Re: Dose to the eyes

[stabin@esper.com (Mike Stabin)]

At 02:14 PM 9/16/96 -0500, Rene Michel wrote:
>>I am interested in finding methods for calculating the dose delivered to the 
>>eyes of a person by a known amount of a beta-gamma contaminated liquid 
>>source which is accidentally splashed or sprayed into a person's eyes.
>>The are numerous resources available to estimate doses due to skin 
>>contamination, but this does not seem to be the case for eye contamination.
>

And Kim McMahan replied:

>The PC computer code VARSKIN Mod. 2 calculates dose at a user-selectable
>depths in tissue; simply enter 300 mg/cm2 as the skin density thickness.
>Note the code isn't validated to provide dose at this depth, but you might
>use the reference below for that purpose. The harder aspect will probably be
>to get the source activity right, but creative conservative assumptions
>never seem to be in short supply.
>
>You might also find the following reference useful:  "Beta Ray Dose
>Distributions from Skin Contamination," W.G. Cross, N.O. Freedman, and P.Y.
>Wong, Radiation Protection Dosimetry, Vol. 40, No. 3, pp. 149-168 (1992).
>The authors provide dose rates from surface contamination at several depths
>in tissue, including 3 mm.
>

This is exactly right.  Both resources make reference to a source (point or
plane) at an air-water boundary, with the dose calculated as a function of
depth into the water medium.  So the dose to the lens of the eye can be
obtained this way, if one assumes a source on the surface of the eye.

Our center also did some calculations regarding radionuclide
dacryoscintigraphy (I hope I spelled that right), where radionuclides are
intentionally administered onto the eye surface, and are assumed to drain
through the tear ducts into the throat, where they then pass through the
system like an oral intake.  I can dig up some of this info, if it's of use
to you.

Mike Stabin
Radiation Internal Dose
  Information Center
Oak Ridge, TN 37831-0117
423-576-3449  ph
423-576-8673  fax
stabinm@orau.gov
http://www.orau.gov/ehsd/ridic.htm