Sensitivity analyses of the standards for the proposed Yucca Mountain repository--a review, evaluation, and commentary

The standards and regulations for the proposed Yucca Mountain high level radioactive waste repository, which were developed and promulgated by the U.S. Environmental Protection Agency and the U.S. Nuclear Regulatory Commission, respectively, are complex and challenging. A major reason is that they are divided into three parts, an Individual Protection Standard, a Human Intrusion Standard, and multiple Ground Water Protection Standards. Because the individual parts are not fully integrated, the one that controls under a specific set of circumstances depends on the radionuclide being evaluated, its mechanisms of transport, its avenues of intake, and differences in the specified limits. Although the coefficients in Federal Guidance Report (FGR) No. 11 are being used to estimate the doses, other sources (for example, Title 10, CFR, Part 20, and/or FGR No. 13) may deserve consideration. Since the regulations specify that the reasonably maximally exposed individual is an adult, this leaves unanswered the estimated doses to other age groups, such as infants and adolescents. Summarized in this paper are comparisons of the dose coefficients for different age groups, as well as evaluations of the sensitivity of effective and organ dose estimates for adults, depending on the source of the coefficients. All the latter analyses were based only on the consumption of ground water. While the dose estimates are different, depending on the sources of the coefficients, this was not unexpected. What these evaluations demonstrate is the caution that must be exercised to ensure that a full range of considerations is taken into account in interpreting the outcome of the dose assessments being made with respect to the proposed repository.     

Defining and managing biohazardous waste in U.S. research-oriented universities: a survey of environmental health and safety professionals

A survey was conducted of environmental health and safety professionals responsible for biohazardous waste management at 122 institutions. The overall response rate was 82.6 percent (100 out of 122). Results indicate that university policies for biohazardous waste are heavily influenced by state environmental regulations, the Occupational Safety and Health Administration Bloodborne Pathogens Standard, and the biosafety guidelines of the Centers for Disease Control and Prevention and the National Institutes of Health. With respect to definition of waste, 84 percent of the universities treat non-infectious human-cell-culture waste as biohazardous. Sharp items, including hypodermic needles, syringes with needles, and scalpel blades, are commonly treated (by 85 percent of universities) as biohazardous sharps regardless of contamination status. Importantly, while 90 percent of universities use autoclave sterilization for waste treatment, only 52 percent use a biological indicator to validate the process. On-site incineration is currently used by 42 percent of universities. Twenty-two of 42 incinerators are hospital/medical/infectious-waste incinerators, and 10 of these will continue to operate under the U.S. Environmental Protection Agency's revised incinerator regulations. Eighty-seven percent of the respondents indicated that some portion of their university's biohazardous waste is treated and disposed of through a licensed medical waste hauler (MWH). To ensure compliance with institutional policy, most universities segregate and package waste, train waste generators, and conduct inspections.     

美国的城市固体废弃物填埋标准

介绍了美国国家环保局颁布的《城市固体废弃物填埋标准》,从选址、运营、设计、地下水监测、关闭及关闭后照管、财政保证6个方面,系统地阐述了其主要内容,对于我国城市垃圾填埋场的建设和管理工作具有的一定的借鉴意义。     

AHA responds to proposals on medical waste incineration

Roger Olson, chairman of facilities operations for the Mayo Clinic, Rochester, MN, testified on behalf of the American Hospital Association before the U.S. Environmental Protection Agency's Office of Air Quality Planning and Standards on the EPA's proposed rules on medical waste incinerators. Here's what he had to say.     

Warren K. Sinclair keynote address: contemporary issues in risk-informed decision making on the disposition of radioactive waste

A consistent and transparent risk-informed approach to managing nuclear waste is plagued with different regulators, different rules and regulations for different waste types, different compliance requirements, and indecisions about probabilistic vs. deterministic models. Low-activity waste management is particularly void of a path forward with respect to being risk-informed. Risk assessment is not referenced in the statutes on low-activity waste even though both the U.S. Environmental Protection Agency and U.S. Nuclear Regulatory Commission (U.S. NRC) have policies to apply consistent risk management approaches to all of their programs. The U.S. NRC has developed guidance on the preparation of probabilistic performance assessments for low-activity waste facilities, but there have been no serious takers and a lack of initiative on the part of licensees. Thus, little to no experience exists on risk-informing low-activity waste. The missed opportunities include establishing a risk basis that would allow for simpler, safer, and much less costly alternatives for low-activity waste disposal while enabling society to have the full benefit of radiation technologies. There is hope that congressional action or regulatory rule making will address some of these issues with the result being the adoption of a more general and unified approach to risk-informed regulation of all types of waste. Just as much of the initiative for risk-informed nuclear power came from industry, it must also be the case for nuclear waste. A start would be the adoption of a basic framework of risk assessment in waste management applicable to all types of waste--radioactive and nonradioactive. The "set of triplets" risk assessment framework that is applicable to any kind of risk is an established alternative. It is believed that such a framework with the support of a regulatory structure made compatible through appropriate rulemaking or congressional action, and the experience of the probabilistic performance assessments for the Waste Isolation Pilot Plant and the proposed Yucca Mountain high-level waste repository, could result in the right path forward for the regulation and management of low-activity waste.     

An in situ gamma-ray spectrometry intercomparison

This paper provides the results of an in situ gamma-ray spectrometry intercomparison that was held from 18-21 October 1999, in Grand Junction, CO. This intercomparison was a collaborative effort between the U.S. Department of Energy's Environmental Measurements Laboratory and the U.S. Environmental Protection Agency's Office of Radiation and Indoor Air. It featured measurements of a background location and the Walker Field Calibration Pads. In this paper, the in situ gamma-ray measurements of the background location were compared to soil samples, and the in situ measurements of the Walker Field Calibration Pads were compared to corrected reference values. The results showed that 84% of the in situ gamma-ray measurements of 226Ra, 232Th, and 40K at the background location fell within 20% of the soil sample mean. Similarly, in situ gamma-ray measurements of the Walker Field Calibration Pads showed that 77% of the in situ concentrations fell within 20% of the corrected reference values.     

Industry efforts to weaken the EPA's classification of the carcinogenicity of 1,3-butadiene

Industry's success in negotiating away science at the level of governmental regulatory agencies is eroding the integrity of the regulatory process. Maneuvers used by industry to weaken the U.S. Environmental Protection Agency's classification of the carcinogenicity of butadiene are described.     

Enhancing compliance at Department of Defense facilities: comparison of three environmental audit tools

To enhance environmental compliance, the U.S. Department of Defense (DOD) recently developed and implemented a standardized environmental audit tool called The Environmental Assessment and Management (TEAM) Guide. Utilization of a common audit tool (TEAM Guide) throughout DOD agencies could be an effective agent of positive change. If, however, the audit tool is inappropriate, environmental compliance at DOD facilities could worsen. Furthermore, existing audit systems such as the U.S. Environmental Protection Agency's (U.S. EPA's) Generic Protocol for Conducting Environmental Audits of Federal Facilities and the International Organization for Standardization's (ISO's) Standard 14001, "Environmental Management System Audits," may be abandoned even if they offer significant advantages over TEAM Guide audit tool. Widespread use of TEAM Guide should not take place until thorough and independent evaluation has been performed. The purpose of this paper is to compare DOD's TEAM Guide audit tool with U.S. EPA's Generic Protocol for Conducting Environmental Audits of Federal Facilities and ISO 14001, in order to assess which is most appropriate and effective for DOD facilities, and in particular those operated by the U.S. Army Corps of Engineers (USACE). USACE was selected as a result of one author's recent experience as a district environmental compliance coordinator responsible for the audit mission at this agency. Specific recommendations for enhancing the quality of environmental audits at all DOD facilities also are given.     

Comparison of environmental radiation monitoring programs in China and the United States

The monitoring of environmental radiation has been carried out across the United States by the U.S. Environmental Protection Agency's RadNet (formerly the Environmental Radiation Ambient Monitoring System, ERAMS) and the Global Network Program (GNP) of the Environmental Measurements Laboratory (EML), and in the People's Republic of China (PRC) by their National Radioactivity Contamination Monitoring System (NRCMS). It is expected that an awareness of the similarities and differences in the structure and operation of these programs will prove helpful to both countries and perhaps others as they continue to develop their monitoring capabilities.     

Ten Years of Addressing Children’s Health through Regulatory Policy at the U.S. Environmental Protection Agency

Background

Executive Order (EO) 13045, Protection of Children From Environmental Health Risks and Safety Risks, directs each federal agency to ensure that its policies, programs, activities, and standards address disproportionate environmental health and safety risks to children.

Objectives

We reviewed regulatory actions published by U.S. Environmental Protection Agency (EPA) in the Federal Register from April 1998 through December 2006 to evaluate applicability of EO 13045 to U.S. EPA actions and consideration of children’s health issues in U.S. EPA rulemakings.

Discussion

Although virtually all actions discussed EO 13045, fewer than two regulations per year, on average, were subject to the EO requirement to evaluate children’s environmental health risks. Nonetheless, U.S. EPA considered children’s environmental health in all actions addressing health or safety risks that may disproportionately affect children.

Conclusion

The EO does not apply to a broad enough set of regulatory actions to ensure protection of children’s health and safety risks, largely because of the small number of rules that are economically significant. However, given the large number of regulations that consider children’s health issues despite not being subject to the EO, other statutory requirements and agency policies reach a larger set of regulations to ensure protection of children’s environmental health.     

A statewide multiagency intervention model for empowering schools to improve indoor environmental quality

A large population of children and adults is potentially exposed to indoor environmental quality (IEQ) hazards in schools. Those with asthma are particularly at risk because IEQ-related hazards in school buildings can trigger asthma episodes. A multiagency consortium created and led by the Connecticut Department of Public Health has successfully implemented and continues to sustain the U.S. Environmental Protection Agency's (U.S. EPA's) Tools for Schools (TfS) program in the majority of Connecticut public schools. TfS is an action kit and program promoting a low-cost, problem-solving team approach to preventing IEQ hazards or improving IEQ. One key to the consortium's success is the array of services it provides to schools, including aggressive outreach and specialized training and consultation. The consortium is also a platform for launching other school IEQ initiatives. The authors present and analyze the consortium model and their efforts at evaluating the impact of TfS in Connecticut.     

An unrecognized source of PCB contamination in schools and other buildings

An investigation of 24 buildings in the Greater Boston Area revealed that one-third (8 of 24) contained caulking materials with polychlorinated biphenyl (PCB) content exceeding 50 ppm by weight, which is the U.S. Environmental Protection Agency (U.S. EPA) specified limit above which this material is considered to be PCB bulk product waste. These buildings included schools and other public buildings. In a university building where similar levels of PCB were found in caulking material, PCB levels in indoor air ranged from 111 to 393 ng/m3; and in dust taken from the building ventilation system, < 1 ppm to 81 ppm. In this building, the U.S. EPA mandated requirements for the removal and disposal of the PCB bulk product waste as well as for confirmatory sampling to ensure that the interior and exterior of the building were decontaminated. Although U.S. EPA regulations under the Toxic Substances Control Act stipulate procedures by which PCB-contaminated materials must be handled and disposed, the regulations apparently do not require that materials such as caulking be tested to determine its PCB content. This limited investigation strongly suggests that were this testing done, many buildings would be found to contain high levels of PCBs in the building materials and potentially in the building environment. The presence of PCBs in schools is of particular concern given evidence suggesting that PCBs are developmental toxins.     

Risk-informed radioactive waste classification and reclassification

Radioactive waste classification systems have been developed to allow wastes having similar hazards to be grouped for purposes of storage, treatment, packaging, transportation, and/or disposal. As recommended in the National Council on Radiation Protection and Measurements' Report No. 139, Risk-Based Classification of Radioactive and Hazardous Chemical Wastes, a preferred classification system would be based primarily on the health risks to the public that arise from waste disposal and secondarily on other attributes such as the near-term practicalities of managing a waste, i.e., the waste classification system would be risk informed. The current U.S. radioactive waste classification system is not risk informed because key definitions--especially that of high-level waste--are based on the source of the waste instead of its inherent characteristics related to risk. A second important reason for concluding the existing U.S. radioactive waste classification system is not risk informed is there are no general principles or provisions for exempting materials from being classified as radioactive waste which would then allow management without regard to its radioactivity. This paper elaborates the current system for classifying and reclassifying radioactive wastes in the United States, analyzes the extent to which the system is risk informed and the ramifications of its not being so, and provides observations on potential future direction of efforts to address shortcomings in the U.S. radioactive waste classification system as of 2004.     

Low-activity radioactive materials management at the U.S. Department of Energy

The U.S. Department of Energy (U.S. DOE) is making significant progress with the cleanup of its legacy radioactively-contaminated facilities and sites left from research and development and production of nuclear materials and weapons. Sites like Rocky Flats, Battelle Columbus Laboratories, Fernald, Mound, Brookhaven National Laboratory, Hanford, and Oak Ridge are faced daily with decisions related to disposition of waste and radioactive material. One key to this success is the disposition of waste arising from cleanup. Most of the generated waste volume has very low levels of radioactive contamination. The waste includes contaminated soil, debris from demolition, or scrap metal and equipment. The cost of disposing of large volumes of waste can be prohibitive, so there is incentive to find innovative ways to disposition wastes. This paper describes the current status of policy development in this area, such as development of a draft programmatic environmental impact statement and monitoring of related rulemaking at the U.S. Nuclear Regulatory Commission. The paper also provides an overview of draft U.S. DOE guidance on control and release of property with residual radioactive material, and site-specific applications of DOE guidance.     

Worker and Environmental Protection Issues in the Remediation Of an Abandoned Source Manufacturing Facility

The Gulf Nuclear Superfund Site located in Odessa, Texas, was an abandoned radioactive source production facility slated for cleanup as a Removal Action under the U.S. Environmental Protection Agency Region VI Superfund program. Prior to cessation of operations and abandonment of the facility in 1992, it was used for the production of radioactive sources used in the oil and gas industry and nuclear medicine applications. Pangea Group was contracted by the U.S. Army Corps of Engineers (USACE) Kansas City District to perform remediation of the site and other contaminated debris, cleaning of interior building surfaces, building demolition, and excavation/removal of contaminated soils and septic system. The project scope also included loading, containerization and transportation of low-level radioactive wastes for offsite disposal. Primary radionuclides present at the facility were Cs, Co, and Am. The project also included packaging and removal of radioactive sources and mixed waste consisting of radiologically contaminated lead shot and lead source containers. Included in the paper is a discussion of primary worker protection and environmental protection measures employed on the project. Worker protection issues included the control of industrial and construction safety hazards as well as control of external and internal radiation dose. Control of air emissions and contaminated wastewater were also very important, especially due to the location of the site. The site was located in an area containing both residential and commercial properties. Several residences and businesses were located immediately adjacent to the site. The project involved the participation of the USACE Kansas City District, EPA Region 6, and the Texas Bureau of Radiological Health. Field work on the project started in April 2001 and was completed approximately five months later.     

Characterization of spirometric function in residents of three comparison communities and of three communities located near waste incinerators in North Carolina

Waste incinerators are an increasingly common means of solid waste disposal. However, little is documented about the physical health of community members who live close to incinerators. During a 3-yr epidemiological study, spirometric lung function was tested once annually among residents from 3 communities surrounding a hazardous waste, biomedical, or municipal incinerator and among residents in 3 comparison communities. A total of 1,016 nonsmoking individuals, aged 8-80 yr, participated during at least 1 of the 3 yr of the study; 358 individuals participated all 3 yr. Daily air-quality sampling was done for 1 mo/yr in all 6 communities. The average monthly concentrations of particulate matter with diameters of 2.5 microns and less (PM2.5 [range = 14.6-31.5 micrograms/m3]) in all communities were similar during the 3 yr of study. The mean daily PM2.5 concentrations were significantly less than the U.S. Environmental Protection Agency's allowable 24-hr standard of 65 micrograms/m3. Individual incinerators contributed less than 2.5% of the areas' total PM2.5 levels. There was no difference in percent predicted forced vital capacity, forced expiratory volume in 1 sec, or forced expiratory flow rate over the middle 50% of the forced vital capacity among members of the incinerator communities, compared with nonincinerator communities, and there were no significant differences in lung function within the 3 sets of communities. There was no evidence from this study that an association existed between residence in these 3 waste incinerator areas, which met state and federal emissions regulations, and average spirometric pulmonary function of nonsmoking community members.     

Probability surveys, conditional probability, and ecological risk assessment

We show that probability-based environmental resource monitoring programs, such as the U.S. Environmental Protection Agency's (U.S. EPA) Environmental Monitoring and Assessment Program, and conditional probability analysis can serve as a basis for estimating ecological risk over broad geographic areas. Under certain conditions (including appropriate stratification of the sampled population, sufficient density of samples, and sufficient range of exposure levels paired with concurrent response values), this empirical approach provides estimates of risk using extant field-derived monitoring data. The monitoring data were used to prescribe the exposure field and to model the exposure-response relationship. We illustrate this approach by estimating risks to benthic communities from low dissolved oxygen (DO) in freshwater streams of the mid-Atlantic region and in estuaries of the Virginian Biogeographical Province of the United States. In both cases, the estimates of risk are consistent with the U.S. EPA's ambient water quality criteria for DO.     

Achieving compliance with the radium standards for drinking water in a midwestern community: a case study

The problem of elevated levels of radium in the drinking-water supply of DeKalb, Illinois, a Midwestern community about 65 miles west of Chicago with approximately 35,000 residents, has been a contentious issue for over a decade. The central players in the controversy include a group of concerned citizens, city officials, the Illinois Pollution Control Board, the Illinois Environmental Protection Agency, and the U.S. Environmental Protection Agency (U.S. EPA). Achieving a satisfactory resolution to the problem has been a long, drawn-out process that illustrates how ill-timed proposals, changing risk assessments, different perceptions of risk, and the high costs of compliance can influence the direction of risk management decisions. The purpose of this study is to analyze how these factors sustained the debate and prevented an expeditious solution to the problem. The study uses document analysis as its primary research tool. The questions raised by the controversy, along with their implications for environmental policy, are discussed, as are some of the more important lessons learned from the case. Because of many uncertainties, there were no clear winners in the controversy, although, in the context of the most recent U.S. EPA risk assessments, the community is now poised for better protection from the potential dangers of radium in drinking water than it might have been had citizen action been absent.     

Comparison of natural background dose rates for residents of the Amargosa Valley, NV, to those in Leadville, CO, and the states of Colorado and Nevada

In the latter half of 2005, the U.S. Environmental Protection Agency (U.S. EPA) published a Proposed Rule (40 CFR Part 197) for establishing a dose rate standard for limiting radionuclide releases from the proposed Yucca Mountain high-level radioactive waste repository during the time period from 10 to 10 years after closure. The proposed standard was based on the difference in the estimated dose rate from natural background in the Amargosa Valley and the "average annual background radiation" for the State of Colorado. As defined by the U.S. EPA, "natural background radiation consists of external exposures from cosmic and terrestrial sources, and internal exposures from indoor exposures to naturally-occurring radon." On the basis of its assessments, the U.S. EPA estimated that the difference in the dose rate in the two identified areas was 3.5 mSv y. The purpose of this paper is to provide an independent evaluation and review of this estimate. One of the first observations was that, because site-specific dose rate measurements for the Amargosa Valley "were not available," the dose rates for various sources of natural background in that area, used by the U.S. EPA in its assessment, were based on modifications of the average values for the State of Nevada. A second observation was that the conversion coefficient applied in estimating the dose rates due to exposures to indoor radon and its decay products was a factor of >2 higher than the currently internationally accepted value. Further review revealed that site-specific data for many natural background sources in the Amargosa Valley were available. One particularly important observation was that about 91% of the residents of that area live in mobile homes which, due to their construction and design, have indoor radon concentrations comparable to, or less than, those outdoors. For that reason, alone, the U.S. EPA estimate of the average dose rate for residents of the Amargosa Valley, due to exposures to indoor radon, was not valid. For purposes of the comparisons in this paper, site-specific dose rates were estimated for all major natural background sources of exposure to residents of the Amargosa Valley, and those in Leadville, CO. The latter community was selected for comparison because of its altitude (3,200 m) and accompanying relatively high cosmic radiation dose rate, and the fact the size of its population is comparable to that of the Amargosa Valley. Another reason for this selection was that a comparison of the average natural background dose rate in the Amargosa Valley to that for the State of Colorado is not suitable because it fails to consider those locations within the State that have dose rates that are higher than the average. Nonetheless, for completeness, and to provide a number that could be compared to the U.S. EPA estimated difference, similar comparisons of the estimated dose rate in the Amargosa Valley to those for average residents of the States of Colorado and Nevada were included in the assessments that follow. The outcome showed that the estimated dose rates in Leadville, the State of Colorado, and the State of Nevada, were higher than those in the Amargosa Valley by 3.94 +/- 1.09, 2.54 +/- 2.18, and 0.95 +/- 0.82 mSv y, respectively. Associated uncertainties were highest for the estimated dose rates due to exposures to radon and its decay products. Had the systematic errors in the radon dose conversion coefficient and the random distribution in radon concentrations been included, the overall uncertainty in the total dose rate estimates could have been as high as 150%.     

Quantitative goals for a 222Rn multimedia mitigation plan.

The U.S. Environmental Protection Agency's revised proposed 222Rn in drinking water regulation gives states or individual community water systems the option of compliance with the maximum contaminant level or compliance with the higher, alternate maximum contaminant level accompanied by the implementation of a multimedia mitigation plan. If states or water suppliers choose to comply with the alternate maximum contaminant level, the health risk reduction achieved by multimedia mitigation programs must be equal to or greater than the health risk reduction that would be achieved by compliance with the maximum contaminant level rather than the alternate maximum contaminant level. We have developed a method to determine quantitative goals for mitigating existing homes and building new 222Rn-resistant homes to achieve a health risk reduction to the public equivalent to the health risk differential between alternate maximum contaminant level and maximum contaminant level compliance. This method can be applied to an entire state, a portion of a state, or to an individual water supplier. The method was applied to North Carolina, and it was concluded that, over time, the health risk reduction achievable from alternate maximum contaminant level compliance and the implementation of a multimedia mitigation program would be much greater than from compliance with the maximum contaminant level.