According to "60 Minutes," a $500 million federal study released last fall "takes the conventional wisdom about acid rain and shoots it full of holes."

According to the Wall Street Journal, the report's findings "expose the irresponsible hysteria fomented by environmental groups and encouraged in hyperventilating media reports."

According to Reed Irvine, head of Accuracy in Media, a conservative media watchdog group, the report discredits "the fearmongers in the environmental movement, the government and the media who have been portraying acid rain as one of those critical problems that must be solved if we are to save the country, civilization and the planet."

The focus of this rhetorical assault is a 10-year study by the National Acid Precipitation Assessment Program (NAPAP), an inter-agency body created by Congress in 1980 to settle once and for all the debate over the effects of acid rain caused by industrial pollutants.

In three volumes weighing more than five pounds, the study concluded that acid rain, while still a problem, has caused far less damage to the nation's forests and lakes than previously estimated. Yet the report was virtually ignored by The Washington Post and given scant attention by most other major news organizations last year, even while Congress debated and approved new acid rain controls that will cost as much as $4 billion a year.

Some reporters say privately that it is difficult to write stories that debunk the conventional wisdom of environmental activists, whom the press treats more deferentially than industry spokesmen and other lobbyists. Striking the right balance is particularly difficult on complex science stories, where reporters must rely on "experts," many of whom have ideological axes to grind.

In that regard, critics say, the recent acid rain report on CBS's "60 Minutes" was one-sided because correspondent Steve Kroft included none of the prominent scientists who believe the NAPAP report understated the dangers of acid rain. Why Was Report Ignored?

Still, the question remains: Why has the most expensive acid rain study ever conducted received so little media coverage? Several factors are involved:

The findings were released in dribs and drabs, in "draft" reports and at scientific conferences, from 1987 through last year, so journalists were never presented with a dramatic "new" report.

The report's credibility was hurt by charges from some scientists and environmentalists in 1987 that NAPAP softened its findings under political pressure from the Reagan administration.

By the time the massive "external review draft" was released in September, Congress, the Bush administration, the utility industry and environmental lobbyists had cut most of their deals on revising the Clean Air Act, and the news coverage was largely being driven by politics. "The legislative debate was essentially over before the report came out," one reporter said.

The study contained such voluminous data that many groups found something to support their view. While industry officials hailed the report, William G. Rosenberg, assistant administrator of the Environmental Protection Agency, said it "did show a lot of damage" from acid rain and that skeptics are "interpreting the data the way they want to. There are people in the tobacco industry who still argue that tobacco is not so bad."

The NAPAP report said there was "no evidence of a general or unusual decline of forests in the United States and Canada due to acid rain," except for red spruce trees at high elevations.

While acid rain is helping to damage aquatic life in about 10 percent of eastern lakes and streams, the study said, the number of lakes damaged has remained unchanged since 1980. The report also said that acid rain is contributing to the erosion of buildings and statues and is reducing visibility in the eastern United States.

Michael Weisskopf, The Washington Post's environmental reporter, said he was on vacation when the report was released. But he said many people involved in the acid rain debate told him it had little news value.

"Just because the government threw a load of money at this thing doesn't mean it's a precious document," Weisskopf said. "There are enough reports on this subject to line your bookshelves. . . . This is such a dynamic city, with so many pressure groups pushing their point of view, you don't have to do investigative reporting to find these reports. If they are truly important, they are promoted and put forward."

New York Times reporter Philip Shabecoff noted in a story last March that the NAPAP report "has come under criticism from some distinguished scientists that are reviewing it," some of whom charged that the program "ignored a number of studies suggesting serious air pollution problems." But he reported that other experts found the conclusions "essentially right."

Shabecoff said last week that the report gave "fairly short shrift" to "a body of evidence compiled by highly regarded scientists that acid rain is one of a number of air pollutants that at high altitudes . . . have led to substantial death and deterioration of trees."

Nevertheless, he said, "It should have been given more serious treatment by the media. There's a lot of good science in it."

The controversy was rekindled two weeks ago when James R. Mahoney, NAPAP's director, said on "60 Minutes" that news accounts had presented an "extreme" view of acid rain.

Mahoney, in an interview, criticized The Washington Post for its acid rain coverage, saying the paper "has never, ever carried any article about this program, even though The Post holds itself out to be the paper of record about government business. . . . If you read only The Washington Post, you wouldn't know this program existed." Weisskopf did mention the NAPAP study in a November story, and The Post published two articles about it in 1987.

Mahoney also said his report never claimed "that acid rain is no problem. We find damage to lakes, damage to materials, risk to public health. . . . The only question is how much reduction is appropriate and how much benefit are we going to get from the cost." 'Documenting the Obvious'

David Hawkins, senior attorney with the Natural Resources Defense Council, called the study "a very expensive exercise in documenting the obvious." For example, he said, NAPAP focused on lakes that are constantly acidified, while three times as many lakes are subject to occasional acidification.

Hawkins, who appeared on the "60 Minutes" broadcast, said the program "essentially took industry's characterization of NAPAP's findings. . . . Many scientists were shocked by the one-sidedness of the scientific presentation."

All the "60 Minutes" guests except Hawkins supported the NAPAP findings, including Sen. John Glenn (D-Ohio), conservative columnist Warren Brookes, an Ohio coal company president, Mahoney and Edward Krug, chief watershed scientist at the University of Illinois, who worked on the study.

Even some of the NAPAP participants disagree on its findings. Twelve scientists who worked on the study have charged in a letter that "60 Minutes" misrepresented the report's data on water damage. And the EPA said in a statement that Krug has "limited scientific credibility" and "is well outside the mainstream of scientific consensus on the acid rain issue."

Krug called the EPA's criticism "peculiar" because the agency was part of the NAPAP study. He said that despite "outrageous claims" by some scientists, the effects of acid rain "are less than 1 percent of what people were claiming 10 years ago."

Jeff Fager, a "60 Minutes" producer, said the segment was meant to focus on "a very expensive government study which wasn't paid much attention."