By Robert Bradley Jr. — May 17, 2023
“Carson used dubious statistics and anecdotes to warn of a cancer epidemic that never came to pass. She rightly noted threats to some birds, like eagles and other raptors, but she wildly imagined a mass ‘biocide.’ She warned that one of the most common American birds, the robin, was ‘on the verge of extinction’ – an especially odd claim given the large numbers of robins recorded in Audubon bird counts before her book.” (John Tierney, New York Times column, June 5, 2007)
Little remembered, the “newspaper of record,” as the New York Times was once known, frankly presented the scientific misconduct and false alarms of the iconic Rachel Carson (d. 1964) fifteen years ago. Still, Carson promoters invoke her memory today in regard to the the climate debate. Physician Hope Ferdowsian recently wrote in the Harvard Public Health:
Sixty years later, the book’s lessons are more relevant than ever…. Rachel Carson might not have known how much climate change would become a defining crisis of our time when she penned Silent Spring. But the combination of her logic and reverence for the natural world offers an example of how we can sustainably address the deepest roots of disease and reframe how we approach the health of the planet, animals, and ourselves.
Has Ferdowsian done her homework on Carson’s book? Did she even want to? Here is the John Tierney column’s true-up, “Carson’s “Silent Spring” fails test of time.”
For Rachel Carson admirers, it has not been a silent spring. They have been celebrating the centennial of her birthday with paeans to her saintliness. A new generation is reading her book in school – and mostly learning the wrong lesson from it.
If students are going to read “Silent Spring” in science classes, I wish it were paired with another work from that same year, 1962, titled “Chemicals and Pests.” It was a review of “Silent Spring” in the journal Science written by I.L. Baldwin, a professor of agricultural bacteriology at the University of Wisconsin.
He did not have Carson’s literary flair, but his science has held up much better. He did not make Carson’s fundamental mistake, which is evident in the opening sentence of her book:
“There was once a town in the heart of America where all life seemed to live in harmony with its surroundings,” she wrote, extolling the peace that had reigned “since the first settlers raised their houses.” Lately, though, a “strange blight” had cast an “evil spell” that killed the flora and fauna, sickened humans and “silenced the rebirth of new life.”
This “Fable for Tomorrow,” as she called it, set the tone for the hodgepodge of science and junk science in the rest of the book. Nature was good; traditional agriculture was all right; modern pesticides were an unprecedented evil. It was a Disneyfied version of Eden.
Carson used dubious statistics and anecdotes to warn of a cancer epidemic that never came to pass. She rightly noted threats to some birds, like eagles and other raptors, but she wildly imagined a mass “biocide.” She warned that one of the most common American birds, the robin, was “on the verge of extinction” – an especially odd claim given the large numbers of robins recorded in Audubon bird counts before her book.
Carson’s many defenders, ecologists as well as other scientists, often excuse her errors by pointing to the primitive state of environmental and cancer research in her day. They argue that she got the big picture right: Without her passion and pioneering work, people would not have recognized the perils of pesticides.
But those arguments are hard to square with Baldwin’s review. He led a committee at the National Academy of Sciences studying the impact of pesticides on wildlife. In his review, he praised Carson’s literary skills and her desire to protect nature. But, he wrote, “Mankind has been engaged in the process of upsetting the balance of nature since the dawn of civilization.”
While Carson imagined life in harmony before DDT, Baldwin saw that civilization depended on farmers and doctors fighting “an unrelenting war” against insects, parasites and disease. He complained that “Silent Spring” was not a scientific balancing of costs and benefits but rather a “prosecuting attorney’s impassioned plea for action.”
Carson presented DDT as a dangerous human carcinogen, but Baldwin said the question was open and noted that most scientists “feel that the danger of damage is slight.” He acknowledged that pesticides were sometimes badly misused, but he also quoted an adage: “There are no harmless chemicals, only harmless use of chemicals.”
Carson considered new chemicals to be inherently different. “For the first time in the history of the world,” she wrote, “every human being is now subjected to contact with dangerous chemicals, from the moment of conception until death.”
She briefly acknowledged that nature manufactured its own carcinogens, but she said they were “few in number and they belong to that ancient array of forces to which life has been accustomed from the beginning.” The new pesticides, by contrast, were “elixirs of death” for which there was “no ‘safe’ dose.”
She cited scary figures showing a recent rise in deaths from cancer, but she did not consider one of the chief causes: fewer people were dying young from other diseases (including the malaria that persisted in the American South until DDT). When that longevity factor as well as the impact of smoking are removed, the cancer death rate was falling in the decade before “Silent Spring,” and it kept falling in the rest of the century.
Why were not all of the new poisons killing people? An important clue emerged in the 1980s when the biochemist Bruce Ames tested thousands of chemicals and found that natural compounds were as likely to be carcinogenic as synthetic ones.
Ames found that 99.99 percent of the carcinogens in our diet were natural, which does not mean that we are being poisoned by the natural pesticides in spinach and lettuce. We ingest most carcinogens, natural or synthetic, in such small quantities that they do not hurt us.
Dosage matters, not whether a chemical is natural, just as Baldwin realized.
But scientists like him were no match for Carson’s rhetoric. DDT became taboo even though there was no evidence that it was carcinogenic (and subsequent studies repeatedly failed to prove harm to humans).
It is often asserted that the severe restrictions on DDT and other pesticides were justified in rich countries like America simply to protect wildlife. But even that is debatable (see http://www.tierneylab.com), and in any case, the chemophobia inspired by Carson’s book has been harmful in various ways. The obsession with eliminating minute risks from synthetic chemicals has wasted vast sums of money: environmental experts say the billions spent cleaning up Superfund sites would be better spent on more serious dangers.
The human costs have been horrific in the poor countries where malaria returned after DDT spraying was abandoned. Malariologists have made a little headway recently in restoring this weapon against the disease, but they have had to fight against Carson’s disciples, who still divide the world into good and bad chemicals, with DDT in their fearsome “dirty dozen.”
Carson did not urge an outright ban on DDT, but she tried to downplay its effectiveness against malaria and refused to acknowledge what it had accomplished. As Baldwin wrote, “No estimates are made of the countless lives that have been saved because of the destruction of insect vectors of disease.” He predicted correctly that people in poor countries would suffer from hunger and disease if they were denied the pesticides that had enabled wealthy nations to increase food production and eliminate scourges.
But Baldwin did make one mistake. After expressing the hope “that someone with Rachel Carson’s ability will write a companion volume dramatizing the improvements in human health and welfare derived from the use of pesticides,” he predicted that “such a story would be far more dramatic than the one told by Ms. Carson in ‘Silent Spring.’ “
That never happened, and I cannot imagine any writer turning such good news into a story more dramatic than Carson’s apocalypse in Eden.
The New York Times a decade later would publish an op-ed by Carson apologist Clyde Haberman (January 22, 2017), Rachel Carson, DDT and the Fight Against Malaria, but the John Tierney column above stands as a fair verdict of no-nonsense science.
For a more recent critical assessment, see “Silent Spring at 50: The False Crises of Rachel Carson” (Reassessing environmentalism’s fateful turn from science to advocacy), published at MasterResource in September 2012. Roger Meiners et al. concluded:
Carson made little effort to provide a balanced perspective and consistently ignored key evidence that would have contradicted her work. Thus, while the book provided a range of notable ideas, a number of Carson’s major arguments rested on what can only be described as deliberate ignorance.
via Watts Up With That?
May 18, 2023 at 12:45AM