EPA 520/4-77-016

                   IN THE
                 *Z   i ^ - - J   "Z-
             WASHINGTON, D.C. 20460

                   PROPOSED GUIDANCE



                        In the

                  GENERAL ENVIRONMENT
                    SUMMARY REPORT
                    September  1977

        U.  S.  Environmental Protection Agency
            Office  of Radiation Programs
            Criteria and  Standards Division
               Washington, D.C.  20460

                        Guidance on Dose Limits
       for the Transuranium Elements in the General Envrionment
                            Table of Contents


1.   Background Information on the Transuranium Elements

     1.1  Introduction 	   1

     1.2  Current Sources of the Transuranium Elements 	   3

     1.3  Movement Through the Biosphere 	   4

     1.4  Potential Health Effects 	   7

2.   Federal Guidance

     2.1  Agency Action and Authorities 	  11

     2.2  Involvement of other Federal Agencies 	  12

     2.3  Existing Standards and Guides 	  13

     2.4  Criteria and Rationale for Proposed
          Guidance 	  14

     2.5  Text of Proposed Guidance 	  20

          2.5.1  Definitions 	  21

3.   Implications of Guidance

     3.1  Scope of Sources and Population Groups 	  23

     3.2  Risk Perspectives 	  24

     3.3  Implementation	,	  28

     3.4  Remedial Measures and Economic Evaluation 	  30

 References 	  32


Annex I    Transuranium Elements in the Environment

Annex II   Environmental Transport and Pathways

Annex III  The Dose and Risk to Health Due to the Inhalation and
             Ingestion of Transuranium Elements

Annex IV   Risk Perspective

Annex V    Guidance Implementation

Annex VI   Environmental Assessment

                                Section 1

           Background Information on the Transuranium Elements

1.1  Introduction

     The transuranium elements include, all of the elements with atomic

number greater than that of uranium.  Only extremely small quantities

of these elements occur naturally and nearly all of the existing

inventory has been created from other elements.  Nuclides of the

transuranium elements are radioactive and are considered to be toxic in

humans.  From the viewpoint of protecting the public health, the trans-

uranium elements of primary interest are those which undergo slow

radioactive decay with the emission of alpha particles and with

half-lives greater than 1 year.  When present in the environment, trans-

uranium elements may be available for intake by humans over very long

periods of time.  Table 1.1 is a listing of such transuranium radio-

nuclides of major interest, their mode of decay, half-life, and daughter


     Plutonium is the most abundant, most studied, and most publicized

of the transuranium elements.  It is a metallic, radioactive element

with atomic number 94, and was the first man-made element to be produced

in relatively large quantities.  Its primary use to date has been as

fissile material in nuclear weapons, but an important potential use may

be nuclear electric power generation.  It is produced in all nuclear

reactors and is a significant component of spent uranium fuels.

     At present, americium and curium are the only other transuranium

elements produced in sufficiently large quantities to be of interest as

a potential environmental hazard.

                                Table 1.1
Nuclear Properties of Environmentally Significant Transuranium Nuclides
Mode of
87.4 y
2.4xl04 y
6.6xl03 y
14.3 y
3.9xl05 y
433 y
7.4xl03 y
0.45 y
18.1 y
*  Included for reference because of potential quantities available
   for release.  Not significant for environmental exposure con-
   siderations because of short persistence.

1.2  Current Sources of the Transuranium Elements

     Present levels of the transuranium elements in the environment have

resulted from several sources - regional and worldwide fallout from the

testing of nuclear weapons in the atmosphere, accidents involving

military and related operations, and local releases from nuclear facil-

ities.  The major portion of the transuranium elements in the environ-

ment is the result of surface and atmospheric nuclear weapons tests

during the period 1945-1963. Atmospheric tests injected .radioactivity

into the stratosphere which has since then been slowly deposited more

or less uniformly over the lands and oceans of the earth.  As a result

of these earlier weapons tests, the existing level of transuranium

element contamination in soils of the United States is about 0.002

microcurie per square meter  (yCi/m ).  More recent weapon tests have not

added significant amounts to this level.  Isolated sites used by the

United States to test nuclear devices, such as  those  in Nevada and  the

Bikini and Enewetak  atolls,  often have significantly  higher amounts of

the  transuranium elements in small areas near the  detonation  point.

Underground nuclear  tests also have produced localized  radioactive

contamination, but  this  is  contained below  the  eartjh's  surface and is

not  expected  to be  readily  available for uptake by humans.

     Areas where there is substantial  localized contamination above the

general background  level are well documented and extensive  environmental

analyses have been  carried  out  at all  these sites.  Areas of  highest

contamination are,  for the  most part,  on Federally owned property

and  therefore are under  the direct  control  of  the  Federal government

 and access  to  these areas may be restricted.  Table 1.2 shows estimates

 of the amount  of plutonium in the environment at known United States

 locations.  More detailed information on the sources and current levels

 of the transuranium elements in the general environment is given in

 Annex I.

 1.3  Movement through the Biosphere

      Plutonium and other transuranium elements can move through the

 environment by a,variety of transport mechanisms and pathways.  These

 are determined by the chemical and physical form of the deposited

 material, the characteristics of the surface,  local land use patterns,

 and other parameters such as  wind or rainfall.    Principal  environmental

 pathways to humans  are indicated in  Fig.  1.

      The principal  modes of transport of  these  elements from a source

 to man are by direct airborne movement from the  source  (source-air-

 humans)  or by resuspension of previously  deposited  small  particles  by

 the action of wind  or  other disturbance (soil-air-humans).   Transuranium

 elements  released to  the environment may  exist as discrete  particles

 or they may  become  attached to soil particles.   Resuspension is  a

 complex phenomenon  affected by a number of  factors, including the

 characteristics of  the surface, vegetative  cover, meteorological con-

 ditions,  and age of the  deposit.  The  resuspension  factor is  defined  as
 the ratio of the concentration in air  (yCi/m ) at a given height  above

 the surface to the average immediately adjacent  surface contamination
level (pCi/m ).  Observed resuspension factor values range from about

10   to 10    per meter for a variety of conditions and sites.   In

                             TABLE  1.2
       Inventory and Levels  of  Plutonium for  Selected U.S.  Sites*
Location Approximate
U.S. (Fallout) ~ 20,000 Ci
Nevada Test Site > 155 Ci
(near Las Vegas, NV)
Rocky Flats Plant 8-10 Ci
(Jefferson County near
Denver, CO)
Mound Laboratory Pu-238 = 5-6 Ci
(Miamisburg near
Dayton, Ohio)
Savannah River Plant 3-5 Ci
(SW part S. Carolina
near Augusta, GA.).
Soil Concentration**
(above background)
ave. =0.06 pCi/g
Area 13: to 18,000 pCi/g
Area 5: to 12,000 pCi/g
off -site: 0.1-10 pCi/g
on-site max > 1,000 pCi/g
boundary: 0.1-4 pCi/g
sediments max > 1000 pCi/g
soils: 0.003-2 pCi/g
N area: 30 pCi/g
F area: 3 pCi/g
perimeter: 0.02 pCi/g

Surface and
in progress
under water
in canals
and higher
Los Alamos Scientific      1-2 Ci
Lab (NW of Santa Fe, NM)
             on-site:  0.02-5 pCi/g
             off-site: 0.005-1 pCi/g
                             High local
                             levels above
                             100 pCi/g
                             in remote
Hanford Site
(Central Washington
near Richland)
             perimeter: 0.01-0.04 pCi/g
                             High levels
                             in trenches
                             on site
Oak Ridge Facilities
(East Tennessee near
             perimeter: 0.01-0.08 pCi/g
                             Research &
Trinity Site
(near Alamogordo, NM)
45 Ci
perimeter: <\» 55 pCi/g
off-site: 0.1-4 pCi/g
Site of
first atomic
bomb test
*   See Annex I for details and references

                                    2                                        3
**  1 pCi/gram of soil = 0.015 uCi/m  for an assumed soil density of 1.5 g/cm
    and a depth of 1 cm.


                  Figure 1

general, the resuspension factor will be relatively high immediately

after initial deposition, gradually decrease with time, and approach

a long-term constant within about one year after deposition.

     Transport of plutonium and other transuranium elements through the

food chain and subsequent ingestion is generally of lesser importance

than the air pathway.  Environmentally distributed transuranium

elements may be deposited on plant surfaces or assimilated through

the plant root system.  The uptake by plants is relatively small and

most animals, including humans, have a high discrimination factor

against transfer of these elements into body tissues.  The solubility of

plutonium in water is very low and nearly all plutonium released into

lakes and streams is ultimately deposited and sorbed onto sediments.

Direct  ingestion of contaminated soils and contamination of wounds  are

other possible routes of entry into humans, but are generally of minor

importance relative to the inhalation and food pathways.

     The environmental transport of the  transuranium elements is

discussed in more detail in Annex  II.

1.4  Potential Health Effects

     The potential health effects  caused by  a specific nuclide  of  a

transuranium element are a function of  several biological  and physical

parameters  including  the biological retention time in  tissue, the  type  of

radioactive emission, and the  half-life of  the nuclide.  For the more

important transuranium nuclides, such as Pu-238  or Pu-239,  biological

retention times  are  very long  and  radioactive decay occurs at such a

 slow rate that uptake of these materials in the humans body will result

 in prolonged exposure of body organs.  Many of the transuranium nuclides

 decay by emission of an alpha particle (ionized helium atom), in a

 manner similar to radium and other naturally occurring alpha emitting

 nuclides.  Alpha particles are highly ionizing, and damaging, but their

 penetration in tissue is very small (about 40 urn).  Thus, biological

 damage is limited to tissue in the immediate vicinity of the radioactive

 material, and a potential health hazard from transuranium elements in

 the environment can only result when these materials are inhaled or

 ingested into the body.   Exposure of the unbroken skin from external

 alpha  emitting sources  is not a health problem.

     Even though there  is no direct evidence of  cancer induction in

 humans due to the inhalation of transuranum elements,  data from animal

 studies with  these radionuclides and from human  experience with other

 alpha-emitting elements  such as radon daughters  indicate that  the in-

 halation of transuranium elements  could  cause  lung cancer and  other

 forms  of cancer  in humans.   Cancer  induction is not the  inevitable

 result  of  such  inhalation, but  rather  the  result  of this  intake is an

 increase in the  probability  that a  cancer may  occur in the  individual.

     Inhaled  particles are initially deposited in  various regions  of  the

 respiratory tract, where  they remain until  either  cleared or translocated

 to other body organs.  Much of  the material  deposited  in  the lungs  is

cleared within a few days, but some of the smaller  particles which

diffuse into the pulmonary regions of the lung are  removed much more

slowly and have a biological half-life of a year or more.  Estimates of


the risk of lung cancer due to the inhalation of transuranium elements

are based on the alpha particle dose delivered to the pulmonary tissue,

which is the portion of the lung receiving the highest dose as a result

of inhalation.  This is likely to overestimate the risk because the pul-

monary region is not considered a probable site for induction of cancers

in humans.  In a recent study the National Academy of Sciences has con-

cluded that the probability of cancer induction increases in proportion

to the dose delivered to various lung tissues and that the incidence of

cancer will not be underestimated by averaging the total alpha energy

Imparted over the mass of the pulmonary region (1).

     Inhaled transuranium elements may also transfer and be retained

in other body organs, and cause cancers of the bone and liver.  For the

less soluble transuranium compounds, such as plutonium oxide,  this will

contribute only marginally to the total risk for the inhalation pathway.

Inhaled radioactivity is also concentrated in the respiratory  lymph

nodes.  The dose delivered to the lymph nodes exceeds that  to  pulmonary

tissues but, if a risk exists, animal studies indicate that  it is  small

compared to the risk due to cancer  in pulmonary  tissue.

     Ingestion of transuranium elements generally represents  a smaller

environmental risk  to humans  than inhalation.  A relatively small

fraction of any ingested transuranium element will be transferred  by  the

bloodstream from the digestive tract and  deposited in bone,  liver,

gonadal tissue, and other  organs.   In most cases, less than one-tenth of

a percent  of  the ingested material  is absorbed by the body, with  the

remainder  excreted.  The cancer  risk  to  individuals  as a  result  of

ingestion of  transuranium elements is mainly due to potential bone and

liver cancers.

     Because  of possible accumulation in gonadal tissues a potential

risk of genetic damage to the progeny of exposed individuals exists

as a result of exposure to transuranium elements.  At the dose limits

recommended in this guidance, this risk is very small compared to the

natural incidence of genetic damage.

     Preferred models for calculating the dose to pulmonary tissue,

bone, gonadal tissue, and to the other organs as a result of inhalation

or ingestion of transuranium elements are described in Annex III.  In

general, these dose models are based on publications prepared by the

International Commission on Radiological Protection (ICRP) (2-4), sup-

plemented by more recent data.  In conjunction with estimates of the

cancer risk due to alpha particle irradiation, these models are used

to estimate the risk from radiation doses to specified body organs.

                                Section 2

                            Federal Guidance

2.1  Agency Action and Authorities

     The Agency announced in the Federal Register on September 23,  1974,

that it intended to review the current and projected environmental

impact of the transuranium elements and consider whether guidelines or

standards under its statutory authorities were needed to assure adequate

protection of the health and safety of the general public (5).

Subsequently, public hearings were held in Washington, D.C.,  on

December 10-11, 1974, and in Denver, Colorado, on January 20, 1975, to

permit interested citizens and organizations to present both  technical

evidence and opinions pertinent  to  this  subject  (6).  Prior  to this

action the Agency had been considering the  control  of plutonium  in soil

as a result of  a  specific request during 1972  from  the  State of  Colorado

in regard  to utilization of  land in the vicinity of the ERDA Rocky Flats

Plant.  As  an  interim measure,  Colorado adopted in  1973 a plutonium

activity  limit of 2 dpm/g  in the top 1/8 inch  of soil as a guide for

protection of  construction workers engaged in  home  building.

      The  Agency concluded  that Federal Radiation Guidance was needed  to

 control the potential health impact of plutonium and other alpha-emitting

 transuranium elements in the environment and that promulgating Federal

 Guides under the authority of the former Federal Radiation Council was

  the  appropriate  procedure.   This  authority was  transferred  to the

  Administrator  of the  Environmental Protection Agency  (EPA)  by the

  President's Reorganization Plan No. 3 of 1970,  (7) and included all the

  functions of the Federal Radiation Council, as  specified in the Atomic

  Energy Act.  Section  274(h) of this Act provides that "the Administrator

  shall advise the  President with respect to radiation matters, directly

  or indirectly affecting health, including guidance for all Federal

 agencies in the formulation of radiation standards and in the establish-

 ment and execution of programs of cooperation within States." Federal

 Guides developed  under this authority and approved by the President are

 considered to be  an adequate means to limit any problems  of environ-

 mental contamination by the transuranium elements,  since  all sources of

 transuranium elements  are  under direct control of the Federal government.

 These Guides are  therefore directed  to all  Federal  agencies having

 regulatory or administrative  control  of  transuranium elements.   However,

 the Guides can  also be viewed  as advice  by  State and  local  governments.

 2.2   Involvement  of Other  Federal  Agencies

      The implementation of  these Federal recommendations  is  the

 responsibility  of those agencies having  regulatory  and administrative

 responsibilities  for the production, utilization, and control of

 transuranium elements,  especially  plutonium.  Therefore,  the

Administrator established an Interagency Working Group to insure the

availability of technical expertise and  interagency coordination in the

development of the Guides.   This Interagency Working Group consisted of

representatives from the Energy Research and Development Administration,


Nuclear Regulatory Commission, National Aeronautics and Space Adminis-

tration, and the Departments of Defense, State, Commerce,  Interior,  and

Health Education and Welfare.  Although EPA has been primarily respon-

sible for the development of these recommendations and supporting

documents, this group has provided valuable assistance and has made

available to the EPA both the expertise and viewpoints of these agencies.

2.3  Existing Standards and Guides

     Several specific standards or guides have been published (8-12)

pertaining to the presence of the transuranium elements in soil, to the

controlled release of such materials into the environment (e.g., the EPA

standard for the uranium fuel cycle*), and the decontamination of

equipment surfaces. With the exception of EPA's uranium fuel cycle

standards, such guides are based for the most part, on recommendations

on numerical limits by the International Commission on Radiological

Protection (ICRP) and by the National Council on Radiation Protection

and Measurements  (NCRP).  Recomendations by  the ICRP  and  the NCRP

include numerical limits on air and water concentrations  applicable  to

individuals in the general population.

     Department of Defense guidelines have been developed to deal with

instances of accidental surface contamination  and  represent  ad  hoc

guidance  for accidents involving nuclear weapons.   The decontamination
 *  Note:   EPA published (F.R.  42:2858,  Jan.  13,  1977)  as title 40;
    Part  190,  Environmental Standards for the Uranium Fuel Cycle,  normal
    operations, a limit of 0.5  millicuries combined of  plutonium-239  and
    other alpha-emitting transuranium radionuclides with half-lives
    greater than one year entering the environment as planned releases
    per gigawatt-year of electrical energy produced by  the fuel cycle.

 guidance prescribes that surface levels of less than 1000 ug/m  plutonium

 (numerically equal to 61 vCi/m  for Pu-239) shall be achieved where such

 reduction is possible and is consistent with reasonable cost and effort.

 Each of the Armed Services has also developed more detailed

 implementation manuals.

      For case of surface contamination of materials for shipment and of

 transport vehicles, the Department of Transportation specifies as "not

 significant", a level of 220 dpm/100 cm2 (0.01 uCi/m2) of removable

 alpha contamination.   There is also a recommendation by the Nuclear

 Regulatory Commission that the average level of alpha contamination for

 reactor equipment to  be released to the general public be no more than

 100 dpm/100 cm2.

      Recommendations  have also been published  by individuals for the

 specific situation of  soil contamination by transuranium elements,  but

 none of these have been adopted  by  government  agencies  (13-15).

 2.4  Criteria and Rationale  for  the Proposed Guidance

      The purpose  of the  proposed guidance is to establish maximum dose

 rates for persons in the general population who might receive radiation

 exposure to  transuranium elements in the environment, which  considers

 all  possible pathways to humans and which the Agency judges  to be

 protective of the public health.  The two primary criteria used  in

 determining the guidance recommendations were:   that the added risk  to

 an individual from exposure to the  transuranium  elements be very small,

and that implementation  of the guidance be feasible in terms of overall

economic impacts.  The Agency has also determined that the costs of

remedial actions and the benefits of risk reduction differ so greatly


between sites, both for those where excess contamination already exists

and for those where accidents might occur in the future, that generic

guidance applicable to all sites cannot be provided by formal benefit-

cost procedures.

     The primary purpose of the guidance is to achieve a level of

public health protection which will minimize the risk to exposed

individuals.  Radiation induced risks can be estimated in a number of

ways, but the most prudent methods assume that there is some finite risk

to humans no matter how small the amount of absorbed radiation might be

and that this risk at any given dose level is directly proportional to

the damage actually observed at much higher dose levels.  Such a cal-

culation, in the absence of data to the contrary, must be considered as

the method appropriate for a regulatory or guidance function.  On this

basis, there is no level of radiation exposure which is absolutely safe

and any radiation dose carries with it some degree of risk.  Balanced

against this is the realization that all persons are exposed to a large

number of competing risks  (including natural background radiation) and

the reduction of a single risk must be viewed from the  overall per-

spective of the costs and benefits to society.

     The guidance recommendations are intended  to achieve adequate

health protection for the small fraction of the  total population at

greatest risk from exposure to transuranium nuclides in the  environment,

and will therefore offer much greater protection to the vast majority of

the population at lesser risk.  The numerical guidance  can be related to

a maximum risk level  to an individual which is-comparable to that used


 for other carcinogens and lower than that for many other competing

 risks.  The level of risk at the proposed guidance level, estimated

 by the above method, is less than one chance per million per year

 and less than ten chances per hundred thousand in a lifetime that an

 individual would develop a cancer from continuous exposure at the stated

 dose rates.   Actual exposures and risks to individuals are expected to

 be well below this level.   It must be recognized that these risk

 estimates are not precise but represent the best judgment of the

 Agency.   There may be differences in reputable scientific opinions on

 their accuracy.

      Other regulatory actions have considered lifetime risk levels for

 carcinogens  but  there is,  at  this time,  no uniformity of approach to

 the regulation of carcinogens.   The Food and Drug Administration (FDA)

 uses a lifetime  risk level of one per million as "virtually safe," and

 has proposed to  ban saccharin because,  for an average consumption,  the

 lifetime  cancer  risk was estimated to be 10/100,000.   EPA has  recom-

 mended an action level  for kepone in fish for which the associated

 lifetime  cancer  risk is 30/100,000.   Differences  in the action levels

 reflect different  regulatory  requirements,  constraints  associated with

 remedial  actions  for  a particular  carcinogen,  uncertainties  in the

 calculations, differences  in methods  used  to  derive lifetime risks,  and

economic considerations.   The proposed guidance  is intended  to be viewed

from the perspective of providing a limit applicable  to  remedial and

restorative actions, and must be distinguished from other risk levels


which provide for a routine level of acceptability.

     The Agency has also considered the costs which may be involved

in implementing the proposed guidance.  These costs were estimated

from soil contamination levels at existing sites of contamination.

The magnitude of areas which might require remedial actions at each site

has been estimated for a soil concentration contour which can with a

very high probability be expected to result in an inhalation dose rate

to an individual not to exceed 1 mrad/year, as well as for soil

concentration contours higher and lower than the reference case by

factors of ten.  Changes by factors of ten are judged to represent the

limit of precision available for such calculations and are considered

sufficient for purposes of a generic assessment.  However, in order to

attempt to more closely define where costs of implementation would begin

to rise rapidly, an intermediate contour of one-third the reference

level was also considered.  The costs of implementing the guidance can

be expected to vary by location, contamination level, and other factors.

A minimum cost of $500 per acre has been assumed for estimating the

costs which may be incurred in bringing all areas above the designated

level into compliance.  Such costs include dilution or removal of

contamination by plowing or scraping as required and restorative actions

needed to prevent erosion and assist ecological recovery.  Costs

necessarily increase as the difference between the existing contamina-

tion levels and those sought becomes greater.  On this basis, costs of

 remedial actions have been estimated  for  those  few  sites  in the United

 States where some environmental  contamination extends beyond the

 boundaries  of the source from where it  originated,  and are shown in

 Table 2.1.   It must  be recognized  that  there are  large uncertainties

 associated  with both the areas involved and in  the  estimates of costs.

 Nonetheless,  the calculations serve a useful purpose of comparison on

 a  common basis.   It  can be concluded  that  the costs of implementing

 the  guidance at  the  reference level would  be reasonable and achievable,

 but  that the cumulative costs increase  rapidly when more  restrictive

 limits are  considered.

      The Agency  has  recognized a difference between those sites

 presently contaminated  and  sites that may  be accidentally contaminated

 in the future, and has  considered whether  separate  numerical guides

 should be developed  for  these two cases.   In the  first case the judgment

 is between  continued  exposure to these  elements at  some given level and

 the  cost of remedial  action to reduce exposures.  In the  second case,

 the  risk of possible  future accidental  contamination events must be

 taken  into account in the initial decision to perform any activity

where  there is risk of accidental contamination, and include the entire

cost of  possible future remedial actions that might be required in

event of an accidental release.   However,  no specific rationale is known

that would justify different guidance based on health risk considera-

tions.  Therefore, the Agency recommends that the same numerical guide

be used in both cases, but that all future contamination be cleaned up

as soon as possible after occurrence to a level as low as reasonably

                                   Table 2.1

           Comparison of Costs of Remedial Actions At Various Sites
           of Existing Plutonium Contamination For Several Possible
          Levels of Maximum Soil Concentrations (Areas are Estimated
       from Contour Maps and Costs Are Arbitrarily Assumed as $500/acre)

Reference Level
0.2 yCi/m2
•v* 0.01 mi2
10 x Ref: Level
2 yCi/m2
* 0.01 mi2
1/3 Ref. Level
0.07 yCi/m2
0.3 mi2
<80 mi2
<20 mi2
* 0.01 mi2
1/10 x Ref. Level
0.02 yCi/m2
^ 1.6 mi
< 165 mi2
* 300 mi2
% 0.01 mi2
*  Most of the existing contamination is in sediments of canals, and
   does not represent a hazard to humans.  Costs of eventual remedial
   actions are indeterminate.

 achievable and with the numerical guide as an upper limit.

      In summary, the Agency has recognized that any radiation exposure

 is potentially harmful and has concluded that the guidance recommenda-

 tions should limit the risk to those persons in the critical segment of

 the population to a level as low as reasonably achievable within the

 constraints of economic considerations.   There is at present no

 uniformity of approach to the regulation of carcinogens among the

 various  Federal agencies.   It is the judgment of the Agency that for

 presently  existing sites  of contamination,  the proposed guidance

 recommendations will provide the necessary  protection of the public

 health and be achievable  at reasonable costs.   It is also the judgment

 of  this Agency that, in some cases  of accidental contamination of the

 environment by the  transuranium elements, cost considerations will

 permit reduction of residual contamination  to  levels below those

 specified  in  this guidance.   In all  cases,  the guidance recommendations

 represent  a maximum value  and  further reduction should  be sought when

 this can be accomplished at  a  cost judged to be reasonable in terms  of

 alternatives  available.

 2.5  Text  of  Proposed Guidance

     The Environmental Protection Agency proposes that  the  following

 recommendations be  submitted by the Administrator to the  President for

 issuance as Federal Radiation Guidance:

     1.    The annual alpha radiation dose rate to members of  the

critical segment of the exposed population as the result of exposure to

transuranium elements in the general environment should not exceed
          a.  1 millirad per year to the pulmonary lung, or
          b.  3 millirad per year to the bone.
     2.   For newly contaminated areas, control measures should be
taken to minimize both residual levels and radiation exposures of
the general public.  The control measures are expected to result in
levels well below those specified in paragraph one.  Compliance with
the guidance recommendations should be achieved within a reasonable
period of time.
     3.   The recommendations are to be used only for guidance on
possible remedial actions for the protection of the public health in
instances of presently existing contamination or of possible future
unplanned releases of transuranium elements.  They are not to be used by
Federal agencies as limits for planned releases of transuranium elements
into the general environment.
2.5.1  Definitions
a.   "critical segment of the exposed population" means that group of
persons within the exposed population receiving the highest radiation
dose to the pulmonary region of the lung or to the bone.
b.   "rad" is the unit of absorbed dose, defined as the energy imparted
to tissue due to ionizing radiation divided by the mass of the tissue.
One rad is equal to the absorption of 100 ergs of radiation energy
per gram of matter.
c.   "pulmonary lung" means that region of the lung consisting of
respiratory bronchioles, alveolar ducts, atria, alveoli, and alveolar

 sacs.   The average total weight  of  this  tissue,  including  the  capillary

 blood,  is  assumed  to  be  570  gins.

 d.   "millirad  per year  to the pulmonary lung" means  the equilibrium

 dose rate  following chronic  inhalation.   This dose  rate is calculated by

 dividing the alpha energy absorbed  per year  in the  pulmonary lung by its


 e.   "bone" means  osseous tissue.   The average total weight of this

 tissue is assumed  to be  5000 gms.

 f.   "millirad per  year  to the bone" means the dose rate attained after

 70 years of chronic exposure.  This dose  rate is calculated by dividing

 the alpha energy absorbed in the bone during the 70th year by  the bone


g.   "general environment" means the total terrestrial, atmospheric

and aquatic environments outside the boundaries of  Federally licensed

facilities or outside the boundaries of sites which-are under  the

direct control of a Federal agency.

h.   "curie (Ci)" is the basic unit to describe the intensity  of radio-

activity in a material.  It is equal to 37 billion  disintegrations per


     1 millicurie  (mCi) = 10~3 Ci

     1 femtocurie  (fCi) - 10~15 Ci

                                Section 3

                        Implications of Guidance

 3.1 Scope of Sources and Population Groups Included

     The objective of the proposed guidance is to assure that the

public health and welfare will be adequately protected from the con-

sequences of environmental contamination by the transuranium elements.

     The proposed guidance is not intended to supersede existing rad-

iation protection guides, such as the individual and population limits

established by the Federal Radiation Council in 1960 (17), but rather to

supplement these by specifying limits for one type of source and for one

group of radionuclides within these broader limits.  The scope of the

proposed guidance includes all transuranium element contamination in the

general environment from all sources.  The recommendations are applicable

to all individuals in the general population outside the boundaries of a

Federal facility, Federally licenced facility, or other site under  the

direct control of a Federal agency.

     The recommendations are expressed in terms of an annual limiting

dose commitment to the pulmonary region  of the lung or to  the bone.  It

should be noted that, although the proposed guidance specifies dose rate

limits to only certain organs, this also limits the potential accum-

ulajtion in gonadal tissues and the attendant genetic risk.  The  limits

apply to the critical segment of the exposed population, which is that

group of persons  in the  general population who, because of residency,

occupation, or other factors can on  the  average be expected  to receive

 the highest lifetime radiation dose from a specified source of

 transuranium elements.*  The annual dose rate to the designated organs

 can be estimated from representative measurements of air concentrations

 or soil contamination levels,  either by use of site-specific data or by

 use of calculations based on reasonable procedures and assumptions.

  3.2 Risk Perspectives

      Exposure to radiation may increase somatic risks, primarily that of

 cancer,  as well  as  genetic risks  to future generations.   The somatic

 risks to persons caused by exposure to  small amounts of  radiation can

 best be  viewed in terms of the probability of death to an individual

 when he  is considered  as  a member of  a  large exposed population group.

 Although the  gejietic risks to  humans  as a  result  of the  assimilation of

 transuranium  elements  cannot be quantified with exactness,  these risks

 may  be estimated  in terms  of the number of expected genetic  defects

 per  100,000 live  births where  both  parents are  assumed to have accumu-

 lated a  given  gonadal  dose.  The development  of this  guidance  is based

 on suitable models chosen by the Agency that  relate environmental levels

 to the dose to internal organs.  Health risks resulting  from radiation

 exposure were  estimated using models and recommendations  of  the  Advisory

 Committee on the Biological Effects of  Ionizing Radiation of the National

Academy of Sciences (NAS-BEIR Committee) in its reports entitled  "The

Effects on Populations of Exposure  to Low Levels of Ionizing Radiation"
 *  The dose received during childhood, and any differences in radio-
    sensitivity between children and adults assumed by the NAS, have
    been taken account of in the derivation of these guides.  Because
    a lifetime radiation dose is, for the most part, received during
    maturity, adults are defined in this guidance as the critical
    population group.


(1972), and "Health Effects of the Alpha-Emitting Particles in the

Respiratory Tract" (1976) as well as information in other technical


     The radiation risk due to inhalation of transuranium elements is

primarily lung cancer.  Additional risks may result from translocation

of a small fraction of the transuranium elements from the lung to other

body organs, especially to the liver, hone, and gonadal tissues.  On the

basis of models, it was estimated that, for a cohort of 100,000 persons*

followed through their entire lifetimes, the continuous inhalation over

their lifetimes of transuranium aerosols leading to an average annual

dose rate to the pulmonary tissue of 1 mrad/year per person could

potentially result in 10 premature deaths.  For an average lifespan of

71 years, the annual risk to each person from lifetime exposure at this

level is about 1x10   per year, and the estimated number of additional

premature deaths would represent an increase of less than  0.1 percent of

the current risk of death due to all cancers.

     The lifetime risk due  to ingestion of  transuranium  elements  is  due

both to cancer mortality and an increased  genetic risk.  In a cohort of

100,000 persons, continuous  ingestion  over  a lifetime  of a transuranium

radionuclide at a level  causing an  average skeletal  (bone)  dose rate of

1 mrad  per year 70 years after the  start of ingestion  is estimated to

result  in less  than 2 premature deaths from bone and liver cancer.   In
 *   Epidemiological studies are generally based on results for a cohort
    of  100,000 persons.   This number is arbitrarily large and bears no
    relation to the number of individuals expected to be exposed to the
    maximum recommended  dose rates of this guidance.

 order to approximate the same risk for the ingestion pathway as was

 estimated for the inhalation pathway, the equivalent bone dose rate

 limit would be about 6 mrad per year after 70 years.  However, as noted

 below, ingestion at this rate entails a greater genetic risk than that

 resulting from the proposed inhalation limit.   Therefore, in order to

 have more comparable risks for either pathway,  the recommended limiting

 dose rate to bone is proposed as 3 mrad per year in the 70th year after

 the start of ingestion.   This could potentially result in 5 premature

 cancer deaths in the cohort under consideration.

      Genetic damage is  possible as a result of  assimilation of trans-

 uranium elements in gonadal tissue.   There is considerable uncertainty

 in  the estimated dose to  gonadal tissue and resultant  genetic risk.   On

 the basis of very limited data it can be estimated that,  for continuous

 ingestion at the limits set by this  guidance, the  total dose to gonadal

 tissue over  30 years  of chronic  exposure would  be  about 10 millirad.

 Such a gonadal dose  to each of  the parents  is estimated to produce 1  to

 20  genetic effects per 100,000 live births  in the  first generation.

 This number  can  be compared  to the approximately 6000  congenital

 abnormalities normally observed  in 100,000  live births.   Potential

 genetic risk  to  succeeding  generations  is not well known  but,  if  the

 guidance  dose rate limit were maintained, may range  as  high  as  5  to 150

 impaired  individuals per 100,000 live births.   The dose rate  to gonadal

 tissue and the resultant genetic risk from  continuous inhalation leading

to the guidance limit is estimated to be about  six times  smaller than

that estimated for continuous ingestion.


     In practice, very few, if any,  individuals are expected to be

subjected to the recommended guidance limits and the total number of

individuals exposed above the level of worldwide fallout will be small.

The Agency also considered the total impact on population groups but,

because the exposed population groups are small and are likely to remain

so, it was deemed unnecessary to separately consider the environmental

radiation dose commitment in developing this guidance.

     The estimated lifetime risk from exposure to transuranium elements

at levels equivalent to the guidance recommendations can be put in

perspective by comparison with other presently experienced risks of

death.  These comparative risks have been derived from Life Table for

the U.S. Population for 1970  (18) and specific mortality rates as

published in Vital Statistics of the United States  (19), both published

by the National  Center for Health Statistics.  Risk estimates are based

on a hypothetical cohort of 100,000 individuals with the  race and sex

distribution of  the U.S. population.  Cohort members are  subjected  to

the same age specific mortality  rates as are observed in  the U.S.

population, and  followed from birth until  all  members of  the  cohort are

dead.   Impacts are derived in terms of  number  of  premature deaths and

ages at death.   The number of adverse health effects attributed to

radiation  doses  from  transuranium elements are projected  from models

which  assume a linear non-threshold hypothesis for the dose effect

relationship.   Therefore,  the calculated risks may be overestimated,

and no deaths  from exposure to transuranium elements in the environment

have been identified.   In contrast,  the number of deaths resulting  from

 diseases are based on actual data taken from existing mortality records.

      On the basis of these analyses, the Agency has concluded that the

 added risks imposed on those persons who might be exposed to environ-

 mental transuranium concentrations at the guidance recommendation levels

 over a prolonged period of time are of the same order of magnitude as

 those for relatively rare events, such as fatalities from bites and

 stings and from electric current in home wiring and appliances.  On the

 basis of comparative life shortening, however,  the potential risk from

 transuranium elements in the environment would be smaller.   Complete

 results of life table models and data for other causes of death in-

 vestigated are given in Annex IV.

 3.3  Implementation

      Implementation of this  guidance will require measurement of the

 ambient concentration level  of transuranium elements in air,  soil,  food,

 or  water.   In  most  cases the critical pathway  for exposure  to trans-

 uranium elements  is  through  inhalation of  airborne particulates derived

 from  resuspension of  soil particles  and   compliance with this dose

 guidance can be demonstrated by  measurements of air and/or  soil con-

 centration.  Air  concentration may be related to  the dose guidance  using

 dosimetry models  that  include consideration of particle  size  distri-

bution and other  parameters  appropriate to the specific  site  of con-

tamination.  Because of  short-term and seasonal meteorological  variations,

results of air concentration measurements are best based  on the  average

of consecutive weekly samples over a  period of at least one year.

     Air measurements may not indicate the specific  source of

contamination, nor provide data for particular land  areas of concern.


Therefore soil measurements may be more advantageous in certain cases.

Such soil measurements are warranted when the air concentrations

indicate that the dose guidance limits are exceeded.  Air concentration

measurements can be related to a corresponding soil contamination level

by use of a resuspension factor, which is obtained either by experi-

mental determination or by calculational techniques based on the mass-

loading concept as described in Annex II.

     For practical reasons of facilitating implementation of this

guidance the Agency has derived a numerical value for a level of soil

contamination which can reasonably be predicted to result in dose rates

less than the guidance recommendations.  On the basis of limited data

available for several existing sites, the Agency suggests that a soil

contamination level of 0.2 yCi/m  , for samples collected at the surface

to a depth of 1 cm and for particle sizes under 2 mm, would establish  a

reasonable "screening level" for  this purpose.  Use of such a numerical

value can serve to reduce the land area  requiring evaluation and

minimize the number of measurements needed.

     In some cases it may be prudent to  specifically  evaluate exposure

from ingestion, although this is  not normally expected to be the

critical exposure pathway.  The procedure suggested above does  not

explicitly consider such alternative pathways.  However, if these are

considered to be of sufficient  importance from the  viewpoint of human

exposures, they must be included  in  the  evaluation  of a  specific site.

     Further information on implementation  of these guides, and on  the

application of environmental measurements to demonstrate compliance with

the recommendations, are discussed in  Annex V.


 3.4  Remedial Actions and Economic Evaluation

      The recommendations of this guidance are primarily intended to

 serve as an indicator of the need for possible remedial actions to

 protect the public health.  The guidance is stated in terms of a

 maximum allowable dose to a critical segment of the population

 occupying lands freely accessible to members of the general public.

 Remedial action may be required at any site that fails to meet these

 criteria.   Economic evaluation is needed to determine the least cost

 method of  achieving the recommendations.

      Where a need for the use of remedial measures arises, two

 alternatives are available:   1) reduction or elimination of the source

 term or 2)  establishing restricted access or use of the area in question.

 Remedial measures which reduce or remove existing surface contamination,

 in order to minimize  the source term and subsequent transport of plu-

 tonium to humans,  Include:

      1.   In-place stabilization by  the  application of a relatively
          impermeable cover, such as  oil,  polymerized  plastics,  or

      2.   Dilution by plowing  or other similar  techniques

      3.   Disposal by removal  of surface soils  and  burial  either
          on-site  or  in a designated  waste storage  repository.

      It can generally be expected  that a variety of techniques  can  be

used  to achieve the guidance level at any site.  The objective of an

economic evaluation is to identify the technique or combination  of

techniques that attains the guidance  level at the least  total cost.

Monetary costs, environmental costs,  and other nonmonetary costs should


all be considered in the evaluation of each alternative combination of

possible remedial actions.

     Monetary costs include those for removal, stabilization and

dilution of contaminated soils, radiological monitoring, protective

measures for workers, and the maintenance of restricted areas if they

are used.  Generally these costs can be readily evaluated.  Environ-

mental costs, especially those of long-term degradation, must be

evaluated to the extent possible.  Nonmonetary costs, including such

intangible factors as disruption of living patterns must be weighed in

the evaluation.  Whenever feasible, costs of alternative remedial

actions should be evaluated monetarily or quantified in the best

available nonmonetary units.

 1.   National Academy of Sciences - National Research Council:  Health
      Effects of Alpha-Emitting Particles in the Respiratory Tract;
      Report of Ad Hoc Committee on "Hot Particles" of the Advisory
      Committee on the Biological Effects of Ionizing Radiation.  Published
      by the Office of Radiation Programs, U.S. Environmental Protection
      Agency, Washington, D.C., Report No. EPA 520/4-76-013 (October 1976).

 2.   ICRU Report 25, 1976.   Conceptual Basis for The Determination
      of Dose Equivalent, International Commission on Radiation Units
      and Measures, Washington, B.C.

 3.   ICRP Publication 19, 1972.   The Metabolism of Compounds of
      Plutonium arid Other Actinides, Pergamon Press, New York.

 4.   ICRP Publication 23, 1975.   Report of the Task Group on Reference
      Man, Pergamon Press, New York.

 5.   U.S. Environmental  Protection Agency:   Plutonium and the Transuranium
      Elements - Contamination Limits:   Intent to Review the Need for
      Establishing New Rules.   Federal  Register Vol. 38,  p.  24098,  Sept.  23,

 6.   U.S.  Environmental  Protection Agency - Office of Radiation Programs:
      Proceedings of  Public Hearings:   Plutonium and the  Other Transuranium
      Elements (3 Volumes).  ORP/CSD-75-1 (1975).

 7.    Presidential Documents.   Federal  Register Vol.  35,  pp  15623-6
      (Oct. 6,  1970).

 8.    International Commission on Radiological  Protection:   Report  of
      Committee  II on Permissible Dose  for Internal Radiation  - ICRP
      Publication 2  (1959).

 9.    National Committee on Radiation Protection and Measurements:
      Maximum Permissible  Body  Burdens  and Maximum  Permissible Concen-
      trations of  Radionuclides in Air  and Water for Occupational
      Exposure - NCRP Report 22 (June 1959).

10.  Atomic Energy Commission  - Defense Atomic  Support Agency:
      Plutonium Contamination Standards.  AEC -  DASA Publication
      TP 20-5  (May 22, 1968).

11.  Department of Transportation:  Chapter 49, Code of Federal
     Regulations 173.397  (1970).

12.  U.S. Nuclear Regulatory Commission:  Regulatory Guide 1.86:
     Termination of Operating Licences for Nuclear Reactors (June 1974).

13.  C.E. Guthrie and J.P. Nichols:  Theoretical Possibilities and
     Consequences of Major Accidents in U-233 and Pu-239 Fuel Fabrica-
     tion and Radioisotope Processing Plants:  Oak Ridge National Lab-
     oratory Document ORNL-3441 (April 1964).

14.  R.L. Kathren:  Toward Interim Acceptable Surface Contamination
     Levels for Environmental PuQ2:  Battelle Northwest Laboratories
     Document BNWL-SA-1510 (1968)7

15.  J.W. Healy:  A Proposed Interim Standard for Plutonium in Soils:
     Los Alamos Laboratory Document LA-5483-MS (January 1974).

16.  International Commission on Radiological Protection:  Implications
     of Commission Recommendations that Doses be kept as Low as Readily
     Achievable.  ICRP Publication 22 (April 1973).

17.  Federal Radiation Council:  Radiation Protection Guidance for
     Federal Agencies.  Federal Register Vol. 25, pp 4402-3  (May 18,

18.  U.S. Department of Health, Education, and Welfare, Public Health
     Service, U.S. Decennial Life Tables for 1969-71. Volume 1,
     Number 1, May 1975.

19.  U.S. Department of Health, Education, and Welfare, Public Health
     Service, National Center for Health Statistics.  Excerpt from
     Vital Statistics of  the United States 1969. Volume H-Mortality.

                 Annex 1

  U.  S. Environmental Protection Agency
        Office Radiation Programs
         Washington, D.C.   20460

                                 Annex 1

                            Table of Contents
1.    Introduction 	      1
2.    The Nevada Test Site (NTS)	      9
3.    Rocky Flats Plant (RFP)	     12
4.    Mound Laboratory (ML)	     23
5.    Savannah River Plant (SRP)	     28
6.    Los Alamos Scientific Laboratory (LASL)	     38
7.    The Trinity Site	     42
8.    Sites of Underground Nuclear Detonations..	     42
9.    Enewetak Atoll	'.	     42
10.  Other Sites	     46


A 1-1  Cumulative Deposit of Fallout Pu-239 at Selected
       Locations in the United States (3)	      3
A 1-2  Concentration of Fallout Pu-239 with Depth at North
       Eastham, Massachusetts  (4)	      4
A 1-3  Fallout Pu-239 in New York City (6)	      5
A 1-4  Nuclear Properties of Environmentally Significant
       Transuranium Radionuclides (7)	      6
A 1-5  Inventories and Concentration Levels of Plutonium at
       Contaminated Sites	     8
A 1-6  Estimated Inventory of Plutonium in  Surface Soil (0-5
       cm depth) at Specific Areas within the National Test
       Site and Tonopah Test Range (11)	    11
A 1-7  Pu-239 in Air Samples - Near the NTS (7)	    15
A 1-8  Plutonium Concentration in Ambient Air at Selective
       Locations - Rocky Flats Site (11)	    22
A 1-9  Concentrations of Plutonium and Americium in Water
       Supplies and in Finished Drinking Water - Rocky Flats
       Site  (10)	    24
A 1-10 Concentration of Pu-238 in Environmental Media Mound
       Laboratory  (10)	    29
A 1-11 Mound Laboratory U.S. Environmental  Protection Agency
       1974  Survey	    33
A 1-12 Plutonium Concentration in Environmental Media Around
       the Savannah River Plant  (10)	    37
A 1-13 Plutonium in Sediments  in the Liquid Waste Receiving
       Canyons  (20) - cy  1975	    39
A 1-14 Plutonium and Americium in Environmental Media - LASL
       Site  -  (10) - CY 1975 -	    40
A 1-15 Underground Testing  Conducted Off  the Nevada Test  Site
        (10)	    44
A 1-16 Plutonium Concentration in Soil on Enewetak Atoll
        (22)	     47

 A 1-17 Plutonium and Americium Concentration in Surface Air
        on Enewetak Atoll (14)	    48
 A 1-18 Plutonium and Americium Concentrations in Various
        Environmental Media on Enewetok Atoll (14)	    49
 A 1-19 Environmental Monitoring for the Transuranium Elements
        at the Pantex Plant Site	    50
 A 1-20 Environmental Monitoring for the Transuranium Elements
        at Argonne National Laboratory	    52
 A 1-21 Environmental Monitoring for the Transuranium Elements
        at Battelle-Columbus Laboratories (West Jefferson
        (Site)	    53
 A 1-22 Environmental Monitoring for the Transuranium Elements
        at the Idaho Engineering Laboratory	    54
 A 1-23 Environmental Monitoring for the Transuranium Elements
        at the Oak Ridge Facilities	    55
 A 1-24 Environmental Monitoring for the Transuranium Elements
        at Hanford	    56
 A 1-25 Environmental Monitoring for the Transuranium Elements
        at the Lawrence  Livermore Laboratory	    57



 A 1-1   Population Distribution  by Azimuth  and Distance	    10
 A 1-2   Cumulative Deposit of  Pu-239, 240 (mCi per km2)	    13
 A 1-3   Cumulative Global Fallout  Deposit of Pu-239,  240  (mCi
        per km2)	    14
 A 1-4   Wind Rose  for the Rocky  Flats Site  (10)	    16
 A 1-5   Population Distribution  Around Rocky Flats	    18
 A 1-6   Rocky  Flats 1974 Plutonium Concentrations  in  Soil
        (Values  in Picocures Per Gram. (10)	    20
 A 1-7   Rocky  Flats Plutonium-239  Contours mCi/km2 (11)	    21
 A 1-8   Population Distribution Around Mound Laboratory (0  to
        10 km) LAT 39.6305 LONG  84.2897)	     25
 A 1-9  Mound  Laboratory Preliminary  Estimate of Plutonium-238
       Airborne Deposition (mCi/km2)  (10)	     27
 A 1-10 Mound  Laboratory	     32
A 1-11  Savannah River Plant Plutonium Deposition  (10)	     36
A 1-12 Trinity Site 1973-1974 Plutonium  Soil Sampling Results
        (n Ci/m2)  (14)	     43

                                 Annex 1


1.   Introduction

     Plutonium and other transuranium elements have been released into

the general environment primarily from four sources.  In order of

quantities released from most to least, these are:

     a.   Aboveground testing of nuclear weapons

     b.   Accidents involving nuclear weapons and satellite power sources

     c.   Accidents at nuclear facilities

     d.   Planned discharges of effluents from nuclear facilities

     The aboveground testing of nuclear weapons during 1945-1963 is

responsible for a worldwide dispersal of plutonium and americium.  For

the most part, this radioactivity was injected into the stratosphere and

has been redeposited more or less uniformly over the earth's lands and

waters.  This redeposited plutonium and americium is available to

people through inhalation and ingestion pathways and exists as a

ubiquitqus source in the general environment upon which is superimposed

the releases of transuranic elements from other sources.

     Fallout plutonium is primarily a mixture of Pu-239 and Pu-240 with

lesser amounts of Pu-238, Pu-241 and Pu-242.  About 58% is Pu-239 and

39% Pu-240; because these two radionuclides are essentially identical

with respect to chemical behavior and alpha energies, the sum of their

activities in the environment is will be referred to in this Annex as

"Pu-239" (1).  The daughter of Pu-241  (t1/2 - 12y)  is Am-241, so that as

the Pu-241 continues to decay, the concentration of Am-241 in the

  environment increases  relative to the amount of Pu-239.   The Am-241/

  Pu-239  activity ratio  in soil is  now about  0.25 and  will eventually

  increase  to 0.40 (2).

      Aboveground nuclear weapons  testing produced approximately

  430 kilocuries  of Pu-239 over  the period 1945  to 1974.   About 105

  kilocuries  deposited quickly near the various  detonation sites.  Of

  the 325 kilocuries injected into the stratosphere, 250 kilocuries have

 deposited in the mid latitudes of the northern hemisphere, 70 kilocuries

 have deposited in other  latitudes and about 5 kilocuries  still remained

 in the stratosphere as of 1974.  This has led to cumulative depositions

 of Pu-239 on ground surfaces in the United States that range from 0.001
 to 0.003 yCi/m .  Since 1967,  sporadic aboveground nuclear tests have

 held the air concentration level of plutonium to relatively constant
 values,  currently ranging from 0.01 to 0.1 fCi/m  in ground level air.

 These  levels are not  believed  to be the result of resuspension from soil

 surfaces (1, 3).

     Table A 1-1 gives  the  cumulative deposition of  fallout Pu-239  at

 selected locations  in the United States  (3).   Table A 1-2 shows  how it

 is  distributed  in soil  with  respect  to depth at both  an undisturbed site

 and a cultivated  site (4,5).   Table  A 1-3 is  a summary of fallout Pu-239

 levels in  New York City for  both air and ground deposition as a  function

 of  time  from 1954 to  1975 (6).   Table A 1-4  is  a listing  of the nuclear

 properties of the more  significant transuranium nuclides  (7).

     The total amount of  Pu-238 injected into  the stratosphere from

aboveground nuclear tests is about 9 kilocuries  (3).   In  addition, 17

                               Table A 1-1
            Cumulative Deposit of Fallout Pu-239 at Selected
                   Locations in the United States (3)
Approximate Location

Richland, Washington

San Francisco, California

Los Angeles, California

National Test Site, Montana

Rapid City, South Dakota

Topeka, Kansas

Tulsa, Oklahoma

Corpus Christi, Texas

Chicago, Illinois

Augusta, Maine

Cape Cod, Massachusetts

Long Island, New York

Raleigh, North Carolina

Miami, Florida
 Pu-239  Concentration (a)















                                Average  (±  2a)
         0.0018 ± 0.0006
 (a)   Top  30  cms of  soil

                                 Table A 1-2

               Concentration  of  Fallout Pu-239  In Soil  as  a
           Function of Depth  at  North Eastham,  Massachusetts  (4)
 0-2 (Includes Vegetation) (a)
    Undisturbed Site
Concentration of Pu-239    % of Total


          0.91xlO~3           52 (a)
          0.37                21
          0.15                 8
          0.12                 7
          0.052                3
          0.035                2
          0.028                2
          0.027                1
          0.047                3
         <0.004               <1

    Cultivated Site
 Concentration of Pu-239   % of Total
                                          (yCi/in )
0.02 ± 0.


(a)  12% of the total plutonium was associated with vegetation

                     Table A 1-3

         Fallout Pu-239 in New York City (6)
Cumulative deposit
Surface air concentration

                                   Table A 1-4

Nuclear Properties of Environmentally Significant Transuranium Radionuclides (7)
                                                     Energy of
Am- 243
Mode of
Major Radiations
5.50; 5.46
5.16; 5.11
5.17; 5.12
0.021 (max)
4.90; 4.86
5.49; 5.44
5.28; 5.23
6.12; 6.07
5.81; 5.77

kilocuries of Pu-238 were released in 'the high stratosphere of the

southern hemisphere when a satellite containing a nuclear power source

(SNAP-9A) failed to orbit and disintegrated (9).  As a result, there are

measurable amounts of Pu-238 in most environmental media.  Also, an

estimated 90 curies of curium (Cm-245 and Cm-246) have been produced as

the result of weapons tests (1).

     The principal additional potential source for future release of

the transuranium elements to the general environment are operations

associated with the Light-Water Reactor Fuel Cycle.  About 250 kg of

Plutonium, which is inside the spent  fuel rods, is removed per year

from a 1000 Mw(e) light-water reactor.  The isotopic composition of

this plutonium is typically 59% Pu-239, 29% Pu-240, 11% Pu-241, 4%

Pu-242 and 2% Pu-238  (9).

     Sections that follow briefly discuss specific controlled sites  and

other areas in the general environment which have become  contaminated

with transuranium elements significantly above  levels  attributed  to

stratospheric fallout.   There are several possible reasons:   local

fallout  from aboveground nuclear  tests,  accidents at nuclear facilities

or  effluent releases  from nuclear facilities.   Data was  selected  to be

representative of conditions at these sites  as  of  1973 to 1975; the

years for which  the most recent reports  on environmental monitoring

have been published.   Much  additional information is  available in the

documents that have been referenced.

     Table A 1-5 provides  a summary of these sites,  their locations,

inventories,  and approximate onsite and offsite maximum soil concentra-

tion levels.

                 Table A 1-5


Nevada Test Site

Rocky Flats Plant
Denver, Colorado

Hound Laboratory
Miaalaburg, Ohio

Savannah Rlvar Plant
South Carolina

Los Alanos Scientific
Los Alaoos, New Mexico
Trinity Site
New Mexico
Enevetak Atoll

Continental United States
Approximate Inventory of
Plutonium released to Soils
> 155 (Pu-239)

11 (Pu-239)
1 (Ao-241)

5 to 6 (Pu-238)

2 (Pu-239)

> 1 (Pu-239 and
•»• 45 (Pu-239)
Not published

16,000 (Pu-239)
4,000 (Pu-238)

Maximum Soil Concentration Levels
Onsite Offsite
6,000 uCi/m2 2xlO"3 yCi/n2
10 pCi/g
> 1000 pCi/g2 « pci/g
> 10 jiCi/nr

4,600 pCi/g

0.001 uCi/m2 0.01 yCi/m2

220 pCi/g < 1 pci/g
0.1 uCt/m2
530 pCi/g 0.3 pCi/gm
0.07 pCl/m

0.001 to 0.003 vCl/m2

Comments v>aft*f *****+*,.,
"**"Siih° — _,- 	 	 Ket erences
Onsite levels refer to small 1,11,12
subregions of the site
It is estimated that 8 curies 14,15,17
of plutonium are onsite; 3 are
offsite. Inventory of Am-241
will double due to ingrowth.
Soil samples are taken 5 cm
Most of the plutonium is 18,19
associated with buried sedi-
ments in waterways' adjacent
to the site.
Offsite plutonium is located 1,10
in a swamp area of the
Savannah River in the top
8 cms of sediment.
Plutonium is associated with 10
soils iix dry canyons (top 5 cms)
Offsite value refers to 23
islands most likely to be
resettled (top 15 cm of soil)
(top 30 cm of soil) 3

1.   The Nevada Test Site (NTS)

     The Nevada Test Site (10) is an area of about 3500 km  located in

Nye County, Nevada, 90 kilometers northwest of Las Vegas.   It is

surrounded by an exclusion area 25 to 100 kms wide between the test site

itself and public lands.  The climate is for the most part arid, with

insufficient rainfall (10 to 25 cm/y precipitation) to support trees or

crops without irrigation.  Winds blow primarily from the north, except

for May through August when they are predominantly from the south-

southwest.  Fig. A 1-1 shows the population distribution around this

site by azimuth and by distance.

     Major programs conducted at NTS have included nuclear weapons

tests, tests for peaceful uses of nuclear explosives, nuclear reactor

engine development, basic high energy nuclear'physics research, and

seismic studies.  As the result of these activities, the test site,

exclusion area and, to a much lesser extent, large areas outside the

exclusion areas have become contaminated with plutonium.

     Although the  total inventory of plutonium in soils within  the NTS

is not known, detailed surveys have been made of certain specific loca-

tions in the site  and the Tonopah Test Range  (TTR) which are believed  to

be the areas most  highly contaminated with  plutonium and americium  (11).

As shown in Table  A 1-6, the  inventory of plutonium  in  these areas  is

about 155 curies.

     Estimates of  offsite plutonium  concentration -in soil  as the result

of activities at NTS have been made  (12).   In units  of  mCi/km



0 - 0»I«T COWS


                    AROUND NTS (10)
                      FIGURE A1-1

                                                    Table  A 1-6

                        Estimated Inventory of Plutonium in Surface Soil at Specific
                       Areas within the National Test Site and Tonopah Test Range (11)
5 (GMX)
Double Track
Clean Slate 1
Clean Slate 2
Clean Slate 3
Plutonium Valley

Size of Estimated Range of Soil b
Area Inventory Concentrations
(m2) (curies Pu-239) (yCi/m2) Pu/Am Activity Ratios
3.6xl06 44 ± 9 2 to 840 9
2.4xl05 3 ± 0.3 3 to 530 10
3-OxlO5 5 ± 1 7 to 2,800"
2.2xl05 5 ± 2 15 to 120 22 to 26
7.9xl05 29 ± 6 4 to 260
1.3xl05 30 ± 5 12 to 370 .
4.8xl06 39 ± 4 1 to 6,200 5 to 8
Total 155
(a)  Inventory as measured to 5 cm soil depth.

(b)  Soil concentration range values refer to concentrations within sub regions of each site
     as selected by stratified random sampling.

          2               2
 (1  mCi/km  = 0.001 pCi/m )  Fig.  A 1-2  shows  isopleths  for  this material;

 Fig.  A 1-3  shows,  for  comparison,  the  additional  amounts of  plutonium  at

 the same  locations due to fallout.   Offsite  levels  of  plutonium  in  soil

 are less  than 0.1  yCi/m , most areas being far  lower.

      A limited special study was made  of  plutonium  concentrations in air

 at  locations close to  the NTS  (13).  Results are  shown in  Table  A 1-7

 and indicate that,  while resuspended plutonium  from NTS has  probably

 been  detected at three locations,  the  air concentration level has not

 exceeded  0.5 fCi/m .   Long  term  air  surveillance  from  1966 to 1972  at

 eight major  centers of population  in western states was performed for

 ambient plutonium  levels in ground level  air (13).  Within annual

 cycles, these levels,  which are  ascribed  entirely to fallout plutonium
 from  the  stratosphere,  varied from 0.01 to 0.5  fCi/m   with mean  annual
 values of approximately 0.1 fCi/m  .

     The milk surveillance  network around the NTS does not analyze

 samples for  plutonium.  Water samples  from wells both  onsite and offsite

 in  surrounding communities  were  analyzed  for Pu-239 and Pu-238.  Plu-

 tonium was not detected, indicating  levels less than about 0.1 pCi/A

 Pu-239 or Pu-238.

 3.   Rocky Flats Plant  (RFP)

     The Rocky Flats Plant  (10)  is located in Jefferson County,

 Colorado,  26 kilometers northwest of Denver.   Currently, the site

 consists of  6,500 areas of  Federally owned land of which 385 acres  is

enclosed within a security  fence.  The area  is arid (40 cm/y precipita-

tion)  with predominant winds from the northwest.  Figure A 1-4 is a



    I                                 __UTAH         ,°
  I'                           ARIZONA"               I —
             (mCi per km2)
              FIGURE A1-2

§1 •1.1*03
I . «.
                               /                3. 3tO."2 •"""--/
                               1                               j o

                                                     03.3,0.3 /
                                                        20±0.2l __ •1.9*0.2

                                                  ol.5i0.4 °
       n n  , «
      • 2.8*1.0
                  , 7 n -J  '
                 •1.7*0.3  /

                        •/1. 7±0.8
• 2



                                                                         2.2±0.1Q  I
                                                                      2.0±0.1°    I

                      I                                                          »O

             I       «r /        """* *"" """" *"" """" """ ••»	                                  O
      "**T p"""       Q |                           "™" ^~" "™* "** "*"• — - — ^. ^_  U t AH      IW

Table A 1-7 Pu-239 in Air Samples - Near the NTS (13)
               Downwind Pu-239
Upwind Pu-239
Furnace Creek, CA

Death Valley Jet.

Beatty, NV

Diablo, NV

Hiko, NV

Indian Springs, NV

Lathrop Wells, NV

Pahrunp, NV

Scotty's Jet., NV

V/»rn Springs, NV





vs Upwind
No difference

No difference


No difference


No difference

No difference

No difference

No difference


                               A = frequency for a direction (%)
                               B = average velocity (meters per
                                  second) for a direction from
                                  which the wind blows
                               C = calms (%)
                               D = variable direction (%)
                            Scale for length of wind frequency lines (%)
                     FIGURE A1-4

wind rose for the site; Fig. A 1-5 provides population densities around

the site by azimuth and distance.  Less than 10 yCi of plutonium was

released from plant stacks and vents to the atmosphere in 1975 (10).

Data on the total amount of plutonium released to surface waters from

1973 to 1975 have not been published.

     The plant produces components for nuclear weapons, which involves

the processing of plutonium.  As the result of leakage from barrels of

plutonium-contaminated cutting oil, parts of the site and, to a lesser

degree, the general environment around the site have been contaminated

with plutonium and americium.  The total amount of plutonium released to

the environment is estimated to be 11 curies of which 3.4 ± 0.9 curies

is estimated to be offsite (14).  Of the approximately 8 curies onsite,

more than half is believed to be stabilized by coverage with an asphalt

pad and remedial measures are being taken to control the remainder to

the extent practicable.

     Figures A 1-6 and A 1-7 show values for Pu-239 concentrations

in soils (5 cm depth) around the site (15, 16).  Concentrations of

Am-241 within the site boundaries are about 10% of Pu-239 values (17).

     Table A 1-8 provides selected yearly average plutonium

concentrations in ambient air within the plant boundary, at distances

of 3 to 6 kilometers from the plant and in nearby communities (10).

     Liquid effluents released from the plant may eventually reach the

Great Western Reservoir, while storm water runoff from the site tends to

collect both there and in Standley Lake.  Both reservoirs are sources of

                 FIGURE A1-5
                 <• Tfl 10 tan)


                 HBURE A1-5
                (10 TO 80 km)

            0 0A ROCKY
             '  FLATS

             FIGURE A1-6

         ROCKY FLATS 1974



               FIGURE A1-7
             ROCKY FLATS
PLUTONIUM-239 CONTOURS mCi/km12 (16),

                                        Table A 1-8

                    Plutonium Concentration in Ambient Air at Selective
                           Locations  -  Rocky Flats  Site,  1975  (10)
                                         Average Plutonium
Station Location with

Three to six
Kilometers Distant
from Plant
Walnut Creek
< 0.02
< 0.06
< 0.03
< 0.04
< 0.03
< 0.03
< 0.03
< 0.04
< 0.03
< 0.04
Respect to the Plant
(a)   Site Boundary

drinking water.  Table A 1-9 gives estimates of plutonium and americium

concentrations in these water supplies as well as in finished drinking

water for nearby communities (10).  Modifications of the Rocky Flats

plant operations have been proposed that will eventually halt all of its

liquid effluent discharges.

     In summary, in offsite areas around the Rocky Flats plant, the

plutonium concentration in ambient air is < 0.06 fCi/m , plutonium in

finished drinking water is < 0.03 pCi/Jl, and plutonium in soil is

< 0.1 yCi/m2 (5 cm deep samples) (17).

A.   Mound Laboratory (ML)

     Mound Laboratory (10) is located in Miamisburg, Ohio, 16

kilometers southwest of Dayton.  The 180 acre site is within an indus-

trialized river valley in a region that is predominantly agricultural.

Corn and soy beans are major crops and livestock is pastured.  Winds are

predominantly from the south or west; average precipitation is 91 cm/yr.

The population distribution around the site is given in Fig. A 1-8.

     The mission of the laboratory includes research, development and

production of components for the nuclear weapons program and fabrica-

tion of radioisotopic heat sources for medical applications and space

operations.  This latter operation involves processing large quantities

of Pu-238 which has become the plutonium radionuclide of primary

concern associated with this site.

     Pu-238 in airborne effluent discharges from the plant has, over

the years, contaminated the site and, to a lesser degree, offsite areas.

Figure A 1-9 shows preliminary estimates of the levels of Pu-238 in

                                 Table A 1-9

         Concentrations of Plutonium and Americium in Water Supplies
        and in Finished Drinking Water - Rocky Flats Site, 1975 (10)
Indiana Street)
Water Supply
Great Western
Plutonium         Americium
Great Western
Stand ley Lake
(Walnut Creek at
Drinking Water
(Discharge to
< 0.1
< 0.04
< 0.007
< 0.04
< 0.008
< 0.009
< 0.007
< 0.04
< 0.03
< 0.03
< 0.006
< 0.03
< 0.04
< 0.009
< 0.007
< 0.03

          (0 to 10 km) (LAT 39.6305 LONG 842897)

                                             TOTAL POPULATION IN SECTOR
                        RGURE A1-8

            (10 to 80 Km) LAT 39,6305 LONG 84,2897)
                   TOTAL P-2,903,384

                   RGURE A1-9

                  (m Ci/km2)(iO)

 soil around the site.  Approximately 0.5 curies of Pu-238 have been

 released to the offsite environment in this manner.

      The concentration of Pu-238 in various environmental media around

 the Mound Laboratory is given in Table A 1-10 for 1975 (10).   The

 annual average concentration of Pu-238 in offsite ambient air did not

 exceed 0.03 fCi/m ; in surface waters it was as high as 1.4  pCi/£ in an

 off-site pond but in water supplies it did not exceed 0.05 pCi/£.

      In 1969,  an underground pipe carrying acid radioactive waste

 solutions ruptured.  During repair work on this pipe, heavy  rains

 eroded the radioactive soil, and carried about 5 curies of Pu-238 off-

 site into waterways adjacent to the Laboratory.   This plutonium now is

 in  sediments  that are mostly buried under approximately 1 to  3 feet of

 additional non-contaminated sediments added by normal processes later

 in  time (18).  A special  study of this incident was also conducted by

 the U.S.  Environmental Protection Agency;  results are given in Fig.

 A 1-10 and Table A 1-11 (19).

 5.   Savannah  River Plant (SRP)

      The  Savannah River Plant  (10)  is located  on a 790 km Federally

 owned site along the Savannah  River in Aiken and Barnwell Counties,

 South Carolina,  about 100 kilometers  southwest of Columbia.   The sur-

 rounding  area  is  predominantly forested with some diversified fanning,

 the main  crops being  cotton, soy  beans, corn,  and small  grains,  with the

 production of beef  cattle.   The climate is mild, with  an annual  rainfall

 of 115 cm/y.  Population  density  around the  site  ranges  from  10  to 400

people per square mile.


                                Table A 1-10

               Concentration of Pu-238 in Environmental Media
                            Mound Laboratory  (10)
                           Ambient Air
Sample Location
(Location Number)

onsite (211)




North of Plant  (101)

East of Plant  (103)

South of Plant  (104)

West of Plant  (105)

Miamisburg (122)

Dayton  (108)

(National Average from Fallout)
Average Concentration of Pu-238












                           Table A 1-10 (Continued)
 Sample  Location
 (Location number)

 Great Miami River

  Above the Plant  (1)
  Below the Plant  (A)

 Canal/pond area

  North Pond
  South Pond

Miamisburg Drinking Water

Private Well J

Private Well B
Average Concentration of Pu-238
          0.019 ± 0.0022
          0.052 ± 0.004

          0.043 ± 0.003

          0.020 ± 0.002

          0.006 ± 0.00003

                          Table A 1-10 (Continued)

                   Foodstuff Collected Close to the Plant


Fruits & Vegetables


Field Crops

Aquatic life
Average Concentration of Pu-238
          < 6x10
          <  3x10

                    FIGURE A1-10
              MOUND LABORATORY (19)

                                                    Tafele A.1-11
                                                   MOUND  LABORATORY

                                         U.S.  ENVIRONMENTAL PROTECTION AGENCY
                                                     1974 SURVEY (19)
                          Plutonium in Samples from the Vicinity of Mound Laboratory
I.D. t
£ EF-1

Location 238Pu
Core sediment samples collected by Mound Laboratory, pCi/g dried weight
North Canal at south end of South Pond 0.13
" 0.13
" 10.8
" 26
" 0.98
North end of North Canal 8.9
< 0.02
< 0.02
< 0.02
< 0.02
< 0.02
GA-1           North end of North  Pond                                              0.48      <  0.02

                                              Table A 1-11  (Continued)
I.D. tf
Middle of North Pond
South end of North Pond
North end of South Pond
Middle of South Pond
South end of South Pond
South Canal at west drainage ditch
South Canal where it crosses US 25
Sediment samples, top 1 inch, pCi/g dried weight
South Canal at west drainage ditch
East drainage ditch, ~200 ft south of Mound Rd culvert
South drainage ditch, 15 ft from junction with South Canal
South Canal, 10 ft from junction with south drainage ditch
Surface soil and mud samples, top 1 inch, pCi/g dried weight
EPA- 14
Railroad cut south of control box
Railroad cut north of control box
Run-off hollow
At shelter house SE of South Pond
NE of Lab, at fence between tennis court and Harmon Field
SE of Lab, at SU corner of Mound Park
SW of Lab, at junction of US 25 with^ South Canal
NW of Lab, at alley south of Mound Rd

     SRP produces plutonium, tritium and other special nuclear materials.

Facilities include nuclear reactors, nuclear fuel and target fabrica-

tion plants, nuclear fuel reprocessing plants, a heavy water production

plant and various supporting laboratories.

     Two airborne releases, in 1955 and 1969, from fuel reprocessing

plant operations are believed to have caused the detectable plutonium

contamination of soil that is found within a 2 km radius around those

facilities within the site perimeter.  Approximately 1 curie of plu-

tonium is estimated to be within the isopleths shown in Fig. A 1-11  (20)

     During the 1960's, radioactive liquid effluents were released

from SRP such that radioactive materials, including Cs-137, Co-60 and

plutonium deposite'd in off site swamp areas.   In these areas plutonium

                                    —3       2                        -3
concentrations range from 3 to 11x10   yCi/m Pu-239 and 0.3  to 6x10

viCi/m  Pu-238.  The amount  attributed to  fallout  sources is approxi-

mately IxlO"3 yCi/m2 Pu-239 and O.lxlO"3  yCi/m2 Pu-238  (10).

     Levels of plutonium in various environmental media in  the general

environment around  SRP are  given in Table A  1-12  for  1975  (10).   Resu-

spended  plutonium from the  contaminated  areas within  the  site was not

detected in offsite ambient air.   Values for plutonium concentration

levels  in ambient air at  onsite  locations have not  been published.   In

1975,  the plant  released  2  mCi Pu-238 and 0.5 mCi Pu-239  to the  atmo-

sphere;  the plant released 8  mCi Np-239 and 19 mCi  Pu-239 in liquid


                                   ON ISOPLETHS (3) - mCl/km2
                                   IM ZONES (1.0) - CURIES
                                   DEPOSITED IN ENTIRE ZONE
                      FIGURE AMI

                               Table A 1-12

              Plutonium Concentration in Environmental Media
               Around the Savannah River Plant - 1975 (10)
Ambient Air.
Sample Location

Plant Perimeter
(Locations not specified)

25 mile radius
(Locations not specified)
Rain Water,
 Sample Location

 Plant Perimeter

 25 mile  radius

 Soil (0-5 cm depth?


 Plant Perimeter
   NW quadrant
 Sprinfield, SC
 Aiken Airport, SC
 Clinton, SC
 Savannah, GA
Average Plutonium Concentration
  Pu-239                 Pu-238
 (fCi/m3)               (fCi/m3)
Average Plutonium Concentration
  Pu-239                 Pu-238
  (pCi/m2)                (pCi/m2)


 Average Plutonium Concentration
   Pu-239                 Pu-238
  (yCi/m2)                (uCi/m2)



  6.   Los Alamos Scientific Laboratory (LASL)

       The Los Alamos Scientific Laboratory (10) is located on a 110 km2

  site in Los Alamos County in North Central New Mexico about 40 kilo-

  meters northwest of Santa Fe.  The site is on a series of mesas

  separated by canyons that run eastward from the Jemez Mountains to the

  Rio Grande Valley.   The climate is semi-arid with rainfall of 46 cm/y.

  While  the land  around  the site is  undeveloped, about  16,000 people

  reside  in the immediate area.

      The  primary mission of LASL is associated with nuclear weapons

  research  and development.  Industrial  effluents from  these operations

  have for  some time been  discharged onsite  into canyons, where  the

  transuranium nuclides in  these effluents soon  become  attached  to soil

 particles.  It is estimated that less  than 1 Ci of transuranic waste

 has been disposed of, in  this fashion, to Pueblo, DP-Los Alamos, and

 Montandad canyons.   Liquid effluents are usually absorbed  in the

 soil so they do  not flow beyond the site boundaries,  but, during periods

 of heavy runoff, storm waters have  carried detectable amounts of trans-

 uranium elements down the canyons and  offsite.  Plutonium concentrations

 in sediments in  the canyons receiving;  liquid waste are given in Table

 A 1-13  (21).

      Concentration  levels of  plutonium and americium  in various

 environmental media  around the LASL site  are  given in  Table A 1-14

 for  1975  (10).   During  the same year,  the Laboratory discharged less

 than 0.3 mCi of  plutonium to the air;  the amount of transuranium ele-

ments discharged in liquid effluents was  not published.

                               Table  A 1-13

           Plutonium in Sediments  in  the Liquid Waste Receiving
                   Canyons on the  LASL Site  - 1975 (20)

                       Average Plutonium Concentration in dry soil
Distance from
Acid Pueblo
Canyon Inventory)

(Average Regional Plutonium
 Concentration in Dry Soil)
DP - Los Alamos
* Canyon

(0.1 to 0.3
(a)  top 5 cm of soil

                                 Table A 1-14
            Plutonium and Americium Concentrations in Environmental
                      Media at the LASL Site - 1975 (10)
 Ambient Air
Station Location
(Station Number)
On Site


Off Site

(Santa Fe) 11
(fCi/in )
                             Average Radionuclide  Concentration
 Surface Water and Water Supplies
                                         (fCi/in )
                                  (fCi/in )
                            Average Radionuclide  Concentration
Sample Location
Regional Surface Waters
Perimeter Surface and
  Ground Waters
Los Alamos Water Supply* '  -3x10

  (a)   Negative values are due to statistical fluctuations in the measurement.

                         Table A 1-14 (Continued).

                                Average Radlonucllde Concentration

                                      Pu-239           Pu-238

Sample Location                       (pCl/g)          (pCl/e)

On site                               40xlO~3          lxlO~3

                                           -3              -3
Site Perimeter and Regional areas     12x10          0.5x10
(a)  Top 5 cms of soil.

  7.    The  Trinity  Site

       The  first nuclear device was  tested at  the Trinity Site, 100

  kilometers northwest of Alamogordo, New Mexico, on July 16, 1945.

  During 1973 and 1974, the site was surveyed by the U.S. Environmental

  Protection Agency to determine the extent of resulting plutonium con-

  tamination (22).  Figure A 1-12 shows plutonium contours based on

  this study.  Highest soil activity levels were 0.05, 0.09 and 0.02

 yCi/m  found along arcs 1A,  2 and 3, respectively.  The total amount of

                                             o                 o
 plutonium estimated to be within the 3 nCi/m  contour (1 nCi/m  =

 0.001 yCi/m )  is approximately 45 curies.

 8.   Sites of  Underground Nuclear Detonations (4)

      Table A 1-15  is a listing of underground tests conducted off the

 Nevada Test Site  (10).  Nuclear devices  containing plutonium may have

 been used  but  all  transuranium elements  are believed to be contained.

 9.   Enewetak  Atoll

      The Enewetak  atoll (23)  consists  of 40  islands  on  an  elliptical

 coral reef-about 3800 km  southwest  of  Honolulu  in  the northern part  of

 Micronesia.  It was  the site  of 43  nuclear weapons  tests during  the

 period 1948-1958.  The total  land area is about 7 km  ,  the largest

 island of  which is 1.5 km  with land heights above sea  level of

 3  to  5 meters.   There are plans for future rehabilitation  and  resettle-

ment  of the atoll by the Enewetak people who were displaced in 1948.

      The soil of many of the islands is highly contaminated with Sr-90,

Cs-137, Co-60 and Pu-239.   Plutonium concentrations vary considerably

from island to  island, depending upon the locations of the detonations

 1973-1974 PLUTONIUM
      FIGURE AM 2

                                        Table A 1-15

             Underground Testing Conducted Off  the Nevada Test Site (10)
Name of Test,
Operation or
Project Gnome/
Project Shoal

Project Dribble
(Salmon Event)

Date Location
12/10/61 48 km (30 mi) SE of
Carlsbad, N.M.

10/26/63 45 kni (28 mi) SK of
Fallen, Nev.

10/22/64 34 km (21 mi) SW of
Hattiesburg, Miss.







Purpose o£
the Event *e

Nuclear test
detection re-
search experi-
Nuclear test
detection re-
search experi-
ment .
Opergtion Long     10/29/65  Amchicka Island,
Shot                         Alaska
Project Dribble    12/03/66  34 km (21 mi) SW of
(Sterling Event)             Hattiesburg, Miss.
Project Gasbuggy   12/10/67  88 km (55 mi)  E of
                             Farmington,  N.M.
Faultless Event0   01/19/68  Central Nevada Test
                             Area 96 km (60 mi)  E
                             of  Tonopah,  Nev.

Project Miracle  .  02/02/69  34  km (21 mi) SW of
Play (Diode Tube)            Hattiesburg, Miss.
Project Rulison    09/10/69  19 km (12 ml) SW of
                             Rifle,  Colorado

Operation Milrow0  10/02/69  Amchitka Island,

Project Miracle    O/t/19/70  J4 km (21 ml) SW of
Play (Humid                  Hattiesburg, Miss.
 •v-80        716
   0.38     823
 Non-       823
 mu-lear  (2700)
 explnti ion

 Non-       823
 nuclear  (2700)
DOD nuclear
test detection

Nuclear test
detection re-
search experi-
ment .

Joint Government-
Industry gas
stimulation ex-

Detonated  in
cavity.  Seismic

Gas stimulation

Calibration  test.
         DeloiKit i'd In
         SaJmuii/Sterl Ing
         cavity.   Seismic
         stud les.

                          Table A 1-15 (continued)
Name of Test,
Operation or

Project Rio

Date . Location (kt)
11/06/71 Amchitka Island, < 3000

05/17/73 48 km (30 mi) SW of 3x30
Meeker, Colorado


Purpose of
the Event >e
Test of war-
head for
Gas stimula-
tion experi-

 Plowshare Events

 Vela Uniform Events

cWeapons Tests

dlnformation from "Revised Nuclear Test  Statistics,"  distributed on September 20, 1974,
 by David C. Jackson,  Director,  Office of  Information Services, U.S. Atomic Energy
 Commission, Las Vegas,  Nevada.

 News release AL-62-50,  A£C Albuquerque  Operations Office, Albuquerque, New Mexico.
 December 1, 1961
 "The Effects  of Nuclear Weapons"  Rev.  Ed.  1964.

and  the fallout patterns  that followed.  Table A 1-16 gives data on

Enewetak soils (23); the  islands most likely to be reoccupied are Fred,

Elmer, David, and eventually Janet.  The average plutonium contamination

level in surface soils on Fred, Elmer, and David which were not as

                                                     -3      2
heavily contaminated as the northern islands, is 9x10   yCi/m , with a

                     -3      2                                 2
range of 0.9 to 70x10   yCi/m ; on Janet the average is 2 yCi/m , with


a range of 0.2 to 4 yCi/m .

     A limited number of measurements have been made on plutonium and

americium concentrations in surface air and in other environmental

media.  These are given in Tables A 1-17 and A 1-18 (23).

10.  Other Sites

     The following tables show levels of the transuranium elements in

the general environment around other facilities known to use the

transuranium elements in their operations.   At this time, the total

amount of the transuranium radionuclides in soils both on and off

such nuclear facility sites is believed to be less than 1 curie.

                               Table A 1-16

          Plutonium Concentration in Soil on Enewetak atoll (23)
(U.S.  Occupational Designation)
                                  Pu-239 in top 15 cm of soil
                                     Mean .            Range
 a.  "dense" and  "light" refer  to vegetation cover
Belle dense
Daisy dense
Kate dense
Olive dense
Pearl hot spot
Tilda dense
Yvonne southern
northern beaches
David, Elmer, Fred
All others
^ r- •-• — w ^ j
xjr***™/ f* J
1 pCi/g in the top 15 cm of soil is approximately equivalent to
0.23 yCi/m2 or 0.045 yCi/m2 if only the top 1 cm of soil is
considered and 20% of the total activity  is assumed to be in the
top 1 cm of soil.

                               Table A 1-17

           Plutonium and Americium Concentration in Surface Air
                          on  Enewetak Atoll (23)

Runit  (Yvonne)

Other  islands

Reunlt  (Yvonne)

Other  islands

Runit  (Yvonne)

Other islands





 < 0.3-0.3

   Not Detected

                              Table A 1-18

            Plutonium and Americium Concentrations in Various
               Environmental Media on Enewetak Atoll (23)


Surface Waters






Coconut Crabs


Ocean (East)

As Found

As Found
As Found





  460 mCi/km^

  170 mCi/km2

  9-40 fCi/£

  0.3 fCi/X,

< 0.022
  0.001-0.1 pCi/ga

  0.004-0.07 pCi/ga

  0.0005-0.02 pCi/g£

  0.001-0.01 pCi/ga
(a)  dry weight

                              Table Al-19
        Environmental Monitoring for the Transuranium Elements
                       at the Pantex Plant Site
Site:      Pantex Plant (10,13,24)
Location:  25 kilometers northeast  of Amarillo,  Texas
Mission:   Atomic Weapons Assembly  involving significant  quantities
           of uranium,  plutonium, tritium

Transuranium Elements Released to the Environment
No releases during
Location of
Media Sample Collection
Air 10 kilometers from
plant in various

25 kilometers from plant

Soil^ ' Off site in various
directions from
the plant
Jackrabbits Onsite
the period
Average Plutonium
Concentrations - CY 1975
0.03 fCi/m3
0.00 ± 0.01
0.00 ± 0.01
0.5 (1 sample only)
0.00 (1 sample only)
0.00 ± 0.02
0.05 ± 0.02 pCi/g
0.00 ± 0.02 pCi/g
(wet) in kidney,
                                                 liver, lung,  flesh,
                                                 and bone

                        Table Al-19  (continued)

     v 'Average air concentrations of plutonium in 1973 ranged from
0.4 to 2  fCi/m3 (10),  which is higher than any other site.   These high
levels are believed to have been caused by analytical errors.

        Soil samples collected to a  depth of 5 cm.

                                        Table Al-20
                  Environmental Monitoring for the Transuranium Elements
                              at Argonne National Laboratory
           Site:      Argonne National Laboratory (10,13,24)
           Location:  DuPage County, Illinois, 43 kilometers southwest of Chicago
           Mission:   Research and Development including chemical and
                      metallurgical plutonium laboratories

           Transuranium Elements Released to the Environment (CY 1975)
                      To air
                      To surface waters (Sawmill Creek)
                                       - not  published
                                       - 0.1  mCi Pu-239;
                                         0.5  mCi Np-237;
                                         0.05 mCi Am-241;
                                         <0.05 mCi Curium and
 Surface Water
(Sawmill Creek)
 Sawmill  Creek

 Des Plains

         Location of
      Sample Collection

       Site Perimeter

    Upstream from Outfall
   Downstream from Outfall

 Upstream from Sawmill Creek
Downstream from Sawmill Creek

  McKinley Woods State Park
 Below Dresden Power Station

       Site Perimeter

                                                 Number of

                                                Av.  of  2  Stations
                                                    1 station
Av. of 10
Av. of 10
                  Average Plutonium
                Concentrations - CY 1975

                0.02  fCi/ra3

                 5 x 10~* pCi/1 Pu-239
               <  3 x 10
                  4 x 10
                  4 x 10
                                                                   <  1
               2.4 x 10 " PCi/g Pu-239
               1.5 x 10         Pu-239
               5 x 10~  pCi/1
               8 x 10
2 x
3 x 10

2 x 10
1 x 10
2 x W
2 x 10



       Soil samples collected to depth of 30 cm.

                              Table A 1-21

        Environmental Monitoring for the Transuranium Elements at
          Battelle-Columbus Laboratories (West Jefferson Site)
Site:      Battelle Laboratories (West Jefferson Site) (10,13,24)
Location:  Columbus, Ohio
Mission;   Reactor Fuel Research (Plutonium Laboratory)

Transuranium Elements Released to the Environment (CY 1975)

           To air            - 1.5 yCi Pu-239
           To surface waters - not published




Food Crops
Sample Collection Location

(Site Boundary concentration as
calculated using atmospheric
dispersion equations)

Above and Below Outfall

Onsite and Various Locations
  Onsite, 3-8 kilometers
   Average Plutonium
Concentrations - CY 1975

   (4xlO~3 fCi/m3)
   <2xlO~2 pCi/g (dry)

   <2xlO~2 pCi/g (dry)
Corn, Soybeans, Rye, Vegetables    <2xlO   pCi/g (dry)
0.4 to 8 kilometers in Various
Directions around Site

                                  Table Al-22
           Environmental  Monitoring for the  Transuranium Elements  at
                   the  Idaho  National Engineering  Laboratory
Idaho National Engineering Laboratory (10,13,24)
Southeastern Idaho; 35 kilometers west of Idaho Falls
Includes - Fuel reprocessing, calcining liquid radio-
active waste,and storage and surveillance of solid
transuranic waste
Transuranium Elements Released to the Environment  (CY 1975)

                   To air           -  2 mCi Pu-238, Pu-239, and Np-237
                   To disposal well -  "very small amounts"
Surface Soils
  Sample Collection Location

       Boundary Stations
       Boundary Stations
          18  Samples

       Distant  Location
          12  Samples
   Average Plutonium
Concentrations-CY 1975

  0.02 fCi/m3 Pu-239
  0.01 fCi/m3 Am-241
  2 ± 2xlO
  3 ±
             Samples Collected to Depth of 5 cm.

                                 Table Al-23
           Environmental Monitoring for the Transuranium Elements
                         at the Oak Ridge Facilities
Oak Ridge Facilities (10,13,23)
Oak Ridge, Tennessee
Multipurpose Research Laboratory, Gaseous Diffusion Plant,
and Nuclear Weapons Operations (Y-12 Plant)
Transuranium Elements Released to the Environment (CY 1975)

                   To air          -  4 yCi  sum of all transuranium elements
                   To Clinch River - 20 mCi  sum of all transuranium elements
                                     (CY 1973 - 80 mCi; CY 1974 - 20 mCi)


  Sample Collection Location

      Perimeter Stations

      Remote Stations

      Perimeter Stations(a)

      White Oak Creek
      Clinch River
   Average Plutonium
Concentrations-CY 1975

  0.014 fCi/m3 Pu-239
< 0.001 fCi/m3 Pu-238

  0.013 fCi/m3 Pu-239
< 0.001 fCi/m3 Pu-238

  4xlO~2 pCi/g Pu-239

  Not published
  Not published
        Soil Samples Collected to Depth of 1 cm.

                                 Table Al-24
           Environmental Monitoring for the Transuranium Elements
                                 at Hanford
Southeastern Washington, 320 kilometers east of Portland, Oregon
Includes Fuel fabrication, liquid waste solidification and
radioactive waste burial.  Originally, plutonium for nuclear
weapons was produced here.
Transuranium Elements Released to the Environment (CY 1975)

                   To air                  1 mCi sum of all plutonium elements
                   To surface waters -   0.9 mCi sum of all plutonium elements
    Media            Sample  Collection Location

    Air                Perimeter  Stations
                       Distant  Stations

    Soil                Perimeter  Stations
   Water              Columbia River-Upstream

   Vegetation        Perimeter  Stations
                                       Average Plutonium
                                    Concentrations-CY 1975

                                  <0.03 fCi/m3 Total Pu
                                  <0.04        Total Pu

                                  <7xlO~3 pCi/g (dry) Pu-239
                                  <4xlO~4             Pu-238

                                  <0.03 pCi/1         Pu-239
                                  <0.02               Pu-239

                                  <2xlO"3 pCi/g (dry) Pu-239

                              Table A 1-25
        Environmental Monitoring for the Transuranium Elements at
                    the Lawrence Livermore Laboratory
Site           Lawrence Livermore Laboratory
Location       Alameda County, California, 64 kilometers east of
                 San Francisco
Mission        Research and development on nuclear weapons

Transuranium Elements Released to the Environment (CY 1975)

               to air            - not published
               To surface waters - not published

                                                     Average Plutonium
Media          Sample Collection Locations        Concentrations-CY 1975

                 Site 300                    0.28 fCi/m3             Pu-239
                                             9.0x15" £Ci/mJ          Pu-238

Air              Perimeter Locations  (6)     0.019-0.034,fCi/m3      Pu-239
                                             1.9-9.5x10              Pu-238

Soil(a)          Site 300  (11)               0.001-0.03 pCi/g  (dry)  Pu-239
                 Livermore Valley (20)       0.001-0.1               Pu-239

Water            Reclamation  Plant           0.6 pCi/1               Pu-239
 (a)   Soil  Samples  Collected  to  Depth of  1 cm.

                                 Annex 1

 1.   Wrenn, McD. E., "Environmental Levels of Plutonium and the
      Transuranium Elements", in Proceeding of Public Hearings:
      Plutonium and the Other Transuranium Elements,  Vol 1 (ORP/CSD-
      75-2), U.S. Environmental Protectioh Agency, Office of Radiation
      Programs, Washington, D.C. (December 1974).

 2.   Krey,  P.W.  et.al., "Mass Istopopic Composition  of Global Fail-Out
      Plutonium In Soil",  IAEA-SM/199-39, International Atomic Energy
      Agency,  Vienna, (1976).

 3.   Hardy  Jr.,  E.  R.,  "Worldwide Distribution of Plutonium", in
      Proceedings of Public Hearings:   Plutonium and  the Other Trans-
      uranium  Elements,  Vol 1 (ORP/CSD-75-2),  U.S. Environmental
      Protection  Agency, Office of Radiation Programs,  Washington,  D.C.
      (December 1974).

 4.   Hardy, E.,  "Depth  Distribution of Global Fallout  Sr-90,  Cs-137 and
      Pu-239  (240)  in Sandy Loan Soil"  in Fallout  Program Quarterly
      Summary  Report (HASL-286)  U.S. Atomic Energy Commission, New  York,
      N.Y. (October  1974).

 5.   Bennett,  B.  G.  HASL,  U.S.  Energy  Research and Development Adminis-
      tration,  New York, N.Y.,  Personnel  Communication,  (December 1976).

 6.    Bennett,  Burton G., "Transfer  of  Plutonium From the Environment
      to Man"  in  Transuranium Nuclides  in the  Environment (IAEA-SM-
      International Atomic  Energy Agency, Vienna (1976).

 7.    Chart of  the Nuclides.  Knolls Atomic Power  Laboratory Naval  Reactor,
      U.S. AEC  (operated by  the  General Electric Company)  llth  Ed,
      Revised  to April 1972.

 8.    Krey, P.  "Atmospheric Burn-up of a  Plutonium-238 Generator, Science,
      158 No. 3802 pp. 769771 (Nov. 10, 1967).

9.    Erdman, C. A. and A.  B. Regnolds, Nuclear  Safety 16 43 (1975).

10.   "Environmental Monitoring at Major U.S.  Energy Research and
     Development Administration Contractor Sites - Calendar Year 1975"
      (ERDA-76-104) Energy Research and Development Administration,
     Division of Safety, Standards and Compliance, Washington, D. C.
      (August 1976) 2 Vols.


11.  Gilbert, R.  0.  et.  al.,  "Statistical Analysis of Pu-239(240)  and
     Am-241 Contamination of  Soil and Vegetation on NAEG Study Sites"
     in the Radioecology of Plutonium and Other Transuranics in
     Desert Environments (NVO-153) U.S.  Energy Research and Develop-
     ment Administration, Nevada Operation Office, Las Vegas,  Nevada
     (June 1975).

12.  Hardy, E., "Plutonium in Soil Northeast of the Nevada Test Site",
     in Health and Safety Laboratory - Environmental Quarterly,
     (HASL-306) Energy Research and Development Administration,
     New York, N.Y.  (July 1976).

13.  "Environmental Monitoring Report for the Nevada Test Site and
     Other Test Areas Used for Underground Nuclear Detonations -
     Jan. through Dec. 1973"  in Environmental Monitoring at Major
     U.S. Atomic Energy Commission Contractor Sites - Calendar Year
     1973, (WASH-1259 (73) U.S. Atomic Energy Commission, Division
     of Operational Safety, Washington,  D.C. (June 1973).

14.  Krey, P. W.  "Remote Plutonium Contamination and Total Inventories
     from Rocky Flats", Health Physics _30, 209 (1976).

15. " Environmental Monitoring at Major U.S. Energy Research and
     Development Administration Contractor Sites - Calendar Year 1974"
     (ERDA-54) U.S.  ERDA, Division of Operational Safety, Washington,
     D.C. (August 1975).

16.  Krey, P. W.  and Hardy, E. P., "Plutonium in Soil around the Rocky
     Flats Plant in Fallout Program Quanterly Summary Report (HASL 235)
     U.S. Atomic Energy Commission, New York, N.Y. (1974).

17.  Werkema, G.  J.  and M. A. Thompson, "Annual Environmental Monitoring
     Report Rocky Flats Plant" in "Proceedings of Public Hearings:
     Plutonium and the Other  Transuranic Element, Vol. 2", ORP/CSD-75-1,
     U.S. Environmental Protection Agency, Office of Radiation Programs,
     Washington,  D.  C.  (Jan.  10, 1975).

18.  Rogers, D. R.,  Mound Laboratory Environmental Plutonium Study-1974,
     (MLM-2249) Mound Laboratory, Miamisburg, Ohio (September 1975).

19.  U.S. Environmental Protection Agency, National Environmental Research
     Center, Cincinnati, Ohio.  Letter to Mr. Gary Bramble, State of
     Ohio, Environmental Protection Agency, from Bernd Kahn (Oct. 1, 1974).

20.  McLandon, H. R., "Soil Monitoring for Plutonium at  the Savannah
     River Plant," Health Physics .28, 347  (1975).

21.  "Annual Report of  the Biomedical and  Environmental  Research Program
     of the LASL Health Division - Jan.  through Dec. 1974"  (LA-5883-PR)
     Los Alamos Scientific Laboratory, Los Alamos, New Mexico  (Feb.  1975).


22.  Douglas, R. L. (Report in Press) U.S. Environmental Protection
     Agency, Office of Radiation Programs, Las Vegas, Nevada.

23.  "Cleanup, Rehabilitation, Resettlement of Enewetak Atoll - Marshall
     Islands (Final EIS) Defense Nuclear Agency, Washington, D. C.,
     4 Vols. (April 1975).

24.  "Environmental Monitoring at Major U.S.  Atomic Energy Commission
     Contractor Sites  - Calendar Year 1973" (WASH-1259) U.S. Atomic
     Energy Commission, Division of Operational Safety, Washington,
     D.C.  (June 1973).

              ANNEX II

  U. S. Environmental Protection Agency
      Office of Radiation Programs
         Washington, D.C.   20460

                               Annex  II



1.  Objective	    1

2.  Environmental Transport 	    2

     2.1  Aerosol Transport  	    2
     2.2  Soil Transport  	    8
     2.3  Aqueous Transport  	   10

3.  Exposure Pathways 	   11

     3.1  Inhalation  	,	   12
     3.2  Ingestion  	   16

4.  Methods of Relating Soil Concentration to
    Airborne Activity 	   18

     4.1  Resuspension Factor  	   18
     4.2  Mass Loading  	   19
     4.3  Resuspension Rate and Other Approaches 	   23

5.   Derivation of the Screening Level for Soil 	   25

     5.1  Enrichment Factor 	   26
     5.2  Correction for Area Size 	   29
     5.3  Calculation of the Soil Screening Level	   30


1.  Introduction

     The purpose of this annex is to provide a brief overview of the

transport of the transuranium elements through the environment and the

subsequent exposure pathways which might occur as a result of their

release into the biosphere.  Availability, uptake, and translocation

of the transuranium elements within the ecosystem depend upon many

factors.  Included among these are:  the mode of release (e.g.,

accidental fire or spillage), the physical form upon release (e.g.,

particulate or liquid), the chemical form (e.g., elemental, oxide, or

nitrate), and the nature of the environment being contaminated (e.g.,

desert soil or aqueous media).  Also important is people's use of the

environment which can significantly affect the mobility of the trans-

uranium elements and, subsequently, their effect upon exposed popula-

tions.  Because there are so many variables, potential pathways of

exposure should be evaluated on a site-by-site basis.  However, some

general conclusions can be made based upon present knowledge of the

environmental behavior of these elements although it is limited.

     For a terrestrial ecosystem, the major environmental transport

pathways are illustrated in Figure A 2-1.  These pathways include:

1) exchange between air and soil, water, and vegetation as a result of

deposition and resuspension, 2) exchange between soil and water by

erosion, leaching, absorption, and precipitation and 3) uptake from air,

soil, and water by plants, animals, and man.  Highlighted in Figure

A 2-1 are the pathways expected to produce the principal exposures to

people, which will be discussed in greater detail in the following


                RGURE A2-1

2.  Environmental Transport

     2.1  Aerosol Transport

     Airborne releases of the transuranium elements result from both

normal and accidental occurrences.   Normal operational releases are

small and are expected to decrease in the future due to improvements in

containment.  At present, doses from normal releases are below the

limits recommended in this guidance.

     Accidental releases — such as those resulting from transportation

accidents and fires — can lead to localized contamination, and would

probably necessitate some form of protective and remedial action.

Generally accidental releases of the transuranium elements will be as

the element, the oxide, or in liquid form.  When the release is in the

form of the element, it will convert rapidly to the oxide form, which is

relatively insoluble and stable thermodynamically.  Airborne releases of

the transuranium elements will generally be as an oxide containing a

substantial percentage of particles with diameters less than 10 vim.

This is the size range roughly corresponding to the respirable range of

particle sizes.  Because of the small settling velocities associated

with such particles they can be transported long distances by air

currents before depositing on the ground as a result of wet and dry

deposition.  These particles then will become incorporated into soil and

aquatic systems.  When deposited on soil, the aerosol  particles can

attach themselves to the larger, less mobile soil particles.  For

example, Mork  (1) found  that plutonium at test sites was  usually

 bound to soil particles with a diameter greater than 44 ym.   Likewise,

 Tamura (2) has analyzed the plutonium bound to soil particles at the

 Nevada Test Site and showed that the plutonium bound to coarse

 particles (5-20 ym)  was present as PuO^, while the plutonium bound

 to fine particles (2-5 Mm)  was present as hydrated PuO~.

      Subsequent transport will be as a result of wind and mechanical

 forces which transfer their energy to the surface particles  causing  them

 to roll,  slide or even become airborne.   The smaller the  particle dia-

 meter the greater will be the tendency for the particle to stay  airborne

 and the greater will be the distance that it will travel  before  return-

 ing to the surface.   Some of the  many factors which  can influence the

 redistribution of surface particles  by wind  are listed  in Table  A 2-1.

 The multiplicity  of  factors  and their complex interrelationship  makes

 the prediction of soil  resuspension  and  transport a  very  complex

 problem.   Accordingly,  the  resuspension  of soil particles has been the

 focus  of much  research  over  the past  several  years.

     One of  the more  commonly used indexes of  resuspension has been

 the  concept  of a  resuspension factor which is  defined as  the ratio of

 the  air concentration to soil concentration  (units; meters  ).  A

wide range of values has been reported for resuspension factors which

covers a variety  of surfaces and modes of disturbance.  Table A 2-2

is a summary of some values  reported  (3) for newly deposited PuO«

released during weapons testing.  Such a wide range of values makes

the prediction of the resuspension factor for a particular set of

                               Table A 2-1

                   Factors Influencing Wind Suspension

AIR                      GROUND                   SOIL
Velocity                 Roughness                Structure affected by:
Turbulence               Cover                      Organic Matter
Density affected by:     Obstructions               Lime Content
  Temperature            Temperature                Texture
  Pressure               Topographic Features     Specific Gravity
Viscosity                                         Moisture


Large-scale surface roughness
  Mechanical turbulence
  Overall sheltering
Small-scale surface roughness
  Sheltering of individual particles
Area of credible surface
Vegetative cover
  Live vegetation
  Plant residue
Cohesiveness of individual particles
  Moisture of surface
  Binding acting of organic materials


Particle size frequency distribution
  Ratio of credible to nonerodible fractions
Particle density
Particle shape


Wind velocity distribution in the surface layer
  Mean wind speed
  Wind direction
  Frequency, period, and intensity of gusts
  Vertical turbulent exchange

Moisture content on ground surface
  Dew and frost
  Drying action of the air

                                 Table A 2-2

            Short Summary of Experimental Results on Resuspension
                of activity in the Air [After Stewart (1967)]
  Measurement Conditions
 Resuspension Factor, R-(i

 	Range	Mean
  Plutonium sampled  at  1 ft  above
  ground  (1)

   Vehicle traffic
   Pedestrian  traffic
  Particle  size:  Mainly 20-60 urn,
  with 1% in hazardous  range
  (^ 3 ym for PuO_)

  Uranium sampled downwind from a
  crater (1)

   At 1 ft. above ground (dust stirred up)
   At 1 ft. above ground
   At 2 ft. above ground

 Brick/plaster dust sample contaminated
 with 1-131 (2)

   Enclosed space
   Open space

 Sample in  cab of Landrover, after
 a test (1)

   Round  1  (H + 18 hr)
   Round  2  (H +  5 hr)

 Airborne material without artificial
 disturbance of ground, consisting of
 limestone  rock and  sand with coarse
 grass  and  small bushes (3)

 Random samples following a  tower  shot,
 without artificial  disturbance,
 near crater  (3)

 On two roads formed by soil  grading
 -no artificial  disturbance  (3)

At back of a moving Landrover (3):
  D-Day + 4 (21 results)
  D-Day + 7 (21 results)
  D-Day + 7 over tailboard
   3xlO~£ to 7xlO~*
 1.5xlO~° to 3xlO~4
   2xlO~4  to  4xlO~5
  lxlO~6 to 8xlO~5
    (12 results)

  IxlO"8 to lxlO~6
    (9 results)
1.5xlO~6 to lxlO~8  2.5xlO~7
    (14 results)
  8xlO~7 to 3xlO~g  1.4x10
  6xlO~  to 4x10    1.5x10
1.6 and 3.1x10      2.5x10
(1)  From nuclear weapon and other tests at Maralinga
(2)  From Civil Defense trial at Falfield, Gloucester
(3)  From Hurricane Trial

conditions a difficult task.  In general, however, values for newly
deposited material seem to fall in the range 10~ (m~ ) to 10  (m  )
under conditions of low mechanical disturbance.  In areas where the
surface is rocky or paved, the resuspension factor may range up to
  -3  -1
10  (m  ) due to these smoother, harder surfaces and because little
mixing with noncontaminated surfaces occurs (A).  Mechanical disturb-
ances, such as vehicular traffic, will also increase the resuspension
factor by as much as a factor of 10 to 100 (5).
     For planning purposes, Stewart (3) and others (6) have recommended
a resuspension factor of 10  (m  ) for freshly deposited material under
quiescent conditions but recommended increasing this value to 10   (m  )
if there is moderate vehicular or other disturbing activity.  As the
freshly deposited material becomes aged, fixed to the soil or mixed with
the soil, the characteristics of the contaminant  approach the resuspen-
sion characteristics of the soil itself.  On  the  basis of empirical
information, a model has been proposed  (7) in which  the  resuspension
                        -5  -1       -9  -1
factor decreases from 10   (m  ) to 10   (m  ) within  two  years.  Bennett
has reportedly  (8) estimated that in a humid  eastern climate the
resuspension factor reaches 10~  (m~ ) to 10~  (m~  ) after the first good
                                                  -9   -1
rain or wet down and then  rapidly decreases to 10  (m ).   If the  trans-
uranium material is released as a solution rather than as the oxide,  its
resuspension will probably be in the low range (see  Section 2.2).
Experiments (3) with yttrium chloride solution sorbed onto  soil have
                                     —9  —1
indicated a resuspension  factor of 10   (m   ),  while  measurements  at

  Mound Laboratory (4)  of  Pu-238 released  from a waste  transfer line

  produced  resuspension factors  in  the  range  of 10   (nT1)  to IcT^m"1).

       Because of  the propensity for greater  mobility on the part of

  freshly deposited material, stabilization of  newly contaminated land

  should be undertaken  as  soon as possible after the initial accident

  in order to reduce the resuspension and inhalation exposure.  In

  addition to the benefit of reducing the hazard from inhalation, prompt

  stabilization of the contamination should result in lower cleanup costs.

 This lower cost arises from the fact that dispersion of the material is

 being minimized through stabilization and,  therefore,  less land area

 will be impacted and require cleanup.

      2.2  Soil  Transport

      Soil  contamination by plutonium has  been the  most prevalent

 situation  encountered  and, therefore,  is  the most  widely  studied.   Plu-

 tonium dispersed  onto  soil has  demonstrated  a tendency to bond  chemically

 and/or physically with the soil rather than  exist  as a separate  entity

 (4,9,10,11,12).   Plutonium oxide is relatively inert and  initially

 attaches itself to the soil matrix as  a result of  adhesive forces

 established between the plutonium  particle and the soil substrate.  Over

 a period of time, weathering processes  such  as freezing,  thawing, and

 precipitation, will begin  to "solubilize" the  oxide.

     Although generally considered to be insoluble, plutonium oxide can

undergo dissolution in a neutral aqueous media.  The plutonium oxide

particle dissolves producing plutonium  ions  until the formation of a

hydrated coating inhibits further  dissolution.  The rate and degree of

dissolution depends on many factors including pH,  temperature,  the

presence of oxidizing, reducing, and complexing agents,  as well as the

specific activity of the radionuclide.   The dissolution rate of    PuO.,

for example, has under certain circumstances been found (13) to be 100

times greater than that of    PuO_.  Plutonium ions formed during the

dissolution can undergo ion exchange reactions with the oxygenated

ligands commonly found in soil  (e.g., silicates) and become sorbed

onto the soil, or react with other agents present in the aqueous phase-

and form soluble complexes.  Chemicals that complex the plutonium

compete with the silicate particles for the plutonium and tend to reduce

the extent of plutonium sorptlon on soil.

     When plutonium is released to soil as a solution (e.g., as a

nitrate) it will already be in  ionic form and, in such situations, has

been shown  (4) to react rapidly with soil.  Plutonium ions  are capable

of displacing most cations (e.g., calcium, magnesium, sodium, etc.)

generally found in soils and of forming strong chemical bands.  Several

studies (2,14,15) have shown that, after sorption of plutonium has

occurred, it will not be readily displaced from the soil by natural


     Once in the soil, the transuranium elements can be depleted  through

the migration of particles down through the  surface or  through  the

resuspension of a fraction of the material back into the  air stream.  Of

these two mechanisms,  the resuspension of soil particles, with which

these nuclides have associated  in  one form or another, will be  the

principal mode of further environmental transport.  The resuspension  of

 soil particles occurs as a result of wind action and more

 intermittently as a result of mechanical forces; such as, plowing and

 vehicular disturbances.

      The size of the particle will determine its distance and mode of
 transport.  Particles with diameters greater than 1000 pm generally

 slide or roll along the surface (creep), while particles with diameters

 in the range of 50 pm to 1000 pm move in short hops along the surface,

 usually at a small distance from the surface (saltation).  The suspen-

 sion of particles is generally restricted to those below 50 pm,  which

 will be carried along with the air stream.

      2.3  Aqueous Transport

      Studies have been conducted on various  water bodies, streams,

 rivers,  lakes,  estuaries and  oceans to determine the final disposition

 of plutonium in these environs.   The following behaviors have been


           (1)   More  than 90%  of  the plutonium   becomes bound to
 suspended  sediments  and  carried  to  the sediment bed.

           (2)   Situations where  reducing  and complexing  agents are both
 present  can  lead  to  resolublization of the plutonium in  the sediment

           (3)   Seaweeds  generally have the ability  to concentrate plu-
 tonium with  concentration factors of ^ 1000.

           (4)   Benthic biota  can alter  the plutonium concentration
 profiles in  the sediment beds.

     Specifically, plutonium  oxide  exposed to an aqueous medium

undergoes slow dissolution, producing various complex ions  of plu-

tonium as well as polymers in colloidal form and the hydrous oxide as a

precipitate  (13).  In 1972 Langham  (16) studied the fate of PuO.

following the Thule incident and found that the majority of the

plutonium agglomerated into inactive debris with only about 1% suspended

as fine particulates in the water.  Further studies (17) after the Thule

incident showed 95% of the plutonium to be associated with the bottom

sediments to a depth of at least 10 cm.  In addition, a study (18) of

nuclear waste discharged into the Irish Sea from Windscale has found

most of the Pu-239 and Am-241 to be associated with the sediments close

to the discharge area.  Similar findings were observed (4) around Mound

Laboratory where plutonium was accidentally discharged into a freshwater

canal.  Again the plutonium was found to be largely associated with the

bottom sediments.  Therefore, although the movement of the transuranium

elements through aqueous systems is not yet well defined, the present

information available would indicate a limited mobility for environ-

mental transport via such systems.

3.   Exposure Pathways

     The principal hazard that arises as a consequence of soil being

contaminated with the transuranium elements is exposure to radiation

through the inhalation and ingestion pathways.

     For a detailed discussion of the entry of plutonium and other

actinides into animals and man and the resultant biological behavior,

the reader is referred to ICRP Publication 19 (19) and Annex III of this

document.  The following section will be limited to a description of

the environmental factors affecting the inhalation and ingestion


      3.1  Inhalation

      Inhalation exposures arise from direct injection of transuranium

 radionuclides into the atmosphere (e.g.,  normal emissions and accidental

 fires)  and also from the resuspension of  previously deposited material.

 For the latter pathway,  only a very small fraction of the material  on

 the surface actually becomes airborne and available to man.   In general,

 the respirable size is considered to be that range -of particles with

 aerodynamic diameters less than 10 urn.

      An assessment can be made,  using dosimetry models,  of the

 potential  health hazard  resulting from the inhalation of airborne

 particles.   Such a model requires knowledge of  the total airborne

 activity and of the activity median aerodynamic diameter associated with

 it.   (Aerodynamic  diameter is the diameter of a unit  density  sphere

 having  the same settling velocity as  the  particle  in  question of what-

 ever  shape and density.)   The assumption  made by most  dosimetry models

 is  that the aerosol distribution is  log normal  and can,  therefore, be

 described  through  the use of  two parameters  - the  activity median aero-

 dynamic diameter (AMAD)  and  the  geometric standard deviation  of the

 distribution, a .   The PAID  code used by  EPA (see  Annex  III)  assumes

 0   to be 1.5  and,  therefore,  only the AMAD of the  distribution need be


     In determining  the AMAD  of  the distribution,  care should be

 exercised  to  assure  that  the  entire distribution is being measured.

Aerosol sampling is  complicated  by  the fact  that every sampler  has its

own characteristic upper size cut-off, which depends on its entry shape,

dimensions, and flow rate.  When the aerosol being sampled contains

large particles with activity associated with them, the gross air

activity being measured may be underestimated.  Likewise, sampling

techniques may be biased against the smaller particle sizes.  If

particles from the resuspending soil have a disproportionate amount of

activity associated with them, the inhalation hazard could be under-

estimated.  Therefore, sampling should be conducted so that (1) the

total airborne distribution is being measured, and (2) the AMAD

determined actually describes the corresponding distribution of

airborne activity.

     Healy (20) and others (21) have emphasized the necessity of

considering the resuspension of soil by mechanisms other than normal

wind activity.  The possibility exists that other mechanisms could,

under certain circumstances, produce exposures exceeding those normally

received via the resuspension pathway.  Although this possibility has

been recognized, relatively little experimental data is currently avail-

able to determine quantitatively the importance of the many possible

secondary resuspension mechanisms.  Two commonly encountered disturb-

ances (agricultural operations and vehicular disturbance) have recently

been investigated, however, and some conclusions can be drawn from these


     For the agricultural situation, the vicinity of a field

contaminated over a period of twenty years was monitored.  Increase in

airborne activity was measured during such activities as plowing,


 disking, and planting (22).  During these operations, the air activity

 was found to increase by a factor of approximately 30 at the location of

 the tractor operator and by a factor of 6 at a distance 30 meters away

 from the edge of the field.  Assuming that these activities take place

 30 days of the year for 8 hours each day (i.e., -rr- of the year), it can

 be calculated that the average yearly air activity will increase by 80

 percent for the tractor operator and 10 percent for an individual in the

 vicinity of the field.   For the individual at the edge of the field,

 this is a conservative calculation,  since it is doubtful that any one

 individual would be standing at that location for the entire period of

 time.   Also,  this level  of increased air activity should occur for only

 the first year.   Subsequent agricultural activities should generate

 lower  air concentrations,  because the activity originally on the sur-

 face will be  diluted through mixing  with soil previously below it.

     The conclusion that can be drawn from such an analysis is that

 these  agricultural  operations would  pose an increased inhalation hazard

 to the vehicle operator  during  the first cultivation cycle,  and some

 protective action might  be  in order  during  that time.   Subsequent

 cultivation,  however, should  not lead  to significant increases in the

 inhalation hazard.   For  surrounding  areas,  no significant inhalation

 hazard  would  be  predicted during any of  these operations.

     Regarding vehicular disturbances, Sehmel (5) has  examined the

 importance of auto  and truck  traffic in  increasing  resuspension.  It

was concluded that  such  disturbances,  in the  case of an asphalt  surface

with newly deposited material, will lead to increased resuspension,

with a fraction resuspended of the order of 10~5 to 10~2 per vehicle

passage.  The higher rates occurred at speeds typical of freeway

driving; after the passage of about 100 cars only a small fraction of

the original contamination would remain on the road surface.  The

material resuspended from the road surface deposited on the ground at

various distances from the road and was again available for resuspen-

sion, but at a much lower rate.

     The potential for increased exposures from such situations will

depend upon many factors in addition to the quantity of contaminating

material, including the time of exposure, the frequency of vehicular

passage and the speeds, and the distance from the road to the receptor.

Based upon Sehmel's experiment, it can be expected that the integrated

inhalation exposure due to the vehicular disturbance will be smaller

than the chronic exposure received from just living within the generally

contaminated area.  The material deposited on the road surface will be

depleted quickly and, once it is removed from there, its resuspension

will be orders of magnitude lower.  Sehmel's results indicate that the

material transferred to the road parking strip resuspends at a rate only

one tenth of that on the road itself.  In addition, the total quantity

of material resuspending at the higher rate would be small relative to

the surrounding area; once redistributed over the larger area, it should

show little increase in the average air concentration.

      3.2  Ingestion

      Under normal circumstances, exposures via ingestion will arise from

 the consumption of crops and animals grown on land contaminated by the

 transuranium elements.  Studies to date have assessed the ingestion

 pathway from two directions.  Some studies have looked at the uptake

 factors for various plant species grown in contaminated soils, while

 others have measured the residual amounts of fallout plutonium in

 processed foods.

      Two recent publications (23,24)  have conveniently tabulated the

 results of the many uptake studies performed on plutonium and other

 transuranium elements.   These studies have shown plant and animal

 uptakes to be very small,  with the concentration in plants (fresh

 weight  basis)  being generally less than 10~  of that in dried soil

 and  the concentration  in animal  tissue (fresh weight)  being about

 10    of that  in the plants they  eat.   Preliminary studies  (23)  of

 transuranium  elements other than plutonium produced uptake factors

 somewhat  higher than comparable  studies with plutonium.   Some initial

 studies (25,26) seem to  indicate an increase in uptake with time,

 possibly  as a  result of  bacterial  action  or  increased  solubilization.

 The use of chelating agents  as a part  of  agricultural  practices may

 also  increase  the uptake of  the  transuranium elements  with time  (27).

     Measurements of plutonium in  "market basket"  food samples, in

which proportions of processed foods are  chosen  to  represent  the annual

 total diet, can be used  (28) as  indicators of the quantity of plutonium

ingested.  Such findings apply to a given soil contamination level when

all consumed food is grown on contaminated lands.  The methodology gives

an overestimate of activity ingested, because foods from other areas not

as highly contaminated will make up part of the diet.  These studies

have observed uptake factors for plutonium in the range of 10   plus

or minus an order of magnitude.  Based upon such uptake factors and food

consumption estimates, the annual estimated intake during 1972 of fall-

out plutonium was 1.6 pCi while the intake for 1965 was estimated to be

2.6 pCi.  There is no reason to believe that the uptake factors for

crops grown on land with concentrations higher than fallout levels

should vary significantly from those obtained through this "market

basket" sampling technique.  Some evidence indicates that americium is

concentrated in certain species of plants relative to plutonium.

However, preliminary analyses (29) of the "market basket" samples

indicate that the Am 241/Pu 239 ratios in diets are not greatly

different from current Am 241/Pu 239 ratios in soil.

     The ingestion of plutonium through drinking water is another

possible pathway to humans.  The concentration of fallout plutonium in

finished drinking water has been found (28) to be low (3 f Ci/Jl).

However, in areas of elevated levels, plutonium could migrate over-

time into cisterns and wells, thus increasing the activity in drinking

water.  Likewise, it has been suggested (20) that a significant inges-

tion pathway could be the accidental ingestion of contaminated  soil by

adults or the deliberate ingestion of soil by children.  However, for

this pathway to be as significant as the inhalation pathway, extreme

assumptions of soil consumption rates would be required because of the


  low uptake  factors and  short residence  time of plutonium in  the
  gastrointestinal tract.
  4.   Methods of Relating Soil Concentration to Airborne Activity
      The relationship between soil and  air concentrations is affected by
 many complex factors (see Table A 2-1).  Attempts to derive values for
 them have resulted in many different approaches; each uses different
 concepts and methods of measurement, selecting some physical factors as
 important and tending to neglect others or include them as constants.
 The purpose of this section is to describe briefly some of the more
 commonly used approaches to relate soil contamination levels to airborne
      4.1  Resuspension  Factor
      One of  the earliest and still most widely used  methods  of
 predicting the  relationship between soil and  air contamination is the
 resuspension factor.  It is defined as  the ratio of  the plutonium
 concentration in air, measured at  some  distance above the  ground,  to
 that of  plutonium in  the soil:

          K/m~l\ = concentration in  air  (activity/m  )           Eq.  1.
                   concentration in  soil (activity/m )

     The resuspension factor, however, does have  limitations  in its
application.  In the first place, it assumes that the air concentra-
tion above a contaminated surface is directly proportional to the
surface contamination level, rather than on the extent of ground con-
tamination upwind of the sampling site which is indeed the case.  In
the second place, the resuspension factor is an empirically determined


value which can be applied only to prevailing conditions at a given

site and at a given time.  Most resuspension experiments have been

conducted for a relatively short duration of time and do not neces-

sarily represent the long-term average situation for a particular area.

Finally, applying a resuspension factor derived at one particular site

to predict airborne contamination levels at another site would be a

questionable extrapolation.  However, for areas where the resuspension

factor has been measured over a period of time, sufficiently long to

average out the variability of the local meteorology, then this approach

can be useful in assessing the potential hazard from existing soil


     4.2  Mass Loading

     One attempt to increase the capability of predicting soil

resuspension has been the mass loading approach.  This technique

assumes the mass loading of the air with particulates to be an index of

resuspension and derives the airborne concentration of a specific radio-

nuclide by a comparison with its concentration on the adjacent surface.


     Air Concentration (fCi/m3) = Soil Concentration (yC1/m2) x

     Mass Loading (yg/m3) x C.F.*                               Eq. 2.

     Airborne particulate mass loading Is one of the criteria for clean

air standards and measurements are widely available for urban and

*  where C.F. is the units conversion factor based upon the depth of
   sampling and the soil density.

  nonurban locations  through  the  National Air  Surveillance Network  (NASN).

  The  data recorded at nonurban stations are a better indicator of  the

  levels  of resuspended material  than are urban measurements.  In general,

  annual  mean mass concentrations of airborne  particulate material  at the

  nonurban stations range from 5-50 micrograms per cubic meter (see Fig.

  A 2-2);  the mean arithmetic average for 1966 of all 30 nonurban NASN

  stations was 38 ng/m3^30\

      Anspaugh (30,31) employed this model to predict air concentrations

 at a number of sites.  Predicted values did not exceed measured values

 by more than a factor of roughly five (Table A 2-3).   This fallacy of

 the model is in assuming that the resuspendible fraction of the soil

 would carry with it  an equal fraction of  the activity, which implies

 essentially that:  1)  activity is distributed hpmogeneously in  the top

 soil and, 2)  activity exists independently of particle size.  For

 instance, if  the specific  ground activity  is  associated mostly  with

 particles of  size greater  than 50 ym,  a very  small  air concentration

 would result, although  the model would predict  the  same air concentra-

 tion  for this case as it would for all the activity being distributed

 among particles  of resuspendible size.  In either case the  model would

 fail.  Data obtained  (2,4,15) at sites of  present contamination have

 shown a  non-uniform distribution of activity  with particle  size,

 probably caused by such factors as:  1) the chemical form of the plu-

 tonium when released 2) the ion exchange capacity of the soil and

 3) the surface area of the soil particles.  It would seem reasonable,

however, that the error associated with using the mass loading

       .3°   20
         AIR SAMPLING NETWORK. 1964 - 1965

                  FIGURE A2-2

                               Table A  2-3
                         ANSPAUGH ET AL. (1974)]
                                                 Air Contentration
Location, etc.
GMX site. USAEC Nevada
Test Site
  NE, 1971-1972
  GZ, 1972, 2 weeks
Lawrence Livermore
7200 aCi/m"
 120 fCi/m3
6600 aCi/m"
  23 fCl/m3
Argonne National
Button, England
Predicted value is
10~4 g/m3.


equal to the soil

150 Pg/m3
150 pg/m3
150 pg/m3
1000 aCi/m

320 pg/m3
215 pg/m3
110 pg/m3

52 pg/m3
100 pg/m
86 pg/m3
3 980 aCi/m3

240 pg/m3
170 pg/m3
62 pg/m3
(activity/g) x
  Most values  are annual averages.

approach would be least for soils in which the contaminant has been

present for some time and in making predictions of average annual

air concentrations.

     4.3  Resuspension Rate and Other Approaches

     Other approaches of a more sophisticated nature have been

developed to describe the resuspension of particles from a soil

surface.  These approaches have attempted to include in their for-

mulations as parameters some of the physical forces which control

the resuspension phenomenon.  One such technique proposed by Healy

and Fuquay (32) is the resuspension rate approach.  This model

combines atmospheric transport and diffusion along with particle

resuspension to calculate airborne concentration.  This is achieved

by assuming that the rate of pickup of particles from a surface is

directly proportional to the ratio of wind forces to gravity forces

on individual particles.  Taking the wind force on a particle as

proportional to the square of the wind velocity and to the particle

area exposed to wind, the model develops a formulation for the resu-

spension rate, i.e., the rate at which particles will be resuspended

by wind from a* soil surface.  Once the resuspension rate has been

determined it can be used as the source term in a standard atmospheric

diffusion equation to predict the resultant air concentration at some

distance from the contaminated site.  Recently, Healy (20) has refined

the model formulations to be capable of handling various geometric

configurations of the contaminated area and the variability of surface

concentration within the contaminated area.  The advantages of a model

 of this type are that it recognizes some of the physical conditions

 and processes which affect resuspension as well as providing a method

 to calculate air concentration at various distances away from the

 contaminated area.

      One assumption by Healy in the original formulation of the

 resuspension rate model (20) was that the pickup rate for particles is

 a function of the square of the wind velocity.   Presently, studies are

 being conducted by Sehmel to establish the relationship between resu-

 spension rate and wind velocity.   One such study conducted by Sehmel

 (33)  at Rocky Flats,  for short time periods and for one sampling

 station,  found the air concentration to be a function of the square of

 the wind  velocity implying  that the pickup rate was a function of the

 cubic power of the  wind  speed.   However,  other  experiments by Sehmel

 (34)  have shown resuspension  rates  to  increase  with wlndspeed to the 6.5

 power.  Studies are continuing  to better  elucidate  this functional


      Other  approaches  (35,36) are also  under development which attempt

 to  relate particle  resuspension to  such factors  as  the  soil erodibility

 index,  surface  roughness factor, and quantity of vegetative cover-to

 mention just a  few.  These models generally require  the  determination  of

 several empirical constants in their formulation.  Although these

 constants may be applicable for the conditions under which  they have

been measured, the general applicability of these formulations in

predicting air concentration has not been demonstrated at this time.

5.   Derivation of the Screening Level for Soil

     A screening level for soil has been derived to minimize the  area

around a contaminated site which must be monitored as well as the number

of soil samples which must be collected and analyzed.  When the trans-

uranium activity in soil is at or below this concentration, it is highly

unlikely that the exposure levels recommended in this Guide will be

exceeded.  The screening level is not to be interpreted as a soil cleanup

standard to which all sites of transuranium contamination must be

decontaminated; instead, when correctly applied, it will identify land

areas where no additional monitoring is required.  Because of the con-

servative assumptions that have been incorporated into the calculation

of the screening level, it is anticipated that present and future

contaminated sites will not require cleanup to the screening level.

     The screening level was derived after careful consideration of all

currently contaminated sites, placing particular emphasis on areas for

which enough site-specific data is available covering factors as

particle size and soil activity distributions.  After examing these

data, a hypothetical site was defined with a combination of parameters

chosen to be conservative, i.e., to produce an acceptable level of

transuranium activity more restrictive than that which would be derived

for any of the existing sites.  This conservative approach has been

taken due to the uncertainties inherent in any calculational model,

and because of the limited experience with contamination by the trans-

uranium elements.  Sites of future contamination are also likely to have

site characteristics which would permit levels of contamination higher

than the screening level.


      Of the various models that have been suggested for relating soil

 contamination levels to airborne concentrations, the Agency has opted

 to use the mass loading approach in deriving a soil screening level.

 This approach has been shown (30,31) to provide some capability in

 predicting air concentrations on an annual basis at existing con-

 taminated sites and, since the objective of this Guidance is to

 relate soil contamination levels to annual dose levels, annual average

 air concentrations are required.  Additionally, since the screening

 level is a generic value with application at all sites, the Agency

 chose not to use one of the more sophisticated resuspension models

 requiring detailed site-specific parameters such as wind speed,  atmo-

 spheric stability class,  soil erodibility index,  etc.   In applying

 the mass loading model  to calculating a soil screening  level,  some

 modifications have been made, however,  in an effort to  overcome  some

 of the  shortcomings which are fundamental to the  approach and which

 were discussed earlier  (Sect. 4.2).

      5.1   Enrichment Factor

      In an effort  to take  into consideration the non-uniform

 distribution of activity with soil particle  size as well  as  the

 non-uniform resuspension of particle sizes,  the Agency  has derived

 an "enrichment factor" which is included  in  the mass loading

 calculation.  Potential exposure due to contaminated soil depends

 largely on the amount of activity associated with particles in the

respirable size range (generally < 10 ym).  It has been suggested by

Johnson (21) that sampling of only those particles in a soil sample

which are within the inhalable size range would give the best measure of

risk to the public health.  However, the weight fraction of particles in

the less than 10 ym range is small in most soils, and sampling, separa-

tion, and analysis techniques are correspondingly more difficult and

inaccurate.  There is also considerable evidence that some of the larger

particles really consist of aggregates and are relatively easily broken

down into smaller ones, so that an instantaneous measurement of a single

size range may not give a good picture of long-term trends.  Another

important objection to limited sampling is that larger particle sizes

may make a substantial contribution to other possible pathways (e.g.,

ingestion), and hence should be measured.

     To assess the potential hazard of the inhalable fraction of soils,

while retaining the advantages and convenience of analyzing the entire

soil sample, the Agency has modified the mass loading approach by use of

an "enrichment factor".  The proposed method weights the fraction of the

activity contained within the respirable range in terms of its deviation

from the activity to mass ratio for the entire sample and at  the same

time addresses the problem of the nonuniform resuspension of  particle

sizes mentioned in the previous section.

     The inhalable fraction of the soil is weighted by  considering  the

relative distribution of activity and soil mass  as a function of

particle size for representative samples of soil.  To accomplish this,

the sample of contaminated soil is segregated into size increments  and

the activity and mass contained within each size increment is

determined.  The factor g± is then defined as the ratio of the fraction


  of the total activity contained within increment i to the fraction of
  the total mass contained within that increment.   A value greater than 1
  for g± implies an enrichment of activity in relation to mass  within that
  incremental  fraction,  while  a value  less than 1  indicates a dilution of
  the activity with respect to mass.   For  gi  equal to 1,  the fraction of
  the activity and  the mass contained  with increment  i are the  same.
      The  nonuniform resuspension of  particle  sizes  must  also  be  con-
  sidered.   This  is achieved in the modification of the mass loading
  calculation by measuring  the mass loading as  a function  of particle
  size.  The fraction of the airborne mass contained within each size
  increment, i, is then calculated and designated as f  .   The factors of
 fi and g± can then be incorporated into the mass loading formulation as

   Air Concentration^^ = Air Mass  Loading xf±x Soil Concentration xg±    Eq.3.

 Summation over all the size increments results in the total air

      Air Concentration =  Air  Mass Loading x  Soil  Concentration
      X  I  fi*i                                                   Eq.4.
                The  term £  f g  weights  the contribution  of the
                           i1  X
Plutonium  from each soil size fraction  to the  total  resuspended material,
thereby taking into account both the nonuniform resuspension of particle
sizes as well as the nonhomogeneous distribution of activity.


For purposes of this guidance,  E f g.  will be referred to as the
                               i 1
"enrichment factor" where the f factor accounts for the distribution of

airborne mass as a function of particle size and the factor g accounts

for the variability of both soil activity and soil mass as a function of

particle size.

     5.2  Correction for Area Size

     Use of the mass loading approach implies that the air concentration

is at equilibrium with the ground surface, i.e., a steady state situa-

tion exists in which the amount of material coming up from the surface

is balanced by the amount of material depositing back onto the surface.

In the strictest since this limit can only be achieved for source areas

approaching infinite dimensions.  For source areas of finite dimensions

a fraction of the airborne mass loading can be arising from an uncon-

taminated area upwind which, although contributing dust  to the atmo-

spheric, contributes no radioactivity.  The smaller  the  size of the

contaminated area the less it will contribute  to  the mass  loading level

and the greater the uncertainties involved  in  applying the mass loading


     Healy  (37) has recently attempted  to quantify the relationship

between the size of the contaminated  area and  the air concentration

that would result  from it.  His calculations show that,  for a contam-

inated area which  is  50 meters  in horizontal depth,  the air concentra-

tion would be  approximately a  factor  of one hundred smaller than  from

an area 5000 meters in depth  (based upon certain  assumptions regarding

prevailing meteorology).   Obviously,  a correction for area size

becomes necessary when applying the mass loading  approach to small


  areas of contamination.

       In deriving the screening level for soil, the Agency has assumed

  the area contaminated to be sufficiently large that a correction for

  area size is not necessary.  It is recognized that this  is a con-

  servative assumption and that areas of  actual contamination will

  require a correction for area size;  however,  since one cannot predict

  a  priori the extent  of  a contamination  incident nor the  prevalent

  meteorology,  the  conservative case has  been assumed.-

       5-3  Calculation of  the  Screening  Level

       The following assumptions were made in deriving  the screening

  level:   1) the mass loading for the hypothetical site was  taken  to be
  100 pg/m  and to have a particle size distribution similar to that

  reported by Chepil (38) for resuspended dust, 2) the soil is enriched

 with activity in the respirable size range relative to the soil as a

 whole, 3) the contamination is widely dispersed and a correction for

 area size is not appropriate and 4) there are no restrictions as to

 land use.

      An annual average mass loading of 100  pg/m3 is higher than the

 annual average for any non-urban site reported by  the NASN (Fig.  A2-2)

 and is indicative  of  higher resuspension for  the hypothetical site.

 Anspaugh (30)  has  examined the data from the NASN  stations  and has

 concluded that 100 yg/m3  is a  sufficiently  conservative value to  use

 in mass  loading calculations.  This level of mass loading is  also

consistent with the value  of 120 pg/m3 arrived at by Healy  (20) in

proposing an interim standard  for plutonium in soil.   In addition,

100 yg/m  was considered to be a sufficiently conservative mass loading

value and was applied in assessing the potential inhalation hazard

from plutonium contamination around Mound Laboratory (4).

     The particle size distribution of the resuspended soil, for use

in calculating the screening level, is from Chepil's (38) data obtained

from fields undergoing wind erosion in Colorado and Kansas.  The

results of his findings have been plotted by Slinn (35) and adapted as

Figure A 2-3.  Comparision of Chepil's data with other studies sub-

stantiates the applicability of his results to other areas.  For

example, Chepil found 30% of the airborne mass to be below 10 ym

versus a study by Sehmel (39) around the Hanford site where 28% of the

mass was below 10 ym (under mass loading conditions of approximately
30 yg/m ) and a study by Willeke (40) in the area around Denver where

33% of the measured airborne mass was below 10 ym (mass loading

< 100 yg/m3).

     Currently, soil particle size and activity distribution data are

available for five sites with plutonium contamination:  Mound Labora-

tory, Oak Ridge National Laboratory, and the Nevada Test Site  (analyses

by Tamura [15]), and the Trinity Test Site and the Rocky Flats Plant

(analysis by the USEPA).  Of these sites, the greatest enrichment of

activity within the fine particle size range is found in samples from

the Rocky Flats area.  For this reason, the Rocky Flats soil distribu-

tion (see Table A 2-3) was used in calculating the screening level.

     Since the size of  the contaminated area varies greatly from site

to site, and because of the inability to predict the extent of future





                                                                           -10 S






                                                            I   I   I   I   I   I

                                                           30 40 60 60 70  80
      12    5   10   20  30 40  SO 60  70  80   90   95    9p  99



                            FIGURE A2-3

contaminated areas, no reduction for area size was incorporated into the

calculation of the screening level.  Likewise, the conservative assump-

tions of free access to the contaminated site with no limitations on

land usage were made in determining the screening level.

     Finally, the air concentration which corresponds to the pulmonary

                                               —15     3
dose rate limit of 1 mrad/yr is equal to 2.6x10    Ci/m .  This con-

centration was obtained from Table A 3-4 of Annex III by assuming an

activity median aerodynamic diameter of 1 urn.

     The above assumptions have been incorporated into the modified

mass loading formula (Eq. 4) and the screening level calculated as


   Screening Level (yC1/m2) = Air Concentration (fCi/m3)	   Eq. 5

                              Mass Loading (yg/m3) x I f±g± x C.F.*

   Screening Level (yCi/m2) = 2.6 fCi/m3	            Eq. 6

                              100 yg/m3 x 1.5x6.6xlO~2

   Screening Level = .26 yCi/m2                                    Eq. 7

     As discussed earlier, it is highly unlikely that any present or

future site would have a combination of site-specific factors which

would produce an acceptable soil concentration more restrictive than

*  C.F. is the units correction factor and is equal to 6.6x10   when

   a soil density of 1.5 g/cm3 is assumed for a 1 cm dry soil sample.

                                                       Table A 2-3

 RF 1A



Size Increment (pm)

Wet. Fract.

Act. Fract.

• V J






1 fl*l




av. 1.49
     'Sampling and analysis by USEPA, Office of Radiation Programs, Las Vegas Facility.

this screening level.  To illustrate this, the resuspension factor for
this hypothetical site can be calculated:

     R. F. (nf1) - 2.6xlO~15 Ci/m3                               Eq. 8
                   2.6xlO~7 Ci/m2

     R. F. - l.OxlO"8 m""1                                        Eq. 9

This value for the resuspension factor is a factor of 5-10 higher than
values reported for any of the existing sites.  Sites of future con-
tamination, after stabilization, should have resuspension factors no
higher than the present unstabilized sites and, therefore, the screening
level value has applicability to sites of future contamination as well.


 1.   H. M. Mork, Redistribution of Plutonium in the Environs of the
      Nevada Test Site. UCLA-12-590, University of California Press,
      Los Angeles (1970).

 2.   T. Tamura, "Distribution and Characterization of Plutonium in
      Soils from Nevada Test Site," in The Dynamics of Plutonium in
      Desert Environments. NVO-142, USAEC, Las Vegas, Nevada (1974).

 3.   K. Stewart, "The Resuspension of Particulate Material from Surfaces,"
      in jmrface Contamination. B.  R.  Fish (ed.),  Pergamon Press, New
      York, N.  Y. (1964),  pp. 63-64.

 4.   D. R. Rogers,  Mound Laboratory Environmental Plutonium Study 1974.
      .MLM-2249, Mound Laboratory (1975).

 5.   G. A. Sehmel,  "Particle Resuspension from an Asphalt Road Caused by
      Car and Truck  Traffic," Atm.  Env..  _7_,  P-  291 (1975).

 6.   W. H. Langham,  Biological Considerations  of  Nonnuclear Incidents
      Involving Nuclear Warheads. UCRL-50639,  Lawrence Livermore
      Laboratory (1969).

 7-   Environmental  Statement for LMFBR.  WASH-1535, Appendix 11.G,  USAEC,
      Washington, D.  C.  (1974).

 8.   B.  L.  Cohen, The  Hazards  in Plutonium  Dispersal.  GE2-6521,  General
      Electric  (1975).

 9.   J.  A.  Hayden,  "Characterization of  Environmental  Plutonium by
      Nuclear Track  Techniques," in  Atmospheric-Surface Exchange of Partic-
      ulate and Gaseous Pollutants.  CONF-740921, ERDA,  Washington,  D.  C.

 10.  M.  W.  Nathans, R. Reinhart, and W.  D. Holland,  "Methods of  Analysis
     Useful in the Study of Alpha-Emitting and Fissionable  Material
     Containing Particles,"  in Atmospheric-Surface Exchange of  Particlate
     and Gaseous Pollutants. CONF 740921, ERDA, Washington, D.  C.  (1974).

 11.  G. A.  Sehmel, "A Possible Explanation of Apparent Anomalous Airborne
     Concentration Profiles of Plutonium at Rocky Flats," Pacific
     Northwest Laboratory Annual Report for 1974. to the USAEC Division
     of Biomedical and Environmental Research. BNWL-1950, Pt. 3, Atmos.
     Sci., p.  221 (1975).

12.  M. W. Nathans,  The Size Distribution and Plutonium Concentration of
     Particles  from the Rocky Flats Area. TLW-6111. LFE Corporation (1972).

13.  J. H. Patterson, G. B.  Nelson, G.  M.  Matlock, The Dissolution of
     239Pu in Environmental and Biological Systems, LA 5624,  Los Alamos
     Laboratory (1974).

14.  M. Sakanoue and T.  Tsuji, "Plutonium Content of Soil at Nagasaki,"
     Nature. 234. p. 92 (1971).

15.  T. Tamura, "Physical and Chemical Characteristics of Plutonium in
     Existing Contaminated Soils and Sediments," in Proceedings of the
     International Symposium on Transuranium Nuclides in the Environ
     ment  (Nov. 1975),  IAEA, Vienna.

16.  W. H. Langham,  "Biological Implications of the Transuranium
     Elements for Man," Health Physics, 22_, p. 943  (1972).

17.  A. Aarkrog, "Radioecological  Investigation of Plutonium in an Artie
     Marine  Environment," Health Physics,  2(3, p.  30  (1971).

18.  A. Preston  and  N.  Mitchell, "Evaluation of Public Radiation
     Exposure from  the  Controlled  Marine  Disposal of  Radioactive
     Waste," in  Radioactive Contamination of the  Marine  Environment,
     IAEA STI/PUB/313,  International Atomic Energy Agency, Vienna,
     p. 575  (1973).

19.  ICRP Publication 19,  1972.  The Metabolism of Compounds of Plutonium
     and  Other Actinides,  Pergaman Press.

 20.  J. W. Healy,  A Proposed Interim Standard  for Plutonium in Soil,
     LA 5483-MS, Los Alamos Scientific Laboratory (1974).

 21.   C.  J. Johnson, R.  R.  Tidball, and R. C.  Severson, "Plutonium
      Hazard in Respirable Dust on the Surface of Soil," Science. 19_3,
      p.  488 (1976).

 22.   R.  C. Milham, J. F. Schubert, J.  R. Watts, A. L. Boni, and J. C.
      Corey, "Measured  Plutonium Resuspension and Resulting  Dose from
      Agricultural Operations on an Old Field at  the Savannah River
      Plant  in the Southeastern U. S.," in Proceedings of the Inter-
      national Symposium on Transuranium Nuclides  in  the  Environment,
       (Nov.  1975), IAEA, Vienna.

 23.  R. L.  Thomas and  J. W. Healy, An Apprasial  of Available Information
      on Uptake by Plants of Transplutonium Elements  and  Neptunium.
      LA  6460-MS, Los Alamos Scientific Laboratory (1976).

 24.  R.  A.  Bulman,  Concentration  of Actinides  in the Food Chain.  NRPB-R44,
      National Radiological Protection Board, Harwell, England  (1976).

 25.   E.  M.  Romney,  H.  M.  Mark,  and K. H. Larson, "Persistence  of
       Plutonium  in Soil, Plants, and Small Mammals," Health  Physics, 19^.
       p.  487 (1970).

 26.   P.  Neubold,  Absorption of  Plutonium-239  by  Plants. ARCRL-8,
      St.  Brit.  Agr.  Res.  Council  (1962).

 27.   W.  V.  Lipton and A.  S.  Goldin,  "Some  Factors  Influencing  the Uptake
      of  Plutonium-239 by  Pea Plants,"  Health  Physics.  31, p.425  (1976).

 28.   B.  G.  Bennett,  "Environmental Pathways of Transuranic  Elements,"
      in  Proceedings  of  Public Hearings;  Phttonium and the  Other
      Transuranium Elements.  Vol.  1,  ORP-CSD-75-1,  USEPA, Washington,
      D.C.,  (1974).

 29.   B.  G.  Bennett,  private  communication.

 30.   L.  R.  Anspaugh, "The Use of  NTS DATA  and Experience to Predict
      Air Concentration  of Plutonium  Due to Resuspension on  the Enewetak
      Atoll," in The  Dynamics  of Plutonium  in  Desert Environment,
      NVO-142, USAEC, Las  Vegas, Nevada (1974).

 31.   L.  R.  Anspaugh, J. H. Slinn, D. W. Wilson,  "Evaluation of the
      Resuspension  Pathway Toward  Protection Guidelines for  Soil Con-
      tamination with Radioactivity," in Proceedings of the  Inter-
      national Symposium on Transuranium Nuclides in the Environment
      (Nov.  1975),  IAEA, Vienna.

 32.   J. W.  Healy and J. J. Fuquay, "Wind Pickup' of Radioactive Particles
      from the Ground,"  Progress in Nuclear Energy  Series XII,  Health
      Physics. V.I, Pergamon Press, Oxford, (1959).

 33.   G. A.  Sehmel atid M. M. Orgill,  "Resuspension by Wind at Rocky
      Flats," Annual Report for 1972. BNWL-1751, pt. 1, Battelle Pacific
      Northwest  Laboratory, Richland  (1973).

 34.   G. A.  Sehmel and F. D. Lloyd, "Particle Resuspension Rates" in
      Atmospheric-Surface  Exchange of Particulate and Gaseous Pollutants,
      CONF 740921, ERDA, Washington,  D.C.,  (1974).

 35.   W. G.  N. Slinn, "Dry Deposition and Resuspension of Aerosol
      Particles  - A New Look at Some  Old Problems," ibid.

 36.   J. H.  Shinn, N. C. Kennedy, J.  S. Koval, B. R. Clegg,  and
     W. M. Porch, "Observations of Dust Flux in the Surface Boundary
     Layer for  Steady and Non-Steady Cases," ibid.

37.  J. W. Healy, An Examination of  the Pathways from Soil  to Man for
     Plutonium.  LA-6741-MS, Los Alamos Scientific Laboratory (1977).

38.  W. S. Chepil, "Sedimentary Characteristic of Dust Storms:  III
     Composition of Suspended Dust," Am.  J_. Sci., 225, p.  206  (1957).

39.  G. A. Sehmel, Radioactive Particle Resuspension Research Experi-
     ments on the Hanford Reservation. BNWL-2081, Battelle Pacific
     Northwest Laboratory, Richland (1977).

40.  K. Willeke, K. Whitby, W. Clark, and V. Marple, "Size Distribu-
     tion of Denver Aerosols-A Comparison of Two Sites," Atm. Env.,
     8, p. 609 (1974).

                    Annex III


      U. S. Environmental Protection Agency
          Office of Radiation Programs
             Washington, D.C.  20460

3.1        Introduction
3.2        Risks
3.3        Exposure Pathways
3.4        Dosimetry of Inhaled and Ingested Plutonium,  Americaurn, and
3.1.1      The Dose to Lung Tissues
3.4.2      The Dose to Bone, Liver, and the Total Body
3.4.3      The Dose to Gonadal Tissue
3.4.4      Dose Models for the Ingestion Pathway
3.5        The Risk of Lung Cancer from Inhaled Transuranics
3.6        The Risk of Bone Cancer
3.6.1      Inhalation Risk Estimates
3.6.2      .Ingestion Risk Estimates
3.7        The Risk of Inducing Cancer of the Liver
3.7.1      Inhalation Risk Estimates
3.7.2      Inyestion Risk Estimates
3.8        The Risk of Genetic Damage
3.8.1      Genetic Risk Estimates
3.9        Other Risks Due to the Inhalation and Ingestion of
3.9.1      Leukemia due to Bone Marrow Irradiation
3.10       Summary of Health Risks
3.10.1     Inhalation Pathway
3.10.2     Ingestion Pathway

                               Annex 3
                The Dose and Risk to Health Due to the
          Inhalation and Ingestion of Transuranium Nuclides
                             May 23, 1977
     The purpose of this -chapter is to outline the methods recommended
by the Agency to estimate the dose and potential health effects from
some of the transuranium elements in the environment.  An attempt has
been made to balance the discussion between scientific details and
understandability by laymen.  Where it is impossible to satisfy both
needs, the documentation cited should supply more details for the
interested reader.
     Information on the biological properties of transuranium elements
is reviewed in "Selected Topics: Plutonium in the Environment" which
includes an extensive bibliography (1) .  The amount known about the
metabolisms of each of the transuranic elements varies depending on
their commercial importance as well as other factors.  Considerable
information is available on the distribution of plutonium in most
human tissues, the gonads being a notable exception.  The biological
data base for the dosimetry of americium and curium is not as
extensive, which limits the accuracy of estimates of the dose due to
these radionuclides.
3.2. Risks
     Although much information is available on the somatic effects of
Plutonium inhalation and ingestion by laboratory animals, no relevant
epidemiological information is available on the effects of plutonium

or other transuranium elements on humans via these exposure pathways
(1).  When human data is available, the Environmental Protection
Agency prefers to base estimates of health risk due to radiation on
the results of human epidemiological studies rather than animal
experiments.  To derive estimates of the cancer risk due to plutonium
and other transuranium elements, the Agency relies on human experience
with other alpha particle emitters.  (In a few cases transuranics emit
radiation other than alpha particles but such emissions make
relatively unimportant contributions to the dose.)  Estimates of
genetic risk are not based directly on human studies.  Assumed
doubling doses for genetic injury are based almost exclusively on
irradiated animal populations.
     Data oh human experience following alpha particle irradiation is
largely confined to occupational and medical exposures.  The Agency's
chief reference documents for the effects of ionizing radiation on
health is the 1972 BEIR Report prepared by the National Academy of
Sciences (2), and the NAS Report, "Health Effects of Alpha-Emitting
Particles in the Respiratory Tract" (3), the latter document being used
to estimate lung cancer risk.  Following the procedure used by the
BEIR Committee in arriving at its "best estimate" of radiation risk,
it is the practice of the Agency to average results obtained by the
two types of risk models utilized in the NAS-BEIR Report (2), absolute*
»Probability of cancer per organ rad.

and relative risk*, respectively.  These two models can yield results
differing by as much as a factor of about seven depending on the
particular cancer being considered, duration of risk following
exposure, etc. (2).  Therefore, in addition to other uncertainties in
the risk estimates there is a residual uncertainty of a factor of
three or more in the average of the risk estimates listed below,
depending pn which of these models is appropriate for a particular
organ system.
     The Agency*s risk estimates are based on an assumed linear
relationship between dose and the probability that a cancer is
induced.  No threshold dose for effects is hypothesized and no
allowance is made for enhanced or reduced effects due to the
relatively low dose and dose rates realized from alpha particle
exposures.  It should be noted that the Agency does not consider the
risks due to ionizing radiation hypothetical and that for highly
ionizing radiation such as alpha particles from plutonium, the linear
non-threshold hypothesis is unlikely to overestimate the actual risks.
     In the case of estimating genetic risks, the overall uncertainty
is larger than for estimating the risk of cancer induction.  The
NAS-BEIR Committee report (2) indicates that this uncertainty has two
components: an estimated uncertainty of a factor of ten in the dose
required to double the human mutation rate and for common diseases
*Percent increase of cancer per organ rad.

thought to have a invitational  component, an additional  uncertainty of a
factor of ten.  Obviously,  only a broadly defined  range  of genetic
risk  due to transuranium radionuclides can be estimated  at the present
      Risk estimates  for  ionizing radiation are often expressed in
terms of the rem, a  unit ~of dose equivalence used  in radiation
protection practice  to provide  at least some degree of equality
between the biological damage produced by different kinds of
radiation.  Since this guidance is limited to alpha particle emitters,
both  dose and risk estimates are expressed in a more fundamental
physical unit, the rad,  the specific energy imparted.  The advantages
of this approach are that it is more straightforward and that the
guidance will not need periodic revision to account for differences
between various kinds of radiation that may be proposed.  Future
information on health effects will, however, be factored into these
guides as the need arises.
     An air concentration yielding 1 mrad per annum to adults will
result in children receiving a  somewhat larger dose rate.  The dose
rate to children cannot be calculated as accurately as for adults
because the necessary lung model parameters are not known.  As a first
approximation to the dose rate as a function of age, the reduced
breathing rate (minute volume) and smaller organ mass of children have
been Used to estimate their increased annual dose.   This provides a
conservative estimate of childhood dose since deposition and retention
in the lung should be less for children due to their smaller lung

area.  A more detailed treatment of the dose to children is not likely
to result in appreciable difference in the risk since most of a
person's body burden is accumulated during adult life, not childhood.
     Specific information on the carcinogenic effects of alpha
particle or other highly ionizing radiations on children's lungs is
not available.  No lung cancer deaths have been reported as yet in
children irradiated at Hiroshima.  Nevertheless, as mentioned in
sections 3.5 and 3.6f the risk estimate of excess lung and liver
cancer mortality allow for observed differences in the
radiosensitivity of children and adults, based on data for other
radiogenic cancers (2).  In the case of lung cancer, these differences
have a large effect on the estimated risks.  Estimates based on the
BEIR absolute risk model include an assumption that children are less
sensitive to radiation than adults.  Estimates based on the relative
risk model assume children are ten times more sensitive.
Unfortunately, there is paucity of information which can lead to a
choice between these two models on scientific grounds.  It should be
noted that the Agency's use of a logarithmic averaging of the results
obtained by the absolute and relative risk models results in a bias in
favor of the former.   However other assumptions in the risk model are
somewhat conservative so that on balance it is unlikely that the true
risks are not underestimated.

     In general, the most important pathway for human exposure from
Plutonium oxide and other transuranium radionuclides in the
environment is expected to be inhalation.  This route provides a
direct pathway for alpha particles to enter a sensitive organ, the
pulmonary lung.  Subsequently, a fraction of the inhaled material is
redistributed via the blood to such important organs as the bone,
liver and gonadal tissues.  This is in contrast to the ingestion
pathway, where the gut walls act as a barrier to plutonium absorption
by blood.  The dose to the gut wall itself is not a major cause of
concern because, unlike other radiations, plutonium alpha particles
have a short.finite range in tissue, «1 microns (u) , i.e., less than
two-thousandths of an inch.  Radiosensitive dividing cells in the qut
wall are over 100 u distant from the gut contents and are effectively
isolated from the alpha radiation.
     The dose to various tissues from inhaled plutonium is highly time
dependent.  Insoluble materials deposited in the pulmonary lung are
removed fairly rapidly; half is assumed to be cleared within 500 days.
Clearance from other organs is much slower; the estimated biological
half-life* in the liver is assumed to be 40 years, and in the case of
bone, 100 years (U).  The dose delivered to an organ is directly
related to the residence time of the radioactive material.  Following
»The -time required to eliminate one-half of the initial organ burden.

a single acute exposure to airborne plutonium, the lung (pulmonary)
dose rate decreases due to the clearance of particles from the lunar  so
that almost all of the dose is received in a few years.  In contrast,
the dose rates to the liver and bone are relatively constant over this
time span.
     In the case of chronic environmental contamination leading to a
constant annual intake, the temporal pattern of the dose rate to
various organs due to inhalation is different.  For pulmonary tissues,
a constant (eguiliorium)  dose rate is realized within a relatively few
years of the start of exposure.  The dose rate to liver increases more
slowly and does not equal that to lung tissue until after about 70
years of exposure.  The dose rate to bone never approaches that in the
lung and liver (Figure A3-1).  Therefore, the total risk from chronic
inhalation will vary with the duration of exposure.  In setting guides
for the dose due to inhalation, the Agency has selected the annual
dose rate to Jtung  (pulmonary tissue) as the appropriate limit.  This
choice is warranted because administrative controls for the inhalation
pathway can be more easily instituted on the basis of  an annual dose
limit to lung rather than a lifetime dose limit for lung and other
tissues.  This does not mean the risks from exposure to organs other
than lung have been overlooked.  The estimates of the  total risk from
inhaled radionuclides of transuranium elements made below account for
the dose to all important organ systems and are, necessarily, a
function of the duration of exposure so as to reflect  the varying dose
rate for liver and bone shown in Figure A3-1.  For highly insoluble

transuranics, the additional risks due to liver and bone irradiation
due to inhalation are believed to be small compared to the risk of
lung cancer, as outlined below.
     Use of lands contaminated with low concentrations of plutonium or
other transuranium radionuclides are expected to be strictly
controlled, unless the resulting doses are below the level specified
in this guidance.  Uncontrolled land utilization implies that such
ordinary uses of land as farming, residency, industrial use, etc. are
not precluded.  All of these activities and particularly residential
use could lead to exposures extending over several decades and in some
cases lifetime exposure.  In the section below, the lung cancer risk
from plutonium inhalation is calculated on the basis of an annual
limiting dose rate of one mrad per annum occurring throughout a
persons life.   In many cases of environmental contamination, the
concentration of plutonium in air would be expected to decrease with
time so that the life time dose, and risk, would be smaller.
3.4.1  The Dose to Lung Tissues
     Dosimetric models for projecting the average distribution of
ionizing radiation within body organs due to the inhalation of
radioactive aerosols are still somewhat crude (1).  The most promising
general model  is diat developed and published in ICRP Report f!9, "The
Metabolism of  Compounds of Plutonium and Other Actinides" (4) , as an
amended version of a model developed earlier for the ICRP (5).  In

general, ICRP report 119 is the basis for the estimates of dose made
in this section.  Where it has been supplemented by more recent data,
specific reference is made.  Since the inhalation model is documented
in ICRP §19 <«)  and in reference 5, only its basic outline is
described here.
     Inhaled aerosols are considered on the basis of particle size and
other aerodynamic parameters.  The fraction of inhaled materials
initially retained or exhaled, and the deposition in various portions
of the respiratory tract, is a given function of a particle's activity
median aerodynamic diameter  (AMAD).  The physiological parameters used
in this study were taken from reference 5.  A diagram of the ICRP Task
Group Lung Model is shown in Figure A3-2.  The rate at which deposited
material is removed from the lungs is considered to be a function only
of the chemical state of the inhaled material, and not of size or
radioactive' content.  Environmental sources of plutonium and other
transuranium elements are likely to be in the oxide or hydroxide form.
Actinides in either form are currently classified as Class Y
 (insoluble) materials by the ICRP (U).  Such materials take years to
be cleared from the lung; their estimated biological half life in
pulmonary tissue being 500 days  (4).  The dose estimates made below
apply only to Class Y compounds.  Dose estimates for the inhalation of
more soluble. Class W, materials are given in reference 6.  The
breathing rate, retention half-time and fraction of material handled
by the various elimination pathways for relatively insoluble material
deposited in the lung that are assumed in this model are shown in

Table  A3-1, from  ICRP  §19  (U).  A  critique of the ICRP model is
included  in  (1) .
     In assessing the  dose and risk due to the inhalation of
transuranium elements  only retention in the pulmonary region is of
primary importance.  Residence time of inhaled materials in the
nasopharyngeal  and tracheobronchial regions is short compared to that
in pulmonary tissues.
     Radioactivity is  assumed to leave the pulmonary tissues by three
routes: elevation up the tracheobronchial tree via the mucus elevator
into the gut by way of the esophagus and stomach, transport of
particulate materials  into the lymphatic system and lymph nodes anci
most important by dissolution into the blood stream.  Most of the
activity in blood is redeposited into the liver and bone.
     The dose to different organs  from inhaled aerosols of various
sizes has been considered by a number of workers who have written
computer codes to quantify the ICRP model (7,9).  Since the ICRP model
is not described in the form of unambigious equations, there are minor
differences between the results obtained with various codes.  The EPA
code PAID (9)  has been used to calculate the annual dose rates due to
isotopes of plutonium, americium, and curium for a number of particle
sizes.  Typical results tor five micron, one micron, and five
one-hundredths micron, AMAD plutonium-239 aerosols (1 fCi/m3)  are
shown in Table A3-2 for the various compartments in the lung for the
case of lifetime exposure (70 years).  It is seen from the Table that
most of the radiation insult is delivered to pulmonary tissue.  Given


equal concentrations in air, the dose to the pulmonary lung is not
very sensitive to particle size.  For example,  the size range from
0.05 to 5.0 micron (AMAD), the pulmonary dose decreases by a factor of
about five, as shown in Figure A3-3.
     Doses calculated by the PAID code are obtained by averaging the
energy deposited by alpha particles throughout the entire organ mass
(570 grams in the case of pulmonary tissues) (10).  While some have
argued (11) that the energy imparted from deposited aerosols should
not be averaged in such a manner, current scientific opinion holds
that it is a sufficiently conservative.way to estimate the radiation
damage even though some cells receive more or less dose than the
average for all cells  (3) .
     The ICRP model assumes that 10% of the radioactive material
transferred to the. lymph nodes from pulmonary lung is retained
permanently, and 90* is retained for a half time of 1000 days before
being released as soluble material into the bloodstream.  As a result,
the dose rate to these nodes is high compared to that received by
pulmonary tissue, as shown in Table A3-3.  This is not believed to be
an important consideration in estimating risk, since the frequency of
radiation induced cancers in respiratory lymph nodes appears to be
very small if not zero.  Prom animal studies, it  is certain that  this
risk is small compared to the frequency of radiogenic cancers  at  other
sites  (12,13).

bone is from material in the lungs and lymph nodes that has been
dissolved and transferred via the blood.  Transfer to blood of
swallowed materials is much less important.  For example, depending on
particle size, only 0.06X to 0.35% of the annual dose to bone shown in
Table A3-3 is due to inhaled plutonium oxide crossing the gut wall.
     Lifetime dose rates ^for plutonium-238, plutonium-239,
Plutonium-240, and the two member radionuclide chains, Pu-24I/Am-241,
Am-241/Np-237, and Cm-244/Pu-240 have been calculated to aid
implementation of this guidance (6, 9) .  Table A3-4 lists the
concentration in air of transuranium element aerosols that should
deliver an annual alpha dose rate ot one mrad per year to adult
pulmonary tissues.  Particle sizes in Table A3-4 range from 0.05 u to
5u.(AMAO) .  Over this range of particle sizes the limiting
concentrations varies by a factor of about five.
3.4.3.  The Dose to Gonadal Tissue
     The degree to which transuranium elements are translocated from
human blood to gonadal tissues is not well known due to the analytical
difficulty of making reasonably precise measurements at the low
activity levels usually involved, and the high variability between
various individuals.  Besides limited information from studies of
laboratory animals, there are three sources of post-mortem human data;
the general population exposed to fallout plutonium, industrially
exposed radiation workers, and a few clinical studies with hospital
patients.   Richmond and Thomas reported that for the five animal
species considered in their 1974 review, an average of 0.03* of the


Plutonium in blood was  transferred  to gonadal tissue  (15).  The data
on which this average is based  varied by  a  factor of  about ten.  A
review of clinical data, based  on only  four persons,  also leads to an
estimate of about .03%  for  transfer from  blood to gonadal tissue  (1U).
     The Medical Research Council  (MRC) also reviewed this problem in
their 1975 analysis of  plutonium toxicity and concluded  that 0.05* of
the plutonium in blood  would be transferred to gonadal tissue  (16).
Since the mass of the ovary is  11 grams,  the MRC estimate on transfer
from blood is equivalent to 0.005*  per  gram of o*'ary.  The mass of
testes is greater than  that of  the  ovary  by a factor  of  about  3.  The
MRC assumed equal quantities of plutonium in each, so that the
concentration (percent  per  gram) in the testes would  be  about
one-third of that in ovarian tissue i.e., 0.002% per  gram.  Richmond
and Thomas estimated that the amount of plutonium in  the smaller
female gonad was a factor of five to ten  less than males, a somewhat
less conservative assumption.   Recent data  reported for  plutonium in
beagle gonads indicates that the concentration per gram  is about
0.0055% in ovaries and  0.0012%  in testes  which supports  the MRC
viewpoint (17).
     For calculational  purposes it  is convient to relate concentration
per gram of transuranics in gonodal tissue  to that in bone.  According
to the ICRP model, 0.09% of the plutonium in blood is concentrated in
one gram of bone (4).  Based on the MRC study and the results  cited
above this is about twice the concentration (% per gram) of plutonium
in the female gonads; and for testes .about  five times greater.


Autoradiographic studies in mouse testes indicate that because of the
deposition of plutonium near the spermatogonial stem cells, the
effective dose to these cells is about 2 to 3 times greater than that
to the testes as a whole.  (No comparable study of the pattern of
deposition for the ovary has been reported).  To account for this
factor, it is assumed that the effective genetic dose due to
transuranium elements in male gonads will be the same as in the
     The turnover rate of transuranium elements in gonadal tissues is
known to be small compared to that of other soft tissues (H, 18, 19).
For these calculations the biological half-life in gonadal tissue is
assumed to be the same as in bone, 100 years.  As in bone, the buildup
of transuranium elements in gonadal tissue will occur rather slowly in
the case of chronic ingestion or inhalation.  The significant gonadal
dose in terms of genetic risk is that received during the first 30
years of life (1).  From Figure A3-1 it is seen that the dose rate to
gonadal tissue* over a 30-year period is considerably less than that
received by pulmonary tissue.  For an equilibrium pulmonary dose rate
of 1 mrad per year, the dose to gonadal tissue in the first 30 years
of life is calculated to be 1.4. mrad (15).  The dose to gonads and
other organs due to ingestion is considered below.

3.4.1.  Dose Models  for the  Ingestion Pathway
     The magnitude of calculated  doses due to the ingestion of
transuranic materials is directly proportional to the fraction of the
ingested material that is assumed to cross the gut wall and enter the
blood stream.  This  fraction  is not well known and it is reasonable to
assume that it varies considerably depending on the solubility of the
ingested material.  Animal experiments to measure gut transfer that
have used highly insoluble laboratory prepared materials in the oxide
form yield transfers in the parts per million range (U).  However,
Plutonium oxide found in the  environment has been shown to be much
more soluble than the refractory  oxides utilized in animal experiments
(20) .  This is in agreement with  recent experiments showing plutonium
oxides formed at low temeratures  are more soluble than those formed at
high temperatures (21) .  Therefore it is reasonable to assume that
Plutonium oxidized in the environment will not be as in soluble as the
materials whioh have been used to determine plutonium gut transfer in
animals.  Moreover, because the quantitative applicability of animal
data to man is unknown, conservative estimates that will not
underestimate the dose to humans  are required.  Information on the
transfer of transuranium elements across the gut wall, as reported in
references U and 22 as well as in the reports of more recent studies
(23, 2U, 25, 26)  were reviewed and the transfer coefficients shown in
Table A3-5 adopted for use in the dose calculations for this Guidance.
The fractional transfers listed are much higher than currently assumed

by the ICRP (4)  and are thought to be conservative estimates
applicable to public health problems.
     The degree of conservatism in these transfer fractions varies
depending on how much is known about a particular material, more
conservatism being applied to materials for which information is less
available.  The lowest transfer, 10-*, is assumed to occur for low
specific activity plutonium oxides, which have been utilized in many
experimental situations with several species.  Oxides of some of the
other transuranium elements may behave similarly but have been studied
less extensively.  Transuranium elements in non oxide form, and the
oxide of high specific activity transuranium elements such as Pu-238,
are somewhat more soluble than plutonium-239 oxide.  Present evidence
indicates the transfer to blood may increase by an order of magnitude
or even more if the element is incorporated into organic materials
 (1).  It should be noted that the  fractions listed in Table A3-5  are
applicable to adults and children  over one year of age.  The special
case of infants is discussed in Section 3.6.
     The estimates shown in Table  A3-5 have been used in the dose
calculations described below.  Most  of the plutonium-239 and
plutonium-2to in  the environment is  assumed  to be  in the oxide  form.
Dose calculations for these radionuclides assume one pCi in 10* pci
 ingested  is transferred to blood;  for all other transuranium elements;
ten pCi per 10* pCi  ingested.  No  allowance  was made for transuranium
 elements  "biologically" incorporated into ingested materials.   This is
assumed to happen when  transuranium elements are  incorporated into


 plant and animal tissues at the molecular level in contrast to the
 surface contamination of foodstuffs.   Where the fraction of such
 material in the diet can be estimated, the dose estimates made below
 should be increased in proportion to  the increased amount transferred
 to blood.  For example, if 10X is incorporated into biological
 material, the dose (and risk)  would be increased by 40%.
      Subsequent to their transfer across the gut wall,  ingested
 radionuclides enter the blood  stream  and are deposited  primarily in
 liver and bone and to a lesser extent gonadal tissue, as  outlined
 above in the description of  the lung  model.   As stated  in Section 3.2,
 the dose to the intestinal walls is not  considered in this analysis
 because of the low likelihood  of alpha particle penetration to
 sensitive cells in  the  intestines.  An ICRP  Task Group  has suggested,
 as  surrogate for information on the dose to  dividing cells,  that
 calculations  of maximum permissible concentration of transuranium
 elements in  air and water  be based  on  the assumption that IX of  the
 alpha energy  is  absorbed  (27,28).   However,  this  is highly unrealistic
 for the  purpose  of  predicting health effects and  is not used here.
     The  transfer factors  from  gut  to blood  shown in Table A3-5  have
 been utilized to calculate annual dose rates as  functions of the
 duration of ingestion.  Dose rates  to bone, liver, and the total body
 of reference man (10) due  to the chronic ingestion of 1000 pCi/annum
 of plutonium-239 oxide, americium-241, and curium-2f» are shown  in
Table A3-6.  Pu-241, half  life  14.8 years, and Cm-244, half  life  17.9
 years, are the most rapidly decaying transuranium elements capable of


causing chronic exposures in a contaminated environment.  Because of
their short half lives, the occurrence of lifetime ingestion of these
radionuclides is remote.  This is even more true of curium-212, half
life 0.45 years, where only acute intake is a plausible mode of
     The dose rate to bone in the 70th year due to a constant rate of
ingestion of 10 nCi per year are listed in Table A3-7 for a number of
transuranium elements.  To determine if the bone dose limit is being
exceeded, the total dose rate due to the ingestion of a combination of
transuranium elements can be calculated from these data.
     Table A3-8 lists the cumulative 30-year dose to gonadal tissue
due to the chronic ingestion of several transuranium elements at an
annual intake of 1000 pCi per year.  The gonadal dose has been
calculated as described above in Section 3.4.3.
     The organ dose rates listed in Table A3-6 were calculated on the
basis of organ masses appropriate for reference man, not children.
However, there is enough proportionality between food intake and organ
mass as a function of age so that the results are applicable to a
lifetime exposure situation.  Because there is some evidence from
animal studies that the newborn have a particularly high transfer of
transuranium elements across the gut walj. to blood, the transfer
fractions listed in Table A3-5 may not be applicable to infants,  (less
than one year old) .  The duration of this increased transfer is
unknown for humans, perhaps a few weeks or considerably longer.  To
test for what effect this may have on lifetime doses, it has been


 assumed  below that the GI tract to blood  transfer factor during the
 first year of life is one hundred times greater than the value shown
 in  Table A3-5,  i.e.,  10~2 in the case of  plutonium oxide (26).  Any
 increased  transfer due to the incorporation  of  the plutonium  into  food
 is  included in this factor of 100.
      Ingestion of  contaminated food by infants  would cause  a  large
 initial  dose rate  to  body organs.   After  the first year,  the  dose rate
 decreases  due to organ growth,  and  possibly  a more rapid turnover rate
 of  minerals  in  infant  bone compared to adults.   However,  because
 turnover rates  for children are poorly known, this factor has not been
 included in  calculating the skeletal  dose.   As  an example of  enhanced
 transfer of  radioactivity across the  infant  gut.  Table A3-9 compares
 the skeletal  dose  rates when transfer is  increased by a  factor of 100
 in  the first year  of life with  the  dose rate, pattern  to  refernce man.
 Increased dose rate during the  first  year of life has less effect on
 lifetime dose rates than  might  be expected.   Risk analyses of the type
 outlined in Section 3.6 indicate that the dose  pattern shown  for
 enhanced transfer  in Table  3.9  would  result  in  50% more bone  cancers
 than are estimated below,  for reference man.
     Because infant feeding  in  the  U.S. relies  heavily on a variety of
 non-local foods, it is unrealistic  to  assume that  100* of the first
 year's intake would be produced  only  in contaminated  areas.   A
 possible exception, milk, would  be  less contaminated  than other
 locally produced food stuffs because the transfer  of  most transuranium
elements into milk  (animal)  following ingestion of the radioisotope is


only about 0.0001 percent per liter (29, 30).   Transfer of americium
and curium to milk is about 100 times greater than other transuranium
elements (31)  but is still small.
     In most cases, the lung is the organ of primary concern when
assessing the risks from plutonium and other transuranium elements in
soil.  Animal studies, particularly those with dogs (15), which have a
relatively long life span, indicate that lung cancer can result from
inhaled plutonium aerosols as do extensive experiments with rats (32).
Even so, the assessment of the risk to humans cannot be directly
inferred from animal evidence.  Almost all lung cancers in dogs
exposed to plutonium occur in a different location than radiogenic
cancers in humans following exposure to radon daughters.  The animal
cancers are in the peripheral parts of the lung and often of different
cell types than human lung cancers.  They are histologically
classified as 'bronchiolar-alveolar carcinomas (a type of
adenocarcinoma) (3).  In humans, the inhalation of alpha particle
emitters (but not transuranium elements) has usually resulted in
bronchial cancers (hilar bronchogenic carcinomas).  These are
primarily epidermoid and anaplastic carcinomas, but include some
adenocarcinomas.  Cancers histologically similar to those in animals
(peripheral adenocarcinomas)  are found much less frequently  (3) .  This
difference may be due to differing exposure conditions but must, in
part, be due to differences in tissue sensitivity between species (3).

      Some insight into this problem is obtained by considering the
 type  of  cancers resulting from highly ionizing radiation that have
 occurred in  survivors  of the Hiroshima bombing.   Examination of these
 data  show that,  even though the dose to the pulmonary lung must have
 been  higher  than that  delivered to the bronchi (33),  the significant
 increases in observed  cancer occurred in the bronchi  rather than in
 the region of higher dose (34).
      An  NAS  committee  recently concluded that "the risk from alpha
 irradiation  of  the deep  lung tissues would  not be underestimated by
 applying risk factors  from human experience with cancer induced by
 irradiation  of the bronchial tree" (3).   Therefore, the risk estimates
 (Tables  A3-10,11) are  based on the highest  dose  rate  received by any
 lung  tissues (pulmonary lung)  and  risk estimates  appropriate for the
 most  sensitive tissues within the  lung,  the site  of bronchial cancers.
 It should be noted that the  dose to bronchial  tissues  following
 Plutonium inhalation is small compared to tnat received in  the
 pulmonary lung. Tables A3-2.
     The number of lung cancers from alpha  irradiation at a  given dose
 appears to be increasing as  the years  at  risk  in  relevant
 epidemiological studies are  extended.  The  1976 NAS report  states that
 the absolute risk (the number of cases that will  result from exposure
 of a given population)  estimate for bronchial cancer in uranium miners
is twenty cases per million organ  rad per year at risk,  not  ten as in
 the 1972 BEIR Report.  The relative risk  (the  ratio of  the risk in
those exposed to the risk to  those not exposed) estimate in  the  1972


BEIR Report is also likely to be low.  Assuming that the relative risk
for D.S. miners has increased in a manner similar to their absolute
risk, it would be comparable to the 1972 BEIR estimate for Canadian
miners who have been similarly exposed, i.e. 6% increase in annual
incidence per rad.  Because an updated analysis of the U.S. uranium
miner cancer experience is not available, this estimate has been
utilized in the life table analysis described below.
     Tumors may occur at any time after a latent period during which
the affected cell or cells progress from the state of initial injury
to a tumor which can be identified clinically.  The duration of this
period is, of course, variable depending on the kind of cancer and
host response.  For many cancers it is estimated as 10 to 20 years.
The 1972 BEIR Report assumed a 15 year latent period for all solid
tumors induced in both children and adults.
     Following the latent period, tumors occur with an increased
frequency in the groups irradiated.  The temporal pattern of cancer
induction is poorly known for human populations exposed to radiation,
mainly because exposed groups have not, as yet, been followed for
sufficiently long enough times.  The 1972 BEIR Committee made two
approximations of the temporal pattern for tumor occurrence.  One
assumes a constant risk per year for the balance of a person's
lifetime following a 15-year latent period; the other, a constant risk
for a 30-year plateau following the latent period.  This may not be
long enough, since 30 years is-the duration of most of the
epidemiclogical studies used to establish the risk estimate.


      Estimates of the risk of cancer.following irradiation in the 1972
 BEIR Report are a function of two parameters:  the type of risk model,
 absolute or relative, and the duration of the  plateau period.  In the
 case of  absolute risk the estimates are relatively independent of the
 plateau  period,  for  either children or adults.   However, results
 obtained with  a relative  risk model are more sensitive to the plateau
 period selected,  particularly when children are included in the
 population  at  risk.   If a 30-year plateau,  relative risk model is
 assumed,  the calculated risk  of  radiation carcinogenesis is small from
 early exposure when  a child1s sensitivity to radiation injury is high.
 Only in the  later years of  life  is the natural  incidence of cancer an
 important cause of death, and the plateau period  does  not extend into
 these years.
      The  life  table analysis  used to estimate the risk of premature
 death following irradiation is described  in reference  35 and in Annex
 4.   Table A3-10 compares  the  risk models  and Plateau periods discussed
 above, for the case of lung cancer due  to lifetime inhalation causing
 a dose rate  (to adults of 1 mrad  per year.  The absolute risk from
 exposures before ten years of age  was assumed to  be one-fifth that of
 adults;  the relative risk ten times  the adult value, as  shown in Table
 A3-2  of reference 2.   In Table A3-10, the risks to the exposed
 population are accounted for by three measures:   (1)   number of  early
deaths per 100,000 exposed, (2) the  total life-shortening for the
group as  a whole and finally,   (3) the average number of  years of  life
lost by an afflicted individual.   The much  larger number of  lung


cancers expected to occur in a cohort of 100,000 persons not exposed
to this additional insult is estimated in Annex H (Table AU-1).
     For the purpose of this report, an estimate of the lung cancer
risk is obtained by averaging the geometric means of the absolute and
relative risk for 30-year and lifetime plateaus, shown in Table A3-10.
The Agency recognizes that these risk estimates must be regarded as
tentative, because information on the radiocarcinogenicity of high LET
particles is being reassessed by several competent scientific groups.
The Agency has an ongoing contract with the NAS to have the BEIR
committee re-evaluate radiation risk, including the risk of lung
cancer.  Pending completion of the new NAS study, the average risk of
early death from a one millirad annual dose to adult pulmonary tissue
has been used to assess the lung cancer risk from inhaled
transuranics.  At this level, lifetime exposure experienced by 100,000
persons could induce about 8 premature deaths.
3.6  The Risk of Bone Cancer
     Unlike radium-226, which is distributed throughout the bone
volume following long term ingestion, plutonium is preferentially
deposited and retained on endostial bone surfaces, principally in the
organic matrix.  In some cases as much as 30-50% of the endostial
plutonium has been shown to be retained on osteogenic cells  (36).
Americium and curium are also retained on bone surfaces.   Alpha
particle emitters which are retained on bone surfaces have been  shown
to be more tumorgenie than radium-226 and other  bone volume  seekers.
Surface seekers deliver a higher dose to osteogenic cells  adjacent to


 bone surfaces,  and such injury is thought to be the cause of
 radiogenic bone sarcomas.
      There is no clinical  evidence of bone cancer being caused by
 plutonium.  The most relevant human data is for medical patients
 treated with radium-224, which,  because of its  short half-life (3.6U
 days),  is retained mainly  on  bone surfaces.   A  large number of
 patients (approximately 900)  who were treated with radium-224  for
 tuberculosis and ankylosing spondylitis have been followed for bone
 cancer  incidence by S pi ess and Mays (37) .   The  dose to  these patients
 has  been calculated by  the authors in terms of  the average skeletal
 dose, defined as total  alpha  energy emitted  divided by  bone mass, even
 though the dose  distribution  is  very nonuniform.   On this basis Mays
 has  estimated that  for chronic irradiation due  to Pu-239,  200  bone
 cancers  will be  produced per  10s  rad to a  7  kg  skeletal mass (38).  In
 terms of the dose to mineral  bone,  mass 5  kg, utilized  in this
 analysis,  these results yield 140 bone cancers  per rad  to osseous
 tissue.  As noted below this  estimate is likely to be too low.
     Because of uncertainties  in the redistribution of  Ra-22U
 following  its initial deposition on bone surfaces.  Mays1  estimate of
 the average skeletal dose delivered in the Ra-224  cases may be  too
 high, leading to an underestimate of the risk per  rad for  radium-224.
 While Mays assumes that half of the skeletal radium-224 decays  on bone
 surfaces and half in the bone volume, Marshall has  stated that only
1.5X of the skeletal radium-224 decays within the bone  volume away
from bone surfaces.  This would increase the risk per rad by 174%.


Furthermore, Marshall's model predicts that, for radium-22«* on bone
surfaces, the dose rate to osteogenic cells near the bone surface is
8.9 times the average skeletal dose rate; for plutonium-239, 12.8
times (39).  In terms of average dose to osseous tissue as calculated
for these risk estimates, plutonium-239 would therefore deliver 1.14
times as much alpha particle dose to osteogenic cells as radium-22U.
This estimate is likely to be too high, since it assurr.es all the
Plutonium is retained on bone surfaces and none is buried in the
remodelling or bone growth process.
     The residence time of plutonivun on bone surfaces depends on acre.
In rapidly growing animals, it is relatively short  (40), while in
adults, as Jee, et al. have pointed out, "Not only is there a
prolonged «»Pu bone surface residence time in adult bone, but they
accumulate more *3«Pu with time  (UO)."   'since almost all of the body
burden is assumed during adult life, the exposure regime due to
chronic plutonium inhalation and ingestion way favor a surface dose
distribution more analogous to Marshall's model than Mays'.  After
giving due consideration to the smaller number of bone precursor cells
in adults, Jee, .et al. have characterized the plutonium-239  injury  to
bone as low in rapidly growing beagles, moderate  for young  adults,  and
high for  adults  (HO).  A similar characterization  for degrees  of
insult would appear to hold for humans, particularly when subjedt  to
chronic exposure.

     Based on these considerations, below is an upper bound estimate
of the risk from  plutonium and  other bone surface seekers in terms of
average skeletal  dose:
     140 x 1.7U x 1.4U       =       350 bone cancers
     10« rad                             10* rad
     Even though  the redistribution of plutonium on adult bone
surfaces is expected to be very uneven on both macroscopic and
microscopic scales, it seems likely that the amount of retained
plutonium irradiating bone surfaces will be between 50» and 90* of
total bone burden.  It should be noted that the extent of plutonium
redistribution affects only the factor of l.UU in the relationship
shown above.
     It is assumed that an average of EPA's upper and lower bound
figures, 250 bone carcinomas per 10* average skeletal rad, is a
reasonable estimate of the actual bone cancer risk.  The same risk is
applied to americium and curium, whose metabolism in bone tissue is
expected to be similar if not identical to plutonium1s.
     The latent period observed for the radium-22U patients was five
years, with a plateau period of ten years.   Therefore, the average
annual risk would be 25 sarcomas per 10* skeletal rsd per year at
risk.  The same risk is assumed for both juveniles and adults, since
Mays' analysis of the radium-22«» results indicates little difference
between these two groups.
     This risk estimate for bone cancer has been used to determine the
risk to a cohort of 100,000 persons receiving a lifetime exposure, as


outlined in Annex <».  A cohort analysis is essential for this risk
estimate since the correlation between accumulated dose and the
duration of exposure is an important factor.   To provide input data
for this risk analysis, annual dose rates to bone have been calculated
using the PAID code, as a function of the duration of exposure from
inhaled and ingested transuranium elements (see Tables'A3-3 and A3-6).
3.6.1  Inhalation Risk Estimates
     The risk of bone cancer due to the lifetime inhalation of
Plutonium causing a one mrad annual dose to pulmonary lung tissue is
shown in Table A3-11.  The estimated excess risk is relatively small
compared to that for lung cancer cf. Table A3-10.  Estimates of
relative risk has not been considered for the case of bone cancer.   In
view of the short duration of the plateau period used in the current
model, tert years, and the small risk of naturally occurring bone
cancer, the Agency believes that the absolute risk provides a suitable
estimate to use for public health protection.
3.6.2  Ingestion Risk Estimates
     The risk of bone cancer mortality occurring in a cohort due to
ingestion has been calculated by means of a life table analysis.  It
has been assumed that the cohort is irradiated for a lifetime due to a
constant intake of plutonium-239 oxide, so that the bone dose in the
70th year is 3.0 mrad.  The estimated risk of bone cancer is shown in
Table A3-12.  Note that while the risk due to the ingestion of Am-2«»l
or Pu-239 in a non-oxide form would be the same, the annual intake

 needed to produce  the  limiting dose rate to bone would  be  ten times
      Included  in Table A3-12  is the bone cancer risk due to the
 chronic ingestion  of Am-2Ul,  Cm-244, and Pu-2Ul.  The latter is a
 short half life  (14.8  years)  beta emitter having an alpha  emitting
 daughter  Am-241.   The  temporal pattern of the alpha dose to bone for
 Pu-241 and Cm-244  differs from that due to Pu-239 and Am-241.  Because
 of the delay caused by the short half life parent, the  alpha dose from
 the Am-241 daughter is delivered relatively late in life and the
 cancer risk is somewhat smaller.  In contrast, Cm-244 (half life 17.9
 years) approaches  the  equilibrium dose rate more rapidly than pu-2-39
 with  a larger dose delivered  early  in life and thus a greater cancer
 risk  (see Table A3-12).
      The magnitude of the potential risk of inducing liver cancer by
 means of plutonium and  other  transuranium elements has been recognized
 only  recently.  Existing governmental regulations are based on the
 1959  NCRP-ICRP assumption that the  critical organ for plutonium
 deposited  from blood is bone  (28).  More recently,  it has been
 recognized that deposition in liver is as likely as in bone.  ICRP 19
 assumes '45% of the plutonium and other transuranium elements dissolved
 in blood is deposited in the  liver and an equal amount in bone (4).
Based on the results of animal studies,  other authorities have
estimated a somewhat lower deposition in liver for plutonium and
somewhat higher for americium and curium (41).  The expected variation


between the transuranium elements is not large enough to change,  by an
appreciable extent, the overall risk estimate made below.  Only the
type of cancer might differ.
     The risk to humans from alpha emitters deposited in the liver can
be assessed on the basis of rather limited information obtained from
epidemiclogical studies af medical patients.  Earlier in this century,
a low specific activity alpha particle emitting contrast medium called
Thorotrast, was utilized in some diagnostic x-ray procedures.  In
subsequent years patients who were treated with it, mainly European,
have been followed clinically and shown to have a higher than expected
incidence of liver cancer.  These data are pertinent although they do
have limitations.  Because the amount of material injected into the
blood in these studies was quite large, its deposition in the liver
was uneven (42, U3).  Liver cancer incidence in this group would not
necessarily be higher than might be expected for a more uniform
deposition.  £n the contrary, there is a general concensus that highly
localized concentrations of alpha particle emitters are likely to be
less carcinogenic than a more uniform distribution (3) .  Another
possible limitation of these data is that the relatively large
quantity of Thorotrast deposited in the liver could lead to a foreign
body response, which might in turn result in cancer.  While the
quantitative applicability of the human experience with Thorotrast to
the prediction of plutonium risks to liver is tentative, there is an
abundance of experimental animal data showing that liver cancers can
be induced by plutonium.  Liver cancers are seen less frequently than


bone cancers in most experiments with animals, but since liver cancers
have a longer latent period than bone cancers, they may be more
important in a longer-lived species such as man.  The primary source
of data on Thorotrast patients is Faber's review  (U«) also cited by
the MRC as a basis for their assessment of plutonium toxicity  (16).
Faber's estimates are: absolute risk, «.2 x 10-*  liver cancer for each
organ rad per year at risk; relative risk, an 11% increase per rad.
3.7.1  Inhalation Risk Estimates
     In Table A3-13, the risk of liver cancer has been evaluated for
the airborne concentration of a plutonium-239 oxide aerosol  (1 u AKAD)
that will cause a pulmonary dose rate to adults of 1 mrad per year.
Unlike the case of ingested material discussed below, the risk of
liver cancer due to various inhaled long half-life transuranics is
nearly the same (for a given lung dose)  as for plutonium oxide.  This
is because gut transfer has little effect on the  dose to liver due to
inhaled materials.  For Cm-2*'» and other comparatively short half life
transuranium elements, the dose to liver relative to lung is mucli
smaller, cf. Table A3-3 and A3-4 so that the risk of inducing liver
cancer is less for such radionuclides than for plutonium.  The average
dose rate to liver relative to lung is nearly independent of particle
size (15).   In computing Table A3-13, the risk to children leas than
10 years of age was assumed to be different from  adults.  Since no
clinical data is available on the effect of Thorotrast on the young,
their risk was estimated from Table 3-2  in reference 2, as described
above for the case of lung cancer.

     The average of the estimated excess deaths shown in Table A3-13,
is 0.34 for a lifetime exposure to 100,000 persons.  This is a much
smaller number of excess cancers than the estimated mortality due to
lung cancer from the same aerosol concentration, cf. Table A3-10.
3.7.2  Ingestion Risk Estimates
     In contrast to inhalation, the ingestion dose to liver and the
resultant risk is a direct function of the amount of radioactivity
transferred to blood via the gastrointestinal tract.  Table A3-14
lists the risk of liver cancer from a lifetime ingestion pattern that
results in a 3 mrad dose to bone after 70 years.  The results shown
are for plutonium-239.  For transuranium elements having a physical
half life comparable to the elements1 residence time in liver the risk
will be somewhat greater since the dose approaches the equilibrium
value earlier in life.  Averaging the estimates of early death shown
in Table A3-1U yields an estimated risk of two deaths per 100,000
exposed persoeis, somewhat less than for cancer of the bone, cf Table
A3-12.  For Am-2«l, Pu-241 and Cm-2«H» this average lifetime risk is
2.1, 1.2 and 3.2 per 100,000 exposed, respectively.
     Risks due to transuranium elements are not only to persons
directly exposed to the radiation but also to their progeny.  Alpha
particles can damage the male progenitor cells producing sperm and the
egg cell (oocyte)  in the female.  The expression of this damage is.
either genetic impairment of the live-bom offspring or fetal death.

 Only the former has, as yet, been quantified in current risk estimates
 of health effects due to radiation.
      NAS-BEIR estimates of genetic risk are based on chronic
 x-irradiation to males, not the dose to both sexes due  to alpha
 particles.   For the reasons given below genetic damage  from alpha
 particles is expected to be about a  factor of 100 greater than that
 assumed in  the BEIR report (2).  Based on current recommendations of
 the ICRP, alpha particles are 20 times more damaging than x-
 irradiation for a number of biological end points,  including genetic
 effects.  This is not necessarily overly conservative since an
 increase  of about 20 compared to x-irradiation has been reported for
 genetic damage from highly ionizing  neutron irradiations (16).
      Alpha  particle damage is believed to be independent of dose rate.
 However BEIR estimates of genetic risk are based  on low dose rate
 x-ray exposures  which had the effect of lowering  genetic damage to
 males by  a  factor of 3.U and  eliminating this damage to females.  The
.British Medical  Radiation Council also assumed no damage to the oocyte
 of females  (16),  an assumption based on Searle's  evaluation (47) of
 mouse experiments with fission neutrons,  performed  by Batchelor,
 et al.  (i»6).   However,  more recent analyses of the  efficacy of chronic
 irradiation  in producing genetic damage indicate  that it may not be
 wise  to disregard potential damage to the ocoytes of the fomale (48) .
 Therefore, at  this time it appears prudent to increase  the  BEIR risk
 estimate  for genetic damage due  to chronic x-irradiation by a factor

of 100 (5 x 20)  when assessing the risk of genetic, damage due to alpha
emitting transuranics in the gonads.
     The range of the BEIR estimates of genetic risk is quite large
Table 4, on page 57 of (2).  They reflect the uncertainty in the
extent of the genetic component in diseases classified as having a
'•complex etiology", i.e., those with a mutational component among many
other causes, such as heart disease.  One recent analysis indicates
that this type of genetic risk may be so small that the actual risk is
near the lower end of the range estimated by the BEIR Committee in
1972 (49).  on the other hand, there are other analyses which indicate
that the 1972 BEIR report may have underestimated the amount of
multifactorial diseases having a genetic component (50).
     In 1976 EPA contracted with the National Academy of Sciences to
provide it with guidance on genetic risk, as part of the BEIR
committee's reevaluation of radiation risk.  The degree to which the
estimate made above may be high or low may be resolved when the BEIR
Committee's ongoing review of this problem is completed.
     It is estimated here that a 30-year dose of one millirad due to
alpha-emitting transuranium elements in gonadal tissue may cause
between 0.1 and 2 genetic effects per 100,000 live births in the first
generation.  If this gonadal dose were to continue indefinitely so
that a new equilibrium of genetic damage was established in the
population, the risk might increase to 0.6 to 1? per 100,000 live
births.  Currently, the observed genetic effects in the U.S. are about
6000 per 100,000 live births.


3.8.1  Genetic Risk Estimates
     Risk estimates for genetic damage are based on the gonadal dose
received in a reproductive generation, i.e., the first 30 years of
life.  Table A3-15 lists the 30-year gonadal doses due to chronic
ingestion of transuranium elements that would also cause a 3 millirad
per year dose rate to bone after 70 years.  Except for cm-244, the
guidance's limitation on the annual dose rate to bone limits the
relevant gonadal dose to about 10 millirad.  The estimated genetic
risks due to this 30 year dose is shown in Table A3-16.  Chronic
ingestion of Cm-2tt4, would cause genetic risks about two times larger
which would cause genetic risks about two times larger than those
shown in Table A3-16.  However, because of Cm-244's relatively short
half life circumstances that would lead to a constant rate of
ingestion for 30-years are difficult to imagine.  For the limiting
dose rates permitted by this guidance, genetic effects due to
inhalation are substantially less important than those due to
ingestion.  Where the gonadal dose is from chronically inhaled
transuranics causing a one millirad dose to lung, the gonadal dose is
l.U mrad in 30 years (Section 3.U.3) .  and the estimated genetic
effects are a factor of seven smaller than the estimates shown in
Table A3-16.

     3.9.1  Leukemia due to Bone Harrow Irradiation
     Recently, several authors have pointed out that leukemia is a
potential risk from plutonium incorporated into bone tissues (51).
Alpha particles originating in trabeculae may irradiate a significant
fraction of the bone marrow, and the plutonium in marrow itself will
act as a source.  Based on autoradiographic studies of bone and ton*
marrow. Spiers and Vaughan have estimated that the dose to trabecular
marrow is 88 percent of the average skeletal dose due to plutonium-239
     Using this factor and the skeletal dose rate from Pu-239, shown
in Figure A3-1, the risk of leukemia has been calculated in a cohort
of 100,000 persons exposed to plutonium-239 aerosol having a 1 u AMAD
and concentration of 2.6 f Ci/m3.  This concentration results in  the
limiting dose rate to pulmonary lung of one mrad per annum.  Excess
leukemia deaths were estimated utilizing the risk coefficients given
in Table 3-2 of the 1972 BEIR Report  (2) and a quality factor of  20
for alpha particle irradiation  (US).  Results are listed in Table
A3-17, which shows that the incremental risk due to leukemia is  rather
small compared to the risk for other cancers associated with a dose of
1 mrad per annum to pulmonary tissue, cf. Table A3-10.
     In the case ot ingested plutonium-239 the estimated risk of
leukemia induction is somewhat greater.  For a 3 mrad  limiting dose to
have in the 70th year, the leukemia risk ranges from O.ft to  1.6  case,s
per 100,000 exposed for absolute and relative risk models  respectively

and  is  therefore smaller but  comparable to the estimated risk of liver
cancer  due to the ingestion of transuranic elements.
     Over a lifetime the average dose to the whole body  (soft tissues)
due  to  the 7* of actinides distributed in the body tissues after
inhalation is about a factor  of 100 less than the dose received by
skeletal tissues.  Leukemia mortality due to excess radiation is about
one-fifth of all radiation induced cancers (2).  Therefore, health
effects due to the plutonium  burden in the whole body are expected to
be about 5% of the early deaths due to leukemia indicated in Table
A3-17.  Inhalation of other transuranium elements at these limits set
by those guides would cause a similar risk relative to leukemia.
     3.10.1  Inhalation Pathway
     Table A3-18 below summarizes the somatic and genetic risk due to
the inhalation of transuranium element aerosols causing an annual dose
to the pulmonary region of 1 mrad per year.   The estimated cancer risk
to a cohort of 100,000 is  nine premature deaths, with an estimated
range of between 3 and 30  early deaths.   Since the average lifespan of
this cohort would be about 71 years, the annual risk of cancer from
lifetime exposure is about 1 x 10-* per year.   The estimated genetic
risk to the first generation is considerably smaller numerically than
the risk of cancer due to  the inhalation of  transuranium elements.

     3.10.2  Ingestion Pathway
     The total risk due to the ingestion of transuranium elements may
include an appreciable genetic component as well as the risk of
cancer.  Therefore, in this guidance the cancer risk due to ingestion
is less than that due to inhalation.  Exact correspondence between the
risks from inhalation and ingestion is not possible, since it depends
on value judgements concerning the acceptability of risk to future
generations as compared to the present.  Moreover, the uncertainty of
the genetic risk estimates makes such a comparison uncertain.
     The guides are expressed in terms of the dose rate to bone after
70 years of chronic ingestion.  Including the risk of leukemia
induction, this would result in an estimated incidence of about five
cases of fatal cancer in a cohort of 100,000 persons.  The range of
estimated genetic effects for the same pattern of exposure are shown
in Table A3-16.  The estimated genetic risk to first generation
progeny may be numerically comparable to the cancer risk to the
parents, while the genetic risk to succeeding generations may exceed
the risk of cancer.

1.   Selected Topics:  Plutonium in the Environment, ORP Technical
     Report (in preparation, 1977).

2.   BEIR Report, 1972.  The Effects on Populations of Exposure to Low
     Levels of Ionizing Radiation,  Report of the Advisory Committee on
     the Biological Effects of Ionizing Radiations, National Academy
     of Sciences, Washington, D.C.

3.   Health Effects of Alpha-Emitting Particles in the Respiratory
     Tract, Report of Ad Hoc Committee on "hot particles" of the
     Advisory Committee on the Biological Effects of Ionizing
     Radiations, National Academy of Sciences, EPA 520/U-76-013,
     Office of Radiation Programs,  Environmental Protection Agency,
     Washington, D.C. 1976.

4.   1CRP Publication 19, 1972.  The Metabolism of Compounds of
     Plutonium and Other Actinides, Pergamon Press, New York.

5.   TGLD (Task Group on Lung Dynamics)  1966.  Deposition and
     Retention Models for Internal  Dosimetry of the Human Respiratory
     Tract, Health Physics 12:173-208-

6.   Hodge, F. A. and Ellett, W. H., 1977.  Dose and Dose Rates Due to
     the Chronic Inhalation and Ingestion of Transuranic
     Radionuclides, EPA/ORP  (to be published).

7.   Kotrappa, P., 1969.  Calculation of the Burden and Dose to the
     Respiratory Tract from Continuous Inhalation of a Radioactive
     Aerosol,  Health Physics, 17:*29-432

8.   Houston,  J. R., Strenge, D. L. and Watson, E. C., 1974.  DACRIN -
     A Computer Program for Calculating Organ Dose from Acute or
     Chronic Ra'dionuclide Inhalation, BNWL-B-389, Battelle Pacific
     Northwest Laboratories, Richland, Washington.

9.   Sullivan, R., 1977.  Plutonium Air Inhalation Dose  (PAID),
     ORP/CSD Technical Note, 77-U (in press) .

10.  ICRP Publication 23, 1975.  Report of the Task Group on Reference
     Man, Pergamon Press, New York.

11.  Tamplin,  A. R. and Cochran, T. B., 197U.  Radiation standards for
     Hot Particles; A Report on the Inadequacy-of Existing Radiation
     Protection Standards Related to Internal Exposure of Man to

     Insoluble Particles of Plutonium and Other Alpha-Emitting Hot
     Particles,  Natural Resources Defense Council,  Washington, D.c.

12.   ICRP Publication It, 1969.   Radiosensitivity and Spatial
     Distribution of Dose, Pergamon Press, New York.

13.   Bair, W.  J., 1974.  Toxicology of Plutonium, Adv. Rad.  Biol.,
     *»; 255-313

14.   Durbin,  P.W. Plutonium in Man: A New Look at Old Data in
     Radiobiology of Plutonium,  Ed. by B.J. Stoer and W.S.. Jee, J.W.
     Press, Univeristy of Utah,  Salt Lake City, 1972.

15.   Richmond, C. R. and Thomas, R. L., 1975.  Plutonium and Other
     Actinide Elements in Gonadal Tissue of Man and Animals, Health
     Physics,  29:241-250.

16.   The Toxicity of Plutonium,  1975.  Medical Research Council, Her
     Majesty's Stationary Office, London.

17.   Stevens,  W., Atherton, D.R., Bruenger, F. w., Buster, D. and
     Bates, D., 1977.  Deposition of *"Pu, zz&Ra, 2330 and z«»Am in
     the Gonads, pp 223-227 in Research in Rdiobiology, COO-119-252,
     Annual Report of the Radiobiology Laboratory, University of Utah,
     College of Medicine, Salt Lake City, Utah.

18.   Taylor, D.M., 1976.  The Uptake, Retnetion and Distribution of
     Plutonium-239 in Rat Gonads, Health Physics, 32:29-31.

19.   Fish, B. R., Keilholz, G. W., Snyder, W.S. and Swisher,  S.D.,
     1972.  Calculation of Doses Due to Accidenta1ly  Released
     Plutonium from an LMFBR. ORNL-NSIC-7a, Oak Ridge National
     Laboratory, Oak Ridge.

20.    Raabe, O.G. Kanapilly, G.M., and Boyd,  H.A., 1973.  Studies of
     in vitro Solubility of Respirable Particles of *"Pu and ««Pu,
     pp 24-30 in Fission Product Inhalation Program Annual  Report,
     1972-1973, LF-46, Lovelace Foundation for Medical Education  and
     Research, Albuquerque.

21.   Muggenburg, B.A., Mewhinney,J.A., Miglio, J.J. Slauson,  D.O. and
     McClellan, R.O.,  1974.  Brochoplumonary  Lavage and DTPA Treatment
     for the Removal of Inhaled ««pu Of Vaired  Soubility inBeagle
     Dogs, II, pp 269-273 in Inhalation Toxicology Research Institute
     Annual Report 1973-1974, LF-49, Lovelace Foundation  for Medical
     Education and Research, Albuquerque.

 22.  Durbin, P.M.,  1974.  Behavior of  Plutonium  in Animals and Man, pp
     30-56 in Plutonium  Information Meeting, CONF-740115, US Atomic
     Energy Commission,  Oak  Ridge.

 23.  Sullivan, M.F. and  Crosby, A.L.,  1976.  Absorption of Transuranic
     Elements from  Rat.  Gut,  pp91-93 in  Pacific  Northwest Laboratory
     Annual Report  for 1975,  Part I Biomedical Sciences, BNWL-2000, PT
     1, Battelle Pacific Northwest Laboratories, Richland.

 24.  Sullivan, M.F. and Crosby, A.L.,  1975.  Absorption of Uranium-
     223, Neptunium-237, Plutonium-238,  Americium-241, Curium-244, and
     Einsteinium-253 from the Gastro-intestinal  Tract of Newborn and
     Adult Rats, pp 105-108  in Battelle  Pacific  Northwest Laboratareis
     Annual Report  for 197U,  BNWL-1950,  Battelle Pacific Northwest
     Laboratories,  Richland.

 25.  Bair, N.J., 1975.  The  Biological Effects of Tansuranium Elements
     in Experimental Animals, pp 464-536 in Proceedings of Public
     Hearings; Plutonium and Other Transuranium  Elements,
     ORP/CSD-75-1,  Volume lj  O.S. Environmental  Protection Agency,
     Washington, D.C.

 26.  Bair, W. J. and Thompson, R. C.,  1977.  Battelle Northwest
     Laboratory, letter communication.

 27.  Dolphin, G. W. and Eve, I. S., 1966.  Dosimetry of the
     Gastrointestinal Tract, Health Physics, 12:163-172.

 28.  ICRP Publication 2, 1959.  Report of Committee II on Permissible
     Dose for Internal Radiation, Pergamon Press, New York.

 29.  Sansom,  B.F.,  1964.  The Transfer of Plutonium-239 from the Diet
     of a Cow to its Milk, Brit. net.  J.  120: 158-161.

 30.  Stanley, R.E., Bretthauer, E.W. and Sutton, w.S., 1974.
     Absorption, Distribution and Excretion of Plutonium by Dairy
     Cattle,  pp 163-185 in Dynamics of Plutonium in Desert
     Environments.  NVO-142,  U.S. Atomic Energy Commission, Nevada
     Operations Office,  Las Vegas.

31.  McClellan, R.O.,  Casey, H.W., and Bustad, L.K., 1962.  Tansfer of
     Some Transuranic Elements to Milk, Health Physics, 8:689-694.

32.  Bair, W. J.  and Thomas, J. M., 1976.  Prediction of ths Health
     Effects  of Inhaled Transuranium Elements from Experimental Animal
     Data, pp 569-585 in Transuranium Nuclides in the Environment,
     International Atomic Energy Agency,  Vienna.

33.   Ken, G. D. and John, T. D.  A Reanalysis of Leukemia Data on
     Atomic Bomb Survivors Based on Estimates of Absorbed Dose to Bone
     Marrow, ORNL paper IL-1, Twenty-first Annual Health Physics
     Meeting, June 23-July 2, 1976.

34.   Ishimaru, T., Cihak, R. W., Land, C. E., Steer, A. and Yamada,
     A., 1972.  Lung Cancer at Autopsy in Atomic Bomb Survivors and
     Controls, Hiroshima nad Nagasaki, 1961-1970, ABCC Technical
     Report 33-72, Atomic Bomb Casualty Commission, Hiroshima.

35.   Bunger, B., Cook, J. and Barrick, K., 1977.  Life Table
     Methodology for Evaluating Radiation Risk.  ORP/CSD Report - in

36.   Vaughan, J. M., 1973.  The Effects of Irradiation on The
     Skeleton, Clarendon Press, Oxford.

37.   Spiess, H. and Mays, C. W., 1973.  Protraction Effect on Bone
     Sarcoma Induction of 2**Ra in Children and Adults,  pp U37-450 in
     Radionuclide Carcinogenesis, OONF-720505, C. L. Saunders, R. H.
     Busch, J. E. Ballou and D. D. Mahlum, editors, AEC Symposium
     Series 29, U.S. Atomic Energy Commission, Oak Ridge.

38.   Mays, C.. W., et al., 1976.  Estimated Risk to Human Bone from
     23«Pu, pp 343-362 in The Health Effects of Plutonium and Radium,
     W. S. S. Jee, editor. The J. W. Press, Salt Lake City.

39.   Rowland, R. E. and Durbin, P. W,, 1976.  Survival, Causes of
     Death and Estimated Tissue Doses in a Group of Human Beings
     Injected with Plutonium, pp 329-341 in The Health Effects of
     Plutonium and Radium. H. S. S. Jee, editor, The J. W. Press,  Salt
     Lake City.

40.   Jee, W. S. S., et al., 1976.  The Current Status of Utah
     Long-Term Z»«PU Studies, in Biological and Environmental Effects
     of Low-Level Radiation. Vol II, International Atomic Energy
     Agency, Vienna.

41.   Durbin, P. W., 1975.  Plutonium in Mammals: Influence of
     Plutonium Chemistry, Route of Administration, and Physiological
     Status of the Animal on Initial Distribution and Long-Term
     Metabolism, Health Physics 29:495-510.

42.   Tessmer, C. F. and Chang, J. P., 1967.  Thorotrast Localization
     by Light and Electron Microscopy  Ann. N. Y. Aca. Sci.,
     145(3) ; 545-575.

43.   Riedel, W., Miller, B. and Kaul, A., 1973.  Non-Radiation Effects
     of Thorotrast and Other Colloidal Substances pp 281-293  in


     Proceedings  of  the Third International Meeting on the Toxicity of
     Thorotrast,  Ris0 Report  No.  294, Danish Atomic Energy Commission,

44.  Faber, M., 1973.  Dose Effect Relationships in Hepatic
     Carcinogenesis, pp 308-316 in Proceedings of the -Third
     International Meeting on the Toxicity of Thgrotrast, Risd Report
     Ho. 291, Danish Atomic Energy Commission, Copenhagen.

45.  ICRP Publication 26, 1977.   Radiation Protection.  Pergamon
     Press, N.Y.

46.  Searle, A. G., 1974.  Mutation Induction in Mice, Adv. Radiat.
     Biol. 4:131-207.

47.  Batchelor, A. L.; Phillips,  R. J. S. and Searle, A. G., 1969.
     The Ineffectiveness of chronic irradiation with neutrons and
     gamma rays in inducing mutations in female mice, Brit. J. Radiol.

48.  Abrahamson, S. and Wolff, S., 1976.  Re-analysis of
     Radiation-Induced Specific Locus Mutations in the Mouse, Nature,

49.  Newcombe, H.  B., 1975.   Mutation and the Amount of Human 111
     Health,  pp 937-946 in Radiation Research; Biomedical, Checmial,
     and Physical  Perspectives, O. F. Nygaard, H. I. Adler and w. K.
     Sinclair, editors. Academic  Press, Inc., New York.

50.  Trimble,  B. K.  Induced Mutation and Human Disease presented at
     the Radiation Research Society Meeting, San Francisco, 1976.

51.  Vaughan,  J.,  1976.  Plutonium a Possible Leukemia Risk, pp
     691-705  in The Health Effects of Plutonium and Radium, W. S. S.
     Jee, editor.  The J.  W.  Press, Salt Lake City,  Utah

52.  Spiers,  F.  W. and Vaughan, J-,  1976.  Hazards of Plutonium with
     Special  Reference to the Skeleton, Nature 259;531-534.

                              Table A3-1

             Retention Halflives, Clearance Patterns and
                 Breathing Rate for Class Y Aerosols
                   Inhaled by Referenced Man (4,10)
Lung Compart mental**
Compartment Half life (days)
Nasopharyngea 1
Tracheobronchia 1


T-B lymph nodes
Breathing rate 2
8 hours restimr)
.3 x
10* liters
Transfer Target
per day (16
to blood
to GI tract
to blood
to QI tract
to blood
to GI tract
via T-B
to GI tract
via T-B
to lymph nodes
to blood
hours lightwork;
**See Figure A3-2 for designation of compartmental pathways  (a) ,
  (b)f etc.

                              Table A3-2

          Annual Dose Rate to Various Lung Compartments from
              Chronic Exposure to Plutonium-239 Aerosols
  Concentration: 1.0 fCi/m' Particle AMAD: 0.05, 1.0 and 5.0 Microns

Duration of
Exposure     Pulmonary             Tracheobronchial         Nasopharyngeal
             mrad/yr. x 10-l       mrad/yr. x 10-2           mrad/yr.  x 10-«
          O.OSu   l.Ou   5.0u     O.OSu   l.Ou   5. Ou     O.OSu   l.Ou   5.Ou

                               Table A3-3

            Annual Dose Rates to Various Organs from Chronic
              Exposure to Plutonium-239 and Americium-241
      Aerosols AMAD=lu; Concentration 1 fci/mJ; class Y Clearance
 Duration of
 (years)      Liver
(mr ad/year)
  Bone    T-B Lymph
Liver    Bone    T-B Lymph
~ .001?
• 13

Bone T-B Lymph
7. H

^IH " * w f w™ " """
Liver Bone T-B Lymph
.0016 4
.017 7
.028 7
.037 8
.049 9
.057 9
.063 10
.068 11

*  a dose only - 70th year beta dose rates: liver, 0.11 urad; bone,  0.049  urad.

                              Table A3-4

             Aerosol Concentrations in fCi/m3 Producing a
          1.0 mrad Annual Dose Rate to the Pulmonary Region
                 of Reference Man; Class Y Clearance
AMAO (u)
AMAD (u)
5.0 .
2 34JJ (a)


* 0 dose rate <  40* of o  dose - only a  dose is considered in setting limit.


                              Table A3-5

            Fraction of Ingestion Material Transferred to
              Blood from the Gastrointestinal Tract

                        Transfer Fraction
Radionuclide                                        Biologically
                      Non-oxide      Oxide          Incorporated

Plutonium-238          10-'          10-'           5 x 10-'

Plutonium-239          10-'          10~*           5 x 10-'

Plutonium-2«0          10-'          10-*           5 x 10-'

Plutonium-2Ul          10-'          10-'           5 x 10-'

Americium-2Ul          10-'          10-'           5 x 10-»

Curium-244             10-'          10-'           5 x 10-'

* Persons over one year of age  (see text).

                           Table A3-6

          Annual Dose Rate Due to Chronic Ingestion of
Plutonium-239 Oxide, Americium-241, Plutonium-241 and Curium-2UU
                  Annual Intake 1000 pCi/Year*
Duration of Plutonium-239 Oxide
Ingest ion (urad/year)
Years Bone Liver Whole
Duration of
Ingest ion
Bone Liver
Bone Liver
a. 7
 •Reference Han (10).
**Alpha dose rate.

                              Table A3-7

          Average Skeletal Dose Rate in the 70th Year Due to
        the Lifetime Ingestion by Reference Man of 10 nCi/yr.

Radionuclide Chain               Millirad Per Year
                              Oxide       Other Inorganics*

23epu(a)/23»u(a)                 H.O                4.0

Z3«pu(a)/Z3su(a)                0.18               U.8

2«opu(a)/«»U(a)                0.»8               U.8

z«ipu(e)/2*lAm(a)              0.11**            0.11**

**iAm(a)/«mp(a)              a.9                H.9

2»*Cm(a)/2*»(o)                 2.1                2.1

     •Biologically incorporated transuranic multiply by  5.0.

     **Only the alpha dose listed in applicable to this  guide.
       The beta dose rate is 1.5 urad/yr. in the 70th year.

                    Table A3-8

    Cumulative 30-year Alpha Particle Dose to
                  Gonadal Tissue
             Annual Intake 1000 pCi/y

      Radionuclide            30-year Dose

      Pu-238  .                  1.80

      Pu-239  (oxide)             0.18

      PU-2UO  (oxide)             0.18

      *Pu-2«l                    0.02

      Am-2«l                     1.9

      Cm-2««                     1.5

* adose only - the  6 dose is 1.2 x 10-* rads.

                          Table A3-9

   Average Skeletal Dose Rates Due to Chronic Ingestion of
 Plutonium-239 Oxide with and Without Increased Infant Uptake
                  Annual Intake 1000 pCi/yr.
 Age               Average skeletal Dose Rate (uRad/yr.)
            Without Enhanced         With Enhanced
            Infant Absorption*       Infant Absorption**

  1              0.86                      86.H

  5              4.26                      37.7

 10              8.37                      32,6

 15             12.1                       21.6

 20             16.2                       23.7

 30             23.5                       30.5

 40             30.3                       36.9

 50             36.fi                       42.7

 70             48.0                       53.3

 *GI tract to blood transfer 10-* all ages.

**GI tr'act to blood transfer 10-* first year of life.

                              Table A3-10

           Measures of  the Lifetime Health Risk Due to Lung
            Cancer Mortality Pulmonary Dose Rate to Adults
  Imrad/yr. Cohort Size 100,000  Persons -  Latent Period =  15  Years.

Measure of Risk         Relative  Risk Estimate     Absolute  Risk Estimate
                        30-Year       Lifetime     30-year      Lifetime
                        Plateau       Plateau      Plateau      Plateau

Premature Deaths         7.02           25.0         2.15          2.80

Aggregate Years of
Life Lost to Cohort      129           368           H7            5<4

Average Years  of Life
Lost to Premature Deaths 18.»          l«.7         22.0          19.u

                         Table A3-11

Estimated Risk of Bone Cancer Mortality Due to the Inhalation
             of Plutonium-239 Oxide (AMAD=1.0 u)
               Pulmonary Dose Rate = 1 mrad/yr.
     Average Skeletal Dose Rate in the 70th Year . U6 mrad
                Cohort Size = 100,000 Persons

 Measure of risk               Absolute Risk Estimate
                               10 Year Risk Plateau

 Premature Deaths                    0.37

 Aggregate Years of Life
 Lost to Cohort                     8.0

 Average Years of Life Lost
 to Premature Deaths               23.3

                            Table A3-12

     Estimated Risk of Bone Cancer Due to a Lifetime Ingestion
Pattern that Results in a 3.0 mrad Alpha Particle Dose Pate Per Year
                      to Bone in the 70th Year

                                        Absolute Risk
                                    10-Year Risk Platue

    Radtonuclide             Premature Deaths per 100,000  Exposed

    Pu-239                                     2.H

    Am-2ttl                                     2.5

    PU-2U1                                     1.9

    Cm-2«4                                     3.2
   Average years of life lost per premature death 	 2H years.

                             Table A3-13

    Measures of the Lifetime Health Risk of Liver Cancer Mortality
          Due to Inhalation of Plutonium-239 Oxide 
                              Table A3-1U

   Estimated  Risk of  Liver Cancer Due to A Lifetime Ingestion Pattern
      That  Results in a 3.0 mrad Alpha Particle  Dose Rate Per Year
   to  Bone  in the 70th Year for Long Half Life Transuranic Elements*
                       Deaths  per 100,000 exposed

Risk  Model              30-year Plateau    Lifetime Plateau

Relative Risk               1.6                   2.8

Absolute Risk               1.5                   i.a
*T »/z   100 years.

                             Table A3-15

         Thirty-year Gonadal Dose Due to  an Ingestion Pattern
Causing a 3 Millirad/yr. Alpha Particle Dose Rate to Bone in the 70th Year
           (Chronic Lifetime Ingestion at a Constant Rate)

           Transuranium Element          Gonadal Dose

                 Pu-238                        13

                 Pu-239                        11

                 Pu-2UO                        11

                 Pu-201                         6

                 Am~2«»l                        12

                 Cm-2U4                        21

                             Table A3-16

         Estimated Genetic Risk  Due to an Alpha  Particle Dose
     of 10 Millirads to the Gonads in the First  30 Years of Life

                             Number of Effects Per
                             100,000 Live Births

Type of Genetic Disease      1st Generation    All Generations
     Dominant                   1-10             5-50

     Multifactorial           0.1 - 10             1 - 100

           Total                1   20             6   150

                        Table A3-17

  Measures of the Lifetime Health Risk of Leukemia Due to
       Inhalation of Plutonium-239 Oxide (AMAD = lu)
               Pulmonary Dose Bate 1 mrad/yr.
                Cohort Size 100,000 Persons
Measure of Risk         Relative Risk     Absolute Risk

Early deaths                0.24              0.06

Decrease in population      2.8               1.4
life expectancy (years)

Average years of life     11.8              23.1
lost per early death

                              Table A3-18
          Estimated Risk Due to the Inhalation of  Transuranic
              Aerosols for a 1 mrad/yr.  Lifetime Exposure
 Estimated Somatic  Risk in a
 Cohort of 100,000  Persons
 Cause  of  early death            Premature deaths      Range
 Lung Cancer                             8             2-25
 Bone Cancer                             0.3          0.2-.7
 Liver  Cancer                            0.3         0.2-0.6
 Leukemia  6 other causes                 0.12        0.06-0.25
 Estimated total
  premature deaths                      9             3-20
Estimated Genetic Risk
per 100,000 Live Births
First generation                      	          0.1-3
All generations                       —            1-20


20       30       40        50

                               FIGURE A3-1

^ °1 -
1 J

i (N-P)


(T-B) j-"

! (P)
1 (h)




f) *
g) ^


S 1
                               FIGURE A3-2

                            PARTICLE AMAD - (MICRONS)

                                 FIGURE A3-3

              Annex IV

U. S. Environmental Protection Agency
    Office of Radiation Programs
       Washington, D.C.  20460

                                Annex IV

                            Table of Contents


1.   Introduction 	   1

2.   Life Table Methodology 	   1

3.   Risk From Background Radiation 	   4

4.   Other Risks Experienced By the General Population....   7

                               Annex IV

                           Risk Perspective

1.   Introduction

     The purpose of this annex is to provide a perspective for

evaluating the somatic component of the  risk from transuranium

elements.  Life table measures of .risk of death are developed for

some of the diseases and accidents presently experienced by the U.S.

population.  They are comparable to the  life table risk measures

provided in Annex III.

     Before proceeding with the discussion of what has been done to

provide a perspective for evaluating this risk, the general character-

istics of life table models will be described.

2.   Life Table Methodology

     Life tables are a method for following hypothetical cohorts of

individuals through their life spans, from birth to death.  The cohort

is assumed to be subject throughout its existence to the age specific

mortality rates observed for an actual population.

     The National Center for Health Statistics  (NCHS) publishes life

table models for the U.S. population, which incorporate age specific

mortality rates for the U.S. population  (1,2).  They are used  to estimate

the life expectancy of the U.S. population.

     EPA has developed life table models  (based on the NCHS models)
             ~ ' •  - C  - .      .     •    ,        "

for measuring  the impact of changes in the rate of mortality.  Changes

 are measured from the mortality rates incorporated into the NCHS tables.

 These changes may represent increases or decreases in the mortality

 rate.  Increases result when people are exposed to additional risks not

 a component of the U.S. population average.  Exposure to the ionizing

 radiation emitted by transuranium elements is an example of an

 increased mortality risk.

      Decreases in mortality would result from the elimination of one

 or more of the causes of death presently experienced.   An example

 (which is used in this annex)  is the hypothetical elimination of lung

 cancer as a cause of death in  the U.S.  population.   When these cal-

 culated results from the EPA model are  compared to  the results of the

 NCHS  model,  the impact of lung cancer mortality on  the U.S.  population

 can be estimated.

      Because of methodological differences,  the discussion of the EPA

 life  tables  will  consider the  case of increased and  decreased mortality


      The  life  table  concept  of life expectancy  has attractive features

 for measuring risk,  for  it is  based on the years of  life lived by the

members of the  cohort.   EPA's  models  rely on  standard  life  table

methodology  to  determine the sum of the years of .life  lived.   The

difference in years  of life lived  in  the EPA and NCHS models  is  the net

change in total years of  life  lived by the two  cohorts.

     For the case of increases in  the rate of mortality caused by

exposure to transuranium  elements,  the net change is downward  (the years

of life lived by the cohort in the EPA model is less than that for the

NCHS model). The EPA model has been designed so that the numbers of

deaths attributable to the increased rate of mortality can be calcu-

lated.  These are premature or early deaths because the individuals die

at an earlier age than they would have, had there been no increase in the

mortality rate (i.e. had they not been exposed to transuranium ele-

ments).  The net decrease in years of life lived divided by the number

of premature deaths is the measure of the average years of life lost to

those dying prematurely as a result of the exposure.

     Lung cancer will be used as an example for discussing decreased

mortality rates resulting from the elimination of a cause of death.

The elimination of other causes of death uses the same methodology. The

years of life lived increases when the mortality effects of lung cancer

are eliminated.  The EPA model determines the numbers of lung cancer

deaths averted by eliminating lung cancer as a mortality risk.  The net

increase in years of life lived divided by the number of lung cancer deaths

is the average years of life gained to those whose deaths by lung cancer

have been averted.  This effect can also be interperted as a change in

the opposite direction, from a situation where there is no lung cancer

mortality to one where lung cancer mortality is the same as presently

experienced in the U.S.  With this change in interpretation, the net

change in years of life lived is considered a decrease, for it measures

the years of life lost to the cohort because of lung cancer mortality.

This value divided by the number of lung cancer deaths gives the average

years of life lost to those dying of lung cancer.  This change in

  interpretation  facilitates  the  comparison of  the  risks  from  transuranium

  elements with the risk of lung  cancer.  This  is the interpretation to be

  used in this Annex.

      A discussion of life table methodology and the technique for

  removing specified causes of death from the life  table are discussed in

  Chiang (3).  Life tables similar to the EPA models, with specified

  causes of death removed, are published by NCHS (4).  The basic methodol-

 ogy used here for developing life table estimates is similar to that

 discussed in the technical report, "Life Table Methodology for Evalua-

 ting Radiation Risk" (5).

      The remainder of this annex is devoted to the estimation of the

 risk of  death from a variety of diseases and accidents.   Results are

 shown in Tables  A 4-1 and A 4-2.  These can be compared  to the risk from

 transuranium elements calculated in Annex III.

 3.    Risk From Background Radiation

      The average annual background  radiation equivalent  dose  received by

 the  U.S. population  is approximately 100 mrem over the whole  body.

 It is assumed  that on a per  rem  basis background radiation will  have  the

 same impact  on cancer incidence  as  other forms of  radiation.   Two sit-

 uations can  be evaluated:  one where all risks of  death  are the  same  as

 presently experienced and the other  (a hypothetical situation) where  the

 risk of mortality from 100 mrem whole body dose is removed. The'results

 are  shown in Table A 4-1.                                         l

     All risk estimates for whole body dose are taken from the BEIR

report, Table 3-2, p. 171.  Results of four models are shown,  based on

relative and absolute risk and on the 30 year and life plateaus  for

cancer other than leukemia as defined in the BEIR report (6).

     Four measures of risk are shown for each life table model shown

in Table 1.  The first measure is the numbers of deaths attributed to

background radiation.  Numbers of deaths furnishes no perspective on the

prematurity of the deaths, since it provides no measure of the years

of lifetime lost because of these deaths.  The other values in Table

A 4-1 are measures of the lifetime lost.

     The basic measure of prematurity of death is the aggregate years

of life lost.  Values for each model are shown in Table A 4-1.  This

aggregate can be used to measure the reduction in average length of life

for the cohort.  This measure expresses the viewpoint at the beginning

of life when all members of  the cohort face equal risk  of death from

background radiation.  The average reduction  in  years of life lived by

the cohort  (reduction in life expectancy at birth)  is calculated by

dividing aggregate years of  life lost by 100,000 (the cohort  size at

birth).  This value  is shown in  the  table.   The  aggregate years of  life

lost  can also be used to measure the average loss of life  to  those  dying

of background radiation induced  cancer.  The members of the cohort  can

be considered in  two groups, those  that die of background  radiation

induced cancer  and  those  that do not.   The  second group has the same

life  expectancy as  it would  if  there were no background radiation.  Those

that  do die from  background  radiation have  a reduction in life expect-

ancy  equal to  the average years of  life lost to premature deaths.

      The four models  (for absolute and relative risk and for 30 year and

 life plateaus) provide estimates of cancer deaths ranging from 69 to 490

 over the life of the  cohort.  Aggregate loss of life ranges from 1700 to

 6600 years.  Reduction in life expectancy at birth ranges from .0017 to

 .0066 years.  The individuals suffering the deaths induced from the

 background radiation suffer an average shortening of their lives ranging

 from 14 to 25 years depending on the model.

      These results can be compared with the measures of risk presented

 in Tables A 3-10 through A 3-14 and A 3-17 and 18 in Annex III.

 Table A 3-10 displays the estimated measures of lifetime risk of lung

 cancer Induced  by inhaled transuranium elements.   Estimated numbers  of

 early deaths range from 2.15 to 25.0 with  an aggregate years of  life

 lost ranging from 47  to 368  years.   The average years  of life lost to

 those suffering early deaths ranges  from 14.7 to 22.0  years.  Exposure to

 1  mrad  per  year is  therfore  estimated  to have a much smaller lifetime

 impact  than does  background  radiation.

      Measures of  lifetime risk  of liver cancer  mortality from inhaled

 Plutonium are shown in Table A  3-13.   This impact  is considerably

 below that  of lung cancer induced by inhaled  transuranium elements,

 and  is  therefore  lower  in comparison to background radiation.

 Tables A 3-10,12,14 and 17 of Annex III display measures of risk to

 other organs from inhaled and ingested transuranics.  Results show that

 lung cancer induced from inhaled plutonium is the major contributor to

 the risk from exposure to transuranium elements.  The cumulative risk

from all organs is not large in comparison to that from background

radiation, as can be seen from the summary of premature deaths  from

inhaled transuranic aerosols for a 1 mrad per year lifetime exposure

(Table A 3-18).

     These life table models show that lost years of life have an

almost insignificant impact on life expectancy at birth, but that those

that die prematurely from the exposure suffer a substantial shortening

of their lives.  The life shortening is approximately the same for both

forms of risk: exposure to transuranium elements and background radiation.

4.   Other Risks Experienced By The General Population

     Table A 4-2 illustrates a few of the risks of death the U.S.

population presently experiences from various causes.  All estimates are

based on the life table model.  Mortality rates are derived from 1969

mortality statistics for the U.S (2).  The measures of risk are the same

as those used in Table A.4-1 and are interpreted in an analogous manner.

The first risk shown is that from malignant neoplasms.  Risk is

measured by removing malignant neoplasms as a cause of death and com-

paring the situation that would then prevail against that for the case
                                                ' *                 '-    *»

where it exists at the presently experienced level.

     The Table shows that a cohort of 100,000 individuals suffers 2900

spontaneously occurring lung cancer deaths.  These deaths take an

aggregate of 45,000 years of life from the cohort.  Therefore, life

expectancy at birth is reduced .45 years due to lung cancer.  The

average loss of life to those individuals that die of lung cancer is 15

years.  These results can be compared to the results in Table A 3-10.

Although the impact of lung cancer is much greater than that for inhaled

 Plutonium or for background radiation, the years of life shortening to

 those that die of lung cancer is approximately the same.

      Other models presented in Table A 4-2 measure the impact of a

 variety of non-cancerous causes of death.* The numbers of deaths range

 from a high of 1000 to a low of 2, and the aggregate years of life lost

 to the cohort ranges from 12000 to 80.  These impacts are considerably

 smaller than those for malignant neoplasms or for lung cancer.

      Some well known diseases are represented in the table.   All

 incorporate some  risk of  death.   Some, such as chicken pox,  are not

 normally believed to cause death.   As  can  be seen chicken pox does

 involve  a small risk of death.   The average of 56 years of life lost  to

 those  dying  of  chicken pox reflects that its  impact  is  primarily on the


     The  table.also has measures of  the impact  of various  accidental

 causes of death.  The  accidental risks shown  range from 1000  deaths due

 to falls  to  8 for deaths from accidents caused by electric current  from

home wiring and appliances.  The average years of life  lost to  those

that die of these accidents reveals  that different forms of accidental

death impact at different ages.

                                     Table IV-1
         Measure  of  Lifetime  Risk of  Mortality from Background Radiation*
                              (Cohort size -  100,000)
                                                        Risk Models
                                      Relative Risk Estimate   Absolute Risk Estimate
Measure of Risk

Premature Deaths

Aggregate Years of Life Lost
to Cohort

Reduction in Life Expectancy
at Birth  (in years)

Average Years of Life Lost
to the Premature Deaths
30 Year



Life      30 Year
Plateau   Plateau
 0.066    0.017



*A11 mortality effects shown are calculated as changes from the U.S. Life Tables for
 1970 to life tables with the risk of mortality from, all forma of cancer reduced to
 account for the removal of background radiation.  These effects also can be interpreted
 as changes in the opposite direction; from life tables with the cause of death removed
 to the 1970 life table.  Therefore, the premature deaths and years of life lost are
 those that would be experienced in changing from an environment where there is no
 background radiation to one where background radiation is present.  Background
 radiation is assumed to be equal 100 mrem per year.  Risk estimates are based
 on the NAS-BEIR Report. All values rounded to no more than two significant figures.

                                                        Table IV-2
                              Measure  of Lifetime Risk of Mortality from a Variety of Causes
                                                 (Cohort size - 100,000)
       Cause of Death

Malignant Neoplasms  (140-209)2

Malignant Neoplasms  of Trachea
Bronchus and Lung  (162)

Accidental Falls (E880-E887)

Accidents Caused by  Fires and
Flames (E890-E899)

Tuberculosis, All Forms  (010-019)

Accidental Drowning  and  Submersion

Asthma (493)

Accidental Poisoning by Drugs and
Medicaments (E850-E859)

Appendicitis (540-543)

Accidents Caused by  Cataclysm

Accidents Caused by  Bites and Stings
of Venomous Animals  and Insects, and
Other Accidents Caused by Animals
(E905, E906)1*
Premature Deaths

                     Reduction, in iife
Aggregate Years of   Expectancy at Birth  Average Years of Life
Life Lost to Cohort  (in Years)
Lost to Premature Deaths


Table IV-2
                                                                          Reduction In Life
                                                     Aggregate Years of   Expectancy at Birth   Average Years of Life
       Cause of Death              Premature Deaths  Life Lost to Cohort  (In Years)	   Lost to Premature Deaths
Accidents  Caused by Electric  Current
     "   lr±n8 "* APPlianCe8                                                                           37
                                               8               290               0.003
Tetanus  (037)                                  *                80               0.001                  20

Chicken  pox  (052)                              2               130               0.001                  56
     mortality effects shown are calculated as changes from  the U.S. Life Tables for 1970 to life tables with the
 cause  of death under Investigation removed.  These effects  also can be interpreted as changes in the °PP^e
 direction,  from life tables with the cause of death removed to the 1970 Life Table.  Therefore the Premature
 dSns £d  years of life  lost are those  that would be experienced in changing from an ^°"*£*»™ *J signif 4.
 indicated cause of death  is not present  to one where it is  present.  All values rounded to no more than two signiri
 cant  figures.

 2ICDA  Codes, 8th Revision.

 3Catacylysm  is defined to  include cloudburst, cyclone, earthquake, flood, hurricane, tidal waves, tornado, torrential
 rain  and volcanic eruption.
 "Accidents by bite and sting of venomous animals and insects includes bites by
  and spiders; stings of bees, insects,  scorpions and wasps;  and other venomous bites and stings
  Caused by animals includes bites by any animal and non-venomous insect; fallen on by  horse or "^ "^'  *£!*'
  kicked or stepped on by animal; ant bites; and run over by horse or other animal.  It  excludes transport accidents
  involving ridden animals; and tripping, falling over an animal. Rabies is also excluded.

 5Accident caused by electric current from home wiring and appliance includes burn by electric current,  electric shock
  or electrocution from exposed wires, faulty appliance, high voltage cable,  live rail  and  open socket.   It excludes
  burn by heat from electrical appliance and lightning.


 1.    U.S.  Department of Health, Education, and Welfare, Public Health
      Service.   U.S.  Decennial Life Tables for 1969-71. Volume 1,
      Number 1,  May 1975.

 2.    U.S.  Department of Health, Education, and Welfare, Public Health
      Service, National Center for Health Statistics.   Excerpt from
      Vital Statistics of  the United States 1969.  Volume II-Mortality.

 3.    Chiang, Chin  Long.   Introduction  to Stochastic Processes in  Bio-
      statistics.   John Wiley &  Sons, Inc.,  New York, London,  Syndney.
      (A Wiley Publication in Applied Statistics).

 4.    U.S.  Department  of Health, Education,  and  Welfare,  Public  Health
      Service, U.S. Decennial  Life  Tables  for 1969-71.  Volume  1, Number 5,
     May 1975.

 5.   Hunger, Byron M., Barrick, Mary Kay, and Cook, John, "Life Table
     Methodology for Evaluating Radiation Risk".  Office of Radiation
     Programs,  U.S. Envrionmental Protection Agency, Technical Note
      (in preparation).

6>   The Effects on Populations of Exposure to Low Levels of Ionizing
     Radiation.   National Academy of Sciences, National Research Council
     Washington, D. C., November 1972.

              ANNEX V

      Guidance Implementation
U. S. Environmental Protection Agency
    Office of Radiation Programs
       Washington, D.  C. 20460


1.0  Introduction 	    1
2.0  Implementation of Guidance by Estimating Dose Rates
     to Lung and Bone 	    4
     2.1  Dose Rate to the Lung 	    4
     2.2  Dose Rate to the Bone	    6
3.0  Implementation of Guidance by Use of a Soil
     "Screening Level" 	    8
4.0  Implementation of Guidance by Means of Soil Data
     Using Site-Specific Parameters 	    9
5.0  Sampling and Analysis Methods 	  11
     5.1  Statistical Criteria 	  12
          5.1.1  Soil Sampling	  12
          5.1.2  Area Acceptance Criteria	  14
6.0  Remedial Actions 	  15
     6.1  Costs of Remedial Actions 	  17

1.0  Introduction

     The Environmental Protection Agency is issuing guidance directed to

all Federal Agencies in response to the problem of environmental contam-

ination by the transuranium elements.  The guidance recommends annual

dose rate limits to members of the public in the critical segment of

the exposed population for pulmonary lung and for bone.  Implementation

procedures that may be used to determine compliance with this guidance

are discussed in this annex.

     Implementation of these recommendations should include an evaluation

of the site, a projection of the radiation dose rate to determine whether

or not guidance values are being exceeded, and remedial actions if there

is indication that guidance values are, or may in the future be exceeded.

A reasonable evaluation of a contaminated site should include a descrip-

tion of the site and environmental measurements of contamination levels

in environmental media at a level of detail sufficient to convey

adequate information to the general public.  All dosimetry  and  environ-

mental pathway models used in estimation of radiation doses to  persons

should be described in sufficient detail to permit evaluation of the

procedures used.   If projected  dose  rates are greater  than  the  guides,

protective or remedial actions  should be performed to  the extent

necessary, so that guidance values are  not exceeded  and  will not be

exceeded in the  foreseeable future.  The implementation  of  these

recommendations  is the responsibility of those Agencies  having

regulatory and administrative responsibilities for the site in  question

and/or  the materials  in use at  that  site.

       The Agency believes that these recommendations  can be  implemented

  by using one  of three  general procedures without  requiring  unreason-

  able, unnecessary, and expensive  regulatory actions.  These procedures,

  which are described  in more detail  in  the following  sections of this

  annex, may be used for the entire site or for portions of the site as


      a.   dose  rates can be calculated, using the appropriate dosimetry

 models, from measurements of the concentration of the transuranium

 elements in air, food,  and water at the point of inhalation and/or

 ingestion by people.   This is the most direct and preferred method.

      b.    soil concentration levels of the transuranium elements can be

 compared to  a  "screening level" for soil,-  defined as  that  level below

 which the concentration of the transuranium elements  are not likely  to

 lead to  dose rates  in excess  of guidance recommendations.

      c.    dose rates  can be calculated  from the  soil  contamination

 levels of the  transuranium elements  using site-specific parameters for

 transport models and  the appropriate dosimetry models.

      An  implementation  program for obtaining needed information  at

 minimum  cost may best be designed according to statistical criteria

 for sampling, measurements, and analysis.  By selecting such criteria

 appropriate to the site,  adequate data can be obtained for making  a

 decision on any  required action without unnecessary cost due to overly

restrictive conservatism or inefficient design.

     In the context of  this guidance, the objective of environmental

sampling and analysis is to derive information for the purpose of

estimating dose rates to pulmonary lung and to bone of exposed

individuals.  These dose estimates are derived on the basis of models

which depict the various pathways by which transuranium elements in the

environment may interact with man and produce exposure to radiation.

These models include parameters which describe the characteristics of

transuranium elements in the environment, the manner in which they may

be transported through the air or through food pathways, modes of

interaction with man (including inhalation or. ingest ion) and, finally,

factors related to the radiation energy deposition in organs and tissues.

In general, the best dose estimates are derived from data acquired  from

measurements in the dose pathway as close as possible to the point  where

transuranium elements interact with man, although  it  is sometimes

necessary to make measurements of the  radionuclide concentrations at

points  in the  environment further from the  receptor,  followed by  the use

of pathway models'  to estimate doses  to individuals or population groups.

      A  soil sampling program may be  utilized  to  determine  compliance

with the recommendations.  Most  sites  where contamination  of the soil

presently exists have been  surveyed  to determine levels of transuranium

 elements.  The data should  be  used  to indicate areas which are clearly

much greater  or much smaller than the limiting soil concentration

 derived from the guidance recommendations.  It is only for those land

 areas in between,  which may or may not exceed the guidance recommenda-

 tions,  that it will be necessary to conduct a sampling program.

      The guidance is intended to be applicable to all sites and all

 types of land utilization.   Evaluation must be made on the basis of

  present and projected conditions and include recognition that

  disturbance of the soil surface may change both the pathway to humans

  and the magnitude of the accumulated dose.  For the inhalation pathway,

  most of the potential hazard is derived from contamination at, or near

  the surface.  Most man-made disturbance will reduce the concentration

  in the top layer either by dilution or removal, but may increase the

  resuspension rate.   The overall effect of such  activities  must be

  considered in the implementation plans.

  2>0  ImPlementation  of  Guidance by  Estimating Dose Rates to  Lung and
       Bone                                           ~~	~^	

  Federal Agencies  may show compliance for  a specific site, or for

  sub-areas  of a specific site, by certifying  that guidance values  for

  dose rates  to the lung and bone of members of the  critical segment of

  the exposed population are not being exceeded.  The most direct method

  is to measure transuranium element concentrations in environmental media

 -such as air, food, and water at the point of interaction with man and to

  then calculate the potential radiation dose rates using the appropriate

 dose conversion factors  and dose model  parameters.   When this procedure

 is  used,  adequate documentation should  be provided  to demonstrate how

 dose rates  are calculated.   The Agency  favors the use of realistic

 environmental  measurements and  realistic model .input parameters;  con-

 servative parameters  should  only be  used  to the  extent  necessary to

 compensate  for uncertainties.

 2.1  Dose Rate to  the Lung

     Lung dose rates are calculated using  appropriate dosimetry models,

which require knowledge of the annual average transuranium element

concentration in air,  aerosol particle size  distributions, and

solubility class of the specific radionuclides  present.   Procedures  for

the sampling and analysis of near-ground level  air for the transuranium

elements have been published and have been used for many years.   Pro-

cedures of sufficient sensitivity, .accuracy, and precision are available

for implementation of this guidance.

     Judgment should be exercised in the design of an air sampling

program to ensure that air concentration levels are representative of

actual exposure conditions.  Environmental measurements of airborne

particulates which bias the dose estimates by the collection of only

certain particle size ranges should be avoided or a suitable correction

should be made.  It is preferable that the particle size distribution be

experimentally measured for a specific site.  Reasonable values can be

assumed based on analogies with similar sites when projected lung dose

rates are small compared  to the guidance level.   The  solubility class of

an aerosol  can usually be determined  from the history of the contam-

inating event and  the subsequent  environmental weathering mechanisms.

Dose conversion  factors  for  lung  dose rates  that  the  Agency believes to

be reasonable for  the purpose of  implementation of  the  guidance  are

presented  in Annex III.

     In certain cases,  the  determination of site-specific parameters

for use  in the  dosimetry models may be difficult  or impossible with the

equipment  available or within the time constraints allowed.   Under these

circumstances,  a derived air concentration limit, which will have a

 very large probability  that the guidance recommendations will not be

 exceeded, may be substituted for the site-specific value.  The Agency

 suggests that such a derived air concentration limit be based on an

 activity median aerodynamic particle diameter (AMAD) not to exceed

 0.1 ym, which is substantially smaller than observed values at all

 known contamination sites.  The calculated limiting concentration for
 this procedure would be about 1 fCi/m  of alpha emitting transuranium

 nuclides, for air samples averaged over a period of one year or more.

 Air concentrations above this value do not necessarily mean that the

 guidance recommendations may be exceeded,  but rather dictate that a

 more thorough evaluation of existing conditions  be made.

      Elevated levels  of  transuranium elements in air indicate that

 these elements may be found in nearby soils.   When these  levels approach

 that of the guidance  recommendation, implementation should  include a

 characterization  of the  environmental source  term,  to provide a means

 of  judgment with  respect to the potential  for future exposure levels and

 the practicality  of remedial measures.

 2.2 Dose Rate to  the Bone

     Bone dose rates are calculated  with appropriate dosimetry models

 using a knowledge of the average amounts of transuranium elements  that

 are Ingested  in a year,  the chemical state of  the transuranium elements

 at  the time of ingestion,  and the proper dose  conversion factor.

 Inhalation of transuranium elements, especially in soluble forms, can

also lead to radiation doses to bone and should be considered where


     Sampling and measurements of transuranium elements  in food and water

at the point of human consumption is the most direct and preferred

procedure for determining the annual average ingested amount of these

elements.  Alternatively, the amounts of ingested radionuclides may be

estimated using environmental pathway models.  The chemical state at  the

time of ingestion is inferred from the medium into which the transuranium

elements are incorporated at the time of ingestion.  In particular,  trans-

uranium elements which are incorporated into biological tissue when

ingested should be considered as "organically complexed" and require a

special dose conversion factor.  Dose conversion factors that the Agency

believes appropriate for the implementation of this guidance with

respect to bone dose rates are given in Annex III.

     The Agency believes that suitable sampling and analytical procedures

are available for the analysis of the transuranium elements in food and

water and that they have the necessary sensitivity, accuracy, and pre-

cision for purposes of implementating of this guidance.  Also, as with

the inhalation pathway, elevated levels of Plutonium and  the trans-

uranium elements in food or water indicate that these elements may be

found in nearby soil or in sediments.  Under such conditions,  imple-

mentation of the guidance should include a characterization of  the

environmental source term, to provide a means of judgment with  respect

to the potential for future exposure levels and the practicality of

remedial measures.

  3.0  Implementation of  Guidance by Use  of  a  Soil  "Screening Level"

       Federal Agencies may  show compliance  for  the total area of a site,

  or for  subareas  of  a site, by certifying  that such areas have trans-

  uranium  element soil concentration levels  less than a screening level

  value of 0.2 yCi/m  .  The  "screening level"  is a  total transuranium

  element  soil concentration level in the top  1 cm  of soil such that, in

  the Agency's opinion, dose rates will not  exceed  guidance recommenda-

  tions under the vast majority of land use  conditions.  Its usefulness

  is limited to the area in close proximity  to the measurement,  in that

  a dynamic equilibrium between the surface and adjacent air column is

  localized and only indirectly contributes to the adjacent areas.

      Because of present  uncertainties in the amount of plant uptake

 for the more soluble transuranium nuclides, such as americium and

 curium,  and the resultant possibility of larger doses via the  ingestion

 pathway than calculated,  the  screening level  concept may not be appli-

 cable when  the  soils of  a contaminated area contain these nuclides  in

 amounts  greater than 20%  of the total  activity.  Lands with  concentra-

 tion levels less than the screening level are judged to be suitable  for

 all  normal  activities including residential and agricultural uses.   The

 use  of this screening level is intended  to  reduce  the land areas

 requiring extensive  evaluation and to minimize  the number  of measure-

 ments needed.

      If land areas have transuranium element  levels greater than the

 screening level, it should not be presumed  that guidance values are

necessarily exceeded, because conservative  assumptions were used in the

derivation of the screening level.   Additional site specific evaluations

of potential dose rates to lung and bone (Section 4) should be made

before remedial actions are initiated.

     Inherent in the application of the screening level is the assumption

that soil contamination by the transuranium elements will cause radia-

tion exposure through pathways such as  the inhalation of resuspended

soil, the ingestion of foodstuffs grown on the soil, the ingestion of

soil by children, and the ingestion of  drinking water contaminated by

soil runoff.  In all cases the cumulative doses to the critical segment

of the population must be considered, with the admonition that the

accumulated doses from all pathways should not exceed those recommended

in this guidance.

4.0  Implementation of Guidance by Means of Soil Data Using
     Site-Specific Parameters

     Federal Agencies may show compliance with this guidance for a

specific site, or for subareas of a specific site, by means of soil

measurements and by using pathway and dosimetry models with parameters

determined for that specific site to certify that  the resulting dose

rates do not exceed guidance values.  This approach differs  from the  use

of a soil screening level because parameters such  as the  resuspension

factor are determined  for a specific site.  It is  expected that use of

site-specific parameters will show  that soil contamination levels  higher

than the suggested screening level may  correspond  to organ doses well

below guidance level.   Implementation by  site-specific  parameters  is

appropriate where land areas have  transuranium element  levels  greater

than the screening level  and  further evaluation  is necessary to

 determine whether or not guidance dose limits are being exceeded.

      The air concentration at the site of the receptor can be generally

 correlated with the adjacent soil concentration by use of a resuspension

 factor, and used to estimate the inhalation dose rate.

      The site-specific resuspension factor may be either measured

 directly or calculated from other data.   Direct experimental determina-

 tions are often difficult to make and  not very reproducible.   Therefore,

 calculational techniques are sometimes preferred although their  cor-

 relation with measured values is subject  to considerable uncertainty.

 The Agency has developed a method,  based  on the concept of  air mass

 loading,  which may  be  useful for this  purpose (see Annex II).  An

 "effective" resuspension factor  is  derived,  defined as the  resuspen-

 sion factor derived from the air mass  loading for the  given location

 and modified by an  "enrichment factor" which takes into account  the

 generally observed  nonuniform distribution of the activity  with  size

 of  particles in calculating the  amount of  transuranium element activity

 in  the  inhalable fraction of  the resuspended material.   The "enrichment

 factor" is  a theoretically derived  parameter,  and its  correlation to

 actually  observed situations  has  not yet been established.  The

 resuspension factor  derived in this manner  is applicable only  to an

 infinite  plane  source, and  must be  further  corrected for the dilution

by uncontaminated materials carried into the generally small contam-

inated area.

     The  ingestion pathway must be  evaluated  separately,  using data

applicable to the specific  site in  terms of  type  of crops, plant uptake

parameters, and pathway to a critical segment of the population.   The

more unusual transfer mechanisms to people,  such as the ingestion of

dirt by children and the contamination of drinking water wells, may

also need to be examined if shown to be of importance.

5.0  Sampling and Analysis Methods

     Choice of Methods

     The choice of suitable methods for sampling and analysis is  the

responsibility of the Agency implementing the guidance.  The implementing

Agency should demonstrate that the methods that are used have the

necessary sensitivity, accuracy and precision for purposes of implementing

this guidance.  A description of the tools and techniques used to collect

the samples, the. procedures for preparing the samples for analysis, and

the method used for radiochemical analysis should be included.

     Sample Collection

     The Agency recommends that for undisturbed sites where soil

measurements are taken to evaluate the inhalation pathway, soil samples

should be taken to a depth of one centimeter and transuranium element

activity be measured in all soil particles less than two millimeters in

size.  Several individual samples may be composited for a single measure-

ment.  At some sampling points it may not be possible to collect samples

to a depth of one centimeter (for example, very stony soil or a thick

grassy area).  In such cases, other means must be found so that repre-

sentative samples are collected.

     Soil Particle Size Distribution Analy«ia

     If a model for determining a transuranium element soil

concentration corresponding to the lung dose rate limit is chosen which

  involves  the  calculation  of  a  soil particle resuspension  factor,

  measurement of  the  soil particle size distribution may need to be made.

  The usual method for determining the distribution is by sedimentation

  analysis  (1).   The  standard  sedimentation technique employs wetting

  agents for dispersing agglomerated soil particles.  Another method

  uses an oscillating air column for the dry separation of particles down

  to 5 ym.  For purposes of this guidance, soil characteristics should be

  altered as little as possible in the collection and preparation of the

  soil sample and care should be taken to choose a method which does not

 cause the breaking up of soil aggregates that were present when the

 sample was taken.

      Radiochemical Analysis

      Techniques  for the determination of transuranium elements in soil

 have been published (2).   Each  of  the more widely used techniques has

 been shown to  be accurate  under certain  conditions.   The principal dif-

 ferences  between them are  the techniques  used  to solublize the plutonium

 in the  sample.   Three solubilization  techniques  are most commonly used:

 acid  leaching, acid  dissolution, and  fusion.   The fusion method is

 considered  to be applicable to  a wider variety of soils than the  other

 two methods.

 5.1  Statistical Criteria

     5.1.1  Soil Sampling

     When planning a soil survey it is advisable  to divide  the  total

area under investigation into units at the very beginning of the survey

rather than to collect samples more or less haphazardly.  Then samples

taken to determine the acceptability of the land by comparison of

measured concentration levels to the screening level may be collected

from sampling units in accordance with a sampling plan.   If it is  later

decided that more sampling is necessary, no change in the sampling plan

is necessary, and the location for additional samples will have already

been determined.

     The number of samples to take within a sampling unit may be

estimated from the specific statistical approach used in the sampling

plan.  An important factor affecting the number of samples to be taken

is the risk of making the wrong decision in deciding whether a sampling

unit is acceptable or requires remedial action.  To reduce the risk of

making the wrong decision, larger numbers of samples must be taken.

Judgment must be used to strike a balance between the desirability of

making the right decision and the difficulties and expense involved in

taking large numbers of samples.  An additional factor affecting the

number of samples is the variability of the transuranium element

concentration within a sampling unit.  If detailed information is not

available on the variability, a simple approach is to take the same

number of samples within each unit.  These could be taken on a grid

system to ensure that all subareas of the sampling unit are sampled.  A

disadvantage of this approach is that if the variability is substantially

different in different units, then the probability of detecting con-

centration levels requiring remedial action will vary from unit to unit.

If estimates of variability are available from past studies,  these can

be used to help determine the number of samples  required within each

 unit so that the probability of making a correct decision will be the

 same for all units.

      5.1.2  Area Acceptance Criteria

      After soil concentration levels have been determined, it must be

 decided if the area under consideration complies with the guidance

 recommendations or whether further evaluation will be needed.   The

 statistical methodology that is used must be such that few assumptions

 regarding the form of the soil concentration distribution will be

 necessary to ensure the validity of the statistical test.   The method

 should  also ensure reasonably low bounds on the risk of making the wrong

 decision,  and the  probability of not accepting an area which meets the

 guidance,  or accepting one which does not*  should be small.  Acceptance

 criteria which allow a maximum chance of error of 5-10% are generally

 considered appropriate.

      Considerable  variation  generally occurs  in environmental  samples

 taken even in closely adjacent locations.   If  one or more  samples  from

 any sampling unit  exceed  the air or soil concentration limits  corre-

 sponding to the guidance  recommendations, a decision must be made  on

 whether the sampling unit  is acceptable.  Such  a  decision  is best based

 on statistical  tests which consider both  the magnitude  of  the  deviations

 from  the average and  the number  of  samples which  are involved.  A number

 of statistical methods are available  for performing such an evaluation,

and the choice must be made  on the basis of the data available and the

results desired.

     The number of samples collected and  analyzed  should be sufficient

to adequately guard against the errors  of falsely  failing  to  accept

a land area when the true fraction does not exceed a lower bound  and  of

falsely accepting an area when the true fraction is equal  to  or greater

than the upper bound.  The upper bound  is a measure of that portion of

the land area which would be considered reasonable to exceed  the  limiting

soil concentration.  A small fraction would provide assurance that the

mean for the entire area, assuming a normal or known skewed distribu-

tion, would not exceed the screening level.

6.0  Remedial Actions

     Remedial actions are required at a site when the projected

radiation dose exceeds the recommended guidance values.  Choosing a

specific action is usually a complex decision affected by the physical

characteristics of the site, the variety  of appropriate remedial actions

possible, and on monetary and non-monetary costs.   The long half-lives

of the transuranium elements makes the decision more difficult because

consideration must be given to long-term care.  The objective at a

specific site is the selection of remedial actions that best assure that

guidance recommendations will not be exceeded at the least possible


     Most remedial actions can be categorized into one of five general

classifications:  removal of the contamination for off-site disposal,

removal for on-site shallow burial, stabilization with no removal of

contamination, dilution of the contaminant with no removal, and measures

restricting the use of the site by members of the public.

      Methods of removing contamination include raking and grubbing out

 vegetation, stripping the top layer of soil by scraping, vacuuming,

 or other similar techniques.  The contaminated soil and other material

 can be transported to especially designated locations on site for

 storage or shallow burial,  or they can be shipped to off site

 depositories with provision for long-term care.

      Stabilization of a contaminated site includes actions such as

 covering the land with an impermeable cover such as oil, polymerized

 plastics or asphalt,  or with soil and vegetation,  or by applying

 chemical stabilizers  to the land area.   The stabilization leaves the

 contamination on site,  but  reduces its  accessibility to wind  and surface

 water erosion and therefore reduces  the potential  exposure dose.

      Plowing and cultivating are the principal methods  of dilution of

 contamination.   The goal is  to mix the  surface contamination  into the

 top  20 cm or more of  soil,  attaining a  form of stabilization  in place.

 Estimates of the amount  of dilution  achieved by  cultivation are suggested

 in Table A  1-2 of Annex  I.

      At  some sites, it may be feasible  to perform  no  cleanup, but rely

 completely  on restricting land use.   Restrictions  are applied to  the

 contaminated area  itself, and may  include a  buffer zone  bordering the

 contamination site.  Land-use restrictions serve two  purposes;  they

 provide  a means  of controlling access to areas where  the radiation

health risk  is excessive and they help  in preventing  the disturbance

of the land  surface.  Land-use restrictions may limit or prohibit  access

to an area, or they may be limited to prescribing  the types of activities

carried out within an area.


6.1  Costs of Remedial Actions

     It is to be expected that a variety of  remedial actions  should be

effective in reducing the exposure dose.   Under these conditions,  the

least costly action or set of actions should be selected.   When costs

are evaluated both monetary costs and nonmonetary costs,  including the

environmental costs, are to be considered.  Whenever possible,  it is

desirable that all costs be quantitied monetarily.  Costs that  cannot

be quantified in monetary terms should, whenever possible, be quantified

in other ways, with narrative descriptions used when quantification is

not possible.  A major difficult is likely to be that different com-

binations of decontamination procedures are expected to have somewhat

different combinations of monetarily and nonmonetarily, quantifiable

and nonquantifiable costs.

     Although it probably is impossible to identify and measure all

costs in the evaluation of various remedial actions, it is desirable

that as many as possible of the larger costs be evaluated.  One con-

straint on any attempt at measuring costs is the cost of acquiring the

information needed.  Some costs may be easy to identify but expensive

to quantify.  Other costs may be quantifiable in nonmonetary terms,

but it may be difficult or impossible to place a monetary value on

them.  Models may be usefull in estimating the difference in costs of

some remedial procedures.  It should be noted that  the cost of any

radiological surveillance carried out to determine  if a site exceeds the

guidance does not impact on the selection of the  least cost remedial

action.  However, all radiological surveillance costs necessary for the

 performance of a cleanup procedure are a cost  to  that particular


      Any  general technique  of  remedial action  is  likely  to  incorporate

 costs associated with  some  combination of the  following  actions or

 procedures:   (1)  radiological  surveillance,  (2) protection  of workers,

 (3)  stabilization of land surface,  (4)  dilution,  (5) removal of con-

 taminated material from  surface,  (6) packaging, (7) transportation of

 contaminated materials,  (8) ultimate disposal  at  storage site, (9)

 restoration of  site, and  (10) maintenance of restricted  access to site.

 Costs  for each must be evaluated as appropriate.  When services are

 needed indefinitely, these future costs  should be expressed as present


     Nonmonetary  costs include all costs  that are difficult or

 impossible to quantify in monetary terms.  They should be quantified

 in nonmonetary terms to the extent possible.  Descriptive discussion

 is appropriate where quantification is not complete or is impossible.

     Examples of such costs would include the increased health risk

 to workers performing the remedial actions, the risk of health effects

 to members of the general population that may result when land surfaces

are disturbed during remedial actions,  and psychological costs resulting

from fears of a little understood environmental contaminant.


1.   Day, P.R., Particle Fractionation and Particle-Size Analysis,
     *n Methods of Soil Analysis.  Part- I.  C.  A. Black, Editor, Amer.
     Soc. of Agronomy,  Inc.,  Madison,  Wisconsin 1965.

2.   Bernhardt, D. E.,  "Evaluation of  Sample  Collection and Analysis
     Techniques for Environmental  Plutonium:"  U.S.  Environmental
     Protection Agency, Technical  Note,  ORP/LV765.

3'   JU"te1?!,?-  1971  Attribute Sampling; Tables and Explanation.
     McGraw-Hill,  New York.^                  ~~	

              ANNEX VI

U. S, Environmental Protection Agency
    Office of Radiation Programs
       Washington, B.C.  20460

                                Annex VI
                            Table of Contents
I.   Introduction 	  1
II.   Generic Impact Assessment 	  2
III. Alternatives to Proposed Action 	  4
IV.   Projected Impact of Guidance at Existing Sites 	  8
V.   Costs of Remedial Actions 	 13

                                Annex VI

                        ENVIRONMENTAL ASSESSMENT

I.   Introduction

     Under the provisions of the National Environmental Policy Act of

1969, it is intended that every major Federal action be examined in

terms of projected impacts and that all available alternatives be

considered.  The purpose of such an analysis is to compare the costs

and benefits of the recommended action with other options in terms of

the broad range of projected health, sociological, economic, and

environmental impacts.

     The implementation of the proposed action would be site-specific.

The portion of the environment affected is that where present or

future transuranium element concentrations may exceed guidance values.

Such areas are likely to be those where the transuranium elements are

prepared, fabricated, used, stored, or transported.  A number of such

areas currently exist within the limits of the continental United States.

Most such contamination is located on lands with restricted or limited

access, but a few instances exist where significant contamination has

spread to privately owned property.

     The proposed guidance does not include recommendations on  specific

methods of cleanup and restoration.   Such methods  are  to be determined

for  each contaminated site by  consideration of  the effectiveness  of

the  techniques, the cost-benefit evaluation,  and  the specific environ-

mental impacts.  Therefore,  the  range of  total  impacts must be  evaluated

separately and  independently for each proposed'major remedial action in

terms of all available and  applicable methods.

  II.   Generic Impact Assessment

       The probable impacts of Implementation of the proposed action will

  vary according to the nature and scale of the method used for affecting

  cleanup and restoration,  and may be particularly sensitive to the

  location of the proposed  actions.   The primary impacts  of most methods

  of effecting desired cleanup and restoration of contaminated areas will

  result  in some temporary  disruption of normal activities  on and near the

  site, slight and  temporary impairment  of  air and water  quality, and

  possibly  significant  effects  on  animals,  flora, and  fauna.   The exact

  nature  of  such  environmental  impact will be  site specific  and

  dependent  on  the nature and extent of  the site, the degree of contamina-

  tion, and  the procedures chosen for cleanup and restoration.  Examples

 of adverse environmental impacts are:  loss of habitat of fish, birds

 and mammals, increased mortality among displaced animals as well as

 loss of trees and other vegetation.   Run-offs from disturbed land can

 lead to pronounced short-term aquatic impacts depending upon the amount

 of the chemical and biotic components of the system.   A detailed study

 of such short- and long-term  ecological impacts has been commissioned

 by the Environmental Protection Agency and results  are expected to  be

 available by late  1977.

      Of  special concern  in the evaluation  of  potential environmental

 impacts  is  the irreversible or irretrievable  commitment  of resources.

 Such  commitments range from permanent removal of the  land  from useful

productivity  to  loss of scenic beauty and other  intangible  values.

Cleanup and restoration inevitably involves a  commitment of money,

labor, and equipment and this must be taken into consideration in an

overall assessment.   Both the temporary and permanent commitment of

resources can be expected to increase as the stringency of the regula-

tion becomes more severe, but not necessarily on a linear proportional


     The principal expected effects of a land cleanup and restoration

action are those related to the anticipated benefit on the health and

safety of individuals in the general population, the short- and long-

term effects on the environment, the costs related to the total action,

and the sociological and political consequences of these changes.  A

number of alternative levels of control need to be considered to gain

an overall perspective from which to evaluate the overall impact.

     Under Section 102(2)0 of the National Environmental Policy Act of

1969, it is required to study, develop, and describe appropriate altema-

tives to the proposed or recommended courses of action.  The purpose is

to analyze the environmental benefits, costs and risks so as not to fore-

close prematurely options which might better advance environmental

quality or have less detrimental effect.  Examples of such alternatives

are those of taking no action, of postponing action pending further

study, of taking actions of a significantly different nature which could

provide similar benefits with less severe environmental impacts, or

the acquisition or condemnation of land and waters.  The analysis of

each alternative should compare the environmental benefit, coats and

risks with the proposed action.  In summary, alternatives to  the pro-

posed action consist of  (1) no action,  (2) more stringent limits  (3)

  less stringent limits (4) alternative ways of implementing guidance (5)

  action which will achieve desired results by other means.

  III. Alternatives to Proposed Action

       A number of realistic alternatives were considered in the

  development of this guidance.   The lowest level of effort would be

  that of maintainance of  the status quo,  with no remedial actions.   This

  would gain zero benefit  in that  committed adverse  health effects would

  not  be reduced,  have zero costs,  and  have no detrimental effect on the

  environment.   .The highest level  of  effort would  be a uniform cleanup to

  fallout  level  background.   This would gain a benefit of  reducing the

  future number  of adverse  health effects  to a very  low number, but have  a

  potential for very large monetary cost and widespread disruption of the

  environment.  Such a level would be virtually impossible to achieve on a

 uniform basis and difficult to enforce because of major variations in

 the background level.  Uniform cleanup to such a limit  on a national

 scale would be prohibitively expensive,  involve significant relocation

 of populations and disruption of  activities,  and result in major eco-

 logical damage.

      A reasonable range of numerical limits for environmental

 contamination  by the  transuranium elements would  appear to range from

 a lower bound  set at  some  reasonable multiple  of  the average background

 level  to  an upper bound set  at the limit  required by consideration  of

public health criteria.  These limits, and  the costs and benefits at

these levels, are considered below in more detail.

     The least restrictive available guidance for population exposures

resulting from soils contaminated by the transuranium elements is that

derived from the numerical guidelines of the International Commission on

Radiological Protection (ICRP)  and given as recommended maximum

permissible concentrations in air and water for specific radionuclides.

For unrestricted occupancy this is 1 pCi/m3 for insoluble and 0.06 pCi/m3

for soluble plutonium-239 in air.  Soil concentrations derived from these

recommendations are of the order of 1000 yCi/m2, or, higher than the

proposed "screening level" by a factor of 5000.  Numerical values of

this magnitude would appear unacceptable for protection of an individual

in the general population, in that the total permissible radiation

exposure of that individual would be allocated to a single source or

activity. , Such numerical values could well be acceptable, however, for

remote or intermittently inhabited areas where the maximum cumulative

individual exposures would be considerable lower.  Such relatively high

contamination limits may also be appropriate where the decontamination

costs are prohibitive and remedial actions must be limited to on-site

stabilization and restricted occupancy.  The costs associated with

remedial actions only to this level could generally be expected  to be

lower than for the more restrictive guidance proposed.

     The lowest presently existing limit applicable to land use  of

contaminated areas is the plutonium-in-soils standard of 2 dpm/g of dry

soil adopted by the State of Colorado in 1973.  This value represents

approximately twenty times the average Plutonium fallout background for

Colorado, and also represents the threshold below which no increase in

  the adjacent airborne particulate concentration was reported observable.

  The Colorado standard is intended as a worker protection level above

  which some control action needs to take place before construction work

  can proceed in a contaminated area.   Because of the increased dust

  loading created by such activities the actual inhalation dose to exposed

  individuals could exceed the proposed guidance recommendation and no

  direct comparison of long-term impacts is  possible.   Because it  is

  intended to achieve only a  limited objective for  a relatively short

  period of time,  the Colorado standard cannot be considered  in the

  context  of long-term general public health protection.

      On  an administrative basis, a number  of alternatives were available

  to this  Agency for promulgation of appropriate, guides or standards.  The

 President's Reorganization Plan No. 3 of 1970  transferred certain

 functions  from the Atomic Energy Commission  to the Environmental Pro-

 tection Agency"...to the extent that such functions of the Commission

 consist of establishing generally applicable environmental standards

 for the protection of the general environment from radioactive material."

 As  a result of this transfer, Section 161(b)  of the Atomic Energy Act

 provides that the Administrator may,  within the above framework,

 "establish by rule,  regulation,  or  order, such standards  to  govern the

 use of  special nuclear material,  source material,  and by-product  material

 as  (he) may deem  necessary or desirable to...  protect health or to

minimize  changes  of life or property."

     The  same Reorganization  Plan also transferred all the functions  of

the  former Federal Radiation  Council, as specified in the Atomic Energy

Act, to the Agency.   Section 274(h) provides that "the Administrator
shall advise the President with respect to radiation matters, directly
or indirectly affecting health, including guidance for all Federal
agencies in the formulation of radiation standards and in the
establishment and execution of programs of cooperation with States."
     The Agency has considered both of the above options and decided
in this instance to promulgate Federal Radiation Guidance.  The
decision was based, in part, on the realization that all transuranium
elements are currently under the direct or indirect control of the
Federal government, that the extent of current contamination is very
limited, and that considerable flexibility may be required in imple-
mentation because of substantial differences between sites.
     Other applicable legislative authorities delegated to the Agency
include sections of the Clean Air Act, as amended, the Safe  Drinking
.Water Act, and the Hazardous Materials Control Act.  These other
authorities are generally  considered to apply to effluent releases
rather than to existing environmental  contamination, and  therefore
have limited applicability to  the  problems  addressed in this guide.
     The above discussion  is intended  only  to convey the  basis  for
the decision making process for a  generic guidance.  Application to
specific sites will necessarily require a more  detailed consideration
of  alternatives for possible remedial  actions and/or  land use restric-
tions where required.   It  is therefore important that  a detailed impact
evaluation be made in  every instance prior  to  implementation of these
guides.                                                  ,

       A further alternative considered would involve issuance of no

  Federal guides, with remedial actions determined solely by State and

  local authorities.  Such a course of action could be expected to result

  in a diversity of standards and regulations,  not all of which may be

  derived on a timely or rational technical basis.  In general, .such

  regulations tend to be unduly restrictive when viewed from the objective

  of protecting the public health and reflect much of  the fear of the

  unknown.   Because the  exact  scope and application of such regulations

  cannot  be  predicted, no  analysis  of expected  impacts can reasonably be


  Iv*  Projected  Impact  of Guidance  at  Existing  Sites

      The proposed guidance is intended to provide a minimization of

  health risk to  that level where no  individual  is exposed  to greater

  than an equilibrium lung dose rate of 1 mrad per year, with an

 attendant maximum risk of one additional fatality per million persons,

 exposed to that level per year.  In terms of environmental contamination

 levels,  this can be equated to approximately one hundred times the

 current  contamination levels derived from fallout.  For a parametric

 analysis of the effect  of changing the proposed guidance in either the

 positive or negative direction,  a  reference case of a deviation by a

 factor of ten  can be assumed.   The lower  bound will then be of the

 order of magnitude of the Colorado  standard  and the upper bound at a

 level currently  exceeded in only a  few instances  on unrestricted lands.

     There are four Federal sites in the United States  that presently

have transuranium element contamination above ambient levels beyond

their boundaries.  These include the Rocky Flats Plant in Jefferson

County, Colorado, Mound Laboratory in Miamisburg, Ohio, Nevada Test

Site in southern Nevada, and Trinity Test Site near Alamogordo,

New Mexico.  The majority of all contamination released is confined

within areas under the direct control of the Federal government, which

imposes restrictions on the access and use of these areas.  Relatively

small amounts of transuranium element contamination exists outside the

boundaries of these sites on lands generally accessible to the public.

The following discussion is intended to supply a perspective of applying

the guidance recommendations to these sites in terms of a soil concen-

tration reference level derived on the basis of generic data, which with

a very high degree of probability would be expected to result in an

inhalation dose to an individual not to exceed the guidance recommendations.

Use of such a soil contamination level is intended solely to provide a

basis for comparisons and does not imply direct correlation with the

dose rate recommendations.  A brief description is given for each site

and the general contamination pattern is indicated.  Numerical compari-

sons to show the estimated areas of limiting contamination to one-third

and one-tenth the reference level, and of allowing ten times greater a

value are given in Table VI-1.  Comparisons are made in terms of areas

outisde the boundaries of these sites.

     The Rocky Flats Plant (RFP) produces components for nuclear

weapons.  Barrels containing plutonium contaminated cutting oil slowly

corroded and some of the contents eventually leaked into the environment

and were dispersed.  On the basis of soil concentration data, all

                                 Annex VI

                                Table VI-1

            Comparison  of  Costs  of  Remedial Actions  At Various  Sites
            of  Existing Plutonium Contamination  For  Several  Possible
           Levels  of Maximum Soil Concentrations (Areas  are  Estimated
        from Contour Maps  and Costs Are Arbitrarily  Assumed  as  $500/acre)

Reference Level
0.2 yCi/m2
* 0.01 m2
10 x Ref. Leve
2 pCi/m2
* 0.01 mi2
1/3 Ref. Leve
0.07 yCi/m2
0.3 mi2
<80 mi2
<20 mi2
^ 0.01 mi2
1/10 x Ref. Level
0.02 uCi/m2
*> 1.6 m2
< 165 mi2
^ 300 mi2
* 0.01 mi2
*  Most of the existing contamination is in sediments of canals, and
   does not represent a hazard to humans.  Costs of eventual remedial
   actions are indeterminate.

off-site areas at the Rocky Flats Plant would probably be in compliance

with guidance recommendations.  However, more intensive evaluation may

be needed to determine the actual dose rates to the general population,

particularly in the most highly contaminated areas east of the plant.

The area is sparsely inhabited and there are few people living in the

particular area of concern.  The off-site area contaminated to a level

one-tenth the screening level comprises about 1.6 mi  with a current

population of less than 600.  No uncontrolled areas are contaminated to

a level greater than ten times the screening level.  All local water

supplies are expected to yield ingestion dose rates well below the

guidance recommendation.

     Mound Laboratory is a major research and development site for

fabrication of radioisotopic heat sources used for space and terrestrial

applications.  In 1969 a pipeline transporting a Pu-238 waste solution

ruptured, spilling the contaminated solution.  The plutonium migrated

slowly into nearby waterways.  The majority of the plutonium is now

sorbed and fixed on the sediments of the North and South Canals.

Maximum concentrations are 1 to 3 ft below the sediment surface and

currently do not pose any radiation problem, since very little of the

plutonium is in soluble form and the canal water is not used for

drinking purposes.  Banks immediately adjacent to the canal and overflow

creek subject to  occasional flooding have maximum plutonium concentra-

tions exceeding the reference level.  The amount of land in question is

about .01 mi  and there are no people living on this land.  There are no

areas with transuranium element contamination 10 times the screening

  level.  The amount of land contaminated to one-tenth  the  screening level

  is the same as the amount of land above the screening level, because the

  nature of the contaminating event limited the contamination to the

  waterways and adjacent banks.  No immediate cleanup is indicated for

  this site, but continued surveillance will be required.

      The Nevada Test Site (NTS) covers an area of 1400 mi2 with an

  additional exclusion zone extending 16 to 48 miles.  Major programs at

 NTS have included nuclear weapons tests, testing for peaceful uses of

 nuclear explosives, and nuclear reactor engine development.  These

 activities have resulted in plutonium contamination in certain areas

 of the test site and exclusion areas and slight contamination (above

 background levels)  outside the exclusion areas.   There are no known

 uncontrolled areas  which have transuranium element contamination

 exceeding  the reference  level.   Land contaminated to one-tenth the

 reference  level  or  less  covers  approximately  165  mi2 with  a resident

 population of  less  than  240 people.

      The Trinity  Test'Site was  the location of  the first nuclear

 explosion.  No other nuclear  explosion  tests were performed at  Trinity.

 A site survey was- performed by  EPA during 1973-74 to determine  residual

 Plutonium concentration contours.  The highest plutonium contamination

 levels in uncontrolled areas ranged  from .02 to .09 uCi/m2.  The amount

 of land contaminated to a level one-tenth the reference level covers
less than 300 mi , with fewer than 500 people living in the area in

small towns, ranches, and farms.  On the basis of the  limited available

data, no major remedial actions would appear to be indicated for this


V.   Costs of Remedial Actions

     The Agency has evaluated the available methods and costs for

cleanup and restoration of contaminated land areas.  For soils with

transuranium element concentrations no higher than about 10-100 times

the guidance recommendations, remedial actions to bring such areas

into compliance would generally involve only plowing or surface removal

followed by restorative actions needed to prevent erosion and assist

ecological recovery.  The most common recommended methods include

plowing, surface stabilization, soil cover, and soil removal.  Specific

steps required for each of these methods, and the associated costs, are

summarized in Table VI-2.  The costs of implementing the guidance can be

expected to vary by location, contamination level, and other factors.

Therefore, the numerical estimates shown can only be considered as a

general approximation and specific values must be established for each

site.  Dollar values are given on a 1975 basis and must be adjusted by

suitable indicators.

     The range of options available for bringing an area into compliance

with the guidance recommendations includes both the method(s) used for

dilution or removal of surface contamination, the stabilization dnd

restoration of the area, and the ultimate disposal of displaced soils.

Certain alternatives may have to be considered, including those of

changing land use or long-term restrictions.  In all cases, the total

costs of remedial actions should be evaluated to the maximum extent

possible in the selection of alternatives.