Ruby Crawford said she was shocked when her son, a student at Ballou High School in Southeast Washington, came home recently and said there were asbestos materials exposed in classrooms there.

"I thought that the problem was over with," said Crawford, an unemployed secretary, who is a member of the Washington Association of Community Organizations for Reform Now (ACORN).

Yesterday, at a press conference held by ACORN in front of the school, Crawford and other parents and students complained about what they see as a problem with cancer-causing asbestos at the school.

Shelton Lee, director of security for D.C. schools, said yesterday, "There's no harmful asbestos in Ballou . The level of asbestos that's being ingested by students meets the standards set forth by the Occupational Safety and Health Administration." Ceiling tiles have been removed so the roof can be repaired, and asbestos can be seen in the cafeteria, print shop, library, art rooms, and other areas in the school, he said.

School officials said in September that areas of asbestos contamination had been sealed off in 121 buildings and corrected in 41 other buildings. The system's asbestos abatement program, which has cost more than $725,000 since April, has been mostly a "stop-gap" effort to cover up crumbling asbestos to prevent minute fibers from becoming airborne. Estimates on the cost of totally removing the asbestos go as high as $50 million.

School board member Calvin Lockridge (D-Ward 8), who represents Ballou, said concern about asbestos contamination at Ballou is not warranted. Lockridge said: "Ballou is the number one school in the city. And if it wasn't safe in there, I wouldn't have let it open this year."