Criteria for air quality and methods of measurement: report of an inter-regional symposium, Geneva, 6-12 August 1963

WORLD HEALTH ORGANIZATION ORGANISATION MONDIALE DE LA SANTE WHO/AP/23 I 10 S~ptember 1963 ORIGINAL: ENGLISH CRITERIA FOR AIR QUALITY AND METHODS OF MEASUREMENT Report of an Inter-Regional Symposium Geneva, 6-12 August 1963 CONTENTS General considerations • • • . • . . • . • . • . . . 2 Rationale for selecting air quality criteria • . . . . 3 Role of epidemiological c.ncl ac;rometriu surveys 6 Damage to vegetation, soiling of surfaces and visibility reduction 7 Medical studies needed for the improvement of data relating to guides to air quality • • • • • • • • • • • • . . • • . . • • • 9 Needs for the standardization of methods of sampling and analysis of ambient air pollutants • • . . • • • . • • • • • • . • • • 11 Need for international collaboration and agreement on air quality criteria and methods of measurement Annex 1. List of working papers Annex 2. List of WHO publications related to air pollution Annex 3. List of participants . . . . . . . . . . . . . . . 13 16 18 19 WHO/AP/2) p~e2 f An Inter-Regional Symposium on Criteria for Air Quality and Methods of Measurement was convened in Geneva from 6-12 August 1963. Twenty experts in the field of air pollution from 15 countries in the American and European Regions of WHO presented technical papers and participated in the discussions. The meeting was opened by Dr P. M. Kaul, Assistant Director-General, who welcomed the members of the Symposium and reviewed WHO activities with regard to air pollution over the past six years. Professor P. Bonnevie was elected Chairman and Mr V. G. MacKenzie Vice-Chairman. The Symposium discussed the rationale for selecting air quality criteria in Member countries, the role of epidemiological surveys in establishing guides to air quality, and studies on effects indirectly related to human well-being, such as damage to vegetation, soiling of surfaces, and reduction in visibility. The Symposium also defined the areas in which further research is needed to produce data that will serve as a sound basis for establishing guides to air quality; the participants emphasized the need for agreement on methods of measurement that, even if not identical, yield comparable data. GENERAL CONSIDERATIONS The dramatic increases in mortality that have been seen to accompany and follow high atmospheric concentrations of pollutants in coal- and oil-burning communities constitute unequivocal evidence of the serious effects of air pollution. There is, however, still considerable doubt concerni11g the identity of the specific pollutants, or combinations of pollutants, that cause the effects leading to these deaths. The concentrations of many pollutants rise together, and this fact, together with the failure so far to reproduce in the laboratory some of the clinical effects commonly seen during episodes of high pollution, makes it difficult to incriminate specific substances. There is a strong likelihood that the physical form in which the pollutants exist in the air is critical and that their effects also depend on temperature and humidity. The number of deaths appears to be related also to the WHO/AP/23 page 3 number of susceptible people in the commun~ty, which depends in turn on the age structure and health of the population. Recent air pollution episodes have provided opportunities to collect many data on the concentrations and nature of various pollutants associated with increases in mortality. Morbidity statistics provide more sensitive indices of the effects of pollution. To be useful, the indices must be selected with great care in order to avoid artifacts. Much work has been done and is continuing in this field, and published results show convincing agreement between indices of pollution and of morbidity. Simple epidemiological techniques have been used to study the reactions of bronchitic patients, and here again the relationship between concentrations of several pollutants and the health of the patients has been close and consistent. The air in cities where coal and oil are burned contains irritant and carcino- genic substances, and it is logical to assume that these may play an important part in the etiology of chronic bronchitis and lung cancer. ~een reported and is in progress. Much work on these topics has Although time did not permit a comprehensive review of available data by the Symposium, many references were made to the results of past and current studies demonstrating the relationship between various levels of air pollutants and the resulting effects on hutu::~n he.al th and welfare. These studies, although admittedly in••omplA+<=> <2.11d in urgent need of augmentation through further research, formed the. main background to the Symposium discussions. RATIONALE FOR SELECTING AIR QUALITY CRITERIA The pollution by man of the earth's atmosphere has become an important problem of our time, and is increasingly attracting the world-wide attention of scientists, government officials and the public. It has come to be realized that man's right to breathe clean air needs to be protected by taking measures to control the pollution of the atmosphere. Among the Governments that have already adopted standards are those of Czechoslovakia, the Federal Republic of Germany, the United States of America (California, Oregon), and the USSR. Other governments are considering such standards. WHO/AP/23 page 4 Standards relating to air quality and accepted in various countries differ, however, because they have been based on nifferent guides which, in turn, have been based on different criteria (different tests and methods used in the relevant research). The purposes of air pollution standards vary from one community to another and from country to country. Standards are also influenced by the history and tradition of scientific institutions in various parts of the vmrld. In the establishment of pubiic health standards of air quality, public health ufficials act as a bridge betvmen science and governments. The scientists produce basic information for determining the constituents of air pollution and their potential for damage, and advise on the criteria to be used, but it is the governments that adopt standards. The Symposium did not concern itself with numerical standards but only with the criteria on which scientific advice may be based, and it has enabled scientists from various countries to present and discuss their viev.rs in an effort to understand and remove seeming discrepancies. It was not considered the purpose of the Symposium to decide on the numerical data that might serve as guides to air quality for specific air pollutants. the discussions resulted in agreement on the following important principles: However, 1. Criteria for guides to air quality are the tests which permit the determination of the nature and magnitude of the effects of air pollution on man and his environment. 2. Guides to air quality are sets of concentrations and exposure times that are associated with specific effects of varying degrees of air pollution on man, animals, vegetation and on the environment in general. 3. In the light of present knowledge, guides to air quality may be presented as four categories of concentrations, exposure times and corresponding effects. These four categories are defined by limiting values which may vary for a given pollutant according to the anticipated effect or the criteria used and in relation to other coexisting pollutants and the relevw~t physical factors, and which take into account the varying responses of different groups of human beings. The Symposium agreed to define the four categories in terms of the following levels: WHO/AP/23 page 5 Level I (level of detectable effect). Concentration and exposure time below which# according to present knowledge# neither direct nor indirect effects (including alteration of reflexes or of adaptive or protective reactions) have been observed. Level II. Concentrations and exposure times at .and above which there is :likely to be irritation of the sensory organs 3 harmful effects on vegetation, visibility reduction, or other adverse effects on the environment. Level III. Concentrations and exposure times at and above which there is likely to be impairment of vital physiological functions or changes that may lead to chronic diseases or shortening of life. Level IV. Concentrations and exposure times at and above which there is likely to be acute illness or death in susceptible groups of the population. For some known pollutants# it may not be possible to state concentrations and exposure times corresponding to all four of these levels because (a) the effects corresponding to one or more of these levels are not known to occur with the substance in question, or (b) exposures producing effects corresponding to certain levels also produce more severe effects, or (c) the present state of knowledge does not permit any valid quantitative assessment, (e.g., of threshold levels for carcinogenic substances) • The possibility that some pollutants may have mutagenic effects must be borne in mind; however# at the present time# tqo little is kno'~ about this subject to permit classification of such pollutants in the above categories. 4. To facilitate the establishment of_ internationally acceptable guides to air quality as proposed above, the participants in the Symposium suggested the setting-up of a special committee or working party to review existing scientific evidence. They look forward to the sharing of results of research being carried out in many countries and believe that this will lead to a scientific consensus regarding guides to air quality. WHO/AP/23 page 6 5. All the Symposium participants agreed that pollution of the air by biologically active substances resulting from man's activities should be avoided to the maximlli~ extent possible. The aim should be nJt to allow pollution to exceed level I below which no biological effect can be detected. (In certain countries, this level corresponds to the so-called maximum allowable concentration.) Should this goal not be immediately attainable, owing to social considerations relating to man's over-all welfare, including temporary economic and technological limitations, somewhat higher levels of pollution may have to be tolerated for a limited time. ROLE OF EPIDEMIOLOGICAL AND AEROMETRIC SURVEYS Epidemiological studies together with aerometric surveys constitute the most promising means of evaluating the magnitude of the health hazard to a population exposed to air pollution. Aerometric surveys should include measurements of a wide variety of air pollutants and their fluctuations with respect to time and geographic location. One important reason for this is that, although a given pollutant (for example so2) may exist in the same concentration in two different regions, the simultaneous occurrence of other pollutants, such as aerosols or oxidizing compounds, in differing concentrations in each region may make the air pollution situations in the two regions different from the health point of view. Other modifying influences such as meteorological and topographical variables should also be taken into account. The data obtained from epidemiological-aerometric surveys permit correlations between exposures and types of effect including effects not only 011 man himself, but also on his property and on the environment in general. Such data are therefore helpful in establishing guides to ~ir quality. The discovery of adverse effects in communities where air quality standards already exist indicates that the standards and/or control measures may not be adequate. The findings from studies conducted in regions not subject to heavy air pollution or adverse effects also provide very useful information with respect to air quality standards. vmo/AP/23. page 7 Since long'-term effects o:f cer·::.ain :forms of air pollution, such as lung cancer and chronic bronchitis, often appear only after several years of exposure, it is important that ii1'places where'air pollution problems are anticipated, aerometric and epidemiological studies be initiated as early as possible. Epidemiological analysis, espeCially o:f re~rted mortality, has often been used in the initial evaluation of the health effects of atmospheric pollution. Greater specificity and_hence greater value in establishing guides to air quality can be obtained through es~cial;Ly designed epidemiologics.l studies of morbidity and mortality. In epldemi.ological surveys consideratio:1 must bG given to such factors as selection of a r~pre~entative apd random sample of adequate size; avoidance of artifa~ts such as intel'Viewer, respondent and "instrument" Effects in the use of questionnaires; adequate reduction and analysis of ·Ghe data collected. The conduct of aerom9tric surveys likewise requires the employment of accurate and reliable instruments and techniques. Of equal importance are such factors as the number and location of sampling sites, frequency and duration of sampline periods, pollutants selected for measurement, and adverse effects selected for evaluation. In both ep~demiological and aerometric surveys, it is essential that plann~ng and execution be in the hands of highly quo.lified investigators. DAVwGE TO VEGETATION, SOILING OF Su!h~ACES ~~ VISIBILITY REDUCTION In considering a:i.r quality, i~ is approprj_ate "to take into account such effects as. visihil.i ty reduction, soilage and inJury to animals and plants, for ·~hese affect man's ,well-being, cause economic loss, a..'!d are often the :first indicators of a developing air pollution problem that may affect ms.n's health. Visibility ·reduction is caused by the pre::;ence in the atmosphere of particulate matt:;r ranging widely in size, cf varying chemical composition and various physical states. Beca1is:; of these diverse :features the Symposium considered that the criterion of visibility is best related to the greatest diztance that can be seen in a given direction rath·'r tha.."1 to the amount of the suspended particles. If, in the future, means ahd metbods are developed for the measurement and description of atmospheric particles ',vhic:'J. C9n jn turn be related to the extent of visibility, it will be possible to develop a criterion based on quantitative measures of such pe.rticles. WHO/AP/23 page 8 While soilage of goods and damage to property are importap.t causes of economic loss and reflect the status of air quality, the totality of these effects results from the interaction of air pollution and other environmental features such as humidity, temperature, rainfall and length of exposure. Because of these factors, it does not at present seem feasible to establish a criterion for soilage. The effects of air pollution on animals are poorly understood except for fluorosis in livestock, resulting from the ingestion of fluoride-contaminated food. Some small animal species are being used in medical research on air pollution. While the dissimilarity between these experimental animals and man makes difficult the direct extrapolation to man of the results obtained, such animal research can provide information of indisputable value on the effects of air pollutants on biochemical and physiological processes. Because changes in morphology and physiology result from. alterations in fundamental biochemical processes, research upon the influence of air contaminants upon the biochemistry of cellular metabolism and growth should be greatly increased and extended.. Some animals, including certain insect species, may prove useful in determining what, if any, are the mutagenic effects of air pollutants, and research in this area should be encouraged. Damage to vegetation, both to native plants and agricultural crops, is important as an indicator of the presence of air pollution and because it provide~ a means of assessing the kind of air pollution, its occurrence and distribution. Such damage is also important because of its economic significance. Damage to plants often occurs at levels below those known to affect man adversely. Plant-damaging effects of air pollutants have been principally recognized for their gross injury to vegetation. Toxicants formed in urban photochemical pollution cause marked growth suppression at atmospheric concentrations below those producing morphological changes. Plants, including bacteria, fungi, lichens and the higher plant ~orms, are useful biological research tools as well as indicators of specific atmospheric pollutants. It was the feeling of the Symposium that research into the means of using these tools more fully than at present should be encouraged for the study of the mode of action of pollutants and of the effect of contaminants on physiological and biochemical systems regulating enzyme activity, cell permeability, and plant metabolism. WHO/AP/23 page 9 The response of lichens to urban pollution in northern latitudes suggests that it be uoed as a survey tool in estimating the extent and severity of pollution associated with smoke and sulfur dioxide. There is a need to stimulate research on the value of lichens as biological indicators and to develop a practical standard procedure for employing these plants in the detection and evaluation of atmospheric pollution. Air quality criteria may be established for those plant-dam&ging pollutants that have individual and direct effects~ since the injury produced is directly related to the cc·ncentration of the toxicant, and the exposure time. Guides may therefore be established for ethylene, ozone~ peroxyacyl nitrates and sulfur dioxide. An ambient air quality criterion for inorganic fluorine compounds is more difficult to establish, since th~ damaging effects of this toxicant are mainly indirect and result only after sufficient quantities of the contaminant have been accumulated. The injurious effects of some pollutants~ such as ozone and the peroxyacyl nitrates~ are additive. Research upon toxic gas mixtures should be undertaken to elucidate the extent and nature of contaminant interactions in order that air quality criteria may be developed which adequately describe the inclusive deleterious effects of ambient air upon vegetation. While there is some knowledge of the plant response to mixtures of identifiable gaseous contaminants, there is very little knowledge concerning the effects of mixtures of aerosols and gases. Research into this should also be encouraged. Two kinds of biologically important air contaminants are recognized - those that have a direct effect in the form in 1:hich they are emitted and those that do not have a direct effect in their original state but that subsequently react in the atmosphere to produce damaging pollutants. It is therefore essential that guides to air quality be developed not only for the originally toxic contaminants but also for those toxicants produced at varying distances from their source of emission and resulting from inter- action with other contamina~ts in the pollution cloud. MEDICAL STUDIES NEEDED FOR THE IMPROVEMENT OF DATA RELATING TO GUIDES TO AIR QUALITY In view of the limited knowledge available. and the urgent need for improving understanding of the relationships between air pollutants and their effects~ the Symposium made the following suge;estions for medical research in this field. WHO/AP/23 page 10 Epidemiological, clinical and laboratory research are all important for the development of guides to air qualHy. ordinate d. Research in all sectors should be closely eo- Much available information is based on animal experimentation. An ethical and technical basis for carrying out hwnan experiments is being developed and needs to be applied to those matters that are not :;mi table for a:.11imal studies and that can be carried out without undue risk. Objective criteria of sensory irritation should be sought. While chronic disease is a most important criterion of high levels of air pollution, it is desirable to test the hypothesis that some significant effects on the functions of the body, if often repeated, may lead to chronic disease. This should be investigated by longitudinal epidemiological studies, using sensitive biochemical and physiological methods, by studies on the effects of continuous exposure on animals, and by studies using animals vlith infections, with physical defects or subjected to stress. Pollutants that are absorbed into the body should be traced to understand better their metabolism and their subtle biochemical effects. Non-human biological and biochemical systems should be used more extensively as indicators of air pollution effects, both because observation of such systems is much simpler in some cases than measurement of pollutants and because they are capable of responding to the joint effects of multiple pollutants. Further studies are needed on the effects of pollutants on human and animal respiratory function - for example, on the effects of oil mists, sulfuric acid, and particle and gas combinations. In this connexion, more fundamental research is needed on the physics and biophysics of aerosols. Particular attention should be given to studies of new synthetic chemicals which become air pollutants, either by their escape from manufacturing plants or by their use in the community, for example, in pesticide applications. Further studies_should be made of the subtle or long-term effects of occupational exposures to low levels of air pollutants, such as nitrogen dioxide, ozone, and new agricultural chemicals, because such exposures may indicate what acute or chronic effects to expect in the case of atmospheric pollution exposures. WHO/AP/23 page 11 The possible mutagenic and carcin~~~nir (offc ':ts o:C p.>ll-xc:::.nts s:~ .. -.uL~ ~ o stur~ie·~. Immunological and allergic reactions to air pollutants are important, and should be studied both as criteria of population sensitivity or susceptibility, and as indicators of reactions to pollutants in the past. The response of the mucc:.~s lJ.yer J.D•l ,::l.li:.:ry a:Jti·,ri ty ·in t~,e r~:;spil~.:ltory' trc..c:t mlly provide a basis for the postulated chronic and other effects of pollutants and should be further investigated; so should the mechanisms of ~ulmonary fibrotic reactions. The effects of pollutants on the odour threshold, on the sensitivity of vision and hearing, and on conditioned and non-conditioned reflexes have provided evidence of the earliest response to pollutants at extremely low levels. 11microtoxicit;y" studies be substantially augmented. It is suggested that such Since pollutants usually occur in combinations, more research on whether these combinations are additive, synergistic or antagonistic is needed. It should be emphasized that temperature, humidity, sunlight ru1d atmospheric pressure may influence pollutant effects; the modifying influence of these and other factors should be studied and these meteorological conditions should be specified in reports on laboratory and epidemiological research. NEEDS FOR THE STANDARDIZATION OF METHODS OF SAMPLING AND ANALYSIS OF AMBIENT AIR POLLUTANTS In view of the growing importance of air pollution in relation to the health and welfare of industrial and urban communities and associated effects on vegetation, visibility and property, investigations into concentration levels of pollutants are in progress in many areas of the world. So that the data resulting from these studies may be readily compared, standardization of nomenclature, units of measurement, methods of air sampling and analytical techniques is necessary. At present there is wide variation in methods of sampling and analysis and in the methods of reporting results (including the units used in reporting data), thus leading to much confusion and diffio~lty in interpretation of results. WHO/AP/23 page 12 In the course of the Symposium, it was suggested that concentration data for contaminants, suspended or dispersed in the atmosphere, or for dustfall, be reported in metric units. Concentration levels involving specific gaseous or vapour compounds may also be expressed in parts per million in air, by volume (at standard temperature and pressure) where the molecular weight is known. Smoke or haze concentrations are frequently determined by the evaluation of spots or deposits on filter-paper by optical transmission or reflection measurements. It is advisable to give the appropriate conversion factor if the results are evaluated by means of reflectance measurements, so that the data may be compared with the corresponding transmission values. Conversion of transmittance or reflectance measurements of filtered deposits into mass-concentration values is not recommended, since the relation between the optical density of a deposit and mass is too complex and variable. The duration of the sampling time for which analysis of the concentration level of a pollutant is reported should be clearly stated. Methods of analysis for a number of common pollutants are available in the scientific literature and have been assessed by committees of various organizations, such as the International Union of Pure and Applied Chemistry (IUPAC). These should be reviewed and international agreement on methods should be reached as soon as possible. For polycyGlic aromatic hydrocarbons, the sampling technique involves the collection of suspended particulate matter, extraction of the soluble fraction in pure benzene or cyclohexane, chromatographic separation, and examinat~on of the eluted, purified compounds by ul tra-'.rioL;-t, o.bsorptton or flu,:;;:·:;scenee tec:ulJqut::s. This procedure may be considered for standardization. The planning of sampling programmes will depend upon the objectives of the study and the nature of the effects of the pollutants to be determined. Ordinarily, a programme of sampling over short periods of time is sufficient to obtai.n data on those. substances that produce eye or other sensory irritation, sensitization, or more acute toxic effects. extended sampling programmes to obtain time-weighted average values are necessary to obtain data on substances that produce cumulative effects and on substances with a potential carcinogenic action. More -- WHO/AP/23 page 13 In order to evaluate daily, weekly, seasonal and annual cycles of pollution, it is necessary to employ continuous sampling and analysis, with automatic instrumentation and recording of peak and average concentrations over definite time intervals. However, much useful information may be gathered in short-term studies on a limited budget. Such a comparatively inexpensive surveillance programme should include 1 measurements of: (a) dustfall, (b) suspended particulate matter by means of the high volume sampler, (c) smoke or haze densities by the paper-tape sampler and evaluation by optical measurement, (d) sulfur dioxide by the rate of sulfation of lead peroxide candles, and (e) specific gases, such as carbon monoxide, oxides of nitrogen, hydrogen sulfide, etc~, by means of silica gel indicating tubes, and other simple procedures. A symposium on the epidemiology of air pollution arranged by the WHO Regional Offic<:; for Europe in 1960 agreed that dustfall should not be recommended as an index of pollution that could be t d t 1 t •th . t d. 1 expec e o corre a e Wl resplra ory lsease. The participants in the present Symposium agreed with this conclusion but considered that in countries where dustfall is used as a measure of coarse particulate pollution it woufd Ee- advisable to adopt methods that yield comparable results. NEED FOR INTERNATIONAL COLLABORATION AND AGREEMENT ON AIR QUALITY CRITERIA .AND METHODS OF MEASUREMENT There is great interest in many countries in common air pollution problems. Unfortunately, no one country has sufficient resources to meet all the needs for progress in this field, though in many areas this could be accelerated by international collaboration end pooling of information. Such co-operation is particularly necessary in view of increasing evidence that air pollution is not merely local in character but can be widely dispersed over extensive areas transcending local and national boundaries. The following ' suggestions r8sulted from the discussions of the Symposium: l. Standardization of nomenclature, units of measurement and methods of presenting results W0rk carried out so far to facilitate international comparison of results of experiments and studies appears to be hampered by lack of uniformity in nomenclature and units of measurement. International agreement on these questions has undoubtedly a high priority. . l Lawther, P. J., Martin, A. E. & vJilkins, E. T. (1962) Epidemiology of air pollution, Geneva, World Health Organization (Public Health Papers No. 15) WHO/AP/23 page 14 2. Standardization of sampling and analysis Many of the methods used in the sampling and analysis of air pollutants are non- specific owing to the complexity of the chemical and physical properties of polluted air. Empirical methods have therefore been adopted in the various countries in order to proceed with aerometric surveys and the study of air pollution effects. Although these empirical . methods may have served their purpose well within the various countries, any attempt to reach international agreement on levels at which effects occur must be based on pre- determined and comparable procedures. 3. Dissemination of information The Symposium considered that the available material such as text-books, periodicals, pamphlets and reprints, should be made widely known and easily accessible to interested workers. The use of existing abstracts on air pollution for the development of an international abstract service in the main languages was considered advisable. 4. Promotion of research, scientific knowledge and control measures The Symposium considered this could best be achieved by: (a) exchange of scientific personnel among countries; (b) provision of fellowships for long-term studies as well as for short-term orientation; (c) organization of courses for technical personnel; (d) organization of exhibitions of scientific instruments and achievements; (e) stimulation and assistance for specific research; (f) preparation of an international guide on air quality criteria for assisting countries in developing national standards; (g) assisting exchange of information among research workers in various countries; (h) organization of international meetings on various aspects of air pollution. 5. Promotion of collaboration among agencies in similar or related fields WHO/AP/23 page 15 It was recognized that many other disciplines 2.s 7 for example, meteorology, have an important bearing on air pollution, and collaboration among the agencies concerned would be of great benefit in promoting air pollution control. Participation in activities of common interest also should be encouraged. 6. Health education and public information Although the Symposium did not have time to discuss in detail this aspect of the air pollution problem, it nevertheless recognized its great importance. The need was emphasized to increase the awareness of air pollution hazards in those responsible for industrial and commercial activities and to develop their interest in methods of reducing pollution. No less important is the education of the public which is interested above all in breathing clean air and ':>Those support is indispensable to an efficient control programme. 7. Role of WHO Because of the growing importru1ce of air pollution problems and because they increasingly affect large population groups all over the world, it is natural that WHO should have a leading role in implementing the suggestions outlined above. urges that the highest priority should be given to the following: (a) standardization of terminology, instrumentation and techniques; The Symposium (b) elaboration of methods for the execution of epidemiological and aerometric surveys; (c) establishment of special committees or working parties to review scientific evidence useful in drm-Jing up internationally acceptable guides to air quality; (d) exchange of qualified technical personnel among member countries; (e) provision of special training programmes; (f) dissemincction of available literature and abstracts; (g) stimulation of specific research projects cmd appropriate international collaboration in their execution. WHO/AP/23 page 16 Bloomfield, J. J. & Haddad, R. ANNEX l LIST OF WORKING PAPERS Atmospheric pollution in Latin America (WHO/AP/21) Bonnevie, P. Atmospheric contaminants and human health (WHO/AP/7) Cederlof, R., Friberg, L. & Jonsson, E. The epidemiological approach in estimating MAC values, with special reference to medica-sociological and statistical methodology (WHO/AP/6) Goldberg, S. The effect on the respiratory organs of quartz-containing dust in the atmosphere (\iHO/AP/2) Goldsmith, J. R. Medical studies needed to produce new data on which to base sound criteria for ambient air quality (WHO/AP/18) Heller, A. Maximum permissible concentrations for air pollution in the Federal Republic of Germany (WHO/AP/8) Hogger, D. Le dioxyde de soufre en tant que composant de la pollution de l'air (WHO/AP/5) Just, J. Criteria for the evaluation of atmospheric air pollution and standards of air quality used in Poland (\~0/AP/12) Katz, M. Standardization of methods of m2asure of air quality in member countries (WHO/AP/9) Lawther, P. J. Compliance with the Clean Air Act - Medical aspects (WHO/AP/16) MacKenzie, V. G. The philosophy of establishing air quality criteria as guides for the setting of air pollution control stand&rds in the United States of America (WHO/ AP/17) Middleton, J. T. Air quality criteria associated with visibility reduction, soilage and damage to vegetation (l~O/AP/15) Petrilli, F. L. & Agnese, G. Le r6le des etudes epidemiologiques dans le developpement des jugements de la qualite de l'air (WHO/AP/22) Petrilli, F. L. & Kanitz, S. Aspects of air pollution by motor vehicles (WHO/AP/19) Rondia, D. Essais de mise au point d'un critere adequat de nocivite des polluants atmospheriques et suggestions sur une campagne de lutte contre la pollution (WHO/AP/4) 1tJHO I AP I ~3 page 17 Annex l Rossano, A. T. Analysis and comparison of available data on air quality criteria in member countries (WHO/AP/11) Rjazanov, V. A. The philosophy RDderlying the adoption of air quality criteria as guides for the establishment of air pollution standards in the USSR (WHO/AP/1) Stocks, P. A study·of tobacco smoking, air pollution, residential and occupational histories and mortality from cancer of the lung in two cities (WHO/AP/.3) Symon, K. Some aspects of air pollution - a public health hazard in Czechoslovakia (WHO/ AP/13) Tesch, J. W. The problem of air pollution in The Netherlands and some considerations regarding norms for air pollution (WHO/AP/20) Truhaut, R. Aperqus sur les risques de cancerisation pouvant resulter'de la pollution de l'air des villes (WHO/AP/14) Vouk, V. B. & Fugas, M. A short review of clean air p!'oblems in Yugoslavia (WHO/AP/10) WHO/AP/23 page 18 LIST OF WHO PUBLICATIONS RELATED TO AIR POLLUTION ANNEX 2 Air pollution: a menace to public health. In: Chron. Wld Hlth Org., 1958, 12, 14 (Article based on WHO Conference on Public Health Aspects of Air Pollution, Milan, 6-14 November 1957) WHO Expert Committee on Environmental Sanitation, fifth report, Wld Hlth Org. techc. Rep. Ser., 1958, 157 Lawther, P. J., Martin, A. E. & Wilki~s, E. T. (1962) Epidemiology of air pollution, Geneva, World Health Organization (Public Health Papers, No. 15) WHO Expert Committee on Radiation, third report, Wld Hlth Org. techn. Rep. Ser., 1962, 248 Air pollution: a survey of existing legislation. 1963, 14, No. 2 Offprint from Int. Dig. Hlth Legis., W1d H1th Org. techn. Rep. Ser., 1961, 213 (Chronic cor pulmonale, report of an Expert Committee) Air pollution: Wld Hlth Org. Monogr. Ser., 1961, 46 (Conference on the Public Health Problems of Air Pollution in Europe, Milan, 6-14 November 1957 (mimeographed volume)) LIST OF PARTICIPANTS Professor G. Agnese, Institute of Hygiene, University of Genoa, Italy WHO/AP/23 page 19 ANNEX 3 Professor P. Bonnevie, Director, Institute of Hygiene, Copenhagen, Denmark (Chairman) Professor L. Friberg, Institute of Hygiene, Karolinska Institutet, Stockholm, Sweden Professor N. S. Goldberg, Institute of General and Municipal Hygiene, Moscow, USSR Dr John R. Goldsmith, Head, Air Pollution Medical Studies, California Department of Public Health, Berkeley, California, United States of America Professor E. Heller, Institute of Water, Soil and Air Hygiene, Berlin-Dahlem, Germany Professor D. Hogger, Chef du Service medical du Travail, Office federal de l'Industrie, des Arts et Metiers et du Travail, Zurich, Switzerland Professor J. Just, State Institute of Hygiene, WarsaH,·Poland Dr M. Katz, Director, Environmental Assessment, Department of National Health and Welfare, Ottawa, Canada Dr P. J. Lawther, Director, Medical Research Council, Air Pollution Research Unit, St Bartholomew's Hospital Medical College, London, England Mr Vernon G. Mackenzie, Chief, Division of Air Pollution, Department of Health, Education and Welfare, United States Public Health Service, Washington, :.:::.,. unitet~ States of America (Vice-Chairman) Dr John T. Middleton, Director, Air Pollution Research Center, University of California, Riverside, California, United States of America Professor L. Petrilli, Director, Institute of Hygiene, University of Genoa, Italy Monsieur D. Rondia, Laboratoire de Chimie medicale, Toxicologie et Hygiene, Universite de Liege, Belgium Dr August T. Rossano, Research Professor, Department of Civil Engineering, University of Washington, Seattle, Washington, United States of America Professor V. A. Rjazanov, Director, Institute of General and Municipal Hygiene, Moscow, USSR Dr K. Symon, Director, Institute of Hygiene, Prague, Czechoslovakia vJHO/AP/23 page 20 Annex 3 Professor J. W. Tesch, President, Organization for Health Research TNO, The Hague, Netherlands Prpfesseur R. Truhaut, Professeur de Toxicologie et d'Hygiene industrielle a la -"'Fiic'ulte de Pharmacie de l'Universite de Paris, France Professor V. B. VoUk, Director, Institute of Medical Research, Zagreb, Yugoslavia WHO Secretariat · Mr J. J. Bloomfield, Adviser in Industrial Hygiene, WHO Regional Office for the Americas, Santiago, Chile Dr A. Kagan, Me.dical Officer, Cardiovascular Diseases, WHO, Geneva . ·.- Mr R. Pavanello, Chief, Air and Water Pollution, WHO, Geneva (Secretary) Mr G. Paghis, Officer for Environ~ental Sanitation, WHO Regional Office for Europe, Copenhagen Mr R. Porter, Programme Officer, Division of Air Pollution, Department of Health, Education & Welfare, United States Public Health Service, Washington, D.C., Un:V.:eC: ,'Jtn.tes of ;i.merio':l. (Consultant) Dr A. J. Tuyns, Medical Officer (Epidemiologist), Cancer, WHO, Geneva