[08-15]

> Every CT scan increases your odds of cancer.

There is no evidence for that statement. More specifically, there is no evidence that a single radiation dose below 100mSv is harmful at all, but plenty of evidence (Taiwanese radioactive apartment buildings, nuclear navy worker study) that it isn't. Muller made it up for political reasons.

[ItsMe000001]

There is evidence:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3660619/

> Title: Cancer risk in 680 000 people exposed to computed tomography scans in childhood or adolescence: data linkage study of 11 million Australians

> Conclusions: The increased incidence of cancer after CT scan exposure in this cohort was mostly due to irradiation. Because the cancer excess was still continuing at the end of follow-up, the eventual lifetime risk from CT scans cannot yet be determined. Radiation doses from contemporary CT scans are likely to be lower than those in 1985-2005, but some increase in cancer risk is still likely from current scans. Future CT scans should be limited to situations where there is a definite clinical indication, with every scan optimised to provide a diagnostic CT image at the lowest possible radiation dose.

And about "a single radiation dose": As soon as you get a CT the chances that you will have only a single one in your life are greatly reduced, because you just had that one. So it still is better if the count remains at zero, or your precondition can easily be invalidated.

[08-15]

The problem with that study is that "people who take a CT scan" is not exactly an unbiased sample of the general population.

Now compare this to

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2477708/

> only a single one in your life

"A single dose" as in "a discrete event". Another single dose the next month is (probably) harmless again. Cells react to radiation with repair mechanisms, and once that activity subsides, the event is over.

Radiation exposure isn't linearly cumulative. The argument that it is was made before we even knew the structure of DNA! Today, we know better.

[ItsMe000001]

I also recommend at least the "Conclusion" section of this document, selected as an example, not as the one definite document: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3611719/ It is a good read overall too. You make it sound as if it does not matter. Apparently that is not the general medical opinion.

I also don't see what the problem with the selection of people is supposed to be. Those selected are more likely to not be able to repair DNA damage? I think this particular selection makes no difference for the purpose.

Overall, OP said "there is no evidence" and it seems that yes, there is. What you think of that evidence is not the question, OP had said there isn't any. When I look at the actual recommendations it seems that most medical people don't think so, after all, the recommendation still is to limit the radiation exposure, not just for the frequently exposed (radiation workers) but also for those one-time patients.

Even on a per-event basis reducing the amounts of radiation was and is a major design goal for the devices. Does not look like those who are involved in all of this think there is no problem.

[08-15]

> Overall, OP said "there is no evidence" and it seems that yes, there is.

This is evidence for a correlation between the number of CT scans and cancer incidence. To jump to the conclusion that the cancer is caused by the radiation from the CT requires a leap of faith.

The funny thing is, if an epidemiological study shows that low dose ionizing radiation is beneficial (radioactive apartment buildings, nuclear navy workers), it's dismissed by a completely ad-hoc "healthy worker effect" or "healthy student effect". But in a study of people who received a CT scan, where you should expect a "sick people effect" (healthy people don't get CT scans), you "don't see a problem".

[HeadsUpHigh]

This study is solely focused on childhood and adolescence CT scans. Any radiation dosage you take during childhood has magnified effects.

[ItsMe000001]

Thanks for pointing that out, but, okay, children and adolescents count too?

OP responded to a specific comment, I responded to OPs comment. I don't understand your point in that given context. I'd think showing one study - I didn't bother to look any further - that shows a risk was sufficient.

Since even adults have plenty of still dividing cells left I see it as reasonable to assume that adults are at risk too, even if that will likely be lower.

I also recommend at least the "Conclusion" section of this document, selected as an example, not as the one definite document: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3611719/ It is a good read overall too.

[HeadsUpHigh]

I don't remember the exact number but when it comes to cancer risk increase getting a regular 100 mSv x-ray as a kid counts something like 10 xrays of an adult done one after another( i.e. single dose). That's because any mutations that happen will stay with you for the rest of your life plus propagate to a lot more cells in total as your body is still growing. So while an important topic for some specialties it would be wrong to make broad statements based on this.

[ItsMe000001]

There is no "broad statement": There only is a specific response to a specific comment. I responded to "there is no evidence" - I don't have to show existence of 100% knowledge in the response, only that "no (zero) evidence" is not true. That is not a "broad statement", especially since I myself did not make one, only pointed to studies for the subject. Those studies don't conclude with "no evidence found".