Document E014oKkmLGo2JoObajZn6egR

cop y p tj- GEKEKAD MOTORS RESEARCH CORPORATION, DAXTOtf, OHIO# December 30, 19Z2 Doctor H, S* Otanming^^urgeon General, Bureau of Public Health Service, Washington, X>* S,. Dear S ir: Your favor of December SOth, addressed to Kr, p , g* DuPont, has been referred to the writer for answer. The question of lead poisoning resu ltin g from the use of lead compounds, has been given ver^^serious consideration by this Labora tory . althoufin~nrT~actual experimenta l data~has beeh^'tahen,^ The reason 'that no experimental data has been tahem is due prim arily to the fa c t that so far we have not ueeh able to get the lead compounds to come out in the exhaust of the motor uniformly. Some of these materials remain in the motor, cylinder and exhaust lines* However, the following f i g ures have been compiled in an attempt to analyse ju st how serious.th problem of lead poisoning from exhaust gas is going to be. The most congested d is tr ic t in the world containing the greatest percentage of exhaust gas, w ill be the vehicular tunnel under the Hudson River* In connection with the ven tilatio n of this tunnel, Doctor Fieldner at the Bureau of Mines, indicates that the percentage of carbon monoxide in the atmosphere, resu lting from the exhaust gas of internal combustion engines, must be Re;pt below two one-hundredths of one per cen t` in~order that human beings may breathe this atmosphere fo r four hours.per day and avoid the serious cons equences of carbon monoxide poisoning* Under these most extreme conditions, the quantity of lead milch w ill be present in the atmosphere as a lead com poundw ill be so minute that a human being w ill inhale only a total o f one m illigran of lead in four hours. This lead compound w ill be in the form of a fin e ly divided dust comparable to cigar smoke. Consequently, a re la tiv e ly small portion of this milligram w ill be retalhed~^y~the"'hiMair"systeinu Doctor YandelX Henderson considers the absorption of one milligram of lead per^d~a^r~as^hSerous We fe e l absolutely confident that under the conditions that w ill exist in the venicuXar^iunnel, that people exposeti tjT th is atmosphere w ill only absorb a very small part of m illigram . The worst congested streets w ill certainly be much better than the ve hicular tunnel; while the average street w ill probably be so free from lead that it w ill be impossible to detect i t or its absorption*  We expect in the near future, to place a small quantity of this lead ccrapouncybn the market in some districts There w ill ; not he enough lead rrted in the early stages of th is development to present any health hasard whatsoever, and during th is period we pro pose to investigate the to xicity o f these exhaust gases very thor oughly so as to determine just what the ultimate lim it to the use of ' lead compounds actu ally i s . We hope to secure your most hearty co operation in carrying on this work* Trusting th is information w ill c la r ify the situation in your mind, I teg to remain Very truly yours. (SICM)} THOMAS MIMLfiT, JR ., Chief Engineer, Fuel Section. 3M-Jr-D HJDB