
Chance of Dying From Backscatter Radiation Same as Chance of Terrorism - mcantelon
http://daringfireball.net/linked/2010/11/18/chances
======
aphyr
Actual web page: <http://www.public.asu.edu/~atppr/bodyscan.html>

Actual article:
[https://docs.google.com/viewer?url=http://www.public.asu.edu...](https://docs.google.com/viewer?url=http://www.public.asu.edu/~atppr/RPD-
Final-Form.pdf&pli=1)

The first thing you'll learn in radiation safety is that the nature of the
dose matters a lot. Sometimes you're A-OK if you can survive the initial dose.
Other doses are accumulative. It depends on the energy of the radiation, the
tissue's scattering cross-section, the time, and the flux, among other things.

This means that the Sievert (a unit of biological impact due to radiation) is
only meaningful in the context of the dose geometry. It's great for talking
about a chest X-ray, where the dose is spread out over a big volume of tissue.
Where it's unclear is in the case of rapidly-thermalizing or compton-scattered
particles: like backscatter. Look at the graph in that article. Something like
half of the energy is deposited in the first couple centimeters of tissue.

We haven't done this before, and don't have a good model for the long-term
effects. My guess? This kind of exposure is a hell of a lot worse for
melanomas than a chest X-ray delivering the same energy. Claiming compliance
to a metric like the ANSI limits is meaningless.

Edit: Oh, and the concern raised over the beam stopping and delivering a
couple Sv to a quarter-sized patch of skin is definitely scary. We did exactly
that to several people with medical cyclotrons.

Edit: I should also mention that tissues have varying tolerance to radiation.
Rapidly-dividing cells tend to be hit the hardest, which is why your stomach
lining, skin, and hair slough off after acute ionizing rad exposure. Your
skin, stomach, lungs, breast and thyroid are also the most frequent to undergo
cancer in radiation-linked longitudinal studies. See, for example,

<http://pats.atsjournals.org/cgi/content/full/5/9/934>

~~~
uvdiv
This is a grossly irresponsible abuse of statistics. What's even stranger is
that _the author agrees_. In his paper (conclusions, page 15):

> _The major public health effect of concern at low doses of ionizing
> radiation is cancer. There is clear evidence of cancer induction at
> effective dose above about 200 mSv. Below an effective dose of about 100 mSv
> radiogenic cancer mortality risk estimates for all cancers is highly
> uncertain. 16 It is not possible to determine reliably whether a radiogenic
> risk is present in an X-ray screening population because of the high
> spontaneous incidence of cancer and multifactorial nature of disease
> causation 17._

> _Use of collective dose to estimate public health impacts when large
> populations are exposed to trivial doses is inappropriate and not
> reasonable. The assumptions implicit in the collective dose calculation
> conceal large biological and statistical uncertainties.16 If an individual
> passenger is not harmed by X-ray screening then the population isn’t
> either._

"Inappropriate and not reasonable". Yet on his webpage (not submitted to peer
review), he does exactly that.

~~~
nubian
> _Use of_ collective _dose to estimate public health impacts when large
> populations are exposed to trivial doses is inappropriate and not
> reasonable._

First, let's make sure we are clear about the difference between collective
(for a population) and _cumulative_ (adding up repeated doses for an
individual).

Second, "inappropriate" and "not reasonable" tend to be weasel words with
regard to scientific findings. The real issue is that the effects of small
doses haven't been rigorously studied, unlike with high doses.

Rather than actually study them, we see brusque dismissals.

------
jerf
So, the risk from a backscatter radiation machine is roughly equal to the risk
from terrorism.

The Federal Government, via the FDA, tells us that the risk of the backscatter
machine is "minuscule".

Therefore, in the Federal government's own risk terminology, the risk from
terrorism is "miniscule".

Why are we spending all this money on a "miniscule" threat? Why are sexually
molesting the population over a "miniscule" threat? (Rhetorical.)

(I say "sexually molesting" on the grounds that if I personally performed
those same actions on a stranger, that is what it would be called. It would
continue to be called that if I tricked this person into giving "consent" for
false reasons. A doctor has a compelling reason. I do not grant that excuse to
the TSA. I also do not think I am being unduly inflammatory, I think it's just
plain fair.)

~~~
josefresco
Terrorism can in both small and very large ways effect entire nations.
backscatter radiation? Not so much. It's illogical to compare the two and make
judgments on based solely on the death rate. You don't need to kill people
(all of them) to influence them.

~~~
rbarooah
So then perhaps the best way to protect a nation from terrorism is not to be
influenced by it.

~~~
auxbuss
I hesitate to say "of course", because it sounds trite, and the underlying
issue is serious. But this is precisely what we did in the UK during the IRA
(Irish terrorist organisation) years. And we were encouraged to do that by the
media and government. And as stiff upper lipped Brits, we did so with pride :)

I myself saw the outcomes of three of the bombs personally -- by which I mean
still smoking -- and picnicked on the Regent's Park bandstand on the Sunday
which was blown up on the Tuesday; the bomb would have been there at the time.

[http://en.wikipedia.org/wiki/Hyde_Park_and_Regent%27s_Park_b...](http://en.wikipedia.org/wiki/Hyde_Park_and_Regent%27s_Park_bombings)

None of this changed my behaviour at the time, nor did it appear to do so for
anyone else, other than being vigilant for strange packages.

So yes, the correct response is not to be influenced by it. In other words, do
not give up your way of life because of murdering cowards.

------
noonespecial
I'm going to go ahead and take this to mean that the TSA just doubled my
chances of death. Seems appropriate in the current climate of hysteria, and
makes an excellent sound bite.

~~~
kwantam
VVVVVV Ahh, ayup, you're correct. Brainfart.

~~~
andrewcooke
Sorry for being pedantic, but no - these are probabilities not random
variates. If the probability of either alone is p then the probability of one
or the other or both is:

1 - (1-p)(1-p) = 1 - (1-2p+p^2) = 2p - p^2 ~ 2p

(where the last step is because p^2 << p because p << 1; the basic idea is
that it's "certainty minus the probability that neither occur")

------
grellas
I don't think I know anyone who isn't spitting mad about this TSA thing.

Quite an accomplishment, really, for the feds to manage to unite the entire
country - left, right, center, and from every strata of society - on a given
issue. I didn't think such a thing was possible.

~~~
lukeqsee
The accomplishment is amazing. I guess our country really still does care
about liberty and -- imagine this -- the constitution.

Trouble is, are people going to do anything with their "spitting mad[ness]?" I
hope they do.

~~~
Groxx
I think they just have an irrational fear of radiation outside the doctor's
office (whether or not that's valid here) - due to it being crammed down their
throats for decades - and a _massive_ aversion to being seen naked - _also_
largely due to it being crammed down their throats for decades.

If they like liberty, why did/do they not get as spitting mad about the
Patriot Act, the DMCA, and the ACTA? I'm guessing it's because their naked
butts aren't staring them in the face after being irradiated.

~~~
Female
Upvoted you, but I would like to add that I'm spitting mad and not afraid of
radiation or being naked. I think at least part of it is simply mass hysteria.
It's very easy when other people are upset to get swept up into it.

------
marze
This discussion is properly focused at the core of the matter, the cost
benefit analysis.

Some of the costs are easy to see, like the acute embarrassment some
experience from an intimate "pat down" if they elect to avoid any risk from
x-ray radiation.

Others are much more difficult, such as potential health consequences of the
x-ray radiation exposure. Since the TSA has refused to disclose the x-ray
flux, it is hard to even get started. The comparisons the TSA makes with other
radiation sources are flawed because they assume the dose is uniform
throughout your body when it is actually highest at the surface.

But even if an outside evaluator did have good numbers to start with, in the
end the best you can expect are extrapolations using data from dramatically
different radiation exposure, which is the nature of calculating radiation
risks. The only way to have a non-extrapolated number is to expose half of a
sample population to the scanner radiation and measure outcomes for 50 years.

Avoided consequences are easier to calculate. Of the 8,000,000,000 or so US
domestic air travelers of the past ten years, zero have smuggled a bomb on
board, and zero have attempted to. Zero out of billions of passengers.

The worst consequences are the loss of an aircraft. A terrorist cannot take
control of an aircraft using a bomb, only destroy it. An X-ray scanner will
not stop someone from bringing a knife onboard (even if it could, it is
probably not possible to take control of an aircraft with a knife due to
cockpit doors, passenger awareness, etc.)

So, cost benefit sum-up: zero attempts to smuggle bomb onto domestic flight
over past 10 years, unknown but likely low health risk, consequences limited
to loss of one aircraft due to screening failure.

~~~
fluidcruft
> Of the 100,000,000,000 or so US domestic air travelers of the past ten
> years, zero have smuggled a bomb on board, and zero have attempted to.

At least two have succeeded in smuggling a bomb on board, but failed to
detonate them. Look up the "Christmas bomber" and the "shoe bomber".

~~~
_delirium
Neither of those were "US domestic air travelers"; both boarded U.S.-bound
international flights in Europe.

~~~
fluidcruft
You're right they're not domestic. I've lived in and have family in Europe so
I have tendency to not view Canada and Europe as completely foreign. So,
anyway, Lockerbie, shoe bomber, Xmas bomber all actually not US departures.
Sorry.

------
cedsav
1 in 30M? so, with over 600M passengers per year, that's roughly 20 people a
year who would get cancer (and die?) because of those machines. I'm not sure
how credible are those stats, but I wouldn't want to be making decisions at
the TSA right now...

~~~
wvenable
Not everyone gets screened. So only a fraction of those 600M passengers are
getting a dose.

~~~
ljf
at the moment... not long ago not everyone went through the metal detectors...

~~~
borism
seriously? when was that? was it not so long ago we had armed plane hijackings
almost every month?

~~~
kscaldef
well, since you asked:
[http://www.schneier.com/blog/archives/2010/11/airplane_terro...](http://www.schneier.com/blog/archives/2010/11/airplane_terror.html)

~~~
ljf
thanks for that, excellent read. many forget that guns were allowed on flights
until relatively recently, not everyone was xrayed and hijacking was common.

also like the point raised in the comments that the main thing that killed off
the IRA as a major terrorist movement in Europe, was when their American
supporters finally remembered what terrorism was in 2001.

------
zbanks
More tellingly, on an average two-hour flight, you'd receive about 100 times
the radiation from a single scan.

But, by using the transitive property, you're more likely to die from
radiation at flying altitudes than from a terrorist attack on said airplane.

EDIT: Sorry, I forgot to include the link:

[http://en.wikipedia.org/wiki/Backscatter_X-
ray#Health_effect...](http://en.wikipedia.org/wiki/Backscatter_X-
ray#Health_effects)

Which comes from:

[http://hyperphysics.phy-
astr.gsu.edu/hbase/nucene/radexp.htm...](http://hyperphysics.phy-
astr.gsu.edu/hbase/nucene/radexp.html)

Which explicitly states its references.

~~~
aphyr
This comparison is meaningless.

The risk of cancer is caused by DNA errors. Your cells are constantly checking
and repairing your DNA for mutations and damage. They can usually repair or
detect a low error rate, like the kind you get from living at high altitude,
in a house with a minor radon source, or flying on a plane. What they _can't_
deal with as well is a sudden burst of many errors. Backscatter X-ray scanners
deliver their entire dose to a tissue region in a few microseconds. That's the
kind of exposure we're talking about, and it has an entirely different
biological impact.

~~~
uvdiv
> _What they can't deal with as well is a sudden burst of many errors._

Actually that is false, as far as low doses:

> _When you are asked whether there is a critical time period over which 1 rem
> of dose may have a greater biological impact than it might otherwise have,
> the answer is "No." One rem of dose is sufficiently low that whether it was
> delivered within one second or spread over a year or more, we would not
> expect any difference in biological effects._

<https://hps.org/publicinformation/ate/q8325.html>

(For comparison, 1 uSv = 0.1 mrem).

> _The risk of cancer is caused by DNA errors. Your cells are constantly
> checking and repairing your DNA for mutations and damage. They can usually
> repair or detect a low error rate_

But in this dose regime, ionization events are so rare, that they are so far
apart that no cell experiences more than one. There is no variation in error
rate.

~~~
nubian
Let me quote from your own source:

 _"There have been numerous biological experiments conducted, with nonhuman
organisms, that demonstrate that the rate at which radiation dose is delivered
can affect the extent of biological response. Thus a sufficiently high dose
delivered over a period of a few minutes may be expected to have a greater
biological impact than the same dose spread over a year."_

The only question is what constitutes a "sufficiently high" dose, due to
extrapolation. See 5).

THEIR OWN POSITION PAPER on backscatter scanners recommends per-screening and
per-year (time limit!) maximums FAR below the threshold that they claimed
wasn't a problem in the first place -- see 8).

4) Further, the terse "no" answer looked disingenuous. The cited position
paper link was broken but I tracked it down.

It appears to be "Radiation Risk in Perspective", PS010-2 (which I assume is
the updated version of PS010-1).

It has nothing to say about doses over short time periods.

<http://www.hps.org/hpspublications/positionstatements.html>

5) The issue seems to be that there is very little data about low-dose
exposures, so regulations are based on extrapolation from high-dose exposures.

See <http://www.ncrponline.org/PDFs/TST_NRC%20_04-08-08.pdf> (third slide)

6) What it does say is this:

"the Health Physics Society recommends against _quantitative_ estimation of
health risks below an individual dose of 5 rem in one year or a lifetime dose
of 10 rem above that received from natural sources."

7) The whole point of their objection was that we lack the empirical evidence
to extrapolate from high doses to low doses. Then the article you cite does
exactly that. They go from saying, "we lack proof that the answer is X" to
saying, "the answer is ~X".

8) The recommended standard _"limits the reference effective dose delivered to
the subject to 0.25 microsieverts (25 microrem) per screening. Additionally, a
screening facility should not expose any individual to more than 250
microsieverts (25 millirem) reference effective dose in a year."_

"Use of Ionizing Radiation for Security Screening Individuals" PS017-1

<http://www.hps.org/hpspublications/positionstatements.html>

How they can go from saying in the first paper, _"However, below 5–10 rem
(which includes occupational and environmental exposures), risks of health
effects are either too small to be observed or are nonexistent"_ to supporting
a maximum of 0.025 rem per year is entirely unclear.

Except that the Health Physics Society seems to have turned into a pro-
industry spokesgroup.

The current president works for Dade Moeller, who are embroiled in a number of
controversies, to put it lightly.

A lot of extremely damaging information is cited in the original link below.

 _""Hirsch then zeroed in on Dade Moeller’s radiation plan and on the
controversial company itself, whose namesake testified back in the 1990s that
money spent on cleaning up Cold War-era nuclear facilities was being wasted
since there would be a cure for cancer."_

Original comment:

<http://news.ycombinator.com/item?id=1889673>

~~~
uvdiv
> _THEIR OWN POSITION PAPER on backscatter scanners recommends per-screening
> and per-year (time limit!) maximums FAR below the threshold that they
> claimed wasn't a problem in the first place -- see 8)._

> _...How they can go from saying in the first paper, "However, below 5–10 rem
> (which includes occupational and environmental exposures), risks of health
> effects are either too small to be observed or are nonexistent" to
> supporting a maximum of 0.025 rem per year is entirely unclear._

Where they support that 0.025 rem/year recommendation, they explain that the
point is to keep "individual doses _as low as reasonably achievable_ (ALARA)
while achieving the desired objective." (Same source, PS017-1).

And you mischarcterize their claims. HPS does not claim <5 rem doses are "not
a problem" -- they said the effects are such are " _either too small to be
observed_ or nonexistent". (It does not follow that a health effect too small
to be epidemologically noticable is "not a problem"). "Too small to be
observed" is NOT a quantifier of significance; it is an explanation for the
lack of empirical observations. That position statement (PS010-2) is a
recommendation against _quantiative estimation_ of the effects of <5 rem
radiation doses, not an assertion of their absolute safety.

> _It appears to be "Radiation Risk in Perspective", PS010-2 (which I assume
> is the updated version of PS010-1). It has nothing to say about doses over
> short time periods._

It does not appear to have been referenced for that purpose.

~~~
nubian
> _It does not appear to have been referenced for that purpose._

Your comment referenced it for that purpose.

Your comment about dose per unit time not mattering referenced an article
which referenced their position paper which didn't support what the article
said. Hence the article was simply the _opinion of the author_.

> _(And you mischarcterize their claims. HPS does not claim <5 rem doses are
> "not a problem" -- they said the effects are such are "either too small to
> be observed or nonexistent". (It does not follow that a health effect too
> small to be epidemologically noticable is "not a problem")._

"Nonexistent" sounds like "not a problem" to me.

"Too small to be observed" is the same. How is a problem that causes _no
observable effects_ a problem? That's the practical definition of "not a
problem".

And if dose per unit time doesn't matter, then their per-screening and annual
limits for these small doses wouldn't matter. They are contradicting
themselves.

Further, as mentioned, they are not an independent safety group. They are an
industry group for the pro-nuclear lobby. This is like relying on the Business
Software Alliance (BSA, a front group for Microsoft and other large software
corporations) for opinions on the harmful nature of DRM, copyright laws, etc.

------
wnoise
Oh, well if they're equal, then that means this is a perfectly proportional
and appropriate response.

~~~
burgerbrain
That only holds if being sexually molested and having naked pictures of
yourself taken is weighted at zero.

Furthermore, this statistic in no way indicates that these screenings reduce
the risk of dying in a terrorist attack. 1 plus 1 does not equal 0. You've
allegedly doubled your risk of dying, not reduced it.

~~~
shasta
Well, you're right to question what the reduction in risk these scanners
produce, but your first point is way off. The cost of terrorist attacks is
hardly limited to death. Those planes and buildings aren't free. Not that
cancer treatments are, either, but if you weigh in the psychological damage to
the public (you know, why they call it "terrorism"), terrorist attacks are far
more costly.

~~~
burgerbrain
The real cost of terrorism is having to deal with all the people talking about
"the real cost of terrorism", and instituting retarded policies like these
scanners/molestation sessions.

Planes and buildings are cheap as shit in comparison.

------
zipdog
> Peter Rez ... calculated the risk of getting cancer from a single scan at
> about 1 in 30 million

His odds were for a single flight, but I wonder if the scanner radiation has a
cumulative effect?

Surviving a plane flight has no impact on the likelihood of the next one, so
taking a lot of flights would edge the odds in favour of dying from the
scanner cancer.

But then there`s the wide difference in the type of death.

~~~
alanh
> _But then there’s the wide difference in the type of death._

Good point, I would rather die in a terrorist attack than after months of
chemo and hospital food… that said, one is a lot more premature! (Edit:
Actually, if you got cancer from the scanner, it would _probably_ kill you
within a few years.)

------
marze
Airport in Orlando opts out of using TSA to screen their passengers:

[http://www.examiner.com/libertarian-in-national/florida-
airp...](http://www.examiner.com/libertarian-in-national/florida-airport-to-
opt-out-of-tsa-screening)

~~~
SoftwareMaven
This is the best news I've heard on this topic. If enough airports were to do
this, things would change at the TSA.

------
muldrake
America is a nation of goose-stepping cowards willing to give up their most
fundamental freedoms based on an incredibly unlikely event. They'll shove
cheeseburgers down their gaping maws and virtually guarantee they get diabetes
and heart disease, which is vastly more likely to kill them, while cowering
and whimpering about terrorism.

I live in Newark. I'd be about 100 times more likely to get killed walking to
the bus to get to the airport than I would be in the plane, even if we had no
security at all.

Anyone willing to tolerate this shit is a drooling fascist who also doesn't
understand security if they think this bullshit will stop even one determined
and competent terrorist.

We should do security like El-Al, modifying it of course for the practical
differences between the threats we face, and for our own constitutional
protections. People say that would be "expensive" but then, these are the same
morons who think we should piss away fundamental rights millions of Americans
have fought and died for for hundreds of years. And these morons want to talk
of "expensive?" Please.

------
butterfi
With all due respect to Dr. Reiz, and the Dept. of Physics at ASU, I think
I'll be taking my advice from the group of doctors from UCSF (a school well
known and respected for its medical research) who wrote a formal letter to the
president's science advisor. The letter is worth reading.

"Agard and several of his UCSF colleagues recently wrote a letter to John
Holdren the president's science adviser, asking for a more thorough look at
the risks of exposing all those airline passengers to X-rays. The other
signers are John Sedat, a molecular biologist and the group's leader; Marc
Shuman, a cancer specialist; and Robert Stroud, a biochemist and
biophysicist."

Story here:
[http://www.npr.org/templates/story/story.php?storyId=1268330...](http://www.npr.org/templates/story/story.php?storyId=126833083)

Letter here: <http://www.npr.org/assets/news/2010/05/17/concern.pdf>

~~~
yummyfajitas
I'll go with the physics prof. He did some calculations, admittedly imperfect,
based on generally known principles of dosimetry, and got what seems like a
reasonable order of magnitude result.

All the MD's at UCSF said was "oh noes, the possibility of radiation danger
isn't ruled out _precisely_ by a previously done study, it might be
dangerous." I'd be very curious to know whether they would use this same logic
on a less politically charged topic.

~~~
butterfi
Reasonable doesn't necessarily mean correct. In the face of specific questions
raised by doctors with expertise in this specific field, is reasonable is good
enough?

From the NPR article:

"The stated dose — about .02 microsieverts, a medical unit of radiation — is
averaged over the whole body, members of the UCSF group said in interviews.
But they maintain that if the dose is calculated as what gets deposited in the
skin, the number would be higher, though how much higher is unclear."

The observation about how high a dose gets deposited is a very specific
observation made by people who actively apply radiation to people on a daily
basis.

~~~
yummyfajitas
_In the face of specific questions raised by doctors with expertise in this
specific field, is reasonable is good enough?_

You are trying to appeal to authority. That's a logical fallacy.

Radiation transport, ionization mechanisms, and dosimetry are all fairly well
understood topics. Not perfectly, but well enough that one can make reasonably
good ab-initio predictions. The physicist is doing exactly that.

Now, ab-initio dosimetry calculations are sometimes off by largish factors,
(e.g., 500%) due to reactions of certain tissues. But they are rarely off by
orders of magnitude, which they would need to be in this case for us to
actually care.

The doctors at UCSF are just scaremongering, regardless of their credentials.

~~~
kenjackson
_Radiation transport, ionization mechanisms, and dosimetry are all fairly well
understood topics. Not perfectly, but well enough that one can make reasonably
good ab-initio predictions._

There are a lot of people that would disagree with this statement as it
applies to the human body. I think its fair to say that there is no such thing
as ab-initio studies when it comes to human reaction to radiation (at least
none that are worth a lick).

------
jdp23
This article from NPR a few days ago has a lot more details, and gives context
for the estimates:
[http://www.npr.org/blogs/health/2010/11/12/131275949/protest...](http://www.npr.org/blogs/health/2010/11/12/131275949/protests-
mount-over-safety-and-privacy-of-airport-scanners)

------
davidj
If the argument that the risk of backscatter radiation damage is acceptable,
and it is the same risk as the chance of terrorism, then by extension the risk
of terrorism is acceptable as well. So basically this isn't about terrorism,
it is about taking away our liberty.

------
gills
Sigh.

While interesting, arguing about the methods used to violate your basic civil
rights only distracts from the real discussion about YOUR CIVIL RIGHTS ARE
BEING VIOLATED BY THE VERY GOVERNMENT FORMED TO PROTECT THEM.

Keep your eye on the ball people.

------
cj
Direct link to article:
[http://cosmiclog.msnbc.msn.com/_news/2010/11/16/5477568-are-...](http://cosmiclog.msnbc.msn.com/_news/2010/11/16/5477568-are-
airport-x-ray-scanners-harmful)

------
bittermang
Do you know who else was told that the product they were dealing with was
completely safe?

<http://en.wikipedia.org/wiki/Radium_Girls>

The group who would come to be known as the Radium Girls. They were told that
Radium was safe if ingested, and many of them would lick the tips of their
paint brushes, or paint their teeth and nails with the substance. Soon after
they began suffering radiation poisoning, but were discredited of their claims
by the company publicly defaming them as contracting syphilis.

------
billybob
I'm just thankful that the TSA makes people mail home their keychain Swiss
Army knives with 1-inch, non-locking blades. Goodness knows what sort of
carnage someone could inflict with that. Almost as much as with a ballpoint
pen, which I notice they are still allowing. For shame.

I will not feel truly safe until each of us is forced to change into a
hospital gown, be cavity-searched, and be duct-taped inside of a cargo
container for the duration of the flight.

------
sequoia
My takeaway: -I don't like the privacy ramifications of these scans. -I don't
like being bombarded with additional radiation for no good reason, regardless
of whether people _think_ it will harm you.

Just as I will get an x-ray for a good reason, but decline getting one for a
silly reason, I would decline this if able. Maybe taking an aspirin a day is
bad for you, maybe it's not, but I'm not going to start doing it for no
reason.

So one more reason I don't like the scan.

------
stretchwithme
Yes, but the peace of mind one experiences while being groped or ionized makes
it all worth while.

Regarding how much radiation you receive on the plane itself, I always try to
sit away from the window and on the north side of the plane if possible.

~~~
jcl
My impression was that the increased radiation experienced on a flight was due
to cosmic radiation, not radiation from the sun. So it shouldn't matter where
you sit on the plane, right?

------
VladRussian
After reading about the backscatter, i'm wondering why i was so much against
the gropping. Nobody got cancer from being gropped, and after 10th or 20th
time i may even start to enjoy it. Some hands would become familiar... :)

------
zoomzoom
I can't believe that even on HN there are so many posts about something so
dumb. Our country is up in arms about some new X-ray machines that a corrupt
defense contractor sold to an overzealous department of homeland security in a
panic after 9/11, and yet we are hardly this angry about the 2 wars we are
fighting or the fact that the New Start treaty is about to be ran over with a
bulldozer.

Please, let's get over the stupid X-rays machines. Let Fox News and CNN cover
this one.

~~~
lukeqsee
I can believe it, and you know why? Because our country still cares about
personal American liberty.

Viva la libertad!

~~~
zoomzoom
Sometimes I get hyperbolic. What I mean to say is that these machines are a
symptom of a larger problem. The time that we spend trying to get rid of these
machines is time that we don't spend on solving the real problems.

I love freedom, too.

------
goldenthunder
Maybe I suck at basic prob/stats but if you remove the scanners, I bet the
chance of a plane getting blown up by a terrorist is significantly increased.
;)

~~~
tibbon
Two things have made the US safer

1- Pilots with guns & keeping the doors closed for the full flight

2- Passengers not willing to allow others on the plane do harm to the plane.
If passengers see things happen now, they will stand up and makes attempts to
stop them. We won't have a 9/11 style hijacking. Even if someone gets a box
cutter in, people will take them down before they'll let them take the plane.

I can't imagine how these body scanners would make us significantly safer.

~~~
BCM43
What we are trying to stop has shifted from someone hijacking the plane to
someone trying to blow it up. However, this is not a new threat at all, and
there are always more ways of getting a bomb on the plane as well as more
targets.

~~~
tibbon
Perhaps, but why do we still focus then so much on 'hijacking' items, like
knitting needles that would do little good in making bombs? We haven't
reverted to pre 9/11 search coverage of hijack items. Actually, we haven't
backed down at all on anything.

It seems that once something is identified a threat, it will always now be
seen as a threat.

------
aneth
The effect of you dying from terrorism is not the same as the effect of you
dying from backscatter radiation.

From a utilitarian standpoint, the chance of dying from something is not the
most important factor in deciding where to put resources.

I'd also say, the neither of these numbers can be known in any accuracy right
now, and there would be fast disagreement on any guess at what they might be.

------
robwgibbons
So my chances of dying have been doubled?

