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Natolx OP t1_j80mbi7 wrote

Reply to comment by iimplodethings in Can the Radiation from a Sample of Depleted Uranium Sterilize? by Natolx

>This is roughly the dose rate of simply being on a plane at cruising altitude.

My initial research suggested this rate was 5 times that of cruising at altitude, but your point is taken. Thank you.

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Pedroarak t1_j80pjrw wrote

I think it's indeed a bit higher than the background radiation in that altitude, but something like an electron beam irradiator can output as much as 11000 Gray per SECOND, the dose required for sterilization is pretty high. Also, in some places like Ramsar (Iran) and Guarapari (Brazil) the background radiation can be as high as 40uSv/h but that's pretty rare

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DJOMaul t1_j81diqd wrote

>The radioactivity is due to the local geology. Underground water dissolves radium in uraniferous igneous rock and carries it to the surface through at least nine known hot springs.[15] These are used as spas by locals and tourists.

Uh. That feels... unsafe.

[https://en.wikipedia.org/wiki/Ramsar,_Iran] (https://en.wikipedia.org/wiki/Ramsar,_Iran)

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Pedroarak t1_j81hq4e wrote

Risks of low doses and low dose rates, such as from elevated natural background radiation exposures, appear not to exist or be lower than such risks that one assumes by applying the LNT model in the evaluation of epidemiological data. This and the unequivocal evidence of experimental findings of adaptive protection speak against the LNT hypothesis, which should be replaced by a model that takes into consideration that low doses can induce alterations in the physiologically individual balance between cancer causation and cancer prevention.

Source: Cancer Mortality Among People Living in Areas With Various Levels of Natural Background Radiation

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adm_akbar t1_j830i1m wrote

Radiation has become a boogeyman. It’s like UV light from the sun. We all experience it. Some places more than others. But it’s not certain cancer if you go to a place with higher radiation. It’s 0.05% more cancer if you hang around all year.

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RebelWithoutAClue t1_j80pd2n wrote

In terms of magnitude, 5x is about the same given the range of emmisivity that is observed with radioactive sources.

When one considers sterilization, one is looking for magnitudes of "kill". For instance, cooking chicken to FDA mandated temps results in log -6 reduction. One in 1 million salmonella survive the cooking process. I think that dental steam sterilization practices are going for log -9 reduction.

A multiple of 5 is not a considerable effect in the consideration of sterilization.

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iimplodethings t1_j82gk6t wrote

Exactly. I had a cosmology professor who rounded pi to 1 in estimating the average density of the universe or something

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UnoSadPeanut t1_j84ds8o wrote

Cosmology and astronomy are the only field of science where I feel that the numbers are just made up, and the measurements don't matter.

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StateChemist t1_j84nxf3 wrote

Had a few classes where if we were within one order of magnitude of the correct answer it was marked close enough.

With numbers so big it’s very easy to be off by wayyy more than that

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GyozaGangsta t1_j83fbcm wrote

In healthcare in America, we have a goal of sterility assurance to 10^-6 log reduction per AAMI standards but most IFU’s for devices set by manufacturers go for even tighter, some devices go beyond the 10^-9 but the trade off is damage to the device due to long exposure.

Part of the reason healthcare is so expensive is processing sterile instruments and replacing them fairly regularly, (a big push for single use disposable items is happening as a result but is also wasteful and expensive, but saves time on reprocessing)

Lastly a fun fact about steam sterilization, if you could fit the entire planet in a saturated steam sterilizer and ran it at 273 Fahrenheit for like 15 minute it would theoretically kill every thing on Earth. Nothing would survive. (Or it would be like .0000000000000001 survival)

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turgidNtremulous t1_j85d5kh wrote

Your imaginary planet-scale autoclave would not come close to killing everything on earth. It would just turn it into a planet full of extremophiles!

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hugglesthemerciless t1_j830f1u wrote

tbf when you're dealing with orders of magnitude a 5x difference is practically a rounding error

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raptorlightning t1_j837z27 wrote

Irradiation of foodstuffs is a thing. It's probably not used as much as it should be.

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dizekat t1_j82niu3 wrote

Keep in mind that the sample is tiny, the dose rate falls off as the distance squared, and only a small fraction of your body can be exposed to what ever the tiny Geiger counter right next to the sample tells you.

As far as bacteria etc goes they are far hardier when it comes to radiation, and to kill them takes billions times more radiation than your sample emits in an hour.

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