the homeostasis of our bodies and minds, or do we want to free ourselves of these stresses and lead happier and more productive lives? We all are responsible for our present crisis, and those of you who make the decisions are now aware of the sociological urgency and the true nature of the problem of air pollution.

SENATOR TYDINGS. Dr. Snell.

We are delighted to welcome you, Dr. Snell.

We will introduce your statement in its entirety in the record and ask you that you summarize it.

TESTIMONY OF DR. ROBERT E. SNELL

Dr. SNELL. Senator, as I have indicated in the prepared statement my competence lies in the field of respiratory disease and respiratory physiology.

The substance we associate with air pollution is an interest to the physician who is interested in chest diseases because they gain entry into the body and to the lungs.

Now, going back to some of your questions to Mr. Griswold concerning the health effects of these agents. I would like to indicate that of all the gases, sulfur dioxide is a strong respiratory irritant because

it narrows the airways and affects breathing. The incidence of asthma is related to the level of sulfur dioxide. This is a report from Japan. Nitrogen oxide, the oxide of nitrogen in general produces scarring of the lung, fibrosis, carbon-monoxide asphyxiation.

And ozone, which is gaining increasing importance with the development of jet aircraft-this has been shown in animals to be capable of producing chronic lung disease, acceleration of the aging process and an increased rate of growth of lung tumors.

The particles listed here and shown in the pictures, these affect according to their size. The ones so evident are the ones that soil our homes, dirty our clothes. It is the smaller particles, the ones that are invisible that are capable of producing disease, because they can penetrate the lower regions of the lung. They can also carry with them hydrocarbons of lead, some of these other metals and these can produce toxic action at some site distant from the lungs.

These would also be the ones in reference to an earlier question that would have the greatest mobility and be able to travel to Maryland and Virginia while the large particles would fall out.

We really have no strict medical proof that chronic emphysema and bronchitis results from air pollution; but I think we have good indirect evidence that this is so. I think that chronic lung disease doesn't develop overnight in an otherwise healthy adult, but results from a series of insults over the years and smoking appears to be one of these and air pollution appears to be another. The fact that we have been unable to demonstrate in the laboratory or in industrial medicine that this is so the relationship between these diseases and air pollution— I don't think we can stress or extrapolate it to the man who lives 50 years breathing dirty, sooty air.

Also in the studies that have been done, attention has been paid to the healthy adult, the middle-aged adult, and it is the very young and very old persons that are susceptible to the effects of pollution. This has been shown in the various disasters.

So we really have a twofold problem. We need more research on the effects of some of these, and currently, as Dr. Feinberg indicated, at the children's convalescent hospital we are developing a unique facility where we will be able to carefully control or monitor the atmospheric conditions, vary these conditions, and observe the effects on pulmonary function.

But I would like to stress that I don't feel that abatement procedures may be contingent on this type of research, on completion of this type of research. We have enough evidence now I think, that we are facing a health burden. This burden is increasing as the population grows and stresses the self-cleansing properties of the atmosphere. There is a need now for better control of open trash burning, incineration, consumption of poor quality fuels and automotive emissions in order to bring down these levels.

In the District of Columbia, air sampling has revealed relatively high levels of sulfur dioxide, oxides of nitrogen and suspended particulate matter, all substances with health damaging potential. Research and abatement activities must proceed hand in hand in this

area.

Senator TYDINGS. I notice that you state in your last paragraph that there is a need now for better control of open trash burning, incinera

tion, consumption of poor quality fuels and automotive emissions in order to bring down these levels. I gather from that that you feel that this is a factor of the utmost urgency.

Dr. SNELL. I think so.

Senator TYDINGS. Would you state unequivocally that the health of the citizen living in the District of Columbia and the Washington metropolitan area is adversely affected by the air pollution emissions from the District of Columbia?

Dr. SNELL. I think so. I think we can say definitely that the health of the already diseased person, the person who has some health burdens such as emphysema or heart disease, is adversely affected.

What we want to show and what we feel is that everyone's health is affected by exposure to this air. This is something that has to be proven, but I think it will be shown to be so.

Senator TYDINGS. Senator Spong?

Senator SPONG. Medically what you are saying is that you cannot yet say it is the proximate cause of any of these diseases, but you can certainly say conclusively that it is an irritant and contributing factor.

is

Dr. SNELL. Right.

Senator TYDINGS. And at least in Japan and some other spots there

Dr. SNELL. We are currently engaged in a similar project and looking at the incidence of admissions for asthma, emergency room treatment for asthma, attempting to show correlation here with such pollution.

Senator TYDINGS. Thank you very much, Dr. Snell.

Your prepared statement will be placed in the hearing record at this point.

(Statement referred to follows:)

STATEMENT OF DR. ROBERT E. SNELL

Mr. Chairman and members of the committee, my name is Robert E. Snell. I am a physician specializing in the study of human respiratory function, a member of the faculty of Georgetown University School of Medicine and Director of the Asthma Research Unit at The Children's Convalescent Hospital in Washington. This unit is founded under a grant from the U. S. Public Health Service, Division of Air Pollution, for a study of the relationships between atmospheric contamination and respiratory disease in man. I am also a member of the Technical Evaluation Committee on Air Pollution of the Metropolitan Council of Governments.

The health hazards of air pollution are of particular interest to the chest physician, since most of the substances associated with unclean air gain entry to the body through the respiratory system. A good deal of research has been done on the pulmonary effects of short term exposures to relatively high levels of these various agents; additional information has been obtained from animal studies and the experiences of industrial medicine. The inferences that can be drawn from such studies with regard to the hazards of urban pollution are limited because of the relatively high levels of agents involved and the short exposure times. By the same token, however, the fact that short exposure to a particular substance in the laboratory has produced no discernible change in bodily function means little when we consider the effect of years of breathing dirty air.

In the next few minutes, I would like to indicate some of what we do know about these contaminants; turning first to the gases and in particular sulfur dioxide. This is a product of the combustion of coal and petroleum. In sufficient amounts, it acts as an irritant to the respiratory system causing narrowing

of the airways and labored breathing. It has been demonstrated both in the United States and abroad that sulfur dioxide can play a role in the causation and perpetuation of an asthmatic state; a recent report from Japan has shown that in certain districts the incidence of bronchial asthma is directly related to the average level of sulfur dioxide in those districts.

Other gaseous contaminants have been shown capable of producing different disease states. The oxides of nitrogen, a product of automobile exhaust, have been implicated in the development of fibrosis or scarring of lung tissue. Carbon monoxide, by reducing the oxygen-carrying capacity of blood, can produce disease states ranging from headache and lethargy to asphyxiation.

Ozone, one of the most potent substances associated with air pollution, has been shown in animals to be capable of producing chronic lung disease as well as acceleration of the aging process and an increased rate of growth of lung tumors.

A second group of contaminants consist of the particulate matter that results from industrial processes, automotive engines and, of particular importance because of their number, incinerators. These particles come in all sizes and affect us in different ways. The larger ones dirty our clothes and soil our homes, but it is the smaller, largely invisible particles that present a health hazard, since they are capable of penetrating to the lower airways and lung tissue. They can then be irritants by themselves or carry other substances such as lead, or hydrocarbons that can gain access to the blood stream and produce toxic effects at sites distant from the respiratory system.

Many of these agents, both particulate and gaseous, have been implicated in the causation of emphysema and chronic bronchitis. While strict medical proof for this is lacking, there is indirect evidence to support such a view. Certainly chronic lung disease does not suddenly develop overnight in an otherwise healthy adult. It is a product of multiple insults to the lung over many years. Smoking appears to be one of those insults and general air pollution another. It has been argued that the concentrations of potentially toxic agents in the atmosphere are too small to present a health hazard and that we are dealing with a cause without a disease. However, the finding in the laboratory or industry that exposure to one half part per million of sulfur dioxide, for limited periods of time, produces no detectable effect, cannot be extrapolated to a fifty year exposure to the same or even smaller concentrations of that gas. In addition, laboratory and industrial attention has generally been focused on the healthy young or middle-aged adult, while practical experience has indicated that it is the very young and very old that are most susceptible to the consequences of polluted air.

From what I have said, I think two things are clear. First, there is a need for research to gain increased quantitative information regarding the chronic effects of urban pollution on human health. At The Children's Convalescent Hospital, where a large number of our patient population consists of children with chronic, intractable bronchial asthma, we are engaged in such a research program.

A systematic analysis of pulmonary function in school-age asthmatic children is being carried out to determine the effects of air pollution on the course of their disease. In addition, we are studying the incidence of acute asthmatic attacks in the Washington metropolitan area and relating changes in this incidence to daily variations in air quality levels. Finally, we have developed a unique structure to be incorporated as part of our new hospital facility. This will be a live-in, Universal Environmental Control Unit; a suite of rooms in which it will be possible to rigidly control and vary the physical characteristics of the environment and study the effects of controlled environmental change on bodily function. This unit will allow such studies to be carried out over a period of weeks or months, rather than minutes or hours. The data that will be obtained in this unit will be applied toward the development of rational air quality standards.

The second point I would make is that programs directed toward abatement of existing pollution should not be contingent on completion of the type of research I have described. The available evidence is enough to strongly suggest that we are dealing with a current health burden. This burden can only be worsened as population growth further stresses the self-cleansing properties of the atmosphere. In the District of Columbia, air sampling has revealed relatively high levels of sulphur dioxide, oxides of nitrogen and suspended particulate matter, all substances with health-damaging potentials. There is a need

now for better control of open trash burning, incineration, consumption of poor quality fuels and automotive emissions in order to bring down these levels. Research and abatement activities must proceed hand in hand in this area.

I thank you for the opportunity of presenting my views on this important medical subject.

Senator TYDINGS. Mr. Augustus C. Johnson, Chairman, Greater Washington Citizens for Clean Air.

STATEMENT OF AUGUSTUS C. JOHNSON, CHAIRMAN, GREATER WASHINGTON CITIZENS FOR CLEAN AIR

Mr. JOHNSON. Thank you, Mr. Chairman.

Senator TYDINGS. We will insert your prepared statement into the hearing record and you may summarize as you wish.

Mr. JOHNSON. I would like to skip over what my friends at the table here before brought up. We would like to associate ourselves with a great deal of that.

First of all, our organization is a citizens organization. Our area of interest covers the same as that represented by the Metropolitan Washington Council of Governments. We operate through public education and through encouraging the people to support activities like our own and to support legislation and official action in the jurisdictions of Washington metropolitan areas to reduce air pollution. We have some very specific recommendations and I would like to put them on the record, if I may.

We are very much in favor of the prompt adoption of the council of governments model ordinance on air pollution as a necessary and useful step, first toward cleaning up our air. We are urging the adoption of this by all 14 jurisdictions in the area and we are carrying this on through a program of needling politicians to make sure they get it done.

Second, better control, through ordinances, enforcement and inspection, of the production of excessive smoke and other pollutants by motor vehicles. Some of the ordinances which now exist are not being enforced, partly because they are impossible and because they are too difficult to enforce. Inspections in general inspect only the automobiles for safety and although the ordinances may specifically spell out that they must not produce excessive smoke this is now generally a well known enforced and inspected matter.

The immediate cessation of open air burning of trash at Kenilworth, and the eventual abandonment of all incineration, public and private, in the metropolitan area.

We don't know how long that will take, but we think, it ought to be a path toward doing it.

My last point is that we have rapid progress toward a radical reduction in the number of internal combustion engines in the area, through the development of rapid transit and the adoption of alternative power sources. As an interim measure, every effort should be encouraged to reduce the pollution produced by today's vehicles.

Senator TYDINGS. Would you comment, Mr. Johnson, on the District of Columbia government's actions and efforts in regard to air pollution and the control program?

Mr. JOHNSON. Yes, I would be glad to.