Document mpGpjExkM6Dmz7ar44dvwxLE4

<\X-i i W i / L t - L i ; i i C L A n i i U A A L n .\ u n i jjj^ *- (f f General M otors Research C orporation Dayton, Oh io . - 2- D o c t o r H. S . Cumming: December 30, 1922. a r e la tiv e ly small portion of th is m illigram w ill be r e t a i n e d by t h e human sy ste m . D o c to r Y a n d e ll Henderson considers the absorption of one m illig ram of l e a d p e r d a y a s d a n g e r o u s . We f e e l a b s o l u t e l y c o n f i dent th at under the conditions th a t w ill e x is t in the v eh icu lar tu n n el, th a t people exposed to th is atmosphere w i l l only absorb a very sm all p a r t of one m illig r a m . The w orst co n g ested s t r e e t s w i l l c e r t a i n l y be much b e t t e r than the vehicular tunnel; while the average s tr e e t w ill p r o b a b ly be so f r e e from lead t h a t i t w ill be im p o s s ib le to d e te c t i t or i ts absorption. We e x p e c t i n t h e n e a r f u t u r e t o p l a c e a sm a ll q u a n t i t y of t h is le a d compound on the m a rk e t in some d i s t r i c t s . There w i l l n o t be enough l e a d used i n the early stag es of th is development to p resent any h e a l t h h a z a r d w h a t s o e v e r and d u r i n g t h i s p e r i o d we p r o pose to in v estig ate the to x ic ity of these exhaust gases very th o ro u g h ly so as to d eterm in e .just what th e u l t i m a t e l i m i t to t h e u s e o f l e a d compounds a c t u a l l y i s . We ho p e to secu re your most h e a rty c o o p eratio n in c a rry in g on. th is work. Trussing this inform ation w ill c la rify the s i t u a t i o n in your mind, I beg to remain Very t r u l y yours, Tli-Jr-D $