Document r0owj0oXr7KeE898oxwpEkJJ

November Zk$ 1937 Dr. S* J* Brad fleld 607 Medical Arts Buildin g Tulsa Oklahoma Dear Doctor Br ad fie ld * In respon se to your le t t e r of November 12th * I am sending you herewith two r ep r in t s of a r t ic le s w ritten on the b asis of our experimental stu d ies on the problem of leaded gasolin e* Prom the study of th ese you w ill fin d t h at no cases of lead poisoning have been reported and moreover* th at no cases are expected as the r e su lt of con tact with eith er liq u id gasolin e or it s vapors* The quan tity of lead in the gasolin e Is very sm all, - so sm all in fa c t th at absorption of the lead compound through the skin i s apparen tly prevented alt oget h er * Moreover the low vapor pressure of the t et r aet h y l lead and the r e lat iv e ly high vapor pressure of the gasolin e r e su lt in a sit u at ion in which no measureable qu an t it ies of lead fumes are found in the vapors r isin g from ordin ary gasolin e. From my experien ce with the commercial product, and from our ex perimental work in t h is laboratory* I am convinced th at i t is not p ossib le to develop lead poisoning as the r e su lt of con tact with the liq u id or vapor of leaded gasolin e* I t i t were p ossib le* I am sure we would have seen cases within the past th irteen years fo r we have been lookin g fo r them over th at period of time* In connection with the case which you mention* but on which you do not give d e t a ils* I th ink i t is worth while to point out to you th at gasolin e in i t s e l f is a t oxic m at er ial* Gasoline vapors presen t in the atmosphere to the exten t of one percent by volume produce acute symptoms and uncon sciousn ess r e su lt s from exposure to vapors very much in excess of t h is le v e l* Thus sh ort exposure to con cen tration s of two and two and a h a lf percent w ill produce uncon sciousn ess with a somewhat delayed post-an aesth etic st age in which there is a con siderable amount of cen t r al nervous system in toxi cation * with tremor and oth er evidences of excit at ion which may alt er n at e with a depressed nervous st a t e * Recen tly some cases of chronic in ju ry to the cen tr al nervous system have been reported in persons who have been unduly exposed to gasolin e vapors* I am very sk ep t ical of th ese observation s and I am disposed to regard them as cases complicated by some oth er fact o r , sin ce* in the main* oases of acute gasolin e in toxication recover without seq u ellae. However it; may be th at an occasion al case m an ifests unusual sequ ellae. Furth er as to the reason fo r your fin din g no lit e r at u r e on the in h alation of t et r aet h yl lead in gasolin e* I ean assu re you th at no cases of poisoning or in ju ry have been reported in any of the medical lit e r a t u r e sin ce thus fa r no cases of t h is so r t have ever been seen* I f th ere are any fu rth er question s which a r ise from the examination of the a r t ic le s which I am sending you* I sh a ll be glad to do my b est to answer them* , Very t r u ly yours* RAKsls Robert"''A. 'Keh ceml"i.i D