Document 6wYokR0Evxeye4x3qJeDRDJn1
July It 1936
Dr. A. Ray Wiley 512 Medical Aria Building Tulsa* Oklahoma
Dear Dr. Wileyf
I am glad to reply to your letter of
June 17th and to give you the faots with regard to exposure
to leaded gasoline# I shall summarize these facts briefly
in iay letter# but I shall send you under separata eover
two articles which refer to all the literature on the subject*
and which give the details of Investigations made for the
purpose of determining the facts.
Exposure to leaded gasoline is apparently not more dangerous than is exposure to any ordinary gasoline* The lead compound present in gasoline to the extent of never
more than 1 part in 126(5* and usually in considerably lower
concentrations# does not result in lead absorption from skin contact* or from inhalation. Tetraethyl lead itself is a compound of low volatility and is absorbed directly through the skin* The absorption is generally interfered with by
dilution in gasoline* and if the dilution is as high as 1 part of tetraethyl lead to 1000 of gasoline# skin absorption is completed prevented* Thus animals exposed for months to daily contact with leaded gasoline do not accumulate lead in their tissues# and when killed and analyzed after such exposure* do not show lead In greater quantities than can be found in the tissues of normal* unexposed animals* Likewise the volatility of gasolines Is so much greater than that of tetraethyl lead that the vapors arising from tanks do not contain appreciable
quantities of lead until between 1|X) or 50 per cent of the
gasoline lias been evaporated* Thus if half the gasoline is
evaporated off* there will be at least 98 per cent of the lead
loft behind in the remaining gasoline. Ihen gasoline is spilled and entirely evaporated* most of the lead goes with it, but under these circumstances the lead concentration has never been found to be high enough to be dangerous* A portion of the tetraethyl lead is left behind in a more or less waxy material# and is absorbed to some extent by the ground or by asphalt or concrete floors* This problem has been investigated in detail not only by ourselves* but by two governmental agencies# one In this country and one in Great Britain. No one has succeeded in finding evidence of the danger of lead absorption* The correctness of the experimental work has been amply confirmed# I believe# fey the experiences of the last twelve years during which leaded fuel has been on the market* We have investigated numerous cases If alleged injury* and have been quite unable to find any case of
bcii: fide lead poisonU (0; Moreover our investigation .of filling station a t t e n`*dan_d__gara.g_ meoha.s.ioa has failed
to'disclose any evidesuMi f significant lead absorption.
"Host of the complaints of injury have badjtS do with various
types of dermatitis nad skin irritation*-^'Shese have not been
different from the}lesions associated wtt&-exposure to ordinary
gasoline, and since the ingredients of Ethyl Fluid are not as
irritating to the. Skin as gasoline* itlsnofc to be expected that any lesion characteristic of lead'would be found as the
'is
result of contact with gasoline.
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. We have no record of any examination of
As a matter of fact* we do not now and never
ive mod'e^periodic examinations of all men exposed to leaded
gasoline^ nor did we ever contemplate any such program. There
are ten of thousands of such men;ls the country and it would
not be possible to maintain medical supervision of all of the
men who are connected with the handling of leaded gasoline.
What we have done is to follow,from tin to time,selected
groups of men with the longest and worst exposures in order
to arrive at definite conclusions as to the magnitude* if any,
of the lead exposure associated with the handling of gasoline.
,
Perhaps it is not quite clear to you that this occupation Is
and. has been apparently entirely free of any incidence of
lead poisoning* It was anticipated from the start that this
would be the case on the basis of experimental evidence which
indicated that no lead absorption occurred in this occupation.
As a matter of fact* if there had ever been any evidence that
the handlers of gasoline could absorb appreciable quantities of
lead in their every day work, no one could ever have contemplated
.
for a moment the continuance of the distribution of this type of
gasoline* It has not been so much our purpose to study this*problem
from the point of view of its incidence of lead poisoning. Rather
it has been our purpose to deteralne if there was any lead absorption.
Rather obviously* with the absence of lead absorption, lead poisoning
can not be expected to occur. I repeat that in my opinion the
evidence is entirely sound and convincing that there Is no danger
of lead poisoning among gasoline handlers. Such cases of tetraethyl
lead poisoning as have been seen, have all occurred in connection
with manufacturing operations, (There have been a few cases of
poisoning In gasoline refineries in connection with the cleaning
.
of gasoline storage tanks which have contained gasoline over a
period of years* A peculiar set of circumstances here resulted
In some degree of lead exposure* This has been discussed In the
literature and the cases have been reported* However* they have
nothing whatever to do with the dally handling of gasoline in tank
cars or in filling stations* } The matter is discussed to some degree In an article which I am sending you.
.
' your ' .
.
How as to patient Mr.
I have
gone over the information available on Mr. H H T a n c ^ i have gone
over your examination record with some interest. It would seem
to me that If lead exposure were eliminated from the situation*
the diagnosis would be fairly clear. It 3eems quite apparent
from your physical examination* and from your report, that his
lilies
cardiovascular condition provides an adequate explanation of
M s Illness* There Is no specific evidence of lead absorption,
and from what I have said in the paragraphs above, I think you will gather that I consider the history of exposure as entirely Insignificant* From the story given iae as to the onset of Mr,
^Illness* I should suspect that he had a slight cerebral accident On the other hand* you have had the privilege of examining him and of going over his story with hira in person, and your opinion on this point should be worth more than mine.
If there is any other way in which 1 can
contribute any*information on this patient, X should be very
glad to 4d so*,
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v Obviously there will be no charge for the
reprints which I am sending you* nor will there any charge-for
the time which I have taken in studying the records and In ,,
writing you*
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Very truly yours,
RAKsis
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' Robert ^"Kaiics, 15.D.
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