Judge Orders NYPD to Release Records on X-ray Vans

After the bomb (esp. after the Crossroads Baker and Castle Bravo test that introduced a lot of the world to the term "fallout") and the changes seen in medicine (x=ray, cancer treatments, fears about cancer in general) I would guess that most of the population is at least aware that ionizing radiation can be dangerous, even if they do not understand the specifics.

Radiophobia and the anti-nuclear movements have certainly amplified the fears about anything involving "radiation". The fact that "radiation" means "always very dangerous" to many people is evidence of this attitude.

So I suggest that trying to claim ignorance about the potential dangers of pointing an active x-ray emitter at someone should be handled the same way as we treat claims of being ignorant about guns. For most cases, claiming "I didn't know that guns were dangerous" is going to be dismissed as an obvious lie or gross negligence. Is there any reason a jury should treat "I didn't know that using an x-ray beam was dangerous" as a valid get-out-of-jail explanation?

Note: I understand that low-level operators may not have been told how the machine works (such things would be for a court to decide). Responsibility flows upwards, and if it was a commercial product, some Professional should have had to sign off on the design. In any case, someone had to authorize these scanners... which I call mens rea.

[edit] A valid defense, of course, would be to have the results of some very rigorous safety analysis that showed there was no danger. Preferably by a 3rd party. If this study existed, I suspect it would have already been shown to the public.

In Kyllo's case, a person's home has a much better expectation of privacy from invasive surveillance than one's person and property in public. If it becomes public that people's homes are being searched without warrants, then I'd assume that they'd rightly be challenged.

It would be interesting and probably frightening to see how invasive surveillance of a person and property, in what might be considered 'public' space, would be challenged in court.

A major problem radiation dosimetry has is definitions are easily confused. The NRC's dose limits for individual members of the public [0] dictate a total effective dose equivalent of 1 mSv a year. The confusing part is keeping all the numbers straight if it is an effective dose, effective dose equivalent, or a dose equivalent. I'll get back to why I bring this up in a second.

I do want to say that I don't see the reference you are getting the 0.1 μSv per 1x1 (cm square?) area from the article (just mentions a per-sweep radiation measurement but doesn't report what kind of dose that is). However, from your sources it actually doesn't surprise me they are reporting the radiation dosage that way, if they are reporting it as an equivalent dose.

An equivalent dose normalizes for radiation type. A gamma or X-ray is weighted much less than alphas (typically 1 vs 20 weighing factors, depending on what standard you follow). But the equivalent dose does NOT take into account what part of a human's body you are irradiating. If I had to choose between a pinky finger and my thyroid, you can probably imagine which one I would pick to be subject to irradiation. Instead, the effective dose accounts for the different parts of the body (and effective dose equivalent for both). This is why I suspect the manufacturer preferred the equivalent dose as opposed to the effective dose - they are normalizing for the type of radiation but not the part of the body they hit. There is the ICRP's notion of an "ideal adult" but each person's natural variation of geometry (height, girth, etc) would skew the manufacturer's number in some way. Of course effective dose is still imperfect as it contains a general biological potency assumption but it would mean a lot more to the public than a count of gamma rays and their energies.

> What is the full body accumulated figure? I'm going to guess as much as .30 μSv per scan.

That would depend on the van's speed, its beam patterns (spatially and temporally), the position of the person, etc. Honestly I can't tell if that is reasonable or not, but (returning to the NRC limits for the general public) keep in mind that the van would have to drive by you 1,000 times in a year to reach .3 mSv of your 1 mSv regulated limit with your guess. Of course, there are people out there that put lead-foil hats on and distrust the regulatory limit.

[0]http://www.nrc.gov/reading-rm/doc-collections/cfr/part020/pa...