Since 'Silent Spring,' meager gains; America the Poisoned, by Lewis Regenstein. Washington, D.C.: Acropolis Books Ltd. 375 pp. $16.95.

Recently I was throwing away tear sheets from a long-ago career as a small-town newspaperman when I came across the front page of the Midland (Mich.) Daily News for Dec. 8, 1962.

Midland, corporate headquarters for both Dow Chemical Company and Dow Corning Corporation, lays claim to the title, ''World's Greatest Chemical Center,'' as the paper's masthead boasted. The banner headline concerned a scientific meeting sponsored by the local section of the American Chemical Society.

''CHALLENGES 'SILENT SPRING' '' blared the 60-point headline. For Robert White-Stevens of American Cyanamid Company had arrived with his much-traveled assault on Rachel Carson and her earth-shaking book.

In a company town, albeit as fine a place to live as Midland, the local press rarely questions good news from the town's company. And so White-Stevens was quoted at length debunking the ''simply ridiculous'' assertion by Miss Carson ''that agricultural chemicals are the sinister companions of radioactive nuclear fallout.

''The real danger to man's survival lies not in the controlled use of chemicals but in the hordes of insects and miasma of disease which would sweep over our crops and our animals, denude our forests, and leave destitution and hunger and want in their wake.

''If the teachings of Miss Carson were to be actually carried out,'' White-Stevens warned, ''life in America and all over the world would return to the Dark Ages and insects and disease and vermin would once again inherit the earth.''

Well, White-Stevens notwithstanding, the teachings of Rachel Carson were indeed heeded. The most pernicious poisons were banished from the land, or their use sharply curtailed. (They are, nonetheless, exported in great quantities from the US to third world nations and come back to haunt America in contaminated crops and in declining numbers of songbirds that winter south of the border.)

Federal laws were passed, and a new agency was created to regulate the makers and purveyors of agricultural chemicals - to determine what poisons reach the marketplace and how they are used.

And contrary to White-Stevens's purple predictions, insects and disease and vermin have not inherited the earth. Nor, fortunately, have we witnessed a spring when the rebirth of life is utterly silenced, as described in ''A Fable for Tomorrow,'' the memorable opening chapter of Miss Carson's book.

Yet in ways more sinister and possibly more deadly, the chemical contamination of our whole environment continues. The facts are laid out in clear, convincing, and unduly frightening fashion in ''America the Poisoned,'' a book that is both an important but somewhat disappointing addition to our environmental literature.

The problem is that the subject cries out for a writer with the eloquence and credentials of a Rachel Carson. And Lewis Regenstein possesses neither. Like Cleveland Amory, his boss at the Fund for Animals, the former CIA agent is a master polemicist. Like its title, his book screams at you, with subtitles such as ''Waiting for More Dead Bodies.'' There is only one side to the story Regenstein has to tell, and thus ''America the Poisoned'' is likely to be left unread by decisionmakers who might be persuaded by a less impassioned, more reasoned, and more precise document.

And all of the author's sources of information appear to have been accepted at face value, especially those with shocking impact.

But these are not fatal flaws. The polemicist's role is to create controversy , to alarm. The poisoning of our only habitable planet is a subject worthy of Lew Regenstein's considerable skills. And he has produced a masterpiece of horror, tracing a chemical-induced nightmare of epidemics, birth defects, miscarriages, sterility, diseases.

We can forgive his excesses, though, if this book brings us a step or two closer to a time of environmental sanity. Like mountaineers climbing higher and higher to reach a peak that is forever hidden in the clouds, we've been striving to reach that elusive goal for 20 years, since ''Silent Spring.''

The real question is: Will our message be any different two decades from today?