WASHINGTON — U.S. import duties for apparel and textiles account for more than one-third of the $70 billion consumers spent in 1990 to protect all domestic industries, a new study has concluded.

Gary C. Hufbauer and Kimberly A. Elliot, economists with the Institute for International Economics, a think tank oriented to free trade, reported Tuesday that consumers feel the biggest single impact from protectionist tariffs in the area of apparel and textile prices. At a press briefing, they dubbed the import barriers in apparel and textiles as “the Mount Everest of U.S. trade protection.”

Their study, “Measuring the Costs of Protection in the U.S.,” claimed that in 1990, special protection for these industries costs U.S. consumers $24 billion. They said “special protection” is defined as import duties of 9 percent and more. They reported average U.S. textile duties are 16 percent and those for apparel average 30.5 percent.

Hufbauer and Elliot said high tariffs protecting consumer products ranging from rubber footwear to autos accounted for another $14 billion in special protections accorded some U.S. industries. The remaining $27 billion represents the import barriers on industrial products.

They said the recently completed Uruguay Round of GATT talks, if adopted by Congress and 116 other member nations, would reduce consumers’ apparel costs by about $15 billion annually, while textile prices would decline $2 billion a year. Overall, they said GATT would cut Americans’ consumer costs by about $30 billion annually.

As for the bad news, the researchers said that the GATT-imposed reduction in U.S. duties for “highly protected industries” likely would result in the loss of 190,000 jobs, with 90 percent of this job loss occurring in the textile and apparel industries — and primarily apparel.

The Institute is headed by C. Fred Bergsten, an assistant Treasury secretary during the Carter administration. “Some of these trade protections have been on the books for 60 years. That is simply outrageous and we are trying to shed some light on them,” Bergsten said.