Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-14 (of 14 Records) |
Query Trace: Shaw PB[original query] |
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Robotic direct reading device with spatial, temporal, and PID sensors for laboratory VOC exposure assessment
Brown KK , Norton AE , Neu DT , Shaw PB . J Occup Environ Hyg 2019 16 (11) 717-726 This study evaluated a novel robotic direct reading method that used a real-time location system to measure the spatial-concentration distribution of volatile organic compounds (VOCs) in a chemistry laboratory. The CEMWIP II is a custom-made sensor that measures VOCs, temperature, humidity, and location, sending data wirelessly in real time to a remote location for display and storage. In this study, the CEMWIP II device was mounted on a robotic platform to create a CEMWIP II-mobile platform. The autonomous mobile platform was released from a corner of the room and allowed to travel randomly along an open floor with the goal of characterizing the spatial distribution of VOCs and identifying their sources in the laboratory. The experiment consisted of 12 runs made of permutations of four corner release sites and four beaker locations, with two beakers containing water and two containing the solvent acetone. The autonomous mobile platform was tasked with locating the two beakers of acetone. The sensor had a detection limit of 100 ppb and the confidence of detecting a source within a 1.46 m(2) area was p = 0.0005 by ANOVA. The CEMWIP II-mobile platform was able to measure the spatial distribution of VOCs within a laboratory that were associated with open solvent containers. |
Noise exposures and perceptions of hearing conservation programs among wildland firefighters
Broyles G , Kardous CA , Shaw PB , Krieg EF . J Occup Environ Hyg 2019 16 (12) 1-10 Wildland firefighters are exposed to numerous noise sources that may be hazardous to their hearing. This study examined the noise exposure profiles for 264 wildland firefighters across 15 job categories. All 264 firefighters completed questionnaires to assess their use of hearing protection devices, enrollment in hearing conservation programs, and their overall perception of their noise exposure. Roughly 54% of firefighters' noise exposures exceeded the National Institute for Occupational Safety and Health recommended exposure limit of 85 decibels, A-weighted, over 8 hr, and 32% exceeded the Occupational Safety and Health Administration permissible exposure limit of 90 decibels, A-weighted, over 8 hr. Questionnaire results indicated good agreement between noise exposures and firefighters' perceptions of the noise hazard. Approximately 65% reported that they used some form of hearing protection; however, only 19% reported receiving any proper training regarding the use of hearing protection devices, with the majority of those firefighters relying on earplugs, including electronic and level-dependent earplugs, over earmuffs or other forms of hearing protectors. The results also suggest that improved communication and situational awareness play a greater role in the consistent use of hearing protection devices than other factors such as risk of developing noise-induced hearing loss. The study highlighted the challenges facing wildland firefighters and their management and the need for a comprehensive wildland fire agencies' hearing conservation program especially for firefighters who were exempt based on their occupational designations. |
The potential use of a NIOSH sound level meter smart device application in mining operations
Sun K , Kardous CA , Shaw PB , Kim B , Mechling J , Azman AS . Noise Control Eng J 2019 67 (1) 23-30 Many mobile sound measurement applications (apps) have been developed to take advantage of the built-in or fit-in sensors of the smartphone. One of the concerns is the accuracy of these apps when compared to professional sound measurement instruments. Previously, a research team from the National Institute for Occupational Safety and Health (NIOSH) developed the NIOSH Sound Level Meter (SLM) app for iOS smart devices. The team found the average accuracy of this app to be within 1 dBA when using calibrated external microphones with a type 1 reference device and measuring pink noise at levels from 65 to 95 dBA in 5-dBA increments. The studies were conducted in a reverberant noise chamber at the NIOSH Acoustics Laboratory in Cincinnati. However, it is still unknown how this app performs in measuring industrial/mining sound levels outside of a controlled laboratory environment. The current NIOSH study evaluates the NIOSH SLM app to measure sound levels from a jumbo drill (a large mining machine). The study was conducted in a hemi-anechoic chamber at the NIOSH Pittsburgh Mining Research Division and followed by a field evaluation in an underground metal mine. Six different iOS smart devices were used with two types of external microphones chosen from previous studies to measure sound levels during jumbo drill operations, and the results were compared with a reference device. Results show that the average sound levels measured by the NIOSH SLM app are within 1 dBA of the reference device both in the laboratory and field. However, the type of operation being performed, the selection and use of external microphones, distance from a noise source, and environmental factors (e.g., air movement) may all influence the accuracy of the app's performance. Although additional validation is still needed, the results from this study suggest a potential for using the NIOSH SLM app, with calibrated external microphones, to measure sound levels in mining operations. |
Meta-analysis of chromosomal aberrations as a biomarker of exposure in healthcare workers occupationally exposed to antineoplastic drugs
Roussel C , Witt KL , Shaw PB , Connor TH . Mutat Res Rev Mutat Res 2017 781 207-217 Many antineoplastic drugs used to treat cancer, particularly alkylating agents and topoisomerase inhibitors, are known to induce genetic damage in patients. Elevated levels of chromosomal aberrations, micronuclei, and DNA damage have been documented in cancer patients. Elevations in these same biomarkers of genetic damage have been reported in numerous studies of healthcare workers, such as nurses and pharmacists, who routinely handle these drugs, but results vary across studies. To obtain an overall assessment of the exposure effect, we performed a meta-analysis on data obtained from peer-reviewed publications reporting chromosomal aberration levels in healthcare workers exposed to antineoplastic drugs. A literature search identified 39 studies reporting on occupational exposure to antineoplastic drugs and measurement of chromosomal aberrations in healthcare workers. After applying strict inclusion criteria for data quality and presentation, data from 17 studies included in 16 publications underwent meta-analysis using Hedges' bias-corrected g and a random-effects model. Results showed the level of chromosomal aberrations in healthcare workers exposed to antineoplastic drugs was significantly higher than in controls. The standardized mean differences (difference of means divided by within sd) from all studies were pooled, yielding a value 1.006 (unitless) with p< 0.001. Thus, in addition to the documented genotoxic effects of antineoplastic drugs in cancer patients, this meta-analysis confirmed a significant association between occupational exposure to antineoplastics during the course of a normal work day and increases in chromosomal aberrations in healthcare workers. Based on the studies reviewed, we were unable to accurately assess whether appropriate use of protective measures might reduce the incidence of genetic damage in healthcare workers. However, given the potential for increased cancer risk linked to increases in chromosomal aberrations, the results of this study support the need to limit occupational exposure of healthcare workers to antineoplastic drugs as much as possible. |
Evaluation of a workplace exercise program for control of shoulder disorders in overhead assembly work
Lowe BD , Shaw PB , Wilson SR , Whitaker JR , Witherspoon GJ , Hudock SD , Barrero M , Ray TK , Wurzelbacher SJ . J Occup Environ Med 2017 59 (6) 563-570 OBJECTIVE: The aim of this study was to assess effects of exercise on shoulder musculoskeletal symptoms among employees with overhead assembly work exposures. METHODS: A voluntary workplace shoulder exercise program was offered to employees in two automotive assembly departments, while two similar departments served as controls. N = 76 total workers participated. Shoulder Rating Questionnaire (SRQ) and Discomfort of the Arm Shoulder and Hand (DASH) symptoms were queried monthly for 7 baseline months, followed by 6 months that included exercise. RESULTS: SRQ scores were higher for exercisers than among controls in the 6 exercising months, but not in the baseline months. Although the group x month interaction was significant (P < 0.05), the temporal trend was inconsistent. CONCLUSIONS: Exercise may have temporarily lessened decline in SRQ. It is not clear whether shorter term differences were clinically meaningful or predictive of longer term disability prevention. |
Evaluation of smartphone sound measurement applications (apps) using external microphones-A follow-up study
Kardous CA , Shaw PB . J Acoust Soc Am 2016 140 (4) El327 This follow-up study examines the accuracy of selected smartphone sound measurement applications (apps) using external calibrated microphones. The initial study examined 192 apps on the iOS and Android platforms and found four iOS apps with mean differences of +/-2 dB of a reference sound level measurement system. This study evaluated the same four apps using external microphones. The results showed measurements within +/-1 dB of the reference. This study suggests that using external calibrated microphones greatly improves the overall accuracy and precision of smartphone sound measurements, and removes much of the variability and limitations associated with the built-in smartphone microphones. |
Development of the chemical exposure monitor with indoor positioning (CEMWIP) for workplace VOC surveys
Brown KK , Shaw PB , Mead KR , Kovein RJ , Voorhees RT , Brandes AR . J Occup Environ Hyg 2016 13 (6) 1-37 The purpose of this project was to research and develop a direct-reading exposure assessment method that combined a real-time location system with a wireless direct-reading personal chemical sensor. The personal chemical sensor was a photoionization device for detecting volatile organic compounds. The combined system was calibrated and tested against the same four standard gas concentrations and calibrated at one standard location and tested at four locations that included the standard locations. Data were wirelessly collected from the chemical sensor every 1.4 seconds, for volatile organic compounds concentration, location, temperature, humidity, and time. Regression analysis of the photo-ionization device voltage response against calibration gases showed the chemical sensor had a limit of detection of 0.2 ppm. The real-time location system was accurate to 13 cm +/- 6 cm (standard deviation) in an open area and to 57 cm +/- 31 cm in a closed room where the radio frequency has to penetrate drywall-finished walls. The streaming data were collected and graphically displayed as a three-dimensional hazard map for assessment of peak exposure with location. A real-time personal exposure assessment device with indoor positioning was practical and provided new knowledge on direct reading exposure assessment methods. |
Measurement of impulse peak insertion loss from two acoustic test fixtures and four hearing protector conditions with an acoustic shock tube
Murphy WJ , Fackler CJ , Berger EH , Shaw PB , Stergar M . Noise Health 2015 17 (78) 364-73 Impulse peak insertion loss (IPIL) was studied with two acoustic test fixtures and four hearing protector conditions at the E-A-RCAL Laboratory. IPIL is the difference between the maximum estimated pressure for the open-ear condition and the maximum pressure measured when a hearing protector is placed on an acoustic test fixture (ATF). Two models of an ATF manufactured by the French-German Research Institute of Saint-Louis (ISL) were evaluated with high-level acoustic impulses created by an acoustic shock tube at levels of 134 decibels (dB), 150 dB, and 168 dB. The fixtures were identical except that the E-A-RCAL ISL fixture had ear canals that were 3 mm longer than the National Institute for Occupational Safety and Health (NIOSH) ISL fixture. Four hearing protection conditions were tested: Combat Arms earplug with the valve open, ETYPlugs (R) earplug, TacticalPro headset, and a dual-protector ETYPlugs earplug with TacticalPro earmuff. The IPILs measured for the E-A-RCAL fixture were 1.4 dB greater than the National Institute for Occupational Safety and Health (NIOSH) ISL ATF. For the E-A-RCAL ISL ATF, the left ear IPIL was 2.0 dB greater than the right ear IPIL. For the NIOSH ATF, the right ear IPIL was 0.3 dB greater than the left ear IPIL. |
Evaluation of smartphone sound measurement applications
Kardous CA , Shaw PB . J Acoust Soc Am 2014 135 (4) EL186-EL192 This study reports on the accuracy of smartphone sound measurement applications (apps) and whether they can be appropriately employed for occupational noise measurements. A representative sample of smartphones and tablets on various platforms were acquired, more than 130 iOS apps were evaluated but only 10 apps met our selection criteria. Only 4 out of 62 Android apps were tested. The results showed two apps with mean differences of 0.07 dB (unweighted) and -0.52 dB (A-weighted) from the reference values. Two other apps had mean differences within +/-2 dB. The study suggests that certain apps may be appropriate for use in occupational noise measurements. |
Occupational exposure to acrylamide in closed system production plants: air levels and biomonitoring
Moorman WJ , Reutman SS , Shaw PB , Blade LM , Marlow D , Vesper H , Clark JC , Schrader SM . J Toxicol Environ Health A 2012 75 (2) 100-11 The aim of this study was to evaluate biomarkers of acrylamide exposure, including hemoglobin adducts and urinary metabolites in acrylamide production workers. Biomarkers are integrated measures of the internal dose, and it is total acrylamide dose from all routes and sources that may present health risks. Workers from three companies were studied. Workers potentially exposed to acrylamide monomer wore personal breathing-zone air samplers. Air samples and surface-wipe samples were collected and analyzed for acrylamide. General-area air samples were collected in chemical processing units and control rooms. Hemoglobin adducts were isolated from ethylenediamine teraacetic acid (EDTA)-whole blood, and adducts of acrylamide and glycidamide, at the N-terminal valines of hemoglobin, were cleaved from the protein chain by use of a modified Edman reaction. Full work-shift, personal breathing zone, and general-area air samples were collected and analyzed for particulate and acrylamide monomer vapor. The highest general-area concentration of acrylamide vapor was 350 mcg/cm(3) in monomer production. Personal breathing zone and general-area concentrations of acrylamide vapor were found to be highest in monomer production operations, and lower levels were in the polymer production operations. Adduct levels varied widely among workers, with the highest in workers in the monomer and polymer production areas. The acrylamide adduct range was 15-1884 pmol/g; glycidamide adducts ranged from 17.8 to 1376 p/mol/g. The highest acrylamide and glycidamide adduct levels were found among monomer production process operators. The primary urinary metabolite N-acetyl-S-(2-carbamoylethyl) cysteine (NACEC) ranged from the limit of detection to 15.4 mcg/ml. Correlation of workplace exposure and sentinel health effects is needed to determine and control safe levels of exposure for regulatory standards. |
Acceptance of a semi-custom hearing protector by manufacturing workers
Davis RR , Murphy WJ , Byrne DC , Shaw PB . J Occup Environ Hyg 2011 8 (12) D125-30 Workers complain about wearing hearing protection for two primary reasons: comfort and communication.(1) Employers are concerned about hearing protection costs. Recent advances in hearing protector technology seemed to address those issues through a semi-custom earplug. This new device was designed to prevent overprotection by incorporating only enough attenuation to bring the worker down into the safe exposure zone. Although initially more expensive than disposable hearing protection devices (HPDs), the semi-custom hearing protector would be expected to last several years. | The Hearing Loss Prevention Team of the National Institute for Occupational Safety and Health (NIOSH) was invited by a major auto manufacturing company and the union (UAW) to supervise a longitudinal trial of a semi-custom hearing protector (SonoCustom by Sonomax Technologies, Inc.,Montreal, Canada). This protectorwas advertised as (1) being more comfortable since each plug was custom molded for each worker, and (2) more effective because each plug’s noise reduction rating was tuned to that worker’s particular job. The company’s hearing conservation contractor partnered with NIOSH by recruiting volunteers for the study and providing follow-up usage reports. The study was conducted over the course of 1 year with NIOSH site visits at the start, at 1 month, at 4 months, and at 1-year time intervals. The goal of this trial was to determine worker acceptance of the semi-custom earplug. | Compared with the non-custom earplugs used in this study, the SonoCustom ear plugs were relatively new to the market and have not been extensively investigated in the literature. Initial studies have focused on a new way to measure and model the acoustical performance.(2–4) Wagoner et al.(5) studied speech intelligibility and attenuation while subjects wore the SonoCustom earplugs or two other non-custom, commercially available hearing protectors in laboratory tests and in the field. In the laboratory they were not able to find any statistically significant difference, between the three earplugs, for speech intelligibility or attenuation. Regarding comfort issues, they briefly mentioned that the two non-custom HPDs were judged by the workers to be more comfortable and easier to use than the SonoCustom earplug. |
Relationship between comfort and attenuation measurements for two types of earplugs
Byrne DC , Davis RR , Shaw PB , Specht BM , Holland AN . Noise Health 2011 13 (51) 86-92 Noise-induced hearing loss is almost always preventable if properly fitted hearing protectors are worn to reduce exposure. Many individuals choose not to wear hearing protection because it may interfere with effective communication in the workplace or it may be uncomfortable. Hearing protector comfort has not received the same amount of attention as noise reduction capability. The present study was conducted to evaluate the comfort level of two different types of insert earplugs as well as the attenuation levels achieved by the earplugs. Attenuation levels were obtained with a commercially available earplug fit-test system, and the comfort ratings were obtained by questionnaire. The primary research objective was to determine whether hearing protector comfort was related to measured attenuation values. A linear mixed effects model provided evidence for an inverse relationship between comfort and attenuation. |
Hearing loss prevention for carpenters: part 2 - demonstration projects using individualized and group training
Stephenson MR , Shaw PB , Stephenson CM , Graydon PS . Noise Health 2011 13 (51) 122-31 Two demonstration projects were conducted to evaluate the effectiveness of a comprehensive training program for carpenters. This training was paired with audiometry and counseling and a survey of attitudes and beliefs in hearing loss prevention. All participants received hearing tests, multimedia instruction on occupational noise exposure/hearing loss, and instruction and practice in using a diverse selection of hearing protection devices (HPDs). A total of 103 apprentice carpenters participated in the Year 1 training, were given a large supply of these HPDs, and instructions on how to get additional free supplies if they ran out during the 1-year interval between initial and follow-up training. Forty-two participants responded to the survey a second time a year later and completed the Year 2 training. Significant test-retest differences were found between the pre-training and the post-training survey scores. Both forms of instruction (individual versus group) produced equivalent outcomes. The results indicated that training was able to bring all apprentice participants up to the same desired level with regard to attitudes, beliefs, and behavioral intentions to use hearing protection properly. It was concluded that the health communication models used to develop the educational and training materials for this effort were extremely effective. |
Heat and humidity buildup under earmuff-type hearing protectors
Davis RR , Shaw PB . Noise Health 2011 13 (51) 93-8 A major barrier to effective wear of hearing protection is comfort. This study examined several comfort indicators in the earmuff-type hearing protectors. Twenty subjects wore hearing protectors instrumented with two different temperature/humidity measurement systems (Omega and iButton) while walking a corridor for about 25 min. The instruments recorded the temperature and humidity every 10 s and their results were compared. In addition, skin surface pH was measured at the ear canal entrance before and after the task. Finally, the subject indicated earmuff comfort at the beginning and end of the session. Earmuff comfort decreased significantly over the course of the walking task. Ear canal pH became slightly less acidic, but the change was not statistically significant. The two temperature/humidity systems provided comparable results. Heat increased at about 0.3 degrees F while humidity built up at about 0.5%/min. However, the study found some limitations on the instrumentation. The complexity of the electrical connections and equipment in the Omega probe system led to loss of three subject's data. The iButton device was more robust, but provided only 256 gradations of temperature and relative humidity. Even with its limitations, the iButton device would be a valuable tool for field studies. The present study showed that the buildup of heat and humidity can be modeled using linear equations. The present study demonstrates that relatively inexpensive tools and a low-exertion task can provide important information about the under-earmuff environment, which can inform assumptions about comfort during use. |
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