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# OAR Box 1112 Prepped by Ryan Dugan



## Document

Number: 

# 5 ) ll-B-2 b Docket Number: 

# A-83-2 2

Printed 4/16/20089:12:05AM

Sheet 5of 97P. 2 

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# ARCON'N E NATIONA L LABORATOR Y 970 0 SOUTI H CAS S AVENUE

. ARQONNE

. llliNoi s 6045 9 TEIEPIION E 512/972 - 8 4 3 0

Februar y15 , 198 5

Dr . Willia m

Yul e Departmen t o f Psycholog y Institut e o f Psychiatr y DeCrespign yPar k London , SE 5 8A F Englan d Dea r Dr . Yule :

I hav e bee n aske d b yth e peopl e i n th e U.S . Environmenta l Protectio n Agency' s (EPA ) Offic e o f Ai r Qualit yPlannin g an d Standard s t o tal k t o yo u abou t a n importan t matter .

A s yo u ma yknow , th e EP Ai s charge d b yth e Clea n Ai r Ac t wit hsettin g an d revisin g Nationa l Ambien t Ai r Qualit yStandard s (NAAQS ) fo r selecte d pollutants , a t level s sufficien t t o protec t th e publi c healt hwit ha n adequat e margi n o f safety . Th e scientifi c base s fo r thes e standard s ar e presente d an d reviewe d i n criteri a documents . A s on e aspec t o f th e revie wprocess , EP A assesse s healt hrisk s b yidentifyin g th e mos t sensitiv e population s fo r eac h pollutan t an d estimatin g probabilisticall yth e number s o f peopl e i n th e popu lation s wh o ma ysuffe r eac ho f variou s well-define d advers e healt h effect s attributabl e t o th e pollutant . I t i s believe d tha t informatio n abou t th e healt hrisk s associate d wit hvariou s potentia l standard s wil l ai d th e EP A administrato r i n selectin g a standar d that , i n hi s judgment , protect s th e publi c healt hwit ha n adequat e margi n o f safety .

Becaus e th e ris k estimate s tha t EP Aseek s ar e ofte n base d i n par t o n dose-respons e relationship s an d lea d exposur e estimate s whic h ar e uncertain , i t i s necessar yt o mak e probabilit yjudgment s abou t relevan t dose-respons e function s base d o n th e availabl e evidenc e an d t o probabilisticall yestimat e lea d exposur e unde r alternativ e NAAQS . Obtainin g th e healt hris k estimate s the n involve s combinin g dose-respons e an d exposur e probabilit yestimates .

Th e EP Abelieve s tha t i t i s importan t an d necessar yt o us e th e scien

tifi c judgment s o f th e bes t an d mos t knowledgeabl e peopl e t o extrapolat e fro m th e availabl e dat a t o th e neede d dose/respons e functions . Th e extrapolatio n i s no t certai n an d i t depend s o n one' s interpretatio n o f th e literature . Thus , differen t peopl e wil l hav e differen t judgments . Fo r eac hhealt heffec t w e inten d t o obtai n th e probabilisti c judgment s o f fiv e peopl e t o sampl e th e rang e o f respecte d opinions . Th e mode l fo r estimatin g risk s wil l no t merg e thes e judgment s int o a singl e averag e judgment , bu t rathe r wil l estimat e th e rang e o f risk s base d o n th e rang e o f judgments . Thi s wil l sho wth e EP A administrato r a rang e o f ris k estimate s base d o n a rang e o f judgments . We . wil l als o b e abl e t o sho wsom e o f th e source s o f tli e disagreements . Indeed , a sid e benefi t tha t w e expec t fro mthi s exercis e I s t o hel p identif ysource s o f greates t disagreement .

U.SDI|AKMMI Mo l rMiv V Hi , LKKiusiivo l ( ]lli < A( ( ( )P. 3

Dr . W . Yul e 2 Februar y 15 , 198 5 Base donth e evidence i nthe leadcriteri a document , tw o population s hav e bee nidentifie da s bein g mos t susceptibl e t o the effect s o f lea dintoxi cation . On e i s childre nfro m birt hthroug hth e sevent hbirthda y an dthe othe r i s pregnan t wome nor , mor e precisely , the fetuse s bein g carrie db y th e pregnan t women . A numbe r o f advers e healt heffect s hav e bee nidentifie dfo r whic hwe woul dlik e to estimat e dose-respons e functions .

Becaus e o f you r experienc e an dknowledge o f leadan dit s possibl e neurologica l effects , we woul dlik e t o invit e youto wor k wit hu s o nthi s matte r an

dserve , i f youwill , a s ananonymou s exper t specificall y o nlead induce dI Q decrement s amon g children .

Th e committmen t onyou r par t woul dbe t o • * 'en dapproximatel y

1-1/ 2 day s wit hmysel f an

dDr . To

m Wallste nfro

m the Universit y

o f Nort hCarolina . We would , o f course , do the travelin g an dwoul dlik e to mee t wit hyouo ntw o occasion s i na 3-da y period . O

nthe firs t day

w e woul dfamiliariz e youwit h the proces s o f judgmenta l probabilit y encoding , discus s the relevan t liter atur e o

nleadhealt heffects , obtai nyou r initia l judgments , an dexplai nho w you r judgment s woul db e use di nth

e ris k assessmen t process . Onth e second day , we woul drefin e you r judgments . Th e firs t meetin g woul drequir e abou t 6 - 7 hour s o f you r time , an dthe secondmeetin g woul drequir e abou t 2- 3 hours . Afte r returnin g to th e U.S. , w e woul dpu t togethe r a packe t o f infor

matio n abou t you r judgment s an d sen d i t t o yo u fo r you r revie w(an d revision , a s needed ) a s par t o f the proces s o f finalizin g you r probabilisti c judgments .

T o hel p yo u plan , i t i s ou r hop e t o b e abl e t o visi t yo u som e tim e i n May . I t woul d probabl yb e bes t i f w e coul d mee t wit h yo u o n Monday , Ma y6 an d Wednesday , Ma y7 . Thi s woul d fi t nicel ywit h ou r pla n t o visi t wit h Dr . Winnek e o f th e F.R.G . o n Ma y1 and 3 . However , al l o f thi s depend s o n you r an d hi s availability . (Incidently , w e als o pla nt o includ e Drs . Dietrich , Ernhart , an

dNeedlema no f the U.S . i nthe study . We hop e t o obtai nthei r judgment s befor e travelin g t o Europe. )

I f yo uagre e t o participat e i nthi s ver y importan t an

dground-breakin g study , I wil l sen dyo umor e informatio nabou t th e study , includin g th e proto co l tha t w

e intendt o us e t o facilitat e th e proces s o f obtainin g you r prob

abilisti c judgments .

I woul d lik e t o arrang e a phon e cal l wit h yo u soo n t o discus s thes e matters . Perhap s yo u coul d le t m e kno w(vi a TELEX? ) o f som e goo d day s an d time s o f th e da yt o cal l you . M yTELE X numbe r i s TW X 910-258-328 5 U S DOE-C H ARGN .P. 4



### Dr . W . Yul e Februar y 15 , 198 5 Al l o f u s sincerel y

hop e tha t yo uca ntak e part i

nth e 6tudy . You

r judgment s ar

e important t

o Ch e U.S . EPA , an

dyou r participatio

nwil l b

e greatl y appreciated . 

### Sincerely ,



# foulb Ronal dG . WhitfielH , Ph.D . Decisio nan dSyste m Science s Sectio

n Energ y an dEnvironmenta l System s Divisio n RGW:b f bcc : T . D . Wolsk o T . Surle s J . Peerenboom T . Wallste n