Document 85yKZge5KJE2Yq7x7ojjNepzK
August 8, I960
xxxxxxxx Avon 1-2568
Dr. L.. E. Curtis, Medical Director Standard Oil Company of California 225 Bush Street San Francisco 20, California
Dear Curt:
Thanks for your letter of August 4, and for its information concerning
certain men. With respect to your other comments and questions, let
me point out first, that I was out of the country from June 11 to July
12, ana then out of town (in New York) from July 23 through July 29.
I have had no chance, therefore, to inspect the results obtained until
the past few days. The analytical workhas proceeded, meanwhile,
and the early results, from my point of vision, were so satisfactory
that I only glanced at the last two reports. An occasional result on a
sample of urine {
.inthe report dated 6-24-60, and
as referred to by yourself in the report of 7-29-60}
has been well above the general level of the other finding, or even
(in the one instance of above the extreme upper normal limit.
I do not believe there is any point in repeating at once the
collection of a sample of urine that has been lost for any reason, or
of a check sample following one that has given a high result, unless
the result so obtained is clearly within the dangerous range. I shall
be able to watch the results as they come through hereafter, and will
notify you if anything further is required of you. In explanation of my
statement that the checking of the results obtainedthus far on the
samples of urine is unnecessary, let me point out that, while you and
I have every reason to be concerned about the status of any individual
in this group who is, or may be, onthe verge of trouble, no such a
situation has developed, so far as analytical evidence fromthe urine
is concerned. -
. ' . v. - i. .
The case of^H^is an example of this type, in that the urinary con centration of lead in a sample of modest volume was relatively high. Thesignificance of this result as a threat of danger is, however, negligible. His blood lead is low, so that he cannot have absorbed any large quantity of inorganic lead recently. Furthermore, he canhardly, in this length of time, have absorbed a dangerous quantity of tetramethyl
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Dr,, L. E. Curtis - (2) - August 8, I960
lead unless he has had some chance for contact with the concentrated material. Onthe other hand, a man who excretes a sample of urine containing as lowa concentration of lead as 0,07 mg, per liter, can, through sweating and limitation of water intake, excrete another sample of three times that concentration in the course of the same day. Unless, ther.dbre, there is reason for concern (as in the manufacturing operations, where one. must follow up every significant deviation as promptly as possible, one simply -waits for the next round of samples, to follow the trend. Since in this survey, you have the responsibility for the men, I suggest that you repeat the sampling of the urine whenever you feel it desirable to do so. I will suggest such a procedure to you when I, independently, think it desirable, for statistical or other reasons. It would satisfy you, I think, to resample Rios, and if you think it worth while, you might check the matter thoroughly by obtaining two samples within'the same day - one in the morning and the other in the afternoon {or early or late in the 8-hour shift).
Ivith respect to
the situation is different, and I
hasten to give you my view of it, after having it brought to my attention
by your letter. If the results on the blood can be believed (unfortunately
the two results were obtained by. the analysis of only one sample, -which
may ve been contaminated), this man has sustained some comparatively
recent exposure to inorganic lead. (The high result in the blood is not an
expression of the absorption of tetraethyl or tetramethyl lead, while the
low value in the urine is almost equally as strong evidence against the
likelihood of significant exposure to organic lead. The results are fully
compatible with exposure (almost certainly occupational) to inorganic lead.
This man, therefore, should be resampled, and the nature of the work he
has been (or may still be }doing should be carefully investigated in his
own interest. This level of lead concentration in the blood is such that
symptoms of intoxication may develop at any time, and while they would
be expected to be mild, they might he more than usually severe.. It is
possible that this manhas not beep long in your Company's employ, and
that he came to you from some occupation in which he was exposed
hazardously to lead. But it is possible that Ms present work (at home or
elsewhere, or even in your Company's employ) involves a significant degree
oi exposure; or his home conditions may involve significant exposure,
although this is unusual. Inany case, he is in danger, unless this sam
pie of blood '.vas contaminated, and his situation should be looked into
careiully ~ carefully on his own behalf, and carefully to avoid any com
plications arising out of this new situation and its investigation. . I would
first investigate his status very carefully, and then resample his blood
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Dr. L. E. Curtis - (3) - August 8, I960
and urine, andthen wait for further analytical results. If his exposure
to lead was incurred in his former employment, you need not be unduly
worried. Ihave never seen lead poisoning develop after the exposure
had been terminated. If he is nofc/incurring exposure to inorganic lead,
such exposure should be discontinued at once.
.
Sincerely yours.
Robert A. Kehoe, M.D.
.RAYi of P. S. I am open to serious criticism that I had not picked up this situation at once, but the other reports have been so innocuous, that-they' encourages me, while deeply involved in catching up with my work, to delay my examination of the later reports. I'lnot fail you hereafter.
R.A. K:
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