Document qa1rZyx10vE6RONK3DkwMGM

1616 i'J* 12th. S t r e e t , Re a d in g, Pe n n *a , May 2 4 ,1 9 3 8 Dr , Po b o r t A. Ke h o e , Un ive r sity o f Cin cin n a ti, Cin cin n a t i, Oh io, Dear Dr , Keh oej Many t h a n k s fo r yo u r ^ iik l l e t t e r -- a ls o c o p ie s o f a s e r ie s o f a r t i c l e s p u b lis h e d in tl^ e In d u s t r ia l & En g in e e r in g Ch e m is t r y-- r e la t in g t o t h e d e t e c t io n o f Lead in B io lo g ic a l sp e cim e n , _ : *4 ' Th e r e a r e a few fa c t s t h a t a r e n o t q u it e c le a r t o me. F i r s t o f a l l , w hat li m i t o f le a d a b s o r p t io n do you co n s id e r s a fe fr om a c l i n i c a l s t a n d p o in t . As p r e v io u s ly m e n t io n e d , we a r e p a in t m a n u fa ct u r e r s , and i t i s ou r t h o u gh t t o keep c lo s e ch e ck on t h e men w o r k in g a r ou n d Lead p r o d u ct s , and a s soon a s t h e y a p p r oach t h e dan ger li n e , remove them t o some o t h e r d ep ar tm en t in w h ich t h e y a r e n o t s u b je c t e d -fee le a d d u s t . "Mould i t b e p o s s ib le fo r you t o g iv e me t h e s a fe lim it s o r any t e s t s t h a t w ou ld in d ic a t e t h a t t h e men a r e a b s o r b in g t o o much le a d in t h e i r s ys t e m , t o be s a fe fr om a c l i n i c a l v ie w p o in t , Dit h izo n e is a ve r y d e lic a t e and s e n s it iv e r e a ge n t -- d e t e ct in g m inute q u a n t it ie s c f, le a d in u r in e , and in view o f t h e fa c t t h a t th e r e a r e many sou r ces o f le a d --s u c h a s !w a t e r , a ls o e a t in g fr u it s ,s p r a y e d w it h t h e common in s e c t ic id e ---Lead a r s e n a t e ,w o u ld show t h e p r e s e n ce o f le a d in p e o p le who h ave no p o s s i b i l i t y o f le a d p oison in g, . E ig h t m e n tion t h e fa c t t h a t a lt h o we h ave ou r men exam ined p e r io d ic a lly by a lo c a l p h y s ic ia n --n e v e r t h e le s s , a man h a v in g a n a ch e o r p a i n ,w i l l in many in s t a n c e s , have i t d iagn osed as le a d p o is o n in g by h is lo c a l p h ys ica n --more s o , upon le a r n in g t h a t the p a tie n t works in a p ain t p la n t . From yo u r many y e a r s o f s t u d y and e xp e r ie n ce w it h ca s e s o f t h i s s o r t , fe e l co n fid e n t you a r e in a p o s it io n t o givd some ve r y v a lu a b le in fo r m a t io n , and any s u gge s t io n s you may o ffe r w i l l be g r e a t ly a p p r e cia t e d . Aga in t h a n k in g you fo r t h e c o u r t e s ie s e xt e n d e d me in t h i s m a t t e r . Ve r y t r u ly y o u r s , June 1 7 , 1938 Mr, Har r y Hlr sch I6 l6 North 12th St r e e t Read in g, Pa# Dear Mr, Hirsch!* In r e p ly to your le t t e r o f May 2l{.th, I must r e fe r you again t o the lit e r a t u r e o f t h is s u b je ct fo r your s t u d y. I t la sim ply im possible to give you any in t e llig e n t answer in a le t t e r to the q u estion s which you r a is e d . I t is q u it e fe a s ib le to d e fin e dangerous le a d exposure in terms o f lead e xcr e t ion in the u r in e and fe c e s , and a ls o In terms of the lead le v e ls in the b lo o d . We have found t h a t when a man under con d it ion s o f lead exposure co n s is t e n t ly keeps below 0 ,1 $ m illigr a m s o f le a d per l i t e r o f u r in e , the lik e lih o o d of lead poisoning is s lig h t . I f the u r in ar y le a d e xcr e t io n i s kep t below 0 ,1 0 m illigr am s per l i t e r co n s is t e n t ly , and i f the le v e l in the blood is kep t below 0 ,0 $ m illigr am s per 100 graas of b lo o d , cases of p oison in g w ill not o ccu r . However these le v e ls ar e s e t on the b a s is o f extr em ely p r e cis e methods o f a n a ly s is , and they have no meaning whatever u n less such p r e cis e a n a ly t ic a l methods are employed, W have a ls o hown t h a t where the fe c a l e xcr e t io n in somewhat dusty lead tr ad es does n ot exceed from 0 ,$0 to 0,75 m illigr am s per tw en ty-fou r h ou r s, the danger o f p oison in g is s u b s t a n t ia lly a b s e n t . Again I am r e fe r r in g to accur ate a n a ly t ic a l methods and I can-'assure you t h a t ther e Is no s h o r t -cu t methods which w ill give you any r e s u lt s worth havin g, ^ You speak In your le t t e r o f Dith lzon e as a "d e lica t e and s e n s it ive r e a g e n t " ,.....# , which "would show the pr esence o f lead in people who have no p o s s ib ilit y o f lead p o is o n in g". In t h is you are q u it e r ig h t . The use o f the Dit h iso n e method or any other accu r at e a n a ly t ic a l method w ill show the presence o f le ad in th e blood and e xcr e t a o f a l l per sons r e ga r d le s s o f occu p a tion . Such methods, however, w ill a ls o show the eviden ce o f abn om a i exposure to lead in t h a t the le a d con ten t o f the t is s u e s and the e xcr e t a w ill in cr ease as exposure in cr e a s e s * I t Is fo r t h is r ea son , and fo r r eason o n ly, t h a t the exam in ation of the xe r e t a of workmen Is u s e fu l in deter m in in g the magnitude o f t h e ir lead exp osur e. However I must warn you again Aga in st any attempt t o make e ith e r q u a lit a t ive or inaccur ate q u a n tita tive te s ts of le a d in blood and u r in e as a means of d e t e ct in g abnormal exposure o n ly . Var iou s persona have t r ie d t o do t h is and 2 no on has succeeded# Moreover no one w ill succeed s in ce ther e is no a n a ly t ic a l method which w ill give you uniform r e s u lt s In d e a lin g with la r ge q u a n t it ie s only# Moreover i t Is s ca r ce ly fe a s ib le t h a t you w ill be ab le In a few weeks or a few months, to d evise methods o f st u d yin g t h is problem when i t has r eq u ir ed from ten to fift e e n years o f concentrated study a t our hands to lear n the background o f in for m ation which makes p ossib le the r e co gn it io n of dangerous exposure# Aga in , t h e r e fo r e , I commend to you a p er iod o f ca r e fu l study o f the a va ila b le in for m ation In the lit e r a t u r e , and I p a r t icu la r ly su ggest t h a t you obtain in some fa s h io n the s e r ie s o f 3 lx a r t ic le s which we p u b lish ed in the Jo u r n a l o f In d u s t r ia l Hygiene in September o f 1933 V/hen you have s t u d ie d these a r t ic le s and when you have gained a knowledge of the p r in cip le s around which you w ill have t o work, I should be ver y much p leased to correspond with you fu r t h e r and to give you the b e n e fit of any a d d it io n a l su ggestion s which we can provide# Moreover, i f i t would ser ve your purpose ad van tageou sly, I * should be glad to have you v is it us a t the la b or a t or y a t some la t e r d ate in or der t o see a t f i r s t hand the d e t a ils o f the methods by means o f which a ccu r at e r e s u lt s can be obtained# Very t r u ly you r s, RAKs is Rober t A#' Kehoe, M.D#