Cyclone Sampler Research Articles

Molecular aerobiology - Plantago allergen Pla l 1 in the atmosphere.

Exposure to airborne pollen from certain plants can cause allergic disease, but allergens can also be found in non-pollen-bearing fractions of ambient air. This may explain why the allergic response in susceptible patients does not always coincide with the presence and magnitude of airborne pollen counts. Plantago pollen is an important cause of pollinosis in northern Mediterranean countries, but it is difficult to determine its incidence in allergies because Plantago pollen appears in the atmosphere at the same time as grass pollen. The study aimed to investigate the relationship between the atmospheric concentration of Pla l 1 aeroallergen and Plantago pollen, and its incidence in a population group. Pollen was sampled using a Hirst-type volumetric trap (Burkard) and Burkard Cyclone sampler (Burkard) for Pla l 1 allergen. Allergen was determined with a Pla l 1-specific ELISA. Serum-specific IgE levels to several plant allergens were measured with the EAST system. The aerobiological dynamics of Plantago pollen grains and Pla l 1 did not follow the same trend, whereas the sum of Plantago with some other pollen types showed a more similar behaviour. Of the 118 subjects tested, sera from 52 contained IgE to Plantago pollen, but only 5 were monosensitized. The presence of Pla l 1 in the atmosphere depends not only on Plantago pollen but also on the pollen of other species from the Oleaceae family. Knowledge of the behaviour of allergen Pla l 1 in the atmosphere can help understand better asthma exacerbations associated with aeroallergens.

Global Stochastic Tropical Cyclone Model Based on Principal Component Analysis and Cluster Analysis

AbstractA global stochastic tropical cyclone model was developed as a means for preparing a large number of artificial tropical cyclone (TC) samples with different values for parameters such as track, minimum sea level pressure, and translation speed. In this paper, the model and the results of its verification are presented in detail. The proposed stochastic model is sensitive to approximations of the joint probability distribution functions (PDFs) of TC parameters and temporal correlations. A newly introduced accurate method for approximating joint PDFs by using principal component analysis and cluster analysis resulted in improved reproducibility of TC parameters. The simulation results were compared with historical observational data from the northwestern Pacific, southwestern Pacific, and North Atlantic Oceans. The grid-averaged mean values and distribution patterns of PDFs of TC parameters were in agreement with observational data.

Outdoor (1→3)-β-D-glucan levels and related climatic factors.

ObjectivesTo evaluate the monthly variation in the airborne (1→3)-β-D-glucan level throughout one year and its relationship with climatic factors (temperature, relative humidity, wind speed, hours of daylight, cloud cover, and pollen counts).MethodsA total of 106 samples were collected using a two-stage cyclone sampler at five outdoor sampling locations (on top of 5 university buildings). The kinetic limulus amebocyte lysate assay was used to obtain (1→3)-β-D-glucan levels.ResultsAirborne (1→3)-β-D-glucan levels were significantly higher in the spring, particularly in April, and temperature was significantly related to (1→3)-β-D-glucan levels (r =0.339, p<0.05).Conclusions(1→3)-β-D-glucan levels may be highest in the spring, and outdoor temperature may influence (1→3)-β-D-glucan levels.

Evaluation of Respirable Crystalline Silica in High School Ceramics Classrooms

Air concentrations of respirable crystalline silica were measured in eleven (11) high school ceramics classrooms located in Salt Lake County, UT, USA. Respirable dust was collected on PVC filters using precision flow pumps and cyclone samplers (n = 44). Filters were subsequently analyzed for respirable dust and percent crystalline silica content. The geometric mean of the silica concentrations was 0.009 mg/m3 near the teacher’s work station and 0.008 mg/m3 near the kilns. The number of students in the classroom was correlated to the silica concentration in the ceramics classroom, but no correlation was found between the silica concentrations and either the size of the classroom or the age of the building. Results from this study indicate that ceramics teachers may be at an increased risk of exposure to crystalline silica based on the ACGIH TLV of 0.025 mg/m3, with an exceedance of 21%.

Evaluation of Air Sampling and Detection Methods to Quantify Airborne Ascospores of Sclerotinia sclerotiorum.

Detection and quantification of airborne ascospores as a component of the Sclerotinia rot of carrot (SRC) forecast model is currently accomplished using the blue plate test (BPT), which uses Sclerotinia semiselective medium (SSM). A quantitative polymerase chain reaction (qPCR) assay was developed to reduce the time to specifically quantify ascospores of Sclerotinia sclerotiorum from air samples collected using a Burkard Multi-Vial Cyclone Sampler. The qPCR assay was highly sensitive and detected DNA from 0.5 to 5 × 104 ascospores within a linear range (R2 = 0.99). The qPCR assay was used to quantify ascospores of S. sclerotiorum in air samples collected over three growing seasons. Initial SRC disease was observed 8 and 34 days following detection of 9.5 and 2 ascospores m-3 of air, respectively. Results from air samples collected using an Andersen N6 Sampler and the qPCR assay were compared with the BPT. Ascospore counts from a Burkard Sampler coupled with the qPCR assay and the BPT followed similar trends. In general, fewer ascospores were detected and bioaerosol sampling efficiency was low using an Anderson Sampler. Three days were required to confirm the number of ascospores using SSM in the BPT and with an Andersen Sampler, whereas results from a Burkard Sampler coupled with the qPCR assay can provide results within 5 h of air sampling. The choice of method will depend on the available resources.

Optimization of the measurement of outdoor airborne allergens using a protein microarrays platform

Increased knowledge on allergenic molecules in the environmental air helps in the information on environmental air quality and in the prevention and treatment of allergies. The aim of this study is to develop and validate a new methodology for the simultaneous detection and quantification of several airborne allergens using protein microarray technology, which has been created for the clinical detection of allergens. The immunological method was performed with Immuno Solid-phase Allergen Chip (ISAC) inhibition assay. Reagents for the validation studies include the following: (1) three sera from patients allergic to grass pollen each with different IgE levels as the detection reagents, (2) recombinant Phl p 1 major allergen as the inhibitor for the inhibition assays, (3) “natural” Phl p 1 released by Phleum pratense (timothy grass) pollen grains as the “biologically” relevant aeroallergen and (4) samples of airborne pollens collected by a Multi-vial Cyclone Sampler for comparison of levels of pollen detection versus the protein allergen detection by the microarray assay. The results obtained showed that ISAC inhibition is a sensitive technique able to detect 2.1 pg/mL of Phl p 1 and the allergens released from 1 grain of natural pollen. Also, the airborne allergen samples analyzed showed a good correlation with the concentration of grass pollen in the air. The use of ISAC inhibition will greatly improve future airborne simultaneous allergen quantification, becoming a valuable option in air quality control.

Method development for the determination of Cd, Cu, Ni and Pb in PM2.5 particles sampled in industrial and urban areas of Greater Cairo, Egypt, using high-resolution continuum source graphite furnace atomic absorption spectrometry

Energy-dispersive X-ray fluorescence (EDXRF) spectrometry is not adequate for the determination of some potentially hazardous trace elements, such as Cd, Cu, Ni and Pb at low concentration in PM2.5 atmospheric aerosol particles. Therefore, a method has been developed for the determination of these elements in atmospheric aerosol particles using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS-GF-AAS) without using modifiers. The pyrolysis and atomization temperatures were optimized for this analysis. The samples were collected from industrial and urban areas of Greater Cairo, Egypt. Atmospheric aerosol particles, PM2.5, have been collected on polycarbonate filters loaded by a cyclone sampler. The duration of the collection was 24h at an air flow-rate of 3Lmin−1. Microwave-assisted acid digestion with ultra-pure nitric acid was used to dissolve the polycarbonate filters, including the atmospheric aerosol particles. For the validation of the methods, the results were compared with those obtained by total reflection X-ray fluorescence (TXRF) and inductively coupled plasma mass spectrometry (ICP-MS). Good agreement between the results of the different spectrometric techniques was found. The measured concentrations of Cd, Cu, Ni, and Pb were below the limits defined by international guidelines and national standards of ambient air quality.

Particle size selective sampling of airborne arsenic during electroplating operations

Arsenic exposure can be a significant problem among a number of industries, including mining, metal refining, construction, agriculture and health care. Airborne arsenic particles are typically collected using either 37-mm closed-face cassettes (CFCs) for determining the “total” particulate mass, or cassette and cyclone assemblies to determine the respirable particulate mass. Alternatively, the Institute of Occupational Medicine (IOM) sampler can be used to collect the inhalable fraction of particles, which is considered to be more relevant to human health. A total of 69 samples (23 side-by-side comparisons) were collected at an electroplating plant using CFC, IOM, and cyclone samplers to measure airborne arsenic. The CFC and IOM measurements were not statistically significantly different from each other. However, most of the respirable samples measured below the limit of detection. Results from this study will be informative for understanding the relationship between different particle size selective sampling methods used for similar operations.

Evaluation of Pump Pulsation in Respirable Size-Selective Sampling: Part I. Pulsation Measurements

Pulsations generated by personal sampling pumps modulate the airflow through the sampling trains, thereby varying sampling efficiencies, and possibly invalidating collection or monitoring. The purpose of this study was to characterize pulsations generated by personal sampling pumps relative to a nominal flow rate at the inlet of different respirable cyclones. Experiments were conducted using a factorial combination of 13 widely used sampling pumps (11 medium and 2 high volumetric flow rate pumps having a diaphragm mechanism) and 7 cyclones [10-mm nylon also known as Dorr-Oliver (DO), Higgins-Dewell (HD), GS-1, GS-3, Aluminum, GK2.69, and FSP-10]. A hot-wire anemometer probe cemented to the inlet of each cyclone type was used to obtain pulsation readings. The three medium flow rate pump models showing the highest, a midrange, and the lowest pulsations and two high flow rate pump models for each cyclone type were tested with dust-loaded filters (0.05, 0.21, and 1.25mg) to determine the effects of filter loading on pulsations. The effects of different tubing materials and lengths on pulsations were also investigated. The fundamental frequency range was 22-110 Hz and the magnitude of pulsation as a proportion of the mean flow rate ranged from 4.4 to 73.1%. Most pump/cyclone combinations generated pulse magnitudes ≥10% (48 out of 59 combinations), while pulse shapes varied considerably. Pulsation magnitudes were not considerably different for the clean and dust-loaded filters for the DO, HD, and Aluminum cyclones, but no consistent pattern was observed for the other cyclone types. Tubing material had less effect on pulsations than tubing length; when the tubing length was 183cm, pronounced damping was observed for a pump with high pulsation (>60%) for all tested tubing materials except for the Tygon Inert tubing. The findings in this study prompted a further study to determine the possibility of shifts in cyclone sampling efficiency due to sampling pump pulsations, and those results are reported subsequently.

Fine Particulates Matter (PM2.5) from Coal-fired Power Plant in Manjung and its Health Impacts

Fine particulates matter (PM2.5) emitted from coal-fired power plant can affect human behaviour. Two times 8hours airborne particulates personal outdoor sampling through 7-hole and cyclone samplers has been conducted nearby Manjung Power Plant and Lumut Power Plant. Two samplers used are the 7-hole and cyclone. This research found that 58.25 per cent (%) from total inhalable dust exceeded the outdoor PM10 DOE 24hours Malaysia Standard. The study also has found that the percentage ratio of respirable towards inhalable dust is at 51.7%. Finally, literature reviews linking coal fine particulates matter to the health impact are done to comprehend this study.

Pla a_1 aeroallergen immunodetection related to the airborne Platanus pollen content

Platanus hispanica pollen is considered an important source of aeroallergens in many Southern European cities. This tree is frequently used in urban green spaces as ornamental specie. The flowering period is greatly influenced by the meteorological conditions, which directly affect its allergenic load in the atmosphere. The purpose of this study is to develop equations to predict the Platanus allergy risk periods as a function of the airborne pollen, the allergen concentration and the main meteorological parameters. The study was conducted by means two volumetric pollen samplers; a Lanzoni VPPS 2000 for the Platanus pollen sampling and a Burkard multivial Cyclone Sampler to collect the aeroallergen particles (Pla a_1). In addiction the Dot-Blot and the Raman spectroscopy methods were used to corroborate the results.The Pla a_1 protein is recorded in the atmosphere after the presence of the Platanus pollen, which extend the Platanus pollen allergy risk periods. The Platanus pollen and the Pla a 1 allergens concentration are associated with statistical significant variations of some meteorological variables: in a positive way with the mean and maximum temperature whereas the sign of the correlation coefficient is negative with the relative humidity. The lineal regression equation elaborated in order to forecast the Platanus pollen content in the air explain the 64.5% of variance of the pollen presence in the environment, whereas the lineal regression equation elaborated in order to forecast the aeroallergen a 54.1% of the Pla a_1 presence variance. The combination of pollen count and the allergen quantification must be assessed in the epidemiologic study of allergic respiratory diseases to prevent the allergy risk periods.

Modeling Liquid Film Evaporation in a Wetted Wall Bioaerosol Sampling Cyclone

The wetted wall bioaerosol sampling cyclone (WWC) is a complex multiphase flow device which collects and concentrates dilute bioaerosols into liquid samples for biological analysis (McFarland et al., 2009, “Wetted Wall Cyclones for Bioaerosol Sampling,” Aerosol Sci. Technol., 44(4), pp. 241–252). Understanding heat and mass transfer processes occurring inside the WWC is the key to enhancing its performance through an effective coupling to lab-on-chip analysis platforms which require small volumes of liquid output. There exists a critical liquid input rate below which there is no sample collection since all liquid is lost to evaporative effects. The purpose of this study was to model critical film evaporation based on first principles and develop semi-empirical WWC performance correlations as an improvement to existing empirical correlations. A one-dimensional, coupled heat and mass transfer model was developed approximating WWC multiphase flow as cocurrent air-film flow. Governing equations were simplified and approximate solutions were used to optimize model parameters like the heat transfer coefficient based on empirical data from previous works. Optimized model parameters were then used in the full numerical solution to calculate liquid evaporation rates within the WWC over the full range of relative humidity and air temperature. Semi-empirical correlations developed in this study were compared to existing empirical models and showed much improvement: proper physical behavior at the extreme limits of temperature and relative humidity was observed, and the nonlinear dependence of evaporative effects on environmental conditions was also captured.

On the elemental composition of PM2.5 in central Cairo, Egypt

Aerosol particles are among the criteria pollutants identified by many countries because of their effects on human health and the environment. Information about the elemental composition of the aerosol particles is useful for source apportionment and determining the possible negative effects of the particulate air pollution. In this study, fine aerosol particles (PM2.5) were collected over 24 h once a week at roof level at the National Research Center in the center of Cairo, Egypt, between September 2010 and May 2011 using a cyclonic sampler. The site is representative of urban residential areas in the center of this megacity. Elemental determination was performed using an energy dispersive X‐ray fluorescence spectrometer with a Mo secondary target, and the measured concentrations were evaluated using the quantitative X‐ray analysis system/AXIL software package. The concentrations of 16 elements were determined in the collected aerosol samples, although some were generally not present at levels above the method's limit of detection. The concentrations of many of the elements exceeded those in other urban environments. The concentration of Pb was 95 ± 200 ng/m3, well below the Egyptian legal limit of 500 ng/m3. This represents a significant decrease since 1997, when concentrations above 3 µg/m3 were measured. The decrease is due to the banning of Pb in vehicle fuel in 1997 and the movement of Pb smelters from the central part of Cairo in 2002. Analysis of the elemental concentrations revealed seasonal variation in their levels and possible sources of the emissions, and enabled us to estimate their effects on human health. Copyright © 2013 John Wiley &amp; Sons, Ltd.

Characterization of the monthly variation in (1 → 3)-β-d-glucan concentrations in university laboratories

We characterize the monthly variation in (1 → 3)-β-D-glucan concentration measured over the course of 1 year, and we evaluate the characteristics of size selection using a two-stage cyclone sampler. The (1 → 3)-β-D-glucan concentrations were measured in four bio-related laboratories. A total of 156 samples were collected using a new two-stage cyclone sampler. Analysis of (1 → 3)-β-D-glucan was performed using the kinetic Limulus amebocyte lysate assay. The study showed that airborne (1 → 3)-β-D-glucan concentrations were significantly higher in laboratory D (mean ± SD 1,105 ± 1,893 pg/m(3)) and in the spring (5,458 pg/m(3)). The highest concentration of (1 → 3)-β-D-glucan occurred in the spring, particularly in May.

CFD modeling of hydrocyclones: Prediction of particle size segregation

The flow behavior in a hydrocyclone is a highly swirling and turbulent multiphase structure. A multiphase CFD model with sub modules for the air-core, turbulence, and particle classification with a suitable slurry viscosity model was used to simulate performance of hydrocyclones. The predicted velocity field from the LES, DRSM turbulence models is compared with the LDA measurements data for a 75mm cyclone. The multiphase CFD model is used to understand the particle size segregation inside a 6in. hydrocyclone. The predictions are validated against the Renner (1976) data, which was originally measured using high-speed sampling probe at different precisely controlled positions. The overall classification curve predicts close to the experimental data. It is observed that the predicted position sample size distributions are in good agreement with the experimental data, at most of the cyclone sampling positions. Close to the forced vortex (inner position), the predicted size distributions slightly deviate from the measured data. The discrepancy may be an effect of sampling turbulence due to probing close to the unstable forced vortex. Simulations are also carried out using two different CFD models, with and without the viscosity correction due to the fines fraction. The predictions are improved with respect to Renner’s data with the fines viscosity corrected CFD model.

Airborne fungal cell fragments in homes in relation to total fungal biomass

Fungal exposure may induce respiratory symptoms. The causative agents are compounds in the fungal cell wall. Fragments of microbes may be present in air samples but are not measurable using conventional spore counting or by the determination of viable organisms. This study assesses the proportion of fungal cell biomass and endotoxin in different particle size fractions in air samples from homes. Air samples were collected from 15 homes using a cyclone sampler, collecting particles in three aerodynamic size fractions: <1.0, 1.0-1.8, and >1.8 μm. N-Acetylhexosaminidase (NAHA) was determined as a marker of fungal cell biomass. Endotoxin was determined using the Limulus amebocyte lysate method. NAHA and endotoxin in the size range <1.0 μm comprised up to 63% (mean 22.7%) and 96.3% (mean 22.6%) of the total concentrations, respectively. There were significant relationships between the amounts of NAHA and endotoxin in the total amount and in the size fraction >1.8 μm but not in the smaller fractions. The results demonstrate significant amounts of fungal cell biomass and endotoxin in particles <1.0 μm. Homes with reported mold damage had a lower concentration of NAHA in particles <1.0 μm than homes without mold damage. To assess airborne exposure for diagnostic and preventive purposes, measurement techniques that include this fraction should be considered.

Detection ofParacoccidioidesspp. in environmental aerosol samples

Taking into account that paracoccidioidomycosis infection occurs by inhalation of the asexual conidia produced by Paracoccidioides spp. in its saprobic phase, this work presents the collection of aerosol samples as an option for environmental detection of this pathogen, by positioning a cyclonic air sampler at the entrance of armadillo burrows. Methods included direct culture, extinction technique culture and Nested PCR of the rRNA coding sequence, comprising the ITS1-5.8S-ITS2 region. In addition, we evaluated one armadillo (Dasypus novemcinctus) as a positive control for the studied area. Although the pathogen could not be isolated by the culturing strategies, the aerosol sampling associated with molecular detection through Nested PCR proved the best method for discovering Paracoccidioides spp. in the environment. Most of the ITS sequences obtained in this investigation proved to be highly similar with the homologous sequences of Paracoccidioides lutzii from the GenBank database, suggesting that this Paracoccidioides species may not be exclusive to mid-western Brazil as proposed so far.

Large Eddy Simulation of the gas–particle flow in cyclone separators

In this work, the particle–gas flows in two small sampling cyclone separators are simulated by means of Large Eddy Simulations (LES). The Eulerian–Lagrangian approach is used to calculate the fluid flow along with the particle motion. Unlike Reynolds-averaged turbulence models (RANS), LES modeling is advantageous as it does not demand turbulence dispersion models for the particles, which in turn requires parameter tuning that may not be applicable to arbitrary cyclone geometries and operating conditions. The results of three integration schemes for the particle motion equations and two collection criteria are shown and discussed. The grade efficiencies computed are compared with the experimental ones and shown to be sensitive to Reynolds numbers and geometry variations. It can be concluded that, besides the independence of ad hoc parameters, LES offers a robust, reliable modeling option for such flows.

A Study on the Airborne Particulates Matter in Selected Museums of Peninsular Malaysia

An indoor pollutant gives harmful effects to human health and became one of the main causes of the cultural heritage deterioration. The research is focuses on the airborne particulates at the indoor of the museum galleries. Equipment used to sample inhalable dust was the 7-hole sampler and the Cyclone sampler for sample respirable dust. The results show that mass concentrations at selected location were exceeding the limit of safety Indoor Air Quality (IAQ) and Malaysia standard limit for TSP and PM10 in 8hours sampling. Thus, it is important to control the level of contaminants within the buildings for safety purposes.

Comparison of quantitative airborne fungi measurements by active and passive sampling methods

The present study compared the airborne fungi collection performance of a two-stage cyclone sampler (active method) to the performance of the Personal Aeroallergen Sampler (passive method) using quantitative polymerase chain reaction (qPCR) assays. Indoor air concentrations of the common fungal species Alternaria alternata, Cladosporium cladosporioides, Epicoccum nigrum, and Penicillium chrysogenum were considered. Good correlations between the two sampling methods for the fungi A. alternata, C. cladosporioides, and E. nigrum were observed and the mean effective passive sampling rates (±std. dev.) for these species were 0.032 (±0.006), 0.058 (±0.006), and 0.066 (±0.044) l min −1, respectively. Gravitational settling was the dominant collection mechanism for A. alternata and E. nigrum. The root mean square precisions for the passive sampler measurements were also comparable to those of the active sampler (49–73% and 50–102%, respectively). The passive sampler did not allow for the collection of P. chrysogenum, likely due to the insufficient gravitational settling velocity of the fungal particle with its aerodynamic diameter of less than 5 μm. The passive sampler, in conjunction with growth-independent qPCR detection methodologies, can be utilized in future exposure assessment studies to deepen our understanding of how individuals are affected by inhalation of airborne fungal pathogens and allergens, especially for those with an aerodynamic diameter greater than 5 μm.