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Subject: Paper coated with red lead

Paper coated with red lead

From: Ellen McCrady <abbeypub>
Date: Saturday, May 16, 1998
In the December 1978 Abbey Newsletter I had a little news item
headed "Orange Endsheets Foil Bookworms for 500 Years."  It provided
some information not brought out in this discussion:

   "A 'Wormproof research group' at the Museum of Chinese History in
    mainland China has rediscovered an ancient means of protecting
    books against bookworms.

   "Books bound in Kwantung Province from about 1400 to 1900 A.D.
    have single endsheets coated orange on one side bound inside the
    front and back covers. These books were found, during a Museum
    inventory, to have very little bookworm damage, whereas most
    books lacking such endsheets did show damage.

   "A critical and convincing example was a book with short
    endsheets, damaged only where the endsheets did not cover the
    book.  Just to make sure, investigators first looked at
    collections in other libraries and found the same pattern of
    damage.  Then they investigated the endsheets, using laser
    microspectometry and X-ray diffraction, and finding that the
    chief ingredient in the coating was red lead (Pb3O4). Tests were
    made on silverfish, the most common kind of bookworm in China.
    When given a choice, silverfish preferred uncoated paper over
    paper coated with red lead; when they were give flour mixed with
    red lead, they were unable to sort out the ingredients, so they
    ate it and died.

   "As a result of this investigation, use of orange endsheets by
    Chinese book restorers has become standard practice.

   "This news item was condensed from a clipping sent in by
    subscriber Marty Simmons of Menlo Park, California:  Chemistry
    [sic] and Engineering News, July 31, 1978, p. 44.  The original
    announcement was in the April issue of China Reconstructs, an
    English-language monthly."

I looked up red lead in the AICGH list of threshold limit values for
1993-94.  It was listed with the dusts rather than the gases and
liquids. The TLV at that time was 0.15 ppm for the dust, and they
expected the limit to be lowered to 0.05 ppm in the future.

I don't see it as a big hazard, if the coating is on a side of the
endleaf that can be pasted (at least around the edge) to an
adjoining sheet.  No one can breathe much of the dust then.  And
anyhow, before regarding this as a serious hazard, wouldn't it make
sense to take the trouble to measure just how much of the red lead
escapes from the book as dust when it is used?  If a lot escapes,
perhaps spraying it with a fixative in a fume hood would make the
book safe to read.  If none escapes, readers and conservators can
relax.

By the way, I think opinion on the hazardous nature of lead paint,
especially when eaten by children off crumbling walls and windows,
is fading.  Someone finally investigated how much lead is absorbed
by the body when dried paint is ingested, and found that it isn't.
So a lot of money was spent scraping and repainting rooms that
didn't need it for health reasons.  Children do absorb a lot of lead
as they grow up, but most of it comes from breathing the air,
because of lead in gasoline.  Lead was only recently banned in
gasoline, after an interval of non-regulation, and its effect is
underestimated:  The ban almost didn't pass.

Ellen McCrady, Editor
Abbey Publications
7105 Geneva Dr.
Austin, TX 78723
512-929-3992
Fax: 512-929-3995

                                  ***
                  Conservation DistList Instance 11:94
                   Distributed: Tuesday, May 19, 1998
                       Message Id: cdl-11-94-006
                                  ***
Received on Saturday, 16 May, 1998

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Timestamp: Wednesday, 05-Oct-2011 15:20:14 PDT
Retrieved: Thursday, 19-Sep-2019 07:01:52 GMT