Robert J. Emery

Assessing maintenance of evaporative cooling systems in Legionellosis outbreaks

This study was designed to conduct systematic reviews of existing evaporative cooling system maintenance guidelines and of published Legionnaires’ disease outbreaks to determine what, if any, maintenance practices were in place at the time of the disease outbreaks and then to contrast the reported practices with the published guidelines for evaporative cooling systems. For the first review, similarities in the reported recommendations were assessed; in the second review, any reported information about the state of the evaporative cooling system during the outbreak investigation was summarized. The systematic reviews yielded 38 current guidelines for evaporative cooling systems and 38 published outbreak investigations. The guidelines varied regarding the recommended type and dose of biocides, frequency of general inspections and total system maintenance, the preferred disinfection and cleaning procedures when testing a system for microbiological contamination, the type and frequency of testing procedures, and interpretation of test results. Overall, the maintenance guidelines did not contain sufficiently detailed procedures to prevent the problems that were observed in the outbreak investigations. These maintenance procedures included lack or improper use of a biocide; infrequent testing for microbiological contamination; improper use or maintenance of drift eliminators; and lack of a total system cleaning within 6 months of the outbreak for cooling systems that were either under continuous use, recently started up, or frequently switched on and off. This study suggests that more specific and standardized maintenance guidelines for the control of Legionella bacteria are needed and that these guidelines must be properly implemented to help reduce further Legionnaires’ disease outbreaks associated with evaporative cooling systems.

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 programs 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.

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 Healths 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.

RELEASE OF BACTERIAL AEROSOLS DURING INFECTIOUS WASTE COMPACTION: AN INITIAL HAZARD EVALUATION FOR HEALTHCARE WORKERS

Compaction has been suggested as an interim processing method for infectious waste. Compaction greatly reduces the volume of waste at the site of generation and produces a more stable package for handling, shipment, and treatment. Preliminary studies have also indicated that when partially compacted waste is burned in an incinerator, the performance of the incineration unit is enhanced. Compaction is not currently used in institutions because the process may lead to the release of infectious aerosols, which could pose a significant hazard to healthcare workers. To determine if bacterial releases can be adequately controlled by a compaction device specially designed and constructed for the task, a prototype infectious waste compactor was challenged by compressing waste containing known quantities of indicator bacteria. Samples were collected to monitor bacterial releases and surface contamination. The data collected from this initial evaluation document that indicator bacteria were released from the unit. Modifications to the design and operation of a compactor of this type are proposed as suggestions that may improve system performance with regard to the health and safety of workers. A critical review of the experimental procedure used in this study is also included for the benefit of any future studies.

Lead and copper in drinking water fountains-information for physicians

Background: Lead and copper are potentially toxic metals. The objective of our work was to test the water from the drinking fountains of a large public access office complex in southwest Houston, Texas, for the presence of lead, copper, and microbiologic contamination. The data for the water fountains were compared with what we found in the local municipal drinking water supplies. Methods: Samples were collected as the first draw at the beginning of the work week. These samples were acidified to prevent the precipitation of heavy metals and analyzed using United States Environmental Protection Agency (USEPA) approved procedures and quality control. Results: Traces of lead were detected in 37.5% and copper in 100% of the tested water fountains. In two buildings, concentrations in some fountains exceeded the USEPA action level for lead (by up to 12-fold) and for copper (by up to 3.9 fold). One sample was positive for total coliform and Escherichia coli bacteria. Comparison with samples from the local municipal drinking water supplies indicated that both metals and bacteria were the result of secondary contamination at the water fountain sites. Conclusions: This study showed that drinking water fountains can be an unexpected and unappreciated source of intake of metal and bacterial contaminants.

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 99mTc 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.

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.

Evaluating the relative status of health and safety programs for minority academic and research institutions

The health and safety programs that support academic and research institutions face many challenges because of the wide variety of potential hazards present and the possibility of simultaneous exposures to several agents. This study investigated whether differences in health and safety programs exist between minority and nonminority state-funded academic and research institutions. A cross-sectional mail survey was conducted that included 24 minority and 51 nonminority schools. Questionnaires solicited information on descriptive institutional parameters, health and safety staffing, the hazards present, programs in place to address hazards, and medical surveillance services. The hazard types identified as present on both campus types were found to be very similar. The mean number of health and safety staff serving minority institutions was lower (1.14 versus 3.12), with the difference reliably predicted by the number of institutional employees, not minority status or regulatory environment. Other targeted parameters were found to be similar, with a consistent lack of awareness of specific medical evaluations noted for both groups. Since on average a single person is charged with controlling a diverse set of potential hazards on the minority campuses studied, the need for a comprehensive awareness of a variety of health and safety issues is discussed.

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.