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BACKGROUND: Work-related stress and its detrimental effects on human health have rapidly increased during the past several years. It causes many different stress reactions, related diseases and unhealthy behavior among workers, but especially women workers. Thus, the aim of this study was to examine the effects of the work-related stress model based Workplace Mental Health Promotion Programme on the job stress, social support, reactions, salivary immunoglobulin A and Cortisol levels, work absenteeism, job performance and coping profiles of women workers. METHODS: This study had a "pre-test post-test non-equivalent control groups" design and included 70 women workers (35 in each study group) selected by randomized sampling from two factories. The programme was delivered as an intervention including 12 weeks of follow-up. Reminder messages, videos, and WhatsApp texts were used at the follow-up stage. The research measurements were; the assessment form, the Brief Job Stress Questionnaire, the Brief Coping Profile Scale, salivary ELISA kits, and a self-reported check-list. RESULTS: There were no differences in sociodemographic characteristics, general health or working conditions between the Intervention and control groups(p > .05). Three months after the intervention, there was a significant decrease in job stress(p ≤ .001), physical and mental reactions' scores(p ≤ .001) and work absenteeism(p < .05), and there was an increase in job performance(p < .05), social support(p ≤ .001) among the intervention group. The programme showed positive effects on coping profiles(p < .05). After the intervention salivary-cortisol and IgA levels showed a statistically significant decrease(p < .05). A majority of effect sizes were very large (ηp2 > .14). CONCLUSIONS: Work-ProMentH was found to be effective and useful in job stress management and promotion of effective coping profiles. It enables its users to holistically assess worker stress and to plan and examine intervention programmes via a systematic approach. There is a need for more empirical studies that may support the data of the present study, but it is thought that the intervention can be maintained for the long-term. We recommend that occupational health professionals at workplaces should consider using this model-based cost-effective intervention, which seems easy and practical to apply in real-life situations. TRIAL REGISTRATION: ISRCTN registration ID: ISRCTN14333710 (2020/10/03, retrospective registration).
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Adaptación Psicológica , Promoción de la Salud/métodos , Salud Mental , Salud Laboral , Estrés Laboral , Evaluación de Programas y Proyectos de Salud , Lugar de Trabajo/psicología , Absentismo , Adulto , Grupos Control , Femenino , Humanos , Hidrocortisona/metabolismo , Inmunoglobulina A/metabolismo , Masculino , Industria Manufacturera , Dolor , Estudios Retrospectivos , Apoyo Social , Estrés Psicológico/etiología , Encuestas y Cuestionarios , Mujeres Trabajadoras , Adulto JovenRESUMEN
New World archaeologists have amply demonstrated that fluted point technology is specific to Terminal Pleistocene American cultures. Base-fluted, and rarer tip-fluted, projectile points from the Americas have been well-documented by archaeologists for nearly a century. Fluting is an iconic stone tool manufacturing method and a specific action that involves the extraction of a channel flake along the longitudinal axis of a bifacial piece. Here we report and synthesize information from Neolithic sites in southern Arabia, demonstrating the presence of fluting on a variety of stone tool types including projectile points. Fluted projectile points are known from both surface sites and stratified contexts in southern Arabia. Fluting technology has been clearly identified at the Manayzah site (Yemen) dating to 8000-7700 cal. BP. Examination of fluted points and channel flakes from southern Arabia enable a reconstruction of stone tool manufacturing techniques and reduction sequences (chaines opératoires). To illustrate the technological similarities and contrasts of fluting methods in Arabia and the Americas, comparative studies and experiments were conducted. Similarities in manufacturing approaches were observed on the fluting scars of bifacial pieces, whereas technological differences are apparent in the nature and localization of the flute and, most probably, the functional objective of fluting in economic, social and cultural contexts. Arabian and American fluted point technologies provide an excellent example of convergence of highly specialized stone tool production methods. Our description of Arabian and American fluting technology demonstrates that similar innovations and inventions were developed under different circumstances, and that highly-skilled and convergent production methods can have different anthropological implications.
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Tecnología/historia , Américas , Arabia , Arqueología , Historia Antigua , Humanos , Invenciones/historia , Industria Manufacturera/historia , YemenRESUMEN
Motivations for food choices may determine consumption, and understanding that relationship may help direct strategies for formulating diets. This study aimed to identify associations between motivations for food choices and consumption of food groups. An observational cross-sectional survey was conducted in 921 manufacturing workers from 33 companies in Brazil, based on a stratified two-stage probability sample. Motivations for food choices were assessed with the Food Choice Questionnaire, and intake of food groups was measured using 24-h dietary recall. Consumption was classified into 31 food groups defined according to their nutritional value and the NOVA classification. Data were analyzed with multilevel mixed-effects regression. The results showed that sensory appeal and price were the most important motivations for food choices, while ethical concern was less important. Sensory appeal was positively associated with consumption of industrialized condiments (p = 0.022), price showed a negative correlation with consumption of plant oils (p = 0.022), ethical concern showed positive correlation within consumption white meat (p = 0.065) and negative correlation within pasta dishes (p < 0.001). Regarding the NOVA classification, health correlated with an increase in consumption of unprocessed foods (p = 0.017) and weight control with a decrease in consumption of processed culinary ingredients (p = 0.057).
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Preferencias Alimentarias , Industria Manufacturera , Motivación , Adulto , Brasil , Estudios Transversales , Dieta , Ingestión de Alimentos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Nutritivo , Estudios Prospectivos , Adulto JovenRESUMEN
What are the consequences of lay beliefs about how things are made? In this article, we describe a Western folk theory of artifact creation, highlighting how intuitive dualism regarding mental and physical labor (i.e., folk psychology) can lead to the perceived transmission of properties from makers to material artifacts (i.e., folk physics), and affect people's interactions with material artifacts. We show how this folk theory structures the conceptual domain of material artifacts by differentiating the contemporary lay concepts of art/craft and industrial production, and how it influences people's evaluations of different types of artifacts and their makers. We propose that the folk theory and lay concepts of art/craft and industrial production are best understood within a specific sociohistorical context, and review potential sources of cross-cultural and cross-temporal variation. We conclude by making recommendations for future research and examining the implications for promoting environmental sustainability and social justice in production systems.
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Cultura , Apego a Objetos , Trabajo , Antropología Cultural , Arte , Humanos , Industria Manufacturera , Teoría Psicológica , Justicia Social , Teoría SocialRESUMEN
The geotechnical, chemical, and mineralogical properties of green liquor dregs (GLDs) generated as byproducts from five paper mills were investigated to assess their buffering and heavy metal immobilization capacities and their roles as water and oxygen barriers. One type of GLD was further studied to test the effects of the retrieval process and the storage, drying, and hydration of GLD. The high water retention capacity of the GLDs is valuable for limiting O2 diffusion. Laboratory results showed that the GLDs had hydraulic conductivities of 3.7 × 10-9-4.6 × 10-8 m/s and varied regularly in plasticity. The chemical and mineralogical compositions of the GLDs varied greatly, reflecting the raw material used to produce paper and the process used to retrieve GLDs. Although they had high total heavy metal contents, none of the leached elements from the GLDs (L/S 10 cm3/kg) exceeded the European Union's limits for landfills of non-hazardous waste. The GLDs exhibited high buffering capacities. In a supplementary test, the buffering capacities varied (0.0041-0.0114 M H+/g GLD) over 72 d after acid was added to the GLD. Changing the filtration process did not greatly affect the GLDs' properties but mainly affected the hydraulic conductivity, total heavy metal contents and sulfur content. Analyzing the storage of GLDs is necessary in the mining industry because remediation measures require large amounts of material over short periods. The buffering capacity of the dried GLD decreased slightly. The effect of dewatering caused by the mixing of 2% Na-lignosulfate with GLD (w/w) was low.
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Restauración y Remediación Ambiental/métodos , Minería , Residuos , Industria Manufacturera , Metales Pesados/análisis , Azufre/análisisRESUMEN
The present study reports on the remediation of an effluent from the wood-laminate industry using Pleurotus ostreatus EB 016 in combination with photo-Fenton oxidation. Fermentation of the effluent with P. ostreatus EB-016 was carried out in agitated flasks to evaluate the influence of pH, and concentrations of carbon and nitrogen sources by a multivariate approach. Subsequently, bioassays was conducted in an air-lift bioreactor using the pre-optimized conditions. In addition, photo-Fenton oxidative treatment was employed to degrade recalcitrant compounds, and the ecotoxicity of the effluents were evaluated using Escherichia coli as a biological model. The crude effluent presented high contents of total phenolics (1,220â¯mg/L), solids (18.45â¯g/L) and color intensity (8,333â¯CU), besides high values of chemical (COD 2,477â¯mg O2./L) and biochemical (BOD5, 8,450â¯mg O2/L) oxygen demand. Another feature was the high inhibition on Escherichia coli (71%). Reduction of 64% COD was obtained under optimized conditions (pH5.7, 7.5â¯g/L sucrose, 4.0â¯g/L ammonium nitrate) in agitated flasks after 10 days treatment. In the air-lift reactor, 50.6% COD and 29.9% total phenols were removed after 10 days. Combination of biotreatment with photo-Fenton oxidation resulted in removal of 99.2% COD and 92.2% phenolics and absence of inhibition on Escherichia coli.
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Reactores Biológicos/microbiología , Peróxido de Hidrógeno/química , Residuos Industriales/análisis , Hierro/química , Industria Manufacturera , Pleurotus/crecimiento & desarrollo , Eliminación de Residuos Líquidos/métodos , Madera/química , Biodegradación Ambiental , Análisis de la Demanda Biológica de Oxígeno , Oxidación-ReducciónAsunto(s)
Industria Manufacturera/organización & administración , Tecnología/organización & administración , Inteligencia Artificial , China , Difusión de Innovaciones , Emprendimiento/economía , Emprendimiento/organización & administración , Historia Antigua , Inversiones en Salud , Industria Manufacturera/economía , Semiconductores , Seda/historia , Tecnología/economía , Universidades/organización & administraciónRESUMEN
Ozone and a Fe2+/TiO2-based catalyst were examined in the degradation of a synthetic solution of benzene toluene and xylene (BTX) in an advanced oxidation process (AOP). The catalyst beads were made from the slurry waste of aluminum production process, by inserting the TiO2 content and subsequent calcination. The reduction of the BTX concentration load was monitored by the reduction of chemical oxygen demand (COD) and BTX concentration. Different levels were used on factors: pH, time of treatment, initial concentration of BTX, and percentage of TiO2. The process was conducted in a bubble column reactor with the insertion of catalyst beads. A response surface methodology technique (CCD) was used to build a model based on COD reduction results. The model was optimized using the normal-boundary intersection (NBI) algorithm to maximize COD reduction and minimize the variance attributed to the process. Optimization led to COD reductions of 80% in 2 h of experiment. Correlation analysis of coefficient models from experimental data R2adj was 0.9966, showing a good fit of model data. In the optimized conditions, the possible increase of the biodegradability ratio of the BTX solution, through the biochemical oxygen demand (BOD) and COD, was also analyzed. Under pre-treatment conditions, the BOD/COD ratio was 0.13. After the treatment, it increased to 0.56. Graphical abstract á .
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Benceno/química , Sedimentos Geológicos/química , Ozono/química , Titanio/química , Tolueno/química , Eliminación de Residuos Líquidos/métodos , Xilenos/química , Algoritmos , Aluminio , Biodegradación Ambiental , Análisis de la Demanda Biológica de Oxígeno , Catálisis , Monitoreo del Ambiente , Peróxido de Hidrógeno/química , Concentración de Iones de Hidrógeno , Industria Manufacturera , Oxidación-Reducción , SolucionesRESUMEN
OBJECTIVE: The aim of this study was to compare estimates of the prevalence and incidence of metabolic syndrome (MetS) using various data sources. METHODS: We integrated health risk assessment (HRA), claims, and biometric screening data from Lockheed Martin Corporation. We measured the extent to which MetS risk factors measured using HRA and medical claims correlated with biometric screening data. RESULTS: Using biometric data, 24.9% of employees were identified as having MetS. Prevalence estimates were much lower using HRA data (6.8%) and claims (3.7%). Between 2012 and 2014, 10.4% of the sample newly acquired MetS. The number of MetS risk factors per employee was predictive of diabetes, heart disease, health care costs, and utilization. CONCLUSION: MetS is prevalent and associated with progression to disease. It is more easily tracked with biometric screening data than with HRA or claims data. Employers should consider efforts to manage and prevent this condition in their workforce.
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Reclamos Administrativos en el Cuidado de la Salud/estadística & datos numéricos , Antropometría , Industria Manufacturera , Síndrome Metabólico/epidemiología , Medición de Riesgo/estadística & datos numéricos , Aeronaves , Glucemia/metabolismo , Estatura , Peso Corporal , Bases de Datos Factuales , Diabetes Mellitus/epidemiología , Femenino , Recursos en Salud/economía , Recursos en Salud/estadística & datos numéricos , Cardiopatías/epidemiología , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Obesidad/epidemiología , Salud Laboral , Prevalencia , Factores de Riesgo , Circunferencia de la CinturaRESUMEN
Artificial neural networks (ANNs) have been widely used to solve the problems because of their reliable, robust, and salient characteristics in capturing the nonlinear relationships between variables in complex systems. In this study, ANN was applied for modeling of Chemical Oxygen Demand (COD) and biodegradable organic matter (BOD) removal from palm oil mill secondary effluent (POMSE) by vetiver system. The independent variable, including POMSE concentration, vetiver slips density, and removal time, has been considered as input parameters to optimize the network, while the removal percentage of COD and BOD were selected as output. To determine the number of hidden layer nodes, the root mean squared error of testing set was minimized, and the topologies of the algorithms were compared by coefficient of determination and absolute average deviation. The comparison indicated that the quick propagation (QP) algorithm had minimum root mean squared error and absolute average deviation, and maximum coefficient of determination. The importance values of the variables was included vetiver slips density with 42.41%, time with 29.8%, and the POMSE concentration with 27.79%, which showed none of them, is negligible. Results show that the ANN has great potential ability in prediction of COD and BOD removal from POMSE with residual standard error (RSE) of less than 0.45%.
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Chrysopogon/metabolismo , Restauración y Remediación Ambiental/métodos , Residuos Industriales/análisis , Redes Neurales de la Computación , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/metabolismo , Biodegradación Ambiental , Análisis de la Demanda Biológica de Oxígeno , Restauración y Remediación Ambiental/instrumentación , Malasia , Industria Manufacturera , Aceite de Palma , Aceites de Plantas , Eliminación de Residuos Líquidos/instrumentaciónRESUMEN
OBJECTIVE: To assess the test-retest variability of hearing thresholds obtained with an innovative, mobile wireless automated hearing-test system (WAHTS) with enhanced sound attenuation to test industrial workers at a worksite as compared to standardised automated hearing thresholds obtained in a mobile trailer sound booth. DESIGN: A within-subject repeated-measures design was used to compare air-conducted threshold tests (500-8000 Hz) measured with the WAHTS in six workplace locations, and a third test using computer-controlled audiometry obtained in a mobile trailer sound booth. Ambient noise levels were measured in all test environments. STUDY SAMPLE: Twenty workers served as listeners and 20 workers served as operators. RESULTS: On average, the WAHTS resulted in equivalent thresholds as the mobile trailer audiometry at 1000, 2000, 3000 and 8000 Hz and thresholds were within ±5 dB at 500, 4000 and 6000 Hz. CONCLUSIONS: Comparable performance may be obtained with the WAHTS in occupational audiometry and valid thresholds may be obtained in diverse test locations without the use of sound-attenuating enclosures.
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Estimulación Acústica/instrumentación , Acústica/instrumentación , Audiometría/instrumentación , Umbral Auditivo , Pérdida Auditiva Provocada por Ruido/diagnóstico , Audición , Industria Manufacturera , Ruido en el Ambiente de Trabajo/efectos adversos , Enfermedades Profesionales/diagnóstico , Exposición Profesional/efectos adversos , Salud Laboral , Tecnología Inalámbrica/instrumentación , Adulto , Automatización , Diseño de Equipo , Femenino , Pérdida Auditiva Provocada por Ruido/etiología , Pérdida Auditiva Provocada por Ruido/fisiopatología , Pérdida Auditiva Provocada por Ruido/psicología , Humanos , Masculino , Persona de Mediana Edad , Enfermedades Profesionales/etiología , Enfermedades Profesionales/fisiopatología , Enfermedades Profesionales/psicología , Valor Predictivo de las Pruebas , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: Because of the long asbestos-related disease latencies (10-50 years), detection, diagnosis, and epidemiologic studies require asbestos exposure history. However, environmental asbestos exposure source (EAES) data are lacking. OBJECTIVES: To survey the available data for past EAES and supplement these data with interviews. METHODS: We constructed an EAES database using a literature review and interviews of experts, former traders, and workers. Exposure sources by time period and type were visualized using a geographic information system (ArcGIS), web-based mapping (Google Maps), and OpenWeatherMap. The data were mounted in the GIS to show the exposure source location and trend. RESULTS: The majority of asbestos mines, factories, and consumption was located in Chungnam; Gyeonggi, Busan, and Gyeongnam; and Gyeonggi, Daejeon, and Busan, respectively. Shipbuilding and repair companies were mostly located in Busan and Gyeongnam. CONCLUSIONS: These tools might help evaluate past exposure from EAES and estimate the future asbestos burden in Korea.
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Amianto , Exposición a Riesgos Ambientales , Humanos , Industria Manufacturera , Minería , Centrales Eléctricas , República de Corea , Navíos , AceroRESUMEN
The industrial treatment of dimension stones, such as marbles and granites, includes a stage of plate polishing, in which resins and abrasives are used, producing a fine grained waste with high moisture content. These wastes pass through decantation tanks in order to separate the solid and liquid phases. Until now, there is no knowledge about the mutagenic effects that this effluent can cause to organisms exposed to it. Thus, this study evaluated the mutagenic potential of dimension stone polishing wastes in onion root cells and fish erythrocytes. The onion seeds were germinated in Petri dishes with filter paper moistened in the liquid phase of the effluent. After germination, the onion roots were prepared for analysis of chromosomal aberrations in meristematic cells. The fishes were exposed during 72h to the solid phase of the effluent diluted in pure groundwater. Blood samples were used for counting of micronucleus and nuclear abnormalities. The onion seeds had similar germination and mitotic index in all treatments. However, it was observed in the seeds exposed to the polishing waste, numbers significantly higher of micronucleus, nuclear buds and other chromosomal aberrations when compared with the negative control. The fishes exposed to the waste showed numbers significantly higher of micronucleus when compared with the negative control. The fishes from all treatments showed significant increase in nuclear abnormalities when compared to the negative control. We concluded that the analysed wastes have mutagenic potential at the studied conditions; this effect can be related to the high content of phenolic compounds identified in the samples.
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Residuos Industriales/análisis , Mutágenos/análisis , Animales , Aberraciones Cromosómicas/inducido químicamente , Cromosomas de las Plantas/efectos de los fármacos , Cíclidos , Eritrocitos/efectos de los fármacos , Eritrocitos/metabolismo , Germinación/efectos de los fármacos , Industria Manufacturera , Meristema/efectos de los fármacos , Índice Mitótico , Mutágenos/toxicidad , Cebollas/efectos de los fármacos , Fenol/análisis , Raíces de Plantas/efectos de los fármacos , Semillas/efectos de los fármacos , Aguas Residuales/químicaRESUMEN
A pilot-scale biotrickling filter (BTF) was established in treating the waste gases that are intermittently produced from an automobile paint-manufacturing workshop. Results showed that the BTF required longer time to adapt to the aromatic compounds. The removal efficiencies (REs) for all aliphatic compounds reached more than 95% on day 80. Aromatic compounds were not easily removed by the BTF. The REs obtained by the BTF for toluene, ethylbenzene, m-xylene, o-xylene and p-xylene on day 80 were 72.7%, 77.2%, 71.9%, 74.8% and 60.0%, respectively. A maximum elimination capacity (EC) of 13.8â g-Câ m(-3)â h(-1) of the BTF was achieved at an inlet loading rate of 19.4â g-Câ m(-3)â h(-1) with an RE of 72%. Glucose addition promoted the biomass accumulation despite the fact that temporal decrease of REs for aromatic compounds occurred. When the inlet loading rates exceed 11.1â g-Câ m(-3)â h(-1), the REs of the aromatic compounds decreased by 10% to 15%. This negative effect of shock loads on the performance of the BTF can be attenuated by the pre-treatment of the photocatalytic reactor. Nearly all components were removed by the combined system with REs of 99%.
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Contaminantes Atmosféricos/química , Contaminación del Aire/prevención & control , Reactores Biológicos , Filtración/métodos , Fotólisis , Compuestos Orgánicos Volátiles/química , Industria Manufacturera , Pintura , Proyectos PilotoRESUMEN
BACKGROUND: Workplace noise exposure gains growing attention in high tech industry. OBJECTIVE: This study investigated the noise effect on physiological and subjective responses in semiconductor manufacturing clean room environment. METHODS: Twenty subjects including 10 males and 10 females completed all phases of the experiment. Each subject was asked to participate in four treatment combinations of two noise intensities [65 dB(A) and 80 dB(A)] × two frequency levels [high and low]. For each treatment condition, the subject was exposed to the specified noise condition in a sound proof cabin for one hour. The physiological measures included blood pressure and heart rate. The subjective measures included noise sensitivity, fatigue and annoyance. RESULTS: The ANOVA results indicate that long-time noise exposure caused significant increase in blood pressure (p< 0.001). Furthermore, the noise intensity by time interaction effect was found to be significant on annoyance and fatigue. CONCLUSIONS: The findings suggest that prolonged exposure to noise intensity at 80 dB(A) would result in a significant increase in physiological cost and subjective discomfort feeling. Thus, some countermeasures should be taken to reduce noise exposure and to promote health, and quality of working life.
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Estimulación Acústica , Industria Manufacturera , Ruido en el Ambiente de Trabajo/efectos adversos , Exposición Profesional/efectos adversos , Estimulación Acústica/psicología , Adulto , Presión Sanguínea , Ambiente Controlado , Fatiga/etiología , Femenino , Frecuencia Cardíaca , Humanos , Genio Irritable/fisiología , Percepción Sonora , Masculino , Semiconductores , Adulto JovenRESUMEN
ETHNOPHARMALOGICAL RELEVANCE: The rapid commodification of plant-based medicines has led to the development of regulatory guidelines and standards by the World Health Organization to ensure the safety of these products. However, these standards have been identified to be selectively implemented, if implemented at all, in many contexts. A primary concern for proving the safety of intrinsic factors of plant-based medicines, may result in less attention paid to the often more problematic extrinsic factors of mass production. This article critically examines the normative global discourse of safety concerning plant-based medicines and problematises many of the assumptions identified in this discourse. MATERIALS AND METHODS: This qualitative research was conducted in the Traditional Medicine Unit of the Western Pacific Regional Office of the World Health Organization (WHO) and in field work in the rural Philippines. Data was collected through archival research, analysis of WHO data sets, semi-structured and structured interviews and surveys, participant observation concerning local plant-based medicine use in the Philippines and participant observation in WHO meetings regarding future strategies for traditional Asian medicines. RESULTS: Although informants reported concerns of safety for every aspect of the production, marketing and sales of plant-based medicines, this research has identified that the implementation (WHO guidelines) has been uneven and inconsistent over the past ten years in the Western Pacific Region of the WHO. Differences in local contexts that are not consistent with global guidelines and standards were reported by informants. Issues have also been identified in the inconsistent regulation of plant-based medicines as pharmaceuticals within only certain, rather than all, processes of production. CONCLUSIONS: It is imperative to understand plant-based medicines as the potent substances they are, whose rapid global commodification may affect both their potency and safety. The WHO discourse of the need for safety in the use of plant-based medicines has justified the need for biomedical oversight through processes of commodification. Yet, it is often through these very processes of commodification and mass production that safety may be compromised. This research suggests that the discourse concerning the safety of the plant-based medicines needs to be reframed from a primary focus on the intrinsic factors of plant-based medicines to a greater focus on the extrinsic factors of global commodification.
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Mercantilización , Medicina Tradicional , Plantas Medicinales , Humanos , Industria Manufacturera/normas , Medicina Tradicional/efectos adversos , Medicina Tradicional/normas , Plantas Medicinales/efectos adversos , Riesgo , Organización Mundial de la SaludRESUMEN
PURPOSE: The aim of the study was to assess external and internal selenium exposure and potential biological effects in employees working in a selenium-processing plant. METHODS: Twenty male employees of a selenium-processing plant (exposed) and 20 age-matched male individuals without occupational selenium exposure (controls) participated in the study. Exposure to selenium at the workplace was determined by personal air sampling. Internal exposure was assessed by measuring total selenium concentration in plasma after a workshift and after holidays as well as by measuring the selenium concentration in urine before and after shift and after holidays. The activity of glutathione peroxidase (GPx) in blood and the prothrombin time were determined as biological effect parameters. RESULTS: The exposure to selenium in the workplace air ranged from 8 to 950 µg/m(3) and exceeded in a large part current occupational exposure limits. The selenium levels in plasma samples of the exposed ranged from 49 to 182 µg/L during exposure and were significantly higher than the plasma levels observed after holidays as well as in the control group. The selenium concentration in pre- and post-shift urine samples did not differ significantly, and the average urinary selenium levels of the employees (18-1,104 µg/g creatinine) were significantly higher than those measured after holidays or determined in controls. Both the concentration of selenium in plasma and in urine did not correlate with the current external exposure of the employees at the workplace. However, we found a strong and significant association between the two biomonitoring parameters. In spite of the considerable high external exposure to elemental selenium, we did not find any effect on the GPx activity in blood as well as on the prothrombin time. CONCLUSIONS: Both the selenium levels in plasma and urine may be used as biological monitoring parameters for the assessment of chronic occupational exposure to selenium. Nevertheless, the toxicokinetics of the urinary excretion of selenium remain still unclear and require further investigations. Moreover, our findings emphasise the necessity of a re-evaluation of occupational exposure limits for elemental selenium and inorganic selenium compounds.
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Contaminantes Ocupacionales del Aire/análisis , Monitoreo del Ambiente/métodos , Industria Manufacturera , Exposición Profesional/análisis , Selenio/análisis , Adulto , Contaminantes Ocupacionales del Aire/toxicidad , Estudios de Casos y Controles , Glutatión Peroxidasa/sangre , Humanos , Masculino , Concentración Máxima Admisible , Persona de Mediana Edad , Enfermedades Profesionales/sangre , Enfermedades Profesionales/orina , Exposición Profesional/efectos adversos , Tiempo de Protrombina , Selenio/toxicidadRESUMEN
OBJECTIVES: There is concern that sound via earphones and headphones attached to headsets used in workplaces may be a risk factor for noise-induced hearing loss (NIHL). Although there are some previous studies investigating exposure to noise from headphones, almost none have assessed the risks to workers who use earphones. We assessed exposure to noise among workers who regularly wear earphones in noisy workplaces. METHODS: The subjects of this study were 21 workers who regularly wear earphones in three manufacturing companies in Japan. The sound pressure output from earphones and personal exposure to occupational noise was measured for each worker. A noise-dosimeter was used to measure individual exposure to occupational noise. The sound pressure output from the earphones was measured by recording the electric signal with a data recorder attached to the earphones, and the recording was analyzed by playing it back in the laboratory through a sound analyzer via an ear simulator. RESULTS: The mean scores for personal exposure and earphone output LAeq were 87.9 dB and 87.6 dB, respectively. Earphone output LAeq exceeded 85 dB for two-thirds of the subjects. Nearly all the subjects lacked hearing protection devices (HPDs) on their earphones. CONCLUSIONS: The results suggest that workers who use earphones in noisy workplaces are exposed to the following NIHL risk factors: (1) they are deprived of the opportunity to fit appropriate HPDs, and (2) the sound pressure output from the earphones themselves exceeds the occupational exposure limit.
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Industria Manufacturera , Ruido en el Ambiente de Trabajo , Exposición Profesional/análisis , Estimulación Acústica/instrumentación , Adulto , Dispositivos de Protección de los Oídos , Pérdida Auditiva Provocada por Ruido/etiología , Pruebas Auditivas , Humanos , Japón , Persona de Mediana Edad , Ruido en el Ambiente de Trabajo/efectos adversos , Enfermedades Profesionales/etiología , Voz , Lugar de TrabajoRESUMEN
The goal of this study is to demonstrate that it is possible to construct a two-stage dispersion model empirically for the purpose of estimating air pollution levels in the vicinity of petrochemical plants. We studied oil refineries and coal-fired power plants in the No. 6 Naphtha Cracking Complex, an area of 2,603-ha situated on the central west coast of Taiwan. The pollutants targeted were vanadium (V) from oil refineries and arsenic (As) from coal-fired power plants. We applied a backward fitting method to determine emission rates of V and As, with 192 PM10 filters originally collected between 2009 and 2012. Our first-stage model estimated emission rates of V and As (median and 95% confidence intervals at 0.0202 (0.0040-0.1063) and 0.1368 (0.0398-0.4782) g/s, respectively. In our second stage model, the predicted zone-average concentrations showed a strong correlation with V, but a poor correlation with As. Our findings show that two-stage dispersion models are relatively precise for estimating V levels at residents' addresses near the petrochemical complex, but they did not work as well for As levels. In conclusion, our model-based approach can be widely used for modeling exposure to air pollution from industrial areas in countries with limited resources.