In 1962, Rachel Carson wrote about the calamitous effects of chemical pollutants on nature and humanity. NewYorkerArchive
Among the new chemicals are many that are used in man’s war against nature. In the past decade and a half, some six hundred basic chemicals have been created for the purpose of killing insects, weeds, rodents, and other organisms described in the modern vernacular as “pests.
Yet such a world is pressed upon us. For the first time in history, virtually every human being is subjected to contact with dangerous chemicals from birth to death. In the less than two decades of their use, DDT and other synthetic pesticides have been thoroughly distributed over all but a few corners of the world. They have been recovered from many of the major river systems, and even from the streams of ground water flowing unseen through the earth.
Scientists are not sure how much DDT can be stored in the human body. Some believe that there is a ceiling beyond which absorption and storage cease. Others do not. For practical purposes, it is not particularly important which view is right. Storage in human beings has been well investigated, and we know roughly how much the average person is storing. According to various studies, individuals with no known exposure except the inevitable dietary one store from 5.3 parts per million to 7.
As long ago as the mid-nineteen-thirties, a special group of hydrocarbons, the chlorinated naphthalenes, had been found to cause hepatitis and a rare and almost invariably fatal disease known as yellow atrophy of the liver in persons subjected to occupational exposure. These chemicals have led to illness and death of workers in electrical industries , and more recently, in agriculture, they have been considered a cause of a mysterious and usually fatal disease of cattle.
The second major group of insecticides, the organic phosphates—esters of phosphoric acid—are among the most poisonous chemicals in the world. The origin of these chemicals has a certain ironic significance. Some of them had been known for many years, but their insecticidal properties were first discovered by a German chemist, Gerhard Schrader, in the late nineteen-thirties.
In Greek mythology, the sorceress Medea, enraged at being supplanted by a rival in the affections of her husband, Jason, presented the new bride with a robe possessing magical properties The wearer of the robe immediately suffered a violent death. This death-by-indirection now has its counterpart in what are known as “systemic insecticides.” These are chemicals that are used to convert plants or animals into a sort of Medea’s robe.
When we turn our attention to herbicides, or weed killers, we quickly come across the legend that they are toxic only to plants. Unfortunately, this is only a legend. The plant killers include a large variety of chemicals that act on animal tissue as well as on vegetation. No general statement can describe the action of all of them.
Another curious effect of 2,4-D has important consequences for livestock and wildlife, and apparently for men as well. Experiments carried out about a decade ago showed that after treatment with this chemical there is a sharp increase in the nitrate content of corn and of sugar beets, and that this might also be true of sorghum, sunflower, spiderwort, lamb’s-quarters, pigweed, and smartweed. Some of these are normally ignored by cattle but are eaten with relish after treatment with 2,4-D.
Anyone who doubts that our waters have become almost universally contaminated with insecticides might well study a brief report issued by the United States Fish and Wildlife Service in 1960. The Service had carried out studies to discover whether fish, like warm-blooded animals, store insecticides in their tissues. The first samples were taken from a creek in a forest area in the West where there had been mass spraying of DDT for the control of the spruce budworm.
A striking example of the contamination of surface waters seems to be building up in the National Wildlife Refuges at Tule Lake and Lower Klamath Lake, both in California. These refuges are part of a group, which also includes the refuge on Upper Klamath Lake, just over the border in Oregon.
There are few studies more fascinating, and at the same time more neglected, than the study of the teeming populations that exist in the dark realms of the soil. We know too little of the links that bind the soil organisms to each other, to their world, and to the world above. Perhaps the most essential organisms in the soil are the smallest—the invisible hosts of bacteria and of threadlike fungi. Statistics of their abundance take us at once into astronomical figures.
One of the most important things to remember about insecticides in soil is their persistence. Aldrin has been recovered after four years, both as traces and, more abundantly, as converted to dieldrin. Ten years after the application of toxaphene to sandy soil, enough remains to kill termites. BHC persists a least eleven years, and heptachlor at least nine. Chlordane has been recovered after twelve years.
Water, soil, and the earth’s green mantle of plants make up the world that supports the animal life of the earth. Although modern man seldom remembers the fact, he could not exist without the plants that harness the sun’s energy and manufacture the basic foodstuffs he depends upon for life. Our attitude toward plants is a singularly narrow one. If we see any immediate utility in a plant, we foster it.
Besides the more than four million acres of range lands sprayed each year, large areas of other types of land are potential or actual recipients of chemical treatments for weed control. For example, in the United States an area larger than all of New England—some fifty million acres—is under the management of utility corporations, and much of it is routinely treated for “brush control.
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