14
OCCUPATIONAL EXPOSURE TO DIMETHYL SULFIDE IN THE HEALTH CARE SETTING.
T. Fuller, Boston University Medical Center, Boston, MA; S. Bloom, Brigham and Women’s Hospital, Boston, MA.
Dimethyl sulfoxide (DMSO) is a chemical vehicle used to deliver a large variety of pharmaceuticals, as well as for infusion of human cells in certain medical treatments. Three to 6% of the DMSO administered to a patient is usually metabolized to dimethyl sulfide (DMS). This odorous compound is exhaled from the patient and also exudes from the pores in the skin, leading to the perception by caregivers that they may be receiving a toxic exposure. Air sampling was performed at varying distances from patients receiving stem cell infusions in which DMSO was used as a cryopreservative and transport medium. A free-standing air cleaner equipped with a sorbent filter was present in each patient room sampled, which was part of the participating hospital’s standard protocol. Samples were collected on charcoal tubes and analyzed by gas chromatography. The odor threshold for DMS vapors is approximately 1 ppb, and the odor in treatment rooms is often quite powerful, leading to symptoms such as nausea in some caregivers. DMS vapors at elevated concentrations can also cause skin and respiratory irritation, headaches, and vomiting. Results of measurements performed to this point indicate that, although exposure levels exceed the odor threshold, they are below the limits of detection for the method used (approximately 15 ppb) and thus below the American Conference of Governmental Industrial Hygienists’ Threshold Limit Value of 10 ppm. Future work will include measurements in areas with nominal ventilation and without area vapor-absorbing devices.
15
DEVELOPMENTS IN BLOODBORNE PATHOGENS SAFETY: AN OSHA UPDATE.
D. Williams, U.S. DOL/OSHA, Washington, DC.
In an age of growing national concern with biosafety, infectious diseases, patients’ rights, and bioterrorism, it is imperative to keep abreast of new developments in OSHA’s enforcement policies and interpretations of applicable standards. The performance oriented nature of OSHA’s bloodborne pathogens standard (29 CFR 1910.1030) is such that it leads to consistent changes to existing OSHA policies. This presentation will provide an update on new industrial hygiene application of OSHA’s bloodborne pathogens standard in health care as well as other industries. Enforcement statistics and recent interpretive guidance will be presented.
16
DOES THE 2004 TLV FOR NATURAL RUBBER LATEX OFFER ADEQUATE PROTECTION TO HEALTH
CARE WORKERS?
C. Hon, L. Bennett, Vancouver Coastal Health, Vancouver, BC, Canada; Q. Danyluk, Fraser Health, Vancouver, BC, Canada.
The 2004 TLV booklet lists a TWA of 0.001 mg/m3 for natural rubber latex (NRL). However, research indicates that this level may not offer adequate protection for workers in the health care industry. Although the TLV is clearly indicated for the “inhalable” route, it must be noted that exposure to NRL in health care can occur through both the dermal route as well as the respiratory route. In health care, dermal exposure occurs predominantly through the use of latex gloves. With respect to airborne exposure, donning and removing gloves has been shown to release latex-carrying powder in the air. These two routes of exposure are worth mentioning since NRL is designated as a sensitizer. This means that a susceptible individual who has been exposed to NRL may experience an intense response upon subsequent exposure to NRL, even at low exposure concentrations. As such, having an exposure limit based solely on the inhalable route may not be practical for health care as exposure to NRL can also occur via the dermal route.
Currently, the amount of latex exposure needed to produce sensitization or an allergic reaction is still unknown. However, several studies have stated that exposure levels in the nanogram per cubic meter range are enough to trigger reactions. If NRL at the ng/m3 level is known to produce signs and symptoms, clearly the exposure limit should reflect this concentration range.
Lastly, the TLV is also disconcerting because it was apparently based on a single study of workers in rubber glove manufacturing. This study did not consider exposures by both routes. In fact, the ACGIH implicitly states that the TLV “will not be protective for workers already sensitized, nor for those primarily exposed via skin contact?” Since skin contact is the primary exposure route within health care, the proposed exposure limit may not be appropriate.
17
FIELD TRAILS OF NOVEL LOCAL EXHAUST VENTILATION DEVICES FOR CONTROL OF
BIOAEROSOLS RELEASED FROM PATIENTS WITH RESPIRATORY INFECTION.
S. Yu, J. Kwan, Hong Kong University of Science and Technology, Kowloon, Hong Kong Special Administrative Region of China.
In the wake of the SARS outbreak, a series of local exhaust ventilation prototypes have been developed for controlling respiratory pathogens in various clinical settings. The concept of these prototypes is to capture and contain bioaerosols generated from respiratory tract of patients, remove bioaerosols by HEPA filtration, and release clean air to the immediate environment. The containment device of these prototypes ranges from a portable hood that fits over a patient’s head to a booth that can house the whole person. The filter and fan unit is of a standalone design, i.e., independent of the building ventilation system, and therefore allows easy transport and deployment.
Although the concept of local exhaust ventilation is commonplace in industrial settings, it has not been applied to the clinical environment, and in particular, for infection control purposes. Successful introduction of these prototypes therefore depends not only on physical performance of the units in capturing and removing bioaerosols, but also acceptance by clinical staff and patients.
This paper reports findings of field trials of these prototypes in clinical environments, which include (1) hazard control performance checks based on a set of validation protocols specifically developed for these prototypes; and (2) surveys of patients and clinical workers who have used the prototypes. Results indicate that the prototypes can effectively control bioaerosols in clinical environments and thus protect clinical workers and other people in the vicinity.
18
ROLE OF INDUSTRIAL HYGIENE IN MEETING THE USP 797 STANDARD.
H. Bhattacharjee, F. Melnick, RJ Lee Group Inc., New York, NY.
Sterile compounding in hospitals and home care settings is undergoing changes. U.S. Pharmacopeia (USP) recently introduced a new procedure chapter (797) on compounding of sterile preparations. Sterile compounding now requires cleanroom facilities, specific training, monitoring and protection of personnel, air quality evaluation, and knowledge of sterilization. The role of industrial hygiene in meeting USP 797 is to assist in preventing harm and fatality to patients and workers from microbial contamination, endotoxins, mycotoxins, and other health hazards. It has been recognized that airborne particles generated in the environment may negatively impact human health and patient recoverability. Such particles include dust, dirt, pollen, viable and nonviable microorganisms, skin flakes, lint, and cosmetics. Cleanrooms provide the controlled environment necessary to the health care industries to prepare safe sterile products. Minimizing the microbial growth controls the incidence of infection. Decreased infection rate means decreased liability. This presentation addresses the design, construction, operation, and maintenance of Class 100 cleanrooms and comprehensive USP 797 compliance services, including worker protection.
Our experience indicates that health care organizations, including many hospitals, lack the necessary cleanroom facilities for sterile preparations and are forced to assess the most cost-effective/risk-free method of compliance with new guidelines. The new regulations require cleanrooms, proper quality assurance checks on in-house preparations, and extensive personnel training and monitoring. The current project includes providing health care organizations with technical guidance regarding the most cost-effective method for compliance, managing the design/build cleanroom installation, including HVAC requirements, determining cleanroom compliance, and setting up a QA/QC program (particulate and microbial enumeration) to prepare and monitor products. Monitoring of air, surfaces, and personnel provides the data required to evaluate compliance and review environmental control. To address any out-of-specification events, a corrective action program, resolution deadline, and preventive procedures are also in place within the comprehensive compliance plan.
19
CONTROL OF AIRBORNE CONTAMINANTS DURING CONSTRUCTION ACTIVITIES IN HEALTH CARE
FACILITIES.
D. Regelbrugge, R. Rottersman, G. Crawford, Boelter & Yates Inc., Park Ridge, IL.
The relationship between construction activities and an increased risk of patient infection in health care facilities has been well documented. The Centers for Disease Control and Prevention (CDC), the Joint Commission on Accreditation of Health Care Organizations (JCAHCO), and the American Institute of Architects (AIA) published guidelines for managing this risk. Interpretation and application of these guidelines can be complex. They all begin with a pre-construction Infection Control Risk Assessment (ICRA) that includes development of a team. Both AIA and JCAHO identify the need for expertise in a number of fields including ventilation, safety, epidemiology, infection control, and risk management. With a broad base of knowledge in each of these disciplines, the industrial hygienist would be a strong asset to the project team. ICRA also includes planning for containment/isolation of areas, monitoring the project, and testing during activities. The extent of precautions depends on a number of factors including the type of construction work and the susceptibility of the patient population. JCAHO has published matrices for containment. The CDC has described advantages and limitations of testing methods but leaves the details to the infection control team. This presentation will provide an overview of the above referenced guidelines. It will also describe the industrial hygienist’s role on two construction projects from project planning through testing. One of the projects will address monitoring operating rooms and a bone marrow transplant unit during construction of a new building near the outside air intakes for these departments. The other project will address the phased renovation of operating rooms in a sterile core. Successes and lessons learned will be included and discussion encouraged.
20
RAPID, ECONOMICAL, AND POPULATION-PROTECTIVE MONITORING OF MOLD DISTURBANCE IN
HOSPITALS.
D. Kahane, D. Cox, J. Martinelli, M. Piercey, Forensic Analytical, Hayward, CA.
Problems. Monitoring of mold disturbance in hospitals requires analytical methods that can quantify species of concern, are rapid, and are economical. Viable methods require 7–10 days and are impractical. Nonviable analytical methods are rapid but cannot differentiate among Pen/Asp species and cannot quantify species that cause nosocomial infections. Quantitative PCR methods are rapid but uneconomical unless focused on a few species. Solution. Utilize combinations of nonviable and quantitative PCR analytical methods in a process that provides the most relevant results rapidly and economically. 1. By visual inspection, determine areas of mold growth typical of the growth that will be disturbed. 2. Collect tape lift and bulk samples of the mold growth. 3. Analyze the tape lift samples utilizing nonviable techniques. 4. Based on the nonviable tape lift results, select a focused panel of species and analyze bulk samples using PCR. 5. Based on the nonviable tape lift and PCR bulk results, select one or more “marker” species to be monitored during and after the mold disturbance. 6. Monitor the mold disturbance, using the best (specific and economical) method(s) of analysis: nonviable, PCR, or both. For example, if Stachybotrys were the predominant species in the growth, analyze air samples by nonviable methods only, which are very good at quantifying Stachybotrys. If Pen/Asp were predominant in the growth, analyze bulk samples by PCR using a Pen/Asp panel to identify marker species. Analyze subsequent air samples by PCR focused on the marker species. If species that cause nosocomial infections (e.g., Aspergillus fumigatus) were detected in the mold growth, analyze air samples by PCR focused on the marker species and on the infectious species. This rapid and economical method has recently been applied successfully to monitor both exterior and interior mold abatement projects at a hospital in California.
21
DEVELOPMENT OF A TEST DRILL FOR ASSESSING PHYSICAL WORK CAPACITY OF PARAMEDICS.
P. Vehmasvaara, South Carelia Polytechnic, Lappeenranta, Finland; V. Louhevaara, University of Kuopio and Finnish Institute of Occupational Health, Kuopio, Finland.
Objective. Paramedic work includes occasional physical peak loads, which lead to near maximal cardiac strain particularly among paramedics with low cardio-respiratory capacity. For avoiding overstrain and health risks, the physical work capacity of paramedics should be screened regularly. The objective of this study was to develop and evaluate a job-related test drill for assessing physical work capacity of applicants to degree programs in emergency health care. Methods. Physically, the most demanding tasks of paramedic work were determined with a questionnaire, and their heart rate (HR) and cardiac strain (% of the maximal HR) were measured. The measurements were repeated in the developed test drill with 12 male and eight female subjects. The drill was based on the analysis of the physically most demanding tasks. The maximal HR and oxygen consumption of the subjects were measured in the laboratory. Results. The job-related test drill consisted of three tasks with a continuous performance of 7 min and 48 s (SD 28 s). The tasks were the carrying of equipment, resuscitation of the heart, and the lifting and carrying of the patient. In the test drill, HR and cardiac strain were 145 beats/min (SD 15) and 75% (SD 7) of the maximal HR, respectively. The cardiac strain of the male subjects was lower than that of the females, highly correlating with the maximal oxygen consumption. Conclusions. The job-related test drill that was developed simulated well the physically most demanding tasks in paramedic work, and proved to be a suitable screening procedure for applicants to degree programs in emergency health care in polytechnics.
Posted May 30, 2005