Consider what would have happened had President Reagan nominated a Christian Scientist -- whose religion tells him to heal himself rather than go to a doctor -- to be the head of the National Institutes of Health. Or consider the uproar had Reagan nominated a doctor on the payroll of the tobacco industry to be surgeon general. It is safe to suggest that such nominations never would have been made, let alone confirmed by Congress.

But essential equivalencies, to borrow a Pentagon term, occurred with the Environmental Protection Agency. And the only surprise about what has happened there is that the administration has come so close to subverting a scientific, public health agency to the interests of industry, and that it took so long for this scandal to blow up.

Virtually all the subordinates to the EPA administrator were plucked from industry and placed in jobs regulating those industries--jobs that repeatedly pitted profits against public health. At the top, President Reagan placed a Colorado legislator with a solid proindustry record, a woman who made free enterprise a religion and President Reagan a demigod.

They succeeded largely because of a cover-up--involving layers of accusations about government interference and regulatory reform--of what EPA is all about. It is not a haven for bureaucrats who have nothing better to do than figure out ways to make Reagan intimate Joseph Coors part with some of his manufacturing profits. It is an agency composed largely of scientists and engineers who are charged with protecting the public from the effects of chemical poisons in the water we drink, the air we breathe and the materials we touch. It is a public health agency. A report issued by the General Accounting Office last December gives a useful picture of the professionals at EPA: As of December 1981 there were 1,199 environmental engineers, 899 general physical scientists, 588 chemists, 526 general biological scientists, 100 general engineers, 122 chemical engineers, and 749 people employed in other scientific occupations.

Daily, they are charged with protecting individual families and towns from the effects of such chemicals as dioxin, a highly poisonous byproduct of herbicide manufacturing that has been found recently in at least 26 sites in Missouri.

But has EPA been doing its job? While it decides to buy out families in a dioxin-contaminated town, it continues to allow sale of herbicides that contain greater levels of dioxin than found in that town. It is not testing herbicides on the market to see if they meet health standards. In July, the agency proposed exempting roughly 400 of the 900 new chemicals developed each year from comprehensive review of their effects on health and the environment.

There is widespread disagreement and a great dearth of knowledge about cumulative effects of toxic substances on people. Yet instead of trying to find out which ones cause cancer or birth defects or destroy nervous systems, the Reagan administration has nearly halved EPA's research budget. It has refused to set up a congressionally mandated registry to help determine the link between toxic chemicals and human illness by doing long-term tracking of people who have been exposed to them. The scandal at EPA goes beyond allegations of conflict of interest, excessively cozy relationships with business, lax law enforcement, and defying the will of Congress. Time after time, when there was a question about the effects of various substances such as pesticides or asbestos, the agency came down on the side of industry rather than public health.

What happened at EPA flies in the face of public will. Last November an extensive survey--done, it is worth noting, during a severe recession--found a strong "environmental ethic" in Americans. A solid majority favors retention of tough environmental laws even if it means that some factories will have to charge more for their products and others will have to close or slow production.

Six congressional committees are now investigating EPA. Out of all this there needs to be a thorough housecleaning of those connected with the current mess. But Congress also needs to find ways of protecting the agency from the politicization that has occurred. EPA's job is not to protect industry. Its job is to protect people. And the Reagan administration's attempt to corrupt this purpose is something people will not forget.