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Stenographic Transcript Of HEARINGS Before The SUBCQMMITTS2 ON AIK AND WATER POLLUTION COMMITTEE ON PUBLIC WORKS SW T3 nAr^kTa EUaDw S0 3112,, S0 3400 AND RELATED BILLS AIR POLLUTION ABATEMENT ) Washington, D. C. June 9,, 1966 Aiderson Reporting Company, inc. O^w l o I 1ZeJjwteAA/ 300 Seventh St., S. W. Washington, D. C. NA 8-2345 N35509 TABLE OP CONTENTS U. S0 Senate 1 Subcommittee on Air and Water Pollution of the Committee crj Public Works6 Washington. D June 9. 1966 STATEMENT OP* The Hon. Lee Metcalf. A United States Senator from fehe State of Montana Dr* Harriet Hardy? Assistant Medical Director Occupational Medical Service., Md.To Drc Robert A. Tahoeg University of Cincinnati College of Medicines Cincinnati PAG 143 155 182 10 11 12 13 14 15 16 17 ****** 10 19 20 21 22 23 24 25 182 1 2 3 4 5 6 7 D 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Senator Muskie. Our next witness will be Dr. Robert A. Kehoe, of the University of Cincinnati College of Medicine, Cincinnati, Ohio. Dr* Kehoe, we appreciate your coming here this morning and further enlightening the committee. Di'- Kehoe. Thank you. Senator Muskie. You may proceed. May Z say for the benefit of all of us that you may cover as much of your prepared testimony as you want orally but we will include it all in the record. We don't object to listening to it if you wish to read it all. STATEMENT OF DR. ROBERT A. KEHOE, UNIVERSITY OF CINCINNATI COLLEGE OF MEDICINE, CINCINNATI, OHIO Dr. Kehoe. First of all I would like to say I appreciate the opportunity of being here. I have no hope whatever of being able to present to your committee other than in terms of documents, pulbished materials, the information that is available then on this subject. I am afraid we would be here the rest of the week if I were to undertake to do this. So that what I shall do is briefly to outline where it appears to me that we stand in this situation at the present time, to briefly refer to the evidence that puts us in my opinion in that position and to refer to you and your ooas&ittee and its staff the published material on this subject which is here. 01 329 183 1 Thereis a much longer memorandum that I should not 2 dare to undertake to present here this morning, with reference 3 material and a series of reproductions of the material that 4 is in various reports, in literature, in this country end 5 abroad which we have put together in this fashion, primarilay 6 because of this -- much of this is very difficult to obtain. 7 It goes clear back to 1923 and 1924 and is not readily 8 available in the journals that exist at the present time. 9 Some of this has actually been lost. to Senator Muskie. Is it your intent to make this available 11 for the files of the committee? 12 Or. Kehoe. That is right. This is for the purpose 13 of making this available. Anothmr copy of this is available /' > 14 if it would be of any interest. 15 Senator Muskie. Mould it make interesting 16 night reeding? 17 Dr. Kehoe. Several nights. It would not be a thousand 18 and one but.it would be several. 19 Z would like to briefly state my own position at the 20 present time if I may. 21 It is the purpose of this statement to present briefly 22 the salient facts concerning the hygienic aspects of the 23 occurrence and distribution of lead in the environment of 24 citisens of the United States of America, with particular 25 reference to the contribution made by the use of leaded 184 1 gasoline. 2 I am a physician, at present too the one Professor 3 Emeritus of Occupational Medicine in the Department of 4 Environmental Health in the College of Medicine, University 5 of Cincinnati. I have been a teacher and professor on the 6 faculty of the college of Medicine in the Department of 7 Pathology, first, in Physiology and later and longer Director 0 of Cuttering Laboratory whiah has been concerned with industris 3 medicine and industrial hygiene from its founding in 1930 10 until my retirement in 1965. 11 Incidentally it still continues. From 1948 until 1965 12 I was the Director of the Department of Preventive Medicine '3 and Occupational Health in the area the laboratory is /' 14 Situated, I was also the Chief Medical Consultant with IS the title and corporate responsibilities of Medical Director 16 of Ethyl Corporation from 1925 until I retired at the 17 end of 1958. IS This having been imperative in the early stages because 19 I was the only person who was involved with the early 20 study of tetraethyl lead. 21 The impression has existed in certain circles that 22 little information is available on this subject, especially 23 as to matters that relate to the safety of the public. 24 The fact is, however, that no other hygienic problem 25 in the field of air pollution has been investigated so i 01 330 185 I intensively, o^tar ailch a prolonged period of time, and with i 2 such definitive results. This is not to claim that there 3 are no significant voids in the available information, nor 4 that all of the eltimate answers are at hand. 5 Nevertheless, it is clear that this specific set of 6 problems has been brought to such a point of understanding, 7 in relation to the public health, as to remove it from the 6 realmof urgency and to consign it into that group of hygiene*? 0 problems on which a watchful and affective surveillance should 10 he &$pt. A considerable measure of assurance for the 11 future may also be derived from the fact that methods of 12 surveillance have been developed, over the years of 13 investigation, which are characterized by a high degree of technical precision and physiological relevance. 14 Senator Muskie. Is it fair to say. Dr. Kehoe, that what 13 you have 'just said is at variance with the position taken 16 by the Public Health Service and the position-taken by Dr. 17 Hardy this morning as to the state of knowledge that we ought 18 to have before reaching final conclusions? 10 20 Dr. Kehoe. Not precisely, no, sir. I would simply 21 say that in developing the information along this line for 22 which Z have had a greater responsibility than any other person in this country, that we have undertaken to answer 23 the question that relates specifically to the public health. 24 Our Interest has been broader, Z may say, more extensive. 23 1 a 3 4 5 6 7 6 3 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 186 in the field of industrial, health in which the problem is most serious and it is most serious. But that with respect to the findings here I would say at this point that we are in the best position that we have ieen at any time in the 35 year period since lead and gasoline was introduced on the American market. With respect to the information that is necessary to answer the questions that are available, they are not all answered and there are still investigations to do. But I repeat that the situation is in no sense urgent. Senator Muskie. With respect to this sentence in your testimony N No other hygienic problem in the field of air pollution has been investigated so intensively over such a /' i long period of time and with such definitive resultsis it your intention that that statement apply not only as to industrial exposure to the problem but also to the exposure of the general public to leads in the atmosphere? Dr. Kehoe. Not at all, sir. The industrial exposure is with us, it is a hasard. Lead poisoning in industry is still one of the most frequent occupational diseases with which we are presented in this country despite the fact that we know how to prevent it. The question with respect to the public has been / from the very start, 1923 on, hypothetical, a potential risk which we have been undertaking to measure by every means 01 331 187 1 which we can gat at and tha evidance at tha present time is 2 batter than it haa bean at any time that this is not a present 3 hasard 4 Senator Muskie. May I ask a further question on this? 5 Tha Bureau of Minas and tha American Petroleum Institute 6 have just entered into a contract involving $480,000 of 7 American Petroleum Institute money to conduct research 8 in this field. Is that in your judgment a reflection of 9 concern or simply routine? 10 Dr. Kahoe. Not with respect to lead. The concern here t! is with other aspects of the use of petroleum hydrocarbon 12 fuel*; which do present us with a series of problems some of L3 which are unsolved. 14 Senator Muskie. I understood the contract does relate 15 to lead. 16 Dr. Kehoe. It relates to both, lead and unleaded ;. 17 gasoline, with the idea of establishing whether the lead 18 introduces an additional factor. There is no question however 19 about the factor of risk of a sort from the petroleum 20 hydrocarbons. The question at issue here which is being 21 carried out along with the general investigation is whether 22 lead enters into this problem and in any way affects the 23 matter disadvantageously. 24 Senator Muskie. Mould you say that from the point of view of health it would be desirable, if not urgent -- 25 you have indicated it is not urgent -- but from the point 188 1 of view of health would it be desirable if a substitute 2 for lead could be found for gasolines? 3 Or. Kelioe. If by this means one could accomplish the 4 same purpose, and mind you I am not interested in the S economics oif the things other than the avoidance of upsetting 6 the whole community, this is not my concern -- there is nothin 7 at the present time that would say to you or to me that 8 we should hurry to eliminate lead frsam the gasoline in the 9 country. 10 There is no evidence that this has introduced a danger 11 in the field of public health. There is still the hypothetical 12 question, and this is largely because we have long known * that lead has the potentiality of grave danger, that it 13 14 produces illness, that it still produces illness. We have known only for a relatively short time, since 15 I may say the work of the Xettering Laboratory in this field, 16 that lead is an' inevitable element in the surface of the 17 earth, in its vegetation, in its animal life, and that there 18 is no way in which man has ever been able to escape the 19 20 absorption of lead if he lived on this planet. Zf there is any other planet this is another matter. 21 This has always been the case and it will continue to be 22 despite our efforts. The question therefore is how much 23 danger is thers4 how much does it take to create danger and 24 what is the margin of safety that exists at the present time 25 10 101332 189 1 between that is what would be dangerous and what is certainly 2 not dangerous. 3 Senator Muskie. Z am not certain you have answered 4 my question so I would like to ask it again. S Or. Xahoe. X am not avoiding it. I am just trying 6 to give you a full answer, sir. 7 Senator Muskie. Z understand. Putting aside the 8 question of economics, which we both agree should be 9 put aside, if you have a substitute for lead, a clearly non 10 toxic substitute for lead that would do the same job that 11 lead does would you think it desirable from the point 12 of view of health to make the substitution. . 13 Dr. KehoeT X should be indeed in this very cautious r j in arriving at any such conclusion. I would not be unable 14 to arrive at it without investigation in advance of the IS fact. Zf investigation demonstrated the truth of what you have 16 just said -- t 17 Senator Muskie. Z have asked you to assume the truth 18 19 of what X have said. Obviously it is hypothetical and the recc 20 will be clear on that point. 21 Assuming the truth of what X have said, assuming in 22 fact you had such a substitute, would you say from the point of view of health that the substitute ought or ought not 23 to be accepted? Because then the only question involved 24 would be economics. 25 190 1 Dr. Kehoe. Yea. I an only saying I cannot make such 2 an assumption because there would have to be information of 3 the various materials that have been recommended, that have 4 been though of in this connection as substitutes for 5 tetra lead. None at the present time has turned out to be 6 satisfactory and none has been devoid of certain considerations 7 in the field of public health which would have to be answered. 0 How I would only take this position. We have have experienced with tetraethyl lead since 1923 which clearly 9 indicates, to me, that this is not a present hazard. We would TO not have that kind of information in relation to any other 11 material that Z cam conceive of as being put in this 12 capacity, and therefore, I am careful about the answer to 13 your question. 14 7 If I could assume that everything is perfect about it, t5 which Z cannot do, then I would agree with you. 16 .Senator Muskife. Z think that is a hypothetical question 17 you can make that assumption. Frankly I am disturbed that you 18 are not sure enough about the body of knowledge upon which 19 you are .relying to answer such a hypothetical question, 20 and Z said assuming, dearly assuming as a fact, recognizing 21 it has yet to be established as a fact, assuming as fact 22 there is a substitute. 23 Or there could be developed a substitute for lead 24 that would do the same thing for gasoline that lead does. 25 191 1 but without any toxicity, any toxic effects, would you say 2 from the point of view of health that it would be desirable 3 or not desirable to make the substitution? > v 4 I ithink that is a question that a man with you: background 5 like this ought to be able to answer. 6 Dr. Kehoe. Z could answer it except that Z take the 7 point of view as a matter of principle that we must 8 Investigate every material that we introduce into our 9 environment -- 10 Senator Muskie. I do quarrel with that. 11 Dr. Kehoe. -- because there are unknown effects. 12 Now to answer your question, if Z could be quite sure that this was the case Z would be glad to dispense with 13 a risk, the question of risk, not the question of hazard 14 / because Z think it does not exist, but the question of 13 potential hazard which is risk* 16 Z would be glad to trade any risk for the 17 certainty of safety. 18 Senator Muskie. All right. Z guess that is as close 19 20 as we con coma together. Dr Kehoe. The bulk of the investigative work which 21 22 bears on lead in the general environment of man has been carried out, under the financial sponsorship of the 23 manufacturers and distributors of lead containing anti knock 24 compounds in tie United States, in the Ketaring Laboratory, 23 192 1 in the Department of Preventive Medicine and Industrial 2 Health of the College of Modicine of the University of 3 Cincinnati, and under the terras of agreements between the 4 executives of the industries concerned and the Board of 5 Directors of the University, whereby the public responsibility 6 of the University have been preserved intact. This Department 7 has been renamed, recently, tie Department of Environmental 0 Health. 9 Pacts brought to light by these investigations have !0 been confirmed by evidence derived from the examination of 11 similar situations by official investigators in other 12 countries^ and from extensive tangential applications of the 13 methods of other countries, and from extensive tangential 14 applications of the methods of our investigations. Principally 15 to the industrial scene. 16 When an investigation, undertaken jointly by the United 17 States Public Health Service, and the Health Departments 18 of the City of Philadelphia and the State of California 19 and the Kettering Laboratory, was completed, and the 20 results were published, in 1965, under the title of a "Survey 21 of Lead in the Atmosphere of Three Urban Communities," 22 these being Philadelphia, Los Angeles, and Cincinnati, 23 the reliability of the past info and the current information, 24 as well on the lead content of the atmosphere of cities was 25 established byond further question. Zt is now possible ^ a 0133 4 l t to consider any future potential threat to the public health 2 in this matter on the background of a body of data which wil 3 serve as a baseline for comparison. 4 Incidentally, thera has been reference, this is off 5 the record here, this ia oral -- therehas been reference 6 to 11 high values found in that survey. X should like to 7 report to you that those values were considered to be pure 8 chance phenomenon that in a statistical distribution of 9 values which begin on the low side and which taper out 10 into the high side. The results of those men who are 11 available at the present time, which consist of four 12 people in Cincinnati, three people in California, have been r. 13 rechecked and the results in this instance, as could more 14 or less be predicted, come right back then into the main 19 body of the data. 16 All of the results fortuitously turned out to be quite : 17 on the low side of the mean value rather than high. 18 Senator Muskle. Let me ask you this. In the statement, 18 simply to give you the opportunity to emphasise what you havi . 20 said, you say that on the basis of the study in Philadelphia 21 Los Angeles, and Cinolnnatl, the reliability of the current 22 information on the lead content of the atmosphere of cities 23 was established beyond further question. 24 That is a pretty strong statement for a scientific 29 man to make unless he means it. 1! 1 Or. Kehoe. I mean it very definitely, sir. 2 Senator Muskie. You can anticipate no variations from 3 the findings in these three cities and any other place in 4 the U. S. any time in the future that would raise a real 5 question? 6 Dr. Kehoe. Not the latter, not in the future. 7 Senator Muskie. You say beyond future question. 0 Any question that would be raised would have to be 9 in the future with reference to the point in time that that fO study is made. 11 Dr. Kehoe. I spoke specifically of current information. 12 Z shall speak of the future a little later. Senator Muskie. So that there is further question if 13 you think in terms of further as referring to the future. 14 Dr. Kehoe. There is this question, yes, to which 15 there is some degree of answer. But the question at this 16 point in our discussion is completely open. X am not 17 anticipating the future at this point. 18 Senator Muskie. Still, Doctor, let me clarify this 19 further. Your next sentence sayi it is now possible to 20 21 consider any future potential threat to the public health in this matter on the background of a body of data which 22 will serve as a baseline for comparison. 23 / That would seem to suggest that your baseline even 24 as to the future is not going to move. 25 tera 01335 195 1 Dir. Kehoe. That was not the intention. That there ia 2 a baseline with which you can compare future observations. 3 One of the primary purposes of this investigation which j 4 was emphasized by the Surgeon General and the Committee was S that there was not enough data distributed over a wide enough 6 number of American cities so that we had a baseline to say, 7 if today is all right, does tomorrow vary from this and 8 particularly does it vary upward? 3 Zsi there in other words a future danger in the ever 10 increasing automobiles, in the increased use of lead in gasoli; 11 in the increased distribution of lead in the atmosphere 12 from any and all sources? j* 13 The hygienic issue, at this time, relates to the total 14 pattern of the concentration of lead, from all sources, in 15 the respire d air of persons in the general population, in 16 conjunction with the quantities ingested with their food 17 and beverages and any other material that is swallowed. The 18 mere abundance of lead in the human environment is not of 13 itself a threat to mankind,nor in the final; analysis is the 20 ere presence of lead within the anatomical structure of 21 man. 22 Abundance is a non-quantitative term, and the outcome 23 of the ^absorption of lead into the human tissues -- the 24 internal media . of the body, depends upon its rate and 25 extent, and upon the physiological mechanisms whichrare 196 1 involved in its entrance and exit, its systemic and 2 cellular distribution, and in the metabolic processes in the 3 tissues, including also, the elimination of absorbed lead from 4 the body, and the extent of the accumulation, if any, in the 5 body with time. 6 The natural environment of mankind is such that lead 7 is taken into the human body in virtually all food and e beverages and in the respired air. The many usages to which 9 lead is put in modern industrial society, one of which 10 is involved in the present discussion, have increased the 11 amounts which the average man ingests and inhales, with the 12 result that somewhat more than natural quantities of lead * 13 enter into the metabolic processes of his body. 14 The quantities are small but not insignificant. The food 15 consumed by an adult in the United States contains lead in 16 amounts which range from less than .1 mg. to 4.0 mg. 17 Occasionally more per day. The higher and lower values 18 mentioned occur infrequently, the larger proportion of the 19 daily quantities grouping themselves regularly and closely 20 around the mean value which is somewhat less than 0.3 mg. 21 per day. 22 The quantities taken in daily with the inspired air are not so well defined, since they must always be calculated. 23 The quantities appear to range between .015 to .09 mg. per day 24 and as in the case of the intake in food, theaverage in any 25 01 3 s A 1S7 1 situation is much nearer the low value than the high. 2 The maximum quantities of lead absorbed into the body 3 from that taken into here the alimentary and respiratory \ 4 tracts of the average man may be estimated on the basis of 5 experimental evidence which shows that somewhat less than 6 10 percent, of that ingested (swallowed) and somewhat less 7 than fifty percent, of that inhaled, are absorbed. 8 Calculations based on these percentages indicate that 9 about .03 mg may be absorbed daily from the alimentary tract, 10 while quantities ranging from .007 to .045 mg and averaging f 1 between .02 and .03 may be absorbed daily from the respiratory 12 tract. As is clear from this there is less likelihood of the 13 'absorption of lead day to day from the air, the quantity is 14 less, than the quantity which is likely to be absorbed from 15? the alimentary tract. 16 Therefore the food and drink side of this environmental 17 ,picture is still the more important side. 18 Evidence obtained by corresponding means has demonstrated 19 that the quantities of lead eliminated from the body daily by 20 the average man are substantially equivalent to those taken 21 in. 22 Thus the lead which is evacuated so with the feces, 23 daily, 1 s only slightly less than that in the food and 24 beverages. That which is excreted in the urine ranges from 25 scmatthat less than .01 mg to about .08 mg per day, and 191 I averages approximately .03 mg per day. The total output of lei 2 in the feces and urine, over a period of months, usually n exceeds slightly the intake in the food and beverages, thereby 4 Indicating, indirectly, that the magnitude of that absorbed ii 5 the respiratory tract of persons investigated in Cincinnati 6 is not less than .02 mg per day. 7 Senator Muskie. Doctor, you have been giving us figures that come from the Philadelphia studies? 8 Dr. Kehoe. Ho. These have come from very carefully carrii 9 out, balanced experiments on human subjects in the Kettering 10 Laboratory. 11 Senator Muskie. As of what date? 12 Dr. Kehoe. Beginning in 1939 and extending to the 13 present time. They are still going on. What we undertook 14 to do back in this period, back in 1939, we gave up any hope 15 of understanding this problem unless we carried out balanced 16 experiments on human beings which told us the source of lead, 17 the manner in which they enter into the body, the manner 18 in which they get out of the body, and what is the relational 19 between intake and output under ordinary normal conditions 20 and under conditions that cueist in industry or whenever there 21 is an unusual exposure. 22 That has told us things about the physiology of the 23 behavior of lead in the human body that we could not have 24 learned by any other means. 25 U& 1 01 337 199 I Senator Muskie. The question 1 was getting at is 2 that since these studies extend ever a period of two or 3 three decades do you have any data as to whether or not 4 the amount taken into the body each day has increased over 5 that period? 6 Dr. Kehoe. The evidtsnee so far as Cincinnati is concerned 7 and our experimental subjects have been in Cincinnati in the e Kettering Laboratory -- this does not apply to other cities specifically, in a general way it does ~ the evidence is 9 10 that over the period of the last thirty years ther has ii been very little change, if any, but the change has been down 12 ward, if any, rather than upward. There has not been an increase in the ilStake of lead 13 by the citisens of Cincinnati as reprsented by our 14 / experimental subjects. 15 Senator Muskie. What is the nature of the samplings 16 you take in Cincinnati? 17 Dr. Kehoe. The sampling is very meticulous. These 18 experimental subjects collect exact duplicates or nearly 19 as exact as can be obtained by Intelligent young men, exact 20 duplicates of everything eaten and drunk during a period, 21 every item of food that passes their lips, every item of 22 drink including cocktails and coca cola must even be in 23 the duplicate sample for analysis. 24 These men also collect every sample of feces every day, 25 200 1 every drop of urine that is passed every day, and this is 2 subject to analysis day by day as the thin? goes on so that we have a day by day observation on experimental subjects * 4 for as long as four and a half years. 3 Senator Muskie. With respect to intake, have you had 6 samples over that period, intake from the air as well as 7 intake -- 8 Or. Kehoe. We know what the content of lead in the 9 air in the Kettering Laboratory which in which these subjects 10 spend their day. We know also what is the lead content 11 of the atmosphere in which they live so that by calculation 12 we can get at this. It is quite fair to say that over the 13 period beginning in 1947 there has been little or no change 14 in the atmospheric conditions in respect to lead in 15 Cincinnati Here again if there has been a change there has been a 16 "s diminttion. 17 Senator Muskie. Youare talking about the lead content 18 in the air. How about the amount of lead that is taken 19 in from the air by human beings? 20 Dr. Kehoe. First of all we carried out experiments 21 that relate to the intake and output in the food and have 22 increased quantities taken by mouth. In 1949 we began 23 experiments on inhalation dealing with known concentrations 24 of lead in the atmosphere and following the intake and output 25 4 fi 1 1V4 hare of subject* that were in atmospheres, low levels and a in atmospheres that approached those of the industrial 3 situation. 4 One of the things we were moat concerned about and have 5 been over the years is to get at the question of a standard 6 which can be applied to industry that will say certainly and 7 without any question of doubt whether the situation under e which a man works is safe or whether it is dangerous. 9 The differentiation of these two in industry is 10 absolutely imperative to industrial control. So that our 11 first work dealt with this in relation to industrial 12 exposure. Zt has for the last five years been concerned 13 specifically with lead of the order of magnitude of that 14 which occurs in the air or might conceivably at some time 15 be thought of as being potentially possible. 16 Senator Muskie. Have you taken samples from people who 17 have a particularly heavy exposure to lead in the air, 16 traffic policemen, service station attendants and so on? 19 Dr. Kehoe. Yes, we have done this systematically over 20 a period of a good many years. So there is a body of data 21 available on this matter in Cincinnati, a body of data that 22 has been published. 23 The information is available in these records -- since 24 the first information obtained by methods now in use so that comparable data year to year were obtained in 1937 and 2S 1938 202 1 Senator Muskie. Is it yo^sr conclusion that in 1937 2 to the present time on tha basis of that data thatthera has Wf> baan no increase in the amount of lead taken in from the 4 atmosphere by traffic policemen/ by attendants at service 5 stations or by the average motorist? 6 Dr. Kehoe. Thera is not the slightest evidence that there 7 has baan a change in this picture during this period of time. 8 Mot tha slightest. 9 Senator Muskie. Is there evidence that assures you that 10 there has been no change? it Dr. Kehoe. Evidence obtained in an effort to find the 12 one thing about it that we have been concerned about in this / 13 situation and for a grood many years have studied/ is that there 14 might be somewhere sometime some combination of strange ( 15 circumstances that would put the lead content of the food 16 and drink high at the same time that the air was high and 17 that under these circumstances we might find an individual, 18 a group of individuals, or a population in a particular area 19 like that of an Industry in which there was an undue 20 exposure and in which there would be real risk. 21 He have looked systematically for such groups for the 22 last fifteen years and we have failed utterly to find them. 23 THis is why we began to study garage mechanics many yearsago, 24 because of two things. First of all, the garage mechanic 25 in the very nature of his work has a heavier exposure to oi Qy 203 1 the exhaust gas of automobiles than morct people do, so much 2 so that a fair number of these men in cold weather go home 3 in the evening with carbon monoxide headache which means 4 exposure to exhaust gasoline. 5 These men however have an occupational exposure to lead 6 by virtue of the fact they do little body work, a little 7 body painting, a little repair work of a variety of kinds, a they handle greases, they sometimes do a certain amount of 9 real repair on storage batteries which are lead containing 10 and these men also get unconscionably dirty which we all 11 know. 12 They crawl around on the floor under automobiles. Their 13 clothes are dirty, their"hands are dity, they smoke /' > 14 cigarettes, they eat sandwiches in their place of work. These 15 men do have an immeasurable exposure to lead which is demon 16 strated quite clearly fromthe fact that these people are 17 differentiated from filling station employees,refinery 18 workmen, traffic policemen, postmen who pound the streets 19 and this sort of thing. 20 This group and this group only of the people that we 21 have looked at have shown a statistically different intake 22 and output of lead from the people in the general population. 23 This Z may say is the mildest occupational exposure 24 that we have found in which there is a certain differentiatior. 25 statistical differentiation in the intake and output of 204 1 lead and yet without lead poisoning. Lead poisoning in the 2 garage mechanic is essentially non-existent unless he oO carries out a specifie job that is known to be hazardous 4 over a long period of tine consistently. 5 Senator Muskie. Over the past thirty years I assume 6 there has been a tremendous growth in automobiles and in the 7 amount of traffic in Cincinnai and yet as I understand it, 8 you say that there has been no increase in the concentration 9 of lead in the ambient area? 10 Dr. Kehoe. That is a fact. Senator Muskie. Over that period of time? II Dr. Kehoe. This is a fact. There has been a change 12 downward, since the period of the Second World War when we had 13 difficulty in Cincinnati getting the kind of control we 14 would like to have and getting it burned in the way we would 15 like to have it and Cincinnait has a very large ooal burning 16 industrial and household problem. 17 During this period we had to take the coal that 18 could be obtained and there was definitely an easy going 19 policy with respect to smoke abatement because of the times. 20 In 1945 this whole situation was changed and in the 21 period imemdiately following this the lead content of the 22 atmosphere of Cincinnati went significantly downward. 23 Senator Muskie. What you have just said is that the " 24 decrease in the concentration in the atmosphere is due to 25 013 4 0 205 t better control of stationary sources of air pollution? 2 Dr. Kehoe. That is right. 3 Senator Muskie. Do you draw any conclusions as to what 4 has happened to concentrations of air attributable to the 5 automobile over that period of time? 6 Dr. Kehoe. All this meant was that there was a significant 7 amount of the air pollution in Cincinnati yielding lead that 8 was due to the burning of coal which has about 14 to 16 to 20 9 parts per million in it, which creates a certain amount of 10 la&d to the atmosphere. 11 Now since that time the concentration of lead in the 12 atmosphere which has been tested on several different 13 occasions in a very significant manner has been substantially 14 stationary. There has been a decrease in recent years as 13 it presumably as the consequence of changed patterns in 16 the traffic of Cincinnati, of loosening up the congestion 17 and getting a more peripheral traffic flow of automobiles. 18 The traffic in Cincinnati is definitely easier now 19 than it waB, say five years ago. 20 Senator Muskie. Have you drawn any conclusions as to 21 whether.or not the concentration of lead in the atmosphere 22 attributable to the automobile in Cincinnati has gone up, 23 gone down or remained stationary? 24 Dr. Kehoe. Z would say from the evidence we have at 25 this point , that it is a little risky to attribute much change 206 to that. What has occurred during this period of time has bee:i 1 within the variability of day to day results. 2 Senator Muskie. So you have a conclusion? O 4 Dr. Kehoe. We havs a conclusion which says that has not increased. 5 Senator Muskie. Let us see if we can generalize that 6 conclusion. Are you saying that the increase in the 7 automobile population of the United States hasnot in the past G and is not likely in the fiture, given the same quality of 9 gasolines that we now use, to increase the concentrations 10 of lead in the atmosphere? 11 Dr. Kehoe. I am not drawing any conclusion. Senator Muski 12 Senator Muskie. We have to draw the conclusion. From 13 what you have told us so far about Cincinnati's situation 14 that you believe that the automobile has not added to the 15 concentration of lead in Cincinnati air. 16 Now I am trying to find out what that means in terms 17 of the United States. 18 Dr. Kehoe. There would be no question in my mind that 19 if you could move a larger number of vehicles through the 20 American city, you would get more lead in the atmosphere. 21 But we have very nearly reached the point of stand still 22 in some of our cities. 23 Senator Muskie. Z guess I have not driven in those cities. 24 Dr. Kehoe. Zn consequence of this in some of these 25 013 41 Vr I this has reached almost a stationary point. Certain areas 2 of Philadelphia, certain areas of Los Angeles, certain areas 3 of New York City. 4 Senator Muskie. It seems to me we are constantly 5 building highways that makes it possible for more automobiles 6 to go to the cities. 7 Dr. Rehoe. Yes. What this results in is a spreading out. 8 Senator Muskie. A spreading out but not a reduction 9 of automobiles in the city? 10 Dr. Rehoe. Nor does it mean a reduction in the total t! lead content in the air. It means that the concentration 12 at particular points where there are people tends to be 13 more widely spread over the community' so that the overall 14 concentration islower than it would be when this reaches / 15 this point of congestion which is almost impossible. 16 Senator Muskie. What you have said to roe suggests 17 that the concentration in some places would be less and. in 18 other places more? 19 Dr. Kehoe. You are quite right. 20 Senator Muskie. We are spereading it out. 21 Dr. Rehoe. You are quite right. 22 Senator Muskie. You seem to have emphasised the less 23 rather than the more. 24 Dr. Kehoe. No, I have not except that there Is this degree of variability and there Is this approaching tendency. 25 208 t I should say# in some of our urban centers to get a lower 2 distribution of a more consistent value from urban areas O to center. 4 Senator Muskie. What is the net result to the city? 5 Is it more lead or less lead? You talk about distribution 6 now. How about the net? 7 Mr. Kehoe. This may be more in the total air of 8 the community but this is less in those areas in which 9 previously it was higher where you find people. So that 10 from the point of view of the person who is exposed -- 11 Senator Muskie. Yes# but Doctor, have you ever filled 12 an empty river basin? The lowest spots get filled up first 13 but eventually the high spots get reached. As the water goes^ 14 up it gets deep enough to drown people. 15 What you are saying is that in Cincinnati# presumably 16 in other cities# as traffic patterns change because of the construction of new highways and so on it loosens up and 17 tends to spread it. 18 19 Z am interested in whether or not the level is going up. 20 This is the question I have been driving at for the last few minutes# whether or not your evidence in Cincinnati 21 indicates that the level is going up with the growth in the 22 automobile population. 23 X still don't have an answer that X can hang on to. 24 Dr. Kehoe. The level at a particular point up to the 23 1 present time has not gone consistently upward because 2 the effect on the population has not altered. This raises 3 the question of what will happen in the future. You don't 4 know and I don't know and nobody knows what will happen in 5 the future. This is the thing which has to be known. 6 Senator Huskie. This is a rather mathematical certainty, 7 if we have the same lead content in gasoline, that as the 8 number of automobiles goes up the amount of lead poured into 9 the atmosphere will go up. 10 Dr. Kehoe. In the total atmosphere, yes. 11 Senator Muskie. Yet the value of -- the value you have 12 given us with respect to Cincinnati suggests, as you have 13 presented it, that this is not inevitable? Dr. Kehoe. It is not inevitable, no, if you change / 14 / 15 the characteristics -- if, for example, you could bring more 16 air into this and sweep it out, the concentration would be 17 low. 18 Senator Muskie. How do you bring more air into the city? 19 Dr. Kehoe. Z am not trying to do that. I say if you 20 could. Tills is hypothetical. Zf you could move the 21 air more rapidly it would get more rapidly diluted. 22 If you then distributed the vehicles so that 23 they are more widely and more uniformly distributed the high 24 results will come down, the lowest results will go up. 25 The question then will be what is the critical concentra 21; 1 whieh becomes dangerous for any man anywhere? a Senator Muskie. With your chief maximum distribution then r> the level will 3tart to go up, or will it? 4 Dr. Kehoe. The level of the total atmosphere will go up 3 but what happens to it at any particular point depends on the manner of its distribution. 6 Senator Muskie. So that with respact to Cincinnati 7 the conclusion must still be regarded as tentative and 0 inconcluaive? 9 Dr. Kehoe. with respect to the future, yes. 10 Senator Muskie. It cannot be taken to justify any conclusi 11 as to any city, any other city? 12 * Dr. Kehoe. Yes and no. 13 /' ) Senator Muskie. That is a vary uncertain answer. 14 Dr. Kehoe. Well, what one daals with in this situation, 15 Mr. Muskie ara the probabilities. The recent survey of !6 Philadelphia, Cincinnati and Los Angeles have shown so many 17 characteristics of this thing that are very nearly Identical 18 that we have not a leg to stand on to believe at the present 19 time that any one of these is particularly unique in this 20 regard. 21 Senator Muskie. As to yaur testimony with respect 22 to Los Angeles, for example, now Los Angeles has done 23 a tremendously effective job of eliminating stationary 24 sources of pollution. 25 i&B 0134 211 I Yet our testimony just tfc; s week is that we have had 2 a recurrence of smog in Los Ar.\eles because of the growth of 3 the automobile population notwithstanding the control of 4 stationary sources. 5 So, all of our evidence is in the testimony up to now is 6 that the automobiles are raising the level of pollutants 7 in the air. Now your testimony f.'.iis morning is that we do 8 not need to e;cpect that with re .'.pact to lead in Cincinnati 9 and now I am so asking you to t:.*y to generalise that with 10 respect to L03 Angeles and othur cities. 11 Dr. Kehoe. All right. Thet\? are spots in Los Angeles 12 at certain times of the year in which the values are relativalj 13 high. When hpvever these are locked at in a esress sectional way tha^ difference between Cincinnati and Los Angeles 14 / is of the order of 1.4 in Cincinnai and tc 2.2 or 3 in 15 Los Angeles. 16 Senator Huskie. 1 agree but that is not relevatn 17 s to my question. 18 Dr. Kehoe. I am trying. 19 20 Senator Muskie. The question is, can we expect again the amount of lead in the atmosphere to go up as the 21 automobile population grows? 22 The evidence in Los Angeles is that pollution from 23 automobiles generally not specifically tied to lead ia going 24 to go up. I am wondering if the lead ia going to go up 25 212 1 with the rest of it. 2 Dr. Kehoe. I think it is very likely that it is. I think 3 where it goes up will depend on a number of circumstances 4 which would have to be investigated in order to give S you the answer. 6 What I have been saying in this, Mr. Muskie, quite 7 consistently for thirty years Is that we must know what we 8 are talking about before we talk. 9 Senator Muskie. Now that is a point on which we can to agree. Dr. Prindle's testimony yesterday with reference to n the studies in Cincinnati, Philadelphia and Los Angeles, 12 included this statement "The average concentration of lead 13 in all samples collected in each city was 1.4 micrograrih' j 14 per cubic meter of air, a microgram being a millionth of / 15 a gram so these are very small amounts we are dealing with, 16 in Cincinnati 1.6, in Philadelphia and 2.5 in Los Angeles. 17 The samples taken in heavy vehicular traffic were considerably 18 higher. 14 micrograms per cubic meter in congested traffic 19 on Cincinnati streets, and 25 micrograms per cubic meter 20 on the Los Angeles Preeway." 21 Now let me ask you this question, Doctor. How do the 22 figure you have given us with respect to Cincinnai relate 23 to vehicular traffic as against outside of the vehicular 24 areas of the city? 25 Dr. Kehoe. Many of these observations that were made I 01344 213 1 with respect to vehicular traffic wv?re made in Cincinnati 2 by ouz: own group. Consequently the statement there is true. 3 The pooint of the thing with respect to human exposure 4 which is the big problem here is that there are really not 5 very many people who spend much of their life time ona freeway 6 They go to work and they return home but they don't 7 spend days on it except for certain individuals who drive 8 trucks, who drive delivery wagons who use these in the 9 course of their normal work and who therefore spend coneiderab 10 time on them. 11 These are the people we need to look at and these are 12 the people we have looked at. 13 Senator Muskie. Dr. Prindle yesterday and the Surgeon , 14 General made a distinction between clinical effects tfom J / 15 exposure to lead as to which he felt there was a pretty good 16 body of data, and low level, subclinical exposure over long 17 periods of time as to which he said we have very unsatisfactory 18 data. 19 Now do your certainties on this point relate to both 20 kinds of exposure or both kinds of results? 21 Dr. Kehoe. yes, rather more I should say than either 22 Dr. Prindle or the Surgeon General. I am not accusing 23 them here of ignorance or drawing a long bow. These 24 gentlemen know this problem as well as Z do and they are 25 concerned about it. The point of the thing is that we have 214 1 shown quite clearly in the industrial situs vion that if you 2 will lower the concentration of lead i.> che atmosphere 3 to a certain point, if you will prevent exposure of the 4 individual to a certain point you will not get lead poisoning. 3 Senator Muskie. iow about these effects which both of 6 these doctors have clearly said they draw no conclusions 7 about they they say he ire uot been established? 8 Dr. Kehoe. Mind you, I realize the difference between 9 the industrial population and the general population. Our 10 evidence comes very strongly from industrial population. If 1! you will maintain tie conditions which we now describe as 12 being safe in induf.try, men continue to work in this industry 13 all their working lives and at no time do they develop lead /' > 14 in/toxication. 15 We have observations on personnel in industrial plants 16 now over aperiod of thirty years in which there has been 17 no case of poisoning, no shortening of life, no evidence 18 of any subclinical injury that we can detect in this 19 population as differentiated from a normal population, that 20 is to say a population working in the same kind of job 21 without lead. 22 Mow this is not in the strictly scientific sense, 23 this in not absolute proof. But thirty years of observation 24 is pretty good evidence which Z don't think one discards 25 readily. 01345 t Senator Muskie. Well, the committee cannot discard 2 readily the apparent conflict between your testimony and 3 that of the Surgeon General. So I want to be sure I understar 4 the difference in your points of view. As I understand S from your testimony you have suggested taht up to a point 6 the accumulation of lead in the body is harmless? 7 Dr. Kehoe. That is right. 8 Senator Muskie. You draw the line just below the 9 lead poisoning? 10 Dr. Kehoe. Considerably below. 11 {Senator Muskie. Does medical opinion agree that there are no harmful effects and results from iead ingestion 12 13 below the level of lead poisoning? 14 / Dr. Kehoe. X don't think that there would be a complete 15 agreement on this at the present time. Z don't think that ( 16 many people would be as certain about this as I am at this point. 17 '\ . Senator Muskie. But you are certain? 18 19 Dr. Kehoe. Not certain about it. X am only saying 20 these are the probabilities and we still have observations 21 yet to make.It so happens that I have had more experience 22 in this field them anybody else alive. Senator Muskie. You agree that two men with the same 23 experience could disagree as to the conclusion? 24 Dr. Kehoe. Z don't think there is any doubt among the 25 21 1 people who are experienced in the industrial situation, 2 Z don't think there is any doubt at all, that if you meet 3 the criteria for safety that now exist in this relationship 4 you can confidently expect that you will have no cases of 5 lead poisoning. Z am talking about none. 6 Senator Muskie. Let me repeat the question so that I can 7 be sure as to where your certainty lies. 1 asked does medical 8 opinion agree that there are no harmful results from lead 9 ingestion below the level of lead poisoning? 10 Dr. Kehoe. Mo, there is no consensus of opinion on tl this point. There will not be for a long time to come. * 12 Senator Muskie. Are you certain on that point, yourself? Dr. Kehoe. Zt is entirely possible to postulate 13 r > that somewhere, sometime, within the universe of the 14 population, you will find individuals who are so especially ' 15 susceptible to lead that under the conditions that exist 16 in the rest of the population that these people will be singl 17 out and poisoned. 18 Senator Muskie. That is a pretty minimal risk as you 19 describe it. Does the medical profession as a whole regard 20 the risk as minimal as you do? 21 Dr. Kehoe. There are a very considerable body of 22 people at the present time who believe as Z do on this. 23 These are people who have had experience with the 24 specific problem. 23 ice a ni 3 46 Zi f Senator MusJcio. This -- in Dr, Prindie's statement 2 yesterday he said this "In the occupational health field 3 when blood levels reach point zero six milligrams per hundred 4 grams of blood the worker is normally removed from an 5 environment in which lead exposure can occur. Concentrations 6 08 milligrams of lead or more per one hundred grams of blood 7 are associated with toxic lead poisoning, the clinical type 8 that Dr. Stewart described. Z would point out the s pa a II 9 difference between .06 milligrams or six parts per ten millio 10 and eight parts per ten million is not a very marked margin 11 of safety." 12 Would you agree with that? 13 Dr. Kehoe. X would agree with that. In a general way 14 Z would agree with this is a small margin but in terms 15 of analytical methods that are available at the present time 16 this is not such a small margin that is insurmountable. 17 X have never seen one case of lead poisoning at the 18 onset in child or adult that has not had at least .08. !9 Now this does not mean that all people become ill at this 20 point. The majority do not -- only a few. This is the 21 lowest level of susceptibility in my experience. 22 Senator Huskie. Let me ask you this. 23 Zs that kind of margin significant or would it 24 become significant if the concentration of lead in the 29 atmosphere were to double? 21 ! Dr. Kehoe. Yes, this margin would be quite adequate 2 for this reason and we have very good evidence for this. 3 If you double the concentration of lead in this that exists, 4 in the ambient atmosphere to which individuals are exposed, 5 you will get no material change in the concentration of lead 6 in their blood within two year's time. 7 Now you have a long time there before there is any 8 kind of build vip that gives you this much difference. The 9 reason for this is that over the long period of time the most 10 of the lead that is absorbed into the body goes into the 11 skeleton. 12 Consequently the level of concentration in the blood 13 moves up very slowly. In our experiments over a period ) of years we have seen that it takes four to six to eight )* 15 months to get a significant difference in the concentration o 16 lead in the blood and the excretion of the lead infthe 17 urine if it'-- if the dosage moves up slowly. 18 Senator Huskie. What is the significance from the 19 health standpoint of the concentration of lead in the bone? 20 Dr. Kehoe* TBis is not negligible but it is slight as compared, for example, with the concentration of lead in 21 the brain. If you have a concentration of lead in the 22 brain, of the order of magnitude of 3/10ths of a milligram 23 per hundred grams, this is usually indicative of a 24 situation which is productive of fatal lead intoxication. 25 01 347 21* f The bone has four times this concentration under perfectly 2 normal circumstances and conditions. You have this in your 3 body and I in mine at the present time. 4 Senator Muskia, Dr. Prindle had something to say on 5 this yeaterday that I would like to get your reaction to. 6 The only way we can evaluate this testimony is to place it side by side so that we can get the clash. 7 8 Dr. Kehoe. I can tell you for the record that you will find very little difference between my views and those of 9 Dr. Prindle. Very little difference with respect to the 10 facts. There will be a little difference with respect to 11 considerations in the future, as is entirely appropriate. 13 Senator Muskie. Bis presentation of the facts and yours 13 at least give the impression of being substantially different. ,4 Dr. Kehoe. But there really is not. sir. IS ( Senator Muskie. X guess we will have to read those 16 more closely. 17 \ Dr. Kehoe. X know Dr. Prindle very well. 18 Senator Muskie. X think the testimony X was referring 19 to .was in thevSurgeon General's testimony rather than in 20 Dr. Prindle's testimony. 21 Dr. Kehoe. X think X could answer that question.air. 22 without being presumptuous. What X think we are talking 23 about here are two different things. One of them is the 24 uncertainly with reference to what a material like lead might 25 22 1 ultimately do. As against^ the probabilities, which are 2 based on evidence, as to what it has done in fact. 3 Fromthe point of view of the Public health we look with 4 considerable concern on any risk that is applied to the publi S health. Z may say we look with a great deal lass concern, anc t 6 Z think unfortunately, on the risk which isassumed by the \ 7 industrial worker. SO 9 10 11 12 13 J / 14 ( 15 16 17 18 19 20 21 22 23 24 23 01 7i 4 R 221 Senator Muskie. I can't find Dr. Stewart's prepared 2 testimony but I have a discussion that took place between him 3 and me on this question. This is the prepared testimony 4 we have finally found: 5 'Evidence was also presented at the symposium which 6 suggests another important respect in which the effects of lead 7 may be largely overlooked because of limitations in our 8 existing knowledge. This aspect of the problem stems from 9 the fact that some of the lead taken into the human body to is stored in the bones. 11 "Any of a number of factors -- including such physiological 12 stresses as peptic ulcer involving excessive bleeding and 13 such physical trauma as accidents in the home ^r onjthe 14 highways -- may release lead previously held in storage. IS In such cases, the released lead may cause greater injury 16 than the event which precipitated its release. Here again, the 17 connection may never be made in the course of routine 18 diagnosis and treatment." Id I then asked him this question: 20 "You also say that the bones of the human body tend to 21 store lead? 22 "The Surgeon General. That is right. 23 'Senator Muskie. Is there any doubt on thi3 point? 24 "The Surgeon General. No, there is no doubt on that. "Senator Muskie. If that is the fact, then the amount 25 222 f of exposure which the human can take must be constantly 2 reduced? * ' * 3 "The SuJrgeon General. Well, the body reached an equilibrium 4 in the amount it is taking in and the amount that the body 5 is putting out, plus this storage factor. There is no solid 6 evidence that the storage factor, that the storage of lead 7 in the bones is itself harmful. Where I was making inference 3 here is that when that storage is suddenly released because 9 of some other event you suddently have a lot of lead in the body 10 that i3 released from/the storage in the bones, like a f 1 fracture or like a severe bleeding. 12 'Senator Muskie* But the release is unpredictable? *J .13 "The urgeon General. . That..i3 right, it is unpredictable. i4 'Senator Muskie:. If it is unpredictable, you have to 15 assume, do you not, that the release will take place? 16 "The Surgeon General. I think so, given some event and / 17 the release, of the lead depends on how susceptible this f8 person is to lead intoxication.*' 19 How would you react to that point? 20 Dr. Kehoe. I would react very strongly to that, sir, by 21 saying that the thing which is feared here has not been seen to 22 occur. We are again talking about what may occur, and not what 23 has occurred. There is not the slightest evidence. 24 Senator Muskie. Which conclusion would you draw, that it 25 will or will not occur? ni X 4 22 t Dr. Kehoe. My conclusion is that lead in the concentrati a that has occurred in your skeleton and mine and in man in 3 generations ahead of us has never been known to produce lead 4 poisoning unless it was at highly elevated levels. We have 5 no evidence that this has ever occurred. 6 Senator Muskie. Why would the Surgeon General raise thi3 7 point? a Dr. Kehoe. Because there is in the literature a series 9 of experimental studies made a number of years ago that indi to cated that under a variety of conditions lead is readily it released from the skeleton. Z think. Senator, it has been 12 quite clearly demonstrated that this is not true. 13 Senator Muskie. You are satisfied that this is not true? 14 Din Kehoe. I am quite satisfied that it is not true. f 15 In fact, I have never seen any situation of this sort reported 16 that to me was in any way plausible except in connection with \ 17 a disease of the kind that results in the virtual disintegratic 18 of the skeleton. Now I have been told by one of my pediatricia 19 friends in whom X have very considerable confidence that there 20 is a situation which has occurred occasionally in children. 21 I sought the evidence. Z was unable to find it. He was 22 unable to find it. He still believes as he believes and I 23 still believe as Z believe. What Z am saying is that the 24 fragmentary evidence that is available in this field is much 25 too fragmentary to be trusted. I am sorry that the Surgeon Gen 224 1 said this because I have to flatly disagree with him and I 2 don't like to do it. 3 Senator Muskie. You say it is fragmentary, too fragments: 4 to be trusted. 5 Dr. Kehoe. Yes, sir. 6 Senator Muskie. Is it too fragmentary to base a disagree 7 ment upon? 8 Dr. Kehoe. In my judgment, no. I am quite sure if the 9 Surgeon General was to read the literature in this field with 10 great care he would change his conclusion. 11 Senator Muskie. Maybe you ought to suggest that to him. 12 Dr. Kehoe. I have suggested it here. I think this will 13 probably come to his attention. 14 Senator Muskie. Speaking as fa Senator now, you can't 15 rely on that. . / ( 16 Why don't you proceed, Doctor? I think I have asked all 17 the questions. 18 Dr. Kehoe. The facts obtained from these experiments and 19 from several field surveys have demonstrated clearly that the 20 quantity of lead which is being absorbed daily by the average 21 adult citizen of the United States who is not subjected to 22 occupational or otherwise unusual types of exposure to lead, 23 is balanced for all practical purposes by the excretion of a 24 corresponding quantity ot' lead. This balance is achieved withi; 25 the first several years of childhood (after the varied diet of < iOCf] G1 3 BO 225 1 adult haa been adopted) during which the levels of concentratlo 2 of lead in the tissues of the new-born infant approach and 3 overtake those of the adult. 4 The newborn infant has some lead in the tissues. The 5 concentrations are quite low and they do not move upward until 6 later. They don't reach an equilibrium until the child is on 7 a full diet. Much of the highest concentration of this lead 8 (of the order of five times that in any other tissue) is found 9 in the skeleton. Moreover, the mass of the skeleton, relative 10 to the other tissues of the body, is such as to reduce the 11 concentration of such a minor constituent as lead, in the other 12 tissues, under ordinary circumstances, to almost negligible 13 proportions. Xt is not negligible since it can be measured / 14 quantitatively. Indeed the concentration of lead in the 15 skeleton of the average child or man in the United States who 16 has not been subjected to any unusual exposure to lead, appears 17 to be of the order of 1 to 3 milligrams per 100 grams of 18 fresh, untreated bone, and this, when restated in the gross 19 relationships of the total weight of the lead contained in the 20 skeleton to the total weight of the skeleton, comes to the 21 average value of about 20 parts per million, which is not far 22 from the natural concentration of lead in soil and coal. This 23 gives you some idea of the relationship to the earth in which 24 we live. 23 So it is that the great proportion of the lead in the body 226 t of the ordinary man is sequestered, in some degree, in that 2 part of the body that is least likely to be affected by it, anc 3 is, in addition, in low concentration even there. 4 The Absorption and Excretion of Lead Under "Abnormal" 5 Conditions of Exposure: 6 The foregoing interpretation of the behavior of lead 7 taken into the body from ordinary sources is supported by the 8 facts observed when individuals have been subjected to the 9 absorption of quantities of lead beyond the range of those 10 which are encountered in ordinary life. Under such circumstanc 11 the rate of the excretion of lead in the urine varies primarily .* 12 with the current rate of the absorption of lead. The concentra 13 tion of lead in the blood also varies with the rate of the 14 absorption of lead, but is relatively slow in reflecting this 13 rate (unless the latter is very rapid). Instead, it tends to 16 represent the approximate state of the body generally, with 17 reference to its over-all burden of lead. Accordingly, if the 18 current rate of the absorption of lead is sufficiently high, 19 as compared to that which characterizes the usual pattern of 20 persons in the general population under ordinary environmental 21 conditions, there is an accumulation of lead in the tissues of 22 the body, including the blood, and the concentration of lead 23 in the blood mounts slowly to a point at which it is indicatie 24 it does not absolutely give you the numbers but it is indicative 25 of the approximate quantity of lead accumulated in the entire b&i oi3H ____________________: 227 1 body. 2 Under the conditions of occupational exposure to lead, it 3 has been possible to develop sound criteria for the safety of 4 workmen, individually and collectively, which, when applied 5 scrupulously, result in the elimination of all cases of lead 6 poisoning. Stated in their simplest terms, these criteria 7 define the point in the absorption of lead, as revealed by the 8 general rate of the excretion of lead in the urine, and more 9 precisely by the concentration of lead in the blood, below whic 10 cases of lead poisoning, even of the mildest type, do not occur !1 The threshold value for the concentration of lead in the urine 12 is approximately 0.15 mg. per liter, while that in the blood is 13 0.08 mg. per 100 grams of whole blood. Allowance must be 14 made in both instances for the known error of the analytical f 15 procedure employed, as well as for the range of the physiologic 16 variability of the results, which in the case of the urine is 17 appreciable but in the case of the blood is minute. Experience 16 has shown, however, that the criteria are reliable, and that 19 men employed ir>. the lead trades remain free of any of the effeci 20 of intoxication by lead, so long as they remain within these 21 limits with respect to their absorption of lead. Freedom from 22 intoxication by lead does not mean the mere avoidance of disable 23 lead poisoning. Or as it has been spoken of, classical lead 24 intoxication, which is a term that might be used, but also 25 should be defined 2 2'i ! Rather, it naans that no symptomatic or objective 2 evidence of intoxication can be detected, as such, by a skillfu 3 and experienced physician. It has been suggested that any 4 single numerical limit such as this is most unusual in 5 connection with the toxic aotion of a chemical agent. To the 6 contrary, it is common, to the point of near regularity, that 7 there should be a minimum toxic, as well as a minimum lethal, 8 dose of a chemical agent. The point here, which has escaped 9 those who have not examined the facts, but have made loose 10 assumptions concerning them, is that the specified limits in 11 the concentration of lead in the urine or blood is not a point 12 above which cases of lead poisoning occur without fail. As a 13 matter of fact, there is no Igvel of lead concentration in the 14 body which means certain/lead poisoning but it is that point 13 in a range of values below which, regardless of human suscept10 ibility (so far as the present record holds), no case of lead 17 poisoning has been found, in our long experie' % nce, to occur. 18 The range of susceptibility, as this term is used in non !9 specific medical parlance, extends from this point upward, 20 over a fairly wide range, but not downward.. Zt is wholly in 21 keeping with the variability in the behavior of men, in 22 response to a great variety of stimuli or stresses, that there 23 should be limits within whioh the response is physiological, 24 and beyond which pathological manifestations occur with 25 increasing frequency and severity. toS'B 0135 2 229 1 I would like to point out as an aside here that during z the entire history of man on this earth he has had lead in his 3 body. He has had lead in his food, ho has had lead in his 4 drinking water and he has had lead in his body. This is 5 inescapable on this planet. The question is not per se whether 6 the lead is dangerous, but whether a certain concentration of 7 lead in his body is dangerous. This is the sole question, 8 physiologically. 9 The applicability of the foregoing criteria of safety from to the effects of the absorption of lead, especially that concerned 11 with the concentration of lead in the blood, within the 12 general field of environmental health is, of course, a crucial 13 matter in determining and ^controlling the risk incurred by our / 14 population from the lead in their environment. It is because 15 this is the case, that the matter has been subjected to rigid 16 examination, with the result that, even in the,case of infants 17 and very young children, the onset of lead poisoning has not 18 been found to occur in association with levels of lead concen 19 tration in the blood under 0.08 mg. per 100 grams of-.whole 20 blood, with' due regard to an analytical deviation of +0.01 mg. 21 per 100 grams, in the case of samples of the usual weight of 10 22 grams. 23 The critique which must be applied in the examination of 24 this matter must take into account the nature of*lead poisoning, 25 and even more pertinently, at the moment, the opinions of 230 t physicians and others concerning its nature -- those which have 2 been handed down among many generations of both critical and 3 uncritical physicians? those which had a sound basis in clinical 4 and experimental observation and judgment, and those which are 5 little more than "old wives tales." Without bringing all 6 aspects of this subject to definitive resolution, modern 7 physiological and biochemical investigation has exerted 8 a clarifying effect upon the toxicological concept of lead 9 poisoning, including certain of its more subtle or insidious 10 characteristics. At this time, therefore, it is especially 11 futile, other than as a stimulus for further extensions of 12 pharmacodynamic and metabolic investigation in the hands of 13 competent and imaginative physiologists, toxicologists, 14 pathologists and physicians, to cherish, in oneself or others, 15 a clairvoyant anticipation of unheralded and disastrous 16 effects of types hitherto unknown among trained observers. 17 Certainlyr however, the concept of lead poisoning that must 18 be held in mind, now and in the future, must Include all dis 19 turbances in physiological function and in well-being that can 20 be attributed, on valid present or future evidence, to the 21 effects of lead. 22 Criteria of Public Safety with Respect to the Absorption 23 of Lead and Methods of Identifying a Threat to the Public: 24 As indicated previously, the opportunities hfforded to 25 the average citizen of the United States (who is' not subjected I 013 E 3 231 1 to occupational or unusual types of exposure to lead) are 2 concerned with his ingestion (swallowing) and inhalation of 3 lead compounds which occur in his general environment. The 4 total quantity of lead that may be absorbed from these combined 5 sources constitutes the total threat, if any, of the environ 6 ment, with respect to lead. However, since these sources 7 differ in their means and ease of penetration into the body, 8 and, to some slight extent at least, in their effect upon the 9 distribution and handling of lead in the body, they must be 10 examined, separately, as to their quantitative significance. 11 Accordingly, the limit of safety, with respect to the absorption 12 of lead from the one, that is, in the air, must be established 13 while the other is being held constant, that is, in the food, 14 and vice versa. This has been done, up to a point, in experime:n 15 in the Kettering Laboratory. 16 (a) The upper safe limit of the daily intake of absorbable 17 lead into the alimentary tract 18 Zn one set of experiments, each of a series of human 19 subjects, after a period of observation of his daily intake of 20 lead in food and beverages, and his daily output of lead in the 21 feces and urine, (under basic conditions with respect to the 22 inhalation of lead from day to day), was given a measured 23 quantity of lead per day, one-third of it with each meal, in , 24 simulation of his ingestion of food contaminated with lead. These experiments have been described in some detail. In 25 232 r 1 brief, however, they have set up a criterion for humon safety. L2 and have reported the results that meet this criterion. It 3 was evident that, under the conditions of these experiments 4 (in which about the same quantity of lead, the sum of that in 5 the food and beverages and that administered, was ingested each 6 day, for all practical purposes), each individual, to whom a 7 [ sufficient guantity of lead was administered dally, gave 81 evidence of the absorption of lead, in proportion to the dose 9 (administered, and excreted lead in his urine at a steadily 10 increasing rate during the entire period of the administration 11 (for somewhat more than 4 years in one exDeriment). He also 12 developed an increase in the concentration of lead in his blood, J* C 13 jat a substantially uniform yearly rate, and accumulated lead in 14 I jhis body (the cumulative difference between intake and output j i; 15 at a uniform yearly rate. No such effect was observed, however. 16 in the subject to whom the least dose, in addition to that in 17 his diet, was administered in 3 doses, each of which was 0.1 18 milligram. Zn this instance, there was a very slight increase 19 pf borderline statistical significance in the output of lend ir 20 jjthe urine, no increase in the concentration of lead in. the blood 21 jltnd evidence (of borderline statistical significance) of tho 22 kccumulation of 12 mg. of lead in his body in the course of 1.5 23 year. This is believed to be as near the vanishing point of a / 24 positive response as one is likely to obtain in an experiment 25 >f this type. In consequence, it ia probably that a young, iHs 1 013 5 4 233 I healthy adult -- I am not talking about the total population, 2 I am talking about a young healthy adult -- can ingest, 3 regularly, throughout his life, an average quantity of lead 4 of the order of 0.5 mg. per day, without any risk of accumulating 5 a significant quantity of lead, so long as there is no persistent 6 and significant increase in the intake of lead from the atmos 7 phere. I might say, incidentally, this is not a wild guess. e There is evidence at the present time from the literature and 9 from the observations of Williams that this is about the level 10 at which England is taking in lead daily in food and beverages. 11 This may be a mistake because the information is indirect 12 rather than direct. * ^ 13 (b) The uppe^: safe limit of the concentration of lead in 14 the ambient atmosphere ( 15 The experimental approach to the determination of the 16 safe limit for the inhalation of lead from the general 17 atmosphere differs from that concerned with the ingestion of 18 lead in food and beverages, the reason being that the quantity 19 of lead which is taken into the body with the air breathed, 20 as indicated previously, cannot be determined directly, but is 21 subject to calculation from the concentration in the air and 22 the volume of air breathed during a specified period of time. 23 A number of variables are involved in this calculation, so 24 that it can be carried out with a reasonable degree of accuracy 25 only under well controlled conditions, with respect to the 234 t measurements of the lead in the air and of the volume of the 2 respired air. Then too, the quantity of lead absorbed in the 3 respiratory tract and lung varies with the rate and depth of 4 the respiration, as well as its volume, and, to an even greater 5 extent, with the dimensions, shape and solubility of the 6 particles of lead-bearing material that is being inhaled. The 7 most satisfactory physiological criterion, with respect to the 8 significance of the absorption of lead in the respiratory 9 apparatus, lies, therefore, in the response that is afforded 10 by the change in the content of lead in the urine and blood. 11 However, while analyses of the urine and, more effectively, 12 the blood, provide definitive evidence of the safety or the 13 potential risk of the individual (and of groups of individuals) / !4 at the time of the analyses, they cannot yield information on 15 which to predict the probable extent of the absorption that 16 will occur ultimately, when lead is being absorbed into the 17 body-at a constant, significant rate. As, for example, an 18 individual in the ambient atmosphere who breathes this atmos 19 phere seven days a week and on indefinitely. This is a 20 different matter. This is the difference,"and it is a funda 21 mental physiological difference, between respiratory exposure 22 to lead according to the noxroal occupational schedule, now 23 standardized, generally, in the United States at 40 hours per 24 week, and that associated with lead in the atmosphere of the 25 community, which, although somewhat variable, from place to 235 1 place and time to time, is continuous throughout the day and 2 week. In the occupational situation, (and as simulated by 3 our experiments in which men were subjected to the inhalation 4 of a known compound of lead in a known state of subdivision S in the air -- nearly ideal for both retention in the lungs and 6 for absorption -- for approximately 40 hours per week), the 7 e ** 9 10 output of lead in the urine and its concentration in the blood Increase for some months until they reach a plateau the height of which is determined, under uniform conditions, by the concentration of lead in the air. Afterward, it remains f! essentially unchanged, on the average, so long as the occu 12 pational (or experimental) exposure continues unchanged. This 13 plateau is an expression of an equilibrium between the / 14 absorption and excretion of lead, which is achieved by reaching 15 a balance between the periods of exposure, when absorption is 16 greater1 than excretion, and those out of exposure, when the 17 excretion is greater than the absorption. 18 There is no opportunity for the achievement of such a 19 balance when the rate of absorption if sustained, as in our 20 experiments during which lead was administered by mouth in 21 three doses through the day, and as it must be when lead- 22 bearing air, within appropriate limits of concentration, is 23 being breathed throughout the twenty-four hours of the days. 24 These facts make it necessary to approach the criterion of 25 the safety of the public, in relation to lead in the ambient 236 I atmosphere, on % different principle than that of the safety 2 of employees in the lead-using industries- It is also 3 necessary to employ a different method of observation from 4 that concerned with the ingestion of lead, although the same 5 principle applies r that of establishing the largest daily 6 dosage of lead derived from the air which, when combined with 7 that derived from food and beverages, will be Insufficient to 8 result in a measurable (or significant) accumulation of lead 9 in the body in the course of a life time. fO He are talking here not about the accumulation up to 11 the point of toxicity. He are talking about whether there 12 is or io not accumulation. The latter ie the criterion. # 13 Experiments'have been carried out in the Kettering 14 r > ' laboratory for three of the past five years, by which the IS methodology of the approach to this problem has been worked 16 out. _ During the past two years, two men have been under 17 observation, in accordance with'these methods, while they have 18 been subjected to respiratory exposure to air containing a 19 lew, uniform concentration of lead (Pb) on an increasing 20 schedule of hours per day during eucee-sive periods of 16 21 weeks. At the conclusion of this experiment, in early July 22 of 1966 -- one of the men is initiated but the other is not -- 23 they will have spent almost half of their time in, such an X 24 atmosphere for 16 weeks. No definitive response to such 25 exposure has been observed, up to the present time,., in the 01 356 237 f font of a significant increase in the output of lead in the 2 urine or in the concentration of lead in the blood. According! 3 in an experiment yet to be performed, the concentration of 4 lead in the respiratory chamber must be increased, and the 5 observations repeated. Prom all of these data -- those availab 6 and those to be obtained soon -- it will be possible to arrive 7 at a standard concentration of lead in the air as a physio 8 logical criterion of public safety, in which a prudent margin 9 against chance may be encorporated. Needless to say, the to validity of the criterior should be put to practical test well 11 before the public shall have been subjected to the projected 12 level of exposure, by means o& periodic surveys such as that a 13 recently x^ede,yin which the reaction of the public to an 14 existing exposure of lesser magnitude can be determined. i IS Certain Basic Conclusions: 16 Prom the consideration of the observed facts and the 17 physiological principles developed in the foregoing statement, 18 it would appear that there is no reasonable basis for anxiety 19 concerning any potential threat that is offered to the public 20 from the lead in the ambient atmosphere in the United States. 21 Moreover, the means now available for the appraisal of the 22 severity of this type of exposure to lead, and of its hygienic 23 significance, would appear to provide ample safeguards in the 24 future, provided such means are employed skillfully and 23 critically, and frequently. 238 1 Senator Muskie. Doctor, I would like to read from a 2 - couple of statements that were made at the symposium on lead 3 that was held by the Public Health Service last December. 4 Dr. Heineman said something that I think might be helpful 5 to us to place some of the points you made this morning in the 6 perspective that you would approve as well as the committee 7 "The first thing 1 would like to point out is that there 8 has been no evidence that has ever come to my attention, 9 including at this meeting, that a little lead is good for you. 10 I say this beaause I believe there are some persons who imply 11 that this is so because of some of the statements which they 12 made. The second point Z would like to make is that it is 13 extremely unusual in medical research that there is only one ----- =r > 14 small group in one place in the country in which research in7 15 the specific area of knowledge is exclusively done. There 16 needs to be repetition and extension of the fine work which 17 has been done at the Kettering Laboratory with regard to 18 the metabolism and the balanced experiments which have been 19 done on lead. It needs to be repeated in many other places and 20 be extended, there needs to be iii my opinion an extension and 21 improvement of the work which was done by the Public Health 22 Service in its tri-city study of lead body burden of people 23 in communities. There needs to be a careful study of the '/ 24 figures Z have given as the safe ones at which lead toxicity 25 will not probably occur. Z say specifically. n-7 r 5o / 239 1 "It is our experience in medicine that to use a single 2 figure as the safe one beyond which poisoning will probably 3 occur and below which poisoning will not occur is a most 4 unusual kind of situation in public health and in medicine. S I believe there needs to be careful study of the figures which 6 I used." 7 Would you want to react to thal., Doctor? 8 Dr. Kehce. Yes. I believe first of all that the obser 9 vations outside of those of the balanced work -- this to balanced work has not been done by anybody else up to the pres< 11 time. It may be that some of it should be repeated for the 12 sake of confirmation. It will be confirmed, I can assure you. / 13 It may be that these experiments should be done in somewhat ) 14 the same manner. I should argue against that. I should argue IS against that because first of all these are very expensive 16 experiments and they should not be carried out wrecklessly 17 without regard to the money that it takas to get this kind of 18 information. The methods that have been used in our obser 19 vation which to me are crucial to this whole situation are 20 being used at the present time on a world-wide basis. They 21 have been used now over a period of years and there is simply 22 no question I think -- perhaps I am prejudiced, but I think 23 there is no question in the minds of a very considerable body 24 of experienced people in industrial hygiene that these results 25 are valid. They have been checked by experts in other countri* ! There is a report that is given here after a translation that 2 has been obtained, that was reported here, that was obtained 3 by oar Swiss colleagues a matter of a few years ago who have 4 used substantially the same methods, who have followed out 5 comprehensive observations, I mean with respect to the field 6 surveys, and have come out with precisely the same results. 7 Now Heineman is right with respect to experiments that 8 are crucial, the methods that have been used in experiments 9 that have been checked by British investigators, by Swiss 10 investigators, by a number of others, as being the crucial 11 points in the determination of whether the information that had * 12 been obtained in our observations was correct. This means only 13 one aspect that is left dpen and that is whether I, myself, 14 and ^y investigators in the Kettering Lab are clever enough 13 to be dishonest about this and get away with it. Frankly, I 16 don't think we have that kind of cleverness. 17 Senator Muskie. Z d' \ on't think that question is involved. 18 Dr. Kehoe. It is theoretically, sir. 19 Senator Muskie. The only question involved is the inter 20 pretation you place upon it. Z will be frank to say that it 21 is unusual for me -- Z am not a scientific man -- to find such 22 certainty in the field of scientific inquiry in a subject such 23 as this. The questions so far as we are concerned are one. 24 What are the effects, or do we know enough about them of 23 low-level sub-total exposure to lead in the atmosphere and. 013 58 240 1 secondly, how will the present answer to that question be 2 affected as the number of automobiles in this country and the 3 consumption of gasoline with lead content increases in the 4 future? These are the two questions we are concerned about. 5 On the question of the sub clinical effects. Dr. Hardy, who 6 testified earlier this morning, had this to say in the 7 symposium. 8 "I have to protest briefly that there is evidence of 9 lead related damage not identifiable as classic lead poisoning. 10 I have listed the following: Layne's studies on Mortality 11 of Lead Workers. Henderson's Australian Work on the 12 Relationship Between Lead and Renal Disease. Doctor Jensen's 13 Work and, more modestly, mine, on the assymptomatlc lead /' ; 14 workers difficulty with his hemalogical abnormalities, and then the large body ok work on children without identifiable 15 16 lead poisoning who through well documented evidence have 17 experienced harmful lead e. ffects either in" -- I am' sure I i 18 am not pronouncing these medical terms correctly -- "hsraalogica] 19 abnormalities or mental retardation." Doctor Hardy apparently, 20 and Z might ask hex to comment on this this morning, says 21 that there is evidence of sub-clinical effects that she feels 22 are of concern as relates to health. You apparently have less doubt on that point. ?3 Dr. Kehoe. No, Z don't because Z know that there axe 24 effects that are residual effects of exposure that have had 25 a significant degree of toxicity. What we are talking about 241 1 here ia not the residual effects of a one-time series of 2 exposures which do exist but the effects of a situation in 3 which we are at a very low level of intake, which has never 4 historically been known to result in a single case of illness 5 in child or adult. This is the difference in the thing. 6 We are not talking here about the residual effects of a 7 one-time intoxication. We are talking about whether signs 6 of intoxication come into existence under the conditions 9 that exist in the community at the present time. I submit fO to you, sir, that there is not the slightest evidence that 11 that is the case in medical literature or in case material. 12 Senator Muskie. We are talking about a condition here -- 13 Dr. Xehoe. We are talking about a condition which may 14 occur. /j / 15 Senator Muskie. We are talking about something physically 16 that is occurrinq that may be producing a different situation. 17 We talk about growing concentrations of lead in the atmosphere 18 and what that may produce. This is a kind of low level, long 18 term exposure that we have not had in the same degree in the 20 past, that we will have in an increasing degree in the future 21 given a continuation of the present methods of transportation 22 by automobiles and the present use of gasoline for fuel. 23 Dr. Rehoe. Let me put it this way. We have had experience 24 with the situation that exists at the present time, with 25 respect to the level of lead absorption in the American -(fee 01359 242 1 population. We have had experience with this over a period of 2 30 years or so during which we have been looking for problems 3 in the general population and have failed to find them. 4 Now, this does not tell us one thing about what will 5 happen five year3, ten years, 15 years from now if, as and when 6 the concentration of lead in the atmosphere goes above a point 7 with which we have had previous experience. 8 Senator Muskie. That is bound to happen, is it not? 9 Dr. Kehoe. What I am prepared to say at this point is to that this is something which just like the food of the country 11 and the beverages of the country has to be watched, to make (2 sure that we know where we are. This will take time, this / 13 will take trouble, this will probably continue and^/ should 14 continue after I am no longer around to be looking at this problem at all. But Z can say very definitely that in my view 15 it is essential that these observations be made. We must know 16 and not have to guess about it. 17 Now I am only saying with respect to the things that 18 might happen that we have no experience of their happening and 19 20 Z simply am not constituted to go on the basis, in the present world in which we live, whioh is full of dangers, Z am not so 21 constituted that Z can be very anxious about a situation that 22 has been with us for 30 years and in which nothing has 23 happened, and which might conceivably happen, that ten years 24 from now something has to be different. 25 243 t In the situation in which we are living at the present 2 time we are confronted with many dangers r the dangers of 3 contamination of the water of the country, the dangers of 4 contamination of the atmosphere with a variety of things are 5 much more imminent than this particular one. Whereas this 6 one must be investigated, it must be followed and we must i 7 know what we are about, we have no reason at the present time 8 to fear what is under the bed somewhere. 9 Senator Muskie. Having listened to all your testimony. 10 Dr. Kehoe, I would say that that last pretty well summarizes 11 my impresion of your position and I do appreciate your coming 12 and taking the time to listen to our questions and to answer 13 them. 14 1 The work of this committee is intended to be educational /' 15 for the committee as well as for the public. So we do appre16 ciate your contribution this morning. 17 Dr. Kehoe. Thank you. 18 Senator Muskie. I wonder if Dr. Hardy would be interested 19 in commenting upon the question that we just discussed. 20 Dr. Hardy. You read from my comments. That is really 21 the heart of what I have to offer. 22 Thank you. 23 Senator Muskie. Thank you very much. 24 The remaining two witnesses on our schedule this morning 25 have been kind enough to agree to come back next Tuesday 01360 244 1 because of the time limitation this morning. I understand that 2 it will not be an inconvenience to either of them to do so. I 3 want to make sure of that. If it is not then Mr. Felix Wormser, 4 Consultant and Former President of the Lead Industries 5 Association. Inc., and Mr. Gammelgard of the American 6 Petroleum Institute, will be the first witnesses when we meet 7 next Tuesday at 9?30. I appreciate that courtesy very, very 8 much. 9 With that we will adjourn until next Tuesday at 9:30. to (Whereupon, at 12:40 p.m. the hearing adjourned, to It reconvene at 9:30 a.m., Tuesday, June 14, 1966.) 12 * 13/ ) / 14 IS ( 16 17 18 19 / 20 21 22 23 24 25