Document jBeDr2yGLYjnbyd7rBoBBb6G9

Aupplesent to Interim Report of aarch 23, 1931 The field investigation, &n vieacribed in the Interim lienort, was carried ot an planned except that the period of time was extended to sixteen tsontha instead of twelve, primarily tor reasons of convenience in the completion o the second scries of clinical examinations. <in this account there were live rounds of sampling of t urine, instead of the intended four, and the final samples of blood were obtained for comparison with the initial samples alter an interval of approximately fifteen months instead of twelve. All of the data, including those of the clinical examinations, hub been asserubied by the end of the year 1901, and were subjected to careful scrutiny and statistical analysis. The final report is in preparation, but has been delayed in its completion because of other duties and obligations within the Scpartsseat of preventive Medicine and Industrial Stealth of which The Pottering laboratory is an integral part) including those associated with graduate instruction. The data of priaayjr importance a.re those indicative of the ! experience of the personnel engaged in the pertinent operations of the petroleum industry.with respect to potential exposure to least in the fora of the ietraosthyllead which has been added to gasoline. Other items of iafor^eatioa bearing on the matter under investigation, but less crucial in relation to the question of exposure to,and absorption of, lead, ur the clinical findings <physical ansi .laboratory findings, including beraatologieal and X-ray observations).' For present purposes these may be disposed of briefly. Mon of the ste-n Included in the survey gave any evidence of illness referable to the absorption of lead, whether of complaints, physical sign ! -2- or &c;uuatological deviations. As to the latter, all of the findings in all of the personnel eome within normal limts, and the terminal findings, to the extent of their differences from the initial data, were in the direction of improvement. (This^almost certainly, was a fortuitous circumstance, whether of seasonal or other import} The differences were significant in the statistical sense, but were not remarkable in the physiological sense. The radiological observations were not intended to be especially relevant with respect to potential exposure to lead, but were regarded as desirable for other hygienic reasons. There were no findings that required further investigation. The terminal samples of urine were obtained in July and August of 1961, the next-to-last series having been obtained in May and June. The second (final) series of samples of blood were obtained in July and August, at the time of the collection of the final series of samples of urine. Only a few of the men who were included initially were missing in the final round of sampling (and examination). Such minor discrepancies are shown by the numbers of samples represented in the several tables of data. The analytical data, relative to the urine and blood, for the entire period of this survey, are assembled in a series of tables numbered from 1 through 10, attached hereto. Tables 1,2,3,7 and 9 are extensions of Tables 7,8,9 and 10 of the Interim Report (with some slight difference in arrangement). The "supplementary" tables, however, contain all of the analytical data and can be substituted for and added to those set forth in Part 2 of the Interim Report. 1/ is a >' 7 n ;'j Kf U x j U t J e- f* Th sliscusaioa begiaaiiies on page 21 of the Xntcrla Report requires little aodificutioa In order to take-into account the additional xinnings. There is, in fact, only on stat.jat la the atrie wMcu requires ^modification or retntftUn - ;--a?sc S3 `the variation showed uo consistent trend with the laps of tia*. This statessont ia at fault, only because of the discovery of a tread Condo significant fey the Just two aeries of urinary findings) toward a generally progressiva decrease ia the con centration of lend iii the urine of the filling statical attendants in both ', Francisco ana loo Angel*, fife concentration of lead ia the blood ox the tea gnKtjW was also lower in the terminal yjroup of samples than in the initial ^rwup), thifi trend is of significance in the statistical b s o m, and if- on somewhat &ore than a fortuitous basis. Just what this basis r.;ay i.-o is i^;riy si^culaUve, however, since the variation in the findings, from the beginning to the end os' the survey, occurred within the ^ysioiojrical rung. gyatenatie investigation of the iatite and output of lead on th cart of s-rperissental subject, se carefully control led conditions of the laboratory, have des?*$trated the ocistettee of a separable degree of variability ia the lead content of the urine and hicod of iadividualuy irosa person to peraca^sad from tine to tine in the experience of a single individual. In these dsperisseats, the variability ia often explained fey the full analytical data, whereas* ia field surveys, one sees only the oteasse of the combination of factors which affect the over all exposure island absorption of)lead by individuals or groups, without feeing able to sort out the individual -factors. The point of lseportonc, in th interpretation of tb findings prowmte her. i( 0007393 ! 4- in that there is no evidence of the fe of occupational exposure to lead, on the part of these men, because of the substitution of tetrasethyllead for tetraethyllead in the gasoline which was being dispensed and otherwise handled by them in the filling stations. Note: The additional information obtained in the final period oi the survey of the lead in the air at the occupational sites contributed nothing new or aberrant. The data presented in Tables 1,2.3,4,5 and S of'/fa 7-fti C-PJW \thxf are entirely adequate in their representation of th facts with reference to lead in the atmospheric environment of the workmen in th various occupations Director, The Kettering laboratory Department of Preventive Medicine and Industrial Health Date: April IS, IS624 ^Prepared in time for a meeting and full discussion of the situation in the Office of th Assistant Secretary of Defense, Washington, D.C., April 17, 1962. ^ o o o v 3 y 4