Statement On Clinical Intoxication From DDT And Other New Insecticides
Presented before the Select Committee to Investiate the Use of Chemicals in Food Products, United States House of Representatives, U.S. December 12, 1950 Westport, Conn.
From Journal Of Insurance Medicine (May, 1951)
[Thanks to Jim West who made this document available] http://www.geocities.com/harpub/biskclin.htm
THE SYMPTOMS Of DDT POISONING
MEDICAL TREATMENT
BUT THIS ILLNESS IS WIDELY ATTRIBUTED TO AN UNIDENTIFIED
VIRUS RATHER THAN TO DDT
PEOPLE ARE OF VARYING SUSCEPTIBLITY TO TOXINS
DDT IS STORED CUMULATIVELY IN HUMAN BODY FAT
HARWELL EXPERIMENT SHOWS INSECTICIDES AFFECT THE INTERNAL
ORGANS OF HENS
REACTION TO RESEARCH FINDINGS
REBUTTAL OF CRITICISM
DDT poisons a mother's milk
The introduction for uncontrolled general use by the public of the insecticide "DDT" (chlorophenothane) and the series of even more deadly substances that followed, has no previous counterpart in history. Beyond question, no other substance known to man was ever before developed so rapidly and spread indiscriminately over so large a portion of the earth in so short a time. This is the more surprising as, at the time DDT was released for public use, a large amount of data was already available in the medical literature showing that this agent was extremely toxic for many different species of animals, that it was cumulatively stored in the body fat and that it appeared in the milk. At this time a few cases of DDT poisoning in human beings had also been reported. These observations were almost completely ignored or misinterpreted.
In the subsequent mass use of DDT and related compounds, a vast amount of additional information on the toxicity of these materials both in animals and in man has become available. Somehow a fantastic myth of human invulnerability has grown up with reference to the use of these substances. Because their effects are cumulative and may be insidiious and because they resemble those of so many other conditions, physicians for the mart part have been unaware of the danger. Elsewhere, the evidence has been treated with disbelief, ignored, misinterpreted, suppressed or subjected to some of the fanciest double-talk ever perpetuated.
Early last year I published a series of observations on DDT poisoning in man. Since shortly after the last war a large number of cases had been observed by physicians all over the country in which a group of symptoms occurred, the most prominent feature of which was gastroenteritis, persistently recurrent nervous symptoms, and extreme muscular weakness. The condition was of unknown origin, and following an outbreak in Los Angeles in 1947, was thereafter widely attreibuted to a "virus X." As with all other physicians, a large number of my patients had this condition. I, like others, found it extremely puzzling; it resemble no infectious process I was acquainted with, and it had features strongly suggesting some kind of intoxication.
I had known that DDT was far more toxic than current mythology admitted, but it was only when I came across an item in the literature indicating the vast amount of DDT already in use in our agricultural economy that the possibility that this agent was involved occurred to me. I immediately consulted available textbooks and found that the signs and symptoms of known DDT poisoning were sufficiently similar to the cases I had seen to warrant further investigation. In fact, in 1945, two British authors had described with great accuracy part of the disorder following exposure to DDT in three human subjects.
The syndrome consists of a group of or all the following: Acute gastroenteritis occurs, with nausea, vomiting, abdominal pain, and diarrhea. A running nose, cough and persistent sore throat are common, often followed by a persistent or recurrent feeling of constriction or a "lump" in the throat; occasionally the sensation of constriction extends into the chest and to the back and shoulders and may be associated with severe pain in either arm and may easily be confused with a heart or gallbladder attack. Pain in the joints, generalized muscle weakness and exhausting fatigue are usual; the latter are often so severe in the acute stage as to be described by some patients as "paralysis." sometimes the initial attack is ushered in by dizziness and fainting. Insomnia, intractable headache and giddniness are not uncommon. Disturbed sensations of various kinds occur in most of the cases; areas of skin become exquisitely hypersensitive and after a few days this diappears only to recur elsewhere, or irregular numbness, tingling sensations, itching or crawling sensations or a feeling of localized heat may occur. Erratic twitching of voluntary muscles is common. Usually there is diminution of ability to feel vibration in the extremities. Loss of weight is not uncommon.
Disturbances of equilibrium may occur. There may be attacks of rapid pulse and palpitation associated with contraction of blood vessels in the skin, sweating of the palms and a sense of impending loss of consciousness, followed by slow pulse, flushing of the skin, relaxation and cessation of palmar perspiration.
The subjective reactions tend to recur in "waves," as numerous patients have described it. Some have actually been able to clock the reaction with considerable precision from day to day. The reactions appear most likely to occur during periods of low blood sugar. Additionally, consumption of alcoholic beverages or acute emotional stress may provoke a sever exacerbation.
Often, patients with this disorder complain of a "hollow feeling" in the epigastrium which bears no constant chronologic relation to the ingestion of food, and in fact may occur immediately after a full meal. Attempts to eat further may provoke sharp repugnance for food and occasionally may lead to an attack of hiccups, or nausea. In other patients, actual overeating indistiguishable from the compulsive types seen in certain psychogenic disturbances may result.
Hardly a single sensory nerve appears to be immune to involvement in this disorder: disorders of vision, smell, taste and hearing may occur. Pain of varying intensity and duration may involve any area of the skin, may localize in a joint or even a tooth. Severe peripheral neuritis involving intense, protracted pain in one or more of the extremities is frequent. Pain in the groin, usually bilateral, is a frequent complaint. In the acute stages, milk convulsions involving mainly the legs, may occur.
After subsidience of the acute attack, irregular spasm through throughout the gastrointestinal tract often persists for weeks or months, associated with increased fatigability, which only gradually regresses. Fever occurs occasionally during the initial stages but is not the rule. Except for a tendency to anemia, and in some cases a relative increase in certain white blood cells, no consant changes are observable in the blood. Many of the patients have an acute bout of apprehension associated with the foregoing symptom complex and rarely is this relieved by reassurance as to the absence of physical findings sufficient to account for the severity of the disturbance.
Most striking about the syndrome is the peristence of some of the symptoms, the tendency to repeated recurrence of others over a period of many months (some patients fail to show complete recovery even after a year) and the lack of detectable lesions sufficient to account for the severity of the subjective reaction.
The high incidence, the usual absence of a febrile reaction, the lack of observable inflammatory lesions, and the resistance even to alliative therapy, as I have already indiczted, suggested an intoxication rather than an infection. The epidemic first appeared at about the time DDT came into widespread use by the civilian population. The signs and symptoms described in the pharmacologic and toxicologic literature as characteristic of DDT poisoning turned out to be identical with those appearing in patients with the affection described.
By far the most disturbing of all the manifestitations are the subjective reactions and the extreme muscular weakness. In the sever acute cases, patient after patient has used identical words, "I felt like I was going to die."
The sensation can perhaps best be described as one of unbearable emotional turbulence. There are at various times excitement, hyperirritability, anxiety, confusion, inability to concentrate, inattentiveness, forgetfulness, depression, and especially extreme apprehensiveness. These episodes can easily be confused with anxiety attacks having a psychiatric basis. The combination of apprehensiveness, confusion and depression has led to suicidal impulses in a number of my patients. Several insisted that they did not want to live if the reaction persisted. This reaction was the more difficult to bear because its source was unknown and, when the cause became apparent, explanation as to the etiology was usually of great help in tiding the patient over this difficult period. One such patient who had been heavily exposed to DDT was treated psychiatrically for his suicidal depression for months without success. This depression vanished within a few weeks when exposure to DDT was reduced to a minimum by removing it from the immediate environment and restricting the foods most heavily contaminated. Parenthetically, one cannot help but wonder how often exposure to the DDT group of compounds has been implicated in otherwise inexplicable suicides. Certainly in a person already mentally disturbed the additional stress of DDT poisoning could be disastrous. In addition, the mental effects of DDT may easily lead to accidents.
A characteristic history is that of a person (and in a number of cases, an entire family simultaneously involved) who, previously well and able to make a satisfactory emotional adjustment to his environment, suddenly is affected with the syndrome described and remains partially disabled for many months. Usually, the condition remains undiagnosed and frequently these patients make the rounds of doctor after doctor and institution after institution seeking at least a diagnosis, if not relief. The extent to which this can go is illustrated in the case of an exterminator who had used both DDT and chlordane.
At the time I first saw this patient he had spent 2 1/2 years visiting various physicians and institutionals seeking relief from his disabling symptoms which consisted of pain and sense of constriction in the throat and chest, irregular headache and pain in his head, neck and shoulders, muscular twitching all over his body, insomnia, inability to concentrate, forgetfulness and inattentiveness, disturbing sensations in various parts of his skin, repeated gastroenteritis and recurrent extreme muscular weakness. In the process of seeking a diagnosis he asked doctor after doctor whether the insecticides were responsible for his ailment and was repeatedly assured they could not be. He was subjected to virtually every test known to medical science and even had his skull opened for injection of air into his cerebral ventricles for X-ray purposes to make sure he had no braintumor. None of the many tests and examinations could account for his symtpoms. Finally one of the psychiatrists to whom hewas referred recongized the ailment as having a toxic basis. When I saw the patient he had an enlarged tender liver, signs of nutritional impairment, reduced ability to feel vibration in his legs and a reduction in his pulse pressure. Under ordinary circumstances none of these signs, no all together, could account for all his symptoms. When he was advised to give up his job and seek less toxic employment to remove all traces of DDT and chlordane from his environment, was given nutritional therapy to alleviate the liver damage and put on a diet low on insecticide residues, he showed prompt improvement within a week. Four months later he was almost free of symptoms. He then unknowlingly was exposed to DDT in a restaurant kitchen which had just previously been aerosoled with DDT. Within half an hour the entire syndrome returned and required more than a week to subside.
Again 2 months later he was inadvertently exposed to chlordane from an old kit he had previously used. This time there was a very severe exacerbation which required nearly 2 months for subsidence. This patient is fortunately almost completely well for the first time since 1947.
The next patient, a woman, also had correctly diagnosed her own ailment as DDT poisoning, also was assured by physician after physician that her diagnosis was fantastic and she spent 2 years, three months of it confined to bed, unsuccessfully seeking relief. She developed pneumonia immediately following spraying of her clother with DDT for moth-proofing purposes and recovered from this only to find that the symptom-complex I have already described persisted for month after month. She noted for herself that her sympmtoms became worse every time she ate cream in any form, or fresh unpeeled vegetables or olives, or when she tried reducing diet (which burns up the body fat and releases the stored DDT). Again physical findings were insufficient to account for her symptoms and she was dubbed neurotic by her various physicians. I advised her to remove all traces of DDT from clothing and home furnishings by dry cleaning, to eat only foods low in insecticide residues and to avoid exposure to DDT in any form. She was also given nutritional therapy to reair the liver damage. Improvement was noticeable in a few days and after 6 months the patient had several acute recurrences of the entire disorder. One of these occurred when her next door neighbor, fortified by recent statements in the press that DDT was safe, insisted on spraying vegetables immediately adjacent her home, despite her protests. Another occurred when she attempted a reducing diet and lost 4 1/2 pounds in a week.
Twice on visiting the houses of friends that, unknown to her, had just been sprayed with DDT, she became violently ill within an hour. Exacerbations also occurred on exposure to tobacco smoke, through previously she had herself been a smoker. (We have found 4 ppm of DDT and an undertermined amount of benzene hexachloride in 1 brand of cigarettes). And that sensitization to DDT also sensitizes to other related compounds is suggested by the fact that this patient could no longer tolerate the moth proofing agent, paradicholorbenzene. I have seen numerous other similar patients.
A six year old girl developed aplastic anemia (an extremely severe form requiring repeated transfusions to maintain life) immediately following spraying of closets and screens in her bedroom with DDT. Though her mother noted that the anemia promptly got worse each time DDT was used, it was not even considered in the diagnosis. Dr. Felix Karpinski of Western Reserve University has recently reported 5 cases of children who developed hemorrhagic purpura, a serious condition in which the blood does not clot properly, after exposure to DDT.
For 8 months a man in his middle 30's had had continuous gastroenteritis associated with extreme and unbearable apprehensiveness, muscular weakness and numerous other symptoms such as I have described. He lost 30 pounds in the first 3 months of his illness and had not regained it. Physical examinations by several doctors were negative. The illness began shortly after spraying of his bed with DDT. In addition he was fond of butter and ate literal slabs of it at each meal. Medications of various sorts failed to provide relief. There was prompt but partial improvement immediately on elimnation of butter fat at my suggestion. There was further dramatic improvement when DDT was removed from his environment and other foods likely to be contaminated with DDT were eliminated. Within a few months all his symptoms had subsided and he had regained all his lost weight.
Another patient developed the symptom complex described, together iwth a severe alleged gallbladder attack immediately after eating cherries which he subsequently discovered had been sprayed with DDT.
Still another patient who like the one described had a great fondness for butter and consumed great quantities of it, developed the syndrome described, lost 20 pounds and was unable to regain it, was virtually unable to contiue at his work because of the nervous symptoms and continous tremors. He had signs of severe liver involvement. Improvement was striking as soon as butterfat was eliminated from his diet, and with added precautions against exposure to DDT, he made a virtually complete recovery in a few months, regaining all his lost weight.These observations with regard to butterfat are not at all surprising in view of the many reports in the literature on the occurence of DDT in cow's milk. We have found as much as 13 ppm in butter on the N.Y. market and Department of Agriculture reports indicate that very much higher values are not all improbable.
I have seen several instances in exposure to DDT sharply increased the insulin requirement of diabetics.
In the types of cases described recovery occurs slowly only when exposure to DDT is reduced to a minimum. Sprayed clothing, textiles and bedding must be cleaned with lipoid solvents, the particles of DDT must be removed from the room dust in places that have been treated with DDT aerosol, preferably by lacquering, painting or waxing affected surfaces. Wall paper impreganted with DDT has caused severe symptoms in a number of cases investigated. Persons sensitive to DDT must avoid as much as possible visiting places known to have been treated with this agent. Foods or portions of foods in which DDT is now known to occur must be avoided. This entails avoidance of butterfat in all its forms, careful peeling of all fruits and vegetables and avoidance of those that cannot be peeled, substitution of fish and seafood and skim milk products as much as possible for the usual sources of protein, and the medicinal grade of peanut oil (which we have found to be free of the DDT group of compounds) for the usual sources of fat.
Repeatedly, I have had patients who lost weight continuously to the extent of 20 or 30 pounds on a full diet containing large amounts of beef and butterfat, who promptly regained all or most of their lost weight on a diet lower in calories but restricted as indicated. Unless further exposure to the newer insecticides is avoided as stringently as possible, both from direct contact or inhalation and from food, no remedies I have tried give any except slight symptomatic relief.
My original experience on more than 200 cases which I reported early last year has since been considerably extended. My subsequent observations have not only confirmed the view that DDT is responsible for a great deal of otherwise inexplicable human disability, but a large number of additional cases have been reported to me by others.
BUT THIS ILLNESS IS WIDELY ATTRIBUTED TO AN UNIDENTIFIED VIRUS RATHER THAN TO DDT
Although the record is clear on this point a great deal of confusion has been raised with respect to "virus X." I do not know, nor have I ever stated that the Los Angeles epidemic in 1947 was caused by DDT poisoning, although Dr. F. M. Pottenger, Jr. has supplied excellent evidence that subsequent similar outbreaks in that community were caused by pesticide poisoning. "X" obviously means "unknown" and unquestionably in medical research many viruses "X" have from time to time been postulated. What I stated in this connection in my original article was that the syndrome I described and which is beyond question caused by DDT poisoning was widely attributed to a virus "X." It was so attributed by myself and by every other physician whose practice in this respect I know, as well as by the public.
And contrary to the implication in an official but anonymous communication on this subject, this particular condition to which the term "virus X" has been so generally applied did not exist prior to introduction of DDT as an insecticide.
I suggested for purposes of investigation that the same etiology may apply to "X disease" of cattle, which has caused tremendous losses of livestock in this country in recent years. Here too I do not know and have never stated that the original outbreaks of this type in 1939 were caused by DDT poisoning -- I have no way of knowing whether DDT was available in this country for experimental or other use a year after its introduction as an insecticide in Switzerland. But here, too, the unknown "X" was subsequently widely applied both by veterinarians and farmers to a condition which all evidence indicates is caused by a toxic and not by an infectious agent. That the insecticides have never adequately been ruled out in this respect is indicated by the latest report appear in the Journal of the American Veterinary Medical Association, in, which the presence in feed and water of "DDT-like compounds" was dismissed as being in "subtoxic amounts." Obviously, if a suspected cause is to be ruled out, it must be eliminated completely. One cannot simply dismiss the amounts to which the animals were exposed as "subtoxic." From the investigations at the Food and Drug Administration, we know that even the smallest trace of DDT may be cumulatively stored in the body fat. It is significant that lactating cows who excrete the accumulated DDT in their milk are much less susceptible to "X disease" than beef cattle.
PEOPLE ARE OF VARYING SUSCEPTIBLITY TO TOXINS
Another question frequently raised is, if DDT and related compounds are toxic why don't all of us show obvious signs of it? Everyone knows that the suceptiblility to poisons varies tremendously from person to person and animal to animal. In determining the fatal dose of any substance the amount is chosen which kills 50 percent of the animals, because the amount that is fatal to 100 percent may often be several times the amount that would kill the more susceptible animals. Two men may work side by side in a storage battery factory, both equally exposed to lead. One will remain at this employment for 20 years in good health, the other may die in 6 months of lead poisoning. (As a matter of fact I have a specific case of this sort in mind.) Such examples may be multiplied indefinitely. There is evidence, however, that repeated exposure to DDT and similar compounds may suddenly increase susceptibility in previously resistant persons.
DDT IS STORED CUMULATIVELY IN HUMAN BODY FAT
Exposure to DDT is now virtually universal, and it is impossible to separate the effects of direct exposure and those which occur following ingestion of contaminated food. Most of my observations have concerned reactions following on known direct exposure to DDT, and the repeated recurrence of the identical symptom complex on repeated known exposure in the same person. As I indicated before, Laug and his collaborators of the Food and Drug Administration have shown that there is no lower limit in the food below which storage of DDT in body fat does not occur, and that as others also have shown, when this fat is mobilized signs of acute DDT poisoning occur. With larger doses, F.D.A. scientists have also shown that it is possible to store in the body fat many times the amount that would be acutely fatal intravenously in a single dose. (Since DDT mobilizes from the body fat into the blood stream the intravenous dose is the logical comparative one.) Cumulative intoxication from extremely small amounts in food can thus be as dangerous as direct exposure to much larger amounts.
HARWELL EXPERIMENT SHOWS INSECTICIDES AFFECT THE INTERNAL ORGANS OF HENS
A study just reported from Britain in the November 1950 issue of the journal "Food Manufacture" confirms the F.D.A. observations:"Atomic bombs and DDT will be regarded by many as the two most notable scientific developments of the war. They have now been brought together in a more direct and scientific sense by recent British research carried out by the Pest Infestation Laboratory. Radioactive isotopes produced at the Harwell Atomic Pile, have been used to study the biological movement of DDT residues upon wheat.
"In point of facts, DDT itself was not used. The radioactive isotope of bromine was more suitable than that of chlorine and an insecticide containing one bromine atom in the place of one of the chlorine atoms in DDT was prepared. This particular chemical was known, however, to have properties closely similar to those of DDT. Wheat grain was sprayed with the "radioactive" insecticide. When fed to hens, it was found that the insecticide had reached many of the hens' organs and tissues within a few days; autopsies five days after feeding showed the insecticide in the gizzard, the liver and kidney, the tissues of the heart and brain, and the sciatic nerve fiber.
"When the wheat was milled, about one-third of the residues was found in the flour, thus showing that the insecticide had quickly penetrated the grain husks. Not only were residues also found in bread made from this flour, but there was an indication of some chemical assocation with wheat protein as a result of the bread baking conditions. Rats fed with the bread, like the hens fed with unmilled grain, showed wide and rapid distribution of the insecticide in their bodies. Indeed, in all these animal tets, some concentration of the insecticide was found in every tissue examined.
"These new results give strong confirmation for the view that DDT is a hazardous contaminant of animal and human foodstuffs. Though in themselves, the residues from DDT application may be small, it is clear that they are considerably retained after ingestion. Toxic effects of a harmful if not lethal nature could arise from the cumulative absorption of DDT residues.
"Too little remains known about the chemistry of DDT within the metabolism of animal life. Fortunately, the use of DDT as a contact insecticide for protecting stored grain has not been encouraged. Volatile fumigants have been preferred. The new research emphasizs the wisdom of this policy. It also suggests that DDT should never be used to dust or spray growing cereal crops."It does not appear that in this country either of these practices has been discouraged.
Publication of my findings drew some sharp criticism. They were characterized as "totally without foundation," "highly uncontrolled," "hysterical" and so on. The only evidence provided in refutation was the alleged lack of toxic effect from the military and public health users of DDT and among workers in manufacturing plants and observations made on 2 human volunteers at the National Institute of Health. The animal work could hardly be cited because virtually all of it shows DDT to be extremely dangerous. Aside from this, when it comes to emotional disorders of the type I have just described, one can ask an experimental animal how he feels but the answer is not likely to be satisfactory. Actually observation of the overt behavior of many species of animals exposed to DDT, from rats to cattle, suggests that the identical disorder occurs in them too -- as they become jumpy, irritable, erratic, confused, weak and disequilibrated, not to mention convulsive.
In clinical medicine there is at present a deplorable tendency to assume that when objective physical findings and laboratory reports are substantially negative, there is nothing wrong with the patient, no matter how severe his symptoms. But a patient is a whole human being, and how he feels is to him the most important aspect of his existence. The patient is the only unimpeachable authority on this subject and no amount of contrary objective data can alter that fact.
It has been claimed that there were no ill effects from the use of DDT among army personnel during the war and that this proves that this substance is absolutely safe for man. There are three things wrong with this claim: (1) It is not true. (2) The ill effects that resulted from DDT were invariably attributed to another cause. (3) Army personnel is highly selected and is far from representative of the population as a whole as it consists mainly of young, active, healthy male adults.
Actually, as I have ascertained by talking with veterans of the North African and Pacific campaigns, including a number of physicians, DDT poisoning was not even considered, though the reactions I have just described occurred frequently. One of my patients had been through the campaigns in New Guinea and Leyte without benefit of DDT or of modern sanitation, and without ailments of any sort. his group was then transferred to the Phillipines, where, because of the tremendous number of green flies, daily fogging with DDT was instituted. Promptly, virtually the entire outfit developed severe intractable gastroenteritis which taxed the samitary facilities of the camp. Medical investigators called in did not even consider DDT as a possible cause of this disorder and attributed it to eating of unwashed fruit from native peddlers, even though no causative bacteria could be found. My patient spent 18 days in the hospital and then made only a partial recovery; he had lost 20 pounds. He had had the entire symptom complex I described and this recurred repeatedly over a period of four years after he was released from the army, and especially after he started spraying DDT in the garden of his own home. He also had numerous acute attacks following the consumption of beef, butterfat, and other foods shown by Department of Agriculture investigators to be heavily contaminated.
In North Africa there was an extremely high incidence of liver affections, almost invariably called "infectious hepatitis." There is no way to be certain that this diagnosis is accurate except that, as indicated by its name, it is transmissable. In the presence of actual cases of this type, and there is no doubt that there were many, the occurrence of another type of liver damage would readily be overlooked. Actually, as Dr. F. M. Pottenger, Jr., has found, there is excellent evidence that a great many of these cases were actually DDT hepatitis.
As to the alleged freedom from toxic reactions in the public health usage, here too evidence gathered by Dr. Robert F. Mobbs of North Carolina, indicates that these reactions occur frequently among affected populations but are not attributed to their actual cause. The use of DDT is an effort to stop the spread of poliomyelitis is a case in point.
Following a recent extensive trip through the South, Dr. Mobbs informed me that wherever DDT had been used intensively against polio, not only was there an epidemic of the syndrome I have described but the incidence of polio continued to rise and in fact appeared where it had not been before. This is not surprising since it is known that not only can DDT poisoning produce a condition that may easily be mistaken for polio in an epidemic but also being a nerve poison itself, may damage cells in the spinal cord and thus increase the susceptibility to the virus.
In this connection, an observation reported by Dr. Albert B. Sabin in the Journal of the A.M.A. in June 1947 is significant: "Since the end of combat in the Phillipines, poliomyelitis has been among the leading causes of death in American troops. Even though only the paralytic cases are reported from there, the incidence of poliomyelitis in American troops in the Phillipines has been at least ten times as high as in the Army within the continental limits of the U.S. during the past two years. Actually, I believe that it is even higher because hundreds of cases which would have been diagnosed as dengue-like or sandfly-like fevers... under conditions which , in my opinion, would preclude the occurrence of both dengue and sandfly fever. And yet checks of the surrounding native population revealed no outbreaks of poliomyelitis."
Can the assiduous protection with DDT afforded our troops in the Phillipines have any connection with this remarkeable phenomenon?
With regard to workers in plants handling DDT and related compounds, Dr. Mobbs has reported: "In checking on the workers in these plants I was struck by the fact those who remained at this work for more than one month showed an average weight loss of 8 pounds per man... other symptoms were frequently reported by individuals directly exposed to these chemicals. These... included a dry cough, burning sensation in the skin and in the eyes... vomiting and bloated abdomen."
From the few cases I have seen among ex-workers in DDT handling plants, it appears that those who become ill from their employment simply cease to work there after a short time.
The experience with the 2 volunteers at the National Institute of Health was in direct contrast with that of 3 exposed British investigators -- the latter became seriously ill with many of the symptoms I have described and the ailment persisted for from 4 weeks to more than a year. The American investigators were presumed unaffected by DDT, although careful reading of the reports does not support this conclusion. Regardless of this, is an investigation, no matter how extensive and detailed, on 2 healthy male adults sufficient to warrant exposure of an entire population consisting of babies, children, and men and women of various ages and states of health?
In April of last year Dr. Bieber and I reported on a pregnant patient who developed the condition I have here described following direct exposure to DDT. Following delivery her milk was examined and found to contain on successive days 116 ppm; 18 ppm, 2 ppm, 5 ppm and 5 ppm of DDT. (For these determinations and all others relating to ourown observations in this report, I am indepted to Messrs. Joseph Truhlar and Murray Corn of the Laboratory of Industrial Hygiene in New York.) Seven weeks later this patient's milk still contained 8 ppm of DDT. During lactation this patient's symptoms improved markedly since she was excreting her body store of this toxic substance. The baby can hardly be said to have benefitted equally; when the last determination was made, nursing was discontinued by the attending pediatrician.
These determinations have been criticized because they were made by the so-called total chloride method, which detects DDT and other compounds with similar chemical properties but is not absolutely specific for DDT (parenthetically, when the same method was applied to cow's milk by investigators of the Dept. of Agriculture it was accepted as valid). In our subsequent studies, the Schecter-Haller method was used; this is specific for DDT and nothing else. Specimens of mother's milk from six successive patients on the 5th day after delivery contained respectively 4,2,2,1, and 0.5 ppm of DDT and in the sixth a "trace" (the last specimen was not large enough for an accurate determination). When calculated to the fat content (and the evidence suggests that this fairly well reflects the amount in the body fat) the result is of course much larger, from about 7 to about 50 ppm. Of course all these patients had a history of known exposure to DDT, but where can one find a patient today who has not been directly exposed to this agent? (As E. B. White indicated in his famous satire in the New Yorker, to escape DDT requires a trip to another planet.) Is there any apologist for DDT who maintains that this poison is a proper ingredient of mother's milk? What happens to the growing baby, already born with DDT in its body fat because this substance passes the placental barrier, as he gradually stores the additional DDT from his diet in his fat deposits?
At a certain stage of growth this body fat is consumed. Is it then surprising that pediatricians have noted a rising incidence of inexplicable persistent and refractory gastro-intestinal ailments in babies and young children? These ailments are not reportable and do not swell the tables of public health statistics. What is happening to the growth curves of children born in the last 4 or 5 years? Must we wait until the predictable effects have been duly summarized in official reports years after the event?
Of course, substitution of cow's milk for mother's milk doesn't solve the problem either. Reports from the Dept. of Agriculture on the DDT content of cow's milk indicate values of from 0.5 to 25 ppm. The butterfat of course contains much more, as high as 259 ppm in one report.
Last year farmers were advised to stop using DDT in dairy barns or on dairy cattle. This of course is futile advice, first, because it is only advice and not mandatory -- hence many have not stopped using it. Second, the fodder continues to be heavily contaminated. As an example, milk and cream which I obtained from one of the best dairies in Connecticut, in which DDT had never been used at any time, contained in the milk 0.5 ppm and in the cream 4 ppm of DDT. The feed had been purchased on the open market.A flagrant example of the unbelievable lengths to which this insecticide business has gone was reported to me by the owner of a certified milk farm in Kentucky. By the use of ordinary sanitary measures the milk produced by this farm always contained less than 6000 bacteria per cc., which is considered very good practice indeed.
Nevertheless a state dairy inspector ordered this dairy to institute the daily use of a 25% preparation of DDT, an order which the owner fortunately refused to comply.
The toxicology of DDT has been investigated extensively in a large number of species and to this our own government investigators have made a magnificent contribution. DDT has been found almost without exception to be lethal to every form of animal life tested, the only limiting feature being the waxy nature of DDT and its solubility mainly in lipoids and lipoid solvents. It is largely this limited solubility which has been depended on (excessively, it now appears) to safeguard man and other mammals from poisoning.
In rats, mice, rabbits, guinea pigs, cats, dogs, chicks, goats, sheep, cattle, horses and monkeys, DDT produces functional disturbances and degenerative changes in the skin, liver, gall bladder, lungs, kidney, spleen, thyroid, adrenals, ovaries, testicles, heart muscle, blood vessels, voluntary muscles, the brain and spinal cord and peripheral nerves, gastrointestinal tract and blood. DDT is as lethal in repeated small doses as in larger single doses. In low-grade chronic poisoning in animals growth is impaired and the implication of this observation for the growth of children must be given serious consideration. In rats tumors in the liver have been produced, by low-grade continuous poisoning with DDT. DDT is stored in the body fat and is excreted in the milk of dogs, rats, goats and cattle and as we have shown, in that of humans too. Virtually all these effects have also repeatedly been observed in known DDT poisonings in human beings. The other agents of the DDT group, chlordate, benzene hexachloride, chlorinated camphene, and methoxychlor, so far as these have been reported, also produce serious tissue changes varying in site and degree with the compound. Chlordane is an especially nerve poison and animals who have received toxic amounts rarely recover even though bodily changes prior to death do not seem at all alarming. Fortunately in my own limited experience with chlordane poisoning in man, I can report that with stringent avoidance of further exposure and intensive nutritional therapy to help repair the tissue damage, recovery does occur, though this may not be complete. Benzene hexachloride changes the chromosomes of plants and probably too those of animals. The possibility that this agent may adversely affect the heredity of human beings must be taken into consideration. Already in one report from Europe seedlings treated with benzene hexachloride were so altered in their heredity that it was suggested that "nondegenerated stocks" be used for seed subsequently. In this country, where a mixture of DDT and BHC has been spread on the cotton crop for several years, is it accidental that this year the cotton crop is very nearly the lowest on record?
We are dealing with double edged swords, for the very substances now promoted to increase the size of our crops, in the long run turn out to be detrimental to agriculture itself. All these substances and the fantastically toxic parathion too, inhibit the growth of certain plants, and compounds of the DDT group also persistently poison the soil -- so far as present evidence goes, for 5 or 6 years and possibly indefinitely.
Some have insisted that without the use of the newer insecticides there would not be enough food to go around, that even though these substances are toxic their use involves a necessary "calculated risk." Somehow, in a short five years people seem to have forgotten that we had good crops, even immense surpluses, prior to 1945, with the use of methods then available. Better methods are always welcome, but certainly it is a reflection on American scientific and technical ingenuity to assume that the DDT and parthion groups of insecticides are the only ones that will adequately serve our purpose. Machines have been developed that remove insects from crops mechanically and no doubt are susceptible of further improvement. Compounds of the much safer pyrethrum and rotenone principles are available and are not being further developed. Preparations such as piperonyl butoxicd and N-propyl isome that enhances the activity of pyrethrum principles are also available. Utilization of predator insects inherent in the balance of nature has been successful with certain crops, and development of further methods such as are now in experimental use to attract mosquitoes to traps by means of sound can no doubt be applied to other insects.
The use of the term "calculated risk" suggests a military campaign that involves casualities on both sides. Shall we sacrifice so many people for so many insects? If we do, we shall leave the world to the insects, for they outnumber us many millions to one, and because their life cycle is shorter they have already developed insecticide resistant strains.
It has been suggested that human beings should be able to tolerate without harm 5 mg. of DDT per day in their food. A little calculation shows this figure to be fantastically optimistic. Laug, Kunze and their co-workers of the FDA, as I have already mentioned, have found that DDT stores up in the body fat no matter how low the level of intake, even down to 0.12 ppm -- in fact, even the controls had DDT in their fat, so pervasive is this substance. With 5 ppm in the diet, observable liver damage occurred. As is customary in animal experiments, this concentration was calculated to the dry weight of the diet. 5 mg. calculated to the dry portion of the average human daily intake would greatly exceed this figure of 5 ppm and would be more nearly 10 ppm. Actually 5 ppm is not safe either, as the FDA investigators have shown, since when the body fat containing stored DDT is for any reason burned up, serious intoxication results, an observation I have repeatedly made in humans also.
What are some of the consequences of the continued use of DDT and related compounds and of the parathion group of substances in agriculture?
The compounds of the DDT group are all extremely active direct liver poisons. DDT and parathion both interfere with the function of the gastrointestinal tract and hence interfere with absorption of essential nutrients. This too causes impairment of liver function. For many years before the problem of DDT poisoning intruded in my life, my collaborators and I had been working on the function of the liver in relation to disturbances in nutrition and other disturbances of the ductless glands. We found that if the liver is deprived of essential vitamins it loses its ability to metabolize certain hormones and that this leads to a variety of more or less severe distrurbances of the endocrine (or glandular) system. Among these are serious disorders of the sexual function in both sexes, diabetes, thyroid disturbances and other changes. Poisoning the liver with a toxic substance has the same effect. The combination of a direct liver poison and a gastrointestinal distrubance which interferes with absorption of vitamins and other essential nutrients may lead to even more serious forms of these disorders. In addition a damaged liver loses its ability to metabolize choloesteral, a waxy substance similar in chemical structure to some of the hormones. As a result the amount of cholesterol circulating in the blood increases beyond normal limits, it deposits in the inner lining of the blood vessels as well as elsewhere in the body. In an artery this gradually narrows the opening of the vessel so that it may stop up altogether. When this happens in one of the coronary arteries which feed the heart muscle, the effect is often sudden death.
In association with liver damage there is often also an increased fragility of the walls of the small blood vessels and they have a tendency to rupture easily. This may well be a factor in the production of cerebral hemorrhage.
There is no doubt in my mind that the widespread use of the new insecticides is implicated in the alarming rise in the incidence of deaths from heart attacks and other forms of vascular disease, especially in relatively young persons. The mortality from this source increased 7 per cent in the year 1946-47 alone.
That exposure to the newer insecticides actually causes a rise in blood cholesteral in human beings, both Dr. F. M. Pottenger, Jr. in California and I have repeatedly observed. Dr. Pottenger informs me that the general level of blood cholesterol in his patients in 1950 is much higher than in 1945. He has seen variants of the syndrome I have described in about one third of his patients.
In addition to this effect DDT is known to increase the excitability of the heart muscle in animals, and it causes disturbances in heart rate and blood pressure in man, effects we have repeatedly observed. The combination of a narrowed coronary artery and the latter effects make DDT even more potentially disastrous.
Virtually all studies on the toxicity of the various insecticides have been made on the individual substances. However this in no way reflects what happens in actual practice, for today in a single day's diet we may readily be exposed to DDT, BHC, chlordane, chlorinated camphene, methoxychlor and parathion as well as some lead and arsenic. how many simultaneous insults can the human body take?
As for parathion, my own experience has been limited. However, one incident may be of interest to this Committee. Two persons developed gastroenteritis, persistent headache, sweating of palms, disturbances of vision and greatly increased fatigability over a period of 10 days. In an effort to trace the source it was recalled that a new brand of flour had been in use for baking since just before the onset of the affection. This had been consumed at the rate of about 1/2 to 3/4 lb. of flour per day in bread and pasry. Another brand of flour made by the same manufacturer was substituted, with rapid subsidence of all the symptoms; the first contained 1 ppm of parathion, the second contained none.
Recent suggestions that human beins may with safety be permitted to ingest from 1 to 2.5 mg of parathion a day appears vastly excessive, in the light of this experience. Or, and I say this without levity, is it seriously believed that if the dose is not immediately fatal it is safe?
The New York Times last April carried items indicating that because the wheat crop was threatened by green bugs and red spiders, more than 200,000 acres had been sprayed with parathion by airplane. What was omitted from the news dispatch was that the crop was threatened only because the prior use of DDT had killed off the normal predators of these two resistant insects, permitting them to flourish uncontrolled. Apparently the remedy for too much poison is still more.
Parathion is everywhere admitted to be deadly for man and all other animals. One manufacturer warns that sprayed areas may not even be entered without a mask and protective clothing for 30 days after application. Failure to heed this precaution has already resulted in numerous serious accidents to man. What happens to the birds and other wildlife who cannot read?
Parathion has an even greater immediate toxicity than such deadly war "gases" as lewisite, for instance. No one would even consider putting lewisite into the hands of untrained personnel with only printed or oral instructions as to safe methods of handling it, as has been done with parathion, with many resultant near-fatal and fatal accidents. According to a recent article in the Journal of the American Medical Association and a dramatic presentation in Life Magazine, compounds of the parathion group are now part of the chemical warfare armamentarium of many nations.
According to J. C. Leary and his collaborators in a book on DDT published in 1946, when DDT arrived here from Switzerland in 1942, "It was received with suspicion. Just previously the Germans had staged a fear propaganda campaign about the new nerve poisons developed by German chemists -- part of the 'war of nerves' presumably. And when the first tests of DDT brought insects down in convulsions, obviously due to nerve effects, the first thought was that maybe this was the nerve poison. Further testing shortly dispelled the idea, however, and the work went forward."
By whom and how this idea was dispelled is not indicated. It is to my mind significant that the Germans did not use DDT andpermitted their troops to become pediculous, although it cannot be said that they did not know about the substance.
The nations of the world are signatories to a agreement forbidding the use of poison in warfare. Surely our own civilian population in peacetime is entitled to the same consideration.
Government investiators who studied the pharmacologic effects of DDT in animals did a remarkable job, and regrettably until now a thankless one. It is unfortunate that their repeated warnings were overrun, when in September 1945 DDT was released to the public. As Leary and his co-authors pointed out in their book, "Many government experts, particularly those who had been working on it, would have preferred to withhold it for a much long period, but the demand was so great that they had to yield."
It is my opinion that the use on crops or in food establishments of any sort, of the chlorinated cyclic hydrocarbons (which include the DDT group of compounds), and the organic phosphates of the parathion group, should be, and if we want to survive, must be specifically forbidden by law. I believe that all insecticides, and all other chemicals which may contaminate food, including all those now in use or to be used in the future, should be under the direct jurisdiction of the Federal Food and Drug Administration, who should be required to pass upon the safety of these substances before the permitting their introduction into general use, or the continuation of those now in use.
Of course, the facilities of this agency must be suitably expanded to cope with this formidable task. The cost, no matter how large, will be more than repaid in improved health and productivity of the people.
Nearly two and a half years ago, the Council on Foods and Nutrition of the American medical Association cites: "The time toestablish controls, voluntary or otherwise, is now, before possible tragic consequences occur."
Facts are stubborn, and refusal to accept them does not avoid their inexorable effects -- the tragic consequences are now upon us.