# OAR Box 1112 Prepped byRyanDugan



### Document

Number: 

# 97 ) II-F-2 C Docket Number: 

# A-83-2 2

Printed 4/16/20089:12:10AM Sheet 97 of 97 P. 1P. 2

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 21 ' 2 2 2 3 2 4 2 5 ENVIRONMENTALPROTECTIO NAGENC Y



### I nth eMatte r

of : SCIENC E ADVISOR YBOAR D CLEA NAI RSCIENTIFI C ADVISOR Y30AR D (CASAC ) SUBCOMMITTE E O NLEAD

Wednesday , Ma y15 , 198 5 Rossly nRoo mA RosslynWes t Par k Hote l 1 9 0 0 N . For t Mye r Driv e Rosslyn , Virgini a Th e above-entitle dmatte r cam e o nfo r hearing , pursuan t t o notice , before :

DR . MORTO NLIPPMANN Chairma n DR . JULIA

NCHISOLM , JR . DR . ANIT AS . CURRA N DR . BE NB . EWING MR. ' ROBER T FLAAK DR . ROBER T FRANK DR . PAU L B . HAMMON D DR . LLOY D HUMPHREY S DR . PAU L KOTI N DR . TIMOTH YLARSO N DR . KATHRYNMAHAFFE Y DR . M . GRANGE RMORGAN DR . D . WARNE RNORT H 

### EXECUTIVE COUR T REPORTER S

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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 21 ' 2 2 2 3 2 4 2 5 SUBCOMMITTE E MEMBER S (Cont. )

DR . RICHAR D ROYAL L DR . ELLE NK . SILBERGEL D DR . JAME S WAR E

- als o - DR . TERR YYOSI E Executiv e Directo r Scienc e Advisor yBoar d Environmenta l Protectio nAgenc y Als o I nAttendance : MR . COHE N MR . JORDA

N MR . HAINE S M S . SLEDG E MR . O'CONNO R MR . GLEASO N DR . SCHWART Z DR . WHITFIEL D DR . WALLSTE N DR . ROSE N



### EXECUTIVE COUR T REPORTER S

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1 0

2 2 2 3 2 4 2 5 PROCEEDING S 2 CHAIRMA NLIPPMANN : W e reviewe d som e o f th e critica l 3 issue s tha t w e nee d t o hel p OAQP S resolv e wit hthei r prep aratio no f thos e draft s an d th e staf f paper . An d w e wil l revie wother s thi s mornin g

I thin k w e wil l as k th e staf f t o recapitulat e wha t

7 the yvie wa s ou r consensu s recommendation s o nth e issue s 8 we'v e alread ydiscusse d s o I ca nmak e sur e tha t w e al l hav e

9 a clea r understandin g o f it . An d tha t i f ther e i s an ycon fusion , w e ca nresolv e i t now . nJeff , ar e yo u goin g t o d o that , o r John ? 1 2 MR . JORDAN : I thin k I'v e bee nelecte d t o try . W e 1 3 ' wil l al l try . 14 _CHAIRMA NLIPPMANN : Th e larges t targe t — 15 MR . JORDAN : We'l l al l tr yi t 16 I thin k w e ha d a goo d exchanc e o f informatio nyes 17 terday . I thin k w e learne d a lot- . An d I thin k w e ca ntak e 1 8 wha t w e learne d an d pu t i t int o perspective . 1 9 I' d lik e t o tr yt o jus t summariz e wha t I thin k we , 2 0 a s th e staff , .hear d yesterda yfro mth e Committe e an d the nge t 2i " "yo u t o fee d m e back .

Firs t o f al l I think , a s w e sor t o f anticipated , w e nee d t o d o a bi t mor e wor k o nth e averagin g time . I don' t thin k th e informatio nw e presente d wa s persuasiv e enoug ht o mak e th e Committe e t o sa ya mont hi s th e righ t time , o r



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1 somethin g shorte r tha na mont hma yb e th e righ t time . 2 S o i nth e nex t versio no f th e staf f paper , w e wil l 3 broade nou r analysi s o ntha t an dge t mor e specific , an dge t 4 muc hbette r defined . 5 | Secon do f all , I thin kther e wa s a lo t o f debat e 6 abou t wh o w e wer e tryin g t o protec t wit hthi s standard . I 7 thin ktha t Dr . Morga ntalke dabou t bette r studyin g th e objec

8 tiv e function . 9 Dee p i nth e bowel s o f th e staf f paper , whe nw e tal k 1 0 abou t th e exposur e analysis , w e do , i nfact , identif ytha t nwe'r e no t kid s tha t ar e expose dt o lea dchi p paint . W e wan t 1 2 t o brin g tha t u p t o th e fron t o f th e paper . I thin kmos t 1 3 ' peopl e say , righ t of f th e bat , w e ough t t o mak e tha t statemen t

1 4 s o tha t it' s clea r an d concis e righ t a t th e beginnin g o f th e

1 5 staf f paper . 1 6 Tha t w e ough t t o identif ybette r wh o w e ar e tryin g 1 7 t o protec t wit hth e standard . S o w e wil l d o that , an dw e wil l 1 8 wor kwit hJewel l (ph ) an d Dr . Hossleblac kt o se e i f w e •• 1 9 can' t com e u p wit ha distributiona l functio ntha t wil l repre 2 0 sen t th e so-calle dhomogeneou s populatio nthat' s ou t there . 2i ' * I s tha t a fai r statement ? O f removin g tha t per 2 2 centag e o f kid s fro mit . 2 3 Then , i nterm s o f th e critica l healt heffects , w e 2 4 ha d quit e a nexchang e o f informatio no nthat . An dI apolo

2 5 gize . Ther e seeme dt o b e som e confusio nbetwee nwha t w e wer e 

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1 2 talkin g abou t wit hth e mea no f th e populatio nan d the nfil l i nth e distribution .

So , i nou r presentation , w e wil l tr yt o improv e an d mayb e mor e clearl ystat e wha t we'r e tryin g t o protec t 5 i nterm s o f th e distribution . 6 Bu t I thin k th e coupl e o f thing s tha t I hear dfro m 7 th e discussion s w e ha d yesterda ywa s tha t I believ e i t wa s 8 prett yclea r tha t mos t o f th e scientifi c communit ywa s 9 saying , "Whe nyo u ge t t o 25 , you'r e reall yi na nare a tha t 1 0 there' s a lo t o f concern. " An d tha t n o ki d shoul d reac h' 2 5 . nTha t woul d b e a nare a o f critica l concern .

I thin k I als o hear d i t sai d tha t jus t a s a nuppe r 1 3 boun d o f wha t yo u shoul d b e shootin g fo r and , perhaps , th e 14 ' bes t "wa yI ca npu t i t int o word s i s yo u ough t t o hav e a very , ver ylo wprobabilit yo f havin g an yki d wh o yo u ca nprotec t wit ha nearl yextende d (ph ) fro mexceedin g 2 0 microgram s pe r cubi c decilite r o f bloo d lead . 18 A s lo wa probabilit ya s yo u ca nreasonabl yachiev e 1 9 o f keepin g an yki d fro mexceedin g 20 . That' s a littl e dif

2 0 feren t fro msayin g there's,n o probabilit ytha t som e ki dwoul d 21 ' . "reac h20. * O nth e othe r hand , I di d hea r a lo t o f concer no r 2 3 expression s abou t kid s gettin g bloo d lea d level s muc hbelo w 2 4 15 . I t seeme d lik e th e rang e betwee n1 5 an d 2 0 wa s wher e 2 5 mos t peopl e wer e focusing . 

### EXECUTIVECOUR

TREPORTER S (301 ) 565-006 4 1 5 1 6 1 7

2 2P. 7

1 0 1 1 S o I believ e wha t I wa s hearin g i s yo u wan t t o 2 kee p a ver ylo wprobabilit ytha t an yki d woul d reac ha s 3 hig ha s 20 . An d I didn' t hea r a lo t o f concer nabou t tryin g t o se t a standar d tha t woul d kee p kid s fro mhavin g a bloo d lea d leve l belo w15 .

S o that' s sor t o f th e wa yw e understoo d it . An d I'l l ope ni t u p fo r you r feedbac k t o me .

CHAIRMA NLIPPMANN : Doe s anybod ywan t t o commen t

o nthat ? D r . Chisolm .

DR . CHISOLM : Thinkin g ove r th e en d o f yesterday' s 1 2 -discussion , i f w e g o —I thin k it' s i nth e staf f pape r bu t 1 3 it' s als o i nChapte r 1 3 t o th e Punell i pape r o nbloo d FE P 1 4 relationship . 1 5 An d i f yo u accep t tha t a norma l rang e i s th e mea n 1 6 plu s o r minu s 2 standar d deviations , an d yo u loo k a t thi s 1 7 thing , yo u woul d se e tha t afte r yo u tak e int o accoun t th e 1 8 natura l frequency , whic hi s mainl yeffectiv e iro ndeficienc y

o nFEP , tha t tha t seem s t o intersec t th e lin e a t abou t 2 5 somewher e there .

* I nothe r words , th e mea npiu s 2 standar d deviation s rise s abov e thi s natura l frequency . An d a t 1 0 percent , that' s abou t th e estimate , I think , o f iro ndeficienc yi nth e youn g 2 4 chil d population . It' s o npag e 134 2 a t th e top . 2 5 I thin k it' s abou t th e onl ything , beside s ALA D 

### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4 1 9 2 0 21 * 2 2 2 3P. 8

wher e yo u reall yhav e dos e populatio nrespons e data . An d 2 it' s a bi t o f dat a tha t yo u ca nstan don . Whereas , th e 3 other s —now , th e mea nha s t o b e dow nsomewher e aroun d12 , o r so , I think , t o achiev e that , 5 I f yo u tak e th e lo g norma l distributio ngeometri c 6 mea nwoul db e somewher e dow naroun d12 . Bu t I thin kthat' s 7 a fairl ysoli dpiec e o f informatio ntha t yo u hav e t o g o on . 8 CHAIRMA NLIPPMANN : I t woul dsee mt o b e roughl y 9 consisten t bu t you r conclusio ni s state dsomewha t differently . 1 0 DR . CHISOLM : Bu t yo u coul dpi ni t t o something- - nj else . An d that' s bee nreplicate dtoo . Ther e ar e a numbe r 1 2 o f thing s tha t sho wwhe nyo u ge t dow nth e range , tha t th e 1 3 FE P i s relate dpoorl yt o th e indice s o f —quit e clearl yt o t h e indice s o f iro ndeficiency . 1 5 CHAIRMA NLIPPMANN : Dr . Curran ?

DR . CURRAN : Well , I looke da t al l o f thes e num 1 7 ber s agai nver ycarefull ylas t nigh t too , plus : som e o f th e 1 8 informatio ntha t Dr . Larso ngav e me . Als o realizin g tha t 1 9 ther e i s a minimu mleve l o r a ver ysmal l numbe r o f childre n 2 0 wh o ar e no t ev.e r goin g t o ge t dow nregardles s o f wha t w e 2 i -d o t o th e ai r lead , fo r a variet yo f reasons , I thin kyou r 2 2 statemen t tha t yo u jus t mad e reall yreflect s wha t I feel . 2 3 An d I wa s lookin g a t i t fro mth e poin t o f vie wo f 2 4 th e statistic s tha t wer e presente dt o u s i ntha t 7-4 2 i nth e 2 5 staf f paper . An d based-upo nthat , th e mea ntha t i s between , 

### EXECUTIVE COUR T REPORTER S

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1 6P. 9 8 i say , 8. 5 and 9 woul d brin g thi s i na positio nwher e w e woul d 2 hav e a very , ver ysmal l numbe r o f children . 3 DR . KOTIN : 7-42 ?

DR . CHISOLM : 7-4 2 i nth e staf f paper . 5 DR . CURRAN. : Pag e 7-42 . There' s n o Tabl e 7-1 2 — 6 7-11 . 7 DR . KOTIN : Yes . It' s o npag e 7-41 . 8 DR . CURRAN : Tabl e 7-1 1 bu t it' s pag e 7-42 , 9 VOICE : 7-4 1 10 DR . CURRAN : 7-41 ? Well , myboo k say s 7-42 . I"' m 1 1 sorry . I hav e a differen t boo k tha nth e rest . N o wonde r 12 I' m

no t wit hth e res t o f you . 13 DR . CHISOLM : I s i t Tabl e 7-1 2 o r 7-11 ?

1 4 • DR . CURRAN : It' s Tabl e 7-11 . An di nm yboo k it' s 15 o npag e 7-42 . I mean , th e othe r peopl e hav e differen t books , 1 6 apparently . 1 7 Anyway , base dupo nthat , th e microgram s pe r mete r 18 cub e o f 0.50 , givin g yo u a predicte dgeometri c mea no f 8.5 1 wit ha maximumbloo dlea do f 1 8 t o 19. 9 dependin g o nwhic h standar d deviatio nyo u us e fit s i nth e are a tha t I fee l mos t comfortabl e wit hknowin g tha t thi s mean s tha t theoreticall y som e childre ncoul d ge t u p t o 20 , no t necessaril ymeanin g tha t the ydo .

An d als o knowin g tha t fro mth e poin t o f vie wo f reality , th e chil dwh o get s up t o 2 0 toda yma yno t necessaril y 1 9 2 0 2i ' 2 2 2 3 2 4 2 5 

### EXECUTIVECOUR TREPORTER S (301 ) 565-006 4P.1 0 9 1 b e th e on e tha t gets : u p t o 2 0 tomorrow . And , therefore , 2 tha t leve l i s somethin g tha t I fee l I coul d liv e with . An d

3 tha t reflect s exactl ywha t yo u hav e jus t sai d CHAIRMA NLIPPMANN : Okay . I thin k w e ca nmov e on , then , t o som e othe r issue s 6 MR . JORDAN : I gues s th e nex t on e woul d b e exposure . 7 MR . COHEN : Yes . Th e tabl e tha t Anit a jus t referre d 8 t o i s par t o f th e nex t topi c tha t we' d lik e yo u t o address , 9 an d tha t i s relatin g variou s ai r lea d level s t o bloo d lea d— io hypothetica l bloo dlea d distributions . An d w e presen t thre e approache s t o th e staf f pape r i norde r t o d o tha t an d we' d lik e you r commen t o nthei r ulti

mat e use s eithe r selectin g on e mode l o r shoul d w e us e th e th e tiiree

- differen t models ? Wha t parameter s tha t w e identify , shoul d w e b e focusin g i non , fo r instance , wha t bloo d lead / ai r lea d rati o seem s t o b e th e mos t appropriate ?

An d o npossibl e way s w e ca nimprov e th e us e o f 1 8 thos e model s

1 9 CHAIRMA NLIPPMANN : Ther e ar e som e "differences , bu t 2 0 no t grea t difference s i nth e thre e approaches , n 1 2 1 3 1 4 1 5 1 6 1 7

2 1 * Ha s anybod yha d an yopinio na s t o whethe r the y 2 2 shoul d prefe r on e approac hove r th e other ? 2 3 DR . MAHAFFEY : I s tha t pag e 1 o f — 2 4 MR . COHEN : Pardo nme ? 2 5 DR . HAMMOND : 'Giv e th e pag e number . 

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

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 2l ' 2 2 2 3 2 4 2 5 MR . JORDAN : Oh , pag e7-12 , Tabl e7-12 .

VOICE : 7-41 ? MR . JORDAN : O r 7-4 2 dependin g o n.whic hversio n ha s gotte nth e —

(Simultaneou s conversation ) DR . MORGAN : Well , i t strike s m e tha t perhap s whe n yo u g o bac k throug handfocu s you r argumen t abou t exactl yth e targe t population , yo u ma yb e abl e t o tighte nsomewha t you r preference s o r chang e o r reproduc e a mode l that' s slightl y mor e reflectiv e o f wha t you'r e after .

Bu t I personall yfoun dth e strateg yo f severa l -alternativ e plausibl e model s andusin g themt o fulfil l som e confidenc e i nth e kind o f answer s yo u got . On e o f th e mor e appealin g aspect s o f thi s document , th e explici t recognitio n tha t ther e ar e severa l alternativ e way s t o approac hsuch' a problem , and th e explici t buildin g o f som e alternativ e model s and explorin g th e exten t t o whic hth e answer s depen d upo nth e mode l yo u use , struc k m e a s mos t appropriate .

An d rathe r tha na mov e toward s convergenc e o none , I woul d argu e .tha t yo u persis t i nth e directio nyo u starte d "in , namely , o f buildin g a nargumen t toward s a nanswe r and buttressin g i t wit ha variet yo f alternativ e analytica l pro cedure s whic htogether , then , buil dyo u toward s som e defen

sibl e position .

I thin k wha t you'v e don e i s appropriate . 

### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.1 2 1 1 CHAIRMA NLIPPMANN : I thin k it' s interestin g i n 2 tha t ligh t tha t whil e th e convergenc e o f th e prediction s 3 . i s relativel ygoo d a t th e 1. 5 ai r lea d level , there' s mor e relativ e differenc e betwee nth e prediction s whe nyou'r e dow n aroun d . 5 ai r lea d level , whic hi s wher e you'r e probabl y 6 goin g t o en d up . 7 S o I don' t kno wwhethe r tha t present s an yproblem s

8 i ngivin g yo u a greate r rang e o f prediction . Bu t it' s certainl ysomethin g t o note . Th e lowe r yo u g o i nai r lea d 1 0 level , th e mor e divergen t th e prediction s become . nDR . MORGAN : Right . An d i t strike s m e tha t th e wa y 1 2 on e begin s t o ge t leverag e o ntha t i s no t s o muc hb ybeatin g 1 3 th e daylight s ou t o f thes e model s a s i t i s workin g mor e o n 1 4 sharpenin g th e focu s o f exactl ywha t i t i s you'r e tryin g 15 t o mode l sinc e mos t o f th e discussio nw e hear d yesterda y 1 6 struc k me , a t least , a s a discussio nove r exactl ywha t i t wa s 1 7 I wa s tryin g t o represen t wit hthes e models . 1 8 CHAIRMA NLIPPMANN : T o wha t exten t d o yo u hav e 1 9 dat a whic htest s thes e predictions ? Becaus e durin g th e 2 0 cours e o f NHANE S yo u ha d a t leas t som e o f th e populatio n represente d b yambien t ai r monitors , an d yo u ha d bloo dlea d levels . An d whil e bot hbloo d lea d an d ai r lea d wer e changin g a t leas t durin g par t o f tha t dat a se t yo u wer e i nth e hal f microgra mpe r cubi c mete r ai r lea d range . An d wher e yo u coul d 21 2 2 2 3 2 4 2 5 

### EXECUTIVECOUR TREPORTER S (301 ) 565-006 4P.1 3 1 2 1 identif yth e childre nwhos e bloo d wa s collecte d a s bein g 2 appropriatel yrepresente d b ya monitor , yo u coul d compar e 3 th e ai r lead/bloo d lea d tha t wa s actuall yobserved . MR . COHEN : Ther e ar e som e limite d opportunitie s 5 t o validat e thes e prediction s fro mNHANES . Fo r example, ' i n 6 th e criteri a document , th e cit ysurve y—ha d a naverag e 7 ai r lea d leve l o f 1. 2 durin g th e perio d o f th e survey . 8 An d th e childre ni nthos e citie s ha d a naverag e 9 bloo d lea d o f approximatel y15. 6 microgram s pe r deciliter , io An d i f yo u — nCHAIRMA NLIPPMANN : Well , that' s prett yslippery . 1 2 I f yo u average d tw o thing s whic hbot hma yb e cur bo r linea r 1 3 an d lookin g a t gran d averages , I' d rathe r disaggregat e tha t i 4 part"an d segregat e eithe r th e ai r lea d o r th e bloo d lea d 1 5 sinc e the yar e narrowe r range s an d loo k fo r th e correspondin g 1 6 othe r value s t o se e ho wthe ytes t th e mode l ove r th e range . 1 7 VOICE : You' d tak e th e citie s — 1 8 CHAIRMA NLIPPMANN : Well , it's..thei r citie s o r 1 9 time s sinc e th e level s wer e changing . I t ma yb e pickin g th e 2 0 righ t yea r an d th e righ t city . Bu t yo u woul d see mt o hav e 2i ' . -availabl e t o yo u a relativel yrobus t dat a se t t o tes t thes e r 2 2 model s 2 3 An d i f yo u ca ntes t th e models , tha t woul d b e 2 4 valuabl e fo r thi s criteri a pollutan t exercis e an d other s a s 2 5 wel l 

### EXECUTIVECOUR TREPORTERS (301 ) 565-006 4P. M

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 1 3

DR . MORGAN : Coul d I pu t i na pitc hals o fo r a t leas t considerin g a bi t o f graphica l presentatio no f som e o f thes e results ?

Tabl e 7-11 , fo r example , coul dnicel yb e combine d wit hsom e cumulativ e distribution s whic hwoul dgiv e peopl e wh o ar e no t quit e a s verse di nprobabilit yrathe r a mor e concret e notio no f wha t i t i s tha t thes e number s correspon d to . (Pause)

-

CHAIRMA

NLIPPMANN : Tim , we'r e lookin g a t Tabl e 7-1 2 i nth e staf f paper , pag e 7-4 2 i nmycop yanyway . And th e issu e i s whethe r t o loo k fo r evidenc e o f on e o f th e thre e approaches , i s i t bette r tha nth e other . Or , a s Dr . Morga n "ha s suggested , continuin g t o us e al l thre e t o loo k fo r th e robustnes s o f th e predictions .

, Di d yo u hav e an

yspecifi c opinio no nthat ? DR . LARSON : I woul dagre e tha t n o on e o f the mi s overpowerin g o r convincing . Therefore , I thin k it' s goo d t o contras t and compar e al l thre e approache s straigh t fro m th e argument .

CHAIRMANLIPPMANN : Ar e ther e any'othe r -opinion s o nthi s topic ?

(N o response ) I thin k w e wil l encourag e yo u t o kee p a nope nmind , then , t o us e the m a s the ybes t serv e you r purposes . 

### EXECUTIVE COUR T REPORTER S

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5 6 7 8 9 1 0 11 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 

### 1 4

MR . JORDAN : I woul d jus t highligh t tha t ther e i s anothe r effor t tha t w e have underwa yt o sor t o f eve nbroade n wha t w e have her e interms o f exposure . An d tha t i s actuall y developing an

d building a

nexposur e model . We'r e tryin g t o a t leas t accoun t for a littl e bi t o f movemen t o f peopl e fro mvariou s microenvironment s an d se e i f w e cange t some ide a o f howthat , itself , may.influenc e the blood lea d leve l rathe r thanputting i t int o a nenvironmen t wher e the ai r lea d i s assume d t o b e constant . Tha t i s a muc hmor e diffcul t problem . And , a s you remember , we looked a t tha t onc e before . W e modifie d a lo t base d upo nthe las t conversation s w e had . An d tha t wil l hopefull ybe i nthe nex t versio no f the staf f paper .

CHAIRMA NLIPPMANN : I thin k tha t provide s additiona l insights . I' mno t sur e howrelevanc e i t i s t o thi s discus

sionbecaus e you'r e taking a contro l activityonambien t ai r lea d s o a s t o influenc e blood lead . And , therefore , i t mayb e mos t appropriat e t o look a t centra l statio nai r lea d an d it' s influenc e onblood lea d directl yfo r thi s exercise , no t negating the valu e o f th e othe r exercis e fdr othe r reasons .

MR . JORDAN : Bu t a s yo u contro l ai r lead , yo u begi n t o als o reduc e som

e o f the othe r microenvironments . An d that' s wha t w e wer e trying a t leas t t o be abl e t o attemp t a t colum

n4 i nthe simulatio nmodel .



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(301 ) 565-006 4P.1 6 

### 1 5 1 CHAIRMA NLIPPMANN : Bu t let' s discus s tha t i nit s 2 ow ncontext . 3 MR . JORDAN : Yes , fine . Yes . 4 CHAIRMA NLIPPMANN : Dr . North ? 5 DR . NORTH : I thin kit' s importan t no t t o los e sigh t 6 o f th e importanc e o f th e indirec t route . An dtha t suggest s 7 t o m e tha t lookin g a t th e microenvironment s ma yb e extremel y 8 importan t to.tr yt o ge t a bette r insigh t o nperhap s wha t 9 aspect s o f th e indirec t rout e ar e mos t important . i o I f we'r e worried , fo r example , primaril yabou t nwin d—dust , ar e w e worrie dabou t situation s wher e childre n 1 2 ar e playin g nea r bus ycit ystreets ? A t thi s poin t w e don' t 1 3 see mt o hav e to o muc hinsigh t i nthes e model s a s t o wha t th e 1 4 leadin g ter mmigh t be . 1 5 I thin ktha t tha t ca nb e obtaine db ylookin g a t th e 1 6 mor e disaggregate dapproac han di t wil l b e extremel yvaluabl e 1 7 in , amon g othe r things , understandin g th e strength s an dweak

1 8 nesse s bette r o f th e thre e existin g approaches . 1 9 CHAIRMA NLIPPMANN : Okay . 2 0 D o yo u wan t t o g o o nt o anothe r topic ? 2 i ' . MR . JORDAN : Th e onl yothe r on e I think , i f I recal l 2 2 th e thing s w e ha d o nth e lis t u p there , wa s th e for m o f th e 2 3 standard . An d w e sai dw e preferre dt o mov e t o a statistica l 2 4 for mo f i t fo r reason s tha t we'v e discussed . 2 5 Becaus e al l th e res t o f ou r standards , w e jus t fee l 

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(301 ) 565-006 4P.1 7

10 1 6 1 tha t that' s a mor e robus t statistic , it' s a bette r approac h 2 t o dealin g wit hth e wa ything s appea r i nnature . 3 S o w e ar e structurin g ou r analyse s andbuildin g towar d convertin g t o a statistica l formo f thi s standard . 5 I thin k Jef f lai d ou t a coupl e o f approache s t o tha t fo r yo u 6 tha t w e wil l hav e unde r consideration . 7 An d anyadvice , an yguidanc e tha t yo u migh t have , 8 w e certainl ywan t t o hea r it . 9 CHAIRMA NLIPPMANN : Dr . Morgan ? DR . MORGAN : Yes . That' s o nm ylis t also , some-*

- nthin g I' m

ver yanxiou s t o se e u s tal k a bi t about . 12 13 14

16 I fin d thi s intellectuall yver yappealing . I' mno t sur e tha t —I gues s I don' t kno wenoug habou t leadt o kno w ho wmuc himportanc e i t i s i nth e specifi c contex t o f lead . 15 Bu t i ngeneral , th e strateg yi s clearl yver yappealing .

However , o nreadin g th e document , I cam e awa yfeel

in g quit e uncomfortabl e becaus e i t wasn' t clea r t o m e wha t woul d constitut e a demonstratio no f havin g me t th e standard . An d i t strike s m e tha t yo u nee d t o tal k a t somewha t greate r lengt habou t issue s o f measuremen t andenforcement .

* I mean , give ntha t you'v e go t a standar dthat' s state d i nthi s frequen t —thi s fashio nrathe r tha na s a singl e har d target , wha t d o I hav e t o d o t o demonstrat e tha t I' mi ncompliance ?

You'r e talkin g abou t a targe t plu s som e varianc e 17 18 19 2 0 2i ' 2 2 2 3 2 4 2 5 

### EXECUTIVECOUR TREPORTER S (301 ) 565-006 4P.1 8

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

aroun d it . I f I' mconsistentl yhig hbu t don' t com e outsid e o f th e range , a

m I i ncompliance ? I mean , ho wd o I know , unti l I've gon e fo r quit e a fe wyears , wha t th e statistic s o f th e ne wtim e serie s loo k like ?

An d s o ho wca nI persuad e yo u tha t thi s on e exceedanc e was , indeed , th e 1 percen t even t tha t I' mallowe d rathe r tha nth e 2 0 percen t even t tha t you'r e tellin g m e I' mno t allowed ?

I' m no t expectin g answer s fromyo u now . Bu t I' m sayin g tha t i t strike s m e thes e ar e issue s tha t wil l aris e and tha t clearl ynee d t o b e talke d throug ha t greate r length .

MR . HAINES : Le t m e respon d i nthi s fashion . Typically , whe nw e cam e downandpropose dthese , "w e ha d develope d fairl yextensiv e appendice s tha t g o ou t a s par t o f th e proposa l packag e doin g exactl ywha t you'r e saying , explainin g t o peopl e wha t th e attainmen t tes t is , ho wyo u calculat e th e data , e t cetera .

An d s o w e se t fort hclearl yi nth e propose dregula

tion s wha t th e requirement s are .

Wit hth e toleranc e interva l approach , frankly , w e hav e t o loo k a t th e dat a andw e hav e —there' s a serie s o f issue s w e hav e t o loo k at , ho ww e specif ya toleranc e inter

val . Mor e importantly , ho wwoul dw e deriv e one . D o w e d o i t o na localit yspecifi c basi s t o deriv e tha t toleranc e interva l base d o nlookin g a t ai l th e nationa l data ?



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(301 ) 565-006 4P.1 9 1 8 1 Ther e ar e som e har d question s w e hav e t o examine . 2 An d w e pla nt o d o tha t i nth e nex t severa l month s an ddecid e 3 ho wviabl e tha t approac hi s vis-a-vi s th e expecte d exceedanc e 4 fo r it . 5 MR . JORDAN : I guess , Dr . Morgan , wha t Joh ni s

6 sayin g i s w e alway s d o tha t i nth e fina l emphasis . I mean , 7 wher e w e propos e a'statistica l for mo f th e standar d lik e 8 th e ozon e standard , ther e ar e othe r form s o f th e standar d 9 wher e w e d o that . 1 0 W e actually , i nth e regulation , d o writ e u p an d

nar e require d t o pu t int o ther e ho ww e woul d d o it . W e had. ' 1 2 though t o f doin g i t i nth e staf f paper , itself , bu t i t coul d 1 3 b e don e i f that' s wha t — 14 " ~ '" ' DR . MORGAN : Well , mayb e it' s no t necessary . Th e 1 5 reaso ntha t I reac t tha t wa yi s tha t give nth e earlie r dis

1 6 cussion s abou t convertin g th e shorte r averagin g time s an d 1 7 th e ambiguitie s abou t th e dat a sets , an d s o on , i t strike s m e 1 8 tha t it' s tightl ycouple d wit htha t othe r issue . 1 9 I t mean s i f you'r e goin g t o hav e a probabilisti c 2 0 standard , you'v e go t t o mak e sur e tha t you'v e go t th e dat a 2 1 i nhan d tha t ar e necessar yt o implemen t it. ' An d sinc e that' s 2 2 als o couple d t o th e firs t hal f o f th e argument , th e tw o see m 2 3 logicall yt o fi t together.i nsom e ways . 2 4 MR . JORDAN : Absolutely . The yd o fi t together . 2 5 I nfact , th e leve l o f healt hprotectio ntha t yo u ultimatel y 

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(301 ) 565-006 4P.2 0

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end up wit hi s ver ystrongl ydependen t upo nbot hth e formo f th e standar d and —

DR . MORGAN : I gues s I coul dcar e les s wher e i t get s writte ndowntha ni t get s fairl ythough t throug handwritte n downbefor e rathe r tha nafte r th e Committe e look s a t it .

MR . JORDAN : Right . DR . NORTH : I' dlik e t o ti e thi s t o th e poin t I wa s jus t raisin g t o th e importanc e o f th e indirec t route . I t seem s t o m e tha t becaus e lea d i s s o unusua l i nterm s o f th e importanc e o f th e indirec t route , tha t make s i t al l th e mor e importan t t o layou t clearl yho wthi s standar di s goin g t o b e use d a s a yardstic k i norde r t o determin e compliance .

Fo r example , som e ver ycarefu l treatmen t o f win d 'velocity , a s i t generate s dust , migh t b e i norder . I t seem s t o m e wha t yo u shoul dd o i s t o explai ntha t andgiv e som e examples . MR . JORDAN : Okay .

CHAIRMANLIPPMANN : Somewha t alon g th e sam e line , th e sampling , now , i s don e wit hth e so-calle dhig hvolum e sample r whic hha s a variabl e i nth e cu t siz e dependin g o n wind , spee d and direction . Asampl e ever ySixt hdaydoesn' t loo k int o th e observatio ntha t lea d i nth e ai r i s a bimoda l i nsiz e distribution , and tha t th e interpretatio no f thing s coul d be , perhaps , materiall yadde d b ylookin g a t fin e lea d and coars e lea d separatel ywhic hwoul drelat e i npar t t o th e



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 42 0

i secondar ytransmissio no f deposite d material . 2 D o yo u anticipat e i nth e nex t grap hlayin g ou t you r 3 thinkin g an d option s o nth e sampling ? Becaus e i t seem s t o 4 m e tha t ver ylittl e though t wen t int o th e standar d samplin g 5 i nth e 197 8 standard . Whethe r there' s an yjustification

- fo r 6 a 24-hou r samplin g interva l an d th e frequenc yo f ever ysixt h 7 day , especiall ya s yo u ge t t o a statistica l form . 8 Obviously , whe nyo u hav e a relativel yinfrequen t an d a ver yrotatin g wea k schedule , i t get s sor t o f arbitrar y a s t o whethe r you'r e goin g t o catc ha nexceedenc e o r not. -

O f cours e also , now , it' s differen t fro m197 8 i n term s o f samplin g i ntha t we'r e dealin g wit hver ymuc hlowe r level s o f lea d i nth e ai r already , le t alon e thos e tha t th e standar d ma ydriv e t o lowe r levels .

S o th e analytica l sensitivit ym a becom e mor e o f

a nissue . S o I thin k it's , i npart , a polic yissu e an dw e hav e t o stee r clea r o f that . Bu t I vie wi t a s a scientifi c 1 8 issue . Wha t i s th e scientificall ydefensibl e mean s o f charac

1 9 terizin g ambien t ai r levels ? 2 0 And-i t depends , i npart , o nyou r definitio no f •averagin g tim e tha t woul d driv e th e samplin g somewhat. . Bu t ther e shoul d b e consideratio nof , perhaps , contijiou s samplin g ove r seve nday s a t lowe r volume s a s compare d t o a snapsho t i ntim e ever ysixt hda ytha t ha s a nadvantag e o f givin g yo u mor e materia l t o collect , perhaps , and , a t th e sam e time , 1 0 n 1 2 13 1 4 1 5 1 6 17

21 2 2 2 3 2 4 2 5 

### EXECUTIVECOUR TREPORTER S (301 ) 565-006 4P.2 2

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 21

- 2 2 2 3 2 4 2 5 gettin g a mor e complet e descriptio no f exposur e sinc e you'r e no t losin g anytim e withou t increasin g th e numbe r o f sample s t o b e analyzed .

Thes e ar e al l option s tha t relate , I think a t leas t

• i npart , i nstrong'part , t o th e scientifi c judgment s w e ca n hel p yo u with . An d althoug hthe yma yeffec t polic ydecisions , I thin k w e ca nloo k a t the mrealisticall yi nterm s o f thei r scientifi c credibility .

DR . WARE : Whe nyo u sampl e on e da yi nsix , i s tha t alway s a particula r dayo f th e week ?

CHAIRMA

NLIPPMANN : Tha t wa s par t o f th e design . It' s allege d to , ove r a year , sampl e ever yweekda ya t equa l

. levels . S o i t ha s som e advantage s fo r som e kind s o f moni

toring . I' mno t sur e it' s appropriat e t o thi s pollutant .

MR . HAINES : I uges s i nrespons e t o you r severa l question s here , w e d o hav e underwa yanalysis , tryin g t o examin e wha t shoul db e th e bes t frequenc yo f sampling , par ticularl yin'ligh t if'w e wen t t o a monthl yo r shorte r averagin g period . W e appreciat e you r comment s wit hregar dt o th e instrument , itself . W e hav e no t give ngrea t thought , a t thi s poin t i ntime , o f movin g awayfro mth e hig hvolum e sample r . i s th e devic e t o eithe r a lo wvolum e a s yo u suggest . W e wil l hav e t o explor e that .

CHAIRMANLIPPMANN : Well , w e certainl yhav e t o 

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### 2 2

1 0 1 1 explor e it , a t least . Whether , i nfact , yo u wan t t o ge t 2 stuc k wit ha hig hvolum e sampler , i f yo u wan t a PM-1 0 i ni t 3 o r not , I' m

no t sayin g on e o r th e other . Bu t yo u certainl ywoul dhav e t o explicitl yaddres s 5 j th e reason s fo r no t puttin g aninle t o f an yparticula r kind 6 o nth e sampler . And yo u shoul dcertainl yaddres s th e issu e 7 o f whethe r t o collec t fin e and coars e separately , whethe r

8 a t hig hvolum e o r a t lowe r volum e 9 Thos e ar e differen t issue s fro mth e sampl e duratio n

DR . MORGAN : Yes . CHAIRMA

NLIPPMANN : S o I hop e tha t i nth e nex t staf f 1 2 pape r yo u wil l addres s thos e issue s 13 Tim , woul dyo u lik e t o commen t o nthos e points ? 14 ~ DR . LARSON : I thin k they'r e definitel ywort h 15 thinkin g about . An d perhap s i nsom e guid e t o tha t thinking , 16 yo u migh t wan t t o loo k a t th e relativ e amount s o f tota l 17 particulat e matte r o nyou r filter s relativ e t o th e amoun t o f 18 lea d becaus e tha t i s som e inde xo f th e variabilit yo f th e compositio no f th e fractio no f lea d withi nth e particle s whic hma yspea#

k t o thi s frequenc ydistributio nissu e

* Becaus e i f they'r e a relativel yconstan t fractio n o f lea d and particulat e matter , the nyo u hav e a nentirel y additiona l dat a bas e o nwhic ht o hel p guid e you r judgment s Bu t there' s n o sens e i nthat . I mean , i t ma yno t b e appro 19 2 0 2i " 2 2 2 3 2 4 2 5 priate . 

### EXECUTIVECOUR TREPORTER S (301 ) 565-006 4P.2 4

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 

### 2 3

Bu t I wa s intereste d whe nw e wer e lookin g throug

h the peak t o mea nratio s i nurbanarea s a s oppose d t o — source s whethe r o r no t thos e sam e peak t o mean s wer e observe d fo r TSP . CHAIRMA

NLIPPMANN : That' s certainl y —Timha s bee nbringing u s bac k repeatedly , an d I thin

k wisely , t o the issu e o f th e peak o r —poin t sources , especiall ya s th e .phasedow

nreduce s ou r concernabou t exposur e i nmuc ho f the res t o f the country .

An d the issue Dr . Nort hraised become s s o important . The typica l distributio nbetwee nfine an d coars e maybe quit e differen t whe nyo u look a t specifi c industria l —sources . It' s jus t furthe r reason , perhaps , fo r taking a good hard 'loo k "at wha t yo u wan t t o d o i nsampling . DR . MORGAN : I gues s I migh t pu t i na ple a to o tha t i nthinking abou t the sampl e o r the measuremen t necessar y fo r standard enforcement , tha t yo u als o reflec t onthe fac t tha t yo u wil l b e bac k here , o r your successor s wil l be bac k her e i na fewyears , talking abou t lea d again . An d i t woul d b e nic e i f the dat a se t tha t yo u develop fo r enforcemen t purpose s i s als o a dat a se t tha t help s yo u t o d o a more:intelligen t jobnex t time yo u hav e t o d o a niteratio nonthis . An d I wouldn' t los e trac k o f tha t fac t i nthe proces s o f designing your measuremen t process .

CHAIRMA NLIPPMANN : An

yothe r comments ? 

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DR . MORGAN : I hav e on e o na differen t subject . MR . JORDAN : There' s a t leas t on e mor e thin g w e neede d t o tal k a littl e bi t about , andthat' s th e secondar y standard . W e haven' t discusse dtha t a t all .

CHAIRMA

NLIPPMANN : S o befor e leavin g th e primar y standard , i s Dr . Morgan' s additiona l commen t onth e primar y standard ? DR . MORGAN : Yes . I wante dsimpl yt o pu t i na ple a tha t i f yo u hav e not , tha t yo u tak e of f Frank' s commen t abou t th e rol e o f lea d fro msmoking , seriously , becaus e i t ha s clea r polic yramifications . I mean , i t introduce s a dimen

sio no f voluntar yexposur e whic hsor t o f muck s u p additionall y som e o f this .

An d i t strike s m e tha t a littl e bi t o f reflectio n o ntha t whol e issu e migh t b e i norder . Yo u ma yb e abl e t o simpl ydemonstrat e tha t it' s a secon dorde r o f fac t t o compar e i t wit hth e thing s tha t yo u tal k about . I t strike s m e tha t i f yo u hav e though t i t through, fine .

I t ma ywoul db e appropriat e t o jus t saya littl e bi t abou t you r thoughts .

MR . JORDAN : Okay . We'v e talke da littl e bi t amongs t ourselves . I thin k therel s somethin g w e ca nd o wit hNHAME S dat a t o —

DR . MORGAN : Well , w e don' t nee dt o hea r detail s a t thi s point . Jus t a suggestion .



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(301 ) 5654)06 4P.2 6 2 5

2 3 4 5 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 2 1 2 2 2 3 2 4 2 5 MR . JORDAN : Okay .



### CHAIRMA NLIPPMANN : Okay . D o yo u wan t t o shif t our focus , then,.t o the secondar ystandard ? An

d I guess , perhaps , i f you weren' t planning t o already , yo u coul d intro

duc e th e reason s wh yyo u need a secondar ystandard a t al l if , i nfact , yo u reall yhave n o convincing evidenc e tha t i s a concernabou t welfar e things .

MR . JORDAN : Well , okay . I' mno t quit e sur e we can conclud e we canconclud e we have n o concernabou t secondar y welfar e things . I thin k it' s muc hmor e difficul t t o pinpoin t wher e thos e secondar yeffect s are . Thos e concern s ma ybe appearing a t probabl y—ar e a lo t mor e difficult ythani t i s fo r the primary .

The attorney s ar e here . Mayb e the ycansa

ysome thin g a s t o wh

yw e ar e concerne d abou t a secondar ystandard , pe r se , i nterms o f lega l requirements .

Ther e i s on e concernI have fo r having a secondar y standard , eve ni f yo u hav e a secondar ystandard that' s equa l t o the primarystandard . Withou t a secondar ystandard a t all , i t tend s t o deemphasiz e a lo t o f neede d research .

An d i f 'yo u don' t have a standard ou t ther e i t tend s t o turnth e researc hcommunityawa yfro mth e welfar e effect s whic hmayb e occurring ou t there . S o that' s a t leas t on e reaso nI se e fo r continuing t o hav e one eve nthoughyo u sai d tha t equa l t o the primary , it , ineffect , doesn' t have a



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 42 3 2 4 2 5 P.2 7 2 6 i o f impact . Yo u mee t th e primar yan dyo u mee t th e secondary . 2 S o that' s on e o f th e reason s I personall ypus h 3 fo r havin g it . 4 Th e othe r reason , I guess , i s tha t th e Ac t require s 5 yo u t o se t on e fc r welfar e effect s i f yo u thin k tha t ther e

6 ar e welfar e effect s appearin g ou t there . 7 CHAIRMA NLIPPMANN : That' s understandabl e i f yo u 8 nee di t t o protec t th e plants , lik e a nozon e o r S0_ , yo u hav e 9 t o tak e a loo k a t i t becaus e yo u kno wi t ca naffec t th e plant s 1 0 o r th e materials , o r whatever . nI' m jus t wonderin g wher e i t appear s tha t th e effects, , 1 2 i f any , ar e muc hles s sensitiv e tha nth e healt heffect s con 1 3 cerne dtha t ar e identifie di nth e primar ystandard , an dth e 1 4 primar ystandar ddrive s th e leve l t o th e lowest , wh yd o yo u 1 5 explicitl yhav e a secondar ystandard ? 1 6 An d yo u sai dyo u hav e a secondar yreaso nan dtha t 1 7 i s t o hel p yo u i nth e managemen t o f th e agenc yan di n 1 8 directin g wha t ma yb e necessar yresearc hfo r th e future . 1 9 MR . HAINES : I thin k w e hav e a primar yreaso ntoo . 2 0 S o I thin k tha t whil e th e dat a i s weak , e t cetera , I thin k 2 i "the yhav e a hig henoug hconcentratio nt o clearl yhav e effect s 2 2 o f lea do nman yec usyste mcomponents . An dwe'r e concerne d abou t th e lon g ter mimplication s o f lea di nth e ec o system .

The nou r proble mi s definin g wha t leve l o f contro l yo ushoul dhave . An dwe'v e ha dt o tak e a backward s approac h



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.2 8 2 7 1 and say , "Wil l th e leve l o f primarie s —a ful l o r adequat e 2 protection."

An d ou r judgmen t a t th e staf f leve l i s yes , i t will , followin g muc hth e sam e rational e tha t wa s use di n 1978 . An d w e als o a t thi s revie whav e a situation . Clearly , 6 fromthi s evidence , there' s n o wa yth e agenc ycoul dsay 7 tha t there' s n o longe r a nee d t o retai na secondar ystandar d

8 sinc e we'v e ha d on e se t

9 An d I thin k practicall ysinc e ou r rational e i n'.7 8

1 0 wit hanimal s basicall yappea r t o b e n o mor e susceptibl e t o

nman , w e ough t t o adjus t th e secondar ystandar da t thi s revie w 12 t o b e equivalen t t o th e primar yparalle l i ntha t rational e 13 CHAIRMA NLIPPMANN : Well , on e coul dloo k a t i t i n u anothe r way , tha t ther e i s alreadya nawfu l lo t o f lea dou t ther e i nsom e soils . An dit' s fairl ystable . It' s goin g t o b e ther e a long tim e

.-, An d on e coul d argu e whethe r th e incremen t whic hi s 18 goin g t o b e allowe dunde r th e ne wsecondar ystandar di s a third , fourt ho r fift horde r effec t t o th e ecologica l effec t whic hma yb e resultin g fro mpas t emissions . So , yo u know , ca nyo u justif ycontrollin g futur e emissions ? 1 5 1 6

1 9 2 0 2l ' 2 2 2 3 2 4 2 5 Don' t yo u hav e t o sho wtha t th e incrementa l addi

tio nt o th e soi l wil l affec t plant s o r animal s incrementall y i norde r t o justif ydoin g that ?

MR . HAINES : I thin k —le t m e respon di nthi s 

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(301 ) 565-006 4P.2 9

1 2 3 4 5 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 2 1 2 2 2 3 2 4 2 5 2 8 fashion . I thin k there' s a grea t dea l o f uncertaint yo hwha t ar e th e combinin g capacitie s o f soil s throughou t th e U.S .

Granted , i ncertai nhig hleadarea s nea r roadway s aroun d majo r poin t sources , we'v e don e a successfu l jo bo f contaminatin g tha t soi l wher e yo u induc e th e effects . We'r e a t hig henoug hlevels .

Manyarea s o f th e countr ywer e uncertai nho wmuc h contaminatio nha s take nplace . An d the ydon' t kno wfo r cer tai nho wmuc hadditiona l capacit yfo r th e soi l t o findthi s lead . S o I thin k it' s pruden t polic yt o —preven t it , main

tai na secondar ystandard , maintai ni t equivalen t t o th e primar yeve nthoug hwe'r e uncertai no n—

CHAIRMA

NLIPPMANN : Well , operationally , I se e n o "problem , then . I f you'r e no t makin g th e state s d o anythin g the ywouldn' t d o anywa yt o mee t th e primar ystandard . It' s no t reall yhurtin g anybodyt o stat e tha t th e secondar y standar d i s th e sam e a s th e primary .

I' m jus t askin g a basi c semanti c issu e o f doe s i t reall yhav e a purpose .

Jerry , d o yo u wan t t o giv e u s a lega l opinio na s t o whethe r w e nee/d a secondar ystandard ?

MR . GLEASON : I don' t kno w— CHAIRMA

NLIPPMAN : Thi s i s Jerr yGleaso nfro mth e Genera l Counsel' s Office .

MR . GLEASON : I thin k whe nth e Ac t wa s amende d 

### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.3 0

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 2 9 i n19 7 0 th e genera l assumptio nwa s tha t secondar ystandard s woul d usuall yb e mor e restrictiv e tha nprimar ystandards . Ho wel l tha t assumptio nwa s based , I don' t know .

Bu t i n1977 * th e Ac t wa s amende d again , a s yo u know . An d somewher e i nth e hundred s o f page s that : resulted , ther e i s som e languag e tha t recognize s tha t a secondar ystandar d migh t b e les s restrictiv e tha nth e primar ystandard .

Logically , yo u woul dhav e t o as k yoursel f wh yd o yo u nee d th e secondar ystandar di f th e primar ystandar d wil l d o it , particularl ywhe ni t i s generall ys o tha t th e pri

mar ystandar d wou l hav e t o b e obtaine dfaste r tha nth e secondar ystandard .

It' s a logica l question . Yo u coul d saytha t "assumin g th e primar ystandar di s —tha t ther e i s n o publi c welfar e proble m

lef t t o address , bu t th e Ac t doesn' t clearl y poin t i ntha t direction . I t say s t o se t a standar dbase do n suc hwelfar e fact s tha t yo u perceiv e migh t occur .

An d i t doesn' t reall yanswe r th e questio nabou t redundancy . An d the nwhe nyo u addi nth e facto r tha t yo u se e possibl e welfar e effect s bu t you'r e no t sur e a t wha t leve l the ywoul d occur, ' the nyou'r e int o a differen t proble mwhic h i s doin g th e bes t yo u ca ni nterm s o f pickin g a number .

CHAIRMANLIPPMANN : Well , o r havin g a differen t kind o f standard . On e o f th e option s raise di nth e staf f pape r wa s havin g som e sor t o f a depositio nstandar drathe r



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 41 4

1 6 1 7

1 9 P.31 3 0 tha na nambien t ai r standard . 2 An d tha t migh t mak e sens e i f there' s an ybasi s fo r 3 i t becaus e i t migh t mor e directl yge t a t th e welfar e issues . S o I thin k perhap s yo u ough t t o la you t th e option s an d let' s loo k a t them .

Bob ?

7 DR . FRANK : I wonder , Jerry , i s ther e an ymean s i 

## | • i 6 j o f implementing , enforcin g a secondar ystandar d a t th e present! ? i 9 MR . GLEASON : I gues s I' mno t sur e quit e wha t J i o you'r e

nDR . FRANK : It' s m yunderstandin g tha t ther e ar e 1 2 tim e constraint s tha t g o alon g wit hprimar ystandards . The y 1 3 mus t b e implemente d b ya certai nperio d o f tim e o r EP Atake s action . 1 5 I s tha t tru e fo r secondar ystandards ? M R . GLEASON : Th e secondar ystandard , accordin g t o th e Act , ha s t o b e attaine d i na reasonabl e time . An dm y 1 8 understandin g i s tha t th e Agenc yi s generall y—whethe r ther e i s a reasonabl e time . An d a s t o wha t sanction s apply , 2 c I'l l le t somebod yfro mOAQP S addres s that . 2i . - * MR . JORDAN : Tw o thing s here . Whe nyo u develo p a 2 2 stip , yo u d o develo p a sti p tha t ultimatel yi s suppose dt o 2 3 mee t th e secondar ystandar d 2 4 Th e rea l clai mo f impac t wit hth e secondar ystandar d 2 5 i s ne wsources . Yo u know , whe nne wsource s ar e permitted , 

### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.3 2

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 2l ' 2 2 2 3 2 4 2 5 3 1 the yar e modele d agains t th e secondar ystandard . S o i t doe s hav e a direct , righ t now , typ e o f impact .

DR . MORGAN : Ca nw e g o bac k t o th e poin t abou t — o r mayb e yo u wer e goin g t o sa yth e sam e thing . Tha t i f on e ha d a secondar ystandar dtha t wa s depositio nrelated , tha t basicall yapplie s t o point s —tha t ha s a majo r impac t fo r larg e poin t sources .

And i t migh t b e correlate d wit hwha t yo u d o a t th e primar ylevel .

DR . LARSON : I wa s goin g t o sa yI think i t raise s a whol e se t o f issue s whic hma yno t b e scientifi c i nnature . Bu t EP Aprobabl ythroug hthe mthrough . I t migh t b e tha t aroun d thos e areas , there' s s o muc hlea di nth e soi l tha t i f yo u hav e a depositio nstandard , wha t you'r e reall ydoin g t o ge t appliance s i na reasonabl e amoun t o f time , yo u assum e it' s goin g t o continu e t o b e windy , you'r e talkin g abou t cleanin g up th e soil , a lo t o f contaminate dsoil .

Becaus e t o trydepositio nmonitorin g i s goin g t o reflec t previou s —i nsoil s and reentrainment . S o i t raise s a whol e separat e se t o f points .

MR . HAINES : I thin k whe nw e lai dou t tha t proposi

tion , w e recognize dw e ha d a lo t o f shortcomings . An dI think , exceptionally , though , I thin k it' s appealing . I think hopefull yw e ca ngenerat e informatio ntha t som e dayw e coul d se t th e prope r standard-whic hI thin k i s a depositio nstandar c



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4r _ _ _P.3 3 3 2

1 t o ge t a t econologica l effects . 2 I think , i nver yters e fashion , w e tr yt o indicate , 3 whil e w e conceptuall yfin d thi s appealing , tha t w e don' t kno wenoug hno wt o pursu e i t wit han ygrea t vigo r wit hou r

curren t informatio nbasis . i j CHAIRMA NLIPPMANN : Well , i t certainl ywoul dserv e j i i Bruce' s mai nobjectiv e whic hi s t o generat e research . j i I MR . HAINES : An d that' s par t of , I think , ou r moti- j 9 vatio no f puttin g i t i ni s t o ge t peopl e thinkin g i nthes e i 

### I 1 0 terms . " i | nDR . MORGAN : Bu t I gues s I shar e som e o f th e concern s 1 2 tha t we'v e bee nhearin g fro mth e Chairman . 1 3 I t strike s m e tha t i f whe nyou'r e throug hthi s an d 1 4 yo u think ' yo u kno wwha t primar ystandar d you'r e goin g t o 1 5 recommend , i f yo u the ntak e tha t an d multipl yi t b ya facto r 1 6 o f tw o o r three , yo u haven' t go t evidenc e tha t yo u fin dreall y 1 7 persuasiv e tha t th e resultin g numbe r wouldn' t b e an yles s 1 8 ba d a s th e secondar ystandard . 1 9 The ni t strike s m e tha t you'r e i na somewha t scien

2 0 tificall yuncomfortabl e position . An d tha t th e substitutin g 2i ' -fo r eac h"other , whil e i t ma yd o n o har mi nth e shor t run , 2 2 set s sor t o f a continuin g preceden t o f playin g a littl e 2 3 fas t an d loos e i nth e scienc e tha t yo u don' t wan t t o b e uncom 2 4 fortabl e abou t 2 5 CHAIRMA NLIPPMANN : Dr . Weing ? 

### EXECUTIVECOUR

TREPORTER S (301 ) 565-006 4

### 3 3 DR . EWING : I' dlik e t o rais e a littl e bi t o f con 2 cer nher e t o th e depositio nrat e standard . 3 Conceptually , I hav e a littl e proble mwit hi t becaus e i t seem s t o b e movin g bac k awayfro mth e measur e o f 5 exposur e t o th e organism , whateve r i t is ; concentratio ni n 6 th e soi l o r concentratio ni nth e water . 7 I I nth e cas e o f soil , whic hi s a majo r syn c i nth e 8 ec o system , th e depositio nrat e i s reall yth e rat e o f accumu 9 latio no r th e rat e o f chang e o f concentration . An di t seem s 10 excep t fo r folia r deposition , whic hi s a majo r exposur e t o 1 1 tha t pathway , excep t fo r that , i t reall yisn' t th e mos t 12 direc t measur e o f th e dos e t o th e organism . 13 I t woul d als o see mt o m e tha t i f yo u alreadyhav e 14 a nare a o f hig haccumulate dconcentration , becaus e o f pas t 1 5 deposition , the nyo u ma yb e approachin g a toxi c leve l suc h 16 tha t yo u migh t wan t a lowe r cumulatio nrate , o r depositio n rate . S o yo u migh t wan t t o hav e t o adjus t tha t depositio n rat e a s yo u ge t close r t o som e sor t o f a threshold .

I t jus t seem s t o m e lik e it' s a nawkwar dwa yt o tr yt o ge t at.th e problem . Th e mor e direc t wa yi s concen tration . * MR . HAINES : You'r e talkin g no wo f soi l concentra tion , no t necessar yai r concentration . See , we'r e lookin g a t i t fro mth e poin t o f vie wo f measurin g concentratio nt o 1 7 1 8 1 9 2 0 2l ' 2 2 2 3 2 4 

### 2 5 ambien t

ai r i s on estep-remove dfro mdeposition . EXECUTIVECOUR

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

An d I thin k you'r e suggestin g ideall yyo u woul d mov e t o — DR . EWING : Mov e t o soi l concentratio no r wate r concentration . 5 MR . HAINES : Right . Which , unfortunately , ma y 6 caus e u s problem s withi nou r regulator yframework . 7 DR . EWING : Yes . Th e immediat e bas e legislatio n 8 yo u dea l tha t wil l mak e tha t ver y—

MR . JORDAN : Mayb e I ca npas s thi s o nt o th e soli d 0 soi l people . n(Laughter ) 1 2 DR . EWING : Mayb e yo u shoul dpas s i t o nt o th e 3 Congress . 1 4 ~

~ MR . HAINES : On e othe r comment , vis-a-vi s ou r dat a 1 5 base , i nman ycase s w e hav e uncertai ndat a andparticularl y 16 wit hrelatin g ambien t concentratio nexposure s t o th e —infor

1 7 mation , w e d o have , fo r animals , yo u know , som e reasonabl e dat a whe nw e hav e qualitativel y—ou r qualitativ e assessmen t o f th e anima l toxicolog ydata , e t cetera .

S o Xthin k —I don' t wan t t o impl yto o blea k a pictur e tha t w e can' t arriv e a t a rational e tha t animal s ar e not , therefore , susceptible . Andou r primar yhealt hbas e standar d shoul d protec t mos t wil dand.domesti c animal s ou t ther e a s a basi s fo r a secondar ystandard . 1 8 1 9 2 0 2l ' 2 2 2 3 2 4 2 5 CHAIRMA NLIPPMANN : But , Ithink , peopl egenerally , 

### EXECUTIVECOUR

TREPORTER S (301 ) 565-006 4P.3 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 2l ' 2 2 2 3 2 4 2 5 3 5 excep t fo r kid s wh o hav e —you'r e no t talkin g abou t direc t ingestion . Fo r you r livestoc k andman yo f you r wil danima l species , it' s ver ylikel ytha t they'r e eatin g th e lead tha t fall s o nth e foliag e wit hth e forag e (ph ) tha t the yea t muc h mor e extensively .

S o whil e the yma yno t b e anymor e o r les s sensitiv e t o a certai nbloo dlea dlevel , the ycoul deasil yhav e muc h highe r dose s fro m deposite dmaterial . W e onl yar e gettin g i t fro m foo d wher e w e don' t full ywas hth e leave s tha t we consume . The ydon' t was hthe ma t all .

An d the yea t mor e o f th e plan t materia l directly . W e pee l awa ysom e o f th e oute r plan t material . S o it' s a differen t situation . Th e sensitivit yt o th e bloo dleadleve l ma yb e simila r bu t tha t doesn' t mea ntha t th e ai r lea dleve l ha s th e sam e relationshi p t o grazin g animals .

DR . EWING : I t seem s t o m e I recal l havin g see ni t o r i t wa s pointe d ou t tha t horse s ar e particularl ysensitive . And , a s I recall , a commen t wa s mad e tha t horse s hav e a tendenc yo f grazin g and pul l th e gras s up b yth e roots . An d •t o inges t them , th e soil , i s attache dt o th e root s wit hit .

S o the yge t lea dfro mth e soi l a s well . An dthat' s i nadditio nt o th e follia r deposition .

DR . LARSON : It' s har dt o do . But , I mean , i nth e idea l worl d yo u woul dmeasur e lea d a s a functio no f th e



### EXECUTIVE COUR T REPORTER S

(301 ) 5654)06 4P.3 7 3 6 particl e size . Andyo u coul d hav e estimate s o f deposition s 2 a s wel l a s ambien t concentration . 3 DR . HAMMOND : I suppos e I shoul dcommen t a s th e onl y veterinaria ni nth e group . 5 (Laughter )

6 Thi s issu e o f poisonin g o f livestoc k ha s bee non e 7 tha t ha s bee nidentifie dandha s bee no f concer nfo r many years . And althoug hI haven' t ha d an ydealing s wit hth e issu e fo r a t leas t 1 5 —well , a t leas t 1 2 years , I d o recal l tha t th e onl yepisode s o f clinica l poisonin g tha t wer e eve r nidentifie d wer e eithe r i nth e vicinit yo f secondar ysmoker s and onl ythe nwhe nthe yha d som e sor t o f acciden t lik e a fir e

1 3 ' i nth e ba g (ph ) hous e whic hallowe dal l thes e fume s t o g o of f int o th e air , o r a s a resul t o f pain t an dbatter ycasings , 1 5 and thing s o f tha t nature .

Bu t neve r an

yepisode s reporte d tha t deal t with , fo r example , th e proble mo f grazin g nea r freeways . A s a matt e 9 1 0

1 2

1 4

1 6 1 7 18 o f fact , a t on e poin t I recal l tha t we.specificall yidenti

19 2 0 2l ' 2 2 2 3 2 4 2 5 fie d som e horse s wh o happene d t o b e passin g alon g th e freewa y t o tryt o ge t .som e ide a a s t o whethe r th e bloo dleve l i s .an ydifferen t i nthos e animal s tha ni t wa s i nthos e tha t wer e < • grazin g i nmor e remot e areas .

Ther e wa s n o difference . S o I thin k tha t th e exper i menta l evidence , too , i nterm s o f wha t i t take s t o —i n livestoc k ha s bee nver y- undefined . An dI thin k tha t al l o f



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.3 8 3 7 1 thi s reveal s tha t ther e reall yi s n o proble mtha t woul d

2 exist , wit han ykin do f a reasonabl e particl e exchange . 3 I nfact , I don' t thin kthere' s a proble mther e really . An d I thin kth e documentatio ni s i nit . 5 bCHAIRMA NLIPPMANN : Nobody' s looke da t th e rela

i i 6 j tionshi p o f th e statur e o f th e anima l t o lea da t lowe r level s 7 an d productivit yt o th e welfar e issue .

i i i 8 [ ! (Laughter )

DR . HAMMOND : W e di dtha t bac ki n197 0 whe nth e 1 0 ai r lead s wer e considerabl e highe r an dth e gasolin e consump n' tio nwa s considerabl yhighe r tha ni t i s today , 2 ; CHAIRMA NLIPPMANN : Well , I don' t kno wi f thi s ha s 1 3 i bee nver yusefu l t o you . Perhap s yo u ough t t o outlin e t o u s 1 4 wha t ""you r thinkin g i s o f thi s secondar ystandard , an dw e 15 ca nreact , then , t o that . 1 6 Y o usai dyo u wante dt o tel l u s somethin g abou t 1 7 th e secondar ystandard ?

M R . HAINES : No . We'v e outline dou r recommendatio n 1 8 1 9 2 0 an dtha t woul db e t o mak e i t equivalen t i nal l respects .

CHAIRMA NLIPPMANN : Well , d o yo u fee l you'v e gotte n 2i ' "an yadvic e fro mu s i nthi s genera l discussio nwhic hi s o f 2 2 an yus e t o you . 2 3 (Laughter ) 2 4 An d i f you'r e onl yconfuse db yi t — 2 5 (Simultaneous'conversation ) 

### EXECUTIVECOUR

TREPORTER S (301 ) 565-006 4P.3 9

1 1 1 2 

### 3 8

CHAIRMA

NLIPPMANN : —and i f you'r e onl yconfuse d 2 byi t o r i f we'v e onl yconfuse d you , mayb e w e coul dclarif y 3 thes e things .

MR . JORDAN : No . I don' t thin k I hear dyo u say 5 anythin g tha t w e haven' t discusse damongs t ourselves . I 6 thin k confusion , a lo t o f times , you ' know , jus t state s wha t th e stat e o f th e ar t is .

An d th e thing s tha t hav e bee nsai dher e ar e thing s 9 tha t we'v e sa t aroun dth e tabl e lot s o f time s an ddiscussed . 1 0 An d th e fac t that , a s yo u chim e i nwit hthes e conversations , jus t basicall yconfir mou r ownsuspicion s o f th e lac k o f dat a and th e lac k o f informatio nou t ther e 13 CHAIRMA NLIPPMANN : Well , you'r e no t currentl y 1 4 thinkin g abou t havin g anystandar dothe r tha nth e reaffirma

1 5 tio no f th e primar ystandard ? 1 6 MR . JORDAN : That' s correc t 17 CHAIRMA NLIPPMANN : Althoug heve ni n ou r discussio n o f th e primar ystandard , w e suggeste dconsideratio no f some thin g yo u weren' t thinkin g o f lik e fin e andcoars e separatel y An d i f yo u did . that , the nyo u migh t wan t t o loo k a t th e secondary " standar d i n term s o f a differen t mixtur e o r a dif

feren t emphasi s o nfin e versu s coars e ai r lea dfo r it s 2 3 differen t

reason s 24Igues s Iwoul dlik e t o se e yo

u mor e explicitl y 2 5 addres s thi s secondar y standardan

dtal k about an y othe r

basi s 

### EXECUTIVECOUR

TREPORTER S (301 ) 565-006 4 1 8 1 9 2 0 2l ' 2 2P.4 0 3 9 1 tha ntha nth e primar ystandar d i f it' s possibl e t o d o so . 2 (Pause ) 3 Hav e w e finishe d ou r discussio no f you r presenta tio no r d o yo u wan t t o emphasiz e anythin g els e o nthat ?

MR . JORDAN : No . 6 CHAIRMA NLIPPMANN : Doe s anybod yels e wan t t o offe r 7 an yopinion s o nth e secondar ystandard ?

8 MR . JORDAN : I' d jus t lik e t o hav e Dr . War e t o 9 hav e a nopportunit yt o mak e an ycomments . I' d appreciat e anythin g tha t yo u migh t ad d t o th e staf f paper . Woul dyo u —

DR . WARE : Well , I' msorr ytha t I couldn' t b e her e fo r th e firs t par t o f i t —o f th e discussio nyesterda yafter

noon . Bu t I' mgoin g t o sa yfirs t tha t I wa s reall yimpresse d wit h"th e thoroughnes s o f th e staf f people . I though t i t wa s

1 5 a nimpressiv e document . An d I' mreall yamaze d a t th e amoun t o f researc h

an d synthesi s tha t goe s int o thes e documents . S o m yoveral l impressio nwa s a ver ypositiv e one .

I didn' t eve nhav e a nopportunit yt o hea r th e discussio nabou t th e statistica l for mo f th e standard . I' m assuming'tha t tha t wa s wel l received . Tha t ther e wasn' t an y<" 2 2 seriou s criticis mo f tha t concep t althoug hI fel t th e discus

2 3 sio no f th e specific s i nth e staf f pape r wa s no t satisfactory . I mean , ther e wa s — th e idea s pu t forwar d wer e

no t pu t forwar d ver yclearly , I didn' t think . An d moreover , 1 0

n 1 2 1 3 1 4

1 6 1 7 1 8 1 9 2 0 2l '

2 4 2 5 

### EXECUTIVECOUR TREPORTER S (301 ) 565-006 4P.4 1 4 0 i t didn' t see mt o m e tha t the ywer e thoroughl yworke d u p 2 yet ,

3 S o I thin k ther e i s som e roo mfo r improvement . An d I recogniz e th e nee d fo r a statistica l for mo f th e standard , 5 I' mi n favo r o f that , bu t I thin k obviousl ysom e wor k i s

6 neede d t o develo p exactl ywha t tha t woul d loo k like , 7 MR . JORDAN : O n thi s point , Dr . Morga nbrough t th e 8 sam e poin t u p i n a discussion . An d I tol d hi mbasicall y 9 w e normall yd o thi s typ e o f discussio ni n th e regulator y

1 0 packag e whe nw e actuall ypromulgat e o r propos e a standard :

nW e hav e not , i n th e past , brough t tha t fort hi n th e staf f 1 2 pape r i n a ful l discussion , bu t there' s n o reaso nw e can' t 1 3 d o it , 1 4 " ' An d you r poin t i s wel l taken , tha t i n thi s yea r w e 1 5 jus t sor t o f mentione d th e statistica l for mo f th e standar d 1 6 and , yo u know , it' s sor t o f —tha t kin d o f thing . Bu t I' d 1 7 b e gla d t o tal k t o yo u som e mor e abou t it . DR . WARE : Okay . MR . JORDAN : Where' s th e appropriat e plac e t o 1 8 1 9 2 0 pu t it ? 2 1 2 2 DR . WARE : Well , I' d be'intereste d a t th e appro priat e tim e t o hea r ho wthat' s coming .

2 3 MR . JORDAN : Okay , 24DR . WARE : Ididn' t

ge t achanc et o hear th edis

2 5 cussio nabou t th equarterl y versu s th emonthly averagin g tim e EXECUTIVECOUR

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

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 21 * 2 2 2 3 2 4 2 5 

### 4 1 either . And m

ygenera l inclinatio nabou t thes e issues , first) , I though t I woul d lik e t o kno wmor e abou t whethe r there' s goo d evidenc e fo r difference s amon g site s and , say , th e varia

bilit yo f th e month-to-mont hvariability , give ntha t there' s no t reall ydramatic , severe , o r no t suc hdramati c difference.s , the nI woul d b e incline dt o staywit hth e quarterl ystandar d becaus e o f th e convenienc e —becaus e o f th e lac k o f problem s wit hmonitoring .

Bu t t o se t th e quarterl ystandar d i nsuc ha way " tha t month-to-mont hexcursion s woul db e adequatel ycontrolled. . I don' t kno wwha t th e discussio nwa s like . I thin k th e counte r argumen t t o tha t woul db e t o poin t t o site s which , i nfact , ar e atypica l and ar e mor e variabl e fro mmont ht o month . An d i f tha t kindo f proble marose , the ni t woul d giv e yo u concern . Yo u woul d feel

- uneas yabou t th e quarterl y standard . Ho wdi dtha t discussio ngo ?

MR . JORDAN : I trie d t o summariz e i t up thi s morn in g wit hth e on e sor t o f cente r site . I thin k no t to o man y peopl e wer e ver ycomfortabl e wit hth e discussio ntha t w e ha d o nth e averagin g tim e i nth e staf f paper . An dw e jus t simpl ynee d t o g o bac k and bee f tha t sectio nup .

W e neve r reall yanticipate dtha t w e wer e a t a poin t t o reall yfinaliz e up tha t discussio no nth e averagin g time .



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.4 3 4 2 1 An d s o w e fee l tha t we'l l hav e t o g o bac k an d tak e righ t 2 int o consideratio nth e thing s tha t you'r e talkin g abou t here . 3 S o w e didn' t expec t o r didn' t ge t an yclea r con sensu s fro mth e Committe e i nterm s o f wha t th e averagin g 5 time s woul d be . 6 I woul d appreciat e an yrecommendatio nan d guidanc e tha t yo u migh t hav e o nho wt o us e wha t availabl e dat a you'v e 8 got . 9 -DR . WARE : Okay . Well , I d o thin k fro mm ypoin t o f view , I thin k ther e ar e tw o ke yissues . First , there' s i , th e biologica l issu e abou t wha t th e sor t o f biologica l averagin g tim e is . An d yo u argu e tha t yo u thin k tha t there' s reaso nt o suspec t i t ma yb e shorte r i nchildre ntha ni n adults . An d the nth e othe r issue , i t woul d see mt o me , woul d ,agai nb e —

an d I thin k th e on e yo u ca nge t a t fro myou r ai r qualit ydata , i s th e exten t t o whic hyo u giv e som e dat a o nth e rati o o f maximu mmonthl ymea nt o th e quarterl ymeans . 1 9 An d yo u sho wtha t thos e ar e number s aroun d 1.4 . 2 0 No w.the questio nwoul d b e ho wheterogeneou s ar e 21 ' . -thos e whe nyo u tak e individua l site s an d averag e thos e ratio s 2 2 ove r time . Ho wheterogeneou s ar e thos e ratio s fo r sites ? Ar e ther e site s that , i nfact , hav e ver yunstabl e month-to

mont hvalue s o r a subjec t t o particularly , I thin k —t o ti e i nanothe r poin t —sinc e th e lea d phasedow ni s goin g t o 10

1 2 13 14 15 16 1 7 18

2 3 2 4 2 5 

### EXECUTIVECOUR TREPORTER S (301 ) 565-006 4

### 4 3

1 0 1 1 1 2 13

17 18 1 9

2 1 2 2 2 3 2 4 2 5 1 reduc e th e proble mo f lea d concentration s awa yfro marea s 2 nea r poin t sources , i t woul d see mt o m e tha t the nth e ques 3 tio nwoul d becom e ar e poin t source s likel yt o b e subjec t t o thes e shor t ter mfluctuations , an d the ywel l ma ybe , actually , 5 Whe nyo u pu t i t tha t way , yo u ma yb e abl e t o mak e

6 a goo d argument . Bu t i t seem s t o m e that' s th e argumen t tha t ha s t o b e made , tha t th e poin t source s tha t you'r e concerne d

8 abou t ar e subjec t t o shor t ter mfluctuations . 9 An d s o quarterl yaverage s reall ywouldn' t d o it .

MR . JORDAN : Okay . Poin t wel l taken . W e wil l " bee f thi s whol e discussio no f th e averagin g time .

DR . WARE : Th e othe r thin g I wis hI coul d hav e hear d wa s th e discussio nabou t wha t woul d b e considere da 1 4 concentratio ntha t woul d provid e a nadequat e marketin g —

1 5 bill , I woul d hav e love d t o hav e hear d tha t conversation .

, 6 (Laughter )

I though t tha t wa s quit e a slipper yslogan . (Laughter ) MR . JORDAN : We'l l fil l yo u in . 2 0 (Laughter )

Wha t I' d lik e t o summariz e up , and , again , Dr . Silbergel d cam e i nafte r w e ha d summarize d u p thos e thing s an d i t wil l provid e a nopportunit yfo r Dr . War e t o hea r wha t w e sai d abou t that .

W e basicall ysummarize d u p th e discussionb ysayin g 

### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 41 2 3 4 5 6 7 6 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2l ' 2 2 2 3 2 4 2 5 P.4 5 4 4 tha t th e Committe e jus t didn' t thin k tha t w e shoul dallo w kid s bloo d lea d level s t o reac ha s hig ha s 25 . An dtha t wa s prett yclea r a s w e talke dabou t it .

I nfact , w e foun d tha t th e Committe e peopl e seeme d j t o b e saying , hey, whe nkids ' bloo dleadlevel s reac h20 , w e ough t t o b e concerne dabou t th e thing . An ds o w e basic

all yconclude d tha t w e ough t t o b e settin g a standar dwhic h woul d giv e u s a ver ylo wprobabilit yo f anykid , tha t w e ca n protec t wit ha nai r standar d — and I differentiat e tha t fro mkid s whos e bloo d lea d leve l i s comin g fro msom e othe r sourc e that' s no t relate d t o th e ai r lik e pain t chip s —bu t whe nyo u ca nprotect , yo u ough t t o b e settin g a standar dtha t wil l giv e yo u a lo wprobabilit yo f kid s fro mai r lea dreachin g a bloo d lea d leve l o f 2 0 microgram s pe r cubi c meter .

O nth e othe r hand , w e didn' t hea r muc ho f anyon e sayin g w e ough t t o b e settin g up a nai r standar dt o tr yt o kee p kid s bloo d lea d level s belo w15 . S o w e sor t o f isolate d i no ntha t w e ough t t o b e havin g tha t rang e somewher e betwee n 1 5 and 20 . DR . .WARE : Yo u ca nmak e a nargumen t tha t w e ough t "t o drive*th e ai r lea da s lo wa s w e can . I mean , tha t woul d b e on e wa yo f pullin g togethe r al l th e informatio nyo u hav e i nth e criteri a document , tha t there' s reall yn o —give nth e backgroun d level s o f lead , tha t there' s reall yn o extr a burde no f ai r lea d that-w e ca nfee l comfortabl e about .



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.4 6

12 

### 4 5

1 CHAIRMA NLIPPMANN : Okay . D o yo u hav e an yfurthe r 2 advic e you'r e seekin g fro mu s o nth e staf f paper ? I f not ,

3 I thin k I spea k fo r th e Committe e i ncommendin g yo u agai n fo r th e wa yi t ha s bee napproache d an d the ' hig hleve l o f 5 performanc e show nhere , no t tha t it' s perfect . An d we'v e

6 certainl yle t yo u kno wwha t w e thin k abou t way s t o improv e 7 it , 8 Bu t w e ar e particularl ypleased , I think , wit hth e 9 wa yi nwhic hyou'v e lai d ou t th e thinkin g an d show nu s tn e 1 0 option s tha t ar e availabl e t o th e staf f paper . W e trus t tha t

nth e criticis mtha t we'v e give nyo u ha s bee nconstructiv e an d wil l enabl e yo u t o produc e substantiall ya nimprove d secon d 1 3 version ,

1 4 -"

* • I thin k w e loo k forwar d t o readin g an d reviewin g 1 5 i t fo r you , M R . JORDAN : O nbehal f o f th e invisibl e staff , thes e youn g peopl e tha t di d th e work , le t m e sa yw e appre ciat e th e Committe e takin g th e tim e t o shar e thei r view s an d

w e valu e thos e views .

An d . 1 assur e yo u tha t th e nex t versio no f i t wil l •incorporat e thos e views . 2 2 CHAIRMA NLIPPMANN : An yfurthe r las t word s fro m 2 3 member s o f th e Committe e t o th e staff ? 2 4 (N o response ) Well , it' s tim e fo r ou r firs t brea k o f th e day , 

### EXECUTIV E COUR T REPORTER S

(301 ) 565-006 4 1 6 1 7 1 8 1 9 2 0 2l 'P.4 7 

### 4 6 1 Let' s resum e a t 10:10 . 2 ( Abrie f reces s wa s taken )

3 CHAIRMANLIPPMANN : Bruce , d o yo u pla nt o introduc e thi s topic ?

MR . JORDAN : Sure . Fo r sometim e no ww e hav e bee n 6 workin g towar d developin g a ris k assessmen t capability . I 7 suspec t tha t a lo t o f peopl e o nCASA C ar e gettin g tire do f 8 hearin g u s saywe'r e doin g it . 9 It' s bee na long and challengin g tas k fo r us . An d 10 thre e member s o f th e Committe e hav e bee ninstrumenta l i n' nhelpin g u s wit hit , Dr . North , Dr . Morga nandDr . Curran . An d w e hav e a t leas t complete da portio no f th e ris k assess 13 men t thin g and that' s wha t w e wan t t o shar e wit hyou .

-W e hav e no t complete d i t al l yet . And , a s I pointe d out , thes e tw o gentlemen , Dr . Wallste nandDr . Whitfield , I believ e arrive d fromEnglan d whe n—yesterda yo r da ybefor e yesterday ? DR' . WHITFIELD : Thursday .

MR . JORDAN : Thursday . S o the ygo t bac k fro m Englan d wher e .the yhav e bee ngoin g som e othe r encodin g ses sion s wit hpeopl e ove r there .

They'r e goin g t o com e andgiv e u s a presentatio n 1 2

1 4 1 5 1 6 1 7 1 8 1 9 2 0 2l ' 2 2

2 4 2 5 2 3 o nth e portio ntha t w e hav e progresse dth e farthes t alon g with . I t i s ou r intentio nt o tak e wha t the ypresen t today , a s wel l a s wha t the ywil l d o wit hth e res t o f th e ris k prograi r



### EXECUTIV E COUR T REPORTER S

(301 ) 565-006 4P.4 8

1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 4 7 1 an d we'l l rout e tha t int o th e staf f pape r whe nyo u se e i t th e 2 nex t time . 3 S o I as k tha t yo u liste nver yattentivel yt o wha t they , giv e an d wha t the ysa ys o tha t w e ca nge t som e feedbac k

5 a s t o wha t th e Committe e member s thin k o f thi s approac h. 6 an d th e technique s tha t w e wil l b e presente d today .

John , d o yo u hav e anythin g further ? MR . HAINES : Jus t i nth e for mo f introduction , 9 Drs . Wallste nan d Whitfiel d ar e goin g t o presen t t o yo u th e basi c methodolog yw e hav e develope d fo r encodin g procedure s an d la ytha t ou t fo r yo u an d giv e yo u th e result s o f th e encodin g session s —a s indicated , w e hav e proceeded , o nou r encodin g o nIQ , an d w e shoul d hop e t o hav e tha t finishe du p i nabou t anothe r month , I guess .

W e hav e som e followu p session s wit hsom e o f th e expert s tha t we'v e encoded . The nw e wil l hopefull ythi s summ e hav e ou r exposur e mode l i nshap e wher e we'l l b e abl e t o estimat e exposures . An d there' s ris k estimates . W e wan t t o indicat e a t th e en d o f thei r presentatio nw e d o giv e som e ris k estimates , usin g th e HANE S distributio na s —fo r 2i ' -exposures . 2 2 2 3

2 5 Thes e ar e hypothetica l ones . Bu t w e wil l giv e th e Committe e som e indicatio no f ho wultimatel yw e wil l presen t 2 4 thes e estimate s t o th e Administrator ,

Ar e ther e any-othe r point s o f clarification ? 

### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4 •?P.4 9 4 8 DR . WALLSTEN : No . I thin k th e onl yothe r thin g t o sayi s tha t I imagin e we'l l b e bac k a t th e nex t meetin g wit ha mor e ful l discussion .

MR . JORDAN : I f h e get s i nth e staf f pape r yo u will , b

ygos h— DR . WALLSTEN : Yes . MR . HAINES : AR e yo u ready ?

8 I ; DR . WALLSTEN : Yes , we'r e ready . Shoul dI start ? I t j 0 j MR . HAINES : Yes . 

# l l 10 j PRESENTATIO NB YDR . RONAL D G . WHITFIEL D AN D l 1 1 ! DR . THOMA S S . WALLSTE N 12 DR . WALLSTEN : Actually , befor e I d o start , le t 13 j j m e saytha t w e hav e no wjus t availabl e a technica l repor t 1 4 1 5 1 6 17 18 19 2 0 2l ' 2 2 2 3 2 4 2 5 that"describe s som e o f th e pilo t wor k w e di dprio r t o beginnin g an

yo f th e encoding s andsom e o f th e consideration s i nmuc hmor e detai l tha nwe'r e goin g t o presen t here .

The ywer e jus t boundandavailabl e yesterday . S o w e hav e a sheet , i f anybodywishe s t o receiv e copies , we'l l circulat e th e shee t and Ro nwil l sendou t copie s fro mArgonn e

Okay . Well , thi s i s th e introductio nt o methodolog y •fo r a probabilisti c ris k assessmen t associate dwit hsettin g r a standar d fo r lead . Now , th e purpos e o f a ris k assessmen t her e i s t o specif yo r t o develo p probabilitie s unde r possibl e alternative s next , tha t variou s fraction s o f th e populatio n a t ris k woul d suffe r certai nwel l define dhealt heffects .



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.5 0 4 9 S o if , i nfact , we'v e ha d ful l informatio nfo r a 2 particula r healt heffect , w e migh t en d u p wit ha noutpu t tha t 3 look s something;lik e th e following . W e woul d have , fo r example , fou r possibl e alternativ e standards . An d unde r 5 eac hstandar d w e woul d hav e develope d th e probabilit ytha t

6 th e percentag e o f th e populatio ntha t suffer s th e healt h effec t i s n o mor e tha nX .

So , i nthi s hypothetica l situation , unde r alterna

tiv e Standar d 1 , there' s a .0 1 probabilit ytha t a percentag e o f th e populatio nsufferin g a healt heffec t i s les s tha n'.5 , one-hal f a percent . Ther e i s a .0 5 probabilit ytha t th e fractio nsufferin g th e healt heffec t i s les s tha n1 percent , an d s o on .

And , presumably , thi s kin d o f outpu t woul d b e o f ai d t o th e administrato r i ndecidin g whic hstandar d migh t protec t th e publi c a t a nadequat e margi no f safety . 1 7 Now , i nprinciple , th e wa ysuc ha noutpu t migh t b e calculate d woul d be , o nth e on e hand , w e hav e informatio n abou t th e dos e respons e relationshi p fo r th e healt heffect . An d thi s informatio ni s base d o ndat a tha t i s fallible , o f course . * " • 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6

1 8 1 9 2 0 21* 2 2 S o ther e ar e statistica l distribution s associate d 2 3 wit hth e data . O nth e othe r hand , w e kno wsomethin g abou t 2 4 th e ai r lea d t o bloo d lea d relationship , presumabl yals o 2 5 base d o ndat a s o tha t there' s statistica l distributio n 

### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.5 1 5 0 associate d wit hthat . 2 The nw e ar e abl e t o specif y—thi s slid e migh t 3 b e a littl e misleadin g —no t necessaril yspecif yprecisel y th e ai r lea d distributio ni f a particula r standar d wer e set , 5 bu t a t leas t w e coul d specif yprobabilitie s ove r wha t th e

6 ai r lea d distributio nwoul d b e i f th e standar d wer e se t whic h

7 woul d the ngiv e u s furthe r probabilitie s ove r wha t th e bloo d

6 lea d distributio nwoul d b e i f th e standar d wer e se t a t tha t value . An d thes e tw o set s o f probabilitie s ar e the ncom bined . S o fo r eac hpossibl e standar d w e woul d en d u p wit h

a probabilit ydistributio no f th e sor t w e jus t showe dyou .

Thi s i s assumin g tha t w e hav e ful l information . 1 4 " A s everybod yi s wel l aware , w e sa yhere , "Ful l 15 informatio ni s generall yno t available. " W e coul d sa yful l informatio ni s virtuall yalway s no t available . Th e informaticj n o r dat a tha t on e ha s wit hrespec t t o a particula r healt h effec t ar e generall ysparse , incomplet e o r indirect , bot hwit h 9 1 0 1 1 1 2 1 3

16 1 7 1 8 1 9 regar d t o a dos e respons e functio nan d wit hregar d t o th e 2 0 ai r lea d t o bloo d lea d relationship . 2i • * Now , thi s additiona l uncertaint ytha t i s du e t o 2 2 th e incomplet e dat a o r t o lac k o f knowledge , mus t alway s 2 3 b e estimate d an d incorporate d int o th e output .

Now , jus t t o mak e perfectl yclear , ther e ar e reall y tw o source s o f uncertaint yinvolve d an d tw o broa d classe s o f 2 4 2 5 

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

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 2l " 2 2 2 3 2 4 2 5 5 1 uncertaint yinvolve d i nan yris k assessment . On e i s th e uncertaint ythat' s actuall yassociate d wit hdata , and thi s i s th e uncertaint ytha t mos t empirica l scientist s ar e use dto , associate d wit hsamplin g ai r wit h measuremen t air , and i t give s ris e t o al l thes e statistic s j tha t w e normall ythin k about . I Bu t there' s als o uncertaint yassociate dwit hlac k j ' o f data . It' s uncertaint yassociate dwit hextrapolatin g fro m 

## j | anima l model s t o th e populatio no f interest . Frequently , ther e ar e dat a fro mhuma npopulation s bu t they'r e no t neces - , saril yth e population s tha t w e conside r t o b e a t risk .

S o w e hav e t o extrapolate , say , fro mdat a regardin g j expose d worker s t o wha t thos e respons e relationship s migh t b e iff children . Thes e extrapolation s generall yaren' t straigh t lin e extrapolations . The yinvolv e certai ntheories . An d there' s uncertaint yassociate dwit hwhic htheor yi s correct .

An d then , o f course , there' s lot s o f othe r uncer tainty . An d s o it' s importan t t o conceptuall ydistinguis h betwee nthes e tw o kind s o f uncertainty .

Now * th e firs t kin do f uncertaint yis , a s I said , 'the sort"that' s usuall yhandle d wit hstandar dstatistics .

Th e second kindo f uncertaint yi s muc hmor e judg

menta l i nnature . An dwha t w e hav e bee ndoin g andwha t othe r decisio nand ris k analyst s d o i s tryt o lis t uncertaint y i nterm s o f subjectiv e probabilities . The yar e matter s o f



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 47 P.5 3 5 2 1 judgmen t a s t o th e natur e an d exten t o f thi s uncertainty . 2 An d differen t expert s migh t hav e differen t judgments . 3 S o w e hav e bee nlookin g a t thi s i na manne r tha t

w e wil l sho wyo u now . Thi s uncertaint y—ther e ma yeve nb e 5 disagreemen t amon g expert s a s t o wha t thi s uncertaint yis . 6 An d w e believ e it' s importan t t o represen t t o th e Administrato r no t onl yth e natur e o f thi s subjectiv e uncertainty , subjectiv e

8 probability , bu t th e exten t o f agreemen t amon g experts . 9 An d s o w e ar e goin g t o d o this .

Now , a possibl e wa yt o modif ythi s idea l tha t w e H starte d u p wit hbefor e i nligh t o f th e incomplet e information , woul d b e t o hav e eithe r a rang e o f probabilitie s o r a bunc h o f differen t probabilit ydistribution s associate d wit heac h 1 4 alternativ e standard . 15 An d wha t we'r e doin g i s w e ar e incorporatin g th e 16 subjectiv e probabilit yjudgment s fro meac hexper t separatel y so , base d o neac hexpert' s judgment , w e ge t a differen t prob

abilit ydistribution . An d thi s i s summarize d here .

Now , awhil e ago , I rea d th e tal k tha t wa s give n b yMr . Ruckleshau s whe nh e wa s th e Administrato r o f EPA . I thin k it*wa s give na t Princeto nUniversit yan d publishe di n th e journa l "Ris k Analysis " i nSeptembe r o f '84 , an d ther e ar e a fe wquotation s ther e tha t I wante d t o rea d becaus e I thin k thi s kin d o f a noutpu t reall yi s on e wa yt o ge t a t wha t h e wa s requestin g a t tha t time . 10

1 2 13

1 7 18 1 9 2 0 2l ' 2 2 2 3 2 4 2 5 

### EXECUTIVECOUR TREPORTERS (301 ) 565-006 4P.5 4 

### 5 3

l 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 

### H e says , "I f I' m going t o propos e control s tha t ma y have seriou s economi c an d socia l effects , I need t o have som e ide a o f howmuc hconfidenc e shoul d be place d i nthe estimate s o f ris k tha t prompte d thos e controls. "

S o that' s on e poin t tha t thi s kin d o f a noutpu t i s trying t o provide , howmuc hconfidenc e ther e shoul d be inan y give nris k estimate .

Furthe r oni nthe sam e talk , h

e says , "Le t me now propos e som

e principle s fro

mmor e reasonabl e discussion s abou t risk .

"First , w e mus t insis t onris k calculation s being expresse d a s distribution s o f estimate s an d no t a s magi c number s tha t canb e manipulate d withou t regard t o wha t they "reallymean .

"W e mus t tr

yt o displa

ymor e realisti c estimate s o f ris k t o showa rang e o f probabilities . T o hel p do this , w e need newtool s fo r quantifying , ordering source s o f uncertainty , an

d fo r putting the

mi nperspective . "Second , we mus t expos e t o publi c scrutin ythe assumption s tha t underl your analysi s i nmanagemen t o f risk. "

So , withou t evenknowing h e had m£d e the

- speech , we'r e trying t o d o thi s an d i t came togethe r ver ynicely . S o thi s i s anattemp t t o serve thos e goals .

Now , th e questio ni s howwoul d w e com e upo n—how woul d w e g o abou t calculation s tha t woul d lea d t o the outpu t

EXECUTIV E COUR T REPORTER S

(301 ) 565-006 4P.5 5

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

o f th e sor t w e jus t showe d you ?

Well , i nprinciple , it' s quit e simila r t o wha t w e ha d indicate d before . W e hav e a dos e respons e relationshi p fo r a particula r healt heffect . An d ther e ma yb e som e dat a and associate d statistica l distributions . Bu t there' s als o uncertaint yo f th e othe r sor t tha t w e talke dabout , andthi s woul d b e quantifie do r w e wil l ge t som e handl e o ni t b y gettin g subjectiv e probabilit ydistribution s fromsuitabl e experts , O nth e othe r hand , there' s th e ai r lead/bloo dlea d relationship , and w e als o mus t includ e som e subjectiv e prob

abilit yjudgment s t o handl e thos e uncertainties . And , again , thos e wer e combine d and ther e ar e manymor e possibl e combi

nation s whic hgiv e ris e t o th e rang e o f probabilit ydistribu

tions . I nthi s talk , we'r e onl ygoin g to - focu s o nth e wor k we'v e don e wit hth e dos e respons e relationship s and , indeed , onl ya smal l par t o f tha t righ t now . S o we'r e onl ygoin g t o tal k abou t th e uppe r left-han d bo xi nthi s slide .

Now , ther e ar e thre e healt heffect s tha t th e whol e projec t i s concerne d with . On e i s lea dinduce dhemoglobi n decrement , an d th e othe r i s lea dinduce delevate dE P and , finally , lea d induce dI Q decrement .

Regardin g E P levels , there' s relativ e complet e data . And s o i t wa s no t necessar yfo r u s t o d o an ysubjectiv e 

### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.5 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 5 5 probabilit yencoding . Peopl e fel t tha t th e dat a bas e wa s sufficientl ygoo d andw e coul d jus t wor k wit hthat . An dw e hav e don e s o bu t w e wil l no t b e presentin g tha t here .

Th e dat a regardin g lea d induce dhemoglobi ndecremen t i s muc hmor e incomplete . An d i t di d requir e tha t encodin g expert s subjecte d probabilities , andwe'r e goin g t o presen t a summar yo f wha t w e di dthere .

Th e dat a o nI Q ca nals o b e calle dincomplete , and mos t generously , I guess . An d*r e ar e currentl yworkin g o n encodin g expert s subjectiv e probabilities , onthat . S o w e ar e onl ytalkin g no wabou t th e left-handcolumn .

Ther e wer e thre e basi c step s tha t w e proceede di n t o d o thi s encoding . W e firs t develope da protoco l fo r th e "probabilit yencoding , an dI wil l discus s tha t i na bi t mor e detai l i na moment . OAQP S selecte d a se t o f expert s wh o spa na rang e o f respectiv e judgments . AndW e visite dthem and carrie d ou t th e encoding .

Now , i t wa s necessar yt o hav e a protocol , a writte n protocol . I believ e copie s o f tha t wer e distributed . S o you'v e see nth e protoco l tha t w e eventuall yende dup with . I t wa s necessar yt o develo p tha t fo r thre e primar yreasons .

First , t o provid e a publi c recor do f ho wth e encodin g wa s accomplished .

Second , t o provid e consisten t methodolog yfro m codin g th e subjectiv e probabilit yo f al l th e experts .



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(301 ) 5654)06 4P.5 7 

### 5 6

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 

### Now , i t wa s ver yimportan t tha t i f w e do fin d difference s i njudgment s amon g the experts , tha t thes e dif

ference s reflec t difference s i nthei r actua l judgment s an d no t difference s i nthe methodology , howw e carried ou t the judgments . S o thi s i s reall yquit e important .

An d finally , we need t o ensur e tha t the judgment s o f the variou s expert s ar e comparabl e s o tha t whe nwe presen t the

mit' s clear . Th e protocol , itself , wa s develope d t o satisf ya numbe r o f requirements . First , i t wa s importan t tha t the advers e healt heffec t be precisel ydefined . The populatio n unde r consideratio nan d the exposur e condition s shoul d als o "b e precisel ydefine d s o tha t al l expert s woul d b e judgin g o r predicting the sam

e event s wit hth e sam e parameters . Again , the poin t i s i f ther e ar e difference s in judgments , w e wan t t o mak e sur e the yar e trul ydifference s i njudgments , no t difference s i nthe particula r parameter s tha t ar e being talked abou t o r howth e pluse s shoul d b e conceptualized .

• I t wa s -important t o pos e question s fo r subjective probabilit yencoding tha t canb e though t abou t simpl yan d responde d t o wit ha minimu mo f motivationa l an d judgmenta l bias . I ngoin g throug hthi s exercise , on ewant s t o ge t

EXECUTIVECOUR

TREPORTER S (301 ) 565-006 4P.5 8

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 

### 5 7 a s precis e a questio na s possibl e tha t ca nbe though t abou t a s precisel ya s possibl e s o tha t there' s n o confusio na s t o wha t i s being discussed . Evidenc e canbe brough t t o bea r i n some way . No t everybod yview s the literatur e the sam e way . No t everybod

yextrapolate s fro

mthe availabl e literatur e t o th e —i nquestio ni nthe same way . I t wa s necessar ytha t w e b e abl e t o accommodat e a variet yo f perspectives . And , finally , i t wa s necessar ytha t w e be abl e t o work wit han d presen t a rang e o f judgments .

S o our protoco l wa s intende d t o serve thes e pur poses . Anumbe r o f peopl e aided inthe developmen t o f the "protocol . The

yar e mentione d here , Dr . Anit a Curran , Dr . JulianChisolm , Dr . Pau l Hammond , Le s Gran t an d hi s entir e staff , Pau l Musha k an d the OAQP S staff . W e wen t through a numbe r o f iteration s i ndeveloping the protocol . An d thes e peopl e wer e consulte d a t a numbe r o f point s along thes e iterations .

The wa yi nwhic hw e develope d the protoco l wa s firs t ti

o become familia r wit hthe problemsinc e ne'ithe r Ron no r I ar e lea

d experts . An

d s o w e di d thi s b

yreading the availabl e draf t o f the criteri a document . W e talked wit hth e OAQP S staff .

Following that , w e talked wit h— discusse d the 

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(301 ) 565-006 4P.5 9

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

### 5 8 issue s wit ha numbe r o f the peopl e wh o wer e mentione d i nthe las t .slid

e onthe telephone , occasionall yi nperson . I nman y differen t ways , w e talked wit hpeopl e t o determin e howt o structur e the probleman d t o learnwha t ar e thei r relevan t variables . The nthe firs t draf t o f the firs t draf t o f the protoco l wa s written . I t wa s sen t t o everybody . W e discussed i t wit heachperson . W e go t thei r feedbac k i nwha t wa s good an d wha t wa s bad abou t it , howthe ycoul d respon

d t o it , factor s w e ha

d lef t off , an

d s o on . W e revised the draf t an d wen t throughtha t a numbe r o f time s unti l finall yeverybod ywa s satisfied . W e wante d t o be specifi c whereve r possible , bu t w e di d need t o accom modat e differen t perspectives , differen t perspectives , say , o r th e effec t o f irondeficiencyonthes e things . An d differen t perspective s onthe effec t o f age , an d s o on . S o w e needed t o b e a s specifi c a s possibl e wit ha lo t o f freedomwher e necessary . An d w e thin

k we finall y. achieve d tha t unti l w e ende d u p wit ha protocol . Oka yRon . I believ e th e protoco l wa s circulate d to - everybody . Bu t jus t t o summariz e quickly , w e ha d anintroductio ntha t describe d wh

yw e wer e doing thi s business . The questio no f wha t hemoglobi nleve l shoul d b e considere d adverse , itself , i s no t precise , an

d w e neede d t o work wit ha precis e healt h 

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(301 ) 565-006 4P.6 0

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 5 9 effec t s o w e define dtw o differen t level s andgo t judgment s separatel yregardin g hemoglobi ni s less - , tha no r equa l t o 9-1/ 2 gram s pe r decilite r and les s tha no r equa l t o 11 .

Th e populatio na t ris k wa s define da s childre n fro m conceptio nt o thei r sevent hbirthday . W e spen t a goo d dea l o f tim e discussin g th e exposur e condition s whic hshoul d b e though t abou t and assum e th e rang e o f physiologica l and environmenta l condition s tha t th e populatio nshoul db e con sidere d t o b e under .

The nw e spen t a goo d dea l o f tim e wit hth e exper t actuall ydiscussin g th e evidence , th e implication s o f th e evidence ; ho wt o interpre t it , wha t i t mean s fo r th e childre n unde r consideration . An dthi s wa s t o serv e tw o purposes . "One Wa s t o hel p peopl e brin g t o min da s muc huncertaint ya s possibl e prio r t o beginning , becaus e frequentl ypeopl e aren' t use d t o thinkin g abou t th e uncertaint yinvolve di nth e evidence , onl yth e centra l tendenc ywher e the ythin k i t point s an d no t ho wmuc huncertaint yi s associate dwit hit .

An d secondly , i t wa s s o tha t i f w e d o ge t differen t judgment s fro m

differen t experts , w e migh t hav e somethin g i nthi s discussio ntha t woul dhel p u s t o interpre t thes e differences . S o w e spen t a goo ddea l o f tim e o nthat .

W e discusse dway s t o minimiz e motivationa l an d cognan t advice . Thes e ar e i nth e judgments . I won' t g o throug htha t here .



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An d finally , w e obtai nth e probabilit yjudgments . An d Ro nwil l tal k abou t tha t mor e specifically .

An d I thin k thi s end s myportion . I wa s suppose d t o tel l yo u ho ww e worke dup t o th e probabilit yencoding . An d Ro nand I wil l chang e place s now , andRo nwil l giv e yo u a summar yo f wha t w e actuall ydi dunles s somebodywishe s t o as k m e a questio na t thi s point .

Yes ? DR . NORTH : Coul dyo u b e a littl e mor e specifi c o nwha t yo u di d o nth e bia s issue ? Wa s tha t a genera l dis

cussio no r di d yo u tak e som e exampl e questions ?

DR . WALLSTEN : I t wa s a littl e mor e tha ngeneral . I didn' t brin g wit hm e th e protocol , bu t w e hav e a sectio n "which " summarize s th e psychologica l researc ho ntha t regard

in g sequentia l effect s o f th e so-calle danchorin g adjustment , various " memor yproblem s and s o on .

W e wen t throug hthos e specifi c effects . S o i t wa s . a littl e mor e tha ngeneral .

DR . NORTH : Di dyo u tak e the mthroug ha question

naire ? DR . WALLSTEN : No , w e di d not .

DR . NORTH : Di dyo u demonstrat e anyo f th e biase s wit hthe m

o r wa s thi s jus t a genera l discussio no f psychologi

ca l literatur e that' s i nth e area ?

DR . WALLSTEN : That' s right . An dw e trie dt o focu s 

### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.6 2

1 2 3 4 5 6 7 8 9 1 0 11 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 6 1 i t — w e focusse d th e discussio no nth e — i nterm s o f think

in g abou t data , pe r se , o f th e sor t here . Bu t w e di dno t focu s o nwha t you'r e askin g about .

DR . HAMMOND : Tom , a s I recall , th e groun drule s wer e tha t th e decremen t i nhemoglobi nwer e exclusiv e o f thos e tha t migh t b e du e t o iro ndeficiency . I nothe r words , i t wa s strictl y—

DR . WALLSTEN : That' s a goo dpoint . DR . HAMMOND : —a s a resul t o f th e lea dexposure . DR . WALLSTEN : That' s right . That' s a ver yimpor

tan t poin t t o us . We'r e talkin g abou t lea dinduce dhemoglobi n that' s ove r and abov e anythin g else .

DR . SILBERGELD : Wer e peopl e aske dt o conside r "eac heffec t i nisolation ?

DR . WALLSTEN : Yo u mea nth e 9-1/ 2 andth e 11 , o r wha t d o yo u mean ?

DR. . SILBERGELD : No . Th e hemoglobi neffects , th e E P effect s and th e I Q effects .

DR . WALLSTEN : Oh , okay . W e di dno t discus s — firs t o f all , w e di dno t discus s th e I Q effect s wit hth e sam e peopl e with'who mw e discusse d th e hemoglobi neffects .

DR . SILBERGELD : No . I understan dthat . Bu t whe n yo u aske d themt o focu s on , say , th e hemoglobi neffect , yo u know , i t come s t o min di nthinkin g abou t .i s tha t a t dos e ranges , whethe r I woul dconside r effect s o nhemoglobi nt o



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(301 ) 565-006 4P.6 3

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 

### 6 2

occur. . Othe r thing s woul dcom e t o mymin da t th e sam e tim e o f what' s goin g o n—

DR . WALLSTEN : Right . DR . SILBERGELD : —insid e th e expose dperson . Di d yo u as k peopl e no t t o thin k abou t thos e othe r things ?

DR . WALLSTEN : No . W e didn' t as k the mno t t o thin k abou t that . I nfact , w e eve nha dsom e genera l discussio n abou t it . Bu t th e onl yquantitativ e discussion s tha t w e ha d focuse d o nth e hemoglobin . W e didn' t discus s specificall y othe r effect s excep t insofa r a s the ymigh t hav e com e up i n th e discussio no f th e evidenc e tha t yo u mentioned .

DR . SILBERGELD : An d yo u wer e askin g the mt o con - "sider " eac heffec t i nit s ownterms , no t necessaril ya s a marker ? DR . WALLSTEN : That' s correct . That' s correct . That' s right .

Now , regardin g th e EP , there , w e onl yha dqualita

tiv e discussion s wit hpeopl e regardin g wha t level s o f E P migh t b e though t t o b e advers e and fo r wha t reasons , eithe r becaus e it' s a nindicator ' o f othe r thing s i nit s ownright' , o r wha t hav e you . Bu t w e didn' t d o an yactua l probabilit yencodin g regardin g E P level s becaus e th e dat a wer e sufficientl ygood , an d i t wasn' t necessar yt o d o that .



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(301 ) 566-006 4P.6 4 

### 6 3 1 MR . SILBERGELD : No . I jus t seem s tha t eac ho f 2 thes e en d point s ha s a slightl ydifferen t status . 3 DR . WALLSTEN : Oh , that' s right .

DR . SILBERGELD : —i nterm s o f wha t i t denote s an d connote s i nterm s o f huma nphysiology .

DR . WALLSTEN : Yes . DR . SILBERGELD : An d I don' t kno who wyo u woul d 8 straighte ntha t out . 9 DR . WALLSTEN : Well , I' mno t sur e tha t I se e wh yi t 1 0 wa s a problem . I mean , I certainl yagre e wit hyo u tha t the y nhav e differen t - - eac hha s it s ow nstatus . Bu t a t a give n 12 poin t i ntime , w e focuse d onl yo non e o f the man d w e didn' t 1 3 reall yconside r th e others . 14 " " ~ W e wer e workin g wit hseparat e healt heffect s bu t 15 workin g wit hthe mseparately . 1 6 DR . SILBERGELD : Well , that' s wha t I wa s tryin g

1 7 t o ask , ho wseparat e the ywere . An d I' mno t sur e tha t I 1 8 understan d fro myou r answe r ho wseparate d the ywer e i nterm s

1 9 o f ho wyo u instructe d people . Bu t that' s — 2 0 DR . WALLSTEN : Okay . Le t m e sa yjus t on e mor e 21 thing , an d i f w e 'don' t ge t i t no ww e ca ntal k abou t i t later . 2 2 Bu t w e di d focu s uniquel yo na singl e healt heffec t a t a 2 3 tim e fo r al l th e probabilit yjudgments . 2 4 DR . MAHAFFEY : Thi s ma yb e eviden t throug hyou r 2 5 protocol . I nth e reduce d hemoglobi nlevel , there' s les s tha n 

### EXECUTIVE COUR T REPORTER S

(301 ) 5654)06 4P.6 5

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 6 4 9. 5 and les s tha n11 . An d i npossibl yeac hrang e o f interes t there' s a lo t o f ag e relate d chang e i nwhat' s considere d norma l hemoglobin .

Ho wdi dyo u handl e this , give ntha t yo u hav e tw o level s i nhere ?

DR . WALLSTEN : On e o f th e place s tha t w e buil t i n freedo mfo r th e individua l exper t t o respon dwa s b yallowin g th e exper t t o divid e th e ag e populatio ns o tha t w e worke d separatel ywit hchildre nfromag e 0 t o 3 andchildre nag e 4 throug h6 .

S o i t wa s a t eac hexpert' s optio nwhethe r h e wante d t o —h e o r sh e wante dt o conside r th e dos e respons e function s fo r th e singl e populatio no r fo r th e tw o subpopulation s "separately .

DR . MAHAFFEY : An dthe ywoul dconside r bot hth e decremen t unde r 9. 5 an d th e decremen t unde r 1 1 —

DR . WALLSTEN : That' s right . DR . MAHAFFEY : —fo r on e o r tw o population s depend

ing o nthei r choice .

DR . WALLSTEN : That' s right . I nRon' s presentation , tha t wil l al l b e mad e mor e clear .

DR . SCHWARTZ : I wa s curiou s a s t o ho wyo u deal t wit hth e fac t tha t ther e migh t b e multiplicativ e rathe r tha n additiv e effect s o f differen t thing s except , fo r example , som e peopl e migh t o r migh t no t thin k tha t th e abilit yo f lea d



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.6 6

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 

### 3egi nT.2 A

£•• • 2 2

23 24 25 6 5 t o reduc e hemoglobi nmigh t b e th e functio no f you r iro n status . DR . WALLSTEN : That' s right .

DR . SCHWARTZ : Ha s a —statu s that' s no t enoug h t o caus e anemi a bu t i t woul db e close r t o you r —ma yals o hav e a greate r decrementa l respons e t o th e dos e o f lea d throug hsomeon e wh o i s farthe r away . An dtherefore , it' s difficul t t o separat e ou t thos e tw o things .

DR . WALLSTEN : Yes . Tha t wa s certainl yth e mos t difficul t issu e tha t w e ha dt o dea l with . An da s a firs t cu t t o dealin g wit htha t issue , w e gav e peopl e th e optio no f dividin g up int o th e tw o ag e group s unde r th e assumptio ntha t mos t o f th e iro ndeficienc ywoul d b e i nth e lowe r ag e group "rathe r tha ni nth e olde r ag e group .

S o tha t wa s th e firs t cu t i ndealin g wit hit . Th e secondcu t wa s t o discus s tha t issu e mor e specificall ya s t o whethe r peopl e though t tha t wa s aninter

actio nor , essentially , additiv e effect s o f th e two . An d differen t peopl e had differen t reaction s t o tha t question .

An d I won' t g o int o detai l no wonl yt o saytha t was , fa r and away , the ' hardes t par t o f th e protoco l t o handle .

Mayb e I shoul dg o chang e th e slide s andle t Ro n talk . 

### DR . WHITFIELD : Just't o b ealittl emor especific , thes ewer eth ehealt heffect s tha t wedeal t

wit hagain . Th e EXECUTIVECOUR

TREPORTER S (301 ) 565-006 4P.6 7

1 2 3 4 5 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 2 1 2 2 2 3 2 4 2 5 6 6 Th e reduce d hemoglobi nlevel s tha t w e define da s advers e healt heffects,o r potentiall yadvers e healt heffects , wer e th e level s 9. 5 gram s per•decilite r an d1 1 gran s pe r decileter . A s fa r a s elevate dE P goes , w e too k th e level s tha t Dr . Pionell i had i nhi s pape r an dworke dwit hthose . An d thos e wer e 3 3 microgram s pe r decilite r and5 3 microgram s pe r deciliter .

Wha t we'r e goin g t o b e developin g fo r intelligenc e quotien t question s ar e tw o sort s o f things . On e i s jus t th e averag e decrement . And th e secon di s a littl e mor e com plicated . We'l l b e talkin g abou t probabilities , change s i n probabilitie s tha t fraction s o f population s wil l hav e IQ s "belo wcritica l value s o f anychoic e —70 , 80 , 90 , whatever .

An d th e result s tha t I wil l sho wyo u ar e goin g t o dea l onl ywit hhemoglobi nagai nandonl ywit hhemoglobi n level s les s tha no r equa l t o 1 1 gram s pe r deciliter . Thes e wer e th e e expert s wh o participate di nth e study .

I nNe wYor k City , w e foundDrs . Davido w(ph) , Piomell i and Rose nagreeabl e t o talkin g wit hus , Dr . Chishol m a t John s Hopkins, ' andDr . Hammond . Thre e o f those ' peopl e ar e her e today .

Th e judgment s wer e obtaine di na four-ste p process . W e bega nwit ha ninitia l encodin g sessio nwher e w e obtaine d th e judgment s fo r th e firs t time . Whe nw e left , w e wen t



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(301 ) 565-006 4P.6 8

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 6 7 bac k and worke d wit hthos e judgments , doin g a numbe r o f things , on e o f whic hwa s jus t interpretin g the mi nword s s o tha t they' d b e mor e understandabl e t o th e expert .

Secon d o f al l wa s fittin g function s t o th e judg

ments . And you'l l se e whyi na minute , whyw e ha dt o d o tha t mor e clearly .

Bu t on e o f th e reason s wa s tha t w e obvsioul ydidn' t hav e th e tim e t o measur e a functio na t ver ysmal l interval s ove r respons e rate . W e ha d t o tak e a limite dnumbe r o f point s and asses s a probabilit ydistributio nt o it .

W e nee dt o interpolat e betwee nthos e points , obviously , t o carr you t th e ris k assessment. - An drathe r tha nd o somethin g simpl e lik e a straigh t lin e linea r inter

polation , whic hbega nt o mak e sens e i nman ycases , w e fi t smoot hfunction s t o thes e judgments .

Th e origina l judgments , alon g wit hth e fitte dfunc

tion s , wer e fe d bac k t o th e expert s prio r t o th e secon d encodin g session . S o h e ha d tim e t o loo k a t thing s i nth e privac yo f hi s ownoffic e and cogitat e andconside r wha t i t wa s —wha t th e implication s were .

' W e came " t o th e secon dsessio nand "discusse d th e result s tha t w e ha dfe dbac k t o him . Andou r goa l wa s t o obtai nfro mhi mconcurrenc e tha t w e ha dindee dcapture dhi s bes t considere d judgment s regardin g th e healt heffect .

(Pause ) 

### EXECUTIVECOUR

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2 3 4 5 6 7 8 9 10 1 1 12 13 14" 1 5 1 6 17 18 19 2 0 2 1 2 2 2 3 2 4 2 5 6 8

Avariet yo f encodin g technique s wer e use dt o obtai nth e probabilit yjudgments . W e bega nb yobtainin g a larg e plausibl e respons e rat e interva l ove r whic hth e prob

abilit yo f th e healt heffec t occurrin g woul dli e i nhi s judgments .Variou s method s wer e use dt o quantif yjudgmenta l probabilitie s i ntha t interval . W e initiall ystarte db y makin g extensiv e us e o f th e famou s SR I probabilit ywhel l tha t Dr . Nort hi s ver yfamilia r with .

An d dependin g o nth e rang e o f th e probabilitie s tha t w e wer e tryin g t o estimat e - - sometime s the ywer e ver y low , clos e t o zero ; o r ver yhigh , clos e t o on e —w e returne d t o thing s lik e odd s o r jus t straigh t probabilities . W e use d "interva l check s t o ensur e th e consistenc yo f th e judgments .

I nshort , w e use dwha t worke dbes t wit hth e expert , himself , afte r awhile . A t times , w e turne d awayfromexclu

siv e us e o f th e wheel , and w e wen t bac k andforth . I t wa s a nadaptiv e process .

A s I mentione dalready , function s wer e use dt o represen t th e judgments . An d the ywer e bein g combine dwit h th e bloo d lea d distributio nt o obtai nwha t w e cal l a derive d ris k distribution .

Dr . Mahaffey , thi s slid e addresse s th e questio n yo u aske d earlier .

(Laughter ) 

### EXECUTIVECOUR

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

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

Yo u no wse e th e fac t tha t w e obtaine djudgment s from'fou r o f th e fiv e experts . On e o f th e experts , no t sur prisingly , wa s uncomfortabl e wit hth e whol e ide a o f givin g u s probabilit yjudgments . H e gav e u s a ver ygoo ddiscussio n o f E P bu t nothin g quantitativ e abou t reduce dhemoglobin .

Fro mth e othe r fou r experts , w e obtaine da tota l o f twelv e set s o f judgments .

Expert s D and E provide du s wit hfou r set s becaus e the ydecide d t o brea k dow nth e H grou p fro mzer o t o si xint o tw o subpopulations . An ds o tha t time s th e tw o healt heffec t level s resul t i nfou r set s o f judgments .

Exper t C di dno t fee l h e neede d t o brea k downth e populatio nint o tw o subpopulations . An ds o w e assesse d 1 4 ~onl ytw o set s o f judgment s fro mhi ma t th e tw o hemoglobi n level s and fo r th e entir e population .

Exper t Agav e u s judgment s fo r onl yth e highe r hemoglobi nlevel , tha t o f 1 1 gram s pe r deciliter , fo r age s zer o t o thre e and fou r t o six . Bu t a s you'l l se e fro mth e result s tha t follow , hi s judgment s implied , whe ncombine d wit ha bloo d lea d distribution , virtuall yn o ris k t o childre n a t th e 1 1 gram s pe r decilite r level .

An d i t wa s pointles s t o pursu e th e interrogatio n o nth e rac k anyfurthe r i ngettin g number s tha t wer e s o nea r zero . S o w e terminate dth e elicitatio nproces s wit hth e singl e healt heffect .



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Thes e ar e Exper t C s probabilit yjudgments , abou t th e fractio no f U.S . childre nag e zer o t o si xtha t woul d hav e lead-induce dhemoglobi nlevel s a t o r belo w1 1 gram s pe r decilite r a t eac ho f th e indicate dbloo dleadlevels . Wha t th e figur e show s i s si xset s o f probabilit ydistribu

tion s . .W

e assesse deac ho f thes e independentl yo f on e anothe r initially . W e assesse dthe mi na rando morder . W e assesse d point s withi neac hdistributio ni na rando morder . An d pleas e don' t b e confuse d byth e fac t tha t ther e ar e si x set s o f curve s o nhere . Let' s focu s o non e o f themrigh t a t th e moment .

Fo r example , th e on e t o th e fa r righ t whic hcorre spond s t o a bloo d lea d leve l o f 5 5 microgram s pe r deciliter , th e curv e shows , fo r example , tha t i f yo u follo wup o nth e wid e axi s wher e i t says , "Probabilit ytha t th e respons e rat e i s les s tha no r equa l t o a specifi c number, " andcu t acros s a t th e . 5 probabilit yleve l ove r t o wher e i t intersect s wit h th e L = 5 5 curve , and the nfollowin g i t downt o th e Xaxi s t o th e respons e rat e axis , yo u se e tha t there' s a media nestimat e o f about'

—

a respons e rat e o f abou t 2 8 percent . Thi s mean s tha t amongs t a group o f childre nag e zer o t o si xhavin g bloo d lead s o f 5 5 microgram s pe r deciliter , tha t th e respons e rat e wil l b e les s tha no r equa l t o abou t 2 8 percen t amon g tha t group .



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### 7 1

Th e curv e ha s a slop e t o i t fro mlef t t o right , increasin g fro m

lef t t o right , and tha t indicate s th e degre e o f uncertaint yabou t th e judgment s regardin g th e respons e rate . Th e slop e o f thi s curv e indicates , fo r example , tha t i f w e talke d abou t wha t w e calle d" a credibl e interval, " o r a ninterva l tha t wit hsom e probabilit ycontain s th e tru e respons e rate , w e ca nsee , fo r example , a 2 5 percen t o r a 5 0 percen t credibl e interva l whic hwoul dbegi na t probabilit y .2 5 o nth e lo wendandg o up t o a probabilit yo f .7 5 o nth e hig hend . I t woul dimpl ya respons e rat e interva l o f abou t 2 2 percen t t o abou t 3 3 percent .

MR . JORDAN : I se e a lo t o f blan k faces . DR . CURRAN : Yes . Yo u los t m e too . An dI though t I kne wwha t wa s goin g o nhere .

(Laughter ) DR . WHITFIELD : I thin k i t woul db e bette r i f I wer e abl e t o complet e th e thin g —

DR . CURRAN : No , no . I don' t thin k that' s th e problem . (Pause )



### DR. SILBERGELD : Idon' t thin k that' s th eproblem . Imean , th efigure s ar e.exactl ywhat' s onth eboard , youknow , onth eslide . Idon' t thin k we'r ehavin g troubl ewit h EXECUTIVECOUR

TREPORTER S (301 ) 565-006 4P.7 3

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 2 followin g wha t you'r e doin g excep t conceptually .

On e proble mtha t strike s m e i s tha t you'r e treatin g thes e a s i f the yar e stochasti c probabilisti c events , and they'r e not . Thes e ar e dos e respons e events , no t like , say , th e probabilit yo f a cance r whic hi s a neither/o r event .

S o I' mno t reall ycertai nwha t thi s mean s whe nyo u saytha t a perso nha s a bloo d lea do f 5 5 bu t there' s a 5 0 percen t chanc e tha t 2 8 percen t o f thos e peopl e wil l hav e hemoglobi nles s tha neleven . I s tha t wha t thi s i s saying ?

DR . WHITFIELD : There' s a ~ DR . SILBERGELD : Bu t that' s turnin g thi s int o a stochasti c response .

DR . WHITFIELD : No , it' s not . Roger , you'v e go t somethin g t o say ? DR . MORGAN : It' s a statemen t abou t —th e exper t doe s no t kno wexactl yho wth e on e correspond s wit hth e other . Thi s i s a statemen t o f hi s subjectiv e odd s a s t o wha t th e on e wil l be , give nth e other . H e doesn' t kno wexactly . S o he' s bein g asked , give ntha t it' s 55 , giv e m e you r odd s o nwha t th e respons e rat e wil l be .

' There' s nothin g stochasti c abou t it . If . yo u coul d ru nth e experimen t and kno wit , ther e woul db e a number . Bu t yo u haven' t go t th e precis e experimenta l results , andthi s i s a substitut e fo r that . Thi s i s th e expert' s subjectiv e judgment . 

### EXECUTIVE COUR T REPORTER S (301 ) 565-006 4P.7 4

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### 7 3

DR . SILBERGELD : The ni t isn' t reall ya respons e rat e .i nterm s o f howI , a s a biologist , woul d thin k o f a populatio nresponse .

DR . MORGAN : I t i s the bes t professiona l judgmen t o f thi s exper t a s t o wha t the respons e rat e woul d be i f you coul d ru

nthe definitive experimen t an d measure . DR . SILBERGELD : Bu t a s a biologist , I woul d no t expec t t o se e a probabilisti c respons e rat e fo r something tha t I thin

k i s a.continuou s effect . DR . MORGAN : No . Bu t thi s i s no t a statemen t tha t it' s a probabilisti c respons e rate .

DR . SILBERGELD : Bu t i t seems t o m e tha t thi s axi s is . DR . MORGAN : No , no . I t i s a statemen t abou t the expert' s judgment . I' mgoing t o leave i n7 minute s fo r the airport . An

d i f you as k m e howlon g it' s going t o tak e t o ge t there , I can' t tel l you . Whe nI' mther e I'l l know .

Wha t I coul d give you righ t nowwoul d be a prob

abilit ydistribution , m ysubjective judgmenta l distribution , o nhowlon

g it' s going t o tak e m e t o ge t t o Nationa l Airport . Whe nI'm ' there , yo u canactuall ychec k an d se e where , i ntha t distribution , the answe r lay .

Bu t thes e ar e thi s expert' s distribution s i nhi s judgmen t abou t wha t tha t respons e rat e woul d be i f he could- , ru nthi s definitive experimen t which , unfortunatel yfo r the

EXECUTIV E COUR T REPORTER S

(301 ) 565-006 4P.7 5

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 7 4 moment , h e can' t run .

DR . SILBERGELD : Well , I gues s I' mhun g up o nthi s phras e "response, " becaus e i t invokes , i nm ymind , th e con cep t o f dos e response . Bu t that' s no t reall ywha t you'r e talkin g abou t here . I s tha t right ? Thi s i s som e psychologi

ca l disciplinar ymeanin g o f th e wor d "response" ?

MR . MORGAN : No . It' s th e sam e a s "time. " I t mean s ho wlong i s i t goin g t o tak e m e t o ge t t o th e airport . It' s ne t goin g t o tak e a probabilit ydistributio ni ntime . It' s goin g t o tak e m e 2 3 minutes . Bu t a t th e moment , I don' t kno wthat . DR . SILBERGELD : I though t h e wa s sayin g tha t thi s woul d indicat e tha 2 8 percen t o f th e populatio nwit h5 5 woul d -hav e les s tha n11 . An d that , t o me , i s lik e a biologica l response . DR . SCHWARTZ : Bu t th e distributio n—I kno wwha t he' s sayin g —tha t th e exper t —

(Simultaneou s conversation) . DR . SILBERGELD : I mean , mayb e thi s isn' t worthwhil e Thi s i s a nexercis e i n—

' DR . SCHWARTS : He' s sayin g tha t th e exper t —ar e n o mor e tha n2 5 percent . Tha t a t 5 5 micrograms , fewe r tha n 2 2 percen t o f th e childre nwoul dhav e lo whemoglobi nlevels . An d th e exper t think s tha t th e odd s ar e n o mor e tha n2 5 per cen t tha t mor e tha n32 , o r whateve r th e numbe r is , percen t o f



### EXECUTIVE COUR T REPORTER S

(301 ) 5654)06 4P.7 6 7 5 th e childre nwoul dhav e lo whemoglobi nlevels . 2 An d h e ha s a rang e o f uncertaint ya s t o wha t per 3 cen t o f th e childre nreall ywil l hav e lo whemoglobi nlevel s bu t thi s coul d —h e think s there' s n o mor e tha na 2 5 percen t chanc e ther e wil l b e fewe r tha n2 2 percen t o f th e children , an d n o mor e tha na 2 5 percen t chanc e tha t ther e wil l b e 3 2 percen t o f th e children . An d th e numbe r i s probabl ysome wher e i nthere . 9 . An d that' s th e probabilit ythat' s bein g approache d 1 0 here . nDR . SILBERGELD : That' s no t wha t I' masking , sir . 1 2 DR . WALLSTEN : An d I thin k there' s — 1 3 DR . SILBERGELD : I' maskin g abou t wha t thi s respons e 1 4 '"is . Tha t still s sound s t o m e lik e treatin g thi s a s a sto 1 5 chasti c event . 1 6 DR . WALLSTEN : If , i nfact , th e experimen t wer e don e 1 7 w e coul d tak e al l thos e childre nwit hlea d level s o f 55 , fo r 1 8 example , an d determin e wha t percentag e o f the mdid , indeed , 1 9 hav e hemoglobin s les s o r equa l t o 1 1 percent . W e coul dsub

2 0 trac t ou t th e bas e rat e percentag e s o w e coul d ge t wha t per 2 1 centag e o f the mhav e lead-induce d hemoglobin s les s tha no r 2 2 euqa l t o 1 1 gram s pe r deciliter . 2 3 An d that , o f course , woul d b e som e dat a fro mth e 2 4 experiment . An d i t woul d b e a respons e rate . I t woul db e 2 5 a particula r numbe r tha t i s alon g th e Xaxis . Maybe.i t woul d 

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(301 ) 565-006 4P.7 7

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 7 6 here , mayb e i t woul d b e here . I t woul db e a particula r num ber . Now , th e experimen t ha s no t bee ndone . An ds o there' s uncertaint ya s t o wha t th e ultimat e woul dbe . An d thi s i s exactl yth e distinctio nbetwee nth e tw o kind s o f uncertaintie s I wa s referrin g t o earlier , th e stochasti c uncertaint yversu s th e judgmenta l uncertainty .

(Pause ) DR . NORTH : I' mwonderin g i f w e hav e a semanti c difficult yabou t th e wor d"response. "

DR . WALLSTEN : Yes . DR . SILBERGELD : .That' s wha t th e proble mis . DR . NOBLE : I f w e wer e sayin g a fractio no f th e "populatio nwit hthi s effect , woul dtha t b e clearer ?

DR . SILBERGELD : No , becaus e I thin k ther e reall yi s a fundamenta l —

I'l l jus t sayi t on e mor e tim e andqui t becaus e thi s i s fa r beyon dwha t I —thi s whol e exercise .

I t seem s t o m e ther e i s a fundamenta l differenc e betwee neffect s whic hoccu r wit ha probabilisti c distribution , leavin g asid e al l thes e word s lik e cance r whic hI —doesn' t occur . ' ' " •

An d the nther e ar e effect s whic har e gradate d (ph ) and continuous . An dthos e hav e a ver ydifferen t fundamenta l biologica l distribution . An dthi s seem s t o b e turnin g a continuou s effec t int o a probabilisti c distributio ni f I



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.7 8 

### 7 7

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 

### understand .

(Choru s .o

f no , noes ) DR . SILBERGELD : Okay . I'l l retrea t an d thin k abou t thi s som

e more . DR . MORGAN : Tr

yrelating i nthe horizonta l axi s percen t wit hlea

d induced hemoglobi nles s thanor equa l t o 1 1 gram s pe r deciliter .

DR . WALLSTEN : See , i f the experimen t wer e don e thi s woul d b e —a t stree t value , ther e woul d be som e per cen t wit hhemoglobi nles s than11 .

DR . SILBERGELD : That' s right . DR . WALLSTEN : Ther e woul d be som e percent . Wha t tha t percen t i s i s uncertain . Differen t expert s have dif

- |~ferent degree s o f uncertainty . And s o thi s represent s the uncertaint yassociate d wit hon e particula r expert' s judgments .

I thin k we canpursu e thi s mor e late r unles s othe r peopl e — DR . NOBLE : Okay . I thin k anothe r thin

g tha t ma

y hel p i s we'v e mad e a rathe r arbitrarydistinctio no f lo whemo

globi na s being les s than11 . An d thenthat' s being asked agai nas'les s tha' n9-1/2 . S o wherea s it' s a continuou s response , we'v e draw na line an

d sai d above the line we'r e going t o coun t the effec t —or , rather , belowthe line we'r e going t o coun t the effect , an d above the line we'r e going t o sa yth e effec t i s no t present .



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An d t o th e degre e tha t we'reuse d t o thinkin g abou t i t a s what' s th e rang e o f hemoglobi ni nth e population , thi s ma ymak e i t difficult .

DR . SILBERGELD : Well , s o i t i s bein g turne d int o a stochasti c event . It' s eithe r occurrin g o r i t isn't .

DR . MORGAN : It' s abov e o r belo w11 . DR . SILBERGELD ; Yes . An d tha t i s makin g i t stochastic .

DR . WARE : W e ar e turnin g i t int o a discree t event , you'r e righ t abou t that .

DR . LARSON : Well , it' s discree t i nth e sens e tha t yo u ca n— (Simultaneou s conversation )

DR . WARE : They'r e takin g a continuou s phenomeno n an d translatin g i t int o a discreet . It' s lik e takin g a bloo d pressur e measuremen t an d translatin g i t int o i s th e individua l hypertensiv e o r not .

DR . SILBERGELD : Right . DR . WARE : I wouldn' t cal l tha t stochastic . I woul d

sa ythey'r e translatin g i t int o a ye s o r n o phenomena .

• CHAIRMA NLIPPMANN : W e ha d better-mov e o ni f we'r e goin g t o continu e t o finis hthis .

DR . WHITFIELD : Oky . No wi f w e loo k a t th e se t o f si xcurves , yo u ca nse e tha t i t wa s har d wor k fo r u s t o obtai nthis . Bu t th e curve s d o no t overlap . Th e curve s



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.8 0

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### '7 9 indicat e tha t wit hthe increasing blood lead s ther e i s now increase d probabilit yo f highe r respons e rate s o r fraction o f childre nhaving hemoglobin s belo wthe prescribe d level .

Thes e ar e al l desirabl e properties . (Pause ) An d a s I'v

e sai d before , w e fi t functions l repre sentation s o f hi s judgments . W e showe d thes e representation s t o th e experts , ther e ar e 1 2 set s o f graph s tha t look like this , an

d thes e ar e th e thing s tha t w e finall yobtaine d hi s sign-of f lin e with , i f yo u will , hi s agreemen t tha t w e ha d capture d hi s bes t judgments .

Whe nfunction s like thos e show ni nthe previou s slid e wer e combine d wit ha blood lea d distribution , an

d the "blood " lea

d distributio ntha t w e used fo r illustrative purpose s wa s the NHANE S I I blood lea d distribution , w e wer e abl e t o calculat e wha t w e cal l a derive d ris k distribution .

Thi s i s a probabilit ydistributio nove r respons e rat e fo r a fractio no f th e populatio ntha t woul d have hemo

globin s les s thano r equa l t o 1 1 gram s pe r decibe l i nthi s case . * An

d yo u read thi s curve , thi s singl e curve , muc h i nth e same fashio na s yo u woul d rea d an yo f the curve s w e showed previously , the famil yo f curves .

Thi s curve , again , shows , fo r example , tha t there' s a . 5 probabilit yreading fro mthe Yaxi s tha t abou t 1 0 percen t 

### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.8 1

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o r les s o f th e populatio nwil l experienc e th e advers e healt h effec t a s w e define d it .

An d w e ca ntal k abou t credibl e interval s aroun d[ tha t estimate , 5 0 percen t credibl e interval s whic hwoul d• correspon d t o probabilitie s o f .2 5 o nth e lo wen dand.7 5 o nth e hig hend fo r 9 0 percen t credibl e intervals , o r 9 9 per— • cen t credibl e interval? , o r whatever .

DR . FRANK : Excus e me . I' mjus t intereste d i nth e methodolog yhere .

T o g o bac k t o th e serie s o f graph s abou t whic h Dr . Silbergel d wa s firs t askin g questions , I thin k yo u con clude d thes e ar e al l graph s tha t were , i na sense , provide d judgmentall yb

yexper t C . DR . WHITFIELD : That' s correct . DR . FRANK : An dyo u note d tha t ther e wa s n o overlap , o r anythin g lik e that .

DR . WHITFIELD : That' s correct . DR . FRANK : Which , yo u know , I expec t tha t i s no t surprisin g t o you . An d—

DR . WHITFIELD : I f w e wer e t o obtai nthat .

' DR . FRANK : Okay , le t m e as k you,'wha t wa s th e sequenc e i nwhic hth e exper t provide dthes e judgments ? Di d yo u firs t star t wit ha given , tha t is , a bloo dleve l o f 55 ?

DR . WHITFIELD : W e randomize dth e orde r i nwhic h w e assesse d thes e curves .



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### 8 1

DR . FRANK : Wa s the exper t —i na sense , di d he or she hav e infron t o f the mthe previou s answer s give no r wa s ther e som

e attemp t t o d o thes e independently ? DR . WHITFIELD : Ther e wa s som e attemp t t o do thes e independently . But , o f course , the expert' s making hi s ow n note s and , sure , w e wer e no t takin g thing s awa

yfro mhim . An d w e di d —yo u know , ther e wer e ove r —

(Simultaneou s conversation ) DR . FRANK : - - onm yow nresponse s an

d hav e the

m dow nthere .

(Laughter ) Yo u know , attempte d t o avoid , i na sense , som e inconsisten t responses .

DR . WHITFIELD : Right . An d i f thi s wer e a

nexperi

menta l problemwher e w e wer e trying t o determin e howofte n tha t occurred , w e woul d hav e stoppe d a t tha t point . Bu t i t wa s not . Our intentio nher e wa s t o ge t the bes t considere d judgment s o f th e expert .

An d s o w e resolve d th e inconsistencies , like thos e tha t I'v

e allude d to . Th e exper t wa s abl e —wa s allowed , i f yo u will , t o tak e a systems viewo f the whol e thing , an d step bac k an

d look a t the entir e pictur e an d mak e comment s like , "Well , tha t doesn' t mak e sense, " an d mov e thing s around , i f yo u will .

DR . NOBLE : An

d thi s ma

yhav e bee nimplici t o r 

### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.8 3

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 8 2 explici t i nsom e o f th e earlie r discussions . Bu t confronted , myself , wit ha nexercis e lik e this , I thin k I' dfee l a littl e uncomfortabl e a t firs t becaus e it' s somethin g I' mno t use d t o doing . DR . WHITFIELD : I thin k tha t wa s a commo nfeeling .

DR . NOBLE : An dI wondere dd o the yhav e practic e session s or , yo u know , d o the ytrythi s mor e tha nonce ?

DR . WHITFIELD : Well , w e di d d o i t twice . W e ha d tw o face-to-fac e encodin g session s wit hthem .

DR . NOBLE : I s thi s th e resul t o f th e second — DR . WHITFIELD : That' s th e resul t o f th e second . Thes e ar e th e final'judgments .

MR . JORDAN : Ron , I thin k th e questio nhe' s gettin g 't o is'a t th e second encodin g sessions , yo u did , i nfact , sho whi m

th e result s o f th e firs t encodin g session . DR . WHITFIELD : That' s correct . W e showe dhi mth e result s o f th e firs t encode dsessio nwhic hh e als o —h e sa w curve s lik e thos e tha t ar e shownrigh t no wwhic har e no t reall ycurves . They'r e jus t assesse dpooint s joine db y straigh t line s s o tha t th e point s don' t ge t messe dup .

' H e sa wtha t befor e w e left . An d the nw e fi t function s t o the mafte r w e lef t an d fe dthos e bac k t o hi m lik e those . An d i t wa s thos e tha t w e worke dwit hhar dth e second tim e around . An d i f an yrevision s wer e needed , w e turne d bac k t o th e encodin g step s onc e again .



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.8 4 8 3 i I nsom e cases , tha t wa s necessar yan d w e di dit . 2 DR . WARE : Jus t t o ge t a littl e clarificatio nabou t 3 th e details , s o yo u selecte d a dos e a t random , an d the nyo u selecte d a probability , a subjectiv e probability , a t random ?

DR . WHITFIELD : Wha t w e did , afte r initiall ydeter

minin g a broa d — 7 DR . WARE : Wh ydon' t yo u actuall yg o throug hth e 8 proces s an d sa yexactl ywha t yo u chos e an d wha t questio nyo u 9 aske d th e exper t jus t s o — 1 0 DR . MORGAN : Woul d yo u min d i f h e finished ? Becaus e

nI hav e t o leav e i na ninstan t an d I woul d lik e t o hea r th e 1 2 th e rest . 1 3 DR . WARE : Okay . 1 4 ~ DR . MORGAN : I' mver ysorry . 1 5 DR . WHITFIELD : Al l right . Wha t I'v e show nyo u 1 6 is , s o far , th e result s fo r Exper t C . Th e whol e proces s wa s 1 7 repeate d fo r eac ho f th e othe r respondin g experts . An dth e 1 8 summar yo f thos e results , tha t is , th e derive d ris k distribu

1 9 tion , i s show no nthi s slide . 2 0 No wyo u ca nse e th e effec t o f Exper t A' s judgment s 2 1 wher e he'ha s tol d u s tha t lead-induce d hemoglobi neffect s 2 2 d o no t begi nt o com e int o pla yunti l muc hhighe r bloo d leads , 2 3 I believ e i t wa s aroun d 4 5 microgram s pe r deciliter . 2 4 An d wit htha t information , whe nthos e judgment s 2 5 ar e combine d wit hth e bloo d lea d distribution , th e resul t i s 

### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.8 5 8 4 1 essentiall yn o lead-induce d —essentiall yn o ris k o f a lead

2 induce d healt heffec t a t th e 1 1 gram s pe r decibl e curv e pe r 3 decilite r leve l amon g childre nage d 0 t o 6 .

Th e result s fo r Expert s C , D an d E ar e muc hclose r 5 t o on e another . I don' t wan t t o us e th e wor d "agreement. " 6 Bu t ther e i s thi s clusterin g that' s obviou s fro mthi s figure . 7 (Pause ) 6 Wha t th e EPA , o f course , i s intereste d i nfro ma 9 regulator yperspectiv e i s th e probabilitie s tha t selecte d 1 0 percentage s o f U.S . childre ni nth e populatio no f interes t nwil l hav e hemoglobin s a t o r belo wth e define d level . 1 2 An d w e ar e abl e t o determine , fro mfigure s lik e 1 3 thos e show npreviously , probabilitie s tha t w e hav e summarize d 14 ""here. " I f i t were , fo r example , importan t t o protec t 99. 5 1 5 percen t o f th e population , the nw e woul d wan t a respons e rat e 1 6 t o b e . 5 percent . 1 7 An d base d o nth e judgment s o f th e fou r experts , 1 8 w e se e tha t th e probabilit yi s 1 i nth e cas e o f Exper t A 1 9 tha t th e respons e rat e woul d b e a t o r belo wthi s level . Th e 2 0 othe r expert s sa ytha t there' s n o probabilit ytha t th e 21 response ' rat e wil l b e les s tha no r equa l to * 1/ 2 of

- a percen t 2 2 It' s no t unti l w e ge t u p aroun d a respons e rat e 2 3 o f aroun d 1 0 percen t wher e w e begi nt o se e probabilitie s 2 4 othe r tha nzer o comin g int o pla yfo r Expert s C , D an dE 2 5 Le t m e poin t out , base d o nth e judgment s o f Exper t D 

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(301 ) 565-006 4P.8 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 8 5 fo r example , there' s a .9 8 fo r almos t a certai nprobabilit y tha t th e respons e rat e wil l b e les s tha n1 0 percent .

(Pause ) Myfina l slid e i s simpl ya statemen t o f wher e w e are , and tha t i s tha t w e ar e nearin g completion . I've shown yo u th e ris k estimate s fo r th e hemoglobi nlevel s bein g les s tha no r equa l t o 1 1 gram s pe r deciliter . I hav e no t shown yo u th e result s fo r 9-1/ 2 gram s pe r deciliter , bu t the yhav e bee nestimated .

An d t o d o those , we , o f course , neede dt o us e a a bloo d lea d distribution , andtha t wa s th e NHANE S I I data .

Th e secondpoin t i s tha t w e hav e als o estimate d th e risk s o f elevate dE P levels , agai nusin g th e NHANE S data . "I Q encoding s ar e nearl ycomplete . W e hav e si xexpert s par ticipating , thre e i nth e Unite dState s andthre e i nEurope .

W e hav e complete dth e firs t roun d o f encoding s wit h th e U.S . experts . An d jus t las t Thursday , a s wa s mentioned , To mand I returne d fro mEurop e wit hth e result s o f th e thre e expert s ove r there .

W e complete d—

whil e ou r metho do f operatio nfo r hemoglobi nand fd r th e America nI Q expert s i s on e -o f havin g th e tw o encodin g session s separate dby , a t times , on e o r tw o months , the ywer e separate d b ya .da yove r i nEurop e fo r rea son s o f savin g a lo t o f money .

Th e exposur e mode l encoding s ar e currentl yunderway , 

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(301 ) 565-006 4P.8 7

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 6 An d whe nthe

yar e complet e an

d theyar e factored int o a n exposur e model , an

d w e ar e abl e t o estimat e o r predic t bloo d lea d distribution s based ontha t model , w e wil l agai nbe combining the healt heffect s mode l her e wit hth e exposur e mode l t o for

mfurthe r ris k estimate s t o thes e children . Ar e ther e an

yquestions ? CHAIRMA NLIPPMANN : Jim , do yo u wan t t o as k a ques tion ? MR . WARE : Well , I did . I though t i t migh t be helpfu l t o jus t simpl ygiv e the specifi c exampl e o f howyo u beganthe encoding sessionan d what , having chosena dos e a t random , wa s you r nex t selectio nan d thenwha t di d you as k the experts . DR . WHITFIELD : Okay . T o simplify , exactl ywha t w e di d wa s the following . W e had our broad rang e ove r whic h the exper t fel t the true valu e migh t lie . And w e wer e ver y— w e intentionall ygo t themt o thin k abou t extremes , trying t o overcome an

ycentra l bia s tendencie s tha t he migh t have , yo u know , having a fixed numbe r i nmind tha t h e though t . wa s mos t likely , t o tr yt o ge t himawa

yfro mtha t mode.'o f thinking ' an

d thinking abou t rar e events . W e the nbrok e tha t interva l u p int o si xsub-interva l And , fo r example , i f i t wer e a respons e rat e o f 1 0 t o 6 0 per cent , w e woul d break i t u p int o 10 , 20 , 30 , 40 , 50 , 60s . An d the nwe , a t random , chos e on e o f thos e respons e rat e level s



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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 8 7

and attempte d t o determin e th e probabilit ytha t th e respons e rat e would , indeed , b e les s tha no r equa l t o tha t level .

And w e hoppe daroun dth e respons e rat e interva l a t random , and w e simpl yuse d a dec k o f card s t o d o tha t and proceeded . DR . WARE : S o tha t wa s al l fo r a give ndose .

DR . WHITFIELD : Tha t wa s fo r a give ndose . DR . WARE : Yo u sai dwha t d o yo u thin k i s th e rang e o f possibl e respons e rate s tha t coul db e conceivable ?

DR . WHITFIELD : That' s correct . DR . WARE : An da perso nmigh t say , well , I thin k i t coul d b e somewher e betwee n1 0 and40 . The nyo u woul dsay, well , let' s conside r - - I see . Now , s o the nyo u trie dt o ge t

" a probabilit yassigne dt o each , on e o f th e si xrespons e rate s tha t ar e i nyou r set .

An d the nwha t di dyo u d o abou t th e fac t thatyo u ha d reversals , and s o on , a t tha t point ?

DR . WHITFIELD : Reversals ? DR . WARE : Yes . I mean , coul d i t happe ntha t ther e woul d b e —tha t yo u ensur e tha t th e probabilitie s wer e con sistent? " DR . WHITFIELD : Oh. , yes . Afte r gettin g thes e response s ove r th e entir e range , w e woul dthe nplo t th e result s o na graph . And the nw e woul dloo k a t th e implica

tion s o f thos e responses . An d if , fo r example , w e ha da



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(301 ) 565-006 4P.8 9

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 8 8 situatio nwher e th e grap hwoul d g o up andthe ncom e down , whic hi s no t a viabl e probabilit ydistribution , w e woul d discus s it . Somethin g had t o b e changed . Wha t di dyo u wan t t o change ? Wha t di dh e conside r whe nh e mad e th e firs t respons e versu s th e secon dresponse ?

Ho wdi dh e wan t t o resolv e it . DR . FRANK : An dmyquestio ni s wha t wa s th e lowes t probabilit yyo u aske dth e questio nof ?

DR . WHITFIELD : I think , well , sinc e w e wer e goin g i nth e revers e direction , w e wer e talkin g abou t respons e rate s and probabilitie s tha t woul d b e les s tha no r equa l t o tha t respons e rate , w e got , sometimes , ver ylo wprobabilitie s lik e .00 1 o r .0001 .

On e chanc e i na thousand , on e chanc e i nte nthousan d DR . WARE : Yo u mea nt o sayho wlikely , give ntha t exposur e o f 5 5 microgram s pe r deciliter , d o yo u thin k i t is ' tha t th e respons e rat e woul d b e belo w5 percent ?

DR . WHITFIELD : That' s correct . DR . WARE : An da perso nmigh t say, " I thin k that' s almos t certainl yno t goin g t o happen . It' s onl y.001 . I' m almos t certai nit' s abov e that. "

DR . WHITFIELD : That' s correct . (Pause ) DR . NOBLE : I thin k i t woul db e usefu l i f w e coul d hea r fro mth e thre e expert s i nth e roo mwhos e judgment s wer e



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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 8 9

wer e assesse d wit hthi s proces s wit hregar dt o ho wthe yfee l abou t it . I nparticular , thei r impressio no f ho wclearl y th e question s wer e posed .

Wer e they , i nfact , th e righ t questions , wel l defined , easil yunderstood ? And , a t th e conclusio no f th e process , ho wd o yo u fee l abou t thi s a s a summar yo f you r judg

- | men t t o b e communicate dt o other s i nth e EP Aprocess ?

CHAIRMA

NLIPPMANN : Anyvolunteers ? (Laughter ) DR . HAMMOND : Well , I mus t begi nb yadmittin g tha t I ha d a difficul t tim e th e firs t tim e aroundgraspin g pre cisel ywha t eac hquestio nrequire do f me . Andthe nI ha dto , i nfact , repea t t o mysel f precisel ywha t wa s stated .

An d further , i nth e initia l process , the yuse da wheel , a probabilit ywheel . An dwoul das k me , "I s th e prob

abilit yles s tha no r greate r tha nth e probabilit ytha t th e colo r o nth e whee l wil l b e mor e o r les s tha nwha t yo u se e here? " An d I neve r di d fee l comfortabl e wit htha t thin g and I basicall yrejecte di t th e secondtim e around .

• Apar t fro mthat , I thin k tha t a nadequat e amoun t o f tim e certainl ywa s spen t i nexplorin g som e o f th e restriction s tha t migh t bea r o nth e judgment s t o b e made . Tha t wa s fine . I didn' t hav e anyproblem s wit hthat .

I think , too , tha t —I' mno t sur e i f i t wa s clearl y 

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(301 ) 565-006 4P.9 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 9 0 state d —wheneve r ther e wer e overlap s i nth e respons e rate , tha t .woul d b e pointe d out . I' d say, "D o yo u reall ymea n that? " Yo u know . An d I' dsay , "M ygod , no . I don' t mea n that. " (Laughter )

I gues s basicall ythat' s m yrecollectio no f m y respons e t o th e process . question , DR . WALLSTEN : Let' s se e i f I ca nanswe r on e mor e

DR . NOBLE : Ho wd o yo u fee l abou t th e result s o f it ? DR . WALLSTEN : Yes . That' s wha t I wa s goin g t o as k DR . HAMMOND : Well , I' dstil l lik e t o se e a dos e respon e curve . And , i nfact , yo u ca n—fo r th e 5 0 percen t probabilit yo r confidenc e leve l o r th e 10 0 percen t confidenc e level , and I thin k tha t would>b e a nic e thin g fo r yo u fellow s t o draw . An d eac hperso nwoul d hav e a famil yo f dos e respons e curve s reflectin g th e level s —

DR . WALLSTEN : W e d o hav e thos e — (Simultaneou s conversation )

' DR . HAMMOND : Th e bloo d lea d— presented . DR . WALLSTEN : W e d o hav e thos e andthey'v e bee n

DR . HAMMOND : —o nth e —whethe r o nth e absciss a (ph ) an d percen t populatio no nth e —woul db e a nic e display , I



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(301 ) 565-006 4P.9 2 

### 9 1

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 think , o f th e resul t i nterm s tha t peopl e understan do r ar e more,comfortabl e with .

DR . WALLSTEN : Bu t whe nw e finall yshowe dyo u th e fina l se t o f judgments , di d yo u fee l comfortabl e tha t the y reflecte d you r thinking ?

DR . HAMMOND : Yes . I fel t i t wa s a s reasonabl e a s possibl e give nth e absenc e o f anyhar ddata .

DR . NOBLE : Bu t you' d lik e t o se e a dos e respons e displa yo f you r judgment s t o hel p yo u i nensurin g that , i n fact , that' s wha t yo u meant ?

DR . HAMMOND : Exactly . I stil l woul dlik e t o se e th e dos e respons e i nth e conventiona l sense . Bu t i t woul d hav e t o b e a family . Right ?

DR . NOBLE : Yes . DR . WALLSTEN : That' s n o problem . DR . WHITFIELD : A s muc ha s I've trie dt o eliminat e al l o f th e detail s o f identity , and everything , i nm ymind , I d o recal l I thin k w e di ddra wsuc ha grap hwit hyou .

DR . HAMMOND : I didn' t hea r you . DR . WHITFIELD : I thin k w e di d dra wsuc ha grap h i nth e roo m

wit h'you . DR . HAMMOND : Yo u did ? Yes . Tha t ma ybe . I don' t recall . MR . JORDAN : I thin k wha t you'r e sayin g i s i nth e fina l report , you' d lik e t o se e that .



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(301 ) 565-006 4P.9 3

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 9 2

MR . HAMMOND : Yes . MR . JORDAN : An dw e d o pla nt o hav e that . CHAIRMA

NLIPPMANN : Dr . Chisolm ? DR . CHISOLM : Well , I recall , i nadditio nt o wha t h e sai d abou t th e whee l —i t too k a bi t o f tim e t o lear nth e wheel ; I' d neve r see nwheel s befor e - - bu t w e ha da ver y lon g discussio na s t o th e groun drules , wha t ar e w e t o considej r

Ar e w e t o conside r thi s purel ya s a leadeffect ? Ar e w e t o tak e th e populatio na s i t is ? Wha t ar e w e goin g t o d o abou t childre nthat , say, hav e sickl e cel l disease'wher e thei r anemia , ha s go t nothin g whatsoeve r t o d o wit h.lea d and othe r type s o f anemia ?

Ar e w e t o disregar dthat ? An dw e ha da long dis

- "cussio nabou t wha t w e shoul d conside r whic hI thin k mad e i t a littl e bi t difficult .

CHAIRMA

NLIPPMANN : Well , th e second questio ni s ar e yo u comfortabl e wit hth e fina l expressio no f you r judgments ?

DR . CHISOLM : Yes , give nwha t I accepte da s a groun d rule , and tha t i s a purel ylead-induce deffect .

DR . LARSEN : Wer e yo u eve r aske d wha t th e probabilit y wa s that ' th e questio nwa s correct ?

(Laughter ) DR . CHISOLM : I t wa s a littl e fuzz ya s t o wha t th e groun d rule s woul d be .

CHAIRMA

NLIPPMANN : Dr . Rosen ? 

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(301 ) 665-006 4P.9 4 9 3

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 DR . ROSEN : Well , lik e Dr . Chisolm , w e spen t a goo d dea l o f tim e figurin g ou t groun drules . AndI thin k i t took . m e a goo d dea l o f tim e t o fee l —knowin g wha t th e groun d

• rule s were . And I also , lik e Dr . Hammond , hada grea t dea l i ; o f difficult ywit hth e wheel . I S o tha t th e wa yw e woun dup doin g i t wa s actuall y i ! makin g bet s abou t ho wthing s woul d—wher e th e number s woul d i ! fall . I I ngeneral , I wa s ver ysurprise d tha t i t wa s rela

tively , I v.'ouldn' t sayeas y- - bu t wit ha grea t dea l o f tim e and concentration , tha t I tende dt o hav e a goo ddea l o f con fidenc e i nth e judgment s tha t I made . AndI thin k tha t con fidenc e wa s furthe r enhance d b yth e fac t tha t a t leas t thre e o f us " reall yconcurre di ngeneral , give ns o manyunknow n factors . CHAIRMA

NLIPPMANN : I woul d like,,fo r m yown curiosity , t o kno whow'thos e respons e tha t yo u go t compare d wit hth e ..response s o f tw o "EPAexperts " a s reporte di nyou r Septembe r 24th , '8 4 repor t tha t w e hadi nadvance .

DR . .WHITFIELD : I don' t thin k that' s fair . D o you ? (Laughter ) MR . WALLSTEN : No . Bu t I thin k w e hav e a neve n bette r answe r tha nthat , andtha t i s tha t w e didn' t loo k a t it . (Laughter )



### EXECUTIVECOUR

TREPORTER S (301 ) 565-006 4P.9 5

9 1 0 1 1 1 2 1 3 9 4

Because , exactl yfo r tha t reason , tha t w e di d— th e pilo t subject s wh o helpe du s t o ge t thi s procedur e se t up wer e no t expert s i nth e sam e sens e tha t th e othe r peopl e were . And w e neve r fel t tha t w e shoul dtak e thei r judgment s wit hth e sam e degre e o f seriousness .

So , i nfact , w e didn' t loo k a t that . CHAIRMA

NLIPPMANN : I nterm s o f judgin g wha t t o d o wit hthi s now , w e hav e a smal l sampl e size . I nfact , w e hav e th e odd situatio nwher e yo u starte d wit hfive . You'v e go t on e tha t couldn' t participate , fo r whateve r reason . You'v e go t on e wh o gav e yo u n o usefu l dat a unles s th e othe r thre e ar e wildl yof f and he' s right .

MR . WALLSTEN : Well , I wouldn' t sa yit' s no t useful .

uj I mean , thos e ar e hi s judgments . AndI don' t thin k w e shoul d 1 5 1 6 , 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 dismiss . CHAIRMANLIPPMAN : Yes , well , okay . I' mwonderin g wha t anybodyca nd o wit hthi s exercis e fro mthi s poin t on . An d whe nyou'r e dealin g wit hsuc ha smal l sampl e size , a s w e d o wit hman yothe r aspect s o f th e criteri a document , th e dat a base , w e .look a t al l relevan t information .

* Now , whe nyo u sayi nhe^r e tha t yo u looke da t tw o peopl e ver yknowedgeabl e i nlead , I' mno t sayin g the yhav e t o giv e a nequa l weight . Bu t i norde r t o judg e this , I' dlik e t o hav e a s muc hinformatio na s possible . An dI don' t thin k it' s unfai r ho wtw o othe r people , familia r wit hth e lea d issu e



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(301 ) 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 P.9 6 9 5 ho wthei r result s compare d wit hthes e thre e o r four , depend

ing o nho wyo u loo k a t it , fromyou r ful l set .

DR . WALLSTEN : Well , I thin k i f i t wer e th e con sensu s tha t w e shoul d includ e the mthe nw e coul deasily . Ou r feelin g up t o thi s poin t wa s tha t i t wasn' t quit e right .

CHAIRMANLIPPMANN : Well , I don' t thin k yo u shoul d hav e u p t o thi s point .

DR . WALLSTEN : Yes . I CHAIRMANLIPPMANN : I woul dhav e assume dtha t yo u 

### i i ha d tha t o nth e tip s o f you r fingers .

DR . WALLSTEN : .No , w e didn't . CHAIRMA

NLIPPMANN : Mayb e I wa s wron g i nassumin g tha t yo u woul d kno wtha t withou t havin g pu t i t int o th e forma l exercise . DR . WALLSTEN : I mean , I ca ntak e —I mean , w e coul d actuall ylook . W e hav e i t al l here . Bu t mygues s i s ther e woul d b e on e o f thes e peopl e wh o woul dfi t ver ymuc h i nwit hth e othe r three , andon e whos e curve s woul db e fa r t o th e right .

VOIQE : Fa r t o th e right . Th e opposit e o f "A" ?

* DR . WALLSTEN : Th e opposit e o f "A" . Yes . DR . WHITFIELD : I nfact , o npag e 2 3 o f th e report , w e hav e summarize d th e result s fo r subjec t 1 andsubjec t 2 . And , b yn o mean s —le t m e pu t th e followin g cavea t here . W e didn' t spen d a s much-tim e i nth e pilo t subjec t mod e wit h



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(301 ) 565-006 46 7 8 9 1 0 1 1 1 2 1 3 1 4 P.97 9 6

eac hperso na s w e di d wit hth e rea l thing .

But , fo r example , a s a resul t o f al l th e caveat s leadin g up t o th e divers e distribution s tha t w e showe dyou , and applie d t o th e result s o f subject s 1 an d3 , w e se e tha t 5 subjec t 1 ha s a media nrespons e rat e o f around1 0 percent , and subjec t 2 i s abou t 2 0 percent .

An d w e ha dshowe dabou t 7 t o 9 percent , I suppose . | S o on e o f th e tw o coul db e adde d i nwit hth e group o f three . An d the nth e pilo t subjec t 2 woul d b e —

CHAIRMA

NLIPPMANN : That' s wha t the ylooke dlike . | l j Bu t furthe r examination , I find i t interestin g tha t th e cas e - - I and I jus t wonde r wha t w e do , wha t EP Adoe s wit hi t i nterm s 

## i | o f th e variatio nan d th e experts ' judgment s a s t o usin g thi s and comin g up wit hadvic e i na standard .

DR . HUMPHREYS : W e di darriv e a t a sor t o f consensu s yesterda yafternoo ntha t wa s summarize dfo r u s thi s morning . Bu t w e di d i t muc hles s systematicall yandther e wer e dif

ference s o f opinio nexpresse dyesterda yafternoo nabou t wha t wen t int o tha t fina l consensus .

I thin k wha t thi s doe s i s t o mak e quit e clea r wha t th e difference s o f opinio nare,.th e differen t variable s i n thi s case . CHAIRMA

NLIPPMANN : Mayb e staf f ca ntel l us . Yo u indicate d earlie r tha t yo u hope dt o brin g thi s exercis e int o th e nex t draf t o f th e staf f paper . An dmayb e yo u ca nindicat e 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 

### EXECUTIVECOUR TREPORTERS (301 ) 565-006 4P.9 8 9 7 ho wyo u thin k yo u coul dd o that . 2 MR . JORDAN : Well , personally , myvie wi s tha t wha t 3 we'r e tryin g t o d o i s capture , i naninformal , systemize d sense , i s wha t th e respectiv e expert s fee l abou t i nth e are a 5 o f uncertai ndata . An dw e thin k it' s a majo r ste p jus t t o 6 formall ypresen t thes e differen t view s s o th e Administrato r 7 ca nse e tha t ther e ar e differen t judgment s abou t ther e abou t 8 thi s uncertai ndata . 9 An d that' s bette r tha nhavin g u s tak e thi s are a 10 o f uncertaint yand arriv e a t a staf f valuation , andou r njudgments . Or , alternatively , hav e thes e randoml ycommente d 12 -i nth e for mo f a consensu s whic hI thin k Dr . Humphrey s i s 3 ' tryin g t o suggest , a formalize dapproac htha t allow s yo u 1 4 j t o captur e thes e difference s o f judgments . 1 5 CHAIRMA NLIPPMANN : Dr . Silbergeld ? 1 6 DR . SILBERGELD : Well , I gues s I woul dhav e t o expres s som e reservation s i f thi s i s goin g t o b e th e forma l wa yi nwhic hyou'r e goin g t o see k t o represen t a specte r o f exper t opinio nfo r th e Agenc yi nterm s o f reachin g deci

1 7 1 8 1 9 2 0 21 * 2 2

2 4 2 5 

### sion s I hav e grav e reservation s abou t abou t it . I thin k fro m listenin g jus t t o Pau l describin g how , i na sense , hi s 2 3 opinion s wer e force d int o nonoverlappin g judgmen t curves , whil e tha t ha s a certai nbeaut yt o i t statisticall yand methodilogically , I' mno t sur e tha t tha t i s a naccurat e



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.9 9 9 8 1 representatio no f th e wa yi nwhic hpeopl e discus s an dreac h 2 consensu s o nissue s wher e ther e i s divisio nan d uncertainty . 3 An d I gues s I' ma littl e bi t concerne d tha t you' d I don' t know , sinc e I'v e com e int o i t a t thi s point , whethe r thi s ha s becom e a CASA C procedur e o r whethe r thi s i s a n 6 experimen t

7 I' mals o struc k tha t i t look s lik e thre e ou t o f 8 a tota l o f what , seve npeopl e see mt o hav e com e someplac e 9 o r fou r ou t o f seve ni f yo u coun t th e EP Apilo t projec t

1 0 peopl e —i t doesn' t see mterrificall ywel l validate d ye t 1 1 DR . WALLSTEN : Well , I' d lik e t o respon d t o —well , 1 2 unles s yo u wan t t o respond , Paul . I wa s goin g t o respon d 1 3 t o th e wor d "forced. " 14 " " Tha t i s t o say , I don' t thin k "forced " i s th e righ t 15 term . Whe nw e obtai njudgments , an d i f ther e wer e set s o f 16 judgment s tha t uncertai nlogica l ground s appeare d t o b e 1 7 mutuall yinconsistent , the nthi s wa s pointe d out . An di t 1 8 wasn' t a matte r o f forcing .

I t wa s matte r o f pointin g ou t th e implicatio no f thes e judgment s an d havin g th e perso ndecid e fo r himsel f -ho wh e wa*nte d t o handl e it .

Now , I don' t thin k it' s th e sam e thin g a s sayin g "force. " It' s simpl yshowin g th e implication s o f judgment s 1 9 2 0 21 ' 2 2 2 3 2 4 an d seein g whethe r th e expert s agre e wit hthos e implications . 2 5 

### Ithin k

there' s alo t

o f differenc ebetwee ntha t an d"forced. " EXECUTIVECOUR

TREPORTERS (301 ) 565-006 4PJ _ 

### 9 9

1 0

n 1 2 Now , a s I pointe d ou t earlier , ther e ar e tw o kind s 2 o f uncertaint ytha t on e mus t wor k with . There' s on e kin do f 3 uncertaint ythat' s grounde d i ndat a an d th e othe r kin do f uncertaint ythat' s grounde d i nlac k o f knowledge . An dthi s

5 i s a ninten t t o wor k wit hth e secon d typ e o f uncertainty .

6 It' s a ver ydifferen t ballgam e tha nworkin g th e 7 firs t type . That , kin d o f uncertaint ydu e t o lac k o f knowledg e 8 i s alway s present . An d th e questio ni s wha t i s th e wa ytha t 9 thi s kin d o f uncertaint yca nb e mad e mos t apparen t an dth e rang e o f agreemen t o nth e leve l o f tha t uncertaint yca nb e mad e apparent .

S o that' s usefu l information . 1 3 DR . SILBERGELD : Ha s thi s becom e th e methodology ?

1 4 " CHAIRMA NLIPPMANN : A s fa r a s it' s CASAC' s role , 1 5 CASA C ha s bee naske d t o revie wth e scienc e behin d thi s developin g approac ho f OHUP S t o ris k assessment .

W e hav e agreed , i nth e past , t o loo k a t i t an d liste nt o it , an d offe r ou r judgment . Insofa r as , I think , 1 9 th e understandin g goes , w e ha d abou t a yea r ag o a meetin g 2 0 o f a subcommitpte e o f CASA C whic hprovide d som e inpu t int o th e developin g proces s a t a muc hearlie r stage .

An d severa l members , a s individuals , hav e bee n calle d upo nb yEP At o hel p the mt o desig nstages . I don' t 2 4 kno wwha t els e t o say . 25 Anita ? 

### EXECUTIVECOUR TREPORTER S (301 ) 565-006 4 1 6 1 7 1 8

2 1 2 2 2 3P. 2

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 21 ' 2 2 2 3 2 4 2 5 10 0

DR . CURRAN : Well , th e page s aren' t numbered . Bu t i nthis , and i f yo u rea d th e protocol , i t indicate dtha t on e o f th e thing s the yattempte d t o d o wa s t o selec t a se t o f expert s wh o spa na rang e o f respectiv e judgments .

And I think , i nessence , that' s wha t they'v e done . And I thin k tha t th e fac t tha t the ydon' t al l agre e i s evi

denc e o f th e fac t tha t the ytrie d t o selec t a range . And I think , fro m

tha t poin t o f vie wi ntha t i t ver yexplicitl y indicate s t o peopl e wh o ar e concerne dabou t thi s wha t th e rang e is , it' s jus t anadditiona l too l —

MR . HAINES : Exactly . DR . CURRAN : —t o add t o andno t a substitut e for . An d I don' t thin k i t wa s eve r intende dt o be .

MR . HAINES : No . Thi s i s no t a decisio nrole . It' s a decisio ntool .

DR . CURRAN : Atool . Right . Yo u tak e you r criteri a documen t wit hal l it s uncertainties , andthe nyo u tak e you r rang e o f experts . An dI thin k i t jus t i s a nadde dtoo l t o assis t th e decisionmake r who , i nthi s case , i s th e Administrator. .

* DR . NOBLE : I' dlik e t o amplif ytha t sam e point . I t seem s t o m e tha t i t woul d be ver yusefu l t o addi nth e presentatio no f thi s materia l a summar yo f th e scientifi c reasonin g fro mth e experts . I nothe r words , th e outpu t i s no t jus t th e number s as.show ni nthos e tables , bu t a summar y



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P,3 _ 

### 10 1 1 o f th e judgmen t o f Exper t C , plus , perhaps , D andE if , i n 2 fact , they'r e clos e enoug htogethe r s o that' s judge dt o b e 3 a consensus .

Ho wdi d thei r reaso nabou t th e proces s compar e t o

5 Exper t Ac r Exper t 1 and2 i nth e pilo t fa r -t o th e right . 6 I t ma yb e tha t ther e ar e thre e ver ydifferen t view s o nth e

7 scienc e o f thi s proble mtha t le dt o th e difference s i nth e 8 9 1 0 1 1

1 8 1 9 2 0 2 1 2 2

24 2 5 numoers . And i t seem s t o m e it' s reall ycritica l tha t tha t b e se t fort hi nterm s o f th e scientifi c judgments , no t simpl ybuil t int o th e numbers . 2 MR . HAINES : That' s par t o f ou r overal l presenta 3 tion . Ro ni s startin g t o develo p those . Onc e h e ha s th e 1 4 write-u p w e wil l fee dthos e bac k t o th e expert s s o the yca n 1 5 revie wthei r narrative , th e narrativ e summation , andu s a 1 6 feedbac k s o w e mak e sur e w e ge t agreemen t o nthei r curves . 17 An d the nw e ge t agreemen t tha t we'r e fairl yrepre sentin g th e narrativ e write-u p i nsessions .

DR . NOBLE : I hav e thre e othe r comment s tha t Dr . Morga ngav e m e jus t a s h e ha d t o leav e fo r th e plan e .wit hwhic hI thoroughl yconcur .

On e i s enthusias mfo r thi s process . Dr . Curran , 2 3 Dr . Morga nand I hav e bee ninvolve dfo r seve nyear s i nth e evolutio no f thes e methods . An dI thin k tha t a t leas t th e tw o o f u s fee l ver yencourage dwit hthi s demonstratio no f



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P. 4

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 21 ' 2 2 2 3 2 4 2 5 10 2 them , o f th e car e wit hwhic hthi s exercis e ha s bee nconducted , and th e possibilitie s o f i t a s a wa yo f enhancin g th e com municatio no nanextremel ydifficult , controversia l and subtl e se t o f issues .

Th e secondcommen t i s that , really , a lo t o f wor k need s t o b e don e o npackaging , explainin g it . Thi s i s extremel ydifficul t material , especiall yfo r peopl e wh o ar e unfamilia r wit hth e concept s and th e terminolog ybein g used .

An d wherea s I fee l you'v e don e a ver ygoo djo b i npresentin g i t t o somebodylik e m e a t a meetin g suc has ' th e Societ yfo r Ris k Analysis , o r somethin g o f th e sort , I' m no t sur e it' s comin g acros s clearl yt o th e peopl e tha t don' t hav e a lo t o f backgroun d i nthi s area .

'And I thin k yo u reall ynee d t o inves t som e tim e and effor t i nthinkin g throug hho wd o yo u presen t i t ver yclearl y t o th e kind o f audienc e tha t you'r e goin g t o nee dt o presen t i t to . Th e thir dpoin t I' dlik e t o mak e i s th e car e tha t you'r e goin g t o nee d i ncarryin g thi s exercis e furthe r a s w e g o towar d th e meetin g nex t fall , especiall yi ndealin g -withth e 'issue s o nth e exposur e side .

I woul d hop e tha t yo u ar e abl e t o d o a s carefu l and a s detaile d a jo bo nthos e uncertaintie s a s yo u hav e don e i n dealin g wit hsom e o f th e uncertaintie s i nth e dos e respons e healt heffect s area .



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P. 5

2 3 4 5 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 2 1 2 2 2 3 2 4 2 5 10 3

CHAIRMA

NLIPPMANN : Ca nyo u indicat e t o u s wha t thinkin g yo u hav e o nexposur e encoding ? I' mno t sur e I understan d wha t you'r e plannin g t o do .

MR . HAINES : Well , a s w e wer e discussin g yesterda y o nth e uncertaintie s i s ho wmuc hdus t a chil dingests . It' s a ver yimportan t parameter . Ca nw e us e subjectiv e encodin g t o peopl e knowledgeabl e o r familia r wit hworkin g wit hchil

dre nand ge t bette r judgment s tha nwha t appear s t o b e a singl e dat a referenc e tha t w e hav e andse e i f w e ca nge t - -

CHAIRMA

NLIPPMANN : I don' t thin k yo u ca nhav e subjectiv e judgment s abou t th e mas s o f dus t tha t somebody ingests . MR . HAINES : I thin k yo u ca ntak e th e proces s o f "thi s "behavior , ho wofte ndoe s a chil dtypicall ya t play , a norma l child , and th e dus t i nth e environment . Wha t kindo f activit ydoe s h e have ? What' s th e frequenc yo f doin g this ? An d the nrang e and judgmen t o f ho wmuc hdus t w e fee l a chil d ca nge t o nhi s hand s andpu t i nhi s mouth .

Granted , it' s uncertain . Bu t we'r e face dher e wit h on e ver yuncertai nestimate . An dwha t we'r e tryin g t o d o i s ge t judgment s tha t wil l giv e u s a distributio no f proba

bilitie s o nimportan t variables .

DR . NOBLE : I thin k i t woul db e muc heasie r and mor e direc t t o d o experimenta l wor k o ntha t wit hchildre ni n controlle d pla ysituation s andyou'l l findout . I can' t



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P. 6

5 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 2 1 2 2 2 3 2 4 2 5 10 4 imagin e ho wjudgment s ca nlea d t o milligram s o r gramestimate s o f ingestion .

MR . HAINES : W e can' t argu e tha t i t woul db e idea l t o d o controlle d experiment s o nthem . The nw e ge t int o ar e controlle d situation s typical . Thi s i s no t t o replac e the dat a —yo u know , -w e hav e th e data . W e wan t t o us e this . An d w e wan t t o encourag e th e developmen t o f goo ddata .

An d it' s th e absenc e o f i t — DR . NOBLE : Rather , i f yo u ca nfindth e data , g o ge t th e dat a rathe r tha ndependin g o nth e encodin g o f sub

jectiv e judgment .

MR . HAINES : Exactly . DR . NOBLE : An dthi s ma yb e a nare a where , i nfact , "one ca ng o ge t reasonabl ygoo d data . Bu t i f yo u can't , i t seem s t o m e yo u don' t wan t t o d o a nanalysi s wher e you'v e don e a ver ycarefu l jo bo f assessin g subjectiv e judgmen t o nhealt heffects , bu t th e analysi s hinge s o non e numbe r pegge d t o on e dat a poin t i na critica l issu e o nth e exposur e side . An d th e sam e kind s o f car e hasn' t bee nexercise d t o ensur e tha t th e bes t informatio nan djudgmen t i s brough t t o bea r o ntha t issu e a s well . Th e analysi s ough t t o b e balanced . An d perhap s a nexploratio no f alternative s throug h sensitivit yanalysi s migh t b e a goo dwa yo f ensurin g that , i nfact , th e analysi s i s balanced .



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P. 7

1 2 3 4 5 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 2 1 2 2 2 3 2 4 2 5 10 5

CHAIRMA

NLIPPMANN : Tim ? DR . LARSON : I wa s goin g t o saytha t i f we , th e Committee , coul d emphasiz e tha t thi s i s a nuncertai- nare a an d tha t i t need s t o b e researched , the nperhap s measurement s coul d b e take nb

yEPA . I f i t come s downt o that . I mean , I thin k that' s a ste p forward .

An d it's , t o mymind , mor e comfortabl e wit htha t kind o f a suggestio ntha nrather , say , askin g peopl e exper t i nwhateve r yo u woul d—howeve r yo u woul dclassif ytha t expert , i ndus t ingestion .

(Laughter ) A s t o wha t th e number s are. . I mean , I thin k that' s sor t o f carryin g i t t o th e extreme .

"" " " " CHAIRMA NLIPPMANN : I don' t fee l tha t yo u haven' t don e ver yusefu l thing s o nthi s particula r thing . And , clearly , it' s bee ngoin g o nfo r manyyears . And , clearly , i t cost s a lo t o f money . And th e implicatio nI gathe r i s tha t yo u fee l tha t gettin g direc t measurement s woul db e to o costly . I can' t believ e it .

' MR . HAINES : No . We'r e no t inferrin g —w e don' t wan t t o infe r tha t thi s replace s it . We'r e sayin g a t thi s poin t i ntim e w e don' t hav e correc t measurements . I mean , w e coul d say, g o ou t and conduc t a stud yo r not . CHAIRMANLIPPMANN : Everybodywant s t o spea k here . 

### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P. 8

5 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 2 1 2 2 2 3 10 6

DR . CURRAN : Havin g bee n- - coul dIjus t fo r on e second ? Havin g bee ninvolve d i nthi s fro mth e ver ybeginnin g a s chairma no f th e initia l Ris k Assessmen t Subcommittee , on e o f th e thing s tha t w e lai ddowna s a groun drule , andon e o f th e concern s I hear draise d ove r her e andi t hasn' t bee n expresse d her e today , I thin k i t shoul db e ver yclearl ystated ^ tha t a t ever ysingl e meeting , and i never ysingl e pape r tha t w e dre wup , w e indicate d tha t thi s methodolog yi s i nn o way t o b e considere d a substitut e fo r th e science , andi nn o wa y i s t o b e considere da substitut e fo r research .

I t i s simpl ya nadde d too l tha t i s bein g presente d unti l suc htim e a s th e scienc e o f th e researc hi s available . "An d I"thin k tha t wa s th e concer ntha t wa s raise dove r here . An d I thin k yo u ough t t o ver yclearl yindicat e t o thes e peopl e her e tha t i nn o wa yd o yo u intend thi s t o b e a substitut e fo r whateve r researc hneed s t o b e don e o r th e science .

MR . HAINES : DR . CURRAN : MR . HAINES : DR . CURRAN : No . W e agree dwholeheartedl yt o that .

Bu t i t hasn' t bee nstated . Okay . An dI thin k i t shoul dbe . CHAIRMA

NLIPPMAN : Julian ? DR . CHISOLM : Th e frequenc yo f han dt o mout hactivit y 2 4 j j unde r variou s circumstance s ha s bee ndone . An d th e behaviora l 2 5 . psychologist s ar e grea t o ncountin g behaviors . An d the yd o 

### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P. 9

1 2 3 4 5 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 2 1 2 2 2 3 2 4 2 5 10 7 tha t sor t o f thing .

CHAIRMA

NLIPPMANN : Bu t yo u hav e t o conver t tha t t o a mass . DR . CHISOLM : Well , I don' t — the yprobabl ycoul d hav e bu t the yweren' t intereste di nthat .

MR . JORDAN : Le t m e jus t amplif ywha t Dr . Curra n wa s saying .

W e ar e i na decisionmakin g mod e base do nth e exist

ing staL e o f knowledge . An d al l thi s too l i s doin g i s tryin g t o saythi s i s th e existin g stat e o f knowledg e that' s ou t there , and thi s i s ho wpeopl e interpre t tha t knowledge . An d that' s simpl e i s wha t i t boil s downto .

I t doesn' t preclud e o r eve nbegi nt o substitut e "fo r doin g goo d research . I nfact , i f don e right , i t shoul d identif ymuc hbette r wher e th e area s o f researc hnee dt o b e focuse d on .

CHAIRMA

NLIPPMANN : Jim ? DR . FRANK : Well , jus t a mino r poin t o f information . I nth e fina l report , woul d yo u includ e som e sor t o f commentar y whic hyo u ma yhav e take nfro mth e transcrip t o r yo u ma yhav e solicite d independentl yfro mth e experts , becaus e I com e bac k t o wha t i s t o m e sor t o f a rang e o f response s amon g expert s a s t o th e eas e o r comfort , or , perhaps , discomfort , mor e accurately , tha t the yfee l whe nthe yhav e t o dea l wit h a nodd wa yo f expressin g thei r expertness .



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.1 0

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 10 8

An d i t woul dhel p m e ver ymuc hi f I coul dge t som e measur e o f wha t tha t exper t fel t a s the ywer e respondin g t o you r questions . Yo u know , woul d yo u includ e this , som e excerp t o r som e commen t b yeac hindividual ? DR . WALLSTEN : Yes . W e d o inten dt o includ e som e summar yo f ho weac hexper t view s th e literature . I assum e that' s wha t you'r e talkin g about , no t a measur e o f th e —

DR . FRANK : No t onl yho wthe yvie wth e literature . I thin k the ymigh t nav e 'ha d a difficult ywit hthat . Bu t I thin k ho wthe yuse d thei r knowledg e o f th e literatur e t o answe r you r forma t o f questions .

DR . WALLSTEN : Well , a s muc ha s possible , w e di d hav e a ver yextensiv e discussio nwit heac hperso nbeforehan d -about"th e literatur e and hi s interpretation . An dw e wil l provid e a summar yo f tha t too .

I f you'r e referrin g to , somehow , ho wth e exper t — DR . FRANK : I notice d tha t Paul' s feelin g toward s thi s evolve d somewhat .

MR . HAINES : Yes . DR . FRANK : I s i t al l righ t t o sayi t improved ? An d that' s fin e i f a t th e end the yfel t comfortabl e —

DR . WALLSTEN : I see . Okay . DR . FRANK : —wit hthi s sor t o f thing . Bu t i f ther e wa s a degre e o f discomfort , tha t the ywer e calle d i n a s expert s and the ywer e goin g t o d o thei r duty , I' dsor t o f



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.1 1

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 10 9 lik e t o kno wthat .

DR . WALLSTEN : Okay . That' s a goo dpoint . I didn' t pic k up o nth e perspectiv e yo u wer e providing .

Well , I thin k tha t wha t Pau l describe dwa s ver y common , and i t woul db e worthwhil e t o poin t tha t out . Ther e wasn' t ver ymuc hdifferen t fro mon e perso nt o th e nex t i n term s o f th e initia l discomfor t andI thin k fina l —I don' t kno wth e bes t wa yt o pu t thi s —bu t ultimatel yfeelin g mor e comfortabl e abou t it , I thin k tha t wa s quit e commo nandwoul d b e wort hou r pointin g tha t out .

Ther e weren' t enormou s differences . Ther e ar e thre e peopl e her e andthe yca nindicat e whethe r the ydisagre e wit hthat . Bu t tha t wa s a fairl ycommo nresult . I t mad e "i t especiall yusefu l t o g o bac k a secon dtime . Bu t w e shoul d mentio nsomethin g abou t that .

CHAIRMANLIPPMANN : Jim , di d yo u wan t t o sa ysome thing ? DR . WARE : Well , I gues s I' mtryin g t o diges t al l thi s discussion .

A s a perso nwh o ha s ha d nothin g directl yt o d o wit h thi s area , I' m

ver ykeenl yintereste di nthi s kind-o f work . An d I' m

tryin g t o thin k abou t and I' mver yintereste dt o hea r th e stron g reservation s tha t ar e bein g expresse dabou t thi s kind o f work .

And I' m

tryin g t o connec t thos e tw o "facts . Fro mm y 

### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.1 2

1 2 3 4 5 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 2 1 2 2 2 3 2 4 2 5 11 0

ownpoin t o f view , par t o f what' s involve dher e i s tha t th e informatio ntha t peopl e ar e mor e comfortabl e providin g i s oftentime s no t th e informatio nthat' s reall yneede do r directl yrelevan t t o th e decisio ntha t ha s t o b e made .

An d I*can understan dtha t peopl e hav e difficult y organizin g th e informatio ni na wa ytha t i s mor e quantitative , let' s say . An d I think tha t i s a ver yrea l par t o f th e process . An d ye t i t seem s t o m e tha t th e payof f fo r tha t i s tha t w e do , then , hav e a quantitative , eve na visuall y quantitative , summar yo f tha t individual' s poin t o f view . An d I thin k tha t tha t kin do f informatio nha s a rol e t o play i ndecisionmaking .

I think , i nfact , t o tak e th e extrem e alternative , I thin k on e alternativ e tha t w e sometime s choos e instea d i s t o leav e thing s sufficientl yvagu e tha t there' s a wid e rang e o f decision s that , i nfact , woul dno t b e accepte dtha t comfortabl yi f th e individual s wh o wer e reall yknowledgeabl e ha d a nopportunit yt o b e mor e interactiv e abou t th e regulator y decisions .

• S o I reall ybeliev e thi s i s a wa yo f articulatin g and communicatin g exper t judgment s abou t informatio ni nareas , a s you'v e said , wher e w e ar e no t abl e t o provid e th e empirica l evidence . Fo r example , yo u mentione d th e proble mo f



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1 2 3 4 5 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 2 1 2 2 2 3 2 4 2 5 11 1 extrapolatio no f th e anima l data . Wha t di dth e anima l dat a tel l us ? What' s goin g t o happe ni f w e chang e th e regulator y standards ? That' s a perfec t example . I f w e change dth e Ai r Oualit yStandar d o f lea d t o 1 from1.5 , what' s goin g t o happe r t o th e distributio no f exposure ? W e can' t gathe r dat a o nthat , question , a t leas t directly .

S o I thin k I woul dhav e quizze d yc u closel yabou t exactl yho wyou'r e goin g t o g o abou t it . An dmayb e I woul d agre e wit hyo u abou t th e details . Bu t personally , I fee l tha t i t remain s t o b e see nwhethe r thi s i s goin g t o wor k o r not . Mayb e peopl e jus t won' t eve r com e t o b e comfortabl e "wit hthi s approach . Bu t I thin k there' s potentia l fo r thi s approach , and it' s grea t enoug htha t w e ough t t o continu e pushin g ahead .

DR . WALLSTEN : I nrespons e t o that . You'v e sai d som e thing s tha t mad e m e thin k abou t som e o f th e othe r reac tion s we'v e had . An d I woul d appreciat e i t i f an ypeopl e wh o too k par t woul d respon dt o wha t I' mgoin g t o sayrigh t now . ' • •

An d tha t i s tha t althoug hpeopl e initiall yfel t somewha t uncomfortabl e expressin g thei r uncertaintie s i n thi s quantitativ e way , b yth e tim e w e go t finishe dI thin k mos t o f th e peopl e wit hwho mw e interacte dfel t tha t the yha d



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P. M

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 11 2

see nthei r ownknowledg e abou t th e are a i na . slightl ydif

feren t wa ytha t mad e the mawar e o f aspect s o f uncertaint y regardin g implication s tha t the yhadn' t though t abou t befor e o r abou t interrelationships .

An d s o rathe r tha nm ysayin g this , I woul dlik e i t i f yo u coul d eithe r agre e o r disagre e wit hm e i ntha t regard . Tha t woul d b e useful .

DR . ROSEN : Well , I ver ymuc hagre e wit hwha t yo u jus t said . I ngeneral , I've foun di t t o b e a nextraordinaril y revealin g and challengin g exercise . Anddurin g th e firs t severa l hours , i t wa s reall ydifficul t t o fee l comfortabl e wit hth e typ e o f question s tha t wer e bein g asked , and , i n a sense , comin g up wit hinformatio ntha t on e i s use dt o eithe r ""seein g i npublication s o r generatin g i nthei r ownlaboratorie s But , i ngeneral , I foun d i t t o b e a remarkabl y revealin g —abou t myself , abou t ho wI looke dupo nal l o f th e lea d childre ntha t I se e o na weekl yanddail ybasis . • S o I cam e ou t o f th e whol e experienc e feelin g ver ypositiv e abou t it . Som e o f thi s feelin g wa s als o passe do nt o colleagu e wh o ar e somewha t close r t o th e larg e numbers " o f lead-burdene d childre ntha t w e followed . An dI thin k i t wa s a ver ycon structiv e experience .

DR . HAMMOND : I woul d lik e t o rais e a question . Wasn' t there , i nfact , a simila r exercis e conducte d 

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1 2 3 4 5 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 2 1 2 2 2 3 2 4 2 5 11 3 i nregar d t o carbo nmonoxid e i nth e incidenc e o f angina ? I recal l seein g a numbe r o f expert s — th e data , rather , from th e encodin g o f a numbe r o f expert s o nwha t the yfel t th e effec t o f variou s level s o f C O i nth e bloo dimplie di nregar d t o th e probabilit yo f increase dangin a frequency .

Doe s anybody— MR . JORDAN : I woul dlik e t o se e that . (Laughter ) DR . HAMMOND : Yo u neve r sawthat ? (Simultaneou s conversation ) VOICE : Tha t wa s experimenta l work . DR . CURRAN : Yes . Tha t wa s on e o f th e paper s tha t wa s passe d ou t a t on e o f ou r meetings .

DR . HAMMOND : Ho wusefu l i s tha t t o th e peopl e wh o wer e involve d i nth e decisionmakin g abou t CO ?

DR . CURRAN : The ydidn*' t us e it . The ydidn' t us e i t fo r that .

MR . HAINES : Tha t wa s a developmen t projec t wher e w e ha d actuall ytw o differen t approache s demonstratin g usin g C O a s a model . Andi t wa s mor e o f lookin g —a coupl e o f differen t methodologica l approaches .

An d wha t w e attempte d t o d o i s dra wup bot hinput s t o that , tak e it..-

- and wor k i t int o ou r curren t methodology .

MR . JORDAN : Tha t wa s reall ya ste p i nleadin g t o wher e we'r e a t today . I t wa s neve r designe do r neve r intende d



### EXECUTIVE COUR T REPORTER S

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1 2 3 4 5 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 2 1 2 2 2 3 2 4 2 5 11 4 t o b e use d i ndecisionmakin g a t all .

DR . CHISOLM : Al l I wil l addi s tha t i t wasn' t purel yguesswor k becaus e I had , I' dsay , fou r set s o f dat a tha t I kne wabou t tha t I dre wupon .

DR . WARE : Actually , tha t remind s m e o f on e othe r commen t I' d lik e t o make .

Yo u mentione d somethin g abou t providin g data . I t seem s t o m e i nsetting s wher e ther e i s a dat a bas e avail

able , th e natura l thin g t o d o i s t o presen t thos e dat a o r a t leas t mak e thos e dat a availabl e t o a commo ndat a base .

An d I wonde r wha t you r attitud e i s abou t th e man agemen t o f th e empirica l evidence .

DR . WALLSTEN : Okay . Wha t I sai dearl yo nwa s tha t "wit h"regard t o on e o f th e healt heffects , namely , elevate dEP , th e dat a wer e s o goo d tha t i t wa s no t necessar yt o ge t judg

ment s a t all . W e coul d d o al l o f th e ris k assessment s jus t purel ywit hth e dat a base .

A s wa s mentione dearlier , i f th e dat a ar e available , then , o f course , it' s no t necessar yt o ge t th e judgments . An d s o - -

• DR . WARE: : Andwha t i f there' s a little'bi t o f dat a available ?

DR . WALLSTEN : Well , i f there' s a littl e bi t o f dat a available , the nw e discus s that . And , I mean , obviously , i f the yar e expert s the nthey'r e goin g t o b e awar e o f it .



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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 2 1 2 2 2 3 2 4 2 5 

### 11 5

DR . WARE : Well , that' s ye s andno . I mean , di d yo u find tha t peopl e ar e no t awar e —ar e no t uniforml y awar e o f th e dat a base . An d I' mintereste d—

MR . JORDAN : Th e criteri a documen t i s th e dat a base . DR . WALLSTEN : That' s right . That' s right . I mean , that' s what' s referre dto . Correct .

DR . CURRAN : Bu t i nth e proces s o f development , w e als o acknowledg e th e fac t tha t sometime s ther e woul db e s o littl e dat a availabl e tha t thi s wa s no t a usefu l too l eithe r

Yo u know , i t depends . There' s tha t rang e i nbetwee r Sometime s there' s s o littl e dat a available . I mean , I wa s acknowledgin g th e process .

CHAIRMA

NLIPPMANN : Les ? MR . GRANT : I jus t aske d —yo u sai dyo u hav e th e data . (Laughter )

MR . GRANT : I — (Simultaneou s conversation ) DR . CHISOLM : Well , th e Kellog g episod e —hemoglobijn s obtained'ther e bu t the yneve r go t muc hpubli'cityanywhere . That's , what , 105 6 —I kno wther e wer e hemoglobins . An d I kno wtha t ther e wer e — I kno wPau l tol dm e th e leve l a t whic hdecremen t —

CHAIRMANLIPPMANN : Well , I thin k i f yo u hav e a n 

### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P . 1 8

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 11 6 informatio nreques t the nyo u ough t t o —

DR . CHISOLM : There' s als o informatio nfro mE l Pas o too . DR . ROSEN : W e als o publishe d a —

CHAIRMA

NLIPPMAN : John , com e up t o th e microphone . DR . ROSEN : W e als o publishe d a pape r i nth e mid-'70 s i nwhic hw e include dhematocrit s (ph ) i nabou t 10 0 childre nwit hvariou s leads .

CHAIRMA

NLIPPMANN : Well , we'r e runnin g ou t o f ou r schedule d time . I don' t begrudg e stayin g somewha t longe r i f yo u wan t t o discus s som e o f thes e issue s further . I t seem s tha t th e consensu s tha t thi s i s a nexercis e whic hha s prove d interestin g and certainl ydeserve s t o b e followe d throug hfurther .

An d I thin k we'r e al l anxiou s t o se e ho wwel l yo u can , i f yo u can , includ e thi s i nth e seconddraf t o f th e criteri a documen t — I' msorry , th e staf f paper . An dfo r th e sampl e we'v e see nand , perhaps , ver ylikel yals o fo r th e I Q encoding , ther e i s thi s middl e groun do f havin g som e data , certainl yno t enough , and usin g you r exper t judgmen t t o d o it : I suspec t tha t th e lea d exposure , you'r e i ntha t are a —a t leas t I thin k yo u are , wher e yo u don' t hav e enoug h dat a t o us e experts ' judgment s properly . I f yo u ca nconvinc e u s otherwise , mor e powe r t o you . Andw e loo k forwar dt o



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(301 ) 565-006 4P.1 9

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 24 2 5 

### 11 7 seein g it . I mean , I don' t kno wwha t els e w e coul dsayi n summatio no f thi s discussion .

Doe s anybodyels e wan t a chanc e t o hav e an yfina l commen t befor e w e clos e th e meeting ?

MR . JORDAN : I' djus t add , Dr . Lippmann , tha t n o on e know s anybette r tha nthi s group tha t yo u se e sittin g aroun d here , that' s bee nworkin g o nth e exposur e endo f it , th e challeng e that' s ou t ther e i nconvincin g people .

An d w e ar e no t comin g her e and wavin g a fla g and sayin g tha t w e ar e ultimatel ygoin g t o d o it . Bu t I' d say on e thing , w e ar e darne d sur e goin g t o try .

CHAIRMA

NLIPPMANN : I wonder , considerin g th e lengt h "of tim e tha t i t ha s take nt o ge t on e o r tw o encodin g opera tion s done , ho wyo u coul dpossibl yd o anothe r on e andrepor t bac k t o u s b

yth e fall . MR . JORDAN : It' s alreadydone . CHAIRMA

NLIPPMANN : Th e IQ . MR . JORDAN : Th e I Q i s alreadydone . CHAIRMA

NLIPPMANN : Yes . Bu t I mea nth e thir d one . You'r e suggestin g tha t you'r e doin g a hencodin g o n exposure . MR . HAINES : W e hav e wor k underwa yrigh t now . An d s o w e ca nhopefull yb e ou t talkin g t o expert s i nth e ver y nea r ter m

and ge t som e exposur e parameters .



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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 

### 11 8

DR . LARSON : Ther e i s a larg e communicabl e CDC study

- i n—smelte r wit harseni c exposur e pathway s wher e they'r e looking int o a lo t o f differen t exposur e routes .

CHAIRMA NLIPPMANN : Well , that' s data . DR . LARSON : Yes , I know . CHAIRMA NLIPPMAN : An

d we-al l applau

d the us e c f data , eve ni f it' s arsenic . I t migh t be relevan t t o this . An d there' s lea

d i ni t too , obviously . Bu t we'v e heard a tease r tha t there' s anencoding exercis e onlea

d exposure . W e haven' t bee nbriefed onan y protocols , onan

yselectionprocedure s fo r picking peopl e wh o knowsomething abou t it . And , therefore , considering the histor yo f al l this , I jus t wonde r personall yhowyou coul d "possibl yd o thi s exercis e i nsufficien t time t o have i t i n the nex t draft .

I jus t don' t se e howthat' s goin g * t o happe nunles s you'v e al l o f a sudde nlearned howt o mov e int o hig hgea r a s compare d t o the progres s i nrecen t years .

Bu t that' s m

yow nobservatio no f this . Dr . North ?

' DR . NORTH : I wa s abou t t o mak e a 'commen t earlier . And the nDr . Curranmad e a beautifu l speec hsaying wha t I wa s jus t abou t t o say .

I don' t wan t m

ycomment s earlie r t o b e interprete d a s urging yo u t o d o a subjective probabilit yexercis e onthe



### EXECUTIVE COUR T REPORTER S

(301 ) 565-006 4P.2 1 11 9 1 exposur e side . 2 I urge d yo u t o b e carefu l an d t o us e th e bes t 3 method s tha t yo u ca ndevelop . An d mayb e thi s wil l win du p 4 bein g a ver ydat a intensiv e exercis e usin g arseni c dat a a s 5 a surrogat e i na Tacom a smelter , o r mayb e i t wil l involv e 6 interview s wit hexpert s i nchil d behavio r wh o hav e studie d

. 7 th e frequenc yo f mouthin g behavior , an d yo u ca nge t a lo t o f 8 dat a fro mtha t source . 9 I a msimpl yurgin g tha t a substantia l effor t b e 1 0 give nt o tha t sid e o f th e proble mt o balanc e th e ver ycarefu l

neffor t tha t you'v e jus t tol d u s about .

1 2 MR . JORDAN : An d als o w e ar e lookin g a t th e possi

1 3 bilit yo f mayb e eve nbreakin g th e NHANE S dat a dow na littl e 14 " bi t farthe r an d the nyo u coul d ge t som e ide a o f wha t kid s

1 5 ar e expose d t o wit hth e ai r lea dlevel s o f dust , an d so , i n i 6 thi s are a a s compare d t o wha t thei r bloo d lea d level s are . ! 7 An d that' s anothe r surrogat e fo r usin g th e direc t 1 8 expsour e model . Again , th e challeng e i s toug han d I don' t 1 9 bac k awa yfro mi t tha t i t i s a toug hchallenge . Bu t I repea t 2 0 m ystatement , we'r e goin g t o darne d sur e try . 2 1 ' CHAIRMA NLIPPMAN : We'v e enjoye d t'h e opportunit y 2 2 t o commen t t o yo u o nyou r staf f pape r an d you r emergin g 2 3 proces s o f subjectiv e probabilit yencoding , an d th e us e o f 2 4 tha t i nth e staf f paper . 2 5 I hop e ou r comment s hav e bee nconstructiv e an d 

### EXECUTIVE COUR T REPORTER S

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### 12 0 1 2 3 4 5 6 7 8 9 1 0 

### usefu l t o you , an d we look forward t o seein g your nex t draft , MR . JORDAN : Than k you . CHAIRMA NLIPPMANN : Than k vo u all . 

### (Whereupon , a t 12:0 2 p.m. , the hearing wa s adjourned. )

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 

### EXECUTIVECOUR TREPORTER S (301 ) 565-006 4P.2 3

oeior e REPORTER' S CERTIFICAT E

Thi s i s t c certif ytha t ih e attache d prcceeding s ENVIRONMENTA L PROTECTIO NAGENC Y 7 j 

### e ; 9 1 0 1 1 1 2 1 3 1 4 1 5 16 1 7 1 8 1 9 2 0 21 2 2 2 3 2 4 2 5 i nth e matte r cf :

SCIENC E ADVISOR YBOARD , CLEA NAI R SCIENTIFI C ADVISOR YBOAR D -(CASAC ) SUBCOMMITTE E O NLEAD . wer e hel d a s herei nappear s an d tha t thi s i s th e origina l itranscrip t thereo f fo r th e fil e o f th e Departmen t 

### I io r Carmiission .

Officia l Reporte r

DATE : JUN E 3 , 1 9 8 5



### EXECUTIVECOUR

TREPORTER S (301 ) 565406 4