# OAR Box 1113 Prepped by Ryan Dugan



### Document

Number: 

# 3 ) ll-F-3 a Docket Number: 

# A-83-2 2

Printed 4/16/200812:45:20PM Sheet 3 of 139 p. 1MJ.'S H

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U..ITE D STATE S ENVIRONMENTA L PROTECTIO NAGENC Y

* * * CLEANAI RSCIENTIFI C ADVISOR YCOMMITTE E

SCIENC E ADVISOR YBOAR D

* * *

7 8 9 1 0 1 1 1 2 1 3 14 1 5 1 6 17 18 1 9 2 0 2 1 2 2 2 3 2 4 2 5 U.S . E.P.A . Environmenta l Researc h Cente r Mai nAuditoriu m Alexande r Driv e an d Rout e 5 4 Researc hTriangl e Park , Nort hCarolin a

Th e abov e entitle d matte r cam e o nfo r hearin g pursuan t t o notic e a t 8:4 0 p.m. :

PANE L MEMBER S PRESENT : DR . MORTO NLIPPMAN NChairma n MR . ROBER T FLAAK , Executiv e Secretar y DR . CARO L R . ANGL E DR . J . JULIA NCHISOLM , JR . DR . BE NB . EWIN G DR . ROBER T FRAN K PROFESSO RA . MYRIC K FREEMA NII I DR . ROBER T GOYE R DR . PAU L B . HAMMON D DR . LLOY D G . HUMPHREY S DR . TIMOTH YLARSO N DR . KATHRY NR . MAHAFFE Y PROFESSO RM . GRANGE RMORGA N

EXECUTIV E COUR T REPORTER S

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. 6 7 8 9 10 1 1 12 13 1 4 15 16 1 7 18 19 PANE L MEMBER S PRESENT : (CONT. )

DR . TERR YYOSIE , DIRECTO R PROFESSO RROIE RG . NOL L DR . D . WARNE RNORT H R . ROBER T D . ROW E DR . ELLE NK . SILBERGEL D DR . JAME S H . WAR E DR . JERR YWESOLOWSK I

2 0 2 1 2 2 2 3 2 4 2 5

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7 8 9 1 0 1 1 1 2 13 14 15 1 6 17 1 8 1 9 2 0 21 2 2 2 3 2 4 2 5 AGEND A Statemen t o f Richar d Smit h Question s an d Remark s iStatemen t o f Dr . Charle s Pfeife r Question s an d Remark s 'Statement s o f Dr . Wallste nan d Dr . Whitfiel d Question s an d Remark s Committe e Discussio n 3 PAGE :

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j _ > j 7 5 9 0 10 7

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• 6 7 8 9 1 0 1 1 12 13 14 15 16 17 18 1 9 2 0 2 1 2 2 2 3 2 4 2 5 

### il.2_~_____-2I_lG._ _

CHAIRMANLIPPMANN : W e than k yo u agai nfo r you r willingnes s t o com e bac k toda yand hel p u s sprea dth e schedul e Ther e i s a handou t fro mMr . Smit htha t we'l l b e discussin g j som e o f th e point s we'l l b e talkin g about . j i i MR . SMITH : Th e Mineral' s Availabilit yFiel dOffic e i i i nDenve r ha s bee ninvolve di nth e las t fe wyear s i nevaluating ! i th e technica l andeconomic s aspect s o f meetin g mor e stringen t j i ai r qualit yrequirement s o nno nferrou s meta l smelters . ; I i W e hav e bee ninvolve di nlookin g a t th e lea dsmelt

- \ ing refinin g industr yfo r a matte r o f tw o year s no wan dhav e j a repor t whic hwil l b e availabl e ver yshortl yandma yb e o f j i interes t t o thi s Committee . Essentially , wha t i s covere db yth e i report , w e hav e take na loo k a t fou r o f th e si xfacilitie s i n\ th e Unite d States .

Thes e includ e Glover , Buic k and Herculaneumi n Missour i an d th e Eas t Helen a Plan t i nMontana . We'v e considere d I ! i t fro m

th e poin t o f vie wo f wha t th e lowes t limi t i s technic

- j all yfeasibl e fro mthes e plants , withou t regar dt o anyexistin g standar d o r propose d standard , base d o ncurren t technology , how

- lo wca nemission s b e gotten .

We'v e no t bee nabl e t o compar e the mt o ambien t ai r reauirement s becaus e ou r facilit ya t presen t doe s no t hav e j i compute r modelin g capabilities . S o ou r result s ar e presente d i nth e for mo f lea demission s o na pe r pound , pound s pe r da y EXECUTIVE COUR T REPORTER S

(301 ) J65-C.6 4P. 6

1 2 3 4 5

• 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0

' 2 1 2 2 2 3 2 4 2 5 I 5 j I basis , i j I Th e base s fo r th e repor t use s publicall yavailabl e

: dat a i nth e for mo f emissio ninventorie s fro mstat e implementa

tio nplan s and . th e annua l report s tha t supplemen t those . I Contrac t studie s performe dfo r th e EPA , plan t visit s an ddat a i i collecte d a t th e plants , performanc e dat a o nvariou s emissio nj i - ! I ^contro l device s fro mvendors , an dpersona l experienc e o nmyj i : ; | par t fo r th e las t 1 8 year s andMr . Kiehn , th e co-author, ' fo r : i j a oerio d c f approximatel y3 0 years . j i Th e metho dw e selecte d a s bein g th e basi s fo r th e .designconsideratio nwoul db e dr ycollection , usin g ba g houses, ] i jar . enclosur e o f th e existin g building s o nth e plan t sites . j iTh e reaso nfo r thi s wa s covere di ntw o areas . j ; Firs t o f all , poin t sourc e emission s ar e bein g 'collecte d presentl ya t greate r tha n9 9 percen t efficiency . Ver ylittl e improvemen t ca nb e expecte di nthos e areas .

Proces s fugitive s o nth e othe r hand , ar e bein g icollecte d i nth e real mo f 70-9 0 percen t efficiency , andd o ali o fo r improvement . Th e ope nfugitive s onl yaccoun t fo r roughl y I 8 percen t o f th e tota l emissio no f th e plan t andwer e deeme d t o b e o f littl e improvemen t fo r th e amoun t o f mone ytha t coul d i ib e expended . j Followin g ou r analysi s —excus e me , on e mor e point . W

>7~e wen t t o th e dr ycollectio nbecaus e usin g othe r method s suc hj a s we t scrubber s woul dcreat e anothe r environmenta l proble mi n

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(3U1 ) 565-006 4 |P. 7

5

• 6 7 8 9 1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 wate r pollution . Andw e fel t tha t thi s wa s a nunacceptabl e alternative .

Ou r evaluatio nindicate dtha t a noveral l plan t i [efficienc yfo r thes e fou r facilitie s whic hpresentl yi s aroun d I j 98. 1 percent , coul db e improve d t o approximatel y99. 4 percent , j i l j Thi s improvemen t woul d resul t i ncapita l cos t o f approximatel yi ! $10 0 millio nwit ha nannua l operatin g cos t o f $13. 6 million .

Certai nassumption s wer e involve d i nthi s i nconsi

derin g tha t 1 5 ai r change s pe r hou r fo r eac hbuildin g woul db e j i I a nacceptabl e figure . Thi s i s based , o ninformatio nfro mth e ; E l Pas o smelte r whic hha s enclose don e o f thei r facilities . j

Th e secon dconsideratio ni s a t a nai r t o clot hi i t i rati o i nth e ba g house s o f 3 t o 1 woul db e acceptable . Th e i j industry , however , use s a 1 t o 1 ai r t o clot hrati o i nmos t I cases . j

Therefore , ther e i s a discrepanc ybetwee nvendo r informatio nan d tha t use db yth e industr ywhic hw e ar e presentl y studyin g t o determin e whic hi s mor e correct . I f "th e industry' s consideratio ni s mor e correct , the nw e ar e lookin g close r t o $30 0 millio ni ninstalle dcapita l cost s anda nappropriat e increas e i nth e operatin g cos t a s wel l sinc e i t woul db e primaril ya nelectrica l energ yan dmaintenanc e manpower .

Now , thi s basi c numbe r overlook s on e importan t consideration . Enclosur e i nth e buildin g create s a proble m fro m occupationa l healt handsafet yperspective .

EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4- —

_. , , , PJ L l i ' 7 j i i :• T o compensat e fo r th e increas e i nlea dlevel s withi n 

## j i 2 i'tr. e puildinqs , a nadditiona l su mo f mone vwoul db e involve d ; j 3 |ji nprovidin g ventilatio nfo r specifi c uni t processe s withi n 4 7 th e plan t and . specia l handlin g feature s fo r material s an dcol

- | i 5 i'lecte dwastes .

. 5 j , Informatio nwhic hIreceive dyesterday , whic hun I ; 7 j j fortunatel yi s no t o nth e on e pag e handou t I hav e here , indicate s 

# \ 

# i 3 : ; tha t to ' additionall ycompl yv/ithOSH Arequirements , a minimu m j i' ! 9 i cos t tota l includin g ou r basi c assumption , th e capita l cos t j 

# i 1

# * " I -,0 : -vouI f approac h$25 0 millio nan d a nannua l oceratin qcos t o f | i' i j i , ij$23. 4 millio npe r year . | i . ; i i ! 1 2 j i Acain , th e ai r t o clot hrati o need s t o b e adjuste d | ! ' • i 13 ! , o nth e ba g hous e configuratio no r othe r consideration s nee dt o ; i ! ! l l 14 i : b e take nint o account , thi s figur e coul dg o considerabl yhigher . j i

. - i j There' s a noveral l vie wgoin c bac k int o th e initia l considera

- 

## ° 

## I! 'jtion , a minimu m

o f 3 cent s pe r poun do f refine dlea dwoul db e th e added , cos t fo r thi s typ e o f a nimprovement .

Th e resul t woul db e o nth e orde r o f a 50 0 shor t to n 1 6 17 13 19 2 0 2 1 2 2 2 3 2 4 2 5 pe r yea r reductio ni nemission s fro mthes e fou r specifi c smelters . Again , tha t doe s not:.includ e th e E l Pas o smelter , becaus e it' s presentl yshu t dow nan di t doe s no t includ e th e Omah a refiner ywhic hha s specifi c problem s uniqu e t o itself .

Th e informatio nwhic hI'v e covere dher e wil l b e !j availabl e i na nope nfil e repor t i nth e ver ynea r futur e fro m th e Burea uo f Mine s i nconsiderabl ymor e detail . An dw e woul d

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1 lik e t o offe r i t t o anyon e wh o i s intereste d t o includ e i n 2 thei r analyse s o f th e problem . A s I say , w e hav e no t carrie d 3 ou r number s beyon d a nemissio nsummar yi nterm s o f pound s pe r 4 i da ybecaus e o f th e compute r modelin g aspec t 5 However , becaus e w e ar e assignin g th e emission s 5 specificall yt o poin t source s an d fugitiv e sources , i t shoul d

7 b e a simpl e matte r fo r an yintereste d individua l t o appl ythi s j 8 t o thei r compute r model . 9 Tha t prett ymuc hcover s th e exten t o f it . Ar e ther e 1 0 an yquestions 9

nCHAIRMA NLIPPMANN : Than k yo u ver ymuch . I gues s

1 2 I coul d rais e a coupl e o f questions . 1 3 QUESTION S AN D REMARKS : 1 4 1 5 1 6 1 7 1 8 1 9 2 0 21 2 2 2 3 2 4 2 5 CHAIRMA NLIPPMANN : I thin k i t woul d b e easie r fo r u s t o gras p thi s materia l whic hi s a bi t outsid e th e norma l activit yo f man yo f th e peopl e here , i f yo u woul d hav e presente d th e changes'i npenetratio nvalues , rathe r tha ncollectio neffi- j cienc yvalues .

Whe nyo u sa y. 8 t o 1. 6 percen t greate r collection , i t doesn' t mea nmuc hunti l yo u tel l u s lik e yo u di d orally , tha t you'r e nettin g u p t o 99. 4 percen t tota l collection , an d the nw e se e th e penetratio nvalue . We'r e intereste d i nth e inpac t o nth e environment .

MR . SMITH : I see . CHAIRMA NLIPPMANN : Penetratio nwoul d hav e bee na nj i j j i EXECUTIV ECOUR TREPORTER S j

(301 ) 565-006 4 jP.1 0 9 easie r thin a t o gras p tha nefficiency .

MR . SMITH : I' mlookin g a t i t fro ma nengineer' s 3 j j poin t o f vie wrathe r tha nwha t would , b e appropriat e here , I' m sure . 5 j i DR . EWING : Coul dI interjec t a t tha t point ? I f I ;understan dir , yo uwoul dchang e fro m98. 1 percen t efficienc y i i jno wt o 99. 4 percent ?

' MR . SMITH : Ye s sir . i .

9 j , DR . EWING : Tha t mean s however , tha t th e par t tha t I I 10 .i s escapin g i s cu t fro m1. 9 percen t dow nt o 0. 6 percen t whic h

1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 nj j i s a three-fol ddecreas e i nth e amoun t c f emission . I s tha t -- i i i : i , , h 1 2'm v interpretatio n- - \ • \ i i l j 1 3 j ! MR . SMITH : I t would " b e a reductio nt o abou t on e > 

# i ' 

# ! 1 4 i l third . Jus t slightl yles s tha non e third . j 

## i DR . EWING : That' s wha t you'r e buyin g wit hth e instal

latio ncos t an doperatin g cos t tha t you'v e cited .

MR.SMITH : Right . Base do nth e mos t recen t informatio n from'th e stat e environmetna l agencies , th e curren t tota l emis

sion s o na pound s pe r da ybasi s i s aroun d4,06 7 pound s pe r day . B yapplyin g th e control s whic hw e envision , we'r e talkin g a reductio nt o 1,317 .

Now , thi s i s no t lik e I say , no t considerin g wha t th e regulatio nmigh t require , it' s als o assumin g tha t cos t i s n o object . It' s a technica l limit'tha t coul db e approached .

CHAIRMA NLIPPMAN : Jus t on e furthe r questio nthen ,

EXECUTIV E COUR T REPORTER S

(301 ) 565-006 4P.1 1 

# I 1 0 ! . • i , a_.t:.ougnyo u haven' t don e th e modelin g yet , th e so-calle d 

# I . 2 ' ' fenc e line , woul d thi s kin d o f improvemen t i na collectio n i j 3 ; | efficienc yreductio nan d penetration , i s tha t intende dt o i i brin g thes e unit s int o complianc e wit hth e curren t standar d

I : 5 ' o r d o bette r tha nachievin g th e curren t ai r standard ?

s Yo u mus t hav e som e ide a o f whethe r thi s muc hexpendi

i - i 7 j , tur e woul d enabl e th e smelter s t o mee t th e curren t ai r qualit yI i 

## ; : j 3 ; ' standards . j o MR.SMITH : It' s har d t o sa ybecaus e o f th e natur e j 

## i i j

- Q j o f th e emissio nsource s i nth e compute r models . I woul dsa yi y t ''i t woul d b e a mixe d answer , i ntha t possibl yhal f o f th e facili- i j l j

. - 7 tie s could , mak e th e curren t standard . I ' * ! ! i i j ' '• 1 3 | CHAIRMA NLIPPMAN : I t woul d tak e a thre e fol dreduc

- ; i . i

, 4 'tio nassumin g tha t thing s wer e tha t simple , the nw e woul d- - j | ! I

. ii..r.ov.'in

c wha t th e curren t ai r cualit vlevel s are , on e coul dI 1 a ' . •* ; ge t a firs t approximatio nb yreducin g th e level s b ythree? .

MR . SMITH : That' s a noversimplifie d approach , i i ! •unfortunately . I f w e wer e t o agre e tha t ther e woul db e a linea r 

# i •relation , th e chance s woul db e ver ygood , al l accep t fo r on e o f th e smelter s woul d comply .

Realizin g tha t i t isn' t a linea r relation' , myow n persona l opinio nis , tha t w e woul d approac hth e curren t stand

ard , bu t I' mno t sur e tha t w e woul d eve r quit e achiev e i t o na consisten t basis . 1 5 1 7 1 8 1 9 2 0 | | 2 1 2 2 2 3 24 i lI ! ; CHAIRMA NLIPPMANN : Ar ether ean yothe r questions ? 2 5 i l I EXECUTIV ECOUR TREPORTER

S (301 ) 565-006 4 I1 2 P.1 2 

# j l 

# ' " u j i DR . ANGLE : Ar e al l o f thes e smelter s i nOSH A ;compliance ? 3 j i -MR . SMITH : Thev'r e havin g difficult yi ntha t area . I : i | I - . . c, j : OSH Arequire s ultimatel ytha t th e facilit yb e s o designe dtha t 5 j . n o artificia l mean s o nth e personne l b e use d fo r compliance , i . !

. 5 ;• suc ha s respirators . ! ii i I , 7 | i Al l o f th e plant s ar e usin a respirator s a t present , j 

### I : 

### " i 8 I and . ver yeffectively . Bu t t o achiev e th e requiremen t b yclearl y 9 1 0 11 1 2 1 3 .engineere d method s i s again , on e o f th e majo r problems . j 

## | j

Thi s i s wher e th e jum p fro messentiall v$10 0 millio n i . , jfo r environmenta l compliance , an d the nth e additio no f anothe r • j $15 0 millio nt o mee t th e OSH Acomplianc e come s in , becaus e ; : ' ! jit' s lookin g a t i t fro ma clearl yengineere d poin t o f view . j ! • i i i 1 4 j ; BR . ANGLE : V 7 ha t i s th e curren t rang e o f ai r value s j l i a t th e standar d ai r quality , th e closes t ai r qualit ymonitor

ing ? MR . SMITH : I'v e see nfigure s reporte d i nth e stat e reports , rangin g anywher e a s lo wa s 1. 2 8 microgram s pe r cubi c mete r t o a s hig ha s 5.28 . There' s considerabl e variation .

CHAIRMA NLIPPMANN : Paul ? DR . HAMMOND : Mos t o f thes e primar ysmelters , i f no t al l o f them , ar e locate d i nrura l areas . That' s m yimpression .

MR . SMITH : Thi s i s correct . Th e onl y- - tw o exceptions , partia l exceptions . Herculaneu mi s adjacen t t o

a tow nan d th e tow ni s essentiall yrich t o nth e wes t sic e o f 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5

EXECUTIV ECOUR TREPORTER S (301 ) 565-0.- 4P.1 3 1 2 1 lith e stree t from'it . An d E l Pas o i s uowin d fro mth e Cit vo f 2 E l Paso . 3 j l Eas t Helena , Glove r an d Buic k ar e essentially ' i n 

## i i 4 ! • rura l areas . 

### i l 

### ! 5 i | DR . HAMMOND : Well , tha t lead s t o m ynex t question , 6 ; ' a s t o whethe r yo u hav e an yknowledg e o f th e complianc e character

i j " 7 !j istic s o f th e secondar ysmelters , mos t o f which , I believe , j j ! ; 8 ! : ar e i nclos e proximit yt o populatio ndensity ? g j i MR . SMITH : I hav e n o informatio no nthat . I hav e '• ii i l i i I Q , : bee nworkin g exclusivel ywit hprimar ysmelters . 1 1 DR . WESOLOWSKI : I f you'r e havin g troubl e meetin g 1 2 j j th e OSH Astandar d no wan d aren' t allowe d t o us e i nth e future , ; 

### ij 

### • ; 1 3 ; respirators , the non e o f th e engineerin g solutions , i s i t simpl y i . : 1 4 | | t o increas e ai r exchang e rat e an d ven t th e lea d t o th e outsid e 1 5 l air ? |

MR . SMITH : No t really . Th e ai r flo wcharacteristic s tha t on e woul d expec t withi nth e smelte r buildings , i s b ynatur e rathe r unpredictabl e becaus e o f th e shap e an d th e locatio n o f th e proces s equipment .

An d a t som e o f th e facilities , th e building s are ' extremel yol d an d hav e bee nadde d ont o severa l times . An di t 1 6 17 1 8 1 9 2 0 21 2 2 2 3 2 4 2 5 i

woul d b e lik e comparin g heatin g an d ai r conditionin g i na nI j offic e buildin g that' s ha d severa l wall s adde d an d remove dove r a perio d o f tim e an d it' s becom e ver ydifficul t t o balanc e I an d ge t unifor mflo wthroughou t th e building . j

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(301 ) 565-006 41

2 3 4 5

. 6 7 8 9 10 1 1 12 13 14 15 16 17 18 19 2 0

' 2 1 2 2 2 3 2 4 2 5 1 3

Th e tendenc ywoul d b e t o shor t circui t an dge t ver y P.1 4

clea nventilatio ni non e area' , ver ypoo r ventilatio ni nanother , i and . b ysimpl yincreasin g th e flo wrate s ou t o f th e buildin g j t o a collecto r an dthe nt o th e atmosphere , probabl ywouldn' t j resul t i nadequat e solution . | I i

i j j I nadditio nt o that , you'r e lookin g a t eithe r havin g 1 ~ I i t o recirculat e th e ai r bac k i nth e col dclimate s t o conserv e i j 1 ! energ yo r add heatin g system s t o it . j CHAIRMANLIPPMANN : Than k yo u ver ymuch . Let' s 1 j mov e o nt o ou r las t presentatio no nth e publi c sid e fro m Dr . , 

### i ; ! j Pfeife r o f D u Pont . j

Copie s o f hi s remark s hav e bee ndistributed . ! STATEMEN T O F DR . CHARLE S PFEIFER , Du PON T 1 DR . PFEIFER : They'v e bee ncirculate dt o CASA C j ^ bym e thi s mornin g and I woul dlik e t o g o i nth e recor dfo r i thi s proceeding . 1

Th e blu e covered , repor t i s ou r writte ncomment s t o EP Ac f Marc h7t handth e othe r handou t i s basicall ya cop yo f th e slide s I' mgoin g t o us e i nmyora l presentation . Ou r comment s thi s mornin g ar e goin g t o mainl yfocu s o nth e result s o f th e NHANE S I I epidemiologica l studyresult s thatwer e dis

cusse d somewha t yesterda ymorning .

• I nparticular , w e believ e tha t thos e —tha t th e result s tha t ar e presente di nth e paper s o f Harla ne t a l and Pirkl e e t al , formth e backbon e o f th e entir e sectio no n

EXECUTIVE COUR T REPORTER S

(3C. J 565-006 4P_l_ _ 1 4 cardi o vascula r ris k i nth e addendum . S o w e fee l a s thoug h it' s pertinen t t o revie wsom e o f ou r finding s i nsom e detai l here . 4 i Jus t t o revie wfo r th e Committe e andtheaudienc e l a littl e backqroun d o f som e ofth e event s tha t hav e take nplac e

'j surroundin g thi s issue . A s I jus t mentione di n'85 , tw o pub

- j lishe d paper s b

yHarla nandPirkl e cam e ou t whic hreporte dj I 8 jsignifican t bloo d lea d bloo d pressur e relationship , an di nour j i | i

. ' i 9 ; i comment s o nth e corrigend a a t EP Alas t yea r andsom e ensuin g >. IQ .discussio na t thi s meeting , D u Pon t identifie da nmethodologica l i i j j yi; : fla wi nthos e analyses , th e fla wo f bein g th e necessar yadjust ' | | 1 2 - j men t fo r sid e effect s an d properl yassessin g bloo d lea dbloo d j i 1 3 i j pressur e relationships . 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 j 2 3 2 4 i 2 5 An d a s a resul t o f that , and . othe r comment s tha t wer e mad e a t tha t meeting , CASA C recommende dth e corrigend a b e relegate d t o th e addendumpendin g som e o f th e resultion s o f th e issue s tha t wer e raised , andbetwee nth e las t meetin g wit hCASA C an d thi s meetin g wit hCASAC , a revie wproces s ensue d tha t mainl yfocuse d o nth e comment s tha t D u Pon t presente d i nwritin g t o EPA .

An d jus t t o highligh t som e o f thos e correspondences ! includ e Dr . Schwartz ' response , no t t o DuPon t i nth e sens e tha t h e sen t i t t o me , bu t Dr . Schwartz ' respons e o nth e DuPon t analysis , mem o o f 6-26-85 . Dr . Landis , on e o f th e co author s o f th e pape r presente d a nanalysis .

EXECUTIVE COUR T REPORTER S

(30! ) 565-006 4— . , . P 1 6 li lf > 1 Dr . War e an d Dr . Royal l o nCASA C reviewe dthos e i . j ! 2 '•• analyses . Dr . Royal l revie wwas , I gues s h e indicate dtha t th e i . 3 ; result s presente d b yDr . Schwart z weren' t satisfyin g an ddidn' t 4 ' answe r th e question s abou t whic hh e wa s mos t concerne dan d 5 anothe r respons e wa s prepare d b yDr . Schwart z an d followin g tha t 5 . v.-a

s Dr . Royall' s fina l response . • i 7 j , Bu t that' s jus t a chronolog yo f th e mai npart s o f 8 : th e revie wproces s tha t di d tak e plac e betwee nth e meetings . j 9 Kha t I woul d lik e t o d o i s just'tak e a fe wminute s an dg o over ; 1 0 , tw o slide s her e tha t tr yt o illustrat e th e importanc e o f thi s nj issu e tha t ha s bee nraised .

i i 1 2 j Fo r th e purpose s o f illustratin g this , wha t I'v e

• i 1 3 ' go t her e ar e tw o variable s o nth e vertica l access , variabl e 1 • 1 4 j an d variabl e 2 and . th e differen t scale s an d yo u ca nthin k o f ! j | i 1 5 ' thos e a s bloo d lea d an d bloo d pressure , o r whatever . An dj

1 6 j : i nth e Hane s I I survey , wha t w e hav e i s thes e 6 4 site s o r I ; 1 7 j; PSU' s wer e sequentiall yvisite d ove r th e fou r yea r period . 1 8 • S o yo u ca nthin k o f a t sit e No" . 1 , you'v e go t a I i mea nvalu e fo r variabl e 1 . A t sit e No . 2 , a t a late r poin t i n i i i time , you'v e go t a mea nvalu e fo r variabl e 1 , an d s o forth . j • An d als o yo u coul d hav e th e sam e kin d o f set s o f 1 9 2 0 21 2 2 

### I I j j relationship s fo r th e othe r variables . Now , i nplottin g the m l: ou t lik e that , it' s ver yapparen t tha t - - well , we'v e go t 2 3 

### l ; i i j „ , I ; tw o declinin g trend s an d th e nex t cuestio nt o as k i nsuc ha 2 4 : ! I . -,

_I : situatio nis , i s on e tren d fo r on e variabl e impactin g o no r _: a' EXECUTIV ECOUR TREPORTER S j (301 ) 565-006 4 jP.1 7 1 6 i causin g th e tren di nth e othe r variable . O r ar e the vtotal l v 2 unrelate dt o on e another . 3 | It' s certainl vpossibl e tha t yo u coul dhav e tw o 

# I " i 4 jcoinciden t trend s tha t hav e n o relationshi p t o on e another . j 5 i'Theyar e jus t observe dt o b e presen t ove r a perio do f tim e j 

## l i ! II i fi 1'ior whateve r reason s migh t ente r int o th e assessmen t a s t o whv. ' ! - uI 7 I Now , i nan yon e case , wha t I'v e go t her e i s thi s j • i 

### ! . . I 8 jjmich t P e a nindividual , o f particula r individua l value , fo r ' i i ' li : 

### 9 variabl e1 a t

sit e1 an dh emigh t b ealittl ebi t

belo w th eI I T O mean , bu t whe nmeasure do nth e othe r variable , h e migh t b e a 

### i : nj | littl e bi t abov e it s mean . S o th e individual s withi nth e site s j 

# I . ! migh t var yaroun dth e mea ni na variet yo f ways . j

Well , on e coul dtak e th e collectio no f thes e dat a I an dplo t variabl e 1 agains t variabl e 2 . (pause ) An dher e i s 

### i a nillustratio no f suc ha plot . !

Now , i f yo u coul djus t focu s attentio nfo r th e momen t o nth e dot s tha t ar e plotte dthere , yo u coul dse e tha t th e collectio no f al l th e plotte dpoint s o f variabl e 1 agains t variabl e 2 can , i nfac t presen t a relationshi p tha t migh t b e summarized , b ytha t line . That " kin do f relationshi p i nthi s cas e woul db e largel yth e resul t o f what' s referre dt o a s betwee nsit e correlation . Tha t i s th e fac t tha t thi s clou di s her e an d th e mea nfo r anothe r sit e i s ove r here , an dth e mea n fo r anothe r sit e i s u p here , whe nth e dat a ar e looke da t a s a whole , on e migh t ver ywel l find , a relationshi p suc ha s that . 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 EXECUTIV ECOUR TREPORTER

S (301 ) 565-006 41 2

3 • 4 5

. 5 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6

• 1 7 i

i 1 8 1 9 2 0

' 2 1 2 2 2 3 i

i 2 4 j i i 2 5 1 7

Th e importan t question , however , i s wha t i s th e re lationshi p whe nyo u adjus t fo r sit e o r wha t i s th e withi n

i i sit e relationship . There' s a clou do f point s her e fo r sit e 1

- P.1 8

j j and a clou d o f point s her e "fo r sit e 2 andsit e 3 , andwha t migh t |b e th e relationshi p withi nthos e sites . i t

I t ver yvei l coul db e a relationshi p tha t i s summer- 1 ! j ize d b yhorizonta l line s o r essentiall yn o relationship . j j : 1 That' s on e possibility . ' I " ! : ' j i I t could , b e tha t eac ho f th e relationship s withi nj j th e site s ar e ver ymuc hmimic ' thi s overal l relationship , i i | ' j :whic hwoul d sugges t tha t th e betwee nsit e relationshi p i s th e ;

i i i i sam e a s th e withi nsit e relationshi p an dth e betwee nsit e ' relationship , therefore , i s no t addin qanypotentia l spuriou s i correlatio nt o th e strengt ho f th e relationship . |

Th e important.poin t t o not e i s tha t whateve r ' relationshi p exists , shoul db e see nwithi nsites . Tha t is , it' s th e withi nsit e relationshi p that' s th e onl yrelationshi p that' s th e onl yrelationshi p tha t i s o f an yconcer nher e what

soever . And . thi s i s particularl ya proble mwit hth e HANE S dat a becaus e th e tw o variable s o f interes t here , bloo dlea d and ' bloo d pressur e hav e coinciden t downwar dtempora l trend s durin g th e cours e o f th e study .

On e ma yver ywel l b e a caus e o f another , bu t i f that' s th e case , the ntha t relationshi p shoul dsho wu p withi n sites . S o that' s th e reall yhear t o f th e issu e surroundin g 

# 1 EXECUTIVE COUR T REPORTER S j

(301 ) 565-006 4 |P.1 9

1 1 1 2 1 3 14 1 5 1 6 1 7 1 8 1 9 2 0 21 2 2 2 3 2 4 2 5 th e discussion s tha t hav e take nplac e i nth e las t year . i 2 DR . WESOLOWSKI : Tha t wasn' t pedagogica l dat a there, ' 3 i t wasn' t factua l dat a fro mth e —

DR . PFEIFER : That' s right . That' s jus t t o mak e a 5 poin t an d b ylookin g a t thi s relationship , w e coul d hav e nega- j 6 tiv e relationship s her e i neac hcase , bu t a noveral l positiv e ' 7 relationshi p betwee nsites . There' s a whol e variet yo f things j ! 8 tha t coul d happen , includin g result s wher e thi s relationship , I i 9 yo u hav e reall yn o betwee nsit e relationship , bu t yo u d o hav e 

## I 1 0 a withi nsit e relationship .

That' s als o possible . Bu t th e importan t thin g t o not e i s it' s onl yth e withi nsit e relationshi p that' s o f an d i concer nher e an dth e betwee nsit e relationshi p will " b e th e sam e 

# i thin g i f it' s reall ythere . , 1 Result s o f th e revie wproces s tha t ou r analyse s j i an d result s wer e no t refuted , ne wanalyse s o f Dr . Schwart z and ; I i Dr . Landi s wer e generall yno t comparabl e t o th e publishe d results . The ywer e narro wan d selectiv e analyse s tha t onl yadd

res s a portio no f al l th e result s i ndifferen t age , rac e an d se xgroup s tha t wer e i nth e publishe d papers .

I nsom e cases , ther e wer e differen t mode l term s used . Ther e wer e differen t statistica l approaches . Ther e wer e a variet yo f difference s tha t mad e a fai r compariso nbetwee n wha t wa s publishe d opposit e th e issu e tha t w e raise dver y difficul t t o assess . EXECUTIV E COUR T REPORTER S

(301 ) 565-0.6 4' ] P.2 0 i i ' 1 9 

## i i

; i Th e reviewers , Dr . Royal l an dDr . Ware , acknowledge d t h e importanc e o f th e sit e issue . I nfact , tha t i s n o longe r 3 j j a nissue . I thin keveryon e agreed , excep t perhap s Dr . Schwartz , • j 4 I : tha t site s ar e appropriat e t o contro l for , no t onl vDrs . 

### i ! " " 5 Royal l an d War e bu t other s a s well . A s I mentione dyesterday , i!

. 6 ';Dr . Littl e an dDr . Bradle yassesse dthi s revie wproces s i 7 i j independentl yan dcam e t o thesam e conclusion . j

. | 8 Ther e wer e numerou s question s tha t wer e no t answere d g tha t wer e raise di nth e review s o f Drs . Rovall'an dWare , ques- i 

# ! | ^ j 1 0 ; • tion s concernin g i nsom e case s a ninconsistenc yo f result s nj j betwee nth e analyse s o f Dr . Schwart z an dou r analyse s fo r thos e 

# I' ! 1 2 ; : analyse s tha t wer e somewha t comparable . 1 3 ! j Som e question s a s t o wha t DuPon t di di nparticula r j j j 1 4 ' • cases . Ther e wer e a variet yo f technica l question s tha t wer e

,j .j c Nraise dtha t the ywoul dhav e like dt o have " known , wha t wa s th e : j 1 C i j rea l situatio nher e tha t woul dhav e helpe dthe mbette r asses s [ i .-, j j th e results . i l 1 8 j j The yresponde dtha t th e availabl e analyse s o f Dr . j Schwart z wer e consisten t wit hth e bloo dpressur e bloo dlea d 1 9 2 0 2 1 2 2 2 3 2 4 2 5 association . Tha t i s o f thos e analyse s tha t wer e given , h e presente dadjustmen t sit e coefficient s fo r selecte dgroup s tha t maintaine dstatistica l significance .

B u t th e reviewer s acknowledge dtha t th e magnitud e o f l i ! j j th e coefficien t wa s drasticall yreduce di nth e publishe dpapers , 

### i ji ! j whethe r

the ywer eDr . Schwartz ' analyse s o r DuPont' s analyses. ! EXECUTIV

ECOUR TREPORTER

S (301 ) 565-006 4P.2 1 j 2 0

• , Wha t I woul dlik e t o jus t sho wher e i s a fe wgraph s i j 2 —I hop e tha t show s u p al l righ t —the ykin do f summariz e th e 

### i 3 result s betwee nbloo dlead , bloo d pressur e coefficient s unadiustie d 

### ': '

### i 4 fo r sit e and the nadjusted , fo r site . Now , wha t I've go t here , ;

= jus t o nthi s horizonta l acces s dow nhere , thi s jus t refer s t o

. 5 th e magnitud e o f th e estimate dcoefficient . 7 j S o thi s horizonta l lin e i s th e reference dlin e o f 8 zero . Th e group s tha t I' mlookin g a t i nth e lef t sid e here , 9 ar e th e variou s age , rac e and se xgroup s tha t wer e considered .

• i

, 0 on e v

r a yo r anothe r i nthos e paper s o f Harla nandPirkle . n. ; Th e bar s tha t ar e no t shade dhere , th e block s tha t 1 2 .ar e no t shaded , represen t th e coefficient s unadjuste dfo r site s 13 ! The ' shade d bar s represen t th e magnitud e o f th e coefficient s i

- l 4 j adjuste d fo r site . ' i Thes e horizonta l line s i nher e reflec t a tw o ! 1 5 16 1 7 1 8 1 9 2 0 2 1 2 2 2 3 24 2 5 . ; standar d deviatio no ncertai nintervals , lik e a 9 5 percen t ;confidenc e interval , andon e ca ninterpre t statistica l signi

i jficanc e a t th e L fiv e level , tha t i s i f thi s horizonta l lin e i l ' i intersect s thi s 0 vertica l lin e a t judgmen t o f statistica l significanc e a t th e .0 5 leve l woul d b e made . j • MR . MORGAN : Whyare'th e lengt ho f thos e bar s th e i sam e whe nI trea t th e dat a thi s way , o r whe nI d o i t i nsit e i analyses ? I t strike s m e tha t th e amoun t o f powe r tha t I hav e

: t o ge t a slop e i nanyon e o f these , i s les s tha nth e powe r I j hav e t o ge t a slop e — ther e ar e a se t o f them , s o I' mconfusjed .

EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.2 2

. 6 7 8 9 1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 2 1

DR . PFEIFER : Allright , ther e ar e tw o reason s fo r j l that . I nthi s particula r dat a set , it'turn s ou t tha t ther e i s ii i l j i ver ylittl e confoundin g of , whe nyo u inser t th e sit e term s i n 

# i j I , th e mode l wit hth e othe r term s tha t ar e alread yin'th e model . 

### j j Nov. 7 , th e mor e confoundin g yo u have , th e mor e in

- ; ' flate d th e standar d error s would , be . Ther e i s ver ylittl e | j confounding . i j Th e othe r poin t t o mak e her e i s tha t althoug hthi s j . i • • crao hwa s fo r illustrativ e purposes , i nactua l practic e i f yo u i 

# ' 1 

# i

. j wer e t o plo t th e HANE S data , thes e cloud s ar e s o bi g andthe yj

i l : i j ar e s o overlappin g wit hon e another , tha t yo u don' t se e thi s , ii I !i fin e distinctio nher e whic hwoul d b e consisten t wit hyou r ob

- ' 

### l i 

### • !

. j > ! j servation , thinkin g i t t o b e mor e variability , associate dwit h• 

### i ; 

### ' I ; : th e betwee nsit e coefficients . Right ? Th e unadjuste dcoeffi

- j cients . MR . MORGAN : I'l l dro p i t here . Bu t I —

DR . PFEIFER : Le t m e jus t saytha t i f yo u loo k a t

- - i f thi s horizonta l acces s wa s a bloo dlea daccess , okay , o f th e tota l variabilit yi nbloo d lea dthroughou t th e entir e HANE S study , 8 3 percen t o f it , and tha t i s i nth e blu e report , J8 3 percen t o f i t i s person-to-perso nvariabilit ywithi nsites .

Ari d al l th e res t o f i t i s accounte dfo r inbetwee nI sites , betwee nsite s withi nstrat a andbetwee nstrata . S o wha t i •I' msavin g tha t i nactua l practic e i nth e HANE S data , althoug h

i • • I 'thes e averag e value s her e acros s site s ar e differen t and

EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4i j ''2 2 i j 

### ij • : ; oresen t a colinea r trend , th e cloud s o f thes e point s ar e grossl y { i 2 i-overlapping . An dthat' s th e reaso nfor th e similarit yi nthes e i i 3 j | standar derrors . j j 4 I ; (Pause ) l i 5 , ' Well , a fev ; point s t o mak e here . Tha t th e analyse s

. 6 •; tha t w e di dwer e onl yintende dt o tr yt o tak e th e result s tha t | i 7 I ; wer e i nth e publishe dpapers , tak e th e model s tha t the yarrive d

: i 8 : a t eventuall ytha t identifie dal l th e term s tha t wer e signi

9 ficantl yrelate dt c bloo dpressure , tak e thos e model s o f th e j ii i ! ' I 1 0 j j startin g poin t an dthe nw e adjusted , thos e coefficient s fo r side

nI j effects . j 

### | | 

### i 1 2 j j Th e inten t wa s t o tr yt o com e u p wit ha s fai r a ;

: i ; 1 3 I I compariso na s possibl e withou t introducin g an yothe r wrinkle s j 1 4 ;j i nth e proble mtha t woul dkin do f clou dth e issue . S o we'r e : i j I 1 C j ; tryin g t o replicat e th e analvse s o f th e paper s a s bes t w e can . | i^*.j-- / - - - - i i 1 6 W e di di t bot hunadjuste dan dadjuste ds o tha t what

- 1 7 j eve r difference s migh t exis t i nou r analysi s fro mth e othe r

1 8 j analyses , w e would , b e lookin g a t a fai r compariso no f th e

1 9 adjuste dversu s unadjuste dsituation . An dthat' s wha t i s mos t importan t here .

I f on e wer e t o loo ka t th e result s o f th e diastoli c bloo dpressur e o nwhole , ancfyou'r e jus t lookin g a t thos e re - j 

### i suit s tha t ar e shade di nre dthere , it' s prett yapparen t tha t j 2 0 2 1 2 2 2 3 2 4 2 5 t h e adjuste dcoefficients , tha t there' s n o statistical l signi

i fican t effect . There' s no t eve na consisten t patter ni nthos e

EXECUTIV E COUR T REPORTER S

(301 ) 565-006 4P.2 4 2 3 I 1 i j adjuste dcoefficients . 

# I| 2 Ij I thin kDr . Humprhey s yesterda ymornin g raise dth e 

### i j 3 j j questio nabou t wha t happen s t o th e female s i nth e las t thre e 

## I ' 4 j j group s dow nhere , th e females , th e unadjuste dnumerica l coeffi

j i 5 : ' cieht s wer e al l positive , bu t statisticall yinsignificant . i 5 j 1 au t whe nyo u adjus t fo r them , the y"al l becom e numericall y i. ' 7 j j negative , bu t stil l statisticall yinsignificant . 8 l: There' s on e othe r peculiarit ytha t I'v e note di n i ; 

### 9 Ithes edat atha t ar esomewha t

troublesom ean dIdon'tkno w wha t 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 th e answe r is , i f w e loo ka t th e whit e males , ag e grou p 40-59 , ; iyo use e tha t numerically'i nthi s set , w e hav e th e larges t j i ~ • ibloo dlea dbloo dpressur e coefficient . j ij Ther e ar e tw o group s tha t wer e looked , a t tha t wer e > 

### i ' I i j sor t c f straddle dthi s ag e group . On e i s whit e male s 56-74 , anc i jth e othe r i s whit e male s 21-55 . I

I nbot ho f thos e cases , th e adjuste dcoefficien t ij i s ver ymuc hnea r zer o an d considerabl ydifferen t fro mth e j; coefficien t dow nhere . Now , tha t i s onl ya proble mo r a n inconsistenc yo f th e dat a a s I se e it , becaus e i neac ho f thes e models , th e ag e wa s correcte d fo r —i nothe r words , the yno t onl ylooke d a t particula r ag e subset s o f th e data , bu t ag e woul d i i idetermin e th e mode l a s well . I j S o ag e i s adjuste dwithi nthos e analyse s whil e w e I j ; ar e lookin g a t differen t ag e group s a t th e sam e time . An d i j iiit' s alittl ebi t troublesom etha t thes ecoefficient s - - yo u EXECUTIV

ECOUR TREPORTER

S (301 ) 565-006 4P.2 5 2 4

5

. 6 7 8 9 10 1 1 12 13 14 15 16 17 18 19 2 0 2 1 2 2 2 3 2 4 2 5 woul o thin K tna t th e natur e o f thi s coefficien t woul c D e some - ] ij wher e betwee nth e magnitud e o f thes e two . Bu t it' s somewha t o f • I i a noutlve r fo r th e diastoli c results , a t least . j 

## ' I I don' t kno wwha t tie explanatio nfo r tha t is . j i Dr . Gartside , I think , las t yea r i npubli c comment s t o thi s j Committe e ha d mentione d th e fragilit yo f th e coefficient s c f th e bloo d lead , bloo dpressur e relationship , dependin g o nwha t i sor t o f ag e group s you'r e lookin g at . j ii An d there' s drasti c chance s a s vo u loo k a t differen t 

## | | j jjac e croups . An d mayb e thi s i s anothe r indicatio no f that . I ; ji j j Th e othe r thin g tha t I wan t to poin t ou t her e i s tha t 

# l l I've go t th e unadjuste dresult s her e fo r compariso npurpose s only . Thos e result s ar e reall yno t vali dresults .

There' s n o questio ntha t thes e coefficient s hav e t o b e adjuste d fo r sites , becaus e it' s ver yapparen t fro mthes e result s tha t sites , whe nyou'r e adjustin g fo r site , th e magni

tud e and th e strengt ho f thos e coefficient s chang e dramaticall y The ywoul d no t chang e a t al l i f sit e ha dn o effect .

Bu t the yar e changin g dramatically . S o th e unadjuste d result s ar e no t appropriat e result s t o dra wanyconclusion s j from . j

Now , her e ar e th e correspondin g systoli c bloo dj pressur e result s an dthos e result s ar e a littl e bi t differen t ! tha nth e diastolic . There' s mor e o f a consisten t pattern , i f yo' u wil l fo r male s i nth e adjuste d coefficients .

EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.2 6 2 5 i 1 •; There' s stil l n o patter na t al l fo r female s i n th e i I 2 "adjuste dcoefficients . I nou r analyses , al lo

f th eadjuste d i j 0 I i i coefficient s wer e no t statisticall ydifferen t fro mzero , excep t fo r th e mal e 12-7 4 wher e we'v e jus t achieve dstatistic ; 5 significance .

. 6 . I n thi s case , alludin g t o th e commen t tha t I mad e 7 7 abou t thi s ac e grou p her e opposit e th e whit e male s u p her e 8 an dth e whit e male s ove r here , th e magnitud e o f thi s coefficien t i i 9 doe s fal l somewher e betwee nthos e tw o whic hi s mor e wha t yo uj

. ; i

. ! j 1 0 , : woul dexpec t t o see . i : ' ' i nj ; DR . FRANK : Whe nyo uus e th e ter msite , yo uar e reall y 1 2 ^referrin g t o difference s ir i time , t o sequence , i s lha t correct ? i 1 3 i j DR . PFEIFER : Yes . I' mreferring't o th e PSU' s i n j 1 4 - j particular . Ther e wer e 6 4 PSU' s an dalthoug ha give nsit e j

• i • j ! i 1 5 : l ma yo r give nare a ma yhav e bee nvisited , agai nlate r o n i n th e j

; i ! I j . j 1 C ' ! studv , i t wa s a differen t PSU . S o I' m talkin g abou t th e 6 4 ! I DI - - 1 , Mi i l i 1 7 j | sequentia l visit s tha t wer e mad e acros s th e NHANE S study . I ii 1 8 i j DR

. FRANK

: Wha t i s th espano

f tim einvolved ? 1 9 2 0 I I ' I DR . PFEIFER : Fou r years .

Give ntha t th e result s tha t ar e show nher e i n re d | | an dher e i n red , wer e th e firs t se t o f result s tha t wer e arrive d 2 1 I j a t i n performin g thes e analyses , I thin k mos t statistician s 

## j ! j woul darriv e a t th e conclusio ntha t there' s little , i f any , | evidence , t o suppor t th e bloo dpressur e bloo dlea drelation

2 5 j ! Shi ? - EXECUTIV E COUR T REPORTER S (301 ) 565-006 41 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 P.2 7 2 6 It' s wea k a t best . Mayb e there' s a littl e bi t o f a nindicatio ni nhere , andmayb e mor e wor k andmor e analyse s ar e i norder . Bu t o nth e basi s o f thes e result s alone , ther e i s no t a whol e lo t o f suppor t t o sa ytha t on e ha dth e signifi

j can t blee d lea d bloo d pressur e relationship .

Nov; , ' her e i s a compariso no f th e result s tha t th e reviewers , Dr . War e and Dr . Royall , focuse dthei r attentio no n i ncomparin g th e analyse s o f Dr . Schwart z tha t wer e comparable j let' s say , t o th e analyse s tha t w e did . i I An d th e DuPon t result s her e wer e showno na previou s jchar t and I've go t Dr . Schwartz ' result s her e andher e i nhi s reanalyse s o f th e dat a whe nadjustin g fo r site s a s shown'i nth e

i red . I nth e cas e o f th e diastoli c bloo dpressure , th e adjuste d i i coefficient , a s yo u ca nse e here , i s ver yno nstatisticall y significant , i f yo u will. .

Dr.-Schwart z foun dtha t coefficient , althoug hre duce d considerabl yi nmagnitude , marginall ystatisticall ysig

- j nificant . I nthi s cas e th e sam e sor t o f thin g happene dalthoug h th e coefficient s wer e reduce d i nmagnitude , Dr.Schwart z stil l achieve d margina l statistica l significance .

Th e inconsistenc yo f thes e result s ' her e wer e some wha t troublesom e t o th e reviewers , an dI frankl ydon' t kno w i al l th e reason s whyther e ar e difference s there . An dthat' s j somethin g tha t need s t o b e looke dint o i f thi s issu e i s pur - J sue d mor e completely . j EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.2 8 2 7 I nthi s particula r cas e here , Dr . Schwart z chos e 2 a nag e grou p o f 21-7 4 whic hwa s a nag e grou p tha t wa s no t use d 3 ! i neithe r o f th e publishe d result s o f Harla nan d Schwart z - - Harla nand . Pirkl e an d that' s wh yw e didn' t us e tha t grou p a t all . 5 I don' t kno wwha t woul d hav e turne d ou t ha dw e

7 j don e ou r analyse s ofth e 21-7 4 ag e group . S o that' s on e pos 

### i l 8 i ! sibl e reaso nt o accoun t fo r th e differences , bu t ther e wer e a 9

1 1 1 2 1 3 14 1 5 1 6 1 7 1 8 1 9 fe wothe r possibl e reasons . Ther e ar e difference s i nth e 1 0 j j analyse s tha t migh t accoun t fo r this , and . th e reason s behin d thos e difference s wer e o f concer nt o th e reviewer s an dI thin k nee d t o b e investigated .

Ou r concern s i nthi s proces s i s tha t th e response s o f Dr . Schwart z an d Landi s an d th e review s wer e onl ybase dupo n partia l information . The ydidn' t loo k a t th e broa dscop e o f age , rac e se xgrou p tha t wer e considere d i nth e publishe d papers , an d whe nyo u look ' a t th e tota l picture , w e fee l tha t th e tota l weigh t o f th e evidenc e i s somewha t differen t tha n focusin g i non.on e o r tw o isolate d cases .

EP Aha s interprete d th e revie wincorrectl ya s w e se e it,

- a s supportin g th e result s o f Harla nan d Pirkle . Th e un adjuste d coefficient s ar e wrong . The yar e no t th e correc t one s 2 0 21 2 2 2 3 2 4 2 5 t o us e i ndevelopin g an ysor t o f polic ydecision s o r ris k assess 

### j men t o r anythin g els e a s the yappea r i nthos e publishe dpapers ] i Th e - - again , th e CASA C reviewei s ar e i nsuppor t o f j i i j EXECUTIV ECOUR TREPORTER S j

(301 ) 565-006 4 iP.2 9 jtha t a s wel l a s others , s o I don' t think'there' s an yquestio n 2 there . i i i l 3 j Als o th e reviewer s onl yaddresse d"th e statistica l 4 isignificance , o r nea r statistica l significanc e o f th e result s 

# i ! 5 . an d Dr . Schwartz ' analysi s fo r th e selecte dgroup s wer e a t o r i i 5 j i maintaine d statistica l significance , eve nwhe nadjustin g fo r l i l i 7 j j sites . | | 8 ; : Ther e i s als o th e othe r sid e o f th e issue , a s t o 9 j i th e maqnitud. e o f thos e coefficient s andi t wa s discusse dyeste r 

# l ! ' j T O j j da ymornin g tha t tha t magnitud e doe s impac t o nth e cardi o ! I . nj , vascula r ris k assessmen t tha t i s par t o f th e addenduma s i t no w i i ! j i 

### 1 2j lstands . 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 Th e EP Amad e n o attemp t a t follow-u p t o answer'th e j i * i i • j question s raised , byth e reviewers , question s tha t coul dhav e ! bee nanswered , som e o f the mcoul dhav e bee nanswere dver y| quickl ywit ha

- phon e call . Th e EP Aan dreviewer s hav e take nth e poin t o f vie wtha t th e burde no f proo f a s I' mdemonstrating , n o association .

Table s 1 an d 2 ar e jus t th e table s tha t giv e th e numerica l result s o f th e firs t tw o graph s tha t I've showed . Tha t i s thos e publishe d paper s purpor t t o sho wtha t ther e i s a significan t bloo d lea d bloo d pressur e relationship .

Give ntha t thos e result s ar e wrong , on e i s no t i n th e mode , a s I se e it , i ntryin g t o dispel l a significan t relationship , th e burde no f proo f i s no t o ndispellin g it . EXECUTIVE COUR T REPORTER S

(2.1 ) 5.5-006 4P.3 0

TIS b 7

8 9 1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 2 9 Th e burde no f proo f i s o ndemonstratin g it .

S o focusin g o nthos e tw o paper s alone , i t seem s t o m e tha t th e presen t stat e o f understandin g o f whethe r ther e i s a significan t relationshi p o r not , remain s t o b e a nope n j. question . We'v e go t som e prett ystron g result s her e tha t indi- , j 1 ( I j cat e tha t ther e i s n o relationship , a t leas t amon g th e i HANE S dat a a s we"se e it . J

Mor e analyse s hav e t o b e done , I think , t o full y resolv e tha t questio nthough . Th e cardiovascula r ris k assess- I ! i men t ^resume s causa l effec t o f lea d andbase do nincorrec t esti



### j : 

### •| ! ; mates . I alread ysai dthat . Th e relationshi p ha s no t eve n; I i ; I I bee nestablishe da s yet . • | •! j Th e fina l thin g her e tha t distresse d m e t o som e j 

# ii exten t wa s tha t w e wer e no t eve ninclude di ntni s revie wpro - I 

### j cess , an d withou t a doubt , th e revie wproces s woul dhav e bee n| fa r mor e productiv e ha d w e bee ninvolve di nth e revie wand give nth e chanc e t o answe r question s o f th e reviewer s andge t t o th e hear t o f th e issue .

A s I se e i t righ t now , I don' t kno wa s i f anymor e i s understoo d abou t th e bloo dlead , bloo dpressur e relationshi p tod-a ytha ni t wa s 1 0 month s ag o a t th e las t CASA C meeting . Ther e wer e a variet yo f technica l issue s tha t wer e raise di n th e reviewer' s comments .

I'l l b e happ yt o answe r anyquestion s afterwards . I don' t reall ywan t t o ge t int o a lo t o f detai l o ntha t unles s EXECUTIVE COUR T REPORTER S

(301 ) 565-0.6 4P.3 1 l l 3 0 , I ; j 1 : vo u wan t m e to . Bu t there' s on e thin g tha t I d o wan t t o Poin t 1 1 2 i cu t her e i s tha t thi s us e o f site s i nadjustmen t o f blood , lead , I j bloo d pressur e coefficient , I sai d befor e tha t i f a relation

shi p i s there , i t shoul d b e presen t whe nadjustin g fo r sites .

An d Tabl e 4 i nth e handout , I racke d u p th e result s

. 6 7 8 9 1 0 1 1 1 2 1 3 14 1 5 1 6 1 7 1 8 1 9 2 0 21 2 2 2 3 2 4 2 5 I o f tw o blood , pressur e correlate s tha t fro mwha t I'v e rea di nth e literature , apparentl yar e well-establishe d correlates , ag e j

an d bod ymas s index . An d thes e ar e take nfro mth e analyse s j tha t th e blood , pressure , bloo d lea d result s wer e base dupo nan d j show nearlier .

And . I thin k wha t you'r e seein g her e i s remarkabl e j consistency , whethe r you'r e adjustin g fo r site s o r you'r e no t I adjustin g fo r sites , i na variet yo f age , rac e an d se xgroup s ; i i nthes e coefficients . The vremai nremarkabl yth e same . . j Site s ha s little , i f any , effec t whatsoeve r o nthos e coeffic

- j i ients , a s woul d b e expecte d t o b e th e cas e i f yo u trul ygo t a j

_ . _

. . i stron g correlat e wit hbloo d pressure . j i i Le t m e wra p u p the nwit hjus t a fe wconclusions . ; Aconsisten t robus t and . statisticall ysignfiican t bloo dlea d bloo d pressur e relationshi p ha s no t bee nestablished .

It' s clea r fro mth e revie wproces s and . independen t review s b ystatistician s Dr . Littl e an d Dr.Bradle ytha t th e coeffiicent s unadjuste d fo r sit e ar e wron g coefficients . Th e i cardiovascula r ris k analysi s tha t i s no wpresente d i nth e adden

du mi s withou t basis . The yar e usin g th e wron g coefficients . ; EXECUTIV E COUR T REPORTER S

(301 ) 565-006 4P.3 2 3 1 Ther e ar e a variet yo f othe r concern s tha t hav e bee n 2 documente d wit hrespec t t o othe r issue s associate dwit htha t I 3 particula r ris k analysis , bu t I' mjus t focusin g her e o nth e co-j

efficien t par t o f it . j

i Ther e i s n o basi s i nth e addendumfo r inclusio nj I o f anyreferenc e t o th e Harla ne t a l andPirkl e e t al , a s I se e i 7 it . Thos e result s ar e misleadin g unles s properl yqualified . j 8 Th e practica l impac t o' f change s o nbloo dpressur e 9 j | du e t o bloo d lead , chances , whe nassumin g causality , ar e exceed ^ l i " | 10 i i ingl ysmall . Exceedingl ysmal l numerically . I' mno t i na posi

tio nt o judg e th e medica l o r th e practica l effect , bu t le t m e j jus t "defe r t o Tabl e 3 whic hi s als o i nth e handou t t o giv e on e , a nide a o f wha t we'r e talkin g abou t wit hrespec t t o th e magni

- \ tud e o f th e chang e i nbloo d pressur e fo r a give n"change i nbloo d 

## i lead . | i Wha t I've get'her e i s a numbe r o f scenario s andher e a variet yo f value s o f th e bloo d pressur e lo g bloo dlea dcoef

ficien t tha t cove r th e _ange o f value s tha t hav e bee nshow ni nth e 

# i literature . Ove r here , we'v e go t —suppos e on e start s ou t wit h a bloo d lea d valu e o f 1 5 microgram s pe r decilite r andtha t bloo d lea d valu e drop s Xmicrograms ? Suppos e i t drop s 5 micro

grams ? I nothe r words , i t goe s dow nt o 10 . j

I f we'r e usin g a coefficien t o f 2 , let' s say , th e impac t o nbloo d pressur e i s .8 1 milimeter s o f mercury . j That' s th e siz e o f th e numerica l effec t tha t we'r e dealin g wit h 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5

EXECUTIV ECOUR TREPORTER S (301 ) 565-006 4P.3 3 

# - T !• ; 

## i' i i •j •, " here . An d yo u ca nloo k ove r th e tabl e a s wel l a s I ca nandi 

# I 

# I 2 ; yo u ca nasses s th e relativ e importanc e o f that . 3 ! I t appear s t o m e tha t thes e number s ar e prett ysmall , j 4 especiall ywhe nthere' s s o muc huncertaint ysurroundin g th e i 5 stabilit yo f th e coefficien t i nth e firs t place . Bu t fo r th e j

c rane e Tha t ha s bee ntalke d abou t here , i t seem s t o m e tha t a i j

- 5 microgra m

pe r decilite r dro p o f bloo dlea dfro meithe r 1 5 j

i 5 o r frc ma startin g poin t o f 20 , produce s a dro p i nbloo d- o pressur e o f somethin g o nth e orde r o f 1 milimete r o f mercury . i

DR . ROWE : Whic hmode l ar e those ? , i DR . PFEIFER : Thi s i s onl ybase d upo nth e coefficient , it' s th e relationshi p tha t blood , pressur e equal s th e coefficien t

' • i ! time s lo c bloo d lead . The nth e fina l statemen t i s tha t CASA C 10 1 1 1 2 1 3 1 4 1 5 16 1 7 18 I mus t determin e th e scientifi c valu e c f th e entir e discussio nj o f lea d effects , th e cardiovascula r functio nthat' s presentl yj I ; i nth e addendum , withou t soli dsuppor t fro mth e reporte dresult s I o f Harla nand . Pirkle . !

Tha t questio nbeg s th e point , i s ho wcritica l ar e Q thos e result s o f Harla nand Pirkl e i nou r presen t stat e o f know

- •ledge ? Th e wa yI se e i t righ t now , ther e i s n o suppor t fro m .thos e paper s withou t a t leas t additiona l wor k t o tr yt o recon 2 1 : • - : cil e som e o f th e difference s andsom e o f th e reason s fo r th e 2 2 fraqilit vi nthes e coefficients , dependin g uoo nho wyo u analyz e 2 3 : th e data , dependin g o nwha t term s vo u includ e i nth e mode l and; 2 4 - I i i s o o nan d s o forth . Than k vo u fo r vou r time . ! 2 5 - i EXECUTIV ECOUR TREPORTER S

(301 ) 5.5-0.6 4P.3 4

1 . . QUESTION S AN D REMARK S i i 2 MR . NOLL : I bea t u p o nDr . Schwart z yesterday . 3 i i Tcca yca nI bea t u p o nyo u a littl e bit ? Yo u sai dtw o thing s j l 4 ! : tha t I woul d lik e t o quarre l with . 5 ' "Th e firs t i s tha t th e result s sho wtha t sit e ha s

6 V neffect . An d th e secon di s tha t th e instabilit yo f th e co 7 j; e f f icients , tha t necessaril yundermine s th e ide a o f th e causa l 8 ', relationship . a An d i t seem s t o m e tha t bot ho f thos e conclusion s 1 0 i i 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 'acai nflo wfro m exactl yth e sam e poin t I wa s makin g yesterday , : j whic hi s th e implici t presuppositio no f independenc e whic hi s \ 

### j i 

### i I'no t true . W e kno wthere' s a stron g correlatio nbetwee nsit e j

! ! • i ; and lead . An d consequently , th e estimate s o f th e coefficient , j ; V-"he nyc u hav e bot hvariable s i nth e model , i s goin g t o b e un 

# i l 

# I l ; Giase d bu t inefficient , andth e calculate dstandar ddeviation s j o f th e coefficien t ar e goin g t o b e overestimate s o f th e tru e jstandar d deviation . i i j W e kno wtha t hypothesi s test s o f th e kin dyo u per forme d i na mode l i nv.'hic hth e independen t variable s ar e highl y correlate d ar e no t goin g t o b e particularl yilluminating . An d moreover , i t seem s t o m e tha t I' msur e tha t yo u jus t sor t o f misspoke . Yo u don' t reall ybeliev e tha t movin g fro mDubuqu e t o Keoko k pe r s e i s th e caus e o f th e differenc e i nmea nbloo d ^'pressure . I t ha s t o d o wit hsomethin g else . EXECUTIVE COUR T REPORTER S

(5.! ) 565-006 4• 6 7 8 9 1 0 1 1 1 2 1 3 P..3 5 3 4 I t ha s t o d o wit hth e - - DR . PFEIFER : I' mno t sayin g tha t a t all . I' msay- I in g tha t tha t kin d o f mov e ca naddspuriou s correlatio nint o th e - - results . i j MR . NOLL : Bu t i t isn' t reall yth e sit e that' s caus 4 inc . It' s somethin g els e that' s immeasurable . Sit e i s a n instrumen t fo r othe r variables . j

i j DR . PFEIFER : That' s right . Puttin g sit e effect s ;

1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 i nth e mode l i s onl vaddressin qwhateve r difference s exis t ;

# I I betwee nsites . S o the yca nb e tim e relate do r anythin g else . i j 1 MR . NOLL : Right . Bu t th e cor e poin t i s a s follows : i •and tha t i s that'ther e ar e thes e unmeasure dvariable s ou t ther e i . I i i |fo r whic hsit e i s a ninstrument . Essentia l cor e question , i t j 

# I ' ! 4 J seem. s t o me , i s whethe r ther e i s interactio neffec t betwee n thos e variable s an damon g themselve s o r betwee nanyon e o f the m and lead . I f indeed , ther e i s interactio neffect , that' s - - the nit' s eve na wors e proble mbecaus e an yattemp t t o parce l ou t th e bloo d pressur e effec t amon g thes e independen t variable s wil l b e inherentl yimpossible . I nothe r words , th e existenc e oi ' interactio neffect s make s i t impossibl e t o procee dstatistic

all ysolel yo nth e basi s o f individua l coefficien t estiamte s a s th e indicato r o f wha t th e tru e causa l relationshi p is .

Wha t strike s m e i s tha t jus t lik e I sai dyesterday , j th e basi c modelin g strateg yher e o f testin g specifi c coefficient s EXECUTIVE COUR T REPORTER S

{j-'-J 565-006 4P.3 6

I • c o f specifi c variables'i na multi-varian t regression , i s jus t j j wrong . It' s jus t no t th e righ t method . j

DR . PFEIFER : I don' t kno wwher e t o star t bu t le t me | 4 tak e a crac k a t som e o f it . Firs t o f all , you'r e startin g from ' 

# I , 5 j j th e presumptio ntha t there' s a lo t o f correlatio namon g th e I j i I : 5 jvariable s tha t hav e bee nconsidere dher e i nthes e analyses . i i 7 i Tha t ha s als o bee nexpressed , b ya variet yo f othe r peopl e . I 7 , . . . . _| 8 I including , I think , i t i s eve ni nth e pape r b yHarla ne t al . 9 I I An di f indee dther e i s a hig hdegre e o f correlatio n' 

## | i 1 0 j | amon g th e predicte r variable s includin g sites , the nwha t yo u i ! 1 1 1 2 1 3 14 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 sa yi s ver ytru e an di t make s th e interpretatio no f th e result s o f multi-variabl e regressio nprocedur e ver ydifficul t indeed . Bu t you'r e speakin g t o th e qualit yo f th e dat a themselves .

An di f th e qualit yo f th e dat a d o no t len dthem

selve s t o properl yseparatin g ou t thes e effects , the nit' s I i i goin g t o b e ver ydifficul t indee dt o d o an yanalysi s t o separat e the m out . Now , le t m e com e bac k t o you r - - i

MR . NOLL : It' s no t a dat a problem . DR . PFEIFER : Oh , ye s i t is . MR . NOLL : Look , i f there' s a join t cause , i f th e independen t effec t o f Aplu s th e independen t effec t o f B , ar e jus t becaus e th e wa yth e worl dworks , les s tha nth e su mo f th e i i two , the nther e i s n o dat a solution . It' s a modelin g solution , j

Ther e i s n o - - i f i t reall yi s tru e ther e ar e causa l interactio neffect s amon g independen t variables , w e alread y EXECUTIV E COUR T REPORTER S

(301 ) 565-0.6 4P.3 7 i '.kno w- - w e alread ykno wthere' s significan t correlatio namon g 2 • th e independen t variable s becaus e tha t is , i nfact , wha t i j 3 j | tn e regressio nresult s sho wb yhavin g th e coefficient s b e j i 

## i! 4 . : unstabl e wit hrespec t t o specification . 

# i i 5 That' s wha t i t shows . W e kno wthere' s correlation . 5 • , W e don' t kno wwhethe r it' s causal . W e don' t kno wwhethe r - - 

### i i 7 j j that' s th e problem . 8 '•' DR . PFEIFER : I' mno t disputin g wha t you'r e saying , 9 bu t w e ar e i na dat a mod e here , an dw e hav e go t t o dea l wit h

i i 1 0 jth e dat a i na nimpirica l analysis . N o impirica l analysi s i ; 11 j . addresse s th e causa l issue . i i ni l Tha t ha s t o b e addresse dexternall vrathe r tha n i i i j 1 3 : j medically , biologicall yan d s o fort hconcerns . Okay ? Le t m e 1 4 : j com e bac kt o thi s correlation , becaus e I thin kyou'r e leavin g

' j i j 1 C th e wron qimoression . I D 16 1 7 The

- correlatio namon g th e variou s predicte r variable s i nth e model , eve nwhe nyo u pu t sid e effect s i nthere , i s ver y

1 D! ! ver vsmall , muc hsmalle r tha neve nI woul dhav e believe dcive n 1 0 i --

-" 1 9 2 0 21 2 2 i i th e siz e o f thi s dat a se t an d th e numbe r o f covariant s tha t ar e i nthere .

Now , I mad e som e comment s fro m th e bac k "o f th e roo m I vesterda vaddressin g thi s issue . Thes e ar e wha t ar e calle d varianc e inflatio nfactor s an d the yar e statistica l measure s 2 3 ji J I o f th e multi-collinearit ypresent . 2 4 v~ 2 5 j Th e value s o f thes e factor s shoul db e on e unde r a i EXECUTIV ECOUR TREPORTER S j

(301 ) 565-006 4 iP.3 8 i situatio nwher e al l th e dat a ar e independent . Al l th e predicto r 2 I variable s ar e independen t o f on e another . 

# I 3 j Th e degre e o f multi-colliriearit yi s measure db yho w i j muc habov e on e thos e number s are . Now , w e ar e lookin g a t num - j 5 j j ber s . comparin g th e regression s tha t wer e show nearlie r withou t i i i

- i sit e effect s an dwit hsit e effect s fo r fou r ke yvariables , i 7 ' bloo dlea dincluded . 8 i . Th e impac t o f puttin g sit e term s i nther e ha s ver y 9 1 0 1 1 1 2 1 3 14 I 1 5 1 6 1 7 1 8 1 9 2 0 21 2 2 2 3 2 4 2 5 : ver ysmal l confoundin g impac t o nan yo f th e othe r variables . j l j I MR . NOLL : Al l tha t sav s i s tha t th e interdependenc e i . . _. j tha t exist s i s betwee nlea dan dsite . Firs t o f all , - - •

i l j ! • DR . PFEIFER : No , i t doe s no t sa ythat . That' s th e I ! wron g conclusion . j j . | j MR . NOLL : Th e righ t wa yt o presen t thi s informatio n i s t o presen t th e whol e covarianc e matrix . No t t o presen t thi s I i nsingl e statistics . j

I mean , I - - DR . PFEIFER : Thi s i s a statisti c fro mth e whol e variance , covarianc e matrix .

MR . NOLL : Bu t wha t on e woul dlik e t o se e i s th e whol e covarianc e matrix . Bu t th e poin t I' mmakin g i s no t in

consisten t wit hwha t you'r e saying .

Wha t i t say s is , w e kno wtha t there'i s - - wha t yo uhav e demonstrate dconvincingl yi s tha t there' s a stron g correlatio nbetwee nth e sit e an dth e lead . That' s wha t you'v e

EXECUTIV E COUR T REPORTER S

(i-i ) 565-036 4. 6 7 8 9 1 0 1 1 1 2 1 3 14 1 5 1 6 1 7 1 8 1 9 2 0 21 2 2 2 3 2 4 2 5 P.3 9 3 8 , cemonsT-rateo: . j i j DR.PFEIFER : I thin k we'r e mayb e usin g th e ter mI correlatio ni ndifferen t way s an d that' s wher e ou r proble mi s

M.R . NOLL : It ' s no t - - j i DR . PFEIFER : Wha t I hav e demonstrate d is , tha t the ! i betwee nsit e relationshi p impact s greatl yo nth e resultin g j j bloo d pressure , bloo d lea d relationship . j

MR . NOLL : I f yo u wer e t o ru na regressio nwhic hwas | ! t o predic t a person' s lea d conten t o f blood , wit hth e independ

en t variabl e bein g th e sites , yo u woul d fin d tha t yo u woul db e abl e t o predic t i t wit h— th e F tes t o ntha t equatio nwoul d

sa ytha t th e equatio nexplaine d something .

I t woul d b e tha t th e equatio nitsel f "hadstatistica l 

## I explanator ypowers . That' s reall ywha t you'r e showinct .

I f yo u wer e t o ru ntha t regression , yo u woul dfin d• i i tha t vo u coul d predic t lea d i nbloo d beyon d th e leve l o f ; 

## I randomnes s b ysimpl yrunnin g a regressiono nth e 6 4 sit e | dummy , o r 6 3 plu s a nintercept .

DR . PFEIFER : Sure . MR . NOLL : Al l right , an d that' s wha t cause s th e problem . Tha t —the nth e nex t ste p ha s t o b e t o figur e ou t wh ycausall ythat' s so , an d i t coul d b e becaus e th e lea dco - j efficien t i na regressio nwithou t th e sites , i s pickin g u p j site-specifi c effect s othe r tha nlead , o r i t coul d b e tha t th e non-linearit yi nth e relationshi p betwee nbloo d pressur e

EXECUTIV E COUR T REPORTER S

(30! ) 565-0J6 4i i 1 i 2 

### j 

# 3 J

1 4 1 • " 3 9 , ' | 

### lead i s causing the sit e variable s t o expres s par t o f tha t j i 

### non-linearit yan

d therefore , destroythe linea r coefficien t o n' lead , i nth e bloo d pressur e equation .

And . eithe r one o f thos e i s equall yplausibl e an d wit h

- 5 cu ~ an yfurther'information . You'r e absolutel yright , i norde r j i i

_ & 't o decid e whic ho f thos e tw o i s true , yo u hav e t o hav e som e sor t • i . I 7 ;jc f ide a abou t causality , an d yo u can' t prov e causalit yon e wa yj ii • 8 V r th e other . o i . Yc u don' t kno wwhethe r th e reaso ntha t th e sit e 

## j i ^variable s destro yth e lea d coefficien t i nth e regressio ni s be

I j : ; caus e o f th e non-linearit yeffect , th e interactio neffec t o r 

# i i ^becaus e th e sit e i s i nfact , th e tru e caus e an d lea disn't . 1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 li t could , bean yo f thos e an d it' s al l equall vlikel ywithou t

i _ • _ . _ . i i 

## i v

## , . _

, ' •'-urthe r information . i

DR . PFEIFER : You r poin t i s wel l taken . Ther e I i i coul d b e som e reason s i nher e a s t o wh ytha t occurs . Bu t i t j i l Ijals o could , b e th e cas e tha t whateve r th e reason s fo r difference' s | ' | jbetwee nlead , the ycoul d b e mainl ysummarize d jus t b yth e fac t j tha t thes e measurement s wer e take nsequentiall yove r time .

M yjudgmen t i s tha t th e kind s o f explanation s tha t they'r e lookin g for , tha t I thin k ar e appropriat e t o investi

jjcat e b yth e way , I' mno t denyin g that , ar e goin g t o hav e ver y ij " i r.ir.o r effect s o nth e coefficien t i f an ya t all . An d th e bi g ; j I ! effec t i s jus t th e sequentia l natur e o f th e sampling . ii i ! i j M.R

. MORGAN: What' s tha t judgmen t

base don ? EXECUTIV

ECOUR TREPORTER

S (3.: ) 56;-..>6 4P.4 1

. 6 7 8

1 1 1 2 1 3 14 15 1 6 17 1 8 1 9 2 0 21 2 2 2 3 2 4 2 5 4 0 ,

DR . PFEIFER : M yimpirica l experience , i ndealin g j .wit hthes e kind s o f larg e dat a sets . Whe nyo u se e suc ha j i [dramati c tempora l tren di nbot hvariable s tha t you'r e correia



## I itin c here , le t

m ejus t tur nth ecloc k

back . i j j Whe nI rea dthos e paper s fo r th e ver yfirs t time , a j jlittl e ove r a yea r aqo , I looke dthroug hther e an dI trie dt o i i i jfin dwher e the yhav e accounted , fo r the'tempora l trend . I nth e j iKarla npaper , the yallude dt o i t a s a proble man dlooke da t i t 

### i l |li nfou r individua l vea r groups . i j I sai dwell , a s a firs t step , i' mjus t goin g t o se e 

## i i jji f there' s a bloo dpressur e trend . I alread ykno wtha t there' s , iibloo dlea dtren di nth e data , an dther e was . : i ' 

### jj j l An d wit htha t then , I wen t int o th e analysi s t o se e i ho wmuc hwhe nadjustin g fo r sites , change s tha t coefficient . An di t changed , i t dramatically .

MR . NOLL : O nth e tabl e yo u showe du s regardin g th e resul t fo r systoli c bloo dpressure , th e - - on e o f th e thing s tha t isn' t don e i s th e tes t o f th e hypothesi s tha t accountin g fo r th e sites , statisticall ysignificantl ychange s th e valu e o f th e coefficien t whic hi s a differen t hypothesi s tes t tha nwhet h they'r e differen t fro mzero .

Unfortunately , yo u can' t tel l fro meyeballing , wha t tha t tes t is , becaus e i t require s takin g a coun t o f covarianc e j j terms . Bu t m yroug horde r gues s woul db e wherea s th e correcte d i coefficient s ar e usuall vno t statisticall vsianificantl v|

EXECUTIV E COUR T REPORTER S

(i.i ) 565-006 4 e r1

2 3 P.4 2 

### 4 1 , I differen t fro mzero , they'r e als o no t statisticall ysignificantl y differen t fro mwha t the ywer e befor e th e - - i nth e othe r esti- j j mate . I t woul db e nic e t o kno wwha t th e fact s wer e i ntha t 5 : j cas e an d th e secon dpoin t is , I' mintrigue db yth e fac t tha t i 

### i i 

### " I l i

• 6 I j ~ ~ wha t correction s wer e undertake no r wha t attempt s wer e mad e j

7 t o correc t .fo r th e fac t tha t th e T statisti c i na nequatio nj 8 j v/ithmulti-collinearit yi s inefficien t t o begi nv/ith . 9 j i DR . PFEIFER : Al l rioht , le t m e addres s th e firs t l 

# " I i i 1 0 j j question . Th e hypothesi s tha t th e chang e i nth e coefficien t

njvalu e fro munadjuste dt o adjusted , wa s certainl yno t done . j 

## i i ! 1 2 j | Certainly , ther e ar e statistica l technique s tha t coul dd o that . 1 3 I 1 4 I i I 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 M ypoin t o f vie wi s it' s irrelevant . I t doesn' t I mak e an ydifference . Unadjuste dcoefficient s ar e no t o f an y, value . The yar e no t useful . The yar e jus t numbers . I i We'v e demonstrated , her e tha t b yadjustin g fo r sites, 1 yo uar e dramaticall ychangin g th e coefficients . That' s th e onl y j thin g tha t i s importan t righ t now , a s a firs t ste p unti l furthe r analyse s ar e don e t o tr yt o addres s som e o f th e causa l - -

MR . NOLL : I woul dsa ytha t th e issue , di d the y i I dramaticall ychang e th e coefficien t i s somethin g that' s suscep tibl e t o statistica l test . Yo u asser t the ydramaticall ychang e them , bu t th e wa yt o bac k u p tha t assertio ni s t o sho wtha t • the ywer e i nfact , statisticall ysignificantl ydifferen t fro mj jeac hother . 

### EXECUTIV E COUR T REPORTERS (301 ) 565-..". -P.4 3

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2 3 4

.. . . 5

. 6 7 8 9 10 1 1 12 1 3 • 1 4 I

1 5 

# I 1 6 j

i I i 1 7 

## I i 1 8 j 1 9 • 2 0

' 2 1 i 2 2 j 1 2 3 | 2 4 ! 2 5 1 1 j I i ' " i - i I 4 2 , i I J

DR . PFEIFER : Doin c tha t presume s tha t there' s som e ! i va_u e mth e unadjuste d coefficient s t o begi nwith . i ; ; 

### ; 1

MR . NOLL : No . • i i | ! I i ;

.DR . PFEIFER : Yes , i t does . j ; j

MR.NOLL : Yo u hav e asserte d tha t they'r e differen t • frc meachother . Tha t i s statistica l hypothesi s whic hyo u fai l

"C O LSSL . i

DR . PFEIFER : W e ca ncertainl yd o that . I hav e no t

• con e tha t a s yo u ca nsee . Al l tha t I trie dt o d o i s t o loo k ! j j a r th e publishe dresult s and . tryt o d o thos e analyse s a s ;

: closel ya s possibl e s o w e ca ncompar e apple s t o apples , bu t i '• 1 adjus t t o sites . ; j • i 1 1 ME, . NOLL : I thin k we'v e probabl yexhauste dth e issue s

* • i

, u. n^. - T

- ' o c na o. . CHAIRMANLIPPMANN : Ar e ther e anyothe r member s o f | th e pane l tha t hav e question s fo r Dr . Pfeifer ? ' ! I DR . HUMPHREYS : I t doe s loo k a s i f ther e isn' t ver y muc hoverla p i nth e competenc e interva l fo r th e male s an dfe

male s i nsomethin g - - i nsevera l cases . (pause )

CHAIRMANLIPPMAN : Dr . Schwartz , a shor t comment ? DR . SCHWARTZ : Yes , I hav e a comment . Firs t o f all , i nrespons e t o you r questio nabou t sit e predictin g bloo dlead, j i that' s somethin g tha t - - bu t gasolin e lea dwhic hals o ha s j tim e tren d durin c th e period , happen s t o b e th e sam e tim e tren d

" j a s bloo d lead , ha s a nF valu e o f abou t 12 2 o npredicte d bloo dj

l 1 1 I EXECUTIVE COUR T REPORTER S j

(i.l ) 565-006 4 jP.4 4 4 3 i j : • lead . Bu t whe nyou , pu t 6 4 site s int o th e equation , 6 4 pseudo

- j 2 samplin g whic har e no t sites , whic hdi dno t d o i nthei r rejecte d j 3 ' analysi s o f th e ca s lea dbloo dlea dissue , ti i a t explain s wha t

- gasolin e lea ddi di f yo utoo kou t al l o f th e tim e trends . I

i 5 And . sqI haven' t don e tha t testin g ye t o nthos e 5 site s an di t wil l b e somethin g o nth e orde r o f 120 . M ybasi c

-, poin t i s tha t ther e i s a differenc e betwee nsit e an dtime . i i c I thin kit' s a ver yimportan t questio nt o say , -loo k : 9 withi nsit e and . se e whethe r yo ugo t th e sam e coefficien t

. ' i •i Gan dZ

shewe dstuf f yesterda ywher e usin g mor e precis e measure s yo f site , actuall ygoin g ou t an dseekin g ou t th e urba nareas , 1 2 the npseudosamplin g unit , ther e wa s ver ylittl e chanq e i nth e 1 3 'coefficien t . I nfac t i nth e mos t precis e on e wher e I ha d6 4 i 1 4 urba narea s plu s a bunc ho f rura l areas , th e coefficien t wen t j I i :u p a little . j

l 6 •' What' s goin g o nher e i s tha t pseudosamplin g i s a j 1 ? ;ver ygoo dprox yfo r tim e i f ther e ar e 6 4 o f them . Now , th e 1J : j tim e structur e o f th e NHANES , again , whic h- - a lon g tim e ag o j j 1 9 bu t yo udidn' t ge t th e opportunit yt o see , i s ther e i s abou t ' i : l a 4 0 percen t dro p i nbloo dlea dove r th e fou r yea r period .

T h e dro p ha dth e followin g moderatel ycomple x contac t —whic hi s tha t ther e v/a s a neve nvariatio nsuper 2 0I i 2 1 ' ' 2 2 ; ' I

„ „ impose do nto p o f a tren dha s a distinc t kin ka t a plac e wher e \ 2 3 ^ i i 'ther e i s a reculator vchanc e i nth e gasolin e lead . I

„ New , th e test s tha t I di dt o loo ka t tim e an dbloo d! 2 5 i EXECUTIV E COUR T REPORTER S

(501 ) 565-0.6 4P.4 5

5

. 6 7 8 9 1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 4 4 lead , bioc d pressure , showe dtha t whe nyo u trie dt o tes t th e significan t differenc e i nth e bloo dlead , bloo dpressur e co efficient , betwee nthos e tw o periods , ther e wa s n c - - .75 . Tha t i s t o saywhe nth e dro p i nblood , lea daccelerate dth e I dro p i nbloo d pressur e accelerated . , i iI Similarly , an d thi s i s i nth e publishe dstuf f fro m | th e - - analysi s and . fro mou r pape r — , whe nyo u looke da t j

' seasons , season s ar e statisticall yinsignifican t whe nlea d i s i nth e picture . S o wha t w e have'is , indee dafte r yo u contro l I fo r site , no t muc heffec t i nth e coefficien t o f lead , bu t

, becaus e there' s a larg e variatio ni nlea dbot hacros s th e four , yea r perio d and seasonall ywithi nit , andsinc e tha t coeffi

cien t i s correlated , wit hbloo dpressure , i f yo u tak e awa yal l • o f tha t content , yo u wil l b e impactin g th e efficienc yo f i estimatin g th e bloo d pressur e relationship . j

Bu t o f course , precisel ywha t CASA C want s t o kno wis t

i bloo d lea d goe s down , wil l bloo dpressur e g o dov/nan d that' s j 

### j precisel ywha t th e tim. e serie s stuf f show s you . An dI d o no t j agre e tha t on e shoul dtak e tim. e ou t o f al l thes e things , tha t that' s completel yirrelevant .

Ther e i s lot s o f tim e serie s dat a that' s not . Yo u wan t t o mak e sur e tha t there' s no t som e othe r covarian t j i i tha t wa s changin g ove r time , andth e stuf f I provided , I showe d tha t i nth e healt hexaminatio nsurve yi nth e '60' s andi nth e : Framingha m

studyi nth e '50's , bloo dpressur e wa s almos t . i

EXECUTIVE COUR T REPORTER S

(5.1 ) 565-J.. 4 jP.4 6

. 6 7 8 9 1 0 1 1 1 2 1 3 14 1 5 1 6 17 1 8 1 9 2 0 21 2 2 2 3 2 4 2 5 HDI 

### I identica l t o mea nblood , pressur e i nHANE S II . I t wa s onl yi nj i HANE S I I wher e thi s tren d starte d downward , an d th e stuf f " I j i di d lookin g a t th e detaile d tim e structur e an d showin g i t was . i

no t jus t a genera l tim e trend , bu t th e fac t tha t bloo dlea d' | , an d bloo d pressur e varie d ver ywel l ove r a comple xtim e pressur e i l " i l i . ! | i tha t I thin k i s prett yconvincin g tha t what' s goin g c ni s tw o I H- i l l j coinciden t tim e frame s tha t ar e s o detaile d an d coinciden t wit h 

### i j eac hother , tha t tha t indee d indicate s tha t on e i s likel yan d j i j i that' s al l yc u ca neve r sa yi nepidemiology , t o b e a causa l 

### j j i' relate d t o th e other . I i An d th e us e o f pseudosamplin g doe s no t indicat e sit e j i |effects . I t indicate s tim e whic hshoul d no t b e removed . ! j CHAIRMA NLIPPMAN : Than k yo u Joe . I thin k yo u j 

### i * | ihav e reemphasize d th e point s you'r e makin g yesterda yan di nj 

## I * | j previou s meeting s and . I thin k thi s Committe e ha s som e ide a now ! i i j j o f wha t th e issue s ar e and . w e appreciat e DuPont' s analysi s an dj | j j th e other s whic hhav e raise d thes e question s an d th e responses j i nth e discussion . i

I would , like , i f I could , t o invit e Dr . Gran t an dj I Jorda nbac k t o th e tabl e t o conside r wit hth e Committe e wha t | 

## I implication s o f al l thi s ar e an d th e use.o f thi s data . j I Than k yo u ver ymuch . j 

### i W e ha d a proposa l vesterda yfro mDr . Ware . I don't j I kno wi f it' s a proposal , bu t h e raised , a possibilit ya t least, } tha t som e furthe r analysi s migh t b e beneficia l i f th e planning ! j EXECUTIV ECOUR TREPORTER S j

(iCl ) 565-..6 4 jP.4 7 j 4 6 1 i o f th e analysi s wer e don e wit hal l thi s inpu t an d s o i t wasn' t

a matte r o f disagreemen t betwee ndat a set s base d o nsom e dif

-

! • I j 3 j j feren t assumption s an d differen t mode l perameter s whic hi s | i 4 | : par t o f ou r difficult vi nreconcilin g this . 

### I I 

### ' i ; 5 j I s EP Aprepare d t o g o tha t on e ste p furthe r t o '

• i \ i 5 j ; resolv e th e technica l uncertaintie s tha t hav e com e ou t o f thes e r 7 j . discussions ?

DR . GRANT : Well , le t m e jus t not e a coupl e o f thing s tha t leav e u s i na bi t o f a difficul t position . j ! I i

, Firs t o f all , I thin k I d o nee d t o respon dt o point s j mad e her e tha t essentiall ysaid , tha t w e ignore d o r exclude dj DuPon t fro mparticipatin g i nth e revie wo r whatever . Quit e j i i ; j I' clearly , thi s issu e wa s discusse d ver yopenl yher e a t th e last ' 

## i i ' I j j meeting , an d DuPon t certainl yha d th e opportunit ya t tha t tim e l i t o provid e inpu t an d the ydid .

W e ha d a quit e extensiv e chang e o f informatio nan d th e comment s fro mthe mtha t wer e i nth e publi c recor dan ds o " 2

• 3

* 5 16 17

* 8 19 2 0 21 2 2 2 3 2 4 2 5 on , eve nprio r t o tha t meeting . W e di d provid e al l o f th e comm.unication s a s note d ther e t o Dr . Royal l an d Dr . War e wh o wer e designate d a s th e individual s her e o nth e Committe e t o hel p sor t thi s ou t further .

An d I though t w e had . mad e i t prett yclea r tha t i n term s o f ECAO' s rol e i nthi s proces s tha t w e wer e availabl e t o jhel p facilitat e an d woul d assis t i na nora l exchang e o f inform a i i tio nan d s o on , an d w e assume d that"i f "furthe r informatio nwas j i i j i EXECUTIV ECOUR TREPORTER S j

(30! ) 565-006 4 jP.4 8 | 1 needed , tha t certainl yth e CASA C reviewer s coul dcontac t u s 2 reaues t ou r assistanc e i nqettin c tha t issu e information , o r i 3 i j tha t the ycertainl ywer e quit e abl e t o contac t Dr . Schwart z i i I j 4 I' o r DuPon t directl vt o ce t mor e information . ; 

### i i 

### " i i i i 5 7 An d i nth e publi c comments , th e blu e boo k o r whatever , •j l ' I 5 i i that' s jus t bee nmentioned , i nfact , DuPon t note s tha t the yj I ; j 7 j j afte r th e meetin g contacte d Dr . War e o r excus e me , Dr . Royall , i 

## I. " I I ; 8 j : o r spok e wit hhi man d indicated , thei r willingnes s t o provid e j mor e informatio no nthei r analyses , t o answe r Question s abou t l! " ; j j them , clarif ywhat' s goin g o ni nterm s o f thei r analyses . j , Eu t tha t the ywer e no t contacte dlater . Ou r impres

- . i • i i sio nafte r al l th e exchang e o f communication s tha t wer e liste d r. J ; i ! her ei nDuPont' s comment s o r presentation , wa s an dbase do nj 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 ith e las t letter s fro mDr . War e an d Dr . Rovall , ou r impressio nj : i i j I wa s tha t althoug hsom e question s remained , tha t the ywer e satis

i i i I jfie d tha t th e Schwart z reanalyses , takin g int o accoun t th e sit e i i i j i adjustment s an ds o forth , did . demonstrat e a significian t asso - I i ' i jciatio nan d s o o nbetwee nbloo dlea dan dbloo dpressure .

Ther e wer e stil l som e question s abou t whyar e ther e difference s betwee nth e specifi c coefficient s an ds o fort h derived , b yDuPon t versu s Schwartz . Bu t i t di dno t see mt o u s tha t tha t represente d wha t seem s no wt o b e a majo r stumblin g poin t o r whatever .

W e di dprocee do nth e basi s o f thei r las t lette r whic hessentiall yw e rea d a s sayin g tha t the ywer e satisfie d EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.4 9

1 2 3

.. .

•

. 6

7 8 g 1 0 11 1 2 1 3 1 4 1 5 1 6 I 1 7

1 8 '• 1 9 2 0 1 • 2 1 ' I 2 2 j 2 3 | 

### ; 4S 

### i j I wit heve ntakin g sit e int o account , significan t association s j I i : wer e demonstrated . An dw e wen t wit htha t i nth e addendum . I

Now , I ma yhav e misunderstoo d wha t the ywer e indica- f

. ' ting , bu t let' s d o g o bac k ove r an drevie wwha t I thin k we'v e i I j hear d here . First , a s fa r a s th e results , eve nafte r adjust

- i i •ment s fo r site , whe nthes e ar e take nint o accoun t i nterm s o f i th e NHANE S data , certainl yth e one s presented , bySchwartz , i ther e ar e stil l significan t association s show na t leas t fo r j th e adul t mal e grou p whic hha s bee nth e majo r focu s o f thi s ! i 1 i discussio nand s o on . i '. And . that' s a t leas t fo r anydiastoli c bloo dpressur e j tha t stil l i s notabl e afte r th e sit e adjustments . An dI thin k -. ; . i 1 i • eve nth e DuPon t reanalyse s tha t the ydi do non e o f th e slide s

: shownthere , th e secon don e o r whatever , wit hth e ba r graphs , ; j stil l show s a prett ysizabl e coefficien t afte r adjustin g fo r j sit e i nthei r analyse s fo r tha t grou p amount . j 

### I . j j Th e nex t poin t is , wha t w e di d no t hea r anythin g i j abou t i nterm s o f th e DuPon t comment s here , wer e an ycomments : o na secon d majo r studywhic hi c als o highlighte di nth e adden

dum . And . tha t i s th e studyo f Pococ k e t al , usin g muc hlarge r jnumber s o f subjects , an d s o forth , wer e writte nquit e clearl y i ij th e Pococ k studyreport s significan t statisticall ysignificant j i | 1 j .association s betwee nbloo dpressure , bloo dlea dandbloo dj i : pressur e an d thos e association s ar e stronges t o r stronge r when j

i i 2 5 j

j j the vinclud e adjustment s fo r site . 1 \ - -a I 1

• EXECUTIVE COUR T REPORTER S j

(30: ) 565-006 4 IP.5 0 Furthermore , th e coefficient s tha t com e ou t o f thos e j analyse s whe nyo u adjus t fo r sit e i nPocock , ar e ver ymuc hi nj th e ballpar k o f th e analyse s o r th e coefficient s tha t com e out j 

# ' l o f th e anlayse s whe nadjuste d fo r sit e a s reporte d b ySchwartz. '

9 1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 5 j Thi s i s noted'i nth e appendice s o r th e addendum . I note di t yesterda yi nm ycomment s an d trie d t o focu s attentio nver y stronglv . i i h | l I hav e no t ve t hear d anvdiscussio no r criticis m 

# | l j l brough t fort htha t ouroort s t o undermin e o r t o destro vi f vo u jv/ill , th e credibilit yo f th e result s obtaine db yPococ k e t al . . ! ; S o let' s b e clear . No t basin g ou r judgmen t i nth e addendum , j ; j wit hregard , to'thi s issue , onl yo nth e NHANE S data .

W e ar e als o takin g int o accoun t th e second , se t o f i j analyses , Pococ k e t al , whic hi nou r vie w"ver ysubstantially , ! i ver yconsistently , come s ou t whe nadjuste dfo r site , prett y\ muc hi nth e sam e directio no f Schwartz ' analyse s whe nadjusted j i j fo r site . j 

### I i W e als o di dno t hea r mentione dher e i nanyo f thes e comments , anyo f th e othe r numbe r o f studies . Thos e byMorea u an d s o forth , severa l othe r one s tha t ar e mentione dhere .

Yesterda yI brough t fort hand provide dt o yo u infor

matio ntha t w e hav e ye t anothe r studyabou t t o appea r fro m Harvar d whic hreport s significan t associatio nanda s Ji mWare j indicated , the yar e i nth e sam e directio na s thos e reporte dby ; i Schwart z and s o forth .

EXECUTIVE COUR T REPORTER S

(501 ) 565-006 4i i P.5 1

" i i I ! 5 0

S o let' s b e clea r o nthi s point . W e ar e no t relyin g onl yo nth e NHANE S data . Tha t i s no t onl yth e onl ybackbone , 

## |i 3 jshal l w e sa yi nquote s here . i i

i 4 i: Ther e ar e no wsevera l differen t studies , som e th i n o 

## I I 5 j lik e a t leas t five,'i f I ca nrecal l correctly , tha t ar e pur - j £ : portin g th e sam e kin do f results , sam e kin do f directio nan d'' 

# f ' \ 7 'is o forth . An d I haven' t hear dan yattemp t o r an yindicatio ntq > ii ! 1 1 . . i 8 ; undermin e o r cal l int o questio nth e credibilit yo f th e analyse s 9 'o f al l th e othe r studies . I 

## li! 1 0i iS o we'r eface dwit habi t o f adifficul t

situatio n i i . i i '• yj j her e i nth e sens e tha t we'r e lookin g a t wha t w e thin k i s a j i : ! • 2 | : prett vconsisten t bod vo f informatio ntha t fro mth e epidemiolog y 

# i i " 

# ! i . I | literatur e tha t ha s com e ou t withi nth e las t fe wyears , tha t 1 4 I j consistentl yshow s statisticall ysignifican t association s be

- i i' ! j j twee nbloo dlea dan dblood , pressur e increases . j

Ther e ar e arauments , ther e ar e point s i nher e tha t I 

## j d o nee d t o b e resolve d further . On e o f the mi s indeed , wha t ar e th e bloo d lea dlevel s a t whic hthes e association s o r thes e increase s occur , an dth e magnitud e o f thos e increase s andall .

Ther e ar e variation s acros s thes e differen t studie s i nterm s o f thos e particula r aspect s o f th e findings . Bu t I thin k a t thi s stage , i t woul db e extremel ydifficul t fo r anyone ' jt o stan d u p an d saytha t ther e doe s no t exis t a rathe r substan

tia l bod yo f literature , epidemiolog yliteratur e tha t point s 1 5 1 6 | j i 1 7 I i 1 8 1 9 2 0 2 1 2 2 2 3 2 4 l ! ^V i nth e directio ntha t ther e ar e association s betwee nbloo dlea d 2 D

EXECUTIVE COUR T REPORTER S (301 ) 565-006 4P.5 2 5 1 1 i an d bloo d pressur e increases . w e ver ymuc hd o appreciat e th e 2 i ! importanc e again , a s I mentione d yesterday , o f tryin g t o ge t 3 j j a resolutio na s t o wha t ar e th e appropriat e coefficient s tha t 4 i 5 migh t b e useful . I thin k tha t prett ymuc hfro mwha t al l I hav e beare d 5 ;• and . th e 'kind s o f input s tha t w e hav e received , bot hfro mCASAC J I - " " i 7 j j fre mth e publi c comments , fro mth e reanalyse s don e b ySchwartz ! ji j 8 ;• and . all , tha t probabl yth e consensu s i s sor t o f closin g togethe r 

## I . j g tha t on e doe s nee d t o us e thos e coefficient s whic hinclud e | i j j TQ jadjustment s fo r site . 11 1 2 1 3 H l i I thin k that' s somethin g tha t prett yconsistentl yj

core s out . Perhap s Joe l disagree s fo r som e reaso nand . s o forth , i bu t overal l th e variou s peopl e tha t I hav e bee nlistenin g to , I

1 5 1 6 1 7 1 8 1 9 1 4 :j statistician s an d others , I thin k tha t come s out . An dwhe nyo u i I i I ;d o us e tnose , yo u the nfin d a prett yconsistent , prett ymuc hj j " j ji nth e sam e ballpar k kin d o f se t o f coefficients , comparin g j | j ihi s stuc vwit hthos e o r hi s reanalvse s wit hthos e o f Pococ k e t i i ' ai . W e d o "hav e a s fa r a s th e matte r o f causalit yan d

s o forth , I thin k agai ni nthi s case , quit e a substantia l bod y

o f literature , an d experimenta l literatur e an d toxicolog yliter

atur e tha t leave s n o questio na t all , tha t lea d can' t caus e increase s i nbloo d pressure . It' s there . I haven' t heard , any i bod ycom e i nan d reall ydisput e tha t o r undermin e th e credibilit y i i o r tnos e stucies . i 2 0 2 1 2 2 2 3 2 4 2 5 I I j EXECUTIV ECOUR TREPORTER S j

(311 ) 565-006 4 i2 3 4 5 P.5 3 5 2 Again , w e com e t o a point , wha t ar e th e level s a t whic hlead , ca nd o that , and wha t i s th e shap e o r for mo f th e relationshi p an ds o forth . An dagain , ther e i s roo mfo r debat e and s o on . Ther e ar e som e indication s tha t w e ma yb e dealin g wit hindeed , a comple xrelationshi p tha t mayb e a U-shape d func 4 tio ntha t i s certainl ynonlinea r fro mal l appearance s ands o i on . j i i

1 1 12 13 1 4 15 16 17 18 1 9 Bu t a t th e ver yleast , i f yo u wil l pu t moderat e I | blood , lea d level s i nth e anima l studies , somethin g i nth e 30-4 0 

## I 10 | o r 5 0 range , a t least'i nthos e areas , it' s wel l established , ! 

### i perhap s a t lowe r levels , we'r e no t sure . | j Again , w e no wcom e t o wha t need s t o b e don e nex t to ; tr yt o resolv e thi s further . An dI di dyesterda yrais e tha t cuestic na s t o jus t ho wclos e w e hav e t o ge t thi s i f —unles s somebod yca nbrin g the mfort ht o me , dat a o r informatio no r evidenc e o r whatever , tha t contradict s wha t I jus t outlined , I a mlef t wit hhavin g t o sayi na revise daddendu mtha t th e associatio nha s bee ndemonstrated , a nepidemiolog yleve l tha t ther e ar e rathe r convicin g anima l toxicolog yresult s that " hel p confir m

that . Tha t ther e ar e plausibl e mechanism s tha t hav e als o bee noutlined .

Now , ho wfa r d o w e nee dt o g o i nnarrowin g downjus t i wha t th e appropriat e coefficient s ar e fro mth e epidemiolog ydata ! I An d I' m

no t sur e ho wmuc hdat a w e nee dt o get . I CHAIRMANLIPPMANN : I thin k i f I ca nparaphras e what i 2 0 2 1 2 2 2 3 2 4 2 5 EXECUTIV ECOUR TREPORTER

S (301 ) 565-006 4P.5 4 5 3

7 i j; Le s ha s jus t tol d us , h e want s u s t o clos e o nth e criteri a

• ! 2 j j documen t addendumand leav e th e remainin g uncertaint yi nBruc e 3 : ; Jordan' s ballpark . I 

## I: ' j 4 i : DR . GRANT : No , I didn' t mea nt o impl ythat . I ; | 5 (laughter ) I' m willin g t o g o th e nex t ste p t o tryt o resolv e j i 5 i t further , i f tha t i s trul ynecessary . I gues s wher e I' ma t and I di d trysom e alternativ e theor yyesterda yandtha t was , j i 8 fo r example , t o tak e th e availabl e coefficient s tha t com e ou t I 9 : o f Pococ k study , fo r example , th e Schwart z study , adjus t i t !

- t 0 fo r sit e an d mak e us e o f thos e coefficients . j

; i yj Ther e i s prett ygoo d agreement . j i ; 1 2 '' CHAIRMANLIPPMANN : I thin k w e hea r you r message . i i ] 13 On e brie f comment , Dr . Col e i s ver yanxiou s t o saysomething , j

, ' • i : ! I 1 4 .An d the nv/e'1 1 ge t som e Committe e discussion . ! 

# '

# I

MR . LYNAM : I' mDo nLynam . I jus t hear dLe s saytha t ther e wa s n o opposition , n o comment s negativ e t o th e paper s | l tha t wer e siane d i nth e addendumandI would , sur e lik e t o cor ijrec t tha t statement .

I thin k perhap s i f Dr . Gran t ha drea dou r comment s tha t w e ha d chose nno t t o commen t verball ya t thi s meeting , bu t 1 5 1 6 1 7 1 8 1 9 2 0 

### i i 

### i j ! t o submi t writte ncomment s t o EP Awhic hw e did. , andw e ha dthes e i 2 2 2 3 2 4 2 5 ; comment s expres s mailed , t o Dr . Grant' s hous e o nSaturda ya t i" • i I hi s recuest , s o tha t h e woul dhav e a nopportunit yt o loo k a t I I" i ii . ' ; : the move r th e weekend , prio r t o th e CASA C meeting . j 

### j | 

### j | Nov.? , obvious yh e hasn' t ha d tim e t o tak e a loo k a t j j : I i - (30! ) 565-006 4 EXECUTIV

ECOUR TREPORTER

S ,P.5 5

T2S a I ! 5 4

i l i j 1 7 thos e comment s becaus e I thin k i f h e woul d loo k an d h e i s ! | 2 \ ci'in g Pococ k and . tha t ther e ha s bee nn o oppositio nt o wha t

; i 3 j l Pococ k says , tha t ma yb e true . l i n 4 j Tn e thin g is , h e ha s no t reall ycite d wha t Pococ k I . i 5 says . An d w e pointe d thi s ou t twic e i nou r comment s an dI woul d

I I i ' I . -o

9 1 0 1 1 12 1 3 14 1 5 1 6 1 7 18 1 9 2 0 21 2 2 2 3 2 4 2 5 ; lik e t o jus t rea d tha t quot e an d thi s i s a direc t quot e fro m i ococ k "Th e associatio ni s ver yweak . Th e stud yi s observation

a l an d i t i s difficul t t o adjus t fo r al l relevan t comfounders . Therefore , i t i s prematur e t o conclud e tha t a nelevate dbod y i lea d burde nha s a causa l influenc e o nblood , pressure. "

Now , that' s fro mth e articl e itself , Les , an dI can j

no t understan d wh yyo u sa ytha t there's.n o opposition . I

DR . GRANT : I di d indicat e Pocock' s conclusion s tha t i . • | ; , h e interpret s the mi nth e directio no r i nthe manne r tha t yo u i' " I i | i'jus t described . An d that' s a tru e fact , tha t h e doe s inter

- ; I pret ythe mtha t way .

Nevertheless , hi s paper s d o sho wstatisticall y significan t association s adjustin g fo r sit e and . thos e coeffi

cient s ar e i nlin e wit hwha t come s ou t o f th e NHANE S adjustment . j fo r site . I ' CHAIRMA NLIPPMANN : I thin k th e Committe e ha s t o j imov e o nt o hi s discussion . Th e questio nI thin k th e Committe e i j jshoul d tr yt o wor k towar d i s whether , i nfact , wha t Le s ha s 'proposed , tha t i s h e feel s tha t th e addendu mi s a statemen t itha t ha s it s uncertaintie s becaus e thes e dat a alwav s hav e thei r EXECUTIV E COUR T REPORTER S

(30! ) 565-006 4P.5 6 - T , D D i j. uncertainty . Myimpressio ni s tha t w e don't , previousl ywit h I 2 ; th e children' s effects , and . w e obviousl ywer e no t completel y 3 i satisfied . W e ha dal l th e dat a w e woul dlik e t o see . 4 j ' Bu t th e questio nis , i s th e addendu ma nadequat e 5 statemen t o f th e literatur e and furthe r refinement s o f th e co 6 ]efficien t probabl ydoe s relat e t o th e ris k assessment s tha t i 7 , ' OAQP S ha s t o do . Bu t i s th e addenduma nadequat e statemen t o f 8 9 10 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 : th e literature , suc htha t i t ca nb e close don ? j

' i i I thin k Elle ni s ver vanxiou s t o saysomething . I

; i i : i j DR . SILBERGELD : Well , I thin k yo u reall ysai dth e j i j . ke yphras e Mort , v/hic hi s tha t w e woul dreall ylik e t o hav e ; ! i l . mor e data . An d I woul dagre e wit hLes , bu t I thin k tha t qive n i i i th e dat a w e have , tha t th e addendumi s anappropriat e expres - • i

• : I I - ' I sio nc f thos e data . j j; I ; I hav e t o saytha t I thin k furthe r tortur e o f th e i j data , v/hich'i s wha t we'r e vergin g on , I don' t thin k resolve s ; thes e issues . It' s goin g t o tak e mor e dat a fro mdifferen t j

, studie s v/hic

hwil l star t t o accumulat e th e informatio no nsuc h J thing s a s th e prope r coefficient s an dho won e take s int o accoun t 

## I "

' ' I i j site . I i I' m no t sur e w e gai nanythin g byredirectin g Le s j I i and hi s staf f an dJoe l t o d o ye t agai nanothe r dat a analysi s i 

### i o f thi s sam e dat a set . W e thin k it' s bee nincredibl ythor

- j oughl yanalyzed .

Appropriat e thing s hav e bee nstate dabou t it , an d

EXECUTIVE COUR T REPORTER S

(301 ) ^iJ-0r-6AP.5 7

1 2 3 4 5

- 6 7 8 9 10 1 1 1 2 . 13 14 1 1 5 1 6 j 

# i 1 7 | 

## i 18 j 

## i



## . . j I 2 0 j 1 1 • 21 j 2 2 j 

## j 2 3 | 

# I 2 4 I 1 2 5 | j 1 I 1 ' • I T• 5 6

• •what' s state d i nterm s o f th e stat e o f knowledg e rich t no wi s j 

# I :appropriate . Th e field , i s goin g t o mov e o nan d w e ca nmak e j recommiendation s fo r furthe r research , bu t I don' t thin k w e ge t i i an yfurthe r b yusin g th e sam e dat a sets .

DR . HAMMOND : I' mno t quit e sur e tha t i s true . An d im vspecifi c questio nt o Le s i s whethe r the yhav e attempted , an y ... . ^ 1 i !segmenta l analvsi s i nth e searc hfo r a threshhol d fo r thes e i j : effect s o nan yse t o f dat a tha t yo u have .

Jus t t o kno wtha t there' s a relationship , an d no t t o i I i . i !b e clea r a s t o wher e th e interactio nbasi s t o b e significant , ; I i i i ji s no t providin g us , I guess , wit hanythin g tha t w e ca ntrans - |

• lat e int o regulatio no r a threshhold . leve l o f acceptabl e blood ;

i ,leade d people . i i i S o I' monl yaskin g yo u whethe r you'v e reall ytake n int o accoun t th e ver yimportan t aspect s tha t yo u com e t o i nth e i en d o f tryingt o fin d th e threshhol d fo r things . • DR . GRANT : Okay , th e questio ni s whethe r m yoffic e

• ha s attempte d t o carr yo nanalyse s o r hav e eithe r othe r part s o f th e Agenc yan d s o o nlookin g fo r a threshhold . i nregar dt o thes e effects , no . I don' t kno wt o wha t exten t Joe l ma yhav e tried , bu t I' d sa y—

DR . SCHWARTZ : Hidde ni non e o f th e bac k paragraphs , w e mentio ntha t w e d o tr yt o fi t function s t o bloo d lead , bloo c pressur e relationships . An d w e di d no t fin d an ythreshhol d withi ntha t —an ylowe r threshhol d withi nth e rang e o f th e

EXECUTIV E COUR T REPORTER S (30! ) 3e.'-..= 4P.5 8 M ' D/ 1 : . data . Ther e ma yb e a nuppe r threshhold , bu t w e don' t hav e 

### ji 2 ! peopl e wit hblood , level s tha t hig ha s w e discusse dearlier . ji 3 ii An da s I said , vesterda vwhe nw e subdivid e bloo dlea d 

# I ' ' ' 4 .-rane e unde r 10 , 10-20 , greate r tha n20 , th e relationshi p wa s ! 

### l l 

### j 5 ' stronger , bot hi ncoefficien t siz e an dsignifican t level s fo r I 6 -unde r 1 0 micrograms . S o i f ther e i s a threshhold , it' s goin g 7 7 t c b e fairl ylow . 8 Now , o nth e othe r hand , w e hav e ver yfe wpeopl e 9 -whos e bloo dlea dlevel s ar e unde r 5 , s o I'don' t wan t t o sa y 1 0 , tha t anythin g muc hi s goin g o nbelo wtha t . Bu t w e di dd o those ,

CHAIRMA NLIPPMANN : Dr . Humphreys ? DR . HUMPHREYS : I thin k tha t Le s misstate dth e pre 1 3 ; sen t natur e o f th e data , i ntha t h e talke dabou t th e relation- , 

### l i 

### ' I 1 4 , : shi p betwee nlea dan dhvpertensio na s i f i t existe dacros s j 

### ! [ ^ ' 

### | 1 5 : ! bot hsexes . An di t look s t o m e a s i f ther e i s i nsevera l case s 1 1 

## i i 1 2 l l : |

16 statisticall ysignifican t differenc e betwee nth e regressio nj

1 7 . ! weight s fo r male s an dfemale s an dI hav e see nn o attemp t o n 1 8 • ! th e par t o f eithe r anyon e involve dher e t o analyz e thi s i n 

# i i i gj th e slightes t degree , an dI a mbothere db ydifference s i ndat a 2 0 2 1 :c r whic hn o on e ha s a nexplanation .

DR . GRANT : I didn' t hea r Le s sa yi t applie d

„ _i | t c females . I f I gav e tha t impression , I apologize . Tha t i s 11 ;i ~ " 2 3 2 4 I i i 2 5 | ne t th e case . ,

Clearly , wha t we'r e talkin g abou t her e ar e acros s severa l studies , significan t associations , bloo dpressure , lea d

EXECUTIV E COUR T REPORTER S

(30! ) 5.5-0-. 4 I

## i i i i nadul t men , middl e age d men . 

# i i 2 : ' CHAIRMA NLIPPMANN : Anybod yels e o nth e pane l hav e j l 3 j j a questio no r commen t here ? Dr . Noll ? i j l 4 : ! DR . NOLL : Thi s i s a genera l poin t o r a specifi c 

## i l 5 , . question . I d o hav e a poin t abou t th e agend a today . j o ; l i

. 5 : i CHAIRMA NLIPPMAN : We'r e trvin c t o com e t o grip s : i l ""-"' , 7 ':'• wit hth e addendu ma t th e moment . I i : j 5 ' DR . NOLL : I thin k th e proble mI hav e i s a s follows : I . * : 9 !j I hav e a ninterna l conflic t here . Par t 1 , i t seem s t o m e tha t • 

## i l i 1 0 J : th e stat e o f statistica l modelin g doesn' t reall ymatc hth e 

### l l 

### ' I nj j theory . I 1 2 I mean , i t seem s t o m e th e righ t wa yt o approac hj 13 l ; analyzin g th e dat a i s whe n—particularl ywhe nyo u kno wtha t j 14 i j ther e i s multipl e cause s an d tha t thev'r e correlated , i s t o i 

## i ! " ' 1 5 I j wor k ou t a theoretica l Qualitativel ytheoretica l understanding ! I S i 16 o f ho wyo u thin k thos e interaction s ough t t o wor k an dthe nt o

1 7 j tes t tha t statistically . I I i g: S o I woul d stat e tha t I thin k tha t i f w e wer e a t 1 9 2 0 21 2 2 2 3 j j 2 4 i i 2 5 I th e beginnin g o f a process , ther e wouT d b e a wa yt o mode l th e statistica l wor k bette r fro mth e standpoin t o f producin g mor e robus t test s o f whethe r ther e i s thi s correlatio nan di f ther e i s one , wha t it' s magnitud e is .

O nth e othe r hand , fro ma decisio ntheoreti c poin t o f view , i t strike s m e tha t th e valu e o f tha t informatio ni s diminimous . I' mno t - - it' s no t clea r t o m e tha t actuall y

i EXECUTIV E COUR T REPORTER S • j

(301 ) 365-006 4 jP.6 0

o i 5 9 , i undertakin g tha t modelin g effor t a t thi s tim e ha s anysignifi

- ' j can t payoff , i npar t becaus e th e rea l variable s tha t underl vi 

## j th e differences , onl yt o PSU , ar e basicall yunavailabl e i nthe ! dat a set , and hence , you'r e stil l stuc k wit hdoin g nothin g but ' 

### j ! 

### ' 5 ; j thi s sillines s o ntim e trend s anddumm vvariables , whic har e i : " " I I ! I 6 j i jus t extremel ycrud e instrument s fo r othe r things . | | - i 7 | j S o I doub t tha t there' s muc hfurthe r ' in f ormatio nt o i 8 ' | b e gaine d 'fro ma decisio ntheoreti c poin t o f view . An dI gues s 9 i i wha t tha t lead s t o i s a conclusio ntha t som e sor t o f statement ' 

## j; j 1 0 , | somewher e i nth e addendumabou t th e natur e o f statistica l nj'testin

g a s it' s proceede dwit hregar dt o lead , I thin k tha t ii ' 1 2 i l th e conclusion s ar e bein g draw ntha t basicall vth e clinica l l l 

### 13 ; j evidenc eha s t o b etake nint o account , that' s absolutel ycor l ! 1 4 jjrect . j i i '

Unfortunately , wha t hint s hav e bee nderive dfor mi

t tha t informatio nhav e basicall ynot , i na ver ysophisticate dj j wa ybee nreflected , i nth e statistica l modelin g byanybody . 

# i 1 8 jAn d I thin k that' s a liabilit ybu t I don' t thin k it' s wort h; curing . j

CHAIRMANLIPPMANN : I s ther e anybodyo nthi s pane l who-feel s tha t th e addendumsubjec t t o cleanin g u p whic hLe s i woul d d o anyway , base d o ncomment s o f thi s transcript , i s no t i I acceptabl e a s a statemen t o f tie scientifi c literatur e o nthi s i issue ? Tim , di d yo u wan t t o saysomething ? •' i

DR . LARSON : Well , Iwoul dprobabl yjus t cavea t

wha t 1 5 1 6 1 7

1 9 2 0 2 1 2 2 2 3 2 4 2 5 EXECUTIV ECOUR TREPORTER

S (30! ) 565-0,5 4P.6 1

. _______ _; -T T, I ! 60 1 

# i sI 1 \ t vc u jus t said , bu t th e wa yi t read s i s tha t you r summar ysay s i 

# I ! 2 j tha r there' s evidenc e fo r stron g associations . An d i nfact , ; l 3 ,j Pccoc k results , amon g others , produc e simila r conclusions .

• i i l

' I 4 Wha t w e jus t hear d thi s befor e thi s wa s tha t th e j 

### i i 

### ! 5 association s ma yb e there , bu t they'r e no t necessaril ystrong. ;

. 5 j DR . HUMPHREYS : They'r e clearl yno t strong .

i ; | 7 I ; DR . LARSON : Bu t that' s wha t i t say s o npag e 6 , an dj

• i 8 • i nth e revie wo f tha t middl e paragraph , i t summarize s al l - - I 9 i : DR . HUMPHREYS : There' s frequentl yconflusio nbetwee n j j i ; . i 1 0 i ; strengt han d statistica l significance . An d th e tw o ar e no t j n| j identical . j l 1 2 ;j DR . LARSON : B yconvincin g evidenc e fo r stron g asso -

' i 1 3 'ciations , furthe r thei r result s ar e consisten t wit hsimila r 1 4 ' ; findings . S o tha t wordin g i s —doesn' t see mt o b e to o - -

1 5 1 . DR . GRANT : Jus t t o b e sure , stron g associatio ni n

1 6 "•'. regar d t o th e Pirkl e Schwart z thin g results , no t necessaril y i ! i ; yj". profile , bu t whe nyo u sa ysimilar , analogous , no t necessaril y

i i 1 8 j j i nstrength . Althoug hwit hth e adjuste d sites , the yar e i nth e 1 9 j j sam e ballpar k a s I said , an d i ntha t case , i f you'r e usin g

• i i I j those , the nit' s no t a s stron g i nth e Pirkl e Schwartz . i j 2 1 j i I agree , ther e need s t o b e adjustmen t i nthi s j -,

_j | terminoloo yhere . j i ! : DR . LARSON : Th e othe r par t o f tha t sentenc e says ,

2 4 | | "an d possibl ydow nt o a s lo wa s 7 microgram s pe r deciliter. " 

# i i

o c il l haven' t hear d an ydiscussio no f that . 2 5 I] EXECUTIV ECOUR TREPORTER

S (30! ) 565-006 4P.6 2 • l " l 6 1 ii j DR . GRANT : Well , jus t t o clarif yv/hvtha t i s there , | | 2 | ; th e analyses , th e NHANE S analyse s include dindividual s mainl y ; i 3 ; | v/it

hbloo d lea dbelo w30 , 40 , whatever , i ntha t ballpark , and• 4 j 1 a s I recall , th e lowe r endo f th e rang e wa s dow nt o 7 , wit hn o 5 .indicatio no f threshhold . 6 And that' s whythe yar e possibl ydownt o tha t leve l

7 j j DR . WESOLOWSKI : Als o th e 7 i s a detectio nlimi t 8 fo r mos t laboratories .

DR . GRANT : Abou t 2 o r 3 . | DR . WESOLOWSKI : Som e hav e a detectio nlimi t o f 4 , i

. , s o yo u hav e t o b e - - that' s on e thin g yo u migh t wan t t o correct . , iBecaus e yo u giv e th e impressio ntha t th e data'i s - - j ". • i 1 DR . GRANT : CDC , thi s study , th e detectio nlimi t wa s • i •i i 7 what , abou t 2 ? : iDR . MAHAFFEY : Abou t 2o r 3 . 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 24 2 5 j lDR . LARSON : Again , tha t wording , wha t

doe s tha t

mean ? i i i l Doe s i t mea ntha t you'r e summarizin g b ysayin g tha t thi s possibl y i i

• j i s stron g associatio ndow nt o tha t level ? It' s possibl yasso ciatio ndow nt o tha t level ?

O r it' s possibl yth e sam e a s th e sam e wea k associa

j tio ntha t you're"dicussing ?

DR . GRANT : Mayb e wha t i t need s t o sayi s essentiall y jtha t whe nadjustin g th e site , there' s evidenc e fo r a nasso - ' l i j ciation , statisticall ysignifican t associatio nfo r dat a acros s i i |th e rang e o f 7-30 , o r i ntha t analysi s whe ncarrie dou t acros s jth e rane e o f 7-3 0 microgram s pe r deciliter . i i | EXECUTIV ECOUR TREPORTER

S I(301 ) 565-.J6 4. 6 7 S 9 1 0 1 1 1 2 1 3 14 1 5 1 6 1 7 1 8 1 9 2 0 21 2 2 2 3 2 4 2 5 P.6 3

! —• | ' 6 2 CHAIRMA NLIPPMANN : Clarif yyou r wording . I 

# I i DR . GRANT : Yeah , I d.o inten d b yth e way , t o tak e I th e recommendation s an d comment s o f th e Committe e an dfo r that ! 

## ' I I matter , th e commen t reall ymterm s o f th e nee d fo r muc hmor e ; | I detaile d clarificatio no f wha t thes e finding s ar e an ds o on , j an d t o brin g the mint o play .

An d th e sam e thin g goe s fo r expandin g i nrelatio n' t o th e statut e discussio na s well . An d fo r example , bringin g int o pla yth e vitami nD calciu mmechanis ma s a possibl e under

- . lyin g mechanis mfo r effect s o nth e lo wstatur e an d othe r sections . CHAIRMA NLIPPMANN : Bob , comment ?

DR . FRANK : I jus t wante d t o ad d tha t i nvie wo f the : reservation s tha t hav e bee nexpresse d abou t th e coefficient s | i o nth e statistic s tha t underl ythes e coefficients , I woul dsug ges t tha t th e predicte d clinica l consequence s whic har e expli

- j ci t i nthei r number s o nth e botto mo f pag e 5 , ar e probabl yno t warranted . DR . GRANT : Yeah , I thin k tha t thi s i s a naccurat e statemen t o f wha t cam e ou t o f that , bu t w e nee d t o clarif y an d CHAIRMA NLIPPMANN : An d mak e i t a completel yhypo

thetica l case , base d solel yo nthos e assumption s an dstat e th e assumption s an d that' s th e onl ywa ytha t tha t fits .

I think , unles s I hea r otherwise , I as k fo r a

EXECUTIV E COUR T REPORTER S

(30! ) 565-0;. 4P.6 4 rt 1

" departur e fro ma consensu s tha t w e wil l b e abl e t o com e t o a I | lette r o f closur e o nth e conclusio no f th e addendu ma s modifie d

. 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 :j an dcomplet e th e criteri a documen t process . I s ther e a con 

## i j i j sensu s amon g th e Committe e fo r tha t view ? i j 

## I I ; • MR . MORGAN : : Subiec t t o prope r incorporatio no f th e i ! :j lette r o f Dr . Nol l an dDr . Larson . i l l i ' ! DR . SILBERGELD : Som e o f u s woul dlik e t o se e i i j j sem e expande dmention , no wtha t we'r e goin g t o b e o nth e issu e j ' ' c f hvpertensio nbloo dpressure , o f th e issu e o f prenata l effect s 

## I 1

## " * " i whic hw e fee l ha s bee na nincreas e i ninformatio nagain , since : j i : j j w e discusse dthi s last , andver yver ydirectl yo nth e issue s o f j | | | j i level s o f lea dsinc e thes e ar e no t centerin g o nbloo dlead s : l i • ; j'i nwome ni nth e rang e o f 8-10 . 

## l l • I I ! i j i An dI thin k som e o f u s fee l i t i s appropriat e t o ad d

, i • 1 1 ; i j somethin g t o th e addendu mwhic hrecocnize s othe r are a o f effect . 

## i! ~ I

CHAIRMA NLIPPMANN : Les , an yreaction ? DR . GRANT : T o b e sure , w e ar e tyin g i nth e informa

tio nmergin g fro mth e Binde r an dNeedlema nwor k i nBoston . Als o th e Cincinnat i wor k an ds o forth .

An dthere' s I think , tw o kind s o f effect s comin g out. - On e i s th e effec t o nth e birt hweigh t i n5 , whic hma y appropriatel yfi t unde r th e stature , whateve r growt han dstat ur e section . An dth e othe r kin do f resul t v/hic hi s o nearl y! neuropsychologi c o r whateve r developmen t i ndeficit s i nBailey '

- - o r whatever . EXECUTIV E COUR T REPORTER S 

### V v ! , 565-006 4P.6 5

8 9 1 0 1 1 1 2 1 3

1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 6 4

Tha t migh t mor e appropriatel yexpan do r whateve r t o som e exten t bac k i nth e criteri a document , th e section s tha t j dea l wit htha t aspect . An dm vinclinatio nwoul db e t o d o i t i i i ntha t way . i I O r w e coul d pu t the mal l i nhere . [ i DR . SILBERGELD : Myonl yconcer ni s tha t byaddin g ;

! '•

. ' i t int o chapter s o f th e criteri a document , w e los e th e concept , i i

i

. tha t w e ar e no w- - yo u know , we'v e ha dthi s traditiona l focu s • i , ! ' j o nthe youn

g chil da s th e populatio na t ris k andI thin k th e

i bloo d pressur e dat a i s sayin g t o us , w e hav e t o loo k a t th e adul t male . ;

Thes e othe r dat a ar e savin g w e bette r loo k a t blood ' level s i nadul t females .

DR . GRANT : Well , I certainl ycoul d creat e a sectio n I anothe r section , i f yo u will , o r a nappropriat e thin g i nthi s j I jaddendum , t o highligh t th e feta l effects .

CHAIRMANLIPPMANN : I thin k w e bea t Le s a s fa r int o th e groun d a s w e can . Befor e - - we'l l tak e a brea k an dcom e bac k an d resum e ou r discussion s wit hOAQP S andtryt o thin k abou t th e question s we'l l b e raising , durin g th e break , abou t vha t you'r e goin g t o d o abou t th e us e o f coefficient s i nany ris k estimation , and whethe r yo u need , t o cal l fo r an yfurthe r i analysi s o f anyo f th e ol d dat a o r no t i norde r t o fee l comfort

-



## . . . I abl e enoug hcoefficient s tha t yo u wil l us e i nyou r ris k assess : i ments . i j EXECUTIV ECOUR TREPORTER S i

^30! ) 565-006 4 |1 5 1 6 1 7

19 2 0 2 1 2 2 2 3 2 4 2 5 

### oreak . P.6 6

"" T| I 6 5 S o let' s thin k abou t that , an d tak e a 1 0 minut e 3 (Whereupon , a brie f reces s wa s taken. ) 4 CHAIRMANLIPPMANN : W e ar e runnin c a bi t late r tha ni i I 5 I thcuoh t we'd , be , and . we'l l resum e th e "discussio nw e pu t asid e

. 5 yesterda yi ninteres t o f tim e an dI've aske dDonn a t o bea r wit h 7 u s and simpl yg o t o he r concludin g slid e andt o acknowledg e 8 tha t som e o f th e conclusion s haven' t bee nfull ydiscussed * I

i 9 Bu t i f w e a s a panel , hav e anyquestion s abou t th e i i 10 conclusions , we'l l tak e th e tim e t o amplif yho wsh e go t tha t 1 1 wa yand perhap s pul l bac k thos e slide s whic hsupported , it , i f th e

i i 1 2 question s com e up . Bu t w e don' t wan t t o spen da s muc htim e a s . 13 i t woul d tak e t o g o throug hi t i nth e w 7a yi t wa s planned , •- 

## I 1 4 considerin g th e tim e schedule , andals o som e basi c problem s j j tha t we'l l b e discussin g abou t th e staf f pape r v/hic hrende r | i i j som e o f thi s analysi s somewha t moo t anyway . j

S o wit hapologie s t o Donn a fo r no t lettin g he r t o | he r thing , w e as k i f sh e could , com e t o a resolutio no f th e I g !ie i -.iixiiy discussion . MS . SLEDGE : Okay , thi s i s th e secon dt o th e las t pag'e'i nyou r handou t and i t i s ou r overal l result s fo r th e j i variou s analvse s tha t we'v e don e fo r ou r exposur e modeling . j I I I thin k I've alreadytouche do nsom e o f th e sensitivit yanalyse s tha t w e hav e don e t o evaluat e ho wou r blood , lea destimate s | ar e influence d byvariou s impu t perameter s i nth e uptak e model .

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(301 ) 565-0.6 4P.6 7

3 4 5

• 6 7 8 9 1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 6 6

Th e averag e dail ydir t ingestio nrat e wa s th e pera mete r tha t ha d th e mos t impac t o nou r estimate dbloo dlead . W e sa wtha t whe nw e double dth e rate , tha t th e blood , lea d increased , b

yapproximatel y6 5 percent . W e als o looke da t anothe r importan t componen t o f ; ou r exposur e model , whic hi s th e indoo r dus t andoutdoo r soi l '• dus t lea d concentration s tha t childre nar e exposed , t o andthes e wer e als o sicnifican t impu t oerameter s influencin c ou r bloo d ;

### I lea d estimate. ; andw e foun d tha t th e indoo r dus t lea dconcent- ; i ratio nhad . a mor e significan t effec . o nou r estimate s tha ndid , th e outdoo r dus t lead . j

An d th e reaso nfo r thi s i s tha t i nou r exposur e i modeling , w e hav e a peramete r fo r th e numbe r o f hour s th e I i I child , spend s outdoors , and typicall ya youn g chil dspend s a • 

### I greate r majorit yo f thei r tim e indoor s andbecaus e ou r estimate s j ar e tim e weighte d averag e reflectin g exposur e t o indoo r dus t i 

## I lead , concentrations , thi s turne d ou t t o b e th e mor e importan t j 

## i facto r influencin g ou r estimate dblood , leads . j

Th e thir dmos t importan t facto r influencin g ou r bloo d lead , estimate s wa s th e dietar ycomponent , i nparticular , th e constitutio no f canne dfoo dlead . An dw e sa wtha t i f w e showe d o r modele d n o furthe r reductio ni nth e contributio no f canne d solde r lea d t o th e dietar yintak e i na child , tha t ou r bloo d lead s increase d b yapproximatel y3 5 percent . Fo r ou r bas e lin e scenario , w e di dhav e on e

EXECUTIVE COUR T REPORTER S

(301 ) 56;-006 4P.6 8 6 7 1 7 opportunit yt o tryt o validat e th e model" , andtha t wa s u s in c li - - i i i i 2 ' scr. e dat a tha t wa s collecte d i nDallas , Texas . 3 i l Wha t w e foun d wa s tha t ou r - - th e uppe r bound s o f 4 ; j ou r mode l predictions , mor e roughl vaproximate dth e actua l j i 

### 5 'measure ddat atha t wer ecollecte di npre-schoo lage dchildre n

. 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 j i nDalla s durin g th e summe r o f 1982 . An da ninterestin g find

j i ing whic hw e thin k i s explaine di npar t b yth e fac t tha t ou r exposur e mode l estimate s were ' base d o nai r qualit ytha t w e wer e predictin g a t th e geographi c centroid s i ncontras t t o th e i imeasure d bloo d lead s tha t wer e collecte d i nDallas , tha t repre sen t childre nlivin g i nth e mos t highl yimpacte darea , j W e foun dtha t wer e wer e slightl yunderestimatin g i and that' s whyou r uppe r boun dmode l prediction s tha t ar e j approximate d and . measure d bloo d lead s i nth e pre-schoo l age d . i ; i l j children . An d a ninterestin g findin g fro mthi s i s tha t th e referenc e are a i nDalla s i neac ho f th e childre nsampled , wa s j i i simila r t o th e poin t sourc e area s i nterm s o f th e socio

- i economi c demographi c andtraffi c peramters , andwa s differen t j fro mth e poin t sourc e area s i ntha t th e referenc e are a wa s no t impacte d bya poin t sourc e emission . | j W e foun dtha t ou r exposur e mode l "reallyha da bette r 

### l i I : i I i fi t i ncomparin g i t t o th e measure dbloo dlead s tha t wer e j 

# | i I collecte d i nth e referenc e area . An dI thin k thi s suggests , j II i ii . i i ! a s w e ha d conclude d whe nw e compare dou r bas e lin e estimat e to ; j i th e NHANE S data , tha t perhap s ou r exposur e mode l estimate s j I

EXECUTIV

ECOUR TREPORTER

S (301 ) 565-006 4P.6 9 i ; 6 8 i 7 i i i ! 1 , tha t ar e base d o nai r aualit vpredicte da t th e geographi c I

, . __ . __ • -J _| 2 '.' centrcic. s mor e closel yrepresen t exposure s i na genera l urban , j 3 I j rathe r tha na poin t sourc e area . I 4 ! Okay , on e o f ou r overal l conclusion s whic hi s a l i I . ' 5 [ poin t tha t v;a

s r.ad e severa l time s yesterday , i s tha t w e d o fee l cI tha t oredictin qimpact s o f childre nlivin o i nandaroun dth e

• wi . • • 

### I I

## * ; 7 ! : poin t sourc e area , base do nai r qualit ya t th e geographi c j i i ; 8 | centrcic.s , doe s underestimat e th e exposure s i nth e children ! j ' g| ; tha t wer e ver ynea r t o th e poin t source . ; i ii j : 1 0

### ;' An

dthi s i s becaus eo f

th efac t

tha t there' s ver y i y\- stee p gradin g i nai r lea d concentratio nv/it hdistanc e an dbyj

, 7 -basin c cu r prediction s o nai r cualit ya t th e geographi c cen - ! ! ' * ; 1 3 j trcids , w e ar e no t capturin g thi s highl yimpacte darea . i i ' • 1 4 I j Anothe r importan t poin t i s tha t th e population s o f j 

## I I I childre nmthes e highl yimpacte darea s i s quit e small . W e saw ' tha t i n19 8 0 fo r th e tw o censu s track s closes t t o sourc e 2 . [

Ther e wer e onl y25 2 childre ni non e o f th e censu s I track s an d 16 1 i nth e other . S o w e ar e talkin g abou t a rela

tivel ysmal l populatio no f children .

Tn e poin t a t whic hI stoppe dyesterday , wa s showin g you-ou r result s fo r ou r grou p poin t bloc k grou p analysis , whic hi s a refinemen t o f ou r geographi c centroi dapproac h whic hattempt s t o mor e precisel yestimat e bloo dlead s base do n 15 1 6 17 18 19 2 0 2 1 2 2 2 3 ! j exposure s b f childre no f variou s ambien t ai r lea dconcentra 2 4 : ; 2 5 ii iition s tha t

we'v emodeled . j !EXECUTIV ECOUR TREPORTER

S | | (301 ) 565-006 4P.7 0

1 2 3 4 5 6 7 8 9 10 1 1 12 13 1 4 1 5 16 17 18 1 9 2 0 2 1 2 2 2 3 2 4 2 5 6 9

An d w e di d se e th e bas e lin e cas e tha t whe nw e looke d a t childre nlivin g wit hth e 1,00 0 mete r radiu s o f th e l j smelter , base d o nou r bloo dlea destimate s v/hic hwer e base do n ai r Qualit ytha t wa s predicte da t ver yclos e distance s t o th e source , suc ha s 200-70 0 meters , th e bloo dlead s fo r thes e childre nsignificantl yincrease dove r ou r prediction s base d o nth e geographi c centroi d analyses .

An d again , th e Dalla s validatio nstudyseem s t o suppor t thi s concep t tha t i norde r t o estimat e exposur e t o childre ntha t liv e nea r ooin t sources , w e reall ynee dt o look ; 

## 1 a t a fine r grai ntha npredictin g ai r qualit ya t th e geographi c center s o f censu s tracks .

I kno wwithou t havin g discusse d a lo t o f this , it' s har d t o jum

p righ t t o th e conclusions , bu t i f anyon e ha s anyquestion s o r woul d lik e m e t o provid e suppor t fo r ou r conclusions , I'l l b e happ yt o d o that .

MS . MAHAFFEY : I' msorr yfo r th e brea k inbetween , becaus e I' msur e we'v e al l los t som e o f wha t w e ma yhav e under ' stood . Is'i t correc t t o saytha t th e validatio no f th e mode l in < that' s bee ndon e i s dealin g wit hpoin t sourc e wher e th e over whelmin g expo'sure s = r e somethin g othe r tha nairborn e lea do r lea d tha t i s currentl yairborne ?

MS . SLEDGE : Okay . Th e studytha t w e used't o compa n ou r baselin e mode l prediction s wa s conducte di nDalla s andth e purpos e o f tha t studywa s t o determin e th e exten t o f elevate d

EXECUTIVE COUR T REPORTER S

(30! ) 365-006 4 J

" i2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 P.7 1 ; . . , : -rr p 7 0 blood , lead s i n"pre-schoo l age d childre nlivin g aroun dtw o poin t sourc e areas . An d the ylooke da t area s ou t t o on e mil e fo r eac hpoin t source .

DR . MAHAFFEY : S o woul di t b e fai r t o sa ytha t som e o f th e question s tha t wer e comin g up yesterday , concerne d whethe r th e variou s model s tha t ha d bee nshown , coul db e vali

date d t o fi t know ndat a wher e yo u hav e somethin g othe r tha n a poin t source , ha s ye t t o b e demonstrated ?

MS . SLEDGE : Well , I thin k ou r compariso no f ou r mode l prediction s t o th e Dalla s lea dstudyd o sho wtha t ou r jmode l base d o npredictin g ai r qualit ya t geographi c centroids , 

# i doe s represen t bette r exposure s o f childre nlivin g i na genera! . urban , rathe r tha na poin t sourc e area .

An d that' s again , becaus e ou r mode l i s basing , o r estimating , bloo dlead s base dof f o f ambien t lea dconcentration s tha t ar e predicte da t relativel yfa r distance s fro mth e source \ i ncompariso nt o a nactua l studytha t onl yevaluate dth e bloo d lea d level s i nchildre nlivin g nea r a poin t source .

DR . MAHAFFEY : Eu t som e o f th e difficultie s I wa s havin g yesterda yi nunderstandin g somethin g lik e whyth e adul t mal e bloo d lea d tha t v/ e observed , i nNHANE S woul db e s o "dramat

icall yhighe r tha nyou r mode l fo r genera l populatio nwoul d predict . Tha t kin d o f validatio nandtha t kin do f compariso n v/ouldn' t b e shownbyth e childre ni nDallas .

MS . SLEDGE : No . I thin k you r questio nreflecte dth e

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(30i ) 365-006 4P.7 2



# l i l ! 1 j | fac t tha t w e wer e makin g projection s int o th e future . An dw e i j 2 i don't ' hav e th e capabilit yo f evaluatin g ho wwel l ou r mode l j i 3 j | i s predictin g int o th e future . W e ca nonl ycompar e actua l j | 4 j l data'that' s bee ncollecte d i nth e past . i . 5 , ! DR . MAHAFFETY : Woul d i t b e possibl e t o us e you r 6 j j mode l v/it hth e informatio ntha t existed , sa yo nairborn e lea d 

### Ij * ; 7 ., . dietar ylead , som egenera lvalu efo r lea di nv/ater , an dth ej

• i I : •i 8 i blood , lea d dat a fo r adul t male s ou t o f NHANE S t o mak e a compari

9 ; i son , say , 197 6 t o 1980 ? l i 1 0 i l MS . SLEDGE : O hyes . An d jus t tha t w e chos e t o i j j yj 1 presen t th e analysi s tha t Jef f presente d yesterda yt o represen t 1 2 I ' a.U e yea r 19 9 0 . W e coul d hav e similarl ydon e tha t fo r an yothe r

1 4

1 6 1 7 1 8 1 9 1 3 ; ; yea r period , an d w e woul d hav e use d value s fo r th e variou s con tribution s o f lead , exposur e tha t would , b e representativ e

1 5 I o f tha t particular'tim e period . DR . MAHAFFEY : I a t leas t woul d hav e fel t muc hmor e comfortabl e wit hth e validation s o f models , ha d tha t typ e o f compariso nbee nmad e firs t tha t demonstrate d tha t th e mode l coul d accoun t fo r variou s source s o f lead . Becaus e I gathere d tha t traditionally , thi s ha s bee na mode l tha t ha s bee ndevel

ope d fo r airborn e "pollutant s wher e ther e wer e relativel yfe w contribution s fro mnon-ai r sources .

M S . SLEDGE : Well , ou r mode l wa s accountin g fo r exposure s fro mal l source s o f lead . Th e ai r qualit ydisper

sion , whic hi s th e startin g poin t o f ou r whol e modelin g process , 2 0 2 1 2 2 2 3 2 4 I I 2 5 EXECUTIV ECOUR TREPORTER

S (30! ) 565-006 4P.7 3 7 2

7 8 9 1 0 1 1 12 13 14 15 16 17 18 19 2 0 21 2 2 2 3 2 4 2 5 that' s representin g ambien t ai r lea d concentrations.

- Bu t w e the nreflec t al l source s o f exposur e i nth e nex t step s tha t w e g o throug hbyusin g th e lea d uptak e model .

CHAIRMANLIPPMANN : Tim ? DR . LARSON : Th e number s yesterda ytha t we'r e 6 j | discusse d byTR C wer e 1 5 o r 2 0 percen t o f th e childre nlivin g nea r thes e sources , wer e typicall yabov e a certai nbloo dlea d level . Doe s you r model , i nan yway, com e u p wit hsom e suc h estimates ? I s i t consisten t wit hthat ?

MS . SLEDGE : W e di dus e ou r grou p poin t analysi s unde r on e pos t contro l scenari o whic hwa s a t th e 1. 5 standar d level . And . I ca nsho wyou " th e result s o f thos e andw e ca n ge t som e fee l fo r —again , thes e ar e populatio nmea nbloo d leads , bu t b

yapplyin g a GS D w e could , ge t som e sens e o f wha t fractio no f th e individual s i na populatio no f childre nwoul d b e abov e a certai nbloo dlea dlevel .

DR.LARSON : I' mno t askin g yo u t o d o i t now , bu t wha t I' msayin g i s tha t i t seem s t o b e a nimportan t "numbe r i n th e othe r - -

DR . SILBERGELD:Well , I thin k i t migh t b e wort hshowin g quickly . I thin k onc e agai nth e issu e i s ho wlon g i t ca npre dic t a rea l situation .

I f yo u kee p givin g u s projection s andth e fac t i s i nth e are a o f lead , w e hav e a nextraordinar yamoun t o f rea l worl d data , and wha t w e kee p tryin g t o as k you , an dI' mno t

EXECUTIVE COUR T REPORTER S

(30! ) 565-006 4P.7 4

sur e we. 1 r e gettin g ou r messag e through , i s "us e you r models , n o 2 | fo r projections , bu t o na rea l world , situation , the ntak e th e rea l dat a an d se e ho wwel l the ycompare . I mea nv/e hav e n o wa yo f knowin g whethe r you r projectio nfo r 199 0 i s goin g t o b e right .

6 MS . SLEDGE : No , don' t thin k I suggeste dtha t

7 yo u tr yt o d o tha t o r tha t anyon e d o that . W e hav e ha dtw o 8 j | opportunitie s t o tr yt o validat e ou r mode l wit hrea l worl d

i 9 idata , th e on e bein g NHANE S ari d th e secon d cas e bein g wit hth e j l 

## J j 1 0 | | Dalla s lea d stud ytha t wa s conducte d i n1S82 .

CHAIRMA NLIPP.MANN : I thin k tha t wha t Dr . Larso nha s 1 1

1 2 |suggeste d i s tha t you'tr yt o se e whethe r th e dat a generate db y 13 14 15 1 6 17 1 8 1 9 2 0 21 2 2 2 3 2 4 2 5 TP. C validate s th e model , o r conflict s wit hth e mode l o r i f not , t o discus s wher e an d wh yi t doesn' t becaus e that' s als o rea l worl d data . An d mor e specificall yrelate s t o a nimportan t clas s o f poin t sourc e pollutants .

MS . SLEDGE : I ca ngiv e on e exampl e o f wha t ou r mod e wil l predic t i nth e futur e unde r on e pos t contro l scenari o level , tha t bein g th e 1. 5 an d a s I said , thes e ar e populatio n mea nlevel s s o w e coul d hav e hire d GS D an d trie d t o estimat e wha t fractio no f th e populatio nwoul d excee d a nindividua l bloo d leve l o f concer nfro m15-20 .

CHAIRMA NLIPPMANN: I thin k tha t rather'tha ng o tr y t o d o tha t now , b yth e sea t o f ou r pants , w e sugges t tha t th e

EXECUTIV E COUR T REPORTER S

(301 ) 565-006 4P.7 5 ii 7 4 

### i l i i i staf f pape r discussio ni nth e nex t draf t presen t tha t kin do f 2 j i analysi s t o compar e th e mode l prediction s o r th e - - fo r th e i i 3 i i case s presente di nterm s o f dat a b yTR C an dse e th e matc hbe

- • | i 4 ' twee nmode l prediction s andth e data . • I 1 5 •; DR . ANGLE : I thin k mayb e mor e tha nthat , i t shoul d 6 i j includ e som e snecifi c recommendatio nbase do nthi s dat a whic h j i n 7 i j i s eithe r t o th e placemen t o f th e monitorin g site , whe nyo u 8 : : hav e a Poin t sourc e o r interpretatio no f dat a fro mth e monitbr

9 7 m g sites . I neffect , th e mode l attempt s t o accoun t fo r th e l | 10 •- concommitan t increase s i nsurfac e depositio nandresidua l soi l i l n l \ lea d whic har e no t theoreticall yavailabl e o r no t actuall y | i 1 2 j : measured , unde r ai r qualit ycriteria . : j 13 'j S o tha t th e criteri a fo r th e ai r lea dhav e t o b e

• I i ! 1 4 '•> modified , o r hav e t o b e interpreted , relativ e t o distanc e i n

i i 1 C ! th e radia l cri d mode l fro mth e poin t source . I s tha t correct ? 1 5 | 1 6 | | MS . SLEDGE : I ha d troubl e hearin g som e o f that . 

## •: l

• I 1 7 ; j Sorry . W e di d loo k a t th e dat a tha t w e hav e i nDalla s i i • i 1 8 j DR . ANGLE : Ar eyo usayin g tha t v/it hapoin t

source , 1 9 2 0 tha t th e acceptabl e level s o f ai r lea dmus t b e lower ?

MS . SLEDGE : W e reall yhaven' t mad e an yjudgment s

„ , ; abou t crive

na certai nexposure , wha t th e standard , leve l shoul d 2 1 ; - - i j be . Thi s whol e "discussio nha s mor e deal t with'th e methodolog y 2 2 * i ; i 2 3 ;j tha t w e used . 

### i ! j I ca nsho wyo u th e result s fo r on e o f ou r pos t con i j o c 7 tro l scenario s wher e w e predicte dth e bloo dlead s tha t woul d / b i i EXECUTIV ECOUR TREPORTER

S (301 ) 565-006 4P.7 6 7 5 resul t fro mexposure s o f a nambien t ai r lea d concentratio na t th e leve l o f th e curren t standard , 1.5 . An d i nthos e cases , som e o f th e mos t highl yimpacte d childre nlivin g withi na fe whundre d meter s o f th e sources , th e mea nbloo d lead s tha t j wer e predicted , woul d excee d a mea nvalu e tha t applyin g a GS T

i jof"1.42 , woul d giv e u s a nindividua l bloo d lea d greate r tha n i j j1 5 microgram s pe r deciliter . 

## j j CHAIRMA NLIPPMANN : Okay , no wI thin k i nth e nex t i g o around , we'd , lik e t o se e th e mode l verificatio nopportunity , 1 0 j j provide d b yth e extensiv e dat a se t fro mTR C take nadvantag e of, ; an d tha t wil l giv e u s som e greate r confidenc e i nth e validit y o f th e mode l fo r th e poin t sourc e impac t prediction , whic hi s reall yth e issu e we'r e comin g to .

Than k yo u ver ymuch . Now , agai nI as k th e indulgenc e o f Drs . Wallste nan d Whitfiel d an d as k the mt o com e an ddiscus s th e lea d ris k assessmen t i na somewha t reduce d tim e fram e tha n| the yha d originall yplanned , coverin g th e mai npoint s an d no t al l th e details , i f that' s possible . 2 3 4 5 6 7 8 9 

## I '

i I 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 21 2 2 2 3 2 4 2 5 STATEMEN T O F DRS . WALLSTEI NAN D WHITFIELD ,

LEA D RIS K ASSESSMEN T DR . WALLSTEN : W e wil l b e a s quic k a s possible . Le t

m e reques t tha t a s we'r e talking , perhap s yo u onl yas k questio n o f informatio nregardin g wha t we'r e presenting .

Ro nan d I hav e divide d thi s presentatio nu p i nsuc h

a wa ytha t w e di d pla nt o leav e som e tim e intermediate , a s wel l

a s a t th e end , fo r questions . An d i t migh t hel p a bi t i f w e EXECUTIV E COUR T REPORTER S

(JOI) 565-006 4P.7 7 7 6 i adher e .t

o tha t 2 ' Ther e i s a handou t tha t I gues s Jef f i s passin g 3 aroun d v/hichcontain s al l th e slides , bu t unfortunatel yth e 4 handou t i s onl yblac k an d white . Now , thi s presentation , we'r e 5 focusin g agai nonl yi nmethodolog yan d w e wil l simpl yhighligh t th e results .

Th e ful l results , a s wel l a s complet e documentatio n 8 ar e containe d i nou r report , o r i nou r draf t report , an d

9 exerot s o f th e result s i nth e staf f paper . Now , th e purpos e o f

-l 0 th e ris k assessmen t o f lea d healt heffect s i s t o develo p prob

y' abilit ydistribution s ove r fraction s o f th e populatio na t risk , 1 2 tha t woul d suffe r certai nwell-define d healt heffect s unde r

1 3 alternativ e standard s fo r lead . 1 4 I nreality , tha t ca nb e considere d th e fina l goa l 1 5 an d on e migh t thin k o f a nintermediat e goa l o f th e ris k assess- -

_. men t i s t o represen t th e uncertaint yregardin g 'dos e respons e

7 . function s fo r specifi c healt heffects . S o i nfact , I' mgoin g i

1 8 j t o tal k abou t th e firs t par t o f thi s an d the nsto p fo r question s

1 9 i|an d the nRo nwil l tal k abou t th e secon d part .

Now , w e fee l tha t th e ris k assessmen t we'v e carrie d

ou t i s responsiv e t c th e suggestion s an d recommendation s o f j Willia mRuckelshau s whe nh e v/as EP AAdministrator , an di n particular , h e sai d h e doesn' t wan t magi c numbers , bu t h e woul d lik e t o hav e a nide a o f ho wmuc hconfidenc e should'b e place d i nestimate s o f ris k an d th e ris k calculatio nshoul db e expresse d 2 0 21 2 2 2 3 i i 2 4 j 2 5 I , EXECUTIV ECOUR TREPORTER

S (501 ) 365-006 4P.7 8 

# I I 1 i a s distribution s o f estimates . S o w e hav e trie dt o b e respon I 2 siv e t o thi s request . I 3 It' s importan t t o poin t ou t tha t ther e ar e tw o | i 4 j source s o f uncertaint yassociate dwit hth e healt heffect . On e 5 i s th e uncertaint yassociate dwit hdata . Thi s i s th e uncertaint y 

## l l 5 | that' s normall yhandle dwit hstatistics . I 7 j An d th e othe r i s th e uncertaint yassociate dwit h I 8 j j lac k o f data . Frequent yjudgment s hav e to ' b e mad e abou t healt h II i 9 jeffect s fo r whic honl yindirec t dat a exist s andthe ni t i s i | 1 0 j | necessar yt o extrapolat e fro mthi s indirec t dat a an dthere' s a I 

## l i I yi ; goo d dea l o f uncertaint yinvolve dher e tha t i s no t handleabl e i 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 i nth e usua l statistica l sense , and wher e necessary , w ; e di d try i i t o ge t som e gras p o nthis . | I Now , OAQP S aske d u s i f w e woul d d o ris k assessmen t j fo r thre e differen t healt heffects , elevate dE P levels , hemo

globi ndecrement s ari d I Q decremen t andv/ e wil l tel l yo u a littl e abou t wha t w e di di neac hone . Now , wit hregar dt o elevate d E P level , ther e ar e ver ygoo d data , base da t leas t - - no wthi s wa s no t ou r judgment , bu t base d o ndiscussio nwit hou r consul

tants , the ytol du s tha t the yfel t th e dat a wa s complet e a s on e coul d possibl yhop e for .

S o w e di dou r ris k assessmen t entirel yusin g th e data . I nth e cas e o f hemoglobi nan dI Q decrement , th e dat a ar e quit e sparse , andi t wa s necessar yt o attac k th e othe r source s o f uncertaint ywhic hinvolv e uncodin g expert s subjectiv e

EXECUTIVE COUR T REPORTER S

(301 ) 565-006 47 8

i Q 1 0 11 1 2 1 3 probabilities . Le t m e discus s th e sampl e o f th e E P results .

Now , th e complet e dat a com e fro ma studyb yPiomell i e t al , tha t peopl e her e kno wabout , andit' s base do nsom e i 1 8 o r 1 9 —observation s o nsom e 1,800-1,90 0 children .

And . Piomell i derive dtw o dos e respons e function s whic hv/

e represen t here . Thes e ar e line s simpl ydraw nt o fi t th e point s tha t the yhave . On e fo r th e percentag e o' f childre n v/it hEP' s abov e 3 3 microgram s pe r decilite r a s a functio no f bloo d lea d an d th e othe r a s a nE P a s abov e 53 .

Thi s represent s 1 and 2 standar d deviation s abov e th e norma l o r th e bas e line . Le t u s jus t focu s o nth e E P 

### j equa l t o 3 3 fo r ou r illustration . I

Thi s represent s th e - - thes e line s represen t th e ! 4 | | dat a bu t o f course , there' s uncertaint yassociate dwit hthes e

, r ijdata . An d simpl vmakm qus e o f th e dat a andth e numbe r o f l b ' - . . 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 childre na t eac hpoint , w e essentiall ycalculate dfo r eac h bloo d lea d leve l distribution s o f populatio nproportion . An d wha t w e ar e tryin g here , th e yello wcurv e isn' t exactl yaccur ate . It' s bee ncorrecte d o nth e handout . I t shoul dhav e th e hocke ystic k loo k tha t th e previou s on e had .

Wha t w e s=ho

wi nthi s curv e i s basicall yth e dos e respons e functio na s wel l a s 9 0 percen t credibl e interval s abov e thi s dos e respons e function . An dwha t thi s —th e wa y thi s shoul d b e rea d i s tha t a t anygive nbloo dlead'level , there' s a . 9 probabilit ywit hth e actua l populatio nrespons e

EXECUTIVE COUR T REPORTER S

(30i ) 565-006 4P.8 0

1 2 3 4 5 6 7 8 9 1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 ' 2 4 2 5 : : 7 9 i : j rat e is.withi nth e dashe dline s and.0 5 probabilit yabov e and •.0 5 probabilit ybelow . j : Thi s i s a fairl ystandar dwa yo f lookin g a t sem e 7 o f thes e data . Ou r analysi s wa s a basia nrathe r tha na classi

i ca l analysis , bu t otherwise , it' s th e way'tha t mos t peopl e ar e use d t o lookin g a t data .

i : ! An d w e wil l b e usin g curve s o f thi s sort . Subsequently , althoug hbase do njudgmenta l probabilitie s rathe r tha nsubjectiv e probabilities .

I a mhurryin g an dthi s i s discusse d i nmor e detai l i nou r report . Le t u s tur nno wt o hemoglobi ndetriments .

W e di dpresen t som e o f thi s a t th e las t CASA C meeting . Thi s i s reall ya summar yjus t tovor k up t o th e I Q

• 'stuff , t o kin d o f war myo u up , s o t o speak .

Now , i nthi s case , th e dat a ar e quit e incomplete , 1

i ; an d s o i t wa s necessar yt o consul t expert s t o d o som e subject

i i liv e probabilit ycoding . Le t m e firs t sho wyo u wha t i s th e

, semi-botto mlin e o f a probabilit ycodin g andthe nI wil l tel l | 

# 1 yo u ho ww e go t it .

Now , w e sho wher e result s fro mth e judgment s o f i 

# I jthre e experts , C , D.and E , regardin g lea dinduce drespons e i i 1 rate s fo r hemoglobin , les s tha nequa l t o 9. 5 gram s pe r deci

ijlite r amon g children , age s 0-3 . I haste nt o poin t ou t t o yo u i 1 tha t th e axi s ar e no t th e sam e fro mon e grap ht o anothe r an d jjand w e will , i njus t a slid e o r two , hav e a mor e comparabl e 

# I 1 EXECUTIVE COUR T REPORTER S I (301 ) 565-006 4P.8 1 8 0 i .graph . .Thi s i s jus t t o giv e yo u a nillustratio no f wha t v/ e 2 7 3 : | Th e yello wcurv e o neac ho f th e thre e panel s 4 represent s wha t w e migh t conside r t o b e eac hexpert' s bes t 5 judgmen t abou t wha t th e dos e respons e functio nlook s like , 6 base d o nth e analysi s w e did , give nth e subjective

- probabilit y 7 ji ncoding , w e woul dsaytha t a t anygive nrespons e rate , th e 8 exper t though t ther e wa s a 5 0 percen t chanc e —sorr y- - any 9 give ndose , ther e wa s a 5 0 percen t chanc e tha t th e respons e 10 rat e wa s abov e tha t lin e and5 0 percen t i t wa s belo wtha t line. ; i i , i Th e re dlin e showe d 9 0 percen t credibl e interval s | i : . - I

1 2 ,an d thi s i s rea d i nexactl yth e sam e wa ya s previou s curve , 13 : c f cours e i t wa s obtaine di na differen t fashion . Now7 , le t m e

1 4 ;g o bac k and sho wyo u ho wv/ e obtaine dit . 1 5 . Again , w e discusse d thi s a t th e previou s CASA C

1 6 'meetin g s o I' mno t goin g t o g o int o a lo t o f detail , bu t

1 7 : v/ e di d visi t eac hexper t twice . Th e firs t probabilit yinclud

1 8 in g th e sessio ngenerall ylaste d a ful l day , andw e ha da goo d

: i i g7dea l o f discussio nrecardin g th e literature , structur e o f th e 

## | j j'proble

man d s o o nand s o on . I j An d whe n.v/ e finall ygo t th e individual' s probabilit y l ; judgments , w e di dfi t th e function s t o them . W e sen t al l o f n jithi s materia l bac k t o th e exper t alon g wit ha lo t o f explana

i . ; : tor ymaterial . 2 5 I W e wen t bac k a secon d tim e andv/ e discusse d al l thi s

EXECUTIVE COUR T REPORTER S

(501 ) 565-006 4P.8 2 1 wit hthe man d finally , whe nw e no t onl yha d th e judgment s 2 wel l represente d i nth e goodnes s o f fi t sense , bu t th e exper t I ; M 3 ijals o agree d tha t the ywer e wel l represente d w e the nuse dth e h 4 j ! function s tha t w e fi t t o th e expert' s judgments . 

## ! i 5 : New , b e carefu l i nreadin g thi s graph . Thi s on e 6 : I stoope d u s fo r 1 5 minute s a t th e las t CASA C meeting . Thi s i s 

## j | 7 j ; differen t fro mwha t i s normall yseen . 8 ' ; W e hav e o nth e Xaxi s respons e rate . W e hav e o nth e I i 9 . ; Yaxi s a judge d probabilit ytha t th e actua l respons e rat e i s j j 1 0 -equa l t o tha t valu e o r less , an d fo r eac hcurve , w e hav e a n| , differen t bloo d level . S o fo r example , t o loo k a t th e re d 1 2 i l curv e o nth e right , L equal s 55 , tha t curv e represent s th e i | 1 3 i j expert' s judgment s abou t populatio nrespons e rat e a t a dos e 

# i i 1 4 j l leve l o f 5 5 microgram s pe r deciliter .

T2S b 1 5

1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 S o on e ca nrea d acros s an d ge t th e expert' s prob

abilit yjudgmen t tha t th e respons e rat e i s les s tha nor'equa l t o an ygive nvalu e o nth e Xaxis . Now , i f on e imagine da |horizonta l lin e draw nfro mth e Yvalue.o f . 5 across , tha t rep resent s th e 5 0 percen t judgment .

An d s o eac hpoint , eac hcurv e that' s intersecte db y thi s horizonta l lin e a t . 5 represent s th e 5 0 percen t judgmen t tha t I showe d yo u previousl yan d s o on . Wha t I showe dyo u previousl ywit hth e judgments , w e fi t function s t o thos e judg

ment s a s I'v e showe d you .

Now , w e too k th e 5 0 percen t slic e acros s i nthes e

EXECUTIV E COUR T REPORTER S

(31 j 565-005 4P.8 3 8 2 curve s and 2 5 percen t slic e acros s i nthis . An dbytakin g thos e slice s across , w e create dth e curve s I showe dyo u before " 

# i | S o thes e ca nb e rea d in'th e sam e wa ya s sa yth e i I dos e respons e function s fo r the

- E P alon g wit hth e confidenc e 

### j interval s abou t wha t the vwer e obtaine d i nterm s o f gettin g 5 | ; judgment s 

## j l

8 7 Prepare d anothe r slid e whic hno ww e thin k i s a reasonabl ygoo d 7 | j Now , thes e ar e a bi t har d t o compare , an ds o w e

9 | i wa yt o loo k a t th e rang e o f judgment s an d uncertaint yregardin g 

# P 1 0 lith e lea d induced , hemoglobi neffects . Now , w e hav e show ni nher e i j nl i jus t fo r th e hemoglobi nleve l 9. 5 an d fo r childre nage d 0-3 . 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 Eac h—v/ e hav e expert s A , C , D andE , fou r o f ou r fiv e experts , th e fift hon e decline dt o provid e probabilit y judgments , a s w e describe d las t tim e andw e hav e showna t eac h lea d level , a summar yo f eac hexpert' s judgments . S o let' s take , fo r example , fo r a lea d leve l o f 3 5 microgram s pe r deci

liter , d o yo u se e tha t exper t Abelieve s tha t th e percentag e o f kid s havin g a lea d induce dhemoglobi nrat e les s tha n9. 5 o f 0 , the nth e othe r thre e line s sho wbot hth e expert' s media njudg

men t o r th e 5 0 percen t judgmen t a s wel l a s 9 0 percen t credibl e interval s abov e tha t value .

S o thi s show s som e indicatio no f th e rang e o f un certaint yfo r eac hexper t a s wel l a s th e leve l o f agreemen t o r disagreemen t o f processes . An d byandlarge , on e migh t summa r iz e thi s b

ysayin g tha t expert s C , D ari dE hav e som e degre e o f

EXECUTIVE COUR T REPORTER S

(301 ) 56.5-006 4; » 8 3 r. l i 1 ' overlap.i nthei r judgments . Exper t Aha s a differenc e o f opin

2 ' : io nwit hthe mand s o on . I won' t g o int o it . 3 ij Bu t ther e ar e a numbe r o f curve s o f thi s sor t tha t • 4 summariz e th e judgment s tha t w e go t fo r th e various , fo r th e 5 tw o level s o f hemoglobi nand th e tw o papers . Now , thi s wa s mor e 5 e r les s a review , althoug hI thin k a littl e nice r presentatio n : ~ j 7 I , tha nw e ha d las t tim e i nterm s o f th e graphics . j 8 : Le t m e no wtur nt o I Q decremen t whic hi s new . | i

. i 9 A s yo u ar e al l painfull yaware , th e dat a o nI Q ar e controver - I i . 1 0 sial , an d s o w e coul d no t wor k directl yfro mth e dat a t o ge t i nI'judgment s abou t I Q decrements . 

# I 12 ! : Whe nw e bega nt o develo p ou r protoco l fo r IQ , fo r 13 •'encoding judgment s abou t I Q decrement , i t becam e clea r earl y i l 1 4 : . on , i t wa s a muc hmor e complicate dproble mtha nhemoglobin .

16 17 18 19 . _iThe'IQ' s influenc e o r a t leas t fro mon e perspective , it' s j influence d bylon g ter mlea dexposur e durin g th e cours e o f •behaviora l i nCN S development . A t leas t that' s th e issu e tha t i s unde r "discussion .

Th e lon g ter mlea dexposure s confounde dwit hothe r jvariable s tha t effec t IQ , an d therefore , som e it' s impossibl e j t o observ e IQ * decrement s i niridividual s andattribut e the mt o

: sinql e causes . Simolv , it' s a muc hmor e complicate dproble m i ... . - jan d i t require d a slightl ydifferen t protocol .

I ndevelopin g th e protoco l fo r doin g th e probabilit y encoding , w e use d1 4 consultants . W e circulate dman ydraft s 2 0 2 1

•2 2 2 3 2 4 2 5

EXECUTIV ECOUR TREPORTER S (30! ) 565-0064P.8 5 8 4 fo r the.protocol ,

W e shifte d ou r focu s t o a hypothetica l experimen t tha t I wil l describ e momentaril yan dw e di da considerabl e amoun t o f pilo t encodin g unti l w e finall yfel t w e ha dth e 5 j proble mwel l structured . Now , i nth e hypothetica l experiment , jw e aske d ou r expert s t o consider , t o imagin e tha t a larg e 

## I i I numbe r o f childre nwer e randoml yassigne dt o exposur e groups . i j The exposur e group s wer e define db ybloo d lea d

gj , o nth e thir d birthdav . Th e contro l grou p wa s sheltere dfro m 

## I j 1 0 jjlead . Th e experimenta l group s wer e expose dsuc htha t th e bloo d lead , o nth e third , birthda ywa s eithe r 5 , 15 , 25 , u p throug h 5 5 microgram s pe r deciliter . An d o nth e sevent hbirthday , w e administere d th e WISC- Rt o ge t thei r I Q source .

S o thi s wa s a hypothetica l experiment . Now , th e expert s wer e give nth e opportunit yt o conside r th e experiment s separatel yfo r lowe r ari d highe r SC S populations , wer e lowe r SC S population s define da s th e lowes t 1 5 percen t o f income . W e di d tha t a s t o a s consisten t wit hth e NHANE S grou p a s w e could . Fiv e ou t o f ou r si xexpert s di d that . Now , thi s hypothetica l experinien t ha s severa l advantage s ove r wha t woul d hav e bee nth e firs t blus hi nou r straigh t forwar dprotocol , namel yth e question s tha t w e aske dou r expert s wer e natura l t o thin k about . Th e hypothetica l dat a ar e simila r i nfor m t o actua l data , bu t withou t th e problem s o f th e covariates . 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 EXECUTIV ECOUR TREPORTER

S (301 ) 565-006 4P.8 6 8 5 Thes e question s allowe du s t o calculat e certai n 2 importan t indicators . On e wa s subjectiv e probabilit ydistribu

3 I tion s ove r dos e effec t functions , mea nI Q decremen t a s a func

tio no f bloo d lead . 5 i An d th e othe r wa s a subjectiv e probabilit ydistribu

6 tion s eve r dos e respons e functions . Apercen t o f childre n havin g a lea d induce dI Q belo wan yparticula r level . W e aske d ou r expert s t o giv e u s probabilit yjudg

i ; 9 | i ment s "about thre e perameters , tha t i s thre e parameter s fo r th e | 

# Pi 1 0 | lo wSE S grou p and thre e perameter s fo r th e hig hSE S group . j 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 On e wa s th e mea no f wha t the ythough t th e mea nI Q o f th e contro l i grou p woul d b e andI'l l com e bac k t o thi s i na minute .

Th e secon di s wha t the yfel t th e withi ngrou p I Q i i standar d deviatio nwoul dbe . An dth e thir di s wha t the yfelt j th e mea nI O decremen t fo r eac ho f th e experimenta l group s rela

tiv e t o th e contro l grou p woul dbe .

An d w e didn' t as k i t i nthi s direc t fasion . Bu t ther e isn' t tim e t o tal k o f th e detail s o f ho ww e di dth e probabilit yencoding .

Now , on e woul d immediatel ythink , wel l fo r point s 1 and 2 , why"not jus t g o t o th e standardize ddata ? Well , w e d o kno wmea nIQ' s andw e d o kno wstandar ddeviation s ands o o n

Th e poin t is , th e standardize ddat a include s kid s wit hlea d i nthei r system . An dwe'r e talkin g her e abou t contro l groups . EXECUTIVE COUR T REPORTER S (301 ) 5 65-006 4P.8 7 1 ' =n~ • 

### 8 6 i i j ' • .S o w e di dbrin g wit hu s t o thes e sessions

- th e bes t i i 2 standardize ddat a w e coul dfin di nstratifie daccordin g t o th e 3 ; suitabl e variable s here , an d w e aske dou r expert s t o consider

4 I ho wthes e group s woul db e i f onl ythe ydidn' t hav e th e leade d

=. kid s i nthem . 6 Now , thi s i s no t somethin g w e coul dcalculate , an d

7 j again , ther e i s no t tim e t o explai nwh ythat' s true . I ca n 8 . • answe r an yquestions . i 9 . Bu t i t wa s u p t o eac hexper t t o tak e th e standard

j 1 0 j ize ddat a a s the ywere , adjus t the ma s h e o r sh e wishe dt o o r | yj wha t hav e you . Ther e wa s on e exper t wh o fel t uncomfortabl e 

### j 1 2 | doin g that , "an dthough t w e shoul db e abl e t o calculat e i t bes t ! 3 | a s v/ e can . j ; 1 4 i S o fiv e o f th e si xexpert s responde dt o al l o f th e

, r I 1 thre e Question s an don e o f the m pointe dt o a thir dcuestion . l b, "

- j j Her e ar e th e peopl e wh o participate di nth e encoding , the yal l I D , ; 7 | i agree dt o d o it . 1 8 vA s I sai dther e ar e si xpeople . Fiv e o f th e si xdi d i 9 jgiv e u s probabilit yjudgment s o nal l thre e o f thos e perameters , ; an don e o f the mo nonl yth e thir done . Ther e wa s a goo dattempt . i I mad e t o spa nth e rarjg e o f opinion s an djudgment s regardin g th e j jI Q effect s o f lead . j I Now , thi s i s a representation , no t a particularl y 2 0 2 1 2 2 2 3 'ieas yon e t o read . An dw e wil l com e t o easie r grap hi njus t a 2 4 i j 2 5 | ; second . Bu t

representatio no f eac hexpert' s probabilit y

EXECUTIV

ECOUR TREPORTER

S (30! ) 565-006 4P.8 8

( • '

1 2 3 4 5 6 7 8 9 1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 8 7 judgment s regardin g th e mea nI Q decremen t a s a functio no f bloo d lead . Thi s i s reall yjus t a representatio no f th e thir d peramete r tha t w e encoded .

Nov/ , not e i nparticula r her e tha t th e ranges , th e 1 1

rang e o f number s o nth e Xan dYaxis , ar e no t th e sam e fro mexper t t o expert . Thes e ar e no t comparabl e graphs .

Bu t let' s g o ont o th e nex t on e a s it' s easie r t o see . Her e i s th e sam e representatio nv/ e ha dfo r hemoglobin , lookin g onl ya t the'judgment s regardin g mea nI Q decrement s t o th e lowe r

I SE S population . j

Again , eac hpoin t represent s th e media njudgmen t an c th e bar s aroun d th e point s represen t thei r 9 0 percen t credibl e 'intervals . An d yo u se e fo r example , tha t ther e i s a - - le t m e tur nt o m ynote s fo r a secon d her e —ther e i s a goo ddea l o f agreemen t throughou t betwee nexpert s G , H an d J an d a good " .dea l o f agreemen t throughou t betwee nexpert s I an d K .

B u t the nb yth e bloo d lea d leve l o f 25 , G , H , I , J

an d K al l hav e overlappin g judgments . Exper t F considere dth e effect s o f lea d t o b e muc hles s an d tha t person r s judgment s begi nt o drif t awa yfro mth e others .

Exper t F.feel s tha t ther e reall yi s n o effec t u p ti l 2 5 o r 3 0 microgram s an d the njus t a ver ytin yone . S o

• ther e i s reall ya goo d dea l o f overla p i nthei r judgments .

Fo r example , a t bloo d lea d o f 25 , no t focusin g o n exper t F , th e lowes t media njudgmen t i s tha t there' s a mea n j j EXECUTIV E COUR T REPORTER S n(3.1 ) 565-006 4 1P.8 9 | . 8 8 | 

# i I iI Q decremen t o f 2 point s andth e highes t i s tha t there' s a mea n iI Q decremen t o f clos e t o 5 points . S o there' s roughl ya 3 I jpoin t differenc e betwee nth e media njudgments . Thi s i s no t I " i icomin g u p fo r fiv e ou t o f th e si xexperts , ands o on . i i 5 S o ther e reall ydoe s appea r t o b e a goo d dea l o f i ' 5 i i cer.era l agreement , considerin g th e leve l o f uncertaintv . W e 

### j i ' _ 7 j j wer e also , no wmakin g us e o f al l thre e perameter s tha t w e aske d j; 8 ; th e expert s about , t o calculat e subjectiv e probabilit ydistfi

-

- ' bution s ove r th e percentag e o f kid s wit hlea dinduce dIQ' s be

l i i jlowan yparticula r level , and fo r illustratio nhere , w e too k 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 

### a nIQo f

8 5 whic hi s bas estandar ddeviatio nbelo w norma l I | Thi s i s mos t analogou s t o a dos e respons e function . 1 ! iThe othe r function s w e showed , yo u ar e analogou s t o dos e effec t jfunctions . Thi s i s analogou s t o dos e respons e function . I ij An d her e i s th e grap htha t i s eas yt o read , wher e again , yo u se e a goo d dea l o f overla p amon g th e implication s o f th e judgment s o f no wfou r o f th e fiv e experts . On e expert , exper t I di d no t fee l comfortabl e makin g th e judgment s regardin g th e contro l grou p ands o on , s o w e couldn' t d o thi s calculatio n fo r tha t person .

I thin k X

se t a ne wrecord . Thi s wa s originall ya 4 0-minut e talk . Le t m e d o th e summary .

Le t m e mak e som e observation s abou t ou r methodolog y First , w e di d mak e us e o f statistica l an djudgmenta l uncertaint y a s appropriate . W e use d statistica l uncertaint ya s fa r a s i t EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.9 0

D | i

8 9 1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 

### 8 9 i t woul d tak e u s an d wen t beyond tha t wit hth e judgmenta l un certaint ywhe nnecessarv .

• _< • 

### It' s fai r t o clai mtha t the participating expert s • a t leas t wit hsome practice , an d som e - - afte r being i nthi s situatio n£>

r a littl e while , wer e comfortabl e wit hth e proces s | It' s importan t t o realiz e tha t b ycarrying ou t thi' s probability 

# i encoding process , we focuse d onwell-define d scientifi c issues , s o tha t whe nther e wer e judgmenta l disagreements , theywer e | ! attributabl e t o interpretation s o f evidenc e an d no t t o differ



# l l fence s o r

definition s o r

polic yimplication s o r wha t have,you . i i

### j Onc e w e di d that , i t turn s ou t ther e reall ywa s o r i

### ji s substantia l overlap i nth e judcments , an d it' s wort hpoint

- | 

### jin g ou t tha t ou r resulting probabilit yestimate s ar e obtaine d ir i a systemati c open , an d defensibl e mariner . Eac hexpert s uncertaintie s represen t itprobabilisti



# I cally . Th e rang e o f uncertaint yacros s expert s i s represente d probabilistically .

Th e implication s o f thes e uncertaintie s canb e explicitl yderive d an d w e believ e tha t thes e representation s an d implication s shoul d b e usefu l t o analyst s an d decisio n fmaker s inconsidering maximu mallowabl e blood lead levels . i i 

### Now , thi s i s a suitabl e plac e fo r m e t o stop t o tak e some ques tion s befor e v/

e tr yt o kind o f ti e thi s i nwit hexposur e analysis . S o le t me stop her e an d se e i f anybod

yha s an

y

EXECUTIV

E COUR T REPORTERS (301 ) 565.006 4P.9 1 9 0 1 1 1 Questions . 2 >\CHAIRMA NLIPPMANN : Granger ? 3 i j MR . MORGAN : Mr . Chairman , I'v e bee ngivin g advic e •

i ; : i 4 - i t c OAQP S o nthi s genera l proble mare a no wa s a membe r o f thre e 5 . differen t SA B committee s o r subcommittees . An dOAQPS , o f 5 ; | course , know s tha t man yo f m ycomment s ove r th e year s hav e 7 I I bee nhighl ycritica l i nthi s area . 8 ' : Fro m everythin g I ca ntel l fro mlookin g a t th e | 9 7 document s supplie di nthi s briefing , I thin k thi s i s a firs t j 

## l l I 1 0 7 clas s piec e o f work . I thin k OAQP S i s t o b e congratulate dj 7 i

' • I 1 1 i j fo r havin g persiste dand . don e i t correctl yan dwell . j | j " * i 1 2 I j I thin k i t set s a nexcellen t precedenc e fo r th e

r i : i 1 3 ' j us e o f thes e kind s o f techniques . I nth e future , I woul donl y i l — 1 4 l | urg e yo u strongl ya s yo u begi nt o thin k abou t usin g simila r 1 5 j technicue s i nupcomin g criteri a reviews , tha t yo u appl yth e 16 sam e qualit yo f hig hleve l judgmen t o nth e qualit ycontro l 1 7 ! ! that' s displaye di nthi s work , i l CHAIRMA NLIPPMANN : Warne r ha s als o participate d fo r a lon g tim e i nthi s development . D o yo u hav e an yadditiona l comments ? DR* . NORTH : I woul dlik e t o ech o Dr . Morgan' s com 2 , ! | ments . I woul dconcu r wit hhi mcompletely . i i 2 3 

### | j Id o feel , however , tha t v/it hrespec t

t o th edraf t 1 8 i i I 1 9 i 2 0 21

l l 24 repor t o nthis , ther e i s som e polishin g that' s needed , an dI 2 5 | ! wil l communicat e tha t directl yt o th e authors ,

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. _____________________——^——

— - 1 • | 9 1 CHAIRMA NLIPPMANN : That' s certainl ytrue . Dr . Mahaffey ? i i 3 | | DR . MAHAFFEY : Thi s i s no t critica l o f you r method , l i I t 4 | ; bu t I thin k it' s importan t t o perhap s brin g t o you r attentio n p 5 . an d th e grou p m

general , th e dat a tha t relate s t o erythro

6 i , cyt e propoporphyri nt o bloo d lead , represent s on e dat a set . 7 j | There' s anothe r larg e dat a se t whic hagai ni s 3 ;'NHANES . W e kno w"tha t erythrocyt e propoporphyri ni s influence d g I I ver vmuc hb yiro nstatus , a s -wel l a s b ylea d exposure . 

# I I 1 0 j , An c I' mver yconcerne d tha t b yusin g th e dat a se t I ; yjo f Piomell i onl yi nwhic hiro nstatu s i s no t measure dan dno t I i 1 2 I accounte d for , tha t perhap s th e kin d o f conclusion s draw nar e M i ; 1 3 j j incomplete , no t becaus e o f you r method , bu t simpl ybecaus e th e I 1 4 idat a sets , w e hav e bee nworkin g with , i s no t providin g ful l I I !, ' - - . , i i mrormation . 1 3 i i 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 An d I don' t kno wwhethe r Dr . Chisol man dDr . Angl e

o r Dr . Hammon d migh t car e t o als o addres s thi s topi c bu t I wil l b e gla d t o provid e a preprin t o f th e pape r a s wel l a s th e NHANE S publicatio ni nwhic hthi s i s deal t with .

B u t there' s firs t o f all , an'interactio nter mbe

twee niro nstatus , lea d exposur e an d th e E P response . An d definitel yi nth e dat a set s whic hyo u hav e hear d t o wor k with .

I thin k you r dos e respons e informatio nma yno t reall yreflec t wha t happen s wit hlead .

DR . WALLSTEN : I f I ca nsa ytw o thing s i nrespons e

EXECUTIV E COUR T REPORTER S

(30i ) 565-006 49 2 I 

### i i ! 1 • i t o that , You r poin t ther e i s ver ywel l taken , tha t jus t th e j 

# l i| 2 I'-sc t tha t th e dat a se t ha s a larg e numbe r o f observations , I 3 i: doesn' t necessaril ymea nvo u shoul d g o v/iththa t dat a se t onlv, ' J ' I 

### i ' 

### - - I 4 '< Tner e ar e consideration s o f a sor t tha t yo u mentioned . ! ' ' ! 5 , An d fo r bette r o r fo r worse , w e onl ywen t t o tha t j I 6 ; dat a se t afte r som e peopl e tol d u s tha t the yfel t ther e wa s a I i " : 7 ' goo d representativ e dat a set . Bu t certainl yi ngeneral , th e j

, i I i 8 I fac t tha t it' s a larg e dat a se t doesn' t mea nit' s a goo don e j 

### i I 9 ' t c us e fo r thi s kin d o f purpose . | 

# ! : 

# . I 1 0 j An d tha t i f ther e ar e factor s o f a sor t tha t we'r e . i 1i 1 1 j ; talkin g about , the non e need s t o b e concerne d wit hthose , sinc e 

### I ! 

### j 12 j . ther e ar e multipl e dat a set s an d on e coul d handl e them . I j ! ' ' i ; ' i 13 | | agre e wit hthat . j i I j i 14 I -.Now , w e wer e awar e o f a secon d dat a se t tha t w e : i 15 •' di d no t us e becaus e o f certai nstatistica l nonindependencie s i j 

### i 1 6 1 7 1 8 j 1 9 2 0 21 2 2 2 3 2 4 2 5 withi ntha t dat a set . I t looked , crudel ya s i f i t wa s give nth e i i ' sam e results , bu t w e couldn' t d o th e sam e kin d o f analysis . i S o tha t poin t i s wel l take ni ngeneral . I agre e I I wha t tha t point . Th e othe r thin g le t m e jus t ask , I though t j tha t Piomell i an d hi s grou p ha d take nou t kid s wh o wer e iro n deficient . DR . MAHAFFEY : Th e thin g tha t pape r state s whe nyo u ge t int o i t ver ycarefully , i s tha t the ywer e selecte dt o min i miz e th e numbe r o f iro ndeficien t childre nb ylookin g a t childre nwho , I think , wer e a t leas t tw o year s old . A s I 

### EXECUTIV

E COUR T REPORTERS (50! ) 565-006 4P.9 4 I I 9 3 l l , i . understan dtha t dat a set , ther e ar e n o actua l measurement s 

### i l 2 ; ' o f iro nstatus . i

3 j j DR . SILBERGELD : I woul djus t lik e t o registe r 4 l agai nm ymisgiving s abou t thi s process . An dit s us e i nth e r i 5 decisio nmakin g o f OAQP S an dEPA . 6 I . I thin ktha t i t enshrine s a tendenc ytoward s con 7 j l sensu s an d majorit yopinio nwhic hi s fundamentall yoppose dt o 8 ! th e progres s o f science . An d tha t b ylookin g toward s th e 9 I centraiit yo f judgment s an d opinions , abou t th e effect s o f l i 1 0 '.toxi c substances , i t tend s t o discar doutlyer s whic hma yi nj 

### j fact , i nth e cours e o f furthe r informatio nan dresearch" , turn j

i i o u t t o b e wha t i s th e case . An dit' s ius t a "fundamenta l I 11 1 2 1 3 I ; philosophi c reservatio nabou t thi s process . I woul djus t lik e 14 t o registe r it , 15 I DR . WALLSTEN : Le t m e respon dt o that , sinc e I dis

- | |agre e wit hyo u strongly . Bu t it' s onl ya matte r o f opinio n 

### I , i j l o f course . I nan ycase , I woul dargu e tha t rathe r tha npu t t h e scientifi c researc hi na secondar yposition , bu t t o some time s hel p t o do , i s i t poin t ou t wher e researc hi s mos t

2 1 needed , b y— * especiall yb ylookin g t o se e wher e ther e ar e outlyer s v/it hrespec t t o th e majorit yopinion .

There' s a distinctio nbetwee nhavin g t o mak e a polic yjudgmen t give navailabl e informatio nan ddecidin g wher e d o pu t resource s fo r futur e scientifi c research . I don' t thin k 1 6 1 7 j l 1 8 1 9 2 0

2 2 2 3 2 4 2 5 

### I !



### H EXECUTIV ECOUR TREPORTER

S (30! ) 565-0064P.9 5 9 4 th e two.shoul d b e confused . I thin k th e proces s i s usefu l fo r 2 both , bu t fo r th e on e want s t o loo k a t th e outlyer s an dthe n 3 questio nwhytha t perso nha s thos e judgments . An dfo r th e other , want s t o expres s a s wel l a s possibl e th e weigh t o f th e 5 curren t judgment . 5 The yar e tw o differen t bu t relate dprocesses .

CHAIRMANLIPPMANN : Than k you . Whydon' t w e mov e 8 j j ahead . i ; i l 9 | MR . MORGAN : Ma yI hav e 3 0 second s o nthis , Chairmanf " 1 0 j j I nth e earlie r wor k tha t OAQP S di d exactl ywha t yo u her e ex j j 1 1 j ! presse d an d wa s reflecte di ntha t work . Namely , expert s wer e 

### I 1 2 | essentiall yaverage d acros s andon e go t a singl e composit e 

### i ! 3 j result . 1 4 Thes e result s no wa s presente di nthi s staf f pape r

1 5 ar e displayed , exper t byexpert , s o on e ca nindee dse e bot h 16 —on e ca nse e t * i e r£n 9 e of exper t opinions . An di f ther e 1 7 ar e peopl e wh o hav e clearl yver ydifferen t opinions , the yar e i 8 i displayed , I certainl yagre e tha t a nactivit ytha t involv e 1 9 averagin g acros s expert s whe nexpert s ar e no t al l tellin g yo u th e sam e thing , i s dangerou s i nthi s kin do f environment . 2 1 DR* . WALLSTEN : Th e pla ntha t w e ha di s tha t a t thi s point , I wil l si t dow nandRo nwoul dtel l yo u ho ww e usuall y

-.

_g o i nexposur e analysi s

2 4 DR . WHITFIELD : Thi s i s wher e w e picke du p wit h

2 5 th e ris k assessment . W e use di t i nfocusin g encode djudgment s

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I I 5 6

9 1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 9 5 and th e .publishe d dat a appropriat e t o develo p functiona l repre- } sentation s fo r dos e respons e relationships .

W e combine d tha t infornatio nwit hbloo dlea ddistri

butio ninformatio nt o for mth e overal l ris k distributions . jTh e bloo d lea d distribution s cam e fro mth e exposur e analysi s i jtha t Donn a ha s s o carefull ydescribe dth e las t coupl e o f day s

i j W e hav e som e statement s t o mak e abou t th e exposur e estimates . On e and I' mreiteratin g wha t Donn a jus t said , o r woul d hav e sai di f sh e ha d a chanc e t o g o i nal l he r details , on e i s tha t th e estimate dmea n- - thes e ar e estimate dmea n bloo d lea d level s andthei r averag e i s ove r wid e area s aroun d th e poin t sources .

Second , thes e mea nbloo d lea dlevel s ar e base do n i ai r qualit yestimate s a t geographi c centroids . Bot ho f thos e I things , bot ho f thos e assumption s coul dlea dt o underestimatin g th e gettin g - - lea d t o estimatin g lowe r bloo dlea dlevels , i. e overlookin g th e mos t sensitiv e childre nclos e i nt o th e poin t sources . EP Ai s workin g o nrefinin g th e analysi s grou p t o ge t a bette r ide a o f ho whig hthos e bloo dlead s ma yindee d be . Th e thir d poin t i s tha t th e bloo dlea dlevel s ar e fo r 8 4 mont h cohort s o f children . An dth e fourt hpoin t i s a nassumptio no n ou r par t whic hseem s t o b e ver ypopula r i nth e literature , on e o f assumin g tha t th e bloo d lea ddistribution s ar e lo g norma l an d w e use d th e bes t estimat e fo r th e geometri c standar d

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(301 ) 565-006 4P.9 7 I j 9 6 

## [

Her e ar e th e mea nbloo dlea dvalue s tha t w e use d 1 ; , deviatio nw e coul dfind , tha t o f 1.4 2 microgram s per - decilite r 2 3 j t o d o th e erythrocyt e propoporphyri nris k estimate s t o develo p 4 Mthem . Th e model s wer e abl e t o produc e bloo dlead , mea nbloo d 

# I ! 5 | , lead , estimate s fo r childre nage d0-6 . j i i i i 6 j; An d tha t mos t closel ymatche dth e age s o f th e childre n j j i 7 j l tha t wer e i nth e Piommel i e t a l studyandthat' s whyw e use d l i 8 j; thes e numbers . Wha t w e hav e her e ar e estimate s aroun dtw o 9 l i poin t sources , whic hw e labe l 5 and2 . Fiv e ha dth e bes t I 

# I " I 10 ' ; ai r quality , i f yo u will , and2 ha dth e wors t ai r quality , and t 

# 5 I n| j th e othe r 3 wer e inbetween . j ii ' I I ! 12 I Thre e scenarios , thre e group s o f scenarios , wer e j 

## j j ' I 13 | l considere d i ndevelopin g mea nbloo dlea destimates . On e wa s 1 4 | th e baselin e a s Donn a ha s discusse dandth e pos t contro l period , a s Donn a als o discussed . 1 5 16 1 7 18 1 9 2 0 2 1 2 2 2 3 2 4 2 5 !

Athir dperio dinbetwee nwa s th e pre-contro l perio d Fo r lac k o f time , we'r e no t focusin g o ntha t righ t now .

Pos t contro l perio dals o considere d fiv e alternat e ambien t ai r qualit ystandard s fo r lead .

DR . SILBERGELD : I nconsiderin g th e dat a tha t hav e bee ncollecte' d aroun dth e world , d o yo u seriousl ythin k tha t i t i s conceivabl e a t anypoin t i nth e foreseeabl e futur e tha t bloo d lead s i nth e Unite d State s wil l b e a t tha t level ?

DR . WHITSTEIN : You'r e referrin g t o th e lo wlevel s ou t o nth e righ t side ?

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(301 ) 565-006 49

1 0 , 1 1 1 2 13 1 4 15 16 17 18 1 9 2 0 2 1 2 2 2 3 2 4 2 5 9 7

DR . SILBERGELD : Yes . I aske dm yfello wcolleague s o nthi s Committe e whethe r the ythin k tha t that' s foreseeable . Katie , d o you ?

DR . ANGLE : It' s seem s especiall yunlikel yi ntha t sourc e too , wher e yo u hav e i nte nyear s yo u propos e complet e irradicatio no f surfac e residues .

DR . WESOLOWSKI : W e hav e t o improv e ou r detectio n limi t quit e a bit , won' t we , t o ge t dow nthere ?

DR . SILBERGELD : Well , th e thin g c f th e Nepales e j j j childre nwer e what , 2-4 ? : j DR . MAHAFFEY : Th e thin g tha t concern s me , thi s take ^ i I of f fro m

th e projection s tha t v/er e give ni nth e earlie r presenta f tio nwhic hI thin k th e consensu s o f th e grou p i s thos e require j som e validation , an dt o the ndevelo p thi s fro mthat , seem s t o b e unrealistic .

MR . HAINES : I thin k tha t - - le t m e clarif ya coupl e o f points . I thin k yesterda yw e trie dt o ge t th e poin t acros s tha t w e ourselve s v/er e no t satisfie d wit hestimatin g geographi c centroids . Yo u raise dothe r concerns . I don' t thin k —s o w e kno ww e hav e "concern s abou t th e ai r qualit yprojections . Unde r themselve s fo r th e purpos e o f Ron' s presentation , I don' t thin k they'r e ver ysignificant .

Wha t he' s tryin g tod o i s sho who wyo u marr ythes e tw o things . W e com e bac k wit hexposur e estimates , everybody EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.9 9 

### I ! 9 8 i j i , ; agree s .to , an d yo u thin k hi s methodolog yi s appropriate , the n il 

### i i 2 j : v/ e ar e goin g t o produc e a viabl e result . S o al l I' mtryin g t o i i 3 i j sugges t i s thos e number s themselve s input , ar e ' immateria l for

- 

## ; i i j 4 i i wha t he' s tryin g t o tel l u s righ t now . 5 I thin k w e shoul d proceed . 5 : MR . JORDAN : I echo , don' t ge t locke d i na t lookin g 7 ; , a t th e numbers . He'i s tryin g t o sho wyo u methodolog yo f ho wyo u i I

• ; i 8 wol d rak e th e ris k number s tha t we'v e generate d befor e an dj i i 9 . : assumin g w e haven' t com e u p wit hth e righ t exposur e model , ho w 

### j j 1 0 yo u the ng o t o estimatin g wha t th e ris k i s goin g t o b e ou t

nj , ther e i nth e population . 1 2 j l DR . SILBERGELD : Well , wit hal l du e respect , I 1 3 ' I thin k we'v e spen t a lo t o f tim e a t thi s meetin g talkin g abou t j i u7 thing' s tha t v/er e the ntol d ma yhav e n o reality . I woul dprefe r

1 5 7 tha t thi s Committe e spen d tim e focusin g i non e wha t w e conside r i j t o b e mor e closel yt o th e rea l worl d situation . j I don' t fee l muc hinteres t i nconsiderin g a scenari o

1 8 7 wher e th e uppe r - - th e rang e o f bloo d lead s i nthi s countr yar e 

# I I 1 9 ;• goin g t o b e somethin g belo wNepal . Becaus e I don' t thin k it' s

eve r goin g t o happen .

I thin k th e transfe r fro mmaterna l t o feta l organis m 1 6 1 7

2 0 2 1 

### I ! j j i s goin g t o b ei nexces s o f that . We'r edealin g wit hris k 

# i | j j assessmen t an d the nsom e implicatio nfo r regulation .

_ , ! , CHAIRMA NLIPPMANN : Warner ? 2 4 i i

„ j | MR . NOLL : I wonde r give nth e discussion s tha t we'v e Z 0 I ! I : j j I j iEXECUTIV ECOUR TREPORTER S | i(301 ) 565-006 4P. 1 "' H ' I 9 9

6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 i j ha d and . th e reservation s tha t man vo f u s hav e ha dabou t th e 

## l i " • i j exposur e analysis , it' s wort hgoin g throug hthes e numbers . i i : j I t seem s t o m e tha t goin g throug hthes e las t slid e i nyou r 

# i ! : ' presentatio nan ddiscussin g thos e conclusion s woul db e usefu l 

## i!

• i ; and appropriate . Bu t th e intervenin g graph s ands o forth , I

. : thin k ar e usefu l onl yi nshowin g th e for mo f a nanalysi s tha t ! i ; ; migh t b e con e i nth e future . i j ' i ! : DR . WHITFIELD : I woul d lik e t o sayon e thin g befor e : . w e ski p t o th e end . I f Ellen , fo r example , th e answe r i s o nI 

## i i ! ;th e righthan d sid e andtur ncu t t o b e close r t o 10 , woul dthat ; i j i j | b e mor e believabl e t o you ? ' !: ' i 

## l i j | DR . SILBERGELD : I jus t wan t t o say , I hav e a plan e ''tha t leave s a t 1:3 0 andI thin k tha t thi s Committee' s tim e 

## i ! j j woul d b e bette r spen t dealin g wit hwha t w e anticipat e t o b e th e residua l effect s o f lea dandth e controllabilit yo f signi

ficanc e sources . /

DR . WHITFIELD : Okay , tut I wan t t o tel l yo u tha t th e ris k estimate s tha t w e deriv e sor t o f botto mou t i f yo u will , an d the ybotto mu p abov e 10 . An d th e fac t tha t w e sho wnumber s her e — DR" . SILBERGELD : Well , that' s wha t I thin k w e nee d t o tal k abou t wit hrespec t t o som e o f th e feta l effects , exactly , instea d o f talkin g abou t poor .

MR . NOLL : Ron , , 1 thin k man yo f u s hav e ver yseriou s reservation s abou t th e dat a fro mwhic hthes e number s came . EXECUTIVE COUR T REPORTER S

(301 ) 363-0'.-64P. 2 10 0 DR . WHITFIELD : Yes , I appreciat e that . CHAIRMANLIPPMANN : Ca nyo u pus hthroug ha littl e faste r tha nand no t (laughter ) - - j DR . WHITFIELD : W e understan dth e growin g concer n i I ; abou t th e ris k estimates . And s o w e d o wan t t o cavea t th e - - j i i j j • exposur e estimate s - - s o w e wan t t o cavea t th e ris k estimate s \ \ tha t w e hav e produced . i ; Ou r mai npoint s no war e th e following : w e hav e 

### i i 9 l i demonstrate d tha t dos e respons e an ddos e effec t relationship s 

# i ! 1 0 j : ca nb e combine dwit hexposur e estimate s t o calculat e ris k j i i estimates . An d o f course , th e whol e i s n o hel p her e tha nth e j su mo f th e parts , and we'reno t questionin g th e sumo f th e part Secon dpoin t i s tha t specifi c ris k estimate s ar e 

# j ope nt o question s du e t o th e preliminar ynatur e o f th e exposur e 

### i estimate s whic har e unde r furthe r evaluation . Th e thir d point ) i s tha t a nimprove d ris k assessmen t woul dincorporat e th e distributio no ngeometri c mea nbloo dlea dlevels , rathe r tha n lowerin g uppe r bounds

W e found , however , tha t th e differenc e betwee nlowe r an d uppe r boun d estimate s wa s no t tha t grea t i nthi s case . That' s notto'sa ytha t tha t wouldn' t b e tru e i nothe r ris k assessments , sayinvolvin g ozone , a s i s the cas e here .

CHAIRMANLIPPMANN : Dr . Noll ? DR . NOLL : I hav e tw o questions . Th e firs t is , I' d lik e t o hea r you r respons e t o th e issu e abou t ove r 2 0 2 1 2 2 2 3 24 2 5 EXECUTIV ECOUR TREPORTER

S (301 ) 565-006 4p ^

. —" • I • 10 1 confiden t i nth e followin g sense . It' s on e thin g t o ge t exper t prediction s abou t wha t da yexpec t t o b e stat e o f th e maximu m likelihood , estimat e o f a neffect . It' s anothe r thin g t o ge t thei r subjectiv e estimate s abou t th e distrubutio nfunction . 5 \: An d I thin k her e i nterm s o f th e wor k o f Lichensteiif i ! ! 6 j i an d Ishof f an d Slovi c wh o sa vtha t expert s svstematicall yunde r 

# l l *

7 i j estimat e th e variant s i nthei r ow nestimates . An dtha t s o 8 9 tha t i f yo u translat e thi s int o a ris k assessment , you'r e goin g t o ge t a nunderestimat e o f th e degre e o f variant s i nth e tru e 1 0 i , stat e o f th e worl db vtakin g th e expert' s estimate s o f variant s 

# I ' I i a t th e base . j

Th e secon dquestio nI hav e ha s t o d o wit hth e dif

- ! ferenc e i na basia nsense , betwee nexper t difference s o f opin

io ntha t diffe r o ndifferen t state s o f information , a s oppose d t o difference s i ninterpretatio no f th e sam e information . An d i nparticular , wha t exten t hav e yo u o r ca nyo u imagin e collect

in g informatio ntha t woul denabl e u s t o separat e thos e effect s Tha t i s t o say , exper t response s tha t diffe r becaus e the yrea d differen t literatur e an d di d differen t experiment s an dlooke d a t differen t data , versu s exper t difference s tha t basicall yar £ route di nsor t o f fundamenta l difference s o f interpretatio no f th e sam e information .

DR . WHITFIELD : Well , I thin k we'v e addressed " al l o f thos e issue s i nth e car e tha t we'v e take ni npreparin g th e protocols . Fo r example , I woul dinvit e To mt o ad d t o m y 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 19 2 0 21 2 2 2 3 2 4 2 5 EXECUTIV ECOUR TREPORTER

S (301 ) 565-006 4P. 4 H '• ' 10 2

• » i i I I

6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 comments , he' s bette r qualifie dtha nI . Bu t I wil l attemp t t o answe r you r questions .

Th e first , regardin g th e behaviora l wor k that' s com e ou t o f Orego nResearc hInstitute , I hesitat e t o cal l the m j i colleagues , a s I've neve r worke d wit hthem , bu t we'r e awar e o f I i thei r work . I t i s ver yimportan t issue . i : I ; j l I nfact , i nth e protocol , w e addres s al l o f th e con - ; • cern s tha t the yhav e raise d "i nth e thei r literature , concernin g l ; j , ove r confidenc e and bia s an ds o fort hands o on . An dt o th e 

### j j | j bes t o f ou r ability , we'v e attempted , t o poin t ou t thes e pit

- j i i fall s i nprovidin g exper t judgment s t o th e peopl e u p fron t and i jmad e the m

awar e o f it , an d reminde d the mo f i t andI don' t i I kno wwha t humanl ycoul db e don e bevon dtha t t o overcom e hope

- | I full yth e effect s o f peopl e havin g differen t information .

I nth e protocol , i t di dpoin t ou t matter s o f re searc htha t w e though t wer e importan t t o b e considered . An d w e trie d t o b e a s complet e a s possible . W e brough t informatio n tha t w e fel t wa s recen t and the yma yno t hav e bee nawar e of , t o mak e sur e tha t peopl e ha d al l th e sam e informatio nthere .

Now , i nth e fina l analysis , a s yo u sa wfro mth e judgment s tha t wer e .pu t u p there , ther e wer e difference s i n judgments , and i nsom e cases , the ywer e dramatic . That' s jus t th e wa y— MR . NOLL : I wasn' t criticizin g wha t you'v e done , an d yo u answere d th e questio ni na differen t wa y—I mea nI kno w EXECUTIVE COUR T REPORTER S

(301 ) 565- 0

306 4P. 5 H 10 3 i i j i jwha t you'v e done . I wa s askin g i t i na sor t o f differen t way , | 2 |'whic

hi s tha t firs t o f all , t o tel l m e tha t m ysubjectiv e 3 j j probabilit yestimate s ar e likel yt o b e ove r confiden t isn' t - - j i 4 ! ' I mea nthat' s no t reall yth e problem . A H right ? I 5 j I mean , th e proble mi s tha t it' s a behaviora l i ; 6 : phenomeno ntha t peopl e subjec t t o probabilit yestimate s hav e ove r confidence . And on e could , i nfact , tak e historica l 8 ! informatio nabou t th e exten t o f ove r confidenc e and — 9 1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 DR . WALLSTEN : I woul dlik e t o respon dt o that . i j I thin k tha t thi s summar yo f Slovic , Lichenstein' s analysi s i tha t you'r e talkin g about , i t i s th e commo nsummar yo f th e re j suits , bu t I thin k it' s a littl e bi t overgeneralized . Muc ho f i ! th e researc ho nwhic hthi s i s base dconcern s askin g differen t I i peopl e almana c questions , whic hcit yi s larger , Raleig ho r Durha m o r wha t hav e you , and ho wconfiden t ar e yo u i nyou r answer . An d th e overwhelmin g resul t o f tha t kin do f researc h i s exactl ya s yo u described . Bu t th e overconfidenc e i s les s tru e whe nyo u as k expert s question s carefull yabou t th e area s o f thei r expertise . An dth e mos t extrem e exampl e o f tha t i s whe non e look' s a t probabilit yestimate s o f weathe r forecaster s and on e compare s — on e look s a t th e so-calle dcalibratio n curve s o r possibilit yestimate s o f weathe r forecaster s and they'r e extremel ygood .

.S o I thin k th e statemen t regardin g th e literatur e

EXECUTIVE COUR T REPORTER S

(;-:i ) 565-006 46 7 8 9 1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 PJ5 _ 10 4 tha t you'r e sayin g i s true , bu t whe non e ask s th e righ t kind s ! o f question s andstructure s th e proble mi nth e righ t way , 

# I j i t become s les s o f a problem . I don' t wan t t o sayit' s n o | problem , bu t I believ e it' s les s o f a problem . i " • I I MR . NOLL : On e commen t an dthe nI'l l kee p quiet . I i s o w e ca nmov e on . I mean , I don' t regar da nanswe r tha t say s I don' t understan d Slovi c and Lichtenstei na s wel l a s yo u have l it' s ridiculous . That' s whyI frame di t i nterm s o f varian t probabilit yestimates .

Th e resul t tha t I' mtalkin g abou t i s askin g experts ] abou t area s o f expertis e wher e yo u basicall yminimiz e th e bia s and th e probabilit yestimat e bu t yo u stil l hav e a signi

fican t effec t i nterm s o f th e estimat e o f th e varianc e i nth e subjectiv e probabilit yestimates . That' s al l I wa s talkin g about . DR . WALLSTEN : I' msorry .

DR . MORGAN : Ho wdid . yo u dea l wit hth e issu e o f insufficien t adjustmen t havin g gotte nth e correc t - -

DR . WALLSTEN : Well , a s muc ha s possible , w e trie d t o questio npeople' s judgment s byposin g hypothetica l out come s tha t woul d be.inconsisten t wit hth e probabilit yjudgment ^ and askin g the mt o conside r whethe r the ycoul dimagin e scenario s tha t woul d lea d t o this .

And . i ngeneral , w e trie d t o stretc hthei r - - I don' t kno wwhethe r th e termi s imaginaticn , bu t w e trie dt o

EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P. 7 •Tl 10 5 i j challeng e thei r probabilit ydistributio ntha t the ygav e u s t o l i 2 j

- se e v.'hethe r o r no t the ycoul d envisio nan yscenario s tha t woul d i j . 3 j | giv e ris e t o result s tha t woul d b e surprising , give nth e prob

j i 4 ! ' abilit yo f distributions . i . 1 1 5 : , S o it' s i ntha t fashion . 6 :j DR . MORGAN : Uppe r an dlowe r bound s o nthes e distri

7 [[ bution s wer e selecte d a t wha t stag e i nth e solicitatio nprocess ? i , 8 ' : DR . WALLSTEN : . The ywer e selecte d initiall yver y 9 ; early , bu t occasional yha d t o L e modifie d becaus e a s w e wen t 1 0 i 1 1 j i 1 2 j 1 3 j j 1 4 ! throug hth e process , w e discovere d tha t th e uppe r an d lowe r bound s wer e to o clos e together , an d the yha d t o b e stretche d out . I apologiz e fo r —I didn' t mea nt o misinterpret .

CHAIRMA NLIPPMANN : I thin k we'l l mov e on . Than k yo u

1 5 | ver ymuch . 16 DR . ROWE : I hav e a question , an d som e o f the mar e

1 7 jj

—an d a mo p up . Bu t wha t I' mtryin g t o understan d is , I don' t 

## j ! 1 8 

### ; j understan dthes egraph s tha t hav epre-contro lan dpost-contro l 1 9 2 0 2 1 2 2 2 3 an d a t th e sam e time , whe nwe'r e comparin g alternativ e contro l level s i nth e pos t contro l period . An d tha t jus t kin do f le a

m e comparin g "tw o differen t tim e period s wit htw o differen t i j lea d an d soil , lea d an d die t bases .

Thi s doesn' t see mt o b e th e questiontha t i a mface d

2 4 l i 

### i i 2 5 wit ho nth e panel . I don' t understan d th e secon d hal f o f thi s analysi s comin g t o thos e graph s a t th e end , ignorin g th e



### EXECUTIV

E COUR T REPORTERS (391 ) 565-006 4 ve sP. 8

^ S a 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 14 15 1 6 17 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 10 6 numbers , tha t ar e i nth e graphs . I t seem s th e graphs

- shoul d ; hav e pos t contro l scenario , .5 , .75 , 1 , 1. 5 o r whatever , an d j j I kno wi nyou r report , yo u sugges t tha t th e result s ar e no t l 

### I| muc hdifferent . i ; S o let' s se e tha t o r whatever . Bu t w e kno wtha t I j th e exposure s ar e goin g dow nthroug htim e an d fo r othe r factor s i j An d tha t sor t o f bein g associate d wit hthi s lea d standard , i t I seem s od d t o me . I jus t don' t understan d it . 

# iI I CHAIRMA NLIPPMANN : I thin k i t wa s difficul t t o fin d j j th e definitio no f thos e terms , pre-contro l an d post-contro l anywhere , an d i t mad e i t har d t o rea d it . An d I thin k th e I explici t statement s nee d t o g o alon g wit hthos e scenarios . 

# i j An d i f i nfact , i t doesn' t matte r wha t th e ai r lea d leve l turn s ou t t o b e o n"wha t th e bloo d lea d leve l is , that' s a nimportan t conclusio nand raise s som e concer nabou t th e validit yo f ambien t ai r qualit yleve l a t thos e levels .

I thin k perhap s w e wan t t o ge t bac k t o a mor e genera! , discussio no f wher e w e stan d wit hth e staf f pape r an dwha t kin d o f recommendation s thi s Committe e ca nprovid e t o OAQP S t o brinc r th e staf f pape r t o som e fina l resolution . W e clearl yhav e focuse d a lot"o f ou r concern s o nth e exposur e estimatio na s a critica l componen t o f th e ris k estimatio nwhic hdrive s th e concer nabou t settin g a standard .

An d i t ma yb e unnecessar yfo r u s t o g o int o to o muc h detai l unti l som e ver ybasi c change s ar e mad e i nth e discussio n EXECUTIV E COUR T REPORTER S

(J.i ) 565-006 4P. 9 ^ 10 7 1 and the.manne r o f treatmen t o f data , enablin g u s t o grappl e 2 wit hwha t vo u reall yfee l confiden t about , a s exposur e t o population s andlikel yeffects .

S o I woul dlik e t o ge t som e Committe e discussio n goin g o ntha t andthe nw e hav e a t leas t fro mon e membe r o f th e 5 j i Committee , a se t o f recommendation s tha t we'l l rais e an ddis



## j j cuss . Jus t som e genera l commen t first . Ellen ?

DR . SILBERGELD : Th e onl ygenera l commen t I woul d l ! 9 i . lik e t o mak e i s somethin g w c haven' t noted , before , andtha t i s 

# • ' i T O j j muc ho f ou r discussio nha s fortunatel ybee nblesse dbyth e larg e i amoun t o f dat a availabl e o nlead , andwe'v e bee nabl e t o focu s dow no nspecifi c bloo d lea d level s tha t see mt o b e associate d wit hth e appearanc e o f advers e effects .

W e hav e no t discusse d th e issu e a s providin g an y kin d o f margi nc f safet ybelo wthos e levels . An dI'jus t wan t t o remin d u s tha t w e hee dt o conside r tha t i f we'r e focusin g 'i na t levels , let' s say , we'r e talkin g abou t th e earlie r recommendatio no f thi s Committe e o f lookin g a t children' s bloo d maximall yi nth e rang e o f —wha t di dw e say- - 1 5 t o 20 , we'r e no wlookin g a t mal e bloo d pressur e dat a i nth e rang e o f 1 0 t o 15 . We'r e lookin g a t possibl e prenata l effect s slightl y belo wtha t level .

I thin k w e nee dt o remin d ourselve s tha t w e ar e dealin g wit ha certai nunusua l settin g now.o f actua l focusin g i no ndat a tha t sho wsignifican t effect s a t thos e levels , and n 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 EXECUTIV ECOUR TREPORTER

S (301 ) 565-006 4P.1 0

- _

_• ' [ •• i : 10 8 1 : . w e have , no t incorporate dan yconcep t o f providin g a protectio nj . i i I I 2 ! • DR . MAHAFFEY : I thin k i nth e area s wher e w e hav e 3 ; • som e numbers , wher e thi s so-called , margi no f safet yissu e 4 ; woul demerg e a bit , I thin k it' s absolutel ycritica l t o loo k 5 a t E ? a s a functio no f thos e iro nan dlead , th e dat a exist s t o 5 • d o it . I woul dmak e tha t a rea l stron g recommendation . 7 ; CHAIRMA NLIPPMANN : An yothe r comments ? 8 . DR . ROWE : Thes e ar e genera l comments . I' m kin do f 9 j curiou s abou t on e thin g tha t seem s neve r t o hav e bee ndiscusse d 1 0 j throughou t here , an dtha t i s thi s geometri c GS D o f 1. 4 2 seem s

., j ; t o b e prett ywel l accepted . An dwhil e I wa s readin g that , I i

1 2 j-accepte dtha t quit e readil ya s well , base dupo nth e wor k tha t

1 3 I' wa s there . 1 4 '•' Bu t th e mor e these'tw o day s hav e progressed , th e

, _l'mor e tha t numbe r seem s t o b e a genera l populatio nnumber , an d 1 5

, _lithe mor e w e see mt o b e talkin g abou t poin t source s fo r peopl e 1 6 1 ! ~ | | j!withi non e t o tw o kilometer s o f th e poin t source . An dI wonde r 1 7 I ! 1 8 1 9 2 0 21 2 2 2 3 2 4 2 5 ji f w e couldn' t g o bac k t o som e o f th e validatio ndat a an d 

# i iloo k a t a GS D fo r som e o f thos e population s close r t o th e sour c ijan dge t on e tha t migh t b e a littl e mor e appropriate . i j CHAIRMA N.LIPPMANN : I thin k tha t thi s i s a goo dtime , ji nligh t o f tha t comment , t o as k Dr . Morga nt o shar e wit hu s i i jhi s ide a o f what' s neede dan dus e tha t a s a basi s fo r a 'committe e discussio no f ou r recommendations . i DR . MORGAN : Thanks . I'v e writte nthi s a s thoug hi t

EXECUTIV E COUR T REPORTER S

(301 ) 565-CJ6 4P.11 I ; 10 9 i i . i t i s m

vownviews , onlv . Althouc hI hav e consulted

- wit ha 

### i ! i ! 2 " numbe r o f other s andwoul d argu e tha. t i t becom e th e basi s fo r 3 . ; som e tex t tha t w e collectivel ywor k up . i • 4 ; ' Thes e ar e suggestion s fo r undertakin g modification s 5 t o th e staf f paper . Ther e ar e fiv e o f them . Th e firs t i s t o 6 7 8 g 1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 . writ e a ne wintroductio nwhic hprovide s a mor e systemati c catalogu e o f th e ai r and non-ai r source s o r exposur e andthei r relativ e contribution s u p front , s o tha t on e get s initiall y calibrate d o nwha t th e proble mi s an dwher e it' s comin g from . I

An d the nmor e clearl yexplain s tha t becaus e o f th e ! ; | ; phase-ou t o f lea di ngasoline , EPA' s par t o f th e lea dproble m ; whic hwa s originall ya distributed , sourc e proble mlik e othe r 1 ambien t Pollutants , i s becomin g increasingl ya proble mo f th e ; contro l o f specifi c localize dsources , i

• On e need s t o not e tha t othe r part s o f th e lea dprob

- |

' lem lik e th e pain t problem , fo r example , ove r whic hEP Adoesn' t j hav e authority , ar e stil l ver yclearl ydistribute dsourc e jproblems . An d on e need s t o mak e i t clea r tha t th e primar y mechanis m

o f exposure , a t leas t fo r tha t par t o f th e problem , fo r whic hEP Aha s responsibility , tend s t o b e a s muc hfo r 

# I I i j muc ho f i t tend s to . b e vi a ingestio no f dir t anddus t andno t 

### ii i j vi a th e direc t ai r exposur e channe l o r no t bya direc t ai r 

### i i ; ! exposure , s o tha t on e ha s frame dth e proble mu p fairl yclearl y ! ! fo r th e reade r i nth e outset . ! l j | ji The nI woul dargu e tha t th e materia l o nhealt h EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.1 2

2 3 4

6 7 8 9 1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 | 11 0 j jeffect s .need s t o com e ou t o f th e middl e o f th e pape r andb e pu t u o front , s o tha t th e discussio no f source s andexposur e pro i ijcesse s ca nprocee d withou t interruption . Currently , on e ha s a bi g jum o whe nyo u g o fro mChapte r 5 t o Chapte r 7 , yo u hav e t o

: sor t o f carr yalon g i nyou r hea d a bunc hc f stuf f ou t o f 5 and j hav e i t bac k i nyou r hea d b yth e tim e yo u com e into-7 . I woul dargu e tha t on e shoul d rewor k th e treatmen t o f exposure , makin g i t cleare r tha t EPA' s primar yconcer ni s individua l sources . An d i nparticular , I thin k ther e need s t o jb e a critica l discussio no f th e problem s o f usin g knowledg e fro m are a source s fo r studie s o f poin t source s an dw e hear da commen t o f on e piec e o f tha t a minut e ago .

W e nee dt o focu s mor e o nand tryt o improv e th e materia l that' s covere di nAppendi xB andespeciall yTabl e B-2 , sinc e i t drive s th e bul k o f th e calculatio nandals o i s th e centra l contributo r t o th e uncertainty . Ther e need s t o b e a rethinkin g a considerabl e reworkin g o f th e poin t sourc e expo sur e estimates .

Ther e need s t o b e greate r discussio no f depositio n an d siz e distributio nissues , bot hi nterm s o f depositio no n and . resuspensio nfro mgroun d surfaces , andals o i nterm s o f depositio ni nth e respirator ytract . An don e need s t o b e mor e explici t abou t wh o i s bein g protected , andwha t th e leve l o f protectio ni s t o be .

I hav e concern s abou t th e 29. 9 Xapproach ,

EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.1 3

• ~ H 11 1 particularl ybecaus e a s it' s no wwritten , it' s ambiguou s whethe r that' s 9 9. 9 percen t o f peopl e livin g aroun dthes e dis

3 j j cree t source s o r 99. 9 percen t o f al l peopl e - - o r al l childre n i nth e country . 5 j ; An d tha t ambiguity , I think , give s ris e t o som e 6 | | considerabl e potentia l difficulty . On e need s t o pu t th e dis

i i •jj cussio no f measuremen t a t th e bac k en d o f th e repor t an dle t i 8 , . th e proceedin g argument s essentiall ymotivat e an d driv e th e 1 1 i : 

### o 'discussio no f

wha t ouah t t o b emeasured . I ! 1 0 i i I thin k tha t ther e ar e reall ytw o need s fo r measure ' 

# II! i ment . 1 ) Yo u hav e t o hav e are a measuremen t t o documen t that i i th e declin e o f ambien t problem s d r t o kee p trac k o f th e ambien t problem s s o that , i nfact , the ydon't.declin e a s anticipated , one' s awar e o f it , and . 2 ) on e need s clearl ymeasuremen t speci

ficall yt o contro l problem s associate d wit hspecifi c sources .

An d thes e presen t differen t dat a needs , th e kind s o f measurement s tha t you'r e likel yt o wan t i nthos e tw o situation s ma yb e different . Finally , I woul d argu e tha t CASA C shoul d recommen d tha t th e nex t tim e around , tha t EP Atrea t th e lea d proble mmor e i nterm s o f source s an d les s a s a nambien t stand

ard . An d i nanticipatin g tha t recommendation , I thin k tha t ther e shoul d b e a discussio no f th e kind s o f dat a tha t ar e goin g t o b e neede d t o d o tha t righ t nex t time . I mean , I thin k we'r e stuc k wit hroughl yth e kin d o f dat a we'v e see n 1 1 I ! 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 I 2 5 EXECUTIV ECOUR TREPORTER

S (301 ) 565-006 4P. M 11 2 1 toda yo nsoil , dust , fate s andmas s balance s o nchildren' s

, |

, i 2 uptak e and thing s o f tha t sort . Bu t there' s n o reaso ntha t 3 : som e year s dow nth e road , face d wit hessentiall yreworkin g 4 • thi s sam e problem , tha t w e shoul db e forced , t o settl e fo r 5 comparabl ylous ydata . 6 CHAIRMANLIPPMANN : Grange r ha s discusse dthi s wit hj 7 j sem e o f us . Other s ar e hearin g thes e recommendation s fo r th e

• t 8 firs t time . S o I woul dlik e thos e wh o nee dt o hea r hi mrestat e 9 somethin g o r clarif ysomething , t o as k thos e questions . , 1 1 0 Bu t befor e that , le t m e jus t amplif yon e thing , 1 1 \ and whic hfollow s i npar t bu t wasn' t specificall ystated , 12 . . tha t is , yo u hav e t o justify , i f yo u can , th e us e o f th e hig h 13 volum e sample r i nligh t o f thes e considerations , o r anyothe r 1 4 : samplin g approach , i nterm s o f frequency , e t cetera . An dho w

1 5 ' monitorin g station s se t u p i nth e er a whe nlea dwa s th e

1 6 j ubiguitou s pollutant . 1 7 An d reall ytel l yo u whethe r you'r e solvin g th e 18 : poin t sourc e lea dexposur e proble mwhic hi s th e futur e proble m i j 

### 1 9 Ian dno t

th epas t

problem . 2 0jj Dr . Rowe ? u 2 1 i i DR' . ROWE ; I hav e a coupl e o f thing s I wante dt o

_ _.'; eithe r add o r clarify . I t seem s a s if , andthi s ha s t o d o wit h

2 3 | | th e ris k assessmen t integratio no f th e exposur e analysis , I

2 4 :ca nunderstan d th e logi c tha t see mt o have.transpire d befor e I

2 5 ' joined , thi s Committe e o f no t lookin g a t childre ni nlea d

EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.1 5 : '" I ' ' 11 3 heme s fo r settin g th e standard , an d ignorin g the mi nth e stand-

- 2 ar d settin g proces s o f healt heffects . Bu t I don' t understan d 3 j ignorin g the mi nth e ris k assessmen t i nth e fac t tha t the y | wil l fac e change s i nthei r ris k an d i t seem s t o b e somethin a i - 1 i 5 j . t c b e considered , i f i nfact , you'r e doin g a ris k assessment .

An d fro myou r ow nnumber s o npag e 6.7 , ther e ar e man ymor e o f thos e type s o f children . Now , I don' t kno wnea r 8 j i i f they'r e nea r th e poin t source s o r not , bu t th e magnitud e j i o f thos e peopl e ar e a lo t larqer . 9 1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 ! I Th e secon d thin g I a maddin g i s Ellen' s poin t before , \ th e fetuses , th e amoun t o f fetuse s i s equa l t o o r large r tha n I j th e childre nnea r thes e poin t source s a s well . S o th e ris k ! assessmen t seem s t o b e narrow . 

# i i i I don' t kno wi f yo u hav e th e resource s t o dea l wit hthat . Bu t i t woul d b e nic e i f tha t coul d b e done .

MR . JORDAN : Dr . Rowe , i t isn' t tha t w e ar e ignorin g thes e kid s i ndoin g th e ris k assessment . Wha t we'r e tryin g t o d o i s asses s wha t yo u ge t b ychangin g alternativ e level s o f th e ambien t ai r qualit ystandard . Ho wyo u alte r th e ris k t o people . An d base d o nwha t w e conclude d a t th e las t meeting , wa s tha t yo u ca nchang e al l th e ai r standar d al l yo u wan t t o chang e it , an d you'r e no t goin g t o chang e th e ris k fo r thos e kids . Th e pain t exposur e the yge t fro mpain t chip s ar e s o high , tha t wha t the yge t fro mlead , i f i t changes , it' s goin g

EXECUTIV E COUR T REPORTER S

(301 ) 365-006 4P.1 6

* • • I • 1 2 3 4

K ml 5 7

o 9 1 0 11 1 2 1 3 1 4 1 5 1 6

- 1 7

1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 ; 11 4 t o b e s o small , it' s goin g t o b e almos t immeasurable . S o i that' s th e reaso nthey'r e no t —

DR.ROWE : That' s becaus e o f th e non-linearit y functio n- - MR . JORDAN : It' s becaus e th e amoun t o f lea dthe y ge t frc meatin g pain t chip s i s s o muc hgreate r tha nwha t the y woul d ge t fro mou t o f th e ambien t air .

DR . ROWE : I understan d that , bu t I gues s it' s stil . th e increment s o f th e childre nwh o ar e gettin g i t fro mth e ai r versu s th e incremen t t o thos e childre nwh o ar e gettin g i t - - i t doesn' t matte r unles s tha t curv e i s non-linea r concave , s o tha t th e respons e functio nshow s n o chang e ou t ther e a t thos e highe r lea dlevels .

I f th e respons e functio ngoe s lik e this , th e incre-

• menta l healt heffec t i s eve ngreate r fo r thos e children . i j Eve nthoug hth e incrementa l percen t chang e i nlea dexposur e i s !ver vsmall . i DR . HAMMOND : I woul d lik e t o commen t ver ybriefl y o nwha t I conside r t o b e th e inadequac yo f th e summar yo f th e acceptabl e bloo dlea d base d o nhealt heffect s i nchildren . i | And . I' m

referrin g specificall yt o th e botto mo f page , 

### i ijChapte r 7-8 4 an dont o Chapte r 7-85 . i That"is , I think , totall yinadequat e i nterm s o f

; indicatin g wha t i s seriou s andwha t i s no t serious , bywa yo f ;a neffect . An d which , i f any, o f thes e effect s yo u ar e i i i i ij EXECUTIVE COUR T REPORTER S ! (301 ) 565-006 4P.1 7 I ! 11 5 

# l i 1 : . takin g int o accoun t i nrecommendin g thi s rang e o f maximu mlea d 

## l l 2 ! ! exposur e o f 1 5 t o 20 . 

### i i 3 i i Al l o f tha t i s ver yinadequatel yexplained . An d 4 : i t doe s not , and I ca nunderstan dthis , tak e int o accoun t tw o 5 ver yimportan t recentl yaccepte d fo r publicatio npaper s b y 6 : Dietric hand byBellinae r andI sayI ca nunderstan di t becaus e ! ' 7 j yo u presumabl ydre wfro mth e quality , QD , criteri a document , j 8 th e C D and a t tha t time , thos e paper s wer e no t included .

S o althoug htha t may , i nfact , b e th e case , I think j 10 tha t wha t thes e paper s sayi s sufficientl yimportan t andha s j ! ' ! 

### 1 1 j . asufficien t

impac t onyou r

consideratio no f

wha t i s anaccept j , ! 2 Fabl e leve l o f lea dexposur e tha t shoul db e treate dseriously . 13 | j -An

d I agree , I thin k too , tha t thi s whol e matte r o f bloo dpres i ! 14 ! ; sure , yo u obviousl yaren' t goin g t o solv e everybody' s concern s i i 1 5 ';. abou t bloo d pressure , bloo d lea drelationship .

Bu t a t leas t yo u ca nmak e a judgmen t a s t o whethe r

1 7 .yo u ar e includin g i t o r usin g i t a s on e o f you r consideration s

1 8 j : i nestablishin g a nacceptabl e maximu mleve l o f lea dexposures . 

## I j 1 9 CHAIRMANLIPPMANN : That' s a nissu e whic hI thin k 

# i jneed s t o b e explicitl ybrough t out . It' s no wi nth e criteri a documen t addendu ma ? a significan t bod yo f literatur e whic h ii I relate s t o th e standard-setting . An dwe , therefore , I gues s i j • ' | I wa s expectin g tha t itwoul d b e treated'i nth e nex t revisio no f i th e staf f paper . ! i; You r preliminar yanalysi s suggeste dtha t i t woul d 1 6

21 2 2 23 24 2 5 EXECUTIV ECOUR TREPORTER

S (30! ) 565-006 4P.1 8 ————————————————————————————————__———_•———————>—————-————————————————»—————~~TMTM~^^^~—TM— TM 11 6 i j j no t b e a limitin g factor , tha t i s a leve l whic hprotect s 

### I 2 ; children , shoul d als o protec t th e adult s agains t bloo dpressur e Eu t tha t need s t o b e mor e firml yestablishe di f tha t i s th e 4 ; case , an

d clearl yi f yo u hav e tw o effect s whic hproduc e a 5 simila r nee d fo r a standard , tha t strengthen s th e basi s fo r a 6 i numerica l standar d i ntha t conceivabl ydat a coul dcom e ou t 

### ! i 7 ; tomorro wwhic hundermine s th e credibilit yo f th e kid s effects. j 8 : An d yo u woul db e lef t wit hn o credibl e basi s fo r 9 i a standar d i f tha t wer e t o happen . I' mno t sayin g tha t i t wil l i ; 10 : DR . FRANK : Yes , tw o effect s andtw o rathe r distinc t i 1 1 j'population s a t risk . i j| 12 j CHAIRMANLIPPMANN : S o I gues s w e encourag e yo u j 

### i i 

### ' ' 13 ! ; t o follo wthroug ho nth e mal e adul t bloo dpressur e populatio nj 

## j; | 14 | ris k and com e t o som e conclusio nabou t th e standar di ntha t | 1 5 j ! regar d a s wel l a s th e neurobehaviora l effects , feta l effects , 1 6 and al l th e effect s tha t hav e com e up . 1 7 j ; MR . JORDAN : We'r e certainl yintendin g t o d o that . j , 1 8 j CHAIRMANLIPPMANN : Ho wyo u dea l wit hit , w e kno w j 1 9

### jit' s difficul t

an dho w yo uresolv ewha t

ris k estimate s t o us e 2 0 2 1 2 2 2 3 j i 2 4 I 2 5 i nparticular , wha t coefficients , i f any, t o extrapolat e jfro mth e huma nexperience , whic hi s les s said , tha t come s fro m 

## j j a numbe r c f source s an dho wyo u evaluat e i t an dus e it , w e i j !wis hyo u well.(laughter )

Member s o f thi s Committe e ma ywel l b e willin g t o hel p vo u i ndealin g wit htha t issue . S o I thin k thes e ar e EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.19

1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 11 7 issue s tha t nee d t o b e resolve d clearly . Thi s i s a staf f pape r 2 whic hi s stil l i na Preliminar ystag e an d we'r e no t read yt o 3 giv e eve na conditiona l approva l fo r i t a s a scientifi c basi s fo r th e standar d setting , i j DR . HAMMOND : Coul d I as k on e thin g regardin g wha t I ; i 6 | I thin k i s a ver yimportan t table ? An d that' s th e on e o npag e i I 7 j 7 2 o f Chapte r 7 , whic hprovide s th e maximum'individua l bloo d 8 | j lead , leve l fo r 99. 5 percen t o f children / assumin g thre e differ

j i 9 j i en t GSD ' s . 

## I I . ! 1 0 I Tha t i s al l ver ynice , bu t I don' t se e anywhere , an d 

### i i mayb e I didn' t rea d thi s carefull yenough , bu t I don' t se e the ! basi s fo r selectin g on e o r anothe r o f thes e thre e GSD' s

a s bein g th e mos t legitimate . Di d yo u d o that ?

MR . COHEN : Yes , w e stat e somewher e i nthi s sectio n tha t w e — DR . HAMMOND : You'v e go t a sectio ni nther e wher e yo u documen t th e basi s fo r selectin g on e o f th e three ?

MR . COHEN : Yes . DR . HAMMOND : O k ay . CHAIRMA NLIPPMANN : I sugges t yo u mov e th e technic a

erro r o f havin g uni.t s o nGSD . GSD , b ydefinition , ha s n o unit s

DR . NORTH : Whil e we'r e commentin g o ntables , I woul d lik e t o not e tha t o npag e 7-7 1 precedin g this , th e assumption s

o nfoo d an d footnot e 4 , an d th e ver ystron g disparit ybetwee n th e number s her e an d th e number s tha t ar e i nth e exposur e 2 0 2 1 2 2 2 3 2 4 2 5 EXECUTIV ECOUR TREPORTER

S (301 ) 565-006 4P.2 0 j ' 11 8 1 j analysi s fo r th e mode l tha t i s prese:ntedt o us . Now, . I under

i , i i 2 istan d thes e ar e differen t models . Thi s i s th e mode l ou t o f h 3 ;the criteri a documen t informatio nan dver ydifferen t i nmany 4 i o f it s characteristic s fro mth e other , i . 

### r 5 j Nonetheless , th e discussio ntha t we'v e bee nhavin g i

6 r l think , note s th e importanc e o f foo di nterm s o f th e back



## i > i 7 j groun d tha t ma yoccu r i nth e future . An dthi s questio no f what . i 8 j , i s th e persistenc e o f lea di nth e soi l an dth e wa ylea dma y 9 ; • ge t int o th e foo d chain , a s i t ma yeffec t bloo dlea di nth e j 10 ; ' future , i s a reasonabl yimportan t issu e t o b e illuminate di n

i , i nj thi s stron g disparit ybetwee nth e tw o mode l calculations , 

### i i 12 !'whic

har e o f course , drive nbyth e assumptions" , thi s trouble s i I' 1 3 ^ e

- 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 MR . COHEN : W e tryt o tak e a coun t o f thos e consi

deration s i nou r outtak e model . Thi s i s straigh t ou t o f Chapte r 1 3 o f th e criteri a document .

DR . NORTH : A s I understan dth e assumption s i nyou r uptak e model , yo u hav e a discontinuit yi nth e assume dlea d i nfoo d fro ma norde r o f magnitud e tha t occur s betwee n198 5 and 1986 . I' m

no t sur e wher e yo u go t that . It " would , see mlik e a ver ydifferen t judgmen t fro m what' s reflecte di nfootnot e 4 i nthi s table .

MS . SLEDGE : Th e value s tha t ar e o nth e tabl e i n Sectio n5 tha t represent s uptak e model , thos e ar e agai nfo r 1990 , th e yea r 1990 . S o w e hav e those , th e contribution s o r

EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.2 1

1 11 9 value s fo r dietar y- - futur e projections ,

DR . NORTH : Th e questio nis , wher e d o thes e number s 

## i i 3 jicom e from ? Wha t evidenc e d o the yrepresen t o r wha t judgment ? | ! 4 j j And tha t isn' t bein g mad e clear . 

## i l 5 j; MS . SLEDGE : They'r e base do nthi s dat a tha t ar e i ! 6 j ! presente d i nth e criteri a documen t fo r dietar yconsumptio n

7 j j o r dietar yintak e o f lea d i nchildren . Thes e ar e base do nth e 

# I 8 | ; Penningto nstudywhic hlooke d a t i t o nfoo dcategorie s and 

## j j 9 I'also include d lookin g a t th e lea dconten t i nfoods . 1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 An d th e curren t mea ndietar ylea dintak e i nchildre n ;ar e presented'i nSectio n7 o f th e criteri a documen t an dthos e i 'represen t th e year s 1982-84 . An d tha t wa s ou r startin g poin t 

# I ji nwhic hw e the nmad e projection s int o th e future . j Th e projection s thatweremad e wer e base do n als o dat a reporte d i nth e criteri a documen t concernin g th e reduction s i nsolde r lea dusag e tha t hav e alreadyoccurre d and tha t ar e anticipate dt o occu r i nth e future .

DE . NORTH : I don' t wan t t o belabo r thi s poin t i nth e interes t o f time , bu t myconcer ni s wit hpag e 6 an da variabl e calle d N

ADiet . An dth e middl e columnof . Tabl e 3 i nth e docu

men t byJohns'onand , Pau l ar e enclosur e 5 , i nwhic hth e numbe r i n198 5 i s 4. 5 andth e numbe r i n198 6 i s .55 .

An d m yreques t is , i f yo u wer e goin g t o us e tha t judgmen t o r anythin g lik e it , pleas e explai nwhytha t judgmien t i s reasonable . EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.2 2 

### 12 0

i 

### 1 | j . MS . SLEDGE : Okay , th e N ADie t tha t i s define d i n th e exposur e report , represent s the contributio no f lea d i n the die t fro

m direc t atmospher e absorption s o f lead . An d thos e 4 j l projection s ar e base d onour projectio no f th e —sourc e 

## i l ' 5 i j contributio nt o ambien t lea d "concentration s . CHAIRMA NLIPPMANN : January1 , 1986 , lea d droppe d i ngasoline . j MS . SLEDGE : Mos t food i s grow ni nrura l areas , an d 9 |l s o

### —| l i I 1 0 j ! MR . HAINES : What' s you r auarrel ? I f I understan di i ! i n

### j wha t you'r e questioning an d it' s ver

yappropriate , is"we hav e i I. ; 1 2

### Iaver ykmr eedg edrop , time do ngasolin ephasedow nan dclearl y n' Iretrospectivel yi t

doesn' t

loo k riaht . 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 

### DR . NORTH : Yo u hav e a knif e edg e i non e mode l an d yo u hav e essentiall yn o chang e i nanothe r mode l an d n o explana tion . Nov/ , it' s no t wort htrying t o di g thi s ou t an d mak e sens e c f it , an

d i nthi s meeting , give nour time limitations . Jus t pu t i t onyou r agenda fo r th e future . CHAIRMA NLIPPMANN : Paul ? DR . HAMMOND : I hav e simila r concerns . Bu t I didn' t sa yanything because , fromour ow ndat a i nCincinnati , I thoug ht j tha t th e numbe r looke d reasonable . I' mtalking abou t th e 4. 4 i s it , o r 2 . An

d I migh t jus t mentio nwha t tha t is . Onewa yo f trying t o estimat e wha t th e background lead i f yo u will , is , i s t o tak e the populatio no f childre no f

EXECUTIV

E COUR T REPORTERS (301 ) 565-006 4P.2 3 12 1 1 i interes t and i nthi s case , I' mtalkin g abou t a populatio no f 2 10 0 and som e 1 8 mont hold s i nou r study , an dassum e tha t th e 3 i majo r proble m s o fa r a s - - i s concerned , th e tantemount . | 4 i j transfe r o f dust . An dI believ e tha t an dI believ e other s i ! ! l 

### 5 j'believ ei t

a s well . 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 ' An d the nt o mak e a regressio no f han dlea dand ibloo d lea d and ae t som e ide a a s t o wher e th e intercep t is . 

## I ' .An d i nthi s particula r populatio no f 1 8 mont holds , i t turn s jou t tha t th e intercep t o nzer o - - o f bloo dlea di s 6.6 . 

### i i | An d i f yo u allo wmayb e 1 o r 2 microgram s pe r deci

i jlite r fro m

inhalatio nbecaus e th e ai r lea di nCincinnat i i s i ! .25 , the nyou'r e u p ther e i na reasonabl e rang e andyou'r e onl y somewha t highe r tha nyou r 4.2 . I didn' t rais e anyquestion s 

# i i j j simpl ybecaus e I ha d som e persona l comfor t wit hth e numbers .

MR . JORDAN : I don' t thin k you'r e arguin g wit hth e j numbers . You'r e arguin g wit hth e explanation . W e didn' t explai n wher e i t cam e fro man d that' s a vali dargument .

DR . SILBERGELD : Well , I thin k tha t thi s speak s t o a continuin g issu e whic hi s sor t o f a lac k o f historica l consciousnes s abou t lead . An d n o matte r wha t yo u d o now , ther e i s a hug e amoun t of.environmenta l lead .

An d I thin k al l ou r concern s abou t thes e prediction s abou t bloo d lead s o f 1. 3 andfoo d lead s fallin g t o ver ysmal l | levels , reflect s som e sens e i nyou r min dtha t thing s ar e goin g t o chang e instantaneousl ythroug hsom e impositio no f on e sourc e EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.2 4

- , • , • , 

### 12 2 the emission s int o air . 2 An

d I thin

k wha t we'r e al l trying t o tel l yo u is , 3 tha t eve ni f yo u wer e t o remov e al l ongoing lead , source s righ t i now , there' s going t o b e anenvironmen t contaminate d wit h i . i 

## i 5 j lea

d an d I thin

k the NA S documen t speak s s o eloquentl yt o this [ i 

## I the 198 0 report , tha t you canno t ignor e that . Yo u can' t pre 7 'ten d that' s going t o vanis ha s yo u d o something abou t thes e | i i i i i 8 j ! source s 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 

### DR . WESOLOWSKI : Anothe r wa yt o pu t i t i s tha t most , o f the lea

d tha t i s i nthe environmen t nowwil l b e i nthe environmen t eve nwhe nyo u ge t don e wit hyou r mos t stringen t regulations . An

d perhap s the Committe e shoul d recommend tha t ther e b e a separat e sectio nbol d one , whic hstate s thi s an d explain s why , s o tha t the reader'i ncontext , realize s tha t you r rol e nowa s regulator s i s no t going t o b e i nthe future , a driving forc e t o ge t ri d o f lead i nthe environment .

S o a separat e section . DR . MORGAN : Thi s i s precisel ywha t I had i n mind whe nI argue d ther e ough t t o b e thi s introductio nwhic h essentiall yprovide s a systemati c catalogu e an d ranking , no t jus t o f th e air , bu t non-ai r an d al l th e othe r sources . S o on e canpu t thi s particula r piec e o f the problemina broade r integrate d parameter .

DR . WESOLOWSKI : S o we'r e helping yo u writ e i t here . DR . SILBERGELD : Tha t get s bac k t o th e poin t tha t

EXECUTIV

E COUR T REPORTERS (301 ) 565-0C6 4P.2 5 12 3 1 ; Dr . P.owe . made , whic hi s the nth e issu e o f th e margina l incre

i j 2 j men t i ncontribution , become s ver yimportant . 3 j 1 MR . JORDAN : I' mno t arguin g tha t th e lea di s goin g 4 i t o b e around , an d I don' t mea nt o argu e tha t away . Bu t whe n j i 5 you'r e tryin g t o asses s wha t th e intak e o f lea di s goin g t o b e 5 ; i nth e huma nbod yi nsom e futur e years , yo u hav e t o brea kth e 7 j ' proble mdow nint o th e individua l element s t o whic hhe' s goin g 8 i t o b e expose dto . 9 ! • A s yo u loo ka t thos e individua l elements , a s w e hav e j l -, 0 ; i nthi s analysis , yo u ge t th e indicatio ntha t thos e thing s ar e 11 1 2 'goin g t o g o down . Fo r example , th e dus t i nth e house , th e lead ] conten t i s goin g t o g o dow na s lea di ngasolin e goe s down . I 1 3 !• I don' t wan t t o ge t int o a belabore dpoin t but-

- | ' Kj [ CHAIRMA NLIPPMANN : Well , we ' r e askin g yo u t o tak e ji

. _j ; al l thes e thing s int o accoun t an dcom e u p wit hyou r bes t 16

1 9 judgment s o nth e futur e source s o f exposur e whic hwil l —th e

1 7 j j di f f eren t proportion s an dpas t source s — | i

1 8 j i DR . MORGAN : Bu t yo u migh t thin ko f i t i nterm s o f relativ e effort . I mean , th e relativ e effor t tha t i s reflecte d o nthi s staf f pape r o ncharacterizin g thos e contributions , an dexplainin g ho wth e projection s wer e mad e an ds o on , o r t h e effor t o nth e ingestio nterm s whic har e tw o ver ycritica l ingredient s t o th e analysis , i s muc hlowe r tha nth e effor t o n 2 0 2 1 2 2 2 3 i a variet vo f othe r thing s whic hI thin kth e Committe e i s tell

2 4 ; . 

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i ' n 1 1 l i j j i j EXECUTIV ECOUR TREPORTER S j j (30i ) 365-005 4P.2 6 f ' line . 12 4

DR . WESOLOWSKI : Andther e ar e section s missing , fo r example , th e numbe r o f childre nwh o us e fol k remedie s whic har e 4 | essentiall ypur e lead .

MR.JORDAN : I' msorry , I didn' t - - DR . WESOLOWSKI : Well , there' s n o mentio na t al l abou t th e populatio no f Mexica nchildre nwh o liv e i nthi s countr ywh o us e fol k medicine , whic hi s - - andjus t a t leas t a mentio nt o aler t peopl e t o thi s proble mbecaus e it' s s o 6 i 

## i I 7 8 9 1 0 1 1 12 13 1 4 15 16 1 7 18 19 2 0 2 1 2 2 2 3 2 4 2 5 deadl yseriou s whe na chil d doe s us e it , eve nthoug hw e don' t hav e a feelin g fo r wha t th e numbe r is .

It' s no t meager , and w e fin d the mever yyear . Tha t coul d b e i nthere .

CHAIRMANLIPPMANN : Tim ? DR . LARSON : I hav e - - give ntha t there' s a consensu s tha t ther e need s t o b e som e focu s o nth e source s tha t wil l continu e t o exis t beyon d som e dat e i nth e nea r future , an d !tha t there' s concern s abou t ho wt o characteriz e th e exposure , i s tha t th e sam e o r differen t fro mth e genera l populatio nexpo sur e u p t o thi s point ?

We*'re operatin g o na nassumptio ntha t a quarterl y averag e o r a monthl yo r somethin g inbetwee ni s anappropriat e averagin g tim e fo r a standard , give ntha t we'r e goin g t o hav e a standar d regulate dtha t way . Bu t I hear dDr . Hammon dmak e a istatemen t yesterda ywhic hintrigue dme . I wis hh e woul dexpan d

EXECUTIVE COUR T REPORTER S

(301 ) 505-006 4P.2 7 

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## j i i •; brie f Iv.o

nthis , and . tha t i s tha t nea r thes e smelter

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### 7 i j averaging time i nthi s case , an d tha t perhap s w e ough t t o b e 8 j concerne d abou t - - dar e I sa yi t - - a annua l averag e o r some 9 i longe r termaverag e fo r a standard tha t reflect s tha t "particu

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## l i 1 3 l ; 

### meanpredictor . : i l ii 1 4j iCHAIRMA NLIPPMANN : Dr . Angle ? 1 

### DR . ANGLE : Certainl ywe'v e al l bee ntalking aroun d the poin t tha t the ai r mode l fo r lead i s no t anymor e appropriat e thanusing th e ai r mode l fo r radium , simpl ybecaus e you'r e j dealing wit hth e questio no f highresidu e whic hdoe s no t dis

appear , eve ni nte nyear s time .

I woul d lik e t o thin k tha t tho . erro r i nthe dis

aaaregat e mode l for . 5. 1 o r migh t b e correcte d fo r Table s i

### j 5. 1 an d the na s interpolate d o n7.10 , i s t o us e th e basi c I uptak e base d o nthe previou s standards . Inothe r words , tha t j j yo u assume tha t the uptak e unde r 1. 5 represent s th e uptak e fromsurfac e residu e an d tha t thi s wil l no t b e changed . 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 

### I I

EXECUTIV ECOUR TREPORTER

S (301 ) 563-006 412 C Thi s i s goin g t o b e relativel ypermanen t fo r a lon g 'period o f time . An dtha t th e calculation s shoul dus e a differ

jj 

### 3 -lent —us eth euptak ea t th etim eo f

th eregulation . 

# s l 4 j 1 CHAIRMANLIPPMANN : Considerin g th e cloc k an dsom e i i 5 ; airlin e schedules , I woul dlik e t o brin g ou r mai nCommitte e i i 6 ''recommendatio nt o som e sor t o f a closur e a s a ninteri m step , i i I j 7 ;!at least . j i 8 j i I as k fo r comment s o nDr . Granger' s proposal . I go t j i 9 |:som e commen t relate dt o i t andsom e commen t relate dt o othe r ! 1 0 jiissues . i i i l i s ther e anybodywh o disagree s i nanyparticula r importan t respec t wit hth e recommendation s a s formulate db y Dr . Grange r a s a committe e consensus ? I' msorry , Dr . Morgan .

DR . MORGAN : I'l l giv e yo u mycop yo f thi s an dyo u 1 1 ' 12 13 1 4 15 16 17 18 19 2 0 21 2 2 2 3 2 4 2 5 ca n- - CHAIRMANLIPPMANN : I f w e d o reac ha consensu s tha t thi s represent s th e majo r committe e recommendations , obviousl y i t wil l b e transmitte dt o yo u word , fo r word , a s edite dwit hou r

—a s a committe e report .

DR . FREEMAN : Thi s i s ou r - - perhap s a clarificatio n o r extensio nb f one.o f Granger' s points . H e raise da concer n abou t usin g a 99. 5 o r 99. 9 percen t leve l andwhethe r tha t should , b e applie dt o al l childre no r specifically , th e smal l grou p o f childre naroun dth e smelters .

Bu t I thin k tha t als o raise s th e questio nandI

EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.2 9

1 2 I 3 4 I!

6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 12 7 don' t kno wwhethe r h e intende d t o o r not , o f whethe r tha t kin d o f safet yfacto r i s appropriat e a t al l o r i s th e righ t wa yt o fram e th e questio nfo r standar dsetting , give nth e sma l number s involve dandtha t i t i s a clearl yidentifiabl e group .

And . i f that' s wha t yo u intend , I heartil ysecon d that . DR . MORGAN : It' s no t clea r t o m e tha t i t make s any sens e t o fram e i t tha t way . I t i s clea r f o m e fro msom e dis

cussio nyesterday , tha t i f on e frame s i t tha t wa yandleave s i t ambiguous , th e argumen t wil l the nb e surfaced . Ther e ar e onl ya fe wthousan dkid s involve dhere . That' s clearl y les s tha n99. 9 percen t o f th e childre ni nth e country , ergo , there' s n o problem .

CHAIRMANLIPPMANN : Hearin g n o descent , essentiall y wha t Dr . Morga nread , t c yo u wil l com e t o yo u a s a committe e recommendatio nan d tha t the nleave s u s wit ha fe wcleanu p detail s fo r u s t o settl e befor e w e ca nadjour nthi s meeting .

CASA C ha s it s ow nschedul e need s anddeliberat e need s an d w e lik e t o hel p th e Agenc ytak e timel yaction s and hav e promised , i nfact , t o mee t certai ntim e tables . S o a closur e lette r on . th e criteri a documen t wil l b e forthcomin g whe nyou r satisfie dtha t yo u tel l u s tha t you'v e satisfie d ou r objections .

An d w e hav e a smal l subcommittee , wh o wil l prepar e a closur e lette r t o th e Agenc yo nth e C D andDrs . Mahaffey , Fran k

EXECUTIVE COUR T REPORTER S

(301 ) 555-006 4P.3 0 12 8 an dLarso nwil l b e assistin g m e o nthat . I wonder , Les , i f j yo u ca ntel l u s wha t you r cours e o f actio ni s i nmakin g thes e change s tha t w e hav e aske dfor , s o tha t w e ca nb e satisfie d

7 I 4 i; tha t th e chanqe s i nou r motion . 

# | i 5 . - Whethe r th e ozon e meetin g i s a goo dtim e fram e be

i , 5 j . caus e w e happe nt o b e al l gettin g togethe r agai ni na littl e ove r a month . j DR . GRANT : Le t m e jus t clarify . You'r e sayin g C D i an d let' s b e clearl yseparate dfro m addendum ? 

### i i j j MR . JORDAN : That' s on e package . j 1 DR . GRANT : Okay , that' s wha t I mean . i j j CHAIRMA NLIPPMANN : W e hop e so . I mean , there' s n o j j i! poin t i nclosin g o npar t o f th e criteri a documen t i f we ' hav e I I - . _ i i j j th e whol e thin g availabl e t o us . i : j j DR . GRANT : Okay , the-criteri a documen t itself , ; i s basicall ya s Dav e Wei l indicate dyesterday , read yt o go . I 

### i !There' s ar e ver yfe wmino r - - I j CHAIRMA NLIPPMANN : I don' t se e an ypoin t i nrushin g t o sa ythat' s close dan dth e addendu misn' t whe nth e addendu m i s no t tha t fa r behind . S o al l yo u ma ystil l wan t t o cal l i t a naddendu man d stabl e i t i nth e bac k instea do f incorporatin g i t int o th e body .

Wha t w e wan t t o clos e o ni s th e ECA O effor t o nlead. j DR . GRANT : Okay , I' mno t sur e ho wlon g i t wil l tak e t o incorporat e revisions , o r whatever , int o th e addendum . 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 21 2 2 2 3 2 4 2 5

EXECUTIV ECOUR TREPORTER S (301 ) 565-036 4P.3 1 r- J 1 12 ! 1 Give nsom e othe r things , lik e preparin g th e PM—bu t I ca n 

### l i 2 'giv e i t a tr yt o incorporat e change s o r whatever , int o it . 3 An d I don' t kno wi f i t ca nb e don e i ntim e fo r you r ver ynex t 4 meetinc f i nApril . I ca ngiv e i t a tr yan d hop e tha t w e ca nd o it . I woul d hav e t o wor k ver yquickl yt o incorporat e th e kind s o f change s you'r e talkin g about . An d basicall yt o clarif ythat , it' s m yunderstandin g a s fa r a s th e hypertensio nthing , fo r example , t o characteriz e th e stat e o f th e publishe d literatur e

an d thes e unpublishe d analyse s wil l com e ou t throug hthi s review , stat e th e uncertainties , characteriz e wha t the yare , an d man ypoint s o f controvery , whatever , an d leav e i t a t that .

An d the nrevie wth e othe r kind s o f expansio ni n 6 7 8 9 IC 11 1 2 1 3

1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 certai narea s tha t hav e bee ndiscussed , fo r example , lik e Elle nSilbergeld . I ca ngiv e i t a tr yt o tr yt o hav e i t

' turne d around .

CHAIRMA NLIPPMANN : W e don' t wan t t o hol d u p th e j publicatio no f th e CD , bu t I reall ydon' t se e an ypoin t i n i i • tellin g yo u t o orin t th e C D withou t th e addendu mwhe nth e j i ['• lea d proces s i s no t over . OAQP S ha s a lo t mor e wor k t o do . \' DR* . GRANT. : Sure . i- CHAIRMANLIPPMANN : S o w e woul dlik e t o ge t bac k I fro m vo u wha t yo u pla nt o d o abou t finishin g th e addendum , and i ' the nw e ca nrespon di nterm s o f coming't o closure . I DR . GRANT : Okay , we'l l giv e i t a sho t an dtryt o 

### j : 

# i i i ! EXECUTIV ECOUR TREPORTER

S j ; j- ! (501 ) *65-C'J64P.3 2i

1 3 4 •

6 7 8

9 1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 j 13 0

i j hav e it.bac k t o yo u essentiall ywithi nth e nex t mont hs o tha t yo u wil l b e i na positio nt o loo k a t it . j CHAIRMANLIPPMANN : A t leas t Lf no t th e complet e 

# I ! document , ho wyou r tim e schedul e andpla nt o finis hi t up , okay ' i DR . GRANT : Okay .

CHAIRMANLIPPMANN : It' s no t to o early , a s w e ar e I ij closin g o nth e criteri a document , t o begi nt o ge t bus yo n i ii anothe r tas k that' s a CASA C responsibility , an dtha t i s re - >

! searc hrecommendations . An da subcommitte e consistin g o f Drs. j ; Weir , Hammond , Silbergeld , North , Larso nan dmysel f wil l j j attemp t t' o com e t o grip s wit hth e researc hissue s relate dt o i j lead . | Whethe r no t thi s i s anothe r fiv e yea r roun d o r not , j ther e ar e stil l researc hneed s wit hrespec t t o lea dtha t EP A I 1 ha s t o grappl e wit hand . sinc e we'v e benefite dfro mthi s revie w o f th e lea d issues , w e fee l obligate dt o follo wthroug ho n researc hrecommendation s o nlead . I An d s o fo r you r information , thi s subcommitte e wil l b e dealin g wit hyou r offic e an dother s o nformulatin g researc h recommendation s o nlead .

DR' . GRAN? : Essentiall yusin g th e sam e sor t o f approac htha t w e di dlas t tim e o nth e othe r ones ? NOX , PM- - okay . DR . MORGAN : Whe ni s th e righ t tim e fo r thi s Committe e t o hol da discussio no nho wthi s proble mough t t o b e

EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4 j

1

1P.3 3

1 2 3 4 5 6 7 8 ! 9 1 0 1 1 12 13 14 15 16 17 18 1 9 2 0 2 1 2 2 2 3 2 4 2 5 ! 13 1 approached , i na futur e itterat.ion ? Shoul dtha t b e mayb e hel d j fo r th e nex t CASA C meetin g o nlead ? i | CHAIRMANLIPPMANN : Wel l — j i DR . MORGAN : I t doe s strik e m e tha t thi s Committe e ough t t o hel d suc ha conversatio na t som e time , althoug hI i i acre e - - j i " i j CHAIRMANLIPPMANN : We'v e alreadydiscusse d it , an dj 1 ! ! . . • sinc e w e d o hav e t o mee t a s a committe e agai nwit hanothe r j i • draf t o f th e staf f paper , w e hav e - - w e wil l tryt o com e t o j i • ' i ! tha t recommendation , I think , a t tha t nex t meetin g i nterm s o f ;

' • i i j | i a forma l recommendation . j 

## | i i ! j DR . WESOLOWSKI : I nligh t o f th e discussion s we'v e j i ha d ove r th e rol e o f lea d andai r an dothe r media , mayb e i t j woul d b e reall yusefu l t o chang e ou r nam e fro mClea nAi r j i i Scientifi c Advisor vCommitte e t o Multi-Medi a Scientifi c j i Advisor yCommitte e (laughter ) s o I mak e tha t a point .

CHAIRMANLIPPMANN : On e wa yt o clea nu p ou r missio n i s t o ge t ri d o f lead . I thin k i ndiscussin g i t wit hstaff , tha t th e bes t thin g t o d o woul db e t o encourag e yo u t o utiliz e member s o f thi s Committe e i nwhateve r effort s yo u nee dt o com e t o grips * wit hf- e ris k assessment-issues . Anyfina l word s fro manybod yo nth e panel ? I f not , the nI than k yo u all . It' s bee na ver yinterestin g meeting , I hop e a productiv e meeting , and I appreciat e you r cooperatio n fro m EP Aan d al l th e contribution s fro mth e peopl e o nth e

EXECUTIVE COUR T REPORTER S

(301 ) 365-006 4m, . 

### 13 2

1 panel . . "JT/S H 2 j

j (Whereupon , a t 12:2 5 p.m. , the meeting wa s concluded , 3 4

! l I j 7 j j i ' i 1

1 0 11 1 2 1 3 1 4 1 5 ! 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 I!

j l

EXECUTIV ECOUR TREPORTER

S (301 ) 565-006 4T T'

ENVIRONMENTA L PROTECTIO NAGENC Y

CLEA NAI R SCIENTIFI C ADVISOR YCOMMITTE E SCIENC E ADVISOR YBOAR D P.3 5

1 7

1 9 Marc h24 , 198 6

EXECUTIVECOUR

TREPORTER S ".Ol' : 5r^-v>" 4