Let me close off such discussion with me, by saying that the interpretations of the rate of the excretion of lead, itself, in the urine, under a variety of conditions, coupled with the determination of the concentration of lead in the blood, have eliminated the necessity for studying (for purposes of control of lead poisoning in industry), by the much less specific changes in the blood.

There must first of all be a sufficiently high con centration of organic lead and the men must be in the tank for a sufficient length of time, the temperature must be high enough to volatilise the lead and the men must have failed to wear protective equipment.

It is my impression that the use of x-rays for diagnosing lead poisoning has been performed mostly by pediatricians who have little knowledge of lead toxicology and who therefore tend to rely on a tool which they already have in their possession.

Boilon Lead Co., 800 Albany Street, Boston; National Lead & Oil CoVod^P&iaHM, 4th Aeeune, Pittsburgh; John T.

Julian Chisolm, Jr., M.D Page 2 July 21, 1969 precisely with minute quantities of lead.

Most of the lead in exhaust gas is in the form of inorganic particulate solids composed of lead halide (PbCl'Sr), or complexes of ammonium halide and lead halide.

There are obvious questions raised by the re port* One of these is that only about 0.73 eo. of tetraethyl lead was found in the Ethyl gasoline* I do not know of any Ethyl gasoline carrying as little lead as this* The other is the apparent assumpt ion that all of the combustion products wore analysed* A rough calculation on my part would indicate that about ZbO cubic feet of air is necessary to burn one pound of gasoline and, therefore* the estimates given in the report of the percentage of lead removed are in error.

$1985.97 by National Lead 1 Oil Company of Pennsylvania for repairs to sheet lead mill at its Armstrong-McKelvy Works.

H*a*ure tba lead ccwmiret ton la tba kldaay.

Minutes of Regular Meeting of the Board of Directors of National Lead Company held at No.

-2- It Is fairly apparent to me that Dr* Quaintance*s report Is the chief reason for the decision of the Commission, for Dr, Quaintance is very definite In his belief that the; patient had lead poisoning, and died of lead poisoning, and yet he comes out with the bizarre statement that there is no evidence that sorbed lead as a con sequence of his occupation* It is, of course, possible for a man to absorb lead from non-occupational sources but it is so improbable in the case of an adult that the Commission was right in not giving this statement much weight.

At that time, from the information gathered and his condition, we were lead to believe that something be sides lead poisoning was his trouble.

The lead output per day depends also upon the water excreted per day and we have shown that where the intake is high, the lead excretion is increased; and where it la lo**, there is a correspondingly low lead output.

Turnbull, Chemical Engineer for the Company's Easton Lead Division, and re lated'to a process for preparing lead silicate pigment by reacting silicate with a basic lead acetate solution.

These daughters rapidly decay to lead-210 in the respiratory passages.