p.1 

OAR Box 1112 

Prepped by Ryan Dugan 

Document Number: 

22) ll-C-1 

Docket Number: 

A-83-22 

Printed 4/16/2008 9:12:06 AM Sheet 22 of 97 
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£ - A \ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

I ^S52Z * Office of Air Quality Planning and Standards 

\T** ^ Research Triangle Park, North Carolina 27711 /} -$ J - Z- TAUG 2 6 ,983 . REC .| V . D jl-C- t 

ENVIRONMENTAL PROTECTION 

AGENCY 

JUL 12 1984 

Dr. Paul Kotin, Chairman CENTRAL. DOCKET 

Subcommittee on Risk Assessment ^ SECTION 

Clean Air Scientific Advisory Committee ••«•?*» 

4505 South Yosemlte #339 

Denver, Colorado 80237 

Dear Dr. Kotin: 

Enclosed for your review are two documents (Keeney, 1982; Smith, 

1982) that describe approaches to the conduct of a health risk assessment 

for carbon monoxide and a third document (Whitfield, 1982) evaluating 

the two approaches. Also enclosed are materials (McCurdy, 1983; Wallsten, 

1983) providing background Information on the development of a health 

risk assessment for lead. Additional documents specific to components 

of the lead risk assessment will be mailed to the Subcommittee by the end 

of this month. We would like to discuss these materials with the Subcommittee 

at the meeting scheduled for September 14-15, 1983. 

As you have discussed with Dr. Terry Yosie 1n the preparation of the 

agenda, we would like to divide the meeting Into two subject areas: a 

review of the carbon monoxide (CO) project and a status report on the 

lead risk assessment. In the former case, the CO review serves two 

purposes: first to provide relevant background on the analytic approaches 

and encoding techniques that will be applied in the lead project; and, 

second, to complete the work of the predecessor advisory committee on 

health risk assessment. 

The Office of Air Quality Planning and Standards (OAQPS) risk assessment 

program has been under development for several years. During this time 

we have consulted periodically with the former Science Advisory Board 

(SAB) Subcommittee on Health Risk Assessment. On the recommendation of 

this Subcommittee, we examined a number of analytical approaches to 

health risk assessment for criteria pollutants. Two approaches were 

selected for application in a trial assessment of alternative NAAQS for 

CO. While some problems exist 1n the underlying data base and exposure 

calculations used to derive the risk estimates presented in the CO reports, 

we believe these do not detract from the objective of the study which 

was to compare the two developmental approaches and assess the feasibility 

of their use 1n setting future NAAQS. It should be noted that the CO 

study has not been used 1n the current CO NAAQS review. 

The final reports on each approach and an evaluation of their relative 

merits are among the materials enclosed. We would appreciate the Subcommittee's 

review and comments on the design and conduct of the CO trial assessment. 
P.3 

In applying our risk assessment methodology to the review of the 

national ambient air quality standards (NAAQS) for lead, we will be 

relying heavily on the relevant portions of the lead criteria document for 

the necessary Input data. Since this document has not yet been released 

for external review, our Initial presentation to the Subcommittee will focus 

on the conceptual basis for and organization of the component models. 

We look foward to the September meeting and the receipt of your 

comments on the risk assessment program and its application to the review 

of the lead NAAQS. By copy of this letter, I am fowarding the enclosed 

materials to the members of the Subcommittee. 

Sincerely yours, 

Di rector 

Strategies and A1r Standards Division 

Enclosures 

cc: Subcommittee Members 

T. Yosie 
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Information Package for Mai lout to CASAC Risk Assessment Subcommittee 

$ 

For Mai lout by 8/24/83: 

T. McCurdy and H. Richmond. "Description of the OAQPS Risk Program and 

the Ongoing Lead NAAQS Risk Assessment Project." Paper 83-7-1 at 

APCA Meeting, 1983. 

R. L. Keeney, et al., Development and Application of a Risk Assessment 

Methodology to Study Alternative National Ambient Carbon Monoxide 

Standards. Woodward and Clyde Consultants, 1982 (Draft). 

A. E. Smith, et al., Development of Decision Analysis Methodology for 

Health Risk Assessment. SRI International, 1982 (Draft). 

T. S. Wallsten, et al. Stability and Coherence of Health Experts' Upper 

and Lower, Subjective Probabilities about Dose-Response Functions. 

Organizational Behavior and Human Performance, 1983. 

R. G. Whitfield. "Letter Report: Evaluation of Two Risk Assessment 

Methodologies." Argonne National Laboratories, September 16, 1982. 

For Mai lout by 8/31/83: 

W. F. Biller. "Description of Lead Exposure Model (Draft)." August 1983. 

W.F. Biller. "Description of Lead Physiological Model (Draft)." 

August 1983. 

R.G. Whitfield. "Description of the Dose-Response and Risk Modeling Effort." 

Argonne National Laboratories, August 1983.