[Federal Register Volume 61, Number 196 (Tuesday, October 8, 1996)]
[Notices]
[Pages 52790-52791]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-25770]


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ENVIRONMENTAL PROTECTION AGENCY
[NCEA-RTP-0976; FRL-5629-2]


Lead Model Validation Workshop

AGENCY: Environmental Protection Agency.

ACTION: Notice of Lead Model Validation Workshop.

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SUMMARY: This notice announces a Lead Model Validation Workshop to 
explore approaches and results for the validation of models that 
predict lead exposure and risk. It is sponsored by EPAs National 
Center for Environmental Assessment, in cooperation with EPAs Office 
of Solid Waste and Emergency Response and the EPA Technical Review 
Workgroup for Lead.

DATES: This scientific workshop will be held Monday, October 21, 1996, 
through Wednesday, October 23, 1996. It will begin at 8:30 a.m. on 
Monday and will conclude at 4:00 p.m. Wednesday. Members of the public 
may attend as observers.

ADDRESSES: The workshop will be held at the Omni Europa Hotel, 1 Europa 
Drive, Chapel Hill, NC 27514, telephone: 919-968-4900, FAX: 919-968-
3520. To attend this workshop as an observer, contact Ms. Emily Lee, 
National Center for Environmental Assessment--RTP office (MD-52), U.S. 
Environmental Protection Agency, Research Triangle Park, NC 27711, 
telephone: 919-541-4169; FAX: 919-541-5078 by October 16, 1996. Space 
is very limited, so call as soon as possible. Copies of the final Lead 
Model Validation Workshop Agenda will be available on or about October 
8, 1996. To obtain a copy of the Agenda, contact Ms. Emily Lee at the 
above address. Copies of journal articles and other reports providing 
information on the lead models and/or their verification/validation to 
be discussed at the workshop will be provided to workshop registrants 
in advance and/or at the meeting site, as circumstances allow.

SUPPLEMENTARY INFORMATION: The purpose of this workshop is to explore 
approaches and results for the validation of models that predict lead 
exposure and risk and to ascertain useful further steps to improve and 
validate such models. Thus, this workshop will (a) examine lead models 
that evaluate impacts on humans exposed to lead in environmental media 
such as soil, dust, paint, drinking water, diet, and air and (b) 
discuss both general concepts regarding model validation and validation 
studies for the subject lead models. Some of these models have been 
used by EPA and other parties in risk assessments of various CERCLA or 
RCRA sites and have generated considerable interest because of 
differences in the scientific foundations and differences in scale of 
remediation implied by the models or their application.
    For purposes of this workshop, EPA has defined model validation as 
an iterative process that describes the plausibility and accuracy of 
model predictions and the potential applications for which a model is 
appropriate. This process includes consideration of the scientific 
foundations of the model, the strength of data used in estimating model 
parameters, correctness of computational implementation of the model, 
and scientific methods for comparing model predictions with 
observational data.
    The workshop will address four basic issues affecting each model:
    1. Scientific foundations of the model structure. Does the model 
adequately represent the biological and physical mechanisms of the 
modeled system? Are these mechanisms understood sufficiently to support 
modeling?
    2. Quality of parameter estimates. How extensive and robust are the 
data used to estimate model parameters? Does the parameter estimation 
process require additional assumptions and approximations?
    3. Verification. Are the mathematical relationships posited by the 
model correctly translated into computer code? Are model inputs free 
from numerical errors?
    4. Empirical comparisons. What are the opportunities for comparison 
between model predictions and data, particularly under conditions under 
which the model will be applied in assessments? Are model predictions 
in reasonable agreement with relevant experimental and observational 
data?
    EPA is using these criteria as part of its validation strategy for 
evaluating the EPA Integrated Exposure/Uptake/Biokinetic Model for Lead 
(IEUBK) and believes it would be useful to ascertain to what extent 
other available lead modeling approaches have addressed these and/or 
other criteria.
    EPA believes that the Agency and interested parties will benefit 
from discussion of the subject lead models, validation concepts and 
their application to date, and the determination of useful future 
validation steps. This workshop will bring together EPA personnel 
(scientific and policy staff) involved in derivation and use of the 
subject lead models and other non-EPA invited experts representing 
extensive experience in theoretical and practical application of

[[Page 52791]]

model development and validation. Interested observers may also attend 
the workshop. There will be opportunity for brief oral comments from 
observers.
    Written versions of workshop presentations and a summary of key 
points emerging from the workshop discussions are expected to be 
included in subsequently published workshop proceedings. Information 
regarding how to obtain copies of the proceedings will be provided to 
workshop registrants at the time of the workshop or shortly thereafter.

    Dated: October 2, 1996.
Robert J. Huggett,
Assistant Administrator for Research and Development.
[FR Doc. 96-25770 Filed 10-07-96; 8:45 am]
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