A known carcinogen in high doses, arsenic can cause cancer in extreme cases, as well as myriad other health problems depending on the exposure. McCaffrey said the city was looking into whether the exposure was high enough to cause serious harm.

The Rotary Club of East Lansing planned to renovate the structure, built in 1995, in September as part of the Playground in the Park.

Community renovation project, but renovations will be put on hold while the city looks into the incident, said East Lansing City Manager Ted Staton.

McCaffrey said the wood used to construct the playground was treated with chromated copper arsenate, or CCA, a common wood treatment product prior to 2003, when wood manufacturers agreed to take it off the market.

Any arsenic damage from CCA would be more likely to affect the people who constructed the play structure rather than children who might be playing on it, McCaffrey said.

Still, the playground has been marked with a sign alerting people of the arsenic on the site, and children should wash their hands after playing on it, McCaffrey said.

“It’s unclear to us, but there may be health risks to individuals,” he said.

The wood was sent to Fibertec Environmental Services in Holt, Mich., for testing, which exposed the arsenic in the wood’s core.

Fibertec Environmental Services Laboratory Director Daryl Strandbergh said the sample showed small concentrated areas of arsenic, but was unable to specify the amount.

The city will continue to research and monitor the incident when more information becomes known.

“We intend to broadcast that message of what we know, as soon as we know what we know,” Staton said.