5 ms·

numbers matter. A human naturally gives off 0.2mSv/year. so basically you are emitting radiation right now, just very slowly. They had 300 counts per minute whi

numbers matter. A human naturally gives off 0.2mSv/year. so basically you are emitting radiation right now, just very slowly. They had 300 counts per minute which would e around 6200 mSv year. But how much is that? the limit in a year for some body parts goes up to 500mSv year for workers. But that's if their body are getting that much radiation for the whole year. TL;DR you're always getting some ionizing radiation, how much matters.

simoncion 1y ago
> They had 300 counts per minute which would e around 6200 mSv year Are you sure about that? 6200 mSv is 6.2 Sv, which I understand to be near-universally deadly. That dosage would be profoundly incompatible with the news that the worker was being sent offsite to seek non-emergency medical attention. Poking around, it looks like "counts per minute" have to get converted to a dosage using an instrument-specific formula. I CBA to go find that formula, but you're quite welcome to.
- grogenaut 1y ago
  no not sure. yeah I used the an average instrument specific rate. The point is a) everything emits, b) we have no idea on severity from the info, could be a little, could be a lot. Could also be short term (haircut) or longer term (ingested) exposures.
  - simoncion 1y ago
    > yeah I used the an average instrument specific rate. Would you provide a link to the source of this average instrument specific rate? I'm interested in knowing which instruments designed to detect low-to-medium-level radiation sources on a human are configured so that five detections per second would equate to a "You're fucking dead; there's really no hope for you" dose. (Did you ask an LLM to "convert counts per minute to mSv" and fail to sanity-check the confident-sounding result it gave you?) > ...everything emits... Given that the crust and sea and air of this planet are chock full of radioactives, and that every living thing on the planet builds itself out of that material, that goes without saying.
    - hunterpayne 1y ago
      You need a device that can measure the different types of radiation. Then you have to do a bunch of calculations to estimate absorption. Only then can you calculate Greys which is the measurement that matters. PS 300 CPM is nothing. There are places where people live where the natural background radiation is higher than that. Also, background radiation is mostly Gamma rays which is more dangerous than what comes off of fission products or nuclear fuel.
      - simoncion 1y ago
        > PS 300 CPM is nothing. That depends on the instrument. It's an instrument-specific rate. I'd say that saying "300 CPM is nothing" absent any information other than the CPM is foolish. As I indicated earlier, given all of the other context we have, we can reasonably suppose that 300 CPM from whichever instrument was used in this incident is nothing to be concerned about.
- hunterpayne 1y ago
  Rate matters. 6.2Sv in a single hour is fatal. 6.2Sv in a single year is probably less than average for a human from background radiation. The measurement units for ionizing radiation are very complicated and confusing. That's why people are told to not try to compute this stuff yourself. I have code that computes these units and conversions, its not simple. Here is a brief and simplified explanation of how you calculate this stuff. There are 4 types of ionizing radiation: alpha, beta, gamma/x-rays and neutron flux. Each one has a different rate it is blocked by different materials (water, air, etc). Each one has a different risk to people. You have to compute counts per unit time emitted from a point source for each of the different types of radiation. Then you have to compute the amount of "arc" the person is in. Then you have counts being absorbed and you next multiply each count by a fixed factor depending on the type of radiation. This final number gives you total Greys per unit time, then you then have to divide by the mass of the person. Then you multiple that number by the total amount of time and that gives you total Greys absorbed. That's the number you use to assess risk to the person. For reference, this guy probably got less than 1 Grey. Someone getting radiation treatment for cancer might get 75 Greys. So please stop trying to calculate this stuff yourself. I'm pretty sure you are doing it wrong. This guy will be fine. PS Sieverts are a physical measure, Greys are a measure of biological "harm".
  - simoncion 1y ago
    > PS Sieverts are a physical measure, Greys are a measure of biological "harm". The US's NRC disagrees with you. From [0], they say this about the sievert and rem: Dose equivalent A measure of the biological damage to living tissue as a result of radiation exposure. Also known as the " biological dose," the dose equivalent is calculated as the product of absorbed dose in tissue multiplied by a quality factor and then sometimes multiplied by other necessary modifying factors at the location of interest. The dose equivalent is expressed numerically in rems or sieverts (Sv) (see 10 CFR 20.1003). For additional information, see Doses in Our Daily Lives and Measuring Radiation. and have this to say about the gray: Dose, absorbed The amount of energy absorbed by an object or person per unit mass. Known as the “absorbed dose,” this reflects the amount of energy that ionizing radiation sources deposit in materials through which they pass, and is measured in units of radiation-absorbed dose (rad). The related international system unit is the gray (Gy), where 1 Gy is equivalent to 100 rad. For additional information, see Doses in Our Daily Lives and Measuring Radiation. Grays seem to be "amount of radiation absorbed per kg". Looking further, the "Measuring Radiation" page at [1] directly contradicts your claim. Speaking about rems and Svs, it says: Dose equivalent (or effective dose) combines the amount of radiation absorbed and the medical effects of that type of radiation. For beta and gamma radiation, the dose equivalent is the same as the absorbed dose. By contrast, the dose equivalent is larger than the absorbed dose for alpha and neutron radiation, because these types of radiation are more damaging to the human body. I'm definitely not an expert, but the NRC is pretty official, and their explanations sound pretty clear to me. Is what they're saying here incorrect? > 6.2Sv in a single year is probably less than average for a human from background radiation. Are you sure about that? <https://xkcd.com/radiation/ https://xkcd.com/radiation/> claims 4 mSv per year as normal radiation dosage, and 50 mSv per year as maximum permitted annual dosage for "US radiation workers", whatever that means. I think you're off by a factor of a thousand for the typical exposure level and off by a factor of a hundred for the exposure level where they stop letting you work near the radioactives for a year. [0] <https://www.nrc.gov/reading-rm/basic-ref/glossary/full-text https://www.nrc.gov/reading-rm/basic-ref/glossary/full-text> [1] <https://www.nrc.gov/about-nrc/radiation/health-effects/measuring-radiation https://www.nrc.gov/about-nrc/radiation/health-effects/measu...>
jojobas 1y ago
Hair can't hold that much water compared to any ingested amount. Whether contaminated or activated, internal irradiation from that much will be pretty bad.

simoncion 1y ago

> They had 300 counts per minute which would e around 6200 mSv year Are you sure about that? 6200 mSv is 6.2 Sv, which I understand to be near-universally deadly. That dosage would be profoundly incompatible with the news that the worker was being sent offsite to seek non-emergency medical attention. Poking around, it looks like "counts per minute" have to get converted to a dosage using an instrument-specific formula. I CBA to go find that formula, but you're quite welcome to.

grogenaut 1y ago
no not sure. yeah I used the an average instrument specific rate. The point is a) everything emits, b) we have no idea on severity from the info, could be a little, could be a lot. Could also be short term (haircut) or longer term (ingested) exposures.
- simoncion 1y ago
  > yeah I used the an average instrument specific rate. Would you provide a link to the source of this average instrument specific rate? I'm interested in knowing which instruments designed to detect low-to-medium-level radiation sources on a human are configured so that five detections per second would equate to a "You're fucking dead; there's really no hope for you" dose. (Did you ask an LLM to "convert counts per minute to mSv" and fail to sanity-check the confident-sounding result it gave you?) > ...everything emits... Given that the crust and sea and air of this planet are chock full of radioactives, and that every living thing on the planet builds itself out of that material, that goes without saying.
  - hunterpayne 1y ago
    You need a device that can measure the different types of radiation. Then you have to do a bunch of calculations to estimate absorption. Only then can you calculate Greys which is the measurement that matters. PS 300 CPM is nothing. There are places where people live where the natural background radiation is higher than that. Also, background radiation is mostly Gamma rays which is more dangerous than what comes off of fission products or nuclear fuel.
    - simoncion 1y ago
      > PS 300 CPM is nothing. That depends on the instrument. It's an instrument-specific rate. I'd say that saying "300 CPM is nothing" absent any information other than the CPM is foolish. As I indicated earlier, given all of the other context we have, we can reasonably suppose that 300 CPM from whichever instrument was used in this incident is nothing to be concerned about.
hunterpayne 1y ago
Rate matters. 6.2Sv in a single hour is fatal. 6.2Sv in a single year is probably less than average for a human from background radiation. The measurement units for ionizing radiation are very complicated and confusing. That's why people are told to not try to compute this stuff yourself. I have code that computes these units and conversions, its not simple. Here is a brief and simplified explanation of how you calculate this stuff. There are 4 types of ionizing radiation: alpha, beta, gamma/x-rays and neutron flux. Each one has a different rate it is blocked by different materials (water, air, etc). Each one has a different risk to people. You have to compute counts per unit time emitted from a point source for each of the different types of radiation. Then you have to compute the amount of "arc" the person is in. Then you have counts being absorbed and you next multiply each count by a fixed factor depending on the type of radiation. This final number gives you total Greys per unit time, then you then have to divide by the mass of the person. Then you multiple that number by the total amount of time and that gives you total Greys absorbed. That's the number you use to assess risk to the person. For reference, this guy probably got less than 1 Grey. Someone getting radiation treatment for cancer might get 75 Greys. So please stop trying to calculate this stuff yourself. I'm pretty sure you are doing it wrong. This guy will be fine. PS Sieverts are a physical measure, Greys are a measure of biological "harm".
- simoncion 1y ago
  > PS Sieverts are a physical measure, Greys are a measure of biological "harm". The US's NRC disagrees with you. From [0], they say this about the sievert and rem: Dose equivalent A measure of the biological damage to living tissue as a result of radiation exposure. Also known as the " biological dose," the dose equivalent is calculated as the product of absorbed dose in tissue multiplied by a quality factor and then sometimes multiplied by other necessary modifying factors at the location of interest. The dose equivalent is expressed numerically in rems or sieverts (Sv) (see 10 CFR 20.1003). For additional information, see Doses in Our Daily Lives and Measuring Radiation. and have this to say about the gray: Dose, absorbed The amount of energy absorbed by an object or person per unit mass. Known as the “absorbed dose,” this reflects the amount of energy that ionizing radiation sources deposit in materials through which they pass, and is measured in units of radiation-absorbed dose (rad). The related international system unit is the gray (Gy), where 1 Gy is equivalent to 100 rad. For additional information, see Doses in Our Daily Lives and Measuring Radiation. Grays seem to be "amount of radiation absorbed per kg". Looking further, the "Measuring Radiation" page at [1] directly contradicts your claim. Speaking about rems and Svs, it says: Dose equivalent (or effective dose) combines the amount of radiation absorbed and the medical effects of that type of radiation. For beta and gamma radiation, the dose equivalent is the same as the absorbed dose. By contrast, the dose equivalent is larger than the absorbed dose for alpha and neutron radiation, because these types of radiation are more damaging to the human body. I'm definitely not an expert, but the NRC is pretty official, and their explanations sound pretty clear to me. Is what they're saying here incorrect? > 6.2Sv in a single year is probably less than average for a human from background radiation. Are you sure about that? <https://xkcd.com/radiation/ https://xkcd.com/radiation/> claims 4 mSv per year as normal radiation dosage, and 50 mSv per year as maximum permitted annual dosage for "US radiation workers", whatever that means. I think you're off by a factor of a thousand for the typical exposure level and off by a factor of a hundred for the exposure level where they stop letting you work near the radioactives for a year. [0] <https://www.nrc.gov/reading-rm/basic-ref/glossary/full-text https://www.nrc.gov/reading-rm/basic-ref/glossary/full-text> [1] <https://www.nrc.gov/about-nrc/radiation/health-effects/measuring-radiation https://www.nrc.gov/about-nrc/radiation/health-effects/measu...>

jojobas 1y ago

Hair can't hold that much water compared to any ingested amount. Whether contaminated or activated, internal irradiation from that much will be pretty bad.