Lead Glasses

[Chris Alston <alstonc@odrge.odr.georgetown.edu>]

>Reply-To: "Montagnese, Anthony D" <ADMontag@LHA.ORG>
>
>I could use some advice.  My radiobiology days are so far behind me now!  I
>have a Cardiologist who wants his department to pay for replacement of his
>broken leaded eyeglasses.  My position since coming here several years ago
>is that the radiation doses that these doctors are receving, although higher
>than most other areas, are insufficient to justify a reasonable cataract
>concern.  This is based on my age-old understanding that radiation
>cataractogenesis is a nonstochastic event, and that the lens retains some
>repair ability from minor damage throughout most adult life.  Thus, unless a
>cardiologist received greater than about 200 rads to the lens in a single
>event (Merriam, Szechter, and Focht, "The Effect of Ionizing Radiations on
>the Eye, in Radiation Therapy and Oncology, Vol. 6, 1972, pp. 346 - 385),
>there is not concern.  His cumulative dose comes at such a low rate -
>millirads per month - that this is also not a concern. My position, then,
>has been to not discourage leaded glasses, per se, but also to not endorse
>them - a matter of diminishing returns, I guess.
>
>I suppose I should add that I recognize that most regulatory agencies have a
>lens dose limit of 15 rems (0.15 Sv) per year.  Taking their collar badges
>as a reasonable estimator of this, the cardiologists are nowhere near such a
>dose.
>
>Am I way off-base on this?  Can anyone cite a reasonable reference to
>support or refute me?
>
>Anthony D. Montagnese, MS, DABR
>Lancaster General Hospital
>Lancaster, Pennsylvania  USA
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