SIOUX FALLS, S.D (KELO) — More than a week after the sudden announced closure of the Delbridge Museum of Natural History at the Great Plains Zoo, city leaders are explaining the decision.

Arsenic was in the spotlight at a news conference Tuesday morning at City Hall; the element can be harmful to people, and zoo president Becky Dewitz said that a detectable level of this carcinogen was found in nearly 80% of specimens at the museum.

A news release from the zoo on August 17 stated that “leaders from the City of Sioux Falls and Great Plains Zoo have agreed to decommission the collection” of taxidermy at the museum. Sioux Falls Mayor Paul TenHaken sought to set the record straight on Tuesday.

“Quite a bit of misinformation floating around about the collection, so we’re here to just talk about that today,” TenHaken said. “There’s a lot of emotion around this topic.”

“I’ve read recent reports that state our intention is to immediately dispose of the collection in the landfill,” Sioux Falls Parks and Recreation Director Don Kearney said. “That is simply not true. There are regulations defining how disposition can occur, and we do expect it to be a months-long process.”

City attorney Dave Pfeifle says the law requires items in the collection to stay in the state, and city officials say the presence of arsenic further complicates the future of the display.

“From our research, the best practice is once you detect arsenic, you remove the specimen, wrap it in plastic and remove it from exhibit,” Dewitz said. “Or you put them in glass. With 80% positive for arsenic and the lack of glass, we really had no other choice at that point in time.”

“This is an example of we have a documented risk to protect the staff and the community from a known carcinogen,” TenHaken said.

City council members have been hearing from constituents since the collection was closed to the public.

“This has been a top 10 issue of when I’ve been on the council, and again, it’s always amazing,” councilor Pat Starr said. “The last thing I ever want to do is tell people what’s important to them. This is important to the community.”

“We’re hearing from a lot of people, and who doesn’t love history and animals and zoos, but there’s also, which was brought up today, a lot of factors that are pretty tough,” city councilor Marshall Selberg said. “Number one, safety. Number two, there’s a lot of legal issues with what we do with it, and then financial.”

Kearney says the city council will receive a presentation about the museum collection on Tuesday, September 5, and then the Parks and Recreation board will consider the issue Wednesday, September 6.