Document JJamqyd1Y6nJ1OQOxB7Km2JrB

A p ril 50# 1955 Dr F r a n c i s D* P a t t e r s o n P. 0 Box ij.0^1 l?e st; Ph* l a d e l p h i a S t a t i o n P h ila d e lp h ia , Pa* D e^r Dr* P a tte r s o n s . I an very happy to 'g iv e you any in fo rm a tio n w hich I can on th e i n t e r p r e t a t i o n o f s tip p le d c e lls In th e blood of a p p lic a n ts fo r employment in a le a d p la n t* I t i s now a c c e p t e d t y a l l b u t a few w orkers th a t a s n a il number o f 3tip p le d c e lls re p re se n ts a norm al or a t le a s t u n -ex p la in a b le fin d in g i n t h e b lo o d * We a r e j u s t m ak in g a s t u d y o f o u r d a t a over a p erio d o f y ears w hich show th a t th e number of s tip p le d c e lls in a p p a re n tly norm al persons w ithout I n d u s t r i a l e x p o su re to le a d v a r ie s a l l th e way from 0 t o 5 o r 6 ,0 0 0 p e r m il l io n o f e r y th r o c y te s . The mean firs d in g i n some 700 p e r s o n s com es t o a b o u t 5^0 p e r m illio n . P ersons #ho a b so rb s ig n if ic a n t amounts of le a d tend to g iv e somewhat h ig h e r f ig u r e s , b u t th e re is a d e fin ite o v erlap p in g of norm al and abnorm al fin d in g s T ilth 'la r g e v a r i a ti o n s among in d iv id u a ls in the g ro u p s . T his makes i t a l i t t l e b i t d i f f i c u l t to say what is norm al and w hat la ab n o rm al I have come to th e g e n e ra l p o in t of view th a t th e number of s tip p le d c e lls found in exposed workmen b e a r s l i t t l e q u a n ti t a t iv e r e l a t i o n s h i p to th e s e v e rity q f th e exposure* However, in th e in d iv id u a l c a s e I am I n c l i n e d to b e l i e v e t h a t a p r o g r e s s i v e in c r e a s e in the number of s tip p le d c e lls in d ic a te s a s ig n ific a n t amount o f lead absorption* T h e re fo re l reg ard s tip p lin g counts as u se fu l co n firm atory evidence b u t I w ill n ot be w illin g to depend upon them f o r any o th e r in f o r m a tio n . The p re lim in a ry ex am in atio n o f a p p lic a n ts fo r p o sitio n is com plicated by the f a c t th a t the h isto ry of previous occupation is lik e ly to be d e ce iv in g . A ppli c a n ts knowing th a t p re v io u s s ig n if ic a n t exposure is l ik e ly to d is q u a lify them ,conceal the tru e s to ry o f th e ir previous employment* T h is i s q u ite a b u g b e ar b ecau se i f one a c c e p ts men who have b e e n p r e v io u s ly le a d e d , th e r e i s a g r e a t e r lik e lih o o d , I b e lie v e , of d if f ic u lty from le a d a b so rp tio n . T herefore I should be in c lin e d to use the p relim in ary blood te s ts along w ith o th e r c lin ic a l evidences as a means o f d eterm in in g a s w e ll as p o s s ib le som ething o f the a p p lic a n t's pv>. 2 /anois P a tte rso n a ffoo * p rev io u s exposure to le a d , A h ig h s tip p le d count m ight w ell be reg ard ed as su g g estiv e evidence of previous le a d exposure w hich co u ld be checked a g a in s t the a p p li c a n t's o c c u p a tio n a l h is to r y , and m ight be u s e fu l in ob ta in in g the tr u th . Furtherm ore unusual h ig h s tip p le d counts m ight w e ll be reg ard ed as a b a s is fo r ex clu sio n m erely as a m a tte r o f s e lf d e fe n se , s in c e i t is s t i l l the p o in t of view of a c o n sid e ra b le number o f people th at stip p lin g Is an in d icatio n of lead in to x icatio n * Any ty p e o f I l l n e s s d e v e lo p in g in s u c h An i n d i v i d u a l would be lik o ly to be re g a rd e d as e v id en ce o f s i g n if ic a n t o c c u p a t i o n a l e x p o s u r e . On t h e o t h e r h an d I w ould p o i n t o u t to you t h a t we -have re c o r d s in o u r f i l e s on a f a i r number o f men who have s t a r t e d o u t t h e i r w ork a t th e m ixing p la n ts in v a rio u s re fin e rie s v w ith a s tip p le d count as th ig h as 20 to 30, o r even m ore, s tip p le d c e l l s p e r f i f t y f i e l d s , ( th is corresponds to about 14*009- to -2ifry03Q- p e r m i l l i o n ) . I n th e a b s e n c e o f o t h e r e v id e n c e s of illn e s s of any k in d , I do not re g a rd th is a3 a d i s q u a l i f i c a t i o n s i n c e wo h a v e th e r e c o r d o f th e i n i t i a l exam ination as evidence of the i n i t i a l presence of stip p lin g , . . However, to be somewhat more s p e c if ic i n |r e p l y to y o u r q u e s t i o n , I am i n th e h a b i t o f r e g a r d i n g th e o ccu rren ce o f more than 10 s tip p le d c e lls p e r f i f t y fie ld s as su g g estiv e evidence (but only sug g estiv e) of ledd a b so rp tio n , and as ju s tify in g th ere fo re a c a re fu l exam ination in to the circum stances of exposure, T his is a p u rely a rb itra ry stan d and u n til the evidence is more th o ro u g h ly s i f t e d , i t Is a somewhat u n s a tis f a c to r ily fo u n d ed p o ih t o t view . However, i t seems to work f a i r l y w e l l i n Tp r a c t i c e , : ' ' r' : I r e a l i z .th a t t h is i s a somewhat u n s a t isfa e tp ry . answ er to your q u estio n b u t i t 3 u n fo rtu n a te ly tru e th a t c o n sid e rin g th e la rg e number of m ethods u se d , and con s id d rin g th e somewhat confused s itu a tio n o f our p o in t of view re g a rd in g s ti p p li n g , i t is alm o st im p o ssib le t th i s tim e to say w hat a re norm al and w hat a re abnorm al fin dings. 'W ith k in d e s t p e rso n a l r e g a rd s , C ordially yours, RAK i i s R o b e r t A , K eh o e, M D,