Document bBvdE87JbrzYn1qNg8q8zyq3

Ju ly 31,. 1958 P r o fe sso r V. G. H eller D epartm en t oi Bioch em istry D ivision of A gricu ltu re O k lah om a State U n iv er sity Stillw ater , O klah om a . D ear P r o fe sso r K e lle r :. M y r e p ly to y o u r la st le t t e r i s t ar d y , b e c a u se of m y p r e o ccu p at io n w ith v ar io u s d u ties th at h ave in t e r fe r e d w ith m y co r r e sp o n d e n ce , but I t r u st it m ay be h elpfu l. ... . W ith r e fe r e n c e to th e le ad an d a r se n ic con ten t of th e w at e r a s list e d , I am p r esu m in g th at th e r e su lt s a r e e x p r e sse d in p a r t s p e r m illio n , i. e . m illigr am s p e r lit e r of w ater. If th is is n ot th e c a se , I m ay be en tirely in e r r o r . On th is assu m p tion th e w ater is not d an gerou s fr o m th e asp e ct of acu te poison in g, an d w h ile it is cer tain ly too h igh fo r p rolon ged o r in defin ite p er io d s of u se , it is not to be regar d ed a s very dan gerou s fo r in term itten t u se o r for com p aratively sh ort p eriod s of tim e. I b a se th is opin ion , w ith r e sp e c t to le ad on e xp e r im e n t s w h ich we h ave c a r r ie d out on h um an su b je ct s. Th e ad m in istr ation of 3 m g. of lead p e r day a s a solu b le sa lt , in ad d ition to the le ad p r e se n t in cid en tally in th e d iet, u n d er car e fu lly con trolled b alan ce exp erim en ts, r esu lted in a str ik in g in cr e ase in the r ate of e x c r e t io n o f Ijsad an d a l so in an a c c u m u la t io n o f le a d in th e b o d y . W ith in th e p eriod of six m on th s, th is accu m u lation did not o ccu r to a d an gerou s exten t, but it w ould h ave b ecom e d an ger o u s at so m e poin t m uch la t e r . Th e leew ay in t e r m s of tim e w as co n sid e r ab le , bu t, n atu r ally , th e exp erim en t w as n ot con tin ued to the poin t of d an ger. Th is lev el of in take in the h um an bein g is equ ivalen t to the co n su m p t io n tjlaily o f a l i t e r o f w a t e r co n t ain in g le a d a t t h e le v e l o f 3 m g . p e r lit e r . I am n ot in position to say th at cattle can take a prop ortion ately lar ge qu an tity of w at e r of co m p ar ab le le ad co n cen tr at io n w ith sa fe t y , but I w ould h az ar d th e opin ion th at th ey p rob ab ly cou ld . I th in k it lik e ly , t h e r e fo r e , th at t h is, the situ ation w h ich you d e sc r ib e , w ould n ot be v e r y d an ge r o u s, fr o m th e asp e ct of lead , u n le ss th is w ere th e on ly so u r ce of drin kin g w ater th rough out the en tire y ear , season after season . In view of th e r e lat iv e e a se of th e excr etio n of a r se n ic , I doubt v e r y m u ch if th e con cen tr ation of a r se n ic w h ich you h ave in d icated w ould b e d an ger ou s u n d er con dition s sim ila r to th o se r e fe r r e d to above in m y com m en ts on lead . N 6021 P r o fe sso r V. G. H e lle r - (2) - Ju ly 31,. 1958 I rep eat th at I can n ot be su r e of m y groun d b ecau se of m y lack of experien ce w ith d o m e st ic a n im a ls, bu t th e evid en ce of an im al exp er im en t at io n p r o v id e s som e b a sis fo r a gen eralization con cern in g th e b eh avior of lead in the bodies of an im als* an d it w ould b e m y b e st an d som ew h at ed u cated gu e ss th at what I h av e sa i d ijs n ot f a r fr o m th e t r u t h . ' In an y c a se , I give you m y opin ion fo r w h at it m ay be w orth . Sin cerely y o u r s,: RAX ef * Robert A. Kehoe, M. D.