Document k6jQzmr0x4ZKNrmw7wXG34eRB

October 11, 19I4.I. Mr. R. L. Forney, Director, Industrial Division, National Safety Council, 20 North Wacker Drive, Chicago, Illinois, Dear Mr. Forney: I am returning to you herewith the second and third drafts of pamphlet #3, ''Dead1', which you were so kind as to send me for an examination. It was quite impossible for me to review the second draft at the time it came to me, but I have taken the time to review the third in some detail and to make numerous suggestions. !q u will find my comments attached to this letter. I am sending also a carbon copy for your convenience. I trust my comments will be found to be useful, and wherein they appear to be critical, 1 hope you.will recognize that it has been my purpose to be brief and to the point, and.yet, I hope, not arbitrary. There has not been time to cover the whole pamphlet, and thus, I have indicated my willing ness to follow through with my suggestions if your committee wishes me to do so. The revisions which I have suggested are based in large part on the content of the report of the committee on lead poi soning of the Industrial Hygiene Section of the A.P.ii.A., of which I am chairman. We are preparing a rather comprehensive report, a portion: of which is completed and will soon be is sued. so far as it is feasible'? to-,do- so, 1 have attempted to bring this pamphlet into harmony'with that report, with the idea that it would be disadvantageous - if the two were to clash with each other. On the other hand. If they are in essential agreement, they will strengthen each other measurably, espe cially in relation to compensation and other medico-legal con siderations. . " Other corrections or suggestions have been based on the fol lowing purposes; (1) The removal of names so far as possible-, except insofar as definite reference to published articles can be cited; (2) The avoidance of controversial statements, par ticularly when they are unnecessary for practical reasons; (3) the avoidance of discussions of medical matters so far as pos sible so as not to raise too many medico-legal difficulties; (J4.) the elimination of relatively unimportant matters for the Mr. R. L. Forney - (2) - October 11, l^l. sake of brevity and conciseness; (<?) the correction of ungrainatical and ambiguous statements, In many instances the explanation for a given criticism or suggestion has been offered in the paragraphs which I have prepared. Obviously, I do not expect your committee to accept my correc tions verbatim. I do wish, however, to stress the fact that every correction or suggestion which I have made has been based on careful consideration and on a.rather broad, experience. I should particularly hope that any authorized pamphlet of this type would avoid controversy over certain relatively. unimpor tant matters and that it would not contribute to keeping alive a number of the misconceptions which have been disposed of by recent investigation. I wish to urge particularly careful attention to the question, of analytic methods. the pamphlet, as represented in the third draft did not deal with this ques tion realistically. what I have lone with, this portion may well be subject to improvement, but the general manner of dealing with the problem of methods Is in lino with the .ludgment of the people who have had the most experience in this field during tne last ten years. I can speak not only for my self and my associates, but also for a number of others whose experience has been broad. Anything that is issued on this matter ought to be up to date and in accordance with recent experience. This matter is; quite serious, since a very great proportion of the present confusion as, to the significance of analytical data is based on uncertainty and ineptitude in the choice of methods of analysis, iour committee, therefore, should be very cautious in Its recommendation of methods and should not authorize the use of any method which is not pu blished in minute, detail, alnd which has not been tested criti cally by competent workers. Very truly yours, HAS ef Robert A. Kehoe, M. D. H 0015726 -1 - assJl X* -I,tmln'fato---^through tests and analyses of samples"---3rd line Change as follows---''processes through properly designed operating, ventilating, and exhaust equipment---- --------- qth line Charge as follows- - - "V?hi ie the avenues of feud absorp tion into the bony and the toxic effects therein will be covered"-------------------- ---------- ----6th and 7th lines Page imsJi i Change as follows---''precautions should be taken against hazardous lead exposure on the part of employees.Lines 2 and 1 from bottom Omit reference to slow absorption of load in oil as prac tically unimportant and change sentence as follows:'^Tetraethyl lead is an oily, liquid, organic compound of load that is.dangerously.volatile at ordinary tempera tures* It is also readily absorbed through the healthy, unbroken skin, for these reasons, it .is a highly dan gerous material and muot be marsufaetured and handled with care against Inflation of vapor and contact with the akin. It Is usedjchiefly as an anti-knock agent in motor gasoline to wnieli it is aculeu- in low concontr&tions that do not give rise:to the danger of lead absorption among persons who nand3,s and dispense gasoline, Tetra ethyl lean has also bden used in assail'quantities in the .innufaoture of other chemicals* Regulations governing the use of tetraethyl lead,.,... .etc. " 8. Change as follows^Commercial products containing lead compounds -ar not always described or labeled in . such a manner that the. managers, foremen, or workmen in an indus trial plant or proces^ are aware .that they are using lead compounds, fifheh such 1 commercial preparations are supplied for uae, it should be the practice of. the supplier to point out the potential lead hazard associated with the use- of . the product by employing suitable warning labels. Employees may......, .etc.1! " 10. Ko useful purpose is served by emphasising the factor of individual susceptibility. To do so encourages men to be lieve .that they can ward off effects that would injur weaker persons, .Moreover, there is much lees validity In the idea of special susceptibility than is commonly be lieved. Still further the question of dosage is so great ly modified by the time factor thqt the acute toxic doso is of little consequence in, relation to occupational lead exposure, `fhe whole question of immediate toxicity should be soft-pedaled, therefore, while stressing the importance of avoiding unknown and uncontrolled exposure to all lead compounds. It is.also important to avoid the discussion of the uncom mon effects of lead intoxication and to call the attention of laymen to the more usual and characteristic effects, so that they may avoid undue apprehension on the one hand and Kf 0015727 9633.0]^ 2 may racoipits the. existence of danger on the other. I should revamp this paragraph as follows! whenever there Is lead exposure there Is potential dan ger from the absorption of load. "The de.-ree of danger depends upon the extent and duration of the exposure. The poisonous effects of load absorption are usually manifes ted in one or more of the following ways: Cl) By disturbances of the digestive system, in the fora of loss of appetite, constipation, vague abdominal discomfort, and in more severe cases by severe cramping abdominal pain (colic}; (2) By painful and stiff joints, bones, and muscles; (3) By general weakness, loss of weight, and pallor; Uj.) By loss cf strength in the fingers, hands, or forearms, and inability to use them in the per formance cf customary tasks; (5) Sy damage to the blood with the production of anemia.rt (Hots that no reference is made here to "stippling" or *lead line**. This omission is deliberate, and necessary, because those arc not "poisonous effects".) 'Too much stress has boon put on kidney damage and injury to the reproductive system in connection with lead poi soning. These are definitely controversial matters from a medical point of view and should not be presented thus factually without adequate discussion. It is bettor her to omit reference to them by calling attention to the more common effects. Pap;a It 11 and 12.1 should omit these sections altogether. They give lit tle or no useful information to industrial executives, hy gienists, or physicians, and they confuse the Issue, which is covered better In paragraph 13. Paragraphs 11 and 12 are technically erudite, but practically unimportant except to the toxicologist. This pamphlet is directed at the specific problem of prolonged occupational load exposure. The'issue should be stated, clearly by emphasizing certain statements In Paragraph 13 as follows: IJ. It must bo recognised that virtually all compounds of lead are poisonous if they are handled in such a manner as to be introduced regularly or frequently, in sufficient quan tity, into the air breathed by industrial workmen, or if they are t aken into the mouth and swallowed in sufficient amount over a long enough period of ti-ae. Some compounds 0015728 -3- of lead are more dangerous than others for a variety of reasons. Some are more soluble in the tissues and fluids of the body than are others. Some of them must be employed or processed In a physical state that makes them difficult to handle without danger of exposure. Thus it may be feasi ble in some instances to select a relatively safe lead com pound for a specific industrial purpose in place of one that would give rise to a much greater potential hazard, -'evertneless it should not: be believed that preventive mea sures can be neglected or reduced In effectiveness, because the compound or compounds in use are allegedly low in toxi city, fage 5 lip. Change as follows;----- "Lead and Its compounds can b taken into the body by inhalation or by ingestion (swallowing), (Tetraethyl lead Is readily absorbed through the skin. See paragraph J.) Inhalation of lead is by far the most com mon and moot dangerous form of industrial lead exposurd. It should not be assumed, however, that it la, unnecessary to warn and protect industrial workers against the ingestion of lead compounds, and against careless and unnecessary skin contact with lead compounds. Every effort should be made to encourage and facilitate the development of care and clean liness on the part of workmen, not only to avoid lead absorp tion, but also to avoid dermatoses." (I should require excellent evidence before I could accept the 'statement that lead In oil is absorbed in appreciable quantities through the healthy or Injured skin. Is there such evidence, either clinical or experimental? Unless there is uncontrovertable evidence, this reference to it should be deleted entirely,) 15. Chapge as follows;---"The remainder is deposited on the sur face of the lung tissue from which it is absorbed and dis tributed into the tissues of the body." (It Is unnecessary and: unwise to d escribe questionable physiological mechanisms. It Is quite improbable that lead is carried in the blood as the phosphate, and there is no point here in making a state ment that most investigators will criticize. In point of fact practically all the lead in the blood is carried in the red blood corpuscles and no one hast he vaguest idea as to whether it is there in organic or inorganic combination.) 16. Change as follows, and for similar reasons UeliminateaNSrd line through the feces. The greater portion of the lead which \ is absorbed from the gastro-enteric tract is carried to the liver. It eventually finds its way into other tissues of the body and also back into the intestine by way of the bile." Page 6 17. Delete completely as repetitious and lacking In useful in formation. Tetraethyl lead is dangerous, not because it is absorbed directly into the blood stream, thereby short-cir cuiting the liver, but because it goes quickly to t he organs of high fat content, that Is, the brain as well as the liver. It does not cause an immediate, but rather a delayed intoxi- cation. 0015729 aad: 9* ' 2&B6m 27* 28. fieri s as . follows; Methods of. Lead, Analysis. sra a number of. general methods wisleh can. be em ployed In the analysis of lead ciusta. Soma of Lhasa one squally satisfactory f or the analysis of loau In biologi cal materials after suitable preparation of such samples* Therefore, it scams advisable at this point to combine all descriptive references to analytical methods and their applications, so far as they cun be dealt writh in this pamphlet. Only quantitative rethods are w-C*nfeioned, sin.ee the mere detection of loan in samples is vlthout value, yethods based on orthodox chemical procedures whereby load is separated from other uet&ls as the sulphide, sulphate, or chromate, ana determined finally by fcitramtrie, colori metric, or turbtdimetrlc techniques have ceen described in numerous modifications by var ious invest lgators. These are laborious and 11mp-consumlng, and are fraught with numerous technical difficult!eo, but they yield satisfac tory results in the hands of careful analysts, if the quantities of lea.;: dealt with are sufficient I.n quantity, i.e, 0.2 nillirrams or more. references to articles de scribing these methods mill be furnished on z-o ^u o s l ., but sii.ee these rr.ot.iodo have boon largely alapluced in recent years by more sensitive, rr.ors accurate, and more convenient methods, they will not be discussed further. (inferences y.iven out hex* should include not only Pairhall's method, but certain modification a and. improvements in it that have been described much more precisely than Pairhall's, They should also Include other methods based on chemical separatory ijrineiplos, a number of which have proved their worth in the hands of Australian, British, ..nd American Investigators, fairly complete reference to these can be found in a number of papers or? methods. I shall be glad to supply them on request.) Several electrolytic technique for fee determination of lead have been, described and employed with reasonable suc cess by various .investigj&tors,. These, too, except for cer tain limited applications have boon superceded to a largo extent by methods developed more recently. Various modifications;, of the Fischer-Leopoidi method* (aiding us of dlthixom (diphenylthio carbason) as a means of extracting:lead quantitatively from its aqueous solutions to fom a colored complex), have been developed in recent years and have eosa to occupy first place among procedures for the dctelmiaatton of load. Xhe method is sufficiently sensitive to deal with the minute quantities of lead present in small samplec of urine, blood, and tissues, and when properly carried out, it is specific for lead and quantitatively precise. Several of ths modifica tions ha* been described in step-by-step detail and can bo relied upon implicitly when employed by careful and experienced analysts. Among those used extensively with tflr 0015730 5 a variety of materials are the methods described by Clifford and ^lchmann, by ^Iikins, miloughby, and JCraerser, a nd by Hubbard. 9. Spectrographic analysis of materials containing lead can be carried out with extreme sensitivity and with accuracy equivalent to that of the bast ditkizone methods. The metnod requires highly specialized and costly equipment, and therefore, it is not widely used* because of this limitation, further discussion of it will not be under taken here* Hoferonce can be made to the papers of Cholsk, et al for details of the technique. 30. Here use paragraph 28 with modifications beginning with line 3 as follows: "lt has in its favor the use of com paratively simple technique and somewhat greater spaed in the final determination of lead, with this as with other methods, however, the preparation of samples re quires tire ana care, and thereby, a considerable limi tation of the speed of analysis is imposed, then pro perly handled, the method will yield results comparable in accuracy with the althizone and 3poetrogr&p:lie methods." defer hero to the paper of Bambach. luge 9 30. maximum permissible concentration (This will become if previous recommendations are followed.) Correct first sentence to a void repetition of "permissible" and "per mitted"; "The lead concentration in workrooms should not be permitted to exceed---"etc. bjgns of lead folsoninft Pages 10, 11, and 12 This section of the pamphlet should be revised drastically, in my opinion, not so much because it la incorrect in its facta, as because It is not directed either to laymen or physicians in such a way as to provide clearly the infor mation required, The layman will not understand the sim ple facts which h should have^because they are mixed in with strictly medical and physiological considerations. The physician will not accept the medical information be cause It is not presented in the manner to which he is ac customed. The discussion, therefore, while fairly clear \ to the specialist, is both too much and too little to ac complish its purpose. In ay opinion the discussion of normal lead absorption and the evidences of increased lead absorption should be included in the previous section on "The Action, of head and Lead Compounds on the Body", since this information concerns lead absorption and could well ^ follow the paragraphs on the "Entrance of lead into the body", just before "Testing for Presence of head in Air and Analysis of sample". Such an arrangement would per mit the Inclusion of a later section for the information of physicians, on "CMnical types of lead poisoning and HE 0015731 the diagnosis of lead poisoning", this to toe substituted for the section now entitlo'd "ligns if bead Poisoning", buch. a section, prepared by a physician for physicians, could be a brief but adequate statement of the present status of the subject, with a few well chosen reference to the literature, ins to aa. of the partial quotation of authorities. I should be glad to assist in the prepara tion of such a section in any */ay possible, hut X cannot develop my suggestions in tine to meet the dead-line ret up in the letter accompanying the draft. I shall also be glad \,o suosiifc this section of the report of the Committee on Lead Poisoning of the a.P.H.A. as soon as it has been ooiaelotu, for such use us it may be here. On the other hand, if it is necessary to issue this p^ap;jlnt quits soon, I should suggest eliminating ttin section, noroly adding sui lble inf ormatior^ fco tno iaynan to the lection on 'fhe motion of Laud and laud lompounda on the 3orlySI, While i have not h&tt. time to review the remaining material In minute detail, it seems to im to ba very satisfactory, except for the last page, on which.the load findings in the urine are expressed in non-quantit&tive terras, I aes sure *tp, Kronen berg would wish to modify this to include quantitative limits in tie case of the urine, deference might also ua j&ade to the quantitative analytical findings in the blood. He 0015732