Those fearful predictions of 20 years ago that environmental demands would cause unemployment and economic stagnation have turned out to be overstated, a business leader says. Experience has shown that combating pollution is compatible with economic growth, said Alexander Trowbridge, a former secretary of commerce and chairman of the National Association of Manufacturers' Industry Coalition for the Environment. ``Environmental improvement has been a corollary to economic growth and has not come in spite of it,'' Trowbridge told a news conference Tuesday. He said the ``dire predictions about environmental improvement coming at the cost of jobs and national economic strength and high prices'' have proven to be exaggerated. At the same time, he said, environmentalists' warnings ``that Lake Erie would be dead, urban dwellers would be wearing gas masks, rivers would be reaching a boiling point,'' also were overdrawn. Trowbridge said he was not contending there will not be tradeoffs between jobs and the environment. But, he said, the record since Earth Day 1970 ``indicates that economic growth, moderate but real, has taken place in these 20 years and environmental improvement has also taken place.'' ``My judgment is that we've made progress both in the economy and the environment and I think we'll continue to do so,'' he said. Trowbridge presented a report that said production of six major pollutants has dropped sharply since 1970, while employment, productivity, per capita income, industrial production and the overall size of the economy have grown steadily. Environmentalists said they suspected that Trowbridge had made an Earth Day conversion. Earth Day is being commemorated on Sunday with events scheduled nationwide. ``Talk is cheap and action is not cheap,'' said David Gardiner, legislative director of the Sierra Club. ``It's the don't-worry-be-happy message at the same time the NAM and their members are spending millions of dollars lobbying against changes in law which would do a better job in improving the environment. ... What we're seeing from industry is Earth Day earth-hype.'' ``It is an encouraging-sounding message, but just in the last month and a half we've seen from the Business Roundtable and other industry groups the most apocalyptical hype about how the Clear Air Act is going to kill the economy,'' added David Doniger, senior attorney for the Natural Resources Defense Council. ``It will be interesting to see if, next time there is a piece of legislation to be acted upon, the NAM will take a more enlightened line,'' he said. But Trowbridge said a fundamental change has taken place in corporate America. Environmental considerations are now being taken into account in business decisions, he said. ``Environmental quality is a very key element of planning, designing, building and producing,'' he said, ``and this has been growing not only as a psychological factor but as a point of stated policy.''