Work to enclose permanently areas that are contaminated by crumbling asbestos will begin over the winter holiday at three D.C. public schools, officials said yesteday.

The school system, which until now has used primarily "stop-gap" measures to combat problems with asbestos in dozens of facilities, said the more substantial corrective measures will begin at McKinley Senior High School, Second and T streets NE, the Grant school building at 21st and G streets NW and Deal Junior High School, Fort Drive and Nebraska Avenue NW.

"Before the beginning of school, we tried to abate asbestos in instructional areas," said James Brown, an associate superintendent for management services. "Since then, we have concentrated on noninstructional areas. Much of the work was temporary," he said. "Now, we are moving into phase two, using more permanent measures, such as removing asbestos material where we can, building walls around it and creating drop ceilings beneath it."

The three schools were chosen after a consulting firm assessed the asbestos problem and recommended that permanent abatement procedures be started immediately at schools containing large quantities of the material.

No cost estimates for the work at the three schools were available yesterday.

Areas of asbestos contamination in 125 buildings were sealed off so they could not be entered by students and employes, officials said.

Contamination from the crumbling, cancer-causing asbestos was corrected in about 40 other facilities by encapsulating the material with spray plastics and Styrofoam.

"There are no health problems caused by asbestos in any of our schools. We are simply trying to permanently prevent any such hazards from occurring," Brown said.