Effect of an Air Cleaner with Electrostatic Filter on the Removal of Airborne House Dust Mite Allergens
01 Nov 2010-Yonsei Medical Journal (Yonsei University College of Medicine)-Vol. 51, Iss: 6, pp 918-923
TL;DR: The electrostatic air cleaner can remove airborne HDM allergens and may be useful as a supplementary environmental control tool for HDM sensitized respiratory allergic patients.
Abstract: PURPOSE The effects of air cleaners on the removal of airborne indoor allergens, especially house dust mites (HDM), are still controversial. The objective of this study is to evaluate the effect of an air cleaner with an electrostatic filter on the removal of airborne mite allergens. MATERIALS AND METHODS A dried HDM culture medium that contained mite body particles and excretions was dispersed in a chamber equipped with an electrostatic air cleaner. The number of airborne particles was recorded continuously by a dust spectrometer for 60 minutes. Airborne particles in the chamber were collected on a sampling filter at a flow rate of 10 L/min and the Der f 1 concentration in the filter extracts was measured by two-site ELISA. RESULTS The air cleaner efficiently removed airborne HDM particles. The air cleaner removed airborne HDM particles (size 2-12.5 µm) 11.4 ± 2.9 fold (cleaner operating for 15 minutes), 5.4 ± 0.7 fold (cleaner operating for 30 minutes), and 2.4 ± 0.2 fold (cleaner operating for 60 minutes) more than the removal of HDM particles by natural settle down. Removal kinetics differed according to the particle size of the airborne particles. The air cleaner decreased the concentration of Der f 1 in the extraction of airborne particles collected on the air sampling filter by 60.3%. CONCLUSION The electrostatic air cleaner can remove airborne HDM allergens and may be useful as a supplementary environmental control tool for HDM sensitized respiratory allergic patients.
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TL;DR: In this article, the average indoor concentrations of fine particles less than 2.5μm were collected from inside ten childcare centers, and from their adjacent outdoor environments in Seoul, Korea during the summer, autumn and winter seasons.
Abstract: Particulate matter (PM) samples were collected from inside ten childcare centers, and from their adjacent outdoor environments in Seoul, Korea during the summer, autumn and winter seasons. The concentrations and distribution of microbial size of the airborne bacteria and fungi in bio-aerosols were also investigated. The average indoor concentrations of fine particles less than 2.5 μm (PM 2.5 ) in the residential areas ranged from 37.1 μg/m 3 (±5.8 μg/m 3 ) to 45.2 μg/m 3 (±5.3 μg/m 3 ), while indoor PM 2.5 concentrations in centers with roadways nearby ranged from 48.9 μg/m 3 (±9.5 μg/m 3 ) to 52.9 μg/m 3 (±7.7 μg/m 3 ), and up to 51.1 μg/m 3 (±6.4 μg/m 3 ) in residential areas located near construction sites. The concentrations of particulate matter indoor in childcare centers were correlated with the corresponding outdoor locations, in residential areas ( R 2 of 0.64 for PM 10 and 0.66 for PM 2.5 ), near roadways ( R 2 of 0.72 for PM 10 and 0.76 for PM 2.5 ), and near construction areas ( R 2 of 0.45 for PM 10 and 0.62 for PM 2.5 ). The distribution of bio-aerosols showed that 69.4% to 78.1% of the airborne bacteria in the outdoor environments existed in stages 1–3 (over 3.3 μm), while from 59.2% to 78.6% existed in stages 2–4 (2.1–7.0 μm) inside the childcare centers. When the efficiency of air purifiers was compared with the location and characteristics of the indoor of child care centers, the removal efficiency of particulate matter with new data that may characterize indoor air quality.
75 citations
Cites background from "Effect of an Air Cleaner with Elect..."
...Using air purifiers seems to be the most effective way to maintain a comfortable indoor environment, and reduces pollutants particles in the air to remove contaminants which could cause allergic diseases [31,62,63]....
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TL;DR: Characterization of allergenic molecules and elucidation of mechanisms by which adjuvant-like molecules modulate allergic reactions will provide valuable information on allergic diseases, and are necessary for the development of diagnostic tools and therapeutic strategies.
Abstract: The house-dust mite (HDM), commonly found in human dwellings, is an important source of inhalant and contact allergens. In this report, the importance of HDM allergy in Korea and the characteristics of allergens from dust mite are reviewed with an emphasis on investigations performed in Korea. In Korea, Dermatophagoides farinae is the dominant species of HDM, followed by D. pteronyssinus. Tyrophagus putrescentiae is also found in Korea, but its role in respiratory allergic disease in Korea is controversial. The relatively low densities of mite populations and concentrations of mite major allergens in dust samples from Korean homes, compared to westernized countries, are thought to reflect not only different climatic conditions, but also cultural differences, such as the use of ‘ondol’ under-floor heating systems in Korean houses. HDM are found in more than 90% of Korean houses, and the level of exposure to HDM is clinically significant. About 40%-60% of Korean patients suffering from respiratory allergies, and more than 40% of patients suffering from atopic dermatitis, are sensitized to HDM. Mite allergens can be summarized according to their inherent auto-adjuvant activities and/or their binding affinities to the adjuvant-like substances: proteolytic enzymes, lipid binding proteins, chitin binding proteins, and allergens not associated with adjuvant-like activity. In general, allergens with a strong adjuvant-like activity or adjuvant-binding activity elicit potent IgE reactivity. In Korea, Der f 2 is the most potent allergen, followed by Der f 1. Immune responses are modulated by the properties of the allergen itself and by the adjuvant-like substances that are concomitantly administered with the antigens. Characterization of allergenic molecules and elucidation of mechanisms by which adjuvant-like molecules modulate allergic reactions, not only in Korea but also worldwide, will provide valuable information on allergic diseases, and are necessary for the development of diagnostic tools and therapeutic strategies.
73 citations
Cites background from "Effect of an Air Cleaner with Elect..."
...HDM species were detected in air conditioner filters,(55) and air cleaners with electrostatic filters were shown to remove the mite allergen effectively.(56) Airborne mite allergens were also measured during normal domestic activity....
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TL;DR: In this article, a seasonal exposure assessment in a hospital environment using several air quality indicators including carbon monoxide (CO), carbon dioxide (CO2), particulate matter (PM10 and PM2.5), and total volatile organic compounds (TVOCs) was conducted.
Abstract: This study involved a seasonal exposure assessment in a hospital environment using several air quality indicators including carbon monoxide (CO), carbon dioxide (CO2), particulate matter (PM10 and PM2.5), and total volatile organic compounds (TVOCs). We examined the distribution of and variation in the indoor and outdoor pollutant concentrations in 12 working areas across three hospitals, with an emphasis on capturing seasonal variations. We assessed correlations between measured indoor and outdoor levels to quantify the importance of indoor sources on air quality relative to outdoor sources. Our results indicated that while indoor and outdoor CO levels were below air quality standards/guidelines, measured PM2.5 and PM10 concentrations at several locations exceeded the standards 2- to 3.5-fold. We generally recorded higher indoor PM levels during the warm season, particularly during regional desert storm events. The ingress of particles from the outdoor to indoor environment was evident with high correlations between indoor and outdoor PM2.5 (r between 0.83 and 0.92) and PM10 (r between 0.74 and 0.86) levels, particularly during the warm season. Indoor to outdoor (I/O) ratios of PM2.5 and PM10 were mostly 1 across all sampling locations. Our paper concludes with implications of high PM exposure and a suggested management framework for limiting such exposure in hospitals.
41 citations
TL;DR: In this paper, the Clean Air Delivery Rate (CADR) of six models of air purifiers with diesel and KCl particles, and measured noise during operation, was determined for total concentration and size-selectively for particles of 0.03-1μm.
Abstract: Exposure to diesel combustion particles is known to cause and exacerbate respiratory conditions, including asthma. High efficiency particulate air (HEPA) purifiers can provide health benefits by reducing concentrations of these particles. National standards call for air purifiers to be tested using tobacco smoke, as well as aerosolized dust, pollen, and potassium chloride (KCl) particles. Little is known about the efficiency of HEPA air purifiers against diesel particles. Previous studies performed with respirator filters have shown higher penetration of combustion generated particles compared to standard test particles. Within a controlled laboratory setting, we compared the Clean Air Delivery Rate (CADR) of six models of air purifiers with diesel and KCl particles, and measured noise during operation. CADR was determined for total concentration and size-selectively for particles of 0.03–1 μm. Lowest CADRs were consistently found for particles
38 citations
TL;DR: In this paper, a shielded sliding discharge reactor at operating voltages as low as 5kV for a gap length of 1.6 cm was used to generate positive and negative streamer discharges in atmospheric pressure air.
Abstract: Positive and negative streamer discharges in atmospheric pressure air were generated in a shielded sliding discharge reactor at operating voltages as low as 5 kV for a gap length of 1.6 cm. In this reactor, electrodes are placed on top of a dielectric layer and one of the electrodes, generally the one on ground potential, is connected to a conductive layer on the opposite side of the dielectric. The energy per pulse, at the same applied voltage, was more than a factor of seven higher than that of pulsed corona discharges, and more than a factor of two higher than that of sliding discharges without a shield. It is explained on the basis of enhanced electric fields, particularly at the plasma emitting electrode. Specific input energy required for 50 % removal from ~1,000 ppm initial NO could be reduced to ~18 eV/molecule when ozone in the exhaust of negative streamers was utilized. For sliding discharges and pulsed corona discharges this value was ~25 eV/molecule and it was 35 eV/molecule for positive shielded sliding discharges. Also, the ozone energy yield from dry air was up to ~130 g/kW h and highest for negative streamer discharges in shielded sliding discharge reactors. The high energy density in negative streamer discharges in the shielded discharge reactor at the relatively low applied voltages might not only allow expansion of basic studies on negative streamers, but also open the path to industrial applications, which have so far been focused on positive streamer discharges.
35 citations
References
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01 Jan 1999
TL;DR: Aerosol Technology, Second Edition as mentioned in this paper is the #1 guide to aerosol science and technology and has been the text of choice among students and professionals who need to acquire a thorough working knowledge of modern aerosol theory and applications.
Abstract: The #1 guide to aerosol science and technology -now better than everSince 1982, Aerosol Technology has been the text of choice among students and professionals who need to acquire a thorough working knowledge of modern aerosol theory and applications. Now revised to reflect the considerable advances that have been made over the past seventeen years across a broad spectrum of aerosol-related application areas - from occupational hygiene and biomedical technology to microelectronics and pollution control -this new edition includes:* A chapter on bioaerosols* New sections on resuspension, transport losses, respiratory deposition models, and fractal characterization of particles* Expanded coverage of atmospheric aerosols, including background aerosols and urban aerosols* A section on the impact of aerosols on global warming and ozone depletion.Aerosol Technology, Second Edition also features dozens of new, fully worked examples drawn from a wide range of industrial and research settings, plus new chapter-end practice problems to help readers master the material quickly.
3,237 citations
TL;DR: In addition to genetic factors, exposure in early childhood to house-dust mite allergens is an important determinant of the subsequent development of asthma.
Abstract: Background and Methods. Children with asthma commonly have positive skin tests for inhaled allergens, and in the United Kingdom the majority of older children with asthma are sensitized to the house-dust mite. In a cohort of British children at risk for allergic disease because of family history, we investigated prospectively from 1978 to 1989 the relation between exposure to the house-dust mite allergen (Der p I) and the development of sensitization and asthma. Results. Of the 67 children studied in 1989, 35 were atopic (positive skin tests), and 32 were nonatopic. Of the 17 with active asthma, 16 were atopic (P<0.005), all of whom were sensitized to the house-dust mite, as judged by positive skin tests and levels of specific IgE antibodies (P<0.001). For house-dust samples collected from the homes of 59 of the children in 1979 and from 65 homes in 1989, the geometric means for the highest Der p I exposure were, respectively, 16.1 and 16.8 μg per gram of sieved dust. There was a trend toward an ...
1,645 citations
TL;DR: The data indicate that avoidance measures in the domestic environment aimed at the primary prevention of allergen-driven sensitization should be introduced at the earliest possible stage, if possible during infancy.
Abstract: Background: The purpose of the study was to investigate the influence of environmental allergen exposure on allergic sensitization in infancy and early childhood. Methods: A cohort of 1314 newborns was recruited and followed up prospectively at the ages 12, 24, and 36 months. The levels of major mite (Der p 1 and Der f 1) and cat (Fel d 1) allergens were determined from domestic carpet dust samples by sandwich ELISA. Specific serum IgE antibodies to mite and cat allergens were determined by CAP fluoroimmunoassay (Pharmacia). Logistic regression was used to assess the effects of allergen exposure, age, family history, and cord blood IgE simultaneously on the risk of sensitization. Results: Children, who had been found to be sensitized at least once during the first 3 years of life, were found to be exposed to significantly higher house dust mite (median, 868 ng/gm vs 210 ng/gm; p =0.001) and cat (median, 150 ng/gm vs 64 ng/gm; p =0.011) allergen concentrations in domestic carpet dust compared with the group without sensitization. In homes with low (≤25th percentile) dust concentrations, the risk of sensitization to mite (1.6%) and cat (2.0%) is low, compared with 6.5% for mite and 6.3% for cat if the domestic exposure is above the 75th percentile. The dose-response relationships between allergen levels and sensitization indicate that the increase in sensitization risk at low allergen levels is more pronounced in cat allergy ( p =0.002) than in mite allergy ( p =0.026). In the group with a positive family history, lower mite and cat allergen concentrations are needed to achieve specific sensitization compared with the group with a negative family history. Conclusion: Our data indicate that avoidance measures in the domestic environment aimed at the primary prevention of allergen-driven sensitization should be introduced at the earliest possible stage, if possible during infancy. (J Allergy Clin Immunol 1997;99:763–9.)
567 citations
TL;DR: Measurements from a radioimmunoassay show that more than 95% of the allergen accumulating in mite cultures is associated with faecal particles.
Abstract: The association between house dust allergy and asthma has long been recognized, and it has been demonstrated that a major allergen in house dust is related to the presence of mites of the genus Dermatophagoides Using extracts of mite culture for skin testing, as many as 10% of the population and up to 90% of allergic asthmatics give positive immediate reactions Although mites may occasionally become airborne during bed-making, it has also been demonstrated that they 'secrete or excrete' some allergen Recently, we have shown that up to three-quarters of the serum IgE antibodies to mites are directed against a major allergen-antigen P1 (molecular weight 24,000) Using a radioimmunoassay it is possible to measure the concentration of this glycoprotein in both dust samples and mite cultures These measurements, which are reported here, show that more than 95% of the allergen accumulating in mite cultures is associated with faecal particles
508 citations
TL;DR: The results suggested that natural exposure to this dust allergen allows occasional fecal particles to enter the lungs and that these particles contain very concentrated allerGEN.
Abstract: Using an inhibition radioimmunoassay for the major allergen from Dermatophagoides pteronyssinus (antigen P1), we studied the distribution of this dust allergen in the houses of patients with asthma. Both bed and floor dust samples contained a wide range of antigen P1, 100 to 100,000 ng/g of fine dust, and this concentration correlated well with the number of mite bodies (r = 0.81, p less than 0.001). We were unable to detect antigen P1 in the air of undisturbed rooms. However, during domestic activity, between 1 and 30 ng were collected on a filter than sampled air for 45 min at 17 L/min. Using a cascade impactor it was shown that greater than 80% of the airborne antigen P1 was associated with particles greater than 10 mu in diameter. Some of the particles containing allergen could be identified because they formed precipitin rings when impacted onto agarose containing rabbit antimite antiserum. These particles had the physical appearance of mite feces, which are the major source of antigen P1 in mite cultures. The results suggested that natural exposure to this dust allergen allows occasional fecal particles to enter the lungs and that these particles contain very concentrated allergen.
295 citations