A congressional advisory panel yesterday called for a crackdown on pollution by aging coal-fired power plants and criticized efforts by the Bush administration to weaken clean air enforcement rules governing utilities, refineries and industrial plants.

Members of the National Academy of Public Administration concluded in a two-year study that a Clean Air Act enforcement program known as New Source Review has effectively controlled pollution from newly built facilities but has performed poorly in reducing health-threatening pollution from the nation's oldest and dirtiest factories and power plants.

The panel called for an overhaul of clean air laws to adopt a new performance-based system that would force older power plants to shut down within 10 years unless they install anti-pollution equipment and reduce their emissions to meet legal standards. The report also called for more vigorous enforcement of New Source Review regulations by the Environmental Protection Agency and the Justice Department and cautioned against creating "even broader loopholes or more exemptions."

"Contrary to congressional intent, many large, highly polluting facilities have continued to operate and have expanded their production (and pollution) over the past 25 years without upgrading to cleaner technologies," the report said. "The result: thousands of premature human deaths, and many thousand additional cases of acute illnesses and chronic diseases caused by air pollution."

The study, mandated by Congress in September 2000, highlights problems with an enforcement program that has been praised by environmental groups and northeastern state attorneys general as the most effective tool available for combating industrial pollution but criticized by industry and administration officials as an impediment to energy industry expansion and investment.

Power plant emissions have been linked to serious illness and premature death, and have been a target of the government's long-term efforts to clean up the nation's air. The Clean Air Act, as amended in 1977, requires new plants and utilities to install the best available pollution-control technology. Aging utilities and refineries were exempted by Congress from installing the new technology unless they made improvements to extend a plant's life and thereby created a new source of emissions.

The administration contends that the existing program creates too much uncertainty for the industry, and last December it outlined proposals that would allow older coal-fired power plants to do "routine maintenance" and upgrade their facilities -- and likely increase their emissions -- without having to install costly anti-pollution equipment as they now must do. The EPA also issued a final set of revised enforcement rules governing the nation's refineries and industrial plants, which will give them new flexibility to make repairs without fear of prosecution under the Clean Air Act.

The EPA and the Justice Department have pledged to continue to vigorously enforce the existing regulations, as they did in reaching the largest settlement ever with a utility last week. Dominion Virginia Power Co. agreed to spend $1.2 billion to reduce pollution at eight power plants in Virginia and West Virginia and to pay a $5.3 million federal fine.

But the administration is determined to phase out the enforcement program in favor of its proposed "Clear Skies" legislation, which would force power plants to gradually reduce overall pollution levels of sulfur dioxide, nitrogen oxide and mercury by 70 percent by 2018.

Jeffrey Holmstead, an assistant EPA administrator for air quality, said he agrees with some of the panel's recommendations, including one to create a national or regional cap-and-trade program for reducing most power plant emissions. But he said that it was unrealistic to think that the utility industry could meet a 10-year deadline for sharply reducing its emissions without creating economic havoc.

The administration strongly opposes another recommendation -- that Congress and the administration consider reductions in carbon dioxide and other greenhouse gas emissions along with other power plant pollutants in drafting new clean air legislation. President Bush has opposed mandatory cuts in carbon dioxide because he says such action would harm the economy.

Sen. James M. Jeffords (I-Vt.), ranking member of the Senate Environment and Public Works Committee, said the academy's report "demonstrates that the New Source Review program is critical for protecting public health, and that this administration's new regulatory changes will only broaden loopholes and further diminish polluter accountability."

Sen. James M. Jeffords (I-Vt.) said the report points to problems of new rules.