The incident was classified as a mass casualty incident, meaning that multiple people may have been injured by the odor.
The hospital initially said patients were among those affected, but Vasapolli said it was only staff members.
Fire crews were dispatched, and both the operating room and emergency room areas were evacuated and closed, according to a hospital spokesperson.
Calls for assistance were made at about 11:15 am. As that number started to increase, the hospital closed the operating room and began transferring people out.
State and local officials are still working to determine a cause. About 40 patients and some staff experienced flu-like symptoms after the odor was reported, the source of which remains a mystery, according to the Boston Globe.
The fire department in neighboring Kingston said it sent two ambulances to the scene.
The cause was not immediately known, she said.
Other staff members in the hospital's operating room later became ill, she said.
Vasapolli said the sick staff members were taken to the hospital's emergency room.