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TSA compton backscattering exposes body to non-negligible radiation (2010)
- bonzini 6y agoThis article is from 2010. These days the TSA is using millimeter wave scanners (with frequencies around 30 GHz).
- djsumdog 6y agoYea I was thinking that. The back-scatter xrays are all gone, but they were not as safe as this article is trying to make. There were a lot of radiologists who were concerned. The millimeter wave machines are less dangerous, but they also don't really work well at all and have a high false positive rate. They're pretty much security theater, which we're seeing a lot of again now.
- deleted 6y ago[deleted]
- m0zg 6y ago> There were a lot of radiologists who were concerned. Would those be the same group of people who are "concerned" about 5G towers today? You can always find a small group of people who are "concerned" about anything you like. The press uses this for nearly every such story they publish. Without statistics quantifying that "a lot" the statement is meaningless. And even if you have the statistics, there being "a lot" of them is not a guarantee that they were right. One would need to present evidence for their concern as well to be treated seriously. Such evidence does not exist, since airplane flights themselves are a source of radiation exposure. https://cdn.vox-cdn.com/thumbor/DZqWhneDEMxElDzz7ZiUk0Jv93w=/0x0:1599x7185/1520x0/filters:focal(0x0:1599x7185):format(webp):no_upscale()/cdn.vox-cdn.com/uploads/chorus_asset/file/4030924/RADIATION-FLIGHT-DOSES.jpg https://cdn.vox-cdn.com/thumbor/DZqWhneDEMxElDzz7ZiUk0Jv93w=...
- X6S1x6Okd1st 6y agoX-rays are reasonable to worry about, the radio waves used in 5g, not so much
- rrss 6y agoNo. People who are concerned about 5G deployment for non-conspiracy theory or ignorance reasons are concerned about unknown effects of increased exposure to nonionizing radiation. X-rays are very much different from the sub-100 GHz bands used for 5G, and the concerns raised at the time about backscatter xray scanners were that the safety of the systems had not been demonstrated sufficiently to start irradiating everyone who got on a plane, because the negative health effects of ionizing radiation are well understood.
- SAI_Peregrinus 6y agoI'm concerned about mm wave 5G because of sideband interference with water absorbtion lines making weather satellites less accurate.
- TeMPOraL 6y agoA very reasonable heuristic for life is: you should not be concerned about non-ionizing radiation (like 5G), unless in doses that could burn your face off. You should, by default, be concerned about ionizing radiation (like x-rays) in any dose above the natural background.
- acidburnNSA 6y agoThat's been the heuristic since the 1950s. Now we have much more data on low-dose ionizing radiation. Regulations still assume linear no-threshold, yet no one has definitively shown that anything below 100 mSv causes harm or good using vast amounts of data (c.f. US natural background of 3 mSv/yr). Thus, my rule of thumb is to start worrying only if I get more than 100 mSv either acutely or integrated over a year. I worry a lot more about eating hamburgers than anything less than 100 mSv.
- hammock 6y agoNot before millions were exposed.
- hammock 6y agoBackscatter x-ray machines are still used in jails and prisons around the US. In fact, the ones in jails have you stand on a 5-sec slow-moving conveyor belt as you pass through the x-rays, giving thousands of innocent people awaiting bail (among others) a much greater dose than the airports were giving. There is no opt-out for these people.
- wavefunction 6y agoI haven't commented in a year but I reset my password and logged in specifically to share this: https://www.technologyreview.com/2009/10/30/208491/how-terahertz-waves-tear-apart-dna/ https://www.technologyreview.com/2009/10/30/208491/how-terah... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4340277/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4340277/ now, I will again mothball this account
- fred_is_fred 6y agoAlso we're not flying anymore.
- georgeburdell 6y agoHas anyone seen these recently? I saw one in Boston many years ago, but every airport I've been through since uses the mm-wave ones, distinguishable by their rotating action
- armitron 6y agoIt boggles my mind that people accept to be treated as lab rats with unknown consequences to their health decades down the line, just so an utterly useless bureaucracy can justify its existence and certain political goals can be met. Of course the TSA is just the tip of the spear. As James Duane so powerfully demonstrates in his talk and book [1], the number of gun&badge toting Federal agencies with the power to ruin one's life, sometimes even making up crimes to do so, has been steadily increasing. As has the number of nonsensical criminal statutes and regulations in the books. [1] https://www.cato.org/events/you-have-right-remain-innocent https://www.cato.org/events/you-have-right-remain-innocent
- banads 6y agoFear is a powerful motivator.
- minaguib 6y agoSince their introduction, I've had no issues telling the agent "I'd like to opt out of the scanner". This adds ~10 minutes as I have to wait and perform a manual pat-down, but personally that's not something I mind. Others obviously may feel otherwise for varying reasons. I've found this article (10 years old now, : https://www.health.harvard.edu/diseases-and-conditions/are-full-body-airport-scanners-safe https://www.health.harvard.edu/diseases-and-conditions/are-f... ) to be fairly well-rounded. I wonder if, since then, there has been a better analysis of actual/measured results of these technologies.
- bonzini 6y agoDo you also opt out of millimeter wave scanners? I did opt out of the backscatter ones, but do not do that anymore.
- johnklos 6y ago.emf files on a web site? There's a reason that the scanner manufacturers got exemptions so they wouldn't have to report measured radiation.
- appleflaxen 6y agoIf everyone opted out of the scanners, they would quickly disappear.
- vinay427 6y agoThese scanners did disappear. They aren't the current millimeter wave scanners.
- natch 6y agoIn every airport of every country? When we sold our last ICE car to go electric, we learned that a lot of used ICE car inventory is being shipped to Mexico and other countries where they are still ok dealing with the smell (or just not in a financial position to move forward as fast). I imagine the same kind of dynamic happens with equipment like this.
- bonzini 6y agoI'm not sure if they were ever in use outside the US.
- tjohns 6y agoI have seen a few at airports outside the US after we switched to millimeter wave. So yes, they are used in other countries. (And unlike the US, opting out sometimes isn’t an option.)
- fwip 6y agoI think something like 4-5% of car sales in the US are electric-only or hybrid, the remaining 95% being old-fashioned ICE. It's not just Mexico still buying them.
- natch 6y agoYeah. It’s still early days.
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- atian 6y agoThe same goes for 5G cell towers.
- acidburnNSA 6y agoWith radiation, I always recommend people study page 6 of this DOE radiation dose range pdf [1] to put dose rates in context. The spectrum of radiation doses spans many orders of magnitude and a single atom decaying is readily detectable. Note in particular that there are places on Earth like Ramsar, Iran that have natural background dose rates above 50 mSv/year and no one has been able to show definitively that dose rates at or below that level do or do not cause harm (or benefit!). [1] https://www.energy.gov/sites/prod/files/2018/01/f46/doe-ionizing-radiation-dose-ranges-jan-2018.pdf https://www.energy.gov/sites/prod/files/2018/01/f46/doe-ioni... Another fun data point is the longitudinal studies of flight crew who spend a good part of their career exposed to higher-than-normal natural cosmic radiation (while flying they are above much of the Earth's protective atmosphere) [2]. We should compare how much dose we get from the scanners at airports to how much we get from intergalactic protons raining down from the cosmos while we're up in the air. [2] https://www.bmj.com/content/325/7364/567 https://www.bmj.com/content/325/7364/567 One time I took a geiger counter on a flight just for fun [3]. It really was clickin'! [3] https://whatisnuclear.com/blog/2014-05-17-radiation-on-flights.html https://whatisnuclear.com/blog/2014-05-17-radiation-on-fligh...
- doodlebugging 6y agoFor a longer term study of the measured cosmic radiation exposure rates that one could expect from commercial flights I have followed this study: https://spaceweather.com/ https://spaceweather.com/ They also regularly launch balloons to track atmospheric changes. This is a long-running experiment with data gathered by high school kids. Pretty awesome. You can sponsor a flight and get a token item that has traveled to the edge of space in exchange. Great website.
- weinzierl 6y agoTo estimate the exposure of real flights there is also the "EPCARD ONLINE Flight Dosimetry for Aviation Personel" online calculator[1]. It is provided by a member of the Helmholtz Association, which is the largest scientific organization in Germany, so it should be credible. [1] https://www1.helmholtz-muenchen.de/epcard/online/fluginput.php?lang=en https://www1.helmholtz-muenchen.de/epcard/online/fluginput.p...
- madengr 6y agoI can’t recall the name of the principle, or the exact dose, but isn’t 1 Sv enough to cause a 50% death probability from radiation sickness, and 3 Sv enough to cause a cancer? There is a good youtube series (IIRC nuclear policy course at MIT) I was watching when the Chernobyl show was on last year. So 0.25 mSv is enough to cause a cancer for every 12,000 people they scan. That’s a lot of people considering the throughput of airports. Lovely. I’m glad this was shit-canned.
- vkou 6y agoYou have 4 litres of blood in your body. You will die if you lose 2 of them. A typical lab blood draw is ~10 ml. Does this mean that for every two hundred people who get their blood drawn, one is killed?
- acidburnNSA 6y agoThis is a great example of the ridiculousness of linear no threshold models.
- madengr 6y agoOf course not, but if I inject you with 2 L of peanut oil, it will kill you. If I do the same at 1 ml to 2000 people, maybe the statistics work out so a single, hyper-allergic person is dead. That’s all the linear approximation is saying, and that lecture series says it has held true. The interesting thing about it, is the dose for a single cancer is above the lethal dosage.
- acidburnNSA 6y agoThe LD50/30 acute dose of ionizing radiation is around 4000 mSv (4 Sv). You're assuming a linear no-threshold dose response for ionizing radiation, which is indeed what radiation people have used since the 1950s when we didn't have enough data to be less conservative. In the US, natural background dose averages around 3 mSv/year. Some places in the world have high backgrounds, in the 30-100 mSv/year range. Even there we have not seen a clear negative (or positive) response.
- toufka 6y agoThe open letter from biophysicists at UCSF _at the time_ outlined many of these concerns [1]. It was clear that the way these machines were being assessed was not scientifically rigorous, and were likely dangerous. The DHS Secretary Michael Chertoff had an interest in the company selling the scanners [2]. The damage done to the public’s trust and the public’s DNA by forcing these machines on people was awful. [1] https://www.thestranger.com/images/blogimages/2010/11/17/1290049297-ucsf-jph-letter.pdf https://www.thestranger.com/images/blogimages/2010/11/17/129... [2] https://en.m.wikipedia.org/wiki/Michael_Chertoff https://en.m.wikipedia.org/wiki/Michael_Chertoff
- javert 6y agoDHS is a far bigger threat to our freedom than terrorism. In "policing" work, there is a line where you become a bigger threat than the bad guys, and you become the bad guys. Many DHS agencies don't care. They are self-perpetuating institutions that act in their own "institutional" interest. Note to DHS language parser: this comment should be classified into your "big" database ("normal patriotic American complaining about gub'ment"), not your "small" one ("actual threats").
- settsu 6y agoIt’d be fascinating to know how many products, or entire businesses, are able to exist or even thrive through broad ignorance (whether willful or naïve) of their true nature.
- ryanmarsh 6y agoLooking forward to the epistemological study in my 70’s after I’ve had my prostate ripped out, wherein we find men who traveled frequently post 9/11 were at increased prostate cancer risk from millimeter wave tech.
- javert 6y agoNeeds to be retitled (2010)
- latchkey 6y agoI really don't worry about the low levels of radiation or not. What I worry about is trusting the TSA to keep these machines operating correctly and within spec. The care they give the machines cannot be greater than the care they give to the employees, and we know how well they treat employees.
- godelski 6y agoThis article is a little absurd. They are talking about uSv (10^-6) than give the big warning > Scary thing, what happens if scan jams and fail-safe mechanism fails -- local dose very high of order a few Sv We can do this with anything. I'm not so concerned about these machines failing in a region that typically has radiation monitors. Sure, we should be concerned with machinery failing, but the amount one should worry isn't proportional.