National Institute For Occupational Safety And Health Researchers Research Articles

Fatalities in Oil and Gas Extraction Database, an Industry-Specific Worker Fatality Surveillance System - United States, 2014-2019.

The U.S. oil and gas extraction (OGE) industry faces unique safety and health hazards and historically elevated fatality rates. The lack of existing surveillance data and occupational safety and health research called for increased efforts to better understand factors contributing to worker fatalities in the OGE industry. This report describes the creation of the Fatalities in Oil and Gas Extraction (FOG) database, presents initial findings from the first 6 years of data collection (2014-2019), highlights ways that FOG data have been used, and describes the benefits and challenges of maintaining the surveillance system. 2014-2019. In 2013, the National Institute for Occupational Safety and Health (NIOSH) created the FOG database, a surveillance system comprising an industry-specific worker fatality database. NIOSH researchers worked with OGE partners to establish inclusion criteria for the database and develop unique database variables to elucidate industry-specific factors related to each fatality (e.g., phase of operation, worker activity, and working alone). FOG cases are identified through various sources, such as Occupational Safety and Health Administration (OSHA) reports, media reports, and notifications from professional contacts. NIOSH researchers compile source documents; OGE-specific database variables are coded by multiple researchers to ensure accuracy. Data collection ceased in 2019 because grant funding ended. During 2014-2019, a total of 470 OGE worker fatalities were identified in the FOG database. A majority of these fatalities (69.4%) were identified from OSHA reports and Google Alerts (44.7% and 24.7%, respectively). Unique database variables created to characterize fatalities in the OGE industry (i.e., phase of operation, worker activity, working alone, and working unobserved) were identified in approximately 85% of OGE worker fatality cases. The most frequent fatal events were vehicle incidents (26.8%), contact injuries (21.7%), and explosions (14.5%). The event type was unknown among 5.7% of worker fatalities. Approximately three fourths of fatalities identified through the FOG database were among contractors. Approximately 20% of cases included workers who were working alone. The FOG database is a resource for identifying safety and health trends and emerging issues among OGE workers (e.g., exposure to hydrocarbon gases and vapors and fatalities resulting from cardiac events) that might not be available in other surveillance systems. The FOG database also helps researchers better identify groups of workers that are at increased risk for injury in an already high-risk industry. Challenges exist when maintaining an industry-specific surveillance system, including labor-intensive data collection, the need for researchers with substantial knowledge of the industry, delays in access to timely data, and missing source file data. Continued surveillance of worker fatalities in the OGE industry is recommended to help identify new safety and health hazards and guide research and prevention activities. Industry, academic institutions, and government can use findings from the FOG database to identify factors contributing to fatal injuries in OGE and develop interventions to improve worker safety and health. The findings in this report also can be used by other industries with high fatality rates to support the development of worker fatality surveillance systems.

Moderate Cover Bleeder Entry and Standing Support Performance in a Longwall Mine: a Case Study.

Bleeder entries are critically important to longwall mining for the moving of supplies, personnel, and the dilution of mine air contaminants. By design, these entries must stay open for many years for ventilation. Standing supports in moderate cover bleeder entries were observed, numerically modeled, and instrumented by researchers at the National Institute for Occupational Safety and Health (NIOSH). The measurements of the installed borehole pressure cells (BPCs), standing support load cells and convergence meters, and roof extensometers are presented in this paper in addition to the numerical modeling results and visual observations made by the NIOSH researchers in the bleeder entries. The results include the effects of multiple panels being extracted in close proximity to the instrumented site as well as over one and a half years of aging. As expected, standing supports closer to the longwall gob showed the greatest load and convergence. The roof sag appeared generally independent of the proximity to the longwall gob. The BPC readings were driven by both the proximity to the gob and the depth into the pillar. The results of this study demonstrated that the entry roof can respond independently of the pillar and standing support loading. In addition, the rear abutment stress experienced by this bleeder entry design was minimal. The closer the mine development, pillar, or supports are to the gob, the greater the applied load due to rear abutment stress.

Coal mine entry rating system: A case study

Coal mines are continuously seeking to determine the performance of entries with different ground control products and installation methods. There are many factors that impact how an entry will perform which include but are not limited to geology, overburden, bolting type and pattern, and mine design. At the National Institute for Occupational Safety and Health (NIOSH), research has been instituted to examine the relationship of the parts of a coal mine entry as a system and not as individual components. To study this relationship, the first step in this study was to create a numeric rating system that accurately reflects visual observations of the mine entry and is easy to implement. NIOSH researchers devised this rating system to improve upon previous ideas, offering increased flexibility which can be incorporated into an overall entry condition that offers different levels of confidence based on the user’s time devoted to the inspection. This new entry rating system was implemented at three different mines over varying periods of time to evaluate the ground response to the geology, bolt installation pattern, stress changes by mining, overburden, and time dependency.

A Laboratory Investigation of Underside Shield Sprays to Improve Dust Control of Longwall Water Spray Systems

Researchers at the National Institute for Occupational Safety and Health (NIOSH) performed laboratory testing to improve longwall dust control by examining the use of underside shield sprays in conjunction with the longwall directional spray system. In a field survey of longwall operations, NIOSH researchers observed dust clouds created by the fracturing and spalling of coal immediately upwind of the headgate drum that migrated into the walkway, exposing mining personnel to respirable coal dust. The goal of this research was to create an effective traveling water curtain to prevent this dust from reaching the personnel walkway by redirecting it toward the longwall face. The location, orientation, and pressure of the water sprays were the primary testing parameters examined for minimizing dust exposure in the walkway. Laboratory testing indicates that the use of underside shield sprays on the longwall face may be beneficial toward reducing respirable dust exposure for mining personnel.

Assessing the Feasibility of a Commercially Available Wireless Internet of Things System to Improve Conveyor Safety.

Conveyor systems persist in being a source of injuries and fatalities in the mining industry. To reduce these incidents, better methods are needed to enhance the monitoring of probable hazards and improve situational awareness during the normal operation and maintenance of conveyor systems. To address these issues, researchers from the National Institute for Occupational Safety and Health (NIOSH) continue to investigate emerging technologies that show the potential to improve miner safety around conveyors. This paper presents a feasibility assessment by NIOSH researchers of a fully integrated, commercially available wireless Internet of Things (IoT) system to improve situational awareness around conveyor systems. Included are discussions of a full-scale laboratory test bed that was designed to simulate a working conveyor system as well as the challenges and successes of integrating the IoT system with the test bed.

Identify the Influence of Risk Attitude, Work Experience, and Safety Training on Hazard Recognition in Mining.

Mineworkers face a challenging and dynamic work environment every workday. To maintain a safe workplace, mineworkers must be able to recognize worksite hazards while they perform their jobs. Though hazard recognition is a critical skill, recent research from the National Institute for Occupational Safety and Health (NIOSH) indicates that mineworkers fail to identify a significant number of hazards. To further the understanding of mineworkers' hazard recognition ability and to begin to address hazard recognition performance, NIOSH researchers analyzed data collected during a laboratory research study to determine the effect of individual mineworker factors including risk attitude, work experience, and safety training on hazard recognition accuracy. The results of this study show that mineworker risk attitude and safety-specific work experience affect hazard recognition performance while hazard-specific safety training does not. These results suggest that some of these individual factors can be overcome through experience and training. Potential strategies that can be used to address these factors are also discussed.

An Improved Method to Calculate the Heat Release Rate of a Mine Fire in Underground Mines

Continuous monitoring of carbon monoxide and other fire-related parameters by means of an atmospheric monitoring system (AMS) has been used by the mining industry for early fire detection in underground mines. The National Institute for Occupational Safety and Health (NIOSH) initiated a project to integrate real-time AMS sensor data with NIOSH’s mine fire simulation program, MFIRE 3.0, to simulate and predict the spread of smoke that would provide assistance to mine fire emergency response personnel. Determining the heat release rate of a fire using the monitored sensor data was a critical component of the successful completion of this project. NIOSH researchers developed a direct method to calculate the heat release rate when a fire is within close range of sensors. However, this method is only applicable to the case where a fire occurs in AMS-monitored airways. This paper presents an improved method for determining the fire heat release rate for complicated scenarios where a fire is distant from sensors and airflow splits and merges are present. The method was validated using a full-scale diesel fuel fire test conducted in the Safety Research Coal Mine at the Pittsburgh Mining Research Division and can help mine operators and safety personnel make informed decisions during a fire emergency.

Industrial Internet of Things: (IIoT) applications in underground coal mines.

The Industrial Internet of Things (IIoT), a concept that combines sensor networks and control systems, has been employed in several industries to improve productivity and safety. U.S. National Institute for Occupational Safety and Health (NIOSH) researchers are investigating IIoT applications to identify the challenges of and potential solutions for transferring IIoT from other industries to the mining industry. Specifically, NIOSH has reviewed existing sensors and communications network systems used in U.S. underground coal mines to determine whether they are capable of supporting IIoT systems. The results show that about 40 percent of the installed post-accident communication systems as of 2014 require minimal or no modification to support IIoT applications. NIOSH researchers also developed an IIoT monitoring and control prototype system using low-cost microcontroller Wi-Fi boards to detect a door opening on a refuge alternative, activate fans located inside the Pittsburgh Experimental Mine and actuate an alarm beacon on the surface. The results of this feasibility study can be used to explore IIoT applications in underground coal mines based on existing communication and tracking infrastructure.

The development and testing of a prototype mini-baghouse to control the release of respirable crystalline silica from sand movers

ABSTRACTInhalation of respirable crystalline silica (RCS) is a significant risk to worker health during well completions operations (which include hydraulic fracturing) at conventional and unconventional oil and gas extraction sites. RCS is generated by pneumatic transfer of quartz-containing sand during hydraulic fracturing operations. National Institute for Occupational Safety and Health (NIOSH) researchers identified concentrations of RCS at hydraulic fracturing sites that exceed 10 times the Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL) and up to 50 times the NIOSH Recommended Exposure Limit (REL). NIOSH research identified at least seven point sources of dust release at contemporary oil and gas extraction sites where RCS aerosols were generated. NIOSH researchers recommend the use of engineering controls wherever they can be implemented to limit the RCS released. A control developed to address one of the largest sources of RCS aerosol generation is the NIOSH mini-baghouse assembly, mounted on the thief hatches on top of the sand mover. This article details the results of a trial of the NIOSH mini-baghouse at a sand mine in Arkansas from November 18–21, 2013. During the trial, area air samples were collected at 12 locations on and around a sand mover with and without the mini-baghouse control installed. Analytical results for respirable dust and RCS indicate the use of the mini-baghouse effectively reduced both respirable dust and RCS downwind of the thief hatches. Reduction of airborne respirable dust ranged from 85–98%; reductions in airborne RCS ranged from 79–99%. A bulk sample of dust collected by the baghouse assembly showed the likely presence of freshly fractured quartz, a particularly hazardous form of RCS. Planned future design enhancements will increase the performance and durability of the mini-baghouse, including an improved bag clamp mechanism and upgraded filter fabric with a modified air-to-cloth ratio. Future trials are planned to determine additional respirable dust and RCS concentration reductions achieved through these design changes.

A noise control package for vibrating screens.

Hearing loss was the second-most common illness reported to the Mine Safety and Health Administration (MSHA) in 2009. Furthermore, between 2000 and 2010, 30% of all noise-related injury complaints reported to MSHA were for coal preparation plant employees. Previous National Institute for Occupational Safety and Health (NIOSH) studies have shown that vibrating screens are key noise sources to address in order to reduce coal preparation plant noise. In response, NIOSH researchers have developed a suite of noise controls for vibrating screens consisting of constrained layer damping (CLD) treatments, a tuned mechanism suspension, an acoustic enclosure, and spring inserts. Laboratory testing demonstrates that this noise control suite reduces the A-weighted sound power level of the vibrating screen by 6 dB. To provide a comparison to laboratory results and prove durability, field testing of two noise controls was performed on a vibrating screen in a working coal preparation plant. The spring inserts and CLD treatments were selected due to their ease of installation and practicability. Field testing of these controls yielded reductions that were comparable to laboratory results.

Still Searching for Better Butter Flavoring

After diacetyl (2,3-butanedione) was shown to cause bronchiolitis obliterans in workers who inhaled high levels of this volatile butter flavoring at microwave popcorn processing plants,1,2,3 some manufacturers switched to a substitute assumed to be safer. Recent rodent studies, however, suggest that the substitute, 2,3-pentanedione, may be as damaging to the respiratory tract as the diacetyl it replaced.4,5 Bronchiolitis obliterans, or “popcorn lung,” is a rare, irreversible, debilitating lung disease in which inflammation and scarring obstruct the smallest airways, the bronchioles. There is no good treatment for the disease short of a lung transplant.6 Ironically, lung transplant itself can trigger bronchiolitis obliterans through organ rejection mechanisms, limiting the survival of many transplant patients.7 After the disease was identified in popcorn workers, researchers at the National Institute for Occupational Safety and Health (NIOSH) reported bronchial epithelial damage in rats inhaling vapors of butter flavoring.8 This type of injury causes fibrosis (thickening and scarring) of the bronchioles, which is the underlying cause of bronchiolitis obliterans. In 2008 some of the same NIOSH researchers narrowed their studies to diacetyl, a major component of butter flavoring vapors, and reported similar acute damage in rats.9 The same year, Daniel Morgan, head of the Respiratory Toxicology Group at the National Institute of Environmental Health Sciences, and colleagues reported that mice develop bronchial epithelial damage after inhaling diacetyl vapors at concentrations equivalent to worker exposures.6 Rats proved even more susceptible than mice and developed full-blown bronchiolitis obliterans after repeated exposure to diacetyl.4,10 Because diacetyl and 2,3-pentanedione, both diketones, are chemically very similar, Morgan suspected that inhaled 2,3-pentanedione may be toxic to the respiratory tract as well. He exposed rats to up to 200 ppm of 2,3-pentanedione for either 10 or 12 days, using the same doses and exposure times as the earlier diacetyl rat experiments. Like diacetyl, 2,3-pentanedione caused fibrosis of the small airways.4,7 Morgan’s team also reported an increase in growth factors and cytokines in the lungs, including C-reactive protein and fibroblast growth factor 9.4 In recent unpublished studies, they observed that the gene for transforming growth factor β was highly upregulated in fibrotic airways of rats exposed to 2,3-pentanedione. This potent fibrogenic agent initiates the fibrosis pathway, causing thickening of bronchial walls and airway obstruction.11 Morgan’s findings provide strong evidence that inhaled diketone vapors can produce airway fibrotic disease and support a causal relationship between workplace exposure to high concentrations of diketones and the development of bronchiolitis obliterans, according to John Morris, a professor of pharmacology and toxicology at the University of Connecticut, Storrs. “Effective control strategies must be implemented to limit worker exposure to diketone vapors,” Morris says. Engineering controls such as ventilated mixing vessels with hinged lids or access ports are the first line of protection against worker exposures to diketones in flavorings. Workers should also wear appropriate personal protective equipment. 2,3-Pentanedione and diacetyl are designated as “generally recognized as safe” by the U.S. Food and Drug Administration and other qualified experts for use in foods or food packaging. However, this designation means only that they are safe to eat and does not imply safety for other routes of exposure, such as inhalation.1 Morgan’s data may help regulatory agencies set exposure limits to protect workers. Both NIOSH and the Occupational Safety and Health Administration currently recommend occupational flavoring control measures including isolating flavor production and handling, installing engineering controls (e.g., engineering hoods and local exhaust ventilation systems), and wearing appropriate respiratory protection.1,12 Additionally, the chemically induced rodent bronchiolitis obliterans model could be used to evaluate drugs that prevent progression of the disease. Transforming growth factor β offers a good drug target to block the start of the fibrosis process. “Hopefully our work will have clinical applications,” Morgan says. Other studies indicate that 2,3-pentanedione may affect bodily systems beyond the respiratory tract. A team led by Ann Hubbs, a veterinary pathologist at NIOSH, observed not only damage to the lining of the airways but also necrosis and apoptosis in the olfactory neuroepithelium and markers of neurotoxicity in the olfactory bulb, striatum, hippocampus, and cerebellum.5 The functional importance of these changes in brain tissue will be addressed in future studies. The immediate message, Hubbs says, is that “if a chemical substitution is intended to control health effects, the substitute should be demonstrably safer than the compound it replaces.”

1.Comparison of the HPDLab and REATMaster software/hardware systems for ANSI S12.6 testing

The American National Standard Methods for Measuring the Real-Ear Attenuation of Hearing Protectors (ANSI S12.6-2008) requires a Békésy procedure for testing occluded and unoccluded thresholds. Since 2002, the National Institute for Occupational Safety and Health (NIOSH) has used the custom-designed HPDLab software operating Tucker-Davis Technologies System 3 hardware. ViAcoustics, Nelson Acoustics, NASA, and NIOSH researchers recently developed REATMaster which runs on National Instruments hardware in the LabVIEW environment. Ten subjects were trained by the experimenter on how to fit a passive earmuff and were qualified according to the requirements of ANSI S12.6-2008. The laboratory was configured such that diffuse sound field thresholds were tested with either the HPDLab or REATmaster hardware by flipping a toggle switch. The earmuff was not touched or re-positioned between test trials with the two different hardware/software systems. The test sequence for the order of open and occluded measurements was counterbalanced across occluded conditions and hardware system. Results from this testing were used to validate the REATMaster system for its ability to produce accurate threshold data. Preliminary results indicate no significant differences between the two systems.

Use of Direct Reading Surface Sampling Methods for Site Characterization and Remediation of Methamphetamine Contaminated Properties

Abstract Residual methamphetamine contamination in Clandestine laboratories represents a hazard to emergency response personnel, remediation workers and the general public. To address this threat, two rapid, sensitive surface sampling techniques to assess the location and level of methamphetamine contamination were developed. Both methods employ established industrial hygiene surface sampling materials (wipes and swabs) but differ in their sensitivity and detection technology. One method, based on colorimetric disclosure, detects and confirms a collected sample or visible residues. The second method uses a lateral flow immunochemical assay (LFIA) for semi-quantitative detection of trace contamination. The National Institute for Occupational Safety and Health (NIOSH) partnered with public health agencies to develop applications of the methods for assessment of methamphetamine contamination of suspected properties. These applications focused on safe strategies for site assessment, hazard characterization, and remediation effectiveness. To conduct the field studies, NIOSH researchers and their partners visited more than a dozen suspected laboratories including mobile labs, abandoned properties, occupied residences, and motel rooms. NIOSH found greater than 95% agreement between positive identification of the presence of methamphetamine by LFIA and laboratory-based, liquid chromatography mass spectroscopy (LC–MS) methods. Test results were used to develop site assessments and make personal protective equipment recommendations. Results were also used to conduct process-based decontamination of properties and to make health-based decisions on remediation, re-occupancy of residences, as well as determine the degree of contamination of personal property in an inactive clandestine laboratory. By partnering with stakeholders, NIOSH was able to achieve two primary goals: (1) to develop a level of awareness in health department sanitarians, law enforcement personnel and other first responders that methamphetamine surface contamination was a potentially significant route of exposure; (2) to validate our methods in the field and to develop protocols for proper use and interpretation of the results.

Occupational Exposures to Styrene Vapor in a Manufacturing Plant for Fiber-Reinforced Composite Wind Turbine Blades

A utility-scale wind turbine blade manufacturing plant requested assistance from the National Institute for Occupational Safety and Health (NIOSH) in controlling worker exposures to styrene at a plant that produced 37 and 42 m long fiber-reinforced wind turbine blades. The plant requested NIOSH assistance because previous air sampling conducted by the company indicated concerns about peak styrene concentrations when workers entered the confined space inside of the wind turbine blade. NIOSH researchers conducted two site visits and collected personal breathing zone and area air samples while workers performed the wind turbine blade manufacturing tasks of vacuum-assisted resin transfer molding (VARTM), gelcoating, glue wiping, and installing the safety platform. All samples were collected during the course of normal employee work activities and analyzed for styrene using NIOSH Method 1501. All sampling was task based since full-shift sampling from a prior Occupational Safety and Health Administration (OSHA) compliance inspection did not show any exposures to styrene above the OSHA permissible exposure limit. During the initial NIOSH site visit, 67 personal breathing zone and 18 area air samples were collected while workers performed tasks of VARTM, gelcoating, glue wipe, and installation of a safety platform. After the initial site visit, the company made changes to the glue wipe task that eliminated the need for workers to enter the confined space inside of the wind turbine blade. During the follow-up site visit, 12 personal breathing zone and 8 area air samples were collected from workers performing the modified glue wipe task. During the initial site visit, the geometric means of the personal breathing zone styrene air samples were 1.8 p.p.m. (n = 21) for workers performing the VARTM task, 68 p.p.m. (n = 5) for workers installing a safety platform, and 340 p.p.m. (n = 14) for workers performing the glue wipe task, where n is the number of workers sampled for a given mean result. Gelcoating workers included job categories of millers, gelcoat machine operators, and gelcoaters. Geometric mean personal breathing zone styrene air samples were 150 p.p.m. (n = 6) for millers, 87 p.p.m. (n = 2) for the gelcoat machine operators, and 66 p.p.m. (n = 19) for gelcoaters. The geometric mean of the personal breathing zone styrene air samples from the glue wipe task measured during the follow-up site visit was 31 p.p.m. (n = 12). The closed molding VARTM process was very effective at controlling worker exposures to styrene. Personal breathing zone styrene air samples were reduced by an order of magnitude after changes were made to the glue wipe task. The company used chemical substitution to eliminate styrene exposure during the installation of the safety platform. Recommendations were provided to reduce styrene concentrations during gelcoating.

Analysis of a mechanism suspension to reduce noise from horizontal vibrating screens

A-weighted sound levels around vibrating screens in coal preparation plants often exceed 90 dB. The National Institute for Occupational Safety and Health (NIOSH) is developing noise controls to reduce noise generated by horizontal vibrating screens. Horizontal vibrating screen noise is dominated by sound radiated from the screen body. NIOSH researchers analyzed a mechanism suspension system that could reduce screen body-radiated noise. A finite element (FE) model of the entire screen was used to analyze the screen with the added mechanism suspension. The spring rates for the mechanism suspension were tuned to transmit vibration at the mechanism operating speed while attenuating vibration transmitted from the mechanisms to the screen body at frequencies above 100 Hz. The FE results were used to estimate the A-weighted sound power level radiated by the screen sides and feedbox for various mechanism suspension spring rates. The results indicate that a tuned mechanism suspension could reduce the A-weighted sound power level radiated by the screen body due to gear and bearing forces inside the mechanisms by 7 to 18 dB

Correlation Between Respirator Fit and Respirator Fit Test Panel Cells by Respirator Size

The National Institute for Occupational Safety and Health (NIOSH), recognizing the difficulties inherent in using old military data to define modern industrial respirator fit test panels, recently completed a study to develop an anthropometric database of the measurements of heads and faces of civilian respirator users. Based on the data collected, NIOSH researchers developed two new panels for fit testing half-facepiece and full-facepiece respirators. One of the new panels (NIOSH bivariate panel) uses face length and face width. The other panel is based on principal component analysis (PCA) to identify the linear combination of facial dimensions that best explains facial variations. The objective of this study was to investigate the correlation between respirator fit and the new NIOSH respirator fit test panel cells for various respirator sizes. This study was carried out on 30 subjects that were selected in part using the new NIOSH bivariate panel. Fit tests were conducted on the test subjects using a PORTACOUNT device and three exercises. Each subject was tested with three replications of four models of P-100 half-facepiece respirators in three sizes. This study found that respirator size significantly influenced fit within a given panel cell. Face size categories also matched the respirator sizing reasonably well, in that the small, medium, and large face size categories achieved the highest geometric mean fit factors in the small, medium, and large respirator sizes, respectively. The same pattern holds for fit test passing rate. Therefore, a correlation was found between respirator fit and the new NIOSH bivariate fit test panel cells for various respirator sizes. Face sizes classified by the PCA panel also followed a similar pattern with respirator fit although not quite as consistently. For the LANL panel, however, both small and medium faces achieved best fit in small size respirators, and large faces achieved best fit in medium respirators. These findings support the selection of the facial dimensions for developing the new NIOSH bivariate respirator fit test panel.

Hexavalent Chromium Exposures and Exposure-Control Technologies in American Enterprise: Results of a NIOSH Field Research Study

The National Institute for Occupational Safety and Health (NIOSH) conducted 21 field surveys in selected industries to characterize workers' exposures to hexavalent chromium-containing airborne particulate and to evaluate existing technologies for controlling these exposures. Hexavalent chromium Cr(VI) is a respiratory irritant and chronic inhalation may cause lung cancer. Primary evaluation methods included collection of full work shift, personal breathing-zone (PBZ) air samples for Cr(VI), measurement of ventilation system parameters, and documentation of processes and work practices. This study emphasized evaluation of engineering exposure control measures, so PBZ exposures were measured on the outside of personal protective equipment, for example, respirators. Field surveys were conducted in two chromium electroplating facilities, including one where full-shift PBZ exposures to Cr(VI) ranged from 3.0 to 16 times the 1 μ g/m 3 NIOSH recommended exposure limit (REL) despite several engineering controls on the plating tanks. At a painting and coating facility that used Cr(VI)-containing products, full-shift exposures of painters and helpers (2.4 to 55 μ g/m 3 ) exceeded the REL, but LEV effectiveness was limited. Other operations evaluated included welding in construction; metal cutting operations on chromium-containing materials in ship breaking; chromate-paint removal with abrasive blasting; atomized alloy-spray coating; foundry operations; printing; and the manufacture of refractory brick, colored glass, prefabricated concrete products, and treated wood products. NIOSH researchers concluded that, in many of the evaluated processes, Cr(VI) exposures at or below the current NIOSH REL are achievable. However, for some processes, it is unclear whether controlling exposures to this range is consistently achievable without respirator use. Some operations involving the application of coatings and finishes may be among those most difficult to control to this range. Most operations judged to be moderately difficult to control to this range involve joining and cutting metals with relatively high chromium content. Nonetheless, exposures in a wide variety of other processes were judged more easily controllable to the current REL or below, or were found to be minimal, including some operations meeting the general descriptions named above but with different specific operating parameters producing lower Cr(VI) exposures.

NIOSH Research Efforts to Prevent Musculoskeletal Disorders in the Healthcare Industry

Healthcare workers, including orthopaedic nurses, face a number of risk factors in the workplace for musculoskeletal disorders such as back and shoulder injuries. These disorders are associated with excessive back and shoulder loading due to manual patient handling, applying excessive forces during pushing and/or pulling of objects, required use of awkward postures during patient care, and working long hours and shiftwork. No healthcare workers are immune from injury because workers in all clinical areas are exposed to occupational risk factors, including hospitals, nursing homes, emergency services, critical care, operating rooms, orthopaedic units, and home healthcare environments. This article includes a summary of the scientific efforts of the researchers and their partners at the National Institute for Occupational Safety and Health (NIOSH) in evaluating and developing the best practice recommendations for reducing risk of these disorders for exposed workers. The studies conducted by NIOSH researchers and their partners approach the problem from a variety of perspectives, ranging from comprehensive epidemiological studies examining the effectiveness of implementation of a safe patient handling and movement program to laboratory studies evaluating the biomechanical stress associated with using patient handling equipment, and education training programs for use in schools of nursing to educate new workers about safe work practices. Results of these studies have provided scientific evidence that significant occupational risks for musculoskeletal disorders exist and that effective interventions are available to reduce the risk for these workers.

Occupational Exposure Visualization Comes of Age

It has been 20 years since video exposure monitoring (VEM) was embraced as an instrument to provide better documentation of at-risk workers both in Europe and in the United States. Although the first VEM efforts started independently, the passion for this new technology and what it can do to improve the occupational environment has been advanced by a small but growing team of researchers on both sides of the Atlantic. As technology advances over the next ten years, VEM is set to become one of the major instruments in the arsenal of occupational exposure assessment and control. The technical aspects and uses of VEM are reviewed in this issue by some of the key players in these developments (Rosen et al., 2005). In the 1980s a small group of researchers from the engineering control technology branch of the National Institute for Occupational Safety and Health (NIOSH) were working on developing controls to reduce worker exposure to airborne chemicals during batch processing at a manufacturing plant in the Midwest. The research team consisted of a chemical engineer and two occupational hygienists, one specializing in the use of real-time instruments and the other in ergonomics. The diverse talents and skill sets of this team formed a synergy that took advantage of emerging technologies in the portable computer, video and realtime sensor markets (McGlothlin et al., 1987; 1996). The result of the application of this new technology, VEM in the United States was very promising. For the first time, researchers could discern exposure sources and the interaction between work practices and engineering controls such as local exhaust ventilation. Pinpointing exposure sources led to cost effective controls and the development of an effective feedback mechanism for showing workers and management where they had exposures and where they could be controlled. Overlaying videography with the real-time particulate sensors proved very effective. At the same time, unknown to the NIOSH researchers, a like-minded group of researchers at the National Board of Occupational Safety and Health in Sweden (now called the National Institute for Working Life) were considering ways to engage exposed workers in environmental control processes (Rosen and Lundstrom, 1987). The goal of this group was to develop methods for workers to see with their own eyes the potential hazards (in real-time) to which they were being exposed. Computer and video technology were getting less expensive and more portable, and real-time instruments (in the United States the instrument was the handheld aerosol monitor or HAM) were being used for particulate monitoring. By visualizing the work being done and combining it with real-time monitoring, occupational hygienists had a formula for success. They could provide a convenient means of feedback for workers and management and they had a new weapon to ‘see’ exposure sources and targeting controls. As the benefits of this new occupational exposure assessment method became obvious, other NIOSH researchers applied this method to their projects, resulting in a popular NIOSH government publication titled ‘Analyzing workplace exposure using direct reading instruments and video exposure monitoring techniques’, (CDC/NIOSH, 1992). Researchers for the National Institute for Working Life in Sweden identified two methodologies to evaluate worker exposure to air contaminants, one of which was commercialized (Walsh, 2002). From 1980 through the 1990s NIOSH researchers explored different ways to use this technology. They concluded that while the technology was unique, it would primarily be used to *Tel: +1 765 469 6359; fax: +1 765 496 1377; e-mail: jdm3@purdue.edu

Remote control of an agricultural tractor in SAE field upset tests

Research by the National Institute for Occupational Safety and Health (NIOSH), Division of Safety Research in Morgantown, West Virginia is addressing the problem of injuries due to agricultural tractor rollovers, and improvements to rollover protective structures (ROPS). As part of this research, the NIOSH, Pittsburgh Research Laboratory modified a Ford model 4600 agricultural tractor for remote control operation, and used this tractor to conduct SAE field upset tests. Modifications to the tractor involved installing a protective framework, electrical actuators for fuel, brake, clutch, and steering controls, and a radio link for remote operation. The tractor has been used to complete over 30 total side and back upset tests, with no failures of the remote control system. These tests have allowed NIOSH researchers to study the performance of currently available ROPS, use this information for the development of improved ROPS designs, and test a NIOSH-developed prototype automatically deploying ROPS.