A scientific study that the Environmental Protection Agency used to set a major air-quality standard was seriously flawed, and there is "considerable concern about the validity of the results reported," a special agency probe has concluded.

As a result, the agency announced yesterday that it will review all the health data available to see if its stringent standard for carbon monoxide should be changed.

At issue is the work of Dr. Wilbert S. Aronow, whose research into the pollutant's effect on heart patients was instrumental in setting the current standard. The EPA formed a team of government and outside scientists to look at Aronow's work last April, after the Food and Drug Administration found he had falsified data on an experimental heart drug.

In their report, released yesterday, the scientists said they "could not resolve the issue of possible falsification of data. However, we had considerable concern about the validity of the results reported. Raw data were lost or discarded, adequate records were not maintained, available data were of poor quality, quality control was nonexistent or inadequate . . . . "

"We conclude that EPA cannot rely on Dr. A's data due to the concerns we have noted," the report said.

The carbon monoxide episode comes atop a major scientific scandal at the EPA, involving hundreds of pesticide tests run by a Chicago-area laboratory that later were ruled scientifically invalid because of slipshod lab practices and falsification of data. Four officials of that facility, the now-defunct Industrial Bio-Test Laboratories, are now on trial for fraud in a case that points up both the government's heavy dependence on such outside research and the fallibility of the system.

In the Aronow case, the scientists reported that it became clear in their initial meetings with the cardiologist that their task would not be easy, "because no data were available."

Aronow told them most of it had been destroyed; all that remained were 60 electrocardiogram (ECG) tests taken from heart patients in the critical 1978 study.

"It was apparent that these ECG records left much to be desired as to quality and the ability of experienced cardiologists to evaluate the records," the report said.

The report said the scientists also had discovered, in interviews with two technicians who had worked with Aronow, that no log books were maintained for Aronow's numerous carbon monoxide studies and that "much of the basic data had been collected . . . on 'bits of paper' or 'looseleaf notepaper.' "

The report also found "rather remarkable" that in 10 years of research, Aronow's studies showed "not even one missing data point."

"Few, if any, other investigators have had such good fortune," it said.

Aronow, director of cardiovascular research at the Creighton University Medical Center in Omaha, defended his study as "accurate and scientifically valid" and said the ECGs were "of a quality sufficient to demonstrate the validity." He said he offered the EPA his original data, after storing it in his garage for more than two years, "and they didn't want it."

"There was no requirement that I keep it," he said. "Three years is all you need for income tax."