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Comment by xpaulbettsx | Hacker News Reader

Consider the following: if that identical machine were in a hospital, it would have been required to go through years of clinical trials to ensure its safety over the long term. The machines they are using are medical equipment.

However, because it's in an airport, none of this has happened. Maybe it is safe. Maybe it isn't. It is unproven.

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Conversely, if the machine was in a hospital there would be a $1000+ charge for your scan and another bill from whoever "reads" the scan.

The claims of effectiveness are also dubious, at best.

Likely unsafe, more than likely useless, proven abuses (stores images), etc.

But they're really really expensive. So it's all good.

And if you complain about the profiteering, you're a terrorist, conspiracy nut, hate the children / troops / puppies.

Airport scanners played out pretty much exactly like the electronic voting machines, with online voting cued up for the next round of cronyism.

Ditto corporate K-12 education, aka charter schools. Prisons. Drug war. Etc.

There's no clinical trial you could possibly do to show that these machines are "safe" in the medical sense (i.e., that the benefits to human subjects outweigh the harm). You could expose animals to the same doses of radiation and see what happens. This has been done for the general types of radiation (with X-rays animals contract cancers and die at sufficiently high power, with millimeter waves there's substantially less evidence for damage), but AFAIK not with the machines themselves.

The biggest danger may not come from chronic exposure, but from an acute failure of the machine or mistake made by the operator, the probability of which could not be determined in a study anyway. (Therac-25 delivered overdoses of radiation to several patients due to a software bug; Cedars-Sinai recently reported that they had accidentally delivered dozens of CT patients doses several times higher than normal; patients get killed by oxygen tanks and other objects sucked into the magnetic fields of MRIs with startling frequency.)

In any case, I think the danger posed by millimeter wave systems is significantly less than that of backscatter machines. There are plenty of studies to show that microwaves don't cause cancer, and it's hard to imagine a malfunctioning machine delivering something harmful.

I was under the impression that since it uses radio waves, there was no question about its safety (unlike the back scatter machines). Or are we also worried about cell phones?

Enjoy your MRIs costing 4 (or maybe 5) digits

Yes, it should be tested for safety, if in one case it looks like a lack of due diligence, in another it looks like an excessive CYA policy with some incentive from tort cases.

Is the radiation worse than a long-distance flight?

Doesn't help the cause if you're already doing a long-distance flight...

Passive mm-wave scanners do not produce radiation. The active mm-wave scanners use non-ionizing radiation which has been studied and shown not to cause cancer. One study even suggested it might reduce metastasis:

http://onlinelibrary.wiley.com/doi/10.1002/bem.20208/abstrac...

The flight itself isn't even that bad, but it is worse than the scanners. You get maybe 5 mrem (50 µSv) flying from London to NYC.

http://hps.org/publicinformation/ate/faqs/commercialflights....

The flight radiation is something you'd want to avoid, but a single flight is almost insignificant. XKCD has a reference chart:

http://xkcd.com/radiation/

Flight radiation is mostly a concern for flight crew.

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