You know, maybe it's not just the C-word risk, either

[deirdre]

I got this flash of insight as I was commenting on this Schneier post (with a ton of great links all collected in one place):

There's a problem with your analysis (and the one you link to) about cancer risk.
First, you assume a person has normal risk of cancer, which isn't always the case. Second, as any cancer survivor will tell you, it's a real pain in the ass for not only one's self, but all one's friends and family, to get cancer.

I'm extremely fair skinned. I'm at elevated risk for skin cancer. I'm at elevated risk for breast cancer due to family history.

Also, what about the risk of, say, lupus? It's often first triggered by a sunburn because of the radiation effects on the skin. Is that something a backscatter machine could trigger? I don't know, but if someone would otherwise have had years (or a life) lupus-free, I doubt it's a tradeoff they'd make. Who wants one's body attacking its own cell nuclei?

For those reasons, the backscatter machines are not ones I can perceive as safe without decades of long-term exposure data and good, independent, epidemiological studies. We don't have that.

Sometimes Rick accuses me of focusing on edge cases, and sometimes he's right. (It's also my day job.) That said, I think people focusing on "cancer" risks from x-rays may have missed some other interesting medical risks.

It's my understanding that lupus is believed to be triggered by radiation causing an incorrect tear-down of a cell, exposing the nuclear proteins to the immune system in ways they wouldn't normally meet.

In short: one develops an autoimmune reaction to one's own DNA. (Or other nuclear proteins, but it's the DNA one that really stuck with me when I took immunology and we had a seminar on lupus.)