Today is the centenary of Rachel Carson’s birth, which has been noted by many environmentalists who cherish her legacy. However, what has been little noted amid the celebrations and commemorations is the dark aspect of that legacy: that Ms. Carson’s views led to the banning of pesticides at a cost of many thousands of lives worldwide.
In 1948, Swiss chemist Paul Hermann Muller was awarded the Nobel Prize in Medicine. He was the first non-physician to win in that category – a surprise given the nature of the celebrated discovery. He had found that dichloro-diphenyl-trichloroethane (DDT) was an extraordinarily effective pesticide. It induces uncontrollable and fatal spasms in most insects.
The Nobel committee recognized his find because of its effects on public health. DDT was used during World War II to fight insect-borne diseases. Its use was continued in farming and disease control long after the war.
It was especially effective against malaria. In Sri Lanka, to take one celebrated example, there were 2.8 million reported cases of malaria in 1948. In 1963, after a DDT campaign, the number of cases dropped to 17, with zero reported fatalities – only to rise into the hundreds of thousands again shortly after DDT was discontinued.
Given the impressive results, many people thought of DDT as a miracle drug. The World Health Organization championed its use. Spraying campaigns were undertaken in most of the world. Here was yet one more example of how the advances of science could improve our lives.
Public opinion began to shift, however, after 1962.
That year marked the publication of Silent Spring, a self-described "fable" about the dangers of pesticides by Ms. Carson, a best-selling nature writer, Johns Hopkins University graduate and longtime Maryland resident.
Against the backdrop of the great good that had been brought about by DDT and other pesticides, Ms. Carson painted a bleak, carcinogenic future.
The book popularized certain fears about DDT by exaggerating them. The pesticide was said to be decimating bird populations not just because it cut down on insect populations but also because it thinned eggshells, which led to far fewer young birds. Worse, what was afflicting birds might be afflicting humans. Ms. Carson – who would die of breast cancer shortly after the book’s publication – alleged that DDT caused cancer in humans and predicted an epidemic if its use wasn’t drastically curtailed.
Dr. Richard Tren of Africa Fighting Malaria charges that Ms. Carson "misrepresented some scientific data while ignoring data that would not support her case." Quite true.
Alleged links between DDT and cancer rates were never strong. In 1972, the U.S. Environmental Protection Agency empanelled administrative law Judge Edmund Sweeney to hold evidentiary hearings to determine the drug’s dangers. After seven months of hearings, he determined it is "not a carcinogenic hazard to man." Further, using DDT according to EPA specifications did "not have a deleterious effect on fresh water fish … wild birds, or other wild life."
Evidence given for the drug’s direct effects on birds was particularly thin. Ms. Carson cited a study by Dr. James DeWitt to argue that quail that were fed DDT laid eggs in decent numbers but "few of the eggs hatched." She had a different working definition of "few" than most people. The DDT-fed quail eggs hatched 80 percent of the time, compared with 83.9 percent for the non-DDT control group.
But misrepresentation had ridden halfway around the world before sound science could get its trousers on.
News reports broadcast allegations of the pesticide’s effects, including poisoning mothers’ breast milk. People were spooked. The EPA mollified their fears by overruling its own finding and banning DDT.
Worse, the State Department made foreign aid contingent upon recipient countries not using banned pesticides, including DDT. Similar aid criteria by other Western nations helped to make the prohibition stick. The result was that malaria and other insect-borne diseases staged a major comeback. Only in the last few years have the U.S. government and international bodies come to their senses and started using DDT again to fight off some nasty diseases.
The death toll during the 30-year DDT ban is hard to fix, but evidence from Sri Lanka and elsewhere suggests that several hundred thousand graves would not be pushing it.
This, of course, is not the legacy many greens have in mind as they celebrate today’s 100th anniversary of Ms. Carson’s birth.
In an afterword to the 40th anniversary edition of Silent Spring, Harvard sociobiologist Edward O. Wilson wrote that, in his opinion, the book marked "an important moment in history, just as Harriet Beecher Stowe’s Uncle Tom’s Cabin [did]. … The examples and arguments it contains are timeless lessons of the kind we need to re-examine."
We agree about the need to re-examine the book’s arguments and lessons, but for different reasons. Silent Spring’s chief contribution was to inject raw emotionalism into the environmental debate. It substituted speculation for facts and fears for judgment. It produced a "win" for the greens at great cost to humanity.