Montgomery County has decided to temporaily stop using crushed stone from a local quarry and to begin oiling heavily traveled roads in an effort to keep potentially cancer-causing asbestos finers from polluting the air.

Montgomery County Executive James P. Gleason said yesterday he was taking these precautionary measures for the next 30 days because preliminary Enviromental Protection Agency tests supported earlier studies that found that crushed serpentinite rock used to roads contains potentially hazaardous concentrations of the asbestos fibers.

If the EPA has not ordered the county to reduce the level of asbestos pollutants within 30 days, Gleason said the county will resume use of crushed stone from the Rockville Crushed Stone Co., which supplies rock for most county roadbeds. The stone is mixed with asphalt to pave roads.

Since last fall, country officials havce been trying to find out how serious a problem they face from the asbestoface from the asbestos peoblem they face from the asbestos fibers, but Gleason said that as of yesterday, "unfortunately we still do not have the answer."

"If there is a problem - and we cannot emphasize this enough, we are not saying there is a problem - then we will do anything to reduce the health hazard to this county," he said.

"We think it is the EPA's legal responsibility to tell us the dimension of our problem," he said.

In preliminary tests conducted at four Montgomery County sites last April, the EPA found that some air samples contained as muchj as 400 times as much asbestos per cubic meter as the average for urban areas in the nation.

However, no one really knows what that means since there are no agreed upon standards for safe and unsafe asbestos exposure.

"This still leaves the county in the position that we can neither move in one direction or another," Gleason said.

"Initially, he said, 55 miles of country roads will be oiled at a cost of $85,000, and "we will be prepared to embark upon a much more extensive program of either removing rock from roads or sealing (the road surfaces) upon receipt of a order from the EPA"

If necessary, the county could use limestone or other kinds of stone to replace the serpentinite rock already used to pave some portions of the county's road system.

William Hussman, chief administration for the county, said that county school and park and planning officials have promised to take similar action in the next 30 days to contain the asbestos - filled dust. Hussman said school officials have estimated it will cost $1,000 for each of 130 school sites to remove crushed stone spread around swings and other playground equipment. He said gravel in parks and school parking lots should also be covered.

Permanent resurfacing or replacement of roads could cost up to $2 million initially with an addition $1 million in maintenance expenses each year, Gleason said.

EPA spokesman here and in the Philadelphia regional office said "substantive decisions" are expected next week.

The EPA released its preliminary test findings to the county last Wednesday at a meeting convened by Gleason.

A second meeting with EPA officials next Wednesday at the National Institutes of Health is expected to produce more extensive information about the county's problem.

Yesterday, Gleason complained that the EPA has said it may take a year to determine permissible levels fo asbestos in the air.

"We don't think that's right," said Gleason. "We think the citizens of this county are entitled to some action" immediately, he said.