Document 8RvvN48eEmZ1qgkK0dgKNmp9m

CH U RCH ILL 5900 Ev e ry t h in 1]' f o r M in a an d I n d u st r ial .Safet y CABLE A DDRESS "M I N SA F" PIT T SBURGH BRAD D OCK,TH OM AS AND M EAD E ST R EET S _ >$ Mr September 9, 1940 Dr. Robert A. Keboe Un iversity o f Cin cin n ati College o f Medicine Cin cin n at i, Ohio _ Dear Dr. Keboe: I t makes me fe e l ashamed t o read your r epor t and th in k t h at I fa il e d t o give you ver y much h e lp . The tempo o f my a c t i v i t i e s h as in cr eased , as you migh t exp ect , durin g th e p a st few months and I have had p r a c t ic a lly no time t o devote t o committee work or r e p o r t s. I h at e t o admit i t but I also fin d t h at I can n ot burn a s much "midnigh t o il" as I have in th e p ast fift e e n or twenty y e ar s. I am n ot ver y oft en fe l i c i t i o u s r egar d in g r e p o r t s but in t h is in st an ce i t was a r e a l p leasu r e t o r ead th e r epor t you prepared. I t not on ly covers th e su b je ct very w ell but in my opin ion i s w ell organ ized and e x p lic it ly pr esen t ed -- su b je ct s t h at can be dispen sed with b r ie fly are h an dled in t h at manner and th ose r e q u ir in g fu r t h e r explan ation ar e given good at t e n t io n . I have no se r io u s conments o r c r it ic ism s t o o ffe r . There a r e , however, a few p oin t s t h at I mention p r im ar ily from th e stan dpoin t of o ffe r in g such a ssist a n c e a s I can. I p er son ally p r e fe r t o r ead sh or t sen t en ces. You might look th e r ep or t over from th e view poin t o f breakin g up some o f th e lon ger sen ten ces* The lon g sen ten ces you u s ar e c le a r bu t t h is i s mentioned m erely as an in cid e n t al comment. Page 8, lin e 14. I t might be w ell t o add "m ist " to th e ot h er forms o f atm osph eric con tam in ation . Page 9, lin e 15. There i s a slig h t typogr aph ical e r r o r . The word "vapor" sh ould be p lu r aliz e d t o "v ap o r s". Page 10, lin e 7. I am wondering i f coverin g th e le ad bath with ch arcoal reduces the lead vapor by th e preven tion of oxidation o f by absorption o f vapor s. Fran kly, I have not stu d ied t h is pro t e c t iv e means but from a t ech n ical con sid er at ion , i t would appear t h at i f th e su r face o f th e lead was kept in a reduced, clean , m e t a llic con dition , th e lead m igh t v o l a t i l i z e more r ap id ly than \ .' V , ' M I N E SA F ET Y A P P L IA N CES CO. -2 - i f th e su r face were coated w ith oxid e* I t would also be expected th at th e vapor p r essu r e was in dependent o f th e ch ar coal coverin g and a s th e vapor escaped th e ch arcoal i t would l a t e r become oxid ized and go in t o th e a i r * I am not sayin g th at the ooatin g of ch arcoal w ill reduce th e amount o f le ad oxide em itted t o th e a i r bu t am m erely con sider in g th e mechanism by which th e escape i s su ppressed by th e ch ar coal. You undoubtedly have a good r eason fo r your statem en t* Page 11 I su ggest th e ad d it ion o f a paragraph r e la t in g t o th e con tamination o f a i r by le ad m ist such a s th e m ist produced in spray coat in g p a in t s and glaz e s t h at con tain lead * Page 15* lin e 11* On r ead in g th e f i r s t tim e, I gain ed th e im pression t h at p a r t ia l absorption in t o th e t issu e s o f th e body r e lat e d p r im ar ily t o th e le ad d eposit ed on th e a lv e o la r su r face s o f the lu n gs* I t i s my opin ion t h at once le ad i s d eposit ed on th e a lv e o la r sp aces very l i t t l e o f i t ge t s away except through absor pt ion in t o th e body* I presume you meant t h at p ar t ie d absorption r e fe r s in p ar t t o the dust t h at i s deposited in the r e sp ir at o r y p assage s and l a t e r swallowed* Th is l a t t e r statem en t i s t r u e but i f your statem en t r e fe r s p r im ar ily to th at deposited in the alv e o lar sp ace s, I b e lie v e th e word ''p a r t ia lly " does n ot express th e q u an titative r e lat io n * Page 17* I have attem pted t o br eak down one o f th e lon g sen t en ces. I su ggest t h at you in d icat e t h at even though th e "le ad lin e " i s n ot u se fu l a s a p r a c t ic a l measure o f var yin g degr ees o f le ad exposure, i t c o n st it u t e s an in d ic a t io n ^ ? g e e ^ fo r immediately lookin g in t o the le ad h azar ds t h at o e c ir in^envii^onment. Although you in d icat e t h e u se fu ln e ss o f th e 'lead lin e " a t a l a t e r p lace , i t would seem w ell t o r e fe r t o - it at t h i s p o in t . I am no con vert o f th e gr e at u se fu ln e ss o f th e nle ad lin e** bu t b e lie v e t h at con sid e r a t io n o f th e su ggest ion w ill ease th e minds o f th ose who ar e con verts* Page 19. There i s a con tin u al argument among in v e st iga t o r s and person s engaged in le ad con t r ol r egar d in g th e number o f "st ip p le d c e lls'* t h at ar e sig n ific a n t * I know you ar e aware o f t h is and h av e so in d icat ed in t h is r ep or t * I t migh t be w ell, however, t o poinlpmore em ph atically t h at I t i s d i ff i c u l t fo r two in v e st iga t o r s t o conpare "st ip p le d c e ll" data u n less th ey use id e n t ic al tech n iqu es. Even th en , i t might be h ard t o say when th e tech n iques ar e id e n t ic a l. I t i s my opin ion t h at each man 's work must st an d on i t s own le gs in r egar d to "st ip p le d c e l l s " and th at no very sound con clu sion s can be drawn from th e d ata obtain ed u n less th e person h as a con t r ol group* In oth er words, have a se r ie s o f pre-exposu re exam in ation s. Although you in d icat e th e r eason s fo r th e v ar ia t io n o f r e su lt s obtain ed, I su gge st t h at more emphasis be placed on t h is su b je c t . M I N E SA F ET Y A P P L IA N CES CO. 3- Page 25 I h ave made a few cor r ect ion s in p en cil on th e m argin . P ages 34 & 35. I h ave h eard many d iscu ssio n s on th e maximum . allow able concentration of lead in th e a ir . In gen eral, the valu e o f 1 .5 mg. per 10 Cubic Meters of a i r i s accepted by th e m ajor it y o f per son s a s r ep r esen t in g th e magnitude of con cen tr ation t h at h as been found n ot t o product any sig n ific a n t eviden ce o f le ad poison in g. However, th e qu estion alw ays a r ise s a s to how t h e 1 .5 sh a ll be determ in ed. Sh ould t h is valu e be obtain ed by a n a ly sis u sin g a r e p r e se n t at iv e sample t h at i s l a t e r computed t o 10 Cu. M. a i r b a sis o r sh ould i t be based on se v e r al d et er m in ation s whose r e su lt s when con sidered w ith time o f exposure would give a valu e r ep r esen t in g th e o v e r all d aily in tak e? In oth er words, a valu e obtain ed a s th e r e su lt o f in t e gr at io n . Many person s fe a r t h at some in sp e ct o r w ill take a sample a t some p a r t ic u la r in st an ce or r e la t iv e sh or t per iod o f th e day and u se th at a s a b a sis fo r determining th e o v e r all d aily exposure. In oth er words, sh a l l th e 1 .5 mg. be r e la t e d t o th e o v e r a ll d aily in t ak e or sh a ll i t be r e la t e d t o a sample taken at a p a r t ic u la r p er iod o f th e day and computed t o a 10 Cu. M. a i r b a si s. I t i s my p er son al opin ion t h at i t sh ould be r e la t e d t o th e t o t a l in t ak e . However, you have st a t e d th e opin ion o f th e lit e r a t u r e and I w ill not ob je ct i f you do n ot change i t . I t w ill be a r e al honor to presen t your report a t the American P u blic H ealth A ssociat ion m eetin g. However, a s I st a t e d in my telegram , I am chairman o f one o f th e sa fe t y m eetin gs o f th e N at ion al Safe t y Con gress and w ill not be a v a ila b le on Th ursday, October 10. In regard to methods of a i r examin ation, I b elieve th at the A.P.H.A. h as a gen er al committee on t h is su b je ct headed by Dr. Hayh urst. The subcommittee meet)era ar e Dr. Sch ren k, Dr. Elk in s, Dr. Smucker, Dr. Colman, Dr. Allan , and Dr. F. H. Goldman o f th e N ation al I n st it u t e o f Health a s ch aim an . I am n ot su r e about t h is bein g th e complete member sh ip. Th is subcommittee had planned t o r ep or t on methods fo r both CO and Lead t h i3 y ear . However, due to th e lack of time th ey ar e d ealin g on ly with CO in t h e ir r e p o r t . I un derstan d, however, t h at th e methods on Lead w ill be th e program fo r n ext y e ar . Th is i s fo r your in for m ation , i f you car e t o add i t t o your r e p o r t . WPY-HL TilH i am P . Yant D ir ect or o f Research and Development P .S. Your telegram h as been r eceived and w ill be brough t t o Mr. Yan t' s at t e n t io n upon h is r et u r n to the o ffic e on Wednesday of t h is week.