3 ms·
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 in
by acidburnNSA 6y ago
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.
- hammock 6y agoI get the point about linear no threshold, but I don't get the point of bringing up background dose. If there is a threshold, then acute doses are worse than cumulative right? Taking even your highest figure 100msv, that's over an entire year. In a 5 sec span, that would be 0.0000159 msv, or 200,000x less than the 3msv from the machine in 5 sec (or less).
- acidburnNSA 6y agoAcute high-dose is indeed worse than cumulative. Less than 100 mSv acute has never been shown to cause (or not cause) harm or benefit. I bring up background just to point out that radiation is very natural and our bodies evolved in a radioactive world and have repair mechanisms that appear to be totally capable of handling low doses relevant to these machines. I can see that that's confusing to a degree. I may be mistaken, I believe you're confusing milli-Sieverts (mSv) with micro-Sieverts (μSv). The machines are spec'd at 0.25 μSv/scan, or 0.00025 mSv.