RESUMEN
We investigated a cluster of SARS-CoV-2 infections in a quarantine hotel in Taiwan in December 2021. The cluster involved 3 case patients who lived in nonadjacent rooms on different floors. They had no direct contact during their stay. By direct exploration of the space above the room ceilings, we found residual tunnels, wall defects, and truncated pipes between their rooms. We conducted a simplified tracer-gas experiment to assess the interconnection between rooms. Aerosol transmission through structural defects in floors and walls in this poorly ventilated hotel was the most likely route of virus transmission. This event demonstrates the high transmissibility of Omicron variants, even across rooms and floors, through structural defects. Our findings emphasize the importance of ventilation and integrity of building structure in quarantine facilities.
Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Cuarentena , Taiwán/epidemiología , Aerosoles y Gotitas RespiratoriasRESUMEN
OBJECTIVE: The purpose of this study was to compare thermal desorption tubes and stainless steel canisters for measuring volatile organic compounds (VOCs) emitted from petrochemical factories. METHODS: Twelve petrochemical factories in the Mailiao Industrial Complex were recruited for conducting the measurements of VOCs. Thermal desorption tubes and 6-l specially prepared stainless steel canisters were used to simultaneously perform active sampling of environmental air samples. The sampling time of the environmental air samples was set up on 6 h close to a full work shift of the workers. A total of 94 pairwise air samples were collected by using the thermal adsorption tubes and stainless steel canisters in these 12 factories in the petrochemical industrial complex. To maximize the number of comparative data points, all the measurements from all the factories in different sampling times were lumped together to perform a linear regression analysis for each selected VOC. Pearson product-moment correlation coefficient was used to examine the correlation between the pairwise measurements of these two sampling methods. A paired t-test was also performed to examine whether the difference in the concentrations of each selected VOC measured by the two methods was statistically significant. RESULTS: The correlation coefficients of seven compounds, including acetone, n-hexane, benzene, toluene, 1,2-dichloroethane, 1,3-butadiene, and styrene were >0.80 indicating the two sampling methods for these VOCs' measurements had high consistency. The paired t-tests for the measurements of n-hexane, benzene, m/p-xylene, o-xylene, 1,2-dichloroethane, and 1,3-butadiene showed statistically significant difference (P-value < 0.05). This indicated that the two sampling methods had various degrees of systematic errors. Looking at the results of six chemicals and these systematic errors probably resulted from the differences of the detection limits in the two sampling methods for these VOCs. CONCLUSIONS: The comparison between the concentrations of each of the 10 selected VOCs measured by the two sampling methods indicted that the thermal desorption tubes provided high accuracy and precision measurements for acetone, benzene, and 1,3-butadiene. The accuracy and precision of using the thermal desorption tubes for measuring the VOCs can be improved due to new developments in sorbent materials, multi-sorbent designs, and thermal desorption instrumentation. More applications of thermal desorption tubes for measuring occupational and environmental hazardous agents can be anticipated.
Asunto(s)
Monitoreo del Ambiente/instrumentación , Acero Inoxidable , Compuestos Orgánicos Volátiles/análisis , Acetona/análisis , Contaminantes Atmosféricos/análisis , Benceno/análisis , Butadienos/análisis , Industria Química , Monitoreo del Ambiente/métodos , Sustancias Peligrosas/análisis , Humanos , Exposición Profesional/análisis , Xilenos/análisisRESUMEN
This study aimed to evaluate the efficacy of powered air-purifying respirators (PAPRs) worn by the workers, and to investigate the effect of this application on exposure and preclinical effects in terms of workplace measuring and biomarker monitoring in ITO sputter target manufacturing plants and workers, respectively. Fifty-four workers were recruited and investigated from 2010-2012, during which PAPRs were provided to on-site workers in September 2011. Each worker completed questionnaires and provided blood and urine samples for analysis of biomarkers of indium exposure and preclinical effects. Area and personal indium air samples were randomly collected from selected worksites and from participants. The penetration percentage of the respirator (concentration inside respirator divided by concentration outside respirator) was 6.6%. Some biomarkers, such as S-In, SOD, GPx, GST, MDA, and TMOM, reflected the decrease in exposure and showed lower levels, after implementation of PAPRs. This study is the first to investigate the efficacy of PAPRs for reducing indium exposure. The measurement results clearly showed that the implementation of PAPRs reduces levels of indium-related biomarkers. These findings have practical applications for minimizing occupational exposure to indium and for managing the health of workers exposed to indium.
Asunto(s)
Contaminantes Ocupacionales del Aire/análisis , Indio/efectos adversos , Exposición Profesional/efectos adversos , Exposición Profesional/prevención & control , Dispositivos de Protección Respiratoria , Adulto , Biomarcadores/sangre , Biomarcadores/orina , Roturas del ADN , Humanos , Indio/sangre , Indio/orina , Estrés Oxidativo , TaiwánRESUMEN
Background: Glove reuse poses risks, as chemicals can persist even after cleaning. Decontamination methods like thermal aeration, recommended by US OSHA, vary in effectiveness. Some studies show promising results, while others emphasize the importance of considering both permeation and tensile strength changes. This research advocates for informed glove reuse, emphasizing optimal thermal aeration temperatures and providing evidence to guide users in maintaining protection efficiency. Methods: The investigation evaluated Neoprene and Nitrile gloves (22 mils). Permeation tests with toluene and acetone adhered to American Society for Testing Materials (ASTM) F739 standards. Decontamination optimization involved aeration at various temperatures. The experiment proceeded with a maximum of 22 re-exposure cycles. Tensile strength and elongation were assessed following ASTM D 412 protocols. Breakthrough time differences were statistically analyzed using t-test and ANOVA. Results: At room temperature, glove residuals decreased, and standardized breakthrough time (SBT)2 was significantly lower than SBT1, indicating reduced protection. Higher temperature decontamination accelerated residual removal, with ΔSBT (SBT2/SBT1) exceeding 100%, signifying restored protection. Tensile tests showed stable neoprene properties postdecontamination. Results underscore thermal aeration's efficacy for gloves reuse, emphasizing temperature's pivotal role. Findings recommend meticulous management strategies, especially post-breakthrough, to uphold glove-protective performance. Conclusions: Thermal aeration at 100°C for 1 hour proves effective, restoring protection without compromising glove strength. The study, covering twenty cycles, suggests safe glove reuse with proper decontamination, reducing costs significantly. However, limitations in chemical-glove combinations and exclusive focus on specific gloves caution against broad generalization. The absence of regulatory directives on glove reuse highlight the importance of informed selection and rigorous decontamination validation for workplace safety practices.
RESUMEN
We investigated a COVID-19 cluster involved seven case-patients lived in a high-rise building in September 2021. We used a simplified tracer-gas experiment and virus sequencing to establish the link between case-patients. Vertical transmission among vertically aligned apartments on different floors in a building was the most likely route of transmission.
Asunto(s)
COVID-19 , Humanos , COVID-19/epidemiología , Taiwán/epidemiología , Transmisión Vertical de Enfermedad InfecciosaRESUMEN
Marked reductions in mean annual rainfall associated with climate change in Eswatini in Southern Africa have encouraged the recycling of irrigation water and the increased use of pesticides in agricultural production, raising concerns about potential ecological and health risks due to long-term exposure to pesticide residues in soil and irrigation water. This probabilistic integrated risk assessment used liquid chromatography with tandem mass spectrometry to analyze the concentrations of four commonly used agricultural pesticides (ametryn, atrazine, pendimethalin, and 2,4-dichlorophenoxyacetic acid (2,4-D)) in irrigation water and topsoil samples from farmlands in Eswatini to assess potential ecological and health risks due to exposure. The concentrations of these pesticides ranged from undetectable to 0.104 µg/L in irrigation water and from undetectable to 2.70 µg/g in soil. The probabilistic multi-pathway and multi-route risk assessments conducted revealed hazard indices exceeding 1.0 for all age groups for ametryn and atrazine, suggesting that the daily consumption of recycled irrigation water and produce from the fields in this area may pose considerable health risks. The indices pertaining to ecological risks had values less than 0.1. Adaptation measures are recommended to efficiently manage pesticide use in agriculture, and further research will ensure that agriculture can adapt to climate change and that the general public and ecosystem are protected.
RESUMEN
BACKGROUND: Overexposure to carbon disulfide (CS(2) ) has been associated with an increase in coronary heart disease, but the mechanisms mediating this effect remain unclear. We aimed to examine the relationship between CS(2) exposure and oxidative stress markers, in order to clarify the oxidative mechanisms involved in CS(2) -induced atherosclerosis. METHODS: A total of 89 workers from a viscose rayon plant were recruited for this study, and 111 workers not exposed to CS(2) served as controls. Cholesterol, triglyceride, malondialdehyde (MDA), superoxide dismutase (SOD), catalase, GSH peroxidase, as well as total antioxidants were analyzed. RESULTS: The workers exposed to CS(2) had significantly higher MDA levels and lower SOD levels than the controls. The average MDA levels were 776 ± 268.2 (240-1,220) in the high exposure (≥10 ppm; n = 38), 751.6 ± 274 (170-1,320) in the low exposure (<10 ppm; n = 51), and 550.4 ± 199 (115-1,050) mM in the control group (n = 111). The average SOD levels were 36.5 ± 38.8 (0-223.5), 39.3 ± 38.8 (0-160), and 58.8 ± 60.8 (5.25, 400) U/ml in the high exposure-, low exposure-, and control group, respectively. MDA level increased significantly at a cumulative CS(2) exposure of over 60 ppm-years. Dyslipoproteinemia was borderline significantly associated with CS(2) exposure and MDA level. CONCLUSIONS: These results indicate that CS(2) exposure can induce oxidative stress as well as reduce the levels of antioxidative enzymes, and that a cumulative exposure level of 60 ppm-years may be a threshold value for the oxidative and the antioxidant response. Am. J. Ind. Med. 54:637-645, 2011. © 2011 Wiley-Liss, Inc.
Asunto(s)
Contaminantes Ocupacionales del Aire/toxicidad , Aterosclerosis/inducido químicamente , Disulfuro de Carbono/toxicidad , Enfermedades Profesionales/inducido químicamente , Exposición Profesional/efectos adversos , Estrés Oxidativo , Adulto , Antioxidantes/análisis , Aterosclerosis/sangre , Aterosclerosis/enzimología , Biomarcadores/sangre , Catalasa/sangre , Celulosa , Colesterol/sangre , Estudios Transversales , Femenino , Glutatión Peroxidasa/sangre , Humanos , Masculino , Malondialdehído/sangre , Persona de Mediana Edad , Enfermedades Profesionales/sangre , Enfermedades Profesionales/enzimología , Superóxido Dismutasa/sangre , Taiwán , Textiles , Triglicéridos/sangreRESUMEN
BACKGROUND: Serious concerns surround the potential risks resulting from inhalation exposure to pesticides amongst agricultural workers when mixing and applying these compounds. In Eswatini (formerly known as Swaziland), Southern Africa, pesticides are widely used to improve the yield and quality of sugar cane production, the largest contributor to the country's economy. We assessed applicators' inhalation exposures from multiple spraying sources to four commonly used herbicides in Eswatini. RESULTS: Analysis of 76 personal air samples by liquid chromatography with tandem mass spectrometry (LC-MS/MS) revealed four pesticides: ametryn, atrazine, pendimethalin and 2,4-dichlorophenoxyacetic acid, with mean concentrations of 36.91, 21.57, 31.05 and 0.89 µg m-3 , respectively. These inhalation exposures are much higher than those recorded in previous similar studies. CONCLUSION: Although all applicators in this study used personal protective equipment (PPE), they nevertheless recorded high levels of inhalation exposure to commonly used pesticides. Our findings suggest that in addition to observing mandated regular changing and cleaning practices with PPE for ultimate personal protection, pesticide applicators should distance themselves from each other when spraying to effectively reduce their exposure to pesticides from multiple spraying sources. Further studies are needed to determine the optimal spraying distance between pesticide applicators. © 2021 Society of Chemical Industry.
Asunto(s)
Exposición Profesional , Plaguicidas , África Austral , Agricultura , Cromatografía Liquida , Esuatini , Humanos , Exposición por Inhalación , Exposición Profesional/análisis , Plaguicidas/análisis , Espectrometría de Masas en TándemRESUMEN
This study compared respirable dust and nanoparticle concentrations measured by different sampling devices at a titanium dioxide pigment factory. Respirable particle mass concentrations, nanoparticle concentrations, particle size distribution and particle metallic content were measured at different sampling locations. The sampling results of the Multi-orifice Uniform Deposit Impactor (MOUDI) showed that the particle size distribution at this titanium dioxide production factory fell in the range of 1-10 mu m. Generally, the higher levels of the respirable particle mass concentrations and nanoparticle number concentrations were near the packing site of the pigment titanium dioxide production factory. Metal analysis results revealed that the titanium dioxide concentrations in respirable dust and nanoparticles were within the limits specified by National Institute for Occupational Safety and Health (NIOSH). During sampling, particle metallic content analysis is essential for identifying the source of particles and for measuring respirable dust and nanoparticle concentrations.
Asunto(s)
Contaminantes Ocupacionales del Aire/análisis , Colorantes , Polvo/análisis , Industrias , Exposición por Inhalación/análisis , Materiales Manufacturados , Nanopartículas/análisis , Titanio/análisis , Colorantes/síntesis química , Humanos , Tamaño de la Partícula , Factores de TiempoRESUMEN
This study used a full scale mockup of a concrete drilling simulator to simulate drilling processes in an exposure chamber. Six drilling conditions were selected with rotating speeds and drill bit sizes varied from 265 to 587 rpm and 16 to 32 mm, respectively. For each drilling condition, the emitted noise power spectrums were measured and dust exposure concentrations of the fractions of the total (C(tot)), inhalable (C(inh)), thoracic (C(tho)), and respirable (C(res)) were estimated. We find that neither the resultant dust exposure levels nor the noise levels can be explained simply by the involved drilling mechanical energy. By dividing the emitted noise power spectrums into the high and low frequency noise (i.e., W(H) and W(L)), we find that 86.3%, 85.6%, 81.5%, and 77.6% variations of C(tot), C(inh), C(tho), and C(res) could be explained by the combination of W(H) and W(L), respectively. We also find that the emissions of coarse particles and W(L) were possibly contributed by two mechanisms of the impact wear and brittle fracture wear, whereas fine particles and W(H) could be contributed by the mechanism of abrasive wear. Although the predictive models obtained from this study could not be directly used in other dust emission sources, the developed methodology would be beneficial to industries in the future for aerosol exposure assessment, particularly when conducting conventional personal aerosol samplings is not possible in the field.
Asunto(s)
Aerosoles/análisis , Materiales de Construcción/análisis , Exposición por Inhalación/análisis , Modelos Químicos , Ruido en el Ambiente de Trabajo , Material Particulado/análisis , Contaminantes Ocupacionales del Aire/análisis , Cámaras de Exposición Atmosférica , Exposición Profesional/análisis , Tamaño de la PartículaRESUMEN
Ultraviolet radiation (UVR) exposure is known to cause potential effects such as erythema in skin. For UV-induced erythema (sunburn), the action spectrum from the Commission Internationale de l'Eclairage, International Commission on Illumination (CIE) was adopted. Erythemal UV effects from UVR lamp exposure were investigated with commercial spectroradiometry devices in this research. Three kinds of portable UV germicidal lamps with broadband UVA (BB UVA, 350-400 nm), broadband UVB (BB UVB, 280-350 nm), and narrowband UVC (NB UVC, 254 nm) wavelengths served as the UVR emission sources. An action spectrum expresses the effectiveness of radiation for assessing the hazard of UVR in the erythemal action spectrum from 250-400 nm. The UV Index (UVI) is an irradiance scale computed by multiplying the CIE erythemal irradiance integral in milliwatts per square meter by 0.04 m mW. A comprehensive approach to detecting erythemal UVR magnitude was developed to monitor the effective exposure from UV lamps. The erythemal UVR measurement was established and the exposure assessment was applied to monitor erythemal UVR magnitude from shield metal arc welding (SMAW) processing. From this study, the erythemal UVR exposures were assessed and evaluated with environmental solar simulation of the UVI exposure.
Asunto(s)
Eritema/prevención & control , Traumatismos por Radiación/prevención & control , Protección Radiológica/métodos , Rayos Ultravioleta/efectos adversos , Soldadura , Eritema/etiología , Traumatismos por Radiación/etiología , Piel/efectos de la radiación , Análisis EspectralRESUMEN
Two-dimensional electron systems have attracted attention as thermoelectric materials, which can directly convert waste heat into electricity. It has been theoretically predicted that thermoelectric power factor can be largely enhanced when the two-dimensional electron layer is far narrower than the de Broglie wavelength. Although many studies have been made, the effectiveness has not been experimentally clarified thus far. Here we experimentally clarify that an enhanced two-dimensionality is efficient to enhance thermoelectric power factor. We fabricated superlattices of [N unit cell SrTi1-xNb x O3|11 unit cell SrTiO3]10-there are two different de Broglie wavelength in the SrTi1-xNb x O3 system. The maximum power factor of the superlattice composed of the longer de Broglie wavelength SrTi1-xNb x O3 exceeded â¼5 mW m-1 K-2, which doubles the value of optimized bulk SrTi1-xNb x O3. The present approach-use of longer de Broglie wavelength-is epoch-making and is fruitful to design good thermoelectric materials showing high power factor.
RESUMEN
This study reports a method for constructing a head model with a continuous airway passage beginning from the nostrils and continuing through the second generation of bronchi, using computerized tomographic (CT) images of facial features and airway passages from a healthy Taiwanese male adult. When combined with a manikin torso and connected to a cyclic breathing machine, the Taiwanese head model can simulate human breathing movement. This model enables investigation of important parameters of deposition efficiency without the inter- and intrasubject variability that often occurs in human studies. Being an assembly of numerous polymethyl methacrylate (PMMA) plastic slabs, the head model can be applied to study particle deposition at specified respiratory regions. The nasal geometry obtained in this study was compared with those obtained in other studies, which demonstrated this head model to be 36% smaller in nostril cross-sectional area than for European Americans. Additionally, this Taiwanese head model was found to be shorter in nasal cavity length, and the minimum cross-sectional area was only 50% compared to that of European Americans. This study also measured the nasal inhalation efficiency and deposition for particles ranging from 1.5 to 15 microm under various ventilation levels to test the feasibility of this head model. Future particle deposition studies using this Taiwanese head model can be compared with the currently available data, which are primarily based on Caucasian cast models or human subjects.
Asunto(s)
Bronquios/metabolismo , Exposición por Inhalación , Mucosa Nasal/metabolismo , Exposición Profesional , Material Particulado/metabolismo , Adulto , Cámaras de Exposición Atmosférica , Cabeza , Humanos , Masculino , Cavidad Nasal/anatomía & histología , Taiwán , Tomografía Computarizada por Rayos XRESUMEN
OBJECTIVE: In 2005, the Taiwan Institute of Occupational Safety and Health started an on-site consulting program for the medical supplies manufacturing industry, which use ethylene oxide (EO) as a sterilant, with the goal of enhancing occupational hygiene practices and controlling EO-related risks. This study presents EO exposure assessment results and examines the effectiveness of control measures. METHODS: Detailed surveys, including exposure monitoring, were conducted at 10 factories. Airborne EO was collected using an HBr-coated charcoal tube and analyzed using GC/MS. RESULTS: Sterilizer operators had an average short-term EO exposure level of 27.61 ppm during unloading; mean time-weighted average workshift exposure was 7.35 ppm. High EO concentrations were also present throughout the facilities. Specifically, mean EO concentrations in the aeration area, near the sterilizer and in the warehouse were 10.19, 5.75, and 8.78 ppm, respectively. These findings indicate that immediate controls are needed, and that EO emissions from sterilized products during storage cannot be overlooked. Worker short-term exposures during unloading was inversely correlated (p < 0.05) with the numbers of poststerilization purge cycle applied. The specific controls implemented and their usefulness is discussed. CONCLUSION: Increasing the number of poststerilization purge cycles is a simple approach to eliminating extremely high exposure during unloading. Improvements to ventilation, particularly in the aeration area and warehouse, were also effective in minimizing worker exposures. Use of effective respirator is recommended until the EO exposure levels, averaging 3.41 ppm after the controls, fall below the permissible exposure limit.
Asunto(s)
Contaminantes Ocupacionales del Aire/análisis , Óxido de Etileno/análisis , Exposición por Inhalación/prevención & control , Exposición Profesional/prevención & control , Esterilización , Contaminantes Ocupacionales del Aire/toxicidad , Monitoreo del Ambiente , Óxido de Etileno/toxicidad , Humanos , Industrias , TaiwánRESUMEN
In order to speculate the physical mechanisms of contaminant leakage during sash movement and walk-bys through a laboratory fume cupboard, the complicated three-dimensional flow patterns and the real-time tracer gas leakage are studied via the laser-assisted flow visualization method and the standard gas sampling technique, respectively, over a transparent, full scale chemical fume cupboard. Through the flow visualization, the evolution of drastic changes of the flow pattern is demonstrated. The highly turbulent jet-like currents are induced by the unsteady flow motion near the cupboard face. Large-scale turbulent eddies accompanied with the jet-like currents obviously bring large amount of in-cupboard smoke out to the atmosphere. The turbulent mixing extends the size and the strength of the large-scale eddy circulations, and predominantly contributes to the mechanism that causes the severe spread of contaminant leakage in few seconds. The tracer gas tests that are conducted by employing pr-EN 14175:2003 method show consistent containment results with the flow visualization findings. The temporally evolving large-scale turbulent eddies induced by the sash movement and the walk-bys cause substantially high contaminant leakage to the environment and the breathing zone of the operator.
Asunto(s)
Contaminantes Ocupacionales del Aire/análisis , Contaminación del Aire Interior/prevención & control , Laboratorios , Exposición Profesional/prevención & control , Ventilación/instrumentación , Movimientos del Aire , Contaminación del Aire Interior/análisis , Contención de Riesgos Biológicos/instrumentación , Diseño de Equipo , Gases , Humanos , Exposición por Inhalación/prevención & control , Maniquíes , Exposición Profesional/análisisRESUMEN
This study established a comprehensive approach to monitoring UVR magnitude from Shield Metal Arc Welding (SMAW) processing and quantified the effective exposure based on measured data. The irradiances from welding UVR were calculated with biological effective parameter (Slambda) for human exposure assessment. The spectral weighting function for UVR measurement and evaluation followed the American Conference of Governmental Industrial Hygienists (ACGIH) guidelines. Arc welding processing scatters bright light with UVR emission over the full UV spectrum (UVA, UVB, and UVC). The worst case of effective irradiance from a 50 cm distance arc spot with a 200 A electric current and an electrode E6011 (4 mm) is 311.0 microW cm(-2) and has the maximum allowance time (Tmax) of 9.6 s. Distance is an important factor affecting the irradiance intensity. The worst case of the effective irradiance values from arc welding at 100, 200, and 300 cm distances are 76.2, 16.6, and 12.1 microW cm(-2) with Tmax of 39.4, 180.7, and 247.9 s, respectively. Protective materials (glove and mask) were demonstrated to protect workers from hazardous UVR exposure. From this study, the methodology of UVR monitoring in SMAW processing was developed and established. It is recommended that welders should be fitted with appropriate protective materials for protection from UVR emission hazards.
Asunto(s)
Exposición Profesional , Monitoreo de Radiación , Rayos Ultravioleta/efectos adversos , Soldadura , Electrodos , Estudios de Evaluación como Asunto , Guantes Protectores , Humanos , Máscaras , Traumatismos por Radiación , Protección RadiológicaRESUMEN
Ultraviolet radiation (UVR) exposure is known to cause serious effects such as conjunctivitis and keratitis in eyes and erythema in skin. The exposure assessment of UVR has not been well established and developed in workplaces due to the lack of suitable UV detecting instruments. Therefore, UV monitoring and measuring procedures were investigated and developed with commercial spectroradiometry devices described in this paper. The UVR irradiance integrated with a biological effective parameter (S lambda) represents the impacts on human skin and eyes as UV effective irradiance. The spectral weighting function derived from the American Conference of Governmental Industrial Hygienists was applied and evaluated to indicate the degree of harmfulness of UVR as a function of wavelength. A portable UV germicidal lamp with short and long wavelengths (254 nm and 365 nm) served as the UVR emission source. The UVR photon count similar to the perceived brightness of a source, irradiance, and effective irradiance (E eff) of the germicidal lamp were measured and analyzed, then the permissible exposure times (T max) were derived for UVR exposure assessment. This monitoring provided a comprehensive approach to detecting UVR magnitude, evaluated the performance of the approach, and quantified the effective exposure based on measured data. From this study, the methodology of UV measurement was established and could be applied to further UVR exposure assessment in the workplace.
Asunto(s)
Monitoreo de Radiación/métodos , Rayos Ultravioleta , Ojo/efectos de la radiación , Humanos , Traumatismos por Radiación/etiología , Monitoreo de Radiación/instrumentación , Protección Radiológica/métodos , Radiometría , Piel/efectos de la radiación , Rayos Ultravioleta/efectos adversosRESUMEN
We synthesized unique one-dimensional (1D) nanorods and two-dimensional (2D) thin-films of NiO on indium-tin-oxide thin-films using a hot-filament metal-oxide vapor deposition technique. The 1D nanorods have an average width and length of â¼100 and â¼500 nm, respectively, and the densely packed 2D thin-films have an average thickness of â¼500 nm. The 1D nanorods perform as parallel units for charge storing. However, the 2D thin-films act as one single unit for charge storing. The 2D thin-films possess a high specific capacitance of â¼746 F/g compared to 1D nanorods (â¼230 F/g) using galvanostatic charge-discharge measurements at a current density of 3 A/g. Because the 1D NiO nanorods provide more plentiful surface areas than those of the 2D thin-films, they are fully active at the first few cycles. However, the capacitance retention of the 1D nanorods decays faster than that of the 2D thin-films. Also, the 1D NiO nanorods suffer from instability due to the fast electrochemical dissolution and high nanocontact resistance. Electrochemical impedance spectroscopy verifies that the low dimensionality of the 1D NiO nanorods induces the unavoidable effects that lead them to have poor supercapacitive performances. On the other hand, the slow electrochemical dissolution and small contact resistance in the 2D NiO thin-films favor to achieve high specific capacitance and great stability.
RESUMEN
STUDY OBJECTIVES: Sleep-disordered breathing (SDB) is associated with an increased risk of motor vehicle crashes. This study aimed to understand SDB progression and related factors among professional drivers. METHODS: A total of 524 professional male drivers from a transportation company were included in this study. These drivers completed overnight in-home pulse oximetry studies both in 2006 and in 2009. Participants with abnormal results (oxygen desaturation index [ODI] ≥ 10 events/h) comprised the SDB group. Data included questionnaire information on demographics, medical history, SDB symptoms, and anthropometric measurements. RESULTS: A total of 318 male workers were recruited for further analysis. Fifty of these workers belonged to the SDB group. Workers with untreated SDB significantly progressed to a more severe state after three years. Baseline body mass index (BMI), baseline ODI, and change in BMI were all significant positive predictors of SDB progression (ß = 0.823, 0.242, and 1.626; p = 0.047, 0.013, and 0.004, respectively). Compared with non-SDB drivers, SDB subjects showed a greater proportion of newly diagnosed cardiovascular disease (38.0%) at follow-up. CONCLUSIONS: Untreated SDB was a gradually progressive disorder in professional drivers over a three-year period. Subjects with high BMI and moderate to severe SDB should be closely monitored to allow for early detection of worsening SDB. Weight control should be highlighted in the management of SDB. COMMENTARY: A commentary on this article appears in this issue on page 409.
Asunto(s)
Síndromes de la Apnea del Sueño/etiología , Conducción de Automóvil/estadística & datos numéricos , Índice de Masa Corporal , Enfermedades Cardiovasculares/etiología , Progresión de la Enfermedad , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Oximetría , Factores de Riesgo , Síndromes de la Apnea del Sueño/complicaciones , Síndromes de la Apnea del Sueño/patología , Encuestas y Cuestionarios , Transportes/estadística & datos numéricosRESUMEN
This article gave a brief introduction of population, labor force, general status of occupational safety and health in Taiwan. Statistics of occupational injuries and health disorders, laws and regulations relevant to occupational health were also covered. Research activities driven by universities, research institutes, society/association were provided. Two multi-lateral collaborative research examples were presented: an intoxication outbreak-initiated CS2 study and an information-demand-motivated 2-methoxy-ethanol study. Industrial hygienists, engineers, epidemiologists, and occupational physicians from both universities and research institutes, governmental agencies, and from non-profit R&D organizations and academic associations were involved in these researches, presenting a promise that integrated collaboration of inter-disciplinary specialty cooperated with governmental participation could benefit not only academic achievement, governmental policy-makeup, but also to the employees themselves.