Document VJXbLx4ZLQxQ4mLV7OYgDbN9o

( 50-199 JNL OF THE AMERICAN VETERINARY MEDICAL ASSN. TWICE MO. 28.000 NOV 1 1975 Identification, Effects, and Control of Food Contamination Kmnath E. Taylor, DVM At a timi when boosting food production is s national and international priority, there is compelling evidence that there is an urgent need to identify food contam inants, to evaluate their hazards, and to take such steps as may be needed to protect consumers against contaminated foods. This report is concerned with the various forms of contamination that can cause severe end sometimes fatal illneaa in animal and man-- namely, biological, chemical, and radioactive environ mental exposures- and with the greet waste of food and economic losses caused by insect infestation and bacterial and other forms of contamination. The purposes of this report are to illustrate the im portant types of contamination, to assess the magnitude and nature of risk, and to examine practical preventive and control approaches in dealing with the many pol lutants and contaminants that may affect the health and well-being of man. Characteristics of Pood Contamination Food contaminants come from the immediate en vironment in which a food is grown, harvested, stored, or prepared.'' " Unlees food is adequately protected, it is subject to environmental contamination at every stage from production to consumption. Two of the more prevalent forma of biological con tamination art filth and raicrobiologic gents,,4MI,4 either of which can inffict illness in both man and lower animals. At least 30 disaaese are considered transmis sible to man through milk, meat, poultry, eggs, and other animal products. Animal products may also be the source of parasitisms. Fish and shellfish grown in polluted waters may carry pathogenic bacteria, viruses, or parasites to man. We alto must recognise the im portance of vermin contamination. Insects infest and damage growing crops to such extent that the crops be come unacceptable for food use. Rodents and insects destroy, infest, or contaminate greet quantities of food. Amid this vast array of exposures, naturally occur ring substance*" "''-4*-44 having extremely high tox icity have bean identified in certain food components. Research on mycotoxins led to the discovery of many toxicogenic fungi as well as many toxic fungal metab olites. The fungi can be toxic only to the plant itself, and control is necessary to prevent lose of the crop. In some cases, however, the fungi produce highly toxic chemicals that present a hazard to the consumer. A specific example would be aflatoxin-related compounds FMs tfc* FomI and Otoe Atoliriatratim. RoekvilW. Md Witt, whan Or. Tajrkar la dkaator o< Ota OSka of iMiraMaatal loapaat. rmilid Mm, iha Swtlan an PuUk Haattk. Utth Mai AVMA MMlnt. July 14--17. ISIS AmMm. Ca, in the milk of animals after the use of feeds contain ing the toxin of this particular fungus. With increasing industrialization, large numbers of new chemical compounds have been contributed to the environment.'-41 The question repeatedly being asked is, "What adverse impacts do uses of chemicals exer cise on man's health today?" Usually the firmest basis for answering this question is to begin from estimates of death linked to chemical causes. Chemical pollu tion10 ,"-1"-91 may be accidental and sometimes have grave consequences but is more often caused by con tamination with unsafe residues vie e variety of routes of exposure. New pesticides1""1 have been synthe sized and widely used; use of antibiotic*4' and other new veterinary drugs and feed additivaa has become common; industrial wastes containing many pollutants and agricultural effluents from animate have been al lowed to burden the environment. All of these sources have increased the opportunity for environmental con tamination and the exposure of tooda to contamination with toxic chemicals. Recent findings by the Food and Drug Administra tion involved 2 such environmental pollutants, poly chlorinated biphenyls (pcb)1''1'-171""1'""71"7 and polybroiiunated biphenyls (pbb). The tetter compound, a highly toxic flame retardant, was reported to have been mistaken for magnesium oxide, a feed supplement, resulting in contamination of several thousand cattle, swine, sheep, chickens, and eggs and chases produced from animals carrying the chemical rcaidua. Though current knowledge of biological activity of pbb is not complete, available evidence dictate* immediate action to preclude environmental expoeure. It is known that, like dot, pcb residues accumulate in fat, including human fat, and that they can be distributed through men's food chain, just like dot has been dispensed into the environment. Certain toxicologic properties of pcb14-*"7 are being discovered only now, more than 40 years after the introduction of pcb into commerce and some 5 years after their identification as widespread environmental pollutants. Recently there has bean increasing concern over metallic contaminanta,',,*l'1*','","J* because of their toxic effects and their importance as environmen tal hazards. Heavy metals such as lead, arssnic, mer cury, copper, antimony, zinc, selenium, end cadmium occur naturally in water and some soils, but usually in trace amounts that present no hazard to human health. Streams may become contaminated with dangerous toads of heavy metals from mine wastas or industrial pollution. Even when the heavy metal content does not make the water unsafe to drink, fish or other organisms November 1, 1978 MONS 086565 It3 may concentrate it to hazardous concentrations. Res* iduee of antibiotics, sulfonamides, nitrofurans, and other veterinary drugs may appear in meat, milk, or other animal foods unless the use is discontinued long enough before the animal is slaughtered for meat or the animal products are marketed. Radiologic contamination has most commonly been the result of fallout of radioactive materials after nu clear blasts. More recently, however, such contamina tion has occurred from radionuclides in wastes released from nuclear energy installations. It has been demon strated that some radionuclides have been concentrated in animal or marine foods, including edible seaweed. Effects of Food Contamination The problem is to assess risks to health from various environmental contaminants. Both the way the threat affects health and the way health workers assign its importance are far from direct. The magnitude and nature of risk varies case by case. Generally, the effects all fall into 2 categories--health hazards and economic implications. A particular threat in sufficient amounts may have acute effects almost immediately or be more subtle and be suspected by its delayed response and have accumulative effects on man or other animals. Good examples of an acute contamination are paralytic shellfish poisoning and arsenic poisoning. Other epi sode* of illness with a high percentage of fatalities due to accidental contamination of foods include poisoning with endrin or parathion. For infective microorganisms,',0'S6'40 like salmonella the effects may be mild, but in the case of infants or the aged, they may be quite severe and often fetal. In the ceeee of diseases such as infectious hepatitis end brucellosis, s prolonged and debilitating illness is followed by slow convales cence. Food contamination from parasites* such as that due to trichinella in pork often causes a delayed, painful condition in man. Serious delayed neurologic damage was caused by methylmarcury1* in fish and shellfish in one area of Japan. In other areas the contaminant caused a num ber of deaths, serious injuries, and congenitally affected babies. In these cases, the direct cause was contam inated fish containing 5 to 20 ppm of methyhnercury. Another reported incident in Japan was the pollution of the environment with cadmium, resulting in the re moval of calcium from affected bones, causing eaay breakage and deformity (Itai Itai disease).41 In the case of antibiotic residues41'41 in food prod ucts from treated animals, the potential hazard to man's health may cause pathogenic bacteria to develop strains of organisms that are resistant to antibiotics used for therapeutic treatment in man or they may sensitize the person so he cannot be treated with antibiotics. Some food contaminants are known to be carcin ogenic to lower animals end are suspected of causing cancer in man. A good example is aflatoxins produced by A$p*rgilUu flavus growing on peanuts, Brazil nuts, com, and certain other foods. Aflatoxins are powerful carcinogens in trout, turkey poults, ducklings, and other animals.* *-41 The nitrosaminee,11 which can be formed in foods treated with nitrates and nitrites,7 have been shown to cause cancer in many animal tissues. Certain pesticides,35 31 including aldrin, odt, <& eldrin, and heptachlor have induced tumors in labora tory animals. Conclusive evidence that they cause cancer in human beings at lower levels of exposure is still lacking. Some of these pesticides are found to con centrate in oysters and mussels grown in polluted wa ter; however, there is yet no definite proof that these substances have caused health hazards to the con sumer. Some chemicals are capable of causing genetic damage, which would not manifest itself until future generations. High energy radiation also has the poten tial of causing this particular health effect. Other chemicals may adversely affect reproduction.3*-41 For example, mercury and cadmium have been shown to cause fetal deaths. The toxic effects resulting from pcb and pbi residues have not been well established. Cases have been re ported in Japan attributed to the ingestion of rice bran contaminated with pcb residues. The acute lathal doae of some of the pcb is relatively low. Tozicologic stud ies* of pcb are complicated by the fact that the pcb consist of mixtures of many isomers with potentially different toxicities. Studies have been further compli cated by the fact that commercial batches were discov ered to contain highly toxic contaminants which may be toxicologically significant at concentrations too tow for detection by existing techniques. Thus the cast of the pcb has demonstrated again that routine toxicologic testing of pure compounds is inadequate to detect all the potential toxic effects that may be significant in our environment. Low-level, long-term exposure to chemical contam inants can cause detrimental health effects. Exposure to mercury, lead, or certain other heavy metals has caused accumulative damage to vital systems and body organa and has adversely affected reproduction. The economic losses due to food contamination are enormous. Even when there is no haxard to human health, growing crops may be rendered unfit for use by damage from insects or contamination with biobgkal agents that cause the food to become so repulsive in taste, appearance, or odor that it is unfit for use. Com mon examples include milk with odors or flavors from certain plants the cow eats. Decaying sludge in estu aries sometimes releases hydrogen sulfide, imparting an unpleasant appearance, odor, and taste to clams or oysters. Remember the old saying about how a horse and rider were lost because somebody neglected to tend to a smell matter like a missing horseshoe nail? Some scientists and agriculturists are worried that the seme sort of ballooning consequences may stem from whet many people probably consider to be e minor irrel evancy. Slowly but steadily, the nation's honeybees are being exterminated; not on purpose, of course, but as the honeybees forage for pollen and nectar they in creasingly are gathering poison, including pesticides that farmers apply to protect their crops from destruc tive insects. Some crops already are threatened by e lack of bees. Among these crops are almonds, applet. 114 JAVMA, Voi itf. No. 9 MONS 086566 chtrrizz, plumz, broccoli, cucumben, cabbage, melon,-- of food contamination reveals decision meH-p in a indwd, virtually all (ruita and baniaa aa wall aa many heavy climate of crisis. This applies to the coOectfon vafatablaa and even aoma livaatock--forage crops auch of data as well as to making decisions on the basis of aa alfalia. Thus, at a time when boosting food produc the information generated. There is a widely recog tion is becoming a global priority, the fate of honeybesa nized need for environmental forecasts that will detail takaa on aoma of the significance of the proverbial horse plans for prevention or containment of adverse impacts. shoe nail. The total plan should develop prioritiee for research In slaughter plants, millions of pounds of meat and aimed at illuminating effects on animal and human poultry and their parts must be condemned each year health as well as the environment--as far in advance because of diseased conditions1 or residues of pesticides, of major decisions snd technologic developments as veterinary drugs, or environmental contaminants in ex possible. cess of legal tolerances. Immediate prevention and control approaches relate During transportation, foods may become spoiled, directly to municipal, state, and national food con infested with insects, or contaminated by rodents. trol laws and to enforcement organisations. The com Many of these foode are sources of high-quality protein petence of the enforcement organizations must be ad and the losses add to the nation's and world's defi equate to deal with complex problems in the processing, ciency of protein. One must not overlook the financial storage, and marketing of foode, and to protect con costs for medical care, hospitalization, and lose of sumers against widespread contamination. The impor wages when persona are made ill by contaminated foods. tance of maintaining enforcement organizstions, labora In addition, potential growing areas are being aban tories with trained staffs, and education of food handlers doned for food end forage because of pollution. Added and consumers cannot be underestimated and is to those are the losses of international trade, incurred an integral part of the problem of prevention and con whenever a food is denied entry in world trade. trol. A food-contamination monitoring system baaod on national monitoring data should be kept currant. Prevention end Control of Food Contamination As new technical advances are made to meet our increased bod production needs, practical prevention and control approaches must be applied in unison to maintain consumer confidence in the wholeaomeneea of the food they purchase and to retain the credibility of the agriculture businessman who produces it Simultansoua actions are needed to provide for the general safety of all involved, to protect consumers against harm from contaminated foode, and to protect the environment against long-term degradation. The Amer ican system depends heavily on the producer and pro cessor for prevention and control of food contamina tion. Tha chemical and drug producer has an inherent Such a system would detect trends in food contamina tion, assess probable effects on human health and food supplies, and inform and advise on how to beet prevent or prepare to handle developing problems that can erode food reeources. The large and growing number of chemical sub stances and environmental pollution problems intro duced into man's environment emphasize the necessity to focus efforts on increasing knowledge of environmen tal effects on human and animal health, thereby pro viding information that will contribute to an early warning system. I am convinced a number of problems in the area of food contamination control can and will be solved through education. responsibility to the farmer.and rancher to meet prod References uct compositional and quality requirements and to provide informative-use labeling, including misuse warn 1. Bailey, 3.. Bunvan, P. J., and Ftahwick, f, B.: Polychlor* inatad Biphanyl Raauluaa. Cham Ind, 22, (1970): 70S. ings. In using drugs, the veterinarian has a responsi 2. Biros. P. J., Walker, A. C., and Medbeiy, A.: Pnhrthlor bility to help the food producer avoid costly problems. Instructions on withdrawal times necessary to meat inatad Biphenyls in Human Adipose Tissue. Ball Environ Contain Toxicol, 6, (1970): 317-328. 3. Brandly, P. J., Mlgalri, O.. and Taylor. K. E.: Moat requirements with respect to residues in animal prod Hygiene. 3rd od. Loo andFebiger, Philadelphia, Pa, 1908. ucts should be provided and followed, as given on la 4. Bryan, F. L.: Diseases Transmitted by Foods (A Ctas* beling and packaging ineerta. The attention of health sillcation and Summary). U.S. Public Health Sendee, renter for Disease Control, Atlanta, Qa, 1971. authorities and educators should be drawn to meet the 5. Council on Environmental Quality: Environmental Quel* needs of practitioners, students, and producers. Thera ity. First Annual Report of Council on Environmental Quality. Washington, DC, 1974. appear to be soma major areas and concepts where 6. Chu, F. S.: Studios of Ochratoxins. Critical Rsvines in public education is needed to avoid contamination of Toxicology. Vol. 2, Issue 4, (1974): 499. foods and food. Because of the scientific and technical nature of the problems sasociated with food contam 7. Committee on Nitrate Accumulation, Accumulation of Nitrate: National Roooorch Council, National ft rarianiii of Sciences, Washington, DC, 1972. ination, scientists must engage actively in the process B. Diener, U. L., and Davis, N. D.: Aflatoain Formation by of interpretation. In the past, some have avoided Aspergillus Flavus. in Aflatoxans. Edited by L A. Ooldblott Academic Prase, Now York, NY (1969): 13. this responsibility because of the hazards of public 9. Doctor, R C,, Sinnhubor, R O.. Wales, J. H., and Loo, i ( controversy. D. J.: Acuta Toxidty and Carcinogenicity of Ochratoxin in In contamination problems, we are confronted in Rainbow Trout Fad Prec. 30. (1971): 578. 10. Duasan. R. E.: Pesticide Residues in Foods. Ann NY each case with weighing the risk involved. The risk/ Acad Sci. 160, (1969): 173-162. benefit ratio must be balanced and carefully considered by the producer, control official, and consumer. Almost any analysis of past decisions in the area 11. Ender, F., and Oh, L.: Occurrence of Nitroeamines in Food'Stuffa for Human and Animal Consumption. Food Cosmet Toxic. 6, (1966): 569-571. 12. Engel, R E., Hammer, D. I., Horton, R J., Lana, N. M., November I. 1976 HONS 086567 915 ml phialM, X* A.: Environmental Lsad and Public Health Invinmanttl Protection Agency, FI--etch Trienglo Perk, NC. It. Environmantol Sciences Monograph: Metallic Contain- binnli end Human Health. Edited Sy H. K. Lee, Academic Prom, New York, NY, 1971 _, 14. FiUbugh, O. O., et al: Chronic Orel Toxicitiss o(_Mer- curiphenyl and Mercuric Balts. AMA Arch Ind Hyg Occup MedT 2, (19801): 448"3-442`. 194. Prim, G.. 1PF..s: Pooll:ychlorinated Biphenyl luciaum in tne MUk at Environmentally and Experimentally Contaminated Cows. Environ Health Petapec. 1, (1972): 8W9. 19. Harada, Y.: Congenital (or fetal) Minamata Diaeaae. Study Group of Minamata Dimem. Kumamoto Univeraity, Kumamoto, Japen (1966): 98-117. 17. Homan, A. V.: Source of Polychlorinated Biphenyl Cftntelntim in the Merino Environment. Nature, 228. (1970): 1220-1221. 16. Inikyama, K., et el: Industrial Waataa Containing Mercury Compounds from Minamata Factory. Kumamoto Med J, 16, (t982):67-66. 19. Jensen, S.: A New Chemical Hnsnrd. New Sci, 32, (1999): 612. 20. Jenmn, S., et el: DDT and PC8 in Marine Animala from Swedish Waters, Nature. 224, (1966): 247-200. 21. Johansson, N., Jenmn, S.. end Olaeon, M.: PCB-Indi* ontien of Effects on Fish. In PCB Conference, Wenner-Orca Center. National Environmental Protection Board, Stockholm, Sweden (Sept 26, 1970): 69-66. 22. Kiwimoe, A., et al: Mathylmercnry Compounds in Em from Hans After Oral Administration of Mercury Compounds. J Ar Food Cham, 17, (1969): 1014. 22. Kolbye, A. C., Jr.: Food Exposures to Polychlorinated Biphenyls. Environ Health Perspec, 1. (1972): 86-80. 24. Lea, D. H., ed: Metallic Conteminetion end Human Health. Academic Prom, New York, NY. 1972. 25. National Scianro Foundation Report: Report of the Panel an Chemicals and Hadth aof the Preeidrat*a Advisory Committee. Setenee and Technology Policy Oflce--National Setanna Peundation, Washington, DC, 1978. 16. raakall. D. B., and Linear, J. L.: Polychlorinated Bi phenyls: Another Long-Life Widespread Chemical in the Environment Bio Sd, 20. (1970): 96S-964. 27. Prim, H. A.: Occurrence of Polychlorinated Biphenyls in Humana. Environ Health Psispoc, 1, (1972): 73-76. 28. Radsleff, R. D.: Veterinary Toxicology, Lea and Fete Igor, Philadelphia. Pa, 1994. 29. Richard, S. L., Tiffany, L. H.. end Pier, A. C.: Toria-*---T*,iuAas\so. cia, ated with Stored Com. Myeepethol Myeal 30. Ricmann. H-, ed: Food-borne Infections and Intoxica tions. Academic Prase, New York, NY, 1996. 31. Secretary's Commission: Report of the Secretary's Cont raission on Pesticides end Their Relationship to Environmental Health. US Department of Health, Education and Welfare, Washington. DC, 1909. 32. skerfving, S., Han--n, K.. and Lindaten. J.: Chrom osome Breakage in Humane Exposed to Methyl Mercury Through Fish Consumption. Arch Environ Health, 21, (1970): 33. Smart N. A., end Lloyd, M. K.: Mercury Rsekhws in Eggs, Flesh end Liven of Hone Fed on Wheat Treated with Methylmercury Dicyandiamide. J Sd Food Agrie, 14, (1998): 34. Stalling, D. L, and Mayer. F. L.: Toxicitics of PCB's to Fiih and Environmental Reeidum in Fish. Environ Health PenpocL 1. (1972): 109-194. 39. Thatcher, F. S., and Clark, D. S., sd: Mlcreorganimn in Foods: Their Significance and Methods of Enumeration. Univenity of Toronto Prose, Toronto, On, Canada, 1996. 36. van Walbeek, W., Scott P. M,, and Thatcher. F. S.: from Food-Borne Fungi Can J Microbiol. 14, 37. Vos, J. G.: Toxicity of PCB on Non-Human Mammnla and on Birds. Environ Contain Toxicol, 1, (1972): 109-107. 38. Wsstoo, G.: Mercury and Methyhnarcury Levola in Soma Animal Food Products. Var Foods, 7, (1966): 137-184. 39. White, P. L., and Robbins, D.: Environmental Quality and Food Supply. Futura Publishing Company, Mount Kioto, 40. WHO Export Committee on the Microbiological Aspects oMPood ^Hjyisna: Report WHO Techn Rap Sor, No. 369; 41. WHO Report: Health Hatarda of the Human Environ ment WHO, Geneva, 1972. 42. WHO Report: The Piddle Health Aspects of Antibiotics in Feedstuffs. WHO, Geneva, 1974. 48. Wogan, G. N., ed: Mycotoxiao in Foodstuffs: Proceed ings of e symposium, Memechusetta Institute of Technology, Cambridge, Ms, 1994. 44. Wogan, G. N.: Chemical Nature and Biological Effects of Aflatoxins. Bacteriol Rev, 80, (1966): 460. Mumpi Suspected in a D09 In November, 1974, a 5-year-old Labrador Retriever-type bitch waa ezaminad becniaa it had f body temperature oi 40 C (104 P), greatly enlarged and painful tubmaxillary lymph nodaa, and edema of the jowl. The dog had been dapreaaad and anorectic for 24 houra. The owner aaked if the dog had mumpa bocauae a 16-month-old child in the family had bean diagramed aa having mumpi the previoue day. Blood aamplee collected 2 day, after initial examination and 7 weak, later ware submitted to a public health laboratory for evaluation. Prune# of antibody titan indicated that tha dog had re sponded to a mumpi viru* challenge and that when tha fint sample waa taken the disease was well established. The signs were similar and occurred at tire same time as those in the child.--R- E. Smith in Vet Ree, 96, (March 39,1976): 396. HONS 066566 lit JAVMA, Vel 147. No. 9