At a time of renewed debate about the environmental dangers of releasing genetically altered organisms into the environment, the U.S. Department of Agriculture is paying for 87 research projects that include the planned release of such organisms, a government report disclosed yesterday.

USDA would have to review any such experiments for potential environmental risks and grant permission before a genetically altered organism could be released.

But environmentalists yesterday challenged the abililty of USDA to evaluate such risks, and a House subcommittee said it would hold a hearing on the subject.

The Environmental Protection Agency is expected next week to approve an outdoor field test of a pesticide that would involve the first release of a genetically altered living organism outside a laboratory.

The test would involve spraying a strawberry field with two strains of bacteria that have been genetically altered to inhibit the formation of frost on the young plants.

That approval would come after more than two years of opposition from environmentalists, who fear that, once released outdoors, genetically altered organisms could migrate, multiply out of control and cause worldwide ecological damage.

Scientists in 28 states from California to Maine are involved in USDA-supported research projects that expect to include outdoor tests of microorganisms, plants and animals with altered genes, according to the report by the General Accounting Office.

Maryland and Virginia were not among the states listed.

The experiments include manipulating genetic material to create a greatly enlarged type of salmon, to improve the disease resistance of beans and to strengthen the insect resistance of wheat.

Some of the projects seek to stimulate the growth or productivity of certain crops, others seek to develop new ways to control pests.

The research projects represent 18 percent of the 495 biotechnology projects being supported with $10.7 million in USDA funds, the report said.

All are now under way at USDA's own research facilities, state agricultural experiment stations and colleges.

Jeremy Rifkin, an activist opposed to the outdoor release of genetically altered organisms, said it would be "unconscionable" to allow these experiments to proceed without better methods to assess the risks involved.

"No predictive ecology method has been established . . . . How can any federal agency begin approving these experiments when they haven't developed the tools to judge them?" he asked.

Jack Doyle, a director for the Environmental Policy Institute, a nonprofit research and lobbying group, said the GAO report "really underscores the need for more congressional debate and further public debate" on the issues involved.

The House Committee on Science and Technology, which had requested the GAO study, said its subcommittee on investigation and oversight will hold a hearing to examine the methods for evaluating thr risks posed by releasing genetically engineered organisms.

Committee Chairman Don Fuqua (D-Fla.) said, "We must examine the adequacy of our research base, particularly in the area of predictive ecology."

Rep. Manuel Lujan Jr. (R-N.M.), the ranking Republican on the Science and Technology Committee, said, "We recognize that there are concerns and, therefore, we should find out as much about these issues as possible."

USDA said that no such release will be approved without the careful scrutiny by the agency's Agricultural Recombinant DNA Research Committee, a panel of agency scientists and administrators with access to outside experts.

The committee will review the experiments on a case-by-case basis, said Patrick Jordan, administrator of USDA's Cooperative State Research Service, which is supporting some of the experiments.

The committee will determine the adequacy of its risk assessment methods according to the specific requirements of each individual proposal, he said.

USDA has years of experience in evaluating the environmental effects of new crops and animals produced through natural breeding methods, he said.

But environmentalists say the greatest risks are posed by microbes that can travel by wind or water far from the original test site, reproduce and disrupt rain patterns or ecological balances.

Other observers note that it is difficult to evaluate the USDA's review committee since its proceedings are not open to the public.

Robert B. Nicholas, an attorney who specializes in the regulation of biotechnology, said, "Looking at current USDA policy, it is difficult to have that assurance that there will be adequate public discussion and evaluation of these issues."