CONGRESSIONAL RECORD — July 12, 1966
PROHIBITION OF SALE OR SHIPMENT FOR USE IN THE UNITED STATES OF DDT
Mr. NELSON. Mr. President, I now introduce, for appropriate reference, a bill to ban the manufacture of DDT for any use in this country.
DDT was first used in the 1940’s to control mosquitoes, flies, and other disease carriers. But strains resistant to the pesticide developed, making spraying less effective. DDT also was used on farm and forestland insects but some of these also developed resistance.
As a result, the industry in recent years has marketed a long list of more selective and short-lived substitutes, making DDT technologically obsolete.
One reason it still is used—for such things as spraying for Dutch Elm disease—is that it is easy to obtain and easy to apply. Another is its low cost of around 18 cents a pound, compared with up to $2.50 a pound for some other common pesticides.
DDT, although sold commercially less than 25 years, has polluted the environment on a worldwide basis. In only one generation it has contaminated the atmosphere, the sea, lakes and streams, and infiltrated the fatty tissue of most of the world’s creatures.
The National Wildlife Federation reports roughly 75 percent of specimens of fish, birds, and mammals collected from various parts of the world, including the Arctic and Antarctic regions, contained DDT, or what it becomes after metabolism.
California marine scientists collected several hundred samples of fish and shellfish from the Pacific, in both salt-water bays and the open sea. They reported 396 of the 400 samples analyzed contained measurable DDT residues.
Interior Department scientists collected 15 samples of air from 9 different locations throughout the country and analysis showed that all contained DDT residues.
The long-range biological effects of this global contamination, which is building up every day that use of DDT continues, are not yet known but the potential is present for a national calamity. Indeed the damage already done is colossal.
DDT remains in toxic form in soil, water, air, and living plants and animals for many years after it is applied. It drifts with the air, flows with the rivers, falls with the rain. So even if the June 30, 1967, cutoff in this bill is approved DDT will persist as a troublesome residue in our ecological system for years to come.
This pesticide is one of the most persistent—remaining toxic for 10 years or more after application—of the more than 60,000 available chemical preparations now registered by the Federal Government.
In connection with this characteristic, its tendency to concentrate in the food chain and cause sublethal chronic effects on fish and wildlife is well established. These effects—which include lowered reproduction, reduced numbers of normal offspring, and sudden death of the organism under stress—mark DDT as a most serious environmental threat.
Whether humans will suffer these same ill effects after longtime exposure to small amounts of DDT still is undetermined.
Banning DDT is consistent with recommendations of two highly regarded Presidential panels that have reported in the last 3 years.
The most important recommendation of the Wiesner Committee in 1963, in my judgment, was the one urging cutbacks in the use of such persistent pesticides as DDT. The panel recommended:
“The accretion of residues in the environment (should) be controlled by orderly reduction In the use of persistent pesticides. As a first step, the various agencies of the Federal government might restrict wide-scale use of persistent insecticides except for necessary control of disease vectors. The federal agencies should exert their leadership to induce the States to take similar actions. Elimination of the use of persistent toxic insecticides should be the goal.”
The report of the Environmental Pollution Panel of the President’s Science Advisory Committee last November also dealt with this point. It recommended:
“Research should be encouraged toward the development of pesticides with greater specificity, additional modes of action, and more rapid degradability than many of those in current use.”
“Pesticidal effectiveness should be increased and total environmental contamination decreased by further research leading to the more efficient application of pesticides to the target organisms.”
DDT is manufactured and sold in large quantities in this country.
Data collected by the subcommittee headed by the Senator from Connecticut [Mr. Ribicoff], shows U.S. chemical companies manufactured 164,180,000 pounds of DDT in 1960, 171,483,000 pounds in 1961, 167,032,000 in 1962, 178,913,000 in 1963, and 124 million in 1964. Total production in the 10-year period ending in 1963 was 1,472,727,000 pounds. This bill would have no effect on the thousands of widely used and less persistent pesticides. These include the many fungicides, insecticides, rodenticides, herbicides, germicides, nematocides, defoliants, repellants, desiccants, and growth regulators.
The evidence is overwhelming that DDT is doing irreparable harm to our surroundings.
One characteristic that makes it so harmful is that it is involved in biological magnification—the ability of organisms to absorb a chemical such as DDT in amounts greatly exceeding those in their surroundings.
A classic example of biological magnification in a food chain occurred in Clear Lake, Calif., in 1957.
To control a troublesome flying insect that hatches in the lake, the water was treated with the insecticide DDD—similar to DDT—to yield a concentration of 0.02 parts per million. Plankton—microscopic waterborne plants and animals—in the lake accumulated the DDT residues at 5 parts per million. Fish that ate the plankton concentrated the DDD in their fat to levels ranging from several hundred to up to 2,000 parts per million. Grebes, diving birds like loons, fed on the fish and died.
The highest concentration of DDT found in tissues of grebes that ate the poison-carrying fish was 1,600 parts per million.
DDT also is involved in another phenomenon. This is the synergistic effect of DDT and certain other chemicals when they occur together.
Research at the Patuxent Wildlife Research Center shows, for example, that DDT and 2, 4-D fed together had several times greater toxicity to mallard ducks than either fed separately.
DDT is a broad-spectrum poison, too, meaning it kills a wide range of friendly insects at the same time that it hits target pests. This characteristic upsets the balance of nature much more than the more selective pesticides do.
DDT, for example, is used against the codling moth in apple orchards but does not control leaf rollers, aphids, mites, and scale insects on the same trees. Instead, DDT kills some of the natural enemies of these pests. Oddly enough, DDT destroys the predatory mites, which prey on the plant-eating mites but does little harm to the latter.
Considerable research on DDT over he past 20 years shows other highly disturbing findings regarding its effect on our surroundings.
Robert J. Anderson, Assistant Surgeon General and an authority on environmental health, ably summed up the thousands of studies of the effects of DDT on the health of nearly all forms of life in a talk about a year ago. This is a major excerpt:
“Most studies of DDT and man’s health, however, have been limited in epidemiological design and of relatively short duration. So we are by no means certain of our health’s safety after many years or a lifetime of continuous exposure to minute quantities. We know that repeated small dosages in test animals have produced more significant cellular changes in the liver than have a few massive doses. In man this presumably could cause serious consequences to Individuals already burdened by disease.
Of concern, too, is the effect of DDT on reproductive systems, as demonstrated la numerous bird and animal studies. Rate fed diets containing from 50 to 600 ppm. of DDT showed a progressive decline in the percentage of young successfully weaned, compared to control rats fed diets containing up to 10 ppm. No effect on the number of rats born alive was evident in the first generation. However, In the second generation those rats which had experienced maximum exposure produced very few living young, of which none survived the nursing period. In wild duck eggs residues are known to have a marked effect on reproduction of some species. Pheasant studies in California have shown the loss of reproductive ability in hens after exposure to DDT used In agriculture.
The variable potency of DDT to various species is well demonstrated by marine life. Commercial shrimp die from exposure to less than 0.001 ppm. On the other hand oysters exposed to minute concentrations have shown an ability to accumulate residues 70,000 times greater than the amount present in environmental waters.
DDT . . . has been shown to induce tumors and liver cancer in rainbow trout after dietary exposure to 80 ppm over periods of 15 to 20 months. Up to now there is no evidence it has caused cancer in man. However, even though its chemical structure does not suggest it likely to be carcinogenic, it nevertheless remains under investigation.”
DDT has a tendency to accumulate in the yolk sac of eggs of birds and fish and these higher concentrations cut fertility and the ability to reproduce. It also has been shown that DDT is transferred from the mother through the placenta into the fetus of dogs, rabbits, mice and men.
Increased concentrations in the environment most certainly threaten the survival of a great variety of marine life, insects, and wildlife.
New York State studies since 1956 have shown conclusively that failure of lake trout to reproduce in many lakes is caused by DDT. Investigators showed that levels of DDT of more than 3 parts per million in lake trout eggs caused virtually complete mortality of the fry.
Low reproductive success of a colony of herring gulls in the Lake Michigan area is blamed on DDT in gull eggs. The average levels found in the eggs were 19 parts per million of DDT, 6 parts per million of DDD, and 202 parts per million of DDE.
Recent field studies also showed that eagle eggs collected in the field contained from 2 to 27 parts per million of DDT residues, a level considered high enough to cause a serious hatching problem.
One of the other serious consequences of using DDT and similar pesticides is that they don’t stay where they are applied. Pesticide residues, as a result, continue to spread rapidly throughout the world.
John L. Buckley of the Interior Department, speaking at a symposium sponsored by the New York State Joint Legislative Committee on Natural Resources in 1963, said this about the problem:
“If these pesticides stayed where we placed them until they become biologically innocuous our problem would be considerable, but its solution relatively simple. In point of fact, they don’t. An increasing body of evidence shows pesticide residues to be nearly ubiquitous. Recent studies reported to the Congress by the U.S. Public Health Service show at least traces of one of the more chlorinated hydrocarbon pesticides in virtually every major river system in the United States. Sampling of air for pesticides has not been extensive, but residues of DDT were found in 15 of 15 samples examined from 9 different locations in the country. DDT residues are found in virtually all samples of human fat examined in the United States….”
The Interior Department has repeatedly expressed to Congress its deep concern over the way pesticides have turned up in unlikely places. It reports DDT residues in penguins and seals in Antarctica and in animals in the far north, both areas far removed from spray programs.
The reports of delayed poisoning by DDT point to further serious consequences of continued use of this pesticide.
Richard Bernard, in a highly significant study at Michigan State, fed two groups of captive English sparrows the same diet with the exception that a small sublethal dose of DDT was added to one group. Both groups of birds fared well and got fat. After several months both groups were starved for 16 hours, and at the end of that time all of the sparrows that had accumulated much DDT in their fat had died. None of the sparrows in the non-DDT group was affected.
Both groups seemed to be equally well and active before the 16-hour fast started.
This study, and others that are similar, show that when birds, fish, mammals, or humans with significant concentrations of DDT in their fat become ill, are starved, or otherwise lose weight, the fat containing DDT is absorbed quickly into the blood stream.
Although DDT residues accumulate in humans at levels not considered harmful at this time, levels in greenhouse workers, spray pilots, and others with occupational exposure reach levels high enough to be considered alarming.
The report of the environmental pollution panel of the President’s Science Advisory Committee noted that these exposed workers sometimes show marginal or definite impairment of an important bodily function as a result of this DDT exposure.
DDT has been recognized as a serious environmental threat in Wisconsin, where its uses have included widespread spraying since 1957 to combat Dutch Elm disease.
The Wisconsin Conservation Department became so concerned that on March 11 it issued a special DDT warning to guide its employees. This warning reaffirmed previous orders to discontinue immediately the use of DDT in all department spraying programs and on all department lands.
It also noted that State permits for the use of DDT in Dutch Elm disease control programs after April 15 would no longer be issued. These permits have been required for several years.
This important announcement was issued by Director L. P. Voigt after careful and extensive laboratory testing showed DDT contamination of birds, wildlife, lades, and rivers in Wisconsin.
A large number of Wisconsin communities became aware of this new evidence and stopped using DDT in community spraying programs. Less toxic and persistent pesticides have been substituted.
DDT was widely used in agriculture in the past, but new pesticides that are more selective and less persistent now are being sold.
I was surprised recently to discover that the U.S. Department of Agriculture still recommends DDT for widespread commercial use. The official recommendations, “Suggested Guide for the Use of Insecticides To Control Insects Affecting Crops, Livestock, and Households 1965,” show 366 instances where DDT is suggested. However, in all but 30 of these instances, another pesticide also is recommended.
The Department, aware of the many dangers of using DDT, specifies detailed restrictions on use of DDT in most instances where it is recommended. This reflects growing concern over the problem of DDT residues showing up in food and animal feed.
Examples of their warnings are:
Do not use cottonseed treated with DDT for food or feed. Heavy doses of DDT may injure beans. Do not feed clover plants treated with DDT, or ensilage made from treated plants, to poultry, dairy animals, or animals being finished for slaughter. Do not apply DDT to forage to be sold or shipped Interstate. Do not use DDT-treated tops for food or feed. Do not use DDT after appearance of any part to be eaten.
It is obvious from these examples that truck gardeners, farmers, and others must exercise the utmost caution in using this dangerous pesticide.
Although DDT has been widely used in orchards, heavy accumulations in orchard soils now are causing serious problems. A recent survey of 35 orchards in Indiana, for example, showed some had DDT residues greater than 100 pounds per acre. Some went as high as 400 pounds per acre. At known disappearance rates, it will take many years for these toxic residues to disappear.
The uptake of pesticides from soils by translocation into plants does take place. However, research in this area is not highly developed and the full extent of this contamination of growing things is not yet known.
The presence of DDT in food has become so common that the Federal Government recently changed its guidelines for removing contaminated foods from the market. A joint announcement of the Agriculture Department and Department of Health, Education, and Welfare said, in part:
Tolerances will be fixed for low levels of pesticides occurring Inadvertently In some foods. The practice of allowing the use of pesticides on a “no-residue” basis will be ended because it is not realistic.
Where a safe, low-level tolerance cannot be established, “zero tolerances” will be set as a basis for removing contaminated foods from the market.
There has been considerable controversy over tolerances, which allow a certain amount of pesticide residue to remain in or on food that is sold. And the pesticide that causes the most residue trouble in food is DDT.
The Congress, in my judgment, should respond to the public’s concern over continued development and wide usage of pesticides, such as DDT, that have broad spectrum action and a high degree of environmental persistence. There probably are hundreds of registered pesticides that should not be used. This is an area that I intend to follow up later.
But DDT should be singled out for special consideration because it is so harmful that it is in a class by itself. It is one pesticide we certainly can and must get along without. It is one of those with the highest persistence. It has the grave flaw of ecological magnification in food organisms. And it has adequate and plentiful substitutes.
This bill will retire DDT from commercial sale in this country and, hopefully, allow it to disappear from our surroundings before permanent damage has been done to fish, wildlife, and even to ourselves.
One thing that 20 years of DDT has proved is that rapidly breeding and mutating forms of life, such as flies and other common insects, have been able to develop immune traits. There is the dangerous likelihood that more and larger members of the animal kingdom are unable to develop a comparable immunity.
We do not know the long-term effect of DDT on humans but the evidence of its devastating effect on wildlife should be due cause for alarm. What a great irony it would be in our frantic effort to kill insects, we eliminated man, making the world safe for bugs.
Mr. President, I ask unanimous consent to insert in the RECORD newspaper articles and other material supporting statements I have made in explaining this proposal.