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Chance of Dying From Backscatter Radiation Same as Chance of Terrorism

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Re: Chance of Dying From Backscatter Radiation Same as Chance of Terrorism

#41

Post by yummyfajitas »

travisp wrote: post #26
naz wrote: post #19

Earlier quoted context omitted.

A single backscatter X-ray scan gives a radiation dose of 0.009 mrems, about the same as eating a banana. http://en.wikipedia.org/wiki/Banana_equivalent_dose Don't get me wrong, I'm opposed to the scanners as much as anyone for privacy reasons and general pointlessness. But I'm seeing a lot of bad science thrown around here.

While I might agree that the worried about an X-ray scan are overblown (I assume that is your position), that number is looking at a whole body number. Part of the argument is that the amount may be significantly higher because the dose is concentrated near the surface of the skin, rather than across the whole body like cosmic ray and chest X-ray exposure.

So instead of being equivalent to eating a banana, it's probably equivalent to mashing one up and using it as skin cream.

In other news, millions of small children who enjoy playing with food exposed to RADIATION! Are bananas safe for your children?

Re: Chance of Dying From Backscatter Radiation Same as Chance of Terrorism

#42

Post by wvenable »

cedsav wrote: post #33

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...

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

Re: Chance of Dying From Backscatter Radiation Same as Chance of Terrorism

#43

Post by 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.)

Re: Chance of Dying From Backscatter Radiation Same as Chance of Terrorism

#44

Post by josefresco »

jerf wrote: post #43

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"…

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.

Re: Chance of Dying From Backscatter Radiation Same as Chance of Terrorism

#45

Post by Confusion »

maninthemirror wrote: post #13
zbanks wrote: post #4

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... Which comes from: http://hyperphysics.phy-astr.gsu.edu/…

You are understating the risk from backscatter radiation. Because the radiation is sent in a burst, and targets skin tissue, the DNA damage may be far greater than a similar dose of cosmic radiation. You are also assuming that the backscatter machines are functioning properly and aren't overdosing people.

  Because the radiation is sent in a burst, [..] the DNA
  damage may be far greater than a similar dose of cosmic
  radiation.
People keep repeating that, but it is not simply true. DNA can get damaged when a single photon excites an electron and consequently influences the molecular structure. The chances of multiple photons operating on the same electron at the same time, even in cases of a radiation burst, are negligible. The person is affected by the same number of photons, which results in the same number of chances of electrons being excited. The number of excited electrons will be equal and the resulting damage will be equal.

Now it may matter that the damage is more localized in both space and time, but no one has shown this. Firstly space: spreading the radiation over only the surface, for instance 1/10th of the body (remember that surface times a small depth is always a relatively large part of a volume), means 10 times as much damage. But if the average amount of damage in the skin was one broken bond per 1000 cells, it will now be one broken bond per 100 cells. As the repair takes place per cell, that doesn't change anything for the total chances to get cancer. Only if the amount of damage in a single cell, and close enough to each other to be relevant, changes, then this type of operation may pose a problem.

Secondly for time: everything depends on the amount of time it takes a cell to repair DNA damage. If the average time of repair takes 3 seconds, then during a flight, some damage will be repaired before other damage takes place. The backscatter machine delivers its dose faster and damage may accumulate. However, if repair takes 30 minutes on average, the difference is again neglible.

The point is not that I know the numbers: the point is that people making claims don't know them. They are just claiming things that seem to make sense to them, when they draw an analogy with a car crash or something. They don't understand what is actually involved.

Re: Chance of Dying From Backscatter Radiation Same as Chance of Terrorism

#46

Post by wiredfool »

shasta wrote: post #29
burgerbrain wrote: post #9

Earlier quoted context omitted.

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.

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.

1 unsuccessful underwear bomber => $500 million in contracts for scanners.

There's your cost of terrorism right there.

Re: Chance of Dying From Backscatter Radiation Same as Chance of Terrorism

#47

Post by nickpinkston »

josefresco wrote: post #44
jerf wrote: post #43

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"…

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.

Isn't this the same utilitarian argument that would restrict all of diets for the sake of healthy, roads for the sake of safety, and civil rights for the sake of efficiency?

Re: Chance of Dying From Backscatter Radiation Same as Chance of Terrorism

#48

Post by yummyfajitas »

butterfi wrote: post #28

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…

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.

Re: Chance of Dying From Backscatter Radiation Same as Chance of Terrorism

#49

Post by rbarooah »

josefresco wrote: post #44
jerf wrote: post #43

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"…

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.

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

Re: Chance of Dying From Backscatter Radiation Same as Chance of Terrorism

#50

Post by roc »

eleusive wrote: post #40
noonespecial wrote: post #16

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.

I'll take it to mean that (given the 1 in 30 million estimate and that there are well over 250 million outgoing airplane seats filled per year by U.S. airlines), the expected number of scans which will cause cancer is nearly 10. That's 10 people who's lives may be put in very real danger. It doesn't make a very good soundbite, but it plays well to the climate of hysteria!

According to the Bureau of Transportation Statistics, there were 617,977,711 passengers on domestic flights in 2009 [1].

At the (incredibly optimistic) risk rate of 1 in 30 million, that's about 20 people given cancer, each year, if this policy goes forward and these devices become standard procedure.

[1] http://www.transtats.bts.gov/Data_Elements.aspx?Data=1

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