OAR Box 1112 

Prepped by Ryan Dugan 

Document Number: 

32) ll-C-3 

Docket Number: 

A-83-22 

Printed 4/16/2008 9:12:07AM Sheet 32 of 97 

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f *£ \ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

I -\-\(2-/ Office of Air Quality Planning and Standards 

"V PBO^' 

/ Research Triangle Park, North Carolina 27711 

October 9, 1984 

Dr. Anita S. Curran 

Commissioner 

Department of Health '____ Rrrnv^ D "~ 

112 East Post Road ENVIRONMENTAL PROTECTION 

White Plains, New York 10601 AGENCY 

Dear Dr. Curran: OCT

 1 6 1Q&4 

Since our discussions las t spring, a number of the initiativ®NTRAL DOCKET 

undertaken in the lead ris k assessment area have come to fruition . A§E£TJON 

result , I am pleased to share with you the following documents: 

1) Protocol for Encoding Probability Judgments About Dose-Response 

Curves for Lead-Induced Hemoglobin Decrements and Discussing Possible 

Adverse Effects of Elevated EP; 

2) Memorandum dated September 25, 1984 from Thomas S. Wallsten to 

John Haines. Development of Hemoglobin Protocol and Selection of Consultants; 

3) Expert Selection Protocol; and 

4) Estimating the Risks of Lead-Induced Hemoglobin Decrements Under 

Conditions of Uncertainty: A Methodology, Pilo t Judgments, and Example 

Calculations. 

The hemoglobin protocol has undergone additional refinement in response to 

consultation with various experts since las t spring. I t has also been 

expanded to provide for the elicitatio n of judgments on the health significance 

of elevated erythrocyte protoporphyrin (EP). Tom Wallsten's memorandum of 

September 25 summarizes the process by which the protocol was developed. 

The Expert Selection Protocol was prepared in order to formalize the 

process by which the experts to be encoded are selected. The protocol 

places responsibilit y for the selection of experts in the hands of the 

OAQPS staff . I t i s recognized that thi s departs from the position expressed 

at las t year's Risk Subcommittee meeting. After careful consideration, 

however, we believe that thi s i s the most appropriate course to follow. 

Specifying our selection criteri a in advance should provide the public and 

the Clean Air Scientifi c Advisory Committee a basis upon which to judge 

whether we have carried out our responsibilit y in an objective and balanced 

manner. 
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The pilot study suggested during our discussions last spring proved to 

be an extremely valuable learning tool in terms of refining the actual encoding 

procedures as well as developing appropriate methods to analyze and summarize 

the elicited judgments. A ful l description of the exercise is provided in 

the enclosed report. 

Having completed these initiatives , we believe that we are now in a 

position to begin encoding on lead-induced hemoglobin decrements and the 

functional significance of elevated EP levels. Our plans call for us to 

select five experts, based on the expert selection protocol, and to begin to 

schedule encoding sessions in November. 

Work is continuing on developing a protocol for encoding on the effects 

of lead on I.Q. We wil l forward a copy as soon as i t is finished. 

With respect to the exposure analysis, we have spent the past several 

months rethinking the approach we outlined last fall . We have developed 

a preliminary framework to estimate exposure, uptake and blood lead levels 

under alternative lead NAAQS. This is currently being reviewed by appropriate 

experts both within and outside the Agency. As input to this process, we 

have taken into consideration the suggestions offered by Keeney, Sarin and 

Winkler in their report "Preliminary Comments on Lead Exposure" (copy enclosed). 

We have also taken the step to involve Bob Winkler more directly in the 

exposure analyses. This should work out well since Bob has recently begun 

teaching at Duke University. Once our revised approach has solidified, we 

wil l be pleased to share i t with you. 

Concerning lead uptake, we have initiated a contract with Dr. Theodore Kneip 

of the New York University Medical Center, Institute of Environmental Medicine. 

Under the contract, Dr. Kneip and his colleagues wil l develop estimates of 

blood and tissue lead levels in children chronically exposed to lead. This 

work expands on and supplements the "baboon study" that Dr. Lippmann referred 

to at the lead risk meeting a year ago. Once completed, Dr. Kneip's work 

should enable us to predict blood lead levels under different exposure levels 

for different stages of childhood (0-6 yrs). We anticipate receiving the 

results from this effort later this fall . 

By copy of this letter, I am forwarding copies of the enclosed reports 

to Drs. Lippmann, Kotin, Morgan, and North. I f you have any comments or 

questions concerning any of the materials provided, please le t me know. You may 

call me on 919-541-5531. 

Your continuing interest in this project is greatly appreciated. 

Sincerely, 

V . M John H. Haines 

Ambient Standards Branch 

Enclosures 

cc: Paul Kotin 

Morton Lippmann 

M. Granger Morgan 

D. Warner North