A surveillance camera at Cardozo Senior High School in Northwest Washington picked up an image of a student spilling the mercury that forced Wednesday's evacuation of about 600 students and closure of the building, school officials said yesterday.
Cardozo Principal Reginald Ballard Jr. said the videotape from the camera, which runs 24 hours a day at an undisclosed location in the school, should help authorities identify the student responsible for the contamination.
"I'm looking at it right now," Ballard said. "We think we're going to have the kid. The camera was working and not grainy."
D.C. police, who are leading the investigation, said they are reviewing the videotape and would not comment further.
D.C. School Superintendent Clifford B. Janey said the person responsible for spreading the mercury put students and staff at risk and would be prosecuted. "This is nothing to play with," he said. "This is not a prank. . . . It's very serious."
Cardozo was closed after school officials Wednesday morning found the silver, marblelike droplets in a hallway, in a stairwell and near a water fountain. Hazardous materials crews from the U.S. Environmental Protection Agency have since found mercury at two other locations in the building, Janey said. School and health officials would not identify the new locations.
The school system banned mercury after a student at Ballou Senior High School in Southeast broke into a chemistry lab in October 2003 and gave the chemical to friends, who spread it through the building. The cleanup kept the school closed for about a month. School officials say they suspect that whoever spilled the mercury at Cardozo brought it into the building.
Janey had said Wednesday that he expected Cardozo to reopen Monday, but yesterday he said that the air contamination inside the building is still dangerously high and that the cleanup might take longer. If Cardozo remains closed Monday, classes will resume at another location, he said.
A total of 2 ounces of mercury was found at Cardozo, said D.C. Health Director Gregg A. Pane. He said that air tests performed yesterday by the EPA showed a concentration of mercury about 10 times as high as the level deemed acceptable.
Janey said he would make an announcement today, based on additional testing, about his plans for Cardozo next week.
Long-term exposure to mercury vapor can cause cancer and other health problems.
Pane said Wednesday's screening of students, staff and responders at Cardozo found that seven people had detectable traces of the chemical on their clothing, shoes or hands, not 15 people as officials had initially reported. Officials said none of the seven is expected to develop any health problems.
About 10 students left Cardozo on Wednesday before being tested for mercury contamination, Pane said. He encouraged those students to call 202-671-5000 to arrange for immediate testing.
Police officials announced that they have set up a hotline at 202-727-9099 for tips about the mercury incident.
"We're soliciting help from anyone -- a student, a staff or a citizen -- that can lead us to the person responsible for this," police Capt. Michael Reese said.