Re: Dental x-ray doses

[Franz Schoenhofer <schoenho@via.at>]

At 14:29 10.03.1999 -0600, you wrote:
>
>Julian Gibbs has supplied answers to the second part of your question as
>follows:
>
>We have developed a Monte Carlo radiation transport code
>that provides specific organ doses to the entire body.  The
>results as effective doses in microsievert:
>Procedure      Typical technique State of the art
>Full mouth intraoral, 21 film 350        45
>Bitewing, 4 film         70        8
>Panoramic, 1 film                  20
>(Gibbs et al, Dentomaxillofacial Radiology 17:15, 1988)

Do I understand the table correctly that a full mouth intraoral X-ray would
need 21 films and would give 350 microSieverts? This would be "horrible",
because the new European Union directive on drinking water has an
"indicative dose value" (I hope this is understandable, even if it might
not be English) of 0.1 mSv per year from the uptake of radionuclides, also
natural ones, from drinking water, excluding radon, K-40 and tritium. This
means, that this value should not be exceeded.

I am always surprised about the difference between medical and other
exposure in legislation. This does of course not mean, that I am of the
opinion that dental X-rays should be forbidden.

My best wishes to New Zealand, I hope you have better weather there than we
have in Vienna!

Franz


Franz Schoenhofer
Habicherg. 31/7
A-1160 Vienna
Austria
Tel.: +43-1-495 53 08
Fax.: same number
mobile phone: +43-664-338 0 333
e-mail: schoenho@via.at

Office:
Hofrat Dr. Franz Schönhofer
Federal Institute for Food Control and Research
Department of Radiochemistry
Kinderspitalg. 15
A-1095 Vienna
Austria
Tel.: +43-1-40 490 27820
e-mail: schoenhofer@baluf.via.at
************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html