Last data update: Sep 23, 2024. (Total: 47723 publications since 2009)
Records 1-30 (of 113 Records) |
Query Trace: Miner C [original query] |
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Size Separation of Amosite by Filtration and Shaking Methods
Lee T , Walker R , Hummer J , Ashley E , Mischler S . Asbestos Other Elongate Miner Part (2021) 12/28/2021 1632 265-280 The objectives of this study are (1) to separate fibrous grunerite (amosite) by its length using filtration and shaking techniques utilized in a previous study and (2) to create two distinct length groups (short and long) of the amosite with higher output in a cost-effective way. The shaking system included an electrodynamic exciter, a linear power amplifier, and an audio-frequency signal generator and was attached to a cowl sampler as a funnel loaded with a polycarbonate filter. A suspension of amosite was passed through the 10-μm pore size polycarbonate filter in the shaking system and was transferred to a filtration system through five different pore sizes of polycarbonate membrane filters in series from the top: 10-, 5-, 2-, 1-, and 0.2-μm pore sizes. Each polycarbonate filter was tightly clamped with two conductive 25-mm spacers with a 25-mm stainless steel support screen to prevent leakage. The amosite length and diameter were manually measured with images from a field emission scanning electron microscope (FESEM). A sequence of fields was selected at random locations, and an image of each field was acquired. The length and width of approximately 500 fibers for each sample were measured with ImageJ software. Two significantly different length groups (short and long) of amosite were collected (p <0.05). Approximately 95% of separated amosite (n = 499) using the filtration system were shorter than 5 μm (short fiber group), and approximately 80% of separated amosite (n = 503) using the shaking system were longer than 5 μm (long fiber group). |
Lifetime excess absolute risk for lung cancer due to exposure to radon: results of the pooled uranium miners cohort study PUMA
Kreuzer M , Sommer M , Deffner V , Bertke S , Demers PA , Kelly-Reif K , Laurier D , Rage E , Richardson DB , Samet JM , Schubauer-Berigan MK , Tomasek L , Wiggins C , Zablotska LB , Fenske N . Radiat Environ Biophys 2024 The Pooled Uranium Miners Analysis (PUMA) study is the largest uranium miners cohort with 119,709 miners, 4.3 million person-years at risk and 7754 lung cancer deaths. Excess relative rate (ERR) estimates for lung cancer mortality per unit of cumulative exposure to radon progeny in working level months (WLM) based on the PUMA study have been reported. The ERR/WLM was modified by attained age, time since exposure or age at exposure, and exposure rate. This pattern was found for the full PUMA cohort and the 1960 + sub-cohort, i.e., miners hired in 1960 or later with chronic low radon exposures and exposure rates. The aim of the present paper is to calculate the lifetime excess absolute risk (LEAR) of lung cancer mortality per WLM using the PUMA risk models, as well as risk models derived in previously published smaller uranium miner studies, some of which are included in PUMA. The same methods were applied for all risk models, i.e., relative risk projection up to <95 years of age, an exposure scenario of 2 WLM per year from age 18-64 years, and baseline mortality rates representing a mixed Euro-American-Asian population. Depending upon the choice of model, the estimated LEAR per WLM are 5.38 × 10(-4) or 5.57 × 10(-4) in the full PUMA cohort and 7.50 × 10(-4) or 7.66 × 10(-4) in the PUMA 1960 + sub-cohort, respectively. The LEAR per WLM estimates derived from risk models reported for previously published uranium miners studies range from 2.5 × 10(-4) to 9.2 × 10(-4). PUMA strengthens knowledge on the radon-related lung cancer LEAR, a useful way to translate models for policy purposes. |
Decolonization in nursing homes to prevent infection and hospitalization
Miller LG , McKinnell JA , Singh RD , Gussin GM , Kleinman K , Saavedra R , Mendez J , Catuna TD , Felix J , Chang J , Heim L , Franco R , Tjoa T , Stone ND , Steinberg K , Beecham N , Montgomery J , Walters D , Park S , Tam S , Gohil SK , Robinson PA , Estevez M , Lewis B , Shimabukuro JA , Tchakalian G , Miner A , Torres C , Evans KD , Bittencourt CE , He J , Lee E , Nedelcu C , Lu J , Agrawal S , Sturdevant SG , Peterson E , Huang SS . N Engl J Med 2023 389 (19) 1766-1777 BACKGROUND: Nursing home residents are at high risk for infection, hospitalization, and colonization with multidrug-resistant organisms. METHODS: We performed a cluster-randomized trial of universal decolonization as compared with routine-care bathing in nursing homes. The trial included an 18-month baseline period and an 18-month intervention period. Decolonization entailed the use of chlorhexidine for all routine bathing and showering and administration of nasal povidone-iodine twice daily for the first 5 days after admission and then twice daily for 5 days every other week. The primary outcome was transfer to a hospital due to infection. The secondary outcome was transfer to a hospital for any reason. An intention-to-treat (as-assigned) difference-in-differences analysis was performed for each outcome with the use of generalized linear mixed models to compare the intervention period with the baseline period across trial groups. RESULTS: Data were obtained from 28 nursing homes with a total of 28,956 residents. Among the transfers to a hospital in the routine-care group, 62.2% (the mean across facilities) were due to infection during the baseline period and 62.6% were due to infection during the intervention period (risk ratio, 1.00; 95% confidence interval [CI], 0.96 to 1.04). The corresponding values in the decolonization group were 62.9% and 52.2% (risk ratio, 0.83; 95% CI, 0.79 to 0.88), for a difference in risk ratio, as compared with routine care, of 16.6% (95% CI, 11.0 to 21.8; P<0.001). Among the discharges from the nursing home in the routine-care group, transfer to a hospital for any reason accounted for 36.6% during the baseline period and for 39.2% during the intervention period (risk ratio, 1.08; 95% CI, 1.04 to 1.12). The corresponding values in the decolonization group were 35.5% and 32.4% (risk ratio, 0.92; 95% CI, 0.88 to 0.96), for a difference in risk ratio, as compared with routine care, of 14.6% (95% CI, 9.7 to 19.2). The number needed to treat was 9.7 to prevent one infection-related hospitalization and 8.9 to prevent one hospitalization for any reason. CONCLUSIONS: In nursing homes, universal decolonization with chlorhexidine and nasal iodophor led to a significantly lower risk of transfer to a hospital due to infection than routine care. (Funded by the Agency for Healthcare Research and Quality; Protect ClinicalTrials.gov number, NCT03118232.). |
Evaluation of seismic potential in a longwall mine with massive sandstone roof under deep overburden: An update
Van Dyke M , Klemetti T , Khademian Z , Wickline J , Beale J . Min Metall Explor 2023 In 2016, a 3.7-ML magnitude event caused by mining activity occurred at a longwall mine in southwestern Virginia which was recorded by the United States Geological Survey (USGS) and felt by local residents. The event was the largest of its kind since a global mine design change by the operator was instituted in 2008 following three large events in 2005, 2006, and 2007 (3.4, 4.3, and 3.4 Moment Magnitude (Mw), respectively). Two of the three pre-2008 events (2005 and 2007) damaged ventilation controls in the mine which fueled a mine fire. In 2016, the mine’s management requested researchers from the National Institute for Occupational Safety and Health (NIOSH) to access geological data and determine what parameters could possibly lead to events of a magnitude of 1.0 ML or greater. Evaluation of 2152 geological data points and modeling revealed three major geological factors in common with the majority of the 181 recorded +1.0 ML events from 2009 through 2016. Three levels of seismic potential were identified as follows: Low potential (1.0+ ML): overburden greater than 579 mModerate potential (1.5+ ML): overburden greater than 579.12 m and 6.1–12.2 m of sandstone within 15.24 m above the top of the Pocahontas 3 coal seamElevated potential (3.0+ ML): overburden greater than 579.12 m, 6.1–12.2 m of sandstone within 15.24 m above the coal seam, and caving height of less than 4.5 m above the coal seam These three factors were used to create a seismic forecast map that produced an accuracy of 74–89% for 1.0 ML or greater events, 72% accuracy for 1.5 ML or greater events, and 100% accuracy for 3.0ML or greater events based on seismic history [1]. The map was created to not only show how geological data can be combined to understand why a mining-related seismic event occurred in a particular area, but how the map could be used to forecast potential seismic areas in future mining. This paper is an update to report the accuracy forecasting large seismic events in areas mined since the map was originally published in 2017 and how the map has helped improve miner safety and health based on its implementation. New changes to the forecasting process include implementing a change to the moderate potential criteria to expand the sandstone thickness to 4.6–12.2 m and decreasing the location error from a 91-m buffer to a 10% (58 m) elevation error based on the first overburden thickness threshold of 579 m. Since the first seismic forecasting map was published, the map has correctly forecasted 54–71% of 115 total 1.0–1.4 ML events, 69–83% of 49 total 1.5–1.9 ML events, and 88% of 9 total 2.0 ML or above events in previously unmined areas. © 2023, This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply. |
Smart monitoring and control system test apparatus
Raj KV , Jacksha RD , Sunderman CB , Pritchard CJ . Trans Soc Min Metall Explor Inc 2018 344 (1) 62-66 In underground metal/nonmetal mines, repeated localized short-term exposure to high levels of airborne contaminants can become a serious health issue. Currently, there are no common mechanisms to control or mitigate these short-term high exposures to contaminants. To improve miners' health and safety, the U.S. National Institute for Occupational Safety and Health's Spokane Mining Research Division (SMRD) is developing a smart monitoring and control (SMAC) system for the real-time monitoring of mine air quality, with integrated countermeasures to reduce high concentrations of airborne contaminants in localized sections of mines. To develop and test a SMAC system capable of being implemented in an underground mine, SMRD researchers built a test apparatus incorporating a fan, louver, ducting and sensors combined with atmospheric monitoring and control software. This system will institute effective countermeasures to reduce contaminant levels, improving miner safety and health. |
Cognitive Task Analysis of Miner Preparedness to Self-Escape from Mine Emergencies
Keeney MJ , Wiggins S , Reynolds KD , Berger JL , Hoebbel CL . J Organ Psychol 2018 18 (4) 57-78 In 2013, the National Research Council (NRC) issued the consensus study report, Improving Self-Escape from Underground Coal Mines (National Research Council, 2013; available at https://www.nap.edu/download/18300). The NRC report (p. 2) defined self-escape in the event of a mine emergency as “the ability of an individual or group of miners to remove themselves from the mine using available resources,” and called for detailed task analysis of self-escape to describe self-escape behaviors and required capabilities, knowledge, and skills. | | In response to this report’s recommendation, the Centers for Disease Control (CDC) and The National Institute for Occupational Safety and Health (NIOSH) funded work to accomplish a detailed task analysis. The scope of this project was bounded between (a) miners making the decision on their own or based on notification by coworkers or mine management of the need to evacuate due to a hazardous situation, and (b) completed self-escape at exit from the underground mine. The goals of this effort were two-fold: (1) to produce a set of specific recommendations to facilitate self-escape that would reduce task demands to operate within individual cognitive capabilities; (2) to facilitate and optimize human performance in meeting task demands, and increase the likelihood of success through eliminating tasks, redesigning tasks to reduce differences between task demands and individual capability, or improving human performance through better training and/or assistive tools and technology. |
Low participation in a job transfer program designed to prevent progression of pneumoconiosis
Laney AS , Hall NB , Reynolds L , Blackley DJ , Weissman DN . Ann Am Thorac Soc 2023 20 (8) 1223-1224 The Coal Mine Health and Safety Act of 1969 and after it the Federal Mine Safety and Health | Act of 1977 provided periodic chest radiographs to underground coal miners at no cost to | themselves.[1] Since the National Institute for Occupational Safety and Health (NIOSH) was | established in 1971, it has administered this health surveillance through the Coal Workers’ | Health Surveillance Program (CWHSP). If a miner has radiographic evidence of pneumoconiosis, | an interstitial lung disease commonly known as black lung, they are afforded the legal right, | authorized under 30 Code of Federal Regulations Part 90, to work under a reduced dust | exposure standard through the use of engineering controls or job reassignment to a less dusty | working environment. After a miner receives confidential notification by NIOSH that they have | radiographic findings consistent with pneumoconiosis and are eligible for Part 90 | accommodations, they can exercise this option by informing the Mine Safety and Health | Administration (MSHA). Participation of eligible underground coal miners in exercising their | Part 90 rights has historically been low; during the period 1970–1989, participation was 23.2% | (2119/9138),[2] during the period 1986–2016 participation was 14.4% (509/3547),[3, 4] and in | the most recent time period, 2016–2022, participation among underground coal miners was | 22.5% (55/244). | MSHA administers and enforces Part 90 provisions and in 2014 published a final rul |
Increased odds of mortality from non-malignant respiratory disease and lung cancer are highest among US coal miners born after 1939
Almberg KS , Halldin CN , Friedman LS , Go LHT , Rose CS , Hall NB , Cohen RA . Occup Environ Med 2023 80 (3) 121-128 OBJECTIVES: Coal miners suffer increased mortality from non-malignant respiratory diseases (NMRD), including pneumoconioses and chronic obstructive pulmonary disease, compared with the US population. We characterised mortality trends from NMRD, lung cancer and ischaemic heart disease (IHD) using data from the Federal Black Lung Program, National Coal Workers' Health Surveillance Program and the National Death Index. METHODS: We compared mortality ORs (MORs) for NMRD, lung cancer and IHD in former US coal miners to US white males. MORs were computed for the study period 1979-2017 by birth cohort (<1920, 1920-1929, 1930-1939, ≥1940), with a subanalysis restricted to Central Appalachia. RESULTS: The study population totalled 235 550 deceased miners, aged >45 years. Odds of death from NMRD and lung cancer across all miner birth cohorts averaged twice those of US males. In Central Appalachia, MORs significantly increased across birth cohorts. There was an eightfold increase in odds of death from NMRD among miners born after 1940 (MOR(BC≥1940) 8.25; 95% CI 7.67 to 8.87). Miners with progressive massive fibrosis (PMF) were younger at death than those without PMF (74 vs 78 years; p<0.0001). We observed a pattern of reduced MORs from IHD in coal miners compared with national and regional counterparts. CONCLUSION: US coal miners have excess mortality from NMRD and lung cancer compared with total US and Appalachian populations. Mortality is highest in the most recent birth cohorts, perhaps reflecting increased rates of severe pneumoconiosis. |
Postexposure progression of pneumoconiosis among former Appalachian coal miners
Hall NB , Blackley DJ , Markle T , Crum JB , Halldin CN , Laney AS . Am J Ind Med 2022 65 (12) 953-958 BACKGROUND: The prevalence of pneumoconiosis among working United States underground coal miners has been increasing for the past two decades, with the highest rates of disease observed among miners in the central Appalachian states of Kentucky, Virginia, and West Virginia. Surveillance for this disease in the United States focuses on working coal miners, who continue to be occupationally exposed to dust. This study examines the radiographic evidence for postexposure progression of pneumoconiosis in a population of former coal miners no longer occupationally exposed to coal mine dust who were seen at a community radiology clinic in eastern Kentucky. METHODS: Data were obtained and analyzed from clinical records of former coal miners who had a clinic encounter during January 1, 2017-August 1, 2019, a recorded final year of employment, and ≥2 postemployment digital chest radiographs. Radiographs were classified according to the International Labour Office guidelines by at least two B Readers. A final summary pneumoconiosis severity score (range, 0-13), accounting for both small and large opacities, was assigned to each chest radiograph. Progression was defined as an increase in severity score between a miner's radiographs over time. RESULTS: Data for 130 former coal miners were analyzed. All miners were male and most (n = 114, 88%) had worked primarily in Kentucky. Information on race/ethnicity was not available. The most common job types were roof bolters (n = 51, 39%) and continuous miner operators (n = 46, 35%). Forty-one (31.5%) miners had evidence of radiographic disease progression after leaving the workforce, with a median of 3.6 years between first and latest postretirement radiograph. A total of 80 (62%) miners had evidence of pneumoconiosis on their latest radiograph, and two-thirds (n = 53) of these were classified as progressive massive fibrosis (PMF), the most severe form of the disease. CONCLUSIONS: Postexposure progression can occur in former coal miners, emphasizing the potential benefits of continued radiographic follow-up postemployment. In addition to participating in disease screening throughout their careers to detect pneumoconiosis early and facilitate intervention, radiographic follow-up of former coal miners can identify new or progressive radiographic findings even after workplace exposure to respirable coal mine dust ends. Identification of progressive pneumoconiosis in former miners has potential implications for clinical management and eligibility for disability compensation. |
The epidemiology of lung cancer following radiation exposure
Zablotska LB , Richardson DB , Golden A , Pasqual E , Smith B , Rage E , Demers PA , Do M , Fenske N , Deffner V , Kreuzer M , Samet J , Bertke S , Kelly-Reif K , Schubauer-Berigan MK , Tomasek L , Wiggins C , Laurier D , Apostoaei I , Thomas BA , Simon SL , Hoffman FO , Boice JDJr , Dauer LT , Howard SC , Cohen SS , Mumma MT , Ellis ED , Eckerman KF , Leggett RW , Pawel DJ . Int J Radiat Biol 2022 99 (3) 1-12 Epidemiological studies of occupational, medical, and environmental exposures have provided important information on lung cancer risk and how those risks might depend on the type of exposure, dose rate, and other potential modifying factors such as sex and age of the exposed. Analyses of data from underground miner cohorts and residential case-control studies provide convincing evidence that radon is a leading cause of lung cancer. For low-LET radiation, risk models derived from results from the Lifespan Study of Japanese atomic bomb survivors suggest that for acute exposures, lifetime attributable risks for lung cancer are greater than for other specific cancer sites and are substantially larger for females than males. However, for protracted and fractionated exposures other than from radon, results from epidemiological studies are seemingly often contradictory. |
Topical Collection: Advancements in hydrogeological knowledge of Haiti for recovery and development
Adamson JK , Gutierrez A , Perez-Monforte S , Rodriquez-Vera M , LaVanchy GT , Jean-Baptiste G , Emmanuel E , Moliere E , Gelting R , Miner WJ , Dykstra S . Hydrogeol J 2022 30 (5) 1345-1348 Haiti’s groundwater resources are poorly understood and scarcely researched, despite their importance as the principal source for water supply. The knowledge gap and its role of inhibiting informed relief, recovery and investments in development are described, along with an update on progress towards the UN Sustainable Development Goals. This essay leads a topical collection of seven articles that advance hydrogeological knowledge of Haiti. Additional data, research and monitoring are identified as urgently needed for the nation’s sustainable development. © 2022, The Author(s). |
Health burdens of uranium miners will extend beyond the radiation exposure compensation act deadline
Kelly-Reif K , Bertke SJ , Samet J , Sood A , Schubauer-Berigan MK . Occup Environ Med 2022 79 (7) 503-4 The US Radiation Exposure Compensation Act (RECA) is a government compensation programme, which provides partial restitution to individuals whose health was affected by nuclear weapons testing or uranium industry employment. RECA covers US uranium miners employed between 1942 and 1971 who developed or died from lung cancer, pulmonary fibrosis, silicosis, pneumoconiosis or cor pulmonale related to lung fibrosis. RECA is set to terminate this year. The filing deadline for living claimants or spouses of deceased claimants is 10 July 2022.1 To assess evidence of whether uranium miners will continue to develop compensable diseases after the termination of RECA, we examined mortality rate trends within the US Colorado Plateau uranium miner cohort. |
Diesel aerosols in an underground coal mine
Bugarski AD , Vanderslice S , Hummer JA , Barone T , Mischler SE , Peters S , Cochrane S , Winkler J . Min Metall Explor 2022 39 (3) 937-945 The case study was conducted in an underground coal mine to characterize submicron aerosols at a continuous miner (CM) section, assess the concentrations of diesel aerosols at the longwall (LW) section, and assess the exposures of selected occupations to elemental carbon (EC) and total carbon (TC). The results show that aerosols at the CM sections were a mixture of aerosols freshly generated at the outby portion of the CM section and those generated in the main drifts that supply fresh air to the section. The relatively low ambient concentrations and personal exposures of selected occupations suggest that currently applied control strategies and technologies are relatively effective in curtailing exposures to diesel aerosols. Further reductions in EC and TC concentrations and personal exposures to those would be possible by more effective curtailment of emissions from high-emitting light duty (LD) vehicles. 2022, This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply. |
Effectiveness of the CPDM in reducing overexposures to coal mine dust
Colinet JF , Mischler SE . Min Metall Explor 2022 39 (2) 283-290 The Mine Safety and Health Administration (MSHA) promulgated a rule in 2014 that required numerous changes in compliance dust sampling requirements for coal mine operators. Two key parts of this rule were the lowering of the respirable coal mine dust standard from 2.0 mg/m3 to 1.5 mg/m3 and requiring operators of underground coal mines to use a continuous personal dust monitor (CPDM) for compliance sampling. The CPDM currently approved for compliance sampling is equipped with a display that provides miners with in-shift information on their respirable dust exposure. The goal is to provide an indication of a potential overexposure and empower the miner and mine operator to implement changes in controls and/or operating practices to prevent an overexposure from occurring. Compliance sampling data for four occupations that have historically had elevated dust exposures were downloaded from the MSHA website and analyzed to assess the impact of the CPDM on overexposures. These occupations include continuous miner operator, roof bolter operator, tailgate-side shearer operator, and jacksetter. MSHA inspector and mine operator sampling data from five years before the rule became effective was compared to sampling results for five years after the dust standard was lowered and CPDM use was required. The analysis indicates that use of the CPDM has resulted in substantially lower percentages of samples exceeding the applicable respirable dust standard for these four occupations. A discussion of key dust rule changes, the CPDM, and compliance sampling results are provided. © 2022, This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply. |
Field test of a canopy air curtain on a ramcar for dust control in an underground coal mine
Reed WR , Colinet JF , Klima SS , Mazzella A , Ross G , Workman M , Morson T , Driscoll J . Min Metall Explor 2022 39 (2) 251-261 The canopy air curtain (CAC) has been proven to reduce the respirable dust exposure of roof bolter operators in underground coal mining. This technology is being adapted for use with shuttle cars and ramcars. The plenum is mounted on the underside of the shuttle car canopy over the operator’s position. The blower providing filtered air to the operator is plumbed into the shuttle car’s existing hydraulic system. After the system was installed on a ramcar, field testing of the CAC’s ability to provide respirable dust control was conducted on a section using blowing face ventilation. Results showed that overall respirable dust reductions during the total time the operator was underneath the canopy ranged from 11 to 34%, demonstrating adequate performance. However, further analysis demonstrated that the CAC performance was exceptional when the ramcar was being loaded by the continuous miner. At this location, a position where the shuttle car operator has their highest potential for respirable dust exposure, the CAC provided dust reductions ranging from 57 to 65%. These results, especially during ramcar loading at the CM, demonstrate that the CAC can be an important dust control device to reduce shuttle car and ramcar operators’ exposure to respirable coal mine dust. © 2022, This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply. |
Longwall mining, shale gas production, and underground miner safety and health
Su DWH , Zhang P , Dougherty H , Van Dyke M , Kimutis R . Int J Min Sci Technol 2021 31 (3) 523-529 This paper presents the results of a unique study conducted by the National Institute for Occupational Safety and Health (NIOSH) from 2016 to 2019 to evaluate the effects of longwall-induced subsurface deformations on shale gas well casing integrity and underground miner safety and health. At both deep-cover and shallow-cover instrumentation sites, surface subsidence measurements, subsurface in-place inclinometer measurements, and underground pillar pressure measurements were conducted as longwall panels were mined. Comparisons of the deep-cover and shallow-cover test site results with those from a similar study under medium cover reveal an interesting longwall-induced response scenario. Under shallow and medium covers, measured horizontal displacements within the abutment pillar are one order of magnitude higher than those measured under deep cover. On the other hand, measured vertical compressions under deep cover are one order of magnitude higher than those under shallow and medium covers. However, FLAC3D simulations of the casings indicate that, in all three cases, the P-110 production casings remain intact under longwall-induced deformations and compressions, which has serious implications for future mine design in areas where shale gas wells have been drilled ahead of mining. |
Mortality among uranium miners in North America and Europe: the Pooled Uranium Miners Analysis (PUMA)
Richardson DB , Rage E , Demers PA , Do MT , DeBono N , Fenske N , Deffner V , Kreuzer M , Samet J , Wiggins C , Schubauer-Berigan MK , Kelly-Reif K , Tomasek L , Zablotska LB , Laurier D . Int J Epidemiol 2020 50 (2) 633-643 BACKGROUND: The Pooled Uranium Miners Analysis (PUMA) study draws together information from cohorts of uranium miners from Canada, the Czech Republic, France, Germany and the USA. METHODS: Vital status and cause of death were ascertained and compared with expectations based upon national mortality rates by computing standardized mortality ratios (SMRs) overall and by categories of time since first hire, calendar period of first employment and duration of employment as a miner. RESULTS: There were 51 787 deaths observed among 118 329 male miners [SMR = 1.05; 95% confidence interval (CI): 1.04, 1.06]. The SMR was elevated for all cancers (n = 16 633, SMR = 1.23; 95% CI: 1.21, 1.25), due primarily to excess mortality from cancers of the lung (n = 7756, SMR = 1.90; 95% CI: 1.86, 1.94), liver and gallbladder (n = 549, SMR = 1.15; 95% CI: 1.06, 1.25), larynx (n = 229, SMR = 1.10; 95% CI: 0.97, 1.26), stomach (n = 1058, SMR = 1.08; 95% CI: 1.02, 1.15) and pleura (n = 39, SMR = 1.06; 95% CI: 0.75, 1.44). Lung-cancer SMRs increased with duration of employment, decreased with calendar period and persisted with time since first hire. Among non-malignant causes, the SMR was elevated for external causes (n = 3362, SMR = 1.41; 95% CI: 1.36, 1.46) and respiratory diseases (n = 4508, SMR = 1.32; 95% CI: 1.28, 1.36), most notably silicosis (n = 814, SMR = 13.56; 95% CI: 12.64, 14.52), but not chronic obstructive pulmonary disease (n = 1729, SMR = 0.98; 95% CI: 0.93, 1.02). CONCLUSIONS: Whereas there are important obstacles to the ability to detect adverse effects of occupational exposures via SMR analyses, PUMA provides evidence of excess mortality among uranium miners due to a range of categories of cause of death. The persistent elevation of SMRs with time since first hire as a uranium miner underscores the importance of long-term follow-up of these workers. |
Health conditions in retired manual labor miners and oil and gas extraction workers: National Health Interview Survey, 2007-2017
Robinson T , Sussell A , Yeoman K , Retzer K , Poplin G . Am J Ind Med 2020 64 (2) 118-126 BACKGROUND: Within the mining industrial sector, workers in the mining and oil and gas extraction (OGE) industries have demonstrated disparities in chronic health status compared with the general working population. However, we know much less about miner and OGE worker health once retired. This study separately compares chronic illnesses in retired miners and OGE workers with all other retirees. METHODS: National Health Interview Survey (NHIS) public data were analyzed for the years 2007-2017 to estimate weighted unadjusted and adjusted prevalence of selected health conditions (cancer, cardiovascular disease, high cholesterol, diabetes, hypertension, respiratory conditions, health status, and hearing loss) in retirees. Three retired worker groups (miners, OGE, and other retirees) were defined using the respondents' longest-held industry and occupation. RESULTS: Higher prevalence of a number of adverse health conditions was noted in miners and OGE workers when compared with all other retirees. A significantly higher adjusted prevalence of hypertension, hearing loss, functionally limiting lung problems, and fair or poor health was seen in miners over other retirees. Retired OGE workers demonstrated a significantly higher adjusted prevalence of both hearing loss and poor health status. CONCLUSIONS: Miners and OGE workers have higher morbidity during their working years, and this study demonstrates that poorer health appears to continue into retirement. These results suggest the need to expand occupational health and safety programs in the mining sector to improve the health of workers into retirement. Future studies that include more robust information on workplace exposures are needed to evaluate the long-term health of retired workers. |
Field testing of roof bolter canopy air curtain operating downwind of the continuous miner
Reed WR , Shahan M , Gangrade V , Ross G , Singh K , Grounds T . Min Metall Explor 2020 38 (1) 581-592 Roof bolter canopy air curtains (CACs) are gaining acceptance as a respirable dust control device that can provide roof bolter operators with protection from overexposure to respirable coal mine dust. Both lab and field studies on the effectiveness of roof bolter CACs have been published. Field studies have shown the effectiveness to be variable. However, in all previous field studies, none has been conducted when the roof bolting machine operates downwind of the continuous miner (CM)—a scenario for which the CAC was designed to provide respirable dust control. This study, performed by researchers from the National Institute for Occupational Safety and Health (NIOSH), was conducted to test a CAC on a roof bolter machine operating downwind of the CM. The results of testing demonstrated that the roof bolter CAC can effectively provide respirable dust protection for roof bolter operators with dust control efficiencies ranging from 11 to 40%. |
Assessing the feasibility of a commercially available wireless Internet of Things system to improve conveyor safety
Jacksha R , Raj KV . Min Metall Explor 2020 38 567-574 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. |
Field comparison of a roof bolter dry dust collection system with an original designed wet collection system for dust control
Reed WR , Shahan M , Ross G , Blackwell D , Peters S . Min Metall Explor 2020 37 1885-1898 Dust collectors for roof bolting machines generally use a dry box to collect the roof bolting material. Recently, an underground mining operation converted a dry box dust collector to a wet box dust collector with a unique exception from MSHA for testing purposes. Water is routed to the roof bolter from the main water line of the continuous miner. The wet box utilizes a water spray to wet the incoming material. Testing was conducted comparing the two different collector types. Respirable dust concentrations surrounding the roof bolter with the different collection boxes were similar. The main difference in respirable dust concentrations occurred when cleaning the dust boxes. The average respirable dust concentration during cleaning of the wet box was 0.475 mg/m3, and during the cleaning of the dry box, the average respirable dust concentration was 1.188 mg/m3, a 60% reduction in respirable dust concentration. The quartz content of the roof material was high, ranging from 28.9 to 52.7% during this study. The results from this study indicate that using the wet box as a collector reduced exposure to respirable dust up to 60% when cleaning the collector boxes. |
Effects of roof bolter canopy air curtain on airflow and dust dispersion in an entry using exhaust curtain ventilation
Zheng Y , Reed WR . Min Metall Explor 2020 37 (6) 1865-1875 A recent study conducted by the National Institute for Occupational Safety and Health (NIOSH) evaluated the roof bolter canopy air curtain (CAC) system in a blowing face ventilation system, demonstrating its effectiveness and illustrating the CAC protection zones. This study evaluates the roof bolter machine CAC while operating in an exhausting face ventilation system. This study considers two similar locations to allow comparison with the previous blowing face ventilation (Zheng et al., Min Metal Explor 36(6):1115–1126, (2019)) study: (1) a roof bolter machine bolting the roof at 20 ft (6.1 m) from the face and (2) a roof bolting machine bolting at 4 ft (1.2 m) from the face. The environment introduces 6.0 mg/m3 of respirable dust to represent the roof bolting machine operating downstream of the continuous miner. However, the exhausting face ventilation uses an exhaust curtain with 9000 cfm (4.25 m3/s) of air. Two roof bolter machine working positions are simulated with the use of dual drill heads in the inward position for two inside bolts and in the outward position for two outside bolts. The influence of the CAC on airflows and dust dispersion is evaluated with the CAC operating at 250 cfm (0.12 m3/s) with dust reductions ranging from 39.5 to 82.8%. When the roof bolter machine operated close to the face, increasing CAC airflow was required for adequate protection since the dust reductions can be as low as 39.5%. Additional CAC airflows of 350 cfm (0.17 m3/s) and 450 cfm (0.21 m3/s) were evaluated and demonstrated that dust reductions increased to 59.7% (350 cfm) and 72.0% (450 cfm) for the worst location where the roof bolter operators located. |
Simulation and measurement of the magnetic field coupling from a proximity detection system to trailing cables
Zhou C , Whisner B , Carr J . IEEE Trans Ind Appl 2020 56 (4) 4356-4364 Some of the common and serious hazards in underground mines are the dangers of being pinned, crushed, or struck by a large mining machine such as a scoop or a continuous mining machine (CMM). Proximity detection systems (PDSs) have been applied to protect miners from these hazards. The primary components of PDSs that are currently approved by the Mine Safety and Health Administration (MSHA) for use in underground coal mines are machine-mounted magnetic field generators and a miner-worn component (MWC), which measures the strength of the magnetic fields produced by the generators. Since these systems are magnetic field based, they can be adversely impacted by nearby cables due to parasitic coupling. Some mobile equipment in underground mines is electrically powered by long trailing cables that are pulled through the mine behind the equipment. Because the components of the PDS (generators and MWC) are frequently in close proximity to these cables, parasitic coupling can occur. Researchers from the National Institute for Occupational Safety and Health investigated the influence of trailing cables on the performance of PDSs. In particular, a three-phase model was proposed to describe the coupling process. The factors for controlling the magnetic field coupled from a field generator to a trailing cable were experimentally studied. The results show that the coupling is primarily controlled by two factors: The distance between the PDS components and the cable and the impedance between the cable and the ground. The coupling can be mitigated by either maintaining some minimum separation distance between the PDS components and the cable or increasing the impedance between the cable and the ground. The results presented in this article can help PDS manufacturers to design systems that are more immune to these effects. |
High prevalence of multidrug-resistant organism colonization in 28 nursing homes: An "iceberg effect"
McKinnell JA , Miller LG , Singh RD , Gussin G , Kleinman K , Mendez J , Laurner B , Catuna TD , Heim L , Saavedra R , Felix J , Torres C , Chang J , Estevez M , Mendez J , Tchakalian G , Bloomfield L , Ceja S , Franco R , Miner A , Hurtado A , Hean R , Varasteh A , Robinson PA , Park S , Tam S , Tjoa T , He J , Agrawal S , Yamaguchi S , Custodio H , Nguyen J , Bittencourt CE , Evans KD , Mor V , McConeghy K , Weinstein RA , Hayden MK , Stone ND , Steinberg K , Beecham N , Montgomery J , DeAnn W , Peterson EM , Huang SS . J Am Med Dir Assoc 2020 21 (12) 1937-1943 e2 OBJECTIVE: Determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus spp. (VRE), extended-spectrum beta-lactamase producing organisms (ESBLs), and carbapenem-resistant Enterobacteriaceae (CRE) among residents and in the environment of nursing homes (NHs). DESIGN: Point prevalence sampling of residents and environmental sampling of high-touch objects in resident rooms and common areas. SETTING: Twenty-eight NHs in Southern California from 2016 to 2017. PARTICIPANTS: NH participants in Project PROTECT, a cluster-randomized trial of enhanced bathing and decolonization vs routine care. METHODS: Fifty residents were randomly sampled per NH. Twenty objects were sampled, including 5 common room objects plus 5 objects in each of 3 rooms (ambulatory, total care, and dementia care residents). RESULTS: A total of 2797 swabs were obtained from 1400 residents in 28 NHs. Median prevalence of multidrug-resistant organism (MDRO) carriage per NH was 50% (range: 24%-70%). Median prevalence of specific MDROs were as follows: MRSA, 36% (range: 20%-54%); ESBL, 16% (range: 2%-34%); VRE, 5% (range: 0%-30%); and CRE, 0% (range: 0%-8%). A median of 45% of residents (range: 24%-67%) harbored an MDRO without a known MDRO history. Environmental MDRO contamination was found in 74% of resident rooms and 93% of common areas. CONCLUSIONS AND IMPLICATIONS: In more than half of the NHs, more than 50% of residents were colonized with MDROs of clinical and public health significance, most commonly MRSA and ESBL. Additionally, the vast majority of resident rooms and common areas were MDRO contaminated. The unknown submerged portion of the iceberg of MDRO carriers in NHs may warrant changes to infection prevention and control practices, particularly high-fidelity adoption of universal strategies such as hand hygiene, environmental cleaning, and decolonization. |
Pneumoconiosis progression patterns in US coal miner participants of a job transfer programme designed to prevent progression of disease
Hall NB , Blackley DJ , Halldin CN , Laney AS . Occup Environ Med 2020 77 (6) 402-406 OBJECTIVES: Pneumoconiosis prevalence and severity among US coal miners has been increasing for the past 20 years. An examination of the current approaches to primary and secondary prevention efforts is warranted. One method of secondary prevention is the Mine Safety and Health Administration-administered part 90 option programme where US coal miners with radiographic evidence of pneumoconiosis can exercise their right to be placed in a less dusty area of the mine. This study focuses on characterising the progression of disease among US coal miners who participated in the National Institute for Occupational Safety and Health-administered Coal Workers' Health Surveillance Programme (CWHSP) and exercised their part 90 job transfer option. METHODS: Chest radiograph classifications of working underground coal miners who exercised their part 90 job transfer option during 1 January 1986 to 21 November 2016 and participated in the CWHSP during 1 January 1981 to 19 March 2019 were analysed. RESULTS: 513 miners exercised their part 90 option and participated in the CWHSP at least once during this time period. Of the 149 miners with >/=2 radiographs available, 48 (32%) showed progression after exercising part 90 and had more severe disease prior to exercising, compared with miners who did not progress (severity score of 2.8 vs 1.7, p=0.0002). CONCLUSION: The part 90 job transfer option programme is not routinely used as intended to prevent progression of pneumoconiosis among US coal miners. The one-third of miners who participated in part 90 and continued to progress, exercised their part 90 option at a later stage of disease compared with non-progressors. |
PUMA - pooled uranium miners analysis: cohort profile
Rage E , Richardson DB , Demers PA , Do M , Fenske N , Kreuzer M , Samet J , Wiggins C , Schubauer-Berigan MK , Kelly-Reif K , Tomasek L , Zablotska LB , Laurier D . Occup Environ Med 2020 77 (3) 194-200 OBJECTIVES: Epidemiological studies of underground miners have provided clear evidence that inhalation of radon decay products causes lung cancer. Moreover, these studies have served as a quantitative basis for estimation of radon-associated excess lung cancer risk. However, questions remain regarding the effects of exposure to the low levels of radon decay products typically encountered in contemporary occupational and environmental settings on the risk of lung cancer and other diseases, and on the modifiers of these associations. These issues are of central importance for estimation of risks associated with residential and occupational radon exposures. METHODS: The Pooled Uranium Miner Analysis (PUMA) assembles information on cohorts of uranium miners in North America and Europe. Data available include individual annual estimates of exposure to radon decay products, demographic and employment history information on each worker and information on vital status, date of death and cause of death. Some, but not all, cohorts also have individual information on cigarette smoking, external gamma radiation exposure and non-radiological occupational exposures. RESULTS: The PUMA study represents the largest study of uranium miners conducted to date, encompassing 124 507 miners, 4.51 million person-years at risk and 54 462 deaths, including 7825 deaths due to lung cancer. Planned research topics include analyses of associations between radon exposure and mortality due to lung cancer, cancers other than lung, non-malignant disease, modifiers of these associations and characterisation of overall relative mortality excesses and lifetime risks. CONCLUSION: PUMA provides opportunities to evaluate new research questions and to conduct analyses to assess potential health risks associated with uranium mining that have greater statistical power than can be achieved with any single cohort. |
Follow-up of the Libby, Montana screening cohort: A 17-year mortality study
Larson TC , Williamson L , Antao VC . J Occup Environ Med 2019 62 (1) e1-e6 OBJECTIVE: To evaluate mortality patterns among participants in a community-based screening program for asbestos-related disease. METHODS: We calculated standardized mortality ratios (SMRs) and stratified results by exposure group (three occupational exposure groups, household contacts and residents without occupational asbestos exposure) and by radiographic abnormality presence. RESULTS: All-cause mortality (15.8%; 1,429/8,043) was statistically lower than expected. Asbestosis was statistically elevated in all exposure groups. Lung cancer was moderately associated with vermiculite miner/miller employment. Mesothelioma was elevated in that same exposure group and among residents. Systemic autoimmune disease mortality was also elevated. Radiographic parenchymal abnormalities were associated with lung cancer mortality. CONCLUSION: In addition to asbestos-related mortality in occupational exposure groups, this initial mortality follow-up of this cohort also shows elevated mortality for some asbestos-related causes in non-occupational exposure groups. |
Shielding material comparison for electromagnetic interference mitigation for the air pump motor of personal dust monitors
Li J , Carr J , DeGennaro C , Whisner B , McElhinney P . Min Metall Explor 2019 37 (1) 211-217 Since 2016, electromagnetic interference (EMI) of personal dust monitors (PDMs) with magnetic proximity detection systems (PDSs) has been observed in underground coal mines. The EMI causes the magnetic field measurements of a PDS to change, which, in turn, alters the calculated location of the miner relative to the machine. Any altered location calculation can potentially cause the PDS to fail to warn a worker who is at an unsafe distance from the machine, arousing a serious concern on safety hazard caused by EMI in underground mines. The search for EMI mitigation strategies led to the development and use of large shielding pouches and boxes to hold the entire PDM to reduce its magnetic emission. Research on these pouches and boxes found that although they were able to reduce the emitted radiation from the PDM, they also disturbed the magnetic field of the PDS, affecting its performance. Researchers from the National Institute for Occupational Safety and Health (NIOSH) have focused on shielding internal PDM components rather than shielding the entire PDM. The PDM air pump motor is one of the PDM components that has been identified as a major source of electromagnetic radiation and has been selected for further study and tests. The measurements show that a small copper or aluminum foil enclosure can effectively reduce the magnetic emission of the motor by between 50 and 85% at 73 kHz. This study compares the test results of the air pump motor with various cost-effective shielding materials. The data provided in this paper can serve as a reference for shielding enclosure design of the PDM air pump motor to reduce its electromagnetic emission as one form of EMI mitigation strategy. |
Influence of temperature on generator current and magnetic field of a proximity detection system
Li J , Smith A , Carr JB , Whisner B . Min Metall Explor 2019 36 (3) 541-545 Electromagnetic-based proximity detection systems (PDSs) are utilized on mining machinery to protect workers from being pinned or struck. These systems generate magnetic fields covering the space around a machine, and a miner-wearable component (MWC) detects the field. The PDS determines the distance of miners relative to the machine based on the detected magnetic flux density in the magnetic field. This information is used to establish warning and shutdown zones around the machine. Maintaining a stable magnetic field is essential for system accuracy. However, components used to generate magnetic fields can be influenced by temperature changes. Depending on ventilation conditions and seasonal alternation, a PDS can be subject to significant temperature fluctuation. To better understand and quantify this phenomenon, researchers from the National Institute for Occupational Safety and Health (NIOSH) developed an experimental apparatus to study the influence of temperature on magnetic field generator circuits used in PDSs. Results from the study show that the electric current through a generator can be influenced by both ambient and internal temperatures, modifying the magnetic field that is produced. These findings show that temperature can significantly influence the ability of PDSs, used in underground coal mines, to accurately determine a workers position in relation to mining machine. 2019, This is a U.S. government work and its text is not subject to copyright protection in the United States; however, its text may be subject to foreign copyright protection. |
Field investigation to measure airflow velocities of a ram dump car using circular routing at a Midwestern underground coal mine: a case study
Reed WR , Shahan M , Ross G , Singh K , Cross R , Grounds T . Environ Monit Assess 2019 191 (8) 515 Due to the successful application of roof bolter canopy air curtains (CACs) to protect roof bolter operators from high levels of coal mine respirable dust, a shuttle car CAC is currently being developed. Since a shuttle car consistently trams from the continuous miner to the feeder and back at a speed up to 9.66 kph (6 mph) or 2.68 m/s (528 fpm), it is thought that the shuttle car may encounter very high air velocities (mine ventilation air velocity + max shuttle speed (2.68 m/s (528 fpm)). Past research and preliminary lab testing showed that CAC protection in high interference air velocities is difficult to achieve. Therefore, testing was conducted at a Midwestern US coal mine to determine the air velocities their shuttle car actually encounters. This mine used ram dump cars as their shuttle cars. Results showed that coal mine dust exposure is generally very low at the feeder and when tramming. Elevated concentrations are encountered at the ram dump car operator position when the car is being loaded by the continuous miner. Recorded air velocities while tramming did not reach the max air velocity of mine ventilation air velocity + 2.68 m/s (528 fpm) calculated as 3.32 m/s (653 fpm). High velocities, while encountered, were of low frequency and associated with low respirable coal mine dust concentrations. Therefore, using this new information, designing the shuttle car CAC for maximum interference air velocity may not be as important as previously thought. |
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