Environmental health problems

Food and Cosmetics Toxicology. Vol. 1, pp. 33-42. Pergamon Press 1963. Printed in Great Britain.

SHORT REVIEWS ENVIRONMENTAL HEALTH PROBLEMS The Report under review presents a study by the "Gross" Committee of the function of the U.S. Public Health Service in relation to possible long-term health hazards now presented by air pollution, milk, food, water and radiation and also occupational hazards (U.S. Publ. Hlth. Set'. Publ. 1962, No. 908). At present the Public Health Service is subdivided according to the particular source of environmental hazard studied, namely water supply and pollution control, air pollution, radiological health, milk and food protection, occupational health and environmental engineering. However, during the last decades, the character of the public health problem has to a large extent changed from that of preventing the transmission of bacterial disease, due to contamination of air, water and food by bacteria, to that of chemical pollution and the possibility that the various pollutants may cause diseases such as cancer. This new emphasis follows the very rapid development of newer technologies, and the consequent introduction of a vast number of new" potential chemical and radiation hazards into food, water, air, clothing, tools and toys. The Committee considers that the multiplicity of these new potential hazards has created a public health problem of such magnitude that a major research and development effort is now required to assess and counter these dangers. It is essential that the Federal Government assumes the leadership of this research, and the Committee's view is that the focus of this national effort should be within the U.S. Public Health Service. The present "category" approach of the Public Health Service does not provide a sound basis for an adequate long-range national programme in environmental health. Such an approach would ultimately lead to duplication of effort and fail to provide the integration that the various common aspects of the separate divisional programmes required. To overcome these problems the Committee recommends the establishment within the Public Health Service of a comprehensive Environmental Health Centre. This would include the headquarter activities of the present Public Health Service divisions and the administrative headquarters of a unified environmental health grants programme for university fellowships and research projects. A new Office of Environmental Health Sciences should also be set up which would include biological, physical and social scientists who were free to carry out research into basic problems over the entire field of environmental health. It would provide central services in mathematics, statistics, data processing, information storage and retrieval, instrumentation and analytical laboratory procedures. The Office of Environmental Health Service would provide a much-needed focal point for the entire national environmental health programme. Included in the Report are reports of the Subcommittees on manpower resources and training, applied mathematics and statistics, pharmacology, toxicology, physiology, and biochemistry, analytical methods and instrumentation, air pollution, environmental engineering, milk and food, occupational health, radiological health, water supply and pollution control. Some of the observations put forward by specific subcommittees are o f particular interest. 33

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Subcommittee on Milk and Food In its consideration of environmental health problems relating to food and milk the Subcommittee's Report states that since 1945, food processing and packaging technologies and distribution have undergone dramatic changes, particularly in the direction of "convenience foods", two-thirds of which have been marketed since 1946. More than 8,000 items of food are now available in supermarkets and the total number is increasing by 24 items a day. Also the food service industry pattern has changed considerably; today practically all American workers and students in urban areas eat one meal away from home. In addition, since 1954 the value of sales made by the automatic vending of hot or cold foods or even complete meals has increased from $10 million to $200 million in 1960..~t present, industry is spending $100 million on new food product developments, all of which, a priori involve new potential problems in food safety. Public health agencies have not so far been able to consider these new problems effectively, because of their overwhelming numbers. Acute illnesses produced by bacterial contamination of food represent only one aspect of the new potential health hazards that are developing, the other, the study of the cumulative effects caused by repeated ingestion of foreign chemicals added to food during production, processing, storage and preparation for serving had hardly begun. The Subcommittee considers that simplified analytical procedures for the determination of pesticide, herbicide and other potentially harmful residues in food should be developed. Toxicological and pharmacological responses of animals to repeated doses of chemicals both singly and in the combinations that may be present in food should be studied. It recommends that the possible correlations between the results of chronic toxicity tests and more rapid procedures which may give an indication of a substance's toxicity should be studied, e.g. its effects on enzyme systems, tissue cultures or micro-organisms. In addition the occurrence, intake and biological effects of radioactive isotopes present in food and other environmental sources should be investigated. Some of the newer forms of food processing, packaging and storage may also lead to the destruction of physiologically important substances such as heat-labile vitamins and amino acids, or affect the availability of calcium or other important mineral elements. Again, compounds that are not digested in the body, e.g. alginates, pectin or modified celluloses, are added to foods in place of normal articles of food in order to improve texture and keeping qualities. If carried to excess this may have serious effects on certain groups of individuals. The biological effects that may result from the introduction of ultra-hightemperature pasteurization of milk, freeze-drying, dehydro-freezing, microwave cooking and sterilization by irradiation are subjects which could usefully be studied. In its conclusions the Subcommittee states that because of the factors discussed above there is an urgent need that the Public Health Service should be made responsible for obtaining information concerning, and methods and criteria which may be applied to, new food products in order to protect the health of consumers. The present annual appropriation of $5 million for the Food Protection Programme should be increased 6-fold in the next 5yr. Subcommittee on Pharmacology, Toxicology, Physiology and Biochemistry The Subcommittee considers that many of the current environmental health hazards arise from individuals becoming exposed to the action of potentially harmful physical or chemical agents as a result of the pollution of air or water, food contamination or a variety .of these sources. Although a different point of entry into the body may be involved in each

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case the damage to health is effected by a single mechanism, damage caused to normal cellular functions. Environmental hazards therefore should be studied on ~ comprehensive basis. Foreign chemicals are finding applications in food technology so quickly that examination of their toxicology must inevitably fall behind. For the next decade therefore, it will be essential to undertake and support both intra- and extra-mural work in toxicology. Of great importance also, is the creation of a strong basic toxicology research unit within the Environmental Health Centre in order that new approaches, methods and instruments may be developed in this subject. Planning for the future in this way will result in ultimate developments, that will be of the greatest value in solving practical problems and also provide an incentive for scientists of the highest standard to enter the field of environmental health research. In addition basic research on the mode of action of toxic agents may be expected to provide the soundest foundation for the assessment of biological hazards. In particular a study of the action of toxic substances upon enzyme systems has already yielded results of considerable value. Biochemical research must find an appropriate place therefore in both intra- and extra-mural programmes, again both from the point of solving practical problems and stimulating recruitment to this field.

E V A L U A T I O N OF C A R C I N O G E N I C H A Z A R D S

In the Fifth Report of the Joint FAO/WHO Expert Committee on Food Additives, the Committee, under the chairmanship of Professor A. C. Frazer, considers the very special hazard of possible carcinogenesis due to ingestion of food additives (Wld. Hlth. Org. techn. Rep. Set'. 1961,220). The value of, and the need for testing for carcinogenicity is stressed by the Committee, for it is possible that the presence of carcinogenic compounds in food may be a factor in 'spontaneous' cancer in man. Safety, demonstrated by feeding compounds to animals unfortunately does not provide irrefutable proof of safety in man, but on the other hand, a number of chemicals known to cause cancer in man, does show similar activityin animals. For this reason, it is prudent to test both intentional and adventitious food additives for carcinogenicity. On the practical side, however, the Committee recognizes the problem presented by such a testing programme in relation to the present dearth of facilities and experienced personnel available to carry out such work. The aim in preparing this report was to produce recommendations which would help to make investigations both as informative as possible and of a standard that would be internationally acceptable. The Committee considers that the minimum examination of any compound should consist of a study of the incidence of tumours in two species of animals, (e.g. rats and mice) fed the compound under test for the lifetimes of these animals. In certain cases, supplementary tests may also be required, such as the study of the toxicity of a substance when given either by injections or to other species. A concise but detailed discussion of factors affecting the design of experiments is presented. The Committee points out that the composition of the test substance and its identity with the additive used in food, must initially be firmly established. Questions of this sort can be difficult especially with, for example, pesticide residues, where breakdown of reaction products of unknown or variable composition may be present. Another consideration, the choice of the experimental animal for chronic feeding tests