I work with this data regularly (in fact am probably a coauthor on at least one of the cited publications). For the vast majority of people who do not have specific contraindications, an occasional diagnostic scan adds imperceptible cancer risk. The data are extremely noisy and the amount of radiation is very small.
That said, older radiation exposures (say before 1960) were much more likely to be unshielded and cause extremely high doses, which *did* have a measurable effect.
Also just wanted to say that I really enjoy your writing and think that you should have a wider audience.
This isn't meant to be criticism, just things I thought of while reading your post.
1. If I lay on the beach for 2 minutes in strong sunlight, I won't get a sunburn. If I stay for 25 minutes, I will get a sunburn. As far as I know, we don't know if ionizing radiation has a similar threshold effect (on the low end).
2. I thought this was going to be a post about confounding factors. The naive way to study this would be to look at the number of CT scans a person gets and how long they live. There is an obvious confounding factor - why did did they get a CT scan in the first place? Humans are made of confounding factors.
Your table doesn't match the calculation in the text -- you said that it was 1.16 hours per mSv, but the table lists coronary angiogram as 1 mSv but 4 hours of life expectancy cost. What's the deal?
(Especially curious since I once had a very long heart-related fluoroscopy procedure.)
If you were interested in going deeper on the per organ risk, there are ICRP standard weighting factors for each organ that can be used to calculate the “effective dose” in millisieverts for the whole body.
Isn't there was lots of evidence that linear model of radiation damage is wrong at low-dosage levels?
For example, living at high altitudes is not associated with more cancer in general but high altitudes get more radiation than low. Similarly, places with more naturally occurring radiation in the soil don't show more cancers in the population. In fact often they show less.
I work with this data regularly (in fact am probably a coauthor on at least one of the cited publications). For the vast majority of people who do not have specific contraindications, an occasional diagnostic scan adds imperceptible cancer risk. The data are extremely noisy and the amount of radiation is very small.
That said, older radiation exposures (say before 1960) were much more likely to be unshielded and cause extremely high doses, which *did* have a measurable effect.
Also just wanted to say that I really enjoy your writing and think that you should have a wider audience.
This isn't meant to be criticism, just things I thought of while reading your post.
1. If I lay on the beach for 2 minutes in strong sunlight, I won't get a sunburn. If I stay for 25 minutes, I will get a sunburn. As far as I know, we don't know if ionizing radiation has a similar threshold effect (on the low end).
2. I thought this was going to be a post about confounding factors. The naive way to study this would be to look at the number of CT scans a person gets and how long they live. There is an obvious confounding factor - why did did they get a CT scan in the first place? Humans are made of confounding factors.
Your table doesn't match the calculation in the text -- you said that it was 1.16 hours per mSv, but the table lists coronary angiogram as 1 mSv but 4 hours of life expectancy cost. What's the deal?
(Especially curious since I once had a very long heart-related fluoroscopy procedure.)
If you were interested in going deeper on the per organ risk, there are ICRP standard weighting factors for each organ that can be used to calculate the “effective dose” in millisieverts for the whole body.
I wanted to add the obligatory XKCD link. (average yearly dose ~4mSv)
https://xkcd.com/radiation/
Isn't there was lots of evidence that linear model of radiation damage is wrong at low-dosage levels?
For example, living at high altitudes is not associated with more cancer in general but high altitudes get more radiation than low. Similarly, places with more naturally occurring radiation in the soil don't show more cancers in the population. In fact often they show less.