The D.C. City Council is considering a bill to protect children from exposure to potentially harmful lead-based paint on residential buildings, but Mayor Marion Barry doesn't want the measure to apply to Washington's nearly 9,000 units of public housing for families because it would cost the city too much.

The D.C. Department of Housing and Community Development would have to spend as much as $21 million to comply with the proposed legislation, according to Pauline A. Schneider, the mayor's director of intergovernmental relations.

" . . . We do not oppose efforts to remove the hazards of lead-based paint to children," Schneider said in a June 10 letter to a council committee. "Our concern is entirely related to the projected high cost of implementing the proposed bill, and the lack of any current or projected funding resources to comply with the requirements of the bill."

Council member Wilhelmina Rolark (D-Ward 8), whose Southeast Washington ward includes eight public housing projects, said yesterday she would attempt to add a provision to the legislation to make it apply to public housing.

"That's where all the kids are," Rolark said. "I think they should be included."

The City Council will vote on the measure next Tuesday.

Dr. Muriel D. Wolf, an official of Children's Hospital and an expert on lead-based-paint poisoning, said she was concerned about any exemption for public housing.

"I feel any building, whether publicly or privately owned, should be applied to the same standard," said Wolf, a member of the Committee for Lead Elimination in the District of Columbia.

The bill, introduced by council member Charlene Drew Jarvis (D-Ward 4), would reduce the permissible lead content of paint used on the interiors and exteriors of residential buildings or nearby structures within the reach of children under the age of eight years.

The housing department would be empowered to order violators to remove any illegal paint within 10 days.

The bill received a hearing before the Housing and Economic Development Committee and was marked up by the Committee on Consumer and Regulatory Affairs.

Council member Betty Ann Kane (D-At Large) had sought in committee to amend the bill to have it apply to public housing. But Jarvis, the chairman of the housing committee, said she had been reluctant to do so because of warnings from city officials that the cost would be prohibitive.

"It sounds absolutely crazy that it would cost that much," Kane said yesterday. "My feeling is that everybody ought to be required to meet the same standards . . . It's not fair to ask private landlords to go to this expense and not ask the city."

Jarvis agreed that the current version of the bill is inequitable, and said if public housing units are not included, she may introduce an amendment that would grant tax credits to landlords and other residential property owners who are forced to meet the proposed new standards.

A decade ago, Washington health officials found that nearly one-third of the children tested suffered from unacceptably high levels of lead in their systems. Last year, only 1.2 percent of the 14,576 children screened for the first time had lead poisoning, according to District figures.