AS IF ANY MORE anxiety needed to grip the increasing numbers of people flying in and out of Dulles International Airport, officials have acknowledged that security there is alarmingly poor. Guards have failed to recognize pistols hidden in carry-on luggage in nearly one out of every four spot-checks conducted by airlines, and as many as 25 percent of the 9,000 identification badges issued to employees at Dulles -- for access to restricted areas -- cannot be accounted for. These are the findings described by an official of the Federal Aviation Administration, which is responsible for assessing security at Dulles and which earlier this year rated it "marginal." While officials note that the FAA has moved to improve security since this evaluation, clearly they've got much more to do.

As it stands, the people who screen departing passengers and baggage are employees of private security firms, and they are not required to have any formal training for their duties. There aren't any educational requirements, either. The pay is less than dazzling, with screeners starting at $3.75 an hour and working up to $4.20. Not surprisingly, the annual turnover rate is about 30 percent.

Is this any way to run a security system at an airport that has been growing faster than any U.S. airport over the past year? You're talking heavy passenger traffic, up from 3.4 million in 1984 to almost 5.1 million last year. Leaving the screen checks to a pickup crew of itinerants with no training or sense of mission is irresponsible. And even though a new identification system is being set up to replace the old one with all the missing badges, what's to ensure that the new system will be monitored any better than the old one?

As long as Dulles remains under federal control -- and that could and should end this year if the House joins the Senate and the administration in support of legislation to lease Dulles and National to a regional authority -- Congress should demand that security be upgraded. More training in security techniques, better pay and closer supervision are essential if the security forces are to be effective. All the sophisticated security machinery in the world isn't worth installing if no one is looking at it.