Document jO9rrpY994QjrD4JdbXypmz2

November 10, 1944 Mr. B. V. Stroop American. Petroleum Institute 50 West 50th Street New York 20, New York Dear Darei I hare a preliminary report on the potential lead hazards associated with the cleaning and repair of tank ships and barges used in the transportation of leaded motor fuels. This came to us under date of November 7, 1944 by Dr. R. A. Kehoe, Kettering Laboratory of Applied Physiology, College of Medicine, University of Cincinnati, Cincinnati, Ohio. Dr. Kehoe does not indicate that this preliminary report is to be distributed! however, I feel his conclusions would be of interest to you and the A.P.I. Tank Ship Committee, at least to tlie extent of being a progress report* Therefore, I am quoting the last two paragraphs of Dr. Kehoe*s report. . 4 "Just as tiie organic lead content of the material taken from tankships was relatively low, so W:s the inorganic lead content. One is tempted to conclude that the maintenance of the cleanliness of tankships is the factor of importance here. No doubt, however, it is wise to await the results of a larger series of analyses before hazarding any explanation of the findings. . "No further breakdown of the data seems to be required at this time, since none of the results obtained thus far has given evidence of the * existence of any very serious lead hazard. One might postulate the creation of an h a z r d from contamination of the atmosphere with particulate lead compounds in the process of scraping and welding operations. The evidence now available Is such that the existence of such an hazard should neither be affirmed nor denied, but at present it would not appear to be of very significant proportions.* Yours very truly, /A 0, 8. LERIS m Manager WB ./ coi Dr. R. A. Kehoe HE 00G6810- N7626 )% PRELIMINARY REPOR? OR THE POTENTIAL LEAD HAZARDS ASSOCIATED WITH THE CLEAKING AND REPAIR OF TANKSHIPS AND BARGES USED FOR THE TRANSPORT ATION OF LEADED MOTOR FUELS From time to time questions have been raised concern ing the extent, of the lead exposure that'might be incurred by workmen engaged In the cleaning and repair of tankships and barges employed for the transportation of leaded gasoline. Ho cases of lead poisoning have been recorded in connection with these occupations and fairly extensive enquiry has failed to bring forth reports or hearsay accounts of the occurrence of such cases. There are, moreover, certain differences in the conditions of storage of leaded gasoline in these vessels, as contrasted with those known to exist in shore tanks, that militate against the creation of lead hazards quantitatively comparable to those of shore tanks. Nevertheless, in view of the seriousness of the dangers of cleaning shore tanks, and in consideration of the precautions taken to overcome such dangers , careful investigation of the potential hazards involved in the operation and repair of tank vessels and barges is amply warranted. Such investigation was initiated in England in the latter part of 1 9 4 3 , and shortly afterward similar observations were begun in this country. The scope of these investigations need not be discussed at this time, nor is it necessary to describe the program adopted for the collection of information about tankships and barges in connection with the sampling of scale and sludge therefrom. When sufficient information and analytical data are available to justify the issuance of a comprehensive report, N7626.01 these matters will he presented in detail. The present report is justified only by the fact that- questions concerning the progress of the investigation are being raised with considerable frequency. Some few data have been collected. These are presented for what they are worth as an indication of the extent of the potential lead exposure encountered thus far. More investigation and a considerably greater number of samples will be required to answer the ques tions at issue. Experimental Procedure and Results Twenty-two samples of scaly deposits have been obtained from five barges and twelve similar samples have been obtained from four ocean-going tankships. Information has been assembled on each of these vessels in an effort to portray its history up> to the time of the cleaning and sampling. The organic and inorganic lead content of the sludge samples has been det-erminted by methods similar to those employed in the investigation of stationary storage tanks. The results of these analyses are given in tabular form, merely to show the range of values that have been obtained. H E 0008 G:i2 The Distribution of Analytical Results Obtained on Samples of Sludge (Scale) 'from 'tankships and Barges Employed In The Transportation of Leaded Gasoline, with Respect to Organic and Inorganic ead Content (Results expressed in percentage of Pb without regard to exact chemical composition) Organic Pb in Frequencies Tankships Barges 0.000 - 0 .0 0 ^ 9 0 .0 0 4 12 Ip 5 0.008 1 0.020 1 0 .0 4 4 0 .0 4 3 1. 1 Lumber 12 22 Pb In io Inorganic Frequencies Tankships Barges 0 .0 0 - 0 .p9 0 .4 0 0.80 1.20 1.60 2.00 2 .4 0 12 7 7 1 3 1 1 2 Lumber 12 22 Discussion Several points of interest are demonstrated by these data. First, and most Important is the fact that the organic lead content of these samples as a group is lower than that of samples of sludge from stationary storage tanks . The mean concentration of lead as organic lead in the latter samples was 0 .0 4 percent, whereas the highest lead concentration found in the present series of samples is seen to be 0 .0 4 8 per cent and only two exceeded 0 .0 2 per cent. In view of the small number of samples available for comparison with the comprehensive data on the stationary tanks, this difference must not be taken as con clusive, but it is suggestive. Second is the fact that the organic lead content of samples from barges is considerably less than that of samples from tankships. This is In keeping with the general manner and 4. frequency of cleaning barges, so far as available accounts Indicate, but it would be presumptuous to give undue weight to this factor at present. There is a further fact that is of interest in this connection, in that the two highest results on samples from barges , which are fairly widely divergent from any of the others, were obtained on samples taken from an essen tially new barge. This barge had transported-only two cargos since its construction, both of these being 100-octane gasoline. The quantity of sludge in this barge, mainly if not entirely scale, was quite small and the entire quantity of organic lead available must be regarded as insignificant. Moreover the con centration of organic lead was less than half of that found previously in association with demonstrable hazardous lead expo sure. Ho very significant conclusion is justified by these high results, but they justify the exercise of considerable care in collecting comprehensive information on cargos in relation to future samp1ing. The third fact of consequence is the high concentration of inorganic as compared to organic lead in these samples. This is no new phenomenon, since a similar observation was made in the case of stationary tanks. The source of the inorganic lead is conjectural, but in all likelihood some of it was derived from tetraethyl lead by the decomposition of the latter. The range of values is low in comparison with that found in stationary tanks, and it is of interest to note that there were no really high values denoting excessive settling of an insoluble "sweeten ing" agent (litharge or sodium plumbite). This, perhaps was to 000oCi4 be anticipated from the fact that such materials would have had previous opportunity to settle out. Just as the organic lead content of the material taken from tankships was relatively low, sovas the inorganic lead content. One is tempted to conclude that the maintenance of the cleanliness of tankships is the factor of importance here. Wo doubt, however, it is wise to await the results of a larger series of analyses before hazarding any explanation of the findings. Wo further breakdown of the data seems to be required at this time, since none of the results obtained thus far has given evidence of the existence of any very serious lead hazard. One night- postulate the creation of an hazard from contamination of the atmosphere with particulate lead compounds in the process of scraping and welding operations. The evidence now available is such that the existence of such an hazard should neither be affirmed nor denied, but at present it would not appear to be of very significant proportions. From the Kettering Laboratory of Applied Physiology, College of Medicine, University of Cincinnati, Cincinnati, Ohio. Analytical work by: J. Cholak Approved : Hov. 7 , 1944 t\ 0006Gi5