Health Protection Branch Symposium, Ottawa, May 12–14, 1975

Health Protection Branch Symposium, Ottawa, May 12–14, 1975

HEALTH PROTECTION BRANCH SYMPOSIUM, OTTAWA, May 12-14, 1975 "Health Effects of Chemicals in Foods" This conference, held at the National Library in Ot...

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HEALTH PROTECTION BRANCH SYMPOSIUM, OTTAWA, May 12-14, 1975 "Health Effects of Chemicals in Foods" This conference, held at the National Library in Ottawa was attended by food technologists, scientists .and educators from across Canada and the United States. Papers were gIVen by many natIOnal and mternatlOnal scientists from different disciplines. The proceedings of the symposium will be published by the Health Protection Branch. Only a summary and opinion of the conference will be given here, except for the extracts from Dr. Georg Borgstrom's paper on changing patterns in world food production and needs (see World Food Crisis). After the introduction and welcome by Dr. W. P. McKinley of the Health Protection Branch, the symposium was opened, and Dr. Borgstrom presented his paper. His presentation on world food production and needs proved to be in stark contrast to the subsequent conslderallons of food safety. It was at times difficult to remember the burgeontng problem of the world's food needs, as we listened to papers on the safety or assessment of safety of the food supply - in Canada, or in other developed countries of the world. The papers tended to be very specific, with the result that the session on "epidemiology and food safety" was probably too specifically oriented to epidemiologists, just as the session on "new concepts in experimental toxicology" was too specifically oriented to toxicologists. At this time, many Canadian consumers are questioning the safety of various "chemicals" in foods. Dr. L. R. A. Bradshaw (Health ProtectIOn Branch, Ottawa) considered the foreign chemical contaminants of foods, while Dr. I. C. Munro (Health Protection Branch, Ottawa) considered the naturally occurring chemical toxicants in foods. Consumer and consumer advocate concerns for these two categories of chemicals are disproportionate, and clearly a sound understanding of both is necessary to make a valid risk-benefit analysis of foods and their conslltuents. Dr. Munro, while eliminating bacterial toxins from his considerations of natural toxins, included the mycotoxins among natural toxicants in foods. The potential capabilities of these "natural" toxins could cause major concern for consumers. In contrast, most concern is expressed for chemical residues, environmental contaminants and food additives. Environmental chemicals could be considered closely related to natural toxins in foods. Chemical residues of pesticides and other agricultural chemicals, and food additives represent a different class of chemicals in food which usually have permitted use concentrations, with specified tolerances. Furthermore, chemicals present in excess of these tolerances are conSIdered to be illegal (see Food Regulations: Adulteration of Foods). Food scientists and educators frequently overlook the importance of natural toxins in foods, not because they are unprepared to face the issue of safety with regard to these constituents of foods, but rather because the varied diets of Canadians make these constituents relatively unimportant in safety considerations. However, the natural toxins represent a valuable teaching tool, and enable the food industry to justify the use of many of the food additives currently employed in food processing. Dr. Munro's paper gave valuable information on "natural toxicants", contrasting the different types of toxic effects that might be caused by eating "natural" foods. In the session on Epidemiology and Food Safety, Dr. H. LeRiche (University of Toronto) brought forth some interesting views of epidemiology in medical schools. He felt that medical schools and government departments of health have not recognized the importance of epidemiology and toxicological studies, yet we live in a "chemical age". Similar statements are made about the relative importance of nutrition in medical studies. Dr. LeRiche emphasized the need for the study of biological signs in disease or deficiency conditions, and considered these more important than studies of the statistical significance of specific observations. He illustrated his point with practical examples. Dr. J. Higginson (international Agency for Research on Cancer, Lyon, France) acknowledged that to increase world food supply requires chemicals, but questioned how this influences food safety. Dr. Higginson gave interesting information on the incidence of different types of cancers, and noted that while the incidence of most types appeared to remain the same or was decreasing, the incidence of lung cancer to a great extent, and of pancreas cancer to a limited extent, appeared to be increasing. He cited data from E. E. Pochin on risks taken that gave a one in a million risk of death as follows: 1'/2 cigarettes 50 miles in a passenger car 250 miles by air 1'/2 minutes of rock climbing 6 minutes of canoeing


20 minutes being aged 60 years I or 2 weeks in a typical factory Food scientists and technologists require this type of background infor. mation in making their own risk-benefit evaluations of foods and foOd additives. This session was of considerable value, but would have been far more pertinent had it related more directly to food safety. Perhaps we were being given the message that food. safety has neglected the epi. demiological aspects and that more attenllon IS necessary m thiS area of study. The session on New Concepts in Experimental Toxicology was gen. erally too technical to determine its relevance to the safety of chemicals in foods. None-the-less, it was apparent that toxicologists experience consid. erable difficulty in extrapolating the results of animal experiments to hu. mans, yet this is the basis of acceptance and rejection of chemicals proposed as food additives. This problem is attributable to differences in rates of metabolism, action site differences, concentration response differ. ences and different antagonistic responses between animal species. Much discussion centred around the "Subclinical Effects of Chemicals". This was the subject of Dr. E. Palmes' (Institute of Environmental Medicine, New York) paper. However, most of the paper was directed toward es. tablishing that there was no such thing as "subclinical". That is, ifno clinical condition exists, there is no condition. However, this term "subclini. cal" is widely used, and requires careful definition if it is used. For example, if "subclinical" is used to describe mild abnormalities or symptoms, that might not be detected by the usual clinical tests so the person is not apparently sick, then the test(s) might be the limiting factor(s) and the symptoms are clinical, not subclinical. Clearly, the food scientist interested in toxicological aspects of food chemicals needs to be wary of the use of this term. However, examples of so-called "subclinical" conditions were given, for example: hepatitis carriers without clinical symptoms (the same could presumably be applied to symptomless Salmonella carriers); Cadmium which causes emphysema at the clinical level, protein urea at the "subclinical" level; methyl mercury which gives a clear cut clinical syndrome and an unrelated weak or "subclinical" syndrome. In the session, on Predicting Carcinogenic, Mutagenic and Teratogenic Activity, difficulties in the interpretation of tests for carcinogenicity were considered by Dr. H. C. Grice (Health Protection Branch, Ottawa). Dr. L. Poirier (National Cancer Institute, Bethesda, U.S.A.) considered relationships between mutagenicity and carcinogenicity. He noted that microbiological mutation tests for potential carcinogenicity of chemicals resulted in over 85% being screened as potential carcinogens. Dr. K. Khera's (Health Protection Branch, Ottawa) paper on the significance of teratogenic testing in food safety evaluation indicated some of the same difficulties that are experienced in other food safety testing, principally that laboratory testing is not always reliable, foetal responses vary between mammalian species, and animal studies require careful inter-, pretation for extrapolation to humans. The final session of the symposium considered the Assessment of Food Safety. Dr. H. B. Jones (University of California, Berkeley) advocated the use of mathematical models to evaluate the risk-benefit situation of using chemical food additives. He used the example of DES to illustrate the infinitesimally low risk of DES. Dr. E. Poulsen (National Food Institutes, Soborg, Denmark) presented a paper on National and International problems in evaluating food safety. He considered it necessary to study the problems of evaluating food safety in the proper context, that is, proper nutrition and hygiene should not be overlooked. It IS not possible to give absolute assurances of Safety. The dosage given cannot take into account persons with unusually high intakes or super-senslllv1ty, but these people should be protected. Cost benefit analyses are not always easy to apply. While consumers might not realize the benefits, researchers may find that it is difficult to determine the benefits of chemicals in foods. International implications of banning of food additives in one country can not be overstated. For instance, the cyclamate ban in the Untted States spread to Canada, Denmark and other countries; similarly, the DDT ban in Sweden spread to other parts of the world. It became a problem of countries getting on the "DDT Band Wagon". Evaluation of food additives for food safety is based on the acceptable daily intake (ADI) for man. The FAO/WHO committee considers: I. Biochemical aspects 2. Acute toxicity 3. Short term studies 4. Long term studies 5. Special studies 6. Observations in man The ADI is the level at which there is no significant toxicological efJ. Inst. Can. Sci. Techno!. Aliment. Vo!. 8. No.3. 1975

reet and is expressed as mg per kilogram body weight per day. This would . elude the entire life span of man with no effects. On the other hand, a :Ierable weekly intake (TWI) is used for heavy metals. This is based on the FAa/WHO expert committee recommendations based on an estimated intake which is determined by: I. Food consumption studies 2. Food basket or total intake estimate However, it must be assumed that there are unusual circumstances in consumption. For instance, if a consumer used I margarine for all fat intake, this consumer mIght have to be protected 10 the case of food additives in that margarIne. Recommended mercury levels for fish of not eater than 0.5 ppm might be completely acceptable for most North rmerican consumers, but totally unacceptable for people or countries for whom fish constitutes a major part of the diet. Dr. A. B. Morrison (Health Protection Branch, Ottawa) gave a paper on Concepts in the Regulatory Control of Chemicals in Foods. He stated that it is necessary for government agencies to satisfy the public, industry and other government people. He noted a growing consumer preference for convenience food, but also a growing consumer apprehension about rood additives. It is the responsibility of the Health Protection Branch to assess the health benefits of foods. It is also necessary to consider if chemicals allow more food production. It is necessary for the Health Protection Branch to be accountable politically through the government, it is only in this way that the Health Protection Branch knows the current interest of consumers. This somewhat lengthy summary of the symposium is presented as infonnation for readers and to indicate the orientation of the symposium. With due respect for the quality of the papers and the professional standingofthe participants in the program, the symposium illustrated in a negative way the gap between scientist and consumer, and even more critically, between the scientist and the consumer educator. From the symposium, it was not difficult to understand the concerns expressed by consumers about food safety, and also the source of lack of credibility or confidence of consumers in food science and technology. An additional, more concerning failure was also reflected by the symposium, namely the failure of the participants to address themselves to the world food crisis which was reviewed by Dr. Borgstrom. The striving for "absolute safety" in the Canadian food supply, even though it is acknowledged as an unachievable goal, conflicts and contradicts the need for increased world food production and avoidance of food spoilage and waste (see World Food Crisis for extracts from the first half of Dr. Borgstrom's paper). If demographic predictions of the World's food needs prove to be correct, then it is necessary that the privileged people and food professionals of the "food sufficient" countries start to address themselves to the growing needs of the people of "food deficient" countries, without delay. M.E.S.

QUOTES FROM THE H.P.B. SYMPOSIUM . "If the present population growth and urbanization rates are maintamed it will take a miracle to meet the world's food, water and sewage requirements over the next 25 years." G. Borstrom "Food adulteration still occurs. In 1969, in Italy, ground umbrella handles were being sold as parmesan cheese!" W. P. McKinley (Possibly an understatement compared to the meat scandal currently unfolding in Canada) "Most Canadians are reasonably confident that chemicals in the food supply are safe." L. R. A. Bradshaw (Note: this statement was not challenged by the audience, but appeared to be contradicted by other speakers). "Human toxicological studies are difficult to conduct, however there are still some nurses and theological students who volunteer." H. LeRiche (Dr. LeRiche ascribed the willingness of the theological students to volUnteer to the "security" of the theologians, but failed to account for nUrses volunteering!) "Subclinical does not mean insignificant" B. L. Oser Can. Insl. Food Sci. Technol. J. Vol. 8. No.3. 1975

THE WORLD FOOD CRISIS In the last issue (CIFST Journal 8 (2) A25), abstracts of a paper presented by T. R. Hilliard were published under the title "Food Technology for Mankind." To date, there have been no responses from readers to the points made in T. R. Hilliard's address, and no comments on the questions about Canada's responsibility and what we are doing relative to World food needs. Those who attended the Health Protection Branch symposium on "Health Effects of Chemicals in Foods" would have had the opportunity to hear Dr. Georg Borgstrom's address on "The World Food Crisis and Its Implications as to Future Patterns". Dr. Borgstrom, well known to food scientists as an author of books on food science, is a Professor at Michigan State University. His background as a geographer and food scientist qualifies him to speak on the world food crisis, and he did so with ability and fearful concern. In addressing ourselves to the World's food needs, it is appropriate to publish abstracts of the address given by Dr. Borgstrom. In this issue, the first part of Dr. Borgstrom's address will be presented, including the demographic and distribution problems related to feeding the world's population. The second part (CIFST 8 (3) October issue) will deal with "the third dimension" of the food issue, i.e. waste, spoilage and utilization. The World Food Crisis by Georg A. Borgstrom Michigan State University

Part I. Demographic and Distribution Problems Despite all the statistical data that swirl around in news media, conference documents and elsewhere, we seem to fail to grasp the magnitude of our calamity and the true nature and implications of what is unfolding. Mankind is facing a situation unprecedented in history by adding more than one billion people in the next ten years (currently close to 80 million a year), i.e. a new Canada each third month or, in less than three years, as many as now live in the United States. Asia is adding a new Japan each second year. Demographic projections anticipating 6 to 8 billion by the year 2000 are an exercise in futility as long as we have very vague notions of how we are going to manage to get through the next ten years. The task is critically compounded chiefly by two overriding complexities: I) the widening disparities as to food, water, energy (fuel), and economy, and 2) a frantic continued thrust into overcrowded cities, in other words urbanization. Current swellings involve the adding of more than 700 million to cities within ten years, two-thirds of which will occur in the "poor" world. A 4-fold increase in human dwellers is predicted for the cities prior to the year 2000. This in itself is creating entirely new demands for food processing and marketing. On almost all counts we provide adequately for merely one-third of the present human family. Nonetheless we seriously believe that we are going to perform the miracle of doubling up on all fronts, and produce in the brief span of some 25 years, much more food, water, energy, forest and mineral products than previously added in all of man's history. Yet after such an herculean accomplishment we would be faced with the same high proportion of starving, underfed, and malnourished people. Man's living domain, his biosphere, is not limited to the almost 4 billion registered in population statistics. It is actually 5 times larger and should read 19 billion, of which livestock, inclusive of poultry, accounts for 15 billion. This is measured on the basis of their protein intake. The feeding burden of U.S. is therefore not limited to 215 million, but in such biological terms, to 1.6 billion. India with its 600 million represents, computed in this way, almost two billion. (Despite India being three times the size of the U.S. in human numbers, their actual feeding requirements are not much bigger than those of the U.S.). Now to the missing historical dimension. This refers to the big European population explosion, 1850-1950. Europe lifted off one-fourth of its population. It is poorly recognized what a world-shaking happening this was on the human scene. For two centuries Europe had persistently raised its food ceiling through agricultural advances. But around 1850, the population critically started to outgrow resources. Poverty, unemployment, and hunger rose despite industrialization. The biggest migration ever in human history unfolded: 100 million left Europe, 25 million returned. "The poorhouses of Europe were emptied on to the North American prairie." This is the key to the riddle, in North America we have at