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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.)
Occupational values for inhalation ALI
(µCi) of Class Y
b
236
Pu
237
Pu
238
Pu
239
Pu
240
Pu
241
Pu
242
Pu
243
Pu
244
Pu
USNRC
Occupational values for inhalation DAC
(µCi/mL) of Class W
b
236
Pu
237
Pu
238
Pu
239
Pu
240
Pu
241
Pu
242
Pu
243
Pu
244
Pu
Occupational values for inhalation DAC
(µCi/mL) of Class Y
b
236
Pu
237
Pu
238
Pu
239
Pu
240
Pu
241
Pu
242
Pu
243
Pu
244
Pu
b. Water
Drinking water standards and health
advisories for gross alpha particle
activity
10
-4
Cancer risk
National primary drinking water
standards for alpha particles
MCLG
MCL
Public health goal
4x10
-2
3x10
+3
2x10
-2
2x10
-2
(bone surface)
2x10
-2
(bone surface)
8x10
-1
(bone surface)
2x10
-2
(bone surface)
4x10
+4
2x10
-2
(bone surface)
8x10
-12
1x10
-6
3x10
-12
3x10
-12
3x10
-12
1x10
-10
3x10
-12
2x10
-5
3x10
-12
2x10
-11
1x10
-6
8x10
-12
7x10
-12
7x10
-12
3x10
-10
7x10
-12
2x10
-5
7x10
-12
15 pCi/L
Zero
15 pCi/L
Zero
USNRC 2007a
10 CFR 20,
Appendix B
EPA 2006
EPA 2003
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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.)
c. Food
No data
FDA
Guidance level for radionuclide in
domestic and imported food
FDA 2004
Derived intervention level
2 Bq/kg
d. Other
ACGIH
Carcinogenicity classification
No data
ACGIH 2006
EPA
Carcinogenicity classification
Group A
c
EPA 2001
EPA
Superfund, emergency planning, and
community right-to-know
EPA 2007c
40 CFR 302.4
Designated CERCLA hazardous
substance
Reportable quantity (Ci)
236
Pu
237
Pu
238
Pu
239
Pu
240
Pu
241
Pu
242
Pu
243
Pu
244
Pu
0.1
1,000
0.01
0.01
0.01
1
0.01
1,000
0.01
NTP
Carcinogenicity classification
Known to be human
carcinogens
NTP 2005
a
Group 1: carcinogenic to humans
b
The ALIs and DACs for inhalation are given for an aerosol with an activity median aerodynamic diameter (AMAD) of
1
μ
m and for three classes (D,W,Y) of radioactive material, which refer to their retention (approximately days, weeks,
or years) in the pulmonary region of the lung. This classification applies to a range of clearance half-times of less
than 10 days for D, for W from 10 to 100 days, and for Y greater than 100 days (USNRC 2007a).
c
Group A: known human carcinogen
ACGIH = American Conference of Governmental Industrial Hygienists; AEGL = Acute Exposure Guideline Levels;
ALI = Annual Limit on Intake; CERCLA = Comprehensive Environmental Response, Compensation, and Liability Act;
CFR = Code of Federal Regulations; DAC = Derived Air Concentration; EPA = Environmental Protection Agency;
FDA = Food and Drug Administration; FRC = Federal Radiation Council; IARC = International Agency for Research
on Cancer; ICRP = International Commission on Radiological Protection; MCL = maximum contaminant level;
MCLG = maximum contaminant level goal; NIOSH = National Institute for Occupational Safety and Health;
NTP = National Toxicology Program; OSHA = Occupational Safety and Health Administration; REL = recommended
exposure limit; RfC = inhalation reference concentration; RfD = oral reference dose; TWA = time-weighted average;
USNRC = U.S. Nuclear Regulatory Commission; WHO = World Health Organization
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8. REGULATIONS, ADVISORIES, AND GUIDELINES
inhalation, and external exposure. The risk values for selected plutonium isotopes are presented in
Table 8-2. The EPA has not derived reference concentrations (RfCs) or reference doses (RfDs) for
plutonium (IRIS 2009), but has derived a maximum contaminant level (MCL) of 15 pCi/L for total alpha-
emitters (including plutonium), less uranium and radon (EPA 2003).
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8. REGULATIONS, ADVISORIES, AND GUIDELINES
Table 8-2. Radionuclide Carcinogenicity—Slope Factors for Plutonium (Federal
Guidance Report No. 13 Morbidity Risk Coefficients, in Units of Picocuries)
a
Slope factor (morbidity risk coefficient) lifetime excess total cancer risk per unit
intake or exposure
Gastro-
External
intestinal
Water
Food
Soil
exposure
absorption ingestion
ingestion
ingestion
Inhalation
(risk/year
Isotope
b
Fraction
c
(risk/pCi)
(risk/pCi)
(risk/pCi)
(risk/pCi)
per pCi/g)
Pu-234
5.00x10
-4
8.58x10
-13
1.25x10
-12
2.39x10
-12
6.85x10
-11
1.61x10
-7
Pu-235
5.00x10
-4
4.37x10
-15
6.03x10
-15
9.73x10
-15
2.39x10
-15
2.37x10
-7
Pu-236
5.00x10
-4
7.47x10
-11
9.92x10
-11
1.74x10
-10
2.28x10
-8
1.19x10
-10
Pu-237
5.00x10
-4
5.77x10
-13
8.40x10
-13
1.62x10
-12
1.27x10
-12
1.12x10
-7
Pu-238
5.00x10
-4
1.31x10
-10
1.69x10
-10
2.72x10
-10
3.36x10
-8
7.22x10
-11
Pu-239
5.00x10
-4
1.35x10
-10
1.74x10
-10
2.76x10
-10
3.33x10
-8
2.00x10
-10
Pu-240
5.00x10
-4
1.35x10
-10
1.74x10
-10
2.77x10
-10
3.33x10
-8
6.98x10
-11
Pu-241
5.00x10
-4
1.76x10
-12
2.28x10
-12
3.29x10
-12
3.34x10
-10
4.11x10
-12
Pu-242
5.00x10
-4
1.28x10
-10
1.65x10
-10
2.63x10
-10
3.13x10
-8
6.25x10
-11
Pu-243
5.00x10
-4
4.74x10
-13
6.92x10
-13
1.34x10
-12
2.94x10
-13
5.50x10
-8
Pu-244
5.00x10
-4
1.37x10
-10
1.80x10
-10
2.94x10
-10
2.93x10
-8
3.01x10
-11
Pu-245
5.00x10
-4
4.48x10
-12
6.55x10
-12
1.28x10
-11
2.07x10
-12
1.77x10
-6
Pu-246
5.00x10
-4
1.73x10
-11
2.53x10
-11
4.92x10
-11
1.73x10
-11
4.04x10
-7
a
EPA classifies all radionuclides as Group A (known human) carcinogens. Radionuclide risk coefficients, or slope
factors, are calculated by EPA's ORIA to assist HEAST users with risk-related evaluations and decision-making at
various stages of the remediation process. Most values presented are taken from EPA (1999, 2000); risk
estimates for the soil ingestion pathway are not addressed, but have been computed using similar methods.
Ingestion and inhalation slope factors are central estimates in a linear model of the age-averaged, lifetime
attributable radiation cancer incidence (fatal and nonfatal cancer) risk per unit of activity inhaled or ingested,
expressed as risk/pCi. Slope factors can be converted into the SI units of becquerels (1 Bq=1 nuclear
transformation per second) by dividing each inhalation, ingestion, or external exposure value by 0.037. Ci, the
customary unit of activity is equal to 3.7x1,010 nuclear transformations per second (1 pCi=10–12 Ci). Inhalation
values for particulates represent the indicated ICRP lung absorption type (medium, particulate). External exposure
slope factors are central estimates of the lifetime attributable radiation cancer incidence risk for each year of
exposure to external radiation from photon-emitting radionuclides uniformly distributed in a thick layer of soil
(expressed as risk/year per pCi/g of soil).
b
For each radionuclide listed, slope factors correspond to the risks per unit intake or exposure for that radionuclide
only.
c
Gastrointestinal absorption fractions are the fractional amounts of each radionuclide absorbed across the
gastrointestinal tract into the bloodstream.
Bq = Becquerel; Ci = curie; EPA = Environmental Protection Agency; HEAST = Health Effects Assessment
Summary Table; ICRP = International Commission on Radiological Protection; ORIA = Office of Radiation and
Indoor Air; pCi = picocurie; SI = International System
Source: EPA 2001
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