May 2000 Volume 22 Number 2

Contaminated Cultural Materials in Museum Collections: Reflections and Recommendations for a NAGPRA Issue

by Nancy Odegaard and Alyce Sadongei

The Arizona State Museum at the University of Arizona in Tucson, was awarded a NAGPRA grant to plan and implement a workshop entitled Contaminated Cultural Materials in Museum Collections. The workshop was held on March 16-18, 2000. On April 4, the authors delivered testimony to the NAGPRA Review Committee during their scheduled meetings in Juneau, Alaska. The following article is based on that testimony.


With the passage of the Native American Graves Protection and Repatriation Act (NAGPRA) in 1990, tribes have begun to receive cultural objects held in museum collections.1 Many of these objects have been previously treated with chemical poisons to aid in preservation. As part of the repatriation process tribes are seeking information specific to objects of cultural patrimony in order to reduce the potential human health risks involved in handling these returned objects.

Concurrent with the implementation of the requirements under NAGPRA, the Arizona State Museum conservation laboratory was working on a study of materials characterization tests for objects of art and archaeology. Due to the success of spot test techniques and their potential utility for detecting the presence of pesticides beyond arsenic and mercury, the ASM lab began a special pesticide detection project for museum objects with funds from the University of Arizona Office of the Vice President.

The conservation staff at the Arizona State Museum had long been concerned that the museum's history of pesticide use was vague and incomplete. While chemical pesticides have not been used on ASM collections during the era of professional conservation (almost 20 years), the museum is 107 years old, and the probability of earlier pesticide use was felt to be significant. In addition, the ASM conservation lab was asked by the Hopi Tribe to participate in a University of Arizona interdepartmental study that included the Arizona Poison Control Center, the Arizona State Museum, and the Chemistry Department. This study examined the potential health effects of handling and exposure to a particular set of contaminated cultural objects that had been repatriated to the Hopi Tribe.

The NAGPRA grant funds enabled the ASM to hire an assistant conservator and expand previous studies in order to complete a thorough study of the ASM records and information. In preparing reference materials for the workshop, it was always understood that the ASM history would not be identical to other museums and that the story of pesticide use in the Southwest could not offer answers for the entire country. Still, the Arizona State Museum was able to offer an example of how a museum history of pesticide use could be partially recovered.

Purpose of the Workshop

The target audience for the workshop were representatives from the 21 American Indian tribes in the state of Arizona. The goals of the workshop were:

  1. to share relevant and current information on the types and levels of chemical contamination found on tribal cultural materials in museum collections;
  2. to provide an introductory understanding of the rationale for the use of chemical poisons in museum collections;
  3. to discuss the potential health risks in re-introducing a functional object back into a community through preservation, handling, restoration, or use;
  4. to disseminate clearinghouse information on medical referrals and/or health professionals including chemical hygienists and toxicologists.

Preparation and Planning

To prepare for the workshop, NAGPRA grant funds were used to conduct consultations with tribal members at their home institutions. The objective of these visits was to determine the issues tribes wanted to see included on the workshop agenda.

From November 1999 to February 2000 the workshop coordinators consulted with tribal representatives from the San Carlos Apache, White Mountain Apache, Yavapai-Apache, Hopi, Navajo, Tohono O'Odham, Ak-Chin Indian Community, Gila River Indian Community, and the Salt River Pima-Maricopa Indian Community. These particular tribes were consulted because the ASM collections contained significant numbers of their artifacts.

The tribal consultations suggested the workshop include the following.

NAGPRA Grant funds were also utilized by the ASM to hire Marilen Pool as an assistant conservator to work with the available conservation files, museum receipts, contract agreements, curatorial diaries, and other documents and to record employee memories. This information resulted in a more complete museum history concerning the use of specific pesticides, the time frames of their use, the techniques of application, and the potential distribution across the collection.

Finally, funds supported the efforts required to compile a database (Microsoft Access version 8) of pesticide information. Information was gathered from material safety data sheets, product labels, and searches through the pesticide and museum literature. The data is organized under various headings such as chemical specifications, chemical abstract service (CAS) number, alternate trade or common names, probable years of use and availability, bibliographic references, published levels of toxicity, and legal registry information. The information provides an important reference source for the chemicals and commercial products that have been used in museums. (This information will be included in the publication in progress. See footnote 2.)

Two key points were learned during the workshop planning and preparation process. The first was depending on the intended disposition of an object (such as ritual use, storage, placement or disposal), the level of risk to humans and the environment may vary considerably. Second, there may be types of cultural protection that individuals may want to consider when handling collections with potential pesticide contamination.

The Workshop Agenda

The formal presentations were made by a wide range of specialists. The tribal perspective was provided to introduce the importance and relevance of the issue. Alyce Sadongei addressed the cultural risk and tribal views on contamination. Leigh Kuwaniwiswma presented the Hopi Pesticide Project. Nancy Odegaard discussed topics such as the how and why of pesticide use in museum collections, the vocabulary of pesticides, and the major pesticides of concern and how they were applied to museum objects.

Marilen Pool made presentations explaining the Arizona State Museum's history of pesticide use. Medical toxicologists Leslie Boyer and Steven Seifert discussed the medical issues and clarified how toxins enter the body, the symptoms of exposure, and who is more at risk. Chemists explained techniques used for detecting pesticide residues on museum objects: David Smith demonstrated analytical laboratory protocols involving instruments; and Werner Zimmt demonstrated low-tech spot test techniques.

Industrial Hygienist, Ed Burroughs shared the results of his recent study involving protective clothing and health risks to museum workers handling contaminated objects. Public Heath Researcher, Mary Kay O'Rourke spoke of studies developed to detect and interpret pesticide use in homes. A presentation and discussion period was led by Jessie Johnson of the National Park Service and Valetta Canouts of the NAGPRA office during an evening session. There was also time on the agenda for participants to raise questions and clarify issues. The agenda was characterized by issue-based discussions and presentations at the beginning and end of the workshop, and technical and reference type presentations in the middle. The coordinators understood that conveying a lot of technical information would be difficult because the group's base of knowledge was extremely diverse and wide. Acknowledging that the topic was complex and large, the coordinators considered this workshop to be a first step.

Issues Identified as a Result of the Workshop

The Contaminated Cultural Materials in Museum Collections Workshop was only a beginning. In general, both tribal members and museums staff are presently unaware of the potential risks of pesticide contamination on museum collections.

There is an urgency to develop tests that can be used by museums to screen for pesticide presence on objects; to develop protocols for the analytical determination of pesticide quantity; and to qualify the potential health risks depending on the intended tribal practices and disposition of repatriated items.

Cooperation among museums during the development of histories is important because many collections were made by the same collectors, and were traded or loaned, thus there may be overlap in pesticide histories. A database of pesticide uses by museum location was suggested.

Due to the wide variation in tribal practices after repatriation (use, burial, deposit, storage, burning) the implications of the human health hazards involved impact at individual and environment levels.

The complexity of the issue requires the formation of cooperative teams that include tribal people, medical toxicologists, conservators, chemists, and/or industrial hygienists or public health professionals. These teams might be organized at a regional level. There is also a need to address and potentially include tribal practices for pest control in the discussions.

Workshops and presentations are needed at the tribal level so that more people are made aware of the issue. Many felt that a wider base of individuals (including those who must handle the collections during a consultation, repatriation or final disposition) needed to be informed of the pesticide issue. Many tribal representatives are interested in further guidance regarding handling, storage, and integrated pest management.

Recommendations to the NAGPRA Review Committee

This type of information gathering workshop should be held in different parts of the United States, and programs such as this should be funded. The issues are not necessarily the same for all locations, tribes, or museums. Resources are needed for dissemination of general pesticide information. It is important to apply discretion in deciding what information is appropriate for dissemination. The coordinators of the ASM workshop determined that compiling the information from this workshop would maintain the historical context and intent. Isolated handouts and small articles are often useful but the information may be misunderstood without the association of other related articles.2

It is obvious that more work needs to be done. There was a consensus among those attending the workshop, however, that the current level of information was of critical importance. For example, though very few are aware of it, all museums should prepare histories of pesticide use. Museums should include conservators in their internal repatriation committees, and if they don't have a conservator on staff, they should contract one for this purpose. It was interesting to learn that few of the conservators attending the workshop were directly involved in the repatriation activities at their museums, yet they were often expected to know something of the pesticide toxicity and were regularly asked to give medical commentary.

There is general confusion about the purpose and techniques of swipe tests, which needs to be clarified. Funding should be provided to use these tests as a general screening technique for preliminary information. Likewise, there is general confusion regarding the services of commercial analytical laboratories and those of professional research laboratories. Because the styles and approachs of the two are very different, the results and recommendations may vary considerably. At present there are no guidelines or recommendations available.

Museum conservators should be aware that all testing that involves sampling of objects must include the consultation and direct participation of tribal members. Conservators should be careful when discussing medical concerns related to human health. Industrial hygienists and medical specialists must be involved in the process of health risk assessment.

The context of any information is important; a simple chart of all the information prepared for the workshop is not possible. The type of pesticide and the amount present on any suspected object is critical information. The type of body entry (ingestion, inhalation, absorption) can allow one chemical to be either safe or highly toxic depending on how it enters the body.

When discussing pesticide contamination, cooperation among a diverse group of professions is essential. The team should include tribal people, medical toxicologists, conservators, chemists, and/or industrial hygienists or public health professionals. Because much of the information is complex and will be new to the diverse audience, clear and effective communication will be essential.

Since the amount of household pesticides commonly used among tribal people is high, the potential additive effects of these products require further understanding. Tribal members should work towards a more comprehensive knowledge of the general pesticide use within their tribes. They should take advantage of the additional resources available and encourage collaboration between local representatives of the Environmental Protection Agency and tribal pesticide (agriculture) officials.

The NAGPRA Regulations

The NAGPRA regulations mention the topic of pesticides only once (in Section 10 under repatriation 10.1 part (e)). The museum official or federal agency official must inform the recipients of repatriations of any presently known treatment of human remains, funerary objects, sacred objects, or objects of cultural patrimony with pesticides, preservatives, or other substances that represent a potential hazard to the objects or to persons handling the objects.

There are problems in following the regulation. These include:

  1. most museums presently know little about pesticides used or the potential hazards they might have to the objects or to the persons handling them;
  2. most tribes are interested in all information regarding the use of historic museum pesticides on their repatriated collections not just those presently known; and
  3. most museums do not have the means to determine historic pesticide use.

It is clear that funding is needed to enable historical research and the development of testing techniques. Further, determining the potential hazard to the objects or to persons handling contaminated objects involves medical implications and these determinations cannot be made without testing and sampling. Sampling is a form of analysis and under the NAGPRA law it requires a tribal consultation, informed consent, and direct involvement by tribes in the process.


The workshop at the Arizona State Museum concerning Contaminated Cultural Materials in Museum Collections identified several points that are important to consider as museums and tribes begin to work together on processing objects for repatriation. First, communication is critical and museums need to bring this issue up during consultations and tribes need to be informed and ask questions throughout the process. Second, not every object's documentation and examination reports will include bad news about potential contamination, but when the news is bad, it is probably very bad. Third, current regulations promote a continued ignorance on this topic. Fourth, the NAGPRA Review Committee should see the pesticide topic as important and determine a path for further clarification.

End Notes

1. See the National Park Service web site for more information about NAGPRA regulations, the NAGPRA grant program, and the NAGPRA Review Committee.

2. The Arizona State Museum is currently compiling the research information and presentation papers developed for the workshop into a single volume.

Nancy Odegaard (Ph.D.) holds the positions of Conservator at the Arizona State Museum and Associate Professor in the Department of Anthropology at the University of Arizona.

Alyce Sadongei (Kiowa/Tohono O'Odham) is the NAGPRA coordinator for ethnographic materials and is the Assistant Curator for Native American Relations at the Arizona State Museum.

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