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No. 68, July 2010

With a warm and humid climate, like most Asian countries, Japan provides a favorable environment for molds and pests to grow. Since there are so many species and numbers of pests which remain active for a long time in the year, damage to materials can be serious. Many libraries have long been afflicted with damage from pests and molds. Therefore, the NDL has taken measures to contain the damage.

Integrated pest management (IPM) differs from traditional countermeasures against pest and mold damage that mainly use chemicals. It is a concept to prevent and control damage caused by pests and molds, using chemicals as little as possible and reasonably combining multiple countermeasures, in order to reduce the harmful effects on the human body and the environment. The concept of IPM appeared in the agricultural sector in the 1960s and has been applied to cultural assets, mainly in museums, since the 1990s. Going with the trend, the NDL has advanced countermeasures against pest and mold based on IPM.

This article introduces the NDL's countermeasures against pest and mold damage based on IPM following a five-stage control model. The model is based on "Framework for Preservation on Museum Collections*" drawn up by the Canadian Conservation Institute (CCI).

• Stage 1: Avoid (reduce the attractants that invite pests and molds)
• Stage 2: Block (block the invasion route of pests and molds)
• Stage 3: Detect (detect pests and molds early)
• Stage 4: Respond (apply appropriate measures to damaged materials)
• Stage 5: Recover/Treat (return materials to the secure stacks)

* Canadian Conservation Institute. Preservation Framework Online,
http://www.cci-icc.gc.ca/tools/framework/index_e.aspx

At the first stage "Avoid," to reduce the attractants that invite pests and molds, we clean the stacks at regular intervals and the materials as the need arises. Though it is necessary to clean more frequently and thoroughly in the future, the stack space is too large and there are too many materials, so we are thinking of determining the area to focus on and starting from what is feasible step by step.

At the second stage "Block," we check materials suspected of pest and mold damage (e.g. purchased materials from antiquarian bookshops and donated materials) at the time of accessioning; if material evidence such as feces or parts of dead insects are found, we apply a process of eradicating pests and bacteria from materials before placing them on the shelves of the stacks. When there are too many such materials, the process is outsourced, while it is done by the Preservation Division when it is manageable. To avoid tracking in dirt on the soles of our shoes into the stacks, we instruct our staff to wear shoes that they use only inside the library, and we provide visitors with shoe covers when they enter the stacks.

Shoe covers

At the third stage "Detect," we have distributed manuals for pest and mold damage to our library staff since 2005 for the early detection of pests and molds. In this manual, directions are given how to report and react when materials with pest and mold damage are found. Anyone who discovers pest or mold damage reports the discovery to the Preservation Division in a "record of damage." The Preservation Division accumulates these records and uses them to review biological damage prevention. In 2009, out of 32 reports, there were 7 cases of actual damage to materials. As we asked our staff to report all cases, including suspected ones, there were cases that, after being checked by staff of the Preservation Division, turned out to be only a spot of dirt, not molds.

In addition, surveys on pests' habitats have been conducted regularly using sticky traps. From the results of surveys so far, we found that despite a few sightings, the damage was not very serious. In September 2008, we organized a forum on preservation to spread IPM to other libraries in Japan and reported the results of the survey.

In 2007, thousands of moldy materials were found in a certain part of the stacks of the Main Building of the Tokyo Main Library. Since the outbreak, we have been trying to patrol the affected areas regularly to find and remove molds promptly. It takes a team of three persons about an hour to check if there are any materials in the stacks affected by mold, and when moldy materials are found, we clean them. In addition, we measure the temperature and humidity of the area using data loggers. When the relative humidity rises to over 60% in summer, we run a small dehumidifier. As a result of that kind of measure, large scale mold outbreaks have not occurred in that area since 2008.

At the fourth stage "Respond" and the fifth stage "Recover/Treat", we try not to rely on chemicals when damage is found. We use methods selected by the amount of throughput, namely the low oxygen method using deoxidant or carbon dioxide for pests and absolute ethanol for bacteria. We are also thinking of such new measures as nitrogen gas or lowered temperature (under -20°C) to remove pests.

The low oxygen method using deoxidant

The low oxygen method using carbon dioxide

In addition to the five stages of control, internal and external cooperation is also an important approach. Information sharing and communication between preservation, materials management and facilities management are necessary to promote countermeasures against pest and mold damage based on IPM inside the NDL. For that purpose, in August 2009 we established a regular meeting inside our library to consult continuously on IPM. We have also been pushing forward to cooperate with outside experts and relevant organizations focusing on the countermeasures on molds discovered in 2007.

We are thinking of promoting IPM by feasible and sustainable measures, and of further enhancing the preservation program. Promotion of IPM is an issue of the IFLA/PAC Regional Centre for Asia hosted in the NDL. Cooperating not only with domestic libraries, but also with Asian libraries, we will promote IPM.