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UNITE D STATE S ENVIRONMENTA L PROTECTIO NAGENC Y

SCIENC E ADVISOR Y BOAR D

CLEA N AI RSCIENTIFI C ADVISORYCOMMITTE E

LEA D EXPOSUR E SUBCOMMITTE E

Ope nMeetin g

Unite dState s Environmenta l Protectio nAgenc y Mal l Level , Conferenc e Roo m Nort h3 40 1 M Street , Southwes t Washington , D . C . 2046 0 Tuesday , Octobe r 25 , 198 8

9:3 0 a.m . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P. 3

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• " 2 3

•:: . 2 4 2 5 APPEARANCE S

DR . TIMOTH Y LARSON , Chairma n Environmenta l Engineerin g an d Scienc e Progra m Departmen t o f Civi 1 Enginee r in g Universit yo f Washingto n A . ROBER T FLAAK , Executiv e Secretar y

Environmenta l Scientis t Scienc e Advisor yBoar d Unite d State s Environmenta l Protectio n Aqenc v

Member s o f th e Subcommitte e DR . J . JULIA

NCHISOLM , JR . Associat e Professo r John s Hopkin s Schoo l o f Medicin e

DR . SCOT T CLAR K Professo r o f Environmenta l Healt h Departmen t o f Environmenta l Healt h Universit yo f Cincinnat i Medica l Cente r

DR . IA N vo n LINDER N Presiden t Terragraphic s Environmenta l Engineerin g DR . KATHRYNR. MAHAFFE Y Scienc e Adviso r Offic e o f th e Directo r Nationa l Institut e o f Environmenta l Healt h, Science s ^ DR . PAU L MUSHA K Consultan t and Adjunc t Professo r Universit yo f Nort hCarolin a DR . MICHAE L B . RABINOWIT Z Investigato r Marin e Biologica l Laborator y DR . ROBER T D . ROW E Senio r Vic e Presiden t RCG/Hagler , Reilly , Inc . P£r£i£jigant s .fro

m Environmenta l Protectio n Agenc y JEF F M . COHE N

JOH N H . HAINE S Offic e o f Ai r Qualit yPlannin g Offic e o f Ai r Qualit yPlannin g an dAssessmen t and Assessmen t DR . ROBER T W . EL IA S Environmenta l Criteri a and Assessmen t Offic e

EXECUTIV E COUR T REPORTER S DR . DAVI D W . McLAM B Offic e o f Ai r Qualit yPlannin g an dAssessmen t

(301 ) 565-006 4P. 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 Other s Presen t

DR . ALLA NH . MARCU S Battell e Memoria l Institut e JAME S GILCHRIST , ESQUIR E Representin g th e America n Minin g Congres s GAL E HOFFNAGL E TR C Environmenta l Consultant s EDWAR D 5EEGER , ESQUIR E Representin g Lea d Industrie s Associat i o n JOH NYODE R Lea d Industrie s Associatio n

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P. 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 "ABL E O ^ CONTENT S

WELCOM E AN DINTRODUCTIO N Dr . Timoth yCohen , Chairma n

OPENIN GREMARK S A . Rober t Flaak , Executiv e Secretar y

OVERVIE WO F DRAF T DOCUMEN T AN D SUBCOMMITTE E COMMENT S Mr . Joh n Haine s Mr . Jef f M.•Cohe n PUBLI C COMMENT S AN D GENERA L DISCUSSION- - Publi c Comments : Gal e Hoffnagle , TR C Environmenta l Co n su 1 1 a n t s

CAS E STUD Y RESULT S AN D DISCUSSIO N Mr . Jef f M . Cohen Dr . Davi dW . McLam b A . Rober t Flaa k

CHAIRMAN' S SUMMAR Y GENERAL DISCUSSION 9 1 1

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12 2 13 2 13 9 14 1 14 2

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P. 6

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CHAIRMA NTIMOTH Y LARSON : W e wil l cal l th e meetin g t o order . Thi s i s th e Subcommitte e o f CASA C meetin g o n Lea d Exposure . WELCOM E AN D INTRODUCTIO N

CHAIRMA NLARSON : I woul d welcom e everybod yhere . W e are gla d t o hav e a distinguishe d grou p o f peopl e t o b e abl e t o revie wth e Exposur e Draf t document .

I woul d lik e for everyon e t o introduc e themselve s briefly , includin g anybod yi nth e audienc e wh o woul dlik e to .

M ynam e i s Ti m

Larson . I a

m th e Chairma no f thi s Subcommittee . I am i nth e Environmenta l Engineerin g an d Science s Progra ma t th e Universit y o f Washington . I a mals o a membe r o f CASAC .

A s th e on e leadin g th e charg e here , s o t o speak , I a m relyin g o nth e particula r expertis e w e hav e her e o nlead . S o I a m

ver y intereste di npeople' s comments . DR . CHISOLM : I am Julia nChisolm . I am from Baltimore , intereste di nlea dpoisoning .

DR . vo nLINDERN : I am Ia nvo nLinder nfrom Moscow , Idaho . I hav e worke do nlea dsmelters .

DR . MAHAFFEY : I am Kat e Mahaffe y

from Nationa l Institut e o f Environmenta l Healt hSciences .

DR . McLAMB : I am Dav e McLambwit hth e

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P. 7



### 6 1 Environmenta l Protectio n Agency , Offic e o f Ai r Qualit y 2 Plannin g an d Standards . I d o relate d document s o n lea d 3 NAAQS , fo r instanc e regulator yimpac t analyse s an d thos e 4 analyse s whic hbuil d it . 5 MR . HAINES : I a mJoh n Haine s wit hth e Offic e o f 6 Ai r Qualit yPlannin g an d Standards . I wor k wit hJef f wit h 7 respec t t o th e NAAQ S review . 8 MR . COHEN : I a mJef f Cohen . I wor k wit hJoh n 9 Haines . 1 0 [Laughter ] 1 1 DR . MARCUS : Alle n Marcus , Battelle , Research

1 2 Triangl e Park , Nort hCarolina . I a mconsultan t t o Offic e o f 1 3 Ai r Qualit yPlannin g an d Standards . 1 4 DR . CLARK : Scot t Clark , Universit yo f Cincinnati ; 1 5 involve d i n lea d studie s an d soi l abatement . 1 6 DR . RABINOWITZ : I a mMichae l Rabinowitz . I a ma 1 7 geochemis t a t Children' s Hospita l i n Boston . 1 8 DR . MUSHAK : Pau l Mushak , consultant , adjunc t 1 9 facult ya t th e Universit yo f Nort hCarolina . 2 0 DR . ROWE : I a mBo bRow e wit hRCQ/Hagler , Bailly ; 2 1 an dI' ma chemist . 2 2 MR . FLAAK : I a mBo bFlaak . I a mth e Executiv e 2 3 Secretar yo f CASAC . B ytraining , I a ma marin e ecologist , 2 4 bu t b yinclinatio n I hav e bee ndoin g thi s fo r a lon g time . 2 5 Member s o f th e audience , woul d yo u min d

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P. 8

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2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 16 17 18 19 2 0 21 2 2 2 3 24 2 5 introducin g yourselve s briefly? '

DR . ELIAS : I' mRo bElias , Environmenta l Criteri a and Assessmen t Offic e a t RTP .

MR . YODER : I' mJohn Yode r fromLea d Industrie s Association .

MR . HOFFNAGLE : Gal e Hoffnagle , TR C Environmenta l Consultants .

MR . SEEGER : E d Seeger , attorne yfo r Lea d Industrie s Association .

MR . GILCHRIST : I amJi mGilchrist , attorne yfo r th e America n Minin g Congress . OPENIN GREMARK S

MR . FLAAK : I hav e a coupl e o f openin g remarks , briefly . Th e large r microphone s i n fron t o f yo u ar e th e one s fo r th e speake r system ; th e smalle r one s ar e th e one s fo r th e Cour t Reporter . I f yo u hav e somethin g t o emphasise , don' t pul l up th e Cour t Reporter' s microphon e up t o yo u becaus e sh e wil l jum p righ t ou t o f he r chair . -Laughter ] Thi s particula r Subcommitte e i s a Subcommitte e o f th e CleanAi r Scientifi c Advisor yCommittee . Normally , ou r subcommittee s are

chaire d bya membe r o f th e ful l CASAC , whic hDr . Larso n is : on e o f th e seve n statutor ymembers .

Th e purpos e o f thi s Subcommitte e revie wi s t o EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P. 9

w-_ _ 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 S review a draf t documen t tha t wa s complete d bac k i n Augus t o n th e LeadExposur e Analysis , Methodolog yand Validation . Thi s documen t ha s bee n reviewe d b yth e Committee . Comment s hav e beensubmitte dt o th e Agenc y and thes e comment s ar e par t o f th e discussio n fo r a goo d par t o f thi s discussio n for today .

Whe n Mr . Cohe n get s int o hi s remarks , h e wil l explai na littl e furthe r wh y w e are doing thi s an

dwha t we hop e to ge t out o f it .

For th e purpose s o f thos e member s o nthi s pane l who hav e no t beenwit hu s before , we operat e inth e publi c ey e unde r th e Federa l Advisory Committe e Act . Al l o f ou r meeting s are

hel dinth e public . Mos t o f th e CASAC meeting s ar e full y transcribe d an dcopie s o f th e transcriptio nar e availabl e usuall y abou t two week s afte r th e meeting .

For an y handou t materia l o r othe r document s tha t yo udon' t manag e t o ge t a cop y o f whil e yo uare

her e today , pleas e advis e me . I wil l se e tha t yo uge t a cop y some tim e afte r th e meeting .

Tim , do yo uhav e anythin g else ? CHAIRMA

N LARSON : No , no t at thi s time . MR . FLAAK : We wil l turnit ove r to John .



# J EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.1 0

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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 OVERVIE WO F DRAF TDOCUMEN TAN D SUBCOMMITTE E COMMENT S !__._

. _!'_:_I Q tJaine s

MR . HAINES : I woul d lik e t o begi n bythankin g th e Subcommitte e for thei r comments . The yprove d mos t helpfu l t o us . I speciall yappreciat e th e tim e spen t preparin g them .

A s yo u ar e al l aware , th e Exposur e Analysi s i s a ke ycomponen t o f our ongoin g revie wo f th e Lea d NAAQS . Yo u ma yrecall , th e Environmenta l Protectio n Agenc yfirs t se t th e NAAQ S fo r lea d i n 1978 .

Unde r th e Clea n Ai r Act , th e Environmenta l Protectio n Agenc yi s reguire d t o periodicall yrevie wal.l . . Nationa l Ai r Qualit yStandard s and th e underlyin g healt h criteri a o n whic hthe yar e based .

A s yo u know , i n 198 6 th e Environmenta l Criteri a an d Assessmen t Offic e complete d th e updat e and revision s t o th e Ai r Qualit yCriteri a fo r lead , and CASA C close d o n tha t documen t i n Augus t 1986 .

I n earl y1986 , w e prepare d a draf t o f ou r staf f pape r whic hwen t befor e CASAC . A s par t o f tha t session , CASAC among othe r thing s recommende dtha t th e staf f refin e it s leadexposur e methodolog yand conduc t appropriat e validation .A s th e resul t o f thos e recommendations , w e hav e produce dth e draf t repor t tha t i s i n fron t o f yo utoday fo r revie wan d comment . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.1 1

t i M_fiC - -e_~ i 1

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Als o becaus e w e vie wthi s documen t a s importan t w e hav e aske dBo band th e SA B and CASA C t o pu t togethe r a Subcommitte e tha t coul d specificall yfocu s i n o n th e exposur e methodolog yand validatio n work . W e thin k it' s importan t tha t thi s receiv e a ver ythoroug hreview .

Thi s wil l hopefull yplac e u s i n a positio n tha t w e ca n mov e ahea d an d pul l togethe r th e nex t draf t o f th e staf f paper , and b e abl e t o bas e ou r projection s of f th e methodolog yse t fort hhere .

Jus t fo r th e poin t o f view o f th e audience , th e comment s submitte d b yth e Subcommitte e member s hav e bee n place dinth e Docket . S o they ar e availabl e t o yo ufolk s i f yo u woul dlik e t o review them . T o facilitat e today' s discussion , Jef f wil l provid e a brie f overview o f ho w th e exposur e methodology relate s t o th e NAAQ S review . Thenh e wil l procee dt o provid e a review

o f th e Subcommittee' s comments . We hav e trie dt o groupthos e comment s int o majo r categorie s an

dou r response s t o them . S o yo ucanse e collectivel y

wha t th e group' s comment s wer e an dho w we plac e t o addres s them .

A s show

nonth e agenda , thi s afternoo nJef f wil l presen t fo

r th e Subcommittee' s informatio nsome initia l result s fro

m two cas e studie s we hav e done . Ther e wil l b e a n opportunit y

t o discus s thos e briefly . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.1 2



## J 1

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dDave McLamb , we wil l outlin e som e of the relate dactivities. Jef f wil l tal kabou t som

e othe r potentia l application s fo r th e mode l outsid e ou

r immediat e program ; Dav e wil l tal kabou t ho w it wil l fi t int o ou

r regulatory

impac t analysi s an dtha t work . Finally , I want t o reiterat e tha t AllanMarcu s ha s beenworking ver

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nth e developmen t o f th e exposur e model . BobElia s ha s provide d invaluabl e input t o u s a s well .

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y t o go , Jeff ? MR . COHEN : Okay . y . . _!_._ . 1-llL_!_

. Qohe n MR . COHEN : Again , I wan t t o thankyo ual l fo r th e comments . We wer e hoping fo r th e leve l o f detai l we actuall y received . I

t wil l b e very

usefu l t o u s infinalizing th e report . I wan t t o star t out b y looking at th e LeadAi r Standar dreview

process . Yo ucanse e wher e th e lea dexposur e modelin g fit s inan dwher e ou

r repor t i s today . Yo ucanals o se e th e differen t point s o f CASAC review .

For example , her e at th e criteri a documen t assessmen t ther e i s a review o f th e benefit s analysi s methodolog y

abou t a yea r ago . W e ar e plannin g ongoing t o CASA C wit ha draf t staf f pape r inearl y 1989 . Thi s pape r wil l incorporat e result s o f th e lead

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4)

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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 2 exposur e modelin g an d als o fol d -i

n the ? overal l healt hris k assessment . Th e staf f pape r wil l the n serv e a s a basi s for th e recommendation s t o th e Administrato r o n alternativ e standards . Ther e shoul d b e anothe r arro where , actually , from th e cas e studyblood-lea d estimate s t o th e benefit s analysis . W e wil l tal k abou t tha t a t th e en d o f th e day . Jus t t o remin d u s all , unlik e th e othe r criteri a ai r pollutant s tha t w e hav e t o review , lea dha s establishe d itsel f inmanydifferen t pathway s o f exposure . S o i t i s a uniqu e exposur e proble m fo r us . W e nee dt o develo pdifferen t kind s o f exposur e methodologies .

Thi s summarize s th e differen t method s tha t we hav e developed , al l accountin g fo r ai r an

dwel l a s non-ai r sources , especiall y ric hinfutur e trend s ingasolin e an d diet . Th e disaggregat e mode l combine s separat e relationship s betwee nbloodleadan dlea dindiet , soil , dus t a s wel l a s ai r leadfro m th e literature . It i s adopte dfro m th e criteri a document .

We mad e some change s t o reflec t newe r data . Lik e th e aggregat e model , it assume s a blood-lea deguilibriu m wit h historica l exposures .

Whil e th e disaggregat e mode l ha s a nai r blood-lea d

EXECUTIV E 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 1 3 leve l tha t reall yreflect s prett ymuc hinhalation , th e aggregat e mode l slop e include s effect s o f indirec t ai r lead exposure : dus t an d soil . Th e uptak e biokineti c mode l use s age-specifi c intake s o n a dail ybasi s fromeac hpathway , a s wel l a s age specifi c absorptio n factors . Blood-lea d and tissue-lea d level s are governe d b ya linea r biokineti c mode l whos e growt h and metaboli c factor s chang e wit hage .

On e o f th e advantage s w e se e i n th e mode l i s tha t i t ca n explicitl yestimat e th e effect s o f relativel yrapi d changes . On e o f th e feature s o f th e biokineti c uptak e mode l i s tha t i t require s a larg e variet yo f assumption s i n inpu t data . Thi s list s th e parameter s tha t w e discus s i n th e report . W e note , jus t a s background , whic hone s appea r t o b e strongl yinfluentia l i n predictin g children' s bloo d leads . Thos e are th e one s o n whic hw e conducte d variou s sensitivit y analyses . Again , jus t t o remin d us , give n th e availabl e dat a th e model s estimat e averag e exposur e conditions . W e ar e concerne dno t onl y wit hth e mea nbloo dlead , bu t wit huppe r percentile s o f bloo dleads .

Give na mea nbloo dleadan dth e fac t tha t bloo d lead s ar e distribute d lea d normal , w e ca n calculat e EXECUTIV E COUR T REPORTER S (301 ) 565-006 41 2 3 4 5 6 7 8 9 1 0 1 1 12 13 14 15 16 17 1 8 19 2 0 21 2 2 2 3 2 4 2 5 1 4 distribution s usin g a geometri c standar d deviatio n in thi s case . Th e valu e tha t w e ar e proposin g t o us e i s derive d froma point-sourc e standard . I t i s coincidentall yidentica l t o tha t whic happeare d i n th e criteri a documen t fromth e NH 2 analysis . Thi s lis t i s for th e differen t sub-populations . W e go t severa l comment s o n this . Ther e wa s a littl e confusio n whic hmodel s ar e bein g use d fo r wha t populations . Fo r youn g children , w e hav e thre e model s we fee l tha t ar e available . W e ar e proposin g tha t th e uptak e . . . biokineti c mode l i s th e on e o f choice .

Fo r adults , give n the lac ko f dat a o nbiokinetics , fo r exampl e durin g pregnancy , w e fee l tha t thi s mode l i s th e appropriat e on e t o use . On e o f th e reason s no t t o us e the mor e detaile dmode l fo r adult s i s tha t it woul drequir e larg e amount s o f inpu t dat a going bac kinhistor y to accoun t fo

r thei r long-ter

m exposure . A s Bobmentioneed , th e bul ko f our tal ktoday , thi s mornin g a t least , wil l b e tryin g t o clarif y th e issue s raise di nth e comment s tha t we receive dfro m you . W e ar e going t o try t o g o throug hthe m quickly , but inenoughdetai l tha t everyon e understand s no t onl y ou r understandin g o f th e comments , but our responses .

We hav e comment s o nthes e issue s here . We wil l

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.1 6

.?__ . 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 1 5 hav e discussio n late r i n th e day . I f anyon e want s t o tal k abou t on e thin g i n particular , i n detai' l later , w e wil l b e gla d t o pu t thi s slid e bac k on .

I thin k ther e i s a numbe r o n eac ho f th e slide s s o

w e ca n readil yfin d it .

W e hav e severa l comment s o n th e organizatio n an d presentatio n o f th e report , especiall yo n th e nee d t o clarif y th e overal l pla n an d ho wthi s exposur e analysi s fit s i n t o th e revie wo f th e standard . W e nee d t o discus s a littl e bi t more , a s well , implication s fo r regulator yactions : Wha t model s are

bein g use d fo r wha t population s an d why ? Bot ho f thos e comments , I think , w e wil l tr yt o addres s wit ha n expande d introductio n wher e w e clarif yth e use s o f th e variou s models . W e ar e als o goin g t o hav e th e Executiv e Summar ywhic hI thin k wil l hel p th e reade r focu s i n o n wha t i s important .

Ho wwil l difference s i n blood-lea d result s b e resolved ? W e ar e plannin g o n presentin g result s fro mal l o f th e models . Again , w e ar e proposin g tha t onl yth e mid-poin t result s from

th e uptak e biokineti c mode l fo r childre n an d th e disaggregat e mode l fo r adult s b e use d fo r furthe r analyses .

Ther e wa s a commen t fo r u s t o defin e th e blood

lea den dpoints , whic hw e wil l b e mor e specifi c on : no t onl y th e mea n blood-lead , bu t percentag e o f level s abov e selecte d

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.1 7

1 6 i I I blood-lea dcutoffs . 2 II W e wil l tal k abou t som e level s late r toda ya s a n 3 | | exampl e whe nw e presen t case-stud yresults . 4 CHAIRMA NLARSON : I f an ySubcommitte e member s hav e 5 an yresponse s o r comments , pleas e fee l fre e t o voic e them . 6 | | MR . FLAAK : Yes . 7 II Now , w e wil l briefl yg o throug hth e comment s 8 classifie d b yth e section s i nth e report , startin gwit hair

9 lea dwher e w e ha d som e informatio no nnon-attainmen t areas . 1 0 Tha t i s a goo d idea . W e are goin g t o ad dsom e mor e recen t 1 1 ai r qualit y

dat a t o tha t I wil l sho w i na minute . 1 2 W e ca ntal k abou t non-attainmen t problem s a s well , 1 3 then . 1 4 Ther e ar e severa l comment s o nth e gasolin e phase 15 down . W e wil l g o throug hthes e sequentially . 1 6 W e shoul ddiscus s tha t th e dat a o nautomotiv e 1 7 airborn e lea di s use dinterchangeabl y wit hdat a fro m

poin t 1 8 sources . I thin kGrange r Morga nmad e tha t comment . H e i s 1 9 | no t her e today . 2 0 W e wil l g o bac kan dchec ktha t w e ar e clea r o n 2 1 this , bu t al l th e dat a tha t w e us e fo r exposur e estimate s are 2 2 point-sourc e specific : fo r exampl e respirator y depositio n 2 3 efficiencies , soi l an ddus t level , an ds o forth . 2 4 Ther e ar e comment s t o illustrat e th e rapi ddeclin e 2 5 i nai r lea dbecaus e o f th e phase-down . Again , w e hav e som e EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.1 8

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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 7

mor e recen t dat a I wil l sho wyo u o n th e nex t slide .

W e discus s th e impact s o f th e declin e o n exposur e estimates . Again , w e wil l g o bac k an d chec k o n this . W e not e thi s i n severa l place s i n th e report . W e wil l tr yt o highligh t tha t somewher e i n th e front .

Acommen t tha t i n estimatin g a futur e baselin e blood-lea d level , w e use d th e gasolin e blood-lea d regressio n analyse s tha t wer e don e a fe wyear s ag o an dtha t wer e updated , actually , i nth e ATSD RReport .

W e shoul ddiscus s th e problem s o f extrapolatin g thos e result s t o poin t source s i nrura l area s an dwhethe r o r

no t i t i s appropriat e t o assum e th e sam e shap e o f th e blood lea ddistributio nbefor e an dafte r th e phase-down .

W e foun dtha t althoug hther e i s a differen t interse t t o th e gasoline/lea drelationship , th e slop e coefficien t i nth e analysi s wa s almos t identica l fo r bot h popula t ions .

W e are usin g test s t o mak e th e distributio no f PSD-directe dpoin t sources , althoug hi t turn s ou t t o b e identica l t o th e analyse s result .

Her e i s som e o f th e dat a tha t w e ar e goin g t o b e addin g t o th e report . Yo uca nse e th e trend s i nai r qualit y

ove r th e las t seve nyear s an dth e dramati c decline s tha t hav e

occurre di nurba narea s i nthes e roadside-oriente dmonitors .

Thi s i s especiall y eviden t lookin g a t th e

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.1 9

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 1 8 microscal e site s whic h^re specificall ydesigne d t o pic k u p hig himpac t lea d emission s frombus yroadways . W e hav e som e mor e recen t dat a o n nationwid e monitorin g tha t work s a s well .

DR . CLARK : Wha t i s th e middl e ther e o n tha t chart ? Wha t i s tha t th e middl e of ?

MR . COHEN : I t i s calle d a middle-scal e sit e an d i t ha s a furthe r setbac k from , a somewha t less-travele d roadwa ytha n wha t th e microscal e monito r pick s up . I amno t sur e o f th e exac t traffic .

Th e neighborhoo d scal e sit e i s a smalle r roadwa y se t bac k a littl e farther . . •

W e go t severa l comment s o n ou r discussio n o f soi l and dus t lea d and th e problem s i n comparin g differen t dat a fromvariou s studies ; also , tha t difference s i n particl e siz e ma yeffec t G I uptak e l f leade d dust .

W e recogniz e thos e problems . On e o f th e thing s w e tr yt o d o i s confin e ou r us e o f dat a t o thos e studie s tha t collecte d th e uppe r laye r o f soil : i n othe r words , tha t laye r tha t childre n ar e mos t expose d to .

Ther e are, o f course , remainin g variation s i n soi l an ddus t level s amon g variou s location s and tha t i s reflecte d i n th e uptak e estimates , especiall yi n th e differenc e o f blood-lea d soi l an d dust-lea d slit s a s talke d abou t i n th e criteri a document ; bu t w e agre e tha t w e shoul d highligh t tha t a littl e bi t more . 

# J EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.2 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 1 9

There ; wa s a questio n o n wh ywa s th e dat a from Silve r Valley , Idaho . Tha t wa s a close d facility . Nevertheless , ther e are dat a i n ther e tha t w e thin k are reall yuseful , especiall yth e soi l an ddus t sli t response s ove r tim e t o negligibl e ai r lead .

We are goin g t o try

t o ad dsome o f tha t dat a a s i t i s available .

A s fa r a s th e soil-lead/blood-lea drelationshi p analyse s tha t CB C presented , w e ar e informe dtha t it i s no t comparabl e t o th e othe r dat a tha t w e site . We hav e aske dCD C fo r furthe r re-analyses .

Ther e wa s a commen t tha t th e Milki e Stud y attribute dto o mucho f the soil-leadin g indowntow nBaltimor e t o automobil e emission s give nth e prevalenc e o f ol dhome s wit hlea

dpain t trim . W e ar e going t o clarif y that . We ar e going t o incorporat e tha t commen t and , also , ad dsome supportin g dat a fro m Chicago .

Thes e next tw

o basicall y

ar e suggestin g tha t we ad dsome supportin g dat a fro m Cincinnat i an

dBosto no

nsoil , o nstree t an

dhous e dust , an

donsoil/blood-lea d relationships : ad dbot hth e Q-HYan dMike' s paper . Ther e wa s a commen t tha t th e Dutc hdat a o f Clause n may b e unrepresentative . I nfact , th e result s are prett y muc hconsisten t wit hth e Binder , et a l finding s fro m Eas t

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.2 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 Helena . On e thing w e di d wa s onl yus e th e Dutc hdata , th e contro l dat a result s fro mth e hospitalize d children . W e though t i t wa s necessar yt o correc t th e Binde r dat a for elementa l absorptio nfro m the die t o f thos e trac e elements . In fact , tha t i s somethin g tha t ha s bee n incorporate d int o th e ongoing Environmenta l Protectio n Agenc y studie s inWashingto nStat e an dthe U-Mass/Amhurs t studie s fro m Calabres e an

dGilbert . W e ar e going t o ad dthos e data . Hopefull y they wil l be availabl e soon .

Ther e wa s a commen t tha t we shoul dreferenc e some o f th e high-soi l lea dproblem s aroundfacilitie s othe r than smelters , variou s manufacturin g facilities . We trie dt o us e al l th e dat a tha t we kne w abou t fromthe literature . If anyon e ha s anything i nthei r files , w

e woul db e gladt o ad

dit . W e needto,clarify , I think , th e distinctio n betwee nstree t dus t an dsoi l dust . Tha t concept , I guess , appeare dinth e criteri a documen t whic hwe referre dto .

We cantry

t o clarif y

tha t a littl e bi t more . We reall y us e tha t inan

y quantitativ e way . Ther e wer e variou s comment s ondietar y lead : one , tha t th e FD

A estimate s o f lea dintak e ar e uncertai nan dcan underestimat e ina lot o f cases . Th e repor t t o Congres s

> EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.2 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 2 1 2 2 2 3 2 4 2 5 2 1 point s ou t a lo t o f thos e problems .

I thin k w e ca n refe r bac k t o tha t discussio n i n th e repor t fo r that ; bu t jus t t o emphasize , th e dietar y estimate s tha t w e us e an d tha t ar e i n tha t repor t t o Congres s reall yrepresen t typica l baselin e levels .

The yar e no t intende d t o captur e th e high-leve l intake s tha t certainl yexist .

On e o f th e thing s w e hop e t o achiev e byusin g th e GS D i s t o captur e tha t variabilit yinexposur e patterns . I thin k we ca n add som e compariso n betwee nth e estimate s tha t w e com e u

p wit hthroug hRobbs ' mode l an dth e ATSDRestimates . They ar e actuall yvery similar . Tha t i s interestin g t o poin t out : they ar e simila r no t onl y

fo r years , but fo

r specifi c age/se xcategories . Ther e wa s a commen t tha t ou r water-lea d projections , base do nOffic e o f Drinking Water' s estimate s fro m thei r Augus t proposal , wer e a littl e optimistic . We agree dabou t th e uncertaint y inthos e projection s resultin g fro m no t onl y

th e propose drevision s t o th e standard , bu t th e recen t solde r ban .

W e ar e jus t no t sur e ho w an y o f tha t i s going t o fal l out . W e fee l that , t o b e conservative , it i s probabl y bette r to maintai nfutur e drinking-wate r level s at curren t concentrations .

W e go t some revise dinpu t fro m OD W t o suppor t ) EXECUTIV E COUR T REPORTER S (301 ) 565-006 4)

•«ati.\. .

• : vV_.;r r 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

,-. that . Mos t o f th e dat a tha t w e cit e o n dietar ylead we;r e base d o n post-197 3 estimates . Mik e pointe d ou t tha t w e shoul d not e th e declin e tha t occurre d befor e 1973 .

DR . MAHAFFEY : I s i t possibl e t o ge t anymor e recen t dat a i n th e las t fewyears ?

MR . COHEN : O n water-lead ? DR . MAHAFFEY : On diet . MR . COHEN : I thin k w e ar e using 1986 . MR . HAINES : 198 5 wa s th e las t tha t relate s t o that . MR . COHEN : 1985 ?

MR . HAINES : I

t i s jus t abou t time t o ge t th e nex t batc havailable . I nfact , w

e wil l probabl y

hav e the

m withi n th e nex t thre e months .

DR . MAHAFFEY : A s I understandfo r th e curren t month' s data , th e number s ar e eve nlower .

MR . HAINES : Ther e ha s bee na definit e trend . MR . COHEN : I f youkno w a way fo r u s t o ge t that , tha t woul db e very helpful . We wil l try t o referenc e tha t pre-197 8 data .

I nfact , tha t kin

do f dat a helpe dvalidat e th e tota l food-leve l criteri a document . S o i t i s a goodpoin t tha t w e shoul dhav e it .

We shoul dnot e tha t lipid s inlactos e may increas e

EXECUTIV E COUR T REPORTER 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 lea d absorption ; an d w e shoul d modif you r statemen t abou t fastin g adults . Thei r absorptio n rat e i s probabl yclose r t o tha t o f children .

I n bot ho f thos e w e wil l mak e thos e changes . DR . MAHAFFEY : Anothe r poin t i n ther e i s tha t I don' t thin k ther e are man ystudie s o n fastin g childre n s o tha t tha t absorptio n rat e coul d b e eve n higher .

MR . COHEN : Yes . W e hav e severa l comment s o n ho wt o improv e ou r discussio n i n pain t lead . Al l o f the mwil l b e incorporated .

Ther e i s a questio n o n whethe r o r no t ther e i s an y mor e recen t housin g data . I don' t kno wo f any . I f anyon e know s o f anything , agai n w e wil l b e happ yt o incorporat e it .

W e are talkin g abou t th e prevalenc e o f lead

painte d home s acros s th e country .

Ther e wa s a genera l agreemen t wit hou r approac ht o exclud e fro mth e analyse s kid s wit hhig hpaint-lea d exposures . Tha t i s a n issu e tha t w e brough t u p wit hth e ful l Committe e i n 1986 . The yendorse d tha t approach .

Althoug hi n thi s repor t w e probabl yshoul d mak e i t clea r tha t w e ar e under-estimatin g potentia l benefit s t o childre nwit hsignifican t lea d exposures , w e di d d o a simplisti c analysi s i n on e o f th e appendice s illustratin g th e potentia l impac t o f pain t lea d relativ e t o thes e othe r exposure s tha t w e ar e talkin g about . W e ca n highligh t tha t

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.2 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 2 4

• u p fron t a littl e bi t more .

W e hav e comment s o n Sectio n V , whic hi s th e sectio n wher e w e tal k abou t th e aggregate/disaggregat e model . T hing s go t a littl e clu t t e r ed .

T o mak e thing s reall y simple , w

e ar e going t o remov e th e tabl e tha t contain s al l th e detaile ddata . W e do want t o keepth e tabl e afte r tha t wher e w e summariz e th e slopes . I t clearl ydistinguishe s th e disaggregat e versu s th e aggregat e slopes .

W e shoul dinclud e dat a o nuncertaintie s associate d wit hth e slope . Thi s i s anothe r commen t tha t Grange r made .

DR . MAHAFFEY : I thin kther e i s a fundamenta l uncertainty , too , o nth e slopes . I thin ktha t virtuall y al l th e dat a o nslope s wa s obtaine dfro m mal e subjects . Sinc e th e populatio ntha t yo uare.ver y concerne d abou t i s pregnan t women , i t i s importan t t o not e tha t thi s i s unknow nandmissin g data .

MR . COHEN : Right . DR . MAHAFFEY : I t i s a majo r problem . MR . COHEN : Goo dpoint . Yes . Ther e wa s a commen t t o compar e th e studie s b y Chamberlain , e t a l an dManto nt o se e ho w thei r bone-lea d resorptio nadjustmen t compares . Alla nha s don e som e wor k recentl y

o nthatd , an dw e ca nincorporat e som e o f thos e results .

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.2 6



### :tm.

) / 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 Bot hpaper s basicall yru n t o s i mila r con e 1u„ion s by differen t methods : basicall ytha t a substantiall yfractio n o f adul t lea d i s du e t o th e releas e o f endogenou s bon e lead . W e wil l addmor e discussio n o n thos e tw o papers : mayb e anythin g els e tha t anyon e ca n identify .

Ther e wa s a questio n abou t th e biokineti c model . Doe s th e fac t tha t th e mode l account s for cumulativ e exposure s mea n tha t th e correlatio n show s a lifetim e averag e blood-lead ? Th e cumulativ e aspec t refers , t o th e long-ter m storag e fro

m prio r exposure . Ne w Yor kUniversit y successfull y

validate dth e mode l agains t autops y data . Age specifi c intake s tha t w e us e are designe dt o allow , o f course , blood-lea destimate s a t any age , though . W e thin ktha t tha t i s on e o f th e mai nadvantages , again , o f th e model : tha t i t ca ncaptur e relativel y short ter m change s i nexposure s compare dt o th e othe r approaches .

Ther e wa s a questio nwher e th e RY Uslop e wa s used . I t wa s use di na coupl e o f places : on e t o illustrate , fo r infants , th e relationshi pbetwee nblood-lea d an duptake . I t i s als o use di nth e criteri a documen t disaggregat e model .

W e als o refe r t o i t agai nwhe nw e tr y t o estimat e th e impac t o f dietar y lea dchange s o nbaselin e blood-lead . Th e slop e o f th e RY Udat a see m t o suppor t that .

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.2 7

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 6 Again , Alla n Marcu s ha s continue d hi s re?analysi s

o f thos e dat a includin g th e ra t data . I wil l tr yt o ad d som e

o f tha t t o th e report .

Ther e i s agreemen t o n ou r approac ht o focu s o n absorbe d lea d dat a t o suppor t ou r absorptio n assumptions . Thes e ar e relcttivel ygoo d compare d t o mos t othe r dat a set s w e hav e t o dea l with .

W e agree d tha t w e shoul d ad d mor e discussio n o n th e importanc e o f th e variou s assumption s u p front .

Ther e wa s a commen t o n th e numbe r o f hour s tha t childre n are estimate d t o spen d outdoors . I t ma yb e misleadin g give n winter/summe r differences , fo r example .

I t i s tru e tha t i n tryin g t o captur e year-'roun d exposure s w e ar e smoothin g ou t seasona l variations . I t woul d b e possibl e t o distinguis hcooler-mont hexposures .

W e woul d presen t thos e blood-lea d estimate s o n a

seasona l basi s a s pea k exposur e levels , fo r example . W e don' t anticipat e tha t the ywoul d b e different , however , fro m th e uppe r boun d estimate s tha t w e generat e now .

Th e en d resul t a t si xyear s o f ag e probabl ywoul d

no t b e muc hdifferent . Th e two-year-ol d blood-lea d certainl y woul db e differen t becaus e o f th e age-dependent . W e ar e lookin g righ t no wt o se e i f th e availabl e dat a ar e sufficien t t o d o som e sensitivit yanalysis .

I f anyon e ha s an yage-specific , seasonal-specifi e

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.2 8

1 2 3 4 5 6 7 8 9 1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 data , i t woul d b e reall yusefu l o n outdoo r behavio r patterns .

Ther « i s a relate d observatio n tha t th e time ? outdoor s a.a.yb e indicativ e no t onl yo f exposur e perio d alone , bu t p 1 a yhabits . I t i s tru e t ha t s&ve r a 1 p a r ame t e r s i n th e mode l ar'B surrogate s t o summariz e mor e comple xvariables .

W e shoul d reall yhighligh t tha t poin t an d som e mor e recen t reference s tha t w e have .

Again , smoothin g o f childhoo d absorptio n rate s ma y b e inappropriate . Th e reaso n w e di d tha t i s tha t w e ha dn o dat a fo r a lo t o f th e ag e groups . W e though t smoothin g wa s th e mos t reasonabl e alternative .

Th e dat a fo r childre n o n tim e spen t outdoor s appear s soft . W e referre d onl yt o a ninforma l parenta l survey . Tha t wa s a n erro r i nou r citations . Actuall y i t come s fro mfou r differen t behaviora l studie s liste d here .

W e trie d t o confir mi t by som e forma l survey . W e shoul dals o not e tha t th e Eas t Helen a Kellog g studie s foun da numbe r o f kid s wh o spen t mor e tha nth e averag e hour s outsid e durin g th e summer .

Ther e wa s a nobservatio ntha t th e predicte dblood lead s ha da les s disperse ddistributio ntha nth e observe d blood-lead s i nth e validatio nexercis e a t Eas t Helena . Again , give nth e availabl e data , w e ar e predictin g averag e exposures . W e compare dthos e tw o distribution s onl y t o

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.2 9



## J 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 illustrat e th e qualit yo f th e consistency . I don' t thin k th e mode l i s eve r givin g t o b e able , unles s w e hav e a Jo t mo ; e data , t o accoun t for al l th e variation s in exposure s an d Ui e source s tha t w e don' t measur e now .

A n importan t poin t i s tha t th e mea n blood-lea d predicte d wa s nearl yidentica l t o th e observe d mea n i n Eas t Helena . Ther e wa s a commen t tha t th e GS T measure d i n Eas t Helen a wa s simila r t o tha t found i nBunke r Hil l Smelter . Tha t i s a nic e thin g for u s t o ad dt o the report . I thinkw e hav e th e appropriat e dat a t o deriv e that .

MR . HAINES : I thinktha t wa s inth e CD C information .

MR . COHEN : Yes . Ther e wer e tw

o comments—again , I thinkGrange r mad e these—tha t ar e related : no indicatio no f th e expecte d accurac y

o f th e inpu t data ; and , ar e w e over-explainin g give n th e inheren t inaccuracies ?

I t wa s difficul t fo r u s t o assig na statistica l uncertaint y

t o th e mode l prediction s give nth e limite ddat a tha t w e hadt o wor kwith . Th e sensitivit y o f th e prediction s ca nb e judge db

y th e lowe r an

duppe r bounds . Some key-mode l parameter s tha t I flashedu p briefl y

befor e wer e adjuste dwithi nth e rang e tha t we fel t plausibl e t o bette r fi t th e observe dlimits . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.3 0

2 9 1 Di d th e validatio n includ e RU NC ? I think , Mike , 2 yo u wer e no t clea r o n that . Actually , RU NC w e though t wa s 3 ou r ultimat e test . I t include d al l th e variables , includin g 4 air , dus t an d soi l relationships , especially , tha t w e hav e t o 5 estimat e whe n w e g o ou t t o d o ou r cas e studies . 6 S o th e answe r is : Yes . Bu t w e probabl yshoul d 7 mak e tha t a littl e mor e clear . 8 Again , w e shoul d clarif yth e discussio n o n ou r us e 9 o f mid-poin t estimate s i n relatio n t o th e lowe r an d uppe r 1 0 boun d estimates . W e fee l tha t th e mid-poin t i s a mor e 1 1 plausibl e an d mor e predictiv e statistic . .. . 1 2 Ther e wa s th e commen t tha t th e finding s fro m Eas t 1 3 Helen a are

consisten t wit hothe r simila r i nDalla s an dBunke r 1 4 Hil l wit hth e mode l prove dwit hmor e discret e exposur e 15 estimates : i n othe r words , lookin g a t block-by-bloc k 1 6 exposure s a s oppose dt o censu s trac kpatterns , fo r example . 1 7 I hop e w e ca nnot e tha t b y referrin g t o som e o f 1 8 th e result s fro m Bunke r Hill . I don' t kno w i f tha t i s 1 9 availabl e yet . 2 0 W e ha ddiscussio no nho w ai r qualit y

interpolatio n 21 procedure s wil l b e used . I nEas t Helena , w e ha da mor e dens e 2 2 monitorin g networ ktha nw e usuall y have . S o w e wer e abl e t o 2 3 compar e interpolate dsmoot hmonitorin gvalue s versu s mode l 2 4 dat a fro m

th e IS E dispersio nmodel , whic ho f cours e i s wha t 2 5 w e ar e limite dt o whe nw e mode l futur e scenarios . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.3 1

3 0 1 I I I t turn s ou t tha t th e result s wer e fai r 3 ysimilar . 2 | | Whe nw e d o ou r ca^s studies , though , w e ar e goin g t o u;; e th e 3 | | IS C dispersio nmodeling . 4 | | Thi s i s somethin g w e talke d abou t earlier . W e 5 | | wil l ad d mor e discussion—hopefull yw e wil l hea r mor e today-

- 6 I I o n ho wth e approache s tha t w e tal k abou t ma yb e applie d t o 7 | | othe r lea d exposur e assessments . 8 W e ar e hearin g a lo t o f interes t fro mothe r 9 programs , no t onl ywithi nth e Agenc ybu t outside , o n usin g 1 0 thes e tool s fo r soil-lead , fo r example , assessments . 1 1 I n Eas t Helena , w e looke d a t are a one , whic hwa s 1 2 withi na mile , an d area two , whic hwa s a littl e farthe r out . 1 3 Ther e appeare d t o b e som e difference s i n th e slope s tha t wer e 1 4 derive d fro mth e model . 1 5 Th e comment s probabl yrelate d t o unmeasure d 1 8 variables : demographi c o r nutritiona l factors , fo r example . 1 7 W e agree d tha t thos e variable s shoul d b e considered . 1 8 On e findin g i n Eas t Helen a wa s tha t ther e wa s n o 1 9 significan t improvemen t i n predictin g blood-lea d afte r 2 0 includin g dietar yhabit s an d income , fo r example . Tha t wa s 21 attribute dt o th e lo wprevalenc e o f detectabl e lea d pain t 2 2 there , an dth e relativ e homogeneit yi n housin g qualit yan d 2 3 socia l status . 2 4 Tha t i s anothe r reaso nwh yEas t Helen a represente d 2 5 a goo d validatio n case . I thin k simila r result s wer e foun d

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.3 2

_£&. , •



## y 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 3 1 i n Bunke r H i 1 1 .

In othe r areas , thes e factor s are potentiall yver y powe r determinate s o f blood-lead ; bu t w e stre no t goin g t o hav e th e dat a tha t i s necessar yt o incorporat e that . Tha t i s on e o f th e reason s wh yw e ar<s usin g the geometri c standar d deviation , for example , t o estimat e th e complet e distributio n o f blood-leads .

W e jus t can' t captur e al l th e variabilit y wit hth e modelin g tha t i s availabl e at thi s time .

Ther e i s a littl e confusion, , probably , abou t ou r baselin e blood-lea dprojectio ninth e aggregat e model . _If . extrapolated , tha t leve l woul dsugges t onl y 20,00 0 kid s woul d hav e blood-lead s abov e 1 0 in199 0 versu s ove r five times " tha t no w jus t living ininne r cit y area s inth e ATSDRReport . I gues s w

e needt o emphasiz e o r be clea r tha t the baselin e blood-lea dproject s represen t rura l non-ai r exposur e wit hminima l pain t lead .

DR . MUSHAK : Th e poin t of th e commen t I mad e ther e wa s th e fac t tha t par t o f it give s yo usome ide a o f ho w muc h o f a populatio no f childre nyo uar e going t o do somethin g for . MR . COHEN : Right .

DR . MUSHAK : Wha t siz e o f populatio nyo uar e not . MR . COHEN : Yes . We probabl y shoul dad

dthat . DR . MUSHAK : I f yo uworkthroug hth e thing a s I

EXECUTIV E COUR T REPORTER S (301 ) 565-006 41 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 25

; gav ei t t o you , yo ufin dtha t one-sevent ho f

al lth echildre n a r egoin g t

o h i av eb 1 o o d- 1 ead1 ev e1 s p r o b abl y ab o v e1 0

mi crograms . A l lo f thes e1ow-SE S inne r cit y children , stil li n 1990 , Iwoul dimagine , woul dhav eblood-lead s nea r 1 0 o r above

. MR

. COHEN : Yes

.

DR . MUSHAK: : S o th e fac t i s tha t tha t yo u eithe r choos e t o writ e the mof f complet e and say, "Tha t i s HUD' s problem " or "Tha t i s som e hybri dproble m o f HUD, " o

r yo utry t o loo k a t a separat e scenari o for the man dsa y tha t eve na smal l amoun t o f air-lea d adjustmen t wil l hel pthem .

MR . COHEN : Yes . Th e othe r thing tha t probabl y woul dhel pis , whe n w e add th e prevalenc e o f childre nliving i n th e vicinit yo f thes e sources, —

DR . MUSHAK : We talke dlas t nigh t abou t th e fac t tha t man

y point s source s are inurbanarea s whic hmultipl y impac t thes e same children .

MR . COHEN : Yes . DR . MUSHAK : Youar e onl y goin g t o catc ha par t o f it . MR . COHEN : Right .

O nHispani c children , w e woul dlov e t o hav e tha t data . We wer e no t abl e t o ge t th e summary dat a s o far . We hav e bee ntrying fo r a coupl e o f years . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.3 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 Joe l Schwart z ha s bee n able ? t o ge t a lo t o f th e thing s o n that . I don' t kno wwhy .

DR . MUSHAK : Le t m e interjec t ou r experience . W e trie d t o ge t Hispani c dat a fo r a repor t t o Congress . Th e super-perfectionist s a t Nationa l Cente r fo r Healt hStatistic s wer e unhapp ywit hho wth e dat a wa s avai 1 able . Plus , I believe , ther e wa s som e unfortunat e earl y politica l capita l tha t wa s mad e o f tha t dat a bas e earlier . S o the yar e ver yants yabou t th e qualit yo f that .

MR . COHEN : Yes . ; • . DR . RABINOWITZ : S o becaus e th e qualit yo f th e dat a ma yno t b e goo d enough , i t ma yno t b e availabl e a t all ?

DR . MUSHAK : Tha t i s thei r version . I amgettin g informatio n secon d hand . W e hav e no t see n th e run .

Tha t ha s bee n ou r experience , too , i n this . MR . COHEN : Ther e wa s th e commen t tha t olde r population s ma yno t experienc e th e projecte d decline s tha t w e ar e predictin g becaus e o f thei r hig hhistorica l exposures .

W e reall ynee d t o emphasiz e tha t poin t u p front , althoug hth e on e opportunit ywe have , really , t o mak e tha t adjustmen t i s usin g th e bone-lea d resorptio n adjustmen t fro m Chamberlain ; bu t w e wil l add som e mor e discussio n o n that .

DR . MUSHAK : I amno t sur e Chamberlai n doe s th e osteopo r o t i c women, — EXECUTIV E COUR T REPORTER S (301 ) 565-006 41 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 MR . COHEN : No , h e doe s not .

DR . MUSHAK : —whic hwoul d b e a multipl e of , like , 2 o r 2-1/2 .

DR . MAHAFFEY : I thin k yo u reall yhav e t o mak e tha t poin t strongly . I di d no t g o bac k t o Chamberlai n o f 1983 , bu t I reall ydon' t believ e tha t ther e i s tha t muc hdat a o n th e t op i c .

I amconcerne d tha t w e are gettin g th e typ e o f mode l validatio n i n her e tha t doe s no t dea l wit hth e fac t tha t ther e i s a lo t o f biological/physiologica l dat a tha t ar e absolutel ymissing . ., .

DR . MUSHAK : Chamberlain' s stil l inth e 1. 3 factor . Didn' t tha t stil l relat e bac kt o th e isotopic ? In othe r words , hal f wen t t o th e bon e an dthe no f tha t hal f came out : 2 5 percent .

MR . COHEN : Yes . Tha t wa s th e trace . DR . MUSHAK : So tha t i s no t eve ngoodfo r us . Tha t i s stil l a short-ter m bon e resorptio nresponse . MR . COHEN : Yes . DR . MARCUS : Ther e wa s some mor e recen t wor ktha t Chamberlai ndi dinth e 198 5 paper . I t wa s a synthesi s o f dat a fro

m a variet y

o f differen t sources : a compartmenta l kinetic-typ e model .

I t stil l came u

pwit hanestimat e o f 20-some percen t fo

r afte r some 5 0 year s o f exposure , pumping th e lea d

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.3 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 

### int o th ebone

.

DR . MUSHAK : Manton' s dat a i s probabl yth e bes t fo r it , woul d yo u say ?

DR . MARCUS : Manton' s dat a i s extremel ysuggestiv e o f th e importanc e o f thi s froma quantitativ e poin t o f view .

Manto n ha d t o mak e som e assumption s abou t th e contribution s fromconcurrent , exposures .

DR . MUSHAK : A s di d anymodelin g use d b y Chambe r 1ain .

DR . MARCUS : Well , Chamberlai n ha d t o mak e a differen t se t o f assumptions . I woul d saytha t eithe r valu e ha s sor t o f bee n cas t i n marble ; bu t the yar e bot hreasonabl y i n concor d tha t a substantia l fraction , certainl yupward s o f 2 0 percen t i n adul t male s wh o hav e ha d substantia l historica l exposur e t o lead , ha s create d a bon e poo l o r bon e reservoi r o f lea d tha t i s goin g t o b e comin g bac k out , and wil l b e detectabl e i n blood-lead .

DR . RABINOWITZ : Anothe r se t o f dat a tha t coul d bea r o n thi s i s fromoccupationally-expose d peopl e wh o hav e muc hhighe r blood-lead s and muc hhighe r bon e stores , and watchin g th e ver yslo wrat e i n declin e o f blood-lea d i n tha t population . It speak s a littl e bi t abou t ho wavailabl e bone

lea d i s fo r late r blood-lea d elevations . I don' t kno who w applicabl e i t i s becaus e the yma yb e kind o f pathologica l

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.3 7

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 3 6 case s i n tha t thei r bone-lead s ars so.high . I don' t kno wi f yo uwan t t o us e tha t t o addres s th e genera l population .

But i t say s somethin g abou t rates , anyhow . DR . MARCUS : Yes . The yhav e a long-ter mhalf-lif e i n bloo d fromlead resorptio n i n th e bon e o f 5-point

something . MR . COHEN : W e als o looke d a t th e Silve r Valle y studya littl e mor e superficiall ytha n Eas t Helena , bu t the contro l area s ther e di dnot hav e measure dair-lea dlevel s an d we wil l not e that .

W e got comment s o

nou r estimate drelationships , betwee nair , soi l an ddust . I

t i s difficul t to quantif y tempora l change s insoi l an ddust , especiall y insome sites : fo r example , highly-contaminate darea s wher e curren t air-lea d effect s are neglible , inclose dfacilities ; o r clea narea s wher e soi l dus t accumulation s ma y be non-linear . Thenwe usedal l th e availabl e dat a fro m a wid e variet y

o f poin t sourc e area s tha t reporte dquality-assur e protocols . Base do nth e limite dlongitudina l data , we hav e 2 1 Dsome assuranc e tha t th e relationship s are , ingenera l 2 2 2 3 2 4 2 5 plausible . Th e uncertainties , however , regardin g th e tempora l pattern s o f soi l an ddus t change s ar e th e reason s tha t w e decide dt o us e tw o differen t assumptions : one , wher e w e kee p

EXECUTIV E COUR T REPORTER S (301 ) 565-006 41 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 soil-lea d constan t ove r time ; an d th e othe r wher e w e var y soil-lea d wit ha i r - 1 _ • a d . Whe n w e tal k abou t th e cas e stud yresults , yo u wil l se e ho wdifferen t th e blood-lea d estimate s are unde r t ho s e tw o a s s u mp t i . o n s . Th e non-linea r relationship s tha t w e looke d a t fo r th e dat a set s tha t w e examine d wer e no t an ybette r tha n th e linea r model s tha t wer e used .

Yes , th e soi l an d dus t equation s d o includ e historica l deposit s o f lea d fro mprio r deposition . "Ar e th e equation s i n Appendi xB intende d t o b e use d recursively?. " . Th e answe r i s no , simply .

Equatio n 3. 3 fo r dust-lea d i s intende d t o b e use d i f onl yair-lea d i s available ; and 3. 2 shoul d b e use d fo r dus t i f bot hair-lea d and soil-lea d are available ; and w e wil l add discussio n o n that .

Ther e wa s a questio n abou t ou r discussio n i n 7.7 : whethe r o r no t tha t implie s tha t th e air-qualit ystandar d shoul d b e establishe d fo r certai n incorporate d soil

- and dust-lea d level s o r tha t soi l shoul d b e reduce d t o a particula r level .

Tha t i s a n interestin g polic yissu e tha t we migh t wan t t o tal k abou t later ; but , analytically , ou r inten t wa s t o accoun t fo r al l pathways , includin g elevate dsoi l an d dust , tha t alread yexis t aroun d poin t sources . EXECUTIV E COUR T REPORTER S (301 ) 565-006 41 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 Th e relationship s wer e derive d fromarea s excludin g thos e close d facilitie s tha t w e talke d about : n o negligibl e air-lead , bu t highly-contaminate d soi l and dust .

Similarly , th e air/blood-lea d slope s tha t w e ha d fromchildre n are

derive d fromoperatin g poin t sources . Ther e wa s a questio n i n air-lea d monitoring : whethe r or

no t w e pla n o n rearrangin g ou r monitorin g networ k awa yfrom

mobil e source s and focu s o n stationar ysources . Th e answe r t o tha t is : Yes .

Tha t i s something tha t w e wil l discus s whe nwe actuall y

propos e th e standard ; but clearl y ther e i s a needt o d o that . Ther e wa s a discussio no nth e heigh t o f monitor s a s it relate s t o the breathin g heigh t o f children . I t i s importan t tha t we shoul dnot e thi s inth e report : tha t anyo f th e dat a ar e fromroof-top , real-worl dmonitors . It i s no t availabl e t o ge t personalize dmonitorin g fo r children . We canad

dfurthe r reference s fro m th e criteri a documen t o

nth e vertica l gradients , but mos t o f tha t dat a i s fro m mobile-sourc e situations .

Tha t i s abou t it fo r ou r summary

o nth e comments . Th e nex t ste pfo

r u s i s t o finaliz e th e exposur e repor t b y incorporatin g th e comments .

Tha t will , inturn , become a sourc e fo r th e staf f pape r case-study

analyse s tha t we wil l ge t int o inearl y J' EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.4 0

1 1939 ; an d als o wil l becom e a referenc e fo r th e regulator y 2 impac t analysis , a s wel l a s othe r regulator yanalyse s bot h 3 insid e an d outsid e th e Environmenta l Protectio n Agency . 4 Hopefully , w e wil l hav e tim e t o discus s thos e 5 othe r analyse s a t th e en d o f th e day . 6 Than k yo u fo r bearin g wit hu s here . 7 CHAIRMA NLARSON : Than k you , Jeff . 8 W e hav e no t ha d a lo t o f bac k an dfort h 9 discussion . S o w e see mt o b e breezin g righ t alon g here . 1 0 Perhap s w e ca ntak e th e tim e a t thi s poin t t o as k 1 1 fo r genera l discussion . 1 2 MR . FLAAK : W e ar e runnin g a littl e ahea do f 1 3 schedule . 1 4 CHAIRMA N LARSON : Let' s hav e th e publi c comment s 1 5 now . Gale , are yo u prepared ? 1 6 MR . HOFFNAGLE : I t i s a littl e early , bu t w e ca n 1 7 tal kabou t ou r comments . 1 8 CHAIRMA N LARSON : Al l right . Woul dyou , please ? 1 9 P_}_>Ii £££_M__:Q_;_? i Gal e HoJ.fnagie.,

. JR C Environmenta l 2 0 £2D5_}I_;_}0_; 3 21 MR . HOFFNAGLE : I a m Gal e Hoffnagl e fro m TR C 2 2 Environmenta l Consultants . I represen t th e Lea dIndustrie s 2 3 Association . 2 4 W e hav e prepare da se t o f comment s abou t th e 2 5 exposur e assessmen t methodology . W e hav e bee nworkin g wit h

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.4 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 4 0 Jef f Cohe n an

d John Haine s sinc e th e las t CASA C meeting . W e reviewe d th e staf f pape r an d provide d wha t dat a w e could , an

d analysi s tha t w e coul d t o b e helpfu l t o the

process . W e hav e take n a loo k a t thi s document . I a msorr y I di d no t us e th e invitatio n t o ge t comment s i n b ySeptembe r 9 , bu t w e ar e a littl e behin d th e eigh t bal l here .

In recognitio n o f you r desir e t o hav e th e publi c comment s b e differen t tha n wha t i s i n th e writte n text , I thin k ther e ar e reall yonl ytw o majo r difference s w e hav e wit hth e exposur e assessmen t methodolog ya t thi s point.* * I woul d lik e t o highligh t those .

W e agre e generall ywit hth e assessmen t methodology . W e fee l tha t i t goe s a lon g wa ytowar d overcomin g som e o f th e objection s tha t w e ha d before , and tha t i t include s a lo t bette r se t o f dat a and mor e realisti c conclusion s directe d a t source s rathe r tha n a lo t mor e generalize d problem .

W e als o agre e wit hJeff' s statement , an d th e conclusio n her e basically , tha t th e uptak e biokineti c mode l i s th e righ t wa ya t thi s poin t t o g o afte r th e problem : tha t i t offer s som e rea l advantage s i n term s o f dividin g ou t amon g th e sourc e categorie s wher e th e problem s lies ; tha t i s i t no t availabl e i n th e aggregat e o r th e disaggregat e model .

Ou r concer n ha s bee n primaril yi n tw o areas : thos e

" > EXECUTIV E COUR T REPORTER S (301 ) 565-006 41

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 2 2 3 2 4 2 5 4 1 ar e inth e actua l relationshi p betwee n air-lead , and soil

an ddust-leadtha t ha s bee n generate d here .

I a mconcerne d abou t i t fromth e poin t o f vie wo f th e selectio n afterwards , afte r th e fact , o f th e dat a tha t i s inTabl e A-3 , th e Appendi xtabl e whic hlist s al l kind s of set s o f data , rathe r tha n goin g ahea d and usin g th e Eas t Helen a results .

I thin k yo u develope d a relationshi pat Eas t Helen a tha t i s correc t an dit i s accurate . I t use s a large r dat a se t t o develo ptha t relationship .

S o we woul dpropos e tha t youdo that . ± . I hav e prepare dt o plot s her e that , I think , hel p u s focus—yo uhav e copie s o f them—o nth e issue . I hav e take nthe Tabl e A- 3 data , whic hrepresen t al l th e set s o f dat a tha t coul db e lookedat , an dlookedat individua l point s o nth e Tabl e A- 3 data .

I hav e take nout o f tha t th e one s tha t were-agree d t o inthe paper , an dwe ha

dagree dtha t thos e shoul db e take n out ; but I hav e als o take nout th e one s tha t ar e no t point sourc e related . S o al l w e hav e lef t i s th e point-source relate dones .

I too kout th e one s fro m Bartlett , th e fiv e smal l

t copper-smelte r typ e facilities . Al l o f thos e air-lea d concentration s ar e lo w s o I don' t thinkthe y ad dmuc ht o th e slope . EXECUTIV E COUR T REPORTER S (301 ) 565-006 41 2 3 4 S 6 7 8 9 1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 4 2

Bu t i n thei r paper , the ycoul d no t fin d any relationshi p betwee n th e air

- an d soil-lead s a t al1 . I f the y .canno t fin

d i t i n th e pape r itself , i t i s har d t o us e i t i n an extrapolatio n lik e this .

Her e i s our air-lead/soi1-lea d versu s air

lead/soi1-lea d concentratio n basicall yi n thousand s o f microgram s pe r gramppmversu s ambien t ai r concentrations .

W e hav e a rang e from2 t o 4 . I don' t thin k tha t

w e shoul d concer n ourselve s wit hth e concentration s tha t are greate r tha n 4 , let' s say . S o I remove dth e one s tha t are high ; and , also , th e soi 1-lea dconcentration s tha t ar e rea l high . I thin k thes e represen t differen t kind s o f c i r c umst an e es .

Thes e ar e th e differen t dat a set s fo r poin t sources . Wha t i s interestin g abou t the m i s th e Toront o dat a andth e Brussel s data . Thi s i s a nOmah a dat a point , thi s i s anothe r Toront o dat a point , bu t al l th e one s tha t ar e u pher e o nto prepresen t urba npoint-sourc e situations : Toront o an d Brussels . Th e one s tha t ar e o nth e botto m represen t rurals , i nessence . Thi s lin e i s th e lin e o f blood-lead/soi1-lea do f 1 5 time s 57 9 air-lea dtha t wa s use di nTabl e 4- 1 an dused , finally , i nth e analysis ; an dthi s lin e i s th e lin e from Eas t Helena . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.4 4

1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 16 1 7 1 8 19 2 0 21 R 2 2 2 3 2 4 2 5 I f I understan d i t correctly , Jeff , th e lin e fro m Eas t Helen a include s a lo t mor e dat a point s tha n th e dat a point s tha t wer e o n Tabl e A-3 . Ther e are som e Eas t Helen a dat a point s here—thi s one , thi s one , thi s one , thi s one , and thi s one—bu t thos e are differen t dat a point s tha n th e on e yo u use d t o develo p thi s lin e o r thi s slope .

MR . COHEN : Tha t i s right . Th e summar ydat a tha t w e use d fro mth e literature , though , i s home-specific . So , i n fact , the yd o includ e mor e home s tha n i s reflected . Th e individua l dat a point s fro mth e differen t studie s represen t a larg e numbe r o f homes .

MR . HOFFNAGLE : Alarg e numbe r o f averag e set s o f homes , right ?

MR . COHEN : Yes . MR . HOFFNAGLE : M ypoin t i s tha t th e slop e o f thi s lin e from

Eas t Helen a i s derive d differentl ytha n jus t thes e fiv e points . S o i f yo u trie d t o dra wa lin e throug hth e Eas t Helen a point s up here , yo u woul d no t ge t thi s one .

W e hav e a tendenc yt o believ e tha t mos t o f th e situation s tha t we ough t t o b e talkin g about , rural-are a situation s wher e we don' t hav e automotive-lea d inpu t o r paint-lea dinpu t and s o forth , ough t t o conside r thi s Eas t Helen a line : tha t i t i s bette r fo r them . I also dotte dinth e rang e o f value s tha t i s use d ono Tabl e A- 4 byplottin g the min . Wha t I don' t know , and ) EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.4 5



# J 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 4 4 wha t I woul dlik e t o ask , is : Ho wwer e th e rarige o f value s se t fo r soi l an

d for househol d dust ? On Tabl e 4- 1 yo u hav e a. range , bu t I don' t understan d fromth e documen t ho wth e rang e wa s developed .

MR . COHEN : In Tabl e A-4 . MR . HOFFNAGLE : Tabl e 4- 1 ha s a range . Appendi xA give s u s a mea n valu e and a slope , bu t I don' t kno who wth e rang e wa s developed .

Table . A- 4 ha s a rang e o f soi l dus t an dhousehol d dust . MR . COHEN : No t Tabl e 4 .

MR . HOFFNAGLE : 4-1 . CPause D MR . COHEN : Lin e 12 ? MR . HOFFNAGLE : Yes . Line s 1 2 an d13 . I don' t kno w ho w thos e range s wer e developed . I nth e staf f paper , we kne w becaus e i t came fro m a tabl e inth e Appendix , ho w th e range s wer e developed . DR . MARCUS : I wil l hav e t o g o bac kan dverif y this , bu t I thinkthes e range s represen t th e 9 5 percen t confidenc e interval s tha t wer e derive dfro m that . MR . HOFFNAGLE : Okay . That' s fine . I norde r t o reproduc e i t fo r thi s slope , whic hyo u hav e no t done , I woul dlik e t o reproduc e th e rang e fo r th e Eas t Helen a slope . I di dno t hav e th e methodology , but it i s

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.4 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 4 5 9 5 percen t confidenc e s o I wil l hav e t o hav e th e data , too .

I t i . s ' importan t bs:HUh r th e rang e o f value s tha t resul t o n Tabl e A-4-- 1 ar e a substantiall ylarge r tota l range , althoug hsomewha t shifte d down , fromthos e i n th e OAQP S staf f pape r from

tw o year s ago . Th e range s ar e larger' . Fo r instance, , a t 1. 5 microgram s pe r cubi c meter , th e highes t valu e tha t appear s o n th e tabl e i s substantiall y large r tha n th e highes t valu e tha t appeare d i n th e origina l OAQP S staf f paper .

S o i f on e i s t o loo k a t th e t op o f th e rang e and mad e one' s decision s o n th e to p o f th e range , i t give s yo u a lo t highe r numbe r tha n i f yo u ar e jus t lookin g a t th e mean . I woul d suggest—an d I thin k th e suggestio n wa s mad e before — tha t yo u pu t th e mea n valu e i n thi s tabl e s o peopl e ca n loo k a t it , and the n th e range s and standar d deviations .

MR . COHEN : Yes , w e shoul d mak e tha t a littl e mor e clear . Again , th e equation s i n A- 4 ar e th e one s tha t w e inten d t o us e wit hth e cas e study .

MR . HOFFNAGLE : Fro mth e Eas t Helen a data ? MR . COHEN : W e ar e proposin g t o us e wha t w e cal l th e SPTA , jus t th e point-sourc e dat a and include , a s yo u did , al l th e urban-specifi c data .

MR . HOFFNAGLE : I gues s m ypoin t wil l b e com e mor e clea r whe n yo u loo k a t th e secon d figure , whic hi s th e

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.4 7

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 househol d dus t figure , t o say tha t w e 'thin

k th e Eas t Helen a data- —whic hyo u spen t a lo t o f tim e developin g and generating—i s a bette r dat a se t t o use .

Thi s i s househol d dus t versu s air-lead . Her e i s th e on e yo u picked . Her e i s th e Eas t Helen a on e which , again , wa s derive d from , a differen t se t o f data , o r i n a differen t methodology , tha n th e point s tha t are o n thi s c u r v e o n thi s line .

A s yo u ca n see , it goe s substantiall y ove r a

t leas t th e dat a set s tha t I picke dfrom,Tabl e A fo r yo ut o lookat ; and th e meanan drang e i s substantiall y higher ; -tha

n th e bul k o f value s tha t I hav e considere d fo r using th e data . Thi s dat a poin t fro m El Paso , whic hi s hardl y th e mos t accurat e dat a se t tha t w e kno w abou t and , I think , i s doubtful , I thinkweight s thi s distributio ni f tha t i s wha t ha s happened ; an

dI a m no t sur e tha t tha t i s wha t happened . MR . COHEN : We trie dt o thro w out thi s -outline . We trie dt o discus s it inth e paper , I though t we did . We wil l g o bac kan

dtak e a looka

t that . MR . HOFFNAGLE : Okay . Pleas e tak e a lookat this . I think , looking a t it thi s way , I a m concerne d abou t it . Wha t concern s me , o f course , i s tha t thes e househol ddust-lea dnumber s d o driv e th e fina l answer . I n othe r words , th e househol ddust , becaus e th e childre nar e insid e mor e tha nthey ar e outside , doe s ten dto driv e tha t

EXECUTIV E COUR T REPORTER S (301 ) 565-005 41 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 20 2 1 22 2 3 2 4 2 5 4 7 fina l answe r quit e substantially .

MR . HAINES : I f I follo wyou r argument , ar e w e focusin g i n o n a rura l situation ? Kee p i n mind , w e have ? t o be: : concerne d no t onl ywit hprimar ysmelter s locate d i n rura l setting s suc ha s i n Eas t Helena , bu t w e als o hav e t o worr y abou t stationar ysources , secondar ysmelter s oriente di n urba n areas .

I a m no t quit e sur e i n m yown mind tha t w e ca n exclud e point-sourc e urba n dat a fromth e analysi s a s yo uar e suggestin g her e an d focu s onl y

o nEast,Helen a becaus e I a m no t sur e tha t Eas t Helen a i s representativ e o f thes e othe r settings . MR . HOFFNAGLE : I agre e wit hthat ; but i f yo uar e going t o d o a separat e mode l fo r th e urba narea , the nyou nee d t o includ e th e othe r source s o f leadintha t urba narea . Yo u needt o b e muchmor e specifi c abou t it .

MR . HAINES : Ar e yousuggesting , then , Gale , tha t fo r a rural-oriente dsource , w e us e Eas t Helen a fo r cas e studies , the nus e th e tota l dat a se t o r segregat e out th e rura l an

donl y us e urbanpoint-sourc e dat a o r mor e urba n locations ? MR . HOFFNAGLE : I a m sayin g tha t the y ar e very differen t dat a set s an dit migh t b e mor e usefu l t o loo kat a n urba ndat a se t tha t wa s mor e convincing .

I lik e t o lookat a cas e study lik e yo uhav e don e 

# Y EXECUTIVE COUR T REPORTER S (301 ) 565-006 4P.4 9

•"•r5__.

-

:->7W . 

# y 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 at Eas t Helen a an d g o throug hi t and understan d i t completely . Rathe r tha n usin g th e STP Adat a set , i f yo u took , for instance , th e Toront o dat a set , whic hI thin k i s prett ygood , and looke d a t Toront o specifically—yo u develope d an urba n mode l fo r Toront o a s compare d t o the ; rura l mode l fo r Eas t Helena— I thin k tha t woul d giv e u s mor e informatio n tha n th e STP Adat a set .

MR . COHEN : Actually , Gale , on e thin g tha t probabl ywa s no t clea r whe n w e di d deriv e th e air/soi1/dus t relationship s i n Appendi xC , w e exclude dthos e dat a tha t wer e no t collecte d aroun d poin t source s inurba narea . {.

I thin k th e dat a set s tha t we looke dat wer e prett y simila r t o th e one s w e hav e here . Yo uexclude dth e Bartesville , Oklahoma : tha t suit e o f data .

MR . HOFFNAGLE : Right , but al l o f tha t dat a i s righ t down i n here , along thi s line .

MR . COHEN : Right . MR . HOFFNAGLE : I thinkit wa s clea r inth e documen t tha t yo uthrew out five set s o f data . I wen t bac k throug hm

y Tabl e A- 3 an

dput a

n"X " nex t t o th e one s tha t yo u sai dyo uthrew

out . Di dyo ueliminat e othe r dat a set s fro m tha t tabl e befor e yo udi dth e progressions ?

MR . COHEN : Yes . MR . HOFFNAGLE : We nee dt o kno w that . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.5 0



# ,_ J 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 MR . COHEN : Thos e dat a wer e th e one s tha t wer e jus t urbandata . I though t w e talke d abou t al l o f the m i n ou r discussio n afte r Tabl e A-3 , bu t I don' t thin k w e go t al l o f them , lik e the ? Janso n table , for example , whic hwa s collecte d i n Chicago .

MR . HOFFNAGLE : Okay . MR . COHEN : S o al l thes e wer e th e point-source

specifi c data . W e di dgroup primary lea d smelter s wit h secondary

lea dsmelter s an

dbattery

plants . MR . HOFFNAGLE : Okay . DR . RABINOWITZ : Coul dI as ka question ? : . MR . COHEN : Sure . DR . RABINOWITZ : I a m no t evensur e t o as kthi s of , bu t intrying t o ge t thi s relationshi pbetwee nsoil-lea d an dair-lead , I hav e a bi t o f troubl e understandin g it becaus e I imagin e air-lea dgoe s u pan ddown , mayb e hourl y o r dail y o r seasonally , wher e soil-leads , I imagine , jus t accumulat e wit htime fro m fall-ou t an

dsuch . S o I a m kin do f doubtfu l o f th e exercis e o f relatin g th e tw

o jus t becaus e o f th e mechanism , I imagine . I a m wondering : Ha s anyon e trie drelatin g soil leadan

dair-lea dwher e yo ulooka t th e integrat e air-lea din some way ? Say , "Okay . We hav e hadthi s air-lea dfo r ten decades . W e hav e hadthi s air-lea dfo r two years. " Mayb e thi s migh t explai nwh y thing s ar e no t al l o n 

# J EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.5 1

-.ty--

. 'JziJb: r<-sU--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 24 2 5 a perfec ts tra i • - h t1 i n e . MR . HOFFNAGLE : Jef f an d I bot hhav e fa*en lookin g fo r a yea r and a hal f or tw o years, a s wel l a s others , t o fin d an appropriat e dat a se t t o d o tha t with .

I thin k w e al l understand—an d I liste d ir i m y comment s there—th e complexitie s tha t ar e involved . .I n fact , I amvery

concerne d abou t thi s complexity , especiall yth e tempora l changes .

W e kno wi n th e tempora l proces s th e depositio n occur s ove r a lon g periodo f tim

e inthe soil : it build s up . What , exactly , ar e those ?

Wha t i s don e her e i s t o try t o giv e u s a quic k methodology , a simplifie dmethodology withou t th e time - dependenc y

t o mak e a relationship . It i s very empirical . Tha t i s wha t ha s happened . We hav e don e the bes t w e can . I thinkther e ar e lot s o f complexitie s t o it . Ther e are

lot s o f reason s wh y w e ma y b e creatin g a problem , wh y we ma y b e inappropriatel y effectiv e at on e locationo r anothe r becaus e o f th e empiricis m tha t we ar e developin g here . I thinkgenerall y we woul dlik e to hav e mor e data . I believ e mor e dat a i s coming .

We ar e stil l trying t o obtai nth e dat a fro m For t Peary inAustrali a wher e they hav e don e a larg e stud y ove r a

> EXECUTIVE COUR T REPORTER S (301 ) 565-006 4P.5 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 2 1 2 2 2 3 2 4 2 5 lon g perio d o f tim e and w e mayb e abl e t o ge t som e mor e information .

Bu t t o sayt hi s i s an i ns t an t aneou s r e l at i o n sh i p i s wrong . I t i s a lo t more ? complex .

DR . MARCUS : I woul d lik e t o add a fewcomment s o n t hi s r e 1 a t io n sh i p .

I t i s com

p 1 ex . Som e o f tiie i n f o r mat i o n w e wo u 1 d hav e like d t o hav e provide d wa s lef t out , otherwis e w e woul d hav e ha d a documen t four time s longe r tha n i t i s now .

Ther e wa s som e discussio n there , a searc hfo r a n underlyin g theory , i n whic hw e pointe d ou t tha t th e relationshi p betwee n air-lea d concentration s and surface-soi l and dus t concentration s depend s als o o n th e amoun t o f non leade d particulat e i n th e air ; and eve n i f yo u ha d exactl y th e sam e concentratio n o f leade d particulate s i n th e ai r i n on e location , bu t th e amoun t o f non-leade d particulate s tha t wa s fallin g ou t wa s large r i n on e locatio n tha n anothe r one , yo u woul d hav e a lowe r surface-soi l concentration .

I don' t sugges t addin g unleade d dir t t o th e ai r s o a s t o dilut e th e soil-lea d concentration ; bu t tha t i s on e o f th e concerns .

S o a completel ygenera l universa l relationshi p i s obviousl yno t on e w e ar e lookin g for .

Fo r technica l reasons , th e Eas t Helen a slop e ma y b e eventuall yles s relevan t becaus e o f wha t coul d b e calle d a EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.5 3

1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 14 15 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 measure.'me?n t

erro r o r errors-in-?variable s proble mi nfittin g regressio noiOciti

O s ; tha t

is , th eair-lea dmeasuremen t fo r eac h househol dor

for ' eac hbloc k

tha t wa s tie dt o asoil

- o r dust

- iest ! (iiecsu r

emen t i nEas t

Helen aa t

aparticula r

location

. Eve nthoug hthe ? networ k o f monitor s i nEas t Helen a wa s mor edens etha nir i an y othe r location—whic hi s on eo f t h ereason s w eselecte dthi s fo r avalidatio nstudy—th eair

- lea dmeasurement s coul dhardl y b esai dt o b es o dens ea s t o provid eaverycomplet eimputatio no f a nair-lea dfo reac h bloc k i nEas t

Helena

. Ther ejus t wer eno ttha tmany monitors

. , . .

I nfittin gthos erelationships , Ihav eaconcer n tha tth eair-lea dvariable , th einpu to rpredicto ro r regresso r

variabl ei nthos erelationships , ha daconsiderabl e amoun to f

uncertaint y i nit . I ti s knowntha tth etechnica l effec to f a n uncertaint yan dimputatio ni s t o attenuat eo rflatte nth e regressio nslopes .

Ther ear eabou tathousan darticle s o nthi s regressio nattenuatio neffect . I tha s also , Ibelieve , bee n discusse db yBrumkreat h an dhi s author s i nth eAm.e_.L_._t_ . jjojarrja l o ! Epidemiolog y i n1987 .

W ebelieve , fo rth eEas tHelen adat aset , i ti s probabl yanot-trivia l facto ri nreducin gth eestimate d slope .

> EXECUTIV E COUR T REPORTER S (301 ) 565-006 41 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 . —-. j : • : i- . Th e mea n value s tha t wer e use d i n th e 40-od c dat a point s ar e including , o f course- , a rang e o f locations . I t i s th e usua l concer n abou t havin g on e or tw o air-lea d monitor s representin g a rtKiio n or metropolita n area . Wha t yo u hav e o n th e othe r sid e o f tha t i s an aggregat e measur e o f soi l or dus t congregation , whic hi s an average . In term s o f th e amoun t o f proportionat e amoun t o f uncertaint yi n thos e numbers , takin g int o accoun t th e fac t tha t ther e are

a lo t o f reason s wh

y ther e shoul db e difference s i

nthos e ratio s fro m on e locationt o anothe r w e believ e tha t thos e probabl y provid e a mor e vali drelationshi p wit hth e uncertaintie s ther e primaril y representin g difference s fro

m on e urbano

r rura l locationt o anothe r urban o r rura l location .

Th e analyse s reall y ar e doing somewha t differen t things . Th e SPTA analysis , w

e believe , i s mor e generalizabl e t o mor e differen t kind s o f conditions .

MR . HOFFNAGLE : I hav e tw o comments . I disagre e wit htha t becaus e I thinkEas t Helen a i s th e bes t dat a se t t o us e an dit work s bette r thananything else . Th e resul t i s tha t your slope , wih t 5 0 part s pe r millio na s th e constandan d57 9 multiplie db y th e ambien t ai r quality , mean s tha t a t 1. 5 microgram s per cubi c mete r youar e sayin g tha t almos t all , 5 0 part s per million , o f th e soil EXECUTIV E COUR T REPORTER S (301 ) 565-006 41 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 4 lea dconcen t r a t i o n i s d e p e r. d e n t u p o n i mm e d i a t e d e p o s i t i o n .

Fro mtha t poin t o f view , th e slop e tha t yo u hav e chose n say s tha t th e soil-lea d concentratio n i s determine d directl yb

yth e air-lea d concentratio n wit honl y5 0 part s pe r millio n bein g soi l tha t wa s there .

T o me , tha t i s th e fa r mos t conservativ e wa ytha t yo u coul d g o i n tha t calculation . I gues s i t coul d b e 1,00 0 part s pe r millio n microgram s pe r cubi c meter , bu t wit ha constan t o f onl y5 0 pp m tha t say s mos t groundi s 5 0 pp m an d everythin g els e come s fro m the air , i s deposite dfro m ambien t air . Th e secon dpar t o f it i s tha t a s we mov e towar d control s o f smelter s an dal l sort s o f lea dpoin t source s we ar e changin g th e particl e siz e distributio no f thos e emission s radically .

An y relationshi pwe developnow , I think , change s th e particl e siz e distributio nfo r a numbe r o f reasons : becaus e th e depositio nfootprin t changes , wher e it i s deposite dchanges , a s wel l a s th e particl e siz e distribution s tha t ar e important .

DR . MARCUS : Th e location s tha t wer e inth e STPA wer e location s tha t hadhadfairl y lon g historie s o f depositio nat concentrations— I gues s yo uwoul dhav e t o say historica l integrate dconcentrations—tha t wer e no t order s o f magnitud e differen t ove r the periodo f time tha t wa s fel t t o 

# J EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.5 6



### )i 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 b e relevan tt o th e ...oi l

_-i

_L.'t'U'. J si t io n Thc-'i " e a r „ . hteres t ir; g question s abciu t wha t woul d happe n i f the ; _ wer e a n abrup t chang e i n ai r concentration s an d a tim e scal e ove r whic ha differen t soi l

an d dus t concentratio n woul d b e achieved .

We ha ve a 1 1 b

_ e n 3. o o k i n g f o r d a t a tha t migh t g i ve

u s a n insigh t int o this . Ther e ma yb e analyse s fo r theomin g fro m th e Kellogg , Idah o are a i n whic ha smelte r ther e ha s close ddow

nt o studyth e change s i nthes e concentration s ove r time a s a resul t of an abrup t chang e ina nair-lea d concentration .

I a m no t awar e o f othe r dat a set s tha t ar e a s usefu l inanswering tha t questio nabou t th e effect s o f thes e changes . Mayb e youcoul danswe r that .

CHAIRMA N LARSON : We wil l mov e ahead . The n perhaps , afte r th e break , w e ca nhav e a mor e wide-rangin g discussion . MR . HOFFNAGLE : Th e othe r poin t i s tha t w e fai l t o se e wh y youdon' t us e the Clausen , et a l numbe r fo r dietary intak e update : dirt , congestio nan dth e like . I

t i s 5 6 milligram s per day .

Th e secon

ddocumen t tha t yo uhav e ther e i s us e o f th e uptak e b

y th e kineti c mode l at fou r differen t smelte r site s wher e we hav e some data . I t i s th e bounddocument . Tha t documen t usedth e availabl e dat a wit hth e EXECUTIVE COUR T REPORTER S (301 ) 565-006 41 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 updat e biokineti c mode? ! t o tryt o develo p t o se e wha t the ? relationshi p wa s aroun d smelter s for fou r smelter s an

d we ? di d Toront o twice , befor e and afte r th e quote/unquot e clea n us .

The * mos t usefu l thin g w e go t ou t o f tha t i s tha t b e back-calculate d a numbe r tha t i s vsry clos e t o Clausen . Whethe r o r no t yo u believ e i n back-calculation , i t seem s tha t 55 , 6 0 milligram s pe r da yrepresent s somethin g i n th e rea l worl d aroun d thes e smelter s a s muc ha s i t di d i n Clausen' s study , whic hha s bee n discusse d i n othe r ways .

I don' t thin k usin g Binder , e t a l o r subtractin g Clause n from

Binder , e t a l i s th e righ t wa yt o go . We ^ woul d urg e tha t yo u g o ahea d and us e th e Clause n a s th e ingestion , rat e supporte d b

you r studyhere . Fo r bot hth e leaded-soi l issu e and fo r this , th e Lea d and Soil s Conferenc e tha t wa s hel d bac k i n May , w e understand , i s t o b e publishe d i n December . S o w e wil l hav e tha t dat a availabl e i n th e journal s a t tha t time.

-

CHAIRMA

NLARSON : Than k you , Gale . Anyquestions ? MR . COHEN : Yes . I jus t wan t t o le t Gal e kno w tha t we mad e som e change s t o th e uptak e estim-ate s sinc e h e di dtha t earlie r analysi s a yea r o r s o ago .

MR . HOFFNAGLE : Yes . Change s tha t ar e i n you r documen t here ?

MR . COHEN : Yes . EXECUTIV E COUR T REPORTER S (301 ) 565-0064P.5 8

1 MR . HOFFNAGLE : Di d I understan dtha t yo u too! : th e 2 Binder , e t a l an d subtracte dClausen , e t a l fro mi t t o com e 3 u p wit hsomethin g lik e 10 0 milligram s pe r da yan d a range ? 4 MR . COKEN : Right . I a mtalk i n gabou t othe r 5 pa r a;net'_rs f though , a s wel l tha t yo u migh t wan t t o mak e thos e 6 adjustment s t o base do n thi s repor t an d se e i f i t stil l 7 compare s well . 8 Th e othe r thin g i s tha t yo u don' t hav e th e 9 biokineti c mode l itself , othe r than , I guess , th e 1 0 relationshi p betwee ndail y lea duptake , assumin gconstan t 1 1 uptake , an d correlate dwit hblood-lead . 1 2 I thin k yo u migh t ge t a differen t resul t i f yo u 1 3 plu gi ndifferen t dail y intake s a s th e ki dage s an dallo w th e 1 4 dynamic s o f lea dmovemen t throug hth e bod y b e accounte dfo r 1 5 a s th e mode l does . 1 6 Yo u ma y ge t a differen t result . 1 7 W e di dloo ka t alternativ e soi l ingestio nrates , 1 8 includin ggoin gdow nt o tha t range , i nEas t Helena . W e foun d 1 9 tha t th e number s tha t w e hav e actuall y arrive da t her e 2 0 predic t better . 2 1 W e under-predicte dblood-lea di nEas t Helen a usin g 2 2 that . 2 3 MR . HOFFNAGLE : Th e uptak e biokineti c mode l ha s a 2 4 lo t o f variable s i nit . Whic hon e yo upla y wit ht o hav e i t 2 5 matc hth e blood-lea di s a Hobson' s Choic e mos t o f th e time . EXECUTIV E COUR T REPORTER S (301 ) 565-006 41 2 3 4 5 6 7 8 9 1 0 1 1 1 2 13 14 15 16 17 18 1 9 2 0 21 2 2 2 3 24 2 5 I I U tha t drive s th e tot a Wha t tha t come s fro mi s th e d^iv : model , though . Tha t i s thi . o i number . I woul d jus t lik e t o add , I wen t bac k i"i f .v;; han

d i n th e result s i s a tabl e tha t show s yo u tw o change s tha ' I have : usin g th e Eas t Helen a air-lea d t o soil

- an d dust-lea d number ; and th e 5 6 milligram s pe r dayingestio n number .

Thes e ar e th e number s tha t tha t updat e come s to , and the yar e very

different . Thes e ans clos e t o the mea n values . The yar e muc hsmaller .

I didn' t kno

w the methodology

t o ge t th e range s tha t we talke daboutm before , an

dw e cand o that . But we woul dopt tha t tha t i s a bette r wa y t o approac hth e situation . I als o wante dt o say , o ningestio nrates , tha t th e Offic e o f Toxi c Substance s i s looking at ingestio nrate s a s well . I woul djus t mak e sur e tha t youar e awar e o f that . I sen t the

m a cop y o f ou r repor t o

ningestio nrates . CHAIRMA N LARSON : Okay , Gale . Thankyoufo r that . D o yo uhav e an

y furthe r questions ? DR . RABINOWITZ : Mayb e I shoul dsay thi s no

w in cas e I forge t it later .

Abou t using smeltere ddat a t o establis hth e regressio nlin e betwee nair-lea dan dsoil-lead , I jus t want t o ge t a sens e fro m people . EXECUTIVE COUR T REPORTER S (301 ) 565-006 4

# J 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 I s ther e a proble m usin g tha t typ e o f data ? In practice? , smelter s don' t alway s work nic e and smoothly . Sometime s yo u hav e a fir e i n a ba g hous e and sometime s thing s happtr' n and yo u suddenl yge t a whol e bunc ho f lea d comin g ou t tha t ma yno t sho wu p i n th e ai r data , bu t it doe s sho wu p i n th e soi l data .

I wonde r i f tha t i s no t anothe r complicatin g factor . I don' t kno wi f tha t i s a rea l problem o r not . Fo r me , i t i s a

nimaginary

problem . I f al l o f thes e problem s are rea l enough , i f you jus t thro

w out th e ide a o f regressing soil-lea dan dair-lead , say yo uar e no t going t o do it , ca nyo ustil l establis ha standard ? Canyo ustil l writ e a nair-lea dstandar dwithou t correlatin g air-lea dan dsoil-lead ? I s ther e stil l some othe r approac ht o getting a t wha t we ar e trying t o do ?

MR . HOFFNAGLE : M y answe r t o tha t i s tha t 9 0 percen t o f th e changing inblood-lea dtha t i s being projecte d her e i s a chang e insoil-lea dconcentration s s o tha t m y answe r i s no . Yo ucanno t se t it unles s yo uhav e som e understandin g o f wha t tha t is .

I wil l respondthat , yes , sometime s yo ublo w a ba g hous e an

dther e ar e accidents , et cetera , tha t chang e th e soil-lea dconcentratio naroundth e facilit y b y a lot . I thinkt o g o bac kan dput i t a differen t wa y is : EXECUTIVE COUR T REPORTER S (301 ) 565-006 4P.6 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 'in darelationshi p betwee nths

- tw o I f w ecanno t

demortstrat e.-. relationship , whic hneithe r Jef f no r Ica ndo,

- betwee na i ; -lead s an ddepositio ntha t is , deposite d] ead—-o nth egroun dwher ew ehav etha t kin do f data , wecann c

I f w ecanno t

fin darelationshi p betwee nair-lead s an ddeposite dlead , ho w ca nweassum etha t w ewil lb eabl et o fin darelationshi p betwee ntha t an dth esoi1-lea d c o nc e nt

r a t i o n? Yo unee dmor edata

. CHAIRMA NLARSON : Idon' t wan t t o sto p th eflo w o f scientifi c thought , bu t Ithin k

wit hthi s foo dfo radditiona l discussio nprio r

t o lunc hwhy don' t w etak ea15-minut ebrea k an dfurthe r

tha t discussion

. Than k you , Gale

. MR . HOFFNAGLE : Than k you . [ Abrie f reces s wa s taken. ] CHAIRMANLARSON : I thin k w e wil l pic k up wher e w e lef t of f o n th e particula r topi c o f th e soil/ai r relationships . Ian ha

- som e comment s h e woul d lik e t o shar e I wit hu s a t thi s time .

DR . vo n LINDERN : I ha d basicall ytw o comment s o n th e Eas t Helen a informatio n tha t wa s presented , on e jus t t o ech o Mik e Rabinowitz ' commen t th e soi l level s ar e almos t assuredl yrelate d t o th e histor yo f th e facilit yan dno t t o th e curren t measurement s tha t w e see . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.6 2

:-..V - •mt~ 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 24 25

.)' • Tf vo u woul d g o bac k an d loo k eithe r a t cortro l equipmen t or at historica l monitorin g dat a i n th e vi • : I. r.i. t yo f thes e smelters , ther e hav e bee n much , muc hhighe r concentration s i n th e past , th e bul k o f i t prio r t o 197 5 an d i t continue s alon g a t a lowe r patter n unti l abou t 197 8 t o 19S 0 unti l control s cam e in in respons e t o th e NAAQS .

S o i t i s a historica l proble mi n relatin g i t t o curren t concentration s whic hi s a specia l difficulty .

A s I understandho w tha t soi l informatio nwa s collection , wit hthe Eas t Helen a dat a I believe dthey used th e same methodology w e usedi

nBunke r Hill . Tha t - • concentratio ni s th e topincho f minera l soil .

I nmos t cases , tha t i s a t leas t a

ninchdee pin th e soi l profile . Wha t w e cal l th e litte r laye r o r th e vegetativ e layer o f th e so di s o nto po f tha t an

dw e sampl e tha t separately . I believ e Eas t Helen a di da s well .

Wha t i s measure dther e ha s a tempora l factor wit h it , a s well . It i s materia l tha t i s a t leas t a coupl e o f season s ol di f no t older , an dthe mos t recen t materia l i s probabl y

relate dt o th e curren t ai r concentration s tha t ar e use dan

dwoul dbe , mor e appropriately , inth e litte r layer . Tha t wa s m

y commen t abou t explainin g soil s dus t versu s soil s stree t dus t situations . I nat leas t mos t o f th e smelte r studies , tha t soi l valu e i s no t a surfac e soi l sample : i s the to pincho f the minerals . EXECUTIV E COUR T REPORTER S (301 ) 565-005 4P.6 3

___ 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 DR

. M A H AFF E Y : I h a v e som e so rto fb roa d ge n e ra 1 comment s an d c.;uest:!

. ons . woul d yo u wan tt o procee d wit h thos e

! iO>'-'" ' C H AI R MANL AR 3 0 N : We 1 1 , p _ • r ha p s a

n yc o n t i n u i r

i g discussio n o n thi s particula r poin t tha t wa s raised ?

.No response. _ MR . COHEN : Ther e i s on e othe r issu e tha t Mike' s questio n bring s up . Wha t d o w e assum e fo r th e future ?

I n th e paper , w e identif ytw o alternativ e scenarios : on e wher e w e assum e tha t soil-lea drespond s t o change s i n air-lead , instantaneously ; an dthenth e othe r wher e w e maintai n soil-lea d ove r time .

W e fee l tha t ove r th e next fe w years , n o matte r wha t w e d o wit hth e air-lea dsituation , th e soil-lea di s no t goin g t o respon d substantially . We thinka mor e plausibl e scenari o i s maintainin g soi1-lea dat whateve r baselin e level s w e ca n defin e base do nthes e empirica l observations . Whe nw e tal kabou t th e cas e studie s a littl e later , I thinkit wil l b e a littl e mor e clear ; but w e ar e keeping soil-lea dinth e propose dapproac ha t constan t level s ove r th e nex t fe

w years . I t ma y b e muchdifferen t t o g o out 2 0 year s fro m now , but I thinktha t i s beyondou r scope . DR . RABINOWITZ : So yo udon' t us e th e derive d regressio nlin e betwee nsoil-lea dan dair-lea di

nyour EXECUTIV E COUR T REPORTER S (301 ) 565-006 41 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 forecas t ing .

MR . COHEN : No t i n th e scenari o tha t .., t , ar e proposin g a s mor e plausible . W e d o us e i t t o establis ha baselin e concen t ra t i or - o f soil-lead . Otherwise , w e wil l hav e nothin g t o pu t i n fo r soil-lea d concentrations . W e thin k tha t thes e ar e reasonabl e relationship s fo r th e equilibrate d concentrations .

MR . MAINE? : Wha t w e thin k w e are capturin g i n that , sinc e w e ars usin g studie s fo r th e relate d air-qualit y soil-lea d level , recognizin g prio r year s t o on e tha t study collecte d th e air-qualit ydata , tha t ther e ma yhav e bee n highe r things .

Bu t tha t i s representativ e o f wha t i s accumulate d up t o tha t poin t and tagge d fo r a give n stud yarea .

S o i t i s a

n air-qualit ymarke r associate d wit h tha t and w e hav e varyin g soil-lea d level s wit hvaryin g air

qualit ylevels .

CHAIRMANLARSON : D o yo u se e anyair-lea d reasonabl yconstant , historically , a t thos e sites ?

MR . COHEN : Yes . W e trie d t o us e studie s tha t di d no t hav e majo r tumultuou s smelte r conditions . • Yo u can' t b e sur e o f tha t i n anyway .

We di d exclud e th e ba g hous e fire s and thing s lik e that . DR . MARCUS : I n fact , a t th e Eas t Helen a sit e for EXECUTIV E COUR T REPORTER S (301 ) 555-00641 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 on e o f the monito r location

- ther e wa s essentiall yfive t si x years - o f continuous

- dat a tha t mad e i t veryclea r tha t condition

- ha d bee n reasonabl yconstan t ove r th e le?ngt ho f tim e tha t th e lea d uptak e historie s o f th e childre n bein g simulate dwer e u

p t o five , si xyear s old . S o t ha t wa s a p ar t i c u 1 a r 1 ocatio n a t wh

i i c hw e definitel yha

dreaso n t o believ e tha t we wer e doin g an essentiall ystabl e o r constan t environment .

MR . HAINES : I hav e one othe r observatio no na concer nexpresse db y Mike . Yo uhave fluctuating emission s arounda smelter . It i s a proces s source . A secondary

smelte r i s th e same thing . Quarterl y being l-in-6-day dat a i s no t th e greatest , but the meanvalu e tend s t o reflect , t o a degree , peaks . Youcanse e day-to-day variatio nwher e yo uhav e highe r peaks , but th e meanwil l mov e u pi nrelatio nt o thos e peaks . S o th e quarterl y averag e i s no t devoi do f some representatio no f that . It ma y no t captur e th e tru e magnitud e o f them , but it i s reflecte dinth e meanvalue .

S o I thinkusing thi s historica l air-qualit y dat a give s u s a reasonabl e basi s t o assume a baselin e going-i n point . CHAIRMA N LARSON : Wha t d o yo ud o abou t historica l

EXECUTIVE COUR T REPORTER S (301 ) 565-006 41 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 ic'-in g thes e backgroun d value s i n

' -''.i.e. 3 ii v

i n qlea d i n urba n area s lea d dat a whe n yi-o u ar e p

r th e presenc e o f f i . •• • _ • y&io:-rfro mothe r sources'" 1

'Ar e thos e change s r_-f 1 ec:ted ? MR . COHEN : W e are ? no t goin g t o mak e an ychange s t o soil-lea d a s a resul t o f tha t decline . Th e area s w e ar e lookin g at.ar e directl yadjacen t t o th e poin t sources , an d the

- soil-lea d ther e i s dominate d byth e emission s fro mtha t fa c i1 i ty . Th e gasolin e contribution s see m t o b e relativel y small . W e thin k w e are capturin g i t by usin g th e empirLca l data , bu t w e ar e no t goin g t o mak e any adjustmen t for th e declines . DR . McLAMB : Well , t o som e exten t w e have . Wha t

w e d o i nou r forecastin g methodolog y i s w e us e th e IF C shor t ter m dispersio nmode l t o figur e ou t th e point s o f interes t wher e peopl e ar e generall y located , wha t th e ambien t concentratio ni s fro m th e source , andthe nw e ad do nassume d background . T o som e extent , i f tha t backgroun dreflect s whateve r residua l lea di s i ngasoline , the ni t wil l b e capture s t o tha t extent .

DR . MAHAFFEY : I hav e anothe r questio nabou t wha t th e ambien t measurement s are.

I nsom e o f th e occupationa l literature , th e

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.6 7

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 problem s o f Ontari o i n revisin g thei r acceptabl e OCCUJ:,: ' '-.::;,, ; standard s analyse d dat a wher e ther e wa s bot hd'ubi en t ai r samplin g plu s th e dus t tha t accumulate d i n variou s plants .

The yreall ycam e t o the . conclusio n tha t the y rea l 1 y.coul d no t rel yo n jus t ambien t samplin g t o reflec t blood-lea d eve n i n occupationa l exposures .

S o i n th e kind o f ambien t sampl e yo u woul d hav e outsid e a plant , woul d yo u b e missin g muc ho f th e heavie r particulat e tha t migh t neve r reall y sho w u pinyour ambien t sampling evenwit hrelativel y high-volume samplers ? I gues s I questio nthe exten t t o whic hth e ambien t sampling—whic hha s certainly , intime , beena relativel y shor t sample—reflect s wha t ma y b e coming ou t o f th e plant . CHAIRMA N LARSON : Ther e mus t b e som e relationshi p here . Fro

m ou r discussion , I a m picking u

pa n interpretatio ntha t thes e ar e relativel y stead y ai r level s ove r time an

dreflec t th e soi l value s that , therefore , reflec t some longer-ter m exposure . Ther e ar e sor t o f steady-stat e points , i f you will , o na graph . Ther e i s no t necessaril y some immediat e relationship .

DR . vonLINDERN : I think , again , it depend s o n wher e yo ulookinth e soi l colum nt o some extent . Whenwe looka t tha t topincho f minera l soil , whic hi s agai nbelo w 

# J- EXECUTIVE COUR T REPORTER S (301 ) 565-006 41 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 15 16 1 7 1 8 19 2 0 21 2 2 2 3 2 4 2 5 th e litter , we* don' t se e muc hchang e ove r 1 5 years .

Ove r tha t 15-yea r period , w e hav e ha d a 100-fol d decreas e i n airborn e levels . S o tha t particula r laye r stay s fairl yconstant , i f yo u wan t t o assume * a constan t fo r that .

Wha t i s immediatel yon th e surface , though , i s mor e o f -

a dus t problem . MR . HAINES : On e o f th e issue s tha t w e don' t hav e a n answe r to , whic hI thin k i s par t o f thi s problem , is : What hi s th e accessibl e soi l level ?

DR . vo n LINDERN : T o children . MR . HAINES : T o children . I think , unfortunately , w e don' t hav e a goo d answer . W e don' t kno who wt o characteriz e that : whethe r o r no t the yare

gettin g th e to p 1 t o 5 centimeters . That , I think , i s goin g t o var ywit hth e situatio n i n whic hthe yar e piaced . I f the yar e o n a dir t pla yyar d i n a n urba n are a an d the yare

chewin g up , yo u hav e t o b e concerne d wit hmuc h deepe r soi l depths . Othe r situation s ma yno t b e ver y accessibl e fo r a ver ylon g perio d o f time .

I n grass yareas , i t work s it s wa ydown . I f yo u cu t of f emissions , the yma yno t hav e read yacces s t o it ; bu t thi s i s somethin g nobodyha s looke d at tha t I a m awar e of . W e don' t kno who wt o addres s it .

Thi s i s on e reason , I think , w e hav e conclude d

EXECUTIV E COUR T REPORTER S (301 ) 565-0064

# _ J

.'JiJmi'y •yj'

> : 1

2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 8 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 • i estimatin g wl-.^. t t h

o f 1 o nc

i '•.. \ u d i. r, a 1 na t u /ha t happen

- t h e -JJ.-J fro m bot hproblem s w : W e don' t hav e an ydc.- i Wi t h• r e d u c t i o ns i ; - , a : tha t ar e accessible ?

S o I thinh : ou r preferre d pat hi s t o tr yt o assume ? wha t th e baselin e i s i n th e are a th e bes t w e ca n usin g a s robus t a dat a set , usin g al l availabl e data . Us e what , loc k i n her e th e soil-lea d a s a constan t an d vary , wit hai r quality , wha t w e cal l th e dust-lead , whic hw e describ e a s tha t bein g immediatel ydeposite d o n the ; surface , whic hw e thin kshoul d b e fairl ycontemporaneou s wit hair-quality levels . W e fee l thi s woul db e th e mos t reasone dapproac h aroun dthi s part' s tota l dat a gap s w e have .

DR . vo n LINDERN : I thin ktha t i s correct , certainly . Th e othe r complicater—an dmayb e w e hav e on e o f th e few

site s wher e thi s become s a seriou s complicater—i s tha t soi l belo w

th e sourc e itself , i nadditio nt o air . MR . HAINES : Yes . DR . vo nLINDERN : It als o get s int o th e pathway . S o wha t yo uar e seein g i nth e hom e a s hous e dus t an ds o o n ha s com e from

tha t a s wel l a s fro m th e airborne . MR . HAINES : Thi s i s from re-entrainmen t sources . Hopefully , thi s i s wher e you r ai r qualit y come s in . A s tha t

EXECUTIV E COUR T REPORTER S (301 ) 565-005 41 2 3 4 5 6 7 8 9 1 0 1 1 12 1 3 1 4 1 5 16 1 7 1 8 19 2 0 21 2 2 2 3 2 4 2 5 4 . 1 i i..

_I : : r 7 i n th e homes , i t ... . _. . .-'.; u b e dus t i s re-suspende d t o se^ti e o u reflecte d o n th e monitors .

DR . vo n LINDERN : Ther e are - a coupl e o f othe r pathway s tha t a t leas t w e dea l with .

On e i s actuall ytrackin g tha t materia l int o th e home , and anothe r on e i s pet s in bringin g tha t materia l in . Thi s i s neve r see n i n th e air-qualit ymonitors .

DR . McLAMB : W e capture d tha t a s muc ha s w e coul d i n th e analysi s w e di d o n soil , air , and lea d dust . In th e househol d dus t equation , w e d o hav e an unexplanabl e variabl e o f soi l whic hcan , I believe , captur e wha t yo u ar e referrin g to . MR . COHEN : Kati e raise d an issue— I don' t kno wi f anybod yha s anydata ; w e migh t a s wel l as k whil e w e are here—o n core-siz e particle s tha t woul d no t b e collecte d b ya high-volum e instrument .

MR . HAINES : Thi s i s basicall yfo r distributio n o f cor e particles .

MR . HOFFNAGLE : Th e dust-fall-bucke t dat a include s somethin g large r tha n th e high-volum e sampler , bu t yo u canno t ge t a particula r siz e o n it . I t i s certainl yno t don e routinely . MR . HAINES : Th e bes t wa yt o com e u p wit ha respons e t o th e issu e i s t o tak e anamoun t o f lea d and loo k a t th e distributio n o f particles , pe r se , an dassum e tha t EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.7 1

1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 13 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 lea d ha s t o behav e-Gn-et;

- d i sir i bu ti on s be eaus ew e w esr eawar eof .

W ecoul d no ti tha tissue

. MR . HOFFNAGLE : 's g lik e tha t fromthes e generalize d

• ;•" ' t hav e i t fo r lead-specifi c tha t

r d an ywhe n w e attempte d t o addres s

Ther e ar e distributions , o f

c o u r s e , i n t hs e IT S i s s i o n s , a n d t he yar e m e a s ur e d . MR . HAINES : Unfortunately , fromth e poin t o f vie w o f th e principa l source s no wbeing futuredinth e storag e piles , I thin k w e eve n hav e spars e dat a ther e insiz e o f that . A s w

e looka

t the worl dtoday , th e stack s i f th e control s are operating ar e reasonabl y wel1-controlle dan d probabl y

are not having a significan t wher e we ar e seeing th e highbloodlevel s i n the children , whic har e quit e close .

Al l w e hav e i s a fugitive dus t problem : eithe r proces s fugitive s coming of f o r handling , yardcontaminatio n being re-entrained .

I a m unawar e tha t thos e particle s hav e eve r bee n sized . CHAIRMA N LARSON : Tha t i s a challengin g an d difficul t problem , mor e difficul t thanit seems .

DR . MAHAFFEY : Coul dwe tur ngenera l fo r a bit ? CHAIRMA N LARSON : Tha t i s fine . I wa s jus t goin g t o sugges t tha t w e g o t o eachindividua l member , perhap s EXECUTIVE COUR T REPORTER S (301 ) 565-006 4

# J 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 starting wit hyou , t o giv e u s you r gene;a l impression s o f Ihe report . DR . MAHAFFEY : Along tim e ag o whe n w e starte d som e o f this , on e o f th e concern s ha d bee n talkin g abou t ai ; - lead/blood-lea d ratio s becaus e whil e ther e i s somethin g tha t traditionally , perhaps , ha s bee n done , ther e wer e som e majo r reason s for doin g jus t that .

Include d i n thes e reason s wer e th e fac t tha t i t seem s simplisti c t o loo k onl y a t ai r wit hthe realizatio n tha t th e lea

dan dai r wind s u

pi nthe street , an

dthi s wa s bac kwhe nthe street s wer e containing 3,00 0 an d4,00 0 part s per millio nlea

dbecaus e o f lea

dingasoline . S o the needt o phas e dow nlea di ngasolin e wa s recognized . No on e need s t o hear tha t histor y again . But w e stil l are

dealing wit htrying t o looka t air-lea dan

ddust-lead . On e o f the question s tha t stand s out t o me i

nthi s modeling exercise—an dthi s i s no t reall y t o spea kharshl y

o f th e model , but t o reall y as kwher e i s thi s going—i s youhave t o questio nwha t kin do f generalization s canb e draw

nfro m thi s model : Wher e cani t b e applied ? We live near , no t to o near , a plan t tha t ha s ha d some problem

wit huraniu

m discharges . I f yo uar e talking abou t particulat e airborn e whatever , ther e i s a temptatio nt o us e thi s mode l tha t it may wel l no t appl y

very directly . I thin kmayb e some o f thi s ha s happene da bi t ove r EXECUTIV E COUR T REPORTER S (301 ) 565-00643 .7 3

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 19 2 0 2 1 2 2 2 3 2 4 2 5 time . Whe n w e starte d worryin g abou t wher e th e lea d i n air

goe s and i t wind s u p i n th e street , w e wer e really , a t tha t time , mor e concerne d wit hc. n urba n environmen t an d ho wmuc h lea d wa s windin g u p i n th e stree t fromgasolin e esm i ssions . I a mmakin g som e assumption s here , bu t on e o f th e reason s yo u were-usin g th e smelter-sit e informatio n o n th e town s i n Montane * i s becaus e the yar e characterized , becaus e ther e tend s t o b e dat a t o loo k a t thes e an dan absenc e o f dat a i s on e o f th e majo r problem s throughout .

Th e kin

do f discussio nwa s hado nwhic hlaye r o f th e soi l an

d dus t reflect s long-ter m lea demission s tha t hav e woun du pi n soil . Contrastin g thes e wit hth e curren t ai r leve l i s on e kin

do f correlatio nrati o regression , whateve r kind s of , analysi s yo ud o wit hit intrying t o estimat e exposure . Yo uar e relating thi s bac kt o a ninterna l marke r o f thos e blood-lead s tha t onl y i npar t reflec t curren t exposures . Ther e i s on e sentenc e bac kinher e tha t evenwit h th e bes t situatio ninterm s o f environmen t measuremen t you coul dexplai n3 0 percen t o f th e variatio ninblood-lead .

Thi s tell s yo uther e i s a nawfu l lot missing . Thi s i s evenwit hth e bes t situation .

S o I thinkinmay way s wha t ha s bee ndon e wit hth e mode l i s clos e to a s gooda s we kno w how to d o righ t now : tha t ther e i s a seriou s absenc e o f informatio nt o wor kwith . EXECUTIV E COUR T REPORTER S (301 ) 565-006 41 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 Tha t i s on - kin d o f problem . I wan t t o • unde r s ::o ; e th e fac t tha t I don' t thirl- : thi s mode l •: j:.r, b e broadl y extrapolate d i n term s o f othe r kind s o f environmenta l problem s of , i f i t is , her e ha s t o b e rea l recognitio n •:. , f wha t part s o t J ; ca n an d canno t be .

Tha t i s a poin t I reall ywan t t o emphasise . I thin k anothe r proble mi s tha t whil e w e ar& intereste d i n biokinetic s yo u canno t forge t th e biology , th e physiolog ytha t undermine s th e biopar t i n biokineti c modeling . The yar e difficul t issues .

Yo u ars attemptin g t o us e informatio n tha t cam e fro madul t male s i n tryin g t o extrapolat e thes e kind s o f patters n o f exposur e an d th e distributio n o f lea d withi n physiologica l system s t o women , i n particula r pregnan t women , an d transfe r o f lea d fro mth e mothe r t o th e fetus .

W e kno wtha t th e lea d i s transferred . Ther e ar e cas e report s tha t tal k abou t congenita l lea d poisoning . W e kno wa littl e bi t abou t this , bu t w e reall ydon' t kno wver y muc habou t i t excep t tha t i t happen s an d that , give n th e longitudina l studie s o n neuro-behaviora l effect s o f low-leve l lea dexposure , lo wblood-lead s ar e quit e important .

W e don' t hav e muc hexperienc e wit htryin g t o mode l exposur e i ndifferen t bod ycompartment s o f lea da t thes e lo w exposures . Ther e jus t i s no t muc hther e t o wor kwith , excep t tha t w e kno wtha t i t i s ver yimportant . EXECUTIV E COUR T REPORTER S (301 ) 555-006 4P.7 5

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 S o agai n I thin k tha t thi s ha s t o b e emphasize d i n th e d i r. c uss i on .

I don' t wan t t o reall yg o o n wit hth e genera l i „a t ions . I realiz e tha t yo u are tryin g t o solv e a spe c i f i c p r ob1e m .

Bu t I wan t t o cautio n strongl yagains t tryin g t o extrapolat e thi s mode l mor e broadl ytha n I expec t wil l happen . CHAIRMAN LARSON : Wh ydon' t w e g o aroun dth e tabl e an dle t peopl e shar e thei r genera l impression s o f th e docket , chapte r by

chapter , membe r by member , I guess . Woul dyo ulik e t o start , Dr . Chisolm ? DR . CHISOLM : Well , I thin ka noveral l commen t i s tha t give nal l th e unknown s an dal l o f th e variability , yo u probabl y

di da s wel l a s yo ucould . I thin kon e o f th e bigges t variabilit y i hal l o f thi s i s th e relativ e amoun t o f soi l tha t childre nwil l ea t an dwhethe r o r no t w e compar e Dutc hchildren .

I am reminde do f a quot e from Rudyar dKiplin g t o th e effec t tha t thos e wh o conside r cleanlines s secon donl y t o godlines s hav e a damnlow opinio no f godliness . CLaughter l I thin kth e Dutc hmigh t plac e i t a littl e highe r tha nman y

segment s o f ou r society . T o me , tha t i s th e bigges t uncertaint y becaus e i t ) EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.7 6

- - 1

2 3 4 5 6 7 8 9 10 1 1 12 13 1 4 15 16 17 1 8 19 2 0 21 2 2 2 3 2 4 2 5 - -.. J i

_ b_-h.~vio' . a l . Yo u ar e talkin g abou t biology , bu t i t i s a behaviora l di f f e r £-.,~r.

- .;-,non g children . Yo u reall yhave. ' t o giv e fairl ybroa d leewa yt o that , I think .

CHAIRMA

NLARSON : D o yo u fee l tha t th e number s tha t wer e presente d ther e captur e th e rang e o f uncertainty ?

DR . CHISOLM : I a mno t sur e abou t that . Suppos e w e se e th e stair-ste p childre n i n town . Yo u ca n ge t a wid e rang e o n blood-lea d concentration s give nth e same genera l c i r c umstan e es .

Yo u ma ysaytha t it i s the two-year-ol dwh o ha s th e highes t blood-lead , but tha t i s no t alway s true . I sometime s wonde r abou t wh y I sa y the five-year-ol dmigh t be muc hhighe r i n th e sam e circumstances .

I ca n thin k o f al l sort s o f things . Mayb e her fathe r wa s no t th e same a s he r husband , yo uknow , an dthi s kin di s rejected .

I a m jus t saying tha t ther e are a lo t o f behaviora l difference s tha t mak e fo r othe r massiv e di fferences .

I recal l a chil dwe hadinth e hospita l n o mor e thanabou t si xweek s ag o wit ha blood-lea din , I think , th e middl e 60 s an

dye t her sibling s wer e no t ove r abou t 20 . They livedinth e same circumstances .

S o ther e ha s t o b e somethin g abou t tha t particula r EXECUTIV E COUR T REPORTER S (301 ) 565-006 4 iP.7 7

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2 3 4 5 6 7 8 9 1 0 1 1 12 1 3 1 4 1 5 1 6 17 1 8 1 9 2 0 2 1 2 2 23 24 25 . _ • individual . Ofte n w e se e a broa d range .

I don' t thin k i t i s commo n t o se e childre n livin o i n th e sam e abod e wit hblood-lead s rangin g fro mG O t o "i'J, Tt i s no t unusua l a t all .

I a mtalkin g abou t childre n i n ol d houses . I t i •-:- . th e sam e genera l exposur e fo r 'everybody . S o I don' t kno w tha t i t reall y

wa s contrary . I n Eas t Helena , thos e ar e fairl ywell-to-d o people . The y

are no t poo r people , I don' t think . Ther e are a lo t o f socioeconomi c differences .

Ther e are

differences , I think , i nth e degre e t o whic hmother s o f differen t ethni c background s wil l tolerate. a lo t o f exces s hand-to-mout hactivity . S o I thin ki f yo uwer e t o g o d o thi s stud y in , say , severa l section s o f Bosto nyo u migh t com e upwit hquit e differen t answers .

Tha t woul db e a

reaso nfor no t extrapolatin g wha t ha s bee nfoun di nNort hHollan do r wha t ha s bee nfoun di n Eas t Helen a t o th e whol e population .

I woul dals o say , tr y t o gro w

som e gras s i nth e bac kyar dwher e yo uhav e youn g children .

CLaughte r _ CHAIRMA N

LARSON : Tha t i s a challenge . DR . CHISOLM : I t is . S o I thin kyou r commen t abou t th e surfac e soi l bein g constan t i s wel l taken .

s EXECUTIV E COUR T REPORTER S (301 ) 565-006 4

•- . •

• 1P.7 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 MR . HAINE- : D o yo u 'wan t u „ t o interjec t an y

o bs e r va t i o n s ?

CHAIRMA

NLARSON : An

yquestions ? MR . HAINES : Tw o points . Goin g bac k t o th e variation , w e hav e tw o stage s here . I s th e mode l recognizin g ther e i s going t o b e a wid e degree ? Hav e w e capture d wel l enoug htha t w e ca n predic t a mea n recognizin g tha t w e ar e goin g t o appl y the GS Do

ntop o f tha t meant o tr

y t o captur e the variabilit y init an

dth e fac t tha t the GS Dderive dfro m th e Eas t Helen a wor ki s simila r t o wha t i s derive dfro m NHANES ? I t i s independentl y arrive dat . I

t may be a perfec t tool , but a t leas t we ar e trying t o interjec t intha t variabilit y

wha t youar e seeing . DR . CHISOLM : I jus t wonde r i f youhave enoughi n it . MR . HAINES : Yes .

I a m no t sur e ho

w t o approac hi t othe r thanwha t we are doing . We ar e trying t o ge t at tha t proble m through , really , a two-stag e approach .

O nth e uptak e side , o nth e us e o f th e Dutc hdat a i t i s m

y understandin g th e wa y Jes s applie dtha t i s basicall y us e thos e childre nthey lookeda

t inth e hospita l itsel f in conjunctio nwit hBinde r t o deriv e th e tru e baseline .

I s tha t the bes t wa y t o sa y it , Jeff : fo

r a bette r EXECUTIV E COUR T REPORTER S (301 ) 565-006 41 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 !;-..] . r o i base'" ' • MR . COHEN : Pinoer , the n • absorptio n o f tiros; , elvmer.-;^ ,

MR . HAINES : Yes . MR . COHEN : Tha t i s a bi g chun k o f th e picture . Th e onl ydat a tha t w e ha d tha t w e though t w e coul d easil y appl yt o tha t wa s th e Clause n data : childre n wh o wer e no t

r o 1 1 i n g ar

ou n d i n t h e d i r t . Unti l th e dat a fro mth e ongoin g studie s ar e available , I don' t thin k w e ca n reall y addres s tha t i nany othe r way . . •

I don' t thin k i t woul db e appropriat e for u s t o us e th e dir t ingestio n rate s tha t Clause nfoun dfo r thos e children . I agre e ther e i s probabl y a whol e differen t se t o f behavior s betwee nth e tw o kind s o f populations .

W e hav e trie dt o us e th e Binde r study , bu t usin g th e Dutc hdat a t o adjus t for th e unmeasure dtrac e elemen t absorption . DR . MARCUS : On e mor e commen t o nth e variatio nand th e cultura l factors .

Som e o f th e Cincinnat i studies , publishe di n §Qv_J_2D_)_-__iiiI Researc habou t thre e year s ago , actuall y showe d ho w variou s subscale s o f th e Caldwel l Hom e Inde x quantitativel y

mediate dthe hdust-lea dt o hend-lea dt o blood lea dpathways . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4J



# Jt

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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 W e ar&vsry muc hawar e o f that . Tha t i s th e reason , a s wa s said , tha t onl y3 0 percen t o f th e varianc e i s explained .

' A s far a s thes e mouel s ar e concerned , thi s i s tht : reaso n wh

yw e belierve thc-?

yar e reflectiv e o f typica l value s i n population s o f children . I believ e w e are awar e o f th e limitation s i n usin g the ma s a too l for predictin g individua l children' s blood-leads .

Ther e ar e a lo t o f source s o f variation . DR . CHISOLM : I wa s not putting it tha t way . DR . MARCUS : Okay . DR . CHISOLM : I wa s putting i t mor e o ndifferen t socia l strat a an

ddifferen t ethni c group s tha t tak e quit e a differen t attitud e o nit . DR . MARCUS : Yes , sometime s eve ni nth e same locatio ni f thi s wer e t o be applie dt o population s abou t whic hon e ha

drelativel y

littl e suchbaselin e information . MR . COHEN : Ther e i s on e othe r poin t tha t Kati e brough t u

po nth e lac ko f biokineti c dat a during pregnancy . We are lef t wit hestimatin g blood-lead s fo r tha t populatio nusing ai r blood-lea dslope s derive dfro m mal e studies , basically . Ther e i s a rea l problem wit hthat . We ar e no t using an y biokineti c adjustment s fo r that . DR . MUSHAK : I n1985 , we hada join t conference . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4 !

1P.8 1

,

4

- • 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 Marc o Zarec hdiscusse d dat a froma .•il l ag e i n Yugoslavia . Tiie yhad a se t o f wome n wh o wer e studied , serial , fo r blood-lead . T believ e thei r lead s are availabl e for tha t period , and probabl ydust-leads , also .

S o tha t i s a group whic hca n probabl yb e probe d i n muc hclose r detail . VQ_ I migh t wan t t o chec k wit hGrazian o from Columbia . He ; probabl yha s al l o f tha t program .

MR . TLAAK : Ther e wa s hig hlea d inpar t o f it ? DR . MUSHAK : Reasonably . DR . MAHAFFEY : The yha d a coupl e differen t groups , didn' t they ? The yhad differen t environmenta l locations " o f blood-lea d exposure ?

DR . MUSHAK : Right . Thi s i s a subgroup inwhic hpregnancie s wer e followe d and the ywer e serial . Ther e wer e somethin g lik e 7 o r 3 point s eac hmont ho f thei r pregnancies.

DR . MARCUS : Ther e i s als o th e Manto nisotop e data . DR . MAHAFFEY : Tha t i s onl y ontw o o r thre e people , though , right ?

DR . MUSHAK : Right . That' s wha t we ar e lef t with . MR . HAINES : Fiv e femal e subject s inth e Dutc h study , but tha t wa s fo r a very

shor t exposure . DR . MAHAFFEY : A s I recal l tha t data , di dthei r blood-lead s g o u

pfaste r o

r they hada greate r respons e fo r a EXECUTIV E COUR T REPORTER S (301 ) 565-006 4

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2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 8 1 7 1 8 1 9 2 0 2 1 22 2 3 2 4 2 5

•x . .- : 1 give nblood-lead ?

Ther e wer e definit e difference s betwee n th e m„ ; ?.

- and fe?mal e subjects .

DR . MARCUS : Yes . MR . HAINES : Thi s raise s a sor t o f provocativ e questio n from

our poin t o f view . W e recogniz e th e limitation s o f tryin g t o estimat e materna l blood-leads . Par t o f our dilemm a i s w e hav e identifie dth e fetu s an dar e trying t o trigge r back . Whenwe tr

y t o mak e us e o f th e data , it may b e s o inappropriat e tha t mayb e w e shoul dno t b e attempting t o .us e thes e model s t o predic t tha t relationshi pbetwee nadul t females ' materna l blood-leads .

CHAIRMA N LARSON : Tha t i s th e sens e o f wha t I a m hearing . MR . HAINES : Wha t I don' t wan t t o d o i s attemp t t o tak e wha t very

limiteddat a w

e have , try

t o appl y

it , an

d the nsay , "No , we shoul dno t b e doing it. " Th e bette r respons e ma

y b e tha t we canno t mak e thos e estimate s at thi s poin t intime an

dwe ough t t o focu s o nchildre nfo

r who m we ca ndo a reasonabl e jo bo f estimatin g exposures . DR . MUSHAK : I don' t thinkanybody i s saying tha t th e pregnanc y

tai l shoul db e wagging th e exposure-analysi s dog . I f yo uhav e th e information , us e it ; but keepwha t you have . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4 i1 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 MR . HAINES : Okay , accordin g t o th e cavea t o f the

limi t a t ion s o f wha t w e ar e doing . Okay .

I jus t wan t t o b e clea r o n that . DR . MAHAFFEY : I reviewe d a lo t o f th e lead-in

pregnanc yinformatio n fo r somethin g tha t w e ar e doin g a t NIH .

I t i s clea r tha t whil e th e cor d blood-lead s are ver yclos e t o th e materna l blood-leads , ther e are a lo t o f additiona l compartments . Yo u hav e t o tak e int o accoun t th e amnioti c fluid , th e membrane s th e placenta .

Ther e are

differen t component s her e tha t ma y no t reall y agre e tha t wel l wit hth e materna l andth e cor dblood lead . Tha t par t i s no t wel1-studied . Wha t w e kno w ma y b e reall y base do nlea dpoisonin g patholog y cases . S o I thin kPaul' s poin t i s wel l taken : tha t yo u don' t ignor e th e issue ; bu t tha t th e othe r sid e o f thi s i s t o recognize , an db e ver y u pfron t about , tha t thes e ar e jus t basicall y

bes t estimate s i nth e absenc e o f dat a fo r th e grou p o f concern , recognizin g th e Manto ndat a tha t show s tha t bone lea ddoe s contribut e an dwhateve r yo uca nobtai nfrom th e Yugoslavia nexperience .

DR . MUSHAK : I thin kyo umigh t als o ad dth e paradoxica l effec t tha t yo uge t i nth e Australia nsubse t wher e yo ufindtha t fetuse s apparentl y ar e servin g a s a sink : tha t is , wit hhighe r lea dexposures . Yo uge t lowe r blood lea dlevel s i nwomen . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.8 4

- • -

** * • T 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 Tha t i s writte n u p i n Mik e Davis-- ' paper . Tha t i s goin g t o b e a furthe r problem : wh yyo u canno t us e a n end .

CHAIRMA NLARSON : Okay . Ian , woul d yo u lik e t o summarize . I kno wyo u hav e alread yshare d wit hu s som e o f you r thoughts .

DR . vo n LINDERN : We? hav e hear d thi s before . I thin ki t i s a goo d jo ban d I thin k i t i s a s comprehensiv e a s i t ca nbe . I spen t th e las t yea r tryin g t o d o thi s for on e sit e andi t ha s drive nm e nuts . The y are tryin g t o d o i t for th e world . : "

CLaughter ] I hav e a coupl e o f thing s t o share . I thin kDr . Chisolm' s commen t i s ver y appropriate . O nou r side , w e hav e develope da ris kprofil e for childre nwh o ar e typica l and thos e wh o are

wha t w e cal l hig hrisk , an dthe y are th e one s tha t w e hav e t o worr y about . W e hav e don e th e bac kcalculation s o ningestio n rates . By

th e way , Regio n1 0 release dtha t documen t o n Frida y s o yo uguy s ca nhav e copie s o f it . At ou r site , i t look s t o u s lik e 5 0 milligram s pe r da y soi l ingestio nmigh t b e appropriat e fo r th e typica l child , bu t whe nyo uloo ka t th e high-ris kchild , th e chil d tha t w e are

concerne dwit hprotecting , i t run s upi nth e 10 0 area. 

### EXECUTIVE COURT REPORTER S (301 ) 565-006 4

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Regio n 10' s positio n o n tha t tha t the yar e offerin g ou t a t thi s tim e i s tha t w e ar e goin g t o us e th e 10 0 milligra mpe r da yvalue . S o ther e i s a wid e variatio n an d i t depend s on ' th e ver yfactor s tha t Dr . Chisol mi s talkin g about . Othe r comments : Th e air-lea d t o soil s and dus t thin g doe s bothe r me . I thin k tha t i s a ver ydifficul t on e t o do . A s I said , th e relationshi p o f th e smelte r situatio n i s a s t o wha t ha s gon e o n a t tha t smelte r ove r th e las t 3 0 year s and no t wha t w e are measurin g today . Th e othe r thin g I not e i n th e smelte r tha t I nee d t o explai n a littl e better , tha t wa s i n mycomments , wa s no t onl yi s lea d uptak e relate d t o th e soi l concentration s tha t w e se e i n children' s yards , bu t ther e seem s t o b e anothe r facto r a s wel l that , fo r us , seem s t o b e explaine d b yjus t th e genera l leve l o f contaminatio n nea r th e smelter .

Mayb e th e othe r soil s tha t childre n ca n ge t i n contac t wit hi n additio n t o th e one s specificall ymeasure d i n thei r ow n yar d and dus t condition s i n streets , and s o o n I thinkar e importan t factors .

Caro l Engel , I think , note d tha t i n he r papers . Th e communit yexposur e ende d u p bein g mor e importan t tha n th e individual' s yar d exposure .

Th e othe r poin t I hav e no t hear d muc hon—an d I EXECUTIV E COUR T REPORTER S (301 ) 565-0064 P.8 5 ]

i 'P.8 6

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 don' t kno wi f thi s i s th e appropriat e place , bu t I thin k w e shoul d sa yit—ha s t o c' o wit hth e monitorin g frequenc yo f th e NWAOS . I thin k th e on e tha t i s i n plac e no wfo r a situatio n lik e our s i s almos t totall yinadequate . Tha t i s a measur e onc e Bvery 6 day s whe n w e probabl yhav e abou t 1 1 day s a year i n whic htranspor t o f materia l int o th e home s an d dus t storm s i s ou r critica l variable .

W e don' t measur e that . I thin k i t als o shoul db e looke da t i nterm s o f upset s an d malfunction s i n smelte r situations . Region. S di d

a n analysi s bac k i n198 4 a t th e Teflu s Smelte r whic hyo u migh t wan t t o tak e a loo kat , i nwhic hI thin ki t wa s 4 5 percen t o f th e tota l exposur e ove r a three-mont hperio dwa s associate d wit hon e upse t a t th e complex , whic hwa s actuall y tie dbac kt o 5 minute s o f a fa nbein g off .

A short-ter m

even t ca nen du pcausin g quit e a bi t o f th e exposur e tha t w e se e i nth e community . Thos e ar e th e type s o f exposure s wher e large r particle s ge t ou t an dge t i n th e hous e dust .

M y othe r poin t wa s I thin ka s muc ha s w e wis ht o sa y tha t thi s i s a nair-qualit y situation , I kno w ther e i s a t leas t on e perso nsittin g a t thi s tabl e an dsevera l i nth e audience , I think , wh o ar e probabl y a s concerne dwit hho w thi s i s applie dt o soi l clean-up s i nth e country . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4• '

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-/• • I think w e shoul d al l recogniz e tha t thi s ca n b e

usedfo

r tha t an

d som e o f th e assumption s tha t w e mak e shoul d bea r tha t inmind .

CHAIRMA N LARSON : D o yo u thin k i t i s appropriat e fo r tha t application : soi l clean-up ?

DR . vo nLINDERN : Absolutely . I thin k i t i s th e bes t tha t ther e is , bu t yo u hav e t o mak e assumptions .

CHAIRMA

NLARSON : Right . DR . vonLINDERN : Youneedt o evaluat e thos e assumption s interm s o f wha t the ultimat e remed y i s going t o b e applie dhere .

CHAIRMA N LARSON : John , di dyo uhav e some questions ? A

comment ? MR . HAINES : I woul djus t mak e th e observatio n tha t w e are concerne dabou t the monitorin g issue . W e wil l b e addressin g tha t inth e staf f pape r bot hwit hregar dt o monitorin g siting requirement s an dt o th e frequenc y o f th e sampling . Earl y

next year , we wil l b e laying tha t out in staff-pape r for

m and , later , looking a t neede drevision s t o th » air-qualit y

surveillanc e requirements . MR . COHEN : I hav e on e mor e comment . Th e fac t tha t communit y exposure , no t necessaril y home-to-home yard-to-yar dsoi1-lea dlevels , may b e mor e predictiv e o

r a bette r surrogat e fo r integrate dexposures , d o EXECUTIV E COUR T REPORTER S (301 ) 565-006 41 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 yo u thin k tha t woul d ten d t o suppor t ou r us e o f th e poole d dat a tha t w e identifie d fro mal l sort s o f situation s i n th e appendi xther e a s oppose d t o th e Eas t Helen a dat a se t wher e th e soi l collection s wer e don e fo r eac hhouse ?

On e o f th e othe r studie s tha t the ywen t ou t t o i s a par k o r a playground , fo r example .

DR . vo n LINDERN : I don' t necessaril ybeliev e tha t i t i s a bette r one . I thin k i t i s a n additiona l one .

I thin k tha t i nth e pathway s i t woul dreflec t that : tha t childre nare expose di nthei r ownhom e yar dan d house , an dthe yals o ge t ou t aroun dth e neighborhoo dan dge t int o th e othe r sources .

S o I thin kthe y

bot hshoul db e used . I nfact , w e hav e mad e anattemp t t o us e bot ho f the m i nth e Regio n1 0 analysis . CHAIRMAN LARSON : Okay . Dr . Clark ? DR . CLARK : Mos t model s sho w tha t i t i s th e uptak e from th e soil s an dth e dus t tha t ge t t o th e children . S o seein g tha t onc e th e lea di s i nth e dus t o r soil , mos t o f th e mode l i s th e sam e regardles s o f ho w th e lea dgo t int o th e dust . I thin ksom e dat a o nrelationship s from othe r studie s ca nb e usefu l i nth e mode l t o exten dth e rang e o f it . W e hav e don e tha t by applyin g ou r mode l t o dat a from

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.8 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 8 3

7 he ybv> t!' ; a p p 1; : • • ve r ywell . Y o u . ge t differen t slopes , bu t th e mode l sti- l works : tha t th e mode l fro mth e lea d an d th e surfac e an d th e soi l int o th e dus t i n th e hom e o n th e child' s hands , the?; ; blood-lead .

S o w e pr obab1 ycou1 d us e othe r dat a i n her e o n tha t portio n o f th e pathwa ybecaus e th e lea d fro mth e soi l coul d b e fro m3 0 year s o f activit yo f th e mil l o r th e mine , o r i t coul d b e fro m3 0 year s or 10 0 year s o f pain t deposition , automobil e exhaus t ove r th e pas t severa l decades .

Ther e i s som e proble mwit hdifference s i n th e availabilit yo f th e lea d i n th e differen t forms , bu t w e thin k probabl ymor e dat a coul d b e use d i n th e modeling .

I thin k ther e i s a majo r impac t o n wha t i s goin g t o happe n o n soil-lea d criteri a fo r clean-up . I thin k tha t i s the ' ultimat e are a wher e w e ar e goin g t o hav e a n impac t becaus e th e exposure s directl yfro mth e ai r ar e no t tha t grea t now . I t i s th e pas t ai r exposure s wher e th e healt h effect s ar e occuring .

DR . MUSHAK : Wha t i f yo u ar e doin g a befor e an d after ? DR . CLARK : Bu t i t i s wha t happene d inth e past , interm s o f th e air , wher e mos t o f th e healt heffect s are occurring . I t i s residual s o f forme r air-lea d level s o r lea d

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.9 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 fro

m othe r sources .

W e hav e a measur e tha t w e pre?fer o n soil . I t i s a surfac e scraping . Som e folk s think i t i s jus t a horribl e metho d scientifically , bu t i t works .

I t i s a scrapin g of f a hard-packe d surfac e o r pave d area . Tha t i s wher e th e chil d ha s acces s now .

I t i s no wdown 1 o r 2 inches . Tha t coul d b e importan t i n th e lon g term , I agree ; bu t th e curren t exposur e i s wha t i s o

nth e surface . W e hav e ha

da hardtim

e convincin g RobEl i a s t o le t u s us e tha t i n additio nt o the soil . We ar e going,to.d o ou r soi l cores , the to pcouple— th e top2-1/ 2 centimeters , the n1 5 centimeters—but , also , w e ar e going t o use . a . surfac e scraping , whic hcanb e usedbot hfo r hard-packe do

r an y kind o f soi l becaus e th e chil dstil l i s o nth e topan

dth e topi s wher e th e highe r level s are .

DR . CHISOLM : Fro

m your poin t o f view , "a s I understandit , i f yo uar e thinking interm s o f th e long rang e an di f yo ukeepscraping it of f an dyo uar e boring int o a laye r wher e it doe s no t chang e fo r Xsonometers , youwoul d no t b e placin g quit e s o muchemphasi s onjus t th e surfac e scraping , I woul dno t think .

I f yo ucome bac kan dscrap e 1 0 year s fro m no w yo u woul dge t th e same thing , I think .

MR . HAINES : Thi s i s par t o f th e dilemm a o f

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.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 findin g wha t i s accessible . A s tha t penetrate s down , doe s it really , i n fact , sta ythere ?

I thin k i n situation s i t ma ysta yi n place . I n a dir t schoo l yar d i t probabl ywil l no t sta yi n plac e because ? t he ? c hi 1 d r e n wil l c on t i nua l ly e hu r n i t u p again .

The? , quote , accessibilit yproble mtha t I thin k w e

ar e dealin g wit hi s wha t trul yi s accessibl e o r not .

DR . CHISOLM : Yo u hav e t o thin k longitudinally , I think .

vary . DR . McLAMB : Yes , tha t i s wha t I mean . I t wil l

CHAIRMA NLARSON : Allan ? DR . MARCUS : O n thi s accessibility , I thin kfo r perhap s ris k assessmen t purpose s a conservativ e approac h regard s th e soi l i n th e core , a t leas t fo r a fe wcentimeters , a s accessible , a potentia l reservoi r o f lea d tha t ca n b e brough t t o th e surface .

Alo t o f peopl e bot hi n rura l an d urba n area s kee p bi g dogs . The ydi g holes , ou r childre n di g hole s i nth e yard . Peopl e pu t i n cabl e TV .

Ther e ar e a lo t o f thing s tha t woul dmak e soil s i n habitation s accessibl e t o a dept ho f a t leas t a fe w centimeters . Thi s i s th e reaso nwh y th e mos t conservativ e approac hwoul dregar deve nthos e sub-surfac e reservoir s a s potentiall ymobile .

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.9 2

m^j 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 DR

. CHISOLM : A s on emeasurement , r i'.'m_l_

- tota l measurement .

DR . MARCUS : I t i s ji'S t on e measure , and thes e hav e differen t purposes .

I f yo u ar e tryin g t o loo k a t curren t blood-leads , th e immediately-accessibl e par t i s th e par t righ t ther e a t th e surface . I f yo u ar e lookin g ahea d toward s ho wthi s or an y othe r mode l woul d b e use d for clean-up , I thin k yc u woul d hav e t o regardthe potentia l accessibilit y o f th e sub-surfac e soiI s a s wel1 .

A s I suspec t thi s o r relate dmodel s wil l b e used fo r ris kassessmen t purposes , thos e difference s inpurpos e do hav e t o be clarified . The generi c relationship s tha t wer e develope dma

y needt o be refine dfo r particula r purpose s fo r othe r applications.

A s yousay , w

e are looking fo

r area s primaril y aroundpoin t source s wher e ther e ha s beena nhistoricall y highdeposition . Othe r purpose s wil l probabl y requir e othe r refinements .

Tha t i s al l I ca

nsay . CHAIRMA N LARSON : I hav e a question" . Th e othe r pathway whic hyo umentione da s include d i nyour model , o

nwhic hI wa s no t clear , wa s th e soil-to hous e dus t route . Yo uha da ter

m inyour regressio nfo r soil , but tha t wa s a tota l soi l sampl e rathe r thana surfac e EXECUTIVE COUR T REPORTER S (301 ) 565-006 4* - -

-

. , .



# i 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 22 2 3 2 4 2 5 9 2 soi l number .

MR . COHEN : Tha t wa s surface . Th e measurement s were ? derive d fro m outdoo r soil . DR . CLARK ; On e o f th e tables , I think , wa s stree t dir t and soi1 .

MR . COHEN : Yes . I t i s reall ysurface-to-surfac e layer s tha t ma yb e 1 , 2 , o r 3 centimeters , no t goin g anyfarthe r tha n that . CHAIRMA

NLARSON : I s tha t th e same surfac e tha t youwer e referring to ?

DR . CLARK : Well , no t really . Actually , ou

r surfac e i s reall y wha t we canscrap e of f wit ha spatul a o na hardpack . I t i s surprising : yo ucan ge t a reall y

quantitativ e measur e there . Yo udon' t di g dow n in . Mos t soil s wher e childre nar e ar e no t loose . You are no t going t o fin dman y schoo l playground s wher e i t i s lik e a garden . I t jus t i s not . Th e hous e dus t i s als o a critica l component . I t canb e tracke dinb y childre no

r pets , b e brough t inb y wind , whatever . I

t doe s no t have t o b e tha t child , it canb e a n adult . But th e pathway appear s t o b e very clearl y

fro m th e outsid e surface , insid e surface , t o th e hand . Regardles s o f how i t go t o

nth e outsid e surface , tha t i s almos t EXECUTIV E COUR T REPORTER S (301 ) 565-006 4 (

i iP.9 4

b- 1

2 3 4 5 6 7 8 9 1 0 11 1 2 1 3 1 4 1 5 1 8 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 9 3 irrelevan t t o th e method , excep t fo r availability . CHAIRMA

NLARSON : I a

mtryin g t o ge t a sens e a s t o wha t exten t doe s a relativel yrapi d chang e i nan ai r leve l

r e f 1 e >:. t o n yo u r c o mp a r t me n t s .

DR . CLARK : Probabl yverylittle , dependin g upon . I f w e wer e doin g thi s 3 0 year s ago , i t woul d be different ; but no t now .

Yo u woul d no t measur e it i nmos t cases . I

nany urba n are a yo u woul d no t measur e it , I don' t thin kbecaus e th e reservoi r i s s o tremendous .

MR . HAINES : Wha t w e are reall y

talking abou t i s wha t i s a reasonabl e approximation : Tim' s questio no f how muc ho f thi s is . laid-down , quote , soil-lea dtha t may b e tracke dinb

y the pet s an

dchildren ; ho

w muc ho f it i s interio r dus t relate dt o contemporary depositio nand , b y "contemporary" , a

t leas t during tha t periodo f time . I gues s w

e are taking the approach , absen t anybod y partitionin g that.out , apportioning it , tha t th e dus t measuremen t insid e i s fairl y contemporaneousl y relate dt o th e air-qualit y

level . S o we fee l tha t i s a reasonabl e assumptio ntha t a s yo ubrin g dow

nair-lea dlevel s tha t dus t wil l mov e wit hi t in a simultaneou s fashion .

DR . CLARK : We hav e seen , I think , some remarkabl e decrease s inth e pas t 3 o r 1 0 year s inou

r surfac e EXECUTIVE COUR T REPORTER S (301 ) 565-006 4 *P.9 5



# ^J

. _>• ' 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 measurement s insid e and outside ? th e home . Ther e i s a definit e lowerin g tha t ha s t o b e associate d wit hsomethin g i n th e ai r o r outside .

Now , i t i s goin g t o tai l off . I t i s tailin g of f now . I t i s harde r t o se e an ymor e changes . Ther e i s a 5 0 percen t i n almos t al l o f ou r areas . whethe r i t i s i n th e publi c housin g area s o r i n th e olde r housin g areas . S o somethin g i s happenin g beside s change s i n th e house . MR . COHEN : Ar e thos e dat a summarized ?

DR . CLARK : No , they are not . Well , they

ar e insom

e reports . We don' t hav e the m publishe dyet .

MR . COHEN : Okay . DR . CLARK : We ar e seeing th e declin e inblood

lead s an

dal l o f ou

r othe r measures . MR . HAINES : Canw e compar e tha t t o reduction s i n gasolin e lead ?

DR . CLARK : Youcould , sure . It i s parallelin g th e chang e i

nth e lea

dadditive s usage . Tha t i s th e pas t 7 year s or so .

DR . CHISOLM : Ar e they tailin g of f towar dth e soi l concentrations ?

DR . CLARK : Oh , they ar e leveling off . Th e decreas e ha s bee nles s inth e pas t yea r o r so . EXECUTIVE COUR T REPORTER S (301 ) 565-006 4i 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 ••"•r r

DR . vo n LINDERN : Art

- an yo f thos e site s nea r thes e poin t sources ?

DR . CLARK : No . Maybe-.

- som e very smal l points , bu t r i o t hi r i g m a j or . W e ha ve som e 1_a d in d us t r i es . Ayea r and a hal f ago , w e ha d a smal 1 foundr ywit h abou t 10 0 employee s tha t had almos t every worke r wit h clinica l lea d poisoning .

The ywer e makin g poo r man' s peuter : th e ol d 9 2 percen t lea d peuter . On e o f th e loca l industrie s decide d thi s wa s a nic e gif t t o giv e thei r employee s an dretiree s a

t Christma s time . : "

S o th e order s fro

m thi s foundry

increase d50-fold . They hadno control s i nthe plant , n o showers , an dpeopl e carrie denormou s amount s of lead . Peopl e are stil l being affecte db

y that . Ther e ar e som

e adult s who ar e actuall y going u

pin blood-lea dafte r a yea r an da half , jus t a very majo r source . Tha t wa s ina suburb . I didn' t hav e muchimpac t o nth e cit y itself . DR . MUSHAK : Youar e looking a t th e children , too ? DR . CLARK : Nobod y ha s concertedl y

becaus e it i s al l ove r th e place .

DR . MUSHAK : They ar e a perfec t target . DR . CLARK : The healt hdepartmen t wa s looking a t a few , doing some screening , an dw e hav e screene dan dteste d

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4

" " " y P.9 6P.9 7

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 som e outside r o f the ? cit yan d don e some ? o i measurements .

D R . MUS H AK : J u d g i n g f r o mt h i e 1 a c k o f o c c : u p a 1 1 o ria l hygiene , I woul d sa ytha t th e home s o f thes e worker s woul d b e mos t affected .

D R . C L A R K : 0 h, yes . T he r e we r e s o m_ • c hi 1 c

l r e n who

wer e affected . On e mothe r i n particular , I know , 'wa_

- pregnan t workin g a t th e foundr yfo r th e whol e pregnancy . Th e chil d i s i n th e SO s o r 90 s an d ha s develope d menta l problems .

Thi s wa s a perso n livin g i n a mobil e hom e 5 0 mile s i n th e country .

CHAIRMA NLARSON : I hav e m yChairman' s ha t o n her e lookin g a t th e agenda . Mayb e w e ca n ge t th e discussio n starte d i n ful l gea r agai n afte r lunch . Perhap s yo u ca n hol d you r comment s unti l them .

I f w e brea k fo r lunc hno wan d retur n a t 1:30 , tha t wil l giv e u s a n hou r t o complet e ou r discussio n her e an d the n hav e a chanc e t o hea r abou t th e cas e stud yapplications .

Okay . Than k you . CA t 12:3 0 p.m. , th e meetin g recesse d t o reconven e a t 2:0 4 p.m. , thi s sam e day. ]

EXECUTIV E COUR T REPORTER S (301 ) 565-005 4~.m>.'.'••.'-

" n.— '.-

. • 5P-= ' ' ."' : '" ' tijjy 1

2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 8 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 9 7 AFTERNOO NSESSIO N CHAIRMA

NLARSON : Wh

ydon' t w e reconvene . I thin k

w e are movin g alon g adequatel ystil l tryin g t o sta yo n targe t for 4:00 . W e wil l pic k u p wher e w e lef t off , wit hadditiona l comment s o n th e genera l document .

Dr . Rabinowitz ? DR . RABINOWITZ : M yfortun e cooki e sai d tha t "I f yo u ea t dirt , yo u shoul d ea t clea n dirt. "

[Laughter 3 Th e documen t i s commendable . I t i s a difficul t tas kan

dI thinkthe author s di da s wel l a s they coul dwit h th e gap s i n th e information .

I gues s tha t i s it b y wa y o f genera l comment . Jus t having the discussio nno w i s helpfu l t o m

e t o kin do f se e wher e thi s i s going . Tha t i s on e thing I misse d inreading it throughth e firs t time : Wh y are we doing thes e differen t models , an dwha t i s th e purpos e o f al l this ? I a m sur e th e next draf t wil l hav e tha t al l take n car e of . CHAIRMA N LARSON : I thin

kw e hav e a

nopportunity , perhaps , t o ge t a fina l se t o f comment s afte r we hea r th e late r presentation s thi s afternoon . I a m sur e yo uwil l hav e some othe r reaction s t o shar e afte r yo uhea r those .

Dr . Mushak ? DR . MUSHAK : I though t the repor t an dth e whol e EXECUTIVE COUR T REPORTER S (301 ) 565-006 4P.9 9

,

te. -__ i 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 9 8 exercis e wa s a coumendabl e job . I thin k tha t i t als o reflect s th e growt ho f sophisticatio n i n ho wth e Environmenta l Protectio n Agenc yi s goin g abou t it s business .

Abou t 1 1 year s ago , I sa t dow n wit ha grou p o f OAQP S type s t o tak e a loo k a t articulatin g a starteg yfo r a n air-le.'a

d standard . Basicall yI gues s yo u ca n encapsulat e th e gis t o f i t i n abou t tw o paragraphs : forge t pag e afte r pag e o f rigmaroles , jus t th e essenc e o f i t wa s tw o paragraphs .

Hav e somethin g o n frequenc ydistribution , loo k a t somethin g abou t everythin g excep t ai r an dge t a PB A lette r o f abou t 2 an d yo u ge t 1.5 .

W e hav e com e a lon g wa y sinc e then . Th e repor t ha s probabl ytake n th e parameter s a s fa r a s w e ca ng o wit h them , bu t I thin k w e ough t no t t o bas hth e uncertaint y becaus e I thin k tha t i t ha s bee nsai dby publi c healt htype s al l th e tim e tha t ther e i s compellin g evidenc e an dthe nther e i s irrefutabl e evidence .

Tha t is , onc e evidenc e i s compellin g w e ough t no t t o insis t tha t i t b e irrefutabl e fro m a publi c healt h protectio nstance .

Thi s i s a stanc e whic hI thin kth e Environmenta l Protectio nAgenc y is , bot hlegall y an dmorally , mandate dt o practice . Also , I thin kneed s are bot hcompellin g an d irrefutable . I thin k tha t a mode l lik e thi s i s a compellin g

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4 *P. 1

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 need . Abou t th e popularit yo f th e mode l for othe r applicatio n —

i.e. , a globa l o r generi c uptak e b1. o '•• : :• . n e I .i . c model-- ! woul d se e som e utilit yin , say , thes e variou s . . 1«_._n

ups . I thin k th e clean-up s are a goo d wa yt o tes t th e irod^ I becaus e apparentl yi n Julian' s cas e i n Boston , an d i n Cincinnati , pre - an d post-blood-lead s ers bein g collect...' .

I s tha t correct ? DR . CHISOLM : That' s correct . DR . MUSHAK : S o yo u coul d validat e th e model' s applicatio n wit hpre - an d post-blood-lead s t o se e ho wthe . predictio n worked .

I woul d als o cautio n tha t i f on e i s t o us e a mode l fo r soi l lead—Jef f Cohe n an d I spok e abou t thi s briefl y before—i f yo u d o somethin g lik e a rathe r broa d traversa l dow n a soil-lead/blood-lea d slop e yo u ma yb e jumpin g fro ma non-linea r par t o f tha t model' s dominanc e t o a linear .

Yo u migh t wan t t o b e careful . A s I remembe r Ian' s curve s wit hth e competenc e limit s betwee n blood-lea d an d soil-lead , yo u ge t extrem e curvalinear it yabove , say , abou t 4,00 0 ppm . I n othe r words , PPB s becom e quit e curvalinea r abov e abou t 4,00 0 pp mo f soil .

S o on e ha s t o b e carefu l wha t rang e o f tha t hypothetica l mode l curv e yo u are speakin g of .

I thin k i t i s probabl ya goo d mode l fo r lea d i n

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4- - 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 IOC. ' certai nothe r contexts . I don' t thin k it' s generi c mode l fo r fill-i nblan k Ameta l an d the n yo u ca n d o it becaus e lead , u n f o r t u r . a t e 1 y , i s 1 1 \ e o n 1 ymo d e 1 tha t i s studie d wel l e n o u . g h tha t I thin k yo u ca n d o a mode l an d bas e thi s on .

Othe r application s o f th e model ? I gues s w e talke d briefl yove r lunc habou t th e prospec t o f pregnant

wome n a t term : loo k a t newbor n blood-lea d modeling , som e hybri d o f Mike' s early modelin g plu s th e KNIP E variation . Tha t i s somethin g t o consider .

O r yo u coul dstic kwit hth e disaggregat e mode l a s yo uar e doin g now , bu t I thin kther e i s som e virtu e in-tryin g t o mode l newbor nbloods . Yo uge t a t leas t on e mor e developmenta l point .

I thin k tha t in-uter o exposur e modelin g i s probabl y

los t t o yo u unti l ther e are som e breakthrough s i n non-hazardou s in-viv o modelin g o f sof t tissues . I don' t se e ho w tha t coul dwork .

Th e uncertaintie s hav e bee nconsidered . I thin k tha t 10 0 milligram s o f dust/soi l combine dintak e i s certainl y righteous . I don' t thin ktha t number s belo w thi s ar e reall y appropriate .

Ther e i s muc hscatte r i nth e dus t an dsoi l average , bu t I thin k10 0 is —

CHAIRMA N

LARSON : A s a mea nvalue ? DR . MUSHAK : A s a mea nvalue , understandin g tha t

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4 P. 2 1

;

iP. 3

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 ther e i =

_a fai r amoun t c f sca t •__.-. • ...roun d it . W P h.ve t o realis e tha t aroun d thi s m__a n the i e are dus k intakes , soi l intake s whic hca n b e quit e huge .

I recal l tha t ther e wer e som e studie s base d o n minera l trac e element s tha t ha d gotte n level s abov e a gram . Whethe r or no t thos e ar e ou t Iye r typ e level s becaus e o f problems , I a

m not sure . I woul dsa

y i f youloo

ka t th e evidenc e i

nthe aggregate , 10 0 i s no t to o ba da number . Tha t i s i t o

nthat . CHAIRMA N LARSON : Bob ? DR . ROWE : I don' t reall y hav e a lot mor e t o sa y interm s o f al l the comment s tha t have bee nwritte nan dsai d her e i nterm s o f conducting a rura l point-source-oriente d NAAQ S exposur e assessment .

I t seem s lik e tha t wil l be fine . M y onl y commen t i s tha t i

nthe idea l o f idea l world s i t woul dsur e b e nic e t o kno w wha t evena smal l chang e inai r woul ddo inth e urba n area s becaus e we woul dprobabl y ultimatel y

hav e mor e peopl e affected . I

t may no t be the mos t cost-effectiv e strategy , bu t tha t woul db e nice . We are going t o hav e jus t smal l peopl e her e compare dt o th e urban-are a problem , but tha t ha s bee na previously-agreed-t o decisio nan dI don' t hav e an y problem

wit htha t decision . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P. 4

*— •

.«*'••

-

w-. V 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 2

So , no , I thin k w e ar e o n track . CHAIRMA NLARSON : I ! • i a v e a c o u p 1 e c o mm e r 1 1 s m ys e 1 f . Jus t fro msomebod yviewin g thi s mode l fro mafar , i t woul d b e nic e t o se e th e prediction s fro mth e f.icilit y t I- i a t yo u are

concerne d wit ho f th e concentration s o f thos e environmenta l variable s tha t are importan t i n th e ultimat e determinatio n o f blood-lead .

Specificall yi f yo u hav e a n observe dgradien t withi na fe

w mile s o f a poin t source , ca nyo uals o predic t wit hyou r mode l th e RUN C typ e o f thinking , th e air-lea dand dust-lea dno w

value s tha t yo use e i nth e mean , perhaps,•tha t yo uar e usin g ultimatel y i nth e prediction . Th e reaso nI sa y tha t i s becaus e i t become s easie r for th e not-so-familia r reade r t o distinguis hbetwee nyou r model' s abilit y

t o predic t uptak e versu s exposure . Yo ucoul d potentiall y

b e righ t for th e wron g reasons . I don' t thin kyo uare, bu t i t woul db e nic e t o hav e som e o f thos e intermediat e mea nvalue s o r media nvalue s i nther e a s well . I thin kw e hear dsom e o f tha t thi s mornin g i nterm s o f thos e particula r issues .

Tha t i s on e genera l comment . I agree , though , tha t yo uhav e com e a lon g wa y i n thi s particula r proces s an dtha t th e observatio no f a gradien t blood-lead , eve ni na limite darea , an dth e abilit y t o forecas t i t wit hsome , a t least , gradien t o r relativ e

EXECUTIV E COUR T REPORTER S (301 ) 565-006 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 20 2 1 2 2 2 3 2 4 2 5

•»• • 10 3 gradien t i s a

n impressiv e ability . Wha t I a

mhearin g i s tha t w e are onl ytalkin g her e abou t forecastin g mea n values . I ge t som e sens e tha t i f w e playe d aroun d wit hsoil-lea d average s o r whatever , w e mayo r may no t b e a s goo d i n agreemen t wit hthes e cas e studie s a s yo u . . _-: • e i n t hi s p a r t i c u 1 a r re p o r t . But , still , som e notion—an d I don' t kno who wyo u d o it-—o f whethe r or no t you r predicte d versu s you r observe d mea n value s a t differen t point s away fro m th e sourc e are differen t fromeac hother .

I don' t hav e a goo d feeling fo r ho w t o appro.ac

h tha t sinc e yo u hav e an rang e o f uncertaintie s an dno t a lot o f informatio n o n th e shap e o f th e point s inbetwee nan dth e range , bu t i t woul d b e nic e t o mak e a nattemp t t o see , eve n i f th e mode l and th e predicte d observe d leadgradient s are no t quit e th e same , tha t ther e i s some overla pther e given al l th e uncertainties .

Jus t sor t o f stepping back , it woul db e nic e t o se e th e intermediat e predictio nof , now , I gues s we ar e talkin g dust-lea dan dair-leadinth e mean , an dthe nth e resultin g forecast s fo r blood-lea dan

dthei r uncertaintie s

• compare dt o th e meanobserve dvalues , whic htake s u s t o th e nex t point .Give nsom e abilit y

t o predic t tha t mea ngradient , i s it reasonabl e t o tak e the next step , whic hi s thent o tak e EXECUTIV E COUR T REPORTER S (301 ) 565-006 4

• • . • P. 5

>P. 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 

### ?1 2 2 2 3 2 4 2 5 tha t mean , o r mea n prediction , fro mth e mode l and appl y, . geometri c standar d deviatio n a s i s propose d her e _n tern s :.. f forecastin g th e numbe r o f children , i n thi s case , tha t ar e ._ ; - ; exces s o f X blood ?

I woul d b e intereste d i n hearin g othe r Commit.e e members ' reaction s t o tha t particula r approac ht o thi s variabilit y

issue . W e hav e hear d a lo t abou t al l th e potentia l source s o f variabilit yi n th e actua l data .

DR . MAHAFFEY : I thin k wha t i s pus s lin g t o m e i s a concer nabou t whethe r o r no t thes e geometri c standar d deviation s woul dappl y a t extremel y

lo w blood-leads , tal-kin g perhap s blood-lead s unde r 10 .

Ther e i s a littl e bi t o f informatio nsuggestin g tha t yo uhav e a differen t slop e i nthe relationshi pbetwee n environmenta l lea dexposur e an

dindicator s o f blood-lead , and tha t tha t slop e wil l diffe r depending o nth e leve l o f exposure . S o whethe r o r no t yo uhav e tha t sam e standar d geometri c deviatio nacros s a wid e rang e I thinki s questionable .

Tha t i s jus t a

nopinion . CHAIRMA N LARSON : Woul dyo uexpec t it t o b e harde r t o characteris e wha t th e variabilit y is ? I s i t tha t give n th e perfec t abilit y t o characteris e i t yo uwoul dexpec t i t t o b e differen t interm s o f measurement , jus t approachin g EXECUTIVE COUR T REPORTER S (301 ) 565-006 4P. 7

10 5 1 measuremen t limits ? 2 I don' t expec t a n answer . I jus t thro wtha t out . 3 I t i s strikin g t o me . I .on' t kno wenoug habou t 4 th e NHANE S dat a set , bu t I a mreadin g i n her e tha t acros s th e 5 whol e spectru mo f blood-lea d level s i n tha t surve ything s 6 see mt o b e log-normall ydistribute d wit ha reasonabl y 7 constan t geometricall ystandar d deviation . 8 DR . MAHAFFEY : W e di dno t hav e suc hlo w lead s i n 9 that . 1 0 CHAIRMA N LARSON : Tha t i s right . 1 1 DR . MUSHAK : Tha t i s a ke y point : tha t th e lo w en d 1 2 o f th e tabl e b y 139 0 i nth e rura l cas e add s mayb e .2 5 o r . 5 . 13 pe r cubi c meter . Yo uwoul dstil l b e lookin g a t something . 14 I thin kth e analytica l varyin g proble m remain s 1 5 severe . Okay . Ther e i s n o reaso nt o expec t tha t goo dlead s 1 6 woul dperfor m an y bette r tha nthe y can ; the y

alread y

are . 1 7 An dI don' t thin ktha t poo r lead s are goin g t o ge t religio n 1 8 an y

tim e soon . 19 Yo uhav e th e analytica l facto r tha t i s drive nb y 2 0 tha t particula r configuration . 2 1 I thin kther e i s somethin g abou t th e 2 2 pharmacokinetic s o f lea dtha t ma y compe l a log-norma l 2 3 distributio nwit ha lingerin g tai l upwards . Yo use e this , 2 4 fo r example . 2 5 Yo uloo ka t foo dstuffs , anythin g tha t ha s a

_ EXECUTIVE COUR T REPORTER S (301 ) 565-006 41

, J



### -J 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 1 O b biologically—interactiv e : i n t e > 'lace. , an d i t ha s a 1 og—r.ordia l distribution . Th e concerv . r ... t ! on s av_ , 3

. i !•-..:- , part s pe r bi11ion . Whe n yo u loo k a t sit, wha t kin d o f distributio n woul d yo u se . i n ai< ?

CHAIRMA NLAF'30!'-.' L I t i s log-normal , fo r th e mos t part . Th e varianc e i s i n proportio n t o th e mea n level .

DR . MUSHAK : I mea n a t th e leve l w e ar e talkin g about , .1 , .2 .

CHAIRMA NLARSON : I thin k a t an ylevel . I thin k yo u ca n slic e i t u p ho wyo u wan t an d i t come s ou t t o be.log

normal , perhap s fo r a differen t se t o f reasons .

MR . HAINES : I t coul d be . CHAIRMA NLARSON : I woul d expec t i f yo u hav e a log-norma l distributio n tha t yo u woul d expec t th e absolut e varianc e t o shrin k a s th e mea n goe s dow n i n a proportiona l way . I t i s har d t o thin k i n lo g terms . I gues s w e ca n se e i n lo g terms .

DR . MARCUS : Actually , I thin k tha t i s it . Th e variabilit y

i n absolut e term s doe s ge t smalle r a s th e level s ge t smaller , bu t i n relativ e term s fo r a lo t o f differen t population s ove r a ver ywid e rang e o f mea n level s o f blood

lead . I f yo u don' t lik e talkin g abou t geometri c standar d

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4 P. 8 I

|P. 9

__.__ :

•th--



### J' 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 deviations , yo u ca n conver t i t int o a coefficien t o f variation , whic hi s a rati o o f a standar d deviatio n t o a mean . I t i s a familia r percentag e measur e o f variabilit yfo r blood—lead s wher e yo u hav e a variet yo f sources , n o on e o f whic hi s reall yoverwhelming .

Thi 5 i s th e situatio n w e ar e lookin g a t mor e an d mor e i n urba n and rura l area s wher e lea d i n die t contribute s somethin g an

d water-lea d contribute s somethin g and the n th e ambien t air , dus t and soi l level s als o contribut e thei r bi t s o non e o f the mi s totall ydominant .

I f yo u hav e severa l contribution s t o blood-lead , the n yo u woul d b e runnin g int o variation s fro mon e individua l t o anothe r eve n wit halmos t exactl yth e sam e exposure , almos t th e sam e location : b e runnin g int o typica l variation s i n blood-lea d whic hwoul d b e plu s o r minu s 4 0 percen t fo r GST s o f 1.4 2 scale d back ,

35 , 4 0 percen t woul d b e a typica l kind o f proportionat e variability . Thi s i s becaus e ther e i s a diversit yo f sources .

Yo u hav e biologica l variability . Peopl e diffe r i n th e amoun t tha t the yca n absor bthroug hth e duct , throug h th e lungs , wher e the yhav e a highe r ventilatio n rate . Ther e ar e lot s o f difference s fromon e individua l t o another , biologica l differences , the n difference s i n exposure .

Som e peopl e ea t mor e dir t tha n othe r peopl e and

EXECUTIV E COUR T REPORTER S (301 ) 565-0064P.1 0

1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 14 1 5 16 1 7 1 8 19 2 0 21 2 2 2 3 2 4 2 5 10 3 al l thes e contribut e tc

- tha t variability . S o a typica l measur e o f variabilit yseem s t o b e reasonabl yproportiona l t o th e mea n eve n dow n t o fairl ylo w levels . Ther e i s somethin g tha t doe s no t see mt o shrin k a t lo wlevels . A s mentioned , tha t i s th e analytica l var i abi1.. 1 y .

Yo u canno t knoc k tha t dow nlowe r thana coupl e o f microgram s pe r deciliter .

CHAIRMA

NLARSON : Tha t i s a constan t o ntopo f thing s tha t are continuall y shrinking . • DR . MARCUS : Ther e hav e no t bee nan y effort s mad e inthi s inciden t t o correc t thes e GSD s fo r th e variation s i n th e analytica l variabilit y becaus e an

y standard s tha t are se t ar e goin g t o hav e t o tak e th e fac t tha t thi s i s a built-i n measurement .

Complianc e test s hav e tha t analytica l variabilit y buil t in . S o w

e di dno t mak e an y adjustment s fo

r analytica l variabilit y

inthes e calculations . DR . MUSHAK : But th e earl y NHANE S analyse s did . MR . COHEN : Yes . I gues s th e decisio nwa s no t t o tak e tha t int o accoun t becaus e o f al l th e healt hstudie s the y wer e going t o be relating to .

CHAIRMA N LARSON : I f we ar e uncertain , collectivel y

o r individually , abou t wha t th e geometri c EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.1 1

•.--S-S.r.

-



### y- r

• V-*. : 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 standar ddeviation s woul d d o aroun d thes e site

- i n . a.icv_r. y th e source , i s ther e an y sens e o f i f the ywoul d b e ip'eaie . or les s t \

. a n the ycurrentl ya r <•

_? 'O r ca n w e no t ±.&y

that ? DR . RABINOWITZ : W e coul d jus t ventur e a guess . I ge t th e sens e tha t containe d withi n thi s log

norma l distributio n o f blood-lead s tha t w e se e ar&really

manysub-populations . Eve n i f yo u plo t the mal l togethe r an d ad dthe m up , it al l look s lik e som e log-norma l straigh t line . Ther e ar e reall y

man y differen t populations . B y changin g exposur e to , say , airborn e leadan dleaving thes e othe r factor s constant , man y peopl e wil l decreas e thei r lea d level s an

dblood-leads . Everybod y wil l tak e a ste pt o th e left , a s it were .

But man

y people , some sub-populations , ar e stil l getting lea

dfro m som e othe r non-ai r source . Thes e peopl e wil l no t trac kwher e the other s track .

Yo uare going t o se e a broadenin g o f th e distribution . Th e magnitud e o f tha t broadening ? Gee , I don' t know , but i t woul db e surprise di f everybody uniforml y kept th e sam

e varianc e an

ddecrease dth e mean . I s i t possibl e t o thinkinterm s o f keeping the varianc e a s larg e a s it i s an djus t decreasin g th e meana s on e extreme se t o f possibilities ? The nyo uwin du pwit h havin g some tail , some high-exposur e tai l which , eve nthough

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 21 2 2 2 3 2 4 2 5 11 0 yo uhav e ser o lea d i n th e air , .yo u ars stil l goin g t o h..v

_ thes e childre n gettin g lea d fro mothe r sources .

DR . MUSHAK : Bu t t he n w e a r e g e1 1 i n g ba c k t o t hi s pain t an d non-paint , ari d rural . W e wen t throug htha t onc e before . Presumabl yyo u are goin g t o b e fairl ywel l ri do f pain t exposures , o r eve n th e idiosyncrati c exposure , cultura l exposure . S o tha t shoul db e minimum .

DR . MARCUS : Thes e are al l plausibl e way s o f dealin g wit hit , bu t shor t o f actuall y lookin g a t a situatio n i nwhic hther e i s goin g t o b e a substantia l chang e i n exposur e an dlookin g a t childre nbefor e an dafter , an d trackin g whic hone s ha dthei r blood-lead s dro pa lo t an d whic hone s di dno t hav e thei r blood-lead s drop s s o muc h becaus e the y

wer e no t gettin g i t fro m tha t kin do f exposur e anyway . Shor t o f actuall y doin g thes e studie s wher e yo ud o manipulat e th e lea dexposur e i nth e environment , I don't ; thin kw e have , quote , th e right , en dquote , answe r t o this .

S o th e attempt , a t least , t o estimat e th e fractio n

o f high-lea dchildre nb y assumin g a constan t proportiona l variabilit y

seeme dlik e a reasonabl e approach . W e ar e certainl y

agreeabl e t o lookin g a t othe r alternative s tha t ar e suggested .

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.1 3

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 CHAIRMA N! . ARSON : Seman t 5 c s l 1 y , don' t w e reall y hav e tw o differen t ft,ode-Is , though , here ? W e hav e a n uptak e biokineti c mode l whic hpredict s th e means , an d the n w e hav e anothe r mode l whic hpredict s th e variabilit ywithi n th e populatio n tha t shoul d no t b e confuse d wit hth e uptak e bi ok i ne t i c model .

S o w e coul d mak e tha t distinction . I thin k i t woul db e useful , a t least , fo r peopl e t o kno w tha t the yar e reall y tw o differen t model s comin g fro mtw o differen t places . MR . COHEN : Ther e wa s on e dat a set , th e NHANE S II , wher e w e di dhav e th e opportunit y t o pla y

wit hth e shap e o f th e distribution . Joe l Schwart z looke da t differen t cut-off s an dmove dchildre ndown , movin g downth e mea nassociate dwit h tha t from

40 , let' s say , or 3 0 microgram s pe r deciliter . I nothe r words , h e woul dtak e al l th e childre n abov e 4 0 andmov e the m downsomewher e else . W e foun dtha t th e GS Dreall y di dno t chang e significantl y

whe nh e di dthat . DR . RABINOWITZ : Ho w di dh e mov e the m down ? Yo u mea ndow nby

selectin g sub-group s wit hlowe r exposure ? MR . COHEN : H e too kth e sub-group s wit hhighe r exposur e an dtaile dthem . I t reall y boile ddownt o th e fac t ther e jus t wer e no t tha t man y childre nu pthere ; bu t i f yo u us e 4 0 a s a cut-off , I thin kth e GS Dchange dfro m 1.4 3 t o 1.42 . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.1 4

1

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. . . _r.•*_:.. - .. . •:k«% M ••

•;-: •

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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 .JJa DR . RABINOWITZ ; Verysmal l difference . MR . COHEN : Yes . I thin k w e talke d abou t doin g tha t kin do f thin g wit hth e Eas t Helen a dat a t o se e wha t effec t i t woul d hav e o n th e overal l GSD , anticipatin g tha t a lo t o f thes e childre n woul d hav e lowe r exposure s i n th e future .

W e hav e no t don e that , bu t w e could . DR . RABINOWITZ : Ar e yo u satisfie d wit hth e biokineti c modeling tha t the variabilit y tha t yo use e wit h al l thes e differen t term s find s it s wa y int o th e en

do f the model ? .. .

Thi s mode l i s usedt o generat e distributio na t th e en dan dit i s basedo

ncertai no f thes e variables . Eac ho f thes e variable s ha s uncertaintie s associate dwit hit .

Whenyouput the

m al l togethe r inth e model , al l thes e uncertaintie s shoul dad do r compoundinsome way . I don' t kno

w i f yo ufee l tha t tha t i s being take nint o account . DR . MARCUS : Wha t youcoul dd o inth e extremel y idea l univers e i s tak e al l thes e 2 0 o r s o inpu t parameters , conven e a pane l o f expert s t o tel l yo uwha t th e distributio n o f parameter s i s inth e biologica l o r exposur e population , an dd o humongou s simulatio nwit ha distributio no f every on e o f thos e parameters .

Thi s woul dgiv e yousom e way o f propogatin g th e uncertaintie s throughth e model . Thi s i s no t a feasibl e EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.1 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 progra m

righ t a t th e moment , I think . W e hav e don e sensitivit yanalyse s wit ha coupl e o f th e parameter s tha t were , a priori , though t t o b e th e mos t sensitive , includin g th e absorptio n rates , whic hha d actuall y som e empirica l support . W e are going t o loo ka t th e Eas t He I e n a . Bu t shor t o f a systemati c exploratio no f th e sensitivit yo f th e mode l t o plausibl e distribution s ove r al l thos e inputs , i

nman y case s w

e woul db e dealing wit ha n almos t non-existen t empirica l dat a bas e t o do that .

Yes , I woul dlik e t o be abl e t o d o tha t an dthen say , "I f youpropogat e al l thes e uncertaintie s through , her e i s th e rea l uncertainty" ; but it look s lik e a lo t o f work righ t now . I suspec t w e woul den

du pcreatin g a versio no f th e centra l limi t ther e whic hsay s tha t i f youad du pa bunc h of things , it turn s out t o b e abou t normall y distributed . Her e we ar e going - t o en du pwit hsor t o f multiplicativ e factor s becaus e uncertaint y inabsorptio nrat e multiplie s t o uncertaint y

inth e amoun t o f dir t tha t i s eate nwhic h multiplie s int o something els e an dyouwil l en

dupwit ha log-norma l distribution , prett y near , becaus e o f th e larg e numbe r o f thing s tha t multipl y eachother . Yes , it i s possible ; but I don' t thinktha t w e ar e going t o hav e grossl y differen t result s eve ni f we coul d

EXECUTIVE COUR T REPORTER S (301 ) 565-006 4P.1 6

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 .) carr you t tha t progra man d i f w e knew.wha t kind s o f

uncertaintie s i n som e :••' thes e inpu t parameter s w e woul d b e dealin g with .

'DR . RABINOWITZ : M yconcern , mayb e echoin g Dr . Marcu s said , wa s tha t whe n yo u ar(.ial l don e yo u don' t wan t t o hav e to o muc hfait htha t you r answe r i s finall yright' , tha t someho wyo u hav e t o have , ai l th e caveat s an d th e uncertaintie s i n th e fina l results .

I don' t kno who wyo u d o tha t carefully . DR . MARCUS : I thin k ou r concer n i s particula r wit hthos e wh o are mos t highl ya t risk ; an d tha t w e are-no t goin g t o b e greatl yunderestimatin g th e high-ris k sub

population . Tha t i s wh yw e ar e tendin g toward s th e us e o f a large r GS D tha n i n som e studies .

DR . MUSHAK : Yes . MR . HAINES : Th e othe r poin t I wante d t o mak e i s ou r purpos e o f th e mode l i s t o loo k a t relativ e difference s betwee n alternativ e strategie s eventually . I a mtryin g t o sa yw e coul d b e of f i n th e absolut e number , bu t i f w e sho w th s delta s betwee n standar d Aan d standar d B , eve n thoug hw e ma y b e lo wi n bot hcase s o r to o hig hi n bot hcases , i t i s th e relativ e additiona l protectio n on e alternativ e ha s ove r anothe r tha t i s wha t w e ar e seeking .

I fee l tha t th e mode l behave s itsel f reasonabl y

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.1 7

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 well . W

e m a y be r , o t qui t e f i n d i n g pr o o f i n o u. r pr e d i c t i v e power , bu t i f w e ca n ge t a reasonabl e benchmar k sn d hel p th e dec i s i or.-make r decid e betwee n tw o alternatives , w e ma yb e somewhere . DR . RABINOWITZ : A s lon g a s peopl e don't , then , us e it fo r somethin g else , i t wil l b e al l right . Tha t i s a hazard . MR . HAINES : W e wil l worr yabou t mis-applicatio n

o f model s later .

[Laughter ] DR . vo n LINDERN : I ca ntel l yo uwha t our experienc e ha s beenbac kinthe day s whenit reall y use dt o rai nleadinou

r communit y

an dou r blood-lea dlevel s wer e 20 , 30 , 40 , SO , 10 0 an dabove . W e sa w tha t standar ddeviatio ncollaps e somewher e dow ntowar d1.3 . I thin ktha t i s probabl y reflectiv e o f a biologica l an

danalytica l variance . Nowaday s we se e i t pushe dbeyond1.4 2 an di t i s u

p abou t 1. 5 now . I thinktha t i s becaus e we ar e dealin g wit h mor e tha non e pathway o r exposur e route . Whe nyouhav e tw

o o r thre e exposur e route s tha t ar e competing , tha t add s t o tha t variance .

I woul dexpect , a s we ge t towar dlowe r blood-lea d level s whe ndifferen t route s canhav e mor e equa l influence , yo uar e going t o hav e t o g o t o a large r number . EXECUTIVE COUR T REPORTER S (301 ) 565-006 4P.1 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 

# J *•:.'.:•••/. rrjr y T i i i • : o c a r r y!..!•-

• i s guess , s i n ::. e w e

ar e guessing , slightl y'a i i'ler , whe n y:. u ar e goin g t o pathway s wher e ther e i s no t suc ha c I ea r dominatio n o f on e

ove r another , yo u ma yhav e som e rea l difference s i n th e bio

availabilit yo f th e differen t sources .

Sem e o f wha t w e se e a s a fairl yincreas e i n intak e

o f bloo d —lead-

- I a mthinkin g o f .h e studie s wit hth e infant s wher e ther e wa s wate r use d fo r makin g infan t formul a an d i t looke d lik e there ? wa s a fairl y rapi d increas e i nblood-lead — tha t ma y

b e age , i t ma y b e a differenc e i npreviou s bod y storie s o f lead . I t coul db e a lo t o f things .

I t coul db e bio-availability . I thin kwit hblood-lead s othe r circumstance s applying standar ddeviation s obtaine dfro m othe r dat a set s i s somethin g tha t i s chanc y t o do . I

na wa y i t i s supporting wha t Ia

nan dMik e hav e beensaying . I a m no t sur e I a

m expressin g i t clearly . CHAIRMA N LARSON : Woul dyo ub e mor e comfortabl e wit ha rang e o f GSDs ?

I f yo uleav e the

m withou t th e optio no f Mode l 2 , whic hi s thi s GS Dapplicatio nt o th e mean , the nthey are bac k to squar e zer o interm s o f predictin g th e level s o f thos e children . DR . vonLINDERN : I thinki t i s th e way t o d o it . Whe nyouse e ou

r document , youwil l se e we di di t tha t way , EXECUTIVE COUR T REPORTER S (301 ) 565-006 4P.1 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 too . -Laughter ]

DR . RABINOWITZ : Whic hwa s ar e yo u referrin g t o now':- ' DR . vo n LINDERN : I t is , bu t I amsur e everyone her e i s awar e tha t tha t become s a very, ver ysensitiv e parameter , though , whe n yo u ar e talkin g abou t th e percentag e o f childre n tha t excee d th e blood-lea d leve l and w e ar e talkin g abou t protectin g inthe 2 , 3 , 5 percen t leve l o r whateve r the yselect .

The. t i s a

nimportan t value . I thinkw e shoul. d recognis e that .

DR . MARCUS : Mayb e I shoul daddres s thi s t o th e Committe e a s a whole .

Woul dyou , then , t o compar e th e sensitivit y o f thes e estimate s t o a populatio nwit hmor e variabilit y t o se e whethe r o

r no t tha t make s a difference ? DR . vonLINDERN : Certainly . I thinkprobabl y th e wa y t o expres s tha t i s inpercen t exceedances , wher e w e en d up . DR . MARCUS : Okay .

DR . vonLINDERN : Th e questio ni s wha t ar e th e blood-lea dvalues ; but tha t i s no t her e t o b e decided .

CHAIRMA N LARSON : I gues s we ar e saying tha t tha t i s a nimportan t parameter . I t shoul dno t b e defended , i f you

> . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.2 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 will , fro m th e pu re 1 yup tak e b i o k i ne ti capp roa.h

. I tcoul d b e defended , bu ti ti s obviousl ya -rsry sensitiv e paramete ri n th e whol e result

.

A r e ther e an yothe rcomment s fro m th e Conin.itte e members' "

r1.1 . . .. . .. . .. . _ _. _-i _r. o f tipoii.- , J W e can no whea r fromyo u fello wabou t th e cas e s t ud i es . MR . COHEN : Okay .

Befor e w e leav e this , befor e th e brea kIa ntalke d abou t typica l soi l ingestio n rate s tha t they derive din Bunke r Hill .

I gues s on e thing tha t we shoul dnot e intha t populatio ni s ther e wa s a lon g history

o f sever e lead poisonin g problems . Ther e wa s a lo t o f publicit y an da very aggressiv e interventio n progra m tha t ma

y hav e resulte dina highe r consciousnes s abou t sanitary nhabit s onth e par t o f parents . I ten

dt o no t us e th e typica l Bunke r Hil l chil da s compare dt o th e quote/unquot e high-ris kcas e fo r extrapolatin g fro m th e mode l t o th e place s an dno t presume tha t thes e othe r place s woul dhav e th e same kind s o f educatio no

r publi c healt hawareness . CHAIRMA N LARSON : I s thi s gettin g bac kt o th e issu e o f ho

w man y milligram s o f dir t we ea t per day ?

EXECUTIVE COUR T REPORTER S (301 ) 565-006 4P.2 1



# __ J 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 . t i '-/1:. ' v. ' hea rin q MR

. COHEN : Right

. CHAIRMA

NLARSON : I t seem s fe w number s gettin g passe d around .

DP . MUSHAK : Thi s busines s o f educatio n _\r. d parenta l apprehensio n i n drivin g down tlia t numbe kno w o f a case—i t ha s no t bee n writte n u p i n an

yforma l way —i n easter n Pennsylvani a wher e afte r ther e ha d bee n a lo t o f communit ypublicit yth e parent s literall ychase d th e childre nint o thei r ow nhouses . I t wa s tha t kin

do f cultur e t o begi nwith : blue collar , very

stringen t attentio no nkids . Thos e kid s wer e literall y

harassed . Some of th e psychologica l problem s ma y b e wors e thanth e problem .

[Laughte r 3 Th e fac t remaining i s I thinkonc e youhav e a pervasiv e communit y awareness , parentally , o f the . problem s in tha t issu e yo uar e going t o turnu pwit hles s an

dles s of a problem . We canse e it anecdotall y inth e Bunke r Hil l situation . S o i t ma y no t be appropriate . I nothe r words , th e idea l cas e i s i f ther e wer e n o awarenes s an deverybody

wa s doing th e same ol dthing , wha t woul db e th e average ?

DR . vonLINDERN : For thos e wh o wan t t o punis h yourselves , thi s i s th e report . I t wa s jus t sent out Friday . EXECUTIVE COUR T REPORTER S (301 ) 565-006 41 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 ) I a m sur e ther e ar e copie s availabl e for t o revie wit .

I t i s a proposa l an d i t i s subjec t t o chang e base d

o n al l th e comment s tha t com e i n ove r th e nex t month ; but , o n Jeff' s point , th e positio n tha t ha s bee n lai d ou t a t thi s tim e i s tha t w e expec t thos e value s ar e depresse d a s a resul t o f year s o f attentio n bein g pai d t o thi s proble mu p there .

I thin k tha t i s particularl ytru e wit hth e typica l child , perhap s no t s o tru e wit hth e high-ris kchild . Mayb e on e o f th e reason s why i t i s a high-ris kchil di s becaus e i t ha s no t worke dwit hth e high-ris kchild .

S o th e recommendatio na t thi s poin t i s t o us e 10 0 milligram s pe r da y t o represen t a two-year-old , an di t i s base donth e recommendatio nof— I canno t remembe r ou t o f whic hoffic e o f Environmenta l Protectio nAgenc y i t came— a symposiu m

onsoi l ingestio nrates . DR . MARCUS : I believ e tha t wa s th e Exposur e Assessmen t Group . I a m no t rea l sure . DR . vo nLINDERN : A t thi s point , w e thin kth e 10 0 milligram s pe r da y i s appropriate . W e don' t se e an y reason , a t leas t i nou r data , t o us e an y othe r number . CHAIRMA N

LARSON : An dyo uappl y a GS Do ntha t mea n prediction ? MR . COHEN : Aroun dthat , that' s right : aroun dth e en dresult . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.2 3

1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 i 2 1 CHAIRMA NLARS0N : I a msomewha t c o n f use d b yt h e notio n o f a high-ris k perso n versu s th e averag e person .

DR . vo n LINDERN : I hop e I anticipat e thi s answer . Yo1.1 . carino t th i n k o f a h i gh- r i s k chil d i n th e Bunke r Hil l situatio n i n term s o f p i us-tw o standar d deviations , tha t typ e o f thing . Ther e i s a fairl y substantia l percentag e o f ou r childre n wh o ar e a t hig hris k becaus e the yar e livin g i n a n environmen t a t a hig h concentration .

Tha t doe s no t appl ythat , statistically , i t i s a plu s o r minu s standar dtw o deviatio ntyp e o f thing . It.i s a profil e tha t w e use .

I don' t kno w

wha t th e exac t percentag e is , bu t i t i s quit e a bi t highe r tha nthat .

CHAIRMA N

LARSON : Woul dtha t typ e o f informatio n b e availabl e fo r thes e othe r place s wher e yo uar e plannin g t o thi s extrapolatio nsor t o f thing ?

MR . COHEN : No t tha t I kno w of . MR . HAINES : Eas t Helen a i s probabl y th e only othe r dat a set .

MR . COHEN : An dEas t Helen a wa s th e stud y locatio n fo r th e Binde r an dal l stud y action , th e sourc e o f ou r estimate . DR . RABINOWITZ : Ar e yo ui ntouc hwit hChuc k Gilbert ?

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.2 4

1 MR . COHEN : Yes . 2 DR . RABINOWITZ : H e ha d numbers . 3 MR . COHEN : I hav e no t talke d t o hi mi n thre e 4 months , bu t I hav e bee n keepin g i n touc hwit hPau l Whit e wh o 5 i s als o doin g a simila r stud you t i n Washingto n State . W e 6 are anticipatin g thos e results . 7 Hopefull yw e wil l b e abl e t o incorporat e thos e 8 int o ou r fina l se t o f parameters . 9 CHAIRMA NLARSON : Okay , Jeff . 1 0 MR . COHEN : I n ou r handouts , i t i s th e secon d 1 1 table . 1 2 DR . vo nLINDERN : I hav e tha t referenc e i f yo uar e 1 3 intereste di n it : £2____oguie m 2J

_Oi l i-Q_

____._--_-_

I _f__E2-l--____' £. 2 1 4 _-2i_

___Q_

_ D___-__J L Ei_____-A_2_-_?<5-2_D_§Q_

_Form . Tha t wa s ORD , March . 1 5 MR . COHEN : Marc h1988 ? 16 CAS E STUD YRESULT S AN DDISCUSSIO N 1 7 MR . COHEN : I a m goin g t o sho w yo usom e 1 8 preliminar y result s actuall y runnin g thi s model , wher e w e 19 hav e bee ndebatin g abou t thi s model . Thes e are i n 2 0 population s o f childre nlivin g nea r Eas t Helen a an da 2 1 secondar y

populatio ni nDallas . 2 2 W e looke da t variou s alternativ e scenarios , 2 3 includin g a quarterl y averag e standard , whic hi s equivalen t 2 4 t o th e curren t level , 1.5 , an dthe nfiv e alternativ e monthl y 2 5 averag e standard s betwee n. 5 an d1.5 . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.2 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 W e als o estimate d •

_ hi . 1 d r en " s b1 oo d - 1 ea d wi t ht he aggregat e mode l an d adults ' usin g th e disaggregat e approach , a s describe d i n th e report . Thi s i s obviousl ytake n u p i n th e recommendation s w e hav e bee n hearin g today .

Again , w e hav e assume d tw o alternativ e soil-lea d scenarios : on e wher e soil-lea d i s maintaine d a t baselin e level s regardles s o f wha t air-lea d change s occurre d afte r 1990 ; an

d th e othe r alternativ e i s assumin g that , fo r whateve r reason , soil-lea d doe s respondinstantaneously .

W e wer e uncertai nwha t th e righ t cal l i s there . We jus t wante dt o balanc e wha t migh t b e plausible .

DR . RABINOWITZ : Baseline . Yo udon' t mea n background . MR . COHEN : Baselin e ai r qualit y a s i t exist s today . DR . RABINOWITZ : Okay .

MR . COHEN : Thi s i s Scenari o 2 , whic hwe fee l i s th e mor e plausibl e scenario , keeping soi l a t constan t ove r th e new

fe w years . Dalla s an dEas t Helen a ar e listed : 24 1 childre ninDallas , 21 7 inEas t Helena .

Meanblood-lead s are show nfo r the - differen t scenario s an

dusing th e GS Do f 1.4 2 we calculate dpercentage s abov e selecte dblood-leads . They ar e jus t show

na s examples . Th e 2 5 is , I think , stil l currentl y CBC' s definitio no f toxicity . I t probabl y

wil l chang e i nth e nea r EXECUTIVE COUR T REPORTER S (301 ) 565-006 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 future , Ii mag in.-: ,

DR . MARCUS : Th e bettin g i s i t wil l drop . MR . COHEN : Right . DR . vo n LINDERN : Wha t i s you r soi l assumptio n there ? MR . COHEN : Th e soi l assumptio n i s tha t i t i s se t a t whateve r ai r qualit yi s i n 1990 , excep t fo r th e baselin e case . I n othe r words , air-lea d ha s bee n fairl yconstan t ove r th e previou s year s and th e soil-lea d i s estimate d base d o n tha t ai r quality .

Afte r th e ne wstandard.i s set , i t remain s fiyed . DR . vo n LINDERN : S o i t cam e fro mtha t formul a yo u discusse d before ?

MR . COHEN : Yes . Tha t i s an equilibrate d soil , and base d o n tha t progressio n model .

Jus t t o rea d acros s th e to p lin e t o giv e yo u an ide a o f wha t i s goin g on , fo r th e 198 8 baselin e i n Dalla s w e hav e a mea n blood-lea d o f 7.5 . 2 0 percen t o r s o o f th e childre n woul d b e abou t 1 0 and 2. 3 percen t woul d b e abou t 1 5 and .0 3 abov e 25 .

DR . MUSHAK : Tha t i s fo r certai n air-lead s and certia nsoil-leads .

MR . COHEN : Yes . I t i s actuall ya certai n air

leadstandar d and th e associate d air-qualit yimpact s aroun d th e sourc e give n tha t standard . 

# J EXECUTIV E COUR T REPORTER S (301 ) 565-006 4

# J

_.-fc . 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 12 5

DR . vo n LINDERN : D o yo u kno wwha t tha t numbe r i s o f th e lea d equilibrated ?

MR . COHEN : W e estimat e ai r qualit ya t th e highes t recepto r point , dus t a t tha t standard , whateve r standar d tha t w e ar e lookin g at .

DR . vo n LINDERN : S o whe n w e ar e lookin g a t 1.5 , w e ar e sayin g 1. 5 i s th e maximum recepto r point . MR . COHEN : The n th e ai r qualit ywoul d b e disperse d i n th e mode l aroun d that . Soil-lea dwoul db e predicte dfo r eac hrecepto r poin t an dspreadout o

na block

— by-bloc kbasi s i n thi s cas e basedo nth e regressio nmodel , o f th e equilibrate dsoi l air-lea drelationships .

I don' t hav e it here , but I wa s going to sho w yo u th e result s tha t w e go t fro

m the aggregat e mode l fo r children . Tha t i s wher e w e us e th e air/blood/soil-leve l slop e simila r t o wha t wa s don e in1978 .

I thinki t i s inth e hand-out . I t i s a plo t o f th e result s looking a t onl y percentage s abov e 1 0 microgram s per decimeter . Yo ucanse e the sensitivit y o f th e result s an dse e wha t soi l scenari o yo ulookat .

Scenari o 1 , again , i s assuming tha t air-lea d produce s a

ninstantaneou s chang e insoil-lea dlevels . Yo u canals o se e tha t ther e ar e some difference s betwee n locations : Dallas , inon e scenari o havin g lowe r blood-leads ; inth e othe r slightl y highe r fo

r th e lowe r standards . EXECUTIV E COUR T REPORTER S (301 ) 565-006 41 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 Of f th e grap hwould-b e baselin e percentages , whic h ar e lis J e d ov^r

there . I think I d o hav e a plo t o f th e result s for th e aggregat e model , obviousl yo n on e scenari o jus t lo o I : ing a t th e ai . r- 1 ead/ b1 ood- 1 e. a d relationshi p directl y withou t goin g throug hsoil-lea d assumptions .

DR . vo n LINDERN : Ther e i s a differenc e i n tha t becaus e o f th e geographi c lay-ou t o f th e area?

MR . COHEN : Yes , an d becaus e o f th e air-qualit y impacts . DR . vo n LINDERN : The modeling impact s wher e th e receptor s are?

DR . McLAMB : An

dth e distributio no f people . MR . HAINES : Ho

w clos e they

are t o th e site . DR . McLAMB : Exactly . Ar e the y coinciden t wit h th e hig hrecepto r value s fo r th e modelin g exercise ? MR . COHEN : We have don e the same kind s o f thing s fo r middle-ag e men , inthi s cas e whites , using th e disaggregat e model . Again , yo ucoul dse e th e mea nblood leads , percentage s abov e variou s selecte dcut-offs .

I nthi s case , w

e wen t dow

nt o 8 , 1 0 at 15 . I n Dallas , fo

r example , we predic t 18-1/ 2 percen t woul db e abov e 8 , 5. 4 percen t woul db e abov e 1 0 in198 8 baseline .

Fro m wha t we heardtoday , I thinkwe nee dt o re examin e th e methodology we us e t o estimat e blood-lead s fo r women ; but using wha t i s describe di nth e repor t a s i t stand s 

# J EXECUTIVE COUR T REPORTER S (301 ) 565-006 41 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 , w e hav e som e result s for them , too .

Again , yo u ca n se e th e smal l incrementa l improvement s a s yo u g o t o lowe r an d lowe r standard s i n th e mean : no t _\

s sensitiv e a s childre n are a t th e highe r end . Onc e w e arriv e a

t cas e studyresult s tha t we . are comfortabl e with , w e woul d lik e t o incorporat e the mint o th e draf t staf f pape r i n earl y1939 . Th e staf f pape r wil l contai n recommendation s o n alternativ e standards .

Th e focu s wil l b e blood-lea dlevel s o f concer n base do

nth e criteri a documen t assessment , whateve r update d assessmen t tha t ECA Owil l win

du pdoing . We wil l als o hav e recommendation s o nth e aggregat e time o f th e standard , monitorin g frequency .

Cas e stud

y result s wil l als o be incorporate dint o th e benefit s analysis . Tha t methodology wa s reviewe db

y a subcommitte e las t year . Thos e result s wil l b e incorporate d int o th e overal l regulator y impac t analyses . Dav e McLam

bwil l tal kabou t thi s b y th e en

do f th e day . Tha t i s al l I wante dt o sho w yo ufo

r now . DR . RABINOWITZ : O nthe hand-outs , o npag e 4 4 wher e we hav e th e result s o f th e disaggregat e mode l fo r wome n o f child-bearin g age , ther e i s a nasteris kan

di t refer s t o children . Tha t i s th e en do f it ?

EXECUTIVE COUR T REPORTER S (301 ) 565-006 4--..__

. 1

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 2 1 2 2 2 3 2 4 2 5 page ' 12 1 MR

. COHEN : No

. DR

. RABINOWITZ : Mayb e tha ti s fro m a differen t

MR

. COHEN : Yes

. DR . RABINOWITZ : Okay . MR . COHEN : I t shoul d rea d "Women , 1 5 t o 4 4 year s o f age. " DR . MUSHAK : Wha t d o thos e refe r to ?

MR . COHEN : Th e actua l numbe r o f peopl e tha t wer e withi nthos e areas . Tha t i s basedo nCensu s data . DR . MUSHAK : S o we ar e talking abou t 2 0 people ? MR . COHEN : 2 0 wome nintha t ag e group : a really , smal l population , a lot mor e children .

DR . MUSHAK : Thi s i s the Cit y o f Dallas ? MR . COHEN : Yes . DR . MUSHAK : Intuitively , tha t seem s lik e a lo w number . I don' t know .

MR . COHEN : 3 kilometers . DR . MUSHAK : Still , 2 0 pregnan t wome nin3 kilometer s ina bi g city —

DR . RABINOWITZ : S o fo r eac ho f thes e 2 0 women , ther e i s a certai nair-lead , a certai nsoil-lea dan dthen they do th e mathematics ?

MR . COHEN : Yes . DR . RABINOWITZ : They ge t a distributio nfo r eac h 

# J EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.3 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 12 9 o fthos e 2 0 wome n an d tha t.',;• : wha ti s show n her.-- ?

MR

. COHEN ; Yes , DR . RABINOWITZ : S o o f th e 20 , ther e wil l b e differen t air-leads , differen t soil-lead s dependin g on —

MR . COHEN : Dependin g o n wha t bloc k the yliv e on . DR . RABINOWITZ : Okay . CHAIRMA NLARSON : Yo u mentione d tha t yo u had prediction s base d o n wher e peopl e live d relativ e t o th e impac t of ai r quality .

DR . McLAMB : Precisely , we looka t th e Censu s data , th e mos t detaile d dat a that.we cange t whenwe appl y thi s t o othe r place s t o se e th e impac t o f alternativ e standards . W

e pretendtha t i t i s lik e a geographi c weighte d averag e o f wher e peopl e ar e locate dwithi na Censu s tract . We us e a

nIS C mode l t o predic t ambien t concentration s unde r alternativ e standards .

I f ther e ar e peopl e tha t ar e block-group-centroi d fo r on e receptor , thenthey wil l ge t whateve r concentratio n the'mode l predicte dfo r tha t receptor . Typically , we fin d severa l block-group-centroid s withi ns o man y kilometer s o f thes e sources .

We wil l hav e en

dgroup s o f peopl e wit hth e same ambien t concentratio nwhich , dependin g o nth e scenari o we lookat , wil l dictat e th e soi l an ddus t levels . EXECUTIV E COUR T REPORTER S (301 ) 565-006 41 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 Doe s tia t answe r you r question ?

MR . HAINES : W e com e u p wit ha mea n and the n w e predic t th e GS D fro mth e mean . DR . McLAMB : Yes . CHAIRMA

NLARSON : Yo u hav e a varianc e predicte d b y th e mode l whic hyo u us e t o jus t collectivel yus e tha t informatio nt o comput e a mean .

DR . McLAMB : Tha t i s correct . CHAIRMA N LARSON : Thenyoupredic t a differen t variou s fromth e secon d step .

DR . McLAMB : Th e secondvarianc e i s give ntha t we discus s earlie r here .

CHAIRMA N LARSON : We don' t fee l tha t th e varianc e predicte db

y th e mode l i s going t o captur e al l th e variables . W e are fortunat e tha t w e hav e dat a o

nthi s measurement .

MR . COHEN : Ar e ther e an y othe r question s o nthat ? [N o response. ] Okay . Do we wan t t o g o t o th e nex t phase ? CHAIRMA N LARSON : I thinki t woul db e usefu l t o kee pgoin g here , i f possible . Pag e 48 .

MR . COHEN : W e hav e bee ntalking abou t othe r application s o f thes e methodologies . Ther e ar e a lot o f analyse s withi nth e agenc y an doutsid e relating t o lead . Naturall y

ther e ha s bee na lo t o f interes t inwha t

) • ' EXECUTIV E COUR T REPORTER S (301 ) 565-006 4

' •P.3 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 21 2 2 2 3 2 4 2 5 1 2 1 ha s bee ngoin g o n i n developin g thes e models . W e though t i t woul db e usefu l t o we t som e feedbac k fro mth e Subcommitte e o n th e potentia l usefulnes s o f extrapolatin c thes e methodologie s t o o t he r s i t u a t i o n s .

Again , I don' t hav e th e slid e bu t it i s i n you r hand-out . Ther e ar e a coupl e o f othe r application s tha t hav e bee n i d e n t if i e d .

Fo r example , w e tal k abou t Supe r Fun dsites , lead

contaminated-soi l problems . Th e Offic e o f Drinkin g Wate r wa s intereste di nho wt o asses s high-leve l pea kintermitten t exposure s fro mschoo l drinkin g fountains , fo r example .

The ythough t th e biokineti c mode l wa s a n appropriat e too l t o measur e th e rapi dchange s associate dwit h that . Lan dapplicatio no f sewag e sludg e i s anothe r potentia l intereste dassessment .

Similarly , municipa l wast e incinerator s produc e som e lea dfro

m th e stacks . Ther e migh t b e som e relevanc e for som e o f thes e models . I t ma y no t b e th e biokineti c model , i t ma y b e th e aggregat e model .

Relativ e rankin g o f differen t pollutant s base do n dail y intak e estimates . A lo t o f ris kassessment s i nth e Environmenta l Protectio nAgenc y ar e base do naverag e dail y o r acceptabl e dail y intake , andth e uptak e mode l produce s thos e kind s o f estimate s for lead .

Th e benefit s analysi s for th e regulato r impac t

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.3 4

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••yne»- analysi s i s par t o f th e lead NAAQ S review . Dav e wil l giv e yo u som e background . D_!_

_ ______!_

_Wj . McLamb 'DR . McLAMB : The.reaso n w e hav e bee n makin g a bi g poin t abou t thi s las t itemi s becaus e i t i s tie d t o th e lead NAAQS . Ther e are

a t leas t thre e peopl e o n thi s Subcommitte e wh o reviewe d th e benefi t analysis .

I jus t wan t t o remin dthos e guys : w e ar e usin g th e output s o f th e blood-lea d modeling exercis e w e hav e seen today t o generat e th e benefi t estimates . A littl e mor e background . A primary

motivatio nfo

r doing th e benefi t estimate s a

t leas t starte dinthe Environmenta l Protectio n Agenc y fro m Executiv e Orde r 12-29 1 whic hrequire s u s t o do benefi t an

dcos t estimate s fo r alternativ e standard s we consider . Hence , we have , inth e past , gotte nsom e pee r review o nho w w e .migh t g o abou t doing benefits . Equall y

important , we wan t t o mak e sur e it i s fairl y consisten t wit hth e scientifi c literatur e a s i t i s graded , i f yo uwill , b y CASAC . Basically , ou

r benefi t analysi s fo r lea dfocuse s onthre e differen t healt hen dpoints , th e firs t being o nth e char t u

phere : elevation s inerythrocyte , protoporphi nan d blood-lead . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.3 5

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- .13 3 Basicall yCD C ha s designe d protocol s whic hdefine ' ho wan d whe n childre n ar e treate d fo r lea d toxicit ybase d o n thes e tw o paramete r values .

I n ou r benefit s analysis , w e basically , fo r alternativ e standards , looke d a t ho wcost s o f screenin g an d treatmen t var ya s yo u lowe r ambien t exposur e t o lead .

Th e secon d benefi t categor yw e loo k a t i s intelligen t quotient , o r 1 0 decrements . A s yo u reduc e an y kin d o f lea d exposure—i n ou r cas e ambien t lead—ther e are a numbe r o f studie s tha t sho wtha t 10 , a t leas t th e averag e 10 , wil l chang e fo r larg e group s o f children . ' .. .

I n ou r valuatio n methodology , w e basicall yloo k a t ho wth e productivit yo f societ ychange s a s I Q improve s marginally , an d w e measur e tha t b ylookin g a t basicall y change s i n expecte d lifetim e earning s an d stuf f lik e that .

Ther e i s a secon d sub-categor yo f thi s I Q stuff . Tha t ha s t o d o wit hcos t o f treatin g childre n wh o ar e severel yretarded .

I f yo u chang e ambien t lea d b ysom e amount , yo u wil l chang e blood-lea d exposur e whic hgive s yo u th e margina l chang e i n10 , whic hagai n shift s th e distribution : ther e wil l b e slightl y

fewe r childre n designate d a s bein g severel y retarde dan dthe ywil l ge t les s remedia l educatio n an d treatment . Th e thir d benefi t categor yw e hav e bee n abl e t o

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.3 6

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" 2 2 2 3 2 4 2 5 13 4 evaluat e ha s t o d o wit helevation s i n bloo d pressure : quit e a controversia l category , I think , ove r th e pas t fewyears . At leas t t o date , w e stil l pla n t o pursu e that , onl yfo r adul t rnales, though , I woul d 1 i k e t o men t i on .

Basicall yhere , whe n w e estimat e benefits , w e loo k a t th e reduction s i n th e cost s o f treatin g hypertensiv e males . Secondly , w e loo k a t th e reduce d cost.o f treatin g cardiovascula r an d cerebral-vascula r consequence s o f elevate d bloo d pressure .

I woul d lik e t o mak e severa l comment s i n regar d t o qualificatio n o f th e limitation s and th e benefit s w e hav e bee n abl e t o estimate .

W e kno wther e ar e a lo t o f othe r significan t healt heffect s that , a t leas t currently , w e don' t fee l w e ca n quantify . Furthermore , th e benefi t categorie s w e ar e estimatin g benefit s fo r are fo r thos e categorie s w e fel t comfortabl e identifyin g a s o f earl y1987 .

A s fa r a s w e ar e concerned , th e jur yi s ou t righ t no wa s t o whethe r o r no t w e ca n expan d ou r benefi t analysi s any a t all . W e wil l wai t t o se e wha t happen s i n th e nex t ful l CASAC meeting .

I t i s m yunderstandin g ther e are quit e a fe w studie s stil l out .

I n Marc h1987 , w e convene d a Subcommitte e ver y 4 EXECUTIV E COUR T REPORTER S (301 ) 565-006 4

-A•

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 1 "?• . i . v . w muc hlik e thi s one . Ther e wer e abou t tw o additiona l economist s o n i t a s wel l a s member s fro mth e Healt h C o mmi 1 1 e e , fr o mth e f u 1 1 0 AS AC .

W e aske d fo r comments . W e responde d t o th e comment s a t th e meeting . W e go t closur e lette r fro mbot h Mor t Lippman , co-signe d b yBo bRow e wh o wa s th e Subcommitte e co-chairman , bac k i n Jun e 193 7 I believe .

W e hav e incorporate d thos e comment s int o th e documen t wit hth e exceptio no f som e comment s I believ e w e go t fro m eithe r Dr . Mahaffe yor Dr . Ch i sol m wh o sai dtha t ou r E P blood-lea drelationship s shoul db e disaggregate db y ARN status . W e ar e currentl y modifyin g thos e physica l effect s function s tha t giv e u s thos e benefi t categories . Alla n Marcu s ha s bee nworkin g wit hu s onthat .

S o w e prett y

muc hincorporat e al l th e benefit s w e go t excep t fo r th e fina l change .

W e hav e ye t t o d o an y benefi t estimatio nfor thes e preliminar y

blood-lea dnumber s yo uhav e see ntoda y becaus e the y wer e jus t availabl e a coupl e o f week s ago . Again , w e hav e no t finishe du pth e blood-lea dEP A stuf f o nAR N

status . Jus t t o giv e yo ua nide a ho w al l thi s fit s int o th e RIA , yo uwil l se e a littl e block . O nth e top , i t say s "blood-lea dexposure" . Tha t i s wha t w e hav e bee ntalkin g abou t today . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4- -.-. /

v - -.".JrCiii?- . • ' 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 In th e RIA , ther e ar e a numbe r o f analyse s goin g o nan dthey fee d int o on e anothe r i n variou s ways . Ther--. . ..r . reall yothe r link s tha t kind o f fee d o n on e anothe r i n s genera l equilibriumsense , bu t I don' t wan t t o clou d th e discussio n wit hthat .

I n an yevent , th e to p ro wdescribe s ou r benefi t estimates . W e loo k a t baselin e ambien t concentration s and , usin g dispersio n modelings , w e estimat e ambien t baselin e concentrations . Thenwe se e ho w w e ad dcontrol s an

dho w lea d concentration s wil l chang e a s we ad dcontrol s to our ambien t impacts - measure , whic hagai ndrive s blood-lea da s we hay e seentoday . Change s inblood-lea dwil l yiel dchange s inhealt h effects , an

dth e healt heffect s are value da s I jus t described . A

t th e same time , th e ambien t impact s ar e driving blood-lea dexposur e al l th e wa y dow nt o benefits . We are estimatin g engineerin g cost s a s w e ad dcontrols . The nthrougha lot o f simple-minde deconomi c models , we estimat e socia l costs . Yo uput th e benefit s an d th e cost s togethe r an dyo ucome u

pwit ha benefit/cos t analysi s prett y

muc ha s th e mandat e inExecutiv e Orde r 12 - 291 . Tha t conclude s m y presentation . DR . MUSHAK : Le t m e understand . EXECUTIVE COUR T REPORTER S (301 ) 565-006 4P.3 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 Th e Clea n Ai r Ac t say s yo u wil l no t consider- —

DR . McLAMB : Absolutely . DR . MUSHAK : Bu t yo u d o thi s anyway . DR . McLAMB : Well , th e Presiden t tol d u s to . CLaughter 1 DR . MUSHAK : 01 : ay . DR . RABINOWITZ : S o yo u sor t o f close d i n term s o f healt heffect s yo u wan t t o conside r fo r th e purpose s o f thi s cost/benefi t analysis ?

DR . McLAMB : W

e ar e close dt o dat e unti l the ful l CASAC convene s agai nan dlook s a

t th e new

literature . . 1 . believ e we ca n quantif y feta l effects , fo r instance . S o righ t no

w it i s fixe

dintime , but we prett y muchhav e t o tak e the lea dunti l th e scientifi c communit y come s t o some sor t o f genera l agreemen t tha t we canactuall y valu e on . MR . HAINES : Isn' t it tru e ther e ar e othe r effect s identifie dinth e literatur e tha t are well-accepte d withi nth e scientifi c communit y tha t yo uhav e problem s evaluating ?

DR . McLAMB : An

dther e ar e some nori-effect s o n whic hw e don' t hav e th e physica l functions , also : a sub categor y

o f th e one s we canno t quantify . MR . HAINES s S o it i s a ninteractiv e type . Befor e h e cancome u

pwit hbenefits , ther e ar e severa l condition s EXECUTIV E COUR T REPORTER S (301 ) 565-006 41



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# fe tha t h a v e t o b e s a. i s f i e d . DR . RAEINOWITZ : S o yo u don' t wari t jus t on e pape r tha t reporte d something . Yo u wan t som e kin d o f consensu s t ha t t hi s i s a s i mi 1 a r p h e no me n o n ?

MR . COHEN : No . W e nee d t o mak e th e distinctio n clea r betwee n th e benefit s analysi s arid th e health-ris k

assessmen t tha t goe s t o tli e staff . W e recommen d a blood-lea d leve l o f concer n wil l incorporat e healt heffect s whethe r o r

no t the y

ca n b e monetised . W e are no t ignorin g thos e othe r healt heffect s i n settin g th e standard . I ndoin g th e benefit s analysis , w e hav e t o dra w

th e lin e tha t thos e effect s tha t ca nb e quantifie di nmonetar y terms . MR . HAINES : Tha t i s th e poin t I wa s tryin g t o make . Davi dha s tw o condition s o

nwha t doe s th e scienc e say abou t a healt heffect . We are going t o us e th e tota l dat e set , a portio nof whic hhe ma y no t be abl e t o monetis e an dcome wit ha monetary valu e on . DR . McLAMB : A

goo dexampl e i s wha t i s th e valu e o f improving forcedexpiratory volume ? We hada toughtime , a s a neconomist , evaluating thos e kind s o f healt heffects , at leas t t o date .

CHAIRMA N LARSON : Prio r t o some discussio namong u s here , I wante dt o turnit ove r briefl y t o Bo bfo r some EXECUTIVE COUR T REPORTER S (301 ) 565-006 4P.4 1



## Jh 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 additiona l comment s o n th e proces s w e are involve d wit hhere . A_ . _--_.-__.___

L F* Laak MR . FLAAK : Befor e th e Subcommitte e get s int o it s fina l wrap-u p toda yan d som e o f th e genera l consensu s point s tha t th e Subcommitte e want s t o brin g t o th e Committee' s attentio n ge t gelle d an d finalised , I wante d t o tal k a littl e bi t abou t th e proces s whereb yth e Committe e operations ; an d her e I sa yth e ful l CASAC , th e seven-membe r Committee .

Fo r thos e individual s wh o ar e ne w t o th e CASA C process—Pau l an d Scot t an d Ian— thi s i s primaril y for yo us o yo uhav e a nunderstandin g o f ho w w e d o business . Fo r the . res t o f yo uwh o hav e bee ninvolve di nthi s before , i t i s a rearrangemen t o f somethin g yo uprobabl y kno w a littl e bi t abouit . Thi s i s a Subcommitte e o f CASAC . A s such , it s recommendation s pas s throug hth e ful l Committee .

CASA C i s th e onl y Committe e withi nth e Scienc e Advisor y

Boar dwhos e recommendation s g o directl y t o th e Administrato r withou t passin g throug hth e Scienc e Advisor y

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2 2 2 3 2 4 2 5 2 0 | | Board' s Executiv e Committe e o r Steerin g Committee .

Tha t i s becaus e CASA C i s mandate da s a separat e committe e b y

separat e legislatio nan di s merel y house dwithi n th e Scienc e Advisor y Boar dfo r administrativ e purposes . A s fa r a s a Subcommitte e i s concerned—an dal l o f ou r subcommittee s are chaire dby

eithe r a membe r o f th e ful l

EXECUTIV E COUR T REPORTER S (301 ) 565-006 41• . 0 1 | | CA3A C o r byano t he r membe r o f th e S c i en c e Adv i so r yBoa r d — 2 | | whateve r deliberation s an d result s com e ou t o f thi s mee-ting 3 | | toda ywil l b e pu t i n som e kin d o f a concise , clear , toTMthe

4 | | poin t writte n for mb yTi man d I , a t som e poin t i n th e nex t 5 | | coupl e week s afte r thi s meeting , an d forwarde daroun d t o th e 6 othe r member s o f th e Subcommitte e fo r concurrence . 7 Onc e th e Subcommitte e member s are satisfie d wit h 8 tli e document , i t wil l b e passe d o nt o th e ful l CASA C seve n 9 member s fo r thei r fina l sign-of f a t tha t point . 1 0 Ther e wil l b e a lea dmeetin g o f th e ful l Committe e 1 1 som e tim e i nth e earl y par t o f 1989 , perhap s i nFebruar y o r 12 so . W e don' t hav e a fir m dat e ontha t yet . 1 3 A

t tha t tim e o r perhap s earlier , certainl y a t tha t 1 4 meeting , Dr . Larso nwil l mak e a presentatio nwhic hwil l 1 5 summaris e th e discussion s here , essentiall y layin g t o res t 1 6 thi s documen t a s far a s tha t meetin g comin g upi nFebruar y i s 1 7 concerned , whic hi s th e purpos e o f havin g thi s meetin g today . 1 8 Ther e ma y b e a nopportunit y t o presen t thi s t o th e 1 9 ful l seven-membe r Committe e a t a nearlie r meetin g t o ge t a 2 0 sign-of f o ni t o r w e ma y d o i t vi a th e mail , whic hw e ofte n 2 1 d o whe na nissu e i s particularl y controversial . 2 2 Ther e i s a noson e meetin g schedule di nth e middl e 2 3 o f December , whic hma y b e a nappropriat e tim e t o brin g thi s 2 4 repor t t o th e ful l Committee' s attentio nfo r a fe w minutes . 2 5 Wit htha t i nmind , whateve r fina l comment s w e hav e

> EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.4 3

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 19 2 0 21 2 2 2 3 2 4 2 5 hop .



# J thi s afternoo nw e wii l loo k ove r wit ha grea t d.. a

interests . W e wil l fol d the mtogethe r int o wha t consensu s po s i t i o n o f e ve r yo n e here .

Than k you . CHAIRMA

NLARSON : Prio r t o m ytas k t o tryin g t o summarise—partl yverball yhere ; bu t als o hopefully , wit h som e mor e considere d thought , I wil l writ e somethin g down , pas s it aroun d an d w e wil l al l tak e a sho t a t it— I woul d lik e t o ge t som e sens e fro mth e Subcommitte e member s o nthei r view s o

na fe w of the questions . CHAIRMAN' S SUMMAR Y CHAIRMA N LARSON : Firs t o f all , wer e th e comment s tha t yo usubmitte dan dwhic hwer e addresse dearlie r today addres s adequately ? Tha t i s t o say , ar e yousatisfied ? Give nth e fac t tha t they migh t respondi

nthe wa

y tha t the y did , d o yo uconside r tha t a nadequat e addressin g o f th e comment s tha t youhave heardtoday ?

Wil l tha t b e sufficien t o r ar e ther e additiona l comment s o

r issue s tha t wer e raise dtoday tha t wer e no t in an y o f thos e comment s tha t we heardthi s morning ?

I hav e mad e a lis t her e o f some o f m y ow ntha t ma

y b e addresse ddirectl y o r indirectl y

insom

e o f th e earlie r comments . Ar e th e modeling approache s reasonabl y structured ? Tha t i s to say , are w e inagreemen t wit hth e type s o f EXECUTIV E COUR T REPORTER S (301 ) 565-006 4tm.

__P 1 2 3 4 S 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

. 14 2

exposur e model s tha t w e hav e seen , a t leas t i n thei r structura l for

mi s no t necessaril yth e inpu t numbers ? Ca n w e ge t som e sens e on this ? Ther e seeme d t o b e a genera l agreemen t abou t th e approac ho f biokineti c uptak e fo r th e childre n an d som e discussion s pr o an d co n abou t th e aggregate/disaggregat e models .

Kate ? GENERAL DISCUSSIO N

DR . MAHAFFEY : I ha da neasie r time wit hth e biokineti c approac hrecognising it i s missing hug e amount s o f information .

CHAIRMA N LARSON : I gues s tha t i s th e second question . Give ntha t we ar e comfortabl e wit htha t approach , ar e th e availabl e dat a t o be usedther e usedappropriately ?

I hada numbe r o f point s tha t wer e possibl y a t leas t unde r some discussion : th e numbe r o f milligram s a da y eate nb

y young children ; th e issue s o f th e constanc y o f soil leadafte r rapi dreductio ninair-lea dversu s some correlatio nbetwee nth e two .

M y feeling wa s ther e wa s some consensu s tha t w e shoul dkeeptha t soil-lea dvalu e constant , but - tha t th e dus t value s perhap s ar e mor e responsiv e t o th e ai r values .

Th e questio no f smoothing o f th e dat a fo r th e intermediate-ag e children , I wa s no t quit e sur e ho w we came dow na s a Subcommitte e o ntha t issue . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4

1 P.4 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 1-. 3

DR

. MUSHAK

: Igue: ;

-- s i nth eabsence , o f information

- eithe r way , probabl y th erathe r abrup t

approac hi s i f

yo uar e ear s old , yo uhav ea...:. , be dalot ; i f yo uare •• w . •z•-.. • ns i u . _r ai . I y

o 1 de r , \

. V O L i S tar t lookiin

qlik e adults . DR . CHISOLM ; J woul d gues s i t woul d slo wdown from , say , si xt o te n an d the n yo u ge t i n th e adolescen t growt hspurt .

DR DR . CHISOLM : I t probabl ydoe s gro wwit hthe growt hrate .

MR . COHEN : Tha t i s wher e w e dra w th e line , . St . really , a t si xyear s old .

DR . CHISOLM : Forge t th e terribl e adolescence , right ? Z Laughter 3

CHAIRMA N LARSON : Anothe r issu e whic hwa s raised : Give nth e assumptio no f a relativel y constan t lea

dsource , ho w d o yo uestimat e wha t tha t i s inthe absenc e o f soi l informatio nwhenyoug o out an dtak e thi s mode l elsewhere ? Ther e wa s som

e discussio nabou t th e difference s in tha t steady-stat e air-lead/soil-lea drelationship . Mayb e w e cantak e a looka t ho w th e result s look . W e canvary tha t ove r th e rang e tha t we wer e discussing .

DR . vonLINDERN : Ca nI as ka questio nan dge t a littl e bi t o f clarificatio no ntha t point ? EXECUTIVE COUR T REPORTER S (301 ) 565-006 4P.4 6

-K__-,..:,i_i. : _i_r*^«*- - .-__J—_ V7t. _H ^ ^ - :!jv-i__.^»3«" . _.:-.<__>_U'~-»-!..: . ;S-_W._.52.V- :

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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 I t look s lik e on e o f thos e end s u p hingin g o n th_

_ prediction s o f th e air-qualit ymodel . I thin k al l o f i t

c o m e s ba c k t o t ha t .

I t seem s i t coul d b e appropriat e t o m e t o g o ou t an d evaluat e site s wher e yo u don' t hav e i nfo r n . a t i o n t o evaluat e th e impac t o f propose d standards .

Ar e w e thinkin g i n term s o f implementatio n tha t

wa yas well ? Whe n w e ge t t o implementation , wil l w e loo k a t actua l soi l value s i n thes e locations' ?

Ha s anybod ygive n tha t an ythought ? MR . HAINES : I thin k thi s go t bac k t o you r questio n o f th e polic ycall . Ou r mandat e i s essentiall yt o se t a n appropriat e ai r qualit ystandard .

W e are estimatin g takin g int o accoun t soil/dust

lead , food , tota l lea d exposure ; bu t w e wil l b e implementin g a n ai r standard , a s th e Administrato r judges , providin g protectio n wit ha n adequat e margi n o f safety .

Separat e an d apart , yo u hav e th e paralle l issu e o f wha t d o yo u d o i n th e soi l clean-up . S o ther e i s clarificatio n i n th e legislativ e mandate s betwee n ou r bes t estimate s o f soil/dust-lea d level s an d tryin g t o arriv e a t a n appropriat e standard , bu t whe n i t come s aroun d t o implementatio n w e wil l b e implementin g th e ai r aspec t o f it . Supe r Fun d an d othe r peopl e wil l b e makin g a n independen t determination , t o som e extent , whethe r o r no t tha t soi l need s

EXECUTIV E COUR T REPORTER S (301 ) 565-006 41 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 t o b ecleane dup .

Ther e i s no t th e jointnes s tha t you r comment s suggeste d a t thi s point .

Tlia t mayb e a questio n w e wil l hav e t o discus s ourselves . I t i s B.n interestin g thin g yo u hav e lai d out : whethe r or no t i t shoul d be .

DR . vo n LINDERN : Wher e w e ar e a

t her e i s t o evaluate — MR . HAINES : The ai r portion . Unde r th e CleanAi r Act , tha t i s wha t w e are her e about . CHAIRMA N LARSON : On e o f th e othe r inputs , perhap s whic hi s mentione dbut I di dno t ge t a sens e o f wher e we wer e wit hit , i s thi s sor t o f communit y exposur e issu e versu s th e bloc ko

r site-specifi c exposure . I s tha t o

r i s tha t not something importan t tha t i s important ; an

di s it takenint o accoun t inyour analysis ? Ian , yo umentione dtha t earlier . DR . vonLINDERN : Again , I thinktha t sor t o f tie s int o th e same thing w e jus t talke dabout . Ther e ar e situation s aroundthes e poin t source s wher e we kno w a lot mor e tha nmaking a mode l estimate .

I nmos t cases , w

e coul dprobabl y

develo pa bette r model ; but a s I understandi t tha t i s no t somethin g t o do here . MR . HAINES : I thinkther e ar e tw o issue s here . EXECUTIV E COUR T REPORTER S (301 ) 565-006 41 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 v.-Ite r situatio n « t e. : t!;.. r „_,,.-.t Helen a o r wha t yo u ar e seein g i n you r location . I n >••.,_..•'..: , ir i effec t on e sourc e i s dominatin g th e ... . oinmun i ty . "!"!•• : -.:• : • • . fi i ...t:-,.

- 7 v i s impacte d b ytha t source- .

B yth e sam e token , whe n w e di d ou r evaluatio n i n Eas t Helen a w e wer e basicall yimpactin g jus t abou t al l lh e kid s i nthat . Wher e w e transfe r thi s t o a n urba n area , sa y Dallas , tha t sourc e i s affectin g a relativel ysmal l are a aroun dthere .

I gues s I a m

tryin g t o differentiat e i s tha t a communit y

i nEas t Helena , whic hI kno w bette r tha nSilver . Valley , i s probabl y th e whol e tow ninfluence db y th e smelte r

o r a t leas t a goo dportio no f i t a s oppose dt o a Dalla s situatio nwher e i t i s onl y a smal l geographi c are a o f th e city . I a m no t sur e i f w e ar e fa r apar t o nwha t w e ar e doin g here . I thin kw e ar e usin g differen t word s t o sa y basicall y

w e shoul db e looke da t th e son e o f influenc e o f tha t stationar y source . CHAIRMA N

LARSON : Thi s get s t o th e questio no f give ntha t w e hav e a structur e tha t w e are comfortabl e with , availabl e data , ther e wa s som e discussio no f variou s uncertaintie s tha t nee dt o b e looke da t i nterm s o f th e fina l output , a s inputs .

Ar e th e propose dapplication s o f thes e approache s

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.4 9

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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 reasonable ? Tha t i s t o say , in thi s case , th e biokineti c uptak e mode l applie d t o tli e childre n and perhaps , or perhap s not , som e disaggregat e mode l applie d t o th e adult s o r som e se t o f adults .

I ge t a consensu s tha t th e applicatio n o f th e firs t mode l t o th e childre n i s mos t appropriate , bu t I am stil l no t quit e sur e abou t wha t w e d o wit hth e disaggregat e mode l an

dth e pregnan t womeno r not , o

r whethe r o

r no t ther e wa s some consensu s abou t that .

I t seem s certai ntha t ther e wa s no t much informatio na

t al l o

nthe fetus , an

dwe shoul dprobabl y mak e sur e w e stay clea r o f that . DR . MUSHAK : I suppos e they coul dhav e equa l billing . Jef f an dI wer e talking a littl e bi t a t lunch abou t using thi s a s a dat a poin t fo r th e newborn , at poin t o f birt hwit hsome assumptions , an dusing a

nadul t mode l hybri d o f thi s plu s wha t Mik e hadpublishe dt o try t o come u

pwit h somethin g fo

r wome nan

dd o a nadjustmen t fo

r th e women' s lead . Tha t is , t o a nadjustmen t fo

r th e resorption : try t o b e a s generou s wit htha t a s possible .

Afte r that , ther e i s a noption . Tha t is , youar e no t reall y

looking a

t a quote/unquot e in-uter o span . Youar e ginning anothe r dat a poin t tha t i s no t available , an dit i s EXECUTIVE COUR T REPORTER S (301 ) 565-006 4P.5 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 25 probabl y

mode l _. . _ . .r . i '-... ._ : i O U qr1 t o _>t-- ,

_ . "•'.. e -••e r th e othe r i s .he question , CHAIRMA

NLARSC.. : I think w e ca n certainl yexpres s th e fac t tha t thes e ar e importan t group s t o consider , and tha t w e sur e wis hw e had mor e dat a tlia n w e d o t o be abl e t o perhap s d o i t better .

DR . MAHAFFEY : I fin d thi s hardt o reall y sa y wha t t o d o with . I don' t thin k anybodywant s t o creat e a situatio n wher e i t look s a s thoughlooking a t pregnan t wome n and th e fetu s i s no t somethin g t o d o because , interrnsro f th e healt hresearch , tha t i s a grou ptha t i s extremel y importan t t o cons i der .

Th e othe r sid e o f i t becomes : Ho w d o yo udo thi s an dd o it wit hsom

e degre e o f sens e i nth e process ? W e ar e kin

do f hardput t o come u pwit ha

nanswer . I t sound s a s thoughi f ther e i s something inYugoslavia ndat a wher e yo uca

nge t som

e blood-lead s ove r time during pregnancy , youmigh t have som e informatio nt o workwith . Ther e i s alway s a temptatio nt o say , "Sure , g o aheadan

dmak e thi s model , se e ho w it looks." ' Th e difficult y i s afte r we hav e don e that , w e si t an

dsay , "Well , we ar e gladyo udi dthat . I t wa s a goodthing t o do. " W e hav e thi s mode l now . Ther e i s alway s a chanc e someon e wil l pic kit u pwit ha fe

w mor e set s o f assumption s EXECUTIVE COUR T REPORTER S (301 ) 565-006 4P.5 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 init . I kee p wonderin g wha t ar e w e creatin g i n th e proces s o f doin g this .

DR . MUSHAK : Tha t woul d b e th e inheren t ris k wit h th e Environmenta l Protectio n Agenc yrunnin g amu k wit hth e generi c realisation .

MR . HAINES : Realistically , thi s bring s m e bac k t o th s questio n I pose d before .

If , i n the collectivel y judgmen t o f the Subcommittee , w e don' t thin kwe are

ina positio nt o appropriatel y

mode l an

dasses s thi s ris kina quantitativ e way , becaus e w

e don' t hav e th e tool s an ddon' t hav e th e data — I want t o mak e sur e w e don' t g o dow

na pathwa y

and do somethin g tha t nobod y ha s an

y confidenc e inbecaus e o f th e absenc e o f data . I f tha t i s th e case , mayb e we ought t o s o stat e an

dsay , "W

e are no t i na positio nt o estimat e thes e exposure s a

t thi s poin t intime . Thi s i s th e researc htha t wil l hav e t o b e carrie dout ove r th e next severa l year s s o we cananswe r tha t question. "

Wha t I a

m trying t o avoi di s w e coul dtak e th e approac hlai dout inth e paper,—yo uknow , th e alternates — put i ntha t caveat , indicat e they wer e develope dfo r adul t males , hav e applicabilit y t o pregnan t females . Tha t i s u pin th e air . EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.5 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 2 1 2 2 2 3 2 4 2 5 W e kno wver ylittl e abou t th e biokinetic s takin g place , bu t w e wil l produc e an answer .

Wha t I gues s I a

msayin g i s tha t if , i n th e wisdo m o f peopl e here , i f tha t answe r i s no t wor t I' i th e pape r i t i s writte n on , wh

ytak e th e tim e t o produc e it ? CHAIRMA

NLARSON : W e simpl yar e no t tellin g yo u t o completel yignor e th e subjec t becaus e w e fee l it i s an importan t targe t group . Whil e i t i s an important

- targe t group , ther e are othe r way s w e tal k abou t i t ina qualitativ e sense ; bu t w e canno t predic t wha t i s happenin g inth e futur e o nthis . DR . MAHAFFEY : I t i s m y experienc e wit hcaveat s tha t thi s i s lik e doing table s an dsomebody

pick s out a coupl e o f number s an dsays , "Yes , thi s i s wha t yousaid. " I t i s a very

importan t group , but interm s o f th e biokinetics , unles s ther e i s a lot mor e inthi s Yugoslavia n dat a thanperhap s other s hav e beenawar e of , I thinkw e out wher e w

e don' t want t o mak e highthe hous e o f cards . MR . HAINES : The botto m line , a s I interpre t it , i s tha t we procee dt o tr y t o quantitat e thos e exposures . The nwe wil l rel y o nth e biokineti c mode l t o estimat e children' s blood-leads .

We wil l looka

t adul t male s fro m th e poin t o f vie w o f hypertensio neffect s an dhav e t o discuss , inexposur e terms , th e chang e infemale/feta l very muchina qualitativ e EXECUTIVE COUR T REPORTER S (301 ) 565-006 4P.5 3

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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

-k-r- •'• sens e i n no t bein g abl e t o predic t i n th e futur e wha t change:; :

th e air-qualit ylevel s nay have . DR . MUSHAK : Katie , i f n o on e i s advancin g *n y Yugoslavia n dat a a s important > i f the yar e elevatin g i t t o th e statu s o f a usefu l dat a set , al l tha t ha s t.appene d i s tha t som e mentio n wa s mad e abou t ther e ar e se-r-ria

l measures . The yp r o ba b1 yhav e s o me i d e a o f a i . r -lea d 1 e vels . DR . MAHAFFEY : Wher e I thin k w e are, apparentl y ther e ar e a fe wresult s o n pregnan t wome n i n th e wor k tha t Bil l Manto n did—whic his , what , mayb e o n thre e subjects—an d ther e i s som e othe r anecdota l kin d o f informatio n tha t i s suggestin g tha t blood-lead s ma yg o u p i n pregnanc yo r ma yg o dow n i n pregnancy .

I f w e ar e no t sure , becaus e o f prio r exposur e historie s i n mobilisatio n probabl yo f blood-lead , whethe r o r no t th e blood-lea d i s goin g t o g o u p o r down , tryin g t o relat e tha t t o a curren t ai r leve l strike s m e a s extremel y chancy . DR . RABINOWITZ : I t i s har d fo r m e t o understan d wha t th e significanc e i s o f sequentia l blood-lead s durin g pregnancy , whethe r the yg o u p o r down . I can'imagin e a situatio nwher e blood-lead s g o down . Tha t mean s lea d goe s int o th e fetus .

I ca n imagin e a situatio n wher e th e blood-lea d goe s up . I t stil l goe s int o th e fetus . EXECUTIV E COUR T REPORTER S (301 ) 565-006 41 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 S o i t i s har d for m e t o kno wwha t t o mak e o f th e healt heffect s o f whethe r th e blood-lead s g o u p o r down i n pregnancy . DR . MUSHAK : Blood-lea d goin g u p o r down doe s no t necessaril ymea n th e fetu s become s a sink . Othe r thing s ha p pe n t o lead .

DR . RABINOWITZ : That' s right . DR . MUSHAK : I

t get s excreted . DR . RABINOWITZ : I t coul db e excrete do r it coul d g o t o th e fetus . I jus t don' t kno w whic hi t is . DR . MUSHAK : Oh , I thin kit goe s t o th e fetus , but no t exclusively . Let' s qualit y it . DR . RABINOWITZ : I hav e heardth e placent a calle d th e thirdkidney . Mayb e the placent a i s a sinkfo r thi s lead . S o whethe r o r not the blood-lea dg o u po r down , I don' t kno

w wha t t o mak e o f that . I hav e enoughfaith , fo r some reason , inbiokineti c modeling tha t i f yo usomewha t diddl e wit hth e mode l an dyoud o th e righ t things , youmigh t approac hwha t i s going on .

I lik e al l th e caveat s yo usai dabou t mayb e it i s no t wort hdoing i f yo ucanno t do i t right . I agre e wit h that . I woul dlik e t o dra w jus t on e possibilit y t o mayb e fine tun e it a littl e bit , tha t migh t b e helpful . EXECUTIVE COUR T REPORTER S (301 ) 565-006 41 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 14 15 16 1 7 1 8 19 2 0 2 1 2 2 2 3 2 4 2 5 Ca n w e tak e a lea f • fro mth e calcium

- stor yi n pregnanc y

an d say , "Okay , i f yo u ar e pregnan t th e FDA , i n thei r wisdom , tell s u s w e nee d thi s manymor e gram s o f calciumpe r mont ho r something, " an

d the n say , "Well , ir i th e huma n bodytir

e rati o o f lead t o calciumi s som e certai n number , dependin g o n i f yo u ar e hig hi nlea do r lo w i nlead. " The n w e ca n say , "Okay , for every gra m o f calcium yo u require , tha t i s equivalen t t o ho w muchskeleto nyouar e losing, " an

d ge t an ide a o f ho w man y microgram s o f lea dare entering circulatio nfro m the skeletonfro m that . DR . MUSHAK : But youstil l need ' a subjec t variabl e bone-lea dburden , an dyouca

neasil y

ge t it . DR . MAHAFFEY : The questio nare : I s th e skeleto n equall y

labeled ? I s it equall y available ? Thi s i s wher e the dat a i s s o limite dtha t w e di d no t kno

w wha t t o writ e excep t tha t it seem s reasonable , fo r whateve r reason,—"reasonable " usedina strang e way here : fo r lac ko f anything els e t o sa y abou t it—tha t ther e are probabl y

physiologicall y

man y smal l pool s o f skeleta l calciu m inleadlevel s tha t ar e resorbe dat differen t times .

CHAIRMA N LARSON : Th e lea dinth e Calcium ? DR . MAHAFFEY : Yes . I don' t thinkwe know . CHAIRMA N LARSON : Thi s ha s serve da usefu l purpos e inth e discussio nhighlightin g th e fac t tha t ther e i s a paucit y

o f dat a intha t area. ) EXECUTIVE COUR T REPORTER S (301 ) 565-006 4:_-_?--__* .

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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 DR . MAHAFFEY : W e hav e somethin g i n Envj.^onm_;nt-__

_ Researc htha t i s ou t i n a mont ho r tw o tha t i s showin g som e increas e i n blood-lead . Ther e wa s on e questio n i n NHANE S abou t menopausa l status : tha t post-menopausa l wome n hav e a sligh t increas e i n blood-lead . I thin k i t i s abou t 1 5 o r 2 0 percent . Tha t i s no t dealin g wit hpeopl e wh o ar e specificall yosteoporotic . I f yo u ha d thi s specifi c osteoporoti c group , i t woul d see mreasonabl e tha t th e increas e i s substantiall ygreater .

DR . MUSHAK : I don' t kno wtha t Tyro l ha d brok e ou t

a physiologicall ydiscernibl e osteoporotic . I believ e i t wa s a n age-foun d analysis .

Whe n yo u analys e th e sam e data , yo u bette r com e u p wit hth e sam e answers .

DR . MAHAFFEY : W e hop e so . CLaughter ] DR . RABINOWITZ : Doe s i t depen d o n whethe r o r no t the y tak e estrogen ? D o yo uhav e tha t information ?

DR . MAHAFFEY : I don' t thin ktha t wa s i nit . CHAIRMA N

LARSON : I gues s w e wil l leav e i t a t that . Anothe r issue , th e secon don e I woul dlik e t o discuss , i s sor t o f a secon dmodel , whic hi s th e propose d approac ht o estimatin g th e varianc e i nblood-lea dusin g th e EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.5 7

1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 13 14 1 5 16 1 7 1 8 19 2 0 21 2 2 2 3 2 4 2 5 geomet r i c s t anda r ddeviat i on .

I s tha t approa c hacc.epta b1 e t o th e Subc o .im i 11ee ? W e hear d fromIa

nsom e comment s abou t possibl e examinatio n o f th e rang e o f values . Tha t migh t b e a usefu l par t o f th e exerc i se . D o yo u thin k i t i s necessar yt o loo k a t a rang e o f GSD s i n this ? Firs t o f all , are w e comfortabl e wit hthi s approach ? Yousa w i t use d her e i

nth e cas e stud

y wher e ther e wa s a meancompute dan dthena varianc e abou t tha t meantha t wa s compute dfo

r thos e plot s baseduponth e GSDs . DR . MAHAFFEY : I thin kther e ar e tw

o problems , at least . On e i s tha t th e coefficien t o f variatio njus t du e t o analytica l a s the blood-lead s go dow nbecome s bigger : tha t they hav e t o someho

w dea l wit hthat . I thinktha t w

e ar e talking abou t blood-lead s o f unde r 1 0 an

ddefinitel y

unde r 5 . Thi s i s a rang e that , give n th e NHANE S wa s usedfo r tha t dat a set , we di dno t hav e very man y blood-lead s unde r 5 .

S o ther e i s a lower boundary o ntha t tha t i s unclea r wha t happen s there .

CHAIRMA N LARSON : Ar e youlooking a t level s in your NAAQ S alternativ e assessmen t i f yo uar e thinking abou t thi s at thos e levels ?

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4•JL

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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 MR . COHEN : Yes . Ther e wil l b e s whol e lobo f childre na t lowe r level s tK-. n wha t w e ar e dealin g wit hno w no matte r wha t w e d o wit hth e ai r standard .

'We presente d a rang e o f GSD s i n th e report . W e decide d t o pic k on e jus t t o simplif ythings . Otherwis e o n every tabl e w e ca n com e u p wit hw e woul d hav e four more . W e nee d t o sor t o f focu s th e analyse s dow n t o a manageabl e level . W e coul d loo k a t th e highe r end o f th e GS D rang e a s presente d a s th e conservativ e choice .

W e decidedt o pic ka mid-poin t becaus e w e ar e no t sur e wha t i s going t o happe ninth e future . I t i s a reall y

a toughcal1 . MR . HAINES : Th e analytica l variation , I think , o f th e lowe r blood-lea dlevel s ar e a seriou s problem . W e hav e th e proble

m wit hthe underlying healt hstudies , too , whic h ha dth e sam

e proble

m associate dwit hthem . I thinkou

r feelin

g is , A , i f youcancorrec t fo r it , B , i s it appropriat e to ? Youcorrec t it o non e sid e o f th e equatio nan

dit i s uncorrecte do nth e othe r sid e o f th e equatio ndoing that .

That , t o me , i s a perplexin g problem ho w t o address : A , wha t woul dyoudo inth e firs t instanc e t o fi x it , i f we could ; but , B , do yo ufixpar t o f it an dthenyou stil l rel y

o nth e healt heffec t studie s fo r whic hit wa s no t corrected . EXECUTIVE COUR T REPORTER S (301 ) 565-006 4

# J 1 2 3 4 5 6 7 8 9 10 1 1 1 2 1 3 1 4 1 5 1 6 17 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 15 7

MR . C0HEN : Ther e i s a pre11 ysubstantia l discussio n i n th e criteri a documen t o n correctin g for analytica l variatio n and th e effec t o n th e GSD s fromNHANES . W e di d fin

d a smalle r varianc e afte r correctin g fo r th e analytica l variance .

Fo r adult s I remembe r i t wa s 1.3 7 fo r urba n white s versu s 1.3 3 i f yo u d o mak e th e adjustment . W e though t i t was , lik e John said , inappropriat e thoug hbecaus e w e woul db e correctin g o n on e sid e an dnot the other . DR . MAHAFFEY : Again , thos e wer e fo r blood-lead s in , what , 15 , 20 , 25 ?

MR . COHEN : Well , thes e wer e adults . They wer e 10 , 15 . DR . MAHAFFEY : I don' t hav e th e answer .

MR . HAINES : I thin kthe onl y

approac hi s t o mak e it clea r inou

r repor t tha t w

e have mad e th e correction. - I thinkyo uhav e t o proceed .

I don' t kno

w ho w we coul ddo it an dwhethe r o

r no t it woul dbe appropriat e withou t making a nadjustmen t acros s al l th e dat a bases . I a m no t sur e we cand o that . I thinksometime s it introduce s a degre e o f uncertaint y

i nth e results , but al l w e cand o i s poin t out tha t thi s exists , unles s Jef f o r Allan , o

r somebody , ha s a solutio nfo

r th e problem . I thinkit i s on e o f recognitio nan dyo uhav e t o EXECUTIVE COUR T REPORTER S (301 ) 565-006 4P.6 0

1 mov e or, . 2 CHAIRMA NLARSON : Mathematicall yspeaking , it i . s 3 presumabl ya mor e sensitiv e paramete r tha n a simpl e 4 multiplicativ e facto r tha t yo u migh t b e changin g b ya certai n 5 value . 6 M yonl yperspectiv e i s i t i s a sensitiv e paramete r 7 t o th e fina l outcome . S o yo u don' t hav e t o necessaril yru n 8 al l th e detaile d numbers , bu t giv e som e sens e o f ho w 9 sensitiv e tha t sensitiv e paramete r is . 10 DR . RABINOWITZ : O nthi s sensitiv e parameter , w e 1 1 don' t hav e an ysens e fo r th e rang e i t coul dacquire . 1 2 MR . HAINES : Tha t i s th e proble m I see . 1 3 W e kno w i t probabl y

exists , bu t w e don' t hav e an y 14 notio no f wha t i t i s o r wha t th e magnitud e o f i t is . 15 DR . RABINOWITZ : Th e GS Ditself? - 16 MR . COHEN : O f th e rati o betwee ntha t an dth e 1 7 mean . 18 DR . RABINOWITZ : Ther e i s a tabl e i nth e documen t 19 showin g a whol e bunc ho f differen t numbers . The nw e hear d 2 0 abou t th e sam e set , perhap s eve na mor e limite drange , tha t 21 Ia nmentione di nhi s study . 2 2 I a m quotin g number s 1.3 , 1.4 , 1. 5 an d1.6 . 2 3 MR . HAINES : I thin kw e wer e talkin g mor e o f th e 2 4 analytica l variatio ntha t impact s a t thi s leve l — 2 5 DR . RABINOWITZ : Oh , I' m sorry . I misunderstoo d

> EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.6 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 you . —vis-a-vi s GSD s tha t Jeffre y

MR . HAINES : discusse d i n th e report .

DR . MUSHAK : A s a n aside , I guess , th e analytica l varianc e yo u se e i n th e NHANE S dat a se t i s no t a v&ry goo d analysis . Yo u recal l tha t wa s on e o f th e argument s a th e tim e tha t wer e use d t o argu e counterpoint .

On e coul d sho wtha t byth e goo d qualit yo f th e NHANE S data-gatherin g analysis . I a mno t sur e yo u coul d ge t

a s muc hwit han yothe r dat a set , an d certainl yno t wit hi t a s i t shifte d th e mea n fo r th e analytica l challeng e yo u have. .

I t i s jus t no t goin g t o d o it . DR . vo n LINDERN : I remembe r I preface d wha t I said.wit ha guess . I t wa s no t quit e a guess , bu t I thin k yo u hav e don e a goo d jo bi n creatin g thi s subject .

I thin k you r poin t i s wel l taken : i t i s a very sensitiv e parameter . Tha t i s reall ywha t I fel t i s th e gis t t o indicat e that .

DR . RABINOWITZ : Thi s show s u p agai n whe n yo u actuall y

tr y t o se e i f thes e standard s are bein g met . B y lookin g a t blood-lead , yo u ca n se e fals e positive s o r fals e negatives . I

t i s th e same proble m showin g u

p ther e also , I guess , basically .

CHAIRMANLARSON : Finally , o n pag e 48 , th e EXECUTIV E COUR T REPORTER S (301 ) 565-00641 question : Ca n thes e modelin g approache s w e hav e discusse d b e 2 applie d t o o t h e r e xp o s u r e se t s ? 3 Thi s ma yno t b e a n all-inclusiv e list , bu t i t 4 give s som e example s o f what — 5 DR . MUSHAK : W e woul d wan t t o g o dow n th e list , 6 woul d we ? 7 Thi s mode l ha s a hig hpotentia l fo r mischie f i f 8 th e Environmenta l Protectio n Agenc yan d othe r office s ge t 9 thei r hand s o n it . I mea n that . 1 0 MR . COHEN : Yes , please . 1 1 DR . RABINOWITZ : I s i t wort hmakin ga lis t o f 1 2 place s wher e i t shoul dno t b e used ? 1 3 MR . COHEN : Yes . 1 4 DR . MUSHAK : I thin ktha t i s almos t a ninfinit e 1 5 list . Th e thin gi s let' s g o wit hwha t the y have . 1 6 I thin k o n th e Supe r Fun dsites , I thin kther e i s 1 7 th e cautio n indicate dearlier . I f on e ha s som e ide a wher e o n 1 8 is , fine : tha t is , i f yo uca nassum e tha t th e pre - an dpost 1 9 differentia l i s a t leas t i na linea r segmen t o f th e overal l 2 0 curve . 2 1 Th e high-leve l intermitten t drinking-wate r 2 2 exposures . I thin ktha t i s les s troublesome . I nothe r 2 3 words , th e onl y variabl e tha t yo unee dconcer nyoursel f wit h 2 4 i s ho w

muc hlea dwa s take nin : tha t is , i f yo uhav e a chil d 2 5 consumptio nrat e durin g th e day—30 0 mill s i s on e numbe r

_ > EXECUTIV E COUR T REPORTER S (301 ) 565-006 4

### J 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 16 1 comin g ou t o fth e Minnesot a sch-oo. 1 survey , I not. ! ced—ari d i f you , say , hav e __:0 0 microgram s |;:-_- rlite rwit h standin g w.-te rf yo u ge ta n amoun to flea d i n wati- ran d yo u coul d pum p i tint o

.. . i.

. . : _.....t. i C h i

_ _I ( I O'.it . J . . I think that , again , base d o n th e Scotis hdata — and I thin k tha t i s th e mai n cavea t here—unles s yo u are way of f thos e levels , agai n yo u ar e i n tha t non-linea r portion . Yo u ma ywan t t o ad d c omment s t o t hat . Bu t I thin k fo r eve n 10 0 t o 20 0 microgram s pe r lite r excursion s for wate r lead , i t i s probabl yokay .

CHAIRMA

NLARSON : I had som e comment s o n th e . drinkin g water , whic hwer e tha t eve n thoug hI don' t doub t tha t i t i s probabl ya reasonabl e thin g t o d o i t i s no t clea r t o m e tha t thi s particula r documen t lend s credenc e t o that .

I gues s i t does . Th e validatio n exercise s assume d a constan t drinkin g wate r lea d leve l acros s al l th e differen t areas . S o i t reall ydi d no t tes t it .

DR . MUSHAK : Bu t th e origina l validatio n o f th e mode l wa s dietar ylead . Thos e wer e feedin g studies . Thos e wer e no t ai r chambers .

CHAIRMANLARSON : S o fin d suppor t fo r i t i n on e o f th e sub-module s here .

DR . MUSHAK : I thin k yo u coul d probabl ymak e a goo d case . CHAIRMANLARSON : I t i s implici t yo u hav e t o EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.6 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 accep t tha t particula r stud yi n orde r t o accep t thi s large r attempte d model . I n tha t sense , thi s doe s validat e that .

DR . MUSHAK : I thin k th e over al l restrict:o n o n th e mode l i s tha t i t sta yi n som e linea r range . Consequently , al l o f your - input s an d uptake s fro mdifferen t source s o f pathway s shoul d giv e yo u som e indicatio n tha t yo u ar e goin g fo r tha t mediu mi n th e linea r range .

Yo u ar e barrin g empirica l dat a t o d o that . MR . COHEN : Okay . DR . RABINOWITZ : Ar e ther e an ycaveat s beside s 1inearity ? DR . MUSHAK : O f course . I mean , b y definition , i f yo u hav e a bolu s o f exposure s fro mdrinkin g wate r o r anythin g els e give n an d i f yo u hav e you r typical , say , suburba n bran d

ne wplumbin g lead-soldere d drinkin g fountai n an d otherwis e th e chil d i s wel 1-nourished , e t cetera , unles s yo u tes t tha t blood-lea dleve l an dhav e i t persist , the nI am no t sur e wha t th e toxicologica l poin t it .

Tha t is , yo uca ng o throug ha nexercis e andsa y th e child' s blood-lea dwoul dhav e bee ntha t high , bu t I don' t kno w wha t t o d o wit hi t i nterm s o f regulatin g it .

DR . MAHAFFEY : T o me , ther e are lo t o f thing s t o b e considere dher e i nterm s o f th e pattern s o f exposure . I f yo uhav e a short-ter m hig hexposur e o f lea di nsomethin g lik e drinkin g water , a t leas t for children , I am no t sur e w e

EXECUTIV E COUR T REPORTER S (301 ) 565-006 41 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 22 23 2 4 25 reall yhav e th e experienc e o funderstandin g wha tth e physiologica l respons e i s goin g t o be : i fthi s absorbed

.

I s i tmor'- - likel ysimpl yt o b e excrete d o rare you goin g t o ha-^ e a transien thig h blood-lead ?

I don' t think w e know . MR . COHEN : W e don't , bu t I gues s th e Offic e o f Drinkin g Water , nevertheless , wante d t o kno wsomething .

Anythin g that , I think , we woul dexpor t t o othe r program s w e woul d tryour bes t t o couc hit i nal l th e appropriat e uncertaintie s and try t o mak e necessar y adjustments . .

I don' t thin

kw e woul dus e th e same exac t inpu t parameter s fo r al l othe r applications .

DR . MAHAFFEY : Again , a s yo usaid , it i s explaine d inth e se t o f circumstance s yo unote : 3 0 percen t o f the var i at i on . I f somebod y want s t o tak e thi s withou t having a s muc hinformatio na s youhav e an dsay , "Okay , w

e cando this, " an d"Gee , thi s tim

e w e wil l explai n2 0 percent, " I don'*

_fin d tha t encouraging .

MR . COHEN : I f youtr y t o predic t individua l blood-leads , it i s right .

DR . MUSHAK : Wha t exactl y ar e yo uobjectin g to ? Ar e yo uobjectin g t o th e notiontha t i f a chil ddrank10 0 microgram s o f lea dinwate r ina give nday , nothing woul d EXECUTIVE COUR T REPORTER S (301 ) 565-006 41 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 t tha t th;.

- mode li :•

. .-no r fo r ach r on i -.. da i 1 y happen ? I s tha t th e point , or i : usefu l vis-a-vi s simila r calcuiati . c hi 1 d e xp o s u r e ?

DR . MAHAFFEY : I gues s m yreaction—an d thi s i s bein g kin d o f blun t abou t i t —i s tha t i f w e tak e pec.p l e wh o

ar e goin g t o drin k wate r tha t i s hig hi n lead , it i s reasonabl e t o thin k th e blood-lea d i s goin g t o g o up .

Ho wmuc hd o w e reall yhav e t o prov e tha t i t onl y goes , u p 5 percent , 3 percent ? DR . MUSHAK : Bu t I thin k th e Offic e o f Drinkin g Wate r i s no t i n th e busines s o f saying , "Well , obviousl yi t goe s up. " I thin k the ywoul d lik e t o han g a numbe r of f o f that . Th e questio n is : Ca n th e mode l b e use d t o relat e X microgram s i n a single-sho t exposur e wit ha chil d t o microgram s pe r deciliter ? Tha t i s th e issue .

O n th e fac e o f it , I woul d sa ytha t give n tha t bo x yo u coul d pu t aroun d it , yes . I thin k yo u hav e les s o f a proble m

wit hthi s tha n i n th e prio r case : th e Supe r Fund site s an

ds o on . Whethe r o r no t yo u hav e anythin g usefu l ou t o f tha t I thin k i s th e mor e relevan t question . I f yo u coul d convinc e th e Offic e o f Drinkin g Wate r that , "Well , yes , w e ca n giv e yo u a number ; bu t wha t i s it s mea t and potatoe s i n 

# J EXECUTIV E COUR T REPORTER S (301 ) 565-0064P.6 7

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 term s o f regulation?" , tha t i s anothe r thing .

CHAIRMA NLARSON : Tha t componen t i s a par t o f ou r mode l an d ou r mode l validation , bu t i t i s certainl yno t individuall yteste d a s a componen t i n an d o f itself .

Certainl yther e i s evidenc e an d par t o f th e revie w proces s her e give s u s suppor t fo r th e fac t tha t yo u ca n us e tha t approach , bu t i t woul d b e misleadin g t o sa ytha t thi s revie wcommitte e gav e a calibrate d mode l t o th e Offic e o f Drinkin g Water .

MR . HAINES : I thin kwha t I a m hearin g yo usa y i s tha t an y

tim e a mode l i s exported , thi s on e i nparticular , anybod y

usin g i t ha s t o approac hi t i na ver y cautiou s manne r an dmak e sure , i nfact , th e mode l produce s plausibl e result s for th e applicatio nfor whic hi t i s bein g used .

DR . MAHAFFEY : I f on e wante dt o stud y lea di n drinkin g water , ther e ar e studie s tha t hav e bee ncarrie dou t i nScotlan dtha t hav e looke da t lea di ndrinkin g water .

MR . COHEN : Yes . DR . MAHAFFEY : Why no t d o that ? MR . COHEN : The y us e tha t wher e the y can . DR . MUSHAK : Yo uca npos e tha t i nrelatio nt o thi s model . Yo uhav e th e smelte r studies . Yo uhav e Eas t Helena , e t cetera . Wh y

d o i t i naggregate/disaggregat e models ? Wh y d o i t biokinetically ? ) EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.6 8

1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 16 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 16 C

r ." . ver yhig hintens e peaks . Th e Scottis hdat a reall ydon' t p r ov i d e t h e n _••>: : _.•• - sa r yre l at : o n .. hi ps . 'DR . MUSHAK : Tha t i s quit e fixed , hig hbu t

c o r " i c s n t r a tec' .

CHAIRMA NLARSON : Ar e an yof . thes e list s o r othe r item s blinkin g ou t a t yo u a s bein g particularl ydangerou s applica t ions ?

DR . MAHAFFEY : Wha t abou t relativ e rankin g o f differen t pollutant s base d o n dail yintak e estimates ?

DR . MUSHAK : I woul dthin ktha t tha t i s somewher e betwee n40,00 0 an d 50,00 0 fee t hig hu pthere .

[Laughte r 1 DR . MUSHAK : An drising , yes . MR . HAINES : A s fa r a s modelin g i s concerned , ther e i s n o wa yw e ca nproduc e a mode l tha t ca nhav e a n idiot-proo f ca po nit .

CLaughter _ MR . HAINES : Wha t happen s i s tha t i f th e model s

ar e use db y

office s withi nth e agency , th e us e o f thos e model s an dth e appropriatenes s o f th e inpu t parameter s wil l b e examine db y

advisor y

committee s a s thi s us e ha s been , an d th e Offic e o f Drinkin g Water' s us e o f th e mode l wil l b e reviewe db y

SAB . S o I thin kth e appropriatenes s o f th e mode l fo r

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.6 9

•



# J

. - —* . ; .. .

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: -r.».-''4«-' v •:^r^,r

. •

- J '.-« . •*•*. . l i 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 th e air-lea d standard s i s wha t w e probabl yca n appropriatel y focu s o n righ t no wand le t othe r peopl e worr yabou t th e othe r applica t ions .

I thin k w e trie d t o provid e a clea r statemen t o f ou r own r ese r va t i o n s abou t t h e app1 i c abi1 i t yand t h e appropriatenes s o f th e parameters , an d w e hav e bee n responsibl e i n our us e o f those . Tha t is . a s muc ha s w e ca n d o fo r anybody .

CHAIRMA

NLARSON : I thin k ther e i s als o som e pressur e t o ge t reservation s o n th e recor d early . I t ma y wel l tur n ou t tha t som e subsequen t committe e usin g this , dat a ca n com e u

p wit hsomething . MR . COHEN : I t i s lik e anythin g els e inth e scientifi c literature .

CHAIRMA

NLARSON : I t i s relativ e t o th e poin t i n time . DR . RABINOWITZ : I s ther e somewher e i n ther e tha t yo u sa ythi s shoul d no t b e use d fo r othe r pollutants ?

[Laughte r D DR . MAHAFFEY : I woul dsa ytha t th e Clea n Ai r Scienc e Advisory

Boardappear s t o hav e a lo t mor e lead consultant s t o i t thansome o f th e others . S o I thinkth e amoun t o f leadreview inth e ai r par t i s base don observation , i t seems , mor e tha nsome other s have .

S o whil e w e canno t defendthi s mode l agains t othe r EXECUTIVE COUR T REPORTER S (301 ) 565-0064P.7 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 incursion s or othe r inappropriat e uses , w e d o nee d t o bea r in

min dtha t th e ai r par t Ira s bee n ver ymuc hreviewed . MR . HAINES : M

ygues s o n thi s topic , from'm y perspectiv e fro

mwha t I a

mhearin g u s tryin g t o say , i s th e Subcommitte e woul d g o fort ha s fa r as , quote , exportin g th e model : tha t you r vie wi s i t shoul d be undertake n wit hcautio n byothe r program s an d appropriatel yreviewe d a s t o it s applicabilit yacros s th e board .

I thin k youfolk s ca nput th e cautionar y not e o

n thi s an

dmak e i

t clear tha t it shoul dno t b e endorsemen t fo r purpose s it withi nthe ai r standards . Tha t shoul dnot.be . construe da s a blanke t endorsemen t t o al l othe r applications .

I thin ktha t i s th e poin t youare tryin g t o ge t across . I thin

ktha t i s a reasonabl e prospectus . CHAIRMA N LARSON : I hav e mad e up-m y ow nlist , but are ther e an

y othe r point s tha t youwoul dlik e t o rais e tha t yo uthinkimpac t th e questio no f whethe r or no t thi s become s a nadequat e supplement , i f yo uwill , t o looking a t th e alternat e air-qualit y standards , give nal l th e caveat s o f thi s writte nsummary ?

I a m not sur e everybod y i s pi ease dwit hit , but ar e ther e an

y point s I hav e missed ? G o ahead . DR . RABINOWITZ : I jus t hada wis htha t whe nth e result s o f th e calculation s o f thes e model s ar e presente d 

# J EXECUTIVE COUR T REPORTER S (301 ) 565-006 4P.7 1

1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 13 1 4 15 16 1 7 1 8 19 2 0 21 2 2 2 3 2 4 2 5 onl ytw o significan t figure s ar e displayed .

[Laughte r 1 MR . COHEN : I neede d tliat , too . I kep t th e m-.arblood-lea d t o that , bu t th e percentage s T agre e on , give n ••'••e histor yo f ho wsom e o f our standard s hav e bee n set : th e .00 5 percen t o f th e population , for example .

CHAIRMA

NLARSON : D o yo u hav e anythin g else ? MR . HAINES : I jus t wan t t o mak e sur e tha t I a m understandin g wha t I a mhearin g i n summation . Goin g down you r lis t o f questions , a s far a s ou r respons e t o comment s pose d b yth e Subcommittee , I think.I.a m readin g yo u a s sayin g wha t Jef f ha s lai d out : Th e wa yi n whic hw e pla n t o approac hthes e i s appropriat e and adequate .

Wit hrespec t t o th e models , I amreadin g th e Subcommitte e a s sayin g th e applicatio n o f th e biokineti c mode l fo r childre n ha s a reasonabl e approac hfo r estimatin g chil d blood-lead .

Whe n i t come s t o females , ther e i s a grea t concer n ove r th e appropriatenes s o f th e approach . W e shoul d mak e thi s clea r an d tr yt o explor e anyothe r way s w e ca n addres s tha t i na bette r fashion .

Wher e I amdrawin g th e lin e is—an d thi s i s whyI am comin g dow n t o th e point—tha t on e interpretatio n is : D o wha t w e lai d out ; se e i f w e hav e augmente d th e Yugoslavia n dat a o r anyothe r sources ; bu t mak e i t ver yclea r that , base d

EXECUTIV E COUR T REPORTER S (301 ) 565-006 4P.7 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 2 1 2 2 2 3 2 4 2 5 o nadul t males , no t females , e t cetera , or altevnati•el yonl y discus s exposur e t o qualitativ e set s an d don' t tryt o quantitat e becaus e w e don' t h.- e appropriat e tools .

CHAIRMANLARSON : I coul d ge t wrong , bu t I go t th e latte r a s th e sens e o f th e Subcommittee .

MR . HAINES : Okay . Tha t i s whyI a mposin g it . DR . MAHAFFEY* . An

d strik e th e wor d "female " an d us e "pregnan t woman " becaus e i t i s no t females , pe r se . MR . HAINES : I recognis e that . DR . MAHAFFEY : The occupationa l peopl e hav e a whol e lo t o f troubl e wit hthat .

MR . HAINES : Okay . CLaughter 3 MR . HAINES : I

nus e of DSD s an

dthat , I thin

kw e hav e lai dout a range . I thin kthe approac hi s agree dt o b y the r Subcommittee .

CHAIRMA N LARSON : We hadsome discussio nabou t a coupl e o f thos e ke y parameter s tha t g o wit hth e biokineti c model , jus t looking a t the sensitivit y

analysi s o

nthe predicte dsoil-lead .

I gues s thos e ar e th e tw o issue s tha t wer e brough t u pan ddiscussed . Anybody

else ? DR . McLAMB : I wa s no t bein g facetiou s abou t estimatin g blood-lead s inadul t males . I woul dlik e t o kno w EXECUTIVE COUR T REPORTER S (301 ) 565-006 4-

/

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V 

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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 • —a} .i . . i whethe r o r no t w_ . ;;:*•. gci;": : to ,

I c wa s no t C-f . a : -'.c

- m . CHAIRMA NLARSON : W e hav e no t discusse d tha t fully . I gues s w e wer e comfortabl e tha t ther e wa s adeuquat e dat a fo r goin g ahea d wit htha t approach .

DR . McLAMB : Okay . CHAIRMA NLARSON : W e wil l draf t something , hopefully , t o th e poin t tha t w e ca n pas s aroun d her e b ywa y

o f summarisin g wha t w e jus t discussed , som e guidance .

Than k yo u al l fo r patientl ymeetin g her e thi s afternoon . MR . HAINES : I wan t t o than kth e Subcommitte e member s fo r workin g har do nthis .

CHAIRMA N

LARSON : Wit hthat , w e cal l th e meetin g adjourned . CA t 4:0 5 p.m. , th e meetin g wa s concluded. ]

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EXECUTIVE COUR T REPORTER S (301 ) 565-006 4 i

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