Document yrkp71mGGK68Ko8Bjzx8Npp6n

Ju ly 21, 1939 Hr, J* J , Bloom field United S tates Public Health Asso, 7 th and Independence Avenues Washington'* D* 0* Dear Mr* Bloom field: . P lease accep t ray thanks f o r your kindness In sending me a copy o f your . l e t t e r to Dr* Schrenk* I am a f r a i d I s h a ll; have to confess to a c e rta in c a relessn ess In having mis* quoted you in ray t a l k a t N orthw estern U n iv e rsity in September o f 1937* My use o f th e fig u re J m illigram s p e r 10 cubic m eters w hich, by th e Way,; was not a p a r t o f my m anuscript* b u t was thrown out somewhat paren* th e tlo a lly * was based on a m isconception o f th e meaning o f one o f your statem en t in th e " lite r a tu r e * Aa you are aware* th e re has been a c e r ta in lo o sen ess in th e ' use of these lim its in th a t sometimes they a re spoken o f in terms of the quan tity of le a d which presumably may be in h aled p e r day* whereas sometimes they a re given in terms of q u a n titie s p er 10 cubic m ters of air* X made th e m istake in t h i s in s ta n c e o f th in k in g th a t you had used the fig u re o f approxim ately 1*5 m illigram s in reference to the daily intake by inhalation rath er th an In term s o f th e q u a n tity in a known volume o f a ir* I have since recognized the mistake and have corrected i t w herever th e o p p o rtu n ity has p re se n te d I t s e l f * The e rro r* I b eliev e* was e rp la n a b le though n o t q u ite ex c u sab le, and I am s o rry th a t i t has occasioned any d i f f i c u l t y o f any kind* I can a ssu re you t h a t In my own. p r a c t i c a l work* I have co nsidered t h a t th e concen tr a tio n s in a i r should be under 2 m illigram s p e r 10 cu b ic meters* In some Instances* by reaso n o f th e nature of the m aterial dissem inated into the atmosphere* I have urged th a t the lim its be lower even than 1-1/2 m illigram s p e r 10 oubic meters* ph : I n c id e n ta lly some o f the work which we hve dbne la te ly * p a r ti c u l a r ly In th e s t e e l in d u stry * has brought me in to co n tac t w ith some o f th e men who were p r se n t a t Northwestern* and I have made i t a p o in t to c o rre c t them as to your p o sitio n * v M 0020083 . ; I am ;pV HASiff : ,`w ' - - 2 * * Wi t h k in d e st p e rso n a l rogars* C ordially yours,, obert A, Kghae, M.. HB