Evaluation of Guidelines for Exposures to Technologically Enhanced Naturally Occurring Radioactive Materials (1999) / Chapter Skim
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10 Comparison of Current Guidances for TENORM in the Environment
10 Comparison of Current Guidances for TENORM in the Environment
Pages 204-217
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From page 204... ...
were considered separately from guidances developed by other organizations. This chapter presents summary comparisons of EPA guidances specific to TENORM with the guidances for TENORM developed by other regulatory or advisory organizations.
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From page 205... ...
A dosimetric approach to estimating lung cancer risks from radon also requires assumptions-for example, the deposition of radon decay products in the respiratory tract and the particular target cells at risk-that may be difficult to verify. Thus, both the BEIR IV Committee (National Research Council 1988)
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From page 206... ...
206 GUIDELINES FOR EXPOSURE TO TENORAI Cal I: o ._ ~s ._ AD o o 4, - o C} Cal CJ ._ ED ·; U
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From page 207... ...
However, the EPA guidance was based for the most part on considerations of average levels of radon in homes and a cost-benefit analysis of reducing these levels with available technologies (EPA and DHHS 1994~; that is, the guidance reflected a greater emphasis on reducing exposures to radon in the greatest number of homes. Thus, the difference between EPA's mitigation level and the values recommended by NCRP and ICRP is explained in part by a difference in emphasis reducing risks to individuals versus reducing risks to whole populations.
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From page 209... ...
. As noted above, this comparison does not consider guidances for naturally occurring radionuclides that apply to operations of the nuclear fuel cycle or the management and disposal of uranium or thorium mill tailings, which are regulated by EPA, the Nuclear Regulatory Commission, and DOE under the Atomic Energy Act.
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From page 211... ...
Therefore, the Federal Radiation Council and EPA guidances in table 10.3 that apply to TENORM other than indoor radon and to human-made radionuclides but not to natural background are not directly comparable with NCRP's recommended remedial-action level for natural sources. However, given that the average annual dose from natural background excluding radon is about 1 mSv (100 mrem)
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From page 213... ...
COMPARISON OF CURRENT GUIDANCES FOR TENORM 213 anti ~ I~ Hi.
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From page 214... ...
For example, for large volumes of contaminated surface soil, the annual dose from external exposure corresponding to the state and Conference of Radiation Control Program Directors (CRCPD) standards for 226Ra expressed in terms of activity concentrations would be about 0.6 mSv (60 mrem)
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From page 215... ...
However, those criteria, especially the limits on surface contamination, are not clearly related to dose and so are not easily compared with the dose constraint in EPA guidance. Bases For Differences In Guidances The information discussed in the previous two sections and summarized in tables 10.3 and 10.4 indicates that current EPA guidances for TENORM other than indoor radon often are substantially more restrictive than similar guidances developed by other organizations.
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From page 216... ...
In addition, the guidances for TENORM in the form of concentration limits for radium and thorium in contaminated soil and other materials often were based primarily on existing EPA standards in 40 CFR Part 192 for cleanup of contaminated soil at uranium or thorium mill tailings sites (see chapter 9~. SUMMARY This chapter has presented summary comparisons of guidances for controlling exposures of the public to TENORM developed by EPA with similar guidances developed by other organizations, including the Nuclear Regulatory Commission, DOE, state organizations, other countries, NCRP, HPS, ICRP, and IAEA.
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From page 217... ...
However, direct comparisons of the various guidances are difficult and potentially misleading because of differences in whether exposures to natural background are included, the difference in concept between a regulatory goal and a limit, and the use of dose criteria in some guidances and activity concentrations of radionuclides in others. The differences between guidances do not reflect the differences in approaches to risk assessment for radionuclides used by EPA and other organizations.
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