Silent Spring

I recently read a short piece by Rachel Carson, and she is quite a good writer. Since Silent Spring, which was first published in 1962, is a classic of the environmental movement, and my edition has an afterword by E.O. Wilson, I decided to give it a go. The book is dedicated to Albert Schweitzer, who said "Man has lost the capacity to foresee and to forestall. He will end by destroying the earth." That was a rather prophetic statement, I think.

Carson provides many examples of biological research that confirm that idea, but the main ones concern the widespread dispensation of insecticides and herbicides. She thinks that Dutch elm disease may have been caused by their clustering in towns as decorative trees, and that this led to fungal infections that traveled everywhere. The fungi were spread by native beetles, which carried the fungi into the trees. That blocks circulation within the trees, and they usually die as a result. The initial response was to spray the trees with DDT, which killed the beetles. However, the unintended consequence was the killing of much of the wildlife in the vicinity of the trees. The title comes from the fact that so many songbirds were killed in some towns that very few returned the following spring. Dutch elm disease is still quite common today, but there is less effort to eradicate it. The accepted practice now is to circulate a fungicide within the trees. One of the reasons why DDT wasn't effective was that the fungus remained in the dead trees, and they weren't disposed of properly. To this day, if you drive around Vermont, there are dead slippery elms along roadsides everywhere. But if you go back into the woods, there are healthy elms everywhere. I would guess that the fungi are transported along roadways. Another example is the attempted eradication of fire ants, which were an invasive species that started spreading in the South. The insecticides used to kill them also killed wildlife in the area. Carson doesn't think that fire ants required eradication, because they were merely a nuisance.

Also mentioned are the poisons that were included in household and gardening products. Several different poisons were present in moth killers. Regarding gardening, she says:

As an example of what may happen to a gardener himself, we might look at the case of a physician – an enthusiastic spare-time gardener – who began using DDT and then malathion on his shrubs and lawn, making regular weekly applications. Sometimes he applied the chemicals with a hand spray, sometimes with an attachment to his hose. In doing so, his skin and clothes were often soaked with spray. After about a year of this sort of thing, he suddenly collapsed and was hospitalized. Examination of a biopsy specimen of fat showed an accumulation of 23 parts per million of DDT. There was extensive nerve damage, which the physicians regarded as permanent. As time went on he lost weight, suffered extreme fatigue, and experienced a peculiar muscular weakness, a characteristic effect of malathion. All of these persisting effects were severe enough to make it difficult for the physician to carry on his practice.

Of related interest is the fact that Rachel Carson herself died at the age of fifty-six, less than two years after the publication of Silent Spring, from breast cancer.

Later in the book, Carson discusses some of the underlying failures that caused the inappropriate use of chemicals for extermination. There is a lack of recognition that ecosystems are what actually control species populations, and the disruption of an ecosystem can have many unintended consequences. Reproduction of one species is affected by the populations of other species. Furthermore, species can, and often do, develop resistance to chemicals:

Darwin himself could scarcely have found a better example of the operation of natural selection than is provided by the way the mechanism of resistance operates. Out of an original population, the members of which vary greatly in qualities of structure, behavior, or physiology, it is the "tough" insects that survive chemical attack. Spraying kills off the weaklings. The only survivors are insects that have some inherent quality that allows them to escape harm. These are the parents of the new generation, which, by simple inheritance, possesses all the qualities of "toughness" inherent in its forebears.

One method of insect control of which Carson does approve is the release of sterile individuals into a population.

At various points in the book, Carson implicates the chemical industry for the aggressive use of dangerous chemicals. One way that they do this is by sponsoring research at universities that supports their business models. These days, they are probably just as likely to fund the campaigns of politicians who support their interests. The corporatization of the federal government is continuing as I write, with the Supreme Court ruling against the regulatory authority of government agencies. I am often amazed to watch decisions regarding complex biological processes being turned over to scientifically illiterate people who wear silly robes.

In the afterword, E.O. Wilson sums up some of the effects of this book. The Environmental Protection Agency was formed in 1970, and the Endangered Species Act was passed in 1973.

Since Silent Spring's publication the United States has come to understand that it is a major player in the deterioration of the global environment. Rachel Carson, who was a quick learner, would be ahead of us in understanding the devastating effects everywhere of still-rocketing population growth combined with consumption of natural resources, the thinning of the ozone layer, global warming, the collapse of marine fisheries, and, less directly through foreign trade, the decimation of tropical forests and mass extinction of species. She would regret, I am sure, the sorry example the United States set with its enormous per capita appropriation of productive land around the world for its consumption – ten times that of developing countries.