Sasol Synthetic Fuels, a petrochemical companysituated at Secunda, South Africa, employs more or less 10000 permanent as well as part-time employees. The company realised in 1996 that the standard at which occupational health was conducted neither addressed the needs of the business environment within which it had to function, nor fulfilled the legal requirements that it had to. The need for an applicable Occupational Health System was born. After an unsuccessful search for a commercially available system, the decision was taken to develop one. It had to be comprehensive and strategically value-adding. This study examines the requirements of an Occupational Health System against the background of the field of study. It states issues and concerns and suggests solutions. The approach to and design of an Occupational Health System from a strategic management viewpoint is contemplated. It suggests a specific architecture for such a system and sets goals and deliverables. The overall system is divided into a number of subsystems, arranged into levels according to management and strategic considerations. Four main subsystems are suggested. A systematic approach towards all aspects of the system, from planning to implementation and conducting thereof, is constantly and strongly advocated. Particular attention is paid to risk profiling, the compilation of a central database and data analysis in order to arrive at accurate health trend determination. The conversion of data into strategic information is specifically addressed. / Prof. H.E.C. de Bruyn

No description available.

Inexpensive instruments that measure concentrations of airborne particles in workplaces have grown to become an efficient way to estimate personal aerosol exposure of workers. This study evaluates the performance of two types of inexpensive instruments: an “active” version which pulls particle-laden air into a sensing zone for measurement, and a “passive” version which does not. The response of these instruments to clean air over time was evaluated as an indicator of contamination in laboratory and factory settings. Additionally, the effect cleaning of the instruments had on performance was evaluated. After exposure to high concentrations of particles in the laboratory, the active and passive versions of the instruments lost partial to full ability to detect particle concentrations. In the factory, this change was only seen in the active version, and occurred over a longer amount of time. Cleaning of the instruments returned some ability to detect particles, but not to the ability a new instrument. The accumulation of particles within instruments used to estimate aerosol exposures can affect the output of and overall performance of the instruments. Cleaning of the instruments after accumulation results a lessening of the effect, but not completely. Cleaning can be a way to extend the lifetime of these instruments. However, the time and financial costs related to cleaning several sensors within a workplace should be considered.

According to the Occupation Safety and Health Administration (OSHA), an estimated five million workers are required to wear respirators in over one million workplaces in the United States. Occupational respiratory diseases are strongly correlated to inhalation exposure to causative agents. Wearing a respirator has the potential to reduce worker exposure to safe concentrations. Many brands of N95 filtering facepiece respirators (FFRs) are available with various designs and sizes. Studies have indicated that respirator use is often low in many industries. Comfort is a factor that workers use both directly and indirectly to decide if they will wear an FFR. The purpose of this study was to evaluate ten N95 FFRs to determine their physical properties. Physical properties were compared to the perceived comfort ratings given by study participants to determine the strength of the associations. Six FFRs were evaluated using qualitative surveys (n=50). Physical properties of FFRs that were evaluated include: breathability, pressure drop, surface area, water vapor transmission and weight. Several methods were used to evaluate the N95 physical properties. A modified American Society for Testing and Materials (ASTM) method was used to measure water vapor transmission. A pass through column apparatus was used to evaluate pressure drop through each sample at 0.6, 1.6, 2.6, and 3.6 LPM. The N95 FFRs were scanned and evaluated using Adobe Photoshop to determine surface area. A temperature probe was used to measure the influence of an exhalation valve on internal temperature. An inverted microscope was used to determine thickness, a balance was used to determine sample weight. Density could then be used to solve for solidity. Physical properties varied between N95 FFRs. Between two similar FFRs, the exhalation valve was attributed to a 0.59 oC lower temperature in the FFR with and exhalation valve. Pressure drop values at a 3.6 LPM applied flow rate varied between 4.55-12.77 mm H2O. The water vapor transmission between masks was very small with a range of 0.16 mg H2O. Solidity values varied between 0.02 and 0.07, surface area from 134.95- 313.87, and total weight from 9.47-109.41 g. The total scores varied from 10.76 to 14.26 (out of 18). Survey participants were asked to evaluate the N95 FFRs on the basis of fit, temperature, and ease of breathing using a Likert scale of 1-6. Six of the N95 FFRs were worn by participants. Based on participant rankings, the Honeywell 4200 had the highest total score, followed by the Moldex 4200, 3M Aura 9210+, 3M 8511, Moldex 2200, and 3M 8210. The scores for fit varied from 3.16-4.36, temperature 3.66-5.24, and ease of breathing 3.94-4.66. Fit was found to be the most important in terms of discomfort followed by temperature, and ease of breathing. The Kruskal-Waillis test results indicate that there is a significant difference in the median scores between masks types for fit, temperature, and ease of breathing (p<0.001). However, participants’ rankings of fit, temperature, and ease of breathing were not strongly related to a physical property. For example, the Spearman’s correlation coefficient between pressure drop and ease of breathing score was 0.2, and 0.6 for water vapor transmission and temperature. Neither Spearman’s coefficient was statistically significant (p=0.7, p=0.2). In general, the differences in physical properties between N95 FFRs were too small for participants to perceive. The magnitude of difference in physical properties and short use duration and sedentary activity level are likely responsible for this finding.

The mutagenicity of 4-monochlorobiphenyl (PCB3) in the liver of male 344 Fisher transgenic rats has been established by Lehmann et al (2007). The evidence that PCBs can be deposited in the lung and bound to a protein creates a need to assess the effect of mutagenic effect of PCBs in the lung. The goal of this study was to assess the mutagenicity of PCB3 in the lung of male 344 Fisher transgenic rats. Big Blue® 334 Fisher transgenic rats were given weekly intraperitoneal injections with corn oil as a negative control, 3-methylcholanthrene (3-MC) as a positive control, PCB 3 or 4-hydrox-PCB 3 (4-OH- PCB 3) weekly for 4 weeks. Lungs were removed and analysis performed to determine mutant frequency, mutation spectra, and pathological changes. There was a 2-fold increase in mutant frequency after treatment with PCB 3 and 4- OH-PCB 3 that was not statistically significant. There were changes in the mutation spectra after treatment with PCB 3 or 4- OH-PCB 3. This study shows that PCB 3 and 4-OH-PCB 3 may create mutations in the lung following exposure.

A shaker dust collector was evaluated to 1. determine filter capacity in terms of mass loading, pressure drop, airflow, and runtime; 2. determine particle collection efficiency by size prior to and following repeated loadings. A shaker dust collector was setup in the laboratory to take in contaminated air, collect dust, and exhaust treated air. For each loading test, Arizona road dust (~1 to 200 μm) was introduced into the airstream entering the dust collector at an emission rate and duration equivalent to 3-months in a swine barn in winter. Filter pressure drop and exhaust velocity pressure were measured throughout loading. Filter collection efficiency was tested using polydisperse solid glass microspheres (~1 to 10 μm) and measured with an aerodynamic particle sizer at the startup and end of loadings. Cleaning cycles were run between loading tests. Overall efficiency was 44% for new filter, and ranged from 27% for 1-μm particles, increasing to 96% for 10-μm particles. Collection efficiency for loaded filter was 99% overall, and 99% over the range of 1 to 10-μm particles. Following cleaning, overall efficiency was 91%, and 91% for 1-μm particles, increasing to 99% for 10-μm particles. Exhaust airflow decreased linearly with pressure drop (r2=0.99) for all three loading tests. At shutdown, system airflows were approximately 700 cfm. Significant recovery of filter residual pressure was observed following primary and secondary cleanings (p<0.001). High removal efficiency was achieved after an initial loading period. The shaker dust collector filter is anticipated to be sufficient to treat air continuously in a swine barn over a 3-month winter period. The engineering control system is recommended for further testing to improve indoor air quality inside a Midwestern farrowing barn during winter.

Data from the Environmental Protection Agency’s Building Assessment and Survey Evaluation (BASE) study was analyzed for culturable fungi detected in air samples collected from 100 office buildings located among ten climate regions in the United States. Fungi identified and quantified in the study were evaluated in indoor and outdoor environments. Evenness of species for both summer and winter, and the diversity and similarity indices of species were calculated between climate region groups in order to observe potential climate-based differences in the fungal microbiome. Respiratory and neurological health symptoms of study building occupants (n = 4,326) were self-reported by questionnaire, and were analyzed in order to assess seasonal and climate differences.

General noise regulations and guidelines protect workers against 8-hour time-weighted average noise exposures > 85-90 dBA that can cause health outcomes and noise induced hearing loss (NIHL), but the bus transportation industry has guidelines limiting lower noise exposures > 75-80 dBA to reduce safety hazards, including distraction and poor communication. These hazards can create dangerous driving conditions, especially for urban bus drivers, potentially causing a collision. Further research was necessary to characterize U.S. urban transit bus driver noise exposures to assess whether they exceeded 75, 80, 85, and 90 dBA, time-weighted, and to identify statistically significant noise exposure risk factors for this local transit system. Time-weighted average noise exposures collected from the local transit system, a small urban bus system serving a university in Iowa City, showed the majority of drivers did not exceed 85 dBA due to short shift times, but these drivers may have been at a safety risk for distractions and poor communication due to loud environments > 75-80 dBA. The driver's AM/FM radio was a statistically significant risk factor (p = 0.004) affecting driver-shift TWA noise exposures. Projected noise exposure calculations showed that with bus driver shifts greater than or equal to 8 hours, the TWA noise exposures measured may exceed 85 dBA. Actual 8- hour time-weighted average noise exposures using sequential bus driver shifts did not exceed 90 dBA.

No description available.

Infectious diseases account for over 15 million deaths worldwide. Those who are at greatest risk of contracting an infectious disease are immunocompromised. These individuals may be admitted to a healthcare-based setting where they may become infected. In the United States, 1.7 million immunocompromised individuals contract a healthcare-associated infection which lengthens stay, increases medical costs, and puts lives at stake. The transmission routes for these infections occur from direct contact with healthcare staff and contaminated surfaces. Indirect contact methods, such as bioaerosols suggest, but are not a well-examined route of infection. One possible bioaerosol generator includes the flushing of loose stools in toilets from infected patients. To date, no study has investigated the particle or bioaerosol changes in the air resulting from toilet flushing loose fecal wastes in a healthcare setting. The purpose of this study was to investigate changes in the air before and after a toilet flush to support hypotheses that toilets can produce an aerosol containing viable microorganisms, potentially spreading infectious disease. Particle and bioaerosol concentrations were measured in hospital bathrooms across 3 sampling conditions; no waste no flush, no waste with flush, and fecal waste with flush. Particle concentrations were measured with a particle counter 3 minutes before a flushing event and throughout the bioaerosol collection period. Bioaerosol concentrations were measured with BioStage impactors fixed on a sampling cart at distances of 0.15, 0.5, and 1 m that was placed in front of a toilet. For each sampling trial, 3 time measurements were recorded after a flushing event (i.e., 5, 10, 15 minutes). Particle concentrations measured before and after the flush were found to be significantly different in 0.3 (p-values= 0.002, 0.002, 0.015), 0.5 (p-values= 0.002, 0.002, 0.018), 1 (p-values= 0.003, 0.003, 0.027), and 3 µm (p-values= 0.016, 0.032) size bins of the no waste with flush and 0.3 (p-values= 0.009, 0.007, 0.007), 0.5 (p-values= 0.018, 0.006, 0.004), 1 µm (p-values= 0.023, 0.013,) size bins of the fecal waste with flush conditions. Bioaerosol concentrations measured in the no waste no flush and fecal waste with flush were found to be significantly different (p-value= 0.005). However, the bioaerosol concentrations measured were not significantly different across time (p-value= 0.977) or distance (p-value= 0.911). From the study, we concluded that toilets in this unit produce particles when flushed. The particles aerosolized include microorganisms remaining from previous use or from loose fecal wastes. Differences in bioaerosol concentrations across conditions also suggest that toilets flushed containing wastes may be a likely source of bioaerosols that could allow transmission of infectious microorganisms. No observed differences across time and distance of bioaerosol concentrations suggests that generated aerosols quickly diffuse in the air. Since this study is the first to quantify particles and bioaerosols produced from flushing a hospital toilet, future studies are needed for comparison and for intervention development.