[Federal Register Volume 65, Number 116 (Thursday, June 15, 2000)]
[Notices]
[Pages 37544-37545]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-15158]


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ENVIRONMENTAL PROTECTION AGENCY

[FRL-6716-8]


Science Advisory Board, Office of Air and Radiation, Office of 
Research and Development Notification of Public Workshop

    Notice is hereby given that the US EPA Offices of Research and 
Development (ORD) and Air and Radiation (OAR), along with the US EPA 
Science Advisory Board (SAB), will jointly host a public workshop on 
the Benefits of Reductions in Exposure to Hazardous Air Pollutants: 
Developing Best Estimates of Dose-Response Functions on the date and 
time noted below. The meeting is open to the public, however, seating 
is limited and available on a first come basis.

SAB/EPA Workshop on the Benefits of Reductions in Exposure to 
Hazardous Air Pollutants (HAPs Workshop): Developing Best Estimates 
of Dose-Response Functions--June 22-23, 2000

    The Workshop will be held on June 22 and 23, 2000 at the Westin 
Grand Hotel, West 2350 M Street, NW, Washington DC 20037, Telephone 
202-429-0100. The meeting will begin by 9 a.m. on June 22, 2000 and 
adjourn no later than 12 p.m. on June 23, 2000.
    Purpose of the Meeting--The workshop will convene experts from 
different disciplines and different backgrounds to discuss ideas for 
dose response assessment methods for hazardous air pollutants (HAPs) 
that are appropriate for use in assessing benefits associated with HAP 
emission control measures. Such benefits assessments are not only 
required by statute to support EPA's Report to Congress under section 
812 of the Clean Air Act Amendments, but they are also required as part 
of the regulatory activities associated with HAPs. EPA is seeking a 
wide spectrum of views at the workshop and is not seeking a consensus 
recommendation from workshop participants.
    Expected outcomes from this workshop will include a report 
documenting: (1) Proposed approaches for hazard assessments for 
selected HAPs that would facilitate benefit assessments for those 
chemicals; (2) expert discussants' views on whether it is possible to 
produce a methodology for developing central tendencies and 
distributions in hazard assessments for HAPs for use in benefits 
analyses and how that might best be done; (3) how best to identify 
limitations and uncertainties in both risk assessment methods and 
economic models; and (4) suggestions and priorities for a research 
agenda to address identified gaps in available data and methods needed 
to conduct HAPs related benefit analyses.
    Background--Hazardous air pollutants (HAPs) have been the focus of 
a number of EPA regulatory actions, which have resulted in significant 
reductions in emissions of HAPs. EPA has been unable to adequately 
assess the economic benefits associated with health improvements from 
these HAP reductions due to a lack of best estimate dose-response 
functions for health endpoints associated with exposure to HAPs and 
also due to the air quality and exposure models for HAPs available for 
use in benefits analysis. EPA is conducting two activities to develop a 
proposed methodology to generate estimates of the quantified and

[[Page 37545]]

monetized benefits of reductions in exposure to HAPs. The first will be 
a workshop focusing on developing best estimates of dose-response 
functions that relate changes in HAP exposure to changes in health 
outcomes. The second activity will focus on (1) integrating these dose-
response functions with appropriate models of HAP concentrations and 
human exposure and (2) translating these into economic benefits that 
would estimate changes in health risks resulting from regulations that 
reduce HAP emissions.
    The overall goal of these two activities is to identify methods for 
the Agency to consider using in estimating changes in health risks 
resulting from HAP regulations that can be combined with valuation 
functions to estimate monetized benefits of HAP reductions.
    Risk assessments for HAPs have been developed to help decision 
makers set health-based standards that are consistent with EPA's 
mission to protect human health. The quantitative toxicity values from 
these assessments (that is, the cancer slope factors and the noncancer 
reference concentrations and reference doses) are typically based on 
animal and epidemiologic studies that involve higher exposures than 
those encountered in the environment. The gap between environmental 
doses and study doses has led to toxicity values that can put a bound 
on the actual risk without being able to provide a reliable central 
estimate or distribution of risks. It is these latter terms (central 
estimates and distributions) that economists have traditionally used to 
estimate the economic value of potential changes in risks.
    In contrast, risk assessments for criteria pollutants have been 
based on epidemiologic and clinical studies of exposures similar to 
those encountered in the environment. This has allowed development of 
standard statistical confidence intervals and distributions. With this 
information, economists have been able to develop economic benefit 
estimates for many health endpoints related to criteria pollutants. 
Criteria pollutant benefit estimates have been feasible because of the 
availability of: (a) Well-defined health endpoints such as hospital 
admissions or premature mortality; (b) dose-response functions from 
epidemiological and clinical studies which support estimates of risk 
reductions in terms amenable to economic valuation; (c) reliable 
estimates of ambient concentration and population exposure change; and 
(d) dose-response functions available from epidemiological and clinical 
studies in which the exposures were similar to those being experienced 
in the ambient environment. Uncertainties related to the health 
benefits of criteria pollutants have generally been represented by 
standard confidence intervals based on measures of within and between 
study variation in the estimated health effects.
    While mortality from HAP-related cancer is a well-defined endpoint, 
there are very few validated exposure-response relationships. For the 
many other potential health effects from exposure to HAPs, such as 
changes in reproductive functions or mutagenic effects, there are major 
information gaps in all aspects of risk assessment, as well as in 
exposure-response and valuation. The focus of this workshop will be the 
development of best-estimates and uncertainty characterizations for 
hazard and dose response functions for use in benefits analyses of HAP 
regulations, with a focus on providing potentially useful data and 
tools to support HAP-related benefit assessments, including national-
scale program evaluations.
    For Further Information--Any member of the public wishing further 
information concerning this workshop should consult the website for 
this workshop at http://www.epa.gov/ttn/ecas/meetings/coverhap.html or 
contact Ms. Heather Hodgeman in EPA's Office of Air and Radiation via 
email at [email protected] or by telephone at (919) 541-5668.

    Dated: June 7, 2000.
John R. Fowle III,
Acting Staff Director, Science Advisory Board.
[FR Doc. 00-15158 Filed 6-14-00; 8:45 am]
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