Defending Rachel Carson

2007 marks the 100th anniversary of Rachel Carson’s birth. And while the writer of “Silent Spring” and the woman credited with launching the modern environmental movement has been praised by many, some have used the anniversary to launch scathing and unfounded attacks. The wrangling over Carson’s legacy has even reached Congress.

Maryland Senators Ben Cardin and Barbara Mikulski have introduced a resolution celebrating Rachel Carson’s life that states: “Congress honors the life of Rachel Carson, a scientist, writer and pioneer in the environmental movement, on the occasion of the centennial of her birth.” Sens. Arlen Specter, a Republican, and Bob Casey, a Democrat, both from Pennsylvania where Carson was born, are co-sponsors.

Meanwhile, Sen. Tom Coburn, an Oklahoma Republican and an opponent of environmental causes, is single-handedly holding up two Senate bills that would honor Rachel Carson and her book, “Silent Spring.”

To clarify this controversy, let’s examine the facts. Rachel Carson was a trained scientist who valued species diversity. In “Silent Spring” she expressed a deep concern about agricultural pesticide use and its impact on all native species; of special concern were organo-chlorine chemicals, such as DDT, poisons that she recognized have the ability to destroy embryos of birds and fish, leading to the near extinction of the bald eagle. The basic message that Rachel Carson conveyed to the public was that “all life on the planet is interrelated and should be considered when major policies are made.”

“Silent Spring” and Rachel Carson were attacked even before the book was released, by pesticide companies, pest control operators and weed control specialists. Despite those attacks, President John Kennedy established a presidential commission to examine whether chlorinated insecticides, including DDT, should be banned. A year later the commission recommended that DDT and related insecticides be taken off the market, a U.S. ban taking effect in 1972.

Since then, opinions pro and con concerning pesticide use have waxed and waned. Despite the strength of Carson’s scientific findings, many pesticide users have expressed their support of the unrestricted use of DDT and other pesticides. Even Norman Borlaug, Nobel Prize winner for his contributions to the Green Revolution, claimed in BioScience in the early 1970s that if DDT and other pesticides were banned, a total of 50 percent of U.S. crops would be lost. Subsequently several graduate students and I found that for the early 1970s the U.S. Department of Agriculture reported that only 20 percent of U.S. crop acreage was then treated with pesticides. In our BioScience rebuttal to Borlaug, we asked the question, how could the U.S. lose 50 percent of its crops, if only 20 percent were treated?

In June of 2007, columnist John Tierney, writing for The New York Times, caricatured Carson’s work as a “hodgepodge of science and junk science, dubious statistics and anecdotes.” He stated that studies have failed to prove that DDT is hazardous to humans. Almost universally, scientists have refuted this statement. In fact, the National Cancer Institute has found an association between DDT and various cancers, and the U.S. Environmental Protection Agency has classified DDT as a probable human carcinogen.

Then in July, Carson came under attack from Rush Limbaugh. He and others blame her for the DDT ban, and for causing the deaths of 30 million people in Africa and Asia from malaria — more deaths, he claims, than caused by Stalin or Mao. Limbaugh is not a scientist, but as the host of a public affairs program he should at least get his facts straight. Although banned in the United States, DDT is not banned in countries where malaria is endemic, including countries in Africa and Asia.

Besides, the fact is that Rachel Carson never recommended banning DDT for mosquito control in reducing the hazards of malaria to the people of Africa and Asia. Carson died in 1964 before the U.S. Environmental Protection Agency was founded, and there was no evidence at the time of her death that she advocated the total ban of the use of DDT. Certainly she never proposed that DDT be banned for use to control mosquito and malaria in developing nations in tropical regions.

Mosquitoes and malaria are responsible for 1.2 million to 2.7 million human deaths each year worldwide. And though we can never know Carson’s final position on the issue, it seems likely that she would not have supported an outright ban on pesticides. She would have likely called for their judicious use, taking into consideration their impacts on the natural environment — exactly the stance she took in “Silent Spring.”

Whether Rachel Carson will be honored by the U.S. Senate, we cannot predict. However, that we’re having a dialogue at all is truly Carson’s legacy. Her fondest hope was that we consider the environment in all our deliberations.

David Pimentel is a professor of entomology at the College of Agriculture and Life Sciences at Cornell University. © 2007 Blue Ridge Press.