The Reagan administration said yesterday, in its second report on the state of the environment, that it has made progress toward cleaner air and water, but warned that the broad environmental laws passed in the 1970s "may not be appropriate for the concerns of the 1980s."

In some respects the 330-page White House Council on Environmental Quality report, much of which was written and approved more than two months ago, was already out of step with the political cadence in Washington.

In the wake of the Environmental Protection Agency controversy and subsequent polls that showed the majority of Americans saying they believe that President Reagan favors industry over the environment, the administration has reversed or softened its positions on several of the issues addressed in the report.

On the subject of acid rain, the report repeats the administration's long-held position that more research is needed to clarify "the causes and effects of acid rain" before the nation imposes stringent new pollution curbs.

"Even if the need is demonstrated, many scientific uncertainties must be resolved before effective control programs can be designed," it says.

But an administration task force conceded earlier this month that the causes and effects of acid rain are widely known. It was the first time the Reagan administration had acknowledged that acid rain is a man-made pollutant, a result of sulfur dioxide and nitrogen oxide emissions that are changed chemically in the atmosphere.

Monday, in an even more dramatic departure from the administration position, a scientific panel appointed by White House science adviser George A. Keyworth II released a report concluding that solutions to the acid rain problem must be found immediately, before environmental damage is irreversible.

" . . . Recommendations for inaction pending collection of all of the desirable data entail even greater risk of damage," the panel said.

In another section of its report, the Council on Environmental Quality warned that the Clean Air Act must be amended immediately to prevent the government from being forced to ban construction and withhold highway funds from areas that have failed to meet clean-air standards.

"Under the existing law, EPA must carry out its legal responsibility and impose sanctions on areas of the country that may have been acting in good faith," the report says.

However, EPA Administrator William D. Ruckelshaus announced last week that the law does not require him to impose sanctions on communities that have made reasonable efforts to meet the standards, and that he has no intention of doing so.

"The policy train is chugging on down the track," council Chairman A. Alan Hill said yesterday.

The CEQ report comes a day ahead of the scheduled release of a long-awaited study by the National Research Council, the investigative arm of the National Academy of Sciences. That report, like the one from the Keyworth advisory panel, is expected to urge immediate steps to curb the pollutants that cause acid rain.

Hill said he expected Ruckelshaus to come up with proposals to address the acid rain problem "by the first part of August."

Industry groups aren't waiting that long, and neither is Congress.

A Senate proposal to reduce sulfur dioxide emissions by 10 million tons in a 31-state area east of the Mississippi has been approved at the committee level. Last week, Reps. Gerry E. Sikorski (D-Minn.) and Henry A. Waxman (D-Calif.) introduced a House proposal that would involve the 48 lower states and reduce sulfur dioxide emissions by 14 million tons.

In a news conference yesterday, the Edison Electric Institute fired a volley in industry's battle against acid rain legislation, saying the Senate proposal would raise electric bills in some areas of the country as much as 50 percent.

Environmental groups immediately took issue with the trade association's figures, saying that government studies had found that rate hikes are likely to be no higher than 10 percent, and considerably lower in most states.