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Subject: Radiation and mold

Radiation and mold

From: Karen Motylewski <nedcc>
Date: Monday, July 18, 1994
Re: irradiation and mold
Johanna Wellheiser gives a good review of the experience and the
literature in "Nonchemical Treatment Processes for Disinfestation of
Insects and Fungi in Library Collections," IFLA Publ. 60, Munich: G.K.
Saur (1992), pp. 39-51.  Essentially she confirms the information in
Walter's not to your posting.  Gamma radiation, which is commercially
available for processing cosmetics, foodstuffs, and some other products,
will kill mold.  Increasing temperature, atmospheric oxygen, and
moisture improve the fungicidal effectiveness.  Spore-producing fungi
are more resistant than other forms, and spores (conidia) can be quite
resistant. We don't have enough experience with this application to know
what constitutes appropriate protocol for limiting unintended damage to
library materials, or what is a minimum effective dose.  There is no
residual fungistatic action, and materials must be cleaned after
irradiation, with health precautions for workers.

Most researchers appear to agree that irradiation sufficient to kill
mold also produces cellulose (and presumably other molecular)
deterioration.  This may or may not be immediately observable as
embrittlement, and accelerated aging in the long term is a risk to
irradiated material.

All in all, it sounds like a bad idea except in very special
circumstances. The best known (and may the only) use of radiation for
disinfestation in this country seems to have been at Johns Hopkins
medial library in 1982. They had about 300 cubic feet of horrifically
contaminated material (bugs, mold, dead animals, etc.) treated.  The
ex-USSR apparently has more experience, but their research reports are
often skimpy or hard to evaluate by U.S. standards.

Karen Motylewski
Northeast Document Conservation Center
Andover, MA 01810

                   Conservation DistList Instance 8:8
                  Distributed: Tuesday, July 19, 1994
                        Message Id: cdl-8-8-006
Received on Monday, 18 July, 1994

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