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OAR Box 1103 

Prepped by RyanDugan 

Document Number: 

84) lll-A-1 

Docket Number: 

A-83-41 

Printed 4/11/2008 1:50:51 PM Sheet 84 of 174 
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ENVIRONMENTAL PROTECTION AGENCY 

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I ________________ _ ] 

RIN2060-AE61 . L^/ ^ :" ^Ig T 

Federal Radiation Protection Guidance 

for Exposure of the Genera! Public A^ <P3 -(-// 

32T-/I-JAGENCY: U.S. Environmental Protection Agency. 

ACTION: Proposed recommendations, request for written comments, and notice of public 

hearings. 

SUMMARY: The Agency is proposing to make recommendations to the President for new 

guidance to Federal agencies on radiation protection which would have two effects: -Jr-Jit would 

cause a five-fold reduction in the maximum allowable risk of cancer from any Federally 

regulated activity involving nuclear materials or other sources of radiation; and Vit would 

decrease the cost of Federal regulation of radiation by promoting uniform treatment of radiation 

by all Federal agencies, and reducing costly duplicative and conflicting requirements. 

The new guidance would replace those portions of previous recommendations that apply 

to protection of the general public, approved by Presidents Eisenhower and Kennedy in 1960 and 

1961, respectively. New Federal guidance issued in 1987 replaced .those portions of the 1960 

and 1961 guidance that applied to protection of workers. 

These proposed recommendations are based on a review of existing guidance in light of 

current scientific understanding of the risks of exposure to ionizing radiation and of the 

experience of Federal agencies in its control. They include both qualitative guidance on 

radiation protection and numerical guides for limiting radiation doses to the general public. The 

most significant proposed changes are that: the Radiation Protection Guide (RPG) be expressed 

in terms of a single weighted sum of doses to organs, and the separate RPGs for individual 

organs deleted; the current RPGs limiting the average genetic dose to members of the U.S. 

C 
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include an outline of the topics to be addressed, the amount of time requested, and the names 

of the participants. EPA may allow testimony to be given at the hearing without prior 

notice, subject to time constraints at the discretion of the hearing officer. 

FOR FURTHER INFORMATION CONTACT: Allan Richardson at the above address 

(telephone (202) 233-9213; FAX (202) 233-9629) concerning these proposed 

recommendations or the public hearing. 

SUPPLEMENTARY INFORMATION: 

Introduction 

The Administrator of the Environmental Protection Agency (EPA) has the 

responsibility to "...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." This authority stems from Executive Order 10831; the Atomic Energy Act of 1954, 

as amended; and Reorganization Plan No. 3 of 1970. Guidance to Federal agencies has 

historically consisted of both qualitative and quantitative recommendations expressed as 

"Federal Radiation Protection Guidance." The guidance proposed here would replace those 

portions of existing Federal Radiation Protection Guidance, adopted in 1960 (25 FR 4402) 

and 1961 (26 FR 9057), that apply to protection of the general public. 

The purpose of Federal guidance is to provide a common framework to help ensure 

that the regulation of exposure to ionizing radiation is carried out by Federal agencies in a 

consistent and adequately protective manner. Although the individual Federal agencies have 

determined, and will continue to determine, the details of specific regulations, it is intended 

that they adhere to these proposed recommendations as basic, minimum requirements. It 

should be recognized, however, that in some situations application of these recommendations 

may be superseded by specific statutory requirements. 

These proposed recommendations have been developed by EPA in cooperation with 

the Departments of Agriculture, Commerce, Defense, Energy, Health and Human Services, 
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healing arts, and of the general public from accidents. They would apply, for example, to 

exposure of members of the general public due to: (a) emissions of radioactive materials or 

radiation from industrial, defense-related, and scientific operations; (b) use of radiation and 

radionuclides in consumer products and medicine (except for beneficial exposure of patients); 

(c) mining an#processing of ores that contain naturally-occurring radioactive materials;(d) 

disposal of wastes generated by any of the above operations; and (e) transportation of 

radioactive materials involved in any of the above operations. 

Specific examples include, but are not limited to: nuclear installations, including 

mines, mills, and processors of uranium and thorium, nuclear fuel fabrication plants, nuclear 

reactors (nuclear power plants, critical and subcritical facilities, and research reactors), spent 

fuel storage and processing facilities, and weapons production, testing, and storage facilities; 

x-ray generators and radioactive sources; irradiation installations, such as particle 

accelerators and large irradiators for teletherapy, radiosterilization, and commercial product 

irradiation; inspection devices in airports; consumer products such as static electricity 

elimination devices, ion generating tubes, smoke detectors, and devices for producing light or 

an ionized atmosphere, such as for dials and laboratory measurements; and radioactive waste 

installations where radioactive wastes are handled, treated and conditioned, temporarily 

stored, or permanently disposed of. 

These proposed recommendations also address most terrestrial sources of exposure 

arising from human activities (these principally involve naturally-occurring radioactive 

materials), but not exposure due solely to background radiation or due to globally-dispersed 

effects of past activities and accidents. Excluded, for example, is consideration of variations 

in exposure which result from geographic location, as well as the small annual dose 

increment from past weapons tests and residual global contributions of past nuclear accidents, 

like that at Chernobyl in 1986, because it is not practicable to contemplate their control. For 

the purpose of these recommendations, "background radiation" includes radiation of cosmic 

and solar origin at the surface of the earth and radiation from naturally-occurring primordial 

and cosmogonic radionuclides found in the earth's crust or produced in the upper atmosphere 

by cosmic or solar radiation (including radioactivity normally ingested in food and water) 

that is not enhanced by human activities. 
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building) may be subject to direct regulatory control or alleviation through Federal or State 

programs. 

The numerical limits for individual dose proposed in this guidance do not include the 

contribution from indoor radon produced by either of the above categories of sources. EPA 

and the Centers for Disease Control have provided separate advice to the public for 

protection against exposure to indoor radon in A Citizen's Guide To Radon (EPA document 

402-K92-001, May 1992, and subsequent editions) and EPA has published a series of other 

'technical publications, pursuant to Pub. L. 100-551 (Oct. 28, 1988, 102 Stat. 2755, 

amending the Toxic Substances Control Act, 15 U.S.C. §§2601-2692). That advice is 

consistent with this proposed guidance, where applicable. 

Finally, these recommendations apply only to the management of normal operations 

of facilities and devices that may expose members of the public to radiation: that is, to 

controllable exposure to radiation and releases of radionuclides that may expose the general 

public. Normal operations include both those conditions that are expected to occur with 

certainty as well as those that may be predicted to occur with a reasonably large probability 

(e.g. anticipated operational occurrences at nuclear reactors), but not conditions with a very 

low probability of occurrence, such as the unintended re-entry of a satellite containing 

radioactive materials. These recommendations also do not apply to nuclear incidents, such as 

a major accident at a nuclear facility or the result of terrorist activity, or to exposure 

resulting from acts of war. Guidance for establishing radiological emergency response plans 

and for making radiation protection decisions during nuclear incidents has been provided by 

EPA in the Manual of Protective Action Guides and Protective Actions for Nuclear Incidents 

(EPA-520/1-75-001-A), pursuant to regulations issued by the Federal Emergency 

Management Agency (47 FR 10758, March 11, 1982). Additional guidance has been 

provided by the Food and Drug Administration on the prophylactic use of potassium iodide 

during radiological emergencies (47 FR 28158, June 29, 1982) and on the use of food and 

animal feed contaminated by an incident (47 FR 47073, October 22, 1982, and, jointly with 

the Department of Agriculture, 51 FR 23155, June 25> 1986). 

Exposure to radiation as a medical patient, which may occur for diagnostic or for 

therapeutic purposes, is not covered by these recommendations. Recommendations of the 
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data on health risks of low levels of ionizing radiation in 1972 and again in 19802. Portions 

of the information presented in the latter report were expanded in a 1988 publication on risks 

from exposure to alpha radiation3. A comprehensive, major new review was completed in 

19904. Similar reviews have been published by the United Nations Scientific Committee on 

the Effects of Atomic Radiation in 1977, 1982, 1986, and 19885. The most important 

results from these reviews, carried out over a period of more than two decades, are that, 

although estimates of the nature and general magnitude of the risks from radiation have not 

undergone fundamental revision, estimates of the principal risk, that of cancer, have 

increased roughly threefold and have become more certain. 

While our knowledge of the effects of radiation has become more definitive, the ' 

extent of our use of radiation has increased and our policies for regulating it have evolved. 

Prior to 1960, major uses of radiation were limited, and the primary concern of radiation 

protection was to ensure that doses to those few individuals that were affected did not exceed 

limits on dose from all sources combined. Since then, the numbers and types of man-made 

radiation sources have greatly increased, and, at the same time, public concern about 

* 

environmental contaminants of all kinds has become an important influence in their 

management. Of particular significance is that the focus of the many environmental policies 

and laws that have emerged during the past two decades has been more on improving the 

levels of control of individual sources of contamination than on establishing a single 

acceptable level of risk to individuals from all sources combined. This shift of concern has 

led to the development of new concepts for determining the appropriate level of control of 

The Effects on Populations of Exposure to Low Levels of Ionizing Radiation. National Academy of Sciences, 

Washington, D.C, 1972; The Effects on Populations of Exposure to Low Levels of Ionizing Radiation: 1980. 

National Academy Press, Washington^D.C, 1980. 

The Health Risks of Radon and Other Internally Deposited Alpha-Emitters. National Academy Press, Washington, 

D.C, 1988. 

Health Effects of Exposure to Low Levels of Ionizing Radiation. National Academy Press, Washington, D.C, 

1990. 

Sources and Effects nf Ionizing Radiation. United Nations. New York, 1977; Ionizing Radiation: Sources and 

Biological Effects. United Nations, New York, 1982; Genetic and Somatic Effects of Ionizing Radiation. UniteNations, New York, 1986; Sources. Effects, and Risks of Ionizing Radiation. United Nations, New York, 1988. 
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All of the above developments ~ improved estimates of radiation risk, experience in 

regulating the constantly expanding complex of applications of ionizing radiation, and the 

evolution of improved basic concepts and methodology for radiation protection - - have 

contributed to the need for this proposed revision of the 1960 guidance. 

Effects of Radiation On Human Health 

Effects on human health of concern from exposure to low levels of ionizing radiation 

may be divided into three categories9. The first of these encompasses all forms of cancer 

(including leukemias). Cancers associated widi radiation are not distinguishable from those 

associated with other causes. Although radiogenic cancers are observed in humans over a 

range of higher doses10, it is necessary to infer the risk of cancer at the exposure levels 

normally encountered by members of the public because there is insufficient information to 

draw direct conclusions based on observations of cancer at these levels. 

The second category encompasses hereditary effects (mutations) induced in the 

reproductive cells of exposed individuals and transmitted to their descendants. The severity 

of hereditary effects ranges from inconsequential to debilitating or fatal. Although such 

effects are observed in studies of animals at high doses, excess hereditary effects have not 

yet been confirmed in epidemiological studies of the descendants of exposed human 

populations. 

Both cancer and hereditary effects are postulated to be caused by "stochastic" (i.e. 

random) direct or indirect interactions of ionizing radiation with the genetic materials in 

living cells. In view of the extensive, albeit incomplete, scientific evidence supporting this 

view, including much theoretical and experimental radiobiology, it is commonly assumed that 

9 

A fourth category of effects, designated "non-stochastic," occurs at dose levels higher than those 

addressed by these recommendations. They are of importance for managing the response to nuclear accidents (see 

EPA-520/1-75-001-A, op. cit.). , 

10

 We use the general term "dose" to mean the dose equivalent, effective dose equivalent, committed dose equivalent, 

or committed effective dose equivalent, with the precise meaning to be inferred from the text. When precision is 

important, we use the full term. In 1990 the International Commission on Radiological Protection adopted new 

terminology (and definitions) for these quantities: equivalent dose in place of dose equivalent, and effective dose in 

place of effective dose equivalent. Although these terms are simpler and are acceptable for use, we use the older, 

more explicit terms. 
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Agency believes that it is appropriate, for radiation protection purposes, to assume that at 

and just above the level of natural background the risk of cancer and most serious hereditary 

effects increases linearly with increasing dose, without a threshold. That is, we assume that 

any increase in exposure ro ionizing radiation carries the potential for causing harm to health. 

This assumption has been employed in the development of this guidance, and is consistent 

with current as well as historical practice for radiation protection world-wide. 

The third category of health effects involves those exposed is utero. It has long been 

believed that the unborn are more sensitive than are adults to the induction of cancer by 

radiation. The unborn are also subject to various radiation-induced physical 

malformations12. Recent studies, however, have drawn renewed attention to the apparently 

greater risk of severe mental retardation from exposure of the unborn. These studies indicate 

that the sensitivity of the fetus is greatest during the period from 8 weeks to 15 weeks after 

conception, and continues at a lower level during the period 16 to 25 weeks4. The risk of 

less severe mental retardation ~ manifested as a lowered Intelligence Quotient - is similarly 

elevated during these periods. Although it is not clear to what extent the occurrence and 

degree of retardation are proportional to the dose (or whether there is a threshold dose for 

these effects), it is prudent to assume, for regulatory purposes, that there is a linear, nonthreshold relationship between these effects and the dose delivered to the fetus during these 

periods. . 

For radiation protection purposes EPA assumes, using a linear, non-threshold model, 

an estimated risk to an average member of the U.S. population of 5 x IO"2 fatal cancers per 

sievert13 (5 x 10** fatal cancers per rem) delivered at low dose rates14. (That is, we 

12

 These include small head circumference (microcephaly), brain size (microencephaly), eye malformations, and 

intrauterine growth retardation. 

13

 The traditional special unit for dose equivalent has been the rem. The special unit sievert (Sv) in the International 

System of Units, adopted in 1979 by the General Conference on Weights and Measures, is now in general use 

throughout the world. The RPGs recommended here may be expressed in either of these units. One sievert is equal 

to 100 rem. The prefix "milii" (m) means one thousandth. 

"Low dose rates" here means dose rates on the order of or less than those from background radiation (see 

footnote 11). This value for the risk from such doses incorporates a dose rate effectiveness factor of two. 
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15 

principles that have governed radiation protection for many decades in the United States and 

in most other countries. Although the precise formulation of these principles has evolved 

over the years, their intent has remained essentially unchanged. 

The first principle is that any activity involving the exposure of people to ionizing 

radiation should be sufficiently beneficial to society to warrant the exposure; i.e., a finding 

should be made that an activity causing exposure is "justified." 

The second is that, for justified activities, exposure of people should be "as low as 

reasonably achievable." This principle commonly has been designated by the acronym 

"ALARA" in the United States, and is called "optimization" of radiation protection in 

international practice. 

The third is that, even for justified and optimized exposures, the maximum dose to 

any individual should be limited so as not to exceed an acceptable level of risk. This is 

referred to as "limitation." 

The objective of the first two principles is to minimize (consistent with benefits and 

costs) the estimated total harm (i.e. health detriment) in the entire population from each 

source of exposure; they do not, however, limit the way that harm is distributed among 

individuals. They are, in this sense, "source-related" radiation protection requirements. The 

purpose of the third principle, that of limitation of the maximum allowed dose, is to provide 

an upper bound on risk to individuals. This principle, which is an "individual-related" 

requirement, may be carried out in two ways: first, through limitation of the potential dose 

from all sources of exposure combined, and second, through additional more specific 

limitations on the doses from individual sources. 

The following seven proposed recommendations directly express, expand upon, and' 

implement these three basic principles in light of current improved knowledge of the risks of 

radiation and of the variety and extent of uses of radiation. In particular, they reflect lower 

upper limits on dose to individuals from all sources combined, they make explicit the need 

for further limitation of doses from individual (or classes of) sources of exposure that is more 

restrictive than that for all sources combined, and they introduce improved methods for 

assuring that all of the various components of risk associated with radiation exposure are 

accounted for in radiation protection requirements for limiting exposure of the public. 
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achieve. The decision was simplified in that example because the risks and benefits accrued 

to the same individuals. This is usually not the case. In extreme cases the determination can 

be far more complex. For a major industrial application of radiation, for example, the 

determination may involve not only the benefits and the costs (direct, health, and 

environmentaftrof construction, operation, waste disposal, accidents, and eventual 

decommissioning, but also the tradeoffs between the activity and the economic, societal, 

environmental, and resource implications of alternative means to achieve the same result. 

In any case, for a major activity the analysis should make a reasonable demonstration 

that the benefit associated with die proposed activity clearly outweighs the risks associated 

with the use of ionizing radiation, including those associated with normal operations, 

reasonably possible incorrect operation or management, and disposal of wastes over the life 

cycle of the activity. When the consequences can be significant, the analysis should include 

low probability events and exposure pathways. 

The process of balancing these factors may eventually involve congressional, 

executive, and judicial inputs. One vehicle for assisting such decision-making is the National 

Environmental Policy Act of 1969 which, in effect, requires Federal agencies to assess and 

consider the above factors for any major Federal action that could significantly affect the 

quality of the human environment. Others include the regulatory analysis process pursued by 

Federal agencies (Executive Order 12866; 58 FR 51735, October 4, 1993), and decision 

processes of public and professional bodies, such as public utility commissions and 

professional medical groups. However, in making these recommendations EPA does not 

propose to specify how or by whom justification should be determined, but simply that the 

detrimental effects of radiation, as well as other detrimental effects, should be considered 

along with the benefits in any situation where an initial decision is being made tiiat involves 

significant exposure of the general public to radiation. 

Recommendation 2: 

A sustained effort should be made to ensure that doses to individuals and to 

populations are maintained as low as reasonably achievable. 
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feasibility and overall economic impact of controls. In rare cases, the optimization process 

could result in the need to make tradeoffs between larger doses to a few individuals (within 

the limits specified in Recommendations 3 and 4) and many small doses in large populations. 

At the dose levels involved in the comparison of alternatives for determining ALARA 

levels, linearity is assumed, and effects on public health may be estimated from the collective 

dose in populations. In cases where it is necessary to estimate the total public health 

detriment from long-lived radionuclides, collective dose will often have to be projected into 

the future, or in distant populations. Regulatory decisions on ALARA levels should take into 

account such projections when their contribution is both a significant part of the total 

collective dose from the activity under examination and its uncertainty is not large compared 

to the differences in collective dose among the alternatives being examined. In some cases, 

it may be appropriate to estimate effects on public health as a function of time or distance, 

and to take their distribution in time or distance into account in decisionmaking. However, it 

will never be appropriate to apply an arbitrary cutoff to such projections based solely on the 

level of dose to individuals, or on the distance from tiie source or in time; such cutoffs 

would have the effect of preempting the decision-making process before the magnitude and 

distribution of the avoidable impact on health has been estimated. 

In some situations, a decision to refrain from applying controls may be the 

appropriate outcome of an ALARA determination. Such a finding for an individual practice, 

or for a group of practices meeting specified requirements, may be used as one criterion for 

exemption from regulatory control. However, in addition to a finding that the total health 

detriment in populations is not large enough to justify control, it is also necessary to ensure 

that individual exposures are sufficiently small, in view of the stipulations of 

Recommendation 4, not to warrant regulation. Exemptions that satisfy each of these criteria 

would be consistent with these proposed recommendations. 

Although the ALARA principle is relevant to a wide variety of radiation protection 

activities, these tend to fall into two general categories. The first is that emphasized above, 

the establishment, of regulatory levels of control over individual sources or categories of 

sources by Federal (or State) agencies. The second, and equally important, is making 

management decisions in day-to-day operations at facilities where ionizing radiation or 
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dose limit based on the critical organ approach. The 1960 limit for dose to the gonads was 

based on an entirely different consideration, that of limiting the incremental rate of mutation 

in the entire genetic pool of the U.S. population. The incremental level of mutation deemed 

unacceptable was on the order of a few per cent. 

These recommendations would replace the system described above witii the 

risk-weighted dose limitation system introduced by the ICRP in 1977

 6

. The ICRP system 

takes into account the individual contribution of each exposed part of the body to total risk. 

It does so by assigning to each organ or tissue of the body a weighting factor that is 

proportional tb the risk per unit dose of inducing cancer or, for the reproductive organs, to 

the risk per unit dose of inducing hereditary effects in offspring. The risk limit is then -

expressed in terms of the sum of weighted dose equivalents to all parts of the body, a 

quantity called the "effective dose equivalent" (EDE).20 A limit in terms of the EDE 

therefore reflects both the distribution of doses among the various organs and tissues and 

their assumed relative sensitivities to cancer and hereditary effects. Further, the EDE does 

not differentiate exposures from external and internal sources; it includes both. 

The effective dose equivalent is defined formally in footnote (b) to Recommendation 3 

and proposed weighting factors are listed in Notes 5 and 6, in the formal statement of 

proposed recommendations at the end of this notice. These factors reflect the organ-specific 

risks of lethal cancer, and, for the reproductive organs, the risk of serious hereditary effects 

in the first two generations of offspring. They are the same weighting factors as those 

adopted in Federal guidance on radiation protection for workers in 1987. Although our 

current best estimates for these effects on health would lead to somewhat different values, the 

differences are sufficiently small that new weighting factors are not proposed as part of these 

recommendations. The Agency has made this choice for several reasons. First, it should be 

noted that changes in the weighting factors, based on new estimates for mortality, would 

have no effect on the level of risk represented by a given dose to the whole body, since the 

sum of the weighting factors is, by definition, normalized to unity. (If these factors were 

The weighting factors are normalized so that the risk associated with a given EDE is equal to that from a uniform 

dose of the same magnitude to the whole body. 
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effective dose equivalent in a year. In so doing, it would create a single limit for combined 

dose from external and internal radiation. 

Certain radionuclides, if inhaled or ingested, may remain in and continue to irradiate 

the body for many years. This proposed recommendation incorporates the use of 

"committed" dose into guidance for the general public (this concept was introduced into 

Federal radiation protection guidance for workers in 1987). It provides that Federal agencies 

should base control of annual intake of such radionuclides upon the future dose that may 

result over time (that is, the committed dose), not just the "annual" dose accrued during the 

first year following intake. This would assure that, in regulating annual intake of such 

materials by members of the public, account is taken of the additional risks committed from 

doses that will be delivered in future years. The standard period for which committed dose 

is calculated is proposed to be taken as 50 years, as in the Agency's previous 

i 

recommendations for workers. Although there are a few radionuclides from which doses can 

accrue for longer periods, the risk associated with intake of such radionuclides will be 

conservatively estimated, compared to the risk from a comparable external dose, because of 

the combined effect of the distribution over time of committed dose and the latency period 

for expression of cancer. 

The proposed RPG is expressed in terms of both the new special SI unit "sievert" and 

the historically-used special unit "rem." It is not the intent of these recommendations to 

express a preference for either system of units, but merely to recognize the existence and 

acceptability of both. Federal agencies would be free to "use either unit under these 

recommendations, but should specify conversion factors between the two systems in new 

regulations. 

The second part of Recommendation 3 reads: 

The Radiation Protection Guide may not be reasonably achievable in some unusual 

situations. It may be exceeded temporarily in situations that are not anticipated to 

recur chronically and when Recommendations 1 and 2 are satisfied, provided that the 

radiation dose incurred in any year does not exceed 5 mSv (500 mrem) effective dose 

equivalent. 
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Basis for the Radiation Protection Guide 

In the latter part of the twentieth century, society has become increasingly unwilling 

to accept risks imposed by activities that produce environmental pollutants. Many of the 

benefits of industrialized society, however, are brought about by activities that carry with 

them some unavoidable elements of risk. This is especially the case for so-called 

"non-threshold" pollutants like radiation, for which it is assumed that there are no risk-free 

levels. The risk to an individual from exposure to ionizing radiation, as discussed above, is 

assumed to depend linearly upon the radiation dose, without a threshold. Under current 

guidance the average member of the public now receives, from all the sources to which that 

guidance has consistently been applied, only a very small dose - less than 0.01 mSv 

(1 mrem) in a year22. The average risk of fatal cancer incurred from such an exposure is 

estimated to be somewhat less than 5 in ten million. 

The cumulative risk to society associated with the variety of current uses of radiation 

is now governed by the dual requirements that each use be justified and that its effect on 

public exposure minimized by optimizing radiation protection. These requirements would be 

continued and strengthened under proposed Recommendations 1 and 2. Typically, this would 

result in a distribution of annual doses from each source of radiation exposure ranging from 

zero for most members of the population to a maximum value (established under 

Recommendation 4) accruing to a small number of individuals. The RPG serves as an upper 

bound on the highest doses resulting from the sum of all such distributions. As such, it acts 

as a limit on the annual increment of risk, now and in the future, to the theoretically most 

exposed individual with typical consumption and other relevant behavior habits. 

In selecting the proposed value for the RPG the Agency has had to consider a number 

of judgmental factors: the relation between a limit on annual dose and the implied lifetime 

risk; the degree of protection achieved through the application, by regulatory authorities, of 

22

 During the period 1960 to the present, the current RPG has not consistently been applied to exposure due to 

natural sources. The primary examples are building materials and radon in domestic groundwater supplies; these 

contribute additional average effective dose equivalents to the U.S. population of 0.035 mSv (3.5 mrem) and 0.01-

0.06 mSv (1-6 mrem), per year, respectively. Tobacco smoke contributes a further, at present incompletely 

characterized, dose. (These estimates are derived from Ionizing Radiation Exposure of the Population of the United 

States, National Council on Radiation Protection and Measurements Report 93. Bethesda, MD (1993).) 
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27 

number of western states. Under the current RPGs, annual doses due to external -vposiire 

up to 5 mSv (500 mrem) are permitted, in addition to organ doses from internal e posure up 

to 15 mSv (1500 mrem), depending on the organ and the radionuclide. Such dos( imply 

lifetime risks up to 250 in one million for each year of external exposure, and up . 40 in 

one million for each year of internal exposure. The proposed RPG of 1 mSv effe 'ive dose 

equivalent would limit the incremental lifetime risk associated with each year of c r.bined 

external and internal exposure to 50 in one million, a significant reduction in risk. 

Finally, the Agency notes that the proposed RPG is consistent with levels i und 

acceptable and in use by the international community. A value of 1 mSv per yea is 

recommended as the upper bound on doses to members of the public by both the j TRP and 

the International Atomic Energy Agency, and is in common use throughout the w< *!d. 

To provide a perspective on the above levels of risk, it may be noted that t e average 

American is exposed annually to an effective dose equivalent of about 3 mSv (30. mrem) 

from natural background radiation, including an average contribution of about 2 n >*. 

(200 mrem) from radon in homes. This exposure is three times the proposed RP( , and each 

year's exposure corresponds to an incremental lifetime risk of 150 in one million. Although 

the average level of exposure to natural background-provides perspective, it does • )t. 

however, provide a justification for the RPG, since it represents an uncontrollable ource of 

risk, and the RPG applies to controllable sources. 

The levels of risk assumed to be associated with radiation exposure may al > be 

compared to involuntary and voluntary risks actually incurred in common activitie For 

example, the essentially involuntary risk of dying of a household accident average about 110 

in a million per year, between 1980 and 1990, and the average probability of dyir of an 

automobile accident in the same decade, a voluntary risk, was 240 in a million pe \ ear. We 

emphasize that all of these examples are provided for perspective only, and that th existence 

of other risks, voluntary or involuntary, is not a justification for any particular incft nental 

radiation risk. 

EPA recognizes that some of the assumptions that underlie the proposed RJI are not 

readily quantified, or are based on experience that may not accurately predict the I ae. We 

will continue to review exposure of the general public, with a view to initiating 
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instead of being higher, is lower. The risk of cancer in this population approaches being an 

order of magnitude smaller than the risk to an average member of the population,' and the 

risk of genetic consequences is normally no longer present. EPA has not proposed a higher 

RPG for this papulation because, as noted for the case of the unborn, these recommendations 

are based on limiting the risks that accrue over a lifetime,, not on a yearly basis. The RPG is 

expressed as an annual limit simply for ease of implementation. We also note that a limit 

that was different for different ages of members of the public would pose severe 

implementation difficulties. 

Implementation of measures for assessment and control of internal exposure to 

radionuclides commonly makes use of intake-to-dose convenion factors. EPA has previously 

tabulated such values for use in implementing the Federal Guidance for Protection of 

Workers, in Federal Guidance Report No. 11, Limiting Values of Radionuclide Intake and 

Air Concentration, and Dose Conversion Factors for Inhalation. Submersion, and Ingestion 

(EPA-520/1-88-020). The dose conversion factors in this report and its subsequent editions 

also apply to intake of radionuclides by members of the general public. For external 

sources, exposure-to-dose conversion factors are tabulated in Federal Guidance Report 

No. 12, External Exposure to Radionuclides in Air. Water, and Soil (EPA 402-R-93-081). 

These dose conversion factors are appropriate for application to any population 

adequately characterized by the set of values for physiological parameters developed by the 

ICRP and collectively known as "Reference Man."23 The actual dose to a particular 

individual from a given intake is dependent upon age and sex, as well as other 

characteristics. As noted earlier, implementing limits for the general public expressed as age 

and sex dependent quantities would be difficult. (Clearly, it would be impracticable to 

conduct an annual survey of age and sex at every location of a potential source of public 

exposure.) More importantly, the variability in dose due to these factors is comparable in 

magnitude to the uncertainty in our estimates of the risks which provide the basis for our 

choice of the RPG. For this reason EPA believes that, for the purpose of providing radiation 

protection under the conditions addressed by these recommendations, the assumptions 

23

 ICRP No. 23, Report of the Task Group on Reference Man. 1974. 
P.17 

31 

guidance with respea to limitation of doses will be satisfied. Implementation of the ALARA 

requirement (Recommendation 2) will involve consideration of collective doses to 

populations24, of control mechanisms, and of other factors that will differ for each category 

of sources, and will usually lead to control levels that result in doses to individuals less than 

the RPG (Recommendation 3). However, there are many different categories of activities 

using radiation that can lead to exposure of members of the public. These currently include 

medical uses of radiation and their supporting activities; nuclear electric power facilities and 

their supporting fuel cycle facilities; research and industrial users; weapons production, 

storage, and disposal facilities; technologically-enhanced exposure to natural radiation 

sources; consumer products; space applications; disposal sites for radioactive wastes; and 

decommissioned sites at which radioactive materials were formerly used. It is therefore also 

necessary to ensure that total doses to individuals, who may be exposed not only to more 

than one source in a given category in a few cases, but more often to a number of different 

categories of sources at one time, are not likely to exceed the RPG. It is not intended that 

this objective be implemented through apportionment of the RPG among categories of 

sources; this would be impracticable. Rather, this consideration, which must encompass the 

potential for doses to the general public both now and in the future, will necessarily be a 

broad judgment, based on general observations of the characteristics of existing activities, 

projections for their use in the future, and the potential for presently unidentified future uses. 

To implement these objectives, authorities responsible for limiting exposure of the 

public should govern sources through use of "authorized limits" established either for 

categories of similar sources or for specific sources. In establishing these authorized limits, 

since the ALARA process considers actual costs and capabilities of controls, it is important 

that assessments of doses to individuals and populations be carried out realistically and 

comprehensively. Such assessments should contain neither unnecessarily unrealistic 

These recommendations are not intended to require numerical limits for collective dose. Although the 

determination of ALARA levels necessarily involves optimization of the collective dose, the regulations that 

implement these levels can be expressed in terms of individual or collective dose, total or concentration of activity 

released, installation and use of specified controls, or any other specification that the regulatory authority finds 

appropriate. 
P.18 

33 

operations of a specific source. These requirements thus serve to avoid the need to perform 

detailed, and in some cases very difficult to validate, evaluations of the combined 

incremental doses from other sources at individual sites. Conversely, if these requirements 

are exceeded (or are absent), then such evaluations may be necessary to assure conformance 

to the RPG (Recommendation 3). 

The second part of Recommendation 4 reads: 

Sources should be designed not to exceed authorized limits, and should be operated so 

as to maintain doses to members of the general public as low as reasonably achievable 

within such limits. 

The ALARA principle applies not only to the establishment of authorized limits, but 

also to detailed management of facilities where sources of radiation are prepared, employed, 

stored, or transported. This is necessary and appropriate because authorized limits must 

usually provide flexibility for anticipated deviations from design performance, and controls 

usually can perform better than their design limits. Thus, exposure of the general public, 

even if a source conforms to authorized limits, will not be ALARA when lower exposures 

are reasonably achievable. 

As exemplified by the performance of many facilities over the past two decades, 

doses to the public usually can be maintained far below authorized limits through responsible 

and skillful control of radiation sources. This has required careful management and 

supervision of radiation protection activities, including the choice and implementation of 

radiation control measures for sources of exposure of members of the public, training in 

procedures to control such exposure, and monitoring, assessment, and reporting of exposure 

levels and doses at appropriate on-site and off-site locations. The routine management of a 

facility and decisions on how, or whether, particular actions should be carried out can, in the 

aggregate, be as (or more) significant for radiation protection of the public as the design of 

the facility and choice of its authorized limit. 

The selection of authorized limits and the application of the ALARA principle to 

operations requires technically informed judgments. Thus, the practice of ALARA must be 

the responsibility primarily of those persons who control and manage sources of radiation 
P.19 

- _**_ 

35 

It is the purpose of this recommendation to ensure that, when Federal agencies 

formulate policies, and make decisions that influence the exposure of the general public, 

information that will adequately inform the public during the decision-making process is 

made available by them in a timely manner. Although it is not intended to require general 

dissemination of information concerning ongoing operations, nor to require major public 

information distribution efforts, such activities are encouraged whenever it is reasonable tc 

carry them out. 

Recommendation 6: 

Assessments and records appropriate to the origin and magnitude of expected doses 

and the exposed population should be performed and maintained to demonstrate 

conformance with requirements which implement these recommendations. The types 

and accuracy of methods and procedures used in these assessments should be 

reviewed periodically to ensure that they are appropriate and are being competently 

applied. 

Control of exposure of the public is normally ensured through analysis of releases 

from sources and modeling of environmental transport to hypothetical "critical groups" of the 

general public assumed to receive the greatest exposure. Unlike the situation for workers 

exposed occupatlonally, it is usually neither appropriate nor feasible to physically momtor 

doses to individual members of the public. Such dose rates and concentrations may be 

determined by measurement of radioactive effluents, mathematical modeling of the dispersal 

of radionuclides in the environment, or both. 

Assessments and records required to ensure conformance with these, recommendations 

will vary, depending upon the nature of the source of exposure. Responsible authorities will 

have to determine what is needed to ensure that exposures of members of the public actually 

are maintained within authorized limits and are ALARA. In some cases, comprehensive 

radiation assessment programs will be needed which include trained personnel, facility and 

environmental measurements, audit procedures, and maintenance of records. In many cases 

conservative assumptions, such as the assessment of doses to a hypothetically most exposed 
37 

are aware of no regulated sources that exceed the proposed RPG. Pertjps the most 

significant implication of these recommendations would be to promote 

Federal agencies by clarifying the basic considerations to be taken into 

development of new standards and regulations, and in their implementa 

recommendations modernize the methodology for expressing dose, and 

relationship of the RPG to standards and regulations for sources, as we 

applications of the principle that doses should be maintained "as low as 

achievable," and they provide, for the first time as a part of their basi 

of the various risks from low levels of ionizing radiation. 

Implementation of the proposed recommendations would require 

changes in Federal regulations, and should be achievable over a short p 

of the changes called for are largely already well under way, major ex; 

revisions recently made by the Department of Energy in their Order N< 

recently promulgated by the Nuclear Regulatory Commission in 10 CF 

expected that Federal agencies will have little difficulty in identifying a 

remaining problem areas, and in providing necessary flexibility and tra .ition periods, to 

avoid undue impacts that might inhibit prompt implementation of new 

We note in passing that in some cases (notably in the regulation 

public from the transportation of radioactive materials) conformance to 

based upon the assumption of "reasonably foreseeable" scenarios for th 

relationship between radioactive materials and members of the public, ; 

this assurance the RPG will never be exceeded cannot be given with at 

These recommendations do not propose any changes in this regard, ane 

such cases the same approach to protection would continue to be empk 

conformance to tiiese new recommendations. 

The anticipated costs of implementing these recommendations a 

would be incurred by the various, agencies in modifying their own regi 

expected to be substantial, since most of the necessary methodological 

-insistency between 

ccount in the 

on. The 

larify the 

as the various 

reasonably 

numerical estimates 

only minimal 

nod of time. Many 

nples being the 

5400.5, and those 

Part 20. It is 

d correcting any 

ndance. 

.f exposure of the 

xisting guidance is 

spatial and temporal 

id that because of 

clute certainty. 

EPA expects that in 

ed to achieve 

. rimarily those that 

ions. These are not 

iiges have already 

been implemented in connection with the revised Federal guidance for ft*, cupational exposure 

issued in 1987. Unlike the situation for occupational exposure, where I _ need to reduce the 
P.21 

39 

protection policy into conformance with that in general international use. EPA expects these 

changes would strengthen the overall system for radiation protection of the members of the 

public in the United States. 

These recommendations would replace those portions of current Federal Radiation 

Protection Guidance (25 FR 4402) that apply to protection of the general public from 

ionizing radiation. It is expected that individual Federal agencies, on the basis of their 

knowledge of specific sources of exposure of the general public, would use this new 

guidance as the basis upon which to revise or develop detailed standards or regulations, to 

the extent that they have regulatory or administrative jurisdiction. Pursuant to my 

responsibilities under Executive Order 10831, the Atomic Energy Act of 1954, as amended, 

and Reorganization Plan No. 3 of 1970,1 would propose to keep informed of Federal agency 

actions to implement this guidance and to interpret and clarify these recommendations, and, 

in consultation with affected Federal agencies, from time to time amend die clarifying notes 

to reflect new technical information, as necessary to promote a consistent and effective 

Federal program of protection of the public from radiation. 

Request for Comments 

EPA requests comments on any and all aspects of these proposed recommendations. 

We would, for example, appreciate comment on the overall approach to protection of the 

public embodied by these proposals, which would continue and expand upon the approach 

recommended for protection against the effects of exposure to radiation by national and 

international professional advisory bodies, and which has formed the basis for previous 

guidance to Federal agencies. In addition to general comments, we are also particularly . 

interested in commenter's views on the following specific matters: 

1. Should EPA consider a lower or higher value for the Radiation Protection Guide 

(RPG); e.g., 0.3, 0.5, or 1.5 mSv (30, 50, or 150 mrem)? What would be the rationale for 

such a value? If a lower value is adopted would it be necessary to modify Recommendation 

4, and, if so, how could it be modified to retain flexibility to provide for possible future 

beneficial uses? 
P.22 

\ FEDERAL REGISTER NOTICE - FEDfiRAfcTtADIATION FRO 

GUIDANCE FOR EXPQSVftBXSFTHE GENERAL PUBI_l£*£*page 41 of 47 

EPA wjl carefully consider all written responses to this request for comments, and 

we encourage interested parties to present their views at the public hearing that will be held 

on these proposals. Following these hearings we will, after consulting with affected Federal 

agencies, formulate and transmit final recommendations to the President for revisions to 

Federal radiation protection guidance for exposure of the general public. 

Dated: DEC 1 A 1994 

^ 

Carol M. Browner 

Administrator 

^ 
SSK^^lfJ^-''^- •• ' <*z -y ^*y, . •••*• '*"""'>-S22J#s|ggf 

43 

Protection Guide of 1 mSv (100 mrem) effective dose equivalent to an individual/4 The 

Radiation Protection Guide applies to the sum of the effective dose equivalent resulting from 

exposure to external sources of radiation during a year and the committed effective dose 

equivalent incurred from the intake of radionuclides during that year. (See Notes 4 through 

7.) 

The Radiation Protection Guide may not be reasonably achievable in some unusual 

situations. It may be exceeded temporarily in situations that are not anticipated to recur 

chronically and when Recommendations 1 and 2 are satisfied, provided that the radiation 

dose incurred in any year does not exceed 5 mSv (500 mrem) effective dose equivalent. 

Continued exposure of an individual over substantial portions of a lifetime at or near 

the level of the Radiation Protection Guide should be avoided. This will normally be 

achieved through conformance of individual sources to Recommendations 2 and 4. 

4. Authorized limits(d> for sources should be established to ensure that individual and 

collective doses in current and future populations satisfy the objectives of this guidance. 

*' Effective dose equivalent is a derived quantity defined as the risk-weighted sum of dose equivalents to specified 

Organs and tissues. 

Dose equivalent is the product of the absorbed dose and a quality factor which varies with the energy and type of 

radiation. In the system of quantities of ionizing radiation historically in use in the United States, the unit of dose 

equivalent is the "rem." In the international system (S.L), the corresponding unit is the "sievert" (Sv). One sievert 

equals 100 rem. 

The effective dose equivalent, Hg, incurred in a given period of time is the sum of the effective dose equivalent, 

Hg^, received from external exposure in that period and the committed effective dose equivalent, ___.», incurred 

from the intake of radionuclide* during that period. That is, 

H_ = Hg^s + H^o = L WT^HT^,, + HTS)), 

where wT is a weighting factor for organ or tissue t; HT_,n is the dose equivalent from external irradiation averaged 

over organ or tissue T; and H-^, the committed dose equivalent, is the sum of all dose equivalents, averaged over 

organ or tissue T, that may accumulate over an individual's anticipated remaining lifetime (taken as SO years) from 

radionuclides retained within die body. The weighting factors satisfy the condition 2. wT = 1. 

The word "dose", when used alone in diese recommendations, is intended to carry the specific dose unit implied 

by the surrounding text. 

(e)

 The term "individual" means a typical member of any critical group of most highly exposed members of the 

general public; it refers to persons with typical consumption and other relevant behavior habits. 

(

* Authorized limits are standards, regulations, or other requirements established by a responsible authority for 

categories of sources or for a specific source. 
- s 

(*?•'52^-*' •--'.:' ~-._ _. _-v_SBtJs_3J|!^gS^ ^ 

45 

NOTES 

The following notes are provided to clarify application of the above recommendations: 

1. Background radiation includes natural sources of background radiation, such as 

cosmic radiation and radiation from nsutuially-occuning radionuclides undisturbed by human 

activities, as well as radiation from certain other sources of exposure beyond Federal 

regulatory control, such as residual fallout from past nuclear accidents and weapons tests. 

2. People may, by technological means, enhance their exposure to natural radiation 

sources that might otherwise be considered sources of background radiation. 

Technologically-enhanced exposures to natural radiation are usually controllable, in that they 

may be avoided or reduced by taking reasonable actions. Unless specifically noted, these 

recommendations apply to controllable technologically-enhanced exposure to such natural 

radiation sources. 

3. The admonition to maintain doses "as low as reasonably achievable" includes 

consideration of economic and societal factors, and applies to radiation exposure that may 

occur now or in the foreseeable future. In making this judgment for doses to populations, 

any incremental doses to individuals that are avoidable and which make a significant 

contribution to collective dose should be considered. 

4. Although indoor radon from proximate natural sources is considered 

technologically-enhanced exposure to natural radiation, Recommendations 3 and 4 of this 

guidance do not apply to such exposure. Specific advice for protection against exposure to 

indoor radon is provided in A Citizen's Guide To Radon (EPA document 402-K92-001 and 

subsequent editions) and in other EPA technical publications. 
P.25 

47 

8. To ensure that specific sources or categories of sources, including their installed 

control capability, are designed and operated to achieve as low as reasonably achievable 

levels of exposure, a variety of quantitative and qualitative analysis and decision methods 

may be used to determine authorized limits. These, in addition to considering radiation 

detriment and risk, and direct costs, may also take into account societal and other economic 

factors. Statutory requirements may impose additional constraints on the selection of 

authorized limits. 

,J*3f 
P.26 

Atta c'-r-.er.t 

DOCKET 

The .-ockeT^should include both the informatic- considered 

by the Agency miring rulemaking (sections II, IIA and IV) and 

the official Statements of the Administrator's position on 

various issues relevant to the rulemaking (sections I, III, and 

V ) . 

Sections II, IIA and IV should consist of all information 

received from outside persons and all relevant factual information 

considered by the Agency. This does not include any internal 

policy recommendations, option memoranda, action memos, etc. 

Sections 1, III, and V are to consist pf the official statements 

of the Administrator's position, represented by the published 

rulemaking documents and any supplementary material (such as 

technical support documents) that form an additional part of 

the official explanation of the Administrator's position. 

Documents should be entered into the docket in the 

apppropriate category and given a sequential docket number as 

they become available. (For example, written public comments 

would be numbered IV-D-1, IV-D-2* etc.) If a document does not 

have internal page numbers, pages should be numbered at this 

time. The docket itself is to consist of, a file containing a 

series of file folders for each category of documents, as well 

as an index in the front of each file folder listing the 

documents contained in the folder with their docket numbers. 

Sometimes a reconsideration of the rulemaking takes place', 

etiher under court order or upon petition for consideration. 

In such a case, an additional docket section or sections would 

•become relevant. See. Docket VI and note 3 .• * 

CATEGORIES 

I. NOTICE OF INTENT OR ANPRM, IF ANY 

II. ITEMS^SbKSUlERED IN DEVELOPING PROPOSAL 1/ 

A. EPA studies or contractor reports 

B. EPA factual memoranda (including technical trip 

reports, data, advisory committee minutes) 

T7 This section of the docket should be closed to further 

.material on the date of signing of the proposal (or sooner 

if the Agency stopped considering material sooner). 
P.27 

y. ' 

-2-

C. EPA correspondence _o persons outside'the Agency 

(including drafts oT~regulations circulated to 

outside persons) 

D. Correspondence received from persons outside the 

Agency -

E.- EPA r.c.?oranda of meetings with outside persons 

and of telephone conversations with outside persons 

F. Interagency Review Materials: drafts sent to other 

Government agencies for comment, a copy of each 

document accompanying such drafts, all comments by 

such agencies, and EPA's written response 

these^corflmen^s, i f any^ --CArA k ^ 

o each of 

IIA. CRITERIA DOCUMENT DOCKET (in^he case of tfAAQS under 

§§108, 109) 

A. All public notices relating to development of a 

criteria document 

B. EPA studies or contractor reports used in developing 

criteria document 

C. EPA factual memoranda (see item II.B. above) used 

in developing criteria document 

D. EPA correspondence to persons outside the Agency 

(including drafts of criteria document circulated 

to outside persons) 

E. . Correspondence received from persons outside the 

Agency 

F. Minutes of SAB meetings, and all written comments 

by SAB members or others submitted at SAB meetings 

G. EPA memoranda of meetings and telephone conversations 

witfcApiitside persons 

E. Final Criteria Document 

I. EPA response to comments received during development 

of criteria document 

III. PROPOSAL 

A. Notice of Proposed Rulemaking 

E. Proposed Support Document 
IV. ADDITIONAL ITEMS CONSIDERED AfTER PROPOSAL 

FINAL RULE 2/ 

A. Additional EPA studies.or contractor reports 

B. Ad*_tT5B__.l EPA factual memoranda (see it.em II.B. 

above^r 

* C. Additional EPA correspondence t£ persons outside 

the Agency 

D. Additional comments received (including any 

correspondence from outsiders, whether or not 

labeled as a public comment) 

E. EPA memoranda of meetings with outside persons and 

of telephone conversations with outside persons. 

F. Transcript of hearings, if any 

G. Post-hearing comments received 

H. Interagency Review Materials (see II.F. above) 

V. FINAL ACTION 

A. Notice of Rulemaking 

B. Final Support Document 

C. Response to Comments Document 

VI. RECONSIDERATION, IF ANY 

. A. ' Rebuest or Order.seeking or directing reconsideration 

B. New factual.materials, correspondence, comments, 

memoranda of meetings of converations, etc., 

relevant to reconsideration 

C. Agency.jdecision granting or denying recons-ideration 2_/ 

VII. REPROPOSAL^' " 

VIII. ADDITIONAL ITEMS CONSIDERED 

ix. FINAL ACTION 

T/This section (Docket IV) is to be opened, as soon as 

Docket II is closed. It is tb be closed on the date of 

signing of the final rule. 

2/ If reconsideration is granted, new sections VII, VIII and 

IX would be sequentially added, and would correspond to 

sections III, IV and V of the original rulemaking docket. 
P.29 

DOCKET: 

CATEGORY: 

•- - — 

DATE SENT DATE OF 

NUMBER TO DOCKET COMMENTER OR ADDRESSEE. TITLE. DESCRIPTION. ETC. DOCUMENT