Re: Pb apron protocol

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

>References: <Pine.PMDF.3.95.980209112509.95131B-100000@oscar.auhs.edu>
>Date:         Mon, 9 Feb 1998 16:25:23 -0500
>Reply-To: Medical Physics Mailing List <MEDPHYS@LISTS.WAYNE.EDU>
>Sender: Medical Physics Listserver <medphys@lists.wayne.edu>
>From: "Dr. Robert Dixon" <rdixon@RAD.BGSM.EDU>
>Subject:      Re: Pb apron protocol
>To: Multiple recipients of list MEDPHYS <MEDPHYS@LISTS.WAYNE.EDU>
>
>
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>Dan:
>How about the big hole in the apron where the head and neck go?
>
>We had a long discussion of this on this "net" about a year ago but I
>have erased all my correspondence. Basically my argument went like this:
>
>If one assumes that the holes are randomly scattered and f is the
>fraction of the apron's area occupied by the holes and T is the apron
>transmission factor, then the effective dose will be increased by a
>factor of roughly:
>D/D0 = (1-f) + f/T
>For example, if one is willing to accept a 20% increase in effective
>dose in an apron having a transmission factor of 5%, then about 1% of
>the total apron area could be holes.(i.e. f=.01, T=.05, D/D0 = 1.19).
>Of course large holes over certain "popular organs" would cause a larger
>increase in effective dose.
>
>Bob Dixon
>
>Dan Beideck wrote:
>>
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>> I have recently been asked to write a protocol for lead apron inspections.
>> I've done a quick literature search and haven't had a lot of luck.  I
>> would be interested in finding a published source for a protocol or would
>> be interested to hear what others are doing.
>>
>> A protocol that we are considering using would be something along the
>> lines of:
>>
>> 1) An apron with a crack should be removed from service.
>> 2) An apron with any single hole with a diameter greater that 5 mm should
>>    be removed from service.
>> 3) An apron with multiple holes with a total area > 2 cm^2 should be
>>     removed from service.
>> 4) The threshold for items 2) & 3) may be doubled in the case where
>>    a) The hole(s) are on a part of the apron that is clearly not covering
>>       a critical organ, i.e. in the sholder region of the apron.
>>    b) The apron is of the wrap around variety and the hole(s) of concern
>>       are covered by another portion of the apron.
>>
>> I would be interested in hearing what others are doing and/or what you
>> think about the protocol proposed here.  The values used for the largest
>> acceptable hole and total surface area are based on somewhat arbitrary
>> guesses.
>>
>> Dan Beideck
>> BEIDECKD@wpo.auhs.edu
>> (215)762-1779
>