Somewhere between 7 and 700 days.
CT Scan: 10-1000 mrem
Grand Central Station: 525 mrem / yr
So OP's statement is true for people who live IN the station.
It's roughly 40 min per workday over a typical year. That's a bit high but not unreasonably so.
That would amount to 10 mrem of radiation per year. I don't believe this is a realistic estimate for a CT scan though. From epa.gov [1]:
- Head CT: 2.0 mSv (200 mrem)
- Chest CT: 8.0 mSv (800 mrem)
- Abdomen CT: 10 mSv (1,000 mrem)
- Pelvis CT: 10 mSv (1,000 mrem)
So for a head CT, one would need to spend more than 13 hours per workday in the station. OP was off at least an order of magnitude.
https://www.epa.gov/radiation/frequent-questions-radiation-m...
This data is from 2006. Over 20 years, there has been substantial progress in CT radiation reduction through model-based iterative reconstruction and now ML-assisted reconstruction, aside from iterative advances in detector sensitivity and now photon-counting CT.
In clinical practice, those doses are about 2-3x what I see on the machine dose reports every day at my place of work.
In thin patients who can hold still, I've done full-cycle cardiac CT and achieved a < 1 mSv dose. We are always trying to get the dose down while still being diagnostic.
Source: Practicing radiologist.
Fair enough. That was the first number I pulled from Google, but I trust your source a good deal more.
I used the word comparable. Given they are in the same ballpark of log scale i stand vindicated in my opinion.
Also there's an apple store there. RIP all the geniuses there i suppose