Document 4v0R4MmmLNwnrO4E3v00Eonvx
MAGNITUDE I.EAD BXPOotJRIS IN MARIcN, INDIANA PLANT OP
ANACONDA WIRE AND CABLE COMPANY
Air samples were taken In the Immediate vicinity of
a melting pot In ehloh scrap lead from cables vas being melted*
Detailed observations vere made over a period of an hour and a
half In order to note the oondltlona which were moet favorable
for the distribution of particulate lead compounds in the atmos*
phere. It so happened that the end of one shift and the beginning
of another came during these observations. This period involved
the removal of dross from the melting pot, an operation whloh
occurs onoe per day, and which Involves much greater dissemination
of dust than that associated with any other procedure. Air samples
were token from several points about the pot, at the height of the
operator^ face, during the period of normal operation. These
samples were composited Into Sample el. Another series of
samples, similarly combined as Sample 2 were obtained during
the filling of the pot and during the removal of the dross.
The analysis of these samples yielded the following
resultsi*
Sample #1 .21,^14.0*0 ml. contained 0.002 mg/Fb
equivalent to 0.09 rag. per cu. meter.
Sample
21,635.0 ml. contained 0.006 mg. Pb
equivalent to 0.28 mg. per cu. meter.
The values for particulate lead in atmosphere are
usually expressed in terms of 10 cubio maters of air, and on
this basis it is currently aocepted that values in excess of 5
N 4039
atUIerflca por 10 cublo natera nro unsafe* Ton orkera give
sllfUtly lover values, to some instances as loe l**> milligrams
per 10 cubic meters* The evidence, however, Is very good in
indicating that basio exposures as loe as that involved in bra .thing
air containing 2 milligrams of load per 10 cubic actors, are sub*
atantialiy safe for all corkers regardless of susceptibility factors*
On this basis of comparison tire values observed in the
vlolnity of the pot aay be regarded as indicative of safety. In
that the basio lead oonee^fcratloo has appeared to be in the
neighborhood of 1 mill i gras par 10 eubio cetera, while the brief
periodic expoeure, during droaslng end shoveling la of the order
of 2*5 to 3*0 csllllgraas per 10 cublo aeters* iiy experience In
industry leads ne to believe that thla degree of exposure dace not
indues sufficient lead absorption to cause lead poisoning*
This conclusion la fully verified by the results obtained
In the examination of 2 employees whose work has Involved daily
exposure to such lead as is regularly distributed into the atmos*
phere around the pot* Neither of the two workmen showed any cltnioel
evidence of occupational lead absorption* Neither had a lead line,
despite the presence of conditions in the nouth (pyorrhoea) uhloh
are favorable to the development of lead doposlts in the guc tissue*
Neither of then shoved any blood changes lanecsla or stippling)
suggestive of lead absorption* Neither of them had abnormal
quantities of load in their blood and urine* I&rrlt uyer had
O.OU mg*
per litar of urine, and 0*03
i*b por 100 .(rams of
whole blood, wh*'e John Difcsler had 0*03
Tb per liter of urine
and 0*033 g* i'b per 1^0 grams of whole blood* These or quite
within the limits of values found In perfectly normal persons with
no occupational exposure to lead compounds*
04410
I conclude, therefore, from the combination of these data, that the occupational conditions studied at this time are not such as to entail the risk of lead poisoning In werkaen* It Is also ny opinion that the conditions described as in sailstenos at the time of the plaintiff*s employment, while probably Invt Ivlng somewhat greater exposure then that which ooours at presant, were not sufficiently different In type or magnitude to Justify an opinion that lead poisoning would have resulted from tbs exposure* Good clinical evidence would be required, therefore, to convince me that tho plaintiff bad lead poisoning at the tire it was claimed that he had* By good ollnioal evidence I mean that characteristic symptoms, associated with lead line of the gums, perhaps, and certainly olth exoeaalve numbers of "stippled0 rod blood corpuscles, should have been present* The preaenee of ab normal quantities of lend in the urine or blood or In both at that ti-e, would have been convincing, while the lack of such evldenoe 13 a serious fault In the plaintIff*a olain* Returning to tho subject of "stippled" erythrocytes (red blood corpuscles} It is necessary to demonstrate the presence of abnormal numbers before signification can be attached to the phenomenon* "stippled" erythro cytes occur in the blood of normal persons up to ton or more por fifty microscopic fields, and they are found In increased numbera In a wide variety of conditions which have nothing whatever to do with lead absorption* Their presence, without reference to numbers, or without knowledge of other concomitant ohanges in the blood. Is wholly without diarnoafclo significance.
Signed Robert A. KKHQS