Conserving Archival Collections Suffering from Fungal Attack

The problem of dealing with mold on papers and books in collections has been an ongoing concern of mine for a number of years. I have responded to biological damage on library and manuscript materials--beginning with a mold damaged photograph that had weathered both Hurricane Katrina and irradiation treatment used for decontamination.

My goal of late has been to develop procedures for mold contaminated collections that keep staff safe, and to develop an isolated collections cleaning space. Hagley Museum and Library, where I am Library Conservator, became a Smithsonian Affiliate a few years ago. When I learned of the Smithsonian Affiliations Visiting Professionals program, I thought that this would be the perfect opportunity to bolster my mold I.Q. I applied for the program and was thrilled to find a kindred spirit at the Smithsonian Institution Archives. Conservator Nora Lockshin who is head of Collections Care agreed to be my mentor for two weeks in Washington D.C. this summer.

I was lucky to have Nora, as she was a welcoming well-connected host. She coordinated visits to several institutions in the D.C. region, including our colleagues at the Library of Congress, Maryland State Archives, and the National Archives and Records Administration. During our tours we learned first-hand from conservators who had responded to mold and water emergencies. Hearing of their experiences shone a light on the importance of having plans, and supplies and facilities readied for dealing with water damaged collections because response time is limited. To prevent the germination of mold, drying or freezing procedures should commence within 48 hours of discovering  damage.

The Maryland State Archives (MdSA) shared with us their experience dealing with historic paper records that had experienced more than one flood. Besides the obvious mold growth, due to the source of the floodwaters, it was likely that bacterial contaminants were present. Because of the volume of these papers (record cartons numbering in the hundreds), they determined that gamma irradiation was their best option. In my own experience, a gamma irradiated photograph that I had treated years ago was browned and “toasted” along the edges, likely due to overheating during the dose. Others who have seen irradiated mail (from the anthrax scare and subsequent irradiation of U.S. Postal mail in the early 2000s) have documented melted plastics, browned papers, and deteriorated photographs. Those items had dosages that were not directed by conservators, however, and the irradiation of the MdSA’s historic papers seemed to have fared much better. Gamma irradiation is definitely effective for sterilization. The mold swab tests and cultures done by the conservators at MdSA as a monitoring procedure confirmed this.  So far, none of the documents that they have attempted to culture contained any viable mold after treatment.

I also learned that alcohol is effective for killing mold. It must be used at the 70 percent concentration with deionized or distilled water. This mixture is able to penetrate the mold cell wall and move into the cell to cause permanent damage to the mold. The 70 percent alcohol mixture may be used for cleaning surfaces after moldy documents are cleaned, or it may be sprayed on objects to dry out active mold.

We met with Sophia Kapranos, our dedicated industrial hygienist within the Smithsonian’s Office of Health, Safety and Environmental Management. She helped sample mold residues on paper items, one with heavy black spots of mold. The method of sampling was the use of a “tape lift”, in reality a thin prepared microscope slide with a section covered by an adhesive layer that was gently placed in contact with an area of mold to pick up spores. The slide was sent for microscopic examination, and we are awaiting results.  

While at the Smithsonian Institution Archives, I made some great connections that will be useful for future collaborations.  On the whole, it was a great experience! Thank you to all at the Smithsonian who made this possible!

Related Resources

The Mold . . ., The Bigger Picture, Smithsonian Institution Archives

I've got mold in my files, Collections Care Guidelines & Resources Forums, Smithsonian Institution Archives