Fairfax County officials met yesterday with three state environmental regulatory agencies to assess the potential hazard of naturally formed asbestos found recently in the soil of at least two construction sites, one of them a public high school.

Discovery of the asbestos prompted the temporary shutdown of construction at the Fair Oaks Commerce Center near Fair Oaks Mall in July and at the Braddock Park High School site on Braddock Road in western Fairfax a month later.

State and local officials agreed tentatively that the amount of asbestos found so far is not high enough to be governed by federal or state environmental regulations designed to protect people from asbestos-caused cancers, but they said further monitoring is needed.

Clarence Wheeling, health enforcement director of the state Department of Labor and Industry, said he recommended that county officials conduct extensive air sampling at construction sites to determine how much asbestos is present, and take standard precautions such as wetting down the ground at those sites to prevent dust from spreading. They accepted his suggestions, he said.

County Executive J. Hamilton Lambert said Fairfax officials hope to meet with state officials again next week to present more data and offer a plan to sample asbestos throughout the county. Lambert did not attend the meetings, but made his comments after speaking with officials who had.

Asbestos is a rock-formed mineral that can be dislodged during construction. The extent of its presence in the county is unknown, but officials have said there is a belt of asbestos-contaminated rock running through the west-central county that may be part of a large vein running from Baltimore to the Blue Ridge Mountains.

The asbestos appears to be formed in fragments, which are not necessarily dangerous, rather than fibers, which are, Wheeling said.

"Preliminarily, it doesn't look like a big problem, but there needs to be more data gathered," Wheeling said. The hazard, if any, will be to construction workers at the job sites, he said. There is little danger to nearby residents or businesses, and no danger once a building is completed, he said.