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stages of silicosis what we tend to find is an accentuation of these lines. They become thickened and extend farther in the periphery of the lungs. There is an enlargement of the shadow normally present about the center, which represents the filter draining the fluids as they return in the circulation from the lung. That would be the X-ray appearance in the early stages.

We might say at this point that such an appearance is frequently found with those who have not been exposed to abnormal amounts of dust. Such a picture is not sufficient to warrant a diagnosis of silicosis.

The second stage of silicosis is characterized by the formation of tiny nodules all throughout the lung. That is the nodular stage of silicosis. This [indicating] is a typical picture. Unfortunately, however, things in medicine are never simple, and an identical picture may be produced by a certan form of tuberculosis.

I ve X-ray films here [indicating] which if projected side by side, could not be told apart by expert X-ray men. After looking at them, the experts would ask for the history before they could tell anything.

Although this appearance of nodulation is characteristic of silicosis, it may be produced by certain forms of tuberculosis; the differentiation can be made on other things, but not solely on the

X-ray.

The third stage is when these nodules tend to clump together in big lumps. In this stage it is frequent and usual for some additional infection to have supervened. Usually that infection is tuberculosis. So that in the third stage of silicosis, as it is ordinarily seen, a superimposed infection with tubercle bacilli is usually present.

I have here (indicating] a specimen of a lung

The CHAIRMAN. If I may interrupt, do you say that in the later stages silicosis and tuberculosis combine and the patient is infected by both of them?

Dr. GOLDWATER. Ordinarily, as we see it—this is not speaking of any particular group or instance-persons by the time they develop the third stage of silicosis have their lungs so damaged and so susceptible to tubercle bacilli that a fairly large percentage of them who have third-stage silicosis are likely also to have tuberculosis on top of it.

The CHAIRMAN. Before reaching the third stage of silicosis, is it possible in a diagnosis to have things that will lead you to differentiate exactly between tuberculosis and silicosis prior to the time of reaching the third stage?

Dr. GOLDWATER. In most cases the differentiation can be made. Take the nodular stage, which is a concrete example and where the X-ray appearance of this type could not be differentiated from certain forms of miliary tuberculosis. The X-ray picture is not the only information we have available; we havė" the history of the patient.

A person with second-stage silicosis would probably give a history of having been exposed to a high concentration of silica dust. Secondly, the clinical picture of a person with tuberculosis is quite different from one with silicosis. The former usually has a high fever and a rapid pulse. There are changes in the blood which would be different in silicosis and in miliary tuberculosis. There would be a high white blood cell count. The patient is acutely sick. A person with secondary stage of silicosis would not have the acute toxic appearance of one with miliary tuberculosis. He would have shortness of breath and

Mr. GRISWOLD. You would avail yourself of a blood count in reaching a diagnosis of such a case ?

Dr. GOLDWATER. That would be one point.

Mr. GRISWOLD. There was a doctor here who did not seem to think much of a blood count in silicosis diagnosis.

Dr. GOLDWATER. You are speaking of silicosis itself. I am speaking of the differentiation of silicosis from such a thing as miliary tuberculosis. Undoubtedly he would agree with that, because this differential diagnosis frequently must be made, particularly in a place like Bellevue Hospital where I have spent much of my time.

We get cases of this sort not infrequently where persons come in and present this X-ray finding. The X-ray man will report nodulation and will say probably either miliary tuberculosis or silicosis. Then it is up to the clinician, the one who looks after the patient, to decide which it is, by using such things, such indications as temperature, pulse, blood findings, sputųm findings, all of which are important. We can then differentiate between the two.

A person with miliary tuberculosis usually has tubercle bacilli in the sputum. A person with nodular silicosis will not have that. The point is that the X-ray alone is not always sufficient to establish a diagnosis of silicosis.

I was about to demonstrate this [indicating] lung. This [indicating] is a lung from a man who worked a great many years as a miner in hard-coal mines, and among his duties was drilling rock, which is one of the common duties of those working in hard-coal mines. This [indicating] lung shows here [indicating) a large, hard mass. It is stony hard, about one-third the way down. In addition there are numerous small nodules about one-eighth or one-fourth inch in diameter studded throughout the entire lung: This is not a pure case of silicosis. It is a case of anthro-silicosis, meaning a combination of coal dust and silica dust, which would be expected in a coal mine. One working in a coal mine breathes rock dust and coal dust also. This sindicating] is a fairly typical appearance.

I can demonstrate, also, an X-ray film that was taken on the patient. This [indicating] shadow represents the spinal column. This [indicating) is the heart. This [indicating] is the collar bone, and these [indicating) are the ribs. Between the ribs is lung tissue as we see it in the film.

This whitish area is the shadow cast by that in tense concretion of rock in this lung. These other finer nodular shadows are cast by these smaller nodules in the lungs. This [indicating] is the way we correlate X-ray findings with what takes place in the lung. In cases where we do not have opportunity actually to examine the lung, we can assume with a certain amount of surety that the shadows are formed by masses such as that [indicating].

This sindicating] is that large area. The normal lung appears black. There is nothing to impede the X-ray. Here [indicating] is a density where a white shadow is cast. This sindicating] is a shadow cast by this hard mass.

As for the clinical picture, I might say a few words. I suppose you are familiar with the three stages of silicosis. During the first or early stages the subject exhibits little or no abnormal things by way

of physical signs, things that can be found by examination, and little by way of abnormal symptoms. There are few complaints. There may be a morning cough, something which anybody may have.

As the disease progresses, it does not go along for a certain time as stage 1 and suddenly become stage 2 and then suddenly stage 3. It is a gradually progressive process. As the disease progresses certain other symptoms set in. There may be a little shortness of breath on exertion, or a little tendency to fatigue, the cough may become more frequent and annoying. There may be certain other indefinite complaints about appetite, loss of weight, and so forth. At this time still there are no very definite findings which one can detect on examination of the individual, but there may be some decrease in intensity of breath as heard with the stethoscope. There may be some impairment of the expansion of the chest, and other things of that sort, with which I am sure you are familiar.

At this time, however, the X-ray appearance may be quite definite. There may be these nodules in the lungs. As the disease progresses still farther all the symptoms become intensified. The shortness of breath becomes more marked; the cough may become more severe; there may be some expectoration or sputum with the cough. There may be loss of weight and appetite, weakness, and that train of symptoms. Usually about this time some infection sets in and at that point the whole picture becomes accelerated. The cough becomes more severe, a fever develops, night sweats develop, and the whole picture is one of infected lungs. That is the picture of the ordinary, common case of silicosis as we ordinarily see it and as it occurs, we will say, in granite-quarry men, in sandblasters, in building workers, in rock drillers in the open, and persons who are exposed to moderate concentrations of silica dust, not in overwhelming amounts which might produce some other picture.

Also, there is an entirely different form of silicosis known as acute silicosis. This is something with which one does not ordinarily meet. It is a sort of thing that is likely to arise where for some reason or other conditions are very unusual in one respect or another in regard to these various factors which may influence the development of silicosis.

Mr. MARCANTONIO. When you say unusual in one respect or another, do you mean an unusual concentration and unusual length of contact with a condition?

Dr. GOLDWATER. Those would be some of the factors which I have in mind. That is the reason I put those facts upon the blackboard. Those are some which would be influencing and controlling factors.

Mr. MARCANTONIO. Those factors would bring about acute silicosis?

Dr. GOLDWATER. Yes; they might. I hope you are not provoked when I say "might.” In medicine nothing is 100 percent. In medicine we speak of possibilities and one can give an opinion.

Mr. GRISWOLD. Doctors in testifying usually answer questions “yes” and “no”, do they not?

Dr. GOLDWATER. That is not due to the choice of the doctor.
Mr. GRISWOLD. But that is usual, is it not?

Dr. GOLDWATER. They do not like to do that. A doctor with a scientific point of view—unfortunately there are some without that, I do not mean to say that all doctors are angels or anythings of that sort, but I think most doctors with a scientific point of view avoid dogmatic statements and avoid assiduously the use of "always" or “never.” Possibly some persons will disagree with that.

Mr. GRISWOLD. The best doctor I have ever known answered questions "yes" and "no."

Dr. GOLDWATER. There are different opinions on that, also.

We were talking about the matter of acute silicosis. It is a condition in which the entire picture is different from what I have described, and it is an unusual sort of thing. The changes in the lungs are not the same as take place in a chronic case of silicosis. They are more in the nature of an acute inflammatory reaction in the lungs. This condition has been described by persons who have produced it experimentally, and it is probably the form which was prevalent in the work that has been done in the building of the Catskill Aqueduct several years ago, where conditions were unusual. I shall not go into those conditions now because they are not germane.

Ordinarily, silicosis does not develop in the matter of a few weeks or a few months. Ordinary chronic silicosis, I mean. Most of the cases which have been described and which I myself have seen have been exposed to dust for, we will say, a year or more. Occasionally there are instances in which the history of exposure is less. I am speaking of the ordinary type of silicosis where there is no unusual set of circumstances.

Mr. MARCANTONIO. How about acute cases of silicosis? What are the possibilities of development, as regards time?

Dr. GOLDWATER. The possibilities are a matter of months.

Mr. GRISWOLD. I should like to ask you this question: We will assume that in the tunnel operations at Gauley Bridge they were drilling both wet and dry; that the rock through which they were tunneling contained as much as 90 percent silica; that the dust probably combined with some moisture made visibility good at only approximately 10 feet; what would you say as to that condition?

Mr. MARCANTONIO. If I may interrupt, please also assume that there was inadequate ventilation.

Mr. GRISWOLD. Yes.

Mr. MARCANTONIO. Assume that there were 16 drills going all the time; 6 drilling wet and 6 drilling dry.

Mr. GRISWOLD. What would you say as to that condition being one which would promote silicosis among the workers and cause them to be infected?

Dr. GOLDWATER. If you will allow me to refer to the board again, in the conditions you have described you say that the silica content was approximately 95 or 98 percent. We know this[indicating], but we do not know anything about this [indicating], the size of the particles.

Mr. MARCANTONIO. We do not.

Dr. GOLDWATER. The dust concentration we know was very high. We do not know anything about the particles. We can only guess as to that

Mr. GRISWOLD. Assuming the conditions were such that a combination of dust and moisture made visibility beyond 10 feet impossible. Dr. GOLDWATER. That, I would say, was a very high concentration. Do we know anything about the length of exposure?

Mr. MARCANTONIO. They worked 10 hours a day.

Dr. GOLDWATER. That is rather a long working day. We know something about that. So far as the individuals were concerned, what do we know? We do not know anything about their nasal filters—that is an individual thing. Referring to the habits of the workers, their working habits. Some would work according to one scheme and some according to another.

Mr. MARCANTONIO. The very nature of the work, 16 drills going at one time, indicates that the work was quite arduous.

Dr. GOLDWATER. Assuming that it was arduous work. This is a hypothetical question? Mr. MARCANTONIO. Yes.

Dr. GOLDWATER. Assume, for the sake of argument, that the work was arduous. They might be working in such a way that they would have to breathe more than in normal inspiration and expiration, where the exchange of air would be about 500 cubic centimeters. We do not know anything about the previous state of their lungs. We do not know anything about individual susceptibility.

Mr. MARCANTONIO. Would you say that colored men are more susceptible to lung diseases than are white people? Is that a medical fact?

Dr. GOLDWATER. The incidence of tuberculosis in this country is higher among the colored people than it is among the white people.

To answer this question: If we assume a purely scientific point of view, we must say that we are not in a position to give an accurate answer. You can see that for yourself, because we do not know many of the factors involved. The conditions which you have described in this hypothetical question are very similar to the conditions that prevailed in the building of the Catskill Aqueduct. On that particular work cases of silicosis did develop in a much shorter time than one ordinarily sees in these other occupations and exposures. There were cases which developed in less than a year of exposure.

Mr. GRISWOLD. Assuming that in a tunnel operation, knowing nothing of the susceptibility of the individual Iungs, taking into consideration the normal individual, the normal individual employed in such a work; and assumng that he was employed as a driller in this tunnel up at the head where the drilling is done; assuming that 6 drills were working wet and 10 drills were working dry; assuming, further, that the ventilation system was imperfect; assuming further, that the concentration of dust and moisture was so thick that visibility was uncertain beyond 10 feet; assuming, further, that the workers were drilling through rock that was more than 90 percent silica what would you say as to the probability of the individual working 10 hours a day under such conditions contracting silicosis!

Dr. GOLDWATER. I would say that conditions such as you outlined are very unusual and that persons so exposed might develop silicosis in a relatively short time, it might be a matter of only months. I was going to complete the picture of silicosis by a few words on prevention, if that phase of the matter is of interest to the gentlemen of the committee.

Mr. GRISWOLD. What can you tell the committee about respirators as preventive measures?

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