Case Studies of Fraud Associated with the Use of Radiation Sources: Practical Avoidance Strategies Based on Lessons Learned

ABSTRACT

Periodically the radiation protection profession has experienced purposeful deception practices that remained undetected for some time. Upon discovery, the cases of fraud revealed gaps in confirmation or validation practices that the radiation protection community should note. Summarized here is a convenience sample of actual cases of fraud involving radiation sources along with the exploited process vulnerabilities. Recommended process improvements that the radiation safety community may consider are presented to improve the collective fidelity of radiation protection processes.

Considerations for Radiation Safety Professionals to Prepare and Respond to the Next Pandemic

ABSTRACT

The Health Physics Society's stated mission is "excellence in the science and practice of radiation safety." Why, then, should we discuss disease outbreaks, epidemics, and pandemics with radiation safety professionals? The answer is simple: all workers are impacted by infectious diseases-and, as safety professionals, we will inevitably be called upon to prepare for and respond to these events. The COVID-19 pandemic has disrupted every facet of life, including home, school, work, and leisure. Moreover, virtually all radiation safety professionals have been impacted by the pandemic either personally, academically, or professionally. Even if radiation safety professionals were not involved directly with COVID-19 response, they were impacted by school closures, remote schooling and work, testing regimes, temperature screenings, vaccination programs, and so forth. However, many radiation safety professionals have been intimately involved in COVID-19 response through activities such as the deployment of personal protective equipment, directional airflow verification for isolation areas, disinfection and decontamination efforts, the design and layout of testing and vaccine centers, and in many other ways. Yet, it is likely that many radiation safety professionals have not received formal training in epidemiology, disease control, or other related topics, and thus may not be attuned to the key aspects to consider when the next pandemic emerges-and it will.

Basic Cyber Security Considerations for Licensees of Radioactive Materials and Registrants of Radiation Producing Devices in an Era of Remote or Hybrid Compliance Inspections

ABSTRACT

The onset of the COVID pandemic impacted various regulatory agencies' ability to safely fulfill their regulatory compliance inspection mandates via on-site inspections. Some agencies shifted to a remote or hybrid inspection process, which necessitates the electronic transmittal of a variety of records that may or may not have been transmitted in this fashion in the past, raising concerns about the records being sent and received securely. Considering this new environment, some basic cyber security diagnostic considerations are described for radiation source permit holders to consider prior to responding to an apparent legitimate regulatory inspection request, both in the current COVID cyber risk environment and the environment likely to exist into the future.

A 30-Year Radiation Safety Prospectus Describing Organizational Drivers, Program Activities, and Outcomes

ABSTRACT

In 1992, the University of Texas Health Science Center at Houston (UTHealth) Radiation Safety Program began assembling data on a monthly basis that described various program drivers and associated activities. A summary of the data was assembled on an annual basis and shared with the professional health physics community at the 10-y and 20-y intervals. With the inclusion of 1991 data points, three decades (1991 to 2020) of data have now been collected and summarized into an updated program prospectus. The prospectus models a commercial enterprise prospectus provided to potential investors and displays various program indicator parameters. The consistent formatting of the data affords an easily digestible and succinct snapshot of program activities and trends. Various program stakeholder's feedback regarding this data continues to be well received. Additionally, UTHealth provides increasing support for UT Physicians clinics throughout the greater Houston, Texas area. The prospectus allows succinct description of the drivers of the program, revealed interesting trends, and has identified training needs for both existing personnel and academic programs that support the radiation protection sciences.

A Pilot Examination of the Methods Used to Counteract Insider Threat Security Risks Associated with the Use of Radioactive Materials in the Research and Clinical Setting

While many organizations maintain multiple layers of security control methodologies to prevent outsiders from gaining unauthorized access, persons such as employees or contractors who have been granted legitimate access can represent an "insider threat" risk. Interestingly, some of the most notable radiological events involving the purposeful contamination or exposure of individuals appear to have been perpetrated by insiders. In the academic and medical settings, radiation safety professionals focus their security efforts on (1) ensuring controls are in place to prevent unauthorized access or removal of sources, and (2) increasing security controls for the unescorted accessing of large sources of radioactivity (known as "quantities of concern"). But these controls may not completely address the threat insiders represent when radioactive materials below these quantities are present. The goal of this research project was to characterize the methodologies currently employed to counteract the insider security threat for the misuse or purposeful divergence of radioactive materials used in the academic and medical settings. A web-based survey was used to assess how practicing radiation safety professionals in academic and medical settings anticipate, evaluate, and control insider threat security risks within their institutions. While all respondents indicated that radioactive sources are being used in amounts below quantities of concern, only 6 % consider insider threat security issues as part of the protocol review for the use of general radioactive materials. The results of this survey identify several opportunities for improvement for institutions to address security gaps.

Local origins impart conserved bone type-related differences in human osteoblast behaviour

Osteogenic behaviour of osteoblasts from trabecular, cortical and subchondral bone were examined to determine any bone type-selective differences in samples from both osteoarthritic (OA) and osteoporotic (OP) patients. Cell growth, differentiation; alkaline phosphatase (TNAP) mRNA and activity, Runt-related transcription factor-2 (RUNX2), SP7-transcription factor (SP7), bone sialoprotein-II (BSP-II), osteocalcin/bone gamma-carboxyglutamate (BGLAP), osteoprotegerin (OPG, TNFRSF11B), receptor activator of nuclear factor-κβ ligand (RANKL, TNFSF11) mRNA levels and proangiogenic vascular endothelial growth factor-A (VEGF-A) mRNA and protein release were assessed in osteoblasts from paired humeral head samples from age-matched, human OA/OP (n = 5/4) patients. Initial outgrowth and increase in cell number were significantly faster (p < 0.01) in subchondral and cortical than trabecular osteoblasts, in OA and OP, and this bone type-related differences were conserved despite consistently faster growth in OA. RUNX2/SP7 levels and TNAP mRNA and protein activity were, however, greater in trabecular than subchondral and cortical osteoblasts in OA and OP. BSP-II levels were significantly greater in trabecular and lowest in cortical osteoblasts in both OA and OP. In contrast, BGLAP levels showed divergent bone type-selective behaviour; highest in osteoblasts from subchondral origins in OA and trabecular origins in OP. We found virtually identical bone type-related differences, however, in TNFRSF11B:TNFSF11 in OA and OP, consistent with greater potential for paracrine effects on osteoclasts in trabecular osteoblasts. Subchondral osteoblasts (OA) exhibited highest VEGF-A mRNA levels and release. Our data indicate that human osteoblasts in trabecular, subchondral and cortical bone have inherent, programmed diversity, with specific bone type-related differences in growth, differentiation and pro-angiogenic potential in vitro.

Surge capacity volunteer perspectives on a field training exercise specifically designed to emphasize likely roles during a disaster response

Experience gained from involvement in a number of emergency response activities since September 2001 in Texas indicated that the likely roles of statewide medical reserve corps units typically included aspects such as crowd control, registration and tracking, and information management. The need for training specifically focused on these likely roles became apparent. A novel field training exercise was developed that specifically focused on these likely roles. The exercise centered on a scenario involving the surreptitious placement of radioactivity in high traffic areas across the country, resulting in the contamination of large numbers of individuals. Because the source of the contamination was unknown, surge capacity contamination screening and data collection centers became necessary. Feedback collected from drill participants was measured to be overwhelmingly positive, with the vast majority of participants indicating a marked improvement in their understanding of their likely roles in a disaster of this type. The approach used in this training effort may be of use to other disaster surge capacity organizations as part of their strategic planning efforts as a means of ensuring that individuals involved in response activities possess familiarity with their likely roles during a wide scale public health disaster event.

Risk communication considerations to facilitate the screening of mass populations for potential contamination with radioactive material

Experience gained during a field training exercise with a Medical Reserve Corps unit on the screening of large groups of individuals for possible contamination with radioactive material revealed that while exercise participants were generally attentive to the proper use of protective equipment and detectors, they tended to overlook important basic risk communications aspects. For example, drill participants did not actively communicate with the persons waiting in line for screening, a step which would provide re-assurance, possibly minimize apprehension, and would clarify expectations. When questioned on this issue of risk communication, drill participants were often able to craft ad hoc messages, but the messages were inconsistent and likely would not have significantly helped diminish anxiety and maintain crowd control. Similar difficulties were encountered regarding messaging for persons determined to be contaminated, those departing the screening center, and those to be delivered to the media. Based on these experiences, the need for a suggested list of risk communication points was identified. To address this need, a set of risk communication templates were developed that focused on the issues likely to be encountered in a mass screening event. The points include issues such as the importance of remaining calm, steps for minimizing possible intake or uptake, considerations for those exhibiting acute injuries, expected screening wait times, the process to be followed and the information to be collected, the process to be undertaken for those exhibiting contamination, and symptoms to watch for after departure. Drill participants indicated in follow-up discussions that such pre-established risk communication templates would serve to enhance their ability to assist in times of emergency and noted the potential broader applicably of the approach for use in responses for other disasters types as well.

Validation of orthopaedic bench models for trauma surgery

The aim of this study was to validate the use of three models of fracture fixation in the assessment of technical skills. We recruited 21 subjects (six experts, seven intermediates, and eight novices) to perform three procedures: application of a dynamic compression plate on a cadaver porcine model, insertion of an unreamed tibial intramedullary nail, and application of a forearm external fixator, both on synthetic bone models. The primary outcome measures were the Objective Structural Assessment of technical skills global rating scale on video recordings of the procedures which were scored by two independent expert observers, and the hand movements of the surgeons which were analysed using the Imperial College Surgical Assessment Device. The video scores were significantly different for the three groups in all three procedures (p < 0.05), with excellent inter-rater reliability (alpha = 0.88). The novice and intermediate groups specifically were significantly different in their performance with dynamic compression plate and intramedullary nails (p < 0.05). Movement analysis distinguished between the three groups in the dynamic compression plate model, but a ceiling effect was demonstrated in the intramedullary nail and external fixator procedures, where intermediates and experts performed to comparable standards (p > 0.6). A total of 85% (18 of 21) of the subjects found the dynamic compression model and 57% (12 of 21) found all the models acceptable tools of assessment. This study has validated a low-cost, high-fidelity porcine dynamic compression plate model using video rating scores for skills assessment and movement analysis. It has also demonstrated that Synbone models for the application of and intramedullary nail and an external fixator are less sensitive and should be improved for further assessment of surgical skills in trauma. The availability of valid objective tools of assessment of surgical skills allows further studies into improving methods of training.

Identifying the cellular basis for reimplantation failure in repair of the rotator cuff

We examined cultured osteoblasts derived from paired samples from the greater tuberosity and acromion from eight patients with large chronic tears of the rotator cuff. We found that osteoblasts from the tuberosity had no apparent response to mechanical stimulation, whereas those derived from the acromion showed an increase in alkaline phosphatase activity and nitric oxide release which is normally a response of bone cells to mechanical strain. By contrast, we found that cells from both regions were able to respond to dexamethasone, a well-established promoter of osteoblastic differentiation, with the expected increase in alkaline phosphatase activity. Our findings indicate that the failure of repair of the rotator cuff may be due, at least in part, to a compromised capacity for mechanoadaptation within the greater tuberosity. It remains to be seen whether this apparent decrease in the sensitivity of bone cells to mechanical stimulation is the specific consequence of the reduced load-bearing history of the greater tuberosity in these patients.

Developments in shoulder arthroplasty

Indications for shoulder arthroplasty are numerous, mainly owing to glenohumeral osteoarthritis, rheumatoid arthritis, or fracture of the proximal humerus. However, the anatomy and the biomechanics of the shoulder are complex and shoulder arthroplasty has evolved significantly over the past 30 years. This paper presents the main recent evolutions in shoulder replacement, the questions not answered yet, and the main future areas of research. The review focuses firstly on the design, positioning, and fixation of the humeral component, secondly on the design, positioning, and fixation of the glenoid implant, and thirdly on other concepts of shoulder arthroplasty such as the reversed prosthesis, the cementless surface replacement arthroplasty, and the bipolar arthroplasty. This review demonstrates that more research is needed. Although, in the long term, large randomized trials are needed to settle the fundamental questions of what type of replacement and which kind of fixation should be used, biomechanical research in the laboratory should be focused primarily on the comprehension of glenoid loosening, which is a major cause of total shoulder arthroplasty failure, and the significance of radiolucent lines which are often seen but with no clear understanding about their relation with failure.

A security vulnerabilities assessment tool for interim storage facilities of low-level radioactive wastes

Limited permanent low-level radioactive waste (LLRW) disposal capacity and correspondingly high disposal costs have resulted in the creation of numerous interim storage facilities for either decay-in-storage operations or longer term accumulation efforts. These facilities, which may be near the site of waste generation or in distal locations, often were not originally designed for the purpose of LLRW storage, particularly with regard to security. Facility security has become particularly important in light of the domestic terrorist acts of 2001, wherein LLRW, along with many other sources of radioactivity, became recognized commodities to those wishing to create disruption through the purposeful dissemination of radioactive materials. Since some LLRW materials may be in facilities that may exhibit varying degrees of security control sophistication, a security vulnerabilities assessment tool grounded in accepted criminal justice theory and security practice has been developed. The tool, which includes dedicated sections on general security, target hardening, criminalization benefits, and the presence of guardians, can be used by those not formally schooled in the security profession to assess the level of protection afforded to their respective facilities. The tool equips radiation safety practitioners with the ability to methodically and systematically assess the presence or relative status of various facility security aspects, many of which may not be considered by individuals from outside the security profession. For example, radiation safety professionals might not ordinarily consider facility lighting aspects, which is a staple for the security profession since it is widely known that crime disproportionately occurs more frequently at night or in poorly lit circumstances. Likewise, the means and associated time dimensions for detecting inventory discrepancies may not be commonly considered. The tool provides a simple means for radiation safety professionals to assess, and perhaps enhance in a reasonable fashion, the security of their interim storage operations. Aspects of the assessment tool can also be applied to other activities involving the protection of sources of radiation as well.

An analysis of 20 years of radiation-related health care complaints in Texas for the purposes of quality improvement

In an effort to reveal the possible underlying causes of radiation-related health care complaints in the State of Texas, complaint data were evaluated using historical Texas Department of Health-Bureau of Radiation Control (TDH-BRC) reports. A major aim of the study was to generate a summary of the most commonly reported complaints that might be generalized to health care providers using sources of radiation across Texas. A generalizable list of common complaints would be a valuable tool for education and prevention programs, serving to possibly reduce the overall incidence of radiation-related medical complaints. Descriptive text summary reports of complaints were obtained from the TDH-BRC for the 20-y period inclusive of 1981 to 2001. The information was systematically coded into a computerized database. During the 20-y period of study, 481 health care-related complaints were identified, with approximately 74% consisting of claims of an "uncredentialed technician" (39%), "overexposure" (21%), or "regulatory violation" (14%). The most common categories of complaints imply some patient understanding or knowledge of the credentialing requirements of workers, the applicable dose limits, or the regulatory requirements associated with medical procedures. Since it is unlikely that an average patient would be aware of such issues, the findings suggest the complaints are not actually indications of the inappropriate uses of radiation, but are rather based on the patient's broader perception of services rendered. Most of the complaints levied during the period of study were done so anonymously (58%) and were levied against a generic facility (61%) rather than a specific technician (5%), doctor (4%), or student (1%). Approximately 61% of the complaints resulted in the issuance of a notice of violation upon investigation by the TDH-BRC, but the available data did not permit definitive linkage between the initial complaint and the violation issued. Taken in aggregate, the analysis suggests that improved communications between health care providers and the patients they serve could possibly serve to prevent future complaints. Although the analysis was limited to the data from a single state, the results may be of use to quality assurance programs on a broader scale because of the objective identification of likely common issues. Possible options for improving the means of systematically collecting initial compliant data in the future are also discussed.

Reported events of stolen radioactive sources in Texas from 1956 to 2000

Incident reports describing stolen source events in Texas from the years 1956 to 2000 were obtained from the Texas Department of Health-Bureau of Radiation Control and recorded into a computerized database using a pre-established set of codes. The data were then analyzed for the identification and characterization of trends. Over the 45-y period of analysis, 113 sources were reported as stolen. The radionuclides most commonly reported in theft events were Am, Cs, and Ir. The proportion of sources including Am as the sole source or Am combined with Be, or as a companion source with Cs, represented 56% of the total reported as stolen. Key risk factors identified as associated with source theft appear to include portability status, transportation status, transporter status, and radionuclide type. Based on the observations noted, suggested improved security measures are postulated including additional permitting controls, enhanced inspections, improved locking and storage procedures, and steps for communication to the public to enhance the prospects for recovery. Suggested enhancements to further improve data collection are proposed so that crime prevention information can be derived in future research.

Characterization and geographic location of sources of radioactivity lost downhole in the course of oil and gas exploration and production activities in Texas, 1956 to 2001

Case reports describing sources of radioactivity lost downhole in Texas from 1956 to 2001 were obtained from the Texas Department of Health Bureau of Radiation Control and entered into a computerized database. The events of the 45-y period of analysis were characterized, examining aspects such as source type, amount of activity, location of loss, depth, and date of occurrence. Results of the study found that 316 downhole source incidents were reported to the agency during this period of time, representing a total of 426 distinct sources of radioactivity lost downhole within the boundaries of the State of Texas. The sources lost were predominantly AmBe, accounting for 74 TBq of radioactivity at the time of loss, and Cs, accounting for 16.3 TBq of radioactivity. A longitudinal analysis of the data showed the average loss per active oil and gas rig in Texas (known as "rig count") at approximately 24 losses per 1,000 rigs. Specific geographic information was largely missing from many of the records, which prevented the geolocation of wells described to contain lost radioactive sources. As a result, most wells could only be located to the county level, and no comprehensive geographical information system (GIS) map could be accurately created from the data. However, when available, source location information was standardized to permit the characterization of the sources reported as lost. This effort produced the first dedicated compendium of lost downhole sources for the State of Texas and provides an important source of information for regulatory agencies. The ability to provide prompt information about the fate and location of sources of radioactivity is important to regulatory officials, given the recent concerns about radiation source inventory control in the post 9/11 world as it relates to the possible creation of radiological dispersal devices.

An analysis of variables influencing the number of radiation overexposure events in Texas from 1970 to 2000

Sources of radiation are used in a variety of modern work settings, including industrial, medical, research, and agricultural applications. Although regulatory controls exist to limit radiation exposures in these different settings, instances of radiation doses in excess of acceptable limits (referred to as overexposures) do occur. A unique study examined overexposure events in Texas over a 45-y period from 1956 to 2001. The primary purpose of the study was to characterize the factors associated with overexposure events. As part of this characterization, an interesting trend in the number of overexposures by year was observed, but not completely explained. The data revealed a dramatic increase in the number of overexposure events, followed by three apparent phases of decline. These declines are of particular interest because, while the increase and subsequent decrease in overexposures occurred, the number of permits to possess radiation sources in Texas generally increased over the same time period. This study focused on the identification of the factors that led to the trends in overexposure events. Data describing the reported overexposure events in Texas from 1970 to 2000 were obtained from the Texas Department of Health Bureau of Radiation Control (TDH BRC) and entered into a computerized database. With the assistance of senior members of the TDH BRC, the three primary factors influencing the number of overexposures were identified. These included domestic oil and gas exploration and production from 1970 to 2000, wherein sources of radiation are employed in various operations; the establishment of a training and certification requirement for industrial radiographers during the period of 1986 to 1988; and modification of the applicable regulations between 1992 and 1994. The generally accepted indicator of oil and gas exploration and production activity, known as "rig count," is the measure of the number of active oil and gas exploration and production platforms at any given time. Rig count is a parameter of particular interest in Texas because the state's economy is significantly tied to the market value of this important natural resource. The rig count parameter was shown to have a strong correlation with overexposure events (Pearson correlation coefficient of 0.82, p < 0.0001). Interestingly, the sources causing the overexposures indicate that the events stem primarily not from the oil and gas exploration activity itself, but rather from support activities in the form of industrial radiographic procedures. The number of overexposure events was also determined to be influenced by the imposition of the training requirement for radiographers and the modification of the applicable regulations (e.g., the elimination of the quarterly dose limit). The relative magnitude of these influences, however, was far overshadowed by the identified predominant predictor of rig count. The determination of rig count as the significant influencing factor in overexposure events is useful in possibly recognizing the potential for future occurrences of the same nature. This assessment also serves to highlight an apparent significant public health success story, as the number of overexposures per radioactive material licensee is shown to have declined significantly over the 30-y period of study. The factors contributing to this phenomenon are described to serve as a model for use in other settings.

A comparison of the results of regulatory compliance inspections in 1999 by the states of Texas, Maine, and Washington

Inspection outcome data provided by the state of Washington Department of Health, Division of Radiation Protection, for licensees of radioactive materials was encoded according to a system established by the Texas Department of Health, Bureau of Radiation Control. The data, representing calendar year 1999 inspection activities, were then analyzed and the results compared to previously published studies for the same year in the states of Texas and Maine. Despite significant differences in regulatory program size, age, and geographic proximity, the most frequently cited violation for radioactive materials licensees were shown to be similar for all three states. Of particular note were the violations that were identified to be consistently issued in all three states. These included physical inventories and utilization logs not performed, not available, or incomplete; leak testing not performed or not performed on schedule; inadequate or unapproved operating and safety procedures; radiation survey and disposal records not available or incomplete; detection or measurement instrument calibration not performed or records not available; and radiation surveys or sampling not performed or performed with a noncalibrated instrument. Comparisons were made in an attempt to generate a summary of the most commonly issued violations that could be generalized to users of radioactive materials across the United States. A generalized list of common violations would be an invaluable tool for radiation protection programs, serving to aid in the reduction of the overall instance of program non-compliance. Any reduction in instances of non-compliance would result in the conservation of finite public health resources that might then be directed to other pressing public health matters.

An analysis of 45 years of reported overexposure incidents in Texas, 1956 to 2001

Sources of ionizing radiation are commonly encountered in a wide variety of modern work settings. The controls in place to ensure the safe use of these sources have proven to be quite effective, as events involving occupational doses in excess of established limits are quite rare. Nonetheless, instances of doses in excess of established limits, commonly referred to as "overexposures," do occur, but the rarity of such events has resulted in a body of scientific knowledge that consists essentially of sporadic case reports. In this study, incident reports describing radiation overexposure events recorded in Texas from the years 1956 to 2001 were obtained and recorded into a computerized database using a pre-established set of codes. The data were then analyzed for the identification of possible trends or commonalties. During the 45-y period of study, overexposure events accounted for 50% (n = 3,796) of all the radiation-related incidents recorded in Texas for the time period (n = 7,534). Of the overexposure events, 65% (n = 2,342) resulted in the actual deposition of energy in the individual exposed. The remainder were determined to be doses recorded only by a personal dosimetry device. In most of the cases where doses were actually delivered to an individual, the doses were less than 0.05 Sv (5 rem). In only 0.5% of the cases (n = 13) were doses greater than 1 Sv (100 rem). The predominant sources reported as involved in the events included 192Ir, 60Co, and 137Cs. The information derived from the analysis may serve as a basis for a variety of interventions, such as preventative education activities, regulatory modifications, and the possible re-design of equipment identified as commonly associated with such events. The results of the study can also assist in the training of health care providers, as the recognition of common causes and sources of overexposures and subsequent treatments can be forecasted and summary treatment protocols developed.

Sonochemical degradation of phenolic pollutants in aqueous solutions

The sonochemical degradation of phenol, 2-chlorophenol and 3,4-dichlorophenol in aqueous solutions as a function of several operating conditions has been investigated. Experiments were performed at initial substrate concentrations of 0.1, 0.5 and 1 g l(-1), liquid phase volumes of 0.05, 0.07 and 0.08 l, electric power outputs of 125, 187.5 and 250 W, liquid bulk temperatures of 20, 35, 50 and 70 degrees C and an ultrasound frequency of 20 kHz. Substrate concentration was determined as a function of time by means of high performance liquid chromatography. At the conditions under consideration, the rate of degradation follows first order kinetics with respect to the substrate concentration and increases with increasing electric power and decreasing liquid volume. The relative reactivity appears to decrease in the order: 2-chlorophenol > 3,4-dichlorophenol > phenol. Measurements of liquid phase total organic carbon content showed that degradation by-products are more recalcitrant than the original substrate. The rate of 2-chlorophenol degradation was also found to decrease with decreasing liquid bulk temperature and increasing initial concentration. Addition of t-butanol as a hydroxyl radical scavenger only partially inhibited degradation, thus implying that degradation is likely to proceed via both radical-induced and thermal reactions. Addition of Fe2+ ions at concentrations as low as about 0.2 x 10(3) g l(-1) resulted in increased degradation rates; this is attributed to iron being capable of readily decomposing hydrogen peroxide (generated by water sonolysis) in a Fenton-like process to form hydroxyl radicals as well as being an effective oxidation catalyst. The implications of the use of ultrasound in wastewater treatment are also discussed.

Statistical validation of a commonly used method for personnel dosimetry issuance determinations

In 1992, the federal requirements for personnel monitoring of occupational radiation doses were modified, making monitoring compulsory only for individuals "likely" to exceed 10% of the applicable annual dose limits. This regulatory change served as a catalyst for many radiation protection programs to re-evaluate their personnel monitoring issuance criteria to determine if some monitoring services might be reduced or eliminated. But in the absence of any clear definition of the term "likely," radiation protection programs relied on adjustments largely based on reviews of previous monitoring results and professional judgment. Although such semi-quantitative assessments may have been appropriate, the approach was not without inherent programmatic risks, as radiation dosimetry programs have been shown to be a consistent source of regulatory non-compliance upon inspection and serve as essential elements in defense against litigation efforts purporting workplace-related radiation injury. The objective of this study was to subject this commonly used method for post-regulatory change dosimetry issuance determinations to statistical validation. Personnel monitoring data from The University of Texas Health Science Center at Houston Radiation Safety Program pre- and post-1992 regulatory changes were accessed and descriptively analyzed. The dynamic nature of the institutional environment made direct comparisons of individuals between years impractical, so 1990 mean dose levels for various independent variables were compared using the Kruskal-Wallis non-parametric ANOVA test at a significance level of alpha = 0.05. The data from 1998 were then analyzed to ascertain if the groupings identified as statistically different in 1990 were still being monitored. The analyses statistically validated the monitoring program reductions made by the University of Texas Health Science Center at Houston radiation protection program. In addition, statistical support for further monitoring program reductions were identified, if such reductions were deemed to be necessary in the future.

An evaluation and comparison of compliance inspection outcomes data for radiation protection programs in Maine and Texas

The coding system used by the State of Texas Department of Health Bureau of Radiation Control to categorize regulatory violations resulting from compliance inspections was applied to the results of similar activities performed by the State of Maine Radiation Control Program for licensees of radioactive materials in calendar year 1999. The coded results from the Maine inspections (n = 37) were then summarized and compared to the data from Texas inspection activities for similar radiation licenses (n = 1,350). Despite significant differences in program size, age, and geographic proximity, the list of most commonly issued violations was almost identical. Other program outcome analogies were also noted, such as similar violation frequency distributions and similar identified root causes of non-compliance. These comparisons mark the first step towards the possible creation of a generalizable list of common items of non-compliance, which could serve to greatly enhance radiation safety preventive education and training programs. The utility of the Texas coding system as the basis for interstate program comparisons is also demonstrated, since the system is based upon categories of non-compliance rather than locally-unique regulatory codes or citations.

An analysis of reported incidents involving radiopharmaceuticals for the development of intervention strategies

Misadministrations and dose irregularities of radiopharmaceuticals are among the most common incidents reported to the Texas Department of Health Bureau of Radiation Control. In an effort to minimize future incidents, utility and process variable trends were evaluated using historical Texas Department of Health Bureau of Radiation Control incident data. An analysis of misapplication events (e.g., misadministration or dose irregularity) was performed by obtaining the quarterly incident summaries from the Texas Department of Health Bureau of Radiation Control for the study period 1988 to 1997. The misapplication data accounted for 355 out of 2,126 (16.7%) incidents during this period. The results indicate 94% of radiation source misapplications involved unsealed sources of radiation (e.g., radiopharmaceuticals). Additionally, 73% of all self-reported events involved 99Tc radiopharmaceuticals. The most frequent radiation source process variable involved in the misapplication was injecting an incorrect compound. The most widely utilized intervention to resolve the incident was training for the individuals responsible for drawing or administering the radiopharmaceutical. Universal application of these results are cautioned due to the bias associated with a single-state study, changes in radiopharmaceutical use during the study period, and state-specific regulations which may vary in other study populations.

The intra- and inter-observer reliability of the Samilson and Prieto grading system of glenohumeral arthropathy

Severity of glenohumeral arthropathy following shoulder instability is often graded radiologically on the basis of osteophyte size according to Samilson and Prieto. Intra- and inter-observer reliability of this popular grading system was determined using standard radiographs of 20 arthritic cadaveric humeri. Using two observers on two occasions, reliability of the grading system using the antero-posterior radiograph varied between fair and poor (kappa coefficients 0.07-0.33). This study shows that the Samilson and Prieto grading of glenohumeral arthropathy is unreliable and, in clinical use, when magnification and rotation is less easy to control, it is likely to be even more so. Another validated classification system must therefore be found.

Using fault tree analysis to identify causes of non-compliance: enhancing violation outcome data for the purposes of education and prevention

An enhanced coding system for the characterization of notices of violation (NOV's) issued to radiation permit holders in the State of Texas was developed based on a series of fault tree analyses serving to identify a set of common causes. The coding system enhancement was retroactively applied to a representative sample (n = 185) of NOV's issued to specific licensees of radioactive materials in Texas during calendar year 1999. The results obtained were then compared to the currently available summary NOV information for the same year. In addition to identifying the most common NOV's, the enhanced coding system revealed that approximately 70% of the sampled NOV's were issued for non-compliance with a specific regulation as opposed to a permit condition. Furthermore, an underlying cause of 94% of the NOV's was the failure on the part of the licensee to execute a specific task. The findings suggest that opportunities exist to improve permit holder compliance through various means, including the creation of summaries which detail specific tasks to be completed, and revising training programs with more focus on the identification and scheduling of permit-related requirements. Broad application of these results is cautioned due to the bias associated with the restricted scope of the project.

Anticipating and addressing workplace static magnetic field effects at levels <0.5 mT

Magnetic resonance, once a research tool limited to the basic sciences, has experienced an increase in popularity due to its unique ability to analyze certain living systems in vivo. Expanding applications in the biomedical sciences have resulted in magnetic sources being located in research institutions nationally. Space and resource limitations sometimes necessitate siting magnetic resonance units in proximity to other institutional operations. For magnetic field shielding and personnel protection considerations, the generally accepted 0.5 mT (milliTesla) limit for implanted cardiac devices is commonly used as the conservative basis for decisions. But the effects of magnetic fields on equipment can be easily observed at levels far below 0.5 mT, often resulting in concern and apprehension on the part of personnel in the surrounding areas. Responding to recurrent worker concerns spawned by noticeable effects on equipment at exposure levels <0.5 mT can strain finite radiation safety program resources. To enhance the ability to anticipate possible facility incompatibility issues associated with the installation of magnetic sources, a literature review was conducted to summarize documented equipment effects. Various types of equipment were found to be impacted at levels ranging down to perhaps 0.001 mT. Armed with this information, practicing radiation safety professionals can better anticipate facility incompatibility issues and improve their responses to worker concerns initiated by observed effects on equipment.

Radioactive waste minimization implications of clinically-indicated exsanguination procedures

Exsanguination is a method of animal euthanasia approved for use in specific circumstances. Animals undergoing exsanguination are fully anesthetized, and the blood is removed resulting in hypovolemia. In situations where radioactive materials are used as part of a research protocol that remain predominantly suspended in the blood, the exsanguination procedure can result in a significant lowering of residual radioactivity content. This reduction can greatly affect the types of waste management and minimization options that can be subsequently applied. In this study, data were collected from 20 rabbits injected with approximately 29.6 MBq (0.8 mCi) of tritiated thymidine as part of a percutaneous transluminal carotid artery angioplasty study. Residual concentrations of radioactivity were consistently reduced by an average of 88%. The reduction was very significant in this instance, since the residual activities were below the established exemption limit of 1.85 kBq g(-1) (0.05 microCi g(-1)) for disposal of these wastes as non-radioactive. Although the exsanguination procedure can result in significant waste minimization opportunities in certain circumstances, this should not be the rationale for its use. Rather, the method of euthanasia should be based exclusively on sound animal care and use principles, and waste management strategies should then be made following that decision. Health Phys. 79(3):291-293; 2000 Key words: waste, low-level; waste management; radiation protection; blood

The forms and sources of cytokinins in developing white lupine seeds and fruits

A comprehensive range of cytokinins (CK) was identified and quantified by gas chromatography-mass spectrometry in tissues of and in xylem and phloem serving developing white lupine (Lupinus albus) fruits. Analyses were initiated at anthesis and included stages of podset, embryogenesis, and seed filling up to physiological maturation 77 d post anthesis (DPA). In the first 10 DPA, fertilized ovaries destined to set pods accumulated CK. The proportion of cis-CK:trans-CK isomers was initially 10:1 but declined to less than 1:1. In ovaries destined to abort, the ratio of cis-isomers to trans-isomers remained high. During early podset, accumulation of CK (30-40 pmol ovary(-1)) was accounted for by xylem and phloem translocation, both containing more than 90% cis-isomers. During embryogenesis and early seed filling (40-46 DPA), translocation accounted for 1% to 14% of the increases of CK in endosperm (20 nmol fruit(-1)) and seed coat (15 nmol fruit(-1)), indicating synthesis in situ. High CK concentrations in seeds (0.6 micromol g(-1) fresh weight) were transient, declining rapidly to less than 1% of maximum levels by physiological maturity. These data pose new questions about the localization and timing of CK synthesis, the significance of translocation, and the role(s) of CK forms in reproductive development.

A comparison of methods for determining lead content in drinking water: a portable anodic stripping voltammetry instrument method versus the standard EPA 239.2 method

Lead levels in drinking water were measured by the standard U.S. Environmental Protection Agency (EPA)-approved atomic absorption spectroscopy-graphite furnace Method 239.2 and compared with determinations made with a newly available portable anodic stripping voltammetry (PASV) instrument. A standard curve was prepared at 2, 5, 10, 15, 20, 25, and 30 microg/L of lead. PASV instrument readings were lower than standard EPA method values, with a mean difference and standard error (SE) of the mean between the two of 1.538+/-0.588 microg/L (n = 7, p = 0.040, significant at the 95% confidence interval [CI]). First-flush drinking water samples collected from 144 water fountains/coolers were preserved with nitric acid. Total lead content was tested twice for 29 EPA method samples and 54 PASV instrument samples to determine the variation within each method; results were not significant at the 95% CI. Total lead content was determined for 144 samples by both methods. PASV instrument readings were lower than standard EPA method values (mean difference and SE of the mean 0.630+/-0.206 microg/L; n = 144, p = 0.0027, significant at the 95% CI). Mean and standard deviation of the 144 samples for the EPA method and the PASV instrument were 6.5+/-11.8 microg/L and 5.9+/-11.6 microg/L, respectively. Means were below the action level for lead of 15 ppb (microg/L), but some values were above the action level (18 [13%] using the EPA method; 20 [14%] using the PASV instrument). Retesting by EPA method showed two false positive PASV values. Results indicate that in some field situations the PASV instrument may prove useful due to its relatively low price, small size, ease of use, and quick readings.

Estimating the administrative cost of regulatory noncompliance: a pilot method for quantifying the value of prevention

Routine regulatory inspections provide a valuable independent quality assurance review of radiation protection programs that ultimately serves to improve overall program performance. But when an item of non-compliance is noted, regardless of its significance or severity the ensuing notice of violation (NOV) results in an added cost to both the permit holder and the regulatory authority. Such added costs may be tangible, in the form of added work to process and resolve the NOV, or intangible, in the form of damage to organizational reputation or worker morale. If the portion of the tangible costs incurred by a regulatory agency for issuing NOVs could be quantified, the analysis could aid in the identification of agency resources that might be dedicated to other areas such as prevention. Ideally, any prevention activities would reduce the overall number of NOVs issued without impacting the routine inspection process. In this study, the administrative costs of NOV issuance and resolution was estimated by obtaining data from the professional staff of the Texas Department of Health, Bureau of Radiation Control (TDH-BRC). Based a focus group model, the data indicate that approximately $106,000 in TDH-BRC personnel resources were expended to process and resolve the 6,800 NOVs issued in Texas during 1997 inspection activities. The study's findings imply that an incremental decrease in the number of NOVs issued would result in corresponding savings of agency resources. Suggested prevention activities that might be financed through any resource savings include the dissemination of common violation data to permit holders or training for improving correspondence with regulatory agencies. The significance of this exercise is that any savings experienced by an agency could enhance permittee compliance without impacting the routine inspection process.

Radiation safety program outcomes as indicated by regulatory compliance activities from 1988 to 1997 in Texas

Occupational radiation protection programs rarely encounter readily observable workplace injuries or illnesses, so upper management must rely on different indicators of relative performance. In many cases, the number of violations, complaints, and reported incidents is used. As with reported workplace injury and illness data, violation, complaint, and incident data provide only a crude indication of a radiation protection program's overall effectiveness. Even so, it is important to recognize that tangible program outcome measures such as these often dictate management decisions. Hence, safety professionals should have access to baseline violation, complaint, and incident trend data so that more informed preventive strategies can be put into place where possible. To assess the outcomes of radiation protection programs in Texas, data from regulatory compliance activities for a 10-y period, inclusive of calendar years 1988 to 1997, were assembled, summarized, and independently verified. For licensees of radioactive material, the ten most frequently cited violations represented 64% of the total issued during the study period. For registrants of radiation producing devices, the ten most frequently cited violations accounted for 73% of the total. A particular emphasis on proper recordkeeping is evident, and should be noted by any internal radiation protection quality assurance programs. Regardless of the permit type, the vast majority of violations issued were classified as low severity. Licensees were found to be involved in approximately 73% of the incidents recorded, with overexposures and badge overexposures representing the largest identifiable types. Registrants were found to be involved in approximately 57% of the complaints recorded, with the largest identifiable issue being concerns about health care provider qualifications or performance. Although this study was limited to a single state, the results can be of benefit to both quality assurance programs and professional health physics training courses by objectively identifying the areas commonly found to be deficient.

A standard method of shoulder strength measurement for the Constant score with a spring balance

The strength component of the Constant score has been criticized for its lack of a precisely defined measurement method. A series of experiments was performed to compare three different methods in normal and pathologic shoulders with the use of a standard test position. These were (1) the Isobex isometric dynamometer, (2) Constant's unsecured spring balance, and (3) a new modification in which the spring balance is fixed at one end and the reading is taken after 5 seconds of maximum effort. The results suggest that this simple modification with a low-cost spring balance can give similar values to those from the Isobex. The need for precision of terms and a definition of the method is discussed, and recommendations for the standardization of the many variables in making this measurement are made.

Acromial morphology: the enigma of terminology

Variation in acromial morphology has been associated with the pathogenesis of subacromial impingement syndrome and rotator cuff disease. However, the use of a multitude of different descriptive terminology has lead to confusion in the literature concerning acromial architecture. This review is aimed to show the discrepancy in the literature of acromial morphology and advise suitable terminology to prevent confusion in the future.

Notices of violation issued to Texas radioactive material licensees inspected in 1995

Notices of violation stemming from the inspection activities of the Texas Department of Health's Bureau of Radiation Control during calendar year 1995 are summarized and characterized. Although eight distinct general categories of radioactive material licenses were included in the analysis, certain general trends were noted, permitting the formulation of an objective list of the ten most frequent violations cited. In order ranked from the most frequent, these include not following operating or safety procedures, radiation surveys not being performed, inadequate personnel monitoring records, instrumentation not used or out of calibration, radioactive material inventories not performed, leak tests not performed, deficiencies in training for industrial uses, inadequate inspection and maintenance of devices, unauthorized users of radioactive material, and incomplete or absent records for receipt or transfer of radioactive material. Although the analysis was limited to a single state, the results can benefit radiation protection quality assurance programs and health physics continuing education efforts by objectively identifying areas commonly cited for being deficient. The results also reiterate the necessity for proper documentation, as at least seven of the ten most frequent violations issued appear to stem predominantly from the records of radiation protection programs.

A biomechanical evaluation of suture anchors in repair of the rotator cuff

Repair of the rotator cuff requires secure reattachment, but large chronic defects cause osteoporosis of the greater tuberosity which may then have insufficient strength to allow proper fixation of the tendon. Recently, suture anchors have been introduced, but have not been fully evaluated. We have investigated the strength of suture-to-anchor attachment, and the use of suture anchors in repairs of the rotator cuff either to the greater tuberosity or the lateral cortex of the humerus. The second method gave a significant increase in the strength of the repair (p = 0.014). The repairs were loaded cyclically and failed at low loads by cutting into bone and tendon, casting doubt on the integrity of the repair in early mobilisation after surgery. Repairs with suture anchors did not perform better than those with conventional transosseous attachment.

A proposed method to minimize waste from institutional radiation safety surveillance programs through the application of expected value statistics

Institutional radiation safety programs routinely use wipe test sampling and liquid scintillation counting analysis to indicate the presence of removable radioactive contamination. Significant volumes of liquid waste can be generated by such surveillance activities, and the subsequent disposal of these materials can sometimes be difficult and costly. In settings where large numbers of negative results are regularly obtained, the limited grouping of samples for analysis based on expected value statistical techniques is possible. To demonstrate the plausibility of the approach, single wipe samples exposed to varying amounts of contamination were analyzed concurrently with nine non-contaminated samples. Although the sample grouping inevitably leads to increased quenching with liquid scintillation counting systems, the effect did not impact the ability to detect removable contamination in amounts well below recommended action levels. Opportunities to further improve this cost effective semi-quantitative screening procedure are described, including improvements in sample collection procedures, enhancing sample-counting media contact through mixing and extending elution periods, increasing sample counting times, and adjusting institutional action levels.

Assessing the service provided by an institutional radiation safety survey program

Routine radiation safety surveys are a required part of every institutional radiation protection program. Although mandated by regulation, surveys are really performed to help clinicians and researchers establish and maintain radiologically-safe working and learning environments. In some cases, however, the priorities established by a radiation protection program may not coincide with the needs perceived by the institution's workers, leading to possible alienation, dissatisfaction, and non-compliance with policies, procedures, and regulations. To determine if a typical survey program was perceived as providing a good or valued service to workers, a simple questionnaire was created and utilized for a 6-mo period The results obtained from this targeted assessment tool indicate that the radiation safety survey services were perceived as useful by most of the workers. In addition, the actual process of comment solicitation provided a positive feedback mechanism from the service recipients to the radiation safety staff, managers, committee members, and institution administrators.

The c/b ratio in the radiological monitoring of the hip joint in congenital dislocation of the hip

We report a method of monitoring hip joint development for congenital dislocation of the hip in children. The c/b ratio was measured on serial radiographs of 41 hips in 38 patients. The measurement was compared to c/b ratio obtained from normal hips. It was used to detect concentric reduction or its loss by migration of the femoral head during growth. The age at diagnosis ranged from 8 months to 10 years 6 months. The normal c/b ratio was found to change little with age. Deviation of the c/b ratio from normal in congenital dislocation of the hip resulted in a poor outcome and identified cases requiring further surgical intervention. This measurement of c/b ratio is simple and accurate, using easily determined points. The graphic display promotes critical analysis of situation and allows selection of cases at risk for treatment.

Simple physical, chemical, and biological safety assessments as part of a routine institutional radiation safety survey program

To assist in providing comprehensive surveillance for potential health and safety hazards, simple assessments of physical, chemical, and biological safety concerns were incorporated into traditional radiation safety facility surveys for a biomedical research and clinical care facility for a 1-y period. Customized training was provided to radiation safety staff members concerning each of the hazard areas identified and a brief checklist was developed. During the 1-y period 802 laboratory and clinic surveys were performed, and of the 372 safety issues noted by the staff, approximately 55% were identified as not related to traditional health physics surveillance activities. The utilization of these simple safety audit tools as part of a routine radiation safety surveillance program can serve as a cost effective way to assist in maintaining a teaching, research, and clinical environment that is free from a variety of recognized hazards.

Pioneers of shoulder replacement: Themistocles Gluck and Jules Emile Péan

Dr. Jules Emile Péan is widely credited with having performed the first total shoulder replacement March 11, 1893, at the Hôpital International in Paris. However, in his original report Péan refers to the work of Themistocles Gluck as being the inspiration for his shoulder prosthesis, a fact understated if not completely overlooked during the last hundred years. This article therefore attempts to reappraise the relative contributions of these two pioneering surgeons to shoulder arthroplasty.

Coracoid transposition for recurrent anterior instability of the shoulder. A 20-year follow-up study

We report the 20-year results of Bonnin's modification of the Bristow-Latarjet procedure in 14 patients operated on by one surgeon. All but one patient had had traumatic dislocations. At review, the Rowe scores were excellent in five, good in eight and fair in one. The functional outcome was satisfactory, with a mean Constant-Murley score of 80 points (68 to 95), but 12 patients had restriction of external rotation (86%). There were radiological degenerative changes in ten shoulders (71%): six in Samilson grade I, one in grade II, and three in grade III. Isometric power was considerably reduced in patients with grade-III degenerative change. This operation provides good long-term shoulder stability, but the high incidence of radiological degenerative change is a cause for concern.

Coracoid transposition for recurrent anterior instability of the shoulder. A 20-year follow-up study

We report the 20-year results of Bonnin's modification of the Bristow-Latarjet procedure in 14 patients operated on by one surgeon. All but one patient had had traumatic dislocations. At review, the Rowe scores were excellent in five, good in eight and fair in one. The functional outcome was satisfactory, with a mean Constant-Murley score of 80 points (68 to 95), but 12 patients had restriction of external rotation (86%). There were radiological degenerative changes in ten shoulders (71%): six in Samilson grade I, one in grade II, and three in grade III. Isometric power was considerably reduced in patients with grade-III degenerative change. This operation provides good long-term shoulder stability, but the high incidence of radiological degenerative change is a cause for concern.

Design and performance of cryogenic, scanning Fabry-Perot interferometers for the Long-Wavelength Spectrometer on the Infrared Space Observatory

The design of cryogenic, scanning Fabry-Perot interferometers for the Long-Wavelength Spectrometer on the ESA Infrared Space Observatory is presented. The interferometers were designed to provide a spectral resolving power of 10(4) over the wavelength range 45-180 µm, with the highest possible transmission efficiency consistent with this requirement. Metal meshes, custom designed with the aid of a theoretical model of metallic reflection, were used as the reflecting elements. The scanning mechanism featured a spring-suspended plate, which was servocontrolled by moving coil actuators and monitored by capacitance micrometers. The spectroscopic performance of the interferometers was measured in the laboratory and is compared with the model developed for the interferometer design. Although the measured resolving powers were somewhat lower than expected because of the laboratory measurement conditions, the transmission efficiencies were in approximate agreement with the design specification.