When the Committee for the Elimination of Lead in D.C. met yesterday, some committee members used words like "startling," "staggering" and "devastating" to describe findings released this week that 42 per cent of 500 youngsters tested in affluent areas of Northwest Washington had undesirably high levels of lead in their blood and in the dust in which they play.

At the same time, however, many of those same committee members were so struck by the report that they questioned its accuracy: Is it possible, they wondered, that the lead situation is that bad without physicians at Children's Hospital National Medical Center - one of the nation's leaders in work against lead poisoning - being aware of it?

According to the study, prepared by Dr. Bailus Walker, director of the District's Department of Environmental Services and an adjunct professor at Howard University medical school, 42 per cent of the 500 children - all of whom come from affluent families and live in homes in good repair - have blood-lead levels between 40 and 59 micrograms per 100 milliliters.

The federal Center for Disease Control in Atlanta has set 30 micrograms per 100 milliliters as the bottom level at which a child is considered to have undue lead absorption. There is a catch, however.

The CDC has said that a child with a blood-lead level of 30 to 49 should also be tested to determine whether his blood is metabilizing iron properly. None of the children in Walker's study was so tested.

The District's study also involved taking only one blood sample from each of the children, and it is well known among lead researchers that blood-lead levels vary markedly throughout the year, rising particularly in the summertime. It is therefore impossible to tell whether the blood-lead levels of the affected children were only temporarily elevated, or were elevated for a long period of time.

In addition, the blood samples were not analyzed at laboratories approved by the CDC for the testing of blood-lead levels, a complicated procedure that often results in a high proportion of false positive readings.

On the other hand, as was noted at yesterday's meeting, 1974 studies in Newark, N.J., produced dust and blood-lead levels strikingly similar to those found by Walker.

Walker agreed yesterday with those who suggested that further testing needs to be done to confirm, or disprove, his original findings.

"I don't think you can go out and mount a scare campaign in Northwest Washington," said one expert in the field of lead poisoning. "The District should go out and verify this data."

"There're a lot of gaps in the study because we didn't have the resources," Walker said, "but it's the best piece of information we have on this community."

Walker said he is going to "try to get funds to carry on this research project. I'm in the process of developing a proposal to do a comprehensive program," selecting a new group of children and following them through a year, testing their blood and their environment several times during the 12 months.

Even if Walker should duplicate his original findings, there is a great deal of disagreement among scientists as to what the findings would mean on terms of child health.

"Dr. Oliver Davis, an assistant professor of psychiatry at Brooklyn's Downstate Medical College, has found what he believes to be a link between low levels of lead absorption, such as those found in the Northwest children, and hyperactivity and borderline mental retardation.

"We dound that in both groups when you compare their lead levels to a comparable group of normal children, (the lead levels of the hyperactive and retarded children) are higher."

David is now involved in cleansing lead from the blood of hyperkinetic children to see if their condition improves.

In a pilot study with 13 children - much too small a number to prove anything conclusively - it was predicted that seven would improve because there seemed to be no other cause for their condition, and six would not, because something other than lead seemed to be affecting them.The children's blood was cleansed. The seven improved and the six did not.

The results of several of David's earlier profects were published in prestigious medical journals, including Lancet, one of the top such publications in the world.

But David's results are not universally accepted Dr. J. Julian Schisholm, one of the nation's leading experts on the subject of pediatric lead poisoning, points out that attempts using animals to repeat David's experiments have been unsuccessful.

"It's a scientifically gray area." Chisholm of the long-term effects of slightly elevated blood-lead levels.

He might well be speaking, however, of the entire current situation surrounding the Walker report.