If present development patterns continue in the area around Dulles International Airport, more than 45,000 people, most of them in Fairfax County, would be subjected to high levels of noise, the newly updated Dulles master plan says.

The high-noise-impact sector, which is larger than previous ones drawn up by the Federal Aviation Administration, now covers present subdividuals and considerable acreage zoned for future single-family dwellings and townhouses.

The revised master plan, prepared for the FAA by Peat, Marwick and Mitchell, consultants of San Francisco, urges Fairfax and Loudoun counties to adopt landuse plans for the area that will minimize noise impact, which now adversely affects only an estimated 6,600 people. But Fairfax officials say angrily that the FAA, which owns and operates Dulles, has made such planning difficult, if not impossible.

"We have had four or five noise 'footprints,' and each one is bigger than the last one," county environmental planner John H. Thillmann said. "The FAA is planning land use in the Dulles area. It's almost all the FAA's responsibility."

Fairfax Supervisor Marie B. Travesky (R-Springfield), whose district includes most of the affected area, said a number of rezoning applications from landowners have been deferred pending completion of the updated Dulles master plan.

The county, Travesky said, cannot stop any development in line with present zoning. She said she believed the county could deny rezonings to a higher density in the high-noise area, but that question is now being researched by members of the legal staff.

Unacceptable noise for a residential area is defined as any level higher than NEF 30. The abbreviation stands for "noise exposure forecast," a value that considers type of aircraft, their mix and noise.

Sections in Fairfax newly included in the 1995 high-noise area are Country Club Manor, Chalet Woods, London Towne, Center Heights, all of the Meadows (the previous noise "footprint" covered only the eastern half), and a larger portion of the Centreville area. North of the airport, in Loudoun County, all of Sterling remains within or near the 1995 high-noise zone, which also extends south of Dulles almost to the Manassas area in northern Prince William County.

The new master plan says the noise zone iwll be broader in years to come because of more air traffic. The number of passenger flights annually is projected as rising from the 61,000 of 1976 to 229,000 in 1995. Passenger traffic in the same period is expected to rise from 1,346,000 annually to 9,006,000 annually.

To reduce the worst noise impact - levels of NEF 40 or greater - the Peat, Marwick and Mitchell study proposes that the FAA pruchase 2,100 acres north and south of the airport. Such a purchase, estimated to cost $14,401,000, would affect only 307 residentially zoned acres in Fairfax, leaving 5,380 such acres for potential development.

The report says that even at present zoning, 38,600 people could be living in high-noise areas in Fairfax, with another 6,600 in such areas in Loundon - for a total of 45,200.

While the report puts the onus on local government to plan land use that minimizes noise impact, Fairfax planner Thillmann said the FAA could narrow the problem area by changing flight patterns and other operating procedures.

He also said there will be pressures to develop vacant land residentially according to the county master plan, rather than industrially, because the FAA wants to market some of its own land within the Dulles perimeter for private, airport-related uses.

The new master plan is certain to intensify the long-standing debate - a national as well as local issue - cover development around a major airport. Airport suppoters says local governments have refused to adopt land-use policies that will keep houses out of high-noise areas.

Fairfax's Thillmann counters that the Dulles problem is compounded because the federal government owns and operates the airport with no local participation in decision making. Furthermore, he said, local planning has been frustrated because as noise abatement schedules have been eased by the FAA, the impact zones have growth.