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Brink Lindsey writes that the threat of a dirty bomb has to be seen in light of rational risk assessment. I'd agree. My problem is that Lindsey seems to be inadvertantly adding to the irrationality of the risk assessment. He links to this Wired article, in which the Federation of American scientists state
"However," the scientists continued, "residents of an area of about five city blocks ... would have a one-in-a-thousand chance of getting cancer. A swath about one mile long covering an area of forty city blocks would exceed EPA contamination limits, with remaining residents having a one-in-ten thousand chance of getting cancer. If decontamination were not possible, these areas would have to be abandoned for decades." and this article from the Washington Post, and this report directly from the FAS (whch was the basis for the Wired article). Scary sounding stuff. But should it be scary? The FAS estimates the current probability of dying of cancer at about 1:500 (they state a death rate of 1:100 is 500% of the current rate, and a death rate of 1:10,000 is 5% of that rate; the report seems to conflate contracting cancer with dying of cancer). The NCI gives the total prevalence of cancer (based on first reported tumor) as about 1:33. How do we resolve this apparent discrepancy? We note, of course, that the FAS report is implicitly considering only those cancers which can reasonably be attributed to ionizing radiation. It is, of course, impossible to say that this cancer was caused by that agent; however, rates of carcinogenesis per unit dose are well-known for many agents, so it is possible to say that if, e.g., radiation dose to a population is increased by so many milliSieverts, there will be so many additional cancers in that population, although we cannot predict when or in whom. Their calculations, although obviously only the conclusions are reported, and those in crude form, seem out of line with those of RERF, which finds an excess death rate for all cancers (leukemia and solid tissue cancer) of about 0.05% for those survivors of Hiroshima and Nagasaki who received significant radiation exposure. The FAS has a long history of over-estimating cancer risk from radiation exposure, and of making severe, uncorrected, and unacknowledged errors in other areas. Whilst what they ought not to be dismissed out of hand, neither ought it to be taken as gospel without confirmation. One thing that Lindsey says, however, I have absolutely no disagreement with
There's only one viable response [to dirty bombs and those who would use them]: We have to rid the world of those people. We have to crush radical Islamism and all the states that breed or foster it. And we have to do it sooner rather than later.
John "Akatsukami" Braue Wednesday, June 12, 2002 |
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