- #1
DeShark
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Hi all, I'm currently learning about nuclear physics at uni and we just covered Sieverts and dangerous levels of radioactive sources. I came across an article today that said cigarettes contain polonium 210 with an activity of 0.01 Bq/gram of tobacco. I therefore couldn't resist doing a calculation. But I became unstuck fairly fast. Basically, I want to work out the dose equivalent for smoking this stuff in Sierverts.
As I'm not a biologist, I don't know how many grams of this polonium are going to end up in a smoker's system, I couldn't really make anything like a good guess on the dosage in a year, but I decided to do some sort of calculation just to get a rough idea of how dangerous these cigarettes are. I just want to make sure I'm going about this the right way, cause we've been told that this sort of question will be on the exam. Think of it as real life revision.
So I made some assumptions. 1) The smoker doesn't smoke the cigarette, they place it in their mouth for 5 minutes, 20 times a week for a year. 2) The cigarette contains 2g of tabacco (http://wiki.answers.com/Q/How_many_gram_tobacco_is_in_one_cigarette) 3) The Polonium only emits alpha particles at an energy of 5300 KeV. (http://en.wikipedia.org/wiki/Image:Alpha1spec.png)
From this, I did the calculation:
[tex]5 \times 60s \times 0.01Bq/g \times 2g = 6 Emissions[/tex]
[tex]6 \times 5.3\cdot10^6 eV \times 1.602 \cdot 10^{-19} J/eV \times 20 (Q factor) \times 1 (N factor) = 1.02 \cdot 10^{-10}Sv[/tex]
[tex]1.02 \cdot 10^{-10}Sv \times 20 (times a week) \times 52 = 0.1 mSv[/tex]
So if I'm right, just placing a cigarette in your mouth for 5 minutes 20 times a week increases your natural dosage of radiation (2.4 mSv) by 5%. Is this right? I dread to think what actually inhaling the stuff into your body might do. Anyone got any thoughts on this? Most importantly, is my calculation right?
P.S. Here's the article (in french) http://www.lefigaro.fr/sante/2008/08/27/01004-20080827ARTFIG00559-le-secret-du-polonium-dans-la-fumee-de-cigarette-.php
As I'm not a biologist, I don't know how many grams of this polonium are going to end up in a smoker's system, I couldn't really make anything like a good guess on the dosage in a year, but I decided to do some sort of calculation just to get a rough idea of how dangerous these cigarettes are. I just want to make sure I'm going about this the right way, cause we've been told that this sort of question will be on the exam. Think of it as real life revision.
So I made some assumptions. 1) The smoker doesn't smoke the cigarette, they place it in their mouth for 5 minutes, 20 times a week for a year. 2) The cigarette contains 2g of tabacco (http://wiki.answers.com/Q/How_many_gram_tobacco_is_in_one_cigarette) 3) The Polonium only emits alpha particles at an energy of 5300 KeV. (http://en.wikipedia.org/wiki/Image:Alpha1spec.png)
From this, I did the calculation:
[tex]5 \times 60s \times 0.01Bq/g \times 2g = 6 Emissions[/tex]
[tex]6 \times 5.3\cdot10^6 eV \times 1.602 \cdot 10^{-19} J/eV \times 20 (Q factor) \times 1 (N factor) = 1.02 \cdot 10^{-10}Sv[/tex]
[tex]1.02 \cdot 10^{-10}Sv \times 20 (times a week) \times 52 = 0.1 mSv[/tex]
So if I'm right, just placing a cigarette in your mouth for 5 minutes 20 times a week increases your natural dosage of radiation (2.4 mSv) by 5%. Is this right? I dread to think what actually inhaling the stuff into your body might do. Anyone got any thoughts on this? Most importantly, is my calculation right?
P.S. Here's the article (in french) http://www.lefigaro.fr/sante/2008/08/27/01004-20080827ARTFIG00559-le-secret-du-polonium-dans-la-fumee-de-cigarette-.php