TSA compton backscattering exposes body to non-negligible radiation (2010) (opens in new tab)

I don't get why a full year's worth of background radiation is always compared to an acute 5-sec (or less) exposure from an x-ray machine.

If the background rate is 50msv/year, and a machine doses that much (50msv) in 5 seconds, that's 6.3 MILLION TIMES greater than the background dose.

For 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/

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.

This is another good chart:

https://xkcd.com/radiation/

It is being proven that 100msv radiation was directly linked with cancer comes from data from Chernobyl, so 50msv I'd still being concerned this is like having 500k X-ray scan at one take, the greter rist doesn't come from the high dose itself, if comes from a time factor, the question needs to be, in how much time you get 50msv? It you tell me in one day I'll very concerned, this is a very high dose for rapidly changing organs like the bone marrow to absorb in one take (causing caners like leukemia ...)

https://xkcd.com/radiation/

Backscatter 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.

Yea 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.

I 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-terah... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4340277/ now, I will again mothball this account

Not before millions were exposed.

Also we're not flying anymore.

I opted out of backscatter back in the day (and looking at the facts retrospectively I feel validated in doing so, for example the miscalibrated units found to be spitting out 20x more radiation than designed).

I don't opt out of Millimeter Wave today, as I'm yet to see convincing scientific arguments or evidence that they're unsafe, or what the mechanism would be outside of mild tissue heating. I do choose to close my eyes when scanned though, take that as you will.

Yup. I have opted out every time. Maybe 50 times since they came out? Just my 3 seconds of civil disobedience.

These scanners did disappear. They aren't the current millimeter wave scanners.

They were retired before May 2013.

Officially retired due to the "FAA Modernization and Reform Act of 2012" which banned scanners that produced nude images, but the scanners came under continuous criticism for safety and were banned in the EU and elsewhere.

I'd be surprised to see them try and re-introduce backscatter x-ray scanners when the less divisive Millimeter Wave scanners work "well enough" for their security function. Backscatter was just a political lightning rod.

The Wikipedia article goes back and forth on the safety aspect:

https://en.wikipedia.org/wiki/Full_body_scanner#Backscatter_...

It 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

The 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.

You 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?

DHS 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").