Congressional chairman of key environmental subcommittees have called on President Carter to support a strong air pollution standard for new coal-fired power plants as a protection of public health.

The letters from Sen. Edmund S. Muskie (D-Maine), chairman of the envirnomental pollution subcommittee, and from nine congressmen sought to counteract recent pressure from the coal industry and senators fromcoal-producing states to adopt a weak standard.

Environmental Protection Agency Administrator Douglas Costle has reportedly decided to retain the current sulfur emissions ceiling and allow partial "scrubbing" - a move which the legislators said sould violate the intent of Congress in the 1977 Clean Air Act.

"Visibility in the national parks is at stake," wrote Rep. Bob Eckhardt (D-Tex.), chairman of the Commerce oversight and investigations subcommittee, and eight other congressmen.Coal-fired power plants, they said, have reduced visibility from 100 miles to 30 miles in parks such as the Grand Canyon, Mesa Verde, Canyonlands and Bryce Canyon.

Muskie wrote, "Pollution from sulfur dioxide, even at low levels, leads to adverse health effects, results in acid rain which impairs plaint and fish growth, and reduces visibility. There is no reason to sustan such negative effects. Technology currently exists to meet improved standards, and those standards should be required."

The issue is a critical one in the battle over the nation's energy future. Coal burning is expected to double by 1990 with the construction of 200 new power plants, many of them in areas of the West with virtually pristive air.

The regulations, among the most expensive pollution rules ever proposed, set off a heated battle in the administration, which had previously testified before Congress in favor of strict standards.

However, after pressure from the coal and utility industries, and after Majority Leader Robert Byrd (D-W.Va.) and other senators personally intervened, the administration apparently changed its mind, according to EPA sources. The decision not to adopt the strict standard proposed last September is expected to be announced in the next few weeks.

The EPA is expected to adopt a standard requiring 90 percent scrubbing of coal for utilities that use a so-called "west scrubber" technology, and allowing 70 percent scrubbing for experimental "dry scrubbers." The scrubbing, which removes sulfur from coal, would cost more than $3.2 billion a year by 1995-about 2 percent of utilitiesh capital costs.

Byrd and other senators from coal-producing states maintain that anything stricter than the present emissions ceiling of 1.2 pounds per million BTU, averaged monthly, would preclude the use of vast amounts of high sulfur coal in the East and Midwest.

Muskie called this argument "inaccurate," adding, "This nation has abundant supplies of coal, and they are scattered throughout the United States. Adequate environmental protection standards will not bar the development of those resources; such standard will, in fact, make the development of these resources more attractive, since damaging side effects will be reduced."

The congressmen asked the president to lower the emissions ceiling to help prevent sulfur-loaded acid rain. "A lowered emmissions ceiling,c they wrote, "will address the problems of acid rain that are already severe in the Great Smoky Mountains National Park, Adirondacks, and Boundary Waters Canoe area and that have degraded water quality and fisheries in our lakes and streams in the East and midwest."

Besides Eckhardt, the letter was signed by Reps. Henry Waxman (D-Calif.), chairman of Commerce health and environmental subcommittee; Lionel Van Deerlin (D-Calif.), chairman of Commerce communications; James H. Scheuer (D-N.Y.), chairman of Commerce consumer preotection and finance; Toby Moffett (D-Conn.), chairman of Government Operations' environment, energy and natural resources; Richardson Preyer (D-N.C.), chairman of Government Operations' government Information; Irchard Ottinger (D-N.Y.) chairman of Science's energy development and applications, and Mickey Leland (D-Tex) and Edward Markey (D-Mass.), Commerce committee members.