A half century ago, George Wallace—and the robins—of MSU helped inspire Rachel Carson’s Silent Spring, arguably the most important book in the 20th century.
By Gary Morgan
The past is a foreign country: they do things differently there. British author L.P. Hartley opens his famous novel, The Go-Between, with these lines. We might think that they could have no truer application than in comparing society’s attitudes towards the environment today to what they were 50 years ago.
And 50 years ago, the world received one of the seminal books of the 20th century. In September 1962, Houghton Mifflin published Rachel Carson’s Silent Spring some months after it had been serialized in the New Yorker. The book caused an immediate conflagration. It divided readers into two camps—those who eulogized it for its revelations, and those who condemned it as hysterical, poorly researched or just bad science.
What was the furor all about? Silent Spring was the first major popular publication that documented the effects of incautious or excessive use of pesticides on the natural environment, and in some cases, on the health of livestock and even humans. In its 355 pages, the book lists hundreds of studies where pesticide use was implicated in unintentional negative effects on living organisms or was shown to have become less effective in controlling target pests over time. Critics raised doubts about her use of scientific data and the justification of her conclusions. Some called her a liar. Carson was a university-trained biologist who had worked for many years with the U.S. Fish and Wildlife Service, yet there were those who cast aspersions on the ability of a woman to write on such weighty matters, the world of science in the 1960s being dominated by men. The majority of the public, however, received the book with acclaim. It opened the eyes of many and confirmed the suspicions of others.
Among the many case studies in her book, none occupies more space or imagery than that of the dying robins of Michigan State University. In this story, the fates of Carson, the reluctant “environmental warrior,” and of an MSU faculty ornithologist, converged. It was Professor George Wallace of MSU who documented the dying birds on campus, of which the robins were a significant proportion. He and his students collected birds from MSU and surrounding suburbs in the late 1950s. The birds were found either dead or dying from tremors. The scientists carried out tests on many of the birds’ carcasses, and in most cases found elevated levels of the pesticide DDT.
It was this study as described in Silent Spring, arguably more than any other, that publicly raised the specter of the possible adverse impacts of one of the most widely used pesticides of the 1950s. These results were rejected by some, who suggested no causal relationship with DDT, or that other toxins such as mercury used to control soil fungi were the cause of the birds’ deaths. There remains some controversy even to the present day, but most scientists now recognize DDT and many other insect-focused pesticides as having significant risks to other living organisms.
In the 1950s, the world had emerged from World War II to rebuild itself on the back of new industrialization and technology. America was affluent and confident, having established itself as the dominant economic power in the world. The cars of Detroit were getting ever bigger, and their fins and chrome ever more extravagant. Economies were becoming global, and success was founded on industry. Where humans faced challenges, we would prevail through our ability to devise new technologies. Nowhere was that faith held more profoundly than in the development and use of chemicals in industry and in environmental management. The variety and quantities of human-made chemicals in common use exploded. Of the many, DDT is one of the best known, and possibly the most infamous.
DDT (or dichlorodiphenyltrichloroethane), is a synthetic organochlorine. DDT was synthesized in 1874 but its properties as a pesticide were not recognized until 1939. It was used in World War II as an effective control of malarial mosquitoes and typhus-carrying body lice. A Swiss chemist, Paul Hermann Müller, won the 1948 Nobel Prize in medicine for revealing the effectiveness of DDT against insect pests that were carriers of disease.
DDT kills insects by over-activating their nerve cells or neurons, causing the insect to go into spasms and then die. By the 1950s, the effectiveness of DDT as a pesticide had resulted in its ever growing application, often in large scale and rather indiscriminate fashion. It could be used as a dust or, once dissolved in petroleum oils, xylene or other organic solvents, as a spray. At the same time, there was growing evidence that DDT and other toxins could enter the food chains and be concentrated in organisms ranging from earth worms to birds and mammals. Rachel Carson mentions many pesticides in Silent Spring, but for her, DDT was the poster child of the chemical industry—heavily promoted, over-used and under-appreciated for its ecological effects.
Insects have shown considerable capacity to develop resistance to DDT and other pesticides. It starts when a few individuals in an insect population have a certain genetic mutation that gives resistance to the effects of the toxin. These individuals survive the treatment, breed, and convey the resistant gene to their offspring, and thus the percentage of resistant individuals continues to grow. After many generations, most of the population may be resistant. Widespread use of DDT in agriculture is one reason that insects such as mosquitoes built up resistance to the toxin. Still, there are those who argue that DDT remains one of the best control agents for major insect pests such as anopheline mosquitoes, the vectors of malaria which continues to kill approximately a million people around the world each year.
Carson was not the first to raise concerns about the potential deleterious impacts of pesticides. In the 1940s and 1950s, many scientists were expressing their views that caution was warranted. We see this clearly in the 1952 U.S. Dept. of Agriculture Yearbook, which cautioned:
“Although the science of entomology has made great progress in the past two decades, the problems caused by insects seem to be bigger than ever. We have more insect pests, although we have better insecticides to use against them and better ways to fight them . . . We must stop the destruction of our crops and forests, but the insecticides we use must leave no dangerous residues on foods, destroy no beneficial wildlife, and do no damage to our soils.
“We thought we had some of the problems solved when we got such good results from the new insecticides. DDT … made medical history in 1943 and 1944 when an outbreak of typhus in Naples was controlled in a few weeks by its use. Entomologists hoped then that DDT could end all insect-borne diseases