IPM: Where art and science meet
California Museum Uses State-of-the-Art Integrated Pest Management to Preserve Priceless Documents
Priceless paintings, photographs and old manuscripts housed in archives and museums are, for many, a sight to behold.
But largely unnoticed, curators, archivists and technicians behind the scenes are constantly working to ensure pests don't take hold and destroy precious artifacts.
Nowadays, efforts to protect these items utilize Integrated Pest Management (IPM) – a pest control strategy that emphasizes prevention and low-toxicity controls to deflect pests.
Institutions have embraced IPM as a welcome alternative to the pest control practices dating decades or even centuries back, which routinely used dangerous chemicals like lead and mercury, and, later, DDT and other synthetic chemicals
"There are museum pieces that have been dipped in arsenic, and now they're quarantined," explained Michelle Andreetta, a DPR scientist and IPM expert. "There are people who have to work around these things. You can imagine a security guard surrounded by these? It's dangerous." Where art meets science Developed on farms, and part of U.S. national environmental policy since the 1970s, IPM in subsequent years moved indoors, where it's now used for everything from controlling bedbugs in hotels, to rats and roaches in school classrooms and cafeterias, to gophers and weeds in parks and playing fields. IPM combines a variety of disciplines, including entomology, biology and chemistry. The main principles of IPM are the same from farms to schools, to libraries and museums. Even homes.
- Monitor for pests. Learn how to spot and identify them. If possible, learn about their behavior.
- Take steps to keep them out of unwelcome areas. This can include use of physical barriers like nets and screening, and plugging openings.
- When practical, remove habitable areas, like piles of clutter.
- Eliminate or carefully stow potential food sources.
- Curb or eliminate sources of water, like standing water in floor drains or under drippy plumbing.
If preventative steps are insufficient, IPM practitioners turn to the least-toxic control method first. So, try sticky traps before spraying a pesticide, and so forth.
IPM emphasizes "management." Pests will always be around, so you're just really keeping them under control.
An ounce of prevention
Pest management is serious business at the California State Archives in downtown Sacramento.
Staff are responsible for taking in and preserving a mindboggling array of documents and items. These include laws and "primary documents" like the state constitution.
"Things to jump-start the government," in the event of an emergency, explained Tamara Martin, Acting State Archivist and Division Chief.
The Archives also houses maps, some legal documents, contracts, old prison records, trademark data, and an assortment of artifacts -- from flags to gifts given to governors from visiting dignitaries.
So what else can one do beyond monitoring?
"Avoiding pest infestations - this building was built with that in mind," Ramos explained.
Storage areas in the labyrinth building are not only protected by thick concrete walls and heavy doors. They are also maintained at temperatures and humidities inhospitable to pests – ranging from rodents, to silverfish, to fungi.
Nick Jackson, documents preservation technician, explained temperatures are maintained at 55-60 degrees, while the relative humidity is kept at 40-45 percent.
"We usually recommend that records be stored in an environment with a stable temperature and relative humidity," he said.
"We also recommend maintaining a clean storage environment that is separate from any sources of food or water."
Without shelter, food or water, there's little reason for a pest to stay around.
Left: California State Archives, on P Street in Sacramento.
Center: State Archives staff (L-R): Archivist Kira Dres, Acting State Archivist and Division Chief for the California State Archives Tamara Martin, and Document Preservation Technicians Juan Ramos and Nick Jackson.
Right: Document Preservation Technician Nick Jackson inspects a trap, used to monitor for insects.
Monitoring
The first line of defense is monitoring. Sticky traps are located throughout the building to catch any insect intruders. Old fashioned observation is also important.
"We try to train the staff – office assistants, interns – to look for things," explained Juan Ramos, a document preservation technician at the Archives.
Low-risk pest management methods
The occasional pest is inevitable, so IPM practitioners look for low-toxicity ways to control them when they get in.
At the San Francisco Museum of Modern Art, where Andreetta attended a workshop earlier this year, small hand vacuums are used to suck up bugs and large sticky traps are set at some entryways to catch anything that could hitchhike indoors on employees' shoes.
State Archive staff put some incoming items into freezers to kill any stowaway bugs
Ramos recalled the archives once received a batch of uniforms from the Preston School of Industry – a now-shuttered reform school, known as "Preston Castle," situated in the town of Ione.
Some earwigs were spotted among the items, so the clothes were hurried into the freezer.
"All them were dead," Ramos said.
Can't be too cautious in this line of work.
"We try to prevent issues before they come in."
Indeed, a good portion of the technicians' time is spent repairing damaged documents that come to them. Some woefully chewed, rotted or stained.
Pesticides as a last resort
IPM may include the judicious use of conventional pesticides as a backstop.
The "integrated" part of IPM involves balancing various strategies to maximize efficacy and effort.
At the Archives, some low-risk chemicals are used - like alcohol for killing mold on manuscripts.
"Our role in pest management is mostly in monitoring," Ramos said.
"If there is a problem, we call the professionals."
Left: Jackson checks the temperature and humidity in one of the archive's rooms.
Center: Behind the scenes, an IPM class at the San Francisco Museum of Modern Art.
Right: Jackson holds up an insect-damaged document sent to the archives for repair and storage.
Takeaways for people interested in protecting their collections:
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“If you love something or have something of value made from organic materials that you want to keep, research the best way to take care of it, store it properly, and inspect it every now and then,” Andreetta said.
“If you shove it in a closet, when you go back to look at it lovingly, it could be full of holes.”
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Thrift store and garage sale enthusiasts should get familiar with identifying pests to avoid inadvertently transporting them into their home. Andreetta notes that museums collect and borrow art from around the world and many have learned lessons the hard way.
“The most common pests are beetles, moths and silverfish. Fungi, like molds, can also be a problem,” she said. “There is something to eat everything. If left to themselves, they’ll just destroy things.”
Andreetta said pest control professionals can also benefit from taking specialty classes in museum and gallery pest management because there are factors to consider beyond deflecting the pests – like cultural considerations should also be factored in, she added.
“For example, Hopi katsina dolls are looked at as vessels for living spirits. An anoxic (oxygen depriving) treatment may be looked at as choking the spirits that live in the doll,” she explained.
“Also, certain pigments used in paint and adhesives might be altered by heat or freezing. Pigments, such as Prussian blue, can change color in low oxygen environments.”
“Communication is key, and some background knowledge and training is very, very helpful.”
For more information on integrated pest management:
- Pest management tips from the IPM Working Group
- The Smithsonian Institution IPM checklist
- Northeast Document Conservation Center’s Preservation Leaflets
- National Park Service Conservogram
Though these are used by professionals, they can easily be adapted for private use.
For content questions, contact:
Craig Cassidy
Public Information Officer I
DPR Office of Communications
1001 I Street, P.O. Box 4015
Sacramento, CA 95812-4015
Phone: (916) 445-5815
E-mail: Craig.Cassidy@cdpr.ca.gov