in 6 times, rolling it just 6 times and it never comes up "3", and saying it therefore has a 0% chance to roll a 3.... no, you need a larger sample size. That can happen in very small samples, but generally not over the long run.
If you roll the dice 100 times or 1000 times it should come up "3" about.... 1 in 6 times. Obviously it won't be exactly 1.0 in 6, but with a larger sample size it will trend towards 1 in 6.
Sooooo if we put 300 million people in the Rape-o-scanner (over 800 million people flew on airlines last year in the USA) we can expect to get about 10 cases of fatal cancer, give or take a couple. Those are the odds. So is it worth it? What are the odds of getting blown up by an underwear bomb on an airplane? Did anyone even ASK this question, before happily spending over $300 million dollars of taxpayers money (while collecting a nice 10% commission for themselves) :? That is my concern, dude.
jwalk, i just flipped a coin 5 times and got heads all five times. what are the odds that i get heads on my sixth flip?
no, he's right
in a sample of six coin flips, you are more likely to get a particular result than in a sample of five
this doesn't mean the sixth flip has a higher likelihood, and he wasn't implying that the 30,000th person to go through the scanner has a higher likelihood of getting cancer
edit: not that we should be putting any credence whatsoever on self-reported incidences of cancer caused by these machines which they cannot possibly have studied
all in all, opting for a soothing rubdown with latex gloves is going to be a fuck of a lot safer than being bombarded with radiation from a machine that hasn't been seriously studied
I'm much less worried about being exposed to one lethal dose because of a malfunction than I am about being exposed to hundreds of different minute doses as we constantly add new sources of exposure to our lives and justify it by saying "oh, it's not really that much more than _______"
jwalk, i just flipped a coin 5 times and got heads all five times. what are the odds that i get heads on my sixth flip?
no, he's right
in a sample of six coin flips, you are more likely to get a particular result than in a sample of five
this doesn't mean the sixth flip has a higher likelihood, and he wasn't implying that the 30,000th person to go through the scanner has a higher likelihood of getting cancer
he's only trivially correct and is still blatantly misunderstanding the relative risk which is the bigger issue
it's like someone trying to argue that black holes can't exist because they think the math (that they don't understand) is incorrect and you're conceding that he at least summed 2+2 correctly
jwalk, i just flipped a coin 5 times and got heads all five times. what are the odds that i get heads on my sixth flip?
no, he's right
in a sample of six coin flips, you are more likely to get a particular result than in a sample of five
this doesn't mean the sixth flip has a higher likelihood, and he wasn't implying that the 30,000th person to go through the scanner has a higher likelihood of getting cancer
he's only trivially correct and is still blatantly misunderstanding the relative risk which is the bigger issue
it's like someone trying to argue that black holes can't exist because they think the math (that they don't understand) is incorrect and you're conceding that he at least summed 2+2 correctly
it's really not like that
the question of the likelihood of someone in the first _____ number of people is a foolish one. People travel by plane constantly, and they are going to continue to do so, regardless of these security features
it is absolutely correct to state that the more people are exposed to a particular risk, the closer the number of people suffering from the result of that risk actually occurring will trend toward the expected value of that risk
what is "trivial" is the question of the likelihood of an event with a probability of occurrence of 1/X occurring in a sample size of X, especially when the actual sample size is much much greater than X and will continue climbing for the foreseeable future.
But again, this is a silly discussion. Needlessly proliferating radiation exposure of human beings isn't justified by "but only a certain number of them will get FATAL CANCER so it's not that big a deal." Many more will likely be negatively affected as this exposure pushes you a little closer to becoming symptomatic. It's not like you smoke for ten years and there's one cigarette out of ten million that gives you emphysema.
jwalk, i just flipped a coin 5 times and got heads all five times. what are the odds that i get heads on my sixth flip?
no, he's right
in a sample of six coin flips, you are more likely to get a particular result than in a sample of five
this doesn't mean the sixth flip has a higher likelihood, and he wasn't implying that the 30,000th person to go through the scanner has a higher likelihood of getting cancer
he's only trivially correct and is still blatantly misunderstanding the relative risk which is the bigger issue
it's like someone trying to argue that black holes can't exist because they think the math (that they don't understand) is incorrect and you're conceding that he at least summed 2+2 correctly
it's really not like that
the question of the likelihood of someone in the first _____ number of people is a foolish one. People travel by plane constantly, and they are going to continue to do so, regardless of these security features
it is absolutely correct to state that the more people are exposed to a particular risk, the closer the number of people suffering from the result of that risk actually occurring will trend toward the expected value of that risk
what is "trivial" is the question of the likelihood of an event with a probability of occurrence of 1/X occurring in a sample size of X, especially when the actual sample size is much much greater than X and will continue climbing for the foreseeable future.
But again, this is a silly discussion. Needlessly proliferating radiation exposure of human beings isn't justified by "but only a certain number of them will get FATAL CANCER so it's not that big a deal." Many more will likely be negatively affected as this exposure pushes you a little closer to becoming symptomatic. It's not like you smoke for ten years and there's one cigarette out of ten million that gives you emphysema.
But that's precisely the point. You have a minuscule increase in your risk of cancer based on the stated probability, and if you're going to assess the risk at all intelligently, you have to consider the risk in light of all the other risk factors you're constantly exposed to. It's idiotic to single out a 1 in 30 million risk compared to all the other risks we all (including jwalk) mindlessly but willingly expose ourselves to every day for even less tangible benefit. But no, let's focus on this one minuscule risk and ignore the fact that we face all sorts of risks every fucking day and that nothing we do is without a risk of injury or death. To focus on that one probability as being somehow much more significant is just ignorant fearmongering, but then that's something our society has developed a knack for.
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Viscount Islands[INSERT SoKo HERE]...it was the summer of my lifeRegistered Userregular
jwalk, i just flipped a coin 5 times and got heads all five times. what are the odds that i get heads on my sixth flip?
no, he's right
in a sample of six coin flips, you are more likely to get a particular result than in a sample of five
this doesn't mean the sixth flip has a higher likelihood, and he wasn't implying that the 30,000th person to go through the scanner has a higher likelihood of getting cancer
he's only trivially correct and is still blatantly misunderstanding the relative risk which is the bigger issue
it's like someone trying to argue that black holes can't exist because they think the math (that they don't understand) is incorrect and you're conceding that he at least summed 2+2 correctly
it's really not like that
the question of the likelihood of someone in the first _____ number of people is a foolish one. People travel by plane constantly, and they are going to continue to do so, regardless of these security features
it is absolutely correct to state that the more people are exposed to a particular risk, the closer the number of people suffering from the result of that risk actually occurring will trend toward the expected value of that risk
what is "trivial" is the question of the likelihood of an event with a probability of occurrence of 1/X occurring in a sample size of X, especially when the actual sample size is much much greater than X and will continue climbing for the foreseeable future.
But again, this is a silly discussion. Needlessly proliferating radiation exposure of human beings isn't justified by "but only a certain number of them will get FATAL CANCER so it's not that big a deal." Many more will likely be negatively affected as this exposure pushes you a little closer to becoming symptomatic. It's not like you smoke for ten years and there's one cigarette out of ten million that gives you emphysema.
But that's precisely the point. You have a minuscule increase in your risk of cancer based on the stated probability, and if you're going to assess the risk at all intelligently, you have to consider the risk in light of all the other risk factors you're constantly exposed to. It's idiotic to single out a 1 in 30 million risk compared to all the other risks we all (including jwalk) mindlessly but willingly expose ourselves to every day for even less tangible benefit. But no, let's focus on this one minuscule risk and ignore the fact that we face all sorts of risks every fucking day and that nothing we do is without a risk of injury or death. To focus on that one probability as being somehow much more significant is just ignorant fearmongering, but then that's something our society has developed a knack for.
And thus the scanners?
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BarcardiAll the WizardsUnder A Rock: AfganistanRegistered Userregular
edited November 2010
Here we go, a nice sciency write up on the TSA scanners, and the concern that radiation specialists have. Specifically when dealing with breast cancer and scanning kids.
I am a biochemist working in the field of biophysics. Specifically, the lab I work in (as well as many others) has spent the better part of the last decade working on the molecular mechanism of how mutations in the breast cancer susceptibility gene, BRCA2, result in cancer. The result of that work is that we now better understand that people who have a deficient BRCA2 gene are hypersensitive to DNA damage, which can be caused by a number of factors including: UV exposure, oxidative stress, improper chromosomal replication and segregation, and radiation exposure. The image below shows what happens to a chromosome of a normal cell when it is exposed to radiation. It most cases, this damage is repaired; however, at high doses or when there is a genetic defect, the cells either die or become cancerous.
Quite some time ago, I posted a short educational video that describes how BRCA1 and BRCA2 mutations cause cancer. In short, when a person who has a mutation in one of these genes is exposed to environmental factors that cause DNA damage, they simply don't repair the damage with the same efficiency as the general population. Over the course of their lifetime, the incremental exposures to relative small and seemingly safe doses of ionizing radiation (which is everything from UV light to X-rays to gamma radiation) statistically accumulate damage (or the effects f damage and improper repair) until the probability of developing cancer becomes almost certain. This is because BRCA1 and BRCA2 are both part of a molecular process that is very similar to the spell-check on your word processor (in oncology parlance, these genes are known as caretakers of the genome for this specific reason). When these genes don't work, mutations accumulate faster and eventually results in cancer.
Its because of my interest in this aspect of cancer biology that I felt compelled to review the safety reports released on the TSA website here. However, my interest is not only professional, but also personal. My grandmother died of breast cancer in 2005 after being in remission for 20+ years. While she was never tested for either BRCA1 or BRCA2, her family history indicates that there is a strong probability of one of these mutations running in my family. Including my grandmother, at least four of her siblings developed cancer: two died of breast cancer, one developed a rare form of leukemia and another died of skin cancer. All of her female siblings had cancer, and its noteworthy that her mother died of a very young age (maybe 30's or early 40's) of an unknown (to me) cause. For these reasons, I fear that inadequate safety evaluation of these machines could unduly expose my family (and myself) to levels of radiation that might be harmful should this high familial cancer rate in fact be hereditary.
Last spring, a group of scientists at the University of California at San Francisco (UCSF) including John Sedat Ph.D., David Agard Ph.D., Robert Stroud, Ph.D. and Marc Shuman, M.D. sent a letter of concern to the TSA regarding the implementation of their 'Advanced Imaging Technology', or body scanners as a routine method of security screening in US airports. Of specific concern is the scanner that uses X-ray back-scattering. In the letter they raise some interesting points, which I've quoted below:
* "Our overriding concern is the extent to which the safety of this scanning device has been adequately demonstrated. This can only be determined by a meeting of an impartial panel of experts that would include medical physicists and radiation biologists at which all of the available relevant data is reviewed."
* "The X-ray dose from these devices has often been compared in the media to the cosmic ray exposure inherent to airplane travel or that of a chest X-ray. However, this comparison is very misleading: both the air travel cosmic ray exposure and chest X-rays have much higher X-ray energies and the health consequences are appropriately understood in terms of the whole body volume dose. In contrast, these new airport scanners are largely depositing their energy into the skin and immediately adjacent tissue, and since this is such a small fraction of body weight/vol, possibly by one to two orders of magnitude, the real dose to the skin is now high."
* "In addition, it appears that real independent safety data do not exist."
* "There is good reason to believe that these scanners will increase the risk of cancer to children and other vulnerable populations. We are unanimous in believing that the potential health consequences need to be rigorously studied before these scanners are adopted."
In order to really understand these concerns, I think its important to consider the type of radiation used in these
scanners, which the TSA has described as 'soft' and 'safe'. First, we need to clarify the definition of 'soft' vs 'hard' X-rays. The TSA has been stating that the X-rays used in the back scatter machines use 'soft' X-rays, which are defined as radiation between 0.12-12 keV (or kilo electron volts) and are generally stopped, or absorbed, by soft tissue or low density matter. 'Hard' X-rays are between 12-128 keV and are absorbed by dense matter like bone. According to the TSA safety documents, AIT uses an 50 keV source that emits a broad spectra (see adjacent graph from here). Essentially, this means that the X-ray source used in the Rapiscan system is the same as those used for mammograms and some dental X-rays, and uses BOTH 'soft' and 'hard' X-rays. Its very disturbing that the TSA has been misleading on this point. Here is the real catch: the softer the X-ray, the more its absorbed by the body, and the higher the biologically relevant dose! This means, that this radiation is potentially worse than an a higher energy medical chest X-ray.
With that being said, because the scanners have both a radiation source AND a detector in the front AND back of the person in the scanner, it is actually possible for the hardware to conduct a classic, through-the-body X-ray. The TSA claims that the machines are not currently being used in that way; however, based on the limited engineering schematics released in the safety documents, they could be certainly be easily reconfigured to do so by altering the aluminum-plate (or equivalent) filter or by changing the software. So the hardware has the capability to output quite high doses of radiation, however a biological dose is a function of the time of exposure as well as the proximity to the source and the power of the power of the source. Unfortunately, it is difficult to determine which zones in the scanner are 'hottest' because that information is masked in the document. An excerpt of the safety evaluation from Johns Hopkins is shown below to give you sense of how much other information is being withheld. Ultimately my point is this: even though the dose may actually be low, these machines are capable of much higher radiation output through device failure or both unauthorized or authorized reconfiguration of either hardware or software.
Which brings me to how the scanner works. Essentially, it appears that an X-ray beam is rastered across the body, which highlights the importance of one of the specific concerns raised by the UCSF scientists... what happens if the machine fails, or gets stuck, during a raster. How much radiation would a person's eye, hand, testicle, stomach, etc be exposed to during such a failure. What is the failure rate of these machines? What is the failure rate in an operational environment? Who services the machine? What is the decay rate of the filter? What is the decay rate of the shielding material? What is the variability in the power of the X-ray source during the manufacturing process? This last question may seem trivial; however, the Johns Hopkins Applied Physics Laboratory noted significant differences in their test models, which were supposed to be precisely up to spec. Its also interesting to note that the Johns Hopkins Applied Physics Laboratory criticized other reports from NIST (the National Institute of Standards and Technology) and a group called Medical and Health Physics Consulting for testing the machine while one of the two X-ray sources was disabled (citations at the bottom of the page).
These questions have not been answered to any satisfaction and the UCSF scientists, all esteemed in their fields and members of the National Academy of Sciences have been dismissed based on a couple of reports seemingly hastily put together by mid-level government lab technicians. The documents that I have reviewed thus far either have NO AUTHOR CREDITS or are NOT authored by anyone with either a Ph.D. or a M.D., raising serious concerns of the extent of the expertise of the individuals and organizations evaluating these machines. Yet, the FDA and TSA continue to dismiss some of the most talented scientists in the country...
With respect to errors in the safety reports and/or misleading information about them, the statement that one scan is equivalent to 2-3 minutes of your flight is VERY misleading. Most cosmic radiation is composed of high energy particles that passes right through our body, the plane and even most of the earth itself without being absorbed or even detected. The spectrum that is dangerous is known as ionizing radiation and most of that is absorbed by the hull of the airplane. So relating non-absorbing cosmic radiation to tissue absorbing man-made radiation is simply misleading and wrong.
Furthermore, when making this comparison, the TSA and FDA are calculating that the dose is absorbed throughout the body. According the simulations performed by NIST, the relative absorption of the radiation is ~20-35-fold higher in the skin, breast, testes and thymus than the brain, or 7-12-fold higher than bone marrow. So a total body dose is misleading, because there is differential absorption in some tissues. Of particular concern is radiation exposure to the testes, which could result in infertility or birth defects, and breasts for women who might carry a BRCA1 or BRCA2 mutation. Even more alarming is that because the radiation energy is the same for all adults, children or infants, the relative absorbed dose is twice as high for small children and infants because they have a smaller body mass (both total and tissue specific) to distribute the dose. Alarmingly, the radiation dose to an infant's testes and skeleton is 60-fold higher than the absorbed dose to an adult brain.
There also appears to be unit conversion error in the Appendix of the report, which was recently cited by the FDA in response to the UCSF scientist's letter of concern, which might mean that the relative skin dose is 1000-fold higher than the report indicates (pg Appendix B, pg ii, units of microSv are used in an example calculation, when it appears that units of milliSv should have been used). I attempted to contact the author, Frank Cerra, to query whether this was a computational mistake or an unexplained conversion; however, none of his web-published email addresses are valid and there was no answer by phone. I cannot rule out that a conversion factor was used that was not described in the methods, and would welcome confirmation or rebuttal of this observation.
Finally, I would like to comment on the safety of the TSA officers (TSO) who will be operating these machines, and will be constant 'bystanders' with respect to the radiation exposure. The range of exposure estimates is a function of where an officer stands during their duty, what percentage of that duty is spent in the same location and how often the machine is running. A TSO could be exposed to as much as 86-1408 mrem per year (assuming 8 hours per day, 40 hours a week, 50 weeks per year and between 30-100% duty and 25-100% occupancy, as defined by the Johns Hopkins report), which is between 86%-141% of the safe exposure of 100 mrem. At the high end, if for example a TSO is standing at the entrance of the scanner when it is running at maximum capacity, then that officer could hit their radiation exposure limit in as few as 20 working days (assuming an 8 hour shift). While we may not be very happy with our TSOs at the moment as the face of these policies, we need to keep in mind that they really should be wearing radiation badges in order to know their specific exposure (especially for those officers who may also have to receive radiation exposure for medical reasons).
As far as I'm concerned, the jury is still out on whether these machines are safe or even could be made safe for this application. Until then, I suggest keeping your family out of these machines and as vile as it is, either submit to a physical search or just don't fly.
Safety reports that should be considered invalid due to the fact that one of the two X-ray sources was disabled during testing:
1. Medical and Health Physics Consulting, Radiation Report on Rapiscan Systems Secure 1000 (March 21, 2006).
2. Medical and Health Physics Consulting, Radiation Report on Rapiscan Systems Secure 1000 (June 5, 2008).
3. Medical and Health Physics Consulting, Supplement to Report dated June 5, 2008 (October 28, 2008).
4. National Institute of Standards and Technology Assessment of Radiation Safety and Compliance with ANSI N43.17-2002 Rapiscan Dual Secure 1000 Personnel Scanner (July 9, 2008).
blah blah blah we can see your childs balls from this xray
jwalk, i just flipped a coin 5 times and got heads all five times. what are the odds that i get heads on my sixth flip?
no, he's right
in a sample of six coin flips, you are more likely to get a particular result than in a sample of five
this doesn't mean the sixth flip has a higher likelihood, and he wasn't implying that the 30,000th person to go through the scanner has a higher likelihood of getting cancer
he's only trivially correct and is still blatantly misunderstanding the relative risk which is the bigger issue
it's like someone trying to argue that black holes can't exist because they think the math (that they don't understand) is incorrect and you're conceding that he at least summed 2+2 correctly
it's really not like that
the question of the likelihood of someone in the first _____ number of people is a foolish one. People travel by plane constantly, and they are going to continue to do so, regardless of these security features
it is absolutely correct to state that the more people are exposed to a particular risk, the closer the number of people suffering from the result of that risk actually occurring will trend toward the expected value of that risk
what is "trivial" is the question of the likelihood of an event with a probability of occurrence of 1/X occurring in a sample size of X, especially when the actual sample size is much much greater than X and will continue climbing for the foreseeable future.
But again, this is a silly discussion. Needlessly proliferating radiation exposure of human beings isn't justified by "but only a certain number of them will get FATAL CANCER so it's not that big a deal." Many more will likely be negatively affected as this exposure pushes you a little closer to becoming symptomatic. It's not like you smoke for ten years and there's one cigarette out of ten million that gives you emphysema.
But that's precisely the point. You have a minuscule increase in your risk of cancer based on the stated probability, and if you're going to assess the risk at all intelligently, you have to consider the risk in light of all the other risk factors you're constantly exposed to. It's idiotic to single out a 1 in 30 million risk compared to all the other risks we all (including jwalk) mindlessly but willingly expose ourselves to every day for even less tangible benefit. But no, let's focus on this one minuscule risk and ignore the fact that we face all sorts of risks every fucking day and that nothing we do is without a risk of injury or death. To focus on that one probability as being somehow much more significant is just ignorant fearmongering, but then that's something our society has developed a knack for.
I also keep my cellphone in my backpack rather than my pants pocket, don't microwave plastic, stay away from foods produced with pesticides or hormones as much as possible... I'm not ignoring those risks, and I'm not going to take it on the word of the people building the fucking things that there's a one in 30 million chance of fatal cancer when they don't have actual data to support that and when there's no low-end threshold below which there is no increased risk of cancer.
What we have in terms of data is extrapolations from actual knowledge about similar types of radiation. There's no longitudinal data, no data about the effect of the machines themselves... We have a lot of moderately well informed hypotheses and very little else.
I have no interest in exposing myself to another risk factor when the reward for that risk is....
what? Lining Rapiscan's balance sheet? Engaging in security theater? Why? We have an unknown risk to which many millions of people will be exposed over the years balanced against a somewhat more known reduction in risk of death by terrorist attack (which is already minuscule and won't be appreciably reduced by scanning one out of every ten people who walk through the airport*). I just don't see why, even if this is a very very small risk, it makes sense to expose ourselves to it willingly when there's no appreciable benefit to the exposure.
*as an exercise in conditional probability, given a 1/10 probability of being scanned at the security line, how many bombs would you have to put in people's underwear on one day in order to be 90% sure that your plot would survive the full-body scan section of the security procedures?
Here we go, a nice sciency write up on the TSA scanners, and the concern that radiation specialists have. Specifically when dealing with breast cancer and scanning kids.
I am a biochemist working in the field of biophysics. Specifically, the lab I work in (as well as many others) has spent the better part of the last decade working on the molecular mechanism of how mutations in the breast cancer susceptibility gene, BRCA2, result in cancer. The result of that work is that we now better understand that people who have a deficient BRCA2 gene are hypersensitive to DNA damage, which can be caused by a number of factors including: UV exposure, oxidative stress, improper chromosomal replication and segregation, and radiation exposure. The image below shows what happens to a chromosome of a normal cell when it is exposed to radiation. It most cases, this damage is repaired; however, at high doses or when there is a genetic defect, the cells either die or become cancerous.
Quite some time ago, I posted a short educational video that describes how BRCA1 and BRCA2 mutations cause cancer. In short, when a person who has a mutation in one of these genes is exposed to environmental factors that cause DNA damage, they simply don't repair the damage with the same efficiency as the general population. Over the course of their lifetime, the incremental exposures to relative small and seemingly safe doses of ionizing radiation (which is everything from UV light to X-rays to gamma radiation) statistically accumulate damage (or the effects f damage and improper repair) until the probability of developing cancer becomes almost certain. This is because BRCA1 and BRCA2 are both part of a molecular process that is very similar to the spell-check on your word processor (in oncology parlance, these genes are known as caretakers of the genome for this specific reason). When these genes don't work, mutations accumulate faster and eventually results in cancer.
Its because of my interest in this aspect of cancer biology that I felt compelled to review the safety reports released on the TSA website here. However, my interest is not only professional, but also personal. My grandmother died of breast cancer in 2005 after being in remission for 20+ years. While she was never tested for either BRCA1 or BRCA2, her family history indicates that there is a strong probability of one of these mutations running in my family. Including my grandmother, at least four of her siblings developed cancer: two died of breast cancer, one developed a rare form of leukemia and another died of skin cancer. All of her female siblings had cancer, and its noteworthy that her mother died of a very young age (maybe 30's or early 40's) of an unknown (to me) cause. For these reasons, I fear that inadequate safety evaluation of these machines could unduly expose my family (and myself) to levels of radiation that might be harmful should this high familial cancer rate in fact be hereditary.
Last spring, a group of scientists at the University of California at San Francisco (UCSF) including John Sedat Ph.D., David Agard Ph.D., Robert Stroud, Ph.D. and Marc Shuman, M.D. sent a letter of concern to the TSA regarding the implementation of their 'Advanced Imaging Technology', or body scanners as a routine method of security screening in US airports. Of specific concern is the scanner that uses X-ray back-scattering. In the letter they raise some interesting points, which I've quoted below:
* "Our overriding concern is the extent to which the safety of this scanning device has been adequately demonstrated. This can only be determined by a meeting of an impartial panel of experts that would include medical physicists and radiation biologists at which all of the available relevant data is reviewed."
* "The X-ray dose from these devices has often been compared in the media to the cosmic ray exposure inherent to airplane travel or that of a chest X-ray. However, this comparison is very misleading: both the air travel cosmic ray exposure and chest X-rays have much higher X-ray energies and the health consequences are appropriately understood in terms of the whole body volume dose. In contrast, these new airport scanners are largely depositing their energy into the skin and immediately adjacent tissue, and since this is such a small fraction of body weight/vol, possibly by one to two orders of magnitude, the real dose to the skin is now high."
* "In addition, it appears that real independent safety data do not exist."
* "There is good reason to believe that these scanners will increase the risk of cancer to children and other vulnerable populations. We are unanimous in believing that the potential health consequences need to be rigorously studied before these scanners are adopted."
In order to really understand these concerns, I think its important to consider the type of radiation used in these
scanners, which the TSA has described as 'soft' and 'safe'. First, we need to clarify the definition of 'soft' vs 'hard' X-rays. The TSA has been stating that the X-rays used in the back scatter machines use 'soft' X-rays, which are defined as radiation between 0.12-12 keV (or kilo electron volts) and are generally stopped, or absorbed, by soft tissue or low density matter. 'Hard' X-rays are between 12-128 keV and are absorbed by dense matter like bone. According to the TSA safety documents, AIT uses an 50 keV source that emits a broad spectra (see adjacent graph from here). Essentially, this means that the X-ray source used in the Rapiscan system is the same as those used for mammograms and some dental X-rays, and uses BOTH 'soft' and 'hard' X-rays. Its very disturbing that the TSA has been misleading on this point. Here is the real catch: the softer the X-ray, the more its absorbed by the body, and the higher the biologically relevant dose! This means, that this radiation is potentially worse than an a higher energy medical chest X-ray.
With that being said, because the scanners have both a radiation source AND a detector in the front AND back of the person in the scanner, it is actually possible for the hardware to conduct a classic, through-the-body X-ray. The TSA claims that the machines are not currently being used in that way; however, based on the limited engineering schematics released in the safety documents, they could be certainly be easily reconfigured to do so by altering the aluminum-plate (or equivalent) filter or by changing the software. So the hardware has the capability to output quite high doses of radiation, however a biological dose is a function of the time of exposure as well as the proximity to the source and the power of the power of the source. Unfortunately, it is difficult to determine which zones in the scanner are 'hottest' because that information is masked in the document. An excerpt of the safety evaluation from Johns Hopkins is shown below to give you sense of how much other information is being withheld. Ultimately my point is this: even though the dose may actually be low, these machines are capable of much higher radiation output through device failure or both unauthorized or authorized reconfiguration of either hardware or software.
Which brings me to how the scanner works. Essentially, it appears that an X-ray beam is rastered across the body, which highlights the importance of one of the specific concerns raised by the UCSF scientists... what happens if the machine fails, or gets stuck, during a raster. How much radiation would a person's eye, hand, testicle, stomach, etc be exposed to during such a failure. What is the failure rate of these machines? What is the failure rate in an operational environment? Who services the machine? What is the decay rate of the filter? What is the decay rate of the shielding material? What is the variability in the power of the X-ray source during the manufacturing process? This last question may seem trivial; however, the Johns Hopkins Applied Physics Laboratory noted significant differences in their test models, which were supposed to be precisely up to spec. Its also interesting to note that the Johns Hopkins Applied Physics Laboratory criticized other reports from NIST (the National Institute of Standards and Technology) and a group called Medical and Health Physics Consulting for testing the machine while one of the two X-ray sources was disabled (citations at the bottom of the page).
These questions have not been answered to any satisfaction and the UCSF scientists, all esteemed in their fields and members of the National Academy of Sciences have been dismissed based on a couple of reports seemingly hastily put together by mid-level government lab technicians. The documents that I have reviewed thus far either have NO AUTHOR CREDITS or are NOT authored by anyone with either a Ph.D. or a M.D., raising serious concerns of the extent of the expertise of the individuals and organizations evaluating these machines. Yet, the FDA and TSA continue to dismiss some of the most talented scientists in the country...
With respect to errors in the safety reports and/or misleading information about them, the statement that one scan is equivalent to 2-3 minutes of your flight is VERY misleading. Most cosmic radiation is composed of high energy particles that passes right through our body, the plane and even most of the earth itself without being absorbed or even detected. The spectrum that is dangerous is known as ionizing radiation and most of that is absorbed by the hull of the airplane. So relating non-absorbing cosmic radiation to tissue absorbing man-made radiation is simply misleading and wrong.
Furthermore, when making this comparison, the TSA and FDA are calculating that the dose is absorbed throughout the body. According the simulations performed by NIST, the relative absorption of the radiation is ~20-35-fold higher in the skin, breast, testes and thymus than the brain, or 7-12-fold higher than bone marrow. So a total body dose is misleading, because there is differential absorption in some tissues. Of particular concern is radiation exposure to the testes, which could result in infertility or birth defects, and breasts for women who might carry a BRCA1 or BRCA2 mutation. Even more alarming is that because the radiation energy is the same for all adults, children or infants, the relative absorbed dose is twice as high for small children and infants because they have a smaller body mass (both total and tissue specific) to distribute the dose. Alarmingly, the radiation dose to an infant's testes and skeleton is 60-fold higher than the absorbed dose to an adult brain.
There also appears to be unit conversion error in the Appendix of the report, which was recently cited by the FDA in response to the UCSF scientist's letter of concern, which might mean that the relative skin dose is 1000-fold higher than the report indicates (pg Appendix B, pg ii, units of microSv are used in an example calculation, when it appears that units of milliSv should have been used). I attempted to contact the author, Frank Cerra, to query whether this was a computational mistake or an unexplained conversion; however, none of his web-published email addresses are valid and there was no answer by phone. I cannot rule out that a conversion factor was used that was not described in the methods, and would welcome confirmation or rebuttal of this observation.
Finally, I would like to comment on the safety of the TSA officers (TSO) who will be operating these machines, and will be constant 'bystanders' with respect to the radiation exposure. The range of exposure estimates is a function of where an officer stands during their duty, what percentage of that duty is spent in the same location and how often the machine is running. A TSO could be exposed to as much as 86-1408 mrem per year (assuming 8 hours per day, 40 hours a week, 50 weeks per year and between 30-100% duty and 25-100% occupancy, as defined by the Johns Hopkins report), which is between 86%-141% of the safe exposure of 100 mrem. At the high end, if for example a TSO is standing at the entrance of the scanner when it is running at maximum capacity, then that officer could hit their radiation exposure limit in as few as 20 working days (assuming an 8 hour shift). While we may not be very happy with our TSOs at the moment as the face of these policies, we need to keep in mind that they really should be wearing radiation badges in order to know their specific exposure (especially for those officers who may also have to receive radiation exposure for medical reasons).
As far as I'm concerned, the jury is still out on whether these machines are safe or even could be made safe for this application. Until then, I suggest keeping your family out of these machines and as vile as it is, either submit to a physical search or just don't fly.
Safety reports that should be considered invalid due to the fact that one of the two X-ray sources was disabled during testing:
1. Medical and Health Physics Consulting, Radiation Report on Rapiscan Systems Secure 1000 (March 21, 2006).
2. Medical and Health Physics Consulting, Radiation Report on Rapiscan Systems Secure 1000 (June 5, 2008).
3. Medical and Health Physics Consulting, Supplement to Report dated June 5, 2008 (October 28, 2008).
4. National Institute of Standards and Technology Assessment of Radiation Safety and Compliance with ANSI N43.17-2002 Rapiscan Dual Secure 1000 Personnel Scanner (July 9, 2008).
blah blah blah we can see your childs balls from this xray
Thanks for posting this. He raises some excellent questions and makes some very good points. Also after reading that I have to give Fram's concern much more credibility than I did before since he specifically states that the software can cause them to increase the x-ray output.
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BarcardiAll the WizardsUnder A Rock: AfganistanRegistered Userregular
edited November 2010
Yeah, it also makes you wonder just why there isnt anyone else out there that is not raising these concerns to a independent public study level.
The tldr of how I read that as a nonscientist guy is that the moment those things need maintenance we all get super x-rayed because there is no way in hell the TSA will have the cash to pay for the regular maintenance/training for not fucking with the software.
jwalk, i just flipped a coin 5 times and got heads all five times. what are the odds that i get heads on my sixth flip?
no, he's right
in a sample of six coin flips, you are more likely to get a particular result than in a sample of five
this doesn't mean the sixth flip has a higher likelihood, and he wasn't implying that the 30,000th person to go through the scanner has a higher likelihood of getting cancer
he's only trivially correct and is still blatantly misunderstanding the relative risk which is the bigger issue
it's like someone trying to argue that black holes can't exist because they think the math (that they don't understand) is incorrect and you're conceding that he at least summed 2+2 correctly
it's really not like that
the question of the likelihood of someone in the first _____ number of people is a foolish one. People travel by plane constantly, and they are going to continue to do so, regardless of these security features
it is absolutely correct to state that the more people are exposed to a particular risk, the closer the number of people suffering from the result of that risk actually occurring will trend toward the expected value of that risk
what is "trivial" is the question of the likelihood of an event with a probability of occurrence of 1/X occurring in a sample size of X, especially when the actual sample size is much much greater than X and will continue climbing for the foreseeable future.
But again, this is a silly discussion. Needlessly proliferating radiation exposure of human beings isn't justified by "but only a certain number of them will get FATAL CANCER so it's not that big a deal." Many more will likely be negatively affected as this exposure pushes you a little closer to becoming symptomatic. It's not like you smoke for ten years and there's one cigarette out of ten million that gives you emphysema.
But that's precisely the point. You have a minuscule increase in your risk of cancer based on the stated probability, and if you're going to assess the risk at all intelligently, you have to consider the risk in light of all the other risk factors you're constantly exposed to. It's idiotic to single out a 1 in 30 million risk compared to all the other risks we all (including jwalk) mindlessly but willingly expose ourselves to every day for even less tangible benefit. But no, let's focus on this one minuscule risk and ignore the fact that we face all sorts of risks every fucking day and that nothing we do is without a risk of injury or death. To focus on that one probability as being somehow much more significant is just ignorant fearmongering, but then that's something our society has developed a knack for.
I also keep my cellphone in my backpack rather than my pants pocket, don't microwave plastic, stay away from foods produced with pesticides or hormones as much as possible... I'm not ignoring those risks, and I'm not going to take it on the word of the people building the fucking things that there's a one in 30 million chance of fatal cancer when they don't have actual data to support that and when there's no low-end threshold below which there is no increased risk of cancer.
What we have in terms of data is extrapolations from actual knowledge about similar types of radiation. There's no longitudinal data, no data about the effect of the machines themselves... We have a lot of moderately well informed hypotheses and very little else.
I have no interest in exposing myself to another risk factor when the reward for that risk is....
what? Lining Rapiscan's balance sheet? Engaging in security theater? Why? We have an unknown risk to which many millions of people will be exposed over the years balanced against a somewhat more known reduction in risk of death by terrorist attack (which is already minuscule and won't be appreciably reduced by scanning one out of every ten people who walk through the airport*). I just don't see why, even if this is a very very small risk, it makes sense to expose ourselves to it willingly when there's no appreciable benefit to the exposure.
*as an exercise in conditional probability, given a 1/10 probability of being scanned at the security line, how many bombs would you have to put in people's underwear on one day in order to be 90% sure that your plot would survive the full-body scan section of the security procedures?
The hilarious thing is that your first example proves me right. Science has pretty firmly established that cellphone radiation is harmless. I understand why people raised questions about their safety, but for decades they've been researched repeatedly and the consensus is clear. You're taking a precaution against an imagined threat and in spite of the other risks you list that you try to manage, my point still stands that you're surrounded by countless other risks you accept or ignore or aren't even aware of. You're an excellent example of what I was talking about. Focusing on specific boogeymen that you imagine are considerable risks while ignoring much more meaningful risks around you because you're either just used to them or blissfully, naively unaware of them. You don't know how to assess where many of the higher relative risks are, so you jump on the risk bandwagon and keep your cellphone in your pocket so you feel safer.
I never said the risk of a single scan (or a few over the course of a lifetime) is a significant risk, or more significant than others. All I'm saying... hell *I* am not saying, the very people who sold us the machines are saying they will kill a few people a year, probably (depending on how many are scanned... even 5% is 40 million people).
Yes I know, you can also get hit by lightning while shaving in the bathtub.. OMG! Yes but we don't PAY someone to hit us with lightning. Why pay someone to expose you to even more risks if the benefit isn't worth it? Is it worth it? That's all I wanna know... if we know the odds of dying to skin cancer from the Rape-o-Trons are in 1 30 million (their best guess basically, what if they're wrong?) what are the odds of getting blown up by an underwear bomb?
It's a simple risk vs reward question. Like dental xrays, the consequences of not having them are very real - a lot of pain, and possibly even an infection in your head that could very well kill you. The risks of that are far worse than the risks of the xray, so you do it.
So, for the scanners to be worth it, they have to be LESS dangerous than the thing we're trying to prevent. You understand this point, yes??
I don't think it's "fearmongering" to suggest that we understand the risks of doing something vs not doing it. To me "fearmongering" is more like "OHH SCARY TERRORISTS WITH BOMBS IN THEIR UNDIES, MUST THROW OUT ALL OUR RIGHTS AND OUR DIGNITY AND EXPOSE OURSELVES TO YET 1 MORE SOURCE OF RADIATION".
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WeaverWho are you?What do you want?Registered Userregular
I never said the risk of a single scan (or a few over the course of a lifetime) is a significant risk, or more significant than others. All I'm saying... hell *I* am not saying, the very people who sold us the machines are saying they will kill a few people a year, probably (depending on how many are scanned... even 5% is 40 million people).
Yes I know, you can also get hit by lightning while shaving in the bathtub.. OMG! Yes but we don't PAY someone to hit us with lightning. Why pay someone to expose you to even more risks if the benefit isn't worth it?
jwalk, most people in the thread would agree with you about risk/benefit concerns, especially as negligible as the benefit appears to be. That's not what most folks are jumpin' on you for. Saying that there's a statistical chance is never the same as saying x percentage will die every year. Hell, it's not even the same as saying x percentage will contract terminal cancer every year, even if those people live varying amounts of time. It's faulty reasoning. Saying you don't pay someone to strike you with lightning in comparison to paying someone to scan you is also a bad analogy. If there's a percentage chance you're going to die in your bathtub, and you're paying rent, then you are paying someone for that risk.
The hilarious thing is that your first example proves me right. Science has pretty firmly established that cellphone radiation is harmless. I understand why people raised questions about their safety, but for decades they've been researched repeatedly and the consensus is clear. You're taking a precaution against an imagined threat and in spite of the other risks you list that you try to manage, my point still stands that you're surrounded by countless other risks you accept or ignore or aren't even aware of. You're an excellent example of what I was talking about. Focusing on specific boogeymen that you imagine are considerable risks while ignoring much more meaningful risks around you because you're either just used to them or blissfully, naively unaware of them. You don't know how to assess where many of the higher relative risks are, so you jump on the risk bandwagon and keep your cellphone in your pocket so you feel safer.
I do not consider it a "considerable" risk. I consider it an unknown one, which is exactly what that article you were just lauding was explaining.
Your conclusion then, as far as I can tell, is that my inability to anticipate threats which I cannot identify means I should take it on faith that this shit is safe because the guy who built the thing has an off the cuff estimate of its danger and that estimate is relatively minimal compared to the ones I do actively avoid, or in the alternative, that the fact that I accept certain risks as necessary means I should accept this one, despite the fact that I don't believe there are any benefits to accepting it.
Let's put it this way: you've got a lot of new indicators in the environment over the years as industry becomes more and more sophisticated, and we ought to evaluate those risks as they appear. We're now talking about introducing a new device into the lives of hundreds of millions of people (let's not forget the TSA agents who work with them every day, either) and we're doing it without evaluating either its efficacy or it's safety. You're constantly repeating how we should be evaluating the risks logically and in comparison to other risks. Well, compare it to the reward we're getting out of implementing these things. On the negative side you have an unestablished risk of increased rates of cancer. On the positive side, you have nothing at fucking all. Why should this be a difficult decision for anyone?
(the cellphone risk, incidentally, is not one related to cancer. I didn't intend to conflate them.)
So you got your pannies in a bunch when I said "x will die" when I should have said "x are very likely to die".. ok yea you got me. Sorry bout that..... Does it make that much difference from a practical standpoint though? When is the chance of something happening significant enough that for all practical purposes it's good enough to just say it "will" happen?
So you got your pannies in a bunch when I said "x will die" when I should have said "x are very likely to die".. ok yea you got me. Sorry bout that..... Does it make that much difference from a practical standpoint though? When is the chance of something happening significant enough that for all practical purposes it's good enough to just say it "will" happen?
Sematics, serious business.
I'm curious that if 1/30 mill is an unacceptable risk, what you you consider appropriate
remember that it's impossible to have 0% risk. Also it's probably impossible to test even risks that small, let alone smaller
I wonder if having a boner will explose your balls to more radiation when you go through the scanner. Like, does a flaccid wang act as a radiation sponge? When you raise the blinds, the sun shines in.
So you got your pannies in a bunch when I said "x will die" when I should have said "x are very likely to die".. ok yea you got me. Sorry bout that..... Does it make that much difference from a practical standpoint though? When is the chance of something happening significant enough that for all practical purposes it's good enough to just say it "will" happen?
I like how we're ignoring the fact that the 1/30 million chance is probably total bullshit. I'd say wait until an independent study is done on- oh wait there'll probably never be one because that would be a "compromise of security procedure" or some bullshit
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MrMonroepassed outon the floor nowRegistered Userregular
So you got your pannies in a bunch when I said "x will die" when I should have said "x are very likely to die".. ok yea you got me. Sorry bout that..... Does it make that much difference from a practical standpoint though? When is the chance of something happening significant enough that for all practical purposes it's good enough to just say it "will" happen?
Sematics, serious business.
Because nobody is going to die.
These scanners are probably going to kill nobody
except that you're just assuming that with no evidence
which is an assumption I tend away from when being bombarded with radiation for no reason at all
Posts
The exact probability of a positive result using a sample size of only 30 million is not going to be a very meaningful number, because that's simply not a large enough sample size, given those odds. It would be like taking a dice, which has a chance to come up any given number 1 in 6 times, rolling it just 6 times and it never comes up "3", and saying it therefore has a 0% chance to roll a 3.... no, you need a larger sample size. That can happen in very small samples, but generally not over the long run.
If you roll the dice 100 times or 1000 times it should come up "3" about.... 1 in 6 times. Obviously it won't be exactly 1.0 in 6, but with a larger sample size it will trend towards 1 in 6.
Sooooo if we put 300 million people in the Rape-o-scanner (over 800 million people flew on airlines last year in the USA) we can expect to get about 10 cases of fatal cancer, give or take a couple. Those are the odds. So is it worth it? What are the odds of getting blown up by an underwear bomb on an airplane? Did anyone even ASK this question, before happily spending over $300 million dollars of taxpayers money (while collecting a nice 10% commission for themselves) :? That is my concern, dude.
IS IT WORTH IT?
PSN: Robo_Wizard1
no one surprised
What spring does with the cherry trees.
no, he's right
in a sample of six coin flips, you are more likely to get a particular result than in a sample of five
this doesn't mean the sixth flip has a higher likelihood, and he wasn't implying that the 30,000th person to go through the scanner has a higher likelihood of getting cancer
edit: not that we should be putting any credence whatsoever on self-reported incidences of cancer caused by these machines which they cannot possibly have studied
all in all, opting for a soothing rubdown with latex gloves is going to be a fuck of a lot safer than being bombarded with radiation from a machine that hasn't been seriously studied
I'm much less worried about being exposed to one lethal dose because of a malfunction than I am about being exposed to hundreds of different minute doses as we constantly add new sources of exposure to our lives and justify it by saying "oh, it's not really that much more than _______"
he's only trivially correct and is still blatantly misunderstanding the relative risk which is the bigger issue
it's like someone trying to argue that black holes can't exist because they think the math (that they don't understand) is incorrect and you're conceding that he at least summed 2+2 correctly
it's really not like that
the question of the likelihood of someone in the first _____ number of people is a foolish one. People travel by plane constantly, and they are going to continue to do so, regardless of these security features
it is absolutely correct to state that the more people are exposed to a particular risk, the closer the number of people suffering from the result of that risk actually occurring will trend toward the expected value of that risk
what is "trivial" is the question of the likelihood of an event with a probability of occurrence of 1/X occurring in a sample size of X, especially when the actual sample size is much much greater than X and will continue climbing for the foreseeable future.
But again, this is a silly discussion. Needlessly proliferating radiation exposure of human beings isn't justified by "but only a certain number of them will get FATAL CANCER so it's not that big a deal." Many more will likely be negatively affected as this exposure pushes you a little closer to becoming symptomatic. It's not like you smoke for ten years and there's one cigarette out of ten million that gives you emphysema.
Yeah, I have never seen that before.
Pretty funny though (I guess).
But that's precisely the point. You have a minuscule increase in your risk of cancer based on the stated probability, and if you're going to assess the risk at all intelligently, you have to consider the risk in light of all the other risk factors you're constantly exposed to. It's idiotic to single out a 1 in 30 million risk compared to all the other risks we all (including jwalk) mindlessly but willingly expose ourselves to every day for even less tangible benefit. But no, let's focus on this one minuscule risk and ignore the fact that we face all sorts of risks every fucking day and that nothing we do is without a risk of injury or death. To focus on that one probability as being somehow much more significant is just ignorant fearmongering, but then that's something our society has developed a knack for.
And thus the scanners?
What spring does with the cherry trees.
http://myhelicaltryst.blogspot.com/2010/11/tsa-x-ray-backscatter-body-scanner.html
blah blah blah we can see your childs balls from this xray
I also keep my cellphone in my backpack rather than my pants pocket, don't microwave plastic, stay away from foods produced with pesticides or hormones as much as possible... I'm not ignoring those risks, and I'm not going to take it on the word of the people building the fucking things that there's a one in 30 million chance of fatal cancer when they don't have actual data to support that and when there's no low-end threshold below which there is no increased risk of cancer.
What we have in terms of data is extrapolations from actual knowledge about similar types of radiation. There's no longitudinal data, no data about the effect of the machines themselves... We have a lot of moderately well informed hypotheses and very little else.
I have no interest in exposing myself to another risk factor when the reward for that risk is....
what? Lining Rapiscan's balance sheet? Engaging in security theater? Why? We have an unknown risk to which many millions of people will be exposed over the years balanced against a somewhat more known reduction in risk of death by terrorist attack (which is already minuscule and won't be appreciably reduced by scanning one out of every ten people who walk through the airport*). I just don't see why, even if this is a very very small risk, it makes sense to expose ourselves to it willingly when there's no appreciable benefit to the exposure.
*as an exercise in conditional probability, given a 1/10 probability of being scanned at the security line, how many bombs would you have to put in people's underwear on one day in order to be 90% sure that your plot would survive the full-body scan section of the security procedures?
Thanks for posting this. He raises some excellent questions and makes some very good points. Also after reading that I have to give Fram's concern much more credibility than I did before since he specifically states that the software can cause them to increase the x-ray output.
The tldr of how I read that as a nonscientist guy is that the moment those things need maintenance we all get super x-rayed because there is no way in hell the TSA will have the cash to pay for the regular maintenance/training for not fucking with the software.
The hilarious thing is that your first example proves me right. Science has pretty firmly established that cellphone radiation is harmless. I understand why people raised questions about their safety, but for decades they've been researched repeatedly and the consensus is clear. You're taking a precaution against an imagined threat and in spite of the other risks you list that you try to manage, my point still stands that you're surrounded by countless other risks you accept or ignore or aren't even aware of. You're an excellent example of what I was talking about. Focusing on specific boogeymen that you imagine are considerable risks while ignoring much more meaningful risks around you because you're either just used to them or blissfully, naively unaware of them. You don't know how to assess where many of the higher relative risks are, so you jump on the risk bandwagon and keep your cellphone in your pocket so you feel safer.
Yes I know, you can also get hit by lightning while shaving in the bathtub.. OMG! Yes but we don't PAY someone to hit us with lightning. Why pay someone to expose you to even more risks if the benefit isn't worth it? Is it worth it? That's all I wanna know... if we know the odds of dying to skin cancer from the Rape-o-Trons are in 1 30 million (their best guess basically, what if they're wrong?) what are the odds of getting blown up by an underwear bomb?
It's a simple risk vs reward question. Like dental xrays, the consequences of not having them are very real - a lot of pain, and possibly even an infection in your head that could very well kill you. The risks of that are far worse than the risks of the xray, so you do it.
So, for the scanners to be worth it, they have to be LESS dangerous than the thing we're trying to prevent. You understand this point, yes??
I don't think it's "fearmongering" to suggest that we understand the risks of doing something vs not doing it. To me "fearmongering" is more like "OHH SCARY TERRORISTS WITH BOMBS IN THEIR UNDIES, MUST THROW OUT ALL OUR RIGHTS AND OUR DIGNITY AND EXPOSE OURSELVES TO YET 1 MORE SOURCE OF RADIATION".
jwalk, most people in the thread would agree with you about risk/benefit concerns, especially as negligible as the benefit appears to be. That's not what most folks are jumpin' on you for. Saying that there's a statistical chance is never the same as saying x percentage will die every year. Hell, it's not even the same as saying x percentage will contract terminal cancer every year, even if those people live varying amounts of time. It's faulty reasoning. Saying you don't pay someone to strike you with lightning in comparison to paying someone to scan you is also a bad analogy. If there's a percentage chance you're going to die in your bathtub, and you're paying rent, then you are paying someone for that risk.
Every time a dam is built there a chance it will burst
WHY DO WE CONDONE PAYING PEOPLE FOR THESE DEATHTRAPS
I demand a realistically impossible 100% guarantee of non failure
PSN: Robo_Wizard1
I do not consider it a "considerable" risk. I consider it an unknown one, which is exactly what that article you were just lauding was explaining.
Your conclusion then, as far as I can tell, is that my inability to anticipate threats which I cannot identify means I should take it on faith that this shit is safe because the guy who built the thing has an off the cuff estimate of its danger and that estimate is relatively minimal compared to the ones I do actively avoid, or in the alternative, that the fact that I accept certain risks as necessary means I should accept this one, despite the fact that I don't believe there are any benefits to accepting it.
Let's put it this way: you've got a lot of new indicators in the environment over the years as industry becomes more and more sophisticated, and we ought to evaluate those risks as they appear. We're now talking about introducing a new device into the lives of hundreds of millions of people (let's not forget the TSA agents who work with them every day, either) and we're doing it without evaluating either its efficacy or it's safety. You're constantly repeating how we should be evaluating the risks logically and in comparison to other risks. Well, compare it to the reward we're getting out of implementing these things. On the negative side you have an unestablished risk of increased rates of cancer. On the positive side, you have nothing at fucking all. Why should this be a difficult decision for anyone?
(the cellphone risk, incidentally, is not one related to cancer. I didn't intend to conflate them.)
I bet its semantics
get a boner before going through the scanner/getting a grope-down
enough people do this, the TSA people are gonna be less inclined to get all up ins our junk
holy shit this is genius
Sematics, serious business.
Like I said
KILT + VIAGRA
"would you remove your belt please"
"ok sure, but my kilt is gonna fall off, and I wear it in the traditional manner of my people, WHY ARE YOU TRYING TO KEEP MY PEOPLE DOWN"..
viral. video. of the. year.
I'm curious that if 1/30 mill is an unacceptable risk, what you you consider appropriate
remember that it's impossible to have 0% risk. Also it's probably impossible to test even risks that small, let alone smaller
PSN: Robo_Wizard1
nah
they can get pretty specific when it comes to things like this
Because nobody is going to die.
These scanners are probably going to kill nobody
I doubt very much they can get pretty specific on chances of contracting terminal cancer
PSN: Robo_Wizard1
except that you're just assuming that with no evidence
which is an assumption I tend away from when being bombarded with radiation for no reason at all
regardless of the level of radiation, it has been pretty well established that radiation is bad
yes
unless you mean to ask "have we managed to reduce the salary of radiologists to 12 bucks an hour yet?"