Historical use of pesticides to protect collections means objects are contaminated by not only colonial heritage
Philip Oltermann in Berlin

The day Santi Hitorangi would touch the human remains of his ancestors was meant to mark the beginning of the end of their 140-year spell in forced exile.

The UN representative for the Polynesian territory known to many Europeans as Easter Island has spent the last four years in Leipzig, eastern Germany, preparing the repatriation of 28 members of the Huki and Hitorangi clans of the Rapa Nui nation whose Ivi tupuna (skeletal remains) were taken from their original places of rest by a German gunboat expedition in 1882 and ended up in the collections of the states of Saxony and Berlin.

Leipzig’s Grassi Museum of Ethnology, one of several German institutions taking steps to return unlawfully acquired objects from their collections, installed a room specifically designated for repatriations, in which Hitorangi and his colleagues Evelyn Huki and Daniel Fabian were to ceremonially transfer their ancestors’ remains from the realm of artefacts to the realm of deceased humans.

The process, which is commonly described as “rehumanisation”, requires wrapping the bones and skulls in fabric made from paper mulberry fibre – and, importantly, human touch. “Physical contact is the only way we can humanise the remains of our ancestors,” said Hitorangi. “It is the only way they can forget the pain.”

Four days before the ceremony, on 29 September the museum got in touch to provide Hitorangi and his colleague with a facial mask, a surgical gown, nitrile gloves, and a warning: his ancestors’ remains were likely to be poisonous.

As a movement to restitute objects from ethnological collections gathers pace across Europe and North America, museums are waking up to an ethical dilemma. The widespread historical use of pesticides means objects in their storage halls are not only toxic in terms of their problematic colonial heritage, but also in terms of them being contaminated with highly hazardous substances.

The idea that these museum objects can again be used in ceremonies and ritualised performances, scientists warn, could prove illusory while they pose a risk to the health of those handling them. Are restitutions completed with the transfer of ownership, or does a duty of care extend beyond that point?

In Pest Control in Museums, a landmark study published last spring, the Berlin-based researcher Helene Tello charts the way in which a booming German chemicals industry of the late 19th and early 20th century aggressively marketed products to museums struggling to protect their collections from infestations of pests such as wood beetles, clothes moths or silverfish.

“At the time, many of these museums were understaffed and completely overwhelmed with the task of handling the objects they had amassed during the colonial era,” said Tello, a former conservator at Berlin’s Ethnological Museum.

Organic materials such as wood, leather, furs and feathers were liberally sprayed with chemicals later found to be highly hazardous. At the Rathgen Research Laboratory, a research institute attached to Berlin’s state-owned museums, analysis of the city’s collections have in recent years discovered traces of heavy metals including arsenic, lead and mercury, as well chlorine-containing compounds such as pentachlorophenol (PCP), which can cause harmful effects to the liver, kidneys, blood, lungs and nervous system.

“We frequently come across objects in our collections with disconcerting levels of biocide contamination,” said Stefan Simon, the laboratory’s director. Some insecticides used, like dichlorodiphenyltrichloroethane (DDT), have been found to be likely to cause cancer.

In some cases, the use of pesticides was meticulously documented. A grey metal storage unit in the Ethnological Museum is marked with a warning sign saying: Schwarzobjekte or “black objects”. Inside there are two wooden masks that date back to the mid-15th century and were made by the Kogi, an indigenous group from the Sierra Nevada de Santa Marta mountains in northern Colombia.

The masks, which were once worn in religious ceremonies, were bought in 1915 by the German ethnologist Konrad Theodor Preuss from the son of a deceased Kogi priest – a purchase the museum says should never have happened. “It’s pretty clear that these masks came to Berlin unlawfully,” said the Berlin state museums curator Manuela Fischer.

Last September, the Prussian Cultural Heritage Foundation, which oversees the city’s museums, announced it had entered talks with Colombia and the Kogi community to repatriate the masks. A spokesperson for the Colombian embassy in Berlin confirmed it had submitted a formal request for repatriation.

But direct skin contact with these face masks, potentially during a physically exerting ceremony, would come with a considerable health risk. In the 1940s and the 50s, records show, the container holding the two masks was repeatedly sprayed with 1,4-dichlorobenzene, a disinfectant that can cause breathing difficulties and is suspected of causing cancer.

Since surviving records of pesticide treatments at German museums are often full of gaps, the scientific basis for evaluating the health risk they pose can be shaky unless determined by chemical analysis.

In some cases, fears have proven to be unfounded. The curators of Berlin’s Humboldt Forum, a new museum, had originally planned to exhibit a climbable 1960s reconstruction of a traditional Tonga sailing boat from the city’s ethnological collection. Instead, they took the costly decision to commission Fiji boatbuilders to build another replica instead. Concerns about pesticides used on the old boat, the museum said, were one factor that had led to that decision. A proper analysis has since found the boat’s contamination “to be below currently applicable thresholds”, however.

Cross-contamination through dust particles means even objects that were not sprayed may have become polluted over time. Tello estimates two-thirds of the 500,000 objects in Berlin’s ethnological collection are contaminated. Other museums are even more pessimistic. “We assume all our objects are affected,” said a spokesperson for Hamburg’s Museum am Rothenbaum – Cultures and Arts of the World.

While objects subject to restitution claims are usually cleaned up before being handed over, scientists have yet to develop a method for fully extracting potential toxins.

“I don’t know of a single scientific procedure that would turn a contaminated object into a harmless object,” said Simon. “There’s still a great naivety among museums and politicians about what science and technology are capable of in that respect. Even after a ‘successful’ decontamination procedure, safety regulations have to be upheld when handling these objects.”

To ensure those safety regulations are adequately highlighted, museums should not just hand back their objects but also the toxicological equivalent of a laundry label and a safety protocol, said Tello. “Most museums now have strict guidelines for what protective gear curators and conservators have to wear in the archives, but not for how to handle these objects outside the museum.”

A too prescriptive set of user instructions risks going against the spirit of restitution, however. “It should be up to communities what they do with the returned objects,” said Léontine Meijer-van Mensch, the director of the Grassi Museum. “If they say: we’re aware of the risks, but we want to touch these objects anyway, then we have to respect that.”

“Restitution is a complex process,” Meijer-van Mensch added. “We want to return these objects, so we can’t just say, it’s all toxic, so we’re going to shut the door. The only way is to be as transparent as possible.”

In spite of being informed of the contamination risk at the last minute, Hitorangi and his colleagues said they were able to perform the ritual in the way they wanted to. As the so-called Repat.A-Take Team, they are trying to crowdfund the final leg of the journey back to Rapa Nui.

Their ancestors, they said, would travel not as museum objects, but as the remains of humans.