THE EFFECT OF EXTERNAL SUCTION AT THE DUST OUTLET OF A CYCLONE

Cyclone is one of the most commonly used particulate dust collectors in industries. It employs centrifugal force generated by a spinning gas stream to separate the particulate matter from the carrier gas. However, cyclone is efficient to collect coarse rather than fine particulate size fraction. In this regard, a study was carried out to determine the effect of creating more negative pressure at the storage hopper of a 100 mm diameter laboratory scale cyclone. The negative pressure was created by drawing out a small portion of the gas stream by means of an air pump attached to the storage hopper. Results showed that there was exponentially related between the pressure drop (ΔP) and the amount of gas stream drawn at the storage hopper, but with an increment of 2.6% with suction compared to without. Interestingly, it was observed that more of the fine particulate matter was drawn from the gas stream as the suction flow rate increases. This is due to the suction velocity which exceeds the terminal falling velocities of the fine particles size range. There was a reduction by weight in the fine particle emitted from the cyclone ranging between 14% to 52% by introduction of the suction. The finding serves as a basis for future work in reducing fine particulates from a cyclone separator.

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Regulatory T Cells Protect Fine Particulate Matter-Induced Inflammatory Responses in Human Umbilical Vein Endothelial Cells

Mediators of Inflammation ◽

10.1155/2014/869148 ◽

2014 ◽

Vol 2014 ◽

pp. 1-14 ◽

Cited By ~ 6

Author(s):

Wen-cai Zhang ◽

Yan-ge Wang ◽

Zheng-feng Zhu ◽

Fang-qin Wu ◽

Yu-dong Peng ◽

...

Keyword(s):

T Cells ◽

Endothelial Cells ◽

Particulate Matter ◽

Inflammatory Cytokines ◽

Fine Particles ◽

Inflammatory Responses ◽

Umbilical Vein ◽

Fine Particulate Matter ◽

Fine Particulate ◽

Umbilical Vein Endothelial Cells

Objective. To investigate the role of CD4+CD25+T cells (Tregs) in protecting fine particulate matter (PM-) induced inflammatory responses, and its potential mechanisms.Methods. Human umbilical vein endothelial cells (HUVECs) were treated with graded concentrations (2, 5, 10, 20, and 40 µg/cm2) of suspension of fine particles for 24h. For coculture experiment, HUVECs were incubated alone, with CD4+CD25−T cells (Teff), or with Tregs in the presence of anti-CD3 monoclonal antibodies for 48 hours, and then were stimulated with or without suspension of fine particles for 24 hours. The expression of adhesion molecules and inflammatory cytokines was examined.Results. Adhesion molecules, including vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1), and inflammatory cytokines, such as interleukin (IL-) 6 and IL-8, were increased in a concentration-dependent manner. Moreover, the adhesion of human acute monocytic leukemia cells (THP-1) to endothelial cells was increased and NF-κB activity was upregulated in HUVECs after treatment with fine particles. However, after Tregs treatment, fine particles-induced inflammatory responses and NF-κB activation were significantly alleviated. Transwell experiments showed that Treg-mediated suppression of HUVECs inflammatory responses impaired by fine particles required cell contact and soluble factors.Conclusions. Tregs could attenuate fine particles-induced inflammatory responses and NF-κB activation in HUVECs.

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Occupational Exposure to Fine Particulate Matter (PM4 and PM2.5) during Hand-Made Cookware Operation: Personal, Indoor and Outdoor Levels

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17207522 ◽

2020 ◽

Vol 17 (20) ◽

pp. 7522

Author(s):

Busisiwe Shezi ◽

Angela Mathee ◽

Nokulunga Cele ◽

Sipho Ndabandaba ◽

Renee A. Street

Keyword(s):

Particulate Matter ◽

Occupational Exposure ◽

Fine Particles ◽

Fine Particulate Matter ◽

Health And Safety ◽

Chemical Characterization ◽

Personal Exposure ◽

Targeted Prevention ◽

Fine Particulate ◽

Indoor And Outdoor

(1) Exposure of informal artisanal cookware makers to fine particles has not yet been characterized. The aim of this study was to characterize occupational exposure to fine particulate matter (PM4 and PM2.5) levels and fine particulate matter (PM2.5) elemental components; (2) Artisanal cookware makers were recruited from five cookware making sites. Exposure to fine particulate matter was measured for 17 male participants. SidePak personal aerosol monitors (AM520) were used to measure personal exposure to PM4, while a DustTrak monitor and an E-sampler were used to assess indoor and outdoor PM2.5 levels, respectively. A questionnaire was administered to capture information on demographic characteristics. The chemical characterization of indoor and outdoor PM2.5 filter mass was conducted using Wavelength Dispersive X-ray Fluorescence. Time series record of 15-min averages for indoor and outdoor PM2.5 levels were assessed; (3) The median (range) was 124 µg/m3 (23−100,000), 64 µg/m3 (1−6097) and 12 µg/m3 (4−1178), respectively, for personal PM4, indoor and outdoor PM2.5. The highest levels for many of the elemental components of PM2.5 were found in the outdoor PM2.5 filter mass and (4). The information generated during this study may assist in extending occupational health and safety strategies to artisanal cookware makers and developing targeted prevention initiatives.

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The Physics of Fine-Particle Movement Through Permeable Aquifers

Society of Petroleum Engineers Journal ◽

10.2118/2946-pa ◽

1971 ◽

Vol 11 (04) ◽

pp. 367-373 ◽

Cited By ~ 4

Author(s):

Jerry B.F. Champlin

Keyword(s):

Particulate Matter ◽

Fine Particles ◽

Fine Particulate Matter ◽

Petroleum Industry ◽

Engineering Practice ◽

Nuclear Explosions ◽

Waste Storage ◽

Fine Particulate ◽

Soluble Ions ◽

Subsurface Reservoir

Abstract The movement of fine particles through porous, permeable materials is closely interwoven with the migration of soluble ions. Since either the particles orthe ions can represent an economic mineral accumulation as a consequence ofgeochemical concentration, it is of great importance to mineral explorationefforts to be able to establish the parameters that influence particulatemigration through aquifers. Not only are economically interesting depositsformed by such migration, but they also may be ruined, as in the case of manyoil fields where standard secondary recovery methods have caused plugging ofthe productive formations. Recent experimental work has shown close alliance between the relative movement of both trace ions and particles and the over-all concentration of common salts dissolved in ground water. Most importantly, the spacial stability of fineparticles such as the sesquioxides and the clays in formations is dependent onthe nature of the anionic portion of the dominant salt in solution. These results have great potential, applied in exploration or exploitation programs for minerals. Not only do they provide answers for particulate migration problems in the oil fields and ore concentration mechanisms in the uranium deposits, but also they explain the untoward migration of certain radioisotopes from waste storage ponds or cribs at the national reactor-fuel reprocessing plants. By careful development and engineering practice, fine particles tagged with almost any radioactive or activatable ions may become one of the most useful tools in tracing subsurface movement of fluids. Introduction Considerable concern has been expressed by several industries during the past several decades about the effects of fine-particulate matter suspended in water passing through permeable rock. An early concern of the petroleum industry included the problem of subsurface reservoir plugging by fine particles during secondary production operations. More recently, the atomic energy industry has been concerned with particulate migration because of the movement of radioactive ions. Even the interest in applications of nuclear explosions underground has included concern over the effects of the fine-particulate matter that makes up large portions of the rubble produced by the explosion.

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Assessment of Population Exposure to Coarse and Fine Particulate Matter in the Urban Areas of Chennai, India

The Scientific World JOURNAL ◽

10.1155/2015/643714 ◽

2015 ◽

Vol 2015 ◽

pp. 1-11 ◽

Cited By ~ 3

Author(s):

Ramachandran Prasannavenkatesh ◽

Ramachandran Andimuthu ◽

Palanivelu Kandasamy ◽

Geetha Rajadurai ◽

Divya Subash Kumar ◽

...

Keyword(s):

Particulate Matter ◽

Urban Areas ◽

Respiratory Health ◽

Fine Particulate Matter ◽

Population Data ◽

Epidemiological Studies ◽

World Health ◽

Population Exposure ◽

Fine Particulates ◽

Fine Particulate

Research outcomes from the epidemiological studies have found that the course (PM10) and the fine particulate matter (PM2.5) are mainly responsible for various respiratory health effects for humans. The population-weighted exposure assessment is used as a vital decision-making tool to analyze the vulnerable areas where the population is exposed to critical concentrations of pollutants. Systemic sampling was carried out at strategic locations of Chennai to estimate the various concentration levels of particulate pollution during November 2013–January 2014. The concentration of the pollutants was classified based on the World Health Organization interim target (IT) guidelines. Using geospatial information systems the pollution and the high-resolution population data were interpolated to study the extent of the pollutants at the urban scale. The results show that approximately 28% of the population resides in vulnerable locations where the coarse particulate matter exceeds the prescribed standards. Alarmingly, the results of the analysis of fine particulates show that about 94% of the inhabitants live in critical areas where the concentration of the fine particulates exceeds the IT guidelines. Results based on human exposure analysis show the vulnerability is more towards the zones which are surrounded by prominent sources of pollution.

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Possible warming effect of fine particulate matter in the atmosphere

Communications Earth & Environment ◽

10.1038/s43247-021-00278-5 ◽

2021 ◽

Vol 2 (1) ◽

Author(s):

Shau-Liang Chen ◽

Sih-Wei Chang ◽

Yen-Jen Chen ◽

Hsuen-Li Chen

Keyword(s):

Particulate Matter ◽

Fine Particles ◽

Fine Particulate Matter ◽

Three Dimensional ◽

Mie Scattering ◽

Dust Particles ◽

Long Wavelength ◽

Inorganic Aerosols ◽

Fine Particulate ◽

Difference Time

AbstractParticulate matter emitted through human activities not only pollutes the air, but also cools the Earth by scattering shortwave solar radiation. However, coarser dust particles have been found to exert a warming effect that could, to some extent compensate for the cooling effect of fine dust. Here we investigate the radiative effects of sulfate containing aerosols of various sizes and core/shell structures using Mie scattering and three-dimensional finite difference time domain simulations of the electromagnetic fields inside and around particulate matter particles. We find that not only coarse dust, but also fine non-light-absorbing inorganic aerosols such as sulfate can have a warming effect. Specifically, although the opacity of fine particles decreases at longer wavelengths, they can strongly absorb and re-emit thermal radiation under resonance conditions at long wavelength. We suggest that these effects need to be taken into account when assessing the contribution of aerosols to climate change.

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Randomized Trial to Reduce Air Particle Levels in Homes of Smokers and Children

10.31234/osf.io/k8jbf ◽

2017 ◽

Author(s):

Vincent Berardi

Keyword(s):

Clinical Trial ◽

At Risk ◽

Particulate Matter ◽

Randomized Trial ◽

Randomized Clinical Trial ◽

Real Time ◽

Fine Particles ◽

Fine Particulate Matter ◽

Children At Risk ◽

Fine Particulate

Exposure to fine particulate matter in the home from sources such as smoking, cooking, and cleaning may put residents, especially children, at risk of detrimental health effects.Data from a randomized clinical trial were analyzed during 2016-2017 to determine whether real-time feedback in the home plus brief coaching of parents or guardians could reduce exposure to fine particles for children living with smokers.

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Characterization of hospital airborne SARS-CoV-2

Respiratory Research ◽

10.1186/s12931-021-01637-8 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Rebecca A. Stern ◽

Petros Koutrakis ◽

Marco A. G. Martins ◽

Bernardo Lemos ◽

Scot E. Dowd ◽

...

Keyword(s):

Particulate Matter ◽

Fine Particles ◽

Fine Particulate Matter ◽

Positive Sample ◽

Airborne Particles ◽

Disease Spread ◽

Fine Particulate ◽

Air Sample ◽

Particulate Matter 2.5

Abstract Background The mechanism for spread of SARS-CoV-2 has been attributed to large particles produced by coughing and sneezing. There is controversy whether smaller airborne particles may transport SARS-CoV-2. Smaller particles, particularly fine particulate matter (≤ 2.5 µm in diameter), can remain airborne for longer periods than larger particles and after inhalation will penetrate deeply into the lungs. Little is known about the size distribution and location of airborne SARS-CoV-2 RNA. Methods As a measure of hospital-related exposure, air samples of three particle sizes (> 10.0 µm, 10.0–2.5 µm, and ≤ 2.5 µm) were collected in a Boston, Massachusetts (USA) hospital from April to May 2020 (N = 90 size-fractionated samples). Locations included outside negative-pressure COVID-19 wards, a hospital ward not directly involved in COVID-19 patient care, and the emergency department. Results SARS-CoV-2 RNA was present in 9% of samples and in all size fractions at concentrations of 5 to 51 copies m−3. Locations outside COVID-19 wards had the fewest positive samples. A non-COVID-19 ward had the highest number of positive samples, likely reflecting staff congregation. The probability of a positive sample was positively associated (r = 0.95, p < 0.01) with the number of COVID-19 patients in the hospital. The number of COVID-19 patients in the hospital was positively associated (r = 0.99, p < 0.01) with the number of new daily cases in Massachusetts. Conclusions More frequent detection of positive samples in non-COVID-19 than COVID-19 hospital areas indicates effectiveness of COVID-ward hospital controls in controlling air concentrations and suggests the potential for disease spread in areas without the strictest precautions. The positive associations regarding the probability of a positive sample, COVID-19 cases in the hospital, and cases in Massachusetts suggests that hospital air sample positivity was related to community burden. SARS-CoV-2 RNA with fine particulate matter supports the possibility of airborne transmission over distances greater than six feet. The findings support guidelines that limit exposure to airborne particles including fine particles capable of longer distance transport and greater lung penetration.

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Association between the concentration of fine particles in the atmosphere and acute respiratory diseases in children

Revista de Saúde Pública ◽

10.1590/s1518-8787.2017051006523 ◽

2017 ◽

Vol 51 (0) ◽

Cited By ~ 6

Author(s):

Antônio Paula Nascimento ◽

Jane Meri Santos ◽

José Geraldo Mill ◽

Juliana Bottoni de Souza ◽

Neyval Costa Reis Júnior ◽

...

Keyword(s):

Particulate Matter ◽

Outpatient Care ◽

Respiratory Diseases ◽

Fine Particles ◽

Fine Particulate Matter ◽

Additive Model ◽

Positive Association ◽

Fine Particulate ◽

Icd 10 ◽

Acute Respiratory Diseases

ABSTRACT OBJECTIVE To analyze the association between fine particulate matter concentration in the atmosphere and hospital care by acute respiratory diseases in children. METHODS Ecological study, carried out in the region of Grande Vitória, Espírito Santo, in the winter (June 21 to September 21, 2013) and summer (December 21, 2013 to March 19, 2014). We assessed data of daily count for outpatient care and hospitalization by respiratory diseases (ICD-10) in children from zero to 12 years in three hospitals in the Region of Grande Vitória. For collecting fine particulate matter, we used portable samplers of particles installed in six locations in the studied region. The Generalized Additive Model with Poisson distribution, fitted for the effects of predictor covariates, was used to evaluate the relationship between respiratory outcomes and concentration of fine particulate matter. RESULTS The increase of 4.2 µg/m3 (interquartile range) in the concentration of fine particulate matter increased in 3.8% and 5.6% the risk of medical care or hospitalization, respectively, on the same day and with six-day lag from the exposure. CONCLUSIONS We identified positive association between outpatient care and hospitalizations of children under 12 years due to acute respiratory diseases and the concentration of fine particulate matter in the atmosphere.

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Leak-Testing of an Endoscopic Aerosol Box for Preventing SARS-CoV-2 Infection during Upper Gastrointestinal Endoscopy

Siriraj Medical Journal ◽

10.33192/smj.2021.90 ◽

2021 ◽

Vol 73 (10) ◽

pp. 702-709

Author(s):

Taya Kitiyakara ◽

Patarapong Kamalaporn ◽

Akharawit Poolsombat ◽

Patthama Anumas ◽

Thanyaluck T. Tawarate ◽

...

Keyword(s):

Particulate Matter ◽

Negative Pressure ◽

Fine Particulate Matter ◽

Upper Gastrointestinal Endoscopy ◽

Fine Particulate ◽

Leak Testing ◽

Viral Aerosol ◽

Risk Of Exposure ◽

Pm2.5 And Pm10 ◽

Upper Gastrointestinal

Objective: The SARS-CoV-2 virus has infected many healthcare professionals. Endoscopy is an aerosol-generating procedure and the endoscopy team is at risk of exposure and infection. We describe the leak-testing of an aerosol box that uses a glove-covering for the endoscope.Materials and Methods: An endoscopic aerosol box with a glove-covering over the endoscope was made for gastroscopy, EUS and ERCP procedures and was tested for leakage of aerosol/airborne particles. Fine particulate matter (PM) from burnt incense sticks was used as a model for viral aerosol. The leakage from the box was measured by comparing readings from 2 PM light-scattering sensors, one placed inside the box and the other just outside the glove opening in a sealed container. Negative pressure conditions were also used to see if this had any effect on the leakage.Results: The concentration levels of the particulate matter differed with different negative pressure conditions and movement of the endoscope through the glove. Very little leakage was seen with the endoscope stationary even with no negative pressure, at 2.4%, 0.17% and 0.07% for PM1, PM2.5 and PM10, respectively. The maximum leakage was 14% for PM1, 8.7% for PM2.5 and 2.6% for PM10 in the moving-endoscope condition and no negative pressure. This reduced to 6.2%, 1.3%and 0.37% respectively when suction was applied at full strength (negative pressure of -0.05 bar). Conclusion: The glove covering significantly reduced the passage of particles. The particulate leak was seen most with the smallest particles and reached 14% for PM1 without negative pressure. This reduced to 6.2% with maximum negative pressure using the wall suction.

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Health risks of air pollution with fine particulate matter

Kazan medical journal ◽

10.17816/kmj2021-862 ◽

2021 ◽

Vol 102 (6) ◽

pp. 862-876

Author(s):

L M Fatkhutdinova ◽

E A Tafeeva ◽

G A Timerbulatova ◽

R R Zalyalov

Keyword(s):

Air Pollution ◽

Particulate Matter ◽

Fine Particles ◽

Fine Particulate Matter ◽

Ambient Air ◽

Epidemiological Studies ◽

Chronic Obstructive ◽

Fine Particulate ◽

Russian Science Citation Index ◽

Wide Range

The review presents up-to-date information on the health effects of ambient fine particulate matter, obtained in large cohort epidemiological studies, as well as in meta-analysis of pooled data. In addition, it summarizes the current data on the potential pathological mechanisms and existing monitoring systems. The literature search used the Scopus, PubMed, Russian Science Citation Index databases for 19902020. The results of epidemiological studies carried out in different countries indicate that fine particles in ambient air pose a serious threat to health. Scientific publications assessing the health impact of particulate matter show a wide range of adverse effects from the increasing incidence of upper and lower respiratory tract diseases, including exacerbations of bronchial asthma, pneumonia, chronic obstructive pulmonary disease, to a high incidence of myocardial infarction, strokes, diabetes mellitus type 2, as well as an increase in overall mortality from natural causes, mainly mortality from respiratory diseases, cardiovascular and cerebrovascular diseases, lung cancer. The effects of short-term exposures are described in more detail, while the effects of long-term exposure to fine particles are not well understood. Potential mechanisms of the harmful effects of fine particulate matter include oxidative stress, inflammatory reactions, disorders of autonomic regulation and heart rhythm, fine particles translocation through the alveolar barrier into the vascular bed with endothelial damage and thrombus formation, and genotoxicity. Ambient fine particulate matter is a manageable risk factor, and reductions in air pollution will have a significant impact on public health outcomes.

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