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R. K* Scales George Roush, JTr., M. D. Review ol the Sehroeder and Tipton Paper on the Human Body Burden of Dead Detroit Hew Orleans January 8, 1969 Enclosed you will find a summary of my thoughts on the Sehroeder and Tipton paper. 1 tried to be concrete and succinct, but if there are questions regarding my comments, I will try to answer them, G E /s Enclosure (1) cc: Dr. A. S. Hawkea (Enel. 1) Dr. George F. Kirby ( Enel. 1) Dr. Robert A, Kehoe ( STA TEM EN T REGARDING THE SCH RO ED ER AND TIPTO N PA P E R "THE HUMAN BODY BURDEN OF LEAD" This p ap er se ts out to evaluate the m agnitude of the body bu rd en of lead in m en around the w orld, the balance o r stead y state of lead in the body, the accum ulation of lead w ith age, the effect of body burden of lead on health, and finally on evidences of subclin ical toxicity fro m lead. . T hese au th o rs use th e ir data to calcu late the body burden of the "stan d a rd m an " and the re s u lts a re c o n siste n t w ith w hat has been re p o rte d in the p a st (the H arb en L e c tu re s of K ehoe), and so th e ir findings a re not unexpected. In th e ir c o m p a riso n of the body b u rd e n in U. S. su b je c ts w ith th o se of o th e r co u n tries, they state th at the body b u rd en in the U nited S tates is sig n ifican tly h ig h er than in S w itzerland, A frica, the M iddle E ast, and the F a r E a st. It is difficu lt to re la te th e ir findings to the blood lead con cen tratio n s around the w o rld as re p o rte d by G o ld w ater and H oover w h ich show th a t the U. S. le v e ls w ere low er than th o se of F inland, U nited K ingdom , New G uinea, Y ugoslavia, Japan, C zechoslovakia, and C hile, the sam e as in Egypt, but h ig h er th an in A rg en tin a, H olland, Poland, Sw eden, and P e ru . In o th er w o rd s, the G oldw ater data says th at the U nited S tates is about in the m iddle of th is w o rld w ide survey. Though th e re is probably not a p e rfe ct c o rre la tio n betw een the blood and the to ta l body burden, the blood co n cen tratio n c ertain ly does re fle c t th e body b u rd e n and th e re is a p o sitiv e c o rre la tio n b etw een the two. .F u rth e r re g a rd in g the G oldw ater data, the blood co n cen tratio n s w ould su g g est that-the F a r E a st w as high, th a t is, Jap an and New G uinea w ere re la tiv e ly h ig h ; thic-data w o u ld be c o n s is te n t w ith th e fin d in g s of S c h ro e d e r an d T ip to n . N e v erth ele ss, w hen we co n sid er th at the co n cen tratio n of lead in the blood in C zech o slo v ak ia w as 19, in F in lan d 25, in Sw eden 10, and in Y ugoslavia 20, it is ap p aren t th a t caution is re q u ire d in the in te rp re ta tio n of data fro m an ap p aren tly s im ila r geographic a re a s as w ell as w ith quite sim ila r c u ltu re s. An explanation for th ese re la tiv e ly la rg e d ifferen ces is not available but undoubted ly is not due to lead in a ir. W hether lead accu m u lates w ith age has b een a su b ject of in te re st fo r m any y e a rs. A rev iew of the g raphs of S ch ro ed er and T ipton could e asily lead to the - 1- 00123;^ N15294.01 co n clu sio n th a t lead does not accu m u late a fte r 30 to 40 y e a rs of age or p o s sib ly ev en a fte r 20 to 30 y e a r s of age, in th e liv e r, sp le e n , kidney, h e a r t, lung, and even in bone. W hen we co n sid er th at 90% of lead is found in the bone, th is is the o rg an th a t m u st be given the g re a te s t attention w hen attem pting to d eterm in e the accu m u latio n w ith age, and thb bone co n ce n tra tio n did plateau. The enorm ous v a ria tio n found by the au th o rs in the lead content of tissu e m akes it d ifficu lt to d raw co n clu sio n s re g a rd in g a c c u m u la tio n and th e re $. irot-m u c b -^ p ^ data a v a ila b le to d i s c u s s th e p r o s an d c o n s o f th is p r o b le m ; th j& ld a ta , t h e r e f o r e . have u se fu ln e ss in thatfjiij th e f i r s t r e a l su ch a cc u m u la tio n . I can r e f e r again to a study on blood conce n tra tio n s and to an a rtic le fro m the WHO C hro n icle, p u b lish ed in 1967 by G o ld w ater, w hich sta te d the follow ing, "T h e se stu d ie s co n f i r m e d -ta p r e v io u s r e p o r t s on bhe u b iq u ity o f le a d . " W h en th e r e s u l t s w e r e co m p ared w ith those of s im ila r stu d ies in individual co u n tries m ade during the p a st th re e decades, th e re is a re m a rk a b le ag reem en t in the range and m eans of co n cen tratio n of lead in both u rin e and blood (w ithout sig n ifican t changes o ver th is tim e). The au th o rs m ake m uch of the ab so rp tio n of lead fro m the lungs. Kehoe in his ch am b er study has found th a t s om ething le ss than 50% of lead inhaled is re ta in e d in the body. P a rt of the lead th a t is re ta in e d is d ep o sited in the u p p er re s p ir a to r y p a ss a g e s and p a rt in the d eep lbng. If we u se the S c h ro e d e r fig u re , th en 1 x 20 c u b ic m e t e r s = 20 m ic r o g r a m s in s p ir e d , a n d s o 10 m ic r o g r a m s is r e ta in e d in th e body. T he fa te of th is 10 m ic ro g ra m s is n o t u n d e rs to o d a t th e p r e s e n t tim e ; . p a rt of it is undoubtedly ab so rb ed fro m the lung and p a rt of it also ends up in the g a stro e n te stin a l tra c t. It has been e stim a te d of th a t d ep o sited in the deep lung, o n e-h alf is elim in ated and sw allow ed in the f ir s t tw enty-four h o u rs; ap p ro x im ately 5 m ic ro g ra m s m ay be ab so rb ed fro m the lung but the p re se n t state of know ledge a n d -te c h n iq u e is s u c h t h a t w e c:a n n o t d e te r m in e th e f a te of th is s m a l l q u a n tity (th e r e m a in in g 5 m i c r o g r a m s rrftay h a v e a h a lf l i f e 'o f 120 d a y s in th e lu n g s ). M y point is th at I c an 't handle this p ro b lem any b e tte r than does S ch ro ed er; I do not know w hat p o rtio n of the inhaled lead does re a c h the deep lung o r its fate, once deposited th ere, The 6 m i p ro g ram s as liste d by S chroeder is probably on the high side. I think it sig n ifican t th a t Schroe d e r found no evidence of ch ro n ic d ise a se in p e rso n s of high body burden of lead, and also th at he found th at the lead burden had no effect on the co n cen tratio n s of sse n tia l tra c e m e ta ls in the body. E qually im portant, S chroeder now states th at lead does not cause a shortening of life span ^ as he had stated in a previous e rie s of a rtic le s in the Jo u rn al of N utrition. 2- And finally, he sta te s th a t lead in a ir has in c re a se d but if we a re to take the T ri-C ity Study as w ell as a p a p er by C holak in 1961 and again in 1968 we find re p o rts th a t sta te o th e rw ise; it is not going up. In su m m ary , S c h ro e d e r's g e n eral co nclusion co n cerning the body burden is about as has been p re sen te d in the p ast. He did d em o n strate a d ifference in the body burden as com pared to th at in o ther co u n tries, and his findings a re d ifficu lt to refu te although th e se co n clusions a re in co n sisten t w ith the blood lev els re p o rte d for th ese co u n tries. W hether th e re is an accum ulation w ith a g e is n o t e s t a b l i s h e d a t a ll, in m y o p in io n . S in c e th e t o t a l b o d y b u r d e n i s n 't changed by S ch ro ed er, the questio n is only w h eth er the m an gets his body b u rd en o v e r a p e rio d of 30 y e a rs as su g g este d by K ehoe o r ov er a life tim e . S c h ro e d e r su g g est th a t this is p ro g re ssiv e o v er a lifetim e but I choose to say th at the accu m u latio n is co m p leted by the age of 40. On the plus s id e , S c h ro e d e r says lead does not produce a shortening o1f^"life ir f A span \ and also he states th at chronic d isea se w as not a sso ciated w ith an in crease in body burden of lead. '7 / - 3- K &1938