Looking online I can find that the BED (Banana Equivalent Dose) is around 0.1uSv, but Brazilian Nuts can have up to 444Bq/kg.

I know both of those foods are safe, I just wanted to understand how those units compare to each other, how much more radioactive is a Brazilian Nut compared to a Banana.

  • $\begingroup$ Do this question belong to chemistry.stackexchange.com ? $\endgroup$
    – baponkar
    Dec 5, 2019 at 2:50
  • $\begingroup$ Isn't radiation physics? $\endgroup$
    – mFeinstein
    Dec 5, 2019 at 2:51
  • $\begingroup$ This question is certainly on topic on Physics. It might also be on topic on Chemistry, but as I am not very active there I don't feel qualified to make a definitive statement. $\endgroup$ Dec 5, 2019 at 2:57
  • $\begingroup$ You can't convert directly these two quantities. However, you may try to reproduce the computations of the banana equivalent dose, applying it to the Brazilian nuts. $\endgroup$ Dec 5, 2019 at 2:58
  • $\begingroup$ And can this be done? $\endgroup$
    – mFeinstein
    Dec 5, 2019 at 3:03

1 Answer 1


Answering directly to "I just wanted to understand how those units compare to each other":

You can't convert directly between Sievert (Sv) and Becquerel, since they represent different physical quantities.

Quoting the definition of Sievert from the Wikipedia:

1 Sv = 1 joule/kilogram – a biological effect.
The sievert represents the equivalent biological effect of the deposit of a joule of radiation energy in a kilogram of human tissue.

And quoting the definition of Becquerel from the Wikipedia:

One becquerel is defined as the activity of a quantity of radioactive material in which one nucleus decays per second.

So, 1 Bq = 1 s$^{-1}$.

Therefore, Sievert and Becquerel are distinct things.

  • $\begingroup$ So I would have to find out how much radioactive potassium there is per banana and get how much Bq this is? I just wanted to know something like "a banana 20x less radioactive than a Brazilian Nut" $\endgroup$
    – mFeinstein
    Dec 5, 2019 at 3:05
  • $\begingroup$ To make the computation you would need to know which isotopes are the main source of radiation of a Brazilian Nut and in which relative quantities they are present. With this, you could compute the estimated biological effect per emitted radiation particle. My suggestion would be to follow the "Dose calculation" section of the Wikipedia of the banana equivalent dose page. $\endgroup$ Dec 5, 2019 at 3:43

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