Re: Radioactive dose from smoking

["Bjorn Cedervall" <bcradsafers@hotmail.com>]

>NCRP 95 states in section 3.2.1 that a 30 cigarette a day smoker >receives 
>a dose of 0.8 to 1.0 rad per year to small areas of the bronchial 
>epithelium at segmental bifurcations.
-----
Comment: An individual who has been smoking heavily for decades has usually 
destroyed the cilia from the trachea, past carina (bifurcation point) and at 
least a few bifurcation generations down. Such an individual may have an 
altered radiation dose distribution for two reasons:
1. There may instead be a mucous layer that actually radioprotects the 
epithelium from some of the alpha particles (I am not trying to say that 
smoking is good for you).
2. There is probably a shift in the fractions of the different particle size 
classes that can reach various depths of the bronchial tree. This could in 
relative terms increase the fraction of alpha particle radiation deeper in 
the lung "tree":

In order to give a quantitative analysis more information (data) is needed - 
I just want to point at some phenomena that probably should be considered 
when lung doses are estimated for smokers.

My reflections only,

Bjorn Cedervall   bcradsafers@hotmail.com

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