"Of the 300-plus languages indigenous to what are now the United States and Canada, nearly a third have disappeared. Only about a quarter of those that survive are being passed on to children. [Without intervention] all of these languages will fall silent within the next few decades. "
Teresa L. McCarty and Lucille J. Watahomigie
Several years ago, the Hopi tribe was consulting on the repatriation of three sacred masks (known as Katsina Friends) from Harvard's Peabody Museum of Archaeology and Ethnology. During the process the tribe discovered the Friends had been treated with pesticides. Further tests, done by the museum, found that some were contaminated with arsenic and mercury. How could this happen? Why were the masks poisoned? Should others involved in repatriation worry?
Imagine if you had to keep moths from your sweaters forever, not just for the few years you wear them. That's what museums have been trying to do ever since they started collecting. To keep insects away they have used a variety of tools, including pesticides.
Many of these deterrents, such as mothballs or No-pest strips, were commonly used in homes too. These chemicals discouraged insect infestations or killed insects after they got in. Unfortunately, some left hazardous residues. Things we now know to be toxic, like arsenic, mercury compounds, and DDT, were used.
Early pesticide techniques were broadly applied. Collectors and museum staff developed their own recipes. A recent article by Lisa Goldberg, a conservator in Cornell, New York, describes a 19th century mix of 1 pint of saturated solution of arsenic acid and alcohol, 25 drops of strong carbolic acid, 20 grains of strychnine, 1 quart of strong alcohol, and 1 pint of naphtha, crude or refined. These homemade concoctions posed risks to the applicator and the artifact. Other chemicals requiring special equipment and expertise, such as the fumigants ethylene oxide and methyl bromide, were also employed (see Goldberg's article under "Resources In Print").
Today many objects are going back to tribal communities, some into people's homes where they are once again being put to use. Tribes and individuals need to be aware of the problems and how to protect themselves. Leigh Kuwanwisiwma, director of the Hopi Tribe cultural preservation office, thought there should be ways to identify hazards before more Katsina Friends were returned. To gather information, he applied for a NAGPRA grant to identify the levels of pesticides on these objects. This year he's working with a group of scientists. His and others' research in museums around the country could become the basis for tribes to deal with the issue.
There are now strict rules for controlling pesticides. Many museums are adopting a new strategy: integrated pest management, or IPM. According to Carol di Salvo, IPM specialist for the Park Service, the approach is holistic. Pesticides are considered only after other methods to remove pests have been ruled out. IPM prevents a reliance on chemicals. For example, museums may stop pests by banning live plants that provide them food, water, and safe haven. Or they monitor where the pests sneak in with sticky traps or roach motels. Once the entry point is known, the insects are blocked using a variety of techniques. From now on, using IPM, museums will be able to keep their collections safe from harm in a way that won't harm people either.
But in the meantime, what can you do to protect yourself? What if you want to return repatriated objects to people in your community? How do you know if there is a risk?
Use this article as a starting point, but be sure to contact local experts for advice. The resources listed here will help you find more information.
First, be informed. The resources will get you started, including the wide range of information on the Internet. Look for training in your area. Nancy Odegaard, conservator at the Arizona State Museum, received an NPS NAGPRA grant to sponsor a workshop for Arizona tribes this March.
Second, ask museum staff. Even a hundred years ago, many museums kept records of pesticide use. There may even be records for specific objects, but at least the museum should be able to give you a general history of pesticide use or infestations. Under NAGPRA, museums must tell the recipients of repatriated objects about any known treatments. However, there is no legal obligation to remove pesticides, and museums are not legally responsible for health risks.
But the people in the museum are concerned about pesticides too, because they work around the collections every day. Dale Kronkright, a conservator at the Museum of New Mexico, developed a set of questions that the museum should be prepared to answer both for their own staff and for tribal members. Working with intern Linda Landry to answer these questions led to a handout, "Health Hazards and Pesticides on Museum Objects." The handout, which accompanies all repatriated items, is required reading for staff, researchers, and people who use the collections for ceremonies.
Unfortunately, museum records are often incomplete. People in the past didn't understand the pros and cons of pesticides; collectors often applied them before donating objects to museums.
Third, examine the artifact. According to Odegaard, if it has been in the collection a long time and shows little or no damage from pests, you should suspect treatment with something that left a residue. Crystals can often (but not always) be residue left from pesticides. It's important to remember that not every museum used all these materials, and not every object got all the treatments.
There are numerous other signs that indicate the presence of pests: holes, chewing marks, cobwebs, and droppings, among others. Insects also leave their moulted skins and waste, which is usually a soft powdery material.
Fourth, get expert help. While museum staff can give you some ideas about the risks they are not experts. Industrial hygienists lay claim to this title. If you are using suspect objects, contact the American Industrial Hygiene Association, (703) 849-8888.
Work with a museum conservator, industrial hygienist, or other qualified expert to identify toxic materials still on the objects. There are simple spot tests for arsenic; other types of materials may be more difficult to identify (see Makos and Dietrich in Resources).
Fifth, take these basic precautions:
Wear protective equipment like vinyl gloves, coveralls, a lab coat, and–as appropriate–head cap, shoe coverings, and a NIOSH-approved respirator with a high efficiency particulate (HEPA) air filter. The equipment you need depends on what you are doing.
Wash exposed skin before eating, drinking, smoking, or applying cosmetics.
Clean work surfaces after use with a HEPA vacuum.
As with much in life, hindsight is 20:20. Museums were using techniques and materials considered proper at the time. No one knew the damage that DDT would do to the environment. When a collector sprinkled arsenic on an object, no one thought it would ever be worn again. Now collections are being used in diverse ways. When objects get used, everyone must be aware and take the proper precautions.
For more information, contact Jessica S. Johnson, Conservator, Museum Management Program, National Park Service, 1849 C St., NW (NC230), Washington, DC 20240, (202) 343-8141, fax (202) 343-1767, e-mail firstname.lastname@example.org.
Resources in Print
Goldberg, Lisa, "A History of Pest Control Measures in the Anthropology Collections," Journal of the American Institute for Conservation of Historic and Artistic Works vol. 35 (1996), pp. 23-42, Washington, DC: National Museum of Natural History, Smithsonian Institution.
Hawks, Cathy A. and Stephen L. Williams, "Arsenic in Natural History Collections," Leather Conservation News vol. 2, no. 2 (spring 1986), pp. 1-4.
Makos, Kathryn A. and Elizabeth C. Dietrich, "Health and Environmental Safety," in Storage of Natural History Collections: A Preventive Conservation Approach, edited by Rose, Carolyn L., Catherine A. Hawks, and Hugh H. Genoways, Iowa City: Society for the Preservation of Natural History Collections, 1995, pp. 233-254.