'Fer cent Bet. s lead cone, in chamber - lead cone, in exhaled air x 100 lead cose, in chamber As in the past, the following samples obtained fro the subject are -

I am sending to you under separate cover a series of articles which have been published from this laboratory on the subject of lead, and on the problem of gasoline containing tetraethyl lead.

Dutch Boy white-lead is pure white-lead.

National Lead Company H.M.4 NATIONAL LEAD COMPANY New York, 111 Broadway Boston. 800 Albany St.

Sales - Hammond lead Products J.

X believe that the excretory figures given by these writers might well be the result of the in clusion within their group of patients,a number of persons with abnormal lead absorption, and, therefore, abnormal lead excretion.

(1) The concentration of flnbly divided lead particles i# act unduly h.l$b, and Sn this instance In which only .7 cc of lead per gallon of gasoline is used, the lead concentration would be quite smllf (2) exhaust gases are meh more dangerous from the point of view of carbon monoxide than they can, ever be from the point of view-of lead* I aa mot quit certain as to the carbon monoxl.de concentration # the exhaust gas from tractors but in tho case of automobiles, the carbon aonoxlde concentration is likely to be about five pereeqt and my be as high aa seven or eight percent, or even more under various conditions of operation* - If- the atmospheric conditions are maintained so as to be endurable to espoisqd parsons thou exhaust gas mat be diluted until the carbon,i&oao^td concentration is at least as small as .05 or .>4 percent.

Urine lead concentrations ex ceeding 0.15 mg/liter are usually indicative of excessive lead exposure.

Sam Convery National Lead Company 111 Broadway New York City, N.

LIA18650 LEAD INDUSTRIES ASSOCIATION, INC.

The human lead data showed urine; levels to be within the normal limits expres sed by yourself.

Write for testihg saucer ,a)id:; sample _ of red-lead.

Lead R.W.

Lead R.W.

With the foregoing statement in mind, I think you may take it that the standard whic. applies to lead fume (which is mainly lead oxide, probably principally tlie sesquioxide) is approximately correct, and that it is applicable to the fairly readily absorbable compounds of lead which reach the pulmonary membrane in particulate form.