The Clean Air Act has created 200,000 jobs and $21.4 billion worth of economic and health benefits annually, a new study by an environmental group says, compared with annual compliance costs of $17 billion.

The study by the Natural Resources Defense Council is designed to refute industry arguments that compliance with the Clean Air Act have hurt many companies, dragging the economy down and pushing unemployment up. Congress is heatedly debating the act, which expires this year.

The council said the study, prepared for by the Public Interest Economic Foundation, shows that "the Clean Air Act has improved the American economy as well as the health of the American people."

The authors of the study said that most conventional measures of the costs of the act fail to consider the positive side-effects of clean-air enforcement, such as preventing human diseases and environmental damage and creating a market for pollution control equipment. The study provided no breakdown, however, of those benefits.

The authors agreed that the standards reduced output, but only about 0.1 percent a year. They also calculated that relaxing the standards to allow a 30 percent reduction in pollution control costs would have less than a 0.1 percent impact on jobs, prices or output.

From 1972 to 1979 total air pollution control expenditures were $65.2 billion, which the study acknowledged were "substantial in absolute terms."

"These expenditures are, however, much less significant when viewed in the context of the aggregate economy," it said: private air-pollution control outlays were 2.7 percent of the total investment industry made in those years.

In addition, requirements to reduce emissions have forced companies to use fuel and materials more efficiently, according to the report. It said some firms found it more economical to change their production processes rather than add particular pollution-control equipment.

For instance, it said, the 3M Co. has reduced annual air emissions by 20 percent, water effluent by 90 percent and solid waste by 70 percent since 1976, while saving $2.4 million from recovered resources. Westvaco found the recovery of materials from mill wastes, previously dumped or burned, so profitable it created a chemical subsidiary with 1980 sales of $45 million.