Geophys J Int

Monitoring mining-induced seismicity (MIS) can help engineers understand the rock mass response to resource extraction. With a thorough understanding of ongoing geomechanical processes, engineers can operate mines, especially those mines with the propensity for rock-bursting, more safely and efficiently. Unfortunately, processing MIS data usually requires significant effort from human analysts, which can result in substantial costs and time commitments. The problem is exacerbated for operations that produce copious amounts of MIS, such as mines with high-stress and/or extraction ratios. Recently, deep learning methods have shown the ability to significantly improve the quality of automated arrival-time picking on earthquake data recorded by regional seismic networks. However, relatively little has been published on applying these techniques to MIS. In this study, we compare the performance of a convolutional neural network (CNN) originally trained to pick arrival times on the Southern California Seismic Network (SCSN) to that of human analysts on coal-mine-related MIS. We perform comparisons on several coal-related MIS data sets recorded at various network scales, sampling rates and mines. We find that the Southern-California-trained CNN does not perform well on any of our data sets without retraining. However, applying the concept of transfer learning, we retrain the SCSN model with relatively little MIS data after which the CNN performs nearly as well as a human analyst. When retrained with data from a single analyst, the analyst-CNN pick time residual variance is lower than the variance observed between human analysts. We also compare the retrained CNN to a simpler, optimized picking algorithm, which falls short of the CNN's performance. We conclude that CNNs can achieve a significant improvement in automated phase picking although some data set-specific training will usually be required. Moreover, initializing training with weights found from other, even very different, data sets can greatly reduce the amount of training data required to achieve a given performance threshold.CC999999/ImCDC/Intramural CDC HHSUnited States/2022-01-01T00:00:00Z34556900PMC845516711761vault:3962

J Int Soc Respir Prot

Elastomeric respirators (elastomerics) may serve as one alternative to disposable N95 respirator use in healthcare. We explored factors which drove elastomeric adoption and continued use in a large academic medical center. We conducted semi-structured and focus group interviews in 2015 with a) 11 leadership key informants (KIs) with involvement in the respiratory protection program (RPP) when elastomerics were introduced and b) 11 healthcare workers (HCWs) recruited from hospital departments assigned to use elastomerics. Interview transcripts and responses were open-coded to capture emergent themes, which were collapsed into broader categories and iteratively refined. Factors identified by leadership KIs as influencing elastomeric adoption included: 1) N95 shortages during 2009's H1N1 influenza pandemic and 2) the presence of trained, certified safety professionals who were familiar with respiratory protection requirements. Factors identified as influencing ongoing use of elastomerics included: 1) cleaning/decontamination practices, 2) storage, 3) safety culture, 4) HCW respirator knowledge, and 5) risk perception. HCW users expressed dissatisfaction related to breathing, communication and cleaning of elastomerics. Other themes included convenience use of N95s rather than assigned elastomerics, despite perceptions that elastomerics are more protective. Through semi-structured and focus group interviews, we learned that 1) leadership introduced elastomerics due to necessity but now face challenges related to ongoing use, and 2) HCWs were not satisfied with elastomerics for routine care and preferentially used N95s because they were conveniently available at point of use. Although the impetus behind incorporation of elastomerics was clear, the most complex themes related to sustainability of this form of RPP. These themes were used to inform a broader questionnaire and will address the utility of elastomerics as a feasible and acceptable practical alternative to N95s in healthcare.CC999999/Intramural CDC HHS/United StatesR21 OH010868/OH/NIOSH CDC HHS/United States2018-03-13T00:00:00Z29545673PMC5849268763

Correction to: Erythrocyte concentrations of chromium, copper, manganese, molybdenum, selenium and zinc in subjects with different physical training levels

Correction to: J Int Soc Sports Nutr 17, 35 (2020) https://doi.org/10.1186/s12970-020-00367-

J Int Soc Respir Prot

In the U.S., respiratory protection is broadly supported by a system of coordinated efforts among governmental organizations, professional associations, researchers, industrial hygienists, manufacturers, and others who produce knowledge, best practice guidance, standards, regulations, technologies, and products to assure workers can be effectively protected. Ultimately, the work of these partners is applied by employers in establishing and implementing an effective ANSI/ASSE Z88.2-2015 conforming respirator program. This article describes key partners and their activities and/or responsibilities to assure an effective respirator program.CC999999/Intramural CDC HHS/United States2016-08-23T00:00:00Z27563169PMC499470

J Int Soc Respir Prot

Background:In the field of respiratory protection for healthcare workers (HCWs), few data are available on respiratory airflow rate when HCWs are performing their work activities. The objective of this study was to assess the performance of two wearable breathing recording devices in a simulated healthcare environment.Methods:Breathing recording devices from two different manufactures \u201cA\u201d and \u201cB\u201d were assessed using 15 subjects while performing a series of simulated healthcare work activities (patient assessment; vitals; IV treatment; changing linen; carrying weight while walking; normal breathing while standing). The minute volume (MV, L/min), mean inhalation flow (MIF, L/min), peak inhalation flow (PIF, L/min), breathing frequency (f, breaths/min), and tidal volume (TV, L/min) measured by each device were analyzed. Bland-Altman method was applied to explore the variability of devices A and B. Duncan\u2019s multiple range test was used to investigate the differences among activity-specific inspiratory flow rates.Results:The average MV, MIF and PIF reported by device A were 23, 54, and 82 L/min with 95% upper confidence intervals (CIs) of 25, 60 and 92 L/min; the mean differences of MV, MIF and PIF presented by the two units of device A were 0.9, 1.3, and 2.8 L/min, respectively. The average values and mean differences of MV, MIF and PIF found with device B were significantly higher than device A (P3.14 and >2, while with speech, the ratios increased to >6 and >3. The f during speech (15 breaths/min) was significantly lower than non-speech activities (20\u201325 breaths/min). Among different simulated work activities, the PIF of \u201cpatient assessment\u201d was the highest.Conclusions:This study demonstrated a novel approach to characterize respiratory flow for healthcare workers using an innovative wearable flow recording device. Data from this investigation could be useful in the development of future respirator test standards.CC999999/ImCDC/Intramural CDC HHS/United States2020-04-23T00:00:00Z32327898PMC7179815763

J Int Soc Respir Prot

Machine and human subject testing of four prototype filtering facepiece respirators (FFR) and two commercial FFR was carried out utilizing recently proposed respirator test criteria that address healthcare worker-identified comfort and tolerance issues. Overall, two FFR (one prototype, one commercial model) were able to pass all eight criteria and three FFR (two prototypes, one commercial model) were able to pass seven of eight criteria. One prototype FFR was not tested against the criteria due to an inability to obtain satisfactory results on human subject quantitative respirator fit testing. Future studies, testing different models and styles of FFR against the proposed criteria, will be required to gauge the overall utility and effectiveness of the criteria in determining FFR comfort and tolerance issues that may impact user compliance and, by extension, protection.CC999999/ImCDC/Intramural CDC HHSUnited States

J Int Soc Respir Prot

Objective:Loose-fitting powered air-purifying respirators (PAPRs) are increasingly being used in healthcare. NIOSH has previously used advanced manikin headforms to develop methods to evaluate filtering facepiece respirator fit; research has now begun to develop methods to evaluate PAPR performance using headforms. This preliminary study investigated the performance of PAPRs at different work rates to support development of a manikin-based test method.Methods:Manikin penetration factors (mPF) of three models of loose-fitting PAPRs were measured at four different work rates (REST: 11 Lpm, LOW: 25 Lpm, MODERATE: 48 Lpm, and HIGH: 88 Lpm) using a medium-sized NIOSH static advanced headform mounted onto a torso. In-mask differential pressure was monitored throughout each test. Two condensation particle counters were used to measure the sodium chloride aerosol concentrations in the test chamber and also inside the PAPR facepiece over a 2-minute sample period. Two test system configurations were evaluated for returning air to the headform in the exhalation cycle (filtered and unfiltered). Geometric mean (GM) and 5th percentile mPFs for each model/work rate combination were computed. Analysis of variance tests were used to assess the variables affecting mPF.Results:PAPR model, work rate, and test configuration significantly affected PAPR performance. PAPR airflow rates for the three models were approximately 185, 210, and 235 Lpm. All models achieved GM mPFs and 5th percentile mPFs greater than their designated Occupational Safety and Health Administration assigned protection factors despite negative minimum pressures observed for some work rate/model combinations.Conclusions:PAPR model, work rate, and test configuration affect PAPR performance. Advanced headforms have potential for assessing PAPR performance once test methods can be matured. A manikin-based inward leakage test method for PAPRs can be further developed using the knowledge gained from this study. Future studies should vary PAPR airflow rate to better understand the effects on performance. Additional future research is needed to evaluate the correlation of PAPR performance using advanced headforms to the performance measured with human subjects.CC999999/Intramural CDC HHS/United States2018-11-27T00:00:00Z30498287PMC6258086763

J Int Soc Respir Prot

This article is the third in a series of four articles on respirator history. This article continues to follow the history of respirator approval, use, and improvements in the US as discussed in our article entitled, |, published in the ISRP Journal, Vol. 35, No. 1, 2018 (Spelce. et. al.2018). In addition, a 1957 respirator decision logic diagram illustrates the U.S. Bureau of Mines (USBM) rules to follow for respirator selection (USBM 1957).CC999999/ImCDC/Intramural CDC HHSUnited States/2022-09-21T00:00:00Z36147685PMC949080611946vault:4329

J Int Soc Respir Prot

As part of development of performance standards, the International Organization for Standardization (ISO) technical committee, ISO/TC 94/SC 15 Respiratory protective devices (RPD), adopted work of breathing (WOB) to evaluate airflow resistance for all designs (classes) of respiratory protective devices. The interests of the National Institute for Occupational Safety and Health's (NIOSH) National Personal Protective Technology Laboratory (NPPTL) are to compare the proposed WOB method and results for current RPD with those for present resistance methods. The objectives here were to assemble a method to meet the ISO SC15 standards, validate operation and conformance, and assess repeatability of WOB measurements for RPD. WOB method implementation and use followed standards ISO 16900-5:2016 and ISO 16900-12:2016. Volume-averaged total work of breathing (WOB|/V| where V| is tidal volume) determined for standard orifices was analyzed for variation and bias. After fabrication and assembly, the method gave preliminary verification orifice results that met ISO requirements and were equivalent to those from other laboratories. Evaluation of additional results from RPD testing showed tidal volume and frequency determined compliance. Appropriate adjustments reduced average absolute bias to 1.7%. Average coefficient of variation for WOB|/V| was 2.3%. Over 97% of results obtained during significant use over time met specifications. WOB|/V| for as-received air-purifying and supplied-air RPD were repeatable (p<0.05). WOB|/V| for unsealed half mask air-purifying RPD was an average of 31% lower compared to sealed. When experimental parameters were appropriately adjusted, the ISO WOB method implemented by NIOSH NPPTL consistently provided ISO-compliant verification WOB|/V|. Results for appropriately sealed RPD were reproducible.CC999999/ImCDC/Intramural CDC HHSUnited States

J Int Soc Respir Prot

During the current COVID-19 infectious disease pandemic, the demand for NIOSH-approved filtering facepiece respirators (FFR) has exceeded supplies and decontamination and reuse of FFRs has been implemented by various user groups. FFR decontamination and reuse is only intended to be implemented as a crisis capacity strategy. This paper provides a review of decontamination procedures in the published literature and calls attention to their benefits and limitations. In most cases, the data are limited to a few FFR models and a limited number of decontamination cycles. Institutions planning to implement a decontamination method must understand its limitations in terms of the degree of inactivation of the intended microorganisms and the treatment's effects on the fit and filtration of the device.CC999999/ImCDC/Intramural CDC HHS/United States2020-12-01T00:00:00Z33268915PMC77071438772vault:3623