Sarah Anderson/MEDILL
Front entryway of the Field Museum in Chicago, Illinois.
It’s a busy Saturday afternoon at the Field Museum in Chicago, Illinois. Tourists snap photos of Sue, the museum’s famous Tyrannosaurus rex skeleton. Parents remind children eager to press their faces against glass-encased taxidermy displays and sparkling gemstones to wait their turn. Centerpieces whoosh overhead as vendors set up for a wedding in the main lobby that evening.
Amid the chaos, a corner of calm remains: the Native North America Hall. The entrance is marked by a black drape and a sign announcing a new exhibit scheduled to open on May 20. Behind the scenes, curators, conservators, and a panel of Native American advisors are working to develop displays and experiences that “highlight Native historic and present-day stories of sovereignty, resilience, continuity, and the future,” according to a press release from the Field Museum.
Unmentioned in the release, the museum’s long to-do list to prepare for the exhibit’s opening includes an odd priority—the need to test artifacts for hazardous chemicals.
“It really needs to be up to those tribes to determine the best course of action for themselves and for their communities.”
Prior museum conservators and private collectors routinely applied pesticides to artifacts containing feathers, leather, and other protein sources to deter hungry insects and rodents. This short-term solution to pest damage has created an enduring problem inherited by today’s museums, which now must identify artifacts contaminated with toxic chemicals to ensure the safety of the people who might encounter them.
The issue came to light in the 1980s when Nancy Odegaard, now head of the Preservation Division at the Arizona State Museum, noticed fading colors, corrosion, and other physical defects in museum artifacts and initiated conversations about the application of pesticides at conferences. The matter gained urgency with the enactment of the 1990 Native American Graves Protection and Repatriation Act, which required that sacred items like masks and headpieces be returned to the affiliated tribe.
Many of these items were going to go back into actual use, including artifacts that would be worn on the head, eyes, nose, and mouth. This was concerning to Odegaard because the previous generation of conservators didn’t keep thorough records of the pesticide treatments they performed, as it had become a standard housekeeping practice: “Do you document every time you wash the dishes or vacuum the floor or clean the bathroom? No,” Odegaard says.
Odegaard gathered as much information as she could from staff memories, books, and inventories at various institutions to piece together what pesticides had been used. She and her team compiled a list of ninety-nine chemicals that museums should look out for, including metals arsenic, mercury, and lead, as well as dichlorodiphenyltrichloroethane (DDT), which has been banned from use in the United States since 1972 and is a possible human carcinogen.
“The curtain has been pulled back,” Odegaard says of the revelations regarding contaminated artifacts in museum collections. “It is up to [museums] to do their historical research on when and how and what products were used to inform and guide their display, storage, repatriation, and educational activities.”
The Field Museum is one institution doing just that.
As part of the museum’s current practice, artifacts that are extensively handled by staff during conservation and display are tested for arsenic, a widely used preservative, explains JP Brown, a conservator at the museum. To test an artifact, he rolls a damp cotton swab over the surface and places it in a test tube containing a chemical solution and an indicator strip. A series of reactions creates a color change on the strip that serves as a measure of the amount of arsenic in the sample.
JP Brown/Chicago Field Museum
An array of samples collected from artifacts at the Field Museum are tested using chemical indicator strips, where a yellow-brown color signals the presence of arsenic.
Items that test positive are flagged to indicate the need for personal protective equipment for workers who handle them. While regular exposure to small quantities of arsenic might not yield any immediate health problems, it can lead to cancer and other chronic illnesses over time, says Dr. David Hinkamp, a physician specializing in occupational and environmental medicine and the founder of the Health in the Arts Program at the University of Illinois Chicago School of Public Health. As transfer from the hands to the face is a primary route of exposure, disposable gloves are an important line of defense, he says.
In a 2013 study, Hinkamp and others tested high-touch surfaces in the Field Museum’s anthropology department for arsenic and found very little cross-contamination from the handling of arsenic-treated objects. Urine analysis of Field Museum staff members found that, while the amount of arsenic detected was low overall, people who had been working at the museum longer tended to show higher levels.
These studies provide just a snapshot of the potential for arsenic exposure at a museum with exceptional health and safety protocols, Hinkamp says. Other museums “may have no education or knowledge about which items have been contaminated or what the toxic effects of those materials are,” he says. “It really needs to become a more widespread aspect of the education of people who go into that field.”
The Field Museum also offers to perform chemical testing on ceremonial artifacts that will be repatriated to Native Americans. This may require grant funding depending on the extent of testing, says Helen Robbins, the repatriation director at the Field Museum. This analysis is typically performed using a technique called X-ray fluorescence (XRF), which measures X-rays emitted from atoms in the sample. The energy of the outgoing X-ray provides a unique signature of each element, allowing the XRF instrument to detect the various chemicals on the surface.
The results of this testing can be used to create a map of the chemical makeup of an artifact. It might show, for example, that arsenic is concentrated in a specific paint or bead. In combination with research on the history of the artifact, this information might indicate that the source of the chemical is likely a pigment originally used to create the item rather than a pesticide that was later applied, says Cheryl Podsiki, a conservator and contaminated objects specialist who has performed XRF testing for the Field Museum.
Patty Talahongva, a journalist and citizen of the Hopi tribe, says pinpointing the origin of the chemical is also vital to informing the way in which the artifact will be repatriated. “When you’re putting something together in your faith or in your religion, that is a different process, and all the good intentions that go into that have a different outcome than somebody just randomly spraying for bugs,” Talahongva says. “In my mind, there’s really no comparison.”
In order for Native people to be able to act upon the testing results, they must be presented clearly. Odegaard has worked with a medical toxicologist to develop a system that classifies items as green (safe because no toxic metals were present), yellow (safety depends on how it will be used because residual chemicals were identified) or red (unsafe because large quantities of pesticide were detected).
While it’s necessary to make sure the testing report is accessible, it’s also important that a museum not dictate what Native people can and cannot do with an artifact, says Debra Yepa-Pappan, community engagement coordinator at the Field Museum's Native North America Hall. “It really needs to be up to those tribes to determine the best course of action for themselves and for their communities,” she says.
Collaboration with Native Americans throughout the testing process is facilitated by their representation within museum staff, says Yepa-Pappan, who is Korean and a tribally enrolled member of the Pueblo of Jemez. “I’m a huge advocate for Native people being in these types of positions to help with communication and relationship-building with Native communities.”