JOHN R. GOLDSMITH Head, Air Pollution Medical Studies California State Department of Public Health Berkeley, Calif.

Air pollution morbidity means sicknesses due to air pollution, and initial efforts at research on health effects of air pollution were concerned with questions such as how many cases of asthma, bronchitis, or emphysema, are caused by air pollution. Similar questions about deaths due to air pollution were raised. We have learned that the methods of study available and the chronic nature of the diseases combine to make these very difficult questions to answer. By population survey methods, however, we have learned that there are widespread health effects reported, which go beyond what are customarily included in morbidity rates, but in some respects are more meaningful.

The questions which the public is asking about air pollution health effects will be put in nontechnical terms and answers, when available, will be outlined.

Public Concern About the Health Effects of Air Pollution

Let us visit together the home of the average well-informed urban citizen. Shall we call this family, from the first initials of their name (Average Well-Informed Urban Citizen At Home) the Awiucah? Without naming the community in which the Awiucahs live, I ask you to imagine that they live in any community experiencing air pollution and troubled by it. On our visit, after identifying ourselves as being from an official agency charged with studying the effects of air pollution, we are cordially admitted. We ask the question, "Are you bothered by air pollution?"

place which his doctor said would be healthier for him. The property values are declining because this isn't as nice a place to live as we had hoped it would be. If something isn't done about it, my family and I will have to give serious thought to moving as well."

It is now Mrs. Awiucah's turn. "Do you remember that bad hot spell we had a few weeks ago? It was so bad that my father died the day the weather cleared up. He had been in a nursing home and was moved to a hospital but, despite what the doctors did for him, his breathing got no better and he finally died. The smog is always worse during hot weather, but hot weather never used to bother our breathing. Our youngsters also suffer. One of the children has asthma, and when the smog is bad, he is worse. He missed 4 days of school during this bad smoggy period last month.

"Not only does it bother our health," Mrs. Awiucah continues, "but it adds to the housekeeping chores. I have to wash the windows and curtains three times as often now as I did 10 years ago, and it's not possible to hang the wash outside without the risk that it will be soiled by cinders or soot."

"It also," says Mr. Awiucah, "interferes with my hobby. I am an amateur orchid grower and since the new freeway went through three blocks from our place, I can't grow first-rate blooms any longer.

"This stuff must be harmful," he goes on; "it is so irritating I cannot drive my delivery truck through town on a bad day without my eyes smarting so that I cry enough to fill a bucket.”

"Besides," says Mrs. Awiucah, lighting a cigarette and offering each of us one, "this dirty stuff in the air can cause lung cancer, can't it? I am worried about myself and my family."

Fortunately, there is no such family as the Awiucahs, and no such community has all of the problems which this family asks about.

Deaths From Air Pollution

In three separate episodes, unusual weather conditions which were associated with low winds and stagnant air have led to mortality clearly beyond what would have been expected otherwise. In Belgium in 1930, in the Meuse River Valley (1), a large number of people had respiratory tract irritation and 60 died. The illness in each of these episodes affected mostly older persons with previously known diseases of the heart and lung.

In 1952, most of the British Isles were covered by fog and temperature inversion during the week of December 5 through 9 (2). An unusually large number of deaths occurred and many, many persons were ill. An increase of mortality at all ages was observed, but the greatest increase was in those in the 7th and 8th decades. The mortality remained elevated for several weeks after the weather had cleared. The total excess was between 3,500 and 4,000 deaths.

In 1948 (3), in the valley of the Monongahela River, Pa., the Donora episode caused 43 percent of the population to become ill and 20 died in a community of less than 15,000.

More recent episodes have been reported for New York (4) in November 1953 and for Los Angeles in August and September 1955 (5), but the number of excess deaths was small in the former episode and the effect of air pollution was complicated by extraordinary high temperature in the latter case. Air Pollution as a Cause of Acute Sickness

Physicians as well as laymen have reported that asthma and other respiratory complaints are worse during smoggy weather. In one study in Los Angeles, a record was made of the occurrence of asthma attacks in a group of asthmatic patients in 1956 (6). These were compared with air pollution measurements, pollen counts, and determinations of temperature and smog damage to vegetation. No environmental factor could be found to precipitate the great majority of asthma atacks; however, there was a slight statistical association between the onset of attacks and typical smog damage to vegetation.

The association could have occurred if about 7 percent of the asthmatics were in fact reacting to air pollution.

Possible relationship between air pollution and asthma attacks has also been recorded from New Orleans (7) and from the Kanto plains area in Japan (8), where American servicemen have experienced much disability as a result of air pollution.

exposures. In the latter two cases, the exact pollutants have not been determined. The possible relationship of air pollution in Nashville, Tenn., to asthma has also been reported by a team from the Public Health Service (9).

Air Pollution and Chronic Disease

Studies of chronic disease rates in Great Britain in relationship to air pollutant levels have demonstrated that there is an impressive relationship between morbidity and mortality rates from chronic bronchitis and air pollution (10), on the one hand, and mortality from lung cancer and air pollution on the other (11). In the United States the evidence is not as clear cut. The rates for chronic bronchitis and lung cancer are in general lower in the United States than in Great Britain, when comparable age and sex groups are compared. However, both of these groups of conditions are more common in urban than in rural areas, and air pollution has been thought of as the possible factor to account for these increases (12). On the other hand, clear-cut relationships of cigarette smoking to both of these conditions have been established in this country as well as Great Britain (13, 14). Because different patterns of decisions are needed for reducing the exposures, we may tend to separate the effects of cigarette smoking on chronic lung. disease from those of community air pollution on the same condition, but it is not reasonable to expect that the cells of the lung will make such a distinction. For this reason it is our current view that the total amount of inhaled pollution, regardless of the source, is probably a single one of the factors which influence the rate of both lung cancer and chronic nontuberculous lung diseases. Attention must be directed to at least three major types of exposure: occupational air pollution, community air pollution, and the air pollution associated with the smoking of cigarettes.

From both experimental and epidemiologic studies, there is every reason to think that some individuals are more sensitive to air pollution than others. We know, for example, that some individuals are unusually sensitive to small amounts of sulfur dioxide (15). In all likelihood, therefore, it will some day be possible to determine which individuals are most susceptible to inhaled pollutants and to direct our preventive efforts to these individuals.

A number of studies have investigated how much aggravation of a preexisting lung condition could

be produced by air pollution. These studies have often taken quite severely ill individuals as their subjects (16). The disadvantage of such studies is that the quite severely ill persons fluctuate in their state of health rather widely even in the absence of air pollutants or other detectable causes. It has been clearly shown by Motley, Leftwich, and Smart (17) that men with severe emphysema, placed in rooms from which smog was filtered, had improved lung function when this procedure was followed during smoggy weather. When they were placed in the same rooms during weather in which the smog levels were low, there was no improvement. There was no improvement detected in persons without emphysema placed in the same rooms during smoggy periods. From this it is suggested that air pollution had produced some decrease in the function of lungs in emphysematous persons.

Interference by Air Pollution With Important Functions of the Body

Two functions have been examined with some

care.

The ability of lungs to move air in and out has been studied by making measurements of the resistance to airflow within the conducting passages of the lung (18). Very sensitive and reliable instruments have been developed in the past few years which make it possible to measure changes in the resistance to airflow of which the subjects themselves are unaware. Increases in the airflow resistance increase the amount of work which must be expended in order to breathe (19). Low concentrations of sulfur dioxide, inert dusts in fairly substantial doses (20), and the smoke from a single cigarette (21) have all been shown to produce increases in the resistance to airflow. Relatively little use has been made of these sensitive methods in investigating community air pollution, though other methods have been used to measure lung function in a variety of field studies. The results of most of these studies are inconclusive. However, the studies of Motley et al. do suggest that in some circumstances such an effect could be found.

A second major function with which air pollution interferes is the transport of oxygen by hemoglobin, the red pigment of the blood. This function is interfered with by relatively small concentrations of carbon monoxide (22). For example, it has been estimated that continued exposure to 30 parts per million of carbon monoxide would tie up about 5 percent of the body's circulating hemoglobin, making it unavailable for the trans

port of oxygen. Even lower concentrations must produce a measurable interference with this function. While most people would be completely unaffected by such a small change in the oxygen capacity of the blood, certain individuals with borderline effectiveness of the heart, lungs, or blood vessels may be affected in an important way.

Irritation of the Eyes, Nose, and Throat

The most widespread effect of smog in Los Angeles is eye irritation with tearing and redness (23). The exact substance responsible for this is not known, but it is known that it can be reproduced by mixtures of hydrocarbon vapors and oxides of nitrogen which are irradiated by strong lights or by sunlight. Almost 75 percent of the population in Los Angeles County is thus bothered by air pollution. Studies so far fail to indicate that any chronic or long-term effects can be attributed to this irritation. In addition, a number of people report that smog in Los Angeles interferes with their breathing and produces throat irritation. In other parts of the country, flyash is a distressing pollutant, in part because the particles get into the eye. Also sulfur dioxide is a respiratory tract irritant. But even in London, where sulfur dioxide and flyash pollution is supposed to be much greater than in urban areas of the United States, there is nothing like the widespread symptoms that occur in Los Angeles from photochemical air pollution.

Many air pollutants have a distasteful odor. Among the worst is hydrogen sulfide, which can be detected by its unpleasant odor at a concentration of one-tenth of a part per million. Ozone also has an unpleasant and irritating odor but is capable in addition of paralyzing the sense of smell (24). Interference With Human Well-Being

Obliteration of the view, obscuring of the sun, and damage to home or commercial garden plants, may not usually be thought of as effects of air pollution on health. But they do interfere with the enjoyment of living. When air pollutants are capable of soiling paint, windows, and fabrics, and harming vegetation, the importance to human wellbeing may not be safely overlooked.

Summary

"Air pollution morbidity and mortality" means the measurable effects of air pollution on human health and well-being. These effects are measured by the collected experience of many urban families.

The experience of a fictitious family which reports all these effects was presented. These include:

1. Effects on death rates which have been measured in the disasters of London, Donora, and the Meuse Valley.

2. The causation of acute illness, primarily asthma and other respiratory conditions which have been detected in New Orleans, Tokyo, Yokohama, and possibly Pasadena.

3. Occurrence of chronic lung disease such as chronic bronchitis, emphysema, and cancer of the lung which have been related to air pollution in England. While there is an excess

of these conditions in urbanized areas, a causal role of community air pollution has not been proven in the United States.

4. Interference with important functions of the body, particularly the function of moving air into and out of the lungs, and the transport of oxygen by the hemoglobin of the blood.

5. Irritation of the eyes, nose, and throat. 6. Impairment of well-being because of interference with view, of property damage, of damage to vegetation, and of interference with the enjoyment of living.

1. J. FIRKET. "Sur les causes des accidents survenus dans la valle de la Meuse, lors des brouillards de decembre 1930. Resultats de l'expertise judiciaire faite par MM. Dehalu, Shoofs, Mage, Batta, Bovy, et Firket. Bull. acad. roy. med. Belg. 11, 683-741 (1931). 2. MINISTRY OF HEALTH. "Mortality and Morbidity During the London Fog of December 1952," Reports on Public Health and Related Subjects No. 95. Her Majesty's Stationery Office, London, 1954. 3. H. H. SCHRENK, H. HEIMANN, G. D. CLAYTON, W. M. GAFAFER, and H. WEXLER. "Air Pollution in Donora, Pennsylvania." Public Health Service Bulletin No. 306. U.S. Public Health Service, Washington, D.C. 1949.

4. Leonard GREENBURG et al. Report of an Air Pollution Incident in New York City, November 1953. Public Health Reports, Vol. 77, No. 1, January 1962.

5. J. R. GOLDSMITH and L. BRESLOW. Epidemiological Aspects of Air Pollution. J. Air Poll. Control Assoc. 9, 129 (1959).

6. C. E. SCHOETTLIN and E. LANDAU. Air Pollution and Asthmatic Attacks in the Los Angeles Area. Public Health Reports, Vol. 76, No. 6, June 1961. 7. RICHARD A. PRINDLE and E. LANDAU. Health Effects From Repeated Exposures to Low Concentrations of Air Pollutants. Am. J. of Public Health, Vol. 77, No. 10, October 1962.

8. HARVEY W. PHELPS and SHIGEO KOIKE. TokyoYokohama Asthma. Am. Rev. Resp. Dis., Vol. 86, No. 1, 1962.

9. L. D. ZeiDBERG, R. A. PRINDLE, and E. LANDAU. The Nashville Air Pollution Study: I. Sulfur dioxide and bronchial asthma. A Preliminary Report. Vol. 84, No. 4, 1961.

10. D. D. REID and A. S. FAIRBAIRN. The Natural History of Chronic Bronchitis. Lancet 1, p. 1147, 1958.

11. P. STOCKS. On the Relations Between Atmospheric Pollution in Urban and Rural Localities and Mortality From Cancer, Bronchitis, and Pneumonia, with Particular Reference to 3,4-benzopyrene, beryllium, molybdenum, vanadium, and arsenic. Brit. J. Cancer 14, 29. 1960.

12. N. E. MANOS. Comparative Mortality Among Metropolitan Areas of the United States, 1949-51.

Public Health Service Publication No. 562, Washington, D. C., 1957.

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13. ROYAL College of PHYSICIANS OF LONDON. ing and Health, p. 27. Pitman, New York, 1962. 14. OSCAR J. BALCHUM et al. A Survey for Chronic Respiratory Disease in an Industrial City. Am. Rev. Resp. Dis., Vol. 86, 675, 1962.

15. R. F. PattLE and H. CULLUMBINE. Toxicity of Some Atmospheric Pollutants. British Med. Jour. 2, pp. 913-916, 1956.

16. J. J. PHAIR and T. STERLING. Epidemiological Methods and Community Air Pollution. Arch. Env. Hlth., Vol. 3, 267, 1961.

17. H. L. MOTLEY, R. H. SMART, and C. I. LEFTWICH. Effect of Polluted Los Angeles Air (Smog) on Lung Volume Measurements. J. Am. Med. Assoc. 171, 1469, 1959.

18. A. B. DUBOIS, S. Y. BOTELHO, and J. H. COMROE, Jr. A New Method for Measuring Airway Resistance in Man Using a Body Plethysmograph. J. Clin. Inv. 35, 327, 1956.

19. J. R. GOLDSMITH. How Air Pollution Has Its Effects on Health. Proc. National Conf. on Air Pollution. Public Health Service Publication No. 654, 1959. Washington, D.C.

20. ARTHUR DUBOIS and LUCIEN DAUTREBANDE.

Acute

JAMES H. STERNER

Medical Director Eastman Kodak Co. Rochester, N.Y.

The objective and realistic conclusions presented by Dr. Goldsmith, in relating what reasonably can be accepted thus far from an examination of morbidity and mortality data associated with air pollution, emphasize the complexity and the difficulty of the problem, and the long road ahead. The increases in illness and death in the three incidents or accidents the Meuse Valley, Donora, and London-serve as a traditional point of departure in every major discussion of the health considerations in air pollution, but are of limited practical value in assessing the diffuse and varied air pollution problems which face our American cities. Similarly, the episodes in Japan and in New Orleans, while connoting that under special circumstances epidemic asthmalike disease is associated with air pollution, contribute very little to the appraisal of the general problem. In the former examples, at least with respect to the Meuse Valley and Donora, the control of industrial plant effluents during periods of severe inversion will at least prevent a major incident. The asthmalike characteristic of the illness in the Kanto plains in Japan suggests a peculiar etiologic factor, or factors, which may bear little relation to the conditions affecting people with asthma in the varieties of air pollution reported in this country. These incidents clearly signal that specific types of pollution above a certain level can and do seriously affect health, but offer little help in extrapolating downward to lower levels of exposure and more chronic effects, which is our major problem.

At the other end of the scale, in measuring the health effects of air pollution, are the damage to vegetation and to property, and in certain situations the marked irritation of eyes, nose, and throat.

The annoyance and frustration value of these characteristics should not be underestimated, but there is no good evidence that they are in themselves indicators of serious pathological conditions. Fortunately, the discomfort factor often serves as a more powerful stimulus to public action than the threat of a more serious but more remote and less readily appreciated effect, such as lung cancer.

The substantial evidence needed to define the effects on health from air pollution must come from broad epidemiologic studies of morbidity and mortality, from realistic and valid experimental toxicology, and from clinical studies contrived to demonstrate meaningful effects from the varied environmental factors encountered in actual air pollution conditions. The interpretation of the results of investigations in any one of these areas frequently is difficult; the synthesis of information from all of the approaches, in terms that are sufficiently convincing to generate acceptance and effective action by the public, will tax the ingenuity and the ability of all of us in environmental health. I would agree with the inference of Dr. Goldsmith's conclusions, that much more epidemiologic evidence is needed to define the relationship of air pollution in this country to such effects as chronic. bronchitis and pulmonary cancer. Similarly, although a beginning has been made in evaluating the factors in air pollution with clinical changes, the surface scarcely has been scratched in this important investigative approach. To the moment, the evidence thus far accumulated demands of the prudent observer that further and better information be acquired.

There are important analogies for the study of the health effects of air pollution from the experi