The use of pesticides and preservatives in museums dates back hundreds of years. But as institutions face public pressure to repatriate cultural items looted over centuries of imperialism, what has long been a common practice to protect collections from pests and mold is now coming under scrutiny. And for the tribal communities involved in these repatriation efforts, the contamination of these objects presents a multitude of questions around the safe handling and use of returned items.
Since the establishment of the Smithsonian Institution’s National Museum of the American Indian (NMAI) in 1989 and the implementation of the Native American Graves Protection and Repatriation Act (NAGPRA) in 1990, US museums involved in repatriation efforts have been grappling with the dilemma of sacred Indigenous objects and remains contaminated by toxic pesticides and preservatives.
“A lot of these items are considered to be living and breathing, and need to maintain that cultural use, and that is something that practitioners in the field within museums have become a lot more aware of over time,” Alex Lucas, NAGPRA’s program manager and interim repatriation coordinator at the University of California, Berkeley (UCB) told Hyperallergic.
In 2001, the National Park Service compiled a list of more than 50 substances that were used to treat collections in many American museums since the 18th century. These include arsenic, heavy metals like lead and mercury, carbon disulfide, paradichlorobenzene (PDB), dichloro-diphenyl-trichloroethane (DDT), and ethylene oxide. Although museums have long since moved away from these hazardous chemical treatments and toward more integrated pest control methods, the likelihood of objects eligible for repatriation being contaminated is still very high, according to NMAI.
“As a matter of standard practice, and I believe in most museums, we operate under the assumption that every item may have something on it because of this history,” Eric Hollinger, a tribal liaison for the repatriation office of the Smithsonian’s National Museum of Natural History, told Hyperallergic.
For tribal members, this history can pose hazards. Those interested in incorporating previously held items such as repatriated regalia back into ceremonial practice worry that contaminated objects might endanger their health. For others seeking the reburial of ancestral remains, there are concerns that preservatives and pesticides could potentially poison the surrounding environment.
“[Before NAGPRA] museums and the conservation profession had been generating information about pesticides, but it was primarily to the focus of how they changed the color, the texture, and the quality of an object or an artwork — not how they damaged people, because nobody knew that objects would ever leave the collections,” said Nancy Odegaard, a conservator at the Arizona State Museum and anthropology professor.
In order to analyze potentially contaminated collections, many institutions have adopted the use of X-ray fluorescence (XRF), which can detect mercury, lead, and arsenic. But Hollinger points out that the technology’s testing capability is limited to these elements.
In recent years, the issue of Native remains and cultural objects held in American institutions has grown more visible. Last month, ProPublica published a new investigation featuring a searchable database tracking over 100,000 Native American remains in US organizations. In New York, confirmed or possible Native remains were reported in institutions including the Brooklyn Museum, the Brooklyn Children’s Museum, and the American Museum of Natural History. According to ProPublica, the University of California, Berkeley holds the remains of at least 9,058 Native American individuals, and the University of Arizona reportedly has at least 2,400 remains. UCB also told Hyperallergic last month that the institution holds an additional 13,000 ceremonial objects and approximately 200,000 archaeological objects that the campus believes are potentially sacred and eligible for repatriation.
Lisa Bruno, the chief conservator for the Brooklyn Museum, shared that in her experience tribal communities have been interested in learning about potential contaminants.
“Sometimes, the objects themselves are decorated with pigments that also have arsenic. So the object may have evidence of arsenic, but it may not have evidence of pesticide because the arsenic is coming from the pigment. That is equally as important for tribal communities to know,” Bruno told Hyperallergic.
But even with the technological advances in testing, there are tribal communities who still view this type of testing of ancestral remains and sacred objects as an invasive and destructive process.
“Too often, people try to be proactive and get this testing done, and may be doing testing that isn’t needed, isn’t wanted, and is potentially damaging,” Melodi McAdams, a tribal heritage specialist for the United Auburn Indian Community, said during a recent NAGPRA Community of Practice Call.
McAdams went on to explain how museums can use alternative information-gathering methods to determine an object’s contamination history, rather than solely relying on testing, in order to provide tribes with informed recommendations for safe handling and use of repatriated objects. Instead of resorting to unnecessary chemical procedures, McAdams said, institutions can use systemic information to identify contaminated collections, such as referring to records of pesticide and preservative use and interviewing current and past curatorial staff. Additionally, minimally invasive examinations, such as testing the container or area around the object, as well as wipe tests, can be highly effective ways to look for contaminants.
Odegaard also advocated for tribal participation when testing potentially contaminated objects, and stressed the importance of this collaboration with tribal communities.
“When I’ve been doing testing, mostly, I will turn around and do it with [a tribal representative],” Odegaard explained. “And I’ll say, ‘You hold it, and we’ll do this together.'”