UNIT-ED STATES ENVIRONMENTAL PROTECTION AGENCY

                          WASHINGTON, D.C  20460
May 27, 1987
                                           SAB-EC~87™Q31
                                                                   O F F I C t Of

                                                               r H fe, AQMINfST^AFQH
Honorable Lee M. Thomas
Administrator
U. S, Environmental Protection Agency
401 M Street, S. W.
Washington, D. C.  20460

tear Mr. Thomas:

     The Science Advisory Board's Integrated Environmental Management
Subcommittee has completed its review of EPA's Draft Kanawha Valley Toxics
Screening Study and is pleased to transmit its tinal report to you.  The
Subcommittee met in public session on March 16, 1987 in Philadelphia,
Pa., to review the study.  During March 11-13, 1987, three representatives
of the Subcommittee visited the Kanawha Valley to become more faroilar
with its environmental problems.

     The Subcommittee unanimously concludes that the Kanawha Valley study!"
represents an important component of EPA's overall effort to develop
methodologies to define public health and environmental priorities.
Studies such as this provide valuable technical challenges and experiences
to EPA staff, particularly those working in regional offices.  And,
finally, they provide a valuable means for developing closer working
relationships with state and local officials and the general public.

     This letter is the Subcormittee's second cortrajn icat ion to you.  On
July 30, 1986 it           "many concerns about the ability of the current
study to satisfy a number of technical issues.  A chief concern is "the
incongruity between  [the study's] .... objectives and the fact that the
study design itself is not an integrated multimedia effort, nor a response
to Bhopal."

     Since the transunittal of that letter, EPA staff have modified the
study's objectives and technical design, and have conducted supplementary
analyses to support the revised objectives and design.  In general, the
Subcommittee believes that the staff have made appropriate responses to  its
major concerns.  The study reaches a number of scientifically supportable
conclusions about health risks from cancer in the Kanawha Valley.  The
study also points EPA and other  interested parties  in a direction  for
conducting further analyses of problems related to  accidental releases of
pollutants and acute health effects.

     Specific issues addressed during the Subcommittee's review include:
the study's objectives and scope; pollution sources} pollution transport
and  fate by media; health effects,- risk communication; and recommendations
for additional  follow-up efforts.  Attachment A presents additional, more-
detailed recommendations for modifying the current  study and future
activities in the Kanawha Valley.  Attachment B lists the Subcommittee
members.

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     In generaj, the Subcommittee views the Draft Kanawha Valley Toxics
Screening Study as one step of a continuing process to        risks.  The
current study addresses chronic health exposures to carcinogens which
represent one of many public health concerns in the Valley.  As a follow-up
to the current study* the Subcommittee recommends two additional steps
that include:

     o  Expanded monitoring of air toxics, and use of monitored values
        to obtain more precise estimates of exposure* and health risks.

     o  Greater focus on accidental releases and fugitive emissions as
        areas of public health concern.

     The Subcommittee appreciates the opportunity to conduct an independent
scientific review of these important public health issues in the Kanawha
Valley.  We request that EPA formally respond to our scientific advice.
                                    Sincerely,
                                    Ronald Wyzga, Chairman
                                    Integrated Environmental
                                       Management Subcommittee
                                    Science Advisory
                                    Norton Nelson, Chairman
                                    Executive Conmittee
                                    Science Advisory Board

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                                   SAB-EC-87-031
       MAJOR FINDINGS AND RECOMMENDATIONS
                     OF 'THE
INTEGRATED ENVIRONMENTAL MANGEMENT SUBCOMMITTEE
                     ON THE
 U. S. ENVIRONMENTAL PROTECTION AGENCY'S DRAFT
     RANAWHA VALLEY TOXICS SCREENING STUDY
INTEGRATED
             SCIENCE ADVISORY
     U. S. ENVIRONMENTAL PROTECTION AGENCY
                   May, 1987

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              u. s.
                              NOTICE
     This report has been written as a part of the activities of
the Science Advisory Board, a public advisory group providing
extramural scientific information and advice to the Administrator
and other officials of the Environmental Protection Agency.  The
Board is structured to provide a balanced expert assessment of
scientific matters related to problems facing the Agency,  This
report has not been reviewed for approval by the Agency, and
hence the contents of this report do not necessarily represent
the views and policies of the Environmental Protection Agency,
nor of other agencies in the Executive Branch of the Federal
government, nor does mention of trade       or ccfirosrcial products
constitute endorsement of recommendation for use.

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     The objectives of the Kanawha Valley study are limited, but reasonably
well-defined.  In most instances, the study seeks to derive an upper bound
for the health risks associated with airborne carcinogens for which
EPA's Cancer Assessment Group has derived potency estimates.  Other
potential carcinogens are minimally considered, and the health risks of
non-carcinogens, including those risks associated with the accidential
release ot chemicals such as occurred at Bhopal, are not considered.
Hence, the health assessment of airborne toxics is far from complete, but
this is clearly articulated in the study report.  Available resources did
not allow a more comprehensive assessment.

     The study attempts "to develop a       of potential public health
concerns" associated with carcinogens in drinking water, surface water
and hazardous wastes.  The efforts are not multimedia efforts, but medium-
specific efforts based upon ver^_J,ijni,t.ed data; thus, conclusions from
      efforts are subject to considerable uncertainty.

Sources

     The air analyses depend very heavily upon an emissions inventory of?"
some 450 substances developed by the Wast Virginia Air Pollution Control •
Ccmrdssion (APCC).  The inventory is as extensive and comprehensive as
any other available information.  Nevertheless, there exist
uncertainties in the  inventory, particularly with respect to fugitive
emissions, which the study identifies as a major source of health risk in
some Kanawha Valley communities.  The possibility that the  inventory  is
incomplete is also suggested by the fact that ethylene oxide     not  included
for either the Belle or Nitro connunities despite      limited monitoring
evidence that it may be present.  If a compound was not in the- inventory
it was not included in subsequent EPA modeling.  This discrepancy underlines
the need for including ethylene oxide in future monitoring programs.

     The drinking water and surface water analyses depend upon monitored
levels of toxics in water supply systems and fish fillets,  respectively,
Data     limited to a subset of all public water suppliers, with no private
well samples, and to a very small number of fish sampled from only  one
location for a very limited number of toxic substances.  The hazardous
waste inventory  is based upon a priority pollutant screening of inventories
for a subset of RCRA  and potential CERCLA sites.  No  information
available on the total quantity and overall composition of  toxic wastes
that may be entering  surface or ground water.   For this reason alone,  the
results of this part  of the study are, at best, suggestive.
      The transport models  used in the studies  generally  appear to be
 congruent with the study objectives.   The air  transport  modeling  addresses
 the concerns  of the Subcommittee in its July 30,  1986 letter,  although better

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docunentation of this modeling is needed.  There is a factor of two
uncertainty on point source air emissions and another uncertainty of a
factor of two in dispersion modeling.  The current modeling efforts do
not address these potential uncertainties, although "worst case" scenarios
should recognize their existence.  Drinking water exposure was estimated
by assuming that individuals consume two liters of the water delivered to
their neighborhoods.  Similar assumptions are often made in risk assessments.
The surface water and hazardous waste studies are greatly hanpered by a
lack of data, making large assumptions necessary to estimate exposure to
toxics.

Health_Effects

     The study evaluated 20 known or suspected cancer causing chanicals
from the West Virginia APCC inventory of more than 450 compounds.  The
Subcommittee concludes that the current study provides useful information
on health effects from cancer and environmental loadings of these 20
compounds.  After finalizing the current study, EPA should conduct additional
efforts that include:

     o  Using the APCC inventory and information on toxicity to evaluate^
        the potential health effects of      of the remaining ccnpounds.v
        Of the remaining 430 or so compounds, relatively few merit further
        attention,,  but EPA and APCC should work together to identify
        compounds that need additional evaluation.  These should be
        identified  by defining the set of those conpounds to which some
        exposure may be likely at known toxic levels.

     o  Broadening  the health endpoints of concern to include non-cancer
        and acute effects.  Concern about the potential effects from
        acute releases is strong within the ccfimunity; hence, some
        priority should be given to addressing this issue.  The
        methodologies used to         these endpoints require further
        development, particularly in estimating the effects of accidential
        releases.       fault-tree or alternative analysis should be
        designed to        this possibility.  Experts fron other groups
        within the  EPA should be enlisted in this effort.

     o  Incorporating frequency plots of pollutant concentrations versus
        time? in addition to stating average pollutant concentrations.

     o  Assessing the conversion of  reference doses from the  ingestion  to
        the  inhalation pathway, where reference dose  information for the
         inhalation  pathway  is not available,

     o  Evaluating  whether  to develop or use biological markers  for health
        assessment.

     o  Comparing risks  from high       emissions  of pollutants  with  low
         toxicity, with  low       emissions ot pollutants with  high  toxicity
        as a means  to  identify  priority risk management needs.

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     o  Exploring other potentially useful sources of data for compounds
        of concern? including monographs prepared by the International
        Agency for Research on Cancer, Health Effects Profiles developed
        by the Office of Research and Development, Reportable Quantities
        for hazardous compounds and gaining access to information through
        the ccnmmity right-to-know provision of Superfund.
     The Subcommittee encourages EPA to continue its- efforts of working
with officials and citizens of the Kanawha Valley to update them on the
sources and magnitude of risks they experience.  In particular, EPA should
seek to further improve its presentation of technical Information to
better enable lay persons to understand the results of technical analyses
and to ensure it is understood that the risk numbers reflect upper bound
estimates.  Clarification of the latter issue  is also        in the
executive summary of the study,

     It is important for citizens, scientists  and public officials to
understand that the principal value of the Kanawha Valley study Is as a
screening study of airborne carcinogens.  As the study acknowledges,
a screening study should strive to ensure that all potential risks are
Identified even at the expense of calling attention  to risks that subsequent
analysis may not confirm, or will be less than indicated In the screening
study.  Accordingly, assumptions in screening  studies are conservative in
nature; assumptions should be avoided that might cause potential risks to
be ignored.  Within the stated scope of the study, conservative assunptions
are made; for example, individuals are assumed to be exposed continuously
to ambient outdoor levels of industrially emitted toxics and upper bound
risk estimates are given.  There are a few instances, however, where the
study did not rigorously pursue conservative assumptions.  These include
potential uncertainties or omissions In the emissions inventory.  The
study suggests that point estimates could be too small (or too large) by
a factor of two.  For fugitive emissions it could be greater.  It is
important that these uncertainties and their likely direction  be clearly
articulated in the report along with a discussion about whether additional
scenarios are necessary to consider these uncertainties.

     In addition, the air quality models are equally likely to under-and-
over predict ambient concentrations.  The biases of  the models are fairly
predictable.  Exposures are likely underestimated at the peaks of ridges
where the river turns and when overlapping models were not used.  On the
other hand, the use of the Box model probably  overpredicts exposure in
some neighborhoods on the Valley  floor, which  are not adjacent to emissions
sources.  Although it is to the study's credit to have implemented two
different modeling approaches  to  estimate exposure,  further discussion
in the  report is merited on the potential model biases and on  their
implications for the risk estimates.

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                                                           Attachment A

                  ADDITIONAL RECOMMENDATIONS TO THE AGENCY
A.
    1.  The technical assumptions for the underlying transport models
        should be documented and made accessible to readers of the
        report.

    2.  Given the comprehensive nature of the airborne toxic risk
        assessment in contrast to the rudimentary nature of the other
        three studies, it may be desirable to more cle'arly separate the
        air toxic studies from the others; moreover, the various studies
        are undertaken for differently defined geographic areas.

    3.  The risk estimate bounds are probably more clearly defined than
        in roost similar documents; nevertheless , further clarification
        raay be necessary.  Cases could be presented as 
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3.  The hazardous waste data considered are very limited.  CERCLA
    requirements can perhaps provide      useful information.  Other
    parts of EPA should be enlisted to improve the source inventory
    for these data.  Analysis of historical operations and land use
    may also be useful to characterize the types of chemicals in
    waste sites.  The fundamental approach to consider risk frcm
    hazardous waste should be replaced, however, by one that examines
    specific waste sites,

4.  Increased monitoring data can aid the analysis of drinking water,
    surface water, and ground water.  For chemicals of concern in the
    Valley? such efforts should be instituted to help ensure that no
    major problems are overlooked.

5.  Health surveys and measurement of biological markers could provide
         validation of the estimated health profile of the Valley.
    Such efforts will not, however, be useful when incremental risk
    estimates are small.

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                                                              Attachment B
                       U. S. ENVIRONMENTAL PROTECTION AGENCY

                               SCIENCE ADVISORY

                 ' Integrated Envirormental Management Subcommittee
Dr. Ronald Wyzga, Chairman
Electric Power Research Institute
3412 Hillview Avenue
Post Office Box 1041
Palo Alto, California  94303
Dr. Stephen L, Brown
Environ Corporation
1000 Potomac Street, N.
Washington, D. C. 20007
w.
Dr. Thomas Clarkson
University of Rochester Medical Center
Box RBB
575 Elrrwood Avenue
Rochester,     York  14642

Dr. Herbert H, Cornish
830 West Clark Road
Ypsilanti, Michigan  48198
Dr. Robert Frank
Johns Hopkins University
Department of Environmental
   Health Sciences - JHSHPH
615 North Wolfe Street
Baltimore, Maryland  21205

Dr. Rolf Hartung
School of Public Health
University of Michigan
Ann Arbor, Michigan  48109
Terry F. Yosie, Director
Science Advisory Board
U." S. Environmental Protection
   Agency
401 M Street, S. W.
Washington, D. C.  20460

Dr. Thomas Burke
New Jersey Department of Health
Div. of Occupational & Environ.
  Health  CN 360
Trenton, New Jersey  08625

Dr. Yoram Cohen
Chemical Engineering Department
U. C, L, A.       5531,
Boelter Hall
Los Angeles, California  90024

Dr. Terry Davies
World Wildlife Fund
The Conservation Foundation
1255 23rd Street, N* W.
Washington, D. C.  20037

Dr. Janes Gruhl
7610 N. Christie Drive
Tucson, Arizona  85718
                             Dr. Paul Lioy
                             University of Medicine and
                                Dentistry of New Jersey
                             675 Hoes Lane
                             Robert Wood Johnson
                                Medical School
                             Piscataway, New Jersey  08854

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Dr. Francis
The                  of
   Environmental Engineering
Department of Civil Engineering
Carnegie Mellon University
5000 Forbes Avenue
       Hall 123A
Pittsburgh, Pennsylvania  15213

Dr. Ellen Silbergeld
Chief Toxics Scientist
Environmental Defense Fund
1525 18th Street, N. W.
Washington, D. C.  20036
Dr.        North
Principal, Decision Focus, Inc.
    Altos Office Center
Suite 200
     El
Los Altos, California  94022

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