3 ms·
Using uniform units, 0.25 μSv acute dose is what the manufacturers claim for these devices. Annual average background from all sources in US (including these) 6
by acidburnNSA 6y ago
Using uniform units, 0.25 μSv acute dose is what the manufacturers claim for these devices. Annual average background from all sources in US (including these) 6,000 μSv/yr. So you need a scan every 21 minutes for a year to roughly double your annual dose. In some parts of the world, the natural background rate is higher. Like 50,000 μSv/yr. Cancers or other harm have never been shown to occur (or not occur) below acute or annual doses of about 100,000 μSv.
So you need 400,000 of these scans (at the manufactuer-claimed dose of μSv) to reach a dose that is thought to have an above-zero increase cancer risk.
- lvs 6y agoYou're not grasping the biology. Damage repair mechanisms have a capacity limit that itself varies with exposure. In particular it's been shown that acute dosage timing of multiple exposures is different than continuous exposure with the same integrated dose.
- acidburnNSA 6y agoI will strengthen my statement. Acute doses below 100 mSv have never been conclusively shown to cause or not cause harm or benefit. Certainly annual doses at that level also have not. The LD50/30 acute dose of radiation is 4,000 mSv. See chart I linked above. Certainly acute high doses are worse than the same dose spread over years or decades. I learned that in nuclear engineering school 20 years ago. Please don't assume I'm not grasping it.