Although the multi-disciplinary profession of industrial hygiene (IH) has been established for many years and IH practitioners have been prolific in developing the technical tools for recognition, evaluation and control of workplace hazards, few in the IH discipline have turned the tools and methods of academic research toward the academic curriculum itself. A review of the literature revealed that published research in IH curriculum has been minimal, and that none has considered comparing faculty and employer expectations. Evaluating the nature of the current IH curriculum, and the preferences and expectations of the IH profession for graduates’ competencies, is true to the goal of IH practice, i.e., conducting research as a basis for on-going evaluation and review of existing programs, and using research findings to plan preventive interventions in order to ensure continued good health of both programs and impacted individuals. This research was an initial, exploratory study to identify and assess the expectations and perceptions of the IH faculty and employers in the areas of IH curriculum content and structure. The expectations and perceptions of IH academic program faculty were compared with those of employers of graduates of IH programs. Characteristics of current IH academic programs were identified, as a baseline for future evaluation of the IH curriculum. Actual and expected undergraduate majors of those entering IH masters programs were identified to aid in targeting effective recruitment programs and efficient resource allocation. The study populations’ skill and capacity with computers and the Internet were assessed as an indicator of readiness to incorporate distance learning methodology and electronic media delivery into traditional classroom delivery of industrial hygiene education. Recommendations were given for model IH curricula derived from the survey participants’ responses, and for future work.

Thesis (M.S.P.H.)--University of Michigan, 1939.

Thesis (M.S.P.H.)--University of Michigan, 1939.

Influenza virus kills thousands of humans annually around the globe. The primary mode of transmission for influenza virus occurs via an aerosol that is generated when infected individuals cough, sneeze, or talk (CDC 2018). Exposure assessment methods for influenza virus aerosols need to be developed to assess risk among workers in occupations were aerosol hazards are present (e.g., health care). Furthermore, developing methods to assess the viability of virus collected during filter-based aerosol sampling will improve exposure assessment methods. The purpose of this study was to determine the effect that filter-based sampling has on the viability of influenza virus. A bioaerosol chamber was used to generate influenza virus and sample the aerosolized influenza virus onto a polystyrene filter. This study consisted of 10 trials that each lasted 30 minutes. For each trial, a polystyrene filter was spiked with influenza virus and then compared to the aerosolized sample from the bioaerosol chamber. After the chamber trial was completed, both filters were washed with Hanks Balanced Salt Solution to remove the viral particles from the filter. After the filters were washed, viral RNA was extracted from the viral solution using the QIAamp Viral RNA Mini Kit. Quantification of the viral particles was completed using quantitative reverse transcription polymerase chain reaction. Viability of the influenza virus was analyzed using propidium monoazide dye. Average total RNA copies were analyzed for the spiked and aerosolized samples. Average total RNA copies were less for aerosolized samples compared to spiked filter samples, suggesting that the aerosolization process may decrease the number of viral particles that are collected on the filter. Viability was analyzed by determining the percent of intact membranes for the spiked and aerosolized samples. No difference was observed in the proportion of intact influenza virus membranes among aerosolized and spiked samples, suggesting that aerosolization and sampling had no effect on the viability of the influenza virus when compared to spiked filter samples.

Industrial hygienists can compare "total" dust concentrations to higher inhalable concentrations using a value called the performance ratio. A commonly used performance ratio of 2.5 is used for dusts found in the workplace, after results from multiple studies were compiled. The objective of this study was to evaluate the "total" and inhalable dust performance ratio over a range of conditions to investigate whether the commonly used value of 2.5 varies between: (1) dust type (2) IOM and Button inhalable samplers and (3) distance from the dust source. Dust concentrations were generated in a still air chamber using three dust types; sawdust, flour, and glass microbeads. The IOM, Button, and CFC samplers were used to measure concentrations at four locations increasing in distance from the source. Linear regressions in the form of [Inhalable mg m-3] = S x ["Total" mg m-3] were used to calculate the appropriate performance ratio, S. The intercept of this regression was forced through the origin. Linear regression was also used to examine whether the effect of distance on S was significant and a distance factor (β1) was calculated. The calculated performance ratios, S, differed between sawdust, flour, and glass microbeads, and were 1.62, 2.82, and 2.97 respectively when comparing IOM concentration to CFC concentration. Performance ratios computed for the Button sampler for sawdust, flour, and glass microbreads were 0.82, 1.04, and 0.57 respectively. Performance ratios were significantly different (p=0.049) between the two inhalable sampler types. The IOM/CFC performance ratio for all three dusts averaged 2.47 (SD=0.74), whereas the Button/CFC performance ratio for the three dusts averaged 0.81 (SD=0.24). Only the IOM/CFC performance ratio had a statistically significant distance factor at α=0.05. The authors caution against using a single performance ratio of 2.5 for all dusts due to the large variance involved with dust sampler and dust type. Distance from the source did not significantly affect the performance ratios computed under laboratory conditions. Industrial hygienists are advised to perform side by side sampling with inhalable and "total" dust samplers to create specific performance ratios appropriate for tasks found in the workplace.

The collection and quantification of influenza virus is important in determining exposure, and in the control of infection. There are a number of bioaerosol samplers and analytical methods available to do this, however few researchers have been able to detect influenza virus in the environment. Therefore, new samplers and methods should be considered. This study compared influenza virus recovery from three filter types (PTFE, PVC, and PS) treated with sampling air or no air, using HBSS or PBS as wash buffers, and the QIAamp Viral RNA Mini Kit or Trizol method in the extraction of viral RNA. Twenty, 30-minute laboratory trials were completed in a sampling chamber designed to control RH at 50%. Samples were analyzed using RT-qPCR. Viral recovery for each filter type was significantly different (p-value < .0001), with the new PS filter material resulting in the recovery of the most viral RNA. Treating filters with simulated sampling air did not affect the recovery of viral RNA from the filter materials (Kit, HBSS: Air vs. No Air p-value = 0.615; Trizol, HBSS: Air vs. No Air p-value = 0.947; Kit, PBS: Air vs. No Air p-value = 0.224; Trizol, PBS: Air vs. No Air p-value = 0.1122). Using HBSS and PBS as a filter wash buffer resulted in viral recoveries that were significantly different, depending on the RNA extraction method used (Kit, Air or No: HBSS vs. PBS p-value = 0.0001, 0.0001; Trizol, Air or No: HBSS vs. PBS p-value = 0.0322, 0.499). Viral RNA counts were significantly different when using the Kit and Trizol extraction methods for all comparisons (HBSS, Air or No-Air: Kit vs. Trizol p-value = 0.0021, 0.0013; PBS, Air or No-Air: Kit vs. Trizol p-value = 0.0001, 0.0002). Our results demonstrated that the novel PS filter material resulted in the highest counts of extracted RNA compared to the commonly used PTFE and PVC, and that sampling air did not have a significant effect on viral recovery. Also, that the combination of HBSS with QIAamp Viral RNA Mini Kit, and PBS with the Trizol method, resulted in the highest counts of RNA extracted.

Thesis PlanB (M.S.)--University of Wisconsin--Stout, 2009. / Includes bibliographical references.

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

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.