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                                      OSWER Directive 9850.4

cc:  Bruce Diamond, OWPE
     Henry L. Longest II, OERR
     Sylvia Lowrance, OSW
     Timothy Fields, ERD
     Stephen Lingle, HSED
     Russell H. Wyer, HSCD
     Joseph Carra, PSPD
     David Bussard, WMD
     Lloyd Guerci, CED
     Susan Bromm, RED
     Directors, Waste Management Divisions, Regions I, IV, v,
     VII,  VIII
     Director, Emergency and Remedial Response Division, Region
     II
     Directors, Hazardous Waste Management Divisions, Region III
     VI
     Director, Toxics and Waste Management Division, Region IX .
     Director, Hazardous Waste Division, Region X
     CERCLA Branch Chiefs, Regions I-X
     RCRA  Branch Chiefs, Regions I-X

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                                             OSWER Dir.  9850.4

Intarin Final a»\A*nc*  for Soil Inoeation Rataa:
     This  interim  final guidance supersedes previous program
related guidance  (Superfund Public Health Evaluation Manual,
October, 1986, OSWER Directive 9285.4-01) only with reference to
soil ingestion rates and should be used by regional staff ••-•a are
responsible  for conducting and evaluating risk assessments  in
OSWER related programs.  This interim final guidance is based on
the most recent reliable data available on soil ingestion rates.
It may be  revised  to reflect new data the Agency may review that
would significantly affect risk assessment results.

     In developing exposure scenarios used in program risk
assessments, a soil ingestion rate of 0.1 grams per day should be
used for adults and a  soil ingestion rate of 0.2 grams per  day
should be  used for children who are- one year through six years of
age.  These  rates  are  based on the most recent reliable data
reviewed by  the Agency, and represent reasonably const: /ative
values.  This guidance does not address children who exnibit
abnormal mouthing  behavior  (pica).  The occurrence of pica
behavior and the associated rates of soil ingestion have not been
well defined,  without this information, risk cannot be
quantified for children with pica behavior.

     There may be  cases where site- or facility-specific data
exist on soil ingestion rates or the occurrence of pica behavior
of children.  In these cases, deviation  from this  guidance  may  be
appropriate.  However, the data supporting this deviation should
be provided  within the related risk assessment.  If the data are
provided by  the potentially responsible party in the Superfund
program or the owner/operator in th« RCRA program, these data
should be  reviewed and verified by the risk assessment  experts  in
the Regions, who may also choose to consult with Headquarters.

Contacts;

     If th«r« art  any  general questions  regarding  this  interim
final guidance, please contact Sherry Sterling,  (FTS)  382-4826,
of my staff.  For  program specific  information,  the  following
staff may  b« contacted:


           RCRA                Alec  McBride   (FTS)382-7045
           CERCLA/Fund         Dave  Bennett   (FTS)475-9486
           CERCLA/Enforcement  Sherry  Sterling (FTS)382-4826

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       I       UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
-t	j?                  WASHINGTON. O.C.  20460
 :.
                              JAN 27 J989
                                        OSWER Directive 9850.4

MEMOPVNPPM

SUBJECT:  Interim,Finalx«uidance  for Soil Ingestion Rates
FROM:     J. Wifiston Porter
          Assistant Administrator

TO:       Regional Administrators
          Regions I-X
     Risk assessments are  conducted  at  Superfund  sites  as  part  of
Remedial Investigations  required  by  the Proposed  National
Contingency Plan, and may  be  conducted  at  RCRA  facilities
undergoing corrective action  as described  in  the  soon-to-be
Proposed RCRA Corrective Action Rule, to estimate the risk from
exposure to substances,  within the  risk assessment,  an exposure
assessment is performed  which is  based  on  various exposure
assumptions such as  soil ingestion rates.   This interim final
guidance provides recommended soil ingestion  rate assumptions  c;
0.2 gram per day for children aged 1 year  through 6 years  and  0.l
gram per day for older age groups, in the  absence of site
specific data.

Introduction 
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     .Joseph Carra, WMD, HQ
     Lloyd Guerci, CED, HQ
     Susan Bromm, RED, HQ
     Ira Leighton, Region I
     John Czapor, Region II
     Bruce Smith, Region III
     Richard Stonebraker, Region IV
     Mary Gade, Region V
    - 3ob Har.neschlager, Region VI
     Robert Morby, Region VII
     Bill Geise, Region VIII
     Jerry Clifford,  Region IX
     Phil Bobeifc, Region IX
     Alexis Strauss,  Region IX
     Phil Millam, Region X
     Dennis Huebner,  Region I
     Gerald Levy, Region I
     Joel Balmat, Region I
     Andrew Belline,  Region II
     George Meyer, Region II
     Stanley Siegel,  Region II
     Bruce Smith, Region III
     James H. Scarbrough, Region IV
     William Miner, Region V
     Randy Brown, Region VI
     Sam Becker, Region VI
     Michael J. Sanderson, Region VII
     Louis W. Johnson, Region VIII
     Diane Shannon, Region VIII
     Karen Schwinn, Region IX
     Michael Gearheard, Region X

Addressees:    Directors, Waste Management  Division,
                 Regions I, IV, VII, VIII
               Director, Emergency and Remedial  Response
                 Division, Region II
               Directors, Hazardous Waste Management  Division,
                 Regions III, VI
               Director, Toxic and Waste Managment Division,
                 Region IX
               Director, Hazardous Waste Division,
                 Region X
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