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1.
Artigo em Chinês | WPRIM | ID: wpr-1036495

RESUMO

The microbiological quality of laboratory animals is crucial for the validity and reproducibility of scientific research data, as well as human health and animal welfare. Currently, individual ventilation cages (IVC) have become the mainstream feeding system for rodent laboratory animals. The most commonly used pathogen monitoring method for this feeding system is soiled bedding sentinels (SBS). This method monitors the microbial carrying status of mouse colony through indirect contact and delayed feedback. It can effectively monitor pathogens transmitted via the fecal-oral route, such as mouse hepatitis virus and reovirus. However, this method has difficulty detecting pathogens mainly transmitted through aerosols or direct contact, such as Sendai virus and Pasteurella pneumotropica. The exhaust air dust (EAD)-PCR monitoring method involves swab sampling in the IVC exhaust ducts to monitor the corresponding racks of the ducts; swab sampling before the prefiltration of the host to monitor the entire IVC rack; and EAD collection device sampling to monitor all racks connected to the same host. Different IVC manufacturers have developed corresponding EAD collection devices for their respective IVC systems, making operations convenient and standardization easy. Compared with the SBS method, the EAD-PCR method significantly improves detection rate and timeliness, with the fastest detection possible after one week of exposure. It can serve as a supplement or replacement for the SBS method. Currently, increasing evidence supports that EAD-PCR testing is a more reliable, sensitive, and cost-effective monitoring method, and is more beneficial to animal welfare. This article reviews the application progress of these two methods for monitoring pathogens, analyzes the existing limitations of the EAD-PCR method, and proposes solutions based on its implementation in our laboratory and examination units. The EAD-PCR method helps reduce the number of live sentinel animals used in pathogen monitoring, in order to better maintain the "3Rs" principle of laboratory animal welfare.

2.
Artigo em Chinês | WPRIM | ID: wpr-973636

RESUMO

The air pollution related health hazards have been a major public health issue for a long time. As an important source of air pollution, diesel exhaust (DE) exposure associates with serious adverse health outcomes. Apart from the exposure in general population, extensive occupational DE exposure populations are reported in many industries, such as transportation, mining, shipping, and construction. Therefore, the studies for internal exposure levels, biomarkers, and toxic mechanisms of DE in occupational population are critical for protecting human from DE-posed health hazards. This special column published some novel findings involving DE exposure (internal & external exposure level), multiple biological effects, toxicity mechanisms, key molecular events, and crucial biomarkers. These studies will provide scientific data for controlling DE associated occupational health hazards, formulating effective DE pollution control strategies, and provide a new scientific perspective and evidence for health risk assessment and prevention.

3.
Artigo em Chinês | WPRIM | ID: wpr-973638

RESUMO

Background Due to the limited availability of established research models, very few studies addressed the health effects and underlying mechanisms following exposure to diesel exhaust during the initiation of pulmonary respiration. It is highly demanded to elucidate such health effects and underlying mechanisms, so as to exert protective measures during the early stages of life. Objective To evaluate the health effects of diesel exhaust very-early-in-life inhalation in hatchling chicken with a novel chicken embryo air cell inhalation exposure model, and to explore the potential roles of aryl hydrocarbon receptor signaling pathways in the observed effects with a specific aryl hydrocarbon receptor inhibitor. Methods Fertilized chicken eggs were assigned into five groups randomly (15 eggs per group): control group, air control group, aryl hydrocarbon receptor inhibitor (PDM2) group, diesel exhaust group, and diesel exhaust + aryl hydrocarbon receptor inhibitor (PDM2) group. Fertilized eggs were incubated with standard procedure. At embryonic day 17 (ED17), aryl hydrocarbon receptor inhibitor was administered to the corresponding animals. During embryonic day 18-19 (ED18-19), chicken embryos were exposed to diesel exhaust via air cell inhalation, then placed back to incubator until hatch. The air control group received clean air infusion during ED18-19, while the control group did not receive any treatment. Within 24 h post-hatch, 26 hatchling chickens were anesthetized with sodium pentobarbital, subjected to electrocardiography, and sacrificed to harvest tissue samples of heart and lung. Cardiopulmonary toxicities were evaluated by histopathology, and potential changes in the protein expression levels of aryl hydrocarbon receptor pathway molecule cytochrome P450, family 1, subfamily A, polypeptide 1 (CYP1A1) and fibrosis-related pathway molecule phosphorylated SMAD family member 2 (pSMAD2) were assessed by Western blotting. The remaining 29 hatchling chickens were reared until two weeks old, and then subjected to identical treatments. Results The inhalation exposure to diesel exhaust at initiation of pulmonary respiration resulted in thickened right ventricular wall (by 220.3% relative to the control group, same hereafter) and elevated heart rate (17.4%) in one-day-old hatchling chickens. Although no remarkable fibrotic lesions were observed at this point, the expression levels of CYP1A1 and phosphorylation levels of SMAD2 in the lung tissues significantly increased (by 81.3% and 71.6%, respectively). Such changes were effectively abolished by the aryl hydrocarbon receptor inhibitor PDM2 pretreatment. In the two-week-old animals, the thickened right ventricular wall (by 339.3%) and elevated heart rate (by 18.9%) persisted, and significant fibrotic lesions were observed in the lung tissue samples under Masson staining. Again, the aryl hydrocarbon receptor inhibitor PDM2 pretreatment effectively abolished such changes. In addition, no statistically significant changes in CYP1A1 expression levels were observed in the two-week-old chicken lung samples, and a remarkable down-regulation of SMAD2 phosphorylation was observed. The aryl hydrocarbon receptor inhibitor PDM2 pretreatment independently decreased the phosphorylation levels of SMAD2 in the two-week-old chicken lung samples. Conclusion Inhalation exposure to diesel exhaust at initiation of pulmonary respiration could result in persistent cardiopulmonary injury in hatchling chickens, and the underlying mechanism might be associated with the regulation of pSMAD2 by the aryl hydrocarbon receptor signaling pathway.

4.
Artigo em Chinês | WPRIM | ID: wpr-973639

RESUMO

Background Air pollution is related to the occurrence and development of mental diseases. Olfactory bulb damage might be the potential prodromal symptom and sign of these diseases. The toxicity of diesel exhaust (DE), one of the main sources of air pollution, on olfactory bulb and the underlying mechanisms remain to be elucidated. Objective To explore the toxicity of DE on mouse olfactory bulb and underlying mechanisms. Methods A total of 40 C57BL/6 mice were randomly divided into four groups for exposure to DE by systemic inhalation: control group (filtered air), low exposure group (750 μg·m−3 DE), medium exposure group (1500 μg·m−3 DE), and high exposure group (3000 μg·m−3 DE). The mouse inhalation exposure to DE was performed 1 h per day for 28 d. HE staining was performed to observe pathological changes in mouse olfactory bulb tissue. TUNEL assay was used to observe apop-tosis in olfactory bulb. Kyoto Encyclopedia of Genes and Genomes (KEGG) was exhibited to explore potential mechanisms of olfactory bulb damage associated with DE. Quantitative real-time PCR (qPCR) was used to determine mRNA expression levels of inflammatory factors including tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Immunofluorescence staining was conducted to observed the microglia and astrocyte activation in olfactory bulb. Results The HE staining results showed that the number of periglomerular cells in the glomerular layer of olfactory bulb decreased in a dose-dependent manner, and the cells in the granule cell layer of olfactory bulb became disordered after DE exposure. The TUNEL staining showed that TUNEL positive cells in olfactory bulb tissue and neuronal apoptosis increased in the exposed groups compared with the control group (P<0.05). The KEGG pathway analysis showed that DE associated with significant enrichment of TNF signaling pathway in olfactory bulb tissue. The qPCR results showed that the TNF-α relative expression level significantly increased by 67% and the IL-6 relative expression level by 340% in the DE high exposure dose group compared with the control group (P<0.05). According to the immunofluorescence staining results, the numbers of activated microglia and astrocytes in olfactory bulb tissue significantly increased in the DE high exposure group, the relative fluorescence intensity of ionized calcium binding adaptor molecule 1 (IBA-1) increased by 120%, the granule cell layer relative fluorescence intensity of glial fibrillary acidic protein (GFAP) increased by 400%, and the glomerular layer relative fluorescence intensity of GFAP increased by 240% than those in the control group (P<0.05). Conclusion Inhalation exposure to DE can lead to glial cell activation including microglia and astrocytes in olfactory bulb tissue by activating inflammatory pathways and releasing inflammatory factors TNF-α and IL-6, leading to neuronal apoptosis in olfactory bulb tissue.

5.
Artigo em Chinês | WPRIM | ID: wpr-973640

RESUMO

Diesel exhaust (DE) is an important pollution source widely existing in the living and production environment, which is closely related to the health of the public and occupational groups. The International Agency for Research on Cancer has classified DE as a Group 1 carcinogen. Considering the negative health impacts on the respiratory system due to DE exposure in vitro, it is crucial to apply reliable test systems allowing accurate assessment of the biological effects of DE. The exposure technology of respiratory system in vitro is considered as one of the feasible measures to implement the 3R (reduce, refine, and replace) principle in animal experiments. Compared with the traditional submerged culture in vitro models, the air-liquid interface (ALI) exposure technology has the advantages including fewer influencing factors, easier exposure condition control, and shorter exposure cycle. ALI has become an important tool to study molecular events associated with physiology and pathology of respiratory system, and action modes and interactions of different cell types. Also, ALI has been increasingly widely used because it can simulate the actual processes of human respiratory system cells and/or tissues to DE exposure. This review was intended to introduce the development and advantages of ALI exposure technology, and further summarized the application progress of ALI exposure technology in studying the respiratory toxicity induced by DE exposure in vitro, so as to provide new ideas and pathways for the use of ALI exposure technology in the study of biomarkers and mechanisms of respiratory toxicity associated with DE exposure, and provide basic data to screen and promote biomarkers for exposed populations.

6.
Artigo em Chinês | WPRIM | ID: wpr-973641

RESUMO

Diesel exhaust (DE) can enter the organism body and cause multiple organ damage. DE contains particles that can be suspended in the air for a long time. Epigenetic regulation is a post transcriptional regulation change that does not involve DNA sequence changes. Many evidences showed that DE can affect the normal physiological functions of multiple organs and systems through epigenetic changes, thus regulating the occurrence and development of multiple diseases. This paper reviewed the research progress of DNA methylation and non-coding RNA in the biological harmful effects of DE. This will provide a basis for the safety evaluation, health risk assessment, and management of DE.

7.
Artigo em Chinês | WPRIM | ID: wpr-973642

RESUMO

As a source of traffic-related air pollution, diesel particulate matter (DPM) associate with a variety of lung-related diseases, but there is no systematic review of the relationship between DPM and the development and progression of asthma. This article reviewed the relationship between DPM and asthma, the effect and mechanism of DPM on airway inflammation and remodeling in asthma, and illustrated that DPM exposure may participate in airway inflammation and remodeling through oxidative stress, immune regulation and regulation of lung and intestinal microecology, so as to promote the development and progression of asthma.

8.
Artigo em Chinês | WPRIM | ID: wpr-973643

RESUMO

Diesel exhaust (DE), Group 1 carcinogen, is an important source of air pollutants. Studies show that DE exposure associates with elevated incidences of respiratory and cardiovascular diseases. The toxic effects of DE are closely related to its components. Polycyclic aromatic hydrocarbons (PAHs) are one of the main toxic components in DE and are often used as human exposure biomarkers to DE. However, the exposure assessment of DE using PAHs as biomarkers could be interfered due to the other sources of PAHs. Therefore, identification of highly specific and reliable PAHs sourced biomarkers of DE exposure has become a hotspot of current research. New biomarkers of DE may play an important role in determining human exposure to DE and establishing dose-response relationship of DE exposure and health outcomes of interest. This paper focused on current progress in terms of PAHs sourced biomarkers of human exposure to DE with the following aims: (1) to clarify the types of PAHs sourced biomarkers to DE; (2) to explore the applicability and limitations of PAHs sourced biomarkers for DE exposure assessment in occupational exposure and environmental exposure analysis; and (3) to summarize the analysis methods for PAHs sourced exposure biomarkers in human urine samples and compare the advantages and disadvantages of different analytical methods.

9.
China Occupational Medicine ; (6): 535-539, 2023.
Artigo em Chinês | WPRIM | ID: wpr-1013322

RESUMO

{L-End}Objective To investigate the effect of motorcycle exhaust (ME) on the level of oxidative stress in different parts of respiratory tract epithelial cells. {L-End}Methods BEAS-2B and A549 cells in logarithmic growth phase were randomly divided into control group, low- and high-dose groups. The two kinds of cells growing on the membrane of Transwell inserts were treated with air-liquid interface (ALI) exposure technique for 60 minutes. The cells in the low- and high- dose groups were treated with diluted gas with the volume ratio of ME to clean air of 1∶20 and 1∶10, respectively, while the cells in the control group were treated with clean air. Cells were collected to detect their relative survival rate using CCK-8 method after exposure. And the levels of malondialdehyde, glutathione and the activity of superoxide dismutase (SOD) of the cells were detected using colorimetry. {L-End}Results The ME exposure dose affected the relative survival rate of cells (P<0.01), which showed a downward trend with the increasing ME exposure doses (all P<0.05). However, there was no significant difference in the main effect of cell types and the interaction effect of ME exposure dose and cell type (all P>0.05). There was a significant interaction between ME exposure dose and cell type in the level of glutathione and the activity of SOD (all P<0.01), and the level of malondialdehyde was a significant main effect of cell type (P<0.01). There was no significant difference in the glutathione level and SOD activity between the low-dose group and the control group (all P>0.05), while the glutathione level and SOD activity in high-dose group were higher than those in the control group and low-dose group in BEAS-2B cells (all P<0.05). The glutathione level decreased with increasing ME exposure dose in A549 cells (all P<0.05). Compared with the control group, the low-dose group had a significantly higher activity of SOD (P<0.05) in A549 cells. The SOD activity of A549 cells in high-dose group was lower than those in control group and low-dose group (all P<0.05). The level of malondialdehyde in A549 cells was higher than those in BEAS-2B cells(P<0.05). {L-End}Conclusion ME exposure can lead to changes in the production of oxidative stress biomarkers in respiratory tract epithelial cells. The oxidative stress response induced by ME exposure varies among respiratory tract epithelial cells from different regions.

10.
Biomed. environ. sci ; Biomed. environ. sci;(12): 272-281, 2021.
Artigo em Inglês | WPRIM | ID: wpr-878359

RESUMO

Objective@#This study aimed to use an air-liquid interface (ALI) exposure system to simulate the inhalation exposure of motorcycle exhaust particulates (MEPs) and then investigate the benchmark dose (BMD) of MEPs by evaluating cell relative viability (CRV) in lung epithelial BEAS-2B cells.@*Methods@#The MEPs dose was characterized by measuring the number concentration (NC), surface area concentration (SAC), and mass concentration (MC). BEAS-2B cells were exposed to MEPs at different concentrations @*Results@#Our results reveal that BMD of NC and SAC were estimated by the best-fitting Hill model, while MC was estimated by Polynomial model. The BMDL for CRV following ALI exposure to MEPs were as follows: 364.2#/cm @*Conclusion@#These results indicate that MEPs exposure


Assuntos
Humanos , Benchmarking/estatística & dados numéricos , Brônquios/fisiologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Epiteliais/fisiologia , Motocicletas , Material Particulado/efeitos adversos , Emissões de Veículos/análise
11.
Eng. sanit. ambient ; Eng. sanit. ambient;25(1): 51-58, jan.-fev. 2020. tab, graf
Artigo em Português | LILACS-Express | LILACS | ID: biblio-1090130

RESUMO

RESUMO Neste trabalho, analisou-se a eficiência de um sistema de exaustão de material particulado em um processo real de eletrofusão. Particularmente, realizaram-se análises de distribuição granulométrica em diferentes estágios do processo. Utilizando os dados da análise granulométrica, avaliou-se a eficiência do ciclone comparando-a com a eficiência de projeto - adicionalmente, a eficiência do ciclone foi também calculada com base no balanço de massa de todo o processo. Apesar de algumas medidas tomadas pela empresa a fim de melhorar a eficiência do sistema de exaustão, resultados indicam eficiência do ciclone da ordem de 50%, e perda de material particulado para atmosfera da ordem de 1 t a cada batelada do processo. Neste trabalho, apresentam-se detalhadamente as etapas da análise de eficiência do sistema de exaustão, particularmente do ciclone, e a proposta de redimensionamento do ciclone.


ABSTRACT In this work, we analyzed the performance of a particulate matter exhaust system of a real electrofusion production process. Particularly, we performed particle size distribution analysis at different stages of the process. Using particle size distribution data, cyclone operation efficiency was evaluated by comparing it with design efficiency - in addition, cyclone efficiency was also calculated based on the mass balance of the entire process. Despite some measures taken by the company in order to improve the exhaust system efficiency, results indicate cyclone efficiency of around 50%, and particulate matter loss to atmosphere of 1t at each batch of the process. This paper presented in detail the steps of the efficiency analysis of the exhaust system, particularly the cyclone, and the proposed cyclone resizing.

12.
Artigo em Inglês | WPRIM | ID: wpr-829757

RESUMO

@#Specific amounts of bacteria and fungi in the room can cause Sick Building Syndrome (SBS). The main reason for bacteria and fungi accumulation is a lack of air circulation in the air-conditioned room. Therefore, we study exhaust fan usage to microorganism concentration in the air-conditioned room. The objective of this study is to find the optimum exhaust fan running time for reducing microorganism concentration until below the threshold value. The quasi-experiment was using with repeated experiments and non-random methodology. The samples were consisting of four air-conditioned classrooms with six repeated measurements. The sampling instrument used a petri dish filled with NA (Nutrient Agar) and PDA (Potato Dextrose Agar) placed at five points in each room. The results showed that the variation of exhaust fan running time sig affected the concentration of bacteria (sig ~0) and fungi (sig 0.023) in the classrooms. We found that exhaust fan can reduce the bacteria concentration. Although we observed that the exhaust fan gives inconsistency effect to reduce the fungi concentration in the classrooms.

13.
Artigo | IMSEAR | ID: sea-205055

RESUMO

This study has tried to focus on the gravity of burnout in medical professionals, its lack of awareness among the medical fraternity and the importance of its knowledge and awareness worldwide. This study represents a fundamental conceptual understanding of burnout among the medical fraternity, create awareness of health hazard in conjecture to their profession and hope to create an interest in developing diagnostic tools, to monitor and manage burnout in medical schools and hospitals. Besides it also stress upon developing laws to compensate those who are suffering from burnout and study their prevalence in developing countries. It also highlights the effect of burnout on the economy of any country with some examples and stressed the importance of its awareness not only in the interest of the medical fraternity but also in the best interest of the country itself.

14.
Artigo | IMSEAR | ID: sea-188024

RESUMO

Background: Diesel vehicles exhaust contains toxic nanoparticles that drastically affect lung tissue due to their direct cytotoxic effects, induction of oxidative stress, inflammatory signaling pathways and DNA damage. Mesenchymal stem cells (MSCs) exhibit anti-inflammatory effects and efficient regenerative capacity in chronic lung diseases. Objectives: Evaluation of the effects of MSCs and MSCs-derived micro vesicles (MSCs-MVs) on pulmonary toxicity induced by diesel exhaust nanoparticles (DENPs). Materials and Methods: Sixty male rats were equally divided into: Group I (Control rats), Group II (DENPs group) received repeated doses of DENPs (180μg/rat) intratracheally every other day for 6 days, Group III (MSCs group) received MSCs intravenously (3×106 cells) after the last dose of DENPs and Group IV (MSCs-MVs group) received MSCs-MVs (0.5 mg/mL) intravenously after the last dose of DENPs. Lung tissue were subjected to histological and immunohistochemical assessment. Inflammatory cytokines and bronchoalveolar lavage fluid (BALF) contents of inflammatory cells, albumin, LDH and total proteins were evaluated. Results: Histological picture of lung tissue in DENPs group showed numerous collapsed alveoli, thick interalveolar septa and marked cellular infiltration. Elastic fibers were markedly decreased by DENPs. Increased optical density of NF-κB/p65 immunoreactivity. Bronchoalveolar lavage fluid showed significant elevation of inflammatory cytokines (TNF-a, IL-6), polymorphonuclear leukocytes (PMN), neutrophils, macrophages, LDH, total proteins and albumin. Treatment with either MSCs or MSCs-MVs led to a significant amelioration of all of the aforementioned studied parameters. Conclusion: MSCs-MVs and MSCs showed significant therapeutic effects against DENPs damaging effects on the lung tissues via their regenerative capacity and anti-inflammatory effects.

15.
Safety and Health at Work ; : 141-150, 2019.
Artigo em Inglês | WPRIM | ID: wpr-761358

RESUMO

BACKGROUND: Evidence on associations between occupational diesel exhaust and gasoline exposure and colorectal cancer is limited. We aimed to assess the effect of workplace exposure to diesel exhaust and gasoline on the risk of colorectal cancer. METHODS: This caseecontrol study included 181,709 colon cancer and 109,227 rectal cancer cases diagnosed between 1961 and 2005 in Finland, Iceland, Norway, and Sweden. Cases and controls were identified from the Nordic Occupational Cancer Study cohort and matched for country, birth year, and sex. Diesel exhaust and gasoline exposure values were assigned by country-specific job-exposure matrices. Odds ratios and 95% confidence intervals were calculated by using conditional logistic regression models. The results were adjusted for physical strain at work and occupational exposure to benzene, formaldehyde, ionizing radiation, chlorinated hydrocarbons, chromium, and wood dust. RESULTS: Diesel exhaust exposure was associated with a small increase in the risk of rectal cancer (odds ratio 1/4 1.05, 95% confidence interval 1.02–1.08). Gasoline exposure was not associated with colorectal cancer risk. CONCLUSION: This study showed a small risk increase for rectal cancer after workplace diesel exhaust exposure. However, this finding could be due to chance, given the limitations of the study.


Assuntos
Benzeno , Estudos de Casos e Controles , Cromo , Estudos de Coortes , Neoplasias do Colo , Neoplasias Colorretais , Poeira , Finlândia , Formaldeído , Gasolina , Hidrocarbonetos Clorados , Islândia , Modelos Logísticos , Noruega , Exposição Ocupacional , Razão de Chances , Parto , Radiação Ionizante , Neoplasias Retais , Países Escandinavos e Nórdicos , Suécia , Emissões de Veículos , Madeira
16.
Rev. bras. saúde ocup ; 44: e4, 2019. tab
Artigo em Português | LILACS | ID: biblio-985370

RESUMO

Resumo Introdução: os sistemas de ventilação local exaustora (SVLE) podem ser utilizados para controlar a exposição ocupacional a agentes químicos. Contudo, muitas vezes são indevidamente concebidos, instalados ou operados, tornando-se ineficazes. Objetivo: avaliar a eficácia de um SVLE empregado para controle da sílica cristalina utilizada na produção da borracha de silicone. Métodos: a avaliação aplicada foi baseada em procedimentos técnicos descritos em literatura referencial de ventilação industrial e sistematizada em três etapas - inspeção inicial, avaliação dos parâmetros do SVLE e avaliação ambiental. Foi realizado um teste de campo em um SVLE instalado em misturador de sílica e silicone utilizado em uma empresa de fabricação de borracha de silicone no Estado de São Paulo. Resultados: as etapas de inspeção e avaliação dos parâmetros do SVLE apontaram deficiências no projeto, na operação e na manutenção do sistema, referendadas por sua reduzida velocidade de captura. Na avaliação ambiental, foram encontradas concentrações de sílica cristalina na fração respirável acima do valor de referência adotado. Conclusão: o estudo ratificou a necessidade de projeto, instalação, operação e manutenção dos SVLE estarem em consonância com os princípios de engenharia de ventilação a fim de se obter o funcionamento eficaz do sistema.


Abstract Introduction: local exhaust ventilation (LEV) systems can be used for controlling chemical occupational exposure. However, sometimes they are improperly designed, installed or operated, becaming ineffective. Objective: to evaluate the effectiveness of a LEV used for controlling crystalline silica employed in the production of silicone rubber. Methodology: the assessment carried out was based on technical procedures described in the industrial ventilation reference literature and was systematized in three steps - initial inspection, evaluation of LEV parameters and environmental assessment. A field test was applied in a LEV installed in a silica and silicone mixer of a rubber manufacturing company located in the state of São Paulo, Brazil. Results: the inspection and evaluation steps of the LEV parameters pointed out deficiencies in the design, operation and maintenance of the system, testified by its reduced capture velocity. Regarding the environmental assessment, concentrations of crystalline silica above the reference value were found in the respirable fraction. Conclusion: the study confirmed that, for the LEV effective functioning, their design, installation, operation and maintenance have to be in conformity with the principles of ventilation engineering.

17.
Eng. sanit. ambient ; Eng. sanit. ambient;23(5): 1013-1025, set.-out. 2018. tab, graf
Artigo em Português | LILACS | ID: biblio-975137

RESUMO

RESUMO No Brasil e no mundo, o setor dos transportes de passageiros e cargas tem contribuído decisivamente para o aumento das emissões de poluentes atmosféricos, com os consequentes problemas para o meio ambiente e para a saúde humana. Assim, muitos estudos têm recorrido a metodologias e/ou ferramentas específicas para modelar e simular poluentes atmosféricos. A frota de veículos no Ceará teve um crescimento de 169% nos últimos 10 anos, mas ainda se desconhece o volume de poluentes emitidos pela frota circulante da Região Metropolitana de Fortaleza (RMF). Nesse contexto, foram estimadas as emissões veiculares de escapamento para a RMF no ano de 2010. A quantificação das emissões de monóxido de carbono (CO), hidrocarbonetos não metano (NMHC), óxidos de nitrogênio (NOx), material particulado (MP) e aldeídos (RCHO) foi realizada através da metodologia bottom-up. De modo geral, as motocicletas apresentaram emissões significativas de poluentes, sobretudo de CO, NOx e MP, devido à grande quantidade de veículos na região. Os veículos ciclo Otto representam mais de 90% das emissões totais de CO, NMHC e RCHO, enquanto os veículos ciclo Diesel emitem mais de 85% das emissões totais de NOx e MP.


ABSTRACT In Brazil and worldwide, the passenger and cargo transportation sectors have decisively been responsible for the increased emissions of air pollutants, which cause serious damages for the environment and human health, as well. Thus, many studies have been carried out to model and simulate pollutant emissions through methodologies and/or specific tools. The vehicle fleet in the state of Ceará has increased by 169% over the last 10 years and, until now, the amount of pollutants released from circulating fleet of the Fortaleza Metropolitan Region (FMR) is unknown. In this context, vehicular exhaust emissions for the FMR were estimated for the year 2010. Emission estimates of carbon monoxide (CO), non-methane hydrocarbons (NMHC), nitrogen oxides (NOx), particulate matter (PM), and aldehydes (RCHO) were performed through the bottom-up methodology. In general, it was observed that motorcycles emitted high amounts of pollutants, mainly CO, NOx and MP, due to the large number of vehicles in the region. Otto cycle vehicles accounted for more than 90% of CO, NMHC and RCHO total emissions, while Diesel cycle vehicles emitted more than 85% of NOx and PM total emissions.

18.
Artigo em Chinês | WPRIM | ID: wpr-843771

RESUMO

Objective: To observe the changes of lung tissue and lung microbiome in mice after inhalation of vehicle exhaust, and to assess the impact of air pollution caused by vehicle exhaust on the respiratory system of the population. Methods: Ten C57BL/6 mice were divided into experimental group and control group randomly. Experimental group was inflicted with continuous exposure to automobile exhaust for 5 d (1 h/d), while the control group was exposed to clean air. After a 5-day of environmental exposure, the lung microbial composition was analyzed by 16S rRNA pyrosequencing and the structure of the lung tissue was assessed by histological analysis. Results: There was no significant difference in pathological changes of lung tissue between the experimental group and the control group. However, there were significant differences in the composition and abundance of bacteria in the experimental and control groups. At the phylum level, comparing with the control group the Firmicutes was significantly increased in the experimental group, while the Bacteroidetes and Proteobacteria were significantly reduced. At the genus level, the increase of the Firmicutes was mainly related to the increase of the Coprococcus. The reduction of the Bacteroidetes was related to the reduction of Cytophaga while the reduction of the Proteobacteria was related to three main strains namely Ochrobactrum, Methylobacterium and Acinetobacter. Amycolatopsis was also reduced significantly. Conclusion: Short-term exposure to vehicle exhaust conditions changes the species composition and abundance of lung microbiome in mice, but no lung tissue lesions were observed.

19.
Artigo em Chinês | WPRIM | ID: wpr-807844

RESUMO

Objective@#To investigate the effect of knee-chest position on exhaust and defecation of gynecologic diseases patients after laparoscopic surgery.@*Methods@#This quasi-experiment trail was conducted between July 2016 to May 2017, in a birth control ward at an obstetrics and gynecology hospital in Beijing, China. The study included a total of 258 patients who had gynecological benign diseases and received gynecological laparoscopic surgery. Participants were recruited in the trail by using a convenient sampling method with 130 patients who received gynecological laparoscopic surgery from July 2016 to December 2016 in the experimental group (on the basis of routine care, patients preformed a knee-chest position intervention after 6 hours of the surgery) and 128 patients who received gynecologic laparoscopic surgery between January 2017 and May 2017 in the control group (patients received a routine care). The primary end point was the postoperative anal exhaust.@*Results@#The ambulation rate before post-operative ventilation of the experimental group was 21.5% (28/130) less than that of the control group (91.4%, 117/128). The difference was statistically significant (χ2=127.903, P<0.01). The incidence of abdominal distension after operation was 0, lower than that of the control group 7.0% (9/128), the difference was statistically significant (χ2=9.471, P<0.01). The postoperative exhaust time and defecation time of the experimental group was (8.17 ± 2.88) h,(27.86 ± 4.29) h, earlier than that of the control group, (21.24 ± 5.90) h,(38.69 ± 7.73) h, and the differences were statistically significant (t=22.580, 13.885, P<0.01).@*Conclusions@#Postoperative knee-chest position significantly improved the exhaust and defecation of patients with gynecological benign disease after laparoscopic surgery.

20.
China Medical Equipment ; (12): 21-24, 2018.
Artigo em Chinês | WPRIM | ID: wpr-706534

RESUMO

Objective: To observe and analyze the clinical effect, satisfaction and life quality of an exhaust device that was applied in patients with pneumothorax in emergency internal medicine. Methods: The clinical data of 90 patients with pneumothorax were analyzed, and all of them were divided into observation group (45 cases) and control group (45 cases) according to the different clinical treatment plan. The patients of observation group received pneumothorax treatment by using exhaust device and that of control group received pneumothorax treatment by using conventional exhaust device. The clinical effect, satisfaction degree and situation of life quality post-treatment between the two groups were analyzed and compared. Results: The total effective rate and satisfaction of observation group (97.78% and 97.78%) were significantly higher than that of control group (80.00% and 77.78%) (x2=7.200, x2=8.389, P<0.05). And the result of follow-up of half a year showed that the difference of total score of life quality between observation group (83.50±14.48) and control group (65.34±13.15) was significant (t=6.228, P<0.05). Conclusion: In the treatment of patients with pneumothorax in emergency internal medicine, the application of an exhaust device of pneumothorax can make the gas was wholly absorbed, and significantly enhance the satisfaction and life quality of patients.

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