Cambridge, Massachusetts. -- A letter to Rachel Carson began the research that ultimately yielded the publication of ''Silent Spring'' 30 years ago this week.
In the summer of 1957 the state of Massachusetts aerially sprayed Plymouth County to kill mosquitoes breeding in marshes. The planes crisscrossed over the bird sanctuary of Olga Owens Huckins near the marshes, killing in their non-selective fashion insects, grasshoppers, bees and songbirds. Ms. Huckins described to state officials the broad-scale death she found, only to be assured that their tests showed the spray used -- DDT in fuel oil -- was entirely harmless. She sent an urgent inquiry to Ms. Carson asking who in Washington could help.
Rachel Carson realized that there would be no peace for herself if she did not speak out against the escalating use of pesticides. What was to be an article took on the proportion of a book. Four and a half years later, after reading thousands of technical reports, after detailed consultations with hundreds of American and European scientists, through a catalog of illnesses (including cancer) and the death of her mother, she would submit the manuscript to her editor.
Six arguments frame this densely documented, toughly argued, yet lyric and compelling indictment of pesticides.
* The pesticide industry is the progeny of World War II, and pesticide-based agriculture constitutes a virtual ''peacetime'' war on nature.
* The tolerance of pesticide residues on food promotes a completely unjustified impression that safe limits have been established and are being adhered to. ''What dose of a carcinogen can be safe except a 'zero' dose?''
* The U.S. Department of Agriculture functioned as the major federal promoter of chemical pesticides with its own mass aerial spraying campaigns.
* Much more money is being invested in research on synthetic chemical insecticides than on naturally occurring biological controls because the former offer patent and profit opportunities that the latter do not.
* Before 1945 about a dozen species were known to have developed resistance to pre-DDT insecticides. By 1960, as many as 137 species were resistant to the new organic pesticides because of more intensive and more frequent pesticide spraying.
* The ''control of nature'' is a phrase conceived in arrogance by men who expect that nature exists for their own convenience and use. Our aim should be to work with nature, not to use brute force.
Response to the book was charged and polarized. A firestorm of protest from the agrichemical industry and parts of government swept the country. Ms. Carson was called a Luddite, a spinster, a nun of nature; and her work, good poetry but poor science.
But President Kennedy's Science Advisory Committee corroborated the findings of ''Silent Spring.'' In an editorial, the New York Times proposed that Rachel Carson receive the Nobel Prize, as had Paul E. Mueller, the Swiss chemist who developed DDT as a pesticide.
Thirty years after its publication, ''Silent Spring'' is regarded as the cornerstone of the modern environmental movement. Yet, while the book has been heard and debated, it has not been heeded. At its most rigorous, the focus of pesticide regulation has been on the individual chemical, not on the model of industrial agriculture. DDT was eventually suspended in the United States in the early 1970s as a consequence of ''Silent Spring.''
But 30 years later nearly five times as many pesticides are manufactured for use in U.S. agriculture, forests and homes and for export than were in 1962. More than 440 insect species are LTC now resistant to certain insecticides. In 1945, 7 percent of crops were destroyed by insects; in 1990, 13 percent. Out of 129,249 employees in the U.S. Department of Agriculture, only two are assigned to the development of organic agriculture. The Environmental Protection Agency has recently detected 74 different pesticides in the wells of 38 states. Farm workers in California (many are children) have the highest illness and injury rate of any workers in that state.
Nearly 50 million pounds of DDT have been manufactured each year and exported to foreign countries after the chemical was suspended in the United States. It is then imported back on fruits and vegetables in what has been labeled a ''circle of poison.''
As for the future of agriculture: Developing herbicide-tolerant plant lines, that is, plants genetically modified to survive being sprayed with an herbicide, constitutes about 40 percent of U.S. biotechnology research in agriculture.
''Silent Spring'' merits, on its 30th anniversary, a fresh reading to recast its singular contribution and to take up its unfinished business -- an ecology-centered agriculture. Otherwise, it will have won a few battles against the war on nature, but not even a cease-fire.
H. Patricia Hynes is the author of ''The Recurring Silent Spring'' (Teachers College Press) and adjunct professor of environmental policy at MIT.
Nancy O'Hanian--Graphic Impressions Thirty years after 'Silent Spring,' nearly five times as many pesticides are available. Yet in 1945, 7 percentof crops were destroyed by insects; in 1990, 13 percent.