Lester B. Lave and Gilbert S. Omenn in "The Clean Air Law Doesn't Work" (op-ed, Nov. 29) and in their recent study, "Clearing the Air: Reforming the Clean Air Act," argue that the Clean Air Act has not been effective in reducing air pollution. To hear them tell the story, one might believe that the Clean Air Act is seriously off course or in danger of foundering.

We take exception to this conclusion. The truth is that the air is significantly cleaner today than it was in 1970, and vastly cleaner than it would have been without the law. The Clean Air Act has worked remarkably well. Now we must improve it over the next 10 years.

Two examples of progress refute Lave and Omenn's indictment of the law.

First, they claim that progress in cleaning up our air is a "myth," sustained "through the 'good luck' of a limping economy and continuing substitution of oil and natural gas for coal."

In fact, from 1970 to 1980, electricity generated using oil and coal increased by more than 50 percent--hardly evidence of a "limping economy." At the same time, sulfur dioxide emissions from these plants remained about level. And in the West, where smelters are the major source of sulfur dioxide, we've done even better. The percentage of sulfur removed from all smelters has risen steadily--from 15.7 percent in 1972 to 50.6 percent in 1980.

Sulfur dioxide emissions cause heart and lung disease, reduced visibility and acid rain. They account for an estimated 50,000 deaths and billions of dollars in damages each year in this country. Reduced sulfur emissions are no "myth"; they are one of the Clean Air Act's success stories.

Second, Lave and Omenn charge that the law has been ineffective in reducing automobile pollution because Congress wrote the emission standards, rather than delegating the authority to set standards to the Environmental Protection Agency.

Yet today's cars produce about 80 percent less carbon monoxide than cars did before the Clean Air Act. As a result, carbon monoxide pollution in the United States--virtually all of which is generated by cars and trucks--has dropped significantly, despite increases in both the number of vehicles on the road and the number of miles they traveled. There have been similarly significant reductions in other automobile emissions. That has been one of the great achievements of the Clean Air Act. It came because Congress took responsibility, instead of leaving it to the bureaucracy.

It is true, as Lave and Omenn point out, that many cars officially meeting the standard set in the law actually produce much higher levels of pollution. Yet, instead of seeing this discrepancy as a good argument for keeping auto inspection and maintenance programs in the law, they view it as grounds for ending those programs. They're wrong. Even if the inspection and maintenance programs required by the Clean Air Act in areas with dirty air catch only catastrophic emissions control failures, they can have real value for keeping our air clean.

Lave and Omenn cap their criticism of the Clean Air Act with the assertion that "environmental goals can no longer be pursued in isolation from other national goals." We agree. In drafting the Clean Air Act, Congress balanced environmental goals and other goals. For example, in setting emission standards for cars, Congress balanced tighter controls and fuel efficiency. Today, as a result, our cars pollute less and get better gas mileage. As the president of General Motors said in unveiling GM's 1981 cars, that company has been able "to reduce emissions to their lowest level ever, while simultaneously recording the highest average fuel economy in GM's history."

Another example: Congress explicitly required the EPA and state agencies to consider the costs of pollution controls when they set emission standards for new plants and factories. And when companies use innovative or more energy-efficient technology, they can be exempted from generic emissions requirements.

Lave and Omenn are correct on several key points. We agree, for example, with their recent study, "Clearing the Air," which states that "environmental policy has been the whipping boy for other social ills....In fact, environmental policy is little more than an irritant in the larger social context of an economy that has been plagued by inflation and slow growth."

It is also true that the Clean Air Act has not concentrated enough on cleaning up existing plants and factories. Strengthening the act in this respect would have great impact in industrial regions where air quality still falls below national health standards.

Such change will be difficult, but it is necessary if pollution control is to be relevant in the 1980s and 1990s. We must preserve--even strengthen--effective programs; streamline--even eliminate-- those that are unduly burdensome; and address new problems discovered since the Clean Air Act was last amended.

Keeping that in mind should clear the air considerably as we work toward reauthorizing the Clean Air Act. Our rewrite of this legislation can be a model of sound government reform.