Browsing by Author "Brazile, William, advisor"
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Item Embargo Community noise exposure from oil and gas drilling operations(Colorado State University. Libraries, 2024) Stepherson, Phillip, author; Brazile, William, advisor; VanDyke, Michael, advisor; Gutilla, Margaret, committee memberDue to an increase in oil and gas (O&G) extraction activity near residential areas in Colorado, many community members may be at a higher risk of harmful noise exposure. The Colorado Energy and Carbon Management Commission (ECMC) has identified multiple sources of high-volume sound associated with O&G site preparation, drilling, and fracking including engines, mud circulation systems, rig top drives, and ancillary equipment. Acute and chronic exposure to elevated levels of environmental noise has been found to cause adverse health effects such as sleep disturbance, annoyance, cognitive performance decline, heart disease, and self-reported impact to overall wellbeing. While there is existing literature quantifying the extent and consequences of community noise exposure from other environmental sources (e.g., air traffic, road traffic, and railway transportation) there are limited published studies on noise exposure from proximity to O&G extraction sites. Researchers suggest, however, that oil and gas extraction operations may be producing harmful levels of noise. It also appears that the noise produced includes substantial low-frequency noise which can make it difficult to control. In addition, low frequency noise exposure may exacerbate the health effects associated with general noise exposure. To assess community noise exposure, a comprehensive environmental noise survey was performed at a new O&G extraction site in Northern Colorado during the drilling phase of operations. The research team collected noise emission data 24 hours per day over two months that included 1-second measurements of sound-pressure level, 1/3 octave bands, and triggered audio recordings. Based on the noise-monitoring results, it was determined that the noise levels from the drilling activities exceeded ECMC published noise exposure limits and noise thresholds related to adverse health effects. Distance was found to be a crucial factor in establishing compliance and reducing exposure, especially for low frequency noise. Increasing the O&G operations setback from community residences to 2,000 feet, as compared to the previous setback distance of 350 feet, was estimated to reduce noise levels by 15dB, which, while a substantial improvement, was not entirely sufficient to eliminate the risk of health effects or establish compliance with low frequency noise limits. High noise levels were found to occur on days that the rig's hoisting mechanism and/or drill were likely in use.Item Open Access Comparison of hexavalent chromium and welding fumes inside and outside of the welding helmet(Colorado State University. Libraries, 2013) Diaz-Rivera, Karen, author; Brazile, William, advisor; Reynolds, Stephen, committee member; Collett, Jeffrey L., committee memberThe primary objective of this study was to determine if welding fumes and specific metal concentrations were significantly different between samples taken inside and outside of the welding helmet to determine the most appropriate location of the personal sampling device and best estimate exposure. Personal air samples were collected simultaneously inside and outside of the welding helmet for concentration comparison of welding fumes (n = 12) and hexavalent chromium (n = 15) during stainless steel tungsten inert gas welding tasks. A total of fifteen welders were sampled in a manufacturing setting and a brewery for a total of 27 inside and outside paired samples. A statistically significance difference (p = 0.05) between inside and outside welding helmet concentrations was found for total welding fumes, iron, total chromium, and nickel using a Wilcoxon paired test, where most of the inside-helmet concentrations were lower. Hexavalent chromium and manganese concentrations were not significantly different when comparing inside and outside welding helmet concentrations. A correlation among welding fumes, iron, nickel, and total chromium concentrations was observed utilizing Spearman's rank-order correlation. The mean for hexavalent chromium concentrations difference was 11 μg/m3, when the outlier was included in the analysis and 0.07 μg/m3 without the outlier. The median concentrations difference was 0.06 μg/m3 with or without the outlier in the analysis. The 95% confidence interval for hexavalent chromium inside concentration was 0.1 μg/m3 to 0.34 μg/m3 and 0.13 μg/m3 to 0.4 μg/m3 for outside of the welding helmet concentration. One sample set for hexavalent chromium exceeded the permissible exposure limit (PEL), recommended exposure limit (REL), and threshold limit value (TLV). Based on the results, a high variation of concentrations was found between the inside and outside of the welding helmet concentrations depending on the metal fume analyzed. Manganese had the lowest metal content in the stainless steel welding rods as well as the sampled welding fumes. The greatest variation in concentration ratios was observed for manganese and hexavalent chromium when comparing inside and outside concentrations. These two factors, lower metal contribution in welding rods and variation in concentrations can be speculated to affect the statistical non significant difference found for manganese and hexavalent chromium inside and outside of the welding helmet concentrations. The welding helmet seemed to be protective for some metals, but it should not be assumed that protection will be provided by the use of it. As for sampling location for best welding fumes assessment monitoring, it is recommended that sampling is done outside. Welders often remove their welding helmets to verify the weld, and inside of the welding helmet sampling location may be compromised as it may change when the welding helmet is in the upward position.Item Open Access Contribution of small scale detonations to daily occupational noise exposure(Colorado State University. Libraries, 2013) Atencio, Victoria, author; Brazile, William, advisor; Sandfort, Delvin, committee member; Lipsey, Tiffany, committee memberHazardous levels of occupational noise exposure are of great concern due to the progressive nature of hearing loss. A one-time exposure to hazardous levels of noise may result in irreversible hair cell damage that could result in permanent hearing loss. This study focused on the contribution of small scale detonations to daily noise at Sandia National Laboratories (SNL). Personal noise monitoring was conducted for eleven employees to evaluate noise exposure for an eight hour period to determine the effects of small detonations and potential risk of noise induced hearing loss. Weights of various explosive materials ranged from 18 milligrams (mg) to 275 grams (g). Sound level meters were also used to determine if peak impulse noise measurements were under the occupational exposure limit of 140 dBC. Noise evaluations were conducted in five facilities that included two indoor boom boxes, two indoor firing pads, and one outdoor firing pad. The results of this study were used to conclude that no employees exceeded published exposure limits (85dBA, 3 dB exchange rate or 90 dBA, 5 dB exchange rate) nor at any point were employees exposed to noise levels above 140 dBC during detonations. According to SNL policy employers are required to enroll employees in a HCP if the 8-hr time weighted average (TWA) is greater than 85 dBA (3 dB exchange rate). A linear regression analysis was performed for each detonation location to determine the potential relationship between explosive weight and TWA for dosimetry results and peak levels of noise for sound level meter results. It was suggested that the relationship between explosive weight and LCPeak levels of the firing pad (p=0.283) and outdoor firing pad (p=0.801) were not statistically significant. Further, boom box activities had a significant relationship (p=0.001) however due to small sample sizes and variation of weights it is unclear whether the difference is due to explosive weight or activity. The p-values for ACGIH criteria (p=0.092) and OSHA criteria (p=0.34) were calculated and it was found that the linear relationship between explosive weight and TWA were not statistically significant. Based on the results of this field study and small sample sizes it was not possible to determine the explosive quantity at which hearing protection should be required. To determine the contribution of small scale detonations to daily noise exposures, noise samples that were collected during detonations were removed from employee TWAs. New TWAs were calculated and compared to the original data output. It was found that detonations increased employee ACGIH TWAs from only 1-8 dB. Impulse noise measurements obtained in this study were used to conclude that controls currently in place, including barriers, distance, and hearing protection, were effective means to employee safety and health.Item Open Access CSU industrial hygiene program training needs analysis(Colorado State University. Libraries, 2022) Moore, Jillian, author; Brazile, William, advisor; Zarestky, Jill, committee member; Reynolds, Stephen, committee memberGraduates of industrial hygiene (IH) programs must be able to meet continuously evolving health and safety needs in a wide variety of occupational settings. Therefore, academic IH graduate programs must regularly evaluate their curricula and solicit input from industry professionals in order to make curricular changes that will better prepare their students for professional roles in industry. The purpose of this study was to identify the training gaps that exist between industry needs, accreditation criteria, and the current curriculum for the CSU Industrial Hygiene graduate program. In Phase 1 of this study, a set of curriculum maps were developed to evaluate training gaps between accreditation criteria, course learning objectives, and course assessment mechanisms for each core course in the IH curriculum. In Phase 2, the research team facilitated two group interviews with the Colorado State University (CSU) IH Advisory Board, collected alumni survey data, and performed a qualitative analysis to identify skills gaps/needs for CSU IH Program graduates. In Phase 1, only one gap was identified between accreditation criteria and IH program course objectives in the nine core departmental courses of the CSU IH graduate curriculum. No gaps were found between IH Program course objectives to course assessment mechanisms. In Phase 2, the research team identified three themes (technical, applied, and soft skills) and selected several skills within each theme that interview participants thought were necessary proficiencies for young IH professionals. The curriculum mapping exercise generally validated the satisfactory accreditation status of the CSU IH Program graduate curriculum. The development of the curriculum mapping tool and evaluation method can aid in providing evidence for the re-accreditation process for the CSU IH Program, as well as other occupational health programs. The skills identified in the qualitative interview and survey data can be incorporated into the curriculum to improve the training of IH students. Additionally, by using qualitative analysis, the researchers uncovered soft skills previously unidentified in IH needs assessments, providing valuable information for all IH graduate programs.Item Open Access Employee noise exposure and octave band analysis in a manufacturing setting(Colorado State University. Libraries, 2023) Gieseck, Darren, author; Brazile, William, advisor; Autenrieth, Daniel, committee member; Gutilla, Margaret, committee memberWorker exposure to hazardous levels of noise continues to be a concern in United States (US) industries. The National Institute for Occupational Safety and Health has estimated that twenty-two million US workers are exposed to hazardous levels of noise each year, increasing the risk for noise-induced hearing loss (NIHL). One industry sector of concern for worker exposure to noise is metal can manufacturing because of the types and number of machines used in the production areas. To help further characterize the risk NIHL in the metal can manufacturing sector, a comprehensive noise evaluation was performed at a manufacturing site that produced aluminum metal cans. The purpose of this study was to (1) determine if workers in a metal can manufacturing facility were overexposed to hazardous levels of noise that could potentially result in NIHL; (2) determine the machinery frequencies greater than 85 dBC to which employees were exposed; and (3) provide sound mitigation recommendations to the facility's safety team. Area noise levels were collected with a sound level meter (SLM) and personal noise samples were taken using wearable noise dosimeters. 30 production employees participated in sampling over the course of five days and their measured work shift noise exposures were compared to published occupational exposure limits to determine if they were at increased risk of hearing loss. Personal noise exposures were compared to the Occupational Safety and Health Administration's (OSHA) noise Action Level (AL) and Permissible Exposure Limit (PEL); the American Conference of Governmental Industrial Hygienists' (ACGIH) Threshold Limit Value (TLV); and the National Institute for Occupational Safety and Health's (NIOSH) Recommended Exposure Level (REL). Of the 30 employees sampled, 100% exceeded the OSHA AL, 100% exceeded the OSHA PEL, and 100% exceeded the NIOSH REL/ACGIH TLV. To provide statistical support of these findings, a 95% confidence interval was calculated for each occupational exposure standard along with upper and lower prediction limits. Additionally, the frequencies greater than 85 dBC obtained from the area noise samples associated with the production machinery ranged from 63 Hz – 6,300 Hz with noise levels that ranged from 97.1 dBC – 99.6 dBC and Z-weighted frequencies greater than 85 dB ranged from 32 Hz – 8,000 Hz. From these findings, noise mitigation recommendations were provided that were focused on establishing hearing attenuation to 80 dBA. This involved ongoing fit testing of hearing protection for employees, training, and addressing the specific frequencies associated with each machine type.Item Open Access Evaluation and resolution of two sampling methods for airborne aromatic diisocyanate monomers(Colorado State University. Libraries, 2013) Schaeffer, Joshua W., author; Brazile, William, advisor; Reynolds, Stephen, committee member; Sandfort, Delvin, committee member; Hanneman, William, committee member; Morley, Paul, committee memberTo view the abstract, please see the full text of the document.Item Open Access "Exposure to respirable crystalline silica during five OSHA Table 1 tasks and the effectiveness of dust controls, the contribution of background silica dust to personal exposures, and the use of a photometric instrument to assess silica dust exposure in real time"(Colorado State University. Libraries, 2021) Cothern, Emily J., author; Brazile, William, advisor; Reynolds, Stephen, committee member; Autenrieth, Daniel, committee member; Fisher, Gwen, committee memberTo view the abstract, please see the full text of the document.Item Open Access Indoor hockey officials' noise exposure, temporary hearing loss, and effect of helmet visor length on exposure to whistle noise(Colorado State University. Libraries, 2016) Adams, Karin L., author; Brazile, William, advisor; Reynolds, Stephen, committee member; Peel, Jennifer, committee member; Legare, Marie, committee member; Lipsey, Tiffany, committee memberTo view the abstract, please see the full text of the document.Item Open Access Noise characterization and exposure of indoor hockey officials(Colorado State University. Libraries, 2015) Langley, Ammon, author; Brazile, William, advisor; Sandfort, Delvin, committee member; Lipsey, Tiffany, committee memberResearchers have recently associated self-reported hearing loss in sports officials who use whistles. However, the actual noise exposures or degree of hearing loss to sports officials have not been determined to date. Researchers have shown that frequent noise exposures to equivalent sound pressure levels that exceed 85 dB may not only contribute to hearing loss, but also incidence of hypertension. Therefore, a pilot study was conducted to assess hockey official noise exposures at two sporting arenas that host junior and collegiate hockey games. The purpose of this study was threefold: (1) to measure the noise to which hockey officials are exposed; (2) to determine if hockey officials are at increased risk of hearing damage from officiating games; and (3) to determine if hearing protection is warranted. This pilot study will help determine if a more comprehensive study, including audiometric testing, at louder, larger sports arenas is necessary. A total of 23 hockey official noise exposure samples were taken over the course of six hockey games. The hockey official noise exposure samples were collected while they were officiating games using Larson Davis personal noise dosimeters Models 706 and 703+. Each game was approximately three hours in duration. The dosimeters were pre-calibrated and attached to the officials with the microphone positioned within a one-foot radius of their heads on their dominant sides. The dosimeters were post-calibrated and the data were downloaded using the Larson Davis Blaze® Software. Analysis of the noise data included descriptive statistics such as the time-weighted average, eight-hour time-weighted average, noise dose percent, the equivalent sound pressure level, and the predicted 8-hour noise dose percent. Although the hockey games were only approximately three hours in duration, 15 of 23 (65%) of the officials were overexposed to noise based on the American Conference of Governmental Industrial Hygienists recommended threshold limit value of 85 dBA as an eight-hour time-weighted average (3 dB exchange rate). Furthermore, all officials sampled had equivalent continuous sound pressure levels that exceeded 85 dBA. None of the hockey officials were exposed to noise levels in excess of the Occupational Safety and Health Administration (OSHA) permissible exposure limit of 90 dBA as an eight-hour TWA (5 dB exchange rate) or the OSHA action limit of 85 dBA (5 dB exchange rate). Based on the results of this pilot study, hockey officials are overexposed to hazardous levels of noise that can likely contribute to hearing loss. Therefore, recommendations that include training and the use of earplugs were provided to reduce hockey official noise exposure and reduce the risk of developing noise-induced hearing loss in this population of workers. However, to determine if temporary hearing loss occurs from hockey game noise, future research using audiometric testing pre- and post-game exposure should be performed.Item Open Access Noise characterization and exposure of indoor hockey officials(Colorado State University. Libraries, 2015) Johnesee, Katherine, author; Brazile, William, advisor; Sandfort, Delvin, committee member; Lipsey, Tiffany, committee memberNoise in the workplace is a common occurrence. These sounds can have various characteristics that can affect each individual. Many people around the world subject themselves to loud noises at recreational activities including concerts, monster truck rallies, and sporting events. Some individuals also work these events as security employees, referees, and concession workers. Depending on the arena and the sport, games may take place one to four days a week at a particular venue. The National Institute for Occupational Safety and Health (NIOSH) identifies exposure to noise as one of the most common hazards associated with workplaces. According to the National USA Hockey League, there are over 20,000 registered officials (referee/linesman) regulating hockey in the United States. The identified hockey official population could be at risk of developing noise induced hearing loss (NIHL) because of the noise exposure at hockey games. For this study, personal noise dosimeters and a sound level meter were used to record noise exposures during hockey games for the 2014 season to ascertain if hockey referees were at increased risk of NIHL. A total of 30 personal noise samples and 20 area noise samples were collected. The study was completed in December 2014. The noise dosimetry results were compared to the Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL), OSHA Action Level (AL), and American Conference for Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV). Noise dose was calculated for each official per game to determine if noise controls were warranted at this specific venue. No referees or linesmen were overexposed to noise when compared to the OSHA PEL. However, twenty-five referees and linesmen (89%) were overexposed to noise according to the ACGIH recommendations (85 dBA, 3 dB exchange rate), and two officials (7%) were exposed above the OSHA Action Level (85 dBA, 5 dB exchange rate). An average equivalent sound-pressure level (Leq) range of 79 dBA to 90 dBA was measured using a sound level meter at four locations in the arena over five games. In addition to area and personal monitoring, the number of whistle blows by the officials was counted during the first period of four games, and the average number of whistle blows per game for referees and linesmen was 60. According to previous researchers, whistle blows are one of the loudest and closest noise sources to referees. Some whistles reach sound levels as high as 116 dBA. Based on the results, it is recommended that this venue take preventative action in reducing noise exposure for hockey referees. Future research should continue sampling at sports arenas and focus on implementing control measures in hockey arenas.Item Open Access Noise characterization and exposure of indoor sporting events(Colorado State University. Libraries, 2012) Cranston, Cory J., author; Brazile, William, advisor; Sandfort, Delvin, committee member; Gotshall, Robert, committee memberNoise, as a hazard in the work place, has long been recognized as an issue facing workers. The National Institute for Occupational Safety and Health (NIOSH) recognizes that control of noise is a critical issue facing today's employers and employees. Occupational hearing loss was identified as one of the 21 priority areas for research in the next century. A report from the EPA in 1981 estimates that over 9 million Americans are exposed to occupational noise greater than 85 decibels (dB) and more recent estimates from NIOSH indicate excessive noise exposures upwards of 30 million. Occupational and recreational noise exposures were evaluated at a two sporting arenas hosting hockey games at the collegiate and semi-professional level. Between the two facilities studied, a total of 54 personal noise dosimetry samples were taken over the course of seven home hockey games, three at Venue 1 and four at Venue 2. This included 15 worker personal noise samples and nine fan personal noise samples at Venue 1; and 19 worker personal noise samples and 11 fan personal noise samples at Venue 2. Extensive area monitoring was conducted at each venue to further characterize the stadium noise on a location by location basis. These data are useful in characterizing occupational exposure of indoor arena support staff and may also provide a foundation for future research No workers or fans from either venue were exposed to noise in excess of the Occupational Safety and Health Administration (OSHA) permissible exposure limit of an eight-hour time-weighted average (TWA) of 90 A-weighted decibels (dBA) or the eight-hour TWA action limit of 85 dBA. However, six of 15 (40%) workers and three of nine (33%) fans sampled at Venue 1 were exposed to noise in excess of the American Conference of Governmental Industrial Hygienists (ACGIH) recommended threshold limit value (TLV) of 85dBA. In addition, eleven of 19 (57%) workers and ten of 11 (90%) fans sampled at Venue 2 were exposed to noise in excess of the ACGIH noise TLV. A two-way analysis of variance (ANOVA) was conducted on the personal noise dosimetry data from workers and fans to determine if there were significant differences between noise exposures to workers and fans within and between the venues investigated. At a 95% confidence level, it was determined that there were significant noise exposure differences between nearly all groups in evaluating both OSHA and ACGIH criteria. However, no significant noise exposure differences were detected between workers at the different venues.Item Open Access Noise characterization of oil and gas operations(Colorado State University. Libraries, 2016) Radtke, Cameron, author; Brazile, William, advisor; Autenrieth, Daniel, committee member; Lipsey, Tiffany, committee memberIn cooperation with The Colorado Oil and Gas Conservation Commission (COGCC), researchers at Colorado State University (CSU) conducted area noise monitoring at 23 oil and gas sites throughout Northern Colorado. The goals of this study were to: (1) measure and compare the sound levels for the different phases of oil and gas development sites; (2) evaluate the effectiveness of sound barriers; and (3) determine if sound levels exceeded the COGCC noise limits. The four phases of oil and gas development include drilling, hydraulic fracturing, completion and production. Sound measurements were collected using the A- and C-weighted scales. Octave band analysis was also performed to characterize the frequency spectra of the sound measurements. Noise measurements were collected using noise dosimeters and a hand-held sound-level meter at specified distances from the development sites in each cardinal direction. Data were analyzed using descriptive statistics and a t-test was used to determine significant differences in noise levels for drilling sites with and without sound barriers. In addition, noise maps were developed to illustrate the behavior of the noise propagation. At 117 yards, the sound-measurement distance specified by the COGCC noise rule, drilling, hydraulic fracturing, and completion sites without sound barriers exceeded the maximum permissible noise levels for residential and commercial zones (55 dBA and 60 dBA, respectively). In addition, drilling and hydraulic fracturing sites with sound barriers exceeded the maximum permissible noise level for residential zones. Production sites were within the COGCC permissible noise level criteria for all zones. At 117 yards from the noise source, all drilling, hydraulic fracturing and completion sites exceeded 65 dBC. Current sound wall mitigation strategies reduced sound levels in both the A- and C-weighted scales. However, this reduction in noise was not sufficient enough to categorize drilling and hydraulic fracturing sites as compliant with the current COGCC noise regulations.Item Open Access Noise exposure and evaluation at tire changing facilities(Colorado State University. Libraries, 2019) Willson-Kerns, Cory, author; Brazile, William, advisor; Adams, Karin, committee member; Fisher, Gwenith, committee memberThe purpose of this study was to (1) determine if workers in the tire changing industry are overexposed to hazardous noise that could result in occupational hearing loss; and (2) determine the maximum number of tire changes that could be performed without exceeding occupational exposure limits. Personal noise dosimetry data were compared to published occupational noise exposure limits to assess compliance. The noise dosimetry results were then extrapolated against the number of tire changes to determine if there was a relationship between the number of tire changes and employee noise exposures. Thirty (30) full-shift noise-exposure samples were collected on tire technicians using Larson-Davis 703 audio dosimeters in three tire-changing facilities. The technicians recorded the number of tires changed during their shift. The eight-hour time weighted averages were recorded for each subject following the Occupational Safety and Health Adminsitration (OSHA) permissible exposure limit (PEL) and action level (AL); and the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV). Each sample was evaluated against the number of tire changes performed in the shift. In addition, area noise samples of specific pieces of tire-changing equipment and processes were taken with a sound level meter. It was determined from the 30-sample data set that only one of the 30 technicians was exposed at or above the OSHA noise action level of 85dBA (as an 8-hour TWA). Eighteen (18) of the 30 employees were exposed above the ACGIH noise TLV and no employees exceeded the OSHA noise PEL. Based on the area noise samples, noise in the tire changing facilities appeared to be largely intermittent with peak noise levels exceeding 140dB. The findings of this study are that tire technicians were not exposed above the OSHA PEL at least up to 40 tire changes per shift but may still be exposed to hazardous levels of noise. A 95% confidence interval for each of the three categories of noise analyses (i.e., PEL, AL, TLV) was calculated to determine the average noise exposure for each number of tire changes. In addition, a 95% prediction interval was calculated to determine the noise exposure level for an individual worker chosen randomly for a specific number of tire changes. Last, it was determined from the area noise sampling that the air ratchet, Cheetah, and tire-changing machine contributed the most to the overall noise exposure.Item Open Access Noise exposure assessment in the Poudre Fire Authority(Colorado State University. Libraries, 2011) Schwennker, Catherine, author; Brazile, William, advisor; Sandfort, Delvin, committee member; Lipsey, Tiffany, committee memberAccording to the National Institute for Occupational Safety and Health (NIOSH), it is estimated that 22 million workers are exposed to hazardous levels of noise. Firefighters are part of this population of workers that are at potential risk of overexposure to such noise and subsequent noise-induced hearing loss. In fact, one NIOSH study found that 53 of 56 (96%) firefighters had detectable hearing loss. To ascertain the sources of firefighter noise exposures, noise samples were taken at ten Poudre Fire Authority stations on the equipment and emergency vehicles using a sound level meter. Results indicated that five of the six pieces of equipment located at the stations exceeded 85 dBA; and 13 of the 15 pieces of equipment on the trucks exceeded 85 dBA. Equipment that exceeds 85 dBA is important to identify since hearing loss can begin to occur at these levels. Code-3 operations that involve fire truck siren were measured at 92 dBA, and the operation of truck pumps at "high" psi was measured at 91 dBA. A 24-hour noise dose to firefighters was estimated to be at 48% of the OSHA permissible exposure limit. According to the OSHA Occupational Noise Control Standard, engineering controls are required to lower the noise levels below the eight-hour permissible exposure limit or hearing protection must worn when engineering controls are not feasible. Given the variability in the time of use of relatively loud firefighting equipment and the difficultly of measuring full-shift firefighter noise exposures, it is recommended that hearing protection be worn to help reduce the risk of noise induced hearing loss.Item Open Access Noise exposure in steel stud construction: noise characterizations and tool limit guidance for commercial framers(Colorado State University. Libraries, 2023) Schutt, David, author; Brazile, William, advisor; Autenrieth, Daniel, committee member; Lipsey, Tiffany, committee member; Van Dyke, Mike, committee memberNoise exposure in construction is well-demonstrated to be hazardous to hearing, with high rates among construction workers of occupational noise-induced hearing loss. This study focused on an under-studied population of construction workers: Commercial framers who cut and install steel studs as their primary task. This study used personal noise dosimetry and task assessments to characterize the noise exposures of this population, and to develop implementable recommendations to decrease hazardous occupational noise exposure for this population of workers. Sound pressure levels of common power saws at the framers' hearing zone was hazardous, with Leq log-transformed means of 107.2 dBA and Lpeak means of 120.1 dBC during saw use. Noise dose among this population ranged from 5.8 – 61.4% of the Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) and from 63.9 – 823.2% for the National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit (REL). Mean ambient noise dose equivalent at the study sites was 1.4% for OSHA PEL criteria and 12.4% for NIOSH REL criteria. Overall, installers had significantly lower REL doses than cut persons (p = 0.016). Octave band analysis showed a slight upward trend of higher sound pressure levels at higher frequencies. Recommendations for task limitations were developed for isolated use of power saws, the powder-actuated tool (PAT) nailer, and the impact driver. Generalized cuts of steel studs without hearing protectors were limited to 13 – 14 cuts per worker per day for any saw and any stud type. Shots with the PAT nailer were limited to <2 shots per day per worker without hearing protectors, 10 – 13 shots per day with foam earplugs, 27 – 34 shots per day with earmuffs, and 86 – 108 shots per day with double hearing protection (earplugs plus earmuffs).Item Open Access Noise exposures of firefighters during training activities(Colorado State University. Libraries, 2011) Root, Kyle, author; Brazile, William, advisor; Sandfort, Delvin, committee member; Lipsey, Tiffany, committee memberOccupational hearing loss is the most common work-related injury in the United States according to the National Institute for Occupational Safety and Health (NIOSH). Consequently, NIOSH recommends that occupational noise exposure be among the top occupational hazard research areas of the next century. Firefighters represent a unique population in which noise exposure data are difficult to obtain. The unique settings in which firefighters perform their duties (e.g., inside burning structures) make it difficult to collect noise exposure data and quantify exposures due to environmental factors and unpredictability. Furthermore, firefighting requires that multiple tasks by each participant be accomplished during emergency responses. In order to address the challenge of obtaining personal noise samples from firefighters during emergency situations, this study was conducted to gather firefighter personal noise samples during training exercises that simulated on-scene firefighting tasks. Noise exposure data were collected on five training days during the summers of 2010 and 2011. Two training exercises were executed each day, totaling ten training exercises. Each training exercise averaged 35 minutes in duration and included ten to eleven participants, resulting in ninety-three total personal noise exposure samples. Noise monitoring results showed that none of the ninety-three (100%) firefighter samples were exposed to noise exceeding the Occupation Safety and Health Administration (OSHA) permissible exposure limit (PEL) of an 8-hour time-weighted average (TWA) of 90 dBA. Nine of ninety-three (9.6%) exposures were above the OSHA action level (AL) of 50% dose when extrapolated across an 8-hour workday. Additional analysis was performed after dividing the noise exposure data into three groups consisting of Interior, Exterior, and Engineering categories. This division showed a statistically significant difference (alpha = 0.1) between the interior and engineer categories in relation to noise exposure.Item Open Access Occupational exposure to bioaerosols at Colorado dairies(Colorado State University. Libraries, 2023) Craig, Amanda, author; Brazile, William, advisor; Reynolds, Stephen, committee member; Clark, Maggie, committee member; Ellis, Bob, committee member; Autenrieth, Dan, committee memberThe dairy industry is vital to the American economy and impacts both the general population and the workers immediately involved in dairy production. The United States is a significant contributor to the global industry producing approximately 14.6% of the global milk supply. To accomplish this, large herd dairy operations (>1000 head of cattle) operate 24 hours a day, 365 days a year. The long production hours and large herd size result in an increase in the number of injuries and illness in dairy workers. One type of illness diagnosed in dairy farmers is respiratory disease. Multiple researchers have shown that some workers in modern dairy operations have pulmonary function cross-shift declines and lower pulmonary function as well as increased rates of obstructive respiratory conditions such as chronic bronchitis, organic dust toxicity syndrome, occupational asthma, chronic obstructive pulmonary disease, and hypersensitivity pneumonitis (Reynolds, Lundqvist et al. 2013, Reynolds, Nonnenmann et al. 2013).Respiratory disease is caused by exposure to bioaerosols that consist of bacteria, fungi (and the corresponding constituents), pollen, animal dander, feed, and manure. Although bioaerosol exposure can cause infection, the immunological response the body has to bioaerosols that result in decreased lung function is more prevalent in dairy workers. Although some researchers have examined culturable bacteria and fungi, the viable organisms only represent a small fraction of what is detected in the air at the dairies (Katja Radon and Jörg Hartung 2002). One method used to identify Gram-negative bacteria is the recombinant factor C (rFC) assay, a rapid diagnostic assay to identify concentrations of endotoxins present in dairy environments. While endotoxins have explained a portion of the respiratory problems in dairy workers, they do not explain all of the respiratory diseases (May, Romberger et al. 2012). Little research has been performed to determine concentrations of fungi at dairies. Some work has been done using GC/MS to identify fungal markers, but the current research is the first study to use the rapid diagnostic (Glucatell) assay to quantify worker exposure to fungi at dairies. The primary goal of this study was to better characterize dairy worker exposure to bioaerosols through two sample analysis techniques: next generation sequencing (NGS) and rapid diagnostic assays (rFC and Gluactell). The specific aims of this dissertation were to 1) identify similarities and differences in bacterial communities between button samplers and biosamplers co-located inside a cattle pen, 2) characterize worker exposure to the microbial community on dairy farms in comparison to environmental sources, and 3) characterize worker exposure to two bioaerosols constituents based on dairy worker task. For Specific Aim 1, area air samples were taken for five consecutive days to compare the button and biosamplers co-located inside a fresh cow pen and then analyzed using NGS to determine the identity and quantity of bacteria. The current study was the first to compare the biosamplers and button samplers for NGS analysis at a dairy. The results from this study will help researchers make better decisions on the type of sampler that should be employed for collecting airborne bacteria. The researchers found that the biosampler was more effective at collecting samples for NGS. The two samplers had significantly different microbial communities that were identified based on the Principle Coordinate Analysis (PCoA) plot. However, upon further analysis the alpha diversity plot showed relatively similar Shannon and Inverse Simpson indices suggesting both samplers were sampling from the same core microbiome. Therefore, the difference between the samplers is likely due to the high variance in the samples and not actual differences in the microbial community. The alpha diversity plot also had a high operational taxonomic units (OTU) count indicating that the dairy microbiome has a high count of rare bacteria and a low count of dominant bacteria. The biosampler had a higher relative abundance of bacteria across all five sampling days. The majority of the top identified bacteria were Gram-positive. Currently, little research has been done to assess the impact of Gram-positive bacteria on worker respiratory health. Based on these results, future research should focus on Gram-positive bacteria as they may substantially contribute to respiratory disease. Some of the identified bacterial genera have potentially pathogenic species, but data on the species level is needed to determine the potential for infection. Both viable and non-viable bacteria and their corresponding constituents can act as inflammagens, potentially causing cross-shift lung function decline and respiratory disease (May, Romberger et al. 2012). Both samplers collected bacterial communities that could be analyzed and used for NGS, but the biosampler was identified as the better sampler because of the higher OTU counts and greater bacterial diversity. However, depending on the type of sample information required, the button sampler may be advantageous because it can be used for personal samples and throughout the entire day. For Specific Aim 2, personal and area air, hand swabs, and soil samples were collected at one dairy for five consecutive days and analyzed using NGS. The sample sets were then compared to identify differences and similarities between the sample type, identity of the bacteria, and potential for worker exposure. The difference between sampler (button vs biosamplers) was significantly different. The sample type explained more than 50% of the differences seen in the microbial community. The biosampler compared to the button sampler had a lot of variation within their respective types which could explain some of the differences between the communities due to the differences in sampling length and time of day. The variation in the biosampler was mainly due to the second sample taken on each day. The area air samples had the highest relative abundance between the sample types. Soil was thought to have the highest relative abundance but because the number of samples were biased toward air samples (n=60 vs n=15) when the most prevalent top bacteria were chosen they were driven by the air samples. The majority of the bacteria were also found to be Gram-positive across all the samples. The most common source of the bacteria based on the genera information was soil which was expected based on the dusty nature of the dairy environment. Some genera identified have potential pathogenic species, but this dataset did not provide information on the species level. No conclusions can be made on the possibility of infection from the bacteria in these samples. For Specific Aim 3, four dairies were recruited to assess airborne concentrations of Gram-negative bacteria, fungi and dust. Workers were binned into eight different tasks, and the task samples were compared to identify differences in exposure between the tasks. Differences in site and season were not statistically significant and were not included in subsequent analyses. The concentration of dust over a full work shift ranged from 0.95-5.6 mg/m3 and were lower than expected. The highest dust concentration was below the Occupational Safety Health Administration Permissible Exposure Limit (OSHA PEL) of 10 mg/m3 but was not below the suggested Occupational Exposure Limit (OEL) from the American Conference of Governmental Industrial Hygienists (ACGIH) of 2.4 mg/m3 indicating that dust exposure may be a concern for some of the tasks. Machine operators and milkers had the highest geometric mean dust concentrations with concentrations of 0.356 and 0.305 mg/m3 respectively. The endotoxin concentrations ranged from 0.078-40 EU/m3 which was lower than other research observing endotoxins concentrations at dairies and below the suggested OEL of 90 EU/m3. Multi-task workers and milkers had the highest endotoxin concentrations (Donham 2000). The β-glucan concentrations ranged from 0.2-212 pg/m3 with the highest task concentrations found in multi-task workers and machine operators. There is not a suggested OEL for β-glucans but concentrations measured in this study were higher than other studies in waste processing facilities (Douwes 2005). Ultimately, there was not one task that was consistently higher between the different exposure variables and there were no significant differences between any of the tasks. No conclusions or recommendations could be made on the task-based exposures at the dairies. However, even at low concentrations, exposure to agricultural dusts have been shown to induce responses from cytokines (Poole, Dooley et al. 2010). The genetic polymorphism TLR4 has also been demonstrated to cause workers to be more predisposed to sensitization to endotoxins at extremely low concentrations (Reynolds 2012).Item Open Access Occupational health and safety management systems in animal production agriculture(Colorado State University. Libraries, 2015) Autenrieth, Dan, author; Brazile, William, advisor; Reynolds, Steven, advisor; Douphrate, David, committee member; Román-Muñiz, Noa, committee member; Sandfort, Delvin, committee memberThe relationship between the level of occupational health and safety management system (OHSMS) programming and the rates of occupational injuries and illnesses in dairy and poultry production industries was investigated in this study. It was hypothesized that higher rates of OHSMS programming would be associated with lower injury rates. The individual OHSMS components and attributes with the strongest associations were identified, and the relationships between workforce size, injury rates, and OHSMS programming were also investigated. Data on OHSMS and injury rates for the U.S. dairy industry were obtained from Occupational Safety and Health Administration (OSHA) On-Site Consultation Service records. The OHSMS and injury data were paired using a non-descript identification number and analysed using Spearman Rank-Order Correlation. Generally, weak-to-moderate negative associations were observed between OHSMS programming and injury and illness rates, overall and by OHSMS component. The observed associations were much stronger and tended to be statistically significant when only those records with the most complete assessments of an organization’s OHSMS were considered in the analysis. A major limitation of correlational studies is the possibility that an unknown variable(s) may explain some or all of the observed association. To account for this limitation, the research method was applied to a second dataset: OSHA consultation records from the U.S. poultry production industry. Similar associations were found, suggesting that the observed relationships are indeed representative of the true relationship between OHSMS programming and injury rates. The lack of temporality was another important limitation, because there were no data available on the potential changes in injury and illness rates that may have occurred due to the OHSMS assistance provided by OSHA consultants. To address this limitation, data from a survey of OSHA consultation clients across a wide range of industries was reviewed to determine the usefulness of the OHSMS assistance provided by OSHA consultation to Colorado small business clients, and identify changes that were enacted as a result of that assistance and what the effects of those changes might be. The survey results indicated that the OHSMS assistance was helpful for clients to enact changes such as improved safety programs and training, and that these changes resulted in positive outcomes, including fewer injuries and improved morale. Ultimately, the results of this study provide important preliminary data supporting further research and development of OHSMS interventions for animal production agriculture industries as part of a comprehensive risk management approach to reduce work-related injuries and illnesses. Management leadership was the OHSMS component with the strongest association with lower injury and illness rates, in both dairy and poultry production industries. In addition, the importance of thorough assessments of client OHSMS programming by OSHA consultants was evident, as were the benefits of OHSMS consultation services to small business clients. Further research is warranted to develop and evaluate OHSMS interventions for animal production industries. Economic outcomes should be considered in this research, as well as OHS outcomes and OHSMS programming.Item Open Access Occupational noise exposure and hearing assessment of hydraulic fracturing workers: quiet versus conventional fleets(Colorado State University. Libraries, 2024) Blevens, Melissa S., author; Brazile, William, advisor; Tsai, Candace Su-Jung, committee member; Van Dyke, Michael, committee member; Autenrieth, Daniel, committee member; Lipsey, Tiffany, committee memberOil and gas extraction companies are exempt from implementing hearing conservation programs for their workers according to the Occupational Safety and Health Administration's (OSHA) noise standard. The occupational noise exposure and hearing status of these workers has not been published in scientific literature before the present study, presumably due to this exemption. In this study, area and personal noise exposures and worker hearing acuity were measured at both conventional and quiet hydraulic fracturing fleets, allowing a comparison between the fleets. Quiet fleets refer to the use of engineering controls to decrease noise levels of the pumps while conventional fleets do not employ these measures. In both fleets, the authors conducted personal noise dosimetry, equipment noise measurements, and pure tone audiometry pre- and post-work shift to determine if there were temporary threshold shifts (TTS) in hearing. Based on the personal noise dosimetry results, 42/50 (84%) of the quiet fleet and 34/34 (100%) of the conventional fleet workers sampled were at or over 100% noise dose according to the American Conference of Governmental Industrial Hygienists' (ACGIH) noise Threshold Limit Value (TLV). Based on the OSHA Permissible Exposure Limit (PEL) noise criteria, 9/50 (18%) of the quiet fleet workers and 15/34 (44.1%) of the conventional fleet workers were at or over 100% noise dose. Workers in both fleets experienced TTS, but no significant difference was observed between the types of fleets in relation to TTS. Most equipment of both fleets exceeded 85 decibels, but the pumps of the quiet fleet were ~14 dB lower than those of the conventional fleet. Although the quiet fleet noise controls reduced personal noise exposure, a portion of the quiet fleet workers sampled still faced noise levels that could increase the risk of hearing loss. The researchers suggest the initiation of a hearing conservation program despite OSHA exemption to safeguard worker health and recommend workers involved in certain job tasks employ dual hearing protection based on the exposure monitoring results.