Document mbqG0OoGkBEJ3MbkbODrN1Ye4

Jarmary 20, 1954 JwLr. d a m e s L,. H a r t Ch em ical En gin eer N ation al Zin c Com pan y, In c. B a r t l e s v i l l e , 0 !ir :h o m ?. D e a r M r. H art.; , I r e g r e t v e r r mucr: 'indeed t h at I.h ave been, co m p elled to d e lay so lon g in replyin g to y cu r le t te r of D ecem b er 3. I h ave been su b m erged b a se r ie s of m a t t e r s th at accu m u lated w h ile I w as out of th e cou n try, an d e n ly t.h';1eo inn )i ;.:tt u r ge :n t it e m s o f c o r r e sp o n d e n c e con i'.: be a t t e n d e d t o . In 1he l-oli4o.-r*..; tlhirait th e 2a v a ila b le d a t a c a c a d m iu m w ou ld n e t p e r m it m e to giv:- 7sr Nt* o;.* in?f;o3 r:-m- ra et Iafd t h a t w ou ld' c o n t r ib u t e sig n ific a n t ly t o t h e sa fe t y o f you bs*"i}-u`-* ?i rc. u , in fa c t , t h e y r e .n o t , a t p r e se n t , a s a g r o u p , be.ire CU.: je .c.e ^ t a *icu.v. en d in sid ip U :.' r i s k s d u e t o e sr p o su r e t o cack r >.:?-r^-r J- h av e i it n e c e s s a r y to d e a l w ith m o r e u r g e n t m a t t e r s at h an d on thi r-tue: en d , in t h o se in .' .o r c e s in w h ich t h e r e su l t s on a n in d lv id u t l, v 'b b .-'.-.do -on- .> to l e - 1, j n "h lie d nay a d v isin g p r e c a u t io n a r y m e a su r e s, I h av e sc- in d i c a t e 5 on th e a n a ly t ic a l r e p o r t c o n c e r n e d . 1 sh ad : ccaonnn-a m t h e fxaxv o t o do th is-, ah ar e scp e r ie n ce e n a b le s u s to . g iv e : v e c i ;:c c c . a ;a c. c. _'c.c. ., rav., .L a . a a. clo sc . . it i s in d ic a t e d , , - i a _~ i .a: v. air t y.vr.r e e r i e tu n n el . . sy act Ev : s- car e t L h c r ofu l*.^ ;Wiha. a d c c u a c e . j r e c i e i o : : . . " ' - ' ' urniiaavm racey-ycur.-cues: o o -an a.v;croc, c r r a ir la c t sa a i requ ired , . - .. sim p le st a t e m e n t s, a i. . . b-i v .iA w* f>.. d iscu ssion is : . Toe variation iu the r e su lt s obtain ed ai the bloc a of in dividu als at d iffer en t : t im e s, m uch iir art be ju dged. to w h eth er t h ey a r e w ith in th e lim it s of e r r e - : of th e n ioth o-da. Th e - -.-mage e r r o r - f an y o f th e r e su lt s on le a d r e p o r t e d x o y ou ab o u t d 0 .0 m-r To 1 r e su lt e r r s on the h igh sid e by 0 . 0 :, r se e sa . :v t e e sam e blood e r r s equ ally on a o ie v ciau , aiifer en V t'~ -- . ;. IOC g r a m ', can a p p e a r by cn u aco alon e:, d o r liis r e a s o n , . w e c a r v ; vi, p a r a ) l e i a n a l y se s h a m o st in st a n c e s an d cube Hie a v e r a g e . It i in c a - n len t to d o t h is in t h e w or k w e a r e d o in g icu \ wiir pet p ie , Uy a u s cd d ie no v e ; ; o f . a n a l y si n g fo r both le a d an d cad m iu m . You v /ill n o t e , by t h is cr iU - r iv ii, t h at th e d iffer en ces in th e r e su lt s r e fe r r e d to a r e n ot gr e a t , b ein g on ly d u b iou sly beyond the ran ge of an alytical variation . A sign ific a n t m a t t e r o f d iffe r e n t ia t io n a r i s e s , hc'-v- in th e c a se of M r . Ja m e s L,'.- H a r t - ( 2 ) -- Ja n u a r y 2 0 , 1954 ." ' . | w h o se f i r s t r e su l t .w a s Q. 085 m g , p e r 100 g r a m s . I t i s e v id e n t fr o m w h a t \ I !la v e sa i d t h at t h is m a y h a v e b e e n a s, lo w a s 0 .0 7 5 o r p e r h a p s even 0 .0 7 ; o r it m igh t h ave been 0, 095. The. situ ation h ere is trou b lesom e b ecau se it 'is ju st at the c r it ical lev el of con cen tration an d, th er efo r e, d an ger is in volved. R eferen ce h e r e 'is trou b lesom e b ecau se it is ju st at the critical level of M r . Ja m e s L., H a r t - {2) * Ja n u a r y 2 0 , 1954 w h ose f i r s t r e su lt w as 0. 085 m g. p e r 100 g r a m s. It is eviden t fr o m what I h ave sa id th at th is m ay h ave been a s low a s 0. 075 o r 'p e r h ap s even 0. 07; o r it m igh t h ave been 0.095- Th e situ ation h ere i s t r o u b le so m e b e c a u se it i s ju s t ait t h e c r i t i c a l le v e l o f c o n c e n t r a t io n an d , t h e r e fo r e , d a n ge r is in volved . R e fe r e n c e to th e r e p o r t w ill sh ow th at I ad vised the rem oval of th is m an fr o m exposu re. One can n ever be ce r t ain th at su ch a m an is ill o r w ill b ecom e w ill, but h e m ay do so a t an y t im e , an d th e r e fo r e n o ch an ce sh ou ld be t ak e s. One m ay d elay lon g en ough to obtain a ch eck a n a ly sis, but if th e r e su lt is con firm ed , t h e r e sh ou ld be no fu r t h e r d e lay . In t h is con n ection , y ou r statem en t in d icates th at ray ad v ice w as not follow ed, an d th at no ch an ge w as in trodu ced in to th is m an 's w ork o r exp o su r e. 1 fu lly r e a lise th at ou r r e latio n sh ip s h ave not been su ch th at th is w ould h ave been done au to m a t ic a lly , and' I r e co gn ise th at D r . ' Aldredge is n ot r eq u ir ed to follow m y ad vice an d to su p p ort m y recom m en dation th at a m an be rem oved fr o m .exp o su r e* I ch n a s su r e , you apd h im , h ow ever,, th at h e sh ou ld do so . M o r e o v e r , sin c e it is n ow ap p ar e n t th at th e le a d e x p o su r e in ;y o u r w ork is h azar d ou s at t im e s, w e sh all n ot con tin ue lon g to p ar ticip ate in the st u d y ox y o u r p r oh let h . u n l e ss y o u r p eo p le, a ,p r e p a r e d t o a c c e p t o u r gu id an ce. T h ese a r e n ot e x e r c ise s in r e se ar ch ;, in so far a s le ad is co n ce r n e d , but r a t h e r th ey a r e sou n d n e a su fe o o f in d u st r ial h ygien e th at r e la t e d e fin it iv e ly to th e sa fe t y c f y ou r m en . You an d th is em ployee a r e lu c k y t h a t h is a b so r p t i o n o f l e a d , f o r so m e u n a c c o u n t a b le ..r e a so n , d eclin ed in se v e r ity , o r at le a st failed to in cr e ase , an d th erefore the n ext r e su lt in d icated th at h is situ ation ' w as n ot h igh ly h azar d o u s. 'Viren c o n d it io n s o f o c c u p a t io n a l e x p o su r e , v a r y sig n ific a n t ly f r o m <k , t o an y , tn o le v e ls o f le a d co n c e n t r at io n in both b lo o d an d u r in e can ch an geap p r e ciab ly w ith in a few d a y s. In each c a se th at you h ave calle d atten tion t o in y o u r ap p en d ed d a t a , t h e r e w as a d e c r e a se in the blood le v e ls in twe m on th s,'m ore o r le ss. A s I h ave in dicated p reviou sly , th is m ay be m o st ly a n aly t ic al '-variation ,'' bu t fr o m th e a sp e c t of p r o b ab ility , a s w ell a s ph ysiology, it is h igh ly u n lik ely t h at th is u n iform ity cou ld h iv e com e abou t fr o m an y oth er fact o r th an a d e c r e a se in the se v e r it y or the d u ration of th e e xp o su r e of t h e se in d ivid u al w orkm en ," o r fr o m a d e c r e a se h i both of t h o se fa c t o r s sim u lt an e o u sly . Th e ch an ge, t o b e su r e , io n ot g r e a t , but it is c le a r ly in d icates a tren d , w h ich r e la t e s n ot n e c e ssa r ily to th e en vir on m en t alo n e , but to th e b e h av io r of th e m en , w ith r e sp e c t to t h e ir ab so r p tio n of le ad . If 1 h ad ad d ition al an aly t ical r e su lt s tout w ould av e r age out th e fa c t o r o f an aly t ical .e r r o r , 1 w ould sa y , u n equ ivocally, th at th ere w as a d e c r e a se in the ab so r p tio n of le ad on th e p ar t of th ese m eu . A h igh r e su lt th at is a r e su lt of 0 .0 8 o r m or e m g. p e r 100 gr a m s - m u st alw ays be taken se r io u sly . If th ere is doubt, in th at the r esu lt is too n ear th e b o r d e r lin e of 0 .0 8 an d , t h e r e fo r e , is w ith in th e ran ge in w h ich th e K 0003730 M r . Ja m e s L . H ar t - (3) - Ja n u a r y 20, 1954 an aly t ical e r r o r is sign ifican t , th e r e su lt sh ou ld be ch ecked a t th e e a r lie st p o ssib le tim e, so a s to know w hat m u st be don e. No m ati at th is le v e l sh ou ld b e le ft a t w ork u n d er u n ch an ged con d ition s of e x p o su r e , sin ce h e m ay q u ick ly d e v e lo p a t e m p o r a r ily d isa b lin g il l n e ss. J d gm e n t car i b e e x e r c ise d h e r e , in th at if th e e xp o su r e h as b een t e m p o r ar ily gr e a t u n d er h igh ly u n u su al cir c u m st a n c e s, th e n igh con cen tration w ill su b sid e qu ickly an d the r isk w ill be over, fo r th at tim e. Xs,W henever h igh r e s u l t s in t h e b lo o d o c c u r u n ac c o u n t ab ly in a sc a t t e r e d m an n er in a grou p w orkin g a t th e sam e kin d of job , the e xp o su r e is e r r a t ic , in a d e q u a t e ly c o n t r o lle d , aad t h e m e n a s a g r o u p a r e in d a n g e r . An alytical r e su lt s, obtain ed p rop erly , a r e fo r th e p u rp ose of brin gin g th e exp osu re u n der con trol, in eith e r on e of two w ays: (a) By p r o p e r en gin eer in g o f th e job an d th en viron m en t. T h is,o f c o u r se , i s th e on ly sa t i sfa c t o r y ' -way.- . , ,, (b) ~Jy e n a b lin g a p h y sic ia n t o a d v i se t h e r e m o v a l o f u n d u ly e x p o se d m e n .from -w ork in volvin g e xp o su r e , h ih tii.excr etion t ak e s car e "o f th e e x c e ss a b so r b e d .' L e g a ll y it i s m a n d a t o r y , f o r a l l p r a c t i c a l p u r p o s e s ,t o fo llo w su ch ad vice, sin ce oth erw ise th e developm en t of illn e ss in an em ployes is a m at te r of p erso n al resp o n sib ility on the p art of the ap p rop riate r e p r e se n tativ e of the em p lo y er , w h ich , in m o st of ou r beatec, r e n d e r s h im liab le to p rosecu tion fo r cr im in al n egligen ce. It is n e c e ssa r y , t h e r e fo r e , th at su ch m e d ical ad v ice b e sou n dly foun ded in fac t an d ju d g- m en i, but it ir rivo n e c o ssa r y th at, it-be follow ed. . in th e t e r m s of rhe fo r egoin g d isc u ssio n , th en , th e an sw er s to you r qu estion :* a r e : . .. ' : ^ ' _ ' . ' .' ' . .iy, ' '" : ' : 1: " (a) Th e blood le v e l cun caan ge quick-/.w ith in a few d a y s, in r e sp o n se to sign ifican t ch aztges in the se v e r it y of th e e xp o su r e , or in r e sp o n se to th e con tin uation of a se v e r e exp o su r e. Un der stab le con dition s of exp osu re the. b lood le v e l m o v e s u p g r a d u a lly over* a p e r io d of m on t h s to a p oin t w h ich is in d icative o: the se v e r it y of e xp o su r e , an d th en ten d s to rem ain fa ir ly con stan t. - . ' '. v (b) Yo u r co n clu sio n co n ce r n in g th e st a t u s of a p a r t ic u la r m an sh ou ld be b a se d on th e t r e n d sh ow n b y a s e r i e s o f r e su lt s, bu t w h en th e c r it ic a l le v e l of d an ge r h as b een r e ach e d , act io n sh ou ld follow p r o m p tly . The in terp retation of the o v e r all situ ation of an occu pation al grou p of m en m u st depen d on the stu dy of a ll of th e d ata av ailab le on a ll of th em . {cj In g e n e r a l , t o fo llo w t h e t r e n d o f a n o c c u p a t io n a l sit u a t io n (w h et h er it M r . Ja m e s L . H ar t - (4) - Ja n u a r y 20, 1954 is im provin g, rem ain in g stab le or gettin g w orse), it is n e c e ssa r y to r ep eat the an alyses on th e grou p fr o m tim e to tim e. Th e sam e is tru e in -th e'case o f th e in dividual m an . hi both in stan ces the p eriod icity of th e an aly t ical su r v e y sh ou ld depen d on the exten t of th e d an ger - i. e. on th e kn ow n o r a p p a r e n t se v e r it y of. th e e x p o su r e - , an d t h is can on ly he determ in ed afte r a p eriod of ob servation s. (d) An y m an w h ose r e su lt s a r e in th e d an ge r o u s r an ge sh ou ld b e r em ov ed fr o m e xp o su r e , o r h is e xp o su r e sh ou ld be con tr o lled an d d im in ish ed , im m ed iately . If t h er e is doubt a s to h is st at u s, th e a n aly se s sh ou ld be r ep eat ed at th e e a r lie st p o ssib le tim e, in o r d e r to r e so lv e th e doubt. C e r t a in o f y c u r - m e n a r e e x p o se d t o h a z a r d o u s c o n d it io n s,_ w it h r e o p e c i to le a d . H e r ge n e r al t h is is can be determ in ed''.on ly aft e r a ''carefu l stu d y c i a ll of th e d ata oh m en w h ose w ork h as been con tin u ou s an d' w ell d ocu m en ted w ith -r esp ect to ty p e, job an d a r e a , hi t h is con n ection the r e s u l t s o f a i r a n a ly se s' .w ilT h o t :c o r r o l a t e t o o w e ll, w it h th ese-' on ilie b lo o d .. a n d 'u r in e , u n t il an d u n le ss t h e c o n d it io n s o f e x p o su r e t h r o u gh o u t t h e p lan t a r e w ell stab ilize d so a s not to be sign ifican tly v ar iab le xrem tim e to tim e, in an y c a se , th ere i s no doubt about th e existen ce of h azard ou s exp osu re to le ad , an d im p r o v e m e n ts in plan t o p e r at io n s sh ou ld b e m ad e. . 2 . V.7it h r e fe r e n c e t o t h e c a d m iu m p r o b le m , I can g iv e y ou l i t t l e so u n d ad vice at p r e se n t , (a) I can say th at th e an aly tical p r o ce d u r e s h ave a'; . . h igh d egr ee of p r e cisio n ~ ap p r o xim ately th at of th e p r o ce d u r e s fo r lead an d t h a t t h e v a r i a b i l it y o b se r v e d i s .due' o n ly in m in o r p a r t "to a n a ly t ic a l variation . Th ere is not en ough in form ation on p h y siological variation to i e n ab le u s to view th e sign ific a n c e cf th e d ata on t h is sc o r e . . . \ 3 . (a) Vfe h av e n o m o r e a d e q u a t e d a t a on an y o t h e r o c c u p a t io n a l sit u a t io n r e la t in g cad m iu m th an w e do on y o u r s, an d so I can n ot a d v ise you p r o p e r ly in r e sp o n se to y o u r q u e st io n s. V/e sh t d l h a v e t o w ait an d s e e . P r e su m a b ly an y t h in g th at is on e ge n e r ally to d e c r e a se th e exp o su r e to le ad w ill in flu en ce the asso ciat e d exp osu re to cadm iu m . b b ' ".k v . .' ' : ; . ' d .. ' lead . ' . (b) U n d er p r e se n t co n d it io n s o f h a z a r d o u s/ e x p o su r e , you sh ou ld r e p e a t th e an aly se s on your m en at an e ar ly date so a s to e st ab lish m ore fu lly 1 the exten t an d sev erity of the h azard . (c) Th e w orkin g con d ition s, w ith r e sp e c t to le ad , n eed im p r ovem en t. V;'; v-.'...,'. id) You a r e lik e ly , u n d er p r e se n t con d ition s, to h ave c a se s of le ad in toxication , at le a st m ild c a se s. The p roced u re h ere is one fo r D octor . ' >,'r. James L. Hdrt - (5) - January 20, ?95b A ld r e d ge to d e a l with., an d th e l e s s an y on e e l se h a s t o do w ith it t h e b e t t e r . C er tain ly th e an aly t ical p r o c e d u r e s an d r e su lt s in th e stu dy of su sp ected c a se s is st r ic t ly con fid en tial in fo r m at io n w h ich sh ou ld n ot u n d er an y cir cu m stan ces be av ailab le ou tside th e m ed ical office. I d ir e ct 'm y r e m ar k s on th is su b ject to h im , t h e r e fo r e . Fir st ., th e m an who co m p lain s of sy m p t o m s sh ou ld be exam in ed car e fu lly . a n d a d ifie n t ia l d ia g n o sis sh o u ld b e a r r i v e d a t , .if t h is i s a t a l l p o ssi b l e , foy ciin ical m ean s. Th ere is no p o ssib le su bstitu te fo r th is. A com plete r e c o r d (con fid en tial) of th e exam in ation sh ou ld be k ep t, an d th e p r o ce d u r e fr o m t h e r e on sh ou ld be r e co r d e d in d e t ail. If t h er e is ju st ificat io n fo r so d o in g, tile d o c t o r sh o u ld o b t ain sa m p l e s {d u p lic a t e ) o f b lo o d , an d a sp o t sam p le c f u r in e ,.'u n d e r h ie own su p e r v isio n , for w ar d in g th em to u s w ith a su m m a r y , a t l e a s t , o f t h e c lin ic a l r e c o r d , a.nd a c o m p le t e st a t e m e n t o f t h e em p lo y m e n t - r ecor d , noting: e sp e c ia lly th e len gth o f em p lo y m en t u n d e r . co n ait im v cf ou p oeu r e, t h e la st d ay on w h ich e xp o su r e o ccu r r e d , an d an y oth er p ertin en t m a t t e r s r elatin g to the e-m ploym ent o r to th e clin ical., p r oaier r i-v. V*c sn a il h en n e a b le t o g iv e so u n d a d v ic e a s t o th e sit u a t io n an d its xu rtaer in v e st igat io n o r h an dlin g. {c) -Th e1e x t r a o r d i n a r i l y h igh r e s u l t s bin in ed1on a fe w - sa m p le r , o f u r in e , a r e orooah ly the r esu lt cf con tam in ation of in s sam p le s, bach con tam in ation o c c u r s fr o m tim e to t im e an d is on e ci th e d an ge r s of r e ly in g on a n a ly se s id u r in e alo n e . We a r e ab le to a p p r a ise th e sign ifican ce .o i t h e se w ith lit t le d ou b t , in th o co.se o f lo a d , bu t w e k n ow t oo l it t le a b o u t t h e v a r ia b ilit y .of th e e xcr e t io n cf cad m iu m to a "r iv e at-m o re th an t en t at ive co n clu sio n s b ase d on st at ist ic al p r o b ab ility . f^ You. w ill g a t h e r t h a t t h e se a r e m an y m a t t e r s t o b e c o n sid e r e d an d d e a lt w ith 'in a situ ation of tn c type v/ith w h ich we a r e p r e se n t e d n o r e . You. w ill se e a l s o why- I d e la y e d an y a t t e m p t t o r e p ly u n t il I h ad d isp o se d , o f t h e so m e w h at m o r e u rgen t c laim s on m y tim e . Th is r ath e r fo r m id ab le le t t e r could be exten ded to m an y m o r e p a ge s, if th er e w e re-.profit in acm g so . On th e w h ole, h ow ever , I h ave attem p ted to d eal w ith th e m a t t e r s of r e a l sign ifi.can ce. an d to r e le gat e u n p r ofit ab le sp ecu lat ion an d d isc u ss ion to th e fu t u r e, when m e r e fa c t s sh ou ld d o av ailab le . Cord ially you rs, ., RAK of Robert A. Kekoe, M. , C .C . : D r. W illiam M . A ld red ge . M r . Ja m e s L. H ar t - (6) - Ja n u a r y 20, 1954 # The reduction of th is exp osu re and ab sorp tion of a m an o r a group m ay be accom p lish ed to som e u n predictable d egree by secu rin g the car e fu l u se of r e sp ir a t o r s, an d th is m ay h ave been th e an sw er in t h ese o r oth er in stan ces. If safe t y depen d s on su ch m e a su r e s in m or e th an t e m p o r ar y situ atio n s, i t i s h igh ly i n s e c u r e .0 D e p e n d e n ce sh o u ld n e v e r b e p u t 1.1 su c h m e a su r e s in con tin uin g situ atio n s. Th e on ly su itab le rem ed y is to co r r e c t th e m atter at its sou rce. .. M . '> .Ml; MM..-;...; . Z:.:, Vbb-Mjv'-- - j - t . ' ....................... ..................................