Are the Airport Scanners Emitting Dangerous Levels of Radiation?

[ndnkyd]

Anyone know the radiation levels that are output by the full body airport scanners? I am not looking for a relative amount, but a quantitive amount. If you do not know, please don't answer.

 

[Gokul43201]

The number I've heard is 25 micro-rems, which is tiny.

EDIT: Confirmed. Here's the source: http://www.whitehouse.gov/sites/default/files/microsites/ostp/fda-backscatter-response.pdf

 

[drizzle]

... If you do not know, please don't answer.

Who would if one doesn't know the answer to your question?

 

[lisab]

Who would if one doesn't know the answer to your question?

I don't know.

 

[Evo]

I don't know.

Never would happen on this forum. He must be thinking about some other forum.

 

[Loren Booda]

Couldn't a scanner be tuned to detect only explosives?

 

[mugaliens]

Actually, yes, within limits. The ones scanning your carry-ons do just that, and highlight different classes of materials in different colors.

 

[Mathnomalous]

http://en.wikipedia.org/wiki/Röntgen_equivalent_man#cite_note-remeffects-3

A dose of under 100 rems is subclinical and will produce nothing other than blood changes. 100 to 200 rems will cause illness but will rarely be fatal. Doses of 200 to 1000 rems will likely cause serious illness with poor outlook at the upper end of the range. Doses of more than 1000 rems are almost invariably fatal.[4] See radiation poisoning for a more complete analysis of effects of various dosage levels.

Going once through the scanner would expose me to about 25 microrems but I would need to be exposed to over 100 rems to experience any adverse health effects. So... I would have to go through the scanner 4 million times to accumulate at least 100 rems..?

 

[Gokul43201]

The mean lethal dose is about 350 rems, but that's for getting it all in one shot. If the dosage is spread out over weeks or months, you can take a lot more.

At 25 microrems, you are exposed to less than a tenth of the radiation that you would absorb just by sitting for an hour in a plane flying at 25,000 feet.

 

[Mathnomalous]

Thank you!

I guess I am not going to develop spidey senses or grow an extra pair or arms from 25 microrems... bummer. The scanners should not pose a risk to newborns and young children, yes?

So... people opting out of the scanner are being irrational? 25 microrems sound like a better deal than some TSA dude touching my junk. Who knows, I might be the lucky person to grow wings and skip the airport altogether!

 

[NobodySpecial]

Paper analysing the dose risk by U Arizona physicist Peter Rez
http://www.public.asu.edu/~atppr/RPD-Final-Form.pdf

 

[Moonbear]

Occupational safety limits are 0.5 rem for a pregnant worker during the course of a pregnancy (9 months). 15 rem to the lens of the eye, and 50 rem to the extremities of a non-pregnant worker. Radiation effects are cumulative, and the most important rule we always follow is ALARA...a low as reasonably achievable. That means NOT exposing yourself to any radiation if you can avoid it. While one scan may not seem like a big deal, consider the frequent fliers already exposed to higher than typical radiation dosages just from flying itself, or those who may already have occupational exposures. It's not much different of a consideration of having x-rays at the hospital. Having a few done to check on a suspected broken arm isn't that big of a deal, but you don't want to be getting them done weekly out of some form of paranoia.

Of course, I think there are 4th amendment considerations that are a bigger issue than a single x-ray dose, or modesty issues with a pat down search, and I think that line was crossed long before these latest scans. These are the ones getting people's attention, but so long as TSA is a government agency, without a search warrant, I'd argue none of these searches are legal without the passengers consenting to them.

 

[NobodySpecial]

So... people opting out of the scanner are being irrational? 25 microrems sound like a better deal than some TSA dude touching my junk

The claimed 25mrem is a little bit optomistic - it's the equivalent dose assuming that the energy is averaged through the entire body. Since the energy here is concentrated in the skin the effective dose may be 3-4x higher.

And of course you trust the TSA to keep these all perfectly maintained, calibrated and monitored don't you ?

 

[fss]

...but so long as TSA is a government agency, without a search warrant, I'd argue none of these searches are legal without the passengers consenting to them.

Use of an airline flying in US airspace constitutes consent to a security screen. Legality of security screening has been challenged and does have limits (http://online.wsj.com/article/SB10001424052970204556804574261940842372518.html"), but the congressional mandate of the TSA to search for explosives and weapons has not been successfully challenged in court.

 

[Moonbear]

Use of an airline flying in US airspace constitutes consent to a security screen. Legality of security screening has been challenged and does have limits (http://online.wsj.com/article/SB10001424052970204556804574261940842372518.html"), but the congressional mandate of the TSA to search for explosives and weapons has not been successfully challenged in court.

I don't think it HAS been challenged recently. Not too many people would bother with the cost of pursuing a lawsuit all the way to the Supreme Court level over a tube of toothpaste confiscated by security screeners. I would argue more, but this thread isn't about the search and seizure part, or the legalities of what constitutes consent, it's about the radiation exposure.

 

[Gokul43201]

When you're talking about tens of microrems, I think you're basically in the noise. You get exposed to about a millirem a day, just from natural sources. A hundred microrems could be the difference between walking to the bus-stop via 6th St and 11th Ave instead of taking 3rd St and 14th Ave. It could be the difference between spending a couple extra hours at the office instead of going home, or between going to the new restaurant that recently opened across town instead of just the usual place.

 

[BobG]

Radiation exposure for different activies:
1 year at sea level: 3 mSv (milliSieverts)
1 year in Colorado (where I live): 4.5 mSv

Airplane ride (coast to coast): 0.03 mSv (about 3.5 days worth in one airplane ride)
X-rays:
- mammography: 0.4 mSv (a little less than 2 months worth in one X-ray)
- Cardiac CT: 3 mSv (about 1 year's worth in one X-ray)
- Tomography CT: 30 mSv (about 10 year's worth in one X-ray)
Backscatter X-rays: .00009 mSv (about 2 hours worth in one 10 second imaging session).

http://www.radiologyinfo.org/en/pdf/sfty_xray.pdf
Backscatter info

A flight attendant flying 200 days a year would be exposed to three times the radiation of the average person just by spending so much time at higher altitude.

 

[OmCheeto]

At 25 microrems, you are exposed to less than a tenth of the radiation that you would absorb just by sitting for an hour in a plane flying at 25,000 feet.

http://www.ornl.gov/sci/env_rpt/aser95/tb-a-2.pdf
300 mrem = Average yearly dose to people in the United States from all sources of natural background radiation

You don't even have to fly to get zapped. Just existing, you get the equivalent of 33 airport TSA xrays every single day of your life.

Ha ha! I just realized that if you opt out of the scan for the grope, and it delays you more than 45 minutes, you'll have received more natural radiation than the scan would have yielded.

For some reason, I find that entertaining.



300.00 mrem/yr
365.24 days/yr
0.82 mrem/day
821.37 microrem/day
25.00 microrem/xray
32.85 natural xrays per day

0.03 days worth of natural radiation per xray
0.73 hours worth of natural radiation per xray
43.83 minutes worth of natural radiation per xray

 

[CRGreathouse]

Ha ha! I just realized that if you opt out of the scan for the grope, and it delays you more than 45 minutes, you'll have received more natural radiation than the scan would have yielded.

Think about that one a bit...

 

[OmCheeto]

Think about that one a bit...

I did. That's why I thought it was so funny. I've had laymen argue about radiation with me before, and they seem to be completely unaware that they are immersed in a bath of background radiation. I was watching Rachel Maddow grill Art Robinson* about a paper he wrote many years ago on http://en.wikipedia.org/wiki/Radiation_hormesis" . His idea seemed to have been a thought experiment whereby you took all the radioactive waste in the country, mixed it with dirt or something, then spread it evenly over the entire nation. I thought the idea was both silly and intriguing at the same time. But anyways, Robinson, who is a scientist, and has no concept of speaking in a political manner, responded to Maddow that he would not explain the process, because she would not understand it. I'd have phrased it a bit differently. "Ms. Maddow, you are, as we speak, being irradiated by your surroundings. And as a matter of fact, if it weren't for radiation, you wouldn't exist."

But I should add that age old rule; "Wear sunscreen".

Ultraviolet (UV) irradiation present in sunlight is an environmental human carcinogen.http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WXH-4B6CP1T-5&_user=10&_coverDate=03%2F15%2F2004&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=a13c4f10eced3a784f084c41cdca71ed&searchtype=a"

*I would post a link to the video, but, although many words were exchanged, there is no knowledge to be extracted from the conversation. Except for perhaps the introduction of the word 'hormesis' to your lexicon, which I've already posted above.

 

[NobodySpecial]

But I should add that age old rule; "Wear sunscreen".

Children are being admitted to hospital suffering from rickets (vitamin D deficency) because of paranoia about skin cancer ;-)

http://www.telegraph.co.uk/health/healthnews/7995128/Vitamin-D-health-warning-for-the-children-who-shun-the-sun.html

 

[OmCheeto]

Children are being admitted to hospital suffering from rickets (vitamin D deficency) because of paranoia about skin cancer ;-)

http://www.telegraph.co.uk/health/healthnews/7995128/Vitamin-D-health-warning-for-the-children-who-shun-the-sun.html

Oh my god!

Casualty departments are dealing with dozens of emergency cases where infants are having seizures as a direct result of not getting enough vitamin D, which is essential for healthy teeth and bones.

In one case, a baby suffered brain damage after a fit.

...

Mr Michie analysed the cases of 17 babies and infants treated at Ealing Hospital for a severe lack of vitamin D between 2006 and 2008. He found many experienced a delay in walking, a problem last common in Victorian times.

Cancer Research UK is considering changing it guidelines concerning sun exposure because of the problem.

Instead of advising people to stay out the midday sun completely, it may suggest that a few minutes exposure could be healthy.

A few minutes a day? People don't even go out in the sun for a few minutes a day?

hmmm... Maybe Well's will have another prophecy come true:

Later in the dark, he is approached menacingly by the Morlocks, pale, apelike people who live in darkness underground, where he discovers the machinery and industry that makes the above-ground paradise possible. He alters his theory, speculating that the human race has evolved into two species: the leisured classes have become the ineffectual Eloi, and the downtrodden working classes have become the brutish light-fearing Morlocks.

 

[NobodySpecial]

the leisured classes have become the ineffectual Eloi, and the downtrodden working classes have become the brutish light-fearing Morlocks.

Always thought that Wells had those the wrong way around - he probably needed to get out more!