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Did you actually discredit someone or have you not properly considered your units in this response?

Commute through the Grand Central station everyday is certainly not a few hours.

And people don't tend to get a CT scan very frequently so the timeline here is massive.

In your opinion how many hours spent in Grand Central station equal the radiation received from a CT scan?

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.

itishappy 5 days ago | parent | next [-]

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.

	▲	riahi 5 days ago \| parent \| next [-]
		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.
	▲	itishappy 5 days ago \| parent \| prev [-]
		Fair enough. That was the first number I pulled from Google, but I trust your source a good deal more.

ramraj07 5 days ago | parent | prev [-]

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