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8. REGULATIONS, ADVISORIES, AND GUIDELINES
International and national regulations and guidelines pertinent to human exposure to plutonium and to
other radioactive substances are summarized in Table 8-1. Recommendations for radiation protection for
people in the general population as a result of exposure to radiation in the environment are found in the
International Commission on Radiological Protection (ICRP) Publication 60 (ICRP 1991). National
guidelines for occupational radiation protection are found in the "Federal Radiation Protection Guidance
for Occupational Exposure" (EPA 1987). The guidance presents general principles for the radiation
protection of workers and specifies the numerical primary guides for limiting occupational exposure.
These recommendations are consistent with the ICRP (ICRP 1991).
The basic philosophy of radiation protection is the concept of ALARA (As Low As Reasonably
Achievable). ALARA
requires that social and economic factors to
be taken into consideration, and
that further reductions in dose are not indicated where the costs of reducing exposure become
disproportionate to the benefit achieved.
As a rule, all exposure should be kept as low as reasonably
achievable and the regulations and guidelines are meant to give an upper limit to exposure. Based on the
primary guidelines (EPA 1987), guides for Annual Limits on Intake (ALIs) and Derived Air
Concentrations (DACs) have been calculated (USNRC 2007a). The ALI is defined as "the annual intake
of a given radionuclide by Reference Man which would result in a committed effective dose equivalent of
5 rems (stochastic) or 50 rems to an organ or tissue (non-stochastic)” (USNRC 2007a). The
DAC is
defined as "the concentration of a given radionuclide in air which, if breathed by the reference man for a
working year of 2,000 hours under conditions of light work (inhalation rate of 1.2 m
3
of air/hour), results
in the intake of one ALI" (USNRC 2009a). The ALIs and DACs refer to occupational situations, but may
be converted to apply to exposure of persons in the general population by application of conversion
factors (Table 8-1).
No inhalation or oral MRLs were derived for plutonium or plutonium compounds.
The EPA IRIS database has withdrawn its cancer classification for radionuclides, but the EPA
Office of
Air and Radiation believes that all radionuclides, including the plutonium isotopes, should be considered
to be known carcinogens, and has assigned them to Group A. Carcinogenic toxicity values for plutonium
isotopes are listed in EPA’s Radionuclide Table: Radionuclide Carcinogenicity – Slope Factors (Federal
Guidance Report No. 13 Morbidity Risk Coefficients, in Units of Picocuries) (EPA 2001). Lifetime
excess total cancer risk per unit intake is included
for water ingestion, food ingestion, soil ingestion,
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8. REGULATIONS, ADVISORIES, AND GUIDELINES
Table 8-1. Regulations, Advisories, and Guidelines Applicable to Plutonium and
Plutonium Compounds
Agency
Description
Information
Reference
INTERNATIONAL
Guidelines:
IARC
Carcinogenicity classification
239
Pu and its decay products (may
contain
240
Pu and other isotopes), as
aerosols
Group 1
a
IARC 2006
ICRP
Occupational—whole body exposure
5 rem/year
ICRP 1977
Individual—short-term, to critical
populations
0.5 rem/year
Individual—chronic exposure
0.1 rem/year
WHO
Air quality guidelines
No data
WHO 2000
Drinking water quality guidelines
No data
WHO 2004
NATIONAL
Regulations and
Guidelines:
a. Air
ACGIH
Dose limits for exposure to ionizing
radiation
ACGIH 2006
Effective dose
In any single year
50 mSv
Averaged over 5 years
20
mSv per year
Annual equivalent dose to
Lens of the eye
150 mSv
Skin
500 mSv
Hands and feet
500 mSv
Embryo-fetus exposures once the
pregnancy is known
Monthly equivalent dose
Dose to the surface of women’s
abdomen (lower trunk)
0.5 mSv
2 mSv for the remainder
of the pregnancy
Intake of radionuclide
1/20 of ALI
EPA
AEGL-1, -2, and -3
No data
EPA 2007b
Occupational—the committed effective
dose equivalent (internal) and
annual
effective dose equivalent (external)
combined
5 rem/year
EPA 1987
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8. REGULATIONS, ADVISORIES, AND GUIDELINES
Table 8-1. Regulations, Advisories, and Guidelines Applicable to Plutonium and
Plutonium Compounds
Agency
Description
Information
Reference
NATIONAL
(cont.)
FRC
Individual—whole body exposure
5 rem/year
Individual—operational guide for
0.17 rem/year
“suitable sample of population” when
individual whole body doses are not
known
EPA
National emission
standards for
10 mrem/year
emissions of radionuclides other than
radon from Department of Energy
facilities
NIOSH
REL (10-hour TWA)
No data
OSHA
Exposure limits of individuals to ionizing
radiation in restricted areas (rems per
calendar quarter)
Whole body: head and trunk; active 1.25 rems
blood-forming organs; lens of eyes;
or gonads
Hands and forearms; feet and ankles 18.75 rems
Skin of whole body
7.5 rems
USNRC
Occupational values for oral ingestion
ALI (µCi) of Class W
236
Pu
2x10
+0
237
Pu
1x10
+4
238
Pu
9x10
-1
(bone surface)
239
Pu
8x10
-1
(bone surface)
240
Pu
8x10
-1
(bone surface)
241
Pu
4x10
+1
(bone surface)
242
Pu
8x10
-1
(bone surface)
243
Pu
2x10
+4
244
Pu
8x10
-1
(bone surface)
Occupational values for inhalation ALI
(µCi) of Class W
b
236
Pu
2x10
-2
237
Pu
3x10
+3
238
Pu
7x10
-3
(bone surface)
239
Pu
6x10
-3
(bone surface)
240
Pu
6x10
-3
(bone surface)
241
Pu
3x10
-1
(bone surface)
242
Pu
7x10
-3
(bone surface)
243
Pu
4x10
+4
244
Pu
7x10
-3
(bone surface)
FRC 1960
EPA 2002
40 CFR Part 61
OSHA 2006
29 CFR 1910.1096
USNRC 2007a
10 CFR 20,
Appendix B