1 15 40 https://www.nal.usda.gov/exhibits/speccoll/files/original/c241d5fc4c85822fde6f309c1bbd2dd5.pdf ca0489f0945f206eb1cbeee1bbec2997 PDF Text Text Item ID Number Author on 37 Anderson, John M. Corporate Author ROpOrt/ArtlClB Title DDT: Sublethal Effects on Brook Trout Nervous System Journal/Book Title science Year 1969 Month/Day A ril 25 Color n Number of Images 2 P Alvin L. Young filed this item under the category "DDT/Human Toxicology and Environmental Fate" Wednesday, April 11, 2001 Page 1187 of 1242 �cent rabbit serum; pH 7.0; without agar), with incubation for 24 hours at 37°C. The end point of activity was complete inhibition of growth. After isolation of metronidazole-resistant organisms, experiments were done in hamsters to compare the efficacy of metronida/ole against the metronidazole-sensitive and -resistant strains. Hamsters were infected with 24-hour cultures of vaginal washings from donor animals infected with either the sensitive or the resistant strain of T. foetus. After 1 week a vaginal smear was taken to confirm infection. Groups of ten animals each were then treated orally with up to 200 mg of metronidazolc per kilogram of body weight, daily for four successive days. A group serving as infection controls was treated with the drug diluent, 0.5 percent gum tragacanth. Twenty-four hours after each treatment, a vaginal washing was taken and placed in Diamond's medium con, taining 100 units of penicillin G and 100 fig of streptomycin per milliliter. The sample was then incubated for 24 hours at 37°C, examined, and scored for trichomonads present. An additional sample was taken 1 week after the last treatment. The degree of infection, designated as the infection score, was . determined by assigning a value of 0, 1, 2, or 3 to each culture examined, 0 indicating no detectable organisms and 3 indicating more than 100 trichomonads per microscopic (X 10) field. The isolate from the animals treated with the aforesaid suboptimum doses of metronidazole was 8 to 16 times more resistant than the parent strain. The minimum inhibitory concentration of metronidazole for the parent strain ranged from 0.0975 to 0.195 /xg/ml, whereas that for organisms isolated from the metronidazole-treated animals ranged from 1.56 to 3.12 /tg/ml. There was no further increase in resistance to metronidazole in infected animals in which treatment was continued for a period of about 3 months. After four oral treatments with metronidazole, hamsters infected with the metronidazole-sensitive strains of T. foetus had a significant reduction in parasites, even at 50 mg/kg per day (Fig. 1). One week after the last treatment, an exacerbation of the infection was observed. Animals infected with the metronidazole-resistant strain of T. foetus and treated with metronidazole, even at 200 mg/kg daily for 4 days, 440 showed no change in parasite numbers during the test period. Resistance to antiprotozoal agents is an important problem in animal and human therapy. Although metronidazole-resistance apparently is not a widespread clinical problem (4), its presence may be more common than believed. Most clinicians do not isolate organisms and test for resistance in cases of therapeutic failure. Furthermore, epidemiological problems cloud the search for resistant organisms in recurrent cases, as the long-term followup required is of little value if the treated individual cannot be isolated (5). Chloroquine-resistance in human malaria first became evident after the drug had been used for many years. Similarly, metronidazole-resistance could prove to be a significant clinical entity. P. ACTOR, D. S. Ziv J. F. PAGANO Research and Development Division, Smith Kline & French Laboratories, Philadelphia, Pennsylvania 19101 References 1. I. dcCarneri, Lancet 1966-1, 1042 (1966). 2. B. M. Ilonigberg, Proc, Int. Congr. Parasltol. 1st Rome, 1, 368 (1966). 3. I. deCarneri, ibid., p. 366. 4. L. Watt, Practitioner 195, 613 (1965). 5. S. C. Robinson and D. W. Johnston, Canad. Med. Ass. ]. 85, 1094 (1961). 13 January 1969 • DDT: Sublethal Effects on Brook Trout Nervous System Abstract. When brook trout are exposed for 24 hours to sublethal doses of DDT, the cold-blocking temperature for a simple reflex, which shows lability related to thermal history, is altered in a way suggesting that DDT is affecting the thermal acclimation mechanism. Sublethal dosage of DDT also prevents the establishment of a visual conditioned avoidance response. Fish show behavioral changes after exposure to sublethal concentrations of pesticides (1, 2) that may act on either peripheral or central (or both) nervous structures. One receptor system (the lateral line) is markedly affected by sublethal concentrations of DDT (3). Although there is little supporting evidence, the central nervous system (CNS) nevertheless seems the most likely site for the pesticide-sensitive region responsible for changes in complex behavior. Two different behavioral responses of brook trout Salvelinus fontinalis to sublethal exposure to DDT implicate the CNS as the target site. The first is represented by changes in the low temperature (cold-block temperature) which is just sufficient to extinguish the propeller tail reflex (4). The spinal cord is the site for this cold blockage (5). The second response involves visual conditioning of an avoidance response that is formed in the optic tectum (6). The fish ranged from 6 months to 2 years old. They were fed DDT-free beef liver once daily. To minimize the amount of detritus present, the fish were not fed for 3 days prior to and during the period of treatment. All DDT exposures were for 24 hours and were carried out in 6 liters of continuously-aerated water at the acclimation temperature in glass jars, one fish per jar (7). The DDT was always added to the water in 0.3 ml of acetone. Control fish were treated the same as were experimental ones, except that no DDT was dissolved in the acetone. The fish were tested in clean water, and, unless otherwise specified, each experiment 9(0), .£ 4 3 ° 2 I - | 3(38 ) 40 60 DDT concentration (ppb) Fig. 1. The effect of acclimation temperature and exposure to DDT on the coldblock temperature of the propeller tail reflex in the brook trout. The numbers refer to the total number of fish tested and (in parentheses) the percentage which failed to block down to the lowest temperature obtainable, 1°C±S.E, also shown. Solid line, fish acclimated at 9°C; broken line, fish acclimated at 18°C. SCIENCE, VOL. 164 �began immediately after the 24-hour ^sposure to DDT. Cold-block temperature was determined as described (5), except that our stimulus was a 10 msec train of square wave pulses (1 msec and approximately 10 volts each at a rate of 400 per second). As expected, for control fish acclimated at 18.0°C, the cold-block temperature was significantly higher than for the ones acclimated at 9.0°C (Fig. 1). Treatment with DDT also altered the cold-block temperature. The response of DDT-treated fish acclimated at 9.0°C was not quite the same as that of those acclimated at 18.0°C (Fig. 1). The difference, however, may be more apparent than real. The lowest temperature obtainable with our apparatus was l°C and not only did many fish acclimated at 9 d C fail to block, but also, for those fish that did block, the blocking temperature was about 1°C. If much lower temperatures had been possible, the response of fish acclimated at 9°C might have differed. To say that DDT can alter the coldblock temperature just as can thermal acclimation, may be more than a convenient analogy. Sublethal concentrations of DDT, like thermal acclimation, shift the selected temperature of brook trout (and other salmonids) (2). Low doses lower the selected temperature; higher doses raise it in a pattern very similar to that shown in Fig. 1 for the cold-block temperatures of fish acclimated at 18°C. The DDT may be interfering somehow with the thermal -acclimation mechanism. This would be consistent with our hypothesis that DDT acts upon central nervous structures because changes in selected temperature are thought to be controlled by the CNS (8). The effect of DDT on a nervous function more complex than the propeller tail reflex was investigated by exposing trout acclimated at 9°C to 20 parts per billion of DDT and then comparing their ability to learn a simple conditioned avoidance response with the ability of untreated fish. Brook trout have an individual preference for either the lighted or darkened side of a two-chambered aquarium. We trained our trout to avoid the side of their preference. The nonpreferred lighting was the conditioning stimulus; electric shock was the unconditioned stimulus. Fish were consid25 APRTL 1969 Table 1. The response of fish during the establishment of the conditioned avoidance response. The "avoidance" response is the one used for the training criterion. The fish tested at various .times after DDT exposure were all different fish and had not previously been tested. Day Pish tested (No.) A e Missest Escapest <%) ( o) 13.0 S (No.) 52.0 35.0 0.0 2.9 7.8 Avoidances§ (%) Untreated 12 30.3 DDT-treated 1 4 7 6 6 6 >25 94.0 6.0 >28.3 >29.5 52.0 43.0 45.1 49.2 * Trials per fish until trained to .avoid preferred side. t Failures to leave the initially preferred side of a two-chambered aquarium during the electric shock period. Misses typically occurred early in the training session. I Successful exit during the electric shock period. § Departure after lighting change but before the electric shock. ercd to be conditioned when they showed eight consecutive proper avoidances. The apparatus and method of training were similar to that used by Roots and Prosser (5). Although untreated naive fish took only about 30 trials to become conditioned, not one of the DDT-treated naive fish became conditioned (Table 1). Training was discontinued after approximately 25 trials because by this time, after almost 6 minutes of intermittent electric shock, the fish had become refractory and were sitting on the bottom, often at an angle, failing to exhibit any overt response to the shock. The duration of the DDT effect was investigated by testing the response of naive fish 4 and 7 days after DDT exposure. These fish showed some improvement in performance. Fewer misses and more escapes and avoidances were observed. However, the improvement was at best slight, for it did not appear that the fish would ever show the required eight consecutive avoidances. Even after 7 days, no fish showed even two consecutive avoidances. Evidently, DDT treatment reduces the ability of fish to form an association between the connecting doorway and escape from shock. There was no apparent impairment in either the swimming or visual abilities of the fish. The effect of DDT treatment on the retention of the conditioned avoidance response was determined by comparing the number of trials initially required to attain full conditioning with the number required for the same fish when tested 24 hours later. Six fish served as controls and six as experimcntals. The second performance of control fish was enhanced by the previous training, the difference between the initial 32.7 ± 3.04 (S.E.) trials and the subsequent 11.2 ± 1.20. trials being significant (P < .005). The fish exposed to DDT required 27.8 ± 1.80 trials before treatment and 24.2 ± 1.80 trials after treatment. The difference is not significant (P > 0.5). It is as if the DDT treatment had converted the previously-trained fish into naive ones. Yet, clearly something has been retained by these fish, for if they had not had the training session prior to the DDT exposure, then, as shown in Table 1, they would not have been able to learn at all. JOHN M. ANDERSON* MARGARET R. PETERSON! Department of Biology, Carleton University, Ottawa, Canada References and Notes 1. D. M. Osilvie and J. M. Anderson, J. Fisheries Res. Board Canada 22, 503 (1965); R. E. Warner, K. K. Peterson, L. Bergman, /. Appl. Ecol. 3 (Suppl.), 223 (1966); R. E. Warner, World Health Organ. Butt. 36, 181 (1967); L. F. Stickel, Report on the Unintended Occurrence of Pesticides in the Environment Sponsored by O.E.C.D, and Development and Natural Environment Council of the United Kingdom (Patuxcnt Wildlife Research Center, Laurel, Maryland, 1967). 2. M. Y. Javaid, thesis, Carleton University, Ottawa (1967). 3. J. M. Anderson, J. Fisheries Res. Board Canada 25, 2677 (1968). 4. This reflex, first described by von Hoist, [Z. Vergl. Physiol. 20, 582 (1934)], consists of a weak propeller-like movement of the tail in response to electric stimulation of the gular region. 5. B. I. Roots and C. L. Prosser, /. Exp. Biol. 39, 617 (1962). 6. F. K. Sanders, ibid. 17, 416 (1940). 7. The DDT was a technical mixture consisting of 80 percent 1, 1, l-trichloro-2,2-bis(p-chlorophenyl) ethane and 20 percent 1, 1, 1-trichloro2-(o-chlorophenyl)-2-(p-chlorophenyl) ethane obtained from Fisher Scientific Company as Reagent Grade. 8. K. C. Fisher, in Physiological Adaptation, C. L. Prosser, Ed. (American Physiological Society, Washington, 1958), p. 3. 9. Supported by grants from Fisheries Research Board of Canada and National Research Council of Canada. * Present address: Fisheries Research Board of Canada Biological Station, St. Andrews, New Brunswick, t Present address: Department of Physiology and Biophysics, University of Illinois, Urbana, 61801. 23 January 1969 441 �Circadian Rhythm of Serotonin in the Pineal Body of Immunosympathectomized Immature Rats Abstract. In the pineal body of the immature rat the circadian rhythm of serotonin persists when sympathetic innervation is abolished by the administration of nerve growth factor antiserum. This rhythm is regulated by a mechanism that does not involve the sympathetic innervation and is, therefore, fundamentally different from that in the adult. In the past 10 years major advances in our knowledge of pineal physiology have been established. Compounds within the pineal body have been identified and their levels measured. Many of them have been shown to have a circadian rhythm that is dependent upon environmental lighting mediated through the retina and the sympathetic nervous system (7). Serotonin is one of these compounds. In the rat pineal it exists in high titers (2) and has a circadian rhythm in which levels are lowest 4 hours after the onset of darkness and highest 6 to 8 hours after the onset of light (3). Sympathetic postganglionic fibers from the superior cervical ganglion (4) regulate the rhythm. After bilateral superior cervical ganglionectomy or severance of preganglionic fibers the cycling of serotonin in the pineal body is abolished (5, 6). Although this role of the sympathetics has been confirmed in the adult rat, the following observations suggest that pineal serotonin may not be regulated through sympathetic innervation in the immature animal. As early as 6 days postpartum the circadian rhythm of serotonin is present (7), but at this age there is a sparsity of intrapineal sympathetic nerve fibers ( 8 ) . To learn the significance of this apparently inadequate innervation we undertook the study, described in this report, of serotonin levels in totally denervated pineals in young rats. Because of stress and mortality after superior cervical ganglionectomy, we chose to den3rvate the pineal by immunosympathectomy (9). Holtzman rats of both sexes were given bovine nerve growth factor antiserum (NGFA) (10) within 6 hours after birth and again 24 hours later. Experimental and control animals were maintained together in a controlled environment. The temperature was 19° ± 1°C, and fluorescent lights were kept on from 5:00 a.m. to 7:00 p.m., that is, a cycle of 14 hours of light and 10 hours of darkness. Animals were decapitated at either 8 or 20 days of age—one group at 1:00 p.m. and another at 11:00 p.m. Pineals were dissected quickly, weighed on saline-moistened filter paper on a Roller Smith torsion balance, homogenized in groups of two in 0.5 ml of 0.1 N HO and 0.5 percent ascorbic acid, and refrigerated. Within 24 hours serotonin was assayed on a Farrand spectrofluorometer (model No. 104244B) according to the method of Quay (11). Since fluorescence microscopy reveals the extent of sympathetic nerve suppression Table 1. Serotonin levels in the pineals of normal and immunosympathcctomizcd young rats. Each group contained 10 or 12 animals. There is no significant difference between pineal weights of groups in each of the four treatment categories. N.S., not significant. Treatment Pineal weight (nig) Serotonin (ng/pineal) Significance of difference Groups Level Rats 8 days old None Day* 'Nightt Night-lighted NGFA (1100 unit g-* day-1) Day Night Night-lighted 0.470 ± 0.035 .502 ± .022 .410 ± .013 30.5 ± 2.20 13.3 ±1.60 23.1 ± 1.50 Day: night Day:night-lighted Night : night-lighted .001 .473 ± .015 .527 ± .030 .483 ± .017 29.6 ± 1.63 10.0 ± 2.33 14.5 ± 2.78 Day:night Day:night-lighted Night: night-lighted .001 .001 N.S. .02 .01 Rats 20 days old None Day Night NGFA (600 unit g-1 day-1) Day Night * Day, 1:00 p.m. 442 0.586 ± 0.039 .632 ± .037 54.5 ± 4.59 13.5 + 4.12 Day: night ,001 .549 ± .031 .550 ± .034 61.0 ± 3.52 19.0 ± 1.81 Day: night .001 t Night, 11 p.m. (12), a sample of pineal bodies frojoj. each group of treated animals was examined by this method. In addition, stretch preparations of the iris of all the 20-day-old animals used in the experiment were examined by fluorescence microscopy. In normal control pineals (from animals 8 and 20 days old), the sympathetic innervation was present and similar to that described elsewhere (8). In animals injected with NGFA (600 unit/g) there was no nerve fluorescence in the iris preparations, and although denervation of the pineal was almost complete, occasionally a few scattered fibers remained. When the dosage was increased to 1100 unit/g, pineal nerve fluorescence was abolished. Prolonging the light period into the normal dark period prevents the nocturnal fall in pineal serotonin in both adult and immature animals (6, 7). To clarify the role of sympathetics in the immature rat, it was important to determine whether prolonged lighting would modify the amount of serotonin in denervated pineals. Thus on the day the animals were killed a third group was given four additional hours of lighting, that is lights remained on until 11:00 p.m., the time they were killed. Results in Table 1 show that at both 8 and 20 days of age there is a circadian rhythm in rat pineal serotonin and that after immunosympathectomy the rhythm persists unchanged. Thus its regulation must be through a mechanism fundamentally different from that in the adult. la the adult, central nervous system stimuli that regulate serotonin levels reach the pineal via sympathetic fibers (5). Since rhythm persists in the young animal after denervation, it seems reasonable to speculate that in the immature rat the rhythm is intrinsic to the pineal itself. However, the origin and nature of its regulator remains unknown. An endocrine influence in immature rats has not been studied, but in the adult, removal of endocrine organs does not modify pineal serotonin rhythm (6). The results of Table 1 also show that in sympathectomized animals additional lighting did not elevate serotonin levels above the nocturnal low. From the first observation—that serotonin rhythm persists in the absence of sympathetics— one might presume that innervation has no regulatory function on serotonin metabolism in the young rat. However, since additional lighting prevents the nocturnal fall in serotonin in intact SCIENCE, VOL. 164 � Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 047 Folder The folder containing the original item. 1187 Series The series number of the original item. Series III Subseries I Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Anderson, John M. Margaret R. Peterson Source A related resource from which the described resource is derived Science Date A point or period of time associated with an event in the lifecycle of the resource April 25 1969 Title A name given to the resource DDT: Sublethal Effects on Brook Trout Nervous System Subject The topic of the resource aquatic animals health effects pesticide toxicology fish population ao_seriesIII https://www.nal.usda.gov/exhibits/speccoll/files/original/705d330b601bd6f010265578c4d03efa.pdf b4e95d1fe9cf25954eae9a55134fb242 PDF Text Text Item ID Number ones Bababunmi, Enitan A. Corporate Author Report/Article TltlB Toxins and Carcinogens in the Environment: An Observation in the Tropics JOUmal/BoOk TltlO Journal of Toxicology and Environmental Health Year Month/Day Color D Number of Images 9 DOSCrlptOn NotOS ^'vin ^- Young filed this item under the category "DDT/Human Toxicology and Environmental Fate" Wednesday, April 11, 2001 Page 1188 of 1242 �TOXINS AND CARCINOGENS IN THE ENVIRONMENT: AN OBSERVATION IN THE TROPICS Department of Biochemistry, School of Medicine, University of Ibadari, Ibadan, Nigeria The incidence of primary liver cancer in the countries of tropical Africa is the highest in the world. There, is a growing belief that the relatively high prevalence of hepatocellular carcinoma in Niyeria may have a multiple chemical factor etiology in such forms as food contaminants, herbal leas, and environmental chemicals. Major chemical toxins and carcinogens that have been identified so far in the tropical environment include supotoxin, cycasin, mushroom toxin, capsaicin, oxalic acid, prussic acid, fluotooleic acid, N-nitroso compounds, aflatoxin, palmotoxin, pyrrolizidine alkaloids, quinine, DOT, and eye/ornate. INTRODUCTION During the past two decades, there has been an increasing awareness of the hazards to human and animal health from various chemical substances Jthat occur in the tropical environment. There is evidence to indicate that azarious health problems, including some forms of cancer, have their origin in the presence of toxic chemicals in medicines, herbal residues, pesticides, foods, and drinks. Some of these problems are common to countries throughout the world, while others are peculiar to Africans who live in the tropics. For example, altogether the incidence of primary liver cancer in adult males is • the highest in the world in African countries such as Nigeria, Uganda, and Mo/ambique (IARC, 1971). The primary objective of the present review is to focus attention on the presence of toxic chemicals in foods and in the environment of tropical African countries, particularly Nigeria, which is the most populous country in Africa. Some of these toxins have been shown to possess carcinogenic (or mutagenic) properties in various biological systems. However; in a large number of cases, adverse effects of some of these toxic substances on human health are not known. It is hoped that this paper will have the important effects of stimulating more research into the special toxicological problems that arc of concern to people living in the tropics. This article was written during the author's tenure as an ICRCTT Fellow of UICC (1977) at the Department of Biochemistry and King's College, University of Cambridge, Cambridge, [England. Requests for reprints should he sent to fcnitan A. Bababunmi, Department of Biochemistry, School'of Medicine, University of Ibadan, Ibadan, Nigeria. 691 journal oi Toxicology and Environmental Health, 4:691-699,1978 Copyright © 1978 by Hemisphere Publishing Corporation 0098-4108/78/040691-09$2.25 �692 E. A. BABABUNMI ENDOGENOUS FOOD TOXINS Endogenous food toxicily is widespread in tropical Africa. Nicholls ct al. (1961) dealt with the various types.of tropical foods that carry toxins. The review of Crampton and Charlcsworth (1975) adequately covers the occurrence of food toxins in the nontropical world. Hypoglycin This toxin is contained in the unripe fruit of the food plant, Blighia sapida. In Nigeria the fruit is called isin, whereas it is commonly known as ak.ee in Jamaica. There are two types of this toxin, A and B. Although both types are biologically active, the A type (/J-mcthylenecyclopropylalaninej is the more toxic. Very little work has been done on the chemistry and the biological function of the B type. Dioscorine This toxic chemical is sometimes referred to simply as dioscorea toxin; it is an alkaloid that is present in Dioscorea hispida. The main toxic species of these tropical yams of West Africa are D. hispida, D. dumctorum, D. sansibarensis, and D. bulbifem. Since the isolation and identification of the related alkaloid dehydrodioscorine by Bevan and H.rst (1958), scientists have not looked into the existence of these or other structures in the other species of the wild yams. Sapotoxin Some tropical foodstuffs such as soybean, breadfruit, tomato, melon, orange, and groundnut contain some sapotoxin, which, at high concentrations, has drastic effects on humans. The toxin can cause gastroenteritis and produce paralysis of the nerve centers. Sapotoxin is a nitrogen-free glycosidc. Cycasin Cycasin occurs in plants of the family Cycadaceae, which are indigenous to tropical and subtropical regions (IARC, 1972). The biologically active moiety of cycasin is the aglycone melhyla/oxymelhanol. Cycad seeds are used as medicine in some parts of Africa, Indochina, and India. Feeding of a cycad diet has been shown to induce malignant tumors of the liver in the rat, mouse, hamster, fish, and guinea pig (IARC, 1972). Mushroom Toxin A large number of mushroom species are edible, but certain species that arc eaten in the tropics are poisonous. Examples of toxins elaborated by these species are agaritine (Ayaric'us bisporus toxin) and champigeon (A. hortemis toxin). Muscarine and Amanita phalloictes toxin have been reported to be toxic by Nicholls el al. (1961). �TOXINS AND CARCINOGENS IN THE TROPICS 693 Names for different species of mushrooms are descriptive in many pails of I he tropics. In the western state of Nigeria, these names give an indication either of the habitat, morphology, and texture or of the growth habitat of the fungi (Oso, 1975). Corprinus ephemerus, a fungus that grows on dunghills, appears at night or early in the morning, and within a very short time the pilcus is fully expanded. However, it deliquesces in the sun. It is considered poisonous by the Yoruba people of Nigeria, and local doctors use it in the preparation of some (harms. (Extracts of the fungus should be tested for mutagenicity. Capsaicin (Red Pepper Toxin) The substance is the active principle of the plants Capsicum annum and C. frutescens. It is a powerful irritant and a skin blister. Although these plants are rich in vitamin C, excessive feeding on them can be dangerous. Species of pepper such as Piper nigrum contain alkaloids and volatile oils that are toxic to both animals and humans. Halogeton Toxin (Oxalic Acid) Plant species such as Halogelon ylomeritus, Celosia argentae, Amaranthus candatus, Celosia laxa, and Talinum are used as food in tropical Africa, especially on the west coast. These vegetables contain significant levels of oxalic acid (Oke, 1967). There are conflicting data on the lethal dose for humans. However, Oke showed that an average healthy Nigerian would consume about 6 g of oxalic acid daily, on the basis that 50 g of fresh vegetables could be consumed at a meal. Cyanogen (Prussic Acid) Tropical plants, cassava, mai/ie, and sugar cane are good sources of cyanogenetic glycosides such as linamarin and dhurrin. Cassava (manioc; Man/hot ulilissima} is the most widely grown of all tropical root crops. It is mainly a carbohydrate food with a very low protein content. In West Africa, manioc flour (gari). has become a major diet. In the West Indies the dried flour is called farina. All over the tropics it is used as food for the young and adults in one form or another. The en/yme linasc liberates prussic acid (HCN) from linamarin. HCN is toxic to many species of animals, including humans. The production of HCN varies with the variety of the plant and the conditions of cultivation (Osuntokun et a!., 1969). Although significant amounts of HCN arc said to occur only in the bitter variety of cassava, there is in fact no clear differentiation between the sweet and hitler strains. The fact that the cortex of the root contains the highest concentrations of the toxin provides biological protection for the plant against invading insects. Chronic cyanide intoxication by laboratory animals has resulted in neural damage in the guinea pig, rabbit, sheep, and cat. �694 E. A. BABABUNMI Fluoruoleic Acid The seeds of the West African plant Dichapctalum toxicarum contain fluoroeleic acid and some minute amounts of shorter-chained fluoro acids. These fluoro compounds arc toxic.'Local, doctors in the countries of West: Africa often administer the seed extracts in an attempt to produce loss of motor activity, loss of sensation, and sometimes death (Peters el al., I960). Free oleic acid uncouples oxidative phosphorylation (Pressman and Lardy, 1956). /V-Nitroso Compounds .Dimclhylnilrosaminc (DMN) and diethylnilrosamine (DEN) have been detected in measurable quantities in several alcoholic beverages in Nigeria (joaquim, 1973). Bababunmi et al. (1977) reviewed the extent of contamination of these drinks by the two carcinogens. There is some evidence that the formation of these nil.rosamines involves bacterial action. FUNGAL TOXIC CONTAMINANTS Fungus-infected foodstuffs are the cause of many types of food poisoning (see Kadis et al., 1972). In the tropics, a Variety of fungal species have been reported to be involved in some toxicity syndromes. Notable examples are Asperyi/lus, Penicil/ium, Stachybotrys, Trichoderma, f-'usarium, Pseudomonas, and .Helminthosporiurn species. The most ubiquitous in Nigeria are Aspergillus and Pcnicillium. Many strains of each of these fungi are toxigenic. Among the common toxic metabolites of the aspergilli arc aspergillic acid, flavacol, j3-nilropropionic acid, kojic acid, sterigrnatocystin, ochratoxin, aspet toxin, aflaloxin, and palmotoxin. Penicillium elaborates the mycotoxins patulin, islandiloxjn, lutcoskyrin, rugulosin, cifrinin, frcquentic acid (citreomycctin), gliotoxin, costaclavine, and citreviridin. Of these, aflatoxin has been studied most extensively, mainly because of its potent carcinogenic properties. A comctabolile of aflaloxin, palmotoxin, has been the subject of investigation for some years in this laboratory. Many other naturally occurring toxins (Table 1) that are known should be tested for carcinogenictty. Aflatoxin The literature on the biochemistry, toxicity, carcinogenicity, and mutagenicity of aflatoxin is enormous (Goldblatt, 1969; Wogan, 1975a, 1975b; IRAC, 1976), The discovery of aflatoxin in the tropics (Asplin and Carnagnan, 1961) as a contaminant of human and animal foodstuffs (groundnuts) aroused the interest of scientists all over the world because of i t . health ha/aids and possible economic effects on the producers of these foods. Nigeria is one .of the world's major exporters of groundnuts. Other tropical foods that arc vectors of aflatoxin are beans, corn, rice, cocoa, and wheat. �TOXINS AND CARCINQGtNS IN lilt. TROPICS 695 TABLE 1. Sonic Known Naturally Occurring Toxins Toxic sulislance Occurrence in l-'usaric acid Fiisariuni oxysp oiium Pcriconin T toxin llclminthosporo'sidc Tabtoxin Javanicin Pcriconia circ'inatu 1 lei min tli ospvrium may dis Hvlniitithosporium sqcchari Pseudomonus coronal aciens f-'usarium solan! Possible human exposure through Tomato, sorghum, maize Sorghum Maize Sugarcane Tobacco Maize Aspergillus flavus, the main source of aflatoxin, is common in air and soil, It will grow on agricultural products and food materials in a favorable environment with a relative humidity of 70-90% and a minimum temperature of about 10°C. In general, the growth of A. flavus can be correlated with the production of aflatoxin except at high temperatures, 40-50°C. !n different regions of Muranga in Kenya (Hast Africa), mean aflaloxin levels of about 0.25 ppm in food and 0.1 mg/l in beer have been detected (IARC, 1972). When common food preparations of Nigeria's principal food crops were sampled from local market stalls and assessed for aflatoxin contamination by conventional techniques, the aflatoxin content was not less than 0.5 ppm in any of the foods (Bababunmi, 1976). Several industrialized countries such as the United States, Denmark, Britain, and Italy consider a level of aflatoxin of the order of 0.25 ppm as dangerous and the contaminated food as unconsumable. Although the proportional contribution of agriculture to the Nigerian economy continues to fall, it will continue to be the single most important sector in the economy for a long time (Aboyadc, 1971). The export value of cocoa ranks second to that of oil in Nigeria. In 1974, Nigeria's foreign trade was $3.462 billion. If oil accounted for 80% of the export value in the 1974-1975 fiscal year, other export products such as cocoa, groundnuts, and palm products should account for about $700 million. Therefore, if aflatoxin contamination in this class of export commodities is not eliminated, Nigeria's foreign reserves may diminish continuously. Palmotoxin Isolation of two additional fluorescent toxins from cultures of A. flavus on unfcrmcnled palm sap (a common West African wine) obtained from a variety of Elacis yuineensis was reported by Bassir and Adekunle (1968). Toxicity titrations of pal rnolox iris B 0 and G0 on 6-d-old White Rock chick embryos indicated that B 0 is as toxic as aflatoxin B t . Recent results of Uwaifo ct al. (1977) suggest that the structures of the palmotoxins could be hetetocyclic and may be similar to those of the aflatoxin family (Asao et al., 1965). Comparative mulagenicily studies by �696 E. A. BABABUNMI Uwaifo el v.al. (1978) show that palrnotoxin B() induces microlesions thai consist of point mutations, in Ames' tester strains of Salmonella typhimurium. However, the ratio of the mutagcnicity of aflatoxin fi, to that of palmotoxin B0 is about 6:1. In Nigeria and several developing African countries, several facilities and preservation techniques for agricultural products are quite inadequate. The combination of this unfortunate situation, the natural warm and moist weather, a dirty environment, human error, and ignorance is conducive to the growth of A. f/avus and consequently to the elaboration of mycotoxins (such as aflatoxin and palrnotoxin) on agricultural commodities. It seems to me, therefore, that the problems associated with mycotoxin contamination of food and agricultural products will remain in the developing tropical regions of the world for some time, at least.in the foreseeable future, unless very drastic control measures a' - c initialed. HERBAL RESIDUES For years, herbalists and local doctors in tropical Africa have used herbs and their concoctions to treat various human diseases (Dal/.iel, 1948). In modern times, countries such as Nigeria and Ghana have intensified their search for authentic medicinal plants ;ind their active principles. Apart from their use as local medicines, many toxic plant species are used as food in many parts of West Africa. Many chemical compounds have been isolated from useful plants of West Africa and characteri/cd in their pure forms. In this respect, scientists in the Department of Chemistry of the University of Ibadan have contributed immensely to the knowledge of the chemistry of active principles in plants. Toxicological and other biological studies of these chemicals are, however, scanty. Miller and Miller (1976) staled that the plant genera Crotolaria, Senecio, Laburnum, and Heliotropium have long been known to contain carcinogenic substances (IARC, 1976), some of which arc pyrroli/idine alkaloids. •; • FOREIGN TOXIC CHEMICALS Environmental toxins of this class exist in such forms as medicines, pesticides, and food additives. With the gradual emergence of some tropical African countries (for example, Nigeria) from the underdeveloped to the developing slate, environmental pollution and the presence of industrial materials such as those used in the processing and packaging of foods are potential sources of toxins. Common examples in this calegory are ioni/ing radiation, plastici/ers, adhesives, paraffins, printing inks, and irea'cd papers. Well-rccogni/.cd environmental toxic (or carcinogenic) chei lical substances in this tropical area of the world include quinine (antirnalarial drug), DDT (insecticide), and cyclarnate (food additive). �TOXINS AND CARCINOGENS IN THt TROPICS 697 Quinine Malaria is a disease that occurs throughout the tropical and subtropical countries. It is actually a group of diseases characterized by recurrent attacks of fever, anemia, and enlargement of the spleen. Malaria can also occur in temperate climates if the environmental temperature is right for the protozoan species (e.g., Plasmodium falciparum) to complete their life cycle in the female Anopheles mosquitoes. The parasite lives in the red blood cells. There are three forms of the malaria parasite in humans corresponding to malignant tertian, benign tertian, and quartan malaria. In the tropics the most common malaria is the malignant tertian, although the other two varieties have been identified in a very few cases. Chloroquinc, mcpacrine, and quinine arc drugs that are very effective in rapidly destroying the parasite in the blood. Chloroquinc (Nivaquine) is the most widely used antimalarial drug and has been reported to be the safest. Mcpacrine (Atebrin) can be given only intramuscularly and is not often used. Quinine is the oldest of all the antimalarial medicines. It is also the quickest acting. For many years quinine was the only drug available for the treatment of malaria. Although quinine has some toxic side effects, it is still used, especially for cases that are resistant to other drugs. Quinine was the first alkaloid isolated from the bark of the Cinchona tree. A single oral dose of about 8 g is regarded as fatal for an adult man. Quinine poisoning usually results in nausea, headache, visual disturbances, nervous system and cardiovascular system disorders, and respiratory arrest. DDT The insecticidal properties of DDT are well known (IARC, 1974). This compound has been extensively used as an insecticide and produced commercially for this purpose since 1943, when a low-cost production technique was developed. It has been widely used for the control of numerous insect pests—for example, as a mosquito larvicide and as a residual spray for eradicating malaria in the tropics. DDT is distributed by the World Health Organi/ation throughout the world for the prevention of yellow fever, sleeping sickness, and malaria. Apart from these uses, quantities of DDT are used for the treatment of peppers, onions, soybeans, groundnuts, cowpeas, and sweet potatoes, in storage. Tropical countries such as the Upper Volta and Ghana use at least 500 kg of DDT annually for agricultural purposes. In 1973, research on the environmental effects of pesticides in the tropics was carried out at the International Institute for Tropical Agriculture (IITA), Ibadan. The study was concerned with the effects of DDT (used as a crop protector) on the fertility of agricultural soil. Cowpca (Vigna unyuiculata var. Prima), which is a high-yielding legume, was selected in the IITA study because it requires regular pesticide applications and also because of its growing �698 C. A. BABABUNMI importance in tropical agriculture. Since 1970, DDT has been restricted to uses other than on human and animal foodstuffs in the more advanced countries. The hepatocarcinogenicity of DDT on oral administration has been amply demonstrated in several strains of mice. Liver cell tumors were produced in both male and female mice, and an increased tumor incidence was reported in some other organs. The most frequent tumor types were leukemia, rcticulum cell sarcoma, carcinoma of the lungs, and hemangioendothclioma (IARC, 1974). Cyclamate Calcium cyclamate (cyclohexylsulfamic acid calcium salt) is still used as a nonnutritivc sweetener in a large number of soft drinks in many African countries. The use of cyclamic acid as a sweetener has been banned in several industrialized' countries because the compound was suspected of being a bladder carcinogen in the rat. CONCLUSION Apart from foods, beverages, and medicines, there are other sources of potential toxins and carcinogens that are introduced by humans into the tropical environment, especially in the cities, in such forms as narcotics and atmospheric pollutants. With the arrival of various industries in big African cities, inhalation of dust, vapors, and exhausts presents a new form of danger. Epidemiologic appraisal of these factors is lacking. There is a need to estimate the total load of toxins and carcinogens in the tropical environment. REFERENCES Aboyadc, O. 1971. Nigeria's economy. In Africa South of the Sahara, 1st ed., pp. 558-563. London: Luropa. Asao, T., Buchi, G., Abdel-Kader, M. M., Chang, S. 13., Wick, E. I . and Wogan, G. N. 1965. The ., structures of aflaloxins B and G,. ]. Am. Chum. Soi: 87:882-886. Asplin, [-". D. and Carnaghan, K. 13. A. 1961. The toxicity o\ certain groundnut meals for poultry with special reference to their effect on ducklings and chickens. Vet. Kec. 73:1215-1219. Bababunrni, Li. A. 1976. Excretion of af'latoxin in the urine of normal individuals and patients with liver diseases in Ibadan (Nigeria). In Di'tuclifin and 1'revcnt/on of Cancer, ed. H. E. Nieburgs. New York: Ueker. Babdbunni, L:. A., Uwaifo, A. O., and Bassir, O. 1977. Hepatocarcinogeris in Nigerian foodstuffs. World Rev. Nutr. Did 28: article 44. Bassir, O. and Adckunle, A. A. 1968. Two new metabolites of Aspcnjillus lluvus (Link). FF.BS Lett. 2:23-25. Bevan, C, W. 1.. and Hirst, ). 1958. A convulsuil alkaloid of Dioscoreu dunu'torurn.' Chcm. Ind, 4: 103. . Crampton, K. l:. and Charlesworlh, I . A. 1975. Occurrence of natural toxins in food. Or. Mvd. B II. 31:209-213. Dal/:iel J. M. 1948. Useful plants of west tropical Africa. In i-loia of West Tropical Africa, cds. J. hutchinson and J. M. Dal/iel. London: Crown Agents for the Colonies. �TOXINS AND CARCINOGENS IN Tilt TROPICS 699 Goldblalt, L A. 1969. Allatoxln. New Yoik: Academic Press. IARC. 1971. Liver Cancer. Sci. I'ubl. no. I. l.yon: International Agency for Research on Cancer. IARC. 1972. Evaluation of Carcinogenic Risk of Chemicals to Man, vol. 1. Lyon: International Agency for Research on Cancer. IARC. 1974. Chemical Carcinogencsis l.'ssays. Sci. Publ, no. 10. Lyon; International Agency for Research on Cancer. IARC. 1976. Evaluation of Carcinogenic Risk of Chemical* to Man, vol. 10. Lyon: International Agency lor Research on Cancer. Joaquim, K. .1973. Nilrosamine contamination of some Nigerian beverages. Ph.D. thesis, Ibadan University. Kadis, $., Ciegler, A., and Ajl, S. J. 1972. In Microbkil Toxins: A Comprehensive Treatise, vol. 8, Fungal Toxins. New York: Academic Press. Miller, j. A. and Miller, !"..• C. 1976. Carcinogens occurring naturally in foods. Fed. Proc. 35:1316-1321. Nicholls, L., Sinclair, H. M., and Jelliffe, D. B. 1961. Tropical Nutrition and Dietetics. London: Bailliere, Tindall & Cox. Oke, O. L. 1967. Oxalic acid in plants and in nutrition. World Rev. Nutr. Diet. 8:262-303. Oso, B. A. 1975. Mushrooms and the Yoruba people of Nigeria. Mycologia 67:311-319. Osuntokun, B. O., Monekosso, G. L., and Wilson, J. 1969. Cassava diet and a chronic degenerative neuropathy. An epidemiological study. Niger, j. Sci. 3:3-15. Peters, R. A., Hall, R. J., Ward, P. l:. V., and Sheppard, N. 1960. The chemical nature of the toxic compounds containing fluorine in the seeds of Dkhapelalum toxicarium. Biochcm. J. 77:17-23, Pressman, B. C. and Lardy, II. A. 1956. Effect of surface active agents on the latent ATP-asc of mitochondria. Biochim. B/ophys. Ada 21:458-466. Uwaifo, A. O., Emcrolu, C. O., and Bassir, O. 1977. Comparative study of the fluorescent characteristics ol solutions of aflatoxins and palmotoxins in chloroform. /. Agric. Food Chem. 25:1218-1220. Uwaifo, A. O., Emcrolc, G. O., Bababunrni, E. A., and Bassir, O. 1978. Comparative rnutagcnicity of palmotoxin U0 and aflatoxin B,. In press. Wogan, G. N. I975a. Mycotoxins. Annii. Rev. Pliarmacol. 15:437-451. Wogan, G. N. 1975b. Dietary lactors and special epidemiological situations of. liver cancer in Thailand and Africa. Cancer Rex. 35:3499-3502. Received March 12, 1978 Accepted April 3, 1978 � Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 047 Folder The folder containing the original item. 1188 Series The series number of the original item. Series III Subseries I Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Bababunmi, Enitan A. Source A related resource from which the described resource is derived Journal of Toxicology and Environmental Health Date A point or period of time associated with an event in the lifecycle of the resource 1978 Title A name given to the resource Toxins and Carcinogens in the Environment: An Observation in the Tropics Subject The topic of the resource heath effects pesticide toxicology ao_seriesIII https://www.nal.usda.gov/exhibits/speccoll/files/original/e62a4e950c53cf75d3fab44903cf304f.pdf 799a41ec4843b6b02e8a48c6744dca19 PDF Text Text Item ID Number on 89 Author Braun, Daniel C. Corporate Author Report/Article TitlB Establishing Environmental Criteria JOIirnal/BOOk Title Archives of Environmental Health Year ™™ Month/Day September Color n Number of Images 3 DOSCriptOll NOtOS ^'v'n *-• Young filed this Item under the category "DDT/Human Toxicology and Environmental Fate" Heading: Pollution Medical Research Conference. Wednesday, April 11, 2001 Page 1189 of 1242 �lution Medical Research Conferefee Establishing j/ Environmental Qrtteria 1 Medical Perspectives , MD; reasonable Nosuggestisthatperson todayofwould pollution the environment not a serious problem, one which demands the application of all the intelligent, scientific, and technical effort we can muster—and can afford. Physicians are aware of this. Industrialists, for the most part, are aware of it. Scientists from a number of disciplines are working diligently to define the problems and to find solutions. Unfortunately, the greatest deterrent to sound progress at present comes from those who engage in unscientific exaggerations while demanding instant results. All sorts of dire predictions are being made by all sorts of people, but those most frightening with respect to health are being made by persons who are not physicians. In their importance to humanity, the possible effects of pollution on health far outweigh aspects of aesthetics or comfort. Health is the Submitted for publication Dec 6, 197% accepted M««h 19,1978. From the Industrial Health Foundation, Inc., PJUfburgh. Mr. tJurgiel it now with Byckman Edgerley Tomiinfon * Awociatew, 8t Loufe. Road before t)te Air Pollution Medical Research Conference of the American Medical A> •ocietion, Chicago, Oct a, 1972, • . |^|^ntr»a«eit« to Induitriil Health Paunda. Won, Inc., 58$1 Centre Av», ntt*b,ur0h, PA if. 0raun)i '-—-,.: iron HMlth/Vol 27, Sept 1973 realm of physicians, and so it is important for physicians to know what substances in the environment are hazardous to health, or potentially so. A major problem is that zealots are calling some situations health hazards when they are in fact merely nuisances, because this makes the sequences dire. Sometimes this is done out of ignorance of the significance of dose-response relationships. Beyond all others, physicians are aware of such relationships; they know that for every substance a certain dosage level is needed to produce an expected response. Because health is the most important concern in community contamination, and because the doctor it best able to understand the physiological response to various levels of contaminanta, the physician should play a more important role in public information about and community rosponse to pollution control. Contaminant* emitted into the atniosphere arise from maty ******** Sorn^ result from communiiy operations, such at garbage diapoaal and incineration. Agricultural burninf, fertilising, and insect-control account tor tome, and still other* have their origin in industrial proceaM* <* &• jjjwration of automobile!, trucks, Establishing Environment* CrtttftyBraun «t at t|| �buses, boats, and airplanes. We call attention to the fact that we said "contaminants" and not "pollutants," The introduction of harmful, impure, or otherwise undesirable substances into something previously untainted constitutes contamination, The result may, for practical purposes, be negligible. It is only when these substances render the atmosphere or water foul or noxious to health or life that the word "pollution" is properly applicable. This may seem to be only an exercise in semantics, but the point of emphasis is that many people have fallen into the sad practice of loose speech and fuzzy definitions in the whole area of environmental control. They cry havoc when what is really needed is merely nuisance abatement. The fact is that the far-out claims about air pollution are, at best, frightening citizens, especially parents, and, at worst, are in a fair way to leading to panic, simply because of the lack of precise understanding of the actual health effects of contaminants in the air we breathe. In a few well-publicized acute episodes of near-disastrous magnitude, serious illness and death have resulted from polluted air. Therefore, pollution in high enough concentrations can be serious. On the other hand, it is perfectly apparent that even in the urban areas of our country the life-span and general state of health continue to improve, and so the concentrations commonly found in urban areas must be less than disastrous. Again we return to dose-response relationships. High enough concentrations can be harmful to health. Lower concentrations, even though they may offend us in terms of aesthetics or comfort, can be completely harmless to health. Physicians know that the respiratory system is equipped with very efficient self-cleansing mechanisms, and can defend against and dispose of even abnormal amounts of foreign substances which are inhaled. One seldom hears or sees this fact referred to, however, in the talks or feature articles on air pollution. Physicians know that the body also has marvelous d«to«ifying mechanisms that can III Arch Environ Health/Vol 27, Sept 1973 handle low doses of a wide variety of /"Spots and gases. Sulfur dioxide has substances with no harmful effects, a in the public press as fact the public press almost unive%^ ttfe" 'jiq|St 'damaging, corrosive, and sally ignores. irritating to humans. Actually, in f/ It is well, too, to keep in mind that concentrations it can "pollution" of the air is an inherent bronchoconstriction. We part of the phenomena of nature. Volioians would not be likely to canic ash has been an important pol- lerm Such effect on airway resistance lutant, as has smoke from forest fires. as "corrosive." Careful research on humans has shown that more than Ozone in high concentrations is tem13,000/ig of SO, per cubic meter of air porarily present in the air following is needed to produce any measurable lightning storms. Many others could bronchoconstriction. This can be be listed. compared with the governmental Man, blamed and maligned as the community air quality standard of worst polluter, produces only about 80/ng of SO, per cubic meter of air. 0.5% of the total air contamination The physiological response to SO, through his inventions and activities. may be enhanced in the presence of It is true that this relatively small particulatefa, moisture, and oxidation, amount can cause serious problems because, in contrast to that from natand is also influenced by individual ural sources, those for which man is susceptibility. But it is apparent that responsible are localized and may be SO, levels in community air must concentrated. reach relatively high concentrations Thus, a power-generating plant to be deleterious to health. may emit several hundred tons of sulfur dioxide (SO,) per day, and air movement across an urban area can increase the participate loading by tenfold compared to the air of a nearby rural area. The articles which follow will deal in greater depth with specific contaminants and their effects. We wish merely to touch on a few examples that, in our judgment, indicate the areas in which physicians have much to offer and in which the medical perspective is essential. Of the millions of tons of material thrown into the atmosphere each year, carbon monoxide (CO), largely from transportation sources, is the major pollutant, constituting about 50% of the total loading by man. Its most serious effects, of course, are to be expected in persons with chronic heart and lung disease, but at low concentrations the effects may be manifested by visual impairment and slowed reaction time. To date, most studies of the effects of CO have employed short-term, high-concentration exposure. Future CO toxicology must be directed to physiological changes produced by low levels ov«r long periods of time. Other major contaminants are the oxides of nitrogen and sulfur, hydrocarbons, particulate matter, and* va-~ Hydrocarbons constitute approximately 15% of the total contamination in the ambient atmosphere. The most important, from the standpoint of being potential photochemical pollutants, ar j the double-bond olefins, substituted aromatic hydrocarbons, and aldehydes and ketones. Polycyclic aromatic hydrocarbons are universally present in the atmosphere, and much attention has been directed to some of them because of their carcinogenic potential. Thus far, experimental production of lung tumors in small animals has not been accomplished by inhalation, and the literature presents no clear-cut correlation between the effects of polynuclear aromatic hydrocarbon pollution and lung tumor production in man. Neitiier does present information indicate any direct health effects due to the gaseous hydrocarbons in ambient a<r, but "present information" is still inadequate to state unequivocally ihat there can be none, for instance, under extremely adverse meteorological conditions. Of the teven oxides of nitrogen known to exist, only two of toxicological importance are present in ambient air-nitric oxide (NO) and nitrogen dioxide (NO,). No data from either aninal or human studies suggest thai NO is a health hazard at Establishing Environmental Criteria/Braun et at �concentrations found in ambient air, but since it readily oxidizes to NO,, it possesses potential toxicity. The toxicology >f NO, is difficult to discuss because of the inadequacy of relevant data from human studies. An article that follows will describe the effects of NO, on schoolchildren in an urban area. The effects of oxides of nitrogen at levels of community air pollution at this time must be considered as potentially irritating Jlnd possibly related to chronic pulmonary fibrosis, but there is insufficient evidence of its qualitative relationship to them. With regard to water pollution, the problems are vastly different today from those of a few decades ago when the major concern wns waterborne bacteria responsible for cholera and typhoid fever. Development of effective filtration and chlorination techniques has virtually eliminated such epidem cs. At present, the volume of industrial and metropolitan wastes is tremendous and includes an ever-increasing number of synthetic chemical contaminants which did not even exist a dozen years ago. Most available data on the effects of chemicals in water svpplies have come from experiences in industry. However, some information has been obtained from episodes of acute illnesses v^iich result from the presence of some uncommon natural constituents in crinking water, or accidental contamination from spillage or jeepage of sc me chemical. More than 500 new chemicals are developed each year, and many of these fir.d their way into our waterways. Sxtch chemicals as nitrates and nitrites, arsenic and selenium, mercury, organic .carcinogens, and tracemetal antagonists present real challenges to w ater pollution central. Scientific data on thii relative importance of heavy metil toxicity are scarce. The Food and Drug Administration admits to little knowledge regarding levels of toxicity for metals in foods. Many chemical processes, for instance, use mercury, which ultimately escapes into waste water and tends to settle in the sediment of lakes and rivers. Small or- ganisms not only ingest the metal, they transform it into a more toxic * form. Bottom-feeding fish eat the small organisms and are in turn eaten by larger game fish. Mercury becomes increasingly concentrated with each successive step. Although mercury probably has been present in high concentrations in fish for many years, and possibly has no effect on persons eating the fish, it is nevertheless a cumulative poison. It exists in food fishes as methyl mercury, which is a highly toxic substance that causes neurological damage, produces chromosomal aberrations, and has teratogenic effects. Stopping the discharge of mercury into our waterways is only one aspect of the problem; of greater concern is what to do with the mercury already lying on the river bottoms. Recent studies raise the question as to whether drinking water which contains minute amounts of carcinogenic pollutants may, over many years, contribute directly or indirectly to cancer in man. Efforts to link organics in drinking water to cancer prevalence have so far been unsuccessful. Of major consequence with regard to soil pollution are the pebiicides. The dilemma of pesticides lies in the fact that while they do much good, they threaten a great deal of harm. They aid in increasing food and fiber production through protection from insects, rodents, and weeds, but by their poisonous nature they may also endanger human life by long-term, low-level effects. Because of recent adverse publicity, the public seems to believe that pesticides have been spread with reckless abandon all over the landscape, contaminating all food and fiber crops and polluting the whole environment beyond reclamation. As a matter of fact, it is impossible to find anything in current popular literature that puta pesticides in a favorable light. If it can be shown that a pesticide has accumulated in animal tissue, there is no end to the allegations made against it For the last decade the dangers of DDT, its buildup in the environment as well as in human tissues, have been a public health issue in this country. It WM almost completely banned from use in the United State* by the Environmental Protection Agency (EPA) this year. However, after seven months of hearings by the EPA during which a stream of scientific witnesses testified, the hearing examiner found that there was no conclusive evidence against DDT. In fact, some of the evidence was clearly questionable. The World Health Organization has recently sought to persuade governments to recognize the fact that although DDT may have certain hazards, they should not be allowed to obscure its immense advantages. The World Health Organization feels that, in spite of the adverse publicity, there is no present justification for abandoning this valuable weapon in the fight against disease. Physicians, especially those concerned with public health, are becoming more aware of the relationship of man's well-being to his environment It is imperative that they maintain a scientific and professional approach, and calmly appraise all the facts relating to health, disease, and ecology, Scientific research is a slow, methodical process, and no amount of hyste ria, government funding, or legisla tion will hasten resolution of the problems of physiological reactions. This article has merely referred U some of the aspects of the various kinds of pollution, meanwhile urging physicians to become involved, albeit on a sound and professional basis While we are all familiar with th< acute episodes of serious pollution such as occurred in Donora, Pa, am the Meuse Valley-and the disastei at Minamata Bay, Japan, in whid more than 100 died of mercury poi soning- we, as physicians must lean how to evaluate realistically the long term effects of these pollutants at \o\ levels. With this background, th medical profession can meet what w consider to be its obligation to help I development of proper criteria ft environmental controls, and in mail taining the medical perspective, � Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 047 Folder The folder containing the original item. 1189 Series The series number of the original item. Series III Subseries I Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Braun, Daniel C. John A. Jurgiel Paul Gross Source A related resource from which the described resource is derived Archives of Environmental Health Date A point or period of time associated with an event in the lifecycle of the resource 1973-09-01 Title A name given to the resource Establishing Environmental Criteria Subject The topic of the resource ecological impact health effects pesticide toxicology risk assessment ao_seriesIII Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 047 Folder The folder containing the original item. 1191 Series The series number of the original item. Series III Subseries I Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Burnett, Robin Source A related resource from which the described resource is derived Science Date A point or period of time associated with an event in the lifecycle of the resource November 5 1971 Title A name given to the resource DDT Residues: Distribution of Concentrations in Emerita analoga (Stimpson) along Coastal California Subject The topic of the resource aquatic animals pesticide toxicology ecological impact ao_seriesIII Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 047 Folder The folder containing the original item. 1192 Series The series number of the original item. Series III Subseries I Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Carlson, Lars A. Birgitta Kolmodin-Hedman Source A related resource from which the described resource is derived Acta Medica Scandinavica Date A point or period of time associated with an event in the lifecycle of the resource 1972 Title A name given to the resource Hyper - [alpha] - Lipoproteinemia in Men Exposed to Chlorinated Hydrocarbon Pesticides Subject The topic of the resource industrial exposure pesticide toxicology human testing health effects ao_seriesIII Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 047 Folder The folder containing the original item. 1193 Series The series number of the original item. Series III Subseries I Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Clifford, Nathan J. Jerry Weil Source A related resource from which the described resource is derived Archives of Environmental Health Date A point or period of time associated with an event in the lifecycle of the resource 1972-02-01 Title A name given to the resource Cortisol Metabolism in Persons Occupationally Exposed to DDT Subject The topic of the resource industrial exposure pesticide toxicology human testing health effects ao_seriesIII Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 048 Folder The folder containing the original item. 1198 Series The series number of the original item. Series III Subseries I Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource D'Ercole, A. Joseph Robert D. Arthur Jimmie D. Cain Ben F. Barrentine Source A related resource from which the described resource is derived Pediatrics Date A point or period of time associated with an event in the lifecycle of the resource 1976-06-01 Title A name given to the resource Insecticide Exposure of Mothers and Newborns in a Rural Agricultural Area Subject The topic of the resource DDT pesticide toxicology human testing ao_seriesIII Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 048 Folder The folder containing the original item. 1196 Series The series number of the original item. Series III Subseries I Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Deichmann, W. B. W. E. MacDonald Source A related resource from which the described resource is derived Food and Cosmetics Toxicology Date A point or period of time associated with an event in the lifecycle of the resource 1971 Title A name given to the resource Organochloride Pesticides and Human Health Subject The topic of the resource adipose tissue testing animal testing pesticide properties pesticide toxicology ao_seriesIII Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 048 Folder The folder containing the original item. 1199 Series The series number of the original item. Series III Subseries I Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Devlin, Robert M. Source A related resource from which the described resource is derived Environmental Science and Technology Date A point or period of time associated with an event in the lifecycle of the resource 1974-04-01 Title A name given to the resource DDT: A Renaissance? Subject The topic of the resource pesticide toxicology ecological impact pesticide regulation safety ao_seriesIII Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 056 Folder The folder containing the original item. 1511 Series The series number of the original item. Series III Subseries II Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Durham, William F. Clara H. Williams Source A related resource from which the described resource is derived Annual Review of Entomology Date A point or period of time associated with an event in the lifecycle of the resource 1972 Title A name given to the resource Mutagenic, Teratogenic and Carcinogenic Properties of Pesticides Subject The topic of the resource pesticide toxicology chromosomal aberrations congenital birth defects animal testing ao_seriesIII Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 033 Folder The folder containing the original item. 0641 Series The series number of the original item. Series III Subseries I Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Fara, G. M. G. Del Corno F. Bonetti F. Caramaschi L. Dardanoni C. Favaretti S. E. Giambelluca E. Marni P. Mocarelli E. Montesarchio V. Puccinelli C. Volpato Source A related resource from which the described resource is derived Chlorinated Dioxins and Related Compounds : Impact on the Environment : Proceedings of a Workshop held at the Instituto superiore di sanita, Rome, Italy, 22-24 October, 1980 Date A point or period of time associated with an event in the lifecycle of the resource 1982 Title A name given to the resource Chloracne After Release of TCDD at Seveso, Italy Subject The topic of the resource ecological impact industrial exposure pesticide toxicology ao_seriesIII Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 048 Folder The folder containing the original item. 1240 Series The series number of the original item. Series III Subseries I Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Gillette, Robert Source A related resource from which the described resource is derived Science Date A point or period of time associated with an event in the lifecycle of the resource December 10 1971 Title A name given to the resource DDT: In Field and Courtroom a Persistent Pesticide Lives On Subject The topic of the resource pesticide regulation pesticide toxicology ao_seriesIII Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 036 Folder The folder containing the original item. 0756 Series The series number of the original item. Series III Subseries I Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Hogsted, Christer Source A related resource from which the described resource is derived Lakartidningen Date A point or period of time associated with an event in the lifecycle of the resource 1980 Title A name given to the resource Cohort Study of Causes of Death for Forestry Workers with and without Exposure to Phenoxy Acid Subject The topic of the resource industrial exposure health effects pesticide toxicology herbicide toxicology ao_seriesIII Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 037 Folder The folder containing the original item. 0800 Series The series number of the original item. Series III Subseries I Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Kay, Kingsley Source A related resource from which the described resource is derived Environmental Research Date A point or period of time associated with an event in the lifecycle of the resource 1973 Title A name given to the resource Toxicology of Pesticides: Recent Advances Subject The topic of the resource pesticide toxicology ao_seriesIII Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 037 Folder The folder containing the original item. 0808 Series The series number of the original item. Series III Subseries I Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Kimbrough, Renate D. Source A related resource from which the described resource is derived Drug Metabolism Reviews Date A point or period of time associated with an event in the lifecycle of the resource 1982 Title A name given to the resource Disposition and Body Burdens of Halogenated Aromatic Compounds: Possible Association with Health Effects in Humans Subject The topic of the resource CDC health effects pesticide toxicology ao_seriesIII