Yet for a week after the application of the insecticide the water remained poisonous, a fact attested by the daily deaths of goldfish suspended in cages downstream.įor the most part this pollution is unseen and invisible, making its presence known when hundreds or thousands of fish die, but more often never detected at all. Two of these streams were sources of municipal water supply. Water from a stream draining sprayed cotton fields remained lethal to fishes even after it had passed through a purifying plant, and in fifteen streams tributary to the Tennessee River in Alabama the runoff from fields treated with toxaphene, a chlorinated hydrocarbon, killed all the fish inhabiting the streams. For example, a sample of drinking water from an orchard area in Pennsylvania, when tested on fish in a laboratory, contained enough insecticide to kill all of the test fish in only four hours. Here and there we have dramatic evidence of the presence of these chemicals in our streams and even in public water supplies. Probably the bulk of such contaminants are the waterborne residues of the millions of pounds of agricultural chemicals that have been applied to farmlands for insect or rodent control and have been leached out of the ground by rains to become part of the universal seaward movement of water. Some come from forest spraying that may blanket two or three million acres of a single state with spray directed against a single insect pest-spray that falls directly into streams or that drips down through the leafy canopy to the forest floor, there to become part of the slow movement of seeping moisture beginning its long journey to the sea. Some are deliberately applied to bodies of water to destroy plants, insect larvae, or undesired fishes. To an ever-increasing degree, chemicals used for the control of insects, rodents, or unwanted vegetation contribute to these organic pollutants. 'What is the effect on the people? We don't know.' 'We don't begin to know what that is,' said Professor Eliassen. Professor Rolf Eliassen of the Massachusetts Institute of Technology testified before a congressional committee to the impossibility of predicting the composite effect of these chemicals, or of identifying the organic matter resulting from the mixture. In rivers, a really incredible variety of pollutants combine to produce deposits that the sanitary engineers can only despairingly refer to as 'gunk'. Most of them are so stable that they cannot be broken down by ordinary processes. When inextricably mixed with domestic and other wastes discharged into the same water, these chemicals sometimes defy detection by the methods in ordinary use by purification plants. It has now reached such proportions that an appalling deluge of chemical pollution is daily poured into the nation's waterways. As we have seen, the production of these synthetic chemicals in large volume began in the 1940s. Many of the chemical agents in this alarming mélange imitate and augment the harmful effects of radiation, and within the groups of chemicals themselves there are sinister and little-understood interactions, transformations, and summations of effect.Įver since chemists began to manufacture substances that nature never invented, the problems of water purification have become complex and the danger to users of water has increased. To these is added a new kind of fallout-the chemical sprays applied to croplands and gardens, forests and fields. The pollution entering our waterways comes from many sources: radioactive wastes from reactors, laboratories, and hospitals fallout from nuclear explosions domestic wastes from cities and towns chemical wastes from factories. The problem of water pollution by pesticides can be understood only in context, as part of the whole to which it belongs-the pollution of the total environment of mankind. In an age when man has forgotten his origins and is blind even to his most essential needs for survival, water along with other resources has become the victim of his indifference. By a strange paradox, most of the earth's abundant water is not usable for agriculture, industry, or human consumption because of its heavy load of sea salts, and so most of the world's population is either experiencing or is threatened with critical shortages. By far the greater part of the earth's surface is covered by its enveloping seas, yet in the midst of this plenty we are in want. OF ALL our natural resources water has become the most precious.
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