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1

Canadian house dust study: lead bioaccessibility and speciation.  

PubMed

Vacuum samples were collected from 1025 randomly selected urban Canadian homes to investigate bioaccessible Pb (Pb(S)) concentrations in settled house dust. Results indicate a polymodal frequency distribution, consisting of three lognormally distributed subpopulations defined as "urban background" (geomean 58 ?g g(-1)), "elevated" (geomean 447 ?g g(-1)), and "anomalous" (geomean 1730 ?g g(-1)). Dust Pb(S) concentrations in 924 homes (90%) fall into the "urban background" category. The elevated and anomalous subpopulations predominantly consist of older homes located in central core areas of cities. The influence of house age is evidenced by a moderate correlation between house age and dust Pb(S) content (R(2) = 0.34; n = 1025; p < 0.01), but it is notable that more than 10% of homes in the elevated/anomalous category were built after 1980. Conversely, the benefit of home remediation is evidenced by the large number of homes (33%) in the background category that were built before 1960. The dominant dust Pb species determined using X-ray Absorption Spectroscopy were as follows: Pb carbonate, Pb hydroxyl carbonate, Pb sulfate, Pb chromate, Pb oxide, Pb citrate, Pb metal, Pb adsorbed to Fe- and Al-oxyhydroxides, and Pb adsorbed to humate. Pb bioaccessibility estimated from solid phase speciation predicts Pb bioaccessibility measured using a simulated gastric extraction (R(2) = 0.85; n = 12; p < 0.0001). The trend toward increased Pb bioaccessibility in the elevated and anomalous subpopulations (75% ± 18% and 81% ± 8%, respectively) compared to background (63% ± 18%) is explained by the higher proportion of bioaccessible compounds used as pigments in older paints (Pb carbonate and Pb hydroxyl carbonate). This population-based study provides a nationally representative urban baseline for applications in human health risk assessment and risk management. PMID:21563758

Rasmussen, Pat E; Beauchemin, Suzanne; Chénier, Marc; Levesque, Christine; MacLean, Lachlan C W; Marro, Leonora; Jones-Otazo, Heather; Petrovic, Sanya; McDonald, Lauren T; Gardner, H David

2011-06-01

2

Canadian House Dust Study: Lead Bioaccessibility and Speciation  

SciTech Connect

Vacuum samples were collected from 1025 randomly selected urban Canadian homes to investigate bioaccessible Pb (Pb{sub S}) concentrations in settled house dust. Results indicate a polymodal frequency distribution, consisting of three lognormally distributed subpopulations defined as 'urban background' (geomean 58 {micro}g g{sup -1}), 'elevated' (geomean 447 {micro}g g{sup -1}), and 'anomalous' (geomean 1730 {micro}g g{sup -1}). Dust Pb{sub S} concentrations in 924 homes (90%) fall into the 'urban background' category. The elevated and anomalous subpopulations predominantly consist of older homes located in central core areas of cities. The influence of house age is evidenced by a moderate correlation between house age and dust Pb{sub S} content (R{sup 2} = 0.34; n = 1025; p < 0.01), but it is notable that more than 10% of homes in the elevated/anomalous category were built after 1980. Conversely, the benefit of home remediation is evidenced by the large number of homes (33%) in the background category that were built before 1960. The dominant dust Pb species determined using X-ray Absorption Spectroscopy were as follows: Pb carbonate, Pb hydroxyl carbonate, Pb sulfate, Pb chromate, Pb oxide, Pb citrate, Pb metal, Pb adsorbed to Fe- and Al-oxyhydroxides, and Pb adsorbed to humate. Pb bioaccessibility estimated from solid phase speciation predicts Pb bioaccessibility measured using a simulated gastric extraction (R{sup 2} = 0.85; n = 12; p < 0.0001). The trend toward increased Pb bioaccessibility in the elevated and anomalous subpopulations (75% {+-} 18% and 81% {+-} 8%, respectively) compared to background (63% {+-} 18%) is explained by the higher proportion of bioaccessible compounds used as pigments in older paints (Pb carbonate and Pb hydroxyl carbonate). This population-based study provides a nationally representative urban baseline for applications in human health risk assessment and risk management.

P Rasmussen; S Beauchemin; M Chenier; C Levesque; L MacLean; L Marrow; H Jones-Otazo; S Petrovic; L McDonald; H Gardner

2011-12-31

3

Evolution of efficient methods to sample lead sources, such as house dust and hand dust, in the homes of children.  

PubMed

Efficient sampling methods to recover lead-containing house dust and hand dust have been evolved so that sufficient lead is collected for analysis, and to ensure that correlational analyses linking these two parameters to blood lead are not dependent on the efficiency of sampling. Precise collection of loose house dust from a 1-unit area (484 cm2) with a Tygon or stainless steel sampling tube connected to a portable sampling pump (1.2 to 2.5 liters/min) required repetitive sampling (three times). The Tygon tube sampling technique for loose house dust less than 177 microns in diameter was around 72% efficient with respect to dust weight and lead collection. A representative house dust contained 81% of its total weight in this fraction. A single handwipe for applied loose hand dust was not acceptably efficient or precise, and at least three wipes were necessary to achieve recoveries of greater than 80% of the lead applied. House dusts of different particle sizes less than 246 microns adhered equally well to hands. Analysis of lead-containing material usually required at least three digestions/decantations using hot plate or microwave techniques to allow at least 90% of the lead to be recovered. It was recommended that other investigators validate their handwiping, house dust sampling, and digestion techniques to facilitate comparison of results across studies. The final methodology for the Cincinnati longitudinal study was three sampling passes for surface dust using a stainless steel sampling tube; three microwave digestions/decantations for analysis of dust and paint; and three wipes with handwipes with one digestion/decantation for the analysis of six handwipes together. PMID:4076114

Que Hee, S S; Peace, B; Clark, C S; Boyle, J R; Bornschein, R L; Hammond, P B

1985-10-01

4

Apportioning the sources of lead in house dusts in the London borough of Richmond, England.  

PubMed

The sources of particulate lead in houses in the London Borough of Richmond, England have been investigated using automated scanning electron microscopy in conjunction with energy dispersive X-ray spectroscopy. Compositional and size information was collected on lead-bearing particles from density and size fractionated floor dusts from 16 residences of various ages. A classification scheme based on the analysis of different types of lead source particles was used to categorize the house dust particles as either auto exhaust, road dust, garden soil, paint, high temperature process emissions, lead of common origin or miscellaneous lead-bearing. Classification results based on both populations of particles and estimated particle volumes suggest that paint, road dust and garden soil are the major contributors of particulate lead to the Richmond households. The primary contributing source in the 64-1000-microm size range of the house dusts appears to be paint. In the 0-64-microm size fraction of the dusts paint, road dust and garden soil all make significant contributions. Variations in the contributions made by the major sources appear to be unrelated to the age of the homes. PMID:8259488

Hunt, A; Johnson, D L; Thornton, I; Watt, J M

1993-09-30

5

A study of urban housing demolitions as sources of lead in ambient dust: demolition practices and exterior dust fall.  

PubMed Central

Demolition of older housing for urban redevelopment purposes benefits communities by removing housing with lead paint and dust hazards and by creating spaces for lead paint-free housing and other community resources. This study was conducted to assess changes, if any, in ambient dust lead levels associated with demolition of blocks of older lead-containing row houses in Baltimore, Maryland (USA). In this article we present results based on dust-fall samples collected from fixed locations within 10 m of three demolition sites. In subsequent reports we will describe dust lead changes on streets, sidewalks, and residential floors within 100 m of the demolition sites. Geometric mean (GM) lead dust-fall rate increased by > 40-fold during demolition to 410 micro g Pb/m2/hr (2,700 micro g Pb/m2 per typical work day) and by > 6-fold during debris removal to 61 micro g Pb/m2/hr (440 micro g Pb/m2 per typical work day). Lead concentrations in dust fall also increased during demolition (GM, 2,600 mg/kg) and debris removal (GM, 1,500 mg/kg) compared with baseline (GM, 950 mg/kg). In the absence of dust-fall standards, the results were compared with the U.S. Environmental Protection Agency's (U.S. EPA's) dust-lead surface loading standard for interior residential floors (40 micro g/ft2, equivalent to 431 micro g/m2); daily lead dust fall during demolition exceeded the U.S. EPA floor standard by 6-fold on average and as much as 81-fold on an individual sample basis. Dust fall is of public health concern because it settles on surfaces and becomes a pathway of ambient lead exposure and a potential pathway of residential exposure via tracking and blowing of exterior dust. The findings highlight the need to minimize demolition lead deposition and to educate urban planners, contractors, health agencies, and the public about lead and other community concerns so that society can maximize the benefits of future demolition activities nationwide. PMID:12842778

Farfel, Mark R; Orlova, Anna O; Lees, Peter S J; Rohde, Charles; Ashley, Peter J; Chisolm, J Julian

2003-01-01

6

Assessment of in vitro lead bioaccessibility in house dust and its relationship to in vivo lead relative bioavailability.  

PubMed

House dust samples containing 25-738 mg of Pb kg(-1) from 15 cities in China were assessed for in vitro Pb bioaccessibility and in vivo Pb relative bioavailability. On the basis of stable Pb isotope ratios, the Pb in dust samples mainly originated from coal combustion. Lead bioaccessibility was determined using gastric (GP) and intestinal phase (IP) of solubility bioaccessibility research consortium (SBRC), in vitro gastrointestinal (IVG), Deutsches Institut für Normunge.V. (DIN), and physiologically based extraction test methods (PBET), while Pb relative bioavailability (RBA) was determined using a mouse blood model. Lead bioaccessibility in 24 house dust samples varied significantly (23-99%) depending on the methods. Values from the IP were considerably lower than those from the GP because of the co-precipitation of Pb with iron and re-adsorption onto the dust matrix. The SBRC assay with lower GP pH produced higher Pb bioaccessibility because of enhanced Pb dissolution. When compared to mouse blood data using 12 dust samples (29-60%), SBRC-GP and DIN-GP data were correlated with Pb RBA with r(2) values of 0.68 and 0.85 and intercepts 3.15 and 17.4, respectively. Overall, SBRC-GP had potential to predict Pb RBA in dust samples. However, our data suggested that more research is needed to develop a valid in vitro method for predicting Pb RBA in house dust. PMID:24968149

Li, Hong-Bo; Cui, Xin-Yi; Li, Kan; Li, Jie; Juhasz, Albert L; Ma, Lena Q

2014-08-01

7

The bioaccessibility of lead (Pb) from vacuumed house dust on carpets in urban residences.  

PubMed

Risk assessments for toxicants in environmental media via oral exposure often rely on measurements of total concentration in a collected sample. However, the human digestive system cannot dissolute all of a toxicant present in the binding matrix, and cannot absorb it with nearly 100% efficiency. In vitro bioaccessibility has been developed as a method to estimate oral bioavailability of a toxicant using a physiologically-based extraction procedure. Bioaccessibility measurements are more physiologically relevant than strong acid leaching measurements of concentration. A method for measuring bioaccessible lead in house dust was derived from the bioaccessibility method currently used for heavy metals in contaminated soils. House dust was collected from carpets in typical urban residences. Bioaccessible lead was measured in house dust (<75 microm) from the homes of 15 participants. The bioaccessibility ranged from 52.4% to 77.2% in gastric fluid, and 4.9% to 32.1% in intestinal fluid. House dust samples from five homes were analyzed to assess the relationship among lead bioaccessibility of three particle size fractions (<75, 75-150, and 150-250 microm). Changes in lead bioaccessibility as a function of particle size fraction were not significant for gastric fluid (p= 0.7019); however they were significant for intestinal fluid (p= 0.0067). This decrease of bioaccessibility may result from the readsorption of dissolved lead onto the dust particles or precipitation of lead with phosphates in a high-pH environment. The bioaccessibility data obtained for two biofluids were applied to the IEUBK model, and results for intestinal bioaccessibility of lead provide support for the model default value of 30% lead bioavailability of dust as a reasonable population indicator for dose, but the higher values for gastric bioaccessibility of lead appeared to provide an upper bound that approached actual blood lead levels in the children living in the studied homes. This upper bound seemed to overcome some of the limitations of the model when it lacks child-specific activity data and characterization of all exposure routes. PMID:16492186

Yu, Chang Ho; Yiin, Lih-Ming; Lioy, Paul J

2006-02-01

8

Chemical speciation and bioaccessibility of lead in surface soil and house dust, Lavrion urban area, Attiki, Hellas  

Microsoft Academic Search

In the Lavrion urban area study, Hellas, a five-step sequential extraction method was applied on samples of ‘soil’ (n = 224), affected by long-term mining and metallurgical activities, and house dust (n = 127), for the purpose of studying the potential bioaccessibility of lead and other metals to humans. In this paper, the\\u000a Pb concentrations in soil and house dust samples are discussed, together

Alecos Demetriades; Xiangdong Li; Michael H. Ramsey; Iain Thornton

2010-01-01

9

House-Dust Allergy  

PubMed Central

House-dust allergy is a common cause of perennial allergic rhinitis and extrinsic asthma. Symptoms tend to be worse when the patient is in bed. A positive skin test properly performed and interpreted confirms the diagnosis. The house-dust mite is the most important antigenic component of house-dust. Treatment consists of environmental control directed at reducing the mite content of bedroom dust, plus control of symptoms with drugs. Immunotherapy is controversial. ImagesFig. 1 PMID:21286201

Johnson, C. A.

1982-01-01

10

[House dust mite allergy].  

PubMed

House dust mites can be found all over the world where human beings live independent from the climate. Proteins from the gastrointestinal tract- almost all known as enzymes - are the allergens which induce chronic allergic diseases. The inhalation of small amounts of allergens on a regular base all night leads to a slow beginning of the disease with chronically stuffed nose and an exercise induced asthma which later on persists. House dust mites grow well in a humid climate - this can be in well isolated dwellings or in the tropical climate - and nourish from human skin dander. Scales are found in mattresses, upholstered furniture and carpets. The clinical picture with slowly aggravating complaints leads quite often to a delayed diagnosis, which is accidently done on the occasion of a wider spectrum of allergy skin testing. The beginning of a medical therapy with topical steroids as nasal spray or inhalation leads to a fast relief of the complaints. Although discussed in extensive controversies in the literature - at least in Switzerland with the cold winter and dry climate - the recommendation of house dust mite avoidance measures is given to patients with good clinical results. The frequent ventilation of the dwelling with cold air in winter time cause a lower indoor humidity. Covering encasings on mattresses, pillow, and duvets reduces the possibility of chronic contact with mite allergens as well as the weekly changing the bed linen. Another option of therapy is the specific immunotherapy with extracts of house dust mites showing good results in children and adults. Using recombinant allergens will show a better quality in diagnostic as well as in therapeutic specific immunotherapy. PMID:22477664

Carrard, A; Pichler, C

2012-04-01

11

Assessment of in Vitro Lead Bioaccessibility in House Dust and Its Relationship to in Vivo Lead Relative Bioavailability  

E-print Network

and Remediation, University of South Australia, Mawson Lakes, SA 5095, Australia ďż˝ Soil and Water Science ABSTRACT: House dust samples containing 25-738 mg of Pb kg-1 from 15 cities in China were assessed a conservative estimate of exposure as not all ingested Pb in dust may be absorbed into the bloodstream because

Ma, Lena

12

Blood Lead Levels in Toronto Children and Abatement of Lead-Contaminated Soil and House Dust  

Microsoft Academic Search

South Riverdale in Toronto, Canada, underwent a lead-abatement program. In 1988, lead-contaminated soil was replaced at 970 properties, and in 1989, professional housecleaning for lead removal was conducted in 717 households. The effect of “abatement” on blood lead levels in young children was investigated. Data were analyzed from 12 cross-sectional blood-screening surveys that were conducted during an 8-y period in

Peter Langlois; Lesbia Smith; Scott Fleming; Richard Gould; Vivek Goel; Brian Gibson

1996-01-01

13

Lead speciation in house dust from Canadian urban homes using EXAFS, micro-XRF, and micro-XRD.  

PubMed

X-ray absorption fine-structure (XAFS) spectroscopy, micro-X-ray fluorescence (?XRF), and micro-X-ray diffraction (?XRD) were used to determine the speciation of Pb in house dust samples from four Canadian urban homes having elevated Pb concentrations (>1000 mg Pb kg(-1)). Linear combination fitting of the XAFS data, supported by ?XRF and ?XRD, shows that Pb is complexed in a variety of molecular environments, associated with both the inorganic and organic fractions of the dust samples. The inorganic species of lead identified were as follows: Pb metal, Pb carbonate, Pb hydroxyl carbonate, Pb oxide, and Pb adsorbed to iron oxyhydroxides. Pb carbonate and/or Pb hydroxyl carbonate occurred in all four dust samples and accounted for 28 to 75% of total Pb. Pb citrate and Pb bound to humate were the organic species identified. The results of this study demonstrate the ability of XAFS to identify Pb speciation in house dust and show the potential to identify Pb sources from new homes versus older homes. Understanding Pb speciation and how it influences bioaccessibility is important for human health risk assessment and risk management decisions which aim to improve indoor environmental health. PMID:21591711

MacLean, Lachlan C W; Beauchemin, Suzanne; Rasmussen, Pat E

2011-07-01

14

Allergies to House Dust Mites  

MedlinePLUS Videos and Cool Tools

... mattress pad, blankets, and bedspread WEEKLY in hot water. Water at a temperature of 130 degrees or higher ... control house dust mites. Although washing in hot water kills house dust mites, the bedding will soon ...

15

House dust mites in Colorado.  

PubMed

Sixty-four samples of house dust from 16 long-established households in the Denver, Colorado area were analyzed for the presence of house dust mites (Dermatophagoides sp.). No mites were found in house dust from 12 of the sampled houses and small numbers (10 to 40 mites/g of house dust) were found from the other four. In an additional four houses which contained furniture recently imported from other areas, 100 to 360 mites/g of dust were found, and 2 years later up to 200 mites/g were still present. Twenty-eight percent of the mites in repeat collections from the latter homes were alive. The mite allergen content of house dust samples was analyzed by RAST inhibition against pooled sera from mite allergic patients. When dust from four long-established Denver households where no mites were found was employed, there was an average binding of 37.2%; with dust from the four Denver households with low levels of mites and no imported furniture, binding averaged 39.5%. In contrast, with house dust from four "positive control" homes in California and New York there was only 26.1% binding (P less than .005). The results of this study suggest that there are small numbers of nonintroduced house dust mites in some Denver houses, but that they contribute little mite antigen and are probably of minimal clinical significance in mite-sensitive patients. Large numbers of mites can be introduced with furnishings and may persist for at least 2 years. Similar small mite populations might be expected in other areas with comparable relative humidity. PMID:4061975

Moyer, D B; Nelson, H S; Arlian, L G

1985-11-01

16

Lead and other elements in house dust of Japanese residences--source of lead and health risks due to metal exposure.  

PubMed

The levels of 25 elements in house dust collected from 100 general Japanese residences were measured. Factor analysis was applied on the multi-element data to explore source of Pb (median concentration 49.1 mg/kg) in house dust. Six factors were extracted and Pb was found to have great loading on the fifth factor with Sb and Sn, suggesting solder (Sn), and plastic and metals (Sb) may be the sources of Pb in the house dust of Japanese residences. No significant loading was found on soil-related factors indicating non-significant contribution of Pb in track-in soil. Seven heavy metals (Cd, Cu, Mo, Pb, Sb, Sn, and Zn) were found in house dust at >10 times more condensed than crustal abundance. Health risk of these elements to children via the ingestion of house dust was estimated based on the comparison with tolerable daily intake and found to be non-significant for most of the elements. PMID:24682073

Yoshinaga, Jun; Yamasaki, Kumiko; Yonemura, Ayumi; Ishibashi, Yuri; Kaido, Takaya; Mizuno, Kodai; Takagi, Mai; Tanaka, Atsushi

2014-06-01

17

Polyfluoroalkyl chemicals in house dust  

Microsoft Academic Search

We developed a high throughput analytical method using on-line solid phase extraction coupled with isotope dilution high-performance liquid chromatography–tandem mass spectrometry (on-line SPE–HPLC–MS\\/MS) to simultaneously determine the concentrations of 17 polyfluoroalkyl chemicals (PFCs) in house dust. The sample preparation includes dispersion of the dust samples in 0.1M formic acid:MeOH (1:1), followed by agitation and filtration, addition of the isotope-labeled internal

Kayoko Kato; Antonia M. Calafat; Larry L. Needham

2009-01-01

18

Influenza A facilitates sensitization to house dust mite in infant mice leading to an asthma phenotype in adulthood.  

PubMed

The origins of allergic asthma, particularly in infancy, remain obscure. Respiratory viral infections and allergen sensitization in early life have been associated with asthma in young children. However, a causal link has not been established. We investigated whether an influenza A infection in early life alters immune responses to house dust mite (HDM) and promotes an asthmatic phenotype later in life. Neonatal (8-day-old) mice were infected with influenza virus and 7 days later, exposed to HDM for 3 weeks. Unlike adults, neonatal mice exposed to HDM exhibited negligible immune responsiveness to HDM, but not to influenza A. HDM responsiveness in adults was associated with distinct Ly6c+ CD11b+ inflammatory dendritic cell and CD8?+ plasmacytoid (pDC) populations that were absent in HDM-exposed infant mice, suggesting an important role in HDM-mediated inflammation. Remarkably, HDM hyporesponsiveness was overcome when exposure occurred concurrently with an acute influenza infection; young mice now displayed robust allergen-specific immunity, allergic inflammation, and lung remodeling. Remodeling persisted into early adulthood, even after prolonged discontinuation of allergen exposure and was associated with marked impairment of lung function. Our data demonstrate that allergen exposure coincident with acute viral infection in early life subverts constitutive allergen hyporesponsiveness and imprints an asthmatic phenotype in adulthood. PMID:21881572

Al-Garawi, A; Fattouh, R; Botelho, F; Walker, T D; Goncharova, S; Moore, C-L; Mori, M; Erjefalt, J S; Chu, D K; Humbles, A A; Kolbeck, R; Stampfli, M R; O'Byrne, P M; Coyle, A J; Jordana, M

2011-11-01

19

Polyfluoroalkyl chemicals in house dust  

SciTech Connect

We developed a high throughput analytical method using on-line solid phase extraction coupled with isotope dilution high-performance liquid chromatography-tandem mass spectrometry (on-line SPE-HPLC-MS/MS) to simultaneously determine the concentrations of 17 polyfluoroalkyl chemicals (PFCs) in house dust. The sample preparation includes dispersion of the dust samples in 0.1 M formic acid:MeOH (1:1), followed by agitation and filtration, addition of the isotope-labeled internal standard solution to the filtrate, and analysis by on-line SPE-HPLC-MS/MS. The limits of quantitation were <4.0 ng/g. The method accuracies ranged between 73.2% and 100.2% for the different analytes at two spike levels. We confirmed the validity of the method by analyzing 39 household dust samples collected in 2004. Of the 17 PFCs measured, 6 of them-perfluorobutane sulfonate (PFBuS), N-ethyl-perfluorooctane sulfonamide, 2-(N-ethyl-perfluorooctane sulfonamido) acetic acid (Et-PFOSA-AcOH), 2-(N-methyl-perfluorooctane sulfonamido) ethanol (Me-PFOSA-EtOH), perfluorohexane sulfonate (PFHxS), and perfluorooctane sulfonate (PFOS)-had detection frequencies >70%. We detected PFOS, PFBuS, and PFHxS at the highest median concentration, followed by Et-PFOSA-AcOH and Me-PFOSA-EtOH.

Kato, Kayoko [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Hwy., Mailstop F53, Atlanta, GA 30341 (United States)] [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Hwy., Mailstop F53, Atlanta, GA 30341 (United States); Calafat, Antonia M., E-mail: acalafat@cdc.gov [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Hwy., Mailstop F53, Atlanta, GA 30341 (United States); Needham, Larry L. [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Hwy., Mailstop F53, Atlanta, GA 30341 (United States)] [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Hwy., Mailstop F53, Atlanta, GA 30341 (United States)

2009-07-15

20

Polyfluoroalkyl chemicals in house dust.  

PubMed

We developed a high throughput analytical method using on-line solid phase extraction coupled with isotope dilution high-performance liquid chromatography-tandem mass spectrometry (on-line SPE-HPLC-MS/MS) to simultaneously determine the concentrations of 17 polyfluoroalkyl chemicals (PFCs) in house dust. The sample preparation includes dispersion of the dust samples in 0.1 M formic acid:MeOH (1:1), followed by agitation and filtration, addition of the isotope-labeled internal standard solution to the filtrate, and analysis by on-line SPE-HPLC-MS/MS. The limits of quantitation were <4.0 ng/g. The method accuracies ranged between 73.2% and 100.2% for the different analytes at two spike levels. We confirmed the validity of the method by analyzing 39 household dust samples collected in 2004. Of the 17 PFCs measured, 6 of them--perfluorobutane sulfonate (PFBuS), N-ethyl-perfluorooctane sulfonamide, 2-(N-ethyl-perfluorooctane sulfonamido) acetic acid (Et-PFOSA-AcOH), 2-(N-methyl-perfluorooctane sulfonamido) ethanol (Me-PFOSA-EtOH), perfluorohexane sulfonate (PFHxS), and perfluorooctane sulfonate (PFOS)--had detection frequencies >70%. We detected PFOS, PFBuS, and PFHxS at the highest median concentration, followed by Et-PFOSA-AcOH and Me-PFOSA-EtOH. PMID:19261270

Kato, Kayoko; Calafat, Antonia M; Needham, Larry L

2009-07-01

21

Options for dust reduction from poultry houses  

Microsoft Academic Search

Large poultry houses emit high amounts of fine dust (PM10) and in many cases they exceed the ambient air quality standard set by the EU. Technologies for PM10 reduction need to be developed on short term to minimize PM10 emissions from poultry houses. Studied options for dust reduction were: application of an oil film on the litter and application of

A. J. A. Aarnink; J. Mosquera; A. Winkel; M. Cambra-López; Harn van J; Buisonjé de F. E; N. W. M. Ogink

2009-01-01

22

House dust mite sensitivity in childhood asthma  

Microsoft Academic Search

The clinical features of perennial asthmatic children with a skin or bronchial reaction to the house dust mite (Dermatophagoides pteronyssinus) were compared with those of asthmatic children without mite sensitivity. Mite sensitive asthma was characterised by an early age of onset of symptoms, these being predominantly nocturnal. A history of wheezing precipitated by dust exposure, during vacuuming, bedmaking, or dusting

J O Warner; J F Price

1978-01-01

23

Microbial communities associated with house dust.  

PubMed

House dust is a complex mixture of inorganic and organic material with microbes in abundance. Few microbial species are actually able to grow and proliferate in dust and only if enough moisture is provided. Hence, most of the microbial content originates from sources other than the dust itself. The most important sources of microbes in house dust are outdoor air and other outdoor material tracked into the buildings, occupants of the buildings including pets and microbial growth on moist construction materials. Based on numerous cultivation studies, Penicillium, Aspergillus, Cladosporium, and about 20 other fungal genera are the most commonly isolated genera from house dust. The cultivable bacterial flora is dominated by Gram-positive genera, such as Staplylococcus, Corynebacterium, and Lactococcus. Culture-independent studies have shown that both the fungal and the bacterial flora are far more diverse, with estimates of up to 500-1000 different species being present in house dust. Concentrations of microbes in house dust vary from nondetectable to 10(9) cells g(-1) dust, depending on the dust type, detection method, type of the indoor environment and season, among other factors. Microbial assemblages in different house dust types usually share the same core species; however, alterations in the composition are caused by differing sources of microbes for different dust types. For example, mattress dust is dominated by species originating from the user of the mattress, whereas floor dust reflects rather outdoor sources. Farming homes contain higher microbial load than urban homes and according to a recent study, temperate climate zones show higher dust microbial diversity than tropical zones. PMID:22305094

Rintala, Helena; Pitkäranta, Miia; Täubel, Martin

2012-01-01

24

Method of suppressing lead dust  

SciTech Connect

A method of suppressing lead dust generated in the manufacture of pasted lead acid storage battery plates by coating the surface of a pasted battery plate with a solution or a suspension comprising ammonium sulfate, copolymer and water. The resultant water insoluble film is made porous by the simultaneous evolution of ammonia gas produced during the coating process. The porous water insoluble film on the battery plate results in an electric storage battery with a lower internal resistance, than previously disclosed coatings and produces a battery with performance characteristics less inhibited than those made with previously disclosed coatings.

Wilson, F.

1985-11-05

25

The clinical effect of environmental control of house dust mites in 60 house dust mite-sensitive dogs.  

PubMed

The purpose of this study was to evaluate the effects of benzyl benzoate, an acaricide for the control of house dust mites, in 60 house dust mite-sensitive dogs. All dogs showed positive reactions on intradermal skin testing for house dust mites (Dermatophagoides farinae, Dermatophagoides pteronyssinus) alone, or house dust mites with storage mites (Acarus siro, Tyrophagus putrescentiae, Glycophagus domesticus). House dust samples from the owners' houses were collected and sent to the clinic, where the authors performed a test (Acarex test) to semi-quantify the amount of guanine, a house dust mite product. Treatment with benzyl benzoate was repeated until the house dust samples were negative for house dust mite guanine. After treatment, 29 out of 60 house dust mite-sensitive dogs (48%) showed no skin lesions or pruritus. Moderate results were achieved in 22 dogs (36%), with reduced pruritus and minimal skin lesions, but still requiring medication. In 13 dogs, this involved regular treatment (3-4 times a year) with antibiotics and anti-yeast medication, and in eight dogs, immunotherapy was used. One dog was controlled with essential fatty acids as monotherapy and one dog was controlled with immunotherapy and essential fatty acids. In the remaining nine dogs (15%), the pruritus remained the same, and these dogs were controlled with oral corticosteroids. These results indicate that house dust mite elimination is a useful tool in the management of house dust mite-sensitive dogs. PMID:14989703

Swinnen, Christine; Vroom, Margreet

2004-02-01

26

Lead, arsenic, and polycyclic aromatic hydrocarbons in soil and house dust in the communities surrounding the Sydney, Nova Scotia, tar ponds.  

PubMed Central

This study evaluated lead, arsenic, and polycyclic aromatic hydrocarbon (PAH) contamination in the residential communities adjacent to the Sydney, Nova Scotia, tar ponds, the area considered Canada's worst contaminated site. The tar pond remediation policy has been limited to the site and some residential properties. We compared background concentrations in 91 soil samples taken 5-20 km from the coke oven site with those in soil samples from the three communities surrounding the tar ponds: Whitney Pier, Ashby, and North End. These surrounding communities were statistically different from background regarding arsenic, lead, and PAHs. Twenty percent of the background soil samples and 95% of the tar pond soil samples were above the Canadian health-risk-based soil guidelines for arsenic (12 ppm), and 5% of the background samples and 80% of the tar pond soil samples were above the Canadian guidelines for lead (140 ppm). Regarding dust lead and arsenic loading, the results provide no evidence that Whitney Pier is significantly different than Ashby and North End. Children in these communities are predicted to have a 1-15% chance of blood lead > 10 microg/dL. The results suggest that lead and arsenic found in the homes originate outside. The lead content of paint in the homes was not evaluated, but consideration of painted wood at the doorway did not confound the results of the study. The results indicate that the residential environment has been adversely affected by PAHs, lead, and arsenic and should be considered for remediation. PMID:14698928

Lambert, Timothy W; Lane, Stephanie

2004-01-01

27

Streptomycetes in house dust: associations with housing characteristics and endotoxin  

PubMed Central

In addition to mold, indoor bioaerosols also contain bacterial components that may have implications for human health. Endotoxin is a cell wall component in Gram-negative bacteria present at varying levels indoors that has been found to have respiratory health implications. Streptomyces is a large genus of Gram-positive bacteria, and some species have been shown to produce inflammatory reactions in vitro and in vivo. The aim of this study was to determine predictors of streptomycetes levels in house dust, and to compare the variation in streptomycetes levels with that in endotoxin levels. Dust was collected by floor vacuuming from 178 homes in the Cincinnati metropolitan area. streptomycetes levels were measured by quantitative PCR and endotoxin was assayed by the Limulus Amebocyte Lysate method. Associations between home characteristics and bacterial contaminants, expressed as concentration and load, were investigated through multiple regression analyses. The presence of two or more dogs was a strong predictor of both streptomycetes and endotoxin levels. Season of dust collection and levels of outdoor molds were predictors of streptomycetes but not endotoxin levels. In contrast, number of inhabitants was a significant predictor of endotoxin load only. Neither streptomycetes nor endotoxin levels were associated with metrics of moisture damage. PMID:21204988

Johansson, Elisabet; Vesper, Stephen; Levin, Linda; LeMasters, Grace; Grinshpun, Sergey; Reponen, Tiina

2011-01-01

28

PERFLUORINATED COMPOUNDS IN ARCHIVED HOUSE-DUST SAMPLES  

EPA Science Inventory

Archived house-dust samples were analyzed for 13 perfluorinated compounds (PFCs). Results show that PFCs are found in house-dust samples, and the data are log-normally distributed. PFOS/PFOA were present in 94.6% and 96.4% of the samples respectively. Concentrations ranged fro...

29

Encapsulation of steel foundry bag house dusts in cement mortar  

Microsoft Academic Search

The purpose of this study was to investigate the properties of bag house dusts generated by steel foundries when stabilized with Portland cement at high levels of cement addition. The main bag house dust studied was obtained as a byproduct of steel manufacture, at Pacific Steel Limited in Auckland, New Zealand, whereas others were sourced from BHP New Zealand Steel,

Ian W Hamilton; Nigel M Sammes

1999-01-01

30

Household surface lead dust: its accumulation in vacant homes.  

PubMed Central

House dust has been suspected as a source of lead in the exposure of children, particularly those whose blood lead levels are in the moderately elevated range. The means by which household surface lead accumulates is at present not clear. By towel wipe sampling, 24 vacant houses in urban Rochester and Buffalo, New York, were examined for lead content on windowsills, floors, and other surfaces. High yields of lead were obtained from windowsills and floor areas adjacent windows. When washed and resampled, these areas yielded greatly reduced lead values. It is suggested that surface lead may represent a deposit phenomenon. The entry of exterior airborne particulate lead around the loose-fitting windows of older homes appears possible. PMID:510237

Sayre, J W; Katzel, M D

1979-01-01

31

House dust mite allergy: environment evaluation and disease prevention  

PubMed Central

There are two groups of dust mites, house dust mites (HDMs) and storage mites (SMs), that have been identified in the household environment. Both could induce airway inflammation through activation of innate and adaptive immunity and lead to asthma. In order to monitor environmental dust mite infestation, different methods can be used to detect their presence, such as the use of floating methods, monoclonal antibodies, and nanostructured biosensor. SM could be identified in the storage room, mainly in contaminated food such as mushrooms and corn starch. In HDM-sensitive subjects and mice that were challenged with HDM or SM after sensitization, these mites could up-regulate IgE levels, T helper 2 associated cytokine production and airway hypersensitivity. Different age groups of subjects were sensitized by different species of mites. More subjects above 70 years were sensitized by SM and more subjects below the age of 40 years were sensitized to HDM. Different allergenic components of dust mite extracts, such as Der p 1, Der p 2, could activate innate immunity through activating pattern recognition receptor (PRR) and then lead to allergic inflammation. The best modality to treat HDM allergy is immunomodulation through Treg cells and IgA production. In the recent years, many studies indicated probiotics could increase IgA secretion and the number of Treg cells. However, some studies conducted in adults have contradictory effects in reducing allergic symptoms. Therefore, probiotics confer inconclusive benefits on the allergic symptoms. PMID:25379484

Yu, Sheng-Jie; Liao, En-Chih

2014-01-01

32

House dust mite allergy: environment evaluation and disease prevention.  

PubMed

There are two groups of dust mites, house dust mites (HDMs) and storage mites (SMs), that have been identified in the household environment. Both could induce airway inflammation through activation of innate and adaptive immunity and lead to asthma. In order to monitor environmental dust mite infestation, different methods can be used to detect their presence, such as the use of floating methods, monoclonal antibodies, and nanostructured biosensor. SM could be identified in the storage room, mainly in contaminated food such as mushrooms and corn starch. In HDM-sensitive subjects and mice that were challenged with HDM or SM after sensitization, these mites could up-regulate IgE levels, T helper 2 associated cytokine production and airway hypersensitivity. Different age groups of subjects were sensitized by different species of mites. More subjects above 70 years were sensitized by SM and more subjects below the age of 40 years were sensitized to HDM. Different allergenic components of dust mite extracts, such as Der p 1, Der p 2, could activate innate immunity through activating pattern recognition receptor (PRR) and then lead to allergic inflammation. The best modality to treat HDM allergy is immunomodulation through Treg cells and IgA production. In the recent years, many studies indicated probiotics could increase IgA secretion and the number of Treg cells. However, some studies conducted in adults have contradictory effects in reducing allergic symptoms. Therefore, probiotics confer inconclusive benefits on the allergic symptoms. PMID:25379484

Yu, Sheng-Jie; Liao, En-Chih; Tsai, Jaw-Ji

2014-10-01

33

POLYBROMINATED DIPHENYL ETHERS IN HOUSE DUST AND CLOTHES DRYER LINT  

EPA Science Inventory

Polybrominated diphenyl ether (PBDE) flame retardants are now considered ubiquitous and persistent pollutants. Few studies have examined the concentrations of these chemicals in the home and here we report measurements of PBDEs in house dust samples collected from the Washington...

34

House dust in seven Danish offices  

NASA Astrophysics Data System (ADS)

Floor dust from Danish offices was collected and analyzed. The dust was to be used in an exposure experiment. The dust was analyzed to show the composition of the dust which can be a source of airborne dust indoors. About 11 kg of dust from vacuum cleaner bags from seven Danish office buildings with about 1047 occupants (12 751 m 2) was processed according to a standardized procedure yielding 5.5 kg of processed bulk dust. The bulk dust contained 130.000-160.000 CFU g -1 microorganisms and 71.000-90.000 CFU g -1 microfungi. The content of culturable microfungi was 65-123 CFU 30 g -1 dust. The content of endotoxins ranged from 5.06-7.24 EU g -1 (1.45 ng g -1 to 1.01 ng g -1). Allergens (ng g -1) were from 147-159 (Mite), 395-746 (dog) and 103-330 (cat). The macro molecular organic compounds (the MOD-content) varied from 7.8-9.8 mg g -1. The threshold of release of histamine from basophil leukocytes provoked by the bulk dust was between 0.3 and 1.0 mg ml -1. The water content was 2% (WGT) and the organic fraction 33%. 6.5-5.9% (dry) was water soluble. The fiber content was less than 0.2-1.5% (WGT) and the desorbable VOCs was 176-319 ?g g -1. Most of the VOC were aldehydes. However, softeners for plastic (DBP and DEHP) were present. The chemical composition includes human and animal skin fragments, paper fibers, glass wool, wood and textilefibers and inorganic and metal particles. The sizes ranged from 0.001-1 mm and the average specific density was 1.0 g m -3. The bulk dust was resuspended and injected into an exposure chamber. The airborne dust was sampled and analyzed to illustrate the exposures that can result from sedimented dirt and dust. The airborne dust resulting from the bulk dust reached concentrations ranging from 0.26-0.75 mg m -3 in average contained 300-170 CFU m -3. The organic fraction was from 55-70% and the water content about 2.5% (WGT). The content of the dust was compared to the similar results reported in the literature and its toxic potency is estimated to be relatively low. The storage of the bulk dust during the experiment had little effect on the specific biological and chemical composition.

Mřlhave, L.; Schneider, T.; Kjćrgaard, S. K.; Larsen, L.; Norn, S.; Jřrgensen, O.

35

Influence of social and environmental factors on dust, lead, hand lead, and blood lead levels in young children  

SciTech Connect

The roles of environmental and behavioral factors in determining blood lead levels were studied in a cohort of young children living in an urban environment. The subjects were observed at 3-month intervals from birth to 24 months of age. Repeated measurements were made of the children's blood lead levels, environmental levels of lead in house dust, and in the dust found on the children's hands. A qualitative rating of the residence and of the socioeconomic status of the family was obtained. Interviews and direct observation of parent and child at home were used to evaluate various aspects of caretaker-child interactions. Data analysis consisted of a comparison of results obtained by (a) simple correlational analysis, (b) multiple regression analysis, and (c) structural equations analysis. The results demonstrated that structural equation modeling offers a useful approach to unraveling the complex interactions present in the data set. In this preliminary analysis, the suspected relationship between the levels of lead in house dust and on hands and the blood lead level was clearly demonstrated. Furthermore, the analyses indicated an important interplay between environmental sources and social factors in the determination of hand lead and blood lead levels in very young children.

Bornschein, R.L.; Succop, P.; Dietrich, K.N.; Clark, C.S.; Que Hee, S.; Hammond, P.B.

1985-10-01

36

Enzymatic activity of allergenic house dust and storage mite extracts.  

PubMed

Proteases are involved in the pathogenicity of allergy, increasing epithelial permeability and acting as adjuvants. Enzymatic activity is therefore important for the allergenicity of an extract and also affects its stability and safety. However, the enzymatic activity of extracts is not usually evaluated. The objective of this study was to evaluate the enzymatic activity of the most allergenic mite extracts and to investigate their allergenic properties. Extracts from nine allergenic mite species (Dermatophagoides pteronyssinus, Dermatophagoides farinae Hughes, Euroglyphus maynei, Lepidoglyphus destructor, Tyrophagus putrescentiae (Schrank), Glycyphagus domesticus (DeGeer), Acarus siro L., Chortoglyphus arcuatus, and Blomia tropicalis) were characterized. Protein and allergen profiles were characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and western-blot, respectively. Gelatinolytic activity was evaluated with a zymogram and the activity of other enzymes (cysteine, serine proteases, and esterases) was evaluated individually or with the API-ZYM system. The main differences in protease activity were found between house dust mites and storage mites. House dust mites presented higher cysteine protease activity while storage mites presented higher serine protease activity. These differences are in line with their trophic specialization. A wide range of different activities was found in all the extracts analyzed, reflecting the fact that the extracts preserve the activity of many enzymes, this being necessary for a correct diagnosis. However, enzymes may act as adjuvants and, therefore, could lead to undesirable effects in immunotherapies, making this activity not suitable for treatment products. Modified extracts with lower enzymatic activity could be more appropriate for immunotherapy. PMID:23427664

Morales, Maria; Iraola, Víctor; Leonor, Jose R; Carnés, Jerónimo

2013-01-01

37

Polybrominated diphenyl ethers in house dust in Singapore.  

PubMed

The use of polybrominated diphenyl ethers (PBDEs) as flame retardants in Singapore is not strictly regulated; therefore these compounds can be readily found in furniture, electronic devices, and building materials. This study was the first of its kind to be conducted in Singapore to measure concentrations of PBDEs in house dust. Samples were collected from 31 homes in various locations across the island-state of Singapore, and a total eight PBDEs congeners were measured. PBDEs were detected in all 31 dust samples and the number of BDE congener detected per home ranged between 3 and 8. The most abundant BDE congeners found were BDE 47, 99 and 209, with a median value of 20 ng g(-1) dust, 24 ng g(-1) dust and 1000 ng g(-1) dust, respectively. BDE 209 contributed 88% to the median of all the congeners, and BDE 47 and 99 contributed 1.8% and 3.5%, respectively. Different congener profiles were observed between this and studies conducted elsewhere, which is consistent with the use of different commercial PBDE around the world. No significant correlations between PBDE dust levels and residential characteristics (number of TVs and computers, floor area or flooring material) were observed. The daily intake of PBDEs via the inhalation pathway was estimated. House dust may be regarded as the most important exposure route of PBDEs for children. PMID:16949640

Tan, Jing; Cheng, Si Min; Loganath, Annamalai; Chong, Yap Seng; Obbard, Jeffrey Philip

2007-01-01

38

Zinc in house dust: speciation, bioaccessibility, and impact of humidity.  

PubMed

Indoor exposures to metals arise from a wide variety of indoor and outdoor sources. This study investigates the impact of humid indoor conditions on the bioaccessibility of Zn in dust, and the transformation of Zn species during weathering. House dust samples were subjected to an oxygenated, highly humid atmosphere in a closed chamber for 4 to 5 months. Zinc bioaccessibility before and after the experiment was determined using a simulated gastric acid extraction. Bulk and micro X-ray absorption structure (XAS) spectroscopy was used to speciate Zn in dust. Exposure to humid conditions led to a significant increase in Zn bioaccessibility in all samples, which was due to a redistribution of Zn from inorganic forms toward the organic pools such as Zn adsorbed on humates. ZnO readily dissolved under humid conditions, whereas ZnS persisted in the dust. Elevated humidity in indoor microenvironments may sustain higher Zn bioaccessibility in settled dust compared to drier conditions, and part of this change may be related to fungal growth in humid dust. These results help to explain the greater bioaccessibility of certain metals in house dust compared to soils. PMID:25041107

Beauchemin, Suzanne; Rasmussen, Pat E; MacKinnon, Ted; Chénier, Marc; Boros, Kristina

2014-08-19

39

DEVELOPING AND IMPLEMENTING A LEAD DUST MONITORING, OUTREACH AND EDUCATION PROGRAM IN YOUR COMMUNITY/SYRACUSE LEAD DUST PROJECT  

EPA Science Inventory

EPA has developed a technology transfer document (case-study) for the EMPACT Syracuse Lead Dust Project. The Lead Dust Project is designed to measure the lead dust content in homes and public buildings within the City of Syracuse, NY. The project also contains an educational comp...

40

Group 1 and 2 Dermatophagoides house dust mite allergens in the microenvironment of cats.  

PubMed

House dust mite allergens (HDMAs) are some of the most common allergens associated with allergic diseases in humans and dogs. The purpose of this study was to determine whether HDMAs could be detected in cat-associated household microenvironments. From 50 cat-only households with 95 cats, dust samples were collected by vacuuming for 2 min m(-2) from three areas where cats slept or rested regularly from September to October 2006. Relative humidity and temperature were measured in each household using a data logger. Each owner completed a questionnaire on potential factors that might influence the prevalence of house dust mites (HDMs). Dust samples were analysed utilizing an ELISA for Der p 1, Der f 1 and HDM group 2 allergens. In 38 of 50 households there was greater than 2 microg g(-1) of dust for at least one HDMA. Using stepwise logistic regression, factors associated with increased HDMA levels included: free-standing houses, number of humans in household, longhaired cats and age of the cat. Factors associated with decreased HDMA concentrations included: forced air heating and central air conditioning, less than 50% carpeting of the home, use of flea control, cats suffering from dermatological disease and the average temperature of the household. Many sleeping/resting areas utilized by cats contain sufficiently high levels of HDMAs to be potential sources of sensitization. This finding should lead to further determination of the role of HDMs in cats suffering from putative allergic conditions such as atopic dermatitis or asthma. PMID:19725913

Loft, Klaus Earl; Rosser, Edmund J

2010-04-01

41

Surface dust wipes are the best predictors of blood leads in young children with elevated blood lead levels  

SciTech Connect

Background: As part of the only national survey of lead in Australian children, which was undertaken in 1996, lead isotopic and lead concentration measurements were obtained from children from 24 dwellings whose blood lead levels were ?15 µg/dL in an attempt to determine the source(s) of their elevated blood lead. Comparisons were made with data for six children with lower blood lead levels (<10 µg/dL). Methods: Thermal ionisation and isotope dilution mass spectrometry were used to determine high precision lead isotopic ratios ({sup 208}Pb/{sup 206}Pb, {sup 207}Pb/{sup 206}Pb and {sup 206}Pb/{sup 204}Pb) and lead concentrations in blood, dust from floor wipes, soil, drinking water and paint (where available). Evaluation of associations between blood and the environmental samples was based on the analysis of individual cases, and Pearson correlations and multiple regression analyses based on the whole dataset. Results and discussion: The correlations showed an association for isotopic ratios in blood and wipes (r=0.52, 95% CI 0.19–0.74), blood and soil (r=0.33, 95% CI ?0.05–0.62), and blood and paint (r=0.56, 95% CI 0.09–0.83). The regression analyses indicated that the only statistically significant relationship for blood isotopic ratios was with dust wipes (B=0.65, 95% CI 0.35–0.95); there were no significant associations for lead concentrations in blood and environmental samples. There is a strong isotopic correlation of soils and house dust (r=0.53, 95% CI 0.20–0.75) indicative of a common source(s) for lead in soil and house dust. In contrast, as with the regression analyses, no such association is present for bulk lead concentrations (r=?0.003, 95% CI ?0.37–0.36), the most common approach employed in source investigations. In evaluation of the isotopic results on a case by case basis, the strongest associations were for dust wipes and blood. -- Highlights: • Children with elevated blood lead ?15 µg/dL compared with a group with <10 µg/dL. • High precision lead isotopic ratios in blood, house dust wipes, soil, water, paint. • Associations for isotopic measures of blood and dust, blood and soil, blood and paint. • Regressions gave significance for isotopic measures of blood/dust and dust/soil.

Gulson, Brian, E-mail: brian.gulson@mq.edu.au [Graduate School of the Environment, Macquarie University, North Ryde NSW 2109 (Australia) [Graduate School of the Environment, Macquarie University, North Ryde NSW 2109 (Australia); CSIRO Earth Science and Resource Engineering, North Ryde NSW 2113 (Australia); Anderson, Phil [Information and Statistics Group, Australian Institute of Health and Welfare, Canberra ACT 2601 (Australia) [Information and Statistics Group, Australian Institute of Health and Welfare, Canberra ACT 2601 (Australia); Faculty of Health, University of Canberra, Canberra ACT 2601 (Australia); Taylor, Alan [Department of Psychology, Macquarie University, Sydney NSW 2109 (Australia)] [Department of Psychology, Macquarie University, Sydney NSW 2109 (Australia)

2013-10-15

42

Application of Neutral Electrolyzed Water Spray for Reducing Dust Levels in a Layer Breeding House  

Microsoft Academic Search

Reducing airborne dust is an essential process for improving hen housing environment. Dust reduction effects of neutral electrolyzed water (pH 8.2) spray were investigated in a commercial tunnel-ventilated layer breeding house during production in Northern China. A multi-point sampler was used to measure airborne dust concentration to study the dust reduction effects and distribution in the house. Compared to the

Weichao Zheng; Baoming Li; Wei Cao; Guoqiang Zhang; Zhanyong Yang

2012-01-01

43

Role of house-dust mites in childhood asthma  

Microsoft Academic Search

The aetiological importance of the house-dust mite, Dermatophagoides sp., was examined in 133 asthmatic children referred to hospital. Evidence of sensitization to this allergen from positive skin tests and the presence of circulating specific IgE was found in the majority of these children and sensitization often began in the preschool years. In vitro studies of specific IgE levels were found

J. K. Sarsfield

1974-01-01

44

Immunomodulation of Skin Cytokine Secretion by House Dust Mite Extracts  

PubMed Central

Background Skin contact with house dust mites may contribute to atopic dermatitis and other skin diseases. We sought to determine if molecules from house dust mites could influence the release of proinflammatory cytokines and chemokines from epidermal keratinocytes and dermal fibroblasts grown in a human skin equivalent (HSE) model. Methods HSEs consisting of an epidermis of keratinocytes with stratum corneum over a dermis of fibroblasts in a collagen matrix were challenged with Dermatophagoides farinae, D. pteronyssinus and Euroglyphus maynei mite extracts. Results HSEs secreted interleukin (IL)-1?, IL-1 receptor antagonist, IL-6, IL-8, cutaneous T cell-attracting chemokine, transforming growth factor-?, granulocyte/macrophage and macrophage colony-stimulating factors and vascular endothelial cell growth factor in response to at least 1 mite extract. Extracts of different mite species stimulated HSEs to release different cytokines. Therefore, extracts of different species contained different molecules or different concentrations of similar molecules. The cytokine release profiles of cells in the HSEs were not the same as for monocultured keratinocytes and fibroblasts. Conclusions Molecules from house dust mites are capable of inducing the release of multiple proinflammatory cytokines and chemokines from epidermal keratinocytes and dermal fibroblasts. Avoiding skin contact with house dust mites would reduce the possibility of mite-induced inflammation in the skin. Therefore, measures to reduce contact with mite molecules such as frequent vacuuming of upholstered furniture and carpets and laundering of clothing and bedding to remove mite molecules and allergens could reduce skin contact with mite molecules and diminish exacerbations of skin inflammation in patients with atopic dermatitis and other skin diseases. PMID:21576987

Arlian, Larry G.; Morgan, Marjorie S.

2011-01-01

45

Monitoring and reducing exposure of infants to pollutants in house dust.  

PubMed

The health risks to babies from pollutants in house dust may be 100 times greater than for adults. The young ingest more dust and are up to ten times more vulnerable to such exposures. House dust is the main exposure source for infants to allergens, lead, and PBDEs, as well as a major source of exposure to pesticides, PAHs, Gram-negative bacteria, arsenic, cadmium, chromium, phthalates, phenols, and other EDCs, mutagens, and carcinogens. Median or upper percentile concentrations in house dust of lead and several pesticides and PAHs may exceed health-based standards in North America. Early contact with pollutants among the very young is associated with higher rates of chronic illness such as asthma, loss of intelligence, ADHD, and cancer in children and adults. The potential of infants, who live in areas with soil contaminated by automotive and industrial emissions, can be given more protection by improved home cleaning and hand washing. Babies who live in houses built before 1978 have a prospective need for protection against lead exposures; homes built before 1940 have even higher lead exposure risks. The concentration of pollutants in house dust may be 2-32 times higher than that found in the soil near a house. Reducing infant exposures, at this critical time in their development, may reduce lifetime health costs, improve early learning, and increase adult productivity. Some interventions show a very rapid payback. Two large studies provide evidence that home visits to reduce the exposure of children with poorly controlled asthma triggers may return more than 100% on investment in 1 yr in reduced health costs. The tools provided to families during home visits, designed to reduce dust exposures, included vacuum cleaners with dirt finders and HEPA filtration, allergy control bedding covers, high-quality door mats, and HEPA air filters. Infants receive their highest exposure to pollutants in dust at home, where they spend the most time, and where the family has the most mitigation control. Normal vacuum cleaning allows deep dust to build up in carpets where it can be brought to the surface and become airborne as a result of activity on the carpet. Vacuums with dirt finders allow families to use the three-spot test to monitor deep dust, which can reinforce good cleaning habits. Motivated families that receive home visits from trained outreach workers can monitor and reduce dust exposures by 90% or more in 1 wk. The cost of such visits is low considering the reduction of risks achieved. Improved home cleaning is one of the first results observed among families who receive home visits from MHEs and CHWs. We believe that proven intervention methods can reduce the exposure of infants to pollutants in house dust, while recognizing that much remains to be learned about improving the effectiveness of such methods. PMID:19484587

Roberts, John W; Wallace, Lance A; Camann, David E; Dickey, Philip; Gilbert, Steven G; Lewis, Robert G; Takaro, Tim K

2009-01-01

46

Flame retardant associations between children's handwipes and house dust.  

PubMed

Polybrominated diphenyl ether (PBDE), flame retardants (FRs) have been ubiquitously detected at high concentrations in indoor environments; however, with their recent phase-out, more attention is being focused on measurements of exposure to alternative FRs such as organophosphate FRs (OPFRs). In our previous research, we found that PBDE residues measured on children's handwipes were a strong predictor of serum PBDE levels. Here we build upon this research to examine longitudinal changes in PBDEs in indoor dust and children's handwipes, and explore the associations between handwipes and dust for alternative FRs. Children from our previous study were re-contacted after approximately two years and new samples of indoor dust and handwipes were collected. PBDE dust-levels were significantly correlated between two different sampling rounds separated by two years; however, PBDE levels in handwipes were not correlated, perhaps suggesting that the sources of PBDEs remained relatively constant in the home, but that behavioral differences in children are changing with age and influencing handwipe levels. OPFRs [i.e. tris(1,3-dichloroisopropyl) phosphate (TDCPP), tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCIPP)], 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB, also known as TBB), di(2-ethylhexyl) tetrabromophthalate (BEH-TEBP, also known as TBPH), and 1,2,5,6,9,10-hexabromocyclododecane (HBCD) were also ubiquitously detected in house dust samples and geometric mean levels were similar to PBDE levels, or higher in the case of the OPFRs. Significant associations between handwipes and house dust were observed for these alternative FRs, particularly for EH-TBB (rs=0.54; p<0.001). Increasing house dust levels and age were associated with higher levels of FRs in handwipes, and high hand washing frequency (>5timesd(-1)) was associated with lower FR levels in handwipes. Overall these data suggest that exposure to these alternative FRs will be similar to PBDE exposure, and the influence of hand-to-mouth behavior in children's exposure needs to be further examined to better estimate exposure potential. PMID:24485814

Stapleton, Heather M; Misenheimer, John; Hoffman, Kate; Webster, Thomas F

2014-12-01

47

MITE ANTIGEN CONCENTRATIONS IN HOUSE DUST AND THE OCCURRENCE OF WHEEZING IN CHILDREN WITH MITE DUST ALLERGY  

EPA Science Inventory

We studied the relationship between dust mite antigen concentrations in house dust samples and the occurrence and frequency of wheezing in 58 children with dust mite allergy (wheal > 4 mm. mean diameter in response to a prick test with either D-. farinae or D pteronyssinus antige...

48

Reliability of spot test kits for detecting lead in household dust  

PubMed Central

There has been a long-standing need for a technique that can provide fast, accurate and precise results regarding the presence of hazardous levels of lead in settled house dust. Several home testing kits are now available. One kit manufactured by Hybrivet (LeadCheck Swabs) is advertised as able to detect lead dust levels that exceed the U.S. Environmental Protection Agency’s dust lead standard for floors (40 ?g/ft2). The purpose of the study was to determine the ability of LeadCheck Swabs to instantly detect lead in dust above EPA’s hazard standard. A trained risk assessor collected two hundred LeadCheck Swab samples side-by-side with standard dust wipe samples. The result of the LeadCheck Swab (positive (pink or red) or negative (yellow to brown)) was compared with the laboratory results for the corresponding dust wipe (over or under 40 ?g/ft2). The LeadCheck Swabs produced a false negative rate of 64% (95% confidence interval: 55%, 72%). The likelihood of a swab producing a false negative depended on substrate (painted or non-painted) and surface type (floor or sill). Changing the interpretation rule by classifying all swab colors except yellow as positive yielded lower false negative rates under some test conditions, but still produced high error rates. LeadCheck Swabs do not reliably detect levels of lead in dust above 40 ?g/ft2 using published methods under field conditions. Further research into alternate methodologies and interpretation guidance is needed to determine whether the swabs can be appropriately used by consumers and others to test homes for lead dust hazards. PMID:17434162

Korfmacher, Katrina Smith; Dixon, Sherry

2007-01-01

49

The prevalence of lead-based paint hazards in U.S. housing.  

PubMed Central

In this study we estimated the number of housing units in the United States with lead-based paint and lead-based paint hazards. We included measurements of lead in intact and deteriorated paint, interior dust, and bare soil. A nationally representative, random sample of 831 housing units was evaluated in a survey between 1998 and 2000; the units and their occupants did not differ significantly from nationwide characteristics. Results indicate that 38 million housing units had lead-based paint, down from the 1990 estimate of 64 million. Twenty-four million had significant lead-based paint hazards. Of those with hazards, 1.2 million units housed low-income families (< 30,000 US dollars/year) with children under 6 years of age. Although 17% of government-supported, low-income housing had hazards, 35% of all low-income housing had hazards. For households with incomes greater than or equal to 30,000 US dollars/year, 19% had hazards. Fourteen percent of all houses had significantly deteriorated lead-based paint, and 16% and 7%, respectively, had dust lead and soil lead levels above current standards of the U.S. Department of Housing and Urban Development and the U.S. Environmental Protection Agency. The prevalence of lead-based paint and hazards increases with age of housing, but most painted surfaces, even in older housing, do not have lead-based paint. Between 2% and 25% of painted building components were coated with lead-based paint. Housing in the Northeast and Midwest had about twice the prevalence of hazards compared with housing in the South and West. The greatest risk occurs in older units with lead-based paint hazards that either will be or are currently occupied by families with children under 6 years of age and are low-income and/or are undergoing renovation or maintenance that disturbs lead-based paint. This study also confirms projections made in 2000 by the President's Task Force on Environmental Health Risks and Safety Risks to Children of the number of houses with lead-based paint hazards. Public- and private-sector resources should be directed to units posing the greatest risk if future lead poisoning is to be prevented. PMID:12361941

Jacobs, David E; Clickner, Robert P; Zhou, Joey Y; Viet, Susan M; Marker, David A; Rogers, John W; Zeldin, Darryl C; Broene, Pamela; Friedman, Warren

2002-01-01

50

The Relationship Between the Dust Lead Concentration and the Particle Sizes of Household Dusts Collected in Jersey City Residences  

Microsoft Academic Search

Lead concentrations measured in total dust samples collected from various environmental surfaces have been used as a surrogate for the lead concentration found in hand dust and subsequently in calculations of lead exposure due to ingestion. However, since the relationship between the characteristics of environmental dust samples and hand dusts is not yet well established, conclusions derived from lead measurements

Eugene Y. Wang; Robert D. Willis; Timothy J. Buckley; George G. Rhoads; Paul J. Lioy

1996-01-01

51

A NEW HOUSE DUST COLLECTION SYSTEM AND ITS USE IN A STUDY OF ASTHMA IN DUST MITE SENSITIVE CHILDREN IN RALEIGH, NORTH CAROLINA  

EPA Science Inventory

A prototype dust collection system, the House Dust Vacuum One (HDVI), was designed for use in a study to investigate the relationship between house dust mite antigen levels and the presence of asthma in dust mite sensitive children. The HDVI was designed for the collection of dus...

52

Polychlorinated biphenyls in house dust and yard soil near a Superfund site  

Microsoft Academic Search

Polychlorinated biphenyls (PCBs) were measured in house dust and yard soil at 34 homes surrounding New Bedford Harbor during dredging of highly contaminated harbor sediments. PCBs can volatilize from sediments and seawater and subsequently deposit on surrounding soil, resulting in potential exposures for nearby residents. House dust was collected from carpet, while yard soil was collected from the main entryway

Donna J. Vorhees; L. M. Altshul; A. C. Cullen

1999-01-01

53

Is permanent parasitism reversible?--critical evidence from early evolution of house dust mites.  

PubMed

Long-term specialization may limit the ability of a species to respond to new environmental conditions and lead to a higher likelihood of extinction. For permanent parasites and other symbionts, the most intriguing question is whether these organisms can return to a free-living lifestyle and, thus, escape an evolutionary "dead end." This question is directly related to Dollo's law, which stipulates that a complex trait (such as being free living vs. parasitic) cannot re-evolve again in the same form. Here, we present conclusive evidence that house dust mites, a group of medically important free-living organisms, evolved from permanent parasites of warm-blooded vertebrates. A robust, multigene topology (315 taxa, 8942 nt), ancestral character state reconstruction, and a test for irreversible evolution (Dollo's law) demonstrate that house dust mites have abandoned a parasitic lifestyle, secondarily becoming free living, and then speciated in several habitats. Hence, as exemplified by this model system, highly specialized permanent parasites may drastically de-specialize to the extent of becoming free living and, thus escape from dead-end evolution. Our phylogenetic and historical ecological framework explains the limited cross-reactivity between allergens from the house dust mites and "storage" mites and the ability of the dust mites to inhibit host immune responses. It also provides insights into how ancestral features related to parasitism (frequent ancestral shifts to unrelated hosts, tolerance to lower humidity, and pre-existing enzymes targeting skin and keratinous materials) played a major role in reversal to the free-living state. We propose that parasitic ancestors of pyroglyphids shifted to nests of vertebrates. Later the nest-inhabiting pyroglyphids expanded into human dwellings to become a major source of allergens. PMID:23417682

Klimov, Pavel B; OConnor, Barry

2013-05-01

54

House-dust mite (Pyroglyphidae) populations in mattresses, and their control by electric blankets.  

PubMed

A reduction in house-dust-mite populations of 19-84% in beds in regular use could be achieved by heating the mattresses with electric blankets, when the beds were not being slept on. The effect of the heating treatment on the temperature and relative humidity inside the mattress is discussed. House-dust mites in the heated portions of the mattress migrated deeper inside the mattress to a depth of 3.5-5.0 cm. Evidence was also found that house-dust mites in non-heated mattresses do not only live near the surface, but that they are also present deep inside the mattress. PMID:2226069

de Boer, R; van der Geest, L P

1990-08-01

55

35. BOILER HOUSE, TRACK FOR COAL CARS LEADING TO COAL ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

35. BOILER HOUSE, TRACK FOR COAL CARS LEADING TO COAL TOWER No. 2 (NOTE: SKYLIGHT ABOVE; COAL CARS IN FAR BACKGROUND) - Delaware County Electric Company, Chester Station, Delaware River at South end of Ward Street, Chester, Delaware County, PA

56

39. BOILER HOUSE, COAL CONVEYOR LEADING FROM COAL TOWER No. ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

39. BOILER HOUSE, COAL CONVEYOR LEADING FROM COAL TOWER No. 1 (WEST) (NOTE: COAL CARS No. 9 & 5 IN BACKGROUND) - Delaware County Electric Company, Chester Station, Delaware River at South end of Ward Street, Chester, Delaware County, PA

57

Prevention of House Dust Mite Induced Allergic Airways Disease in Mice through Immune Tolerance  

PubMed Central

Allergic airways disease is a consequence of a Th2 response to an allergen leading to a series of manifestations such as production of allergen-specific IgE, inflammatory infiltrates in the airways, and airway hyper-reactivity (AHR). Several strategies have been reported for tolerance induction to allergens leading to protection from allergic airways disease. We now show that CD4 blockade at the time of house dust mite sensitization induces antigen-specific tolerance in mice. Tolerance induction is robust enough to be effective in pre-sensitized animals, even in those where AHR was pre-established. Tolerant mice are protected from airways eosinophilia, Th2 lung infiltration, and AHR. Furthermore, anti-CD4 treated mice remain immune competent to mount immune responses, including Th2, to unrelated antigens. Our findings, therefore, describe a strategy for tolerance induction potentially applicable to other immunogenic proteins besides allergens. PMID:21818308

Agua-Doce, Ana; Graca, Luis

2011-01-01

58

Development of a Simultaneous Extraction and Cleanup Method for Pyrethroid Pesticides from Indoor House Dust Samples  

EPA Science Inventory

An efżcient and reliable analytical method was developed for the sensitive and selective quantiżcation of pyrethroid pesticides (PYRs) in house dust samples. The method is based on selective pressurized liquid extraction (SPLE) of the dust-bound PYRs into dichloromethane (DCM) wi...

59

Occurrence of Respiratory Symptoms Resulting from Exposure to House Dust Mites in Early Childhood  

ERIC Educational Resources Information Center

The aim of the study was to describe the distribution of house dust mite (HDM) allergens within homes of three-year-old children, to identify factors responsible for its variation and to test the hypothesis whether the content of HDM allergens exceeding 2 [mu]g/g dust may be regarded as a risk level of sensitization possibly affecting respiratory…

Jedrychowski, Wieslaw; Maugeri, Umberto; Zembala, Marek; Hajto, Barbara; Flak, Elzbieta; Mroz, Elzbieta; Jacek, Ryszard; Sowa, Agata; Perera, Frederica P.

2009-01-01

60

Lead-Safe Housing Policy Guidance  

E-print Network

Gumm. The Alliance thanks the Childhood Lead Poisoning Prevention Branch of the Centers for Disease Control and Prevention, which funded the development of these materials. For additional information......................................................................................................27 PART IV Reference Materials

61

The high cost of improper removal of lead-based paint from housing: a case report.  

PubMed Central

The costs of lead-based paint hazard control in housing are well documented, but the costs of cleanup after improper, inherently dangerous, methods of removing lead-based paint are not. In this article we report a case of childhood lead poisoning and document the costs of decontamination after uncontained power sanding was used to remove paint down to bare wood from approximately 3,000 ft(2) of exterior siding on a large, well-maintained 75-year-old house in a middle-income neighborhood. After the uncontrolled removal of lead-based paint, interior dust lead levels ranged from 390 to 27,600 micro g Pb/ft(2) (on floors and windowsills) and bare soil lead levels ranged from 360 ppm in the yard to 3,900 ppm along the foundation to 130,000 ppm in the child's play area, well above applicable U.S. Department of Housing and Urban Development/U.S. Environmental Protection Agency standards. The hard costs of decontamination were over $195,000, which greatly exceeds the incremental cost of incorporating lead-safe work practices into repainting. This case report highlights the need to incorporate lead-safe work practices into routine repainting, remodeling, and other renovation and maintenance jobs that may disturb lead-based paint. PMID:12573903

Jacobs, David E; Mielke, Howard; Pavur, Nancy

2003-01-01

62

Application of neutral electrolyzed water spray for reducing dust levels in a layer breeding house.  

PubMed

Reducing airborne dust is an essential process for improving hen housing environment. Dust reduction effects of neutral electrolyzed water (pH 8.2) spray were investigated in a commercial tunnel-ventilated layer breeding house during production in northern China. A multipoint sampler was used to measure airborne dust concentration to study the dust reduction effects and distribution in the house. Compared with the control treatment (without spray), airborne dust level was reduced 34% in the 3 hr after spraying 216 mL m(-2) neutral electrolyzed water in the breeding house. The dust concentration was significantly higher during the periods of feed distribution (1.13 +/- 0.13 mg m(-3)) and artificial insemination (0.72 +/- 0.13 mg m(-3)) compared with after spray (0.47 +/- 0.09 mg m(-3)) and during lights-off period (0.29 +/- 0.08 mg m(-3)) in the three consecutive testing days (P <0.05). The experimental cage area was divided into four zones along the length of the house, with zone 1 nearest to the evaporative cooling pad and zone 4 nearest to the fans. The air temperature, relative humidity, airflow rate, and dust concentration were measured at the sampling points of the four zones in 3 consecutive days and mortality of the birds for the duration of a month were investigated. The results showed that the air temperature, airflow rate, dust concentration, and number of dead birds increase from zone 1 to zone 4 in the tunnel-ventilated layer breeding house. PMID:23210224

Zheng, Weichao; Li, Baoming; Cao, Wei; Zhang, Guoqiang; Yang, Zhanyong

2012-11-01

63

Rhinovirus Exacerbates House-Dust-Mite Induced Lung Disease in Adult Mice  

PubMed Central

Human rhinovirus is a key viral trigger for asthma exacerbations. To date, murine studies investigating rhinovirus-induced exacerbation of allergic airways disease have employed systemic sensitisation/intranasal challenge with ovalbumin. In this study, we combined human-rhinovirus infection with a clinically relevant mouse model of aero-allergen exposure using house-dust-mite in an attempt to more accurately understand the links between human-rhinovirus infection and exacerbations of asthma. Adult BALB/c mice were intranasally exposed to low-dose house-dust-mite (or vehicle) daily for 10 days. On day 9, mice were inoculated with human-rhinovirus-1B (or UV-inactivated human-rhinovirus-1B). Forty-eight hours after inoculation, we assessed bronchoalveolar cellular inflammation, levels of relevant cytokines/serum antibodies, lung function and responsiveness/sensitivity to methacholine. House-dust-mite exposure did not result in a classical TH2-driven response, but was more representative of noneosinophilic asthma. However, there were significant effects of house-dust-mite exposure on most of the parameters measured including increased cellular inflammation (primarily macrophages and neutrophils), increased total IgE and house-dust-mite-specific IgG1 and increased responsiveness/sensitivity to methacholine. There were limited effects of human-rhinovirus-1B infection alone, and the combination of the two insults resulted in additive increases in neutrophil levels and lung parenchymal responses to methacholine (tissue elastance). We conclude that acute rhinovirus infection exacerbates house-dust-mite-induced lung disease in adult mice. The similarity of our results using the naturally occurring allergen house-dust-mite, to previous studies using ovalbumin, suggests that the exacerbation of allergic airways disease by rhinovirus infection could act via multiple or conserved mechanisms. PMID:24632596

Phan, Jennifer A.; Kicic, Anthony; Berry, Luke J.; Fernandes, Lynette B.; Zosky, Graeme R.; Sly, Peter D.; Larcombe, Alexander N.

2014-01-01

64

Rhinovirus exacerbates house-dust-mite induced lung disease in adult mice.  

PubMed

Human rhinovirus is a key viral trigger for asthma exacerbations. To date, murine studies investigating rhinovirus-induced exacerbation of allergic airways disease have employed systemic sensitisation/intranasal challenge with ovalbumin. In this study, we combined human-rhinovirus infection with a clinically relevant mouse model of aero-allergen exposure using house-dust-mite in an attempt to more accurately understand the links between human-rhinovirus infection and exacerbations of asthma. Adult BALB/c mice were intranasally exposed to low-dose house-dust-mite (or vehicle) daily for 10 days. On day 9, mice were inoculated with human-rhinovirus-1B (or UV-inactivated human-rhinovirus-1B). Forty-eight hours after inoculation, we assessed bronchoalveolar cellular inflammation, levels of relevant cytokines/serum antibodies, lung function and responsiveness/sensitivity to methacholine. House-dust-mite exposure did not result in a classical TH2-driven response, but was more representative of noneosinophilic asthma. However, there were significant effects of house-dust-mite exposure on most of the parameters measured including increased cellular inflammation (primarily macrophages and neutrophils), increased total IgE and house-dust-mite-specific IgG1 and increased responsiveness/sensitivity to methacholine. There were limited effects of human-rhinovirus-1B infection alone, and the combination of the two insults resulted in additive increases in neutrophil levels and lung parenchymal responses to methacholine (tissue elastance). We conclude that acute rhinovirus infection exacerbates house-dust-mite-induced lung disease in adult mice. The similarity of our results using the naturally occurring allergen house-dust-mite, to previous studies using ovalbumin, suggests that the exacerbation of allergic airways disease by rhinovirus infection could act via multiple or conserved mechanisms. PMID:24632596

Phan, Jennifer A; Kicic, Anthony; Berry, Luke J; Fernandes, Lynette B; Zosky, Graeme R; Sly, Peter D; Larcombe, Alexander N

2014-01-01

65

Do new wipe materials outperform traditional lead dust cleaning methods?  

PubMed

Government guidelines have traditionally recommended the use of wet mopping, sponging, or vacuuming for removal of lead-contaminated dust from hard surfaces in homes. The emergence of new technologies, such as the electrostatic dry cloth and wet disposable clothes used on mopheads, for removal of dust provides an opportunity to evaluate their ability to remove lead compared with more established methods. The purpose of this study was to determine if relative differences exist between two new and two older methods for removal of lead-contaminated dust (LCD) from three wood surfaces that were characterized by different roughness or texture. Standard leaded dust, <75 ?m, was deposited by gravity onto the wood specimens. Specimens were cleaned using an automated device. Electrostatic dry cloths (dry Swiffer), wet Swiffer cloths, paper shop towels with non-ionic detergent, and vacuuming were used for cleaning LCD from the specimens. Lead analysis was by anodic stripping voltammetry. After the cleaning study was conducted, a study of the coefficient of friction was performed for each wipe material. Analysis of variance was used to evaluate the surface and cleaning methods. There were significant interactions between cleaning method and surface types, p = 0.007. Cleaning method was found be a significant factor in removal of lead, p <0.001, indicating that effectiveness of each cleaning methods is different. However, cleaning was not affected by types of surfaces. The coefficient of friction, significantly different among the three wipes, is likely to influence the cleaning action. Cleaning method appears to be more important than texture in LCD removal from hard surfaces. There are some small but important factors in cleaning LCD from hard surfaces, including the limits of a Swiffer mop to conform to curved surfaces and the efficiency of the wetted shop towel and vacuuming for cleaning all surface textures. The mean percentage reduction in lead dust achieved by the traditional methods (vacuuming and wet wiping) was greater and more consistent compared to the new methods (electrostatic dry cloth and wet Swiffer mop). Vacuuming and wet wiping achieved lead reductions of 92% ± 4% and 91%, ± 4%, respectively, while the electrostatic dry cloth and wet Swiffer mops achieved lead reductions of only 89 ± 8% and  81 ± 17%, respectively. PMID:22746281

Lewis, Roger D; Ong, Kee Hean; Emo, Brett; Kennedy, Jason; Brown, Christopher A; Condoor, Sridhar; Thummalakunta, Laxmi

2012-01-01

66

Organophosphorous pesticide breakdown products in house dust and children's urine  

PubMed Central

Human exposure to preformed dialkylphosphates (DAPs) in food or the environment may affect the reliability of DAP urinary metabolites as biomarkers of organophosphate (OP) pesticide exposure. We conducted a study to investigate the presence of DAPs in indoor residential environments and their association with children’s urinary DAP levels. We collected dust samples from homes in farmworker and urban communities (40 homes total, n = 79 samples) and up to two urine samples from resident children ages 3–6 years. We measured six DAPs in all samples and eight DAP-devolving OP pesticides in a subset of dust samples (n = 54). DAPs were detected in dust with diethylphosphate (DEP) being the most frequently detected (?60%); detection frequencies for other DAPs were ?50%. DEP dust concentrations did not significantly differ between communities, nor were concentrations significantly correlated with concentrations of chlorpyrifos and diazinon, the most frequently detected diethyl-OP pesticides (Spearman ? = ?0.41 to 0.38, P>0.05). Detection of DEP, chlorpyrifos, or diazinon, was not associated with DEP and/or DEP + diethylthiophosphate detection in urine (Kappa coefficients = ?0.33 to 0.16). Finally, estimated non-dietary ingestion intake from DEP in dust was found to be ?5% of the dose calculated from DEP levels in urine, suggesting that ingestion of dust is not a significant source of DAPs in urine if they are excreted unchanged. PMID:22781438

Quiros-Alcala, Lesliam; Bradman, Asa; Smith, Kimberly; Weerasekera, Gayanga; Odetokun, Martins; Barr, Dana Boyd; Nishioka, Marcia; Castorina, Rosemary; Hubbard, Alan E.; Nicas, Mark; Hammond, S. Katharine; McKone, Thomas E.; Eskenazi, Brenda

2014-01-01

67

Investigating A Novel Flame Retardant Known as V6: Measurements in Baby Products, House Dust and Car Dust  

PubMed Central

With the phase-out of polybrominated diphenyl ether (PBDE) flame retardants, the use of new and alternate flame retardants has been increasing. 2,2-bis(chloromethyl)propane-1,3-diyltetrakis(2-chloroethyl) bisphosphate, known as V6, is a flame retardant applied to polyurethane foam commonly found in furniture and automobile foam. However, to the authors’ knowledge, no research has been conducted on V6 levels in the environment. The intention of this study was to measure the concentration of V6 in foam collected from baby products where it was recently detected, and measure levels in dust samples collected from homes and automobiles in the Boston, MA area. To accomplish this a pure V6 commercial standard was purchased from a Chinese manufacturer and purified (> 98%). An analytical method to measure V6 in dust samples using liquid chromatography tandem mass spectrometry (LC/MS-MS) was developed. Extraction was conducted using Accelerated Solvent Extraction (ASE) and extracts were purified using an ENVI-Florisil SPE column (500 mg, 3mL). V6 was measured in foam samples collected from baby products with a concentration ranging from 24,500,000 to 59,500,000 ng/g of foam (n = 12, average ± sd: 46,500,000 ± 12,000,000 ng/g; i.e., on average, 4.6 % of the foam mass was V6). V6 was also detected in 19 of 20 car dust samples and 14 of 20 house dust samples analyzed. The concentration of V6 in the house dust ranged from < 5 ng/g to 1,110 ng/g with a median of 12.5 ng/g, and < 5 ng/g to 6,160 ng/g in the car dust with a median of 103.0 ng/g. Concentrations in car dust were significantly higher than the house dust, potentially indicating higher use of V6 in automobiles compared to products found in the home. Furthermore, tris (2-chloroethyl) phosphate (TCEP), a known carcinogen, was found in the V6 commercial mixture (14% by weight) as an impurity and was consistently detected with V6 in the foam samples analyzed. A significant correlation was also observed between V6 and TCEP in the dust samples, suggesting that the use of V6 is a significant source of TCEP in the indoor environment. PMID:23565680

Fang, Mingliang; Webster, Thomas F.; Gooden, David; Cooper, Ellen M.; McClean, Michael D.; Carignan, Courtney; Makey, Colleen; Stapleton, Heather M.

2013-01-01

68

Common antigenic determinants in extracts of house dust and dermatophagoides species  

PubMed Central

Antisera were prepared in rabbits by injection in Freund's adjuvant of extracts from a number of species of mite. Antigenic relationships were examined by geldiffusion precipitation tests. At least one, and probably two antigens were found to be common to the house dust mite, Dermatophagoides pteronyssinus and the related species Dermatophagoidesfarinae. These antigens were not detected in mites of the three other genera examined. The presence of common antigens to Dermatophagoides species would explain the high sensitivity to Dermatophagoides farinae reported among individuals sensitive to house dust. During the examination of four antisera to house dust made in rabbits, one was found to contain a precipitin to Dermatophagoides spp. ImagesFig. 1Fig. 2Fig. 3Fig. 4 PMID:4097808

Dasgupta, A.; Cunliffe, A. C.

1970-01-01

69

Organophosphorus flame retardants (PFRs) and plasticizers in house and car dust and the influence of electronic equipment.  

PubMed

All nine PFRs studied were detected in house and car dust from the Netherlands with the exception of tris(butyl) phosphate (TNBP) and tris(isobutyl) phosphate (TIBP) in car dust. Tris(2-butoxyethyl) phosphate (TBOEP, median 22 ?g g(-1)) was dominant in house dust collected around and on electronics followed by tris(2-chloroisopropyl) phosphate (TCIPP, median 1.3 ?g g(-1)), tris(2-chloroethyl) phosphate (TCEP, median 1.3 ?g g(-1)) and tris(phenyl) phosphate (TPHP, median 0.8 ?g g(-1)). Levels of TPHP and tris(methylphenyl) phosphate (TMPP, also known as TCP) in house dust on electronics were significantly higher than in house dust collected around electronics, suggesting that electronic equipment has limited contribution to the PFR levels in house dust, with the exception of TPHP and TMPP. Car dust was dominated by tris(1,3-dichloroisopropyl) phosphate (TDCIPP) with the highest levels found in dust collected from the car seats (1100 ?g g(-1)). The mean TDCIPP and TCIPP levels observed in car dust were significantly higher than the levels observed in dust collected around electronics. Significantly higher mean TMPP levels in dust taken from car seats were found compared to dust collected around the equipment (p<0.05). This is probably influenced by the use of TDCIPP, TCIPP in polyurethane foam (car seats) and the use of TMPP as plasticizer in car interiors. Worldwide four PFR patterns were observed in house dust. The PFR pattern in the Netherlands of TDCIPP, TMPP, TCEP, TCIPP and TPHP in house dust is comparable to the pattern found in six other countries, which may point to identical sources of these PFRs in the indoor environment. However, the PFR levels between the countries and within countries showed high variation. PMID:24703013

Brandsma, Sicco H; de Boer, Jacob; van Velzen, Martin J M; Leonards, Pim E G

2014-12-01

70

Exposure to house dust mite allergens and the clinical activity of asthma  

Microsoft Academic Search

Background: House dust mite allergens play an important role in inducing IgE-mediated sensitization and the development of bronchial hyperresponsiveness (BHR) and asthma. This study investigated the relationship between mite allergen exposure and the clinical activity and severity of asthma. Methods: Nonsmoking adult patients with asthma (n = 53) were randomly recruited from the asthma registry of two large family practitioner

Adnan Custovic; Simon C. O. Taggart; Helen C. Francis; Martin D. Chapman; Ashley Woodcock

1996-01-01

71

DIESEL AND CARBON PARTICLES ENHANCE HOUSE DUST MITE-INDUCED PULMONARY HYPERSENSITIVITY IN BROWN NORWAY RATS  

EPA Science Inventory

Diesel and Carbon Particles Enhance House Dust Mite-Induced Pulmonary Hypersensitivity in Brown Norway Rats. P. Singh1, M.J. Daniels2, D. Winsett2, J. Richards2, K. Crissman2, M. Madden2 and M.I. Gilmour2. 1NCSU, Raleigh, NC and 2 USEPA, Research Triangle Park, NC. Ep...

72

The allergen of Ficus benjamina in house dust.  

PubMed

Ficus benjamina, a member of the Moraceae family, is a tropical, non-flowering green plant which is widely used for ornamental purposes. It is an occupational allergen in plant keepers but sensitization is also increasingly found in non-occupationally exposed atopic and non-atopic patients. The allergen of Ficus benjamina is located in the plant sap, a so-called latex. By radioallergosorbent test-(RAST)-inhibition studies allergen could also be demonstrated in the dust collected from the leaf surface and in dust samples from the floor of rooms where the plant was placed. These findings could result in more extensive preventive measures in patients sensitized to Ficus benjamina. In addition there is some evidence that possibly a crossreactivity between latex of Ficus benjamina and latex from the rubber tree Hevea brasiliensis, a member of the Euphorbiaceae family, may exist. PMID:7788569

Bircher, A J; Langauer, S; Levy, F; Wahl, R

1995-03-01

73

The impact of drinking water, indoor dust and paint on blood lead levels of children aged 1-5 years in Montr?al (Qu?bec, Canada)  

PubMed Central

Lead is neurotoxic at very low dose and there is a need to better characterize the impact of domestic sources of lead on the biological exposure of young children. A cross-sectional survey evaluated the contribution of drinking water, house dust and paint to blood lead levels (BLLs) of young children living in old boroughs of Montréal (Canada). Three hundred and six children aged 1 to 5 years and currently drinking tap water participated in the study. For each participant, residential lead was measured in kitchen tap water, floor dust, windowsill dust and house paint and a venous blood sample was analyzed. Multivariate logistic regression was used to evaluate the association between elevated BLL in the children (? 75th percentile) and indoor lead contamination by means of odds ratios (OR) using 95% confidence intervals (CI). There was an association between BLL ?75th percentile (1.78??g/dL) and water lead when the mean water concentration was >3.3??g/L: adjusted OR=4.7 (95% CI: 2.1–10.2). Windowsill dust loading >14.1??g/ft2 was also associated with BLL ?1.78??g/dL: adjusted OR=3.2 (95% CI: 1.3–7.8). Despite relatively low BLLs, tap water and house dust lead contribute to an increase of BLLs in exposed young children. PMID:23361441

Levallois, Patrick; St-Laurent, Julie; Gauvin, Denis; Courteau, Marilene; Prevost, Michele; Campagna, Celine; Lemieux, France; Nour, Shokoufeh; D'Amour, Monique; Rasmussen, Pat E

2014-01-01

74

ANALYSIS OF SOIL AND HOUSE DUST FOR POLYCYCLIC AROMATIC HYDROCARBONS  

EPA Science Inventory

It has been conjectured that jet turbine exhaust near airplane flight paths may result in significant human exposure to PAH. The fallout from the aerosol plume could be introduced into the residence directly as drafts through the interior of the house or through accumulation of ...

75

Analysis of soil and house dust for polycyclic aromatic hydrocarbons. Final report, July 1995-January 1996  

SciTech Connect

It has been conjectured that jet turbine exhaust near airplane flight paths may result in significant human exposure to Polycyclic Aromatic Hydrocarbons (PAHs). The EPA Risk Reduction Engineering Laboratory (RREL) arranged access to a household located approximately eight miles from the end of a runway at the Greater Cincinnati and Northern Kentucky Airport, and collected soil, wipe, and dust samples in and around the household. A total of 19 PAH ranging from naphthalene (2-ring) to coronene (7-ring) were measured. The general concentration trend for the 19 PAH is house dust > entryway dust > soil. The house dust samples were colleted inside the household and the entryway dust and soil samples were collected outside. Seven of the target PAH are ranked as probable human carcinogens (B2) in the U.S. EPA`s Integrated Risk Information System. The concentrations of B2 PAH account for roughly half of the concentrations of the sums of 19 PAH in most soil and dust samples but not in wipe samples.

Chuang, J.C.

1996-07-01

76

Levels and profiles of organochlorines and flame retardants in car and house dust from Kuwait and Pakistan: implication for human exposure via dust ingestion.  

PubMed

There are only few studies documenting indoor pollution in the Middle East and the Indian subcontinent. In present study, we have evaluated the occurrence of various organochlorines (OCs) and flame retardants (FRs) in dust from cars and houses of Pakistan and Kuwait. Polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs), organophosphate FRs (PFRs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) were investigated in indoor dust from urban houses (N=15 per country) and cars (N=15 per country). PFRs were the major analytes in all four microenvironments, followed by PBDEs>NBFRs>OCPs>PCBs. For all classes of analytes, relatively lower levels were observed in car and house dust from Pakistan than Kuwait. Levels of ?PBDEs, ?NBFRs and ?PFRs were higher in car dust, while ?OCPs and ?PCBs were higher in house dust from both countries. ?PFRs occurred at average concentrations of 16,900, 87,900, 475, and 2500ng/g in Kuwaiti house and car, and Pakistani house and car dust, respectively. For both countries, the profiles of analytes in car dust were different from those in the house dust. Different exposure scenarios using 5th percentile, median, mean, and 95th percentile levels were estimated for adult, taxi drivers and toddlers. For Kuwaiti toddlers, assuming high dust intake and mean and 95th percentile concentrations, the values computed for ?OCPs (1500ng/kg bw/day) were higher than RfD values, while for ?PCBs (14.5ng/kg bw/day) it was only two-fold lower than the corresponding RfDs. PMID:23523855

Ali, Nadeem; Ali, Lulwa; Mehdi, Toufeer; Dirtu, Alin C; Al-Shammari, Fatema; Neels, Hugo; Covaci, Adrian

2013-05-01

77

42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Lead fume test for dust, fume, and mist respirators...and Combination Gas Masks § 84.1146 Lead fume test for dust, fume, and mist respirators...than 20 milligrams of freshly generated lead-oxide fume, calculated as lead...

2010-10-01

78

42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Lead fume test for dust, fume, and mist respirators...and Combination Gas Masks § 84.1146 Lead fume test for dust, fume, and mist respirators...than 20 milligrams of freshly generated lead-oxide fume, calculated as lead...

2013-10-01

79

42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Lead fume test for dust, fume, and mist respirators...and Combination Gas Masks § 84.1146 Lead fume test for dust, fume, and mist respirators...than 20 milligrams of freshly generated lead-oxide fume, calculated as lead...

2011-10-01

80

42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Lead fume test for dust, fume, and mist respirators...and Combination Gas Masks § 84.1146 Lead fume test for dust, fume, and mist respirators...than 20 milligrams of freshly generated lead-oxide fume, calculated as lead...

2012-10-01

81

Application of Synchrotron X-ray Techniques for the Determination of Metal Speciation in (House) Dust Particles  

Microsoft Academic Search

\\u000a An overview of synchrotron radiation-based X-ray absorption and scattering techniques for characterizing the speciation of\\u000a metals in complex, heterogeneous samples, such as house dust, is presented. The complementary techniques are demonstrated\\u000a on a house dust sample elevated in Pb (1,670 mg kg?1). The X-ray techniques successfully identified the speciation and sources of Pb in house dust samples, and provided an explanation\\u000a for

Lachlan C. W. MacLean; Suzanne Beauchemin; Pat E. Rasmussen

82

Pyrethroids in house dust from the homes of farm worker families in the MICASA study.  

PubMed

Indoor pesticide exposure is a growing concern, particularly for pyrethroids, a commonly used class of pesticides. Pyrethroid concentrations may be especially high in homes of immigrant farm worker families, who often live in close proximity to agricultural fields and are faced with poor housing conditions, potentially causing high pest infestation and pesticide use. We investigate levels of pyrethroids in the house dust of farm worker family homes in a study of mothers and children living in Mendota, CA, within the population-based Mexican Immigration to California: Agricultural Safety and Acculturation (MICASA) Study. We present pesticide use data and levels of pyrethroid pesticides in indoor dust collected in 2009 as measured by questionnaires and a GC/MS analysis of the pyrethroids cis- and trans-permethrin, cypermethrin, deltamethrin, esfenvalerate and resmethrin in single dust samples collected from 55 households. Cis- and trans-permethrin had the highest detection frequencies at 67%, with median concentrations of 244 and 172ng/g dust, respectively. Cypermethrin was detected in 52% of the homes and had a median concentration of 186ng/g dust. Esfenvalerate, resmethrin and deltamethrin were detected in less than half the samples. We compared the pyrethroid concentrations found in our study to other studies looking at both rural and urban homes and daycares. Lower detection frequencies and/or lower median concentrations of cis- and trans-permethrin and cypermethrin were observed in our study as compared to those studies. However, deltamethrin, esfenvalerate and resmethrin were detected more frequently in the house dust from our study than in the other studies. Because households whose children had higher urinary pyrethroid metabolite levels were more likely to be analyzed in this study, a positive bias in our estimates of household pyrethroid levels may be expected. A positive association was observed with reported outdoor pesticide use and cypermethrin levels found in the indoor dust samples (rs=0.28, p=0.0450). There was also a positive association seen with summed pyrethroid levels in house dust and the results of a pesticide inventory conducted by field staff (rs=0.32, p=0.018), a potentially useful predictor of pesticide exposure in farm worker family homes. Further research is warranted to fully investigate the utility of such a measure. PMID:24096042

Trunnelle, Kelly J; Bennett, Deborah H; Tancredi, Daniel J; Gee, Shirley J; Stoecklin-Marois, Maria T; Hennessy-Burt, Tamara E; Hammock, Bruce D; Schenker, Marc B

2013-11-01

83

Pyrethroids in house dust from the homes of farm worker families in the MICASA study  

PubMed Central

Indoor pesticide exposure is a growing concern, particularly for pyrethroids, a commonly used class of pesticides. Pyrethroid concentrations may be especially high in homes of immigrant farm worker families, who often live in close proximity to agricultural fields and are faced with poor housing conditions, potentially causing high pest infestation and pesticide use. We investigate levels of pyrethroids in the house dust of farm worker family homes in a study of mothers and children living in Mendota, CA, within the population-based Mexican Immigration to California: Agricultural Safety and Acculturation (MICASA) Study. We present pesticide use data and levels of pyrethroid pesticides in indoor dust collected in 2009 as measured by questionnaires and a GC/MS analysis of the pyrethroids cis- and trans-permethrin, cypermethrin, deltamethrin, esfenvalerate and resmethrin in single dust samples collected from 55 households. Cis- and trans-permethrin had the highest detection frequencies at 67%, with median concentrations of 244 and 172 ng/g dust, respectively. Cypermethrin was detected in 52% of the homes and had a median concentration of 186 ng/g dust. Esfenvalerate, resmethrin and deltamethrin were detected in less than half the samples. We compared the pyrethroid concentrations found in our study to other studies looking at both rural and urban homes and daycares. Lower detection frequencies and/or lower median concentrations of cis- and trans-permethrin and cypermethrin were observed in our study as compared to those studies. However, deltamethrin, esfenvalerate and resmethrin were detected more frequently in the house dust from our study than in the other studies. Because households whose children had higher urinary pyrethroid metabolite levels were more likely to be analyzed in this study, a positive bias in our estimates of household pyrethroid levels may be expected. A positive association was observed with reported outdoor pesticide use and cypermethrin levels found in the indoor dust samples (rs = 0.28, p = 0.0450). There was also a positive association seen with summed pyrethroid levels in house dust and the results of a pesticide inventory conducted by field staff (rs = 0.32, p = 0.018), a potentially useful predictor of pesticide exposure in farm worker family homes. Further research is warranted to fully investigate the utility of such a measure. PMID:24096042

Trunnelle, Kelly J.; Bennett, Deborah H.; Tancredi, Daniel J.; Gee, Shirley J.; Stoecklin-Marois, Maria T.; Hennessy-Burt, Tamara E.; Hammock, Bruce D.; Schenker, Marc B.

2014-01-01

84

Detection of Organophosphate Flame Retardants in Furniture Foam and US House Dust  

PubMed Central

Restrictions on the use of polybrominated diphenyl ethers (PBDEs) have resulted in the increased use of alternate flame retardant chemicals to meet flammability standards. However, it has been difficult to determine which chemical formulations are currently being used in high volumes to meet flammability standards since the use of flame retardant formulations in consumer products is not transparent (i.e. not provided to customers). To investigate chemicals being used as replacements for PentaBDE in polyurethane foam, we analyzed foam samples from 26 different pieces of furniture purchased in the United States primarily between 2003 and 2009 using gas chromatography mass spectrometry. Samples included foam from couches, chairs, mattress pads, pillows, and, in one case, foam from a sound proofing system of a laboratory grade dust sieve. Fifteen of the foam samples contained the flame retardant tris(1,3-dichloro-2-propyl) phosphate (TDCPP; 1–5% by weight), four samples contained tris(1-chloro-2-propyl) phosphate (TCPP; 0.5 –2.2 % by weight), one sample contained brominated chemicals found in a new flame retardant mixture called Firemaster 550 (4.2% by weight), and one foam sample collected from a futon likely purchased prior to 2004 contained PentaBDE (0.5% by weight). Due to the high frequency of detection of the chlorinated phosphate compounds in furniture foam, we analyzed extracts from 50 house dust samples collected between 2002 and 2007 in the Boston, MA area for TDCPP, TCPP, and another high volume use organophosphate-based flame retardant used in foam, triphenylphosphate (TPP). Detection frequencies for TDCPP and TPP in the dust samples were >96% and were log normally distributed, similar to observations for PBDEs. TCPP was positively detected in dust in only 24% of the samples, but detection was significantly limited by a co-elution problem. The geometric mean concentrations for TCPP, TDCPP and TPP in house dust were 570, 1890, and 7360 ng/g, respectively, and maximum values detected in dust were 5490, 56,080 and 1,798,000 ng/g, respectively. These data suggest that levels of these organophosphate flame retardants are comparable, or in some cases, greater than, levels of PBDEs in house dust. The high prevalence of these chemicals in foam and the high concentrations measured in dust (as high as 1.8 mg/g), warrant further studies to evaluate potential health effects from dust exposure, particularly for children. PMID:19848166

Stapleton, Heather M.; Klosterhaus, Susan; Eagle, Sarah; Fuh, Jennifer; Meeker, John D.; Blum, Arlene; Webster, Thomas F.

2009-01-01

85

Pesticides in house dust from urban and farmworker households in California: an observational measurement study  

Microsoft Academic Search

Background  Studies report that residential use of pesticides in low-income homes is common because of poor housing conditions and pest\\u000a infestations; however, exposure data on contemporary-use pesticides in low-income households is limited. We conducted a study\\u000a in low-income homes from urban and agricultural communities to: characterize and compare house dust levels of agricultural\\u000a and residential-use pesticides; evaluate the correlation of pesticide

Lesliam Quirós-Alcalá; Asa Bradman; Marcia Nishioka; Martha E Harnly; Alan Hubbard; Thomas E McKone; Jeannette Ferber; Brenda Eskenazi

2011-01-01

86

Molecular identification of house dust mites and storage mites.  

PubMed

Mites are known causes of allergic diseases. Currently, identification of mites based on morphology is difficult if only one mite is isolated from a (dust) sample, or when only one gender is found, or when the specimen is not intact especially with the loss of the legs. The purpose of this study was to use polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of the ITS2 gene, to complement the morphological data for the identification of mites to the species level. For this, six species were cultured: Dermatophagoides pteronyssinus, D. farinae, Blomia tropicalis, Tyrophagus putrescentiae, Aleuroglyphus ovatus and Glycycometus malaysiensis. Genomic DNA of the mites was extracted, quantified, amplified and digested individually with restriction enzymes. Hinf I and Ple I differentiated the restriction patterns of D. pteronyssinus and D. farinae. Bfa I and Alu I enzymes differentiated B. tropicalis and G. malaysiensis. Ple I enzyme was useful for the differentiation between T. putrescentiae and A. ovatus. Bfa I was useful for the differentiation of G. malaysiensis from the rest of the species. In conclusion, different species of mites can be differentiated using PCR-RFLP of ITS2 region. With the established PCR-RFLP method in this study, identification of these mites to the species level is possible even if complete and intact adult specimens of both sexes are not available. As no study to date has reported PCR-RFLP method for the identification of domestic mites, the established method should be validated for the identification of other species of mites that were not included in this study. PMID:21468750

Wong, Shew Fung; Chong, Ai Ling; Mak, Joon Wah; Tan, Jessie; Ling, Suk Jiun; Ho, Tze Ming

2011-10-01

87

Paradoxical Effects of Rapamycin on Experimental House Dust Mite-Induced Asthma  

Microsoft Academic Search

The mammalian target of rapamycin (mTOR) modulates immune responses and cellular proliferation. The objective of this study was to assess whether inhibition of mTOR with rapamycin modifies disease severity in two experimental murine models of house dust mite (HDM)-induced asthma. In an induction model, rapamycin was administered to BALB\\/c mice coincident with nasal HDM challenges for 3 weeks. In a

Karin Fredriksson; Jill A. Fielhaber; Jonathan K. Lam; Xianglan Yao; Katharine S. Meyer; Karen J. Keeran; Gayle J. Zywicke; Xuan Qu; Zu-Xi Yu; Joel Moss; Arnold S. Kristof; Stewart J. Levine

2012-01-01

88

Impact of Sublingual Immunotherapy on Specific Antibody Levels in Asthmatic Children Allergic to House Dust Mites  

Microsoft Academic Search

Objective: To evaluate the clinical outcome and changes in allergen-specific antibodies during sublingual immunotherapy (SLIT) in house dust mite (HDM)-allergic asthma patients and to compare levels of allergen-specific antibodies in HDM-allergic patients before and after treatment with that of healthy controls. Method: Thirty-one asthma patients allergic to HDM were studied. Patients in groups I (n = 17) and II (n

Nerin N. Bahceciler; Cigdem Arikan; Alison Taylor; Mubeccel Akdis; Kurt Blaser; Isil B. Barlan; Cezmi A. Akdis

2005-01-01

89

Quantification of [i]C. globosum [/i]spores in house dust samples.  

PubMed

Chaetomium globosum is one of the most common fungi that grows in damp buildings and occurs in agricultural and forestry workplaces. Using sera from atopic patients, we characterized and purified an extracellular chitosanase (Chg47) from C. globosum that is antigenic to humans. The study reports the production of monoclonal antibodies to the protein. Three capture ELISAs were developed for Chg47 for detection of spores and spore and mycelial fragments in dust samples using different mono- and polyclonal antibody combinations. One method is based on an enhanced biotinylated polyclonal antibody as the secondary antibody and coating anti-IgM to capture one of two clones of IgM monoclonal antibodies as the capture antibody. The other method makes use of an enhanced rabbit polyclonal antibody as both the primary and capture antibody. The detection limit of the double PAb method for the Chg47 antigen was 7.6 pg/ml. When the anti-IgM+10B3 clone was used, the detection limit was 61 pg/ml and for anti-IgM+5F12, 122 pg/ml. The detection limit of double PAb method is comparable to methods for the allergen and spores of Aspergillus versicolor in house dust and is more sensitive than other immunoassays for allergens in house including for Stachybotrys chartarum, Aspergillus fumigatus and Alternaria alternata. All three methods had limited cross-reactivity to fungi common in house dust representing a diverse array of taxa. PMID:25292122

Shi, Chunhua; Provost, Natacha B; Desroches, Tamara; Miller, J David

2014-09-01

90

Linking PBDEs in house dust to consumer products using X-ray fluorescence.  

PubMed

The indoor environment is an important source of exposure to polybrominated diphenyl ethers (PBDEs), a class of fire retardants used in many household products. Previous attempts to link PBDE concentrations in house dust to consumer products have been hampered by the inability to determine the presence of PBDEs in otherwise similar products. We used a portable X-rayfluorescence (XRF) analyzer to nondestructively quantify bromine concentrations in consumer goods. In the validation phase, XRF-measured bromine was highly correlated with GC/MS-measured bromine for furniture foam and plastic from electronics (n = 29, r = 0.93, p < 0.0001). In the field study phase, the XRF-measured bromine in room furniture was associated with pentaBDE concentrations in room dust in the bedroom (r = 0.68, p = 0.001) and main living area (r = 0.51, p = 0.02). We also found an association between XRF-measured bromine levels in electronics and decaBDE levels in dust, largely driven by the high levels in televisions (r = 0.64, p = 0.003 for bedrooms). For the main living area, predicting decaBDE in dust improved when we included an interaction effect between the bromine content of televisions and the number of persons in the house (p < 0.005), a potential surrogate for television usage. PMID:18589991

Allen, Joseph G; McClean, Michael D; Stapleton, Heather M; Webster, Thomas F

2008-06-01

91

A comparison of lead hazards in the housing environment of lead poisoned children versus non poisoned controls  

Microsoft Academic Search

An epidemiological study was undertaken to compare the lead hazards in the housing environment of lead poisoned children (aged 1–7) and matched non?poisoned control children. The results indicated a greater frequency and higher levels of lead in paint on both interior and exterior surfaces of the houses of the cases compared to the controls and suggested that intact painted surfaces

Charles Gilbert; Robert W. Tuthill; Edward J. Calabrese; Howard A. Peters

1979-01-01

92

Assessment of cleaning to control lead dust in homes of children with moderate lead poisoning: treatment of lead-exposed children trial.  

PubMed Central

In this article we describe the assessment and control of lead dust exposure in the Treatment of Lead-exposed Children (TLC) Trial, a clinical trial of the effects of oral chelation on developmental end points in urban children with moderately elevated blood lead levels. To reduce potential lead exposure from settled dust or deteriorated paint during the drug treatment phase of the trial, the homes of 765 (98%) of the randomized children (both active and placebo drug treatment groups) were professionally cleaned. Lead dust measurements were made in a sample of 213 homes before and after cleaning. Geometric mean dust lead loadings before cleaning were 43, 29, 308, and 707 micro g/ft2 in the kitchen floor, playroom floor, playroom windowsill, and playroom window well samples respectively. Following cleaning, floor dust lead loadings were reduced on average 32% for paired floor samples (p < 0.0001), 66% for windowsills (p < 0.0001), and 93% for window wells (p < 0.0001). Cleaning was most effective for 146 homes with precleaning dust lead levels above the recommended clearance levels, with average reductions of 44%, 74%, and 93% for floors (p < 0.0001), windowsills (p < 0.0001), and window wells (p < 0.0001), respectively. Despite these substantial reductions in dust lead loadings, a single professional cleaning did not reduce the lead loadings of all dust samples to levels below current federal standards for lead in residential dust. Attainment of dust levels below current standards will require more intensive cleaning and lead hazard reduction strategies. PMID:12460817

Ettinger, Adrienne S; Bornschein, Robert L; Farfel, Mark; Campbell, Carla; Ragan, N Beth; Rhoads, George G; Brophy, Merrill; Wilkens, Sherry; Dockery, Douglas W

2002-01-01

93

Serum PBDEs in a North Carolina Toddler Cohort: Associations with Handwipes, House Dust, and Socioeconomic Variables  

PubMed Central

Background: Polybrominated diphenyl ethers (PBDEs) are persistent, bioaccumulative, and endocrine-disrupting chemicals. Objectives: We used handwipes to estimate exposure to PBDEs in house dust among toddlers and examined sex, age, breast-feeding, race, and parents’ education as predictors of serum PBDEs. Methods: Eighty-three children from 12 to 36 months of age were enrolled in North Carolina between May 2009 and November 2010. Blood, handwipe, and house dust samples were collected and analyzed for PBDEs. A questionnaire was administered to collect demographic data. Results: PBDEs were detected in all serum samples (geometric mean for ?pentaBDE in serum was 43.3 ng/g lipid), 98% of the handwipe samples, and 100% of the dust samples. Serum ?pentaBDEs were significantly correlated with both handwipe and house dust ?pentaBDE levels, but were more strongly associated with handwipe levels (r = 0.57; p < 0.001 vs. r = 0.35; p < 0.01). Multivariate model estimates revealed that handwipe levels, child’s sex, child’s age, and father’s education accounted for 39% of the variation in serum ?BDE3 levels (sum of BDEs 47, 99, and 100). In contrast, age, handwipe levels, and breast-feeding duration explained 39% of the variation in serum BDE 153. Conclusions: Our study suggests that hand-to-mouth activity may be a significant source of exposure to PBDEs. Furthermore, age, socioeconomic status, and breast-feeding were significant predictors of exposure, but associations varied by congener. Specifically, serum ?BDE3 was inversely associated with socioeconomic status, whereas serum BDE-153 was positively associated with duration of breast-feeding and mother’s education. PMID:22763040

Eagle, Sarah; Sjödin, Andreas; Webster, Thomas F.

2012-01-01

94

39Terra Satellite Measures Dangerous Dust Dust particles can cause many serious diseases when inhaled, and lead to  

E-print Network

details can be found at 'New Map Offers Global View of Health-Sapping Air Pollution'; http University, Provo, Utah and one of the world's leading experts on the health impacts of air pollution. That inhaled, and lead to millions of premature deaths each year around the world. The dust particles are less

95

Characterization of lead, chromium, and cadmium in dust emitted from municipal solid waste incineration plants  

NASA Astrophysics Data System (ADS)

The dust is emitted from municipal solid waste incinerators (MSWIs). Volatile toxic heavy metals are abundant in smaller dust particles and influence the toxicity of particulate matter such as fine particles <2.5 ?m (PM2.5). However, little is known about the properties of these metals in fine dust particles. Therefore, X-ray absorption fine structure (XAFS) spectroscopy was used to investigate the chemical states of lead (Pb), chromium (Cr), and cadmium (Cd) in MSWI dust collected for nine particle size fractions at the inlet of the dust collector and the stacks of two MSWI plants. XAFS spectroscopy of the dust in the inlet of the dust collectors showed that finer dust contained predominantly Pb as PbCl2 with some PbSiO3, coarser dust consisted of Cr forms, including more toxic Cr(VI) species, and all dust contained CdCl2. Although the dust collector removed almost all of the Pb, trace amounts of PbCl2 remained in the stack gas after passing through the dust collector.

Shiota, K.; Imai, G.; Oshita, K.; Takaoka, M.

2013-04-01

96

Levels of phthalate esters in settled house dust from urban dwellings with young children in Nanjing, China  

NASA Astrophysics Data System (ADS)

To investigate the levels and possible determinants of phthalate esters (PEs) in settled house dust from urban dwellings with young children, dust was collected from 215 urban houses in Nanjing, China, and 145 outdoor settled dust samples were collected nearby. Six PEs were measured by gas chromatography/mass spectrometry. All PEs were detected in the dust from approximately 90% of the houses, with the exception of dioctyl phthalate (DOP), which had only a 59% detection rate. Di-2-ethylhexyl phthalate (DEHP) and di-n-butyl phthalate (DBP) were the most abundant PEs, with geometric means of 110 and 16.4 ?g g-1, respectively, and maximal concentrations 9950 and 2150 ?g g-1. Factor analysis showed that DBP, DEHP and benzyl butyl phthalate (BBP) might come from the same source and were significantly influenced by the use of solid-wood floor wax. High BBP, DEHP, DOP and total PE levels were associated with indices of dampness, and high DOP was associated with humidifier use. In conclusion, six PEs are ubiquitous in urban settled house dust in Nanjing, China, and both plastic materials and cosmetic and personal care products are important sources. Flooring material, dampness and humidifier use potentially influence house dust PE levels.

Zhang, Qi; Lu, Xiao-Mei; Zhang, Xiao-Ling; Sun, Yong-Gang; Zhu, Dong-Mei; Wang, Bing-Ling; Zhao, Ren-Zheng; Zhang, Zheng-Dong

2013-04-01

97

Effects of physical interventions on house dust mite allergen levels in carpet, bed, and upholstery dust in low-income, urban homes.  

PubMed Central

House dust mite allergen exposure is a postulated risk factor for allergic sensitization, asthma development, and asthma morbidity; however, practical and effective methods to mitigate these allergens from low-income, urban home environments remain elusive. The purpose of this study was to assess the feasibility and effectiveness of physical interventions to mitigate house dust mite allergens in this setting. Homes with high levels of house dust mite allergen (Der f 1 + Der p 1 > or = 10 microg/g dust by enzyme-linked immunosorbent assay) in the bed, bedroom carpet, and/or upholstered furniture were enrolled in the study. Carpets and upholstered furniture were subjected to a single treatment of either dry steam cleaning plus vacuuming (carpet only) or intensive vacuuming alone. Bed interventions consisted of complete encasement of the mattress, box spring, and pillows plus either weekly professional or in-home laundering of nonencased bedding. Dust samples were collected at baseline and again at 3 days (carpet and upholstery only) and 2, 4, and 8 weeks posttreatment. We compared pretreatment mean allergen concentrations and loads to posttreatment values and performed between-group analyses after adjusting for differences in the pretreatment means. Both dry steam cleaning plus vacuuming and vacuuming alone resulted in a significant reduction in carpet house dust mite allergen concentration and load (p < 0.05). Levels approached pretreatment values by 4 weeks posttreatment in the intensive vacuuming group, whereas steam cleaning plus vacuuming effected a decrease that persisted for up to 8 weeks. Significant decreases in bed house dust mite allergen concentration and load were obtained in response to encasement and either professional or in-home laundering (p < 0.001). Between-group analysis revealed significantly less postintervention house dust mite allergen load in professionally laundered compared to home-laundered beds (p < 0.05). Intensive vacuuming and dry steam cleaning both caused a significant reduction in allergen concentration and load in upholstered furniture samples (p < 0.005). Based on these data, we conclude that physical interventions offer practical, effective means of reducing house dust mite allergen levels in low-income, urban home environments. PMID:11564617

Vojta, P J; Randels, S P; Stout, J; Muilenberg, M; Burge, H A; Lynn, H; Mitchell, H; O'Connor, G T; Zeldin, D C

2001-01-01

98

Coal-Tar-Based Parking Lot Sealcoat: An Unrecognized Source of PAH to Settled House Dust  

PubMed Central

Despite much speculation, the principal factors controlling concentrations of polycyclic aromatic hydrocarbons (PAH) in settled house dust (SHD) have not yet been identified. In response to recent reports that dust from pavement with coal-tar-based sealcoat contains extremely high concentrations of PAH, we measured PAH in SHD from 23 apartments and in dust from their associated parking lots, one-half of which had coal-tar-based sealcoat (CT). The median concentration of total PAH (T-PAH) in dust from CT parking lots (4760 ?g/g, n = 11) was 530 times higher than that from parking lots with other pavement surface types (asphalt-based sealcoat, unsealed asphalt, concrete [median 9.0 ?g/g, n = 12]). T-PAH in SHD from apartments with CT parking lots (median 129 ?g/g) was 25 times higher than that in SHD from apartments with parking lots with other pavement surface types (median 5.1 ?g/g). Presence or absence of CT on a parking lot explained 48% of the variance in log-transformed T-PAH in SHD. Urban land-use intensity near the residence also had a significant but weaker relation to T-PAH. No other variables tested, including carpeting, frequency of vacuuming, and indoor burning, were significant. PMID:20063893

2010-01-01

99

The distribution of dust mite allergen in the houses of patients with asthma  

SciTech Connect

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.

Tovey, E.R.; Chapman, M.D.; Wells, C.W.; Platts-Mills, T.A.

1981-11-01

100

House Dust Mite Allergy in Korea: The Most Important Inhalant Allergen in Current and Future  

PubMed Central

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. PMID:23115727

Jeong, Kyoung Yong; Park, Jung-Won

2012-01-01

101

House dust mite allergy in Korea: the most important inhalant allergen in current and future.  

PubMed

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. PMID:23115727

Jeong, Kyoung Yong; Park, Jung-Won; Hong, Chein-Soo

2012-11-01

102

Reduction of house-dust mite allergen concentrations in carpets by aluminium potassium sulfate dodecahydrate (alum).  

PubMed

Special tools and skilled labor are required to reduce house-dust mite allergens in carpets. The main house-dust mite allergen is Der p 1, a soluble protein found in high abundance in woolen carpets. Current chemical treatment options are either unsafe or ineffective in eradicating Der p 1. Here, we present an effective, safe, and easy application reagent to reduce the allergen levels in carpets. Sixty woolen carpets with Der p 1 concentrations >2 microg/g in fine dust were divided into three homogeneous groups of 20 carpets each, according to their allergen load. We tested alum dissolved in 60 mL of water at doses of 3, 6, and 9 g/m2 against Der p 1 in groups 1, 2, and 3, respectively. The test side of the carpets was sprayed with the reagent. The control side was treated with the 60 mL of tap water. Dust particles were collected from a 1-m2 area on each carpet side 24 hours after treatment and were analyzed for Der p 1 content with a monoclonal ELISA. Alum reduced the Der p 1 concentrations by 48.6 +/- 6.2%, 78.8 +/- 7.2%, and 95.2 +/- 3.0% at 3, 6, and 9 g/m2 in the carpets, respectively. Moreover, there were no complaints registered by the residents against the alum applications. Alum, at 9 g/m2 (in a solution at 15%) in water, can be used for decreasing existing Der p 1 concentrations in woolen carpets. PMID:17063663

Sevki, Coskun; Levent, Aydin; Ender, Gulegen; Firdevs, Mor

2006-01-01

103

Assessment of cross-reactivity among five species of house dust and storage mites.  

PubMed

In vitro cross-reactivity among two house dust (Dermatophagoides farinae, D. pteronyssinus) and three storage (Acarus siro, Tyrophagus putrescentiae, Lepidoglyphus destructor) mites was examined in 20 mite-sensitive dogs with natural occurring atopic dermatitis (group A), 13 high-IgE beagles experimentally sensitized to D. farinae (group B), and five healthy beagles (group C). Intradermal testing (IDT) and serology for allergen-specific IgE demonstrated that co-sensitization for all possible pairs of the five mites was generally 45% or higher among group A dogs. In the same dogs, enzyme-linked immunosorbent assay cross-inhibition results indicated that each one of D. farinae, A. siro and T. putrescentiae was a strong inhibitor of all the remaining mites, whereas D. pteronyssinus was a strong inhibitor of L. destructor. A high number of positive IDT and serology test results for D. pteronyssinus, A. siro, T. putrescentiae and L. destructor were recorded among group B dogs. No conclusive evidence of exposure to these mites was found upon analysis of dust samples from their environment and their food for the presence of mites and guanine. Also, the number of positive test results was generally higher among group B than among group C dogs. Enzyme-linked immunosorbent assay cross-inhibition revealed that D. farinae was a strong inhibitor of D. pteronyssinus, A. siro and T. putrescentiae. Collectively, these results demonstrated extensive in vitro cross-reactivity among house dust and/or storage mites that can explain false-positive results upon testing of dust mite-sensitive dogs with atopic dermatitis. PMID:18336423

Saridomichelakis, Manolis N; Marsella, Rosanna; Lee, Kenneth W; Esch, Robert E; Farmaki, Rania; Koutinas, Alexander F

2008-04-01

104

Vacuum cleaning decreases the levels of mite allergens in house dust.  

PubMed

To investigate the capacity of chemical treatment of surfaces and the difference in capacity among common vacuum cleaners to reduce mite allergen content in house dust, we recruited 52 families with allergic children. Ten families used their central vacuum cleaners. Forty-two families were randomly divided into four groups with 10 or 11 families in each. These families used either new vacuum cleaners with either HEPA (High Efficiency Particulate Air) or micro-filters, or their own vacuum cleaners with either tannic acid or placebo. Dust samples were collected from carpets and upholstered furniture in the living rooms and from the mattresses of the children at Days 0, 7, 21, and 35. Der pI and Der fI allergens were determined by sandwich ELISA. After one week, tannic acid reduced the concentration of mite allergens/g of dust and the total amount/sampling area by 30% and 34%, respectively (p < 0.05), but there was no significant decrease in relation to placebo. After 5 weeks, central, HEPA- and micro-filter vacuum cleaners decreased the mite allergen concentration by 10-50% (p < 0.05) and the total amount of mite allergen from the investigated areas by 50-85% (p < 0.01). In relation to the placebo group the decrease was significant for HEPA- and micro-filter vacuums (p < 0.05). The total amount of mite allergens/sampling area was more significantly (p < 0.05) reduced than the concentration/g of dust. We conclude, that tannic acid reduces mite allergen concentrations in dust and total amount/sampling area for a short period of time.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8220802

Munir, A K; Einarsson, R; Dreborg, S K

1993-08-01

105

Exposure to house dust phthalates in relation to asthma and allergies in both children and adults.  

PubMed

Although an association between exposure to phthalates in house dust and childhood asthma or allergies has been reported in recent years, there have been no reports of these associations focusing on both adults and children. We aimed to investigate the relationships between phthalate levels in Japanese dwellings and the prevalence of asthma and allergies in both children and adult inhabitants in a cross-sectional study. The levels of seven phthalates in floor dust and multi-surface dust in 156 single-family homes were measured. According to a self-reported questionnaire, the prevalence of bronchial asthma, allergic rhinitis, allergic conjunctivitis, and atopic dermatitis in the 2 years preceding the study was 4.7%, 18.6%, 7.6%, and 10.3%, respectively. After evaluating the interaction effects of age and exposure categories with generalized liner mixed models, interaction effects were obtained for DiNP and bronchial asthma in adults (Pinteraction=0.028) and for DMP and allergic rhinitis in children (Pinteraction=0.015). Although not statistically significant, children had higher ORs of allergic rhinitis for DiNP, allergic conjunctivitis for DEHP, and atopic dermatitis for DiBP and BBzP than adults, and liner associations were observed (Ptrend<0.05). On the other hand, adults had a higher OR for atopic dermatitis and DEHP compared to children. No significant associations were found in phthalates levels collected from multi-surfaces. This study suggests that the levels of DMP, DEHP, DiBP, and BBzP in floor dust were associated with the prevalence of allergic rhinitis, conjunctivitis, and atopic dermatitis in children, and children are more vulnerable to phthalate exposure via household floor dust than are adults. The results from this study were shown by cross-sectional nature of the analyses and elaborate assessments for metabolism of phthalates were not considered. Further studies are needed to advance our understanding of phthalate toxicity. PMID:24704966

Ait Bamai, Yu; Shibata, Eiji; Saito, Ikue; Araki, Atsuko; Kanazawa, Ayako; Morimoto, Kanehisa; Nakayama, Kunio; Tanaka, Masatoshi; Takigawa, Tomoko; Yoshimura, Takesumi; Chikara, Hisao; Saijo, Yasuaki; Kishi, Reiko

2014-07-01

106

The Effectiveness of Acupuncture Compared to Loratadine in Patients Allergic to House Dust Mites  

PubMed Central

Background. The aim of this work was to evaluate the clinical effectiveness of acupuncture and its impact on the immune system in comparison to loratadine in the treatment of persistent allergic rhinitis caused by house dust mites. Methods. In this study, 24 patients suffering from persistent allergic rhinitis induced by house dust mites were treated either with acupuncture (n = 15) or with loratadine (n = 9). The evaluation of the data was based on the subjective and the objective rhinoconjunctivitis symptom scores, specific and total IgE, and interleukins (IL-4, IL-10, and IFN-?) as markers for the activity of Th1 or Th2 cells. Results. The treatments with acupuncture as well as with loratadine were considered effective in the patients' subjective assessment, whereby the effect of the acupuncture tended to be assessed as more persistent after the end of treatment. A change in the specific or the total IgE was not detectable in either group. The interleukin profile showed the tendency of an increasing IL-10 value in the acupuncture group. The results of the study show that the effectiveness of acupuncture is comparable to that of loratadine. Conclusion. Acupuncture is a clinically effective form of therapy in the treatment of patients suffering from persistent allergic rhinitis. The results indicate the probability of an immunomodulatory effect. PMID:24995021

Hauswald, Bettina; Dill, Christina; Boxberger, Jurgen; Kuhlisch, Eberhard; Zahnert, Thomas; Yarin, Yury M.

2014-01-01

107

House dust mite control measures in the management of asthma: meta-analysis  

PubMed Central

Objective To determine whether patients with asthma who are sensitive to mites benefit from measures designed to reduce their exposure to house dust mite antigen in the home. Design Meta-analysis of randomised trials that investigated the effects on asthma patients of chemical or physical measures to control mites, or both, in comparison with an untreated control group. All trials in any language were eligible for inclusion. Subjects Patients with bronchial asthma as diagnosed by a doctor and sensitisation to mites as determined by skin prick testing, bronchial provocation testing, or serum assays for specific IgE antibodies. Main outcome measures Number of patients whose allergic symptoms improved, improvement in asthma symptoms, improvement in peak expiratory flow rate. Outcomes measured on different scales were combined using the standardised effect size method (the difference in effect was divided by the standard deviation of the measurements). Results 23 studies were included in the meta-analysis; 6 studies used chemical methods to reduce exposure to mites, 13 used physical methods, and 4 used a combination. Altogether, 41/113 patients exposed to treatment interventions improved compared with 38/117 in the control groups (odds ratio 1.20, 95% confidence interval 0.66 to 2.18). The standardised mean difference for improvement in asthma symptoms was ?0.06 (95% confidence interval ?0.54 to 0.41). For peak flow rate measured in the morning the standardised mean difference was ?0.03 (?0.25 to 0.19). As measured in the original units this difference between the treatment and the control group corresponds to ?3?l/min (95% confidence interval ?25?l/min to 19?l/min). The results were similar in the subgroups of trials that reported successful reduction in exposure to mites or had long follow up times. Conclusion Current chemical and physical methods aimed at reducing exposure to allergens from house dust mites seem to be ineffective and cannot be recommended as prophylactic treatment for asthma patients sensitive to mites. Key messagesCurrent chemical and physical methods aimed at reducing exposure to allergens from house dust mites seem to be ineffective; these methods cannot be recommended as prophylactic treatment for asthma patients who are sensitive to mitesIt is unlikely that a worthwhile effect has been overlooked in this meta-analysis since the confidence interval for the peak expiratory flow rate was quite narrowFuture studies should be much larger and more rigorous than those in this meta-analysis and should evaluate other methods of mite control than those used to date PMID:9784442

G?tzsche, Peter C; Hammarquist, Cecilia; Burr, Michael

1998-01-01

108

40 CFR 745.226 - Certification of individuals and firms engaged in lead-based paint activities: target housing and...  

Code of Federal Regulations, 2013 CFR

...lead-based paint activities: target housing and child-occupied facilities. 745.226 ...POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Lead-Based Paint Activities § 745...lead-based paint activities: target housing and child-occupied facilities. (a)...

2013-07-01

109

40 CFR 745.226 - Certification of individuals and firms engaged in lead-based paint activities: target housing and...  

Code of Federal Regulations, 2011 CFR

...lead-based paint activities: target housing and child-occupied facilities. 745.226 ...POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Lead-Based Paint Activities § 745...lead-based paint activities: target housing and child-occupied facilities. (a)...

2011-07-01

110

Dose of house dust mite antigen (P1) inhaled by infants aged one month  

SciTech Connect

A survey of the habitats occupied by 12 infants of one month of age revealed that approximately 10% of their day was spent in conditions of potential exposure to the major (P1) allergen of the house dust mite, Dermatophagoides pteronyssinus. A respiratory pump which reproduced the minute ventilation of an infant was placed in representative infant habitats. The P1 allergen trapped by the filter in this pump was measured as an estimate of infants' allergen intake. Detectable P1 intake was only present when there was active air disturbance (bed making and vacuuming). The average P1 intake was approximately 3 ng P1/24 hours. Comparison of this P1 intake with that which sensitizes in other situations suggests that it is usually inadequate to sensitize infants.

Carswell, F.; Clark, J.; Robinson, P.; Platts-Mills, T.A.

1983-11-01

111

House dust mite allergen induces asthma via TLR4 triggering of airway structural cells  

PubMed Central

Barrier epithelial cells and airway dendritic cells (DC) make up the first line of defence against inhaled substances like house dust mite (HDM) allergen and endotoxin. We hypothesized that these cells need to communicate to cause allergic disease. Using irradiated chimeric mice, we demonstrate that TLR4 expression on radioresistant lung structural cells is required and sufficient for DC activation in the lung and for priming of effector T helper responses to HDM. TLR4 triggering on structural cells caused production of the innate proallergic cytokines thymic stromal lymphopoietin, granulocyte-macrophage colony stimulating factor, interleukin-25 and IL-33. The absence of TLR4 on structural cells, but not on hematopoietic cells, abolished HDM driven allergic airway inflammation. Finally, inhalation of a TLR4 antagonist to target exposed epithelial cells suppressed the salient features of asthma including bronchial hyperreactivity. Our data identify an innate immune function of airway epithelial cells that drives allergic inflammation via activation of mucosal DCs. PMID:19330007

HAMMAD, Hamida; CHIEPPA, Marcello; PERROS, Frederic; WILLART, Monique A.; GERMAIN, Ronald N.; LAMBRECHT, Bart N.

2009-01-01

112

Molecular Determinants for Antibody Binding on Group 1 House Dust Mite Allergens  

SciTech Connect

House dust mites produce potent allergens, Der p 1 and Der f 1, that cause allergic sensitization and asthma. Der p 1 and Der f 1 are cysteine proteases that elicit IgE responses in 80% of mite-allergic subjects and have proinflammatory properties. Their antigenic structure is unknown. Here, we present crystal structures of natural Der p 1 and Der f 1 in complex with a monoclonal antibody, 4C1, which binds to a unique cross-reactive epitope on both allergens associated with IgE recognition. The 4C1 epitope is formed by almost identical amino acid sequences and contact residues. Mutations of the contact residues abrogate mAb 4C1 binding and reduce IgE antibody binding. These surface-exposed residues are molecular targets that can be exploited for development of recombinant allergen vaccines.

Chruszcz, Maksymilian; Pomés, Anna; Glesner, Jill; Vailes, Lisa D.; Osinski, Tomasz; Porebski, Przemyslaw J.; Majorek, Karolina A.; Heymann, Peter W.; Platts-Mills, Thomas A.E.; Minor, Wladek; Chapman, Martin D. (INDOOR Bio.); (UV); (UVHS)

2012-07-11

113

Pesticides in house dust from urban and farmworker households in California: an observational measurement study  

PubMed Central

Background Studies report that residential use of pesticides in low-income homes is common because of poor housing conditions and pest infestations; however, exposure data on contemporary-use pesticides in low-income households is limited. We conducted a study in low-income homes from urban and agricultural communities to: characterize and compare house dust levels of agricultural and residential-use pesticides; evaluate the correlation of pesticide concentrations in samples collected several days apart; examine whether concentrations of pesticides phased-out for residential uses, but still used in agriculture (i.e., chlorpyrifos and diazinon) have declined in homes in the agricultural community; and estimate resident children's pesticide exposures via inadvertent dust ingestion. Methods In 2006, we collected up to two dust samples 5-8 days apart from each of 13 urban homes in Oakland, California and 15 farmworker homes in Salinas, California, an agricultural community (54 samples total). We measured 22 insecticides including organophosphates (chlorpyrifos, diazinon, diazinon-oxon, malathion, methidathion, methyl parathion, phorate, and tetrachlorvinphos) and pyrethroids (allethrin-two isomers, bifenthrin, cypermethrin-four isomers, deltamethrin, esfenvalerate, imiprothrin, permethrin-two isomers, prallethrin, and sumithrin), one phthalate herbicide (chlorthal-dimethyl), one dicarboximide fungicide (iprodione), and one pesticide synergist (piperonyl butoxide). Results More than half of the households reported applying pesticides indoors. Analytes frequently detected in both locations included chlorpyrifos, diazinon, permethrin, allethrin, cypermethrin, and piperonyl butoxide; no differences in concentrations or loadings were observed between locations for these analytes. Chlorthal-dimethyl was detected solely in farmworker homes, suggesting contamination due to regional agricultural use. Concentrations in samples collected 5-8 days apart in the same home were strongly correlated for the majority of the frequently detected analytes (Spearman ? = 0.70-1.00, p < 0.01). Additionally, diazinon and chlorpyrifos concentrations in Salinas farmworker homes were 40-80% lower than concentrations reported in samples from Salinas farmworker homes studied between 2000-2002, suggesting a temporal reduction after their residential phase-out. Finally, estimated non-dietary pesticide intake for resident children did not exceed current U.S. Environmental Protection Agency's (U.S. EPA) recommended chronic reference doses (RfDs). Conclusion Low-income children are potentially exposed to a mixture of pesticides as a result of poorer housing quality. Historical or current pesticide use indoors is likely to contribute to ongoing exposures. Agricultural pesticide use may also contribute to additional exposures to some pesticides in rural areas. Although children's non-dietary intake did not exceed U.S. EPA RfDs for select pesticides, this does not ensure that children are free of any health risks as RfDs have their own limitations, and the children may be exposed indoors via other pathways. The frequent pesticide use reported and high detection of several home-use pesticides in house dust suggests that families would benefit from integrated pest management strategies to control pests and minimize current and future exposures. PMID:21410986

2011-01-01

114

Utilizing Pyrosequencing and Quantitative PCR to Characterize Fungal Populations among House Dust Samples  

PubMed Central

Molecular techniques are replacing culturing and counting methods in quantifying indoor fungal contamination. Pyrosequencing offers the possibility of identifying unexpected indoor fungi. In this study, 50 house dust samples were collected from homes in the Yakima Valley, WA. Each sample was analyzed by quantitative PCR (QPCR) for 36 common fungi and by fungal tag-encoded flexible (FLX) amplicon pyrosequencing (fTEFAP) for these and additional fungi. Only 24 of the samples yielded amplified results using fTEFAP but QPCR successfully amplified all 50 samples. Over 450 fungal species were detected by fTEFAP but most were rare. Twenty-two fungi were found by fTEFAP to occur with at least an average of ? 0.5% relative occurrence. Many of these fungi seem to be associated with plants, soil or human skin. Combining fTEFAP and QPCR can enhance studies of fungal contamination in homes. PMID:22767010

Nonnenmann, Matthew W.; Coronado, Gloria; Thompson, Beti; Griffith, William C.; Hanson, John Delton; Vesper, Stephen; Faustman, Elaine M.

2014-01-01

115

Progress in the development of specific immunotherapies for house dust mite allergies.  

PubMed

Allergen-specific immunotherapy is used to treat patients exposed and co-sensitized to the two common house dust mites, Dermatophagoides pteronyssinus and Dermatophagoides farinae. Based on seroepidemiological studies and a detailed characterization of mite allergens, an optimal immunotherapeutic product should associate extracts from the two Dermatophagoides species, and include both bodies and fecal particles. Both subcutaneous and sublingual immunotherapies performed with aqueous mite extracts are safe and efficacious in children and adults with mite-induced rhinitis and/or asthma. Double-blind placebo-controlled studies are conducted to further document the efficacy of immunotherapeutic products, with promising results that were obtained already with sublingual tablets. Current developments of second-generation products relying upon recombinant allergens and peptides are reviewed. PMID:25187166

Moingeon, Philippe

2014-12-01

116

Lead (Pb) in old Antarctic ice: Some from dust, some from other sources  

USGS Publications Warehouse

Recently published data on amounts and isotopic compositions of lead (Pb) and on amounts of mineral dust in pre-industrial Antarctic ice can be further interpreted by means of simple calculations. These show that two distinct types of Pb were provided by the atmosphere to the continent in varying proportions during Pleistocene and Holocene time. One type of Pb is that contained in the mineral lattices of dust. It has non-radiogenic isotopic proportions. The other type of Pb is not associated with dust minerals, is more radiogenic, and is consistent with an origin in emissions from ocean island volcanoes worldwide, or from some Antarctic volcanoes.

Hinkley, T.

2007-01-01

117

Duration of exposure--histological effects on broiler lungs, performance, and house environment with Mt. St. Helens volcanic ash dust  

Microsoft Academic Search

Fourteen hundred broilers were exposed to Mt. St. Helens volcanic ash (VA) dust (D) from 28 to 49 days of age to correlate the duration of exposure time to histological effect on lungs and to determine the effects on broiler performance and house environment. Histological examinations of the lungs from birds exposed each day for 4 days to either VAD

M. C. Bland; H. S. Nakaue; M. P. Goeger; D. H. Helfer

1985-01-01

118

Antioxidant Enzymatic Activities in Human Blood Cells after an Allergic Reaction to Pollen or House Dust Mite  

Microsoft Academic Search

Several diseases have been related to oxidative stress. Recently, antioxidant functions have also been linked to anti-inflammatory properties. Cell defenses against reactive oxygen species include antioxidant enzymes. We studied the enzymatic antioxidant capacity in human blood of both red blood and mononuclear cells from patients suffering from an allergic reaction to pollen or house dust mite. We determined superoxide dismutases

José M. Matés; José M. Segura; Cristina Pérez-Gómez; Rafael Rosado; Lucia Olalla; Miguel Blanca; Francisca M. Sánchez-Jiménez

119

Antioxidant Enzymatic Activities in Human Blood Cells after an Allergic Reaction to Pollen or House Dust Mite  

Microsoft Academic Search

ABSTRACT: Several diseases have been related to oxidative stress. Recently, antioxidant functions have also been linked to anti-inflammatory properties. Cell defenses against reactive oxygen species include antioxidant enzymes. We studied the enzymatic antioxidant capacity in human blood of both red blood and mononuclear cells from patients suffering from an allergic reaction to pollen or house dust mite. We determined superoxide

José M. Matés; José M. Segura; Cristina Pérez-Gómez; Rafael Rosado; Lucia Olalla; Miguel Blanca; Francisca M. Sánchez-Jiménez

1999-01-01

120

Comparison of the Allergic Responses Induced by PeniciIlium chrysogenum and House Dust Mite Extracts in a Mouse Model  

EPA Science Inventory

A report by the Institute of Medicine suggested that more research is needed to better understand mold effects on allergic disease, particularly asthma development. We compared the ability of the fungal Penicillium chrysogenum (PCE) and house dust mite (HDM) extracts to induce al...

121

Acaricidal activities against house dust mites of spearmint oil and its constituents.  

PubMed

The aim of this study was to evaluate the acaricidal activities of spearmint oil and carvone derivatives against house dust mites using contact and fumigant toxicity bioassays to replace benzyl benzoate as a synthetic acaricide. Based on the LD50 values, the contact toxicity bioassay revealed that dihydrocarvone (0.95 and 0.88?µg/cm2) was 7.7 and 6.8 times more toxic than benzyl benzoate (7.33 and 6.01?µg/cm2) against Dermatophagoides farinae and Dermatophagoides pteronyssinus, respectively, followed by carvone (3.78 and 3.23?µg/cm2), spearmint oil (5.16 and 4.64?µg/cm2), carveol (6.00 and 5.80?µg/cm2), and dihydrocarveol (8.23 and 7.10?µg/cm2). Results of the fumigant toxicity bioassay showed that dihydrocarvone (2.73 and 2.16?µg/cm2) was approximately 4.0 and 4.8 times more effective than benzyl benzoate (11.00 and 10.27?µg/cm2), followed by carvone (6.63 and 5.78?µg/cm2), carveol (7.58 and 7.24?µg/cm2), spearmint oil (9.55 and 8.10?µg/cm2), and dihydrocarveol (9.79 and 8.14?µg/cm2). Taken together, spearmint oil and carvone derivatives are a likely viable alternative to synthetic acaricides for managing house dust mites. PMID:24488719

Yang, Ji-Yeon; Kim, Min-Gi; Lee, Sung-Eun; Lee, Hoi-Seon

2014-02-01

122

Effectiveness of education for control of house dust mites and cockroaches in Seoul, Korea  

PubMed Central

We evaluated the efficacy of health education in reducing indoor arthropod allergens in Seoul. The mite control measures comprised the use of mite-proof mattress and pillow coverings, regular washing of potentially infested materials, maintenance of a low humidity, removal of carpets, and frequent vacuum cleaning. Cockroach control measures included trapping, application of insecticides, and protecting food. Of 201 homes enrolled in October 1999, 63 volunteers were included in a 2-year follow-up survey between April 2000 and January 2002. Before intervention, the density of mites/g of dust varied greatly; 27.1/g in children's bedding, 20/g in adult bedding, 7.2/g on the floors of children's bedrooms, 6.8/g in sofas, 5.9/g on the floors of adult's bedrooms, 3.9/g on living room floors, 3.7/g in carpets, and 1.9 mites/g on kitchen floors. The predominant mite species and house percentages infested were; Dermatophagoides farinae 93%, D. pteronyssinus 9%, and Tyrophagus putrescentiae 8%. Comparing 1999 and 2001 infestations, before and after 25 mo of education, mite abundance was reduced by 98%, from 23.7 to 0.57 mites/g of dust. In 1999, cockroaches were detected in 62% homes: 36% Blattella germanica and 35% Periplaneta spp., including 9% double infestations of B. germanica and P. americana. Following intervention, cockroach infestation rates decreased to 22% of houses in 2000 and 23% in 2001. We conclude that continuous and repetitive health education resulted in the effective control of domestic arthropods. PMID:16514286

Jeong, Kyoung Yong; Lee, In-Yong; Lee, Jongweon; Ree, Han-Il; Hong, Chein-Soo

2006-01-01

123

VIEASURING THE AMOUNT OF LEAD IN IN DOOR DUST: LONG-TERI DUSTFALL ACCUMULATION IN PETRI DISHES (A PILOT STUDY)  

Microsoft Academic Search

ead from dust is potentially the major contributor to blood lead levels in children living in urban environments in Australia' and is likely to make a substantial contribution to blood lead levels of children living in the vicinity of lead smelters. We undertook a trial of measuring dust in petri dishes to estimate the long-term flux of lead in indoor

John Wlodarczyk; Ruth Toneguzzi; Charles Gruszynski

124

ETHAN'S HOUSE GETS HEALTHIER  

E-print Network

separate. Wash toys, bottles and pacifiers regularly to remove lead dust and soil. Regularly wash childrenETHAN'S HOUSE GETS HEALTHIER WithaVisitfromthe LeadPoisoningPreventionTeam #12;http://www.cdc.gov/nceh/lead Prevent Lead Poisoning U.S. Department of Health and Human Services Centers for Disease Control

125

Health and housing collaboration at LAST: the Philadelphia Lead Abatement Strike Team.  

PubMed Central

The Lead Abatement Strike Team (LAST) was developed in 2002 by the Philadelphia Department of Public Health (PDPH) in response to community concern about management of children with elevated blood lead levels (EBLLs). Fourteen hundred backlog properties (housing at least one child with EBLLs) were identified through inspection as having housing-based lead hazards for which no satisfactory environmental remediation (control of lead hazards) had been achieved. In the first two years of LAST, 834 new housing cases also were identified. The heightened awareness of this problem, sparked in part by community advocacy efforts, led to the appropriation of 1.5 million dollars for environmental remediation. A collaborative group of health, housing, and other officials was convened. Enforcement for remediation of properties with lead hazards was strengthened with the development of the Lead Court, a special judicial court devoted exclusively to hearing cases where owners had violated local lead poisoning prevention laws. Identifying a group of Pennsylvania-certified lead abatement contractors, expanding the health department's abatement team, creating temporary relocation capacity, and providing funding for basic housing system repair work were crucial to obtaining rapid remediation of homes. In the first two years of the LAST program, 1,037 properties (both backlog and new properties) that housed 1,476 children were remediated, representing a significant increase in remediation capacity. PMID:16134560

Campbell, Carla; Himmelsbach, Robert; Palermo, Peter; Tobin, Richard

2005-01-01

126

Tracing geogenic and anthropogenic sources in urban dusts: Insights from lead isotopes  

NASA Astrophysics Data System (ADS)

Tracing the source of metals in the environment is critical to understanding their pollution level and fate. Geologic materials are an important source of airborne particulate matter, but the contribution of contaminated soil to concentrations of Pb in airborne dust is not yet widely documented. To examine the potential significance of this mechanism, surface soil samples were collected, as well as wind-transported dust trapped at 1 and 2 m height at seven different locations including residential, industrial, high-traffic and rural sites. Samples of dust deposited on roofs from 24 schools were also obtained and analyzed for Pb isotope ratios. Spatial distribution of Pb of airborne and sedimented dust suggests a process dominated by re-suspension/sedimentation, which was controlled by erosion, traffic and topography of the urban area. Anthropogenic lead input in the city grades outward the urban zone toward geogenic values. Our results shows that Pb-isotopic signatures of leaded gasoline are imprinted in dust sedimented on roofs. Considering that leaded-gasoline has not been in use in Mexico since two decades ago, this signature shows not only a Pb-legacy in soil, but also a re-suspension process affecting air column below 3 m in height. The combination of the 207Pb/206Pb data of the surrounding rocks and urban dust, reveal three well-defined zones with remarkable anthropogenic influence, which correspond to the oldest urban sectors. This work highlights the importance of spatial characterization of metals in particles suspended below a height of 3 m of the airborne column, a fact that should be considered to identify exposure paths to humans and the potential risks. Lead isotope signatures allowed the identification of geogenic and anthropogenic emission sources for dust, a matter that deserves consideration in the efforts to control airborne metal emissions.

Del Rio-Salas, R.; Ruiz, J.; De la O-Villanueva, M.; Valencia-Moreno, M.; Moreno-Rodríguez, V.; Gómez-Alvarez, A.; Grijalva, T.; Mendivil, H.; Paz-Moreno, F.; Meza-Figueroa, D.

2012-12-01

127

111 Taxonomic Identification of the House Dust Mites Associated to Allergic Patients in 6 Locations From Mexico  

PubMed Central

Background Taxonomic research on house dust mites carried out by acarologists doesn't exist in Mexico since 1991. However, the allergologists should know the sources of allergens present in their country. A survey of dust samples from 6 locations was made in Mexico to determine the diversity of indoor acarofauna. Methods All the samples of dust (1 g each) were collected with vacuum cleaners from mattresses of allergic patients from 10 georeferenced houses in each of 6 localities (3 coastal and 3 continental) from Mexico during February 2010 and May 2011. The mites were isolated by the sedimentation flotation method Spieskma-Boezeman 1967. All the identified material was deposited in a Basic Collection from Rocel Laboratories in Puebla and in the National Collection of Acarology from the Institute of Biology, UNAM, Mexico. Results Eleven mite species were found of which the most important were house dust mites, specially: Dermatophagoides pteronyssinus (Trouessart, 1897) and Dermatophagoides farinae Hughes, 1961. Both species were reported for the first time for the 6 localities under study. Dermatophagoides siboney Dusbabek, Cuervo and Cruz, 1982 is a vicariant species of D. farinae and was registered for the first time for Mexico in Ciudad del Carmen, Campeche, but we consider this result should be corroborated in future studies. Blomia tropicalis (Bronswijk, Cook and Oshima, 1973) was also registered for the first time for Mexico in 3 of the 6 Mexican localities and it has a tropical distribution. This last species has been used in Mexico for skin tests and this result favours its use for diagnosis and inmunotherapy. Conclusions This survey revealed the existence of house dust mites in Mexico. It seems there are differences between the geographical distribution of the species because of the local conditions of temperature and humidity of each urban ecosystem. This knowledge may be useful in the field of allergy medicine.

Cuervo, Naomi; Fernandez, Barbara; Rodriguez, Jesus; Murillo, Celio; Perez, Tila M.; Juarez, Daniel

2012-01-01

128

Environmental endotoxin measurement: interference and sources of variation in the Limulus assay of house dust.  

PubMed

Studies suggest that endotoxin levels in offices and homes may be associated with sick building syndrome or increased asthma severity. However, reported endotoxin levels in these studies were highly inconsistent, suggesting incompatible measurements from various laboratories. Therefore, an investigation of Limulus assay for endotoxin in house dust was undertaken. Interference with the assay was common and could produce endotoxin estimates varying by a factor of > 100, depending on the dilution used. Analysis of dose-response curves allowed detection of two types of interference: dilution-dependent and dilution-independent. Dilution-dependent interference persisted when samples were reassayed, but valid estimates could be obtained by appropriate dilution and data analysis. Valid estimates could not be obtained from assay showing dilution-independent interference. However, dilution-independent interference was frequently overcome by repeating the assay. Estimates based on a single sample dilution produced reasonable results on average when a dilution factor of 900 was used. However, the results were less precise from a single dilution (median coefficient of variation [CV] 40%) than from the complete dose-response curve (median CV 23%) and ranged from 11 to 240% of the estimates based on complete dose-response data. A comparison of extraction methods found that sonication in a phosphate-triethylamine buffer produced greater endotoxin activity than extraction in buffer with addition of saponin or sodium dodecyl sulfate. Endotoxin activity was stable for 8 to 10 weeks in dust samples stored at 4 and -20 degrees C but was not stable in extracts. The lot of Limulus amebocyte lysate reagent and method of detecting a response in the kinetic Limulus assay had significant effects on endotoxin estimates. PMID:9425646

Milton, D K; Johnson, D K; Park, J H

1997-12-01

129

Importance of house dust and storage mites in canine atopic dermatitis in the geographic region of Galicia, Spain.  

PubMed

Sensitisation to mites is frequent in atopic dogs. The main mite genus involved in canine atopic dermatitis is Dermatophagoides. The importance of storage mite allergens in dogs has been controversial. The aim of this study was to evaluate the sensitisation rates against storage mites (Lepidoglyphus destructor and Tyrophagus putrescentiae) and house dust mites (Dermatophagoides farinae and D. pteronyssinus) in atopic dogs from Galicia, a highly humid and temperate region of Spain, using a FcepsilonRIalpha-based immunoglobulin E (IgE) in vitro test. The study was performed on 95 dogs suffering from atopic dermatitis and presenting detectable specific serum IgE levels: 91.6% of the dogs tested positive for storage mites, whereas sensitisation to house dust mites was detected in 87.4%. These results indicate the importance of storage mites in this specific geographic area. PMID:18669243

Goicoa, Ana; Espino, Luciano; Rodriguez, Isabel; Puigdemont, Anna; Brazis, Pilar; Rejas, Juan

2008-06-01

130

Acaricidal activities of some essential oils and their monoterpenoidal constituents against house dust mite, Dermatophagoides pteronyssinus (Acari: Pyroglyphidae)  

PubMed Central

The acaricidal activities of fourteen essential oils and fourteen of their major monoterpenoids were tested against house dust mites Dermatophagoides pteronyssinus. Five concentrations were used over two different time intervals 24 and 48 h under laboratory conditions. In general, it was noticed that the acaricidal effect based on LC 50 of either essential oils or monoterpenoids against the mite was time dependant. The LC 50 values were decreased by increasing of exposure time. Clove, matrecary, chenopodium, rosemary, eucalyptus and caraway oils were shown to have high activity. As for the monoterpenoids, cinnamaldehyde and chlorothymol were found to be the most effective followed by citronellol. This study suggests the use of the essential oils and their major constituents as ecofriendly biodegradable agents for the control of house dust mite, D. pteronyssinus. PMID:17111463

Saad, El-Zemity; Hussien, Rezk; Saher, Farok; Ahmed, Zaitoon

2006-01-01

131

IN-HOUSE COPPER AND LEAD SOLUBILITY/CORROSION STUDIES  

EPA Science Inventory

Understanding and predicting metal release from pipes of all sizes and types from the treatment plant to the consumer?s tap is critical, specifically for regulatory compliance with the Lead and Copper Rule, as well as the performance, corrosion morphology, and longevity of infras...

132

Orchestration of an Uncommon Maturation Cascade of the House Dust Mite Protease Allergen Quartet  

PubMed Central

In more than 20% of the world population, sensitization to house dust mite allergens triggers typical allergic diseases such as allergic rhinitis and asthma. Amongst the 23 mite allergen groups hitherto identified, group 1 is cysteine proteases belonging to the papain-like family whereas groups 3, 6, and 9 are serine proteases displaying trypsin, chymotrypsin, and collagenolytic activities, respectively. While these proteases are more likely to be involved in the mite digestive system, they also play critical roles in the initiation and in the chronicity of the allergic response notably through the activation of innate immune pathways. All these allergenic proteases are expressed in mite as inactive precursor form. Until recently, the exact mechanisms of their maturation into active proteases remained to be fully elucidated. Recent breakthroughs in the understanding of the activation mechanisms of mite allergenic protease precursors have highlighted an uncommon and unique maturation pathway orchestrated by group 1 proteases that tightly regulates the proteolytic activities of groups 1, 3, 6, and 9 through complex intra- or inter-molecular mechanisms. This review presents and discusses the currently available knowledge of the activation mechanisms of group 1, 3, 6, and 9 allergens of Dermatophagoides pteronyssinus laying special emphasis on their localization, regulation, and interconnection. PMID:24744761

Dumez, Marie-Eve; Herman, Julie; Campizi, Vincenzo; Galleni, Moreno; Jacquet, Alain; Chevigne, Andy

2014-01-01

133

House Dust Mite Induced Lung Inflammation Does Not Alter Circulating Vitamin D Levels  

PubMed Central

Low circulating levels of 25-hydroxyvitamin D [25(OH)D] are associated with chronic lung diseases such as asthma. However, it is unclear whether vitamin D is involved in disease pathogenesis or is modified by the inflammation associated with the disease process. We hypothesized that allergic inflammation decreases the level of circulating 25(OH)D and tested this using a mice model of house dust mite (HDM) induced allergic airway inflammation. Cellular influx was measured in bronchoalvelar lavage (BAL) fluid, and allergic sensitization and 25(OH)D levels were measured in serum. Exposure to HDM caused a robust inflammatory response in the lung that was enhanced by prior influenza infection. These responses were not associated with any change in circulating levels of 25(OH)D. These data suggest that alterations in circulating 25(OH)D levels induced by Th-2 driven inflammation are unlikely to explain the cross-sectional epidemiological association between vitamin D deficiency and asthma. PMID:25391140

Chen, Ling; Perks, Kara L.; Stick, Stephen M.; Kicic, Anthony; Larcombe, Alexander N.; Zosky, Graeme

2014-01-01

134

Effective hyposensitization in allergic rhinitis using a potent partially purified extract of house dust mite.  

PubMed

Thirty-eight adults with allergic rhinitis have been treated with a new partially purified extract of house dust mite (Dermatophagoides pteronyssinus) in a double-blind placebo-controlled trial. Patients were randomized to active (Pharmalgen, D. pteronyssinus) and placebo (histamine) treatment by sensitivity to D. pteronyssinus on nasal challenge. In the actively treated group nasal symptoms, assessed by visual analogue score, improved (P less than 0.01), sensitivity on nasal challenge with allergen was reduced (P less than 0.05) and weal size on skin-prick test with allergen was reduced (P less than 0.01), compared with the placebo group. These results occurred after 3 months of treatment. Reduction in target organ sensitivity occurred, while the serum level of D. pteronyssinus IgE rose in the active group from 14.2 to 22.5 PRU/ml (geometric mean) but did not change significantly in the placebo group. As anticipated, because of the treatment schedule used, a number of generalized allergic reactions were induced by injections, but all responded promptly and easily to treatment. These results suggest this is an effective form of therapy, which now offers us the opportunity to study the immunological mechanisms of hyposensitization and to devise a modified schedule causing fewer reactions. PMID:3069238

Ewan, P W; Alexander, M M; Snape, C; Ind, P W; Agrell, B; Dreborg, S

1988-09-01

135

House Dust Mite Der p 1 Effects on Sinonasal Epithelial Tight Junctions  

PubMed Central

Background Epithelial permeability is highly dependent upon the integrity of tight junctions, cell-cell adhesion complexes located at the apical aspect of the lateral membrane of polarized epithelial cells. We hypothesize that sinonasal epithelial exposure to Der p 1 house dust mite antigen decreases expression of tight junction proteins (TJPs), representing a potential mechanism for increased permeability and presentation of antigens across the sinonasal epithelial layer. Methods Confluent cultured primary human sinonasal epithelial cells were exposed to recombinant Der p 1 antigen versus control, and transepithelial resistance measurements were performed over 24 hours. Antibody staining for a panel of tight junction proteins was examined with immunofluorescence/confocal microscopy and Western blotting. Tissue for these experiments was obtained from 4 patients total. Results Der p 1 exposed sinonasal cells showed a marked decrease in transepithelial resistance when compared to control cells. In addition, results of Western immunoblot and immunofluorescent labeling demonstrated decreased expression of TJPs claudin-1 and junction adhesion molecule-A (JAM-A) in Der p 1 exposed cultured sinonasal cells versus controls. Conclusion Der p 1 antigen exposure decreases sinonasal epithelium TJP expression, most notably seen in JAM-A and claudin-1 in these preliminary experiments. This decreased TJP expression likely contributes to increased epithelial permeability and represents a potential mechanism for transepithelial antigen exposure in allergic rhinitis. PMID:23592402

Henriquez, Oswaldo A.; Beste, Kyle Den; Hoddeson, Elizabeth K.; Parkos, Charles A.; Nusrat, Asma; Wise, Sarah K.

2013-01-01

136

A milestone in house dust-mite-allergen immunotherapy: the new sublingual tablet S-524101 (actair).  

PubMed

Subcutaneous allergen-specific immunotherapy has long been used in the treatment of allergic rhinitis and/or asthma and its efficacy has been confirmed. However, due to the discomfort of injections and the risk of severe adverse reactions, alternative routes of allergen administration have emerged. Delivery of allergens through the mucosal route had been proposed and investigated thoroughly, confirming the sublingual route to be the most efficacious. Later, the efficacy and safety of this route have been documented by numerous controlled trials both for house dust mite (HDM) and pollens. Recently, sublingual orodispersable grass pollen allergen tablets were in use followed by the newly developed HDM allergen tablets with satisfactory clinical results: Moreover, very recently 1 year of HDM tablet treatment was demonstrated to exert its clinical efficacy 1 year after discontinuation of tablet IT. The persistence of efficacy after only 1 year of treatment is a new and promising era. Currently, Sublingual Immunotherapy is the most easily administered and safe treatment option until more immunogenic, less allergenic and more efficient allergen extracts are developed. PMID:25345538

Bahceciler, Nerin N; Babayigit Hocaoglu, Arzu; Galip, Nilufer

2014-12-01

137

Lyn mitigates mouse airway remodeling by downregulating the TGF-?3 isoform in house dust mite models.  

PubMed

Chronic airway remodeling is a serious consequence of asthma, which is caused by complex but largely unknown mechanisms. Despite versatile functions, the role of Lyn in chronic airway remodeling remains undefined. Using Lyn(-/-) mice, we show that continual exposure (for 8 wk) of house dust mite extracts induced a severe phenotype of chronic airway remodeling, including exacerbated mucus production, collagen deposition, dysregulated cytokine secretion, and elevated inflammation. Strikingly, a significant increase in TGF-?3 rather than TGF-?1 was observed in Lyn(-/-) mouse lungs compared with lungs in wild-type mice. Furthermore, TGF-?3 neutralizing Abs not only inhibited the expression of STAT6 and Smad2/3 but also decreased phosphorylation of Smad2 and NF-?B in Lyn(-/-) mouse lungs. In addition, both recombinant and adenoviral TGF-?3 significantly promoted epithelial-to-mesenchymal transition and intensified collagen I production and MUC5AC expression. Further examination of chronic asthma patients showed that a decreased Lyn correlated with the severity of airway inflammation and mucus hypersecretion. Finally, Lyn may critically regulate airway remodeling by directly interacting with TGF-?3. Collectively, these findings revealed that Lyn regulates TGF-?3 isoform and modulates the development of airway remodeling, which may have therapeutic implications for severe chronic asthma. PMID:24127553

Li, Guoping; Fox, John; Liu, Zhigang; Liu, Jun; Gao, George F; Jin, Yang; Gao, Hongwei; Wu, Min

2013-12-01

138

A house dust mite allergen homologue from poultry red mite Dermanyssus gallinae (De Geer).  

PubMed

Tropomyosin is an allergenic, actin-binding protein and a proposed vaccine candidate from several species of parasite. Tropomyosin cDNA, obtained by polymerase chain reaction (PCR) amplification from Dermanyssus gallinae RNA, encoded a predicted protein with 89% and 88% identity to tropomyosins from the ticks Boophilus microplus and Haemaphysalis longicornis, respectively, and 85% identity to the house dust mite (HDM) tropomyosin Der p 10. Mouse antibodies raised against HDM tropomyosin reacted with a band of 38 kDa on Western blots of D. gallinae extract, consistent with the molecular masses of acarine tropomyosins and the putative product of the cDNA encoding D. gallinae tropomyosin. When the same preparation of D. gallinae proteins was used in Western blots with serum from infested hens, the IgY component of the serum bound to a number of mite proteins, but not to tropomyosin, indicating that hens are not directly exposed to this allergen during a natural infestation. Immunolocalization of tropomyosin in mites indicated a ubiquitous distribution of the molecule in mite tissues. Immunolocalization and Western blotting also indicated that poultry red mites ingest host IgY. PMID:16879312

Nisbet, A J; Huntley, J F; Mackellar, A; Sparks, N; McDevitt, R

2006-08-01

139

Acaricidal activity of Cymbopogon citratus and Azadirachta indica against house dust mites  

PubMed Central

Objective To examine the acaricidal effects of the essential oil of Cymbopogon citratus leaf extract (lemongrass) and ethanolic Azadirachta indica leaf extract (neem) against house dust mites Dermatophagoides farinae (D. farinae) and Dermatophagoides pteronyssinus (D. pteronyssinus). Methods Twenty-five adults mites were placed onto treated filter paper that is soaked with plant extract and been tested at different concentrations (50.00%, 25.00%, 12.50%, 6.25% and 3.13%) and exposure times (24hrs, 48hrs, 72hrs and 96 hrs). All treatments were replicated 7 times, and the experiment repeated once. The topical and contact activities of the two herbs were investigated. Results Mortalities from lemongrass extract were higher than neem for both topical and contact activities. At 50 % concentration, both 24 hrs topical and contact exposures to lemongrass resulted in more than 91% mortalities for both species of mites. At the same concentration and exposure time, neem resulted in topical mortalities of 40.3% and 15.7% against D. pteronyssinus and D. farinae respectively; contact mortalities were 8.0% and 8.9% against the 2 mites, respectively. There was no difference in topical mortalities of D. pteronyssinus from exposure to concentrations of lemongrass and neem up to 12.50%; lemongrass was more effective than neem at the higher concentrations. Conclusions Generally, topical mortalities of D. farinae due to lemongrass are higher than that due to neem. Contact mortalities of lemongrass are always higher that neem against both species of mites. PMID:23569794

Hanifah, Azima Laili; Awang, Siti Hazar; Ming, Ho Tze; Abidin, Suhaili Zainal; Omar, Maizatul Hashima

2011-01-01

140

The University of Michigan Dioxin Exposure Study: estimating residential soil and house dust exposures to young children.  

PubMed

The University of Michigan Dioxin Exposure Study provides extensive data on elevated residential soil and house dust concentrations of polychlorinated dioxins and dibenzofurans (PCDD/Fs) and adult body burdens among residents near a chemical manufacturing plant in Midland, Michigan. Recent reports found no significant contribution of residential soil/dust concentrations to serum lipid PCDD/Fs in adults. Although child body burdens were not studied by the University of Michigan, internal dose modeling that incorporates recent findings on demonstrated shorter elimination half life of PCDD/Fs in children (1-2 year half life in children vs. ~7 years in older adults) can be applied to assess this important issue. The model examines children (ages 0-7 years) with background dietary intake and exposure to residential soils at selected concentrations (10, 100 and 1000 pg/g 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents, TEQ) using the congener patterns observed in Midland. Model predictions assuming 50th percentile TEQ uptake from soil/dust-related dermal and ingestion exposures indicate no measurable changes in serum lipid TEQ concentrations up to 1000 pg/g in soil/dust. Assuming 95th percentile uptake, the model shows no measurable serum lipid TEQ change up to 100 pg/g in soil/dust, but serum lipid TEQ levels rose ~2 pg/g at 1000 pg/g in soil/dust. Since the vast majority of soil/dust data were below 100 pg/g, Michigan children exposed to such soil/dust TEQ concentrations are not reasonably expected to exhibit measurable changes in serum lipid TEQ concentrations when compared to typical background dietary exposures. With adequate data, this approach can be applied to evaluate child dose and risk for other persistent chemicals. PMID:23351485

Paustenbach, Dennis J; Kerger, Brent D

2013-04-01

141

House dust exposure mediates gut microbiome Lactobacillus enrichment and airway immune defense against allergens and virus infection  

PubMed Central

Exposure to dogs in early infancy has been shown to reduce the risk of childhood allergic disease development, and dog ownership is associated with a distinct house dust microbial exposure. Here, we demonstrate, using murine models, that exposure of mice to dog-associated house dust protects against ovalbumin or cockroach allergen-mediated airway pathology. Protected animals exhibited significant reduction in the total number of airway T cells, down-regulation of Th2-related airway responses, as well as mucin secretion. Following dog-associated dust exposure, the cecal microbiome of protected animals was extensively restructured with significant enrichment of, amongst others, Lactobacillus johnsonii. Supplementation of wild-type animals with L. johnsonii protected them against both airway allergen challenge or infection with respiratory syncytial virus. L. johnsonii-mediated protection was associated with significant reductions in the total number and proportion of activated CD11c+/CD11b+ and CD11c+/CD8+ cells, as well as significantly reduced airway Th2 cytokine expression. Our results reveal that exposure to dog-associated household dust results in protection against airway allergen challenge and a distinct gastrointestinal microbiome composition. Moreover, the study identifies L. johnsonii as a pivotal species within the gastrointestinal tract capable of influencing adaptive immunity at remote mucosal surfaces in a manner that is protective against a variety of respiratory insults. PMID:24344318

Fujimura, Kei E.; Demoor, Tine; Rauch, Marcus; Faruqi, Ali A.; Jang, Sihyug; Johnson, Christine C.; Boushey, Homer A.; Zoratti, Edward; Ownby, Dennis; Lukacs, Nicholas W.; Lynch, Susan V.

2014-01-01

142

The Indoor Level of House Dust Mite Allergen Is Associated with Severity of Atopic Dermatitis in Children  

PubMed Central

We attempted to investigate the correlation between the severity of atopic dermatitis (AD) in children and the indoor level of house dust mite (HDM) allergens. Ninety-five patients (31.1 ± 19.5 months of age) with AD were enrolled in this study, and serum specific IgE against Dermatophagoides pteronyssinus and D. farinae was measured. The severity of AD was assessed using the visual analogue scale on the same day of house dust collection. Living rooms and mattresses where the child usually slept were vacuumed for 2 minutes and concentrations of Der f 1 were measured by enzyme-linked immunosorbent assay. The skin symptoms were more severe in patients with Der f 1 concentrations in living room > 2 µg/g dust than ? 2 µg/g dust (P = 0.018). This difference was noted in AD patients without sensitization to HDM (P = 0.004), but not in patients with sensitization. There was no difference in symptom severity according to Der f 1 concentrations in mattresses (P = 0.062). The severity of skin symptoms is associated with indoor concentrations of HDM in children with AD, and it is likely to act as nonspecific irritants as well as allergens in AD skin lesions. PMID:23341715

Kim, Jihyun; Lee, Sangwoon; Woo, Sook-young; Han, Youngshin; Lee, Jung Hyun; Lee, In-Yong; Lim, In-Seok; Choi, Eung-Sang; Choi, Byoung-Whi; Cheong, Hae-Kwan; Lee, Sang-Il

2013-01-01

143

After the PBDE Phase-Out: A Broad Suite of Flame Retardants in Repeat House Dust Samples from California  

PubMed Central

Higher house dust levels of PBDE flame retardants (FRs) have been reported in California than other parts of the world, due to the state’s furniture flammability standard. However, changing levels of these and other FRs have not been evaluated following the 2004 U.S. phase-out of PentaBDE and OctaBDE. We analyzed dust collected in 16 California homes in 2006 and again in 2011 for 62 FRs and organohalogens, which represents the broadest investigation of FRs in homes. Fifty-five compounds were detected in at least one sample; 41 in at least 50% of samples. Concentrations of chlorinated OPFRs, including two (TCEP and TDCIPP) listed as carcinogens under California’s Proposition 65, were found up to 0.01% in dust, higher than previously reported in the U.S. In 75% of the homes, we detected TDBPP, or brominated “Tris,” which was banned in children’s sleepwear because of carcinogenicity. To our knowledge, this is the first report on TDBPP in house dust. Concentrations of Firemaster 550 components (EH-TBB, BEH-TEBP, and TPHP) were higher in 2011 than 2006, consistent with its use as a PentaBDE replacement. Results highlight the evolving nature of FR exposures and suggest that manufacturers continue to use hazardous chemicals and replace chemicals of concern with chemicals with uncharacterized toxicity. PMID:23185960

2012-01-01

144

Lead dust in Broken Hill homes: Effect of remediation on indoor lead levels  

Microsoft Academic Search

This study was undertaken to determine whether home remediation effectively reduced indoor lead levels in Broken Hill, a long-established silver–lead–zinc mining town in outback Australia. A before–after study of the effect of home remediation on indoor lead levels was embedded into a randomized controlled trial of the effectiveness of remediation for reducing elevated blood lead levels in young children. Moist

F. Boreland; D. M. Lyle

2006-01-01

145

Reactivity to intradermal injections of extracts of house dust and housedust mite in healthy dogs and dogs suspected of being atopic.  

PubMed

Fifty dogs underwent intradermal allergy testing with housedust mite and house dust extracts, using concentrations recommended by the manufacturer. Twelve dogs (group I) were healthy dogs obtained from a pound; 12 dogs (group II) were healthy, privately owned dogs; 15 dogs (group III) were suspected of being atopic and had had multiple positive reactions to intradermal injections of allergens of specific trees, weeds, grasses, or molds; and 11 dogs (group IV) were suspected of being atopic, but only had had positive reactions to intradermal injections of housedust mite, house dust, and flea antigen extracts. Use of the concentrations of housedust mite and house dust extracts currently recommended for intradermal allergy testing resulted in false-positive reactions in 14 of 24 (58%) and 12 of 24 (50%) healthy dogs tested, respectively. Differences in number of dogs with positive reactions or grade of reaction to housedust mite or house dust allergens were not detected between groups of healthy dogs (groups I vs II), between groups of suspected atopic dogs (groups III vs IV), or between healthy dogs and dogs suspected of being atopic (groups I and II vs III and IV). Therefore, clinical importance of positive results of intradermal allergy testing of house dust or housedust mite allergens was equivocal for dogs suspected of being atopic. Threshold concentrations for intradermal allergy testing were determined in 24 healthy dogs (group I and II) by intradermal administration of 5 dilutions each of housedust mite extract and house dust extract.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7759333

Codner, E C; Tinker, M K

1995-03-15

146

IgE cross-reactivity between house dust mite allergens and Ascaris lumbricoides antigens  

PubMed Central

Background Common antigens between intestinal parasites and environmental allergens may play a role in the modulation of allergic immune responses. There is a growing interest in investigating cross-reactivity between common helminths and dust mites affecting humans, particularly in the tropics. Objective This study examined the cross-reactivity between the human roundworm Ascaris lumbricoides (Al) and three house dust mite (HDM) species. Methods Specific serum IgE levels to HDM species Blomia tropicalis (Bt), Dermatophagoides pteronyssinus (Dp), and Dermatophagoides farinae (Df ); and Al extracts among allergic (n=100) and ascariasis (n=60) subjects were measured through enzyme-linked immunosorbent assay (ELISA). IgE-reactive components of HDM and Al extracts were detected through Western-Blot Analysis. Cross-reactivity between HDMs and Al was determined by ELISA inhibition using HDM and Al-specific sera from allergic (n=15) and ascariasis (n=15) subjects. The IgE-binding capacity of a recombinant paramyosin peptide (Blo t 11-fD) to allergic (n=50) and ascariasis (n=50) subjects' sera were likewise determined. Results Among allergic subjects, 70% exhibited Al-specific positive IgE-reactivity, while 20-28% of ascariasis subjects demonstrated HDM-specific positive IgE-reactivity. Multiple IgE-reactive components of HDM allergens (14-240 kDa) and Al antigens (15-250 kDa) were detected, indicating multi-allergen sensitization among the subjects tested. Al antigens can inhibit up to 92% of HDM-specific IgE-reactivity among allergic subjects, while up to 54% of Al-specific IgE-reactivity among ascariasis subjects was inhibited by HDM allergens. Positive rBlo t 11-fD-specific IgE reactivity was observed in 80% of the allergic subjects and 46% of the ascariasis subjects. Conclusions This study showed the presence of multiple cross-reactive antigens in HDM and Al extracts. Identification of these molecules may provide basis for designing novel diagnostic and therapeutic strategies. The potential role of paramyosin as a specific cross-reactive allergen present in HDMs and Al has been shown. PMID:22348205

Cauyan, Gil A.; Ramos, John Donnie A.

2012-01-01

147

Isomer Profiles of Perfluorochemicals in Matched Maternal, Cord, and House Dust Samples: Manufacturing Sources and Transplacental Transfer  

PubMed Central

Background: Perfluorochemicals (PFCs) are detectable in the general population and in the human environment, including house dust. Sources are not well characterized, but isomer patterns should enable differentiation of historical and contemporary manufacturing sources. Isomer-specific maternal–fetal transfer of PFCs has not been examined despite known developmental toxicity of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in rodents. Objectives: We elucidated relative contributions of electrochemical (phased out in 2001) and telomer (contemporary) PFCs in dust and measured how transplacental transfer efficiency (TTE; based on a comparison of maternal and cord sera concentrations) is affected by perfluorinated chain length and isomer branching pattern. Methods: We analyzed matching samples of house dust (n = 18), maternal sera (n = 20), and umbilical cord sera (n = 20) by isomer-specific high-performance liquid chromatography tandem mass spectrometry. Results: PFOA isomer signatures revealed that telomer sources accounted for 0–95% of total PFOA in house dust (median, 31%). This may partly explain why serum PFOA concentrations are not declining in some countries despite the phase-out of electrochemical PFOA. TTE data indicate that total branched isomers crossed the placenta more efficiently than did linear isomers for both PFOS (p < 0.01) and PFOA (p = 0.02) and that placental transfer of branched isomers of PFOS increased as the branching point moved closer to the sulfonate (SO3–) end of the molecule. Conclusions: Results suggest that humans are exposed to telomer PFOA, but larger studies that also account for dietary sources should be conducted. The exposure profile of PFOS and PFOA isomers can differ between the mother and fetus—an important consideration for perinatal epidemiology studies of PFCs. PMID:21757419

Beesoon, Sanjay; Webster, Glenys M.; Shoeib, Mahiba; Harner, Tom; Benskin, Jonathan P.

2011-01-01

148

Lung Macrophages Contribute to House Dust Mite Driven Airway Remodeling via HIF-1?  

PubMed Central

HIF-1? is a transcription factor that is activated during hypoxia and inflammation and is a key regulator of angiogenesis in vivo. During the development of asthma, peribronchial angiogenesis is induced in response to aeroallergens and is thought to be an important feature of sustained chronic allergic inflammation. Recently, elevated HIF-1? levels have been demonstrated in both the lung tissue and bronchoalveolar lavage of allergic patients, respectively. Therefore, we investigated the role of HIF-1? on the development of angiogenesis and inflammation following acute and chronic allergen exposure. Our data shows that intranasal exposure to house dust mite (HDM) increases the expression of HIF-1? in the lung, whilst reducing the expression of the HIF-1? negative regulators, PHD1 and PHD3. Blockade of HIF-1? in vivo, significantly decreased allergic inflammation and eosinophilia induced by allergen, due to a reduction in the levels of IL-5 and Eotaxin-2. Importantly, HIF-1? blockade significantly decreased levels of VEGF-A and CXCL1 in the lungs, which in turn led to a profound decrease in the recruitment of endothelial progenitor cells and a reduction of peribronchial angiogenesis. Furthermore, HDM or IL-4 treatment of primary lung macrophages resulted in significant production of both VEGF-A and CXCL1; inhibition of HIF-1? activity abrogated the production of these factors via an up-regulation of PHD1 and PHD3. These findings suggest that novel strategies to reduce the expression and activation of HIF-1? in lung macrophages may be used to attenuate allergen-induced airway inflammation and angiogenesis through the modulation of VEGF-A and CXCL1 expression. Clinical Relevance This study provides new insights into the role of HIF-1? in the development of peribronchial angiogenesis and inflammation in a murine model of allergic airway disease. These findings indicate that strategies to reduce activation of macrophage derived HIF-1? may be used as a target to improve asthma pathology. PMID:23935964

Gowers, Kate; Rankin, Sara M.; Lloyd, Clare M.

2013-01-01

149

Peptidoglycan recognition protein 1 promotes house dust mite-induced airway inflammation in mice.  

PubMed

Peptidoglycan recognition protein (Pglyrp) 1 is a pattern-recognition protein that mediates antibacterial host defense. Because we had previously shown that Pglyrp1 expression is increased in the lungs of house dust mite (HDM)-challenged mice, we hypothesized that it might modulate the pathogenesis of asthma. Wild-type and Pglyrp1(-/-) mice on a BALB/c background received intranasal HDM or saline, 5 days/week for 3 weeks. HDM-challenged Pglyrp1(-/-) mice showed decreases in bronchoalveolar lavage fluid eosinophils and lymphocytes, serum IgE, and mucous cell metaplasia, whereas airway hyperresponsiveness was not changed when compared with wild-type mice. T helper type 2 (Th2) cytokines were reduced in the lungs of HDM-challenged Pglyrp1(-/-) mice, which reflected a decreased number of CD4(+) Th2 cells. There was also a reduction in C-C chemokines in bronchoalveolar lavage fluid and lung homogenates from HDM-challenged Pglyrp1(-/-) mice. Furthermore, secretion of CCL17, CCL22, and CCL24 by alveolar macrophages from HDM-challenged Pglyrp1(-/-) mice was markedly reduced. As both inflammatory cells and airway epithelial cells express Pglyrp1, bone marrow transplantation was performed to generate chimeric mice and assess which cell type promotes HDM-induced airway inflammation. Chimeric mice lacking Pglyrp1 on hematopoietic cells, not structural cells, showed a reduction in HDM-induced eosinophilic and lymphocytic airway inflammation. We conclude that Pglyrp1 expressed by hematopoietic cells, such as alveolar macrophages, mediates HDM-induced airway inflammation by up-regulating the production of C-C chemokines that recruit eosinophils and Th2 cells to the lung. This identifies a new family of innate immune response proteins that promotes HDM-induced airway inflammation in asthma. PMID:23808363

Yao, Xianglan; Gao, Meixia; Dai, Cuilian; Meyer, Katharine S; Chen, Jichun; Keeran, Karen J; Nugent, Gayle Z; Qu, Xuan; Yu, Zu-Xi; Dagur, Pradeep K; McCoy, J Philip; Levine, Stewart J

2013-12-01

150

Human apolipoprotein E genotypes differentially modify house dust mite-induced airway disease in mice.  

PubMed

Apolipoprotein E (apoE) is an endogenous negative regulator of airway hyperreactivity (AHR) and mucous cell metaplasia in experimental models of house dust mite (HDM)-induced airway disease. The gene encoding human apoE is polymorphic, with three common alleles (?2, ?3, and ?4) reflecting single amino acid substitutions at amino acids 112 and 158. The objective of this study was to assess whether the human apoE alleles modify airway responses to repeated nasal HDM challenges. Mice expressing the human apoE ?2 (huApoE2), ?3 (huApoE3), or ?4 (huApoE4) alleles received nasal HDM challenges, and airway responses were compared with mice expressing the endogenous murine apoE gene (muApoE). huApoE3 mice displayed significant reductions in AHR, mucous cell metaplasia, and airway inflammation compared with muApoE mice. The attenuated severity of airway inflammation in huApoE3 mice was associated with reductions in lung mRNA levels of Th2 and Th17 cytokines, as well as chemokines (CCL7, CCL11, CCL24). huApoE4 mice had an intermediate phenotype, with attenuated AHR and IgE production, compared with muApoE mice, whereas airway inflammation and mucous cell metaplasia were not reduced. In contrast, HDM-induced airway responses were not modified in mice expressing the huApoE2 allele. We conclude that the polymorphic huApoE alleles differentially modulate HDM-induced airway disease, which can be stratified, in rank order of increasing disease severity, ?3 < ?4 < ?2. These results raise the possibility that the polymorphic apoE alleles may modify disease severity in human asthma. PMID:22058162

Yao, Xianglan; Dai, Cuilian; Fredriksson, Karin; Lam, Jonathan; Gao, Meixia; Keeran, Karen J; Nugent, Gayle Zywicke; Qu, Xuan; Yu, Zu-Xi; Jeffries, Neal; Lin, JingPing; Kaler, Maryann; Shamburek, Robert; Costello, Rene; Csako, Gyorgy; Dahl, Morten; Nordestgaard, Břrge G; Remaley, Alan T; Levine, Stewart J

2012-01-15

151

Cigarette smoke differentially affects eosinophilia and remodeling in a model of house dust mite asthma.  

PubMed

Although a similar prevalence of smoking is evident among patients with asthma and the general population, little is known about the impact of cigarette smoke on the immune inflammatory processes elicited by common environmental allergens. We investigated the impact of exposure to cigarette smoke on house dust mite (HDM)-induced allergic airway inflammation and its consequences for tissue remodeling and lung physiology in mice. BALB/c mice received intranasal HDMs daily, 5 days per week, for 3 weeks to establish chronic airway inflammation. Subsequently, mice were concurrently exposed to HDMs plus cigarette smoke, 5 days per week, for 2 weeks (HDMs + smoke). We observed significantly attenuated eosinophilia in the bronchoalveolar lavage of mice exposed to HDMs + smoke, compared with animals exposed only to HDMs. A similar activation of CD4 T cells and expression of IL-5, IL-13, and transforming growth factor-? was observed between HDM-treated and HDM + smoke-treated animals. Consistent with an effect on eosinophil trafficking, HDMs + smoke exposure attenuated the HDM-induced expression of eotaxin-1 and vascular cell adhesion molecule-1, whereas the survival of eosinophils and the numbers of blood eosinophils were not affected. Exposure to cigarette smoke also reduced the activation of B cells and the concentrations of serum IgE. Although the production of mucus decreased, collagen deposition significantly increased in animals exposed to HDMs + smoke, compared with animals exposed only to HDMs. Although airway resistance was unaffected, tissue resistance was significantly decreased in mice exposed to HDMs + smoke. Our findings demonstrate that cigarette smoke affects eosinophil migration without affecting airway resistance or modifying Th2 cell adaptive immunity in a murine model of HDM-induced asthma. PMID:21317378

Botelho, Fernando M; Llop-Guevara, Alba; Trimble, Nancy J; Nikota, Jake K; Bauer, Carla M T; Lambert, Kristen N; Kianpour, Sussan; Jordana, Manel; Stämpfli, Martin R

2011-10-01

152

Shifting of immune responsiveness to house dust mite by influenza A infection: genomic insights.  

PubMed

Respiratory viral infections have been associated with an increased incidence of allergic asthma. However, the mechanisms by which respiratory infections facilitate allergic airway disease are incompletely understood. We previously showed that exposure to a low dose of house dust mite (HDM) resulted in enhanced HDM-mediated allergic airway inflammation, and, importantly, marked airway hyperreactivity only when allergen exposure occurred during an acute influenza A infection. In this study, we evaluated the impact of concurrent influenza infection and allergen exposure at the genomic level, using whole-genome microarray. Our data showed that, in contrast to exposure to a low dose of HDM, influenza A infection led to a dramatic increase in gene expression, particularly of TLRs, C-type lectin receptors, several complement components, as well as Fc?R1. Additionally, we observed increased expression of a number of genes encoding chemokines and cytokines associated with the recruitment of proinflammatory cells. Moreover, HDM exposure in the context of an influenza A infection resulted in the induction of unique genes, including calgranulin A (S100a8), an endogenous damage-associated molecular pattern and TLR4 agonist. In addition, we observed significantly increased expression of serum amyloid A (Saa3) and serine protease inhibitor 3n (Serpina3n). This study showed that influenza infection markedly increased the expression of multiple gene classes capable of sensing allergens and amplifying the ensuing immune-inflammatory response. We propose that influenza A infection primes the lung environment in such a way as to lower the threshold of allergen responsiveness, thus facilitating the emergence of a clinically significant allergic phenotype. PMID:22174454

Al-Garawi, Amal; Husain, Mainul; Ilieva, Dora; Humbles, Alison A; Kolbeck, Roland; Stampfli, Martin R; O'Byrne, Paul M; Coyle, Anthony J; Jordana, Manel

2012-01-15

153

Epigenetic alterations by DNA methylation in house dust mite-induced airway hyperresponsiveness.  

PubMed

Asthma is one of the most prevalent chronic lung diseases, affecting 235 million individuals around the world, with its related morbidity and mortality increasing steadily over the last 20 years. Exposure to the environmental allergen, house dust mite (HDM), results in airway inflammation with a variable degree of airway obstruction. Although there has been much experimental work in the past using HDM challenge models to understand mechanistic details in allergic inflammation and airway hyperresponsiveness (AHR), there has been no study on reprogramming of lung or airways mediated through epigenetic mechanisms in response to an acute HDM exposure. Male mice, 6 weeks of age, were administrated HDM extracts or saline at Days 1, 14, and 21. Exposure of mice to HDM extracts caused significant airway inflammation and increased AHR. These HDM-challenged mice also exhibited a change in global DNA methylation as compared with saline-exposed (control) mice. Next, by employing methylation-sensitive restriction fingerprinting, we identified a set of genes, showing aberrant methylation status, associated with the HDM-induced AHR. These candidate genes are known to be involved in cAMP signaling (pde4 d), Akt-signaling (akt1 s1), ion transport (tm6 sf1, pom121l2, and slc8a3), and fatty acid metabolism (acsl3). Slc8a3 and acsl3 were down-regulated, whereas pde4 d, akt1 s1, tm6 sf1, and pom121l2 were up-regulated in the mice exposed to HDM. Hence, our results suggest that HDM exposure induces a series of aberrant methylated genes that are potentially important for the development of allergic AHR. PMID:23526225

Shang, Yan; Das, Sandhya; Rabold, Richard; Sham, James S K; Mitzner, Wayne; Tang, Wan-yee

2013-08-01

154

Endoplasmic reticulum stress mediates house dust mite-induced airway epithelial apoptosis and fibrosis  

PubMed Central

Background The endoplasmic reticulum (ER) stress response participates in many chronic inflammatory and autoimmune diseases. In the current study, we sought to examine the contribution of ER stress transducers in the pathogenesis of three principal facets of allergic asthma: inflammation, airway fibrosis, and airways hyperresponsiveness. Methods House Dust Mite (HDM) was used as an allergen for in vitro and in vivo challenge of primary human and murine airway epithelial cells. ER stress transducers were modulated using specific small interfering RNAs (siRNAs) in vivo. Inflammation, airway remodeling, and hyperresponsiveness were measured by total bronchoalveolar lavage (BAL) cell counts, determination of collagen, and methacholine responsiveness in mice, respectively. Results Challenge of human bronchiolar and nasal epithelial cells with HDM extract induced the ER stress transducer, activating transcription factor 6 ? (ATF6?) as well as protein disulfide isomerase, ERp57, in association with activation of caspase-3. SiRNA-mediated knockdown of ATF6? and ERp57 during HDM administration in mice resulted in a decrease in components of HDM-induced ER stress, disulfide mediated oligomerization of Bak, and activation of caspase-3. Furthermore, siRNA-mediated knockdown of ATF6? and ERp57 led to decreased inflammation, airway hyperresponsiveness and airway fibrosis. Conclusion Collectively, our work indicates that HDM induces ER stress in airway epithelial cells and that ATF6? and ERp57 play a significant role in the development of cardinal features of allergic airways disease. Inhibition of ER stress responses may provide a potential therapeutic avenue in chronic asthma and sub-epithelial fibrosis associated with loss of lung function. PMID:24364984

2013-01-01

155

Epigenetic Alterations by DNA Methylation in House Dust Mite-Induced Airway Hyperresponsiveness  

PubMed Central

Asthma is one of the most prevalent chronic lung diseases, affecting 235 million individuals around the world, with its related morbidity and mortality increasing steadily over the last 20 years. Exposure to the environmental allergen, house dust mite (HDM), results in airway inflammation with a variable degree of airway obstruction. Although there has been much experimental work in the past using HDM challenge models to understand mechanistic details in allergic inflammation and airway hyperresponsiveness (AHR), there has been no study on reprogramming of lung or airways mediated through epigenetic mechanisms in response to an acute HDM exposure. Male mice, 6 weeks of age, were administrated HDM extracts or saline at Days 1, 14, and 21. Exposure of mice to HDM extracts caused significant airway inflammation and increased AHR. These HDM-challenged mice also exhibited a change in global DNA methylation as compared with saline-exposed (control) mice. Next, by employing methylation-sensitive restriction fingerprinting, we identified a set of genes, showing aberrant methylation status, associated with the HDM-induced AHR. These candidate genes are known to be involved in cAMP signaling (pde4 d), Akt-signaling (akt1 s1), ion transport (tm6 sf1, pom121l2, and slc8a3), and fatty acid metabolism (acsl3). Slc8a3 and acsl3 were down-regulated, whereas pde4 d, akt1 s1, tm6 sf1, and pom121l2 were up-regulated in the mice exposed to HDM. Hence, our results suggest that HDM exposure induces a series of aberrant methylated genes that are potentially important for the development of allergic AHR. PMID:23526225

Shang, Yan; Das, Sandhya; Rabold, Richard; Sham, James S. K.; Mitzner, Wayne

2013-01-01

156

Cognitive Factors Mediate Placebo Responses in Patients with House Dust Mite Allergy  

PubMed Central

Background Placebo effects have been reported in type I allergic reactions. However the neuropsychological mechanisms steering placebo responses in allergies are largely unknown. The study analyzed whether and to what extend a conditioned placebo response is affecting type I allergic reactions and whether this response can be reproduced at multiple occasions. Methods 62 patients with house dust mite allergy were randomly allocated to either a conditioned (n?=?25), sham-conditioned (n?=?25) or natural history (n?=?12) group. During the learning phase (acquisition), patients in the conditioned group received the H1-receptor antagonist desloratadine (5mg) (unconditioned stimulus/US) together with a novel tasting gustatory stimulus (conditioned stimulus/CS). Patients in the sham-conditioned control group received the CS together with a placebo pill. After a wash out time of 9 days patients in the conditioned and sham-conditioned group received placebo pills together with the CS during evocation. Allergic responses documented by wheal size after skin prick test and symptom scores after nasal provocation were analyzed at baseline, after last desloratadine treatment and after the 1st and 5th CS re-exposure. Results Both conditioned and sham-conditioned patients showed significantly decreased wheal sizes after the 1st CS-evocation and significantly decreased symptom scores after the 1st as well as after the 5th evocation compared to the natural history control group. Conclusions These results indicate that placebo responses in type I allergy are not primarily mediated by learning processes, but seemed to be induced by cognitive factors such as patients’ expectation, with these effects not restricted to a single evocation. PMID:24260254

Benson, Sven; Rueckert, Annika; Hillen, Uwe; Schadendorf, Dirk; Schedlowski, Manfred

2013-01-01

157

Gene Expression in the Skin of Dogs Sensitized to the House Dust Mite Dermatophagoides farinae  

PubMed Central

Atopic dermatitis is a multifactorial allergic skin disease in humans and dogs. Genetic predisposition, immunologic hyperreactivity, a defective skin barrier, and environmental factors play a role in its pathogenesis. The aim of this study was to analyze gene expression in the skin of dogs sensitized to house dust mite antigens. Skin biopsy samples were collected from six sensitized and six nonsensitized Beagle dogs before and 6 hr and 24 hr after challenge using skin patches with allergen or saline as a negative control. Transcriptome analysis was performed by the use of DNA microarrays and expression of selected genes was validated by quantitative real-time RT-PCR. Expression data were compared between groups (unpaired design). After 24 hr, 597 differentially expressed genes were detected, 361 with higher and 226 with lower mRNA concentrations in allergen-treated skin of sensitized dogs compared with their saline-treated skin and compared with the control specimens. Functional annotation clustering and pathway- and co-citation analysis showed that the genes with increased expression were involved in inflammation, wound healing, and immune response. In contrast, genes with decreased expression in sensitized dogs were associated with differentiation and barrier function of the skin. Because the sensitized dogs did not show differences in the untreated skin compared with controls, inflammation after allergen patch test probably led to a decrease in the expression of genes important for barrier formation. Our results further confirm the similar pathophysiology of human and canine atopic dermatitis and revealed genes previously not known to be involved in canine atopic dermatitis. PMID:25098772

Schamber, Paz; Schwab-Richards, Rachel; Bauersachs, Stefan; Mueller, Ralf S.

2014-01-01

158

Sensitivity to Five Types of House Dust Mite in a Group of Allergic Egyptian Children  

PubMed Central

Background: The published data on house dust mite (HDM) sensitization from Egypt are scanty. We sought to investigate the sensitization to five different types of HDM among a group of allergic children in a trial to outline the most frequent sensitizing strains in the Cairo Province. Methods: We consecutively enrolled 100 asthmatic patients, aged 1–7 years, of whom 22 had concomitant skin allergy. Skin prick testing was performed using allergen extracts of Dermatophagoides pteronyssinus, Dermatophagoides farinae, Lepidoglyphus destructor, Tyrophagus putrescentiae, and Acarus siro. Results: Twenty-four patients (24%) were sensitized to one or more strains of HDM. Sensitization to one strain was revealed in 12% of the studied sample, while sensitization to two or three strains was detected in 8% and 4% respectively. Twelve percent of the enrolled children were sensitive to D. pteronyssinus, 11% to D. farinae, 7% to L. destructor, 6% to T. putrescentiae, and 4% to A. siro. Eight out of the 12 (66%) children sensitive to one strain had mild intermittent asthma, while five out of eight (62.5%) sensitive to two strains had moderate persistent asthma. All children sensitized to three strains of HDM had persistent rather than intermittent asthma. HDM sensitization did not correlate significantly to the history of sun exposure, bed mattresses and pillows, living in farms, or exposure to stored grains. The co-existence of atopic dermatitis tended to have a higher rate of HDM sensitization. Conclusion: D. pteronyssinus and D. farinae represent the most common sensitizing strains in the studied sample. Wider-scale population-based studies are needed to assess the prevalence of HDM allergy and its clinical correlates in our country.

El-Sayed, Shereen; Abdul-Rahman, Nahla

2014-01-01

159

Concentrations and emission rates of aerial ammonia, nitrous oxide, methane, carbon dioxide, dust and endotoxin in UK broiler and layer houses  

Microsoft Academic Search

1. A survey of the concentration and emission rates of aerial ammonia, nitrous oxide, methane, carbon dioxide, dust and endotoxin was undertaken in 4 examples each of typical UK broiler, cage and perchery houses over 24 h during winter and summer.2. Overall the air quality within the poultry houses was unsatisfactory as judged by the dual criteria of farmer health

C. M. Wathes; M. R. Holden; R. W. Sneath; R. P. White; V. R. Phillips

1997-01-01

160

Evaluation of four sampling methods for determining exposure of children to lead-contaminated household dust  

SciTech Connect

Childhood exposure to lead has been demonstrated to result in health effects and lead-contaminated household dust is a primary exposure source. There is a need to establish reliable methods for sampling surfaces to determine levels of lead contamination. Three vacuums (HVS3, GS80, and MVM) and one wipe method were evaluated for the collection of household floor dust under field sampling conditions within a Superfund site and demographically similar control area. Side-by-side floor samples were taken from three locations within 41 randomly selected households between August and September 1995: a child's bedroom, primary play area, and primary entrance. Analysis was performed to assess the relative collection performance of each sampler, spatial distribution of lead within a household, and correlation of lead loading with observed blood lead level, and to determine if discrete or composites samples were more predictive of blood lead levels. Approximately 90% of the floor surfaces were carpeted. The rank order of sampling methods from greatest to lowest collection efficiency was HVS3 > G80 > wipe > MVM. The HVS3 had the highest level of precision (CV = 0.05), with the GS80 and wipe precisions 0.48 and 0.053, respectively.

Sterling, D.A.; Roegner, K.C.; Lewis, R.D.; Luke, D.A. (Saint Louis Univ. School of Public Health, MO (United States). Div. of Environmental and Occupational Health); Wilder, L.C. (Agency for Toxic Substances and Disease Registry, Atlanta, GA (United States). Div. of Health Assessment and Consultation); Burchette, S.M. (Environmental Protection Agency, Edison, NJ (United States))

1999-08-01

161

Effectiveness of lead-hazard control interventions on dust lead loadings: Findings from the evaluation of the HUD Lead-Based Paint Hazard Control Grant Program  

Microsoft Academic Search

From 1994 to 1999, the Evaluation of the US Department of Housing and Urban Development Lead-Based Paint Hazard Control Grant Program studied the intervention experiences of over 2800 homes in 11 states in the USA. Each interior intervention was categorized as (in order of increasing intensity) (a) cleaning\\/spot painting; (b) complete repainting; (c) complete repainting plus window treatments; (d) window

Sherry L. Dixon; Jonathan W. Wilson; C. Scott Clark; Warren A. Galke; Paul A. Succop; Mei Chen

2005-01-01

162

Acute, but not resolved, influenza A infection enhances susceptibility to house dust mite-induced allergic disease.  

PubMed

The impact of respiratory viral infections on the emergence of the asthmatic phenotype is a subject of intense investigation. Most experimental studies addressing this issue have used the inert Ag OVA with controversial results. We examined the consequences of exposure to a low dose of the common aeroallergen house dust mite (HDM) during the course of an influenza A infection. First, we delineated the kinetics of the immune-inflammatory response in the lung of mice following intranasal infection with influenza A/PR8/34. Our data demonstrate a peak response during the first 10 days, with considerable albeit not complete resolution at day 39 postinfection (p.i.). At day 7 p.i., mice were exposed, intranasally, to HDM for 10 consecutive days. We observed significantly enhanced eosinophilic inflammation, an expansion in Th2 cells, enhanced HDM-specific IgE and IgG1 responses and increased mucous production. Furthermore, lung mononuclear cells produced enhanced IFN-gamma and IL-5, unchanged IL-13, and reduced IL-4. These immunologic and structural changes lead to marked lung dysfunction. This allergic phenotype occurs at a time when there is a preferential increase in plasmacytoid dendritic cells over myeloid dendritic cells, activated CD8(+) T cells, and increased IFN-gamma production, all of which have been proposed to inhibit allergic responses. In contrast, the inflammatory response elicited by HDM was reduced when exposure occurred during the resolution phase (day 40 p.i.). Interestingly, this was not associated with a reduction in sensitization. Thus, the proinflammatory environment established during an acute influenza A infection enhances Th2-polarized immunity to a low dose of HDM and precipitates marked lung dysfunction. PMID:19234206

Al-Garawi, Amal A; Fattouh, Ramzi; Walker, Tina D; Jamula, Erin B; Botelho, Fernando; Goncharova, Susanna; Reed, Jennifer; Stampfli, Martin R; O'Byrne, Paul M; Coyle, Anthony J; Jordana, Manel

2009-03-01

163

Concentration of the genera Aspergillus, Eurotium and Penicillium in 63-?m house dust fraction as a method to predict hidden moisture damage in homes  

PubMed Central

Background Quantitative measurements of mould enrichment of indoor air or house dust might be suitable surrogates to evaluate present but hidden moisture damage. Our intent was to develop a house-dust monitoring method to detect hidden moisture damage excluding the influence of outdoor air, accumulated old dust, and dust swirled up from room surfaces. Methods Based on standardized measurement of mould spores in the 63-?m fraction of house dust yielded by carpets, the background concentrations were determined and compared to simultaneously obtained colony numbers and total spore numbers of the indoor air in 80 non-mouldy living areas during summer and winter periods. Additionally, sampling with a vacuum-cleaner or manual sieve was compared to sampling with a filter holder or sieving machine, and the evaluative power of an established two-step assessment model (lower and upper limits) was compared to that of a one-step model (one limit) in order to derive concentration limits for mould load in house dust. Results Comparison with existing evaluation procedures proved the developed method to be the most reliable means of evaluating hidden moisture damage, yielding the lowest false-positive results (specificity 98.7%). Background measurements and measurements in 14 mouldy rooms show that even by evaluating just the indicator genera in summer and winter, a relatively certain assessment of mould infestation is possible. Conclusion A one-step evaluation is finally possible for house dust. The house-dust evaluation method is based on analysis of the indicator genera Aspergillus, Eurotium and Penicillium spp., which depend on the total fungal count. Inclusion of further moisture indicators currently appears questionable, because of outdoor air influence and the paucity of measurements. PMID:19615082

Baudisch, Christoph; Assadian, Ojan; Kramer, Axel

2009-01-01

164

Fact Sheet: Facilities UC San Diego Health Sciences facilities house leading-edge technologies, investigational therapies,  

E-print Network

March 2014 Fact Sheet: Facilities UC San Diego Health Sciences facilities house leading procedures within its walls. UC San Diego Medical Center Opened: 1966 | Size: 490,000 GSF 200 West Arbor Drive San Diego, CA 92103 Facility Highlights >> 392 beds >> UC San Diego Stroke Center >> The area

Squire, Larry R.

165

Simultaneous determination of thirteen organophosphate esters in settled indoor house dust and a comparison between two sampling techniques.  

PubMed

An analytical method for the simultaneous determination of 13 organophosphate esters (OPEs) in house dust was developed. The method is based on solvent extraction by sonication, sample cleanup by solid phase extraction (SPE), and analysis by gas chromatography-positive chemical ionization-tandem mass spectrometry (GC/PCI-MS/MS). Method detection limits (MDLs) ranged from 0.03 to 0.43 ?g/g and recoveries from 60% to 118%. The inter- and intra-day variations ranged from 3% to 23%. The method was applied to dust samples collected using two vacuum sampling techniques from 134 urban Canadian homes: a sample of fresh or "active" dust (FD) collected by technicians and a composite sample taken from the household vacuum cleaner (HD). Results show that the two sampling methods (i.e., FD vs HD) provided comparable results. Tributoxyethyl phosphate (TBEP), triphenyl phosphate (TPhP), tris(chloropropyl) phosphate (TCPP), tri(2-chloroethyl) phosphate (TCEP), tris(dichloro-isopropyl) phosphate (TDCPP), tricresyl phosphate (TCrP), and tri-n-butyl phosphate (TnBP) were detected in the majority of samples. The most predominant OPE was TBEP, with median concentrations of 31.9 ?g/g and 22.8 ?g/g in FD and HD samples, respectively, 1 to 2 orders of magnitude higher than other OPEs. The method was also applied to the analysis of OPEs in the National Institute of Standards and Technology (NIST) standard reference material (NIST SRM 2585, organic contaminants in house dust). The results from SRM 2585 may contribute to the certification of OPE concentration values in this SRM. PMID:24462133

Fan, Xinghua; Kubwabo, Cariton; Rasmussen, Pat E; Wu, Fang

2014-09-01

166

Determination of synthetic musk compounds in indoor house dust by gas chromatography-ion trap mass spectrometry.  

PubMed

A new method for the simultaneous determination of 11 synthetic musks and one fragrance compound in house dust was developed. The nitro musks included musk ketone (MK, 4-tert-butyl-3,5-dinitro-2,6-dimethylacetophenone), musk xylene (MX, 1-tert-butyl-3,5-dimethyl-2,4,6-trinitrobenzene), musk ambrette (1-tert-butyl-2-methoxy-4-methyl-3,5-dinitrobenzene) and musk moskene (1,1,3,3,5-pentamethyl-4,6-dinitroindane). The polycyclic musk compounds were 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(?)-2-benzopyran (HHCB), 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN), 4-acetyl-1,1-dimethyl-6-tert-butylindane, 6-acetyl-1,1,2,3,3,5-hexamethylindane, 5-acetyl-1,1,2,6-tetramethyl-3-isopropylindane, 6,7-dihydro-1,1,2,3,3-pentamethyl-4(5H)-indanon. The one macrocyclic musk was 1,4-dioxacycloheptadecane-5,17-dione. The bicyclic hydrocarbon fragrance compound (1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethylnaphthalen-2yl)ethan-1-one (OTNE) and HHCB-lactone (4,6,6,7,8,8-hexamethyl-1H,3H,4H,6H,7H, 8H-indeno[5,6-c]pyran-1-one), a degradation product of HHCB, were also analysed. NIST SRM 2781 (domestic sludge) and SRM 2585 (organic contaminants in house dust) were analysed for these target compounds. The method was applied for the analysis of 49 paired samples collected using two vacuum sampling methods: a sample of fresh or "active" dust (FD) collected using a Pullman-Holt vacuum sampler, and a household dust (HD) sample taken from the participants' vacuum cleaners. Method detection limits and recoveries ranged from 12 to 48 ng/g and 54 to 117 %, respectively. AHTN, HHCB, OTNE and HHCB-lactone were detected in all samples, with median concentrations of 552, 676, 252 and 453 ng/g for FD samples, respectively; and 405, 992, 212 and 492 ng/g for HD samples, respectively. MX and MK were detected with high frequencies but with much lower concentrations. The two sampling methods produced comparable results for the target analytes. Widely scattered concentration levels were observed for target analytes from this set of 49 house dust samples, suggesting a wide variability in Canadian household exposure to synthetic musks. PMID:22684881

Kubwabo, Cariton; Fan, Xinghua; Rasmussen, Pat E; Wu, Fang

2012-08-01

167

Dust detector using piezoelectric lead zirconate titanate with current-to-voltage converting amplifier for functional advancement  

NASA Astrophysics Data System (ADS)

This paper describes the concept of a dust monitor using lead zirconate titanate (PZT) ceramics with a large detection area. Its potential as a dust detector is experimentally demonstrated. The dust monitor has a small volume compared to an impact ionization detector with the same detection area, due to the PZT sensor. The PZT sensor, as a traditional device for the in-situ observation of hypervelocity dust particles, has been used for momentum measurement. The hypervelocity impact signals of PZT sensors are typically read by charge-sensitive amplifiers. Instead, we suggest a new method that a current-to-voltage converting amplifier is useful for interpreting the impact signal of a PZT sensor arising from dust particles down to 0.5 ?m in radius. We propose that datasets of dust impacts can be obtained with a higher statistical accuracy, if the new method is applied to instruments on forthcoming interplanetary-space-cruising spacecrafts.

Kobayashi, M.; Miyachi, T.; Hattori, M.; Sugita, S.; Takechi, S.; Okada, N.

2013-03-01

168

Lead in United Kingdom soils and dusts in relation to environmental standards and guidelines  

SciTech Connect

Concentrations of lead in British soils are frequently elevated due to both natural and man-made sources. A long history of mining and smelting has resulted in extensive metal pollution in specific areas. These extend to some 6000 sq km of agricultural land and include some small towns and villages. In these geochemical hot-spot areas lead passes in limited amounts into the food chain resulting in moderate elevations in blood lead concentrations in both grazing livestock and in children living in the old mining communities. There are no reported adverse effects on the health of livestock or the human population. A national survey of metals in dusts and soils in urban areas of Britain has shown elevated concentrations of lead in a significant proportion of households particularly those sampled in London. The results of this survey are compared with national standards and guidelines. 22 references, 3 tables.

Thornton, I.

1986-01-01

169

A side-by-side comparison of three allergen sampling methods in settled house dust.  

PubMed

Understanding allergen exposure and potential relationships with asthma requires allergen sampling methods, but methods have yet to be standardized. We compared allergen measurements from dust collected from 200 households with asthmatics and conducted a side-by-side vacuum sampling of settled dust in each home's kitchen, living room and subject's bedroom by three methods (EMM, HVS4 and AIHA). Each sample was analyzed for dust mite, cockroach, mouse, rat, cat and dog allergens. The number of samples with sufficient dust mass for allergen analysis was significantly higher for Eureka Mighty Mite (EMM) and high volume small surface sampler (HVS4) compared with American Industrial Hygiene Association (AIHA) in all rooms and surfaces tested (all P<0.05). The allergen concentration (weight of allergen divided by total weight of dust sampled) measured by the EMM and HVS4 methods was higher than that measured by the AIHA. Allergen loadings (weight of allergen divided by surface area sampled) were significantly higher for HVS4 than for AIHA and EMM. Cockroach and rat allergens were rarely detected via any method. The EMM method is most likely to collect sufficient dust from surfaces in the home and is relatively practical and easy. The AIHA and HVS4 methods suffer from insufficient dust collection and/or difficulty in use. PMID:24802556

Sandel, Megan; Murphy, Johnna S; Dixon, Sherry L; Adgate, John L; Chew, Ginger L; Dorevitch, Samuel; Jacobs, David E

2014-11-01

170

Results of a field study on the influence of HygienicWood mattress toppers on the number of mites in bed dust and the state of health of people with house dust mite allergies  

PubMed Central

Objectives: So far, there has been no practical or toxicologically non-hazardous way to decimate mites – without interrupting use of beds – in their main reservoir on bed mattresses to such an extent that the allergic condtion of people suffering from house dust mite allergies is reduced or even remedied. As so-called HygienicWood was effective against mites under simulated conditions, the influence of a mattress topper filled with HygienicWood chips on the content of mite antigen Der p1 was to be investigated and the influence on the state of health of the persons concerned analysed at the same time. Procedure: 32 test persons suffering from dust mite allergy were randomly selected. During the course of 5 months, the influence of a HygienicWood mattress topper on the content of the mite antigen Der p1 as well as the number of bacteria, dermatophytes and yeasts in the bed dust were determined and compared with the values obtained during the 5 weeks prior to the application of HygienicWood mattress toppers. The samples were taken from between the HygienicWood mattress topper and the sheet below. At the same time, changes in well-being, state of health, typical allergy symptoms and frequency of taking antihistamines and glucocorticoids were recorded as self-assessments in the form of questionnaires. Findings: The most striking finding was the significant decrease (p=0.000) of the house dust mite antigen Der p1 during usage of the HygienicWood mattress toppers. The effect started immediately after applying the toppers and continued with little fluctuation until the end of the observation period without lessening. At the end of the study, 43% of the test persons stated a slight improvement in their well-being. 13% of the test persons felt no change, and 6% of the test persons stated a slight deterioration. The situation was similar with regard to allergy symptoms: 43% reported a significant reduction, 38% a slight reduction, and 19% did not notice any change. The improvement in symptomatology could not be ascribed to an increased intake of antihistamines or glucocorticoids. The dermatophytes, too, showed a slight, albeit statistically not significant decrease after application of HygienicWood mattress toppers. In contrast, the pollution of bed dust with yeasts rose significantly (p=0.002), whereas there was only a tendency towards an increase in the number of bacteria, which, if one considers the slight increase, is without hygienic relevance. Conclusion: HygienicWood mattress toppers are able to reduce the house dust mite allergen load. This leads to a distinct reduction in the allergy symptomatology, and the well-being of the persons concerned increased significantly. PMID:20941342

Koburger, Torsten; Pitts, Deike; Kramer, Axel

2010-01-01

171

Chamber studies on mass-transfer of di(2-ethylhexyl)phthalate (DEHP) and di- n-butylphthalate (DnBP) from emission sources into house dust  

NASA Astrophysics Data System (ADS)

For a number of phthalates and especially for di(2-ethylhexyl)phthalate (DEHP), surprisingly high house dust concentrations are reported in the literature. Therefore, the uptake of the most prominent compounds DEHP and di- n-butylphthalate (DnBP) from plasticized indoor materials into house dust samples of different organic content has been experimentally determined. The experiments have been performed within 45 days which is sufficient for the more volatile phthalate (DnBP) to reach equilibrium conditions. DnBP reaches considerably higher concentrations in the chamber air compared to real room measurements and, thus, also elevated dust concentrations. In contrast, the mass transfer of DEHP in the dust via the gas phase was significantly lower. However, small chamber experiments showed elevated mass transfer of DEHP in case of direct contact between emission source and sink. This aspect is experimentally determined using an plasticized PVC polymer with and without direct contact to house dust. A transfer into the dust could be observed in dependence of the initial concentration in the material. However, the results do not allow the differentiation between the two uptake mechanisms via capillary forces and contact to the material's boundary layer. The results illustrate that the reasons for elevated DEHP concentrations in dust indoors can be traced back to direct contact of source and sink, abrasion from the source, and transport via airborne particles.

Schripp, Tobias; Fauck, Christian; Salthammer, Tunga

2010-08-01

172

A new exposure metric for traffic-related air pollution? An analysis of determinants of hopanes in settled indoor house dust  

PubMed Central

Background Exposure to traffic-related air pollution (TRAP) can adversely impact health but epidemiologic studies are limited in their abilities to assess long-term exposures and incorporate variability in indoor pollutant infiltration. Methods In order to examine settled house dust levels of hopanes, engine lubricating oil byproducts found in vehicle exhaust, as a novel TRAP exposure measure, dust samples were collected from 171 homes in five Canadian cities and analyzed by gas chromatography–mass spectrometry. To evaluate source contributions, the relative abundance of the highest concentration hopane monomer in house dust was compared to that in outdoor air. Geographic variables related to TRAP emissions and outdoor NO2 concentrations from city-specific TRAP land use regression (LUR) models were calculated at each georeferenced residence location and assessed as predictors of variability in dust hopanes. Results Hopanes relative abundance in house dust and ambient air were significantly correlated (Pearson’s r=0.48, p<0.05), suggesting that dust hopanes likely result from traffic emissions. The proportion of variance in dust hopanes concentrations explained by LUR NO2 was less than 10% in Vancouver, Winnipeg and Toronto while the correlations in Edmonton and Windsor explained 20 to 40% of the variance. Modeling with household factors such as air conditioning and shoe removal along with geographic predictors related to TRAP generally increased the proportion of explained variability (10-80%) in measured indoor hopanes dust levels. Conclusions Hopanes can consistently be detected in house dust and may be a useful tracer of TRAP exposure if determinants of their spatiotemporal variability are well-characterized, and when home-specific factors are considered. PMID:23782977

2013-01-01

173

Cycling of Lead Through Soil, Air, and Household Dust in El Paso, Texas  

NASA Astrophysics Data System (ADS)

Elimination of leaded gasoline in the US is associated with a dramatic overall decrease in ambient lead in the environment and blood lead levels in our population. However, Pb is such a potent neurotoxin for children during the formative growth years that legislation for additional reduction of airborne lead levels is under consideration. X-ray absorption spectroscopy of a suite of samples of local (El Paso) soil, airborne particulate matter, and household dust reveals that lead humate is the dominant Pb species in these diverse environmental materials. Lead humate is a stable complex of Pb with the humus component of soil, a product of interaction between the humus and such introduced contaminant lead species as lead oxide, lead sulfate, etc. Because lead humate forms only in soil, we conclude that the source of the majority of the lead in El Paso's airborne particulate matter and household dust is local soils. Analysis of lead isotopes in selected samples is consistent with this conclusion. Re-entrainment of low-density (relative to most Pb species) humus soil particles is the apparent pathway from soil to air. Deposition of airborne particulate matter and pedal traction are the presumed mechanisms for transfer to household interiors. Reduction of airborne lead in El Paso by reducing input from its dominant local source may require extensive soil remediation, a tedious and expensive prospect. X-Ray absorption spectroscopy experiments were conducted at the Stanford Synchrotron Radiation Laboratory on beam lines 7-3, 10-2, and 11-2. Spectra were collected at the Pb L-III absorption edge in fluorescence mode using a 13-element or a 30-element Ge solid-state detector. This publication was made possible by grant numbers 1RO1-ES11367 and 1 S11 ES013339-04 from the National Institute of Environmental Health Sciences (NIEHS), NIH. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIEHS, NIH. Partial travel support provided by SSRL-DOE- UTEP Gateway Program.

Pingitore, N. E.; Clague, J.; Amaya, M. A.

2008-12-01

174

[Pyrethroids in house dust of the German housing population--results of 2 nationwide cross-sectional studies].  

PubMed

As a part of the German Environmental Surveys performed in 1985/86 (West Germany), 1990/91 (West Germany) and 1991/92 (East Germany), dust samples were collected in the households of about 1600 randomly selected adults (25 to 69 years) and an analysis of these samples was performed in respect of their content of 8 different pyrethroids and of the synergist piperonyl butoxide (PBO). In the 1990-92 survey about 90% of the samples contained permethrin in concentrations above the limit of quantification. This showed permethrin to be the most widespread of the 8 compounds investigated. The geometric mean of the permethrin content in domestic dust was 0.22 mg/kg. Only about 8% of the samples contained one or more of the other investigated substances (cyfluthrin, lambda-cyhalothrin, cypermethrin, alpha-cypermethrin, deltamethrin, empenthrin, d-phenothrin) in quantifiable amounts. About 76% of the samples contained quantifiable amounts of PBO. In East Germany the geometric mean of the PBO content (0.21 mg/kg) was significantly higher than in West Germany (0.07 mg/kg), but no difference for permethrin was found. Significant associations could be shown for the permethrin content and the application of biocides as well as for the PBO content and regional factors (size of community, type of dwelling area). Samples collected in 1985/86 (West Germany) showed a geometric mean for permethrin of 0.06 mg/kg and for PBO of 0.07 mg/kg. Comparing the values of 1985/86 and 1990/91, a significant increase can be observed for permethrin, whereas the PBO concentration remained constant. PMID:9553309

Friedrich, C; Becker, K; Hoffmann, G; Hoffmann, K; Krause, C; Nöllke, P; Schulz, C; Schwabe, R; Seiwert, M

1998-02-01

175

Modification of house dust mite allergens by monomethoxypolyethylene glycol. Allergenicity measured by in vitro and in vivo methods.  

PubMed

In animal models, allergen modification by coupling to monomethoxypolyethylene glycol (mPEG) molecules can reduce allergenicity of the extract and makes the allergen capable of suppressing boosted IgE response. To investigate in a human system the degree of attenuation implied by a mPEG modification of a house dust mite (Dermatophagoides pteronyssinus) extract, 55 adults with asthma caused by house dust mites were tested by skin prick test (SPT) and histamine release assay (HR). RAST inhibition was performed on sera from 6 additional patients. Modified extract containing 0.42 mmol mPEG/g protein was used for the analyses. In order to get the same response of the two extracts when assessed by HR and SPT, a median increase in concentration of 10-fold of the mPEG-modified extract compared to the unmodified extract was needed. Interindividual variation was limited. Sixty-four to 72% needed a dose increase within +/- half a decade from this value. In 42-49% of the patients, results from SPT and HR deviated less than half a decade. The relative potency of the modified extract as measured by RAST inhibition was reduced to 17-78% (mean 39%). Reduced allergenicity would by itself mean less side effects in immunotherapy. When planning such therapy it is important to know that mPEG modification reduces the allergenicity to a similar extent in a majority of patients. PMID:2448247

Mosbech, H; Dreborg, S; Pĺhlman, I; Stahl Skov, P; Steringer, I; Weeke, B

1988-01-01

176

Effect of Alpinia katsumadai Hayata on House Dust Mite-Induced Atopic Dermatitis in NC/Nga Mice  

PubMed Central

We evaluated the effects of Alpinia katsumadai Hayata (AKH, Zingiberaceae) extract on the production of nitric oxide (NO) and prostaglandin E2 (PGE2) in RAW 264.7 cells, thymus- and-activation-regulated chemokine (TARC/CCL17) in HaCaT cells, and histamine level in HMC-1 cells. In an in vivo experiment, atopic dermatitis was induced by topical application of house dust mites for 4 weeks, and the protective effects of AKH was investigated by measuring the severity of the skin reaction on the back and ears, and plasma levels of immunoglobulin E (IgE) and histamine. AKH extract suppressed the production of NO and PGE2 in RAW 264.7 cells, TARC in HaCaT cells, and histamine in HMC-1 cells in a dose-dependent manner. In in vivo experiments, the severity of dermatitis, including erythema/hemorrhage, edema, erosion and scaling, and plasma levels of IgE, and histamine were lower in NC/Nga mice with atopic dermatitis, treated with AKH extract than in untreated mice. AKH extract reduced the histological manifestations of atopic dermatitis-like skin lesions such as erosion, hyperplasia of the epidermis and dermis, and inflammatory cell infiltration on the skin of the back and ear. These results suggest that AKH inhibits the development of house dust mite-induced atopic dermatitis in NC/Nga mice. PMID:23082085

Lim, Hye-Sun; Seo, Chang-Seob; Ha, Hyekyung; Lee, Hoyoung; Lee, Jun Kyung; Lee, Mee-Young; Shin, HyeunKyoo

2012-01-01

177

76 FR 12106 - Lead-Based Paint Renovation, Repair and Painting Activities in Target Housing and Child Occupied...  

Federal Register 2010, 2011, 2012, 2013

...protective of human health and the environment as the Federal program and...administered regulations concerning lead- based paint in housing since...Kansas Department of Health and Environment (KDHE) to operate a lead poisoning prevention...

2011-03-04

178

[Polychlorinated biphenyls in house dust at an e-waste site and urban site in the Pearl River Delta, southern China: sources and human exposure and health risks].  

PubMed

Polychlorinated biphenyls (PCBs) were measured in house dust from an e-waste site and urban site in the Pearl River Delta, southern China. The PCB concentrations in house dust at the e-waste site ranged from 12.4 to 87 765 ng x g(-1), with an average of 10 167 ng x g(-1). There was no significant difference in the PCB concentrations between indoor and outdoor dust. The PCB homologue pattern was dominated by tri-, penta-, hexa-, and tetra-CBs, which was not similar to that in Chinese technical PCB product. There was also no significant difference in the PCB compositions between indoor and outdoor dust. PCB sources in house dust at the e-waste site were apportioned by chemical mass balance (CMB) model. The results showed that the PCBs were derived primarily from Aroclor 1262 (36.7% ), Aroclor 1254 (26.7%), Aroclor 1242 (21.4%), and Aroclor 1248 (18.5%). The daily exposure doses were 42, 17, and 2.9 ng x (kg x d)(-1) for toddlers, children/adolescents, and adults in the e-waste area, respectively. Risk assessment indicated that the hazard quotients were higher than 1 for toddlers and children/adolescents indicating adverse effects for them. The lifetime average excess carcinogenic risk for population in the e-waste area was 4.5 x 10(-5), within the acceptable range of U. S. Environmental Protection Agency. The mean concentrations of PCBs in house dust in Guangzhou was 48.7 ng x g(-1). The low PCB level is consistent with the fact that technical PCBs were not widely used in China in the past. The risks of exposure to PCBs via house dust in Guangzhou are very low. PMID:25338381

Zhu, Zhi-Cheng; Chen, She-Jun; Ding, Nan; Wang, Jing; Luo, Xiao-Jun; Mai, Bi-Xian

2014-08-01

179

Heavy metals in food, house dust, and water from an e-waste recycling area in South China and the potential risk to human health.  

PubMed

Concentrations of heavy metals (Cd, Pb, Cu, Zn, and Ni) were measured in the foodstuffs, house dust, underground/drinking water, and soil from an electronic waste (e-waste) area in South China. Elevated concentrations of these potentially toxic metals were observed in the samples but not in drinking water. The health risks for metal exposure via food consumption, dust ingestion, and drinking water were evaluated for local residents. For the average residents in the e-waste area, the non-carcinogenic risks arise predominantly from rice (hazard index=3.3), vegetables (2.2), and house dust (1.9) for adults, while the risks for young children are dominated by house dust (15). Drinking water may provide a negligible contribution to risk. However, local residents who use groundwater as a water supply source are at high non-carcinogenic risk. The potential cancer risks from oral intake of Pb are 8×10(-5) and 3×10(-4) for average adults and children, and thus groundwater would have a great potential to induce cancer (5×10(-4) and 1×10(-3)) in a highly exposed population. The results also reveal that the risk from oral exposure is much higher than the risk from inhalation and dermal contact with house dust. PMID:23849468

Zheng, Jing; Chen, Ke-hui; Yan, Xiao; Chen, She-Jun; Hu, Guo-Cheng; Peng, Xiao-Wu; Yuan, Jian-gang; Mai, Bi-Xian; Yang, Zhong-Yi

2013-10-01

180

Pyrethroids in house dust from the homes of farm worker families in the MICASA study  

E-print Network

of the pyrethroids cis- and trans-permethrin, cypermethrin, deltamethrin, esfenvalerate and resmethrin in single dust samples collected from 55 households. Cis- and trans-permethrin had the highest detection frequencies frequencies and/or lower median concentrations of cis- and trans-permethrin and cypermethrin were observed

Hammock, Bruce D.

181

Exposure to herbicides in house dust and risk of childhood acute lymphoblastic leukemia.  

PubMed

We examine the association between exposure to herbicides and childhood acute lymphoblastic leukemia (ALL). Dust samples were collected from homes of 269 ALL cases and 333 healthy controls (<8 years of age at diagnosis/reference date and residing in same home since diagnosis/reference date) in California, using a high-volume surface sampler or household vacuum bags. Amounts of agricultural or professional herbicides (alachlor, metolachlor, bromoxynil, bromoxynil octanoate, pebulate, butylate, prometryn, simazine, ethalfluralin, and pendimethalin) and residential herbicides (cyanazine, trifluralin, 2-methyl-4-chlorophenoxyacetic acid (MCPA), mecoprop, 2,4-dichlorophenoxyacetic acid (2,4-D), chlorthal, and dicamba) were measured. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by logistic regression. Models included the herbicide of interest, age, sex, race/ethnicity, household income, year and season of dust sampling, neighborhood type, and residence type. The risk of childhood ALL was associated with dust levels of chlorthal; compared to homes with no detections, ORs for the first, second, and third tertiles were 1.49 (95% CI: 0.82-2.72), 1.49 (95% CI: 0.83-2.67), and 1.57 (95% CI: 0.90-2.73), respectively (P-value for linear trend=0.05). The magnitude of this association appeared to be higher in the presence of alachlor. No other herbicides were identified as risk factors of childhood ALL. The data suggest that home dust levels of chlorthal, and possibly alachlor, are associated with increased risks of childhood ALL. PMID:23321862

Metayer, Catherine; Colt, Joanne S; Buffler, Patricia A; Reed, Helen D; Selvin, Steve; Crouse, Vonda; Ward, Mary H

2013-07-01

182

Kinetics of allergen expression in cultures of house dust mites, Dermatophagoides pteronyssinus and D. farinae (Acari: Pyroglyphidae).  

PubMed

Laboratory cultures of house dust mites Dermatophagoides pteronyssinus (Trouessart, 1897) and Dermatophagoides farinae Hughes, 1961 were used to study the population dynamics of the mites and the kinetics of antigen appearance. The analysis of extracts obtained after different incubation periods, carried out by SDS-PAGE, immunoblotting, and enzyme-linked immunosorbent assay, allows for the definition of 3 different growth phases: the latency phase (F1); the exponential growth phase (F2) during which the allergenic proteins, including the Der 1 and Der 2 major allergens, were expressed more intensely and in larger quantities; and a final phase (F3), death, in which the lowest rates of allergenic components with a clearly different pattern were seen. The data obtained from this work demonstrates that mite cultures during the maximum growth phase (F2) contain the largest amount of allergenic components as well as the highest major allergen concentrations. PMID:9439123

Eraso, E; Guisantes, J A; Martínez, J; Sáenz-de-Santamaría, M; Martínez, A; Palacios, R; Cisterna, R

1997-11-01

183

Eighteen-month outcomes of house dust mite avoidance and dietary fatty acid modification in the childhood asthma prevention study (CAPS)  

Microsoft Academic Search

Background: Observational studies have linked house dust mite (HDM) exposure and dietary fatty acid intake with asthma in childhood. However, definitive evidence of their role in the etiology of asthma requires a randomized controlled trial. Objective: We hypothesized that the incidence of asthma and allergy in high-risk children would be reduced by avoidance of HDM allergens, supplementation with omega-3 fatty

Seema Mihrshahi; Jennifer K. Peat; Guy B. Marks; Craig M. Mellis; Euan R. Tovey; Karen Webb; Warwick J. Britton; Stephen R. Leeder

2003-01-01

184

A High-Molecular-Weight Mite Antigen (HM1) Fraction Aggravates Airway Hyperresponsiveness of Allergic Mice to House Dusts and Whole Mite Cultures  

Microsoft Academic Search

Background: The house dust mite Dermatophagoides farinae is the most common aeroallergen causing human allergic asthma. Previously, we demonstrated that a high-molecular-weight allergenic fraction (HM1), which was abundant in D. farinae extracts, induced a proliferative response of T cells from healthy donors. The induction was mediated through the activation of macrophages without MHC class II restriction. In this study, we

Airo Tategaki; Seiji Kawamoto; Takahide Okuda; Tsunehiro Aki; Hiroshi Yasueda; Osamu Suzuki; Kazuhisa Ono; Seiko Shigeta

2002-01-01

185

CHARACTERIZATION OF IMMEDIATE AND LATE PHASE AIRWAY RESPONSES TO HOUSE DUST MITE CHALLENGE IN BROWN NORWAY RATS AND CORRELATIONS AMONG PHYSIOLOGICAL MEDIATORS  

EPA Science Inventory

CHARACTERIZATION OF IMMEDIATE AND LATE PHASE AIRWAY RESPONSES TO HOUSE DUST MITE CHALLENGE IN BROWN NORWAY RATS AND CORRELATIONS AMONG PATHOPHYSIOLOGICAL MEDIATORS (P. SinghI, D.W. Winsett2, M.J. Daniels2, J. Richards2, K. Crissman2, D.L. Doerfler2 and M.I. Gilmour2, 1NCSU, Ra...

186

Acaricidal activities of major constituents of essential oil of Juniperus chinensis leaves against house dust and stored food mites.  

PubMed

The acaricidal activities of major constituents from the oil of Juniperus chinensis (var. globosa) leaves were compared with those of DEET (N,N-diethyl-m-toluamide) by using impregnated fabric disk bioassay against Dermatophagoides spp. and Tyrophagus putrescentiae. Toxicity varied with doses as well as chemical composition. The 50% lethal doses (LD50) of J. chinensis oil against Dermatophagoides farinae, Dermatophagoides pteronyssinus, and T. putrescentiae were 21.60, 19.89, and 38.10 microg/cm2, respectively. The active constituent was purified using silica gel chromatography and high-performance liquid chromatography. The acaricidal component was identified as bomyl acetate through gas chromatography-mass spectrometry, 1H nuclear magnetic resonance (NMR), 13C-NMR, 1H-13C shift correlation spectrum-NMR, and distortionless enhancement by polarization transfer-NMR. The LD50 of bornyl acetate (2.94 microg/cm2) against D. farinae was significantly lower than those of DEET (37.13 microg/cm2) and alpha-eudesmol (29.72 microg/cm2). Similar results were observed when bomyl acetate and alpha-eudesmol were tested against D. pteronyssinus and T. putrescentiae. The lower LD50 of bornyl acetate indicates that it may be responsible for the major acaricidal activity against house dust and stored food mites, even though it constitutes only 19.5% of J. chinensis oil. Overall, these findings indicated that bornyl acetate and c-eudesmol have potential for use as control agents against house dust and stored food mites. PMID:19722401

Lee, Chi-Hoon; Park, Joon-Moh; Song, Ha-Yun; Jeong, Eun-Young; Lee, Hoi-Seon

2009-08-01

187

Occurrence, speciation and bioaccessibility of lead in Chinese rural household dust and the associated health risk to children  

NASA Astrophysics Data System (ADS)

Lead (Pb) concentration, speciation and bioaccessibility were measured in 122 household dust samples collected in rural areas of eight provinces of China. The mean Pb concentration in the household dust was 208 mg kg -1, of which samples from sites in Hunan (538 mg kg -1) and Yunnan (280 mg kg -1) provinces exhibited the highest Pb concentrations while those from Shaanxi (96 mg kg -1) and Fujian (80 mg kg -1) provinces had a relatively low Pb content. The major fraction of Pb in the household dust samples was found to be strongly bound to Fe-Mn oxide phases (37%) while Pb present in minor fractions individually making up between 14 and 18% was characterized in falling orders as residual, carbonate, organic/sulphide, and exchangeable fractions by the sequential extraction method applied. Bioaccessible Pb making up an average proportion of 53% in the household dusts was significantly correlated to the Fe-Mn oxide phases of Pb. According to the Hazard Quotient (HQ), the ingestion of dust particles pose the highest risk to children in Chinese rural areas, followed by dermal contact and inhalation. Hazard Index (HI) values for most samples were lower than 1, indicating that the domestic Pb exposure in rural areas of China were relatively safe for children when they exposure to the household dust. However, dust Pb in 4.1% of the studied families having HI values higher than 1 may pose adverse health effect to the children.

Han, Zhixuan; Bi, Xiangyang; Li, Zhonggen; Yang, Wenlin; Wang, Lixing; Yang, Huan; Li, Fanglin; Ma, Zhendong

2012-01-01

188

Indirect contact with pets can confound the effect of cleaning procedures for reduction of animal allergen levels in house dust.  

PubMed

To investigate the capacity of common vacuum cleaners and chemical treatment to reduce cat (Fel d I) and dog (Can f I) allergen content in house dust, 52 families with allergic children and no pets at home were recruited. Five groups of 10-11 families used their central vacuum cleaners (n = 10), their own old vacuum cleaners plus either tannic acid (n = 10) or placebo (n = 10) applied to carpets and upholstry after the first sample was collected on Day 0 or new vacuum cleaners equipped with either HEPA (high efficiency particulate air)- (n = 11) or microfilters (n = 10). Dust samples were collected from carpets and upholstered furniture in the living rooms and from the mattresses of the children on Days 0, 7, 21, and 35. Fel d I and Can f I allergens were determined by sandwich ELISA methods. Central, micro-filter and HEPA-filter vacuum cleaners did not reduce the concentrations nor the total amount/sampling area of Fel d I or Can f I. Tannic acid initially reduced (p < 0.05) both the concentration and the total amount of Fel d I by 30% and Can f I by 10%, but only for one week. The levels increased to base-line after 21-35 days. The concentrations of Fel d I increased 10-30 times in homes visited by cats or cat owners. We conclude, that tannic acid treatment reduced pet allergen concentrations and total amounts in dust for one week only.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8173637

Munir, A K; Einarsson, R; Dreborg, S K

1994-02-01

189

Risk assessment of non-dietary exposure to polycyclic aromatic hydrocarbons (PAHs) via house PM2.5, TSP and dust and the implications from human hair  

NASA Astrophysics Data System (ADS)

To evaluate the cancer risk due to non-dietary PAHs exposure in home environment (inhalation and ingestion), exposure to fine particles (PM2.5) and polycyclic aromatic hydrocarbons (PAHs) of PM2.5, total suspend particles (TSP) and dust in homes at two urban centers of Pearl River Delta were assessed. House PM2.5 bound PAHs in Guangzhou (GZ) ranged from 10.0 to 61.9 ng m-3 and 0.72 to 8.15 ng m-3 in Hong Kong (HK). PAH profiles found in PM2.5, TSP and dust were different than that in hair (dominated by Nap and Phe). Pyr and Flu in house dust significantly correlated with that in hair (r = 0.69; 0.55, p < 0.05) but no correlation was found between PAHs in hair and PM2.5. High correlation coefficients (r2 = 0.97/0.95, p < 0.01) were noted between dibenzo(a,h)anthracene (DBA) and Toxicity Equivalent Concentrations (TEQs) of dust and PM2.5. The lung cancer risks based on PM2.5 bound PAHs exposure in houses of GZ (10-5-10-4) were significantly higher than those of HK (10-6-10-5), which were also significantly higher than the cancer risks associated with house dust intake (10-7-10-5) in GZ. PAHs exposure via non-dietary route (PM2.5 and dust) was found to be 1-3 times higher than fish consumption for children and contributed to 52-76% of total PAHs intake for children and 24-50% for adults in GZ.

Wang, Wei; Huang, Min-juan; Chan, Chuen-Yu; Cheung, Kwai Chung; Wong, Ming Hung

2013-07-01

190

Interleukin-1? controls allergic sensitization to inhaled house dust mite via the epithelial release of GM-CSF and IL-33  

PubMed Central

House dust mite (HDM) is one of the most common allergens worldwide. In this study, we have addressed the involvement of IL-1 in the interaction between HDM and the innate immune response driven by lung epithelial cells (ECs) and dendritic cells (DCs) that leads to asthma. Mice lacking IL-1R on radioresistant cells, but not hematopoietic cells, failed to mount a Th2 immune response and did not develop asthma to HDM. Experiments performed in vivo and in isolated air–liquid interface cultures of bronchial ECs showed that TLR4 signals induced the release of IL-1?, which then acted in an autocrine manner to trigger the release of DC-attracting chemokines, GM-CSF, and IL-33. Consequently, allergic sensitization to HDM was abolished in vivo when IL-1?, GM-CSF, or IL-33 was neutralized. Thymic stromal lymphopoietin (TSLP) became important only when high doses of allergen were administered. These findings put IL-1? upstream in the cytokine cascade leading to epithelial and DC activation in response to inhaled HDM allergen. PMID:22802353

Willart, Monique A.M.; Deswarte, Kim; Pouliot, Philippe; Braun, Harald; Beyaert, Rudi; Lambrecht, Bart N.

2012-01-01

191

77 FR 16796 - Lead Requirements for Lead-Based Paint Activities in Target Housing and Child-Occupied Facilities...  

Federal Register 2010, 2011, 2012, 2013

...activities in target housing and child-occupied facilities under...activities in target housing and child-occupied facilities under...buildings, bridges and other structures or superstructures. Those...activities in target housing and child-occupied facilities (a...

2012-03-22

192

24 CFR 1000.40 - Do lead-based paint poisoning prevention requirements apply to affordable housing activities...  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Do lead-based paint poisoning prevention requirements...ACTIVITIES General § 1000.40 Do lead-based paint poisoning prevention requirements...housing activities under NAHASDA? Yes, lead-based paint requirements apply...

2012-04-01

193

24 CFR 1000.40 - Do lead-based paint poisoning prevention requirements apply to affordable housing activities...  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Do lead-based paint poisoning prevention requirements...ACTIVITIES General § 1000.40 Do lead-based paint poisoning prevention requirements...housing activities under NAHASDA? Yes, lead-based paint requirements apply...

2011-04-01

194

24 CFR 1000.40 - Do lead-based paint poisoning prevention requirements apply to affordable housing activities...  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Do lead-based paint poisoning prevention requirements...ACTIVITIES General § 1000.40 Do lead-based paint poisoning prevention requirements...housing activities under NAHASDA? Yes, lead-based paint requirements apply...

2013-04-01

195

24 CFR 1000.40 - Do lead-based paint poisoning prevention requirements apply to affordable housing activities...  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Do lead-based paint poisoning prevention requirements...ACTIVITIES General § 1000.40 Do lead-based paint poisoning prevention requirements...housing activities under NAHASDA? Yes, lead-based paint requirements apply...

2010-04-01

196

24 CFR 1000.40 - Do lead-based paint poisoning prevention requirements apply to affordable housing activities...  

...2014-04-01 2014-04-01 false Do lead-based paint poisoning prevention requirements...ACTIVITIES General § 1000.40 Do lead-based paint poisoning prevention requirements...housing activities under NAHASDA? Yes, lead-based paint requirements apply...

2014-04-01

197

Divergent immune responses to house dust mite lead to distinct structural-functional phenotypes.  

PubMed

Asthma is a chronic airway inflammatory disease that encompasses three cardinal processes: T helper (Th) cell type 2 (Th2)-polarized inflammation, bronchial hyperreactivity, and airway wall remodeling. However, the link between the immune-inflammatory phenotype and the structural-functional phenotype remains to be fully defined. The objective of these studies was to evaluate the relationship between the immunologic nature of chronic airway inflammation and the development of abnormal airway structure and function in a mouse model of chronic asthma. Using IL-4-competent and IL-4-deficient mice, we created divergent immune-inflammatory responses to chronic aeroallergen challenge. Immune-inflammatory, structural, and physiological parameters of chronic allergic airway disease were evaluated in both strains of mice. Although both strains developed airway inflammation, the profiles of the immune-inflammatory responses were markedly different: IL-4-competent mice elicited a Th2-polarized response and IL-4-deficient mice developed a Th1-polarized response. Importantly, this chronic Th1-polarized immune response was not associated with airway remodeling or bronchial hyperresponsiveness. Transient reconstitution of IL-4 in IL-4-deficient mice via an airway gene transfer approach led to partial Th2 repolarization and increased bronchial hyperresponsiveness, along with full reconstitution of airway remodeling. These data show that distinct structural-functional phenotypes associated with chronic airway inflammation are strictly dependent on the nature of the immune-inflammatory response. PMID:17586699

Johnson, Jill R; Swirski, Filip K; Gajewska, Beata U; Wiley, Ryan E; Fattouh, Ramzi; Pacitto, Stephanie R; Wong, Jonathan K; Stämpfli, Martin R; Jordana, Manel

2007-09-01

198

Housing  

MedlinePLUS

... AIDS.gov Mission and Team • Contact Us • Privacy Policy • Disclaimer Network blog.aids.gov • locator.aids.gov • facing.aids.gov • providertools.aids.gov • HIV/AIDS Service Locator Locator ... & Viewers HHS 508 Privacy Policy White House USA.gov This is an official ...

199

Airborne Lead, Dust, and Asbestos-like Fibers in Mechanical Street Cleaner Environments and an Evaluation of Some Contributory Factors  

Microsoft Academic Search

Exposures of mechanical street sweeper operators to lead, asbestos, and dust were determined, and an evaluation of the factors contributing to the level of exposure was conducted. Factors evaluated included rain, frequency of sweeping, traffic volume, and age of the dwellings in the sweeping areas. Sampling was conducted during the months of July through September. Sweeping routes were categorized according

Patrick Bohan; Vicki Hertzberg; William Burg; Scott Clark

1991-01-01

200

Hydrometallurgical recovery of zinc and lead from electric arc furnace dust using mononitrilotriacetate anion and hexahydrated ferric chloride  

Microsoft Academic Search

The purpose of this work was to study the feasibility at laboratory-scale of a new hydrometallurgical process for treating electric arc furnace dusts (EAFD). The proposed process is intended to extract zinc and lead from EAFD without destroying the iron oxides matrix. So, this material can be recycled by the steel industry. Independently of the origin of the samples, major

Nathalie Leclerc; Eric Meux; Jean-Marie Lecuire

2002-01-01

201

Duration of exposure--histological effects on broiler lungs, performance, and house environment with Mt. St. Helens volcanic ash dust  

SciTech Connect

Fourteen hundred broilers were exposed to Mt. St. Helens volcanic ash (VA) dust (D) from 28 to 49 days of age to correlate the duration of exposure time to histological effect on lungs and to determine the effects on broiler performance and house environment. Histological examinations of the lungs from birds exposed each day for 4 days to either VAD for 60 min (VAD 60) in the morning and afternoon (3276 g VA/day), or VAD after one direct application (DiAp) (20 kg/m2) on wood shaving litter revealed mild lymphoid hyperplasia and granuloma formation accompanied by phagocytized crystalline material seen in some alveolar macrophages; however, no effect was observed in lung tissues from broilers exposed each day for 4 days to VAD for 15 min (VAD 15) in the morning and afternoon (82 g VAD/day). Birds exposed to all VAD treatments and examined after 7 days had histological changes in the lungs, including giant cell granuloma formation, similar to those seen at 4 days. No significant histopathological changes were found in the turbinates with any VAD treatments. Levels of mean body weight, ammonia concentration, mortality, and respiratory dust (particles ranging in size from .5 to 10 micron) levels were not significantly different among the treatments. Significantly poorer mean feed conversion was observed with broilers exposed to VAD 60 than the VA DiAp exposure. No difference in feed conversion was observed between the control and either VAD 15 or VAD 60 treatments. From this experiment, the observed histological changes in the lungs occurred with 4 days or less exposure to VAD 60 (3276 g/day).

Bland, M.C.; Nakaue, H.S.; Goeger, M.P.; Helfer, D.H.

1985-01-01

202

Genetically Engineered Lactococcus lactis Protect against House Dust Mite Allergy in a BALB/c Mouse Model  

PubMed Central

Background Mucosal vaccine based on lactic acid bacteria is an attractive concept for the prevention and treatment of allergic diseases, but their mechanisms of action in vivo are poorly understood. Therefore, we sought to investigate how recombinant major dust mite allergen Der p2-expressing Lactococcus lactis as a mucosal vaccine induced the immune tolerance against house dust mite allergy in a mouse model. Methods Three strains of recombinant L. lactis producing Der p2 in different cell components (extracellular, intracellular and cell wall) were firstly constructed. Their prophylactic potential was evaluated in a Der p2-sensitised mouse model, and immunomodulation properties at the cellular level were determined by measuring cytokine production in vitro. Results Der p2 expressed in the different recombinant L. lactis strains was recognized by a polyclonal anti-Der p2 antibody. Oral treatment with the recombinant L. lactis prior sensitization significantly prevented the development of airway inflammation in the Der p2-sensitized mice, as determined by the attenuation of inflammatory cells infiltration in the lung tissues and decrease of Th2 cytokines IL-4 and IL-5 levels in bronchoalveolar lavage. In addition, the serum allergen-specific IgE levels were significantly reduced, and the levels of IL-4 in the spleen and mesenteric lymph nodes cell cultures were also markedly decreased upon allergen stimulation in the mice fed with the recombinant L. lactis strains. These protective effects correlated with a significant up-regulation of regulatory T cells in the mesenteric lymph nodes. Conclusion Oral pretreatment with live recombinant L. lactis prevented the development of allergen-induced airway inflammation primarily by the induction of specific mucosal immune tolerance. PMID:25290938

Ai, Chunqing; Zhang, Qiuxiang; Ren, Chengcheng; Wang, Gang; Liu, Xiaoming; Tian, Fengwei; Zhao, Jianxin; Zhang, Hao; Chen, Yong Q.; Chen, Wei

2014-01-01

203

Protease-Activated Receptor-2 Activation Contributes to House Dust Mite-Induced IgE Responses in Mice  

PubMed Central

Aeroallergens such as house dust mite (HDM), cockroach, and grass or tree pollen are innocuous substances that can induce allergic sensitization upon inhalation. The serine proteases present in these allergens are thought to activate the protease-activated receptor (PAR)-2, on the airway epithelium, thereby potentially inducing allergic sensitization at the expense of inhalation tolerance. We hypothesized that the proteolytic activity of allergens may play an important factor in the allergenicity to house dust mite and is essential to overcome airway tolerance. Here, we aimed to investigate the role of PAR-2 activation in allergic sensitization and HDM-induced allergic airway inflammation. In our study, Par-2 deficient mice were treated with two different HDM extracts containing high and low serine protease activities twice a week for a period of 5 weeks. We determined airway inflammation through quantification of percentages of mononuclear cells, eosinophils and neutrophils in the bronchial alveolar lavage fluid and measured total IgE and HDM-specific IgE and IgG1 levels in serum. Furthermore, Th2 and pro-inflammatory cytokines including IL-5, IL-13, Eotaxin-1, IL-17, KC, Chemokine (C-C motif) ligand 17 (CCL17) and thymic stromal lymphopoietin (TSLP), were measured in lung tissue homogenates. We observed that independent of the serine protease content, HDM was able to induce elevated levels of eosinophils and neutrophils in the airways of both wild-type (WT) and Par-2 deficient mice. Furthermore, we show that induction of pro-inflammatory cytokines by HDM exposure is independent of Par-2 activation. In contrast, serine protease activity of HDM does contribute to enhanced levels of total IgE, but not HDM-specific IgE. We conclude that, while Par-2 activation contributes to the development of IgE responses, it is largely dispensable for the HDM-induced induction of pro-inflammatory cytokines and airway inflammation in an experimental mouse model of HDM-driven allergic airway disease. PMID:24651123

Post, Sijranke; Heijink, Irene H.; Petersen, Arjen H.; de Bruin, Harold G.; van Oosterhout, Antoon J. M.; Nawijn, Martijn C.

2014-01-01

204

A GM-CSF/IL-33 pathway facilitates allergic airway responses to sub-threshold house dust mite exposure.  

PubMed

Allergic asthma is a chronic immune-inflammatory disease of the airways. Despite aeroallergen exposure being universal, allergic asthma affects only a fraction of individuals. This is likely related, at least in part, to the extent of allergen exposure. Regarding house dust mite (HDM), we previously identified the threshold required to elicit allergic responses in BALB/c mice. Here, we investigated the impact of an initial immune perturbation on the response to sub-threshold HDM exposure. We show that transient GM-CSF expression in the lung facilitated robust eosinophilic inflammation, long-lasting antigen-specific Th2 responses, mucus production and airway hyperresponsiveness. This was associated with increased IL-33 levels and activated CD11b(+) DCs expressing OX40L. GM-CSF-driven allergic responses were significantly blunted in IL-33-deficient mice. IL-33 was localized on alveolar type II cells and in vitro stimulation of human epithelial cells with GM-CSF enhanced intracellular IL-33 independently of IL-1?. Likewise, GM-CSF administration in vivo resulted in increased levels of IL-33 but not IL-1?. These findings suggest that exposures to environmental agents associated with GM-CSF production, including airway infections and pollutants, may decrease the threshold of allergen responsiveness and, hence, increase the susceptibility to develop allergic asthma through a GM-CSF/IL-33/OX40L pathway. PMID:24551140

Llop-Guevara, Alba; Chu, Derek K; Walker, Tina D; Goncharova, Susanna; Fattouh, Ramzi; Silver, Jonathan S; Moore, Cheryl Lynn; Xie, Juliana L; O'Byrne, Paul M; Coyle, Anthony J; Kolbeck, Roland; Humbles, Alison A; Stämpfli, Martin R; Jordana, Manel

2014-01-01

205

A GM-CSF/IL-33 Pathway Facilitates Allergic Airway Responses to Sub-Threshold House Dust Mite Exposure  

PubMed Central

Allergic asthma is a chronic immune-inflammatory disease of the airways. Despite aeroallergen exposure being universal, allergic asthma affects only a fraction of individuals. This is likely related, at least in part, to the extent of allergen exposure. Regarding house dust mite (HDM), we previously identified the threshold required to elicit allergic responses in BALB/c mice. Here, we investigated the impact of an initial immune perturbation on the response to sub-threshold HDM exposure. We show that transient GM-CSF expression in the lung facilitated robust eosinophilic inflammation, long-lasting antigen-specific Th2 responses, mucus production and airway hyperresponsiveness. This was associated with increased IL-33 levels and activated CD11b+ DCs expressing OX40L. GM-CSF-driven allergic responses were significantly blunted in IL-33-deficient mice. IL-33 was localized on alveolar type II cells and in vitro stimulation of human epithelial cells with GM-CSF enhanced intracellular IL-33 independently of IL-1?. Likewise, GM-CSF administration in vivo resulted in increased levels of IL-33 but not IL-1?. These findings suggest that exposures to environmental agents associated with GM-CSF production, including airway infections and pollutants, may decrease the threshold of allergen responsiveness and, hence, increase the susceptibility to develop allergic asthma through a GM-CSF/IL-33/OX40L pathway. PMID:24551140

Llop-Guevara, Alba; Chu, Derek K.; Walker, Tina D.; Goncharova, Susanna; Fattouh, Ramzi; Silver, Jonathan S.; Moore, Cheryl Lynn; Xie, Juliana L.; O'Byrne, Paul M.; Coyle, Anthony J.; Kolbeck, Roland; Humbles, Alison A.; Stampfli, Martin R.; Jordana, Manel

2014-01-01

206

Diesel Exhaust Particles Induce Cysteine Oxidation and S-Glutathionylation in House Dust Mite Induced Murine Asthma  

PubMed Central

Background Diesel exhaust particle (DEP) exposure enhances allergic inflammation and has been linked to the incidence of asthma. Oxidative stress on the thiol molecules cysteine (Cys) and glutathione (GSH) can promote inflammatory host responses. The effect of DEP on the thiol oxidation/reduction (redox) state in the asthmatic lung is unknown. Objective To determine if DEP exposure alters the Cys or GSH redox state in the asthmatic airway. Methods Bronchoalveolar lavage fluid was obtained from a house dust mite (HDM) induced murine asthma model exposed to DEP. GSH, glutathione disulfide (GSSG), Cys, cystine (CySS), and s-glutathionylated cysteine (CySSG) were determined by high pressure liquid chromatography. Results DEP co-administered with HDM, but not DEP or HDM alone, decreased total Cys, increased CySS, and increased CySSG without significantly altering GSH or GSSG. Conclusions DEP exposure promotes oxidation and S-glutathionylation of cysteine amino acids in the asthmatic airway, suggesting a novel mechanism by which DEP may enhance allergic inflammatory responses. PMID:23555996

Lee, Gerald B.; Brandt, Eric B.; Xiao, Chang; Gibson, Aaron M.; Le Cras, Timothy D.; Brown, Lou Ann S.; Fitzpatrick, Anne M.; Khurana Hershey, Gurjit K.

2013-01-01

207

Crystallization and Preliminary X-ray Analysis of Der f 2, a Potent Allergen Derived from the House Dust Mite  

NASA Technical Reports Server (NTRS)

Although a number of allergens have been identified and isolated, the underlying molecular basis for the potent immune response is poorly understood. House dust mites (Dermatophugoides sp.) are particularly ubiquitous contributors to atopy in developed countries. The rhinitis, dermatitis, and asthma associated with allergic reactions to these arthropods are often caused by relatively small (125-129 amino acids) mite proteins of unclear biological function. Der f 2, a major allergen from the mite Dermatophagoides farinae, has been recombinantly expressed and characterized. The Der f 2 protein has been crystallized in our laboratory and a native data set collected at a synchrotron source. The crystals belong to the orthorhombic space group I422 with unit cell parameters of a = 95.2 Angstroms, b = 95.2 Angstroms, and c = 103.3 Angstroms. An essentially complete (97.2%) data set has been collected to 2.4 Angstroms. Attempts to solve the crystal structure of Der f 2 by molecular replacement using the available NMR coordinates for either Der f 2 or Der p 2 (the homologous protein from D. pterovssinus) failed to reveal a creditable solution.

Roeber, Dana; Achari, Aniruddha; Takai, Toshiro; Okumura, Yasushi; Scott, David L.; Curreri, Peter (Technical Monitor)

2002-01-01

208

Long-term Effects of Specific Allergen Immunotherapy Against House Dust Mites in Polysensitized Patients With Allergic Rhinitis  

PubMed Central

Purpose Allergen-specific immunotherapy is the only currently available treatment to modify the natural history of allergic rhinitis (AR). If patients are polysensitized, it is difficult to identify the allergen causing the allergic symptoms. We evaluated the effectiveness of immunotherapy against house dust mites (HDMs) in AR patients polysensitized to both HDMs and seasonal allergens. Methods Thirty AR patients polysensitized to both HDMs and seasonal allergens (group A) and 30 patients sensitized to HDMs only (group B) were enrolled in this study. All subjects who received immunotherapy against HDMs for more than 2 years were evaluated by the multiple allergen simultaneous test (MAST) to determine the specific IgE level in luminescence units, total eosinophil counts in peripheral blood, serum total IgE, total nasal symptom scores, and the rhinoconjunctivitis quality of life questionnaire (RQLQ) before and after immunotherapy. Results There were no statistical differences in levels of total and specific IgE, or total eosinophil count between the two groups. The total nasal symptom scores, RQLQ and medication scores significantly decreased after immunotherapy in both groups, however no significant differences were noted between the two groups. Conclusions We determined that the primary causative allergen of AR in Seoul, Korea is perennial allergens, such as HDMs, rather than seasonal allergens. This study provides a reference for the selection of allergens to use in immunotherapy for polysensitized AR patients living in an urban environment. PMID:25374753

Kim, Sang Hoon; Lee, Kun Hee; Kim, Sung Wan; Cho, Joong Saeng

2014-01-01

209

Group 10 allergens (tropomyosins) from house-dust mites may cause covariation of sensitization to allergens from other invertebrates  

PubMed Central

Group 10 allergens (tropomyosins) have been assumed to be a major cause of cross-reactivity between house-dust mites (HDMs) and other invertebrates. Despite all of the published data regarding the epidemiology, percent IgE binding and level of sensitization in the population, the role of tropomyosin as a cross-reactive allergen in patients with multiple allergy syndrome still remains to be elucidated. Homology between amino acid sequences reported in allergen databases of selected invertebrate tropomyosins was determined with Der f 10 as the reference allergen. The 66.9 and 54.4% identities were found with selected crustacean and insect species, respectively, whereas only 20.4% identity was seen with mollusks. A similar analysis was performed using reported B-cell IgE-binding epitopes from Met e1 (shrimp allergen) and Bla g7 (cockroach allergen) with other invertebrate tropomyosins. The percent identity in linear sequences was higher than 35% in mites, crustaceans, and cockroaches. The polar and hydrophobic regions in these groups were highly conserved. These findings suggest that tropomyosin may be a major cause of covariation of sensitization between HDMs, crustaceans, and some species of insects and mollusks. PMID:23342293

Inam, Muhammad; Ismail, Muhammad; Chaudhary, Farhana Riaz

2012-01-01

210

Interference in foraging behaviour of European and American house dust mites Dermatophagoides pteronyssinus and Dermatophagoides farinae (Acari: Pyroglyphidae) by catmint, Nepeta cataria (Lamiaceae).  

PubMed

The European and American house dust mites, Dermatophagoides pteronyssinus and D. farinae, have a huge impact upon human health worldwide due to being the most important indoor trigger of atopic diseases such as asthma, rhinitis and atopic dermatitis. Preceding studies have shown that the behavioural response of house dust mites towards volatile chemicals from food sources can be assessed using a Y-tube olfactometer assay. In the current study, we used this assay to investigate, for the first time, the ability of the essential oil of the catmint plant, Nepeta cataria (Lamiaceae), known to repel other ectoparasites affecting human and animal health, to interfere with the attraction of D. pteronyssinus and D. farinae towards a standard food source (fish flakes). Two distinct chemotypes (A and B), enriched in the iridoid compounds (4aS,7S,7aR)-nepetalactone and (4aS,7S,7aS)-nepetalactone, and the sesquiterpene (E)-(1R,9S)-caryophyllene, were used. Initial assays with a hexane extract of fish flakes (FF extract) confirmed attraction of mites to this positive control (P < 0.001 and P < 0.05 for D. pteronyssinus and D. farinae respectively), but when presented in combination with either N. cataria chemotype, tested across a range of doses (10, 1, 0.1 and 0.01 ?g), decreasing attraction of mites to their food source was observed as the dose augmented. Our study shows that N. cataria, enriched in iridoid nepetalactones and (E)-(1R,9S)-caryophyllene, exhibits potent repellent activity for house dust mites, and has the potential for deployment in control programmes based on interference with normal house dust mite behaviour. PMID:22382713

Khan, M A; Jones, I; Loza-Reyes, E; Cameron, M M; Pickett, J A; Birkett, M A

2012-05-01

211

Lead analysis in urban dust on St. Thomas, U.S. Virgin Islands  

NASA Astrophysics Data System (ADS)

The average concentration of Pb in urban dust in central Charlotte Amalie, St. Thomas, U.S. Virgin Islands, was found to be 803 ppm. On the hills in the town the level was higher, over 2000 ppm. The Pb content of dust was found to depend on the distance from the street of the sampling site, but the dependence was less than expected. Urban dust samples taken on the neighbouring island of St. Croix, where there is lower traffic density, showed an average Pb level of 327 ppm.

Brown, D. R.

212

Relationship between the level of lead absorption in children and the age, type, and condition of housing  

SciTech Connect

A group of 184 preschool-aged children with pretreatment blood lead concentrations (PbB) greater than or equal to 50 g/dl, who received in-patient chelation therapy, were followed prospectively as out-patients for 12 months after discharge. Of these, 160 were followed for 24-30 months. Serial PbB data were analyzed according to the type of housing to which each child was discharged. Following therapy, PbB stabilized by 3 months. Thereafter, highly significant differences existed between those living in or visiting old houses in which lead-in-paint hazards had been abated according to local ordinances (anti m PbB = 38.5 g/dl) and those discharged to lead-free public housing (anti m PbB = 28.8 g/dl) or to recently, totally gutted and renovated old housing (anti m PbB = 28.7 g/dl). During the period of study (1978-1982), no downward trend in PbB within housing groups was found during the first 12 months of follow-up. Of the 152 children discharged to old housing, 75 had 127 recurrences of PbB greater than or equal to 50 g/dl. This emphasizes the need for close and prolonged follow-up in all cases. These data indicate that substantially improved methods of detection, classification, and abatement of lead hazards must replace traditional methods if lead exposure for young children in old housing is to be reduced to an acceptable level.

Chisolm, J.J. Jr.; Mellits, E.D.; Quaskey, S.A.

1985-10-01

213

Effects of one-year hyposensitization in allergic rhinitis. Comparison of two house dust mite extracts.  

PubMed

In an open study, 21 patients suffering from chronic non-seasonal rhinitis and allergic to house mites (HDM) have been treated for 1 year with either a new extract (Pharmalagen; n = 10) or an allergoid, pyridine denatured, extract (Alavac; n = 11), both precipitated with AlOH3 (depot). The following investigations were performed before and after therapy: clinical scoring (for 4 weeks), quantified skin prick tests (SPT) and nasal provocation tests (NPT) with HDM, and determination in serum of HDM-specific IgE and IgG. Both groups were compared with six patients who remained untreated and underwent the same investigations. Hyposensitization with either extract induced an improvement in clinical scores (P less than 0.05), a decrease in SPT reactivity (Pharmalgen: P less than 0.001; Alavac: P less than 0.01), a marked increase in the nasal tolerance to HDM (P less than 0.001) and in HDM-specific IgG (P less than 0.001). In the group of untreated patients, all these parameters remained unchanged. Compared with the Alavac extract, the Pharmalgen extract was more active in decreasing SPT reactions (P less than 0.05) and inducing a HDM-specific IgG rise (P less than 0.05). Although both extracts induced some untoward allergic reactions, no adrenaline was used at any time during the study. These data suggest that hyposensitization with depot extracts of HDM can be considered a safe and active adjunct to the treatment of allergic rhinitis. PMID:2378442

Pécoud, A; Nicod, L; Badan, M; Agrell, B; Dreborg, S; Kolly, M

1990-07-01

214

5A, an apolipoprotein A-I mimetic peptide, attenuates the induction of house dust mite-induced asthma.  

PubMed

New treatment approaches are needed for patients with asthma. Apolipoprotein A-I (apoA-I), the major structural protein of high-density lipoproteins, mediates reverse cholesterol transport and has atheroprotective and anti-inflammatory effects. In this study, we hypothesized that an apoA-I mimetic peptide might be effective at inhibiting asthmatic airway inflammation. A 5A peptide, which is a synthetic, bihelical apoA-I mimetic, was administered to wild-type A/J mice via osmotic mini-pump prior to the induction of house dust mite (HDM)-induced asthma. HDM-challenged mice that received the 5A apoA-I mimetic peptide had significant reductions in the number of bronchoalveolar lavage fluid eosinophils, lymphocytes, and neutrophils, as well as in histopathological evidence of airway inflammation. The reduction in airway inflammation was mediated by a reduction in the expression of Th2- and Th17-type cytokines, as well as in chemokines that promote T cell and eosinophil chemotaxis, including CCL7, CCL17, CCL11, and CCL24. Furthermore, the 5A apoA-I mimetic peptide inhibited the alternative activation of pulmonary macrophages in the lungs of HDM-challenged mice. It also abrogated the development of airway hyperresponsiveness and reduced several key features of airway remodeling, including goblet cell hyperplasia and the expression of collagen genes (Col1a1 and Col3a1). Our results demonstrate that the 5A apoA-I mimetic peptide attenuates the development of airway inflammation and airway hyperresponsiveness in an experimental murine model of HDM-induced asthma. These data support the conclusion that strategies using apoA-I mimetic peptides, such as 5A, might be developed further as a possible new treatment approach for asthma. PMID:21115733

Yao, Xianglan; Dai, Cuilian; Fredriksson, Karin; Dagur, Pradeep K; McCoy, J Philip; Qu, Xuan; Yu, Zu-Xi; Keeran, Karen J; Zywicke, Gayle J; Amar, Marcelo J A; Remaley, Alan T; Levine, Stewart J

2011-01-01

215

Proteolytic Activity Present in House-Dust-Mite Extracts Degrades ENA-78/CXCL5 and Reduces Neutrophil Migration  

PubMed Central

Background. Bronchial smooth muscle cells (BSMC) are a major source of proinflammatory and proangiogenic cytokines and chemokines, including VEGF and CXC-chemokines. CXC-chemokines act primarily on neutrophils, mediating their recruitment to and activation at the site of inflammation. In humans, house-dust mite (HDM) allergens can cause asthmatic exacerbations and trigger an inflammatory response through protease-dependent mechanisms. Objective. We investigated the effect HDM extract on the release of pro-angiogenic and proinflammatory cytokines from BSMC. Methods. Human primary BSMC were stimulated with HDM extract in the absence or presence of fetal calf serum (FCS). Twenty angiogenic cytokines were detected by a specific antibody array and modified protein levels were confirmed by ELISA. Neutrophil migration was measured using a 96-well Boyden chamber. Results. ENA-78/CXCL5 protein levels in conditioned medium of BSMC stimulated with HDM extract were significantly reduced (n = 10, P < 0.05) but restored in the presence of 5% FCS. HDM extracts did not affect ENA-78/CXCL5 mRNA levels. Recombinant ENA-78/CXCL5 was degraded after incubation with HDM extracts (n = 7, P < 0.05) but restored after the addition of the serine protease AEBSF. Neutrophil migration towards recombinant ENA-78/CXCL5 was also reduced in the presence of HDM extract. Conclusion. HDM proteases degrade ENA-78/CXCL5. Thus exposure to HDM allergens may alter ENA-78/CXCL5 levels in the lungs and may affect angiogenesis and the inflammatory response in the airways of asthma patients. PMID:24883064

Keglowich, Laura; Tamm, Michael; Zhong, Jun; Miglino, Nicola; Borger, Pieter

2014-01-01

216

Regulation of Constitutive Neutrophil Apoptosis Due to House Dust Mite Allergen in Normal and Allergic Rhinitis Subjects  

PubMed Central

House dust mite (HDM) is a primary allergen in allergic rhinitis (AR) and asthma. Neutrophil apoptosis is associated with allergic diseases and innate immunity to infection. The present study examined how HDM affects constitutive neutrophil apoptosis in normal and AR subjects. Total IgE increased in AR subjects when compared to normal subjects, and patients with AR were HDM-specific IgE positive (+), which is specific IgE to Dermatophagoides pteronissinus and Dermatophagoides farinae. In normal and AR subjects, neutrophil apoptosis was inhibited by extract of Dermatophagoides pteronissinus (DP), but not by extract of Dermatophagoides farina (DF). Aprotinin (serine protease inhibitor) and E64 (cysteine protease inhibitor) have no effect on neutrophil apoptosis due to DP. The anti-apoptotic effect of DP was blocked by TLR4i, an inhibitor of TLR4, rottlerin, an inhibitor of PKC?, PD98059, an inhibitor of ERK, and BAY-11-7085, an inhibitor of NF-?B. DP induced PKC?, ERK, and NF-?B activation in a time-dependent manner. DP inhibited the cleavage of procaspase 3 and procaspase 9. The expression of IL-6, IL-8, TNF-?, G-CSF, GM-CSF, and CCL2 increased in the supernatant collected from the normal and AR neutrophils after DP treatment and the supernatant inhibited the apoptosis of normal and AR neutrophils. In summary, DP has anti-apoptotic effects on neutrophils of normal and AR subjects through the TLR4/PKC?/ERK/NF-?B pathway, and this finding may contribute to solution of the pathogenic mechanism of allergic diseases triggered by DP. PMID:25243400

Kim, Eun Hye; Lee, Ji-Sook; Lee, Na Rae; Baek, Seung Yeop; Kim, Eun Jeong; Lee, Soo Jin; Kim, In Sik

2014-01-01

217

Morus alba L. suppresses the development of atopic dermatitis induced by the house dust mite in NC/Nga mice  

PubMed Central

Background Morus alba, a medicinal plant in Asia, has been used traditionally to treat diabetes mellitus and hypoglycemia. However, the effects of M. alba extract (MAE) on atopic dermatitis have not been verified scientifically. We investigated the effects of MAE on atopic dermatitis through in vitro and in vivo experiments. Methods We evaluated the effects of MAE on the production of nitric oxide (NO) and prostaglandin E2 (PGE2) in RAW 264.7, as well as thymus and activation-regulated chemokine (TARC/CCL17) in HaCaT cells. In an in vivo experiment, atopic dermatitis was induced by topical application of house dust mites for four weeks, and the protective effects of MAE were investigated by measuring the severity of the skin reaction on the back and ears, the plasma levels of immunoglobulin E (IgE) and histamine, and histopathological changes in the skin on the back and ears. Results MAE suppressed the production of NO and PGE2 in RAW 264.7 cells, as well as TARC in HaCaT cells, in a dose-dependent manner. MAE treatment of NC/Nga mice reduced the severity of dermatitis and the plasma levels of IgE and histamine. MAE also reduced the histological manifestations of atopic dermatitis-like skin lesions such as erosion, hyperplasia of the epidermis and dermis, and inflammatory cell infiltration in the skin on the back and ears. Conclusion Our results suggest that MAE has potent inhibitory effects on atopic dermatitis-like lesion and may be a beneficial natural resource for the treatment of atopic dermatitis. PMID:24755250

2014-01-01

218

High Degree of Overlap between Responses to a Virus and to the House Dust Mite Allergen in Airway Epithelial Cells  

PubMed Central

Background Airway epithelium is widely considered to play an active role in immune responses through its ability to detect changes in the environment and to generate a microenvironment for immune competent cells. Therefore, besides its role as a physical barrier, epithelium affects the outcome of the immune response by the production of various pro-inflammatory mediators. Methods We stimulated airway epithelial cells with viral double stranded RNA analogue poly(I:C) or with house dust mite in a time course of 24 hours. In order to determine cytokines production by stimulated cells, we performed multiplex enzyme linked immunosorbant assay (ELISA). Results We demonstrate that the temporal pattern of the genes that respond to virus exposure in airway epithelium resembles to a significant degree their pattern of response to HDM. The gene expression pattern of EGR1, DUSP1, FOSL1, JUN, MYC, and IL6 is rather similar after viral (poly(I:C)) and HDM exposure. However, both triggers also induce a specific response (e.g. ATF3, FOS, and NFKB1). We confirmed these data by showing that epithelial cells produce a variety of similar mediators in response to both poly(I:C) and HDM challenge (IL1-RA, IL-17, IFN-? and MIP1-?), sometimes with a quantitative difference in response (IL2-R, IL-6, IL-8, MCP-1, MIG, and HGF). Interestingly, only four mediators (IL-12, IP-10, RANTES and VEGF) where up-regulated specifically by poly(I:C) and not by HDM. Additionally, we report that pre-exposure to HDM deregulates production of cytokines and mediators in response to poly(I:C). Conclusions Epithelial cells responses to the HDM-allergen and a virus strongly resemble both in gene expression and in protein level explaining why these two responses may affect each other. PMID:24498371

Golebski, Korneliusz; Luiten, Silvia; van Egmond, Danielle; de Groot, Esther; Roschmann, Kristina Irene Lisolette; Fokkens, Wytske Johanna; van Drunen, Cornelis Maria

2014-01-01

219

Acaricidal toxicities of 1-hydroxynaphthalene from Scutellaria barbata and its derivatives against house dust and storage mites.  

PubMed

The essential oil of Scutellaria barbata was extracted using a steam distillation and then evaluated via fumigant and contact toxicity bioassays against Dermatophagoides farinae, Dermatophagoides pteronyssinus, and Tyrophagus putrescentiae. The acaricidal toxicities of 1-hydroxynaphthalene from S. barbata oil and its derivatives were determined and compared with those of benzyl benzoate. Based on the LD50 values of 1-hydroxynaphthalene derivatives against D. farinae, D. pteronyssinus, and T. putrescentiae, obtained using a fumigant toxicity bioassay, the acaricidal activity of 1-hydroxynaphthalene (2.11, 2.37, and 4.50 µg/cm2) was 4.76, 6.00, and 2.68 times higher than that of benzyl benzoate (10.05, 9.50, and 12.50 µg/cm2) in the corresponding order, which was followed by that of 2-hydroxynaphthalene (9.50, 9.00, and 11.50 µg/cm2). On the contact toxicity bioassay, the acaricidal activity of 1-hydroxynaphthalene (0.79, 0.92, and 2.50 µg/cm2) was 9.49, 6.52, and 3.76 times higher than that of benzyl benzoate (7.50, 6.00, and 9.41 µg/cm2), which was followed by that of 2-hydroxynaphthalene (4.21, 4.80, and 6.50 µg/cm2). In conclusion, our results indicate that S. barbata oil and 1-hydroxynaphthalene derivatives might be effective natural agents for the management of house dust and storage mites. PMID:23757178

Yang, Ji-Yeon; Kim, Min-Gi; Lee, Hoi-Seon

2013-07-01

220

Evaluating the bioaccessibility of flame retardants in house dust using an in vitro tenax bead-assisted sorptive physiologically based method.  

PubMed

Exposure to house dust is a significant source of exposure to flame retardant chemicals (FRs), particularly in the US. Given the high exposure there is a need to understand the bioaccessibility of FRs from dust. In this study, Tenax beads (TA) encapsulated within a stainless steel insert were used as an adsorption sink to estimate the dynamic absorption of a suite of FRs commonly detected in indoor dust samples (n = 17), and from a few polyurethane foam samples for comparison. Organophosphate flame retardants (OPFRs) had the highest estimated bioaccessibility (?80%) compared to brominated compounds (e.g., PBDEs), and values generally decreased with increasing Log Kow, with <30% bioaccessibility measured for BDE209. These measurements were in very close agreement with reported PBDE bioavailability measures from an in vivo rat exposure study using indoor dust. The bioaccessibility of very hydrophobic FRs (Log Kow > 6) in foam was much less than that in house dust, and increasing bioaccessibility was observed with decreasing particle size. In addition, we examined the stability of more labile FRs containing ester groups (e.g., OPFRs and 2-ethylhexyl-tetrabromo-benzoate (EH-TBB)) in a mock-digestive fluid matrix. No significant changes in the OPFR concentrations were observed in this fluid; however, EH-TBB was found to readily hydrolyze to tetrabromobenzoic acid (TBBA) in the intestinal fluid in the presence of lipases. In conclusion, our study demonstrates that the bioaccessibility and stability of FRs following ingestion varies by chemical and sample matrix and thus should be considered in exposure assessments. PMID:25330458

Fang, Mingliang; Stapleton, Heather M

2014-11-18

221

Lung-Homing of Endothelial Progenitor Cells and Airway Vascularization Is Only Partially Dependant on Eosinophils in a House Dust Mite-Exposed Mouse Model of Allergic Asthma  

PubMed Central

Background Asthmatic responses involve a systemic component where activation of the bone marrow leads to mobilization and lung-homing of progenitor cells. This traffic may be driven by stromal cell derived factor-1 (SDF-1), a potent progenitor chemoattractant. We have previously shown that airway angiogenesis, an early remodeling event, can be inhibited by preventing the migration of endothelial progenitor cells (EPC) to the lungs. Given intranasally, AMD3100, a CXCR4 antagonist that inhibits SDF-1 mediated effects, attenuated allergen-induced lung-homing of EPC, vascularization of pulmonary tissue, airway eosinophilia and development of airway hyperresponsiveness. Since SDF-1 is also an eosinophil chemoattractant, we investigated, using a transgenic eosinophil deficient mouse strain (PHIL) whether EPC lung accumulation and lung vascularization in allergic airway responses is dependent on eosinophilic inflammation. Methods Wild-type (WT) BALB/c and eosinophil deficient (PHIL) mice were sensitized to house dust mite (HDM) using a chronic exposure protocol and treated with AMD3100 to modulate SDF-1 stimulated progenitor traffic. Following HDM challenge, lung-extracted EPCs were enumerated along with airway inflammation, microvessel density (MVD) and airway methacholine responsiveness (AHR). Results Following Ag sensitization, both WT and PHIL mice exhibited HDM-induced increase in airway inflammation, EPC lung-accumulation, lung angiogenesis and AHR. Treatment with AMD3100 significantly attenuated outcome measures in both groups of mice. Significantly lower levels of EPC and a trend for lower vascularization were detected in PHIL versus WT mice. Conclusions This study shows that while allergen-induced lung-homing of endothelial progenitor cells, increased tissue vascularization and development lung dysfunction can occur in the absence of eosinophils, the presence of these cells worsens the pathology of the allergic response. PMID:25279605

Sivapalan, Nirooya; Wattie, Jennifer; Inman, Mark D.; Sehmi, Roma

2014-01-01

222

Absence of c-Jun NH2-terminal kinase 1 protects against house dust mite-induced pulmonary remodeling but not airway hyperresponsiveness and inflammation.  

PubMed

Chronic allergic asthma leads to airway remodeling and subepithelial fibrosis via mechanisms not fully understood. Airway remodeling is amplified by profibrotic mediators, such as transforming growth factor-?1 (TGF-?1), which plays a cardinal role in various models of fibrosis. We recently have identified a critical role for c-Jun-NH2-terminal-kinase (JNK) 1 in augmenting the profibrotic effects of TGF-?1, linked to epithelial-to-mesenchymal transition of airway epithelial cells. To examine the role of JNK1 in house dust mite (HDM)-induced airway remodeling, we induced allergic airway inflammation in wild-type (WT) and JNK1-/- mice by intranasal administration of HDM extract. WT and JNK1-/- mice were sensitized with intranasal aspirations of HDM extract for 15 days over 3 wk. HDM caused similar increases in airway hyperresponsiveness, mucus metaplasia, and airway inflammation in WT and JNK1-/- mice. In addition, the profibrotic cytokine TGF-?1 and phosphorylation of Smad3 were equally increased in WT and JNK1-/- mice. In contrast, increases in collagen content in lung tissue induced by HDM were significantly attenuated in JNK1-/- mice compared with WT controls. Furthermore HDM-induced increases of ?-smooth muscle actin (?-SMA) protein and mRNA expression as well as the mesenchymal markers high-mobility group AT-hook 2 and collagen1A1 in WT mice were attenuated in JNK1-/- mice. The let-7 family of microRNAs has previously been linked to fibrosis. HDM exposure in WT mice and primary lung epithelial cells resulted in striking decreases in let-7g miRNA that were not observed in mice or primary lung epithelial cells lacking JNK1-/- mice. Overexpression of let-7g in lung epithelial cells reversed the HDM-induced increases in ?-SMA. Collectively, these findings demonstrate an important requirement for JNK1 in promoting HDM-induced fibrotic airway remodeling. PMID:24610935

van der Velden, Jos L J; Hoffman, Sidra M; Alcorn, John F; Tully, Jane E; Chapman, David G; Lahue, Karolyn G; Guala, Amy S; Lundblad, Lennart K A; Aliyeva, Minara; Daphtary, Nirav; Irvin, Charles G; Janssen-Heininger, Yvonne M W

2014-05-01

223

Class specific inhibition of house dust mite proteinases which cleave cell adhesion, induce cell death and which increase the permeability of lung epithelium  

PubMed Central

House dust mite (HDM) allergens with cysteine and serine proteinase activity are risk factors for allergic sensitization and asthma. A simple method to fractionate proteinase activity from HDM faecal pellets into cysteine and serine class activity is described. Both proteinase fractions increased the permeability of epithelial cell monolayers. The effects of the serine proteinase fraction were inhibited by 4-(2-aminoethyl)-benzenesulphonyl fluoride hydrochloride (AEBSF) and soybean trypsin inhibitor (SBTI). The effects of the cysteine proteinase fraction could be inhibited by E-64. No reciprocity of action was found. Treatment of epithelial monolayers with either proteinase fraction caused breakdown of tight junctions (TJs). AEBSF inhibited TJ breakdown caused by the serine proteinase fraction, whereas E-64 inhibited the cysteine proteinase fraction. Agarose gel electrophoresis revealed that the proteinases induced DNA cleavage which was inhibited by the matrix metalloproteinase inhibitor BB-250. Compound E-64 inhibited DNA fragmentation caused by the cysteine proteinase fraction, but was without effect on the serine proteinase fraction. Staining of proteinase-treated cells with annexin V (AV) and propidium iodide (PI) revealed a diversity of cellular responses. Some cells stained only with AV indicating early apoptosis, whilst others were dead and stained with both AV and PI. HDM proteinases exert profound effects on epithelial cells which will promote allergic sensitization; namely disruption of intercellular adhesion, increased paracellular permeability and initiation of cell death. Attenuation of these actions by proteinase inhibitors leads to the conclusion that compounds designed to be selective for the HDM enzymes may represent a novel therapy for asthma. PMID:9720772

Winton, Helen L; Wan, Hong; Cannell, Mark B; Thompson, Philip J; Garrod, David R; Stewart, Geoffrey A; Robinson, Clive

1998-01-01

224

Determinants of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in house dust samples from four areas of the United States  

PubMed Central

Determinants of levels of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) in dust in U.S. homes are not well characterized. We conducted a pilot study to evaluate the relationship between concentrations of PCDD/F in house dust and residential proximity to known sources, including industrial facilities and traffic. Samples from vacuum bag dust from homes of 40 residents of Detroit, Los Angeles, Seattle, or Iowa who participated in a population-based case-control study of non-Hodgkin lymphoma conducted in 1998–2000 were analyzed using high resolution gas chromatography/high resolution mass spectrometry for 7 PCDD and 10 PCDF congeners considered toxic by the U.S. Environmental Protection Agency (EPA). Locations of 10 types of PCDD/F-emitting facilities were obtained from the EPA; however only 4 types were located near study homes (non-hazardous waste cement kilns, coal-fired power plants, sewage sludge incinerators, and medical waste incinerators). Relationships between concentrations of each PCDD/F and proximity to industrial facilities, freight routes, and major roads were evaluated using separate multivariate regression models for each congener. The median (inter-quartile range [IQR]) toxic equivalence (TEQ) concentration of these congeners in the house dust was 20.3 pg/g (IQR=14.3, 32.7). Homes within 3 or 5 km of a cement kiln had 2 to 9-fold higher concentrations of 5 PCDD and 5 PCDF (p<0.1 in each model). Proximity to freight routes and major roads was associated with elevated concentrations of 1 PCDD and 8 PCDF. Higher concentrations of certain PCDD/F in homes near cement kilns, freight routes, and major roads suggest these outdoor sources are contributing to indoor environmental exposures. Further study of the contribution of these sources and other facility types to total PCDD/F exposure in a larger number of homes is warranted. PMID:22832089

NC, Deziel; Nuckols; JS, Colt; AJ, De Roos; A, Pronk; C, Gourley; RK, Severson; W, Cozen; Cerhan; P, Hartge; MH, Ward

2012-01-01

225

Dectin-2 regulates the effector phase of house dust mite-elicited pulmonary inflammation independently from its role in sensitization.  

PubMed

The myeloid C-type lectin receptor Dectin-2 directs the generation of Th2 and Th17 immune responses to the house dust mite Dermatophagoides farinae through the generation of cysteinyl leukotrienes and proinflammatory cytokines, respectively, but a role for Dectin-2 in effector phase responses has not been described. In this study, we demonstrate that administration of the Dectin-2 mAb solely at the time of D. farinae challenge abrogated eosinophilic and neutrophilic inflammation in the bronchoalveolar lavage fluid and Th1, Th2, and Th17 inflammation in the lung of previously sensitized mice. Furthermore, Dectin-2 null mice (Clec4n(-/-)) sensitized with the adoptive transfer of D. farinae-pulsed wild-type (WT) bone marrow-derived dendritic cells (DCs) also had less D. farinae-elicited pulmonary inflammation, supporting an effector function for Dectin-2. The protection from pulmonary inflammation seen with the Dectin-2 mAb or in Clec4n(-/-) mice was associated with little or no reduction in lung-draining lymph node cells or their cytokine production and with no reduction in serum IgE. WT and Clec4n(-/-) mice recipients, sensitized with D. farinae-pulsed WT bone marrow-derived DCs, had comparable levels of D. farinae-elicited IL-6, IL-23, TNF-?, and cysteinyl leukotrienes in the lung. By contrast, D. farinae-elicited CCL4 and CCL8 production from pulmonary CD11c(+)CD11b(+)Ly6C(+) and CD11c(+)CD11b(+)Ly6C(-)CD64(+) monocyte-derived DCs was reduced in Clec4n(-/-) recipients. Addition of CCL8 at the time of D. farinae challenge abrogated the protection from eosinophilic, neutrophilic, and Th2 pulmonary inflammation seen in Clec4n(-/-) recipients. Taken together, these results reveal that Dectin-2 regulates monocyte-derived DC function in the pulmonary microenvironment at D. farinae challenge to promote the local inflammatory response. PMID:24453247

Parsons, Matthew W; Li, Li; Wallace, Aaron M; Lee, Min Jung; Katz, Howard R; Fernandez, James M; Saijo, Shinobu; Iwakura, Yoichiro; Austen, K Frank; Kanaoka, Yoshihide; Barrett, Nora A

2014-02-15

226

Development, application, and results of routine monitoring of Marek's disease virus in broiler house dust using real-time quantitative PCR.  

PubMed

Results are presented from four studies between 2002 and 2011 into the feasibility of routinely monitoring Marek's disease virus serotype 1 (MDV-1) in broiler house dust using real-time quantitative PCR (qPCR) measurement. Study 1 on two farms showed that detection of MDV-1 occurred earlier on average in dust samples tested using qPCR than standard PCR and in spleen samples from five birds per shed assayed for MDV-1 by qPCR or standard PCR. DNA quality following extraction from dust had no effect on detection of MDV-1. Study 2 demonstrated that herpesvirus of turkeys (HVT) and MDV serotype 2 (MDV-2) in addition to MDV-1 could be readily amplified from commercial farm dust samples, often in mixtures. MDV-2 was detected in 11 of 20 samples despite the absence of vaccination with this serotype. Study 3 investigated the reproducibility and sensitivity of the qPCR test and the presence of inhibitors in the samples. Samples extracted and amplified in triplicate showed a high level of reproducibility except at very low levels of virus near the limit of detection. Mixing of samples prior to extraction provided results consistent with the proportions in the mixture. Tests for inhibition showed that if the template contained DNA in the range 0.5-20 ng/microl no inhibition of the reaction was detectable. The sensitivity of the tests in terms of viral copy number (VCN) per milligram of dust was calculated to be in the range 24-600 VCN/mg for MDV-1, 48-1200 VCN/mg for MDV-2, and 182-4560 VCN/mg for HVT. In study 4 the results of 1976 commercial tests carried out for one company were analyzed. Overall 23.1% of samples were positive for MDV-1, 26.1% in unvaccinated and 16.4% in vaccinated chickens. There was marked regional and temporal variation in the proportion of positive samples and the MDV-1 load. The tests were useful in formulating Marek's disease vaccination strategies. The number of samples submitted has increased recently, as has the incidence of positive samples. These studies provide strong evidence that detection and quantitation of MDV-1, HVT, and MDV-2 in poultry house dust using qPCR is robust, sensitive, reproducible, and meaningful, both biologically and commercially. Tactical vaccination based on monitoring of MDV-1 rather than routine vaccination may reduce selection pressure for increased virulence in MDV-1. PMID:23901774

Walkden-Brown, Stephen W; Islam, A F Aminul; Groves, Peter J; Rubite, Ambrosio; Sharpe, Sue M; Burgess, Susan K

2013-06-01

227

Decreased Mitochondrial DNA Content in Association with Exposure to Polycyclic Aromatic Hydrocarbons in House Dust during Wintertime: From a Population Enquiry to Cell Culture  

PubMed Central

Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants that are formed in combustion processes. At the cellular level, exposure to PAHs causes oxidative stress and/or some of it congeners bind to DNA, which may interact with mitochondrial function. However, the influence of these pollutants on mitochondrial DNA (mtDNA) content remains largely unknown. We determined whether indoor exposure to PAHs is associated with mitochondrial damage as represented by blood mtDNA content. Blood mtDNA content (ratio mitochondrial/nuclear DNA copy number) was determined by real-time qPCR in 46 persons, both in winter and summer. Indoor PAH exposure was estimated by measuring PAHs in sedimented house dust, including 6 volatile PAHs and 8 non-volatile PAHs. Biomarkers of oxidative stress at the level of DNA and lipid peroxidation were measured. In addition to the epidemiologic enquiry, we exposed human TK6 cells during 24 h at various concentrations (range: 0 to 500 µM) of benzo(a)pyrene and determined mtDNA content. Mean blood mtDNA content averaged (±SD) 0.95±0.185. The median PAH content amounted 554.1 ng/g dust (25th–75th percentile: 390.7–767.3) and 1385ng/g dust (25th–75th percentile: 1000–1980) in winter for volatile and non-volatile PAHs respectively. Independent for gender, age, BMI and the consumption of grilled meat or fish, blood mtDNA content decreased by 9.85% (95% CI: ?15.16 to ?4.2; p?=?0.002) for each doubling of non-volatile PAH content in the house dust in winter. The corresponding estimate for volatile PAHs was ?7.3% (95% CI: ?13.71 to ?0.42; p?=?0.04). Measurements of oxidative stress were not correlated with PAH exposure. During summer months no association was found between mtDNA content and PAH concentration. The ability of benzo(a)pyrene (range 0 µM to 500 µM) to lower mtDNA content was confirmed in vitro in human TK6 cells. Based on these findings, mtDNA content can be a target of PAH toxicity in humans. PMID:23658810

Pieters, Nicky; Koppen, Gudrun; Smeets, Karen; Napierska, Dorota; Plusquin, Michelle; De Prins, Sofie; Van De Weghe, Hendrik; Nelen, Vera; Cox, Bianca; Cuypers, Ann; Hoet, Peter; Schoeters, Greet; Nawrot, Tim S.

2013-01-01

228

INVESTIGATION OF LEAD TEST KITS FOR ANALYSIS OF PAINT, DUST, AND SOIL  

EPA Science Inventory

A study of commercial lead test kits available as of fall, 1990, was performed. he intent was to perform an initial study of the general behavior and responsiveness of all kits to the same but limited number of test parameters and materials. he manufacturers' instructions provide...

229

Effectiveness of omalizumab in a patient with a life-threatening episode of bronchospasm and larynx angioedema after exposure to house dust  

PubMed Central

Omalizumab is a monoclonal antibody against IgE, nowadays approved for the treatment of persistent severe (EU) or moderate-to severe (USA) IgE-mediated asthma but there is also some evidence (case reports and four published clinical trials) on the effectiveness of this medication in urticaria and angioedema. The case of a 42-year-old woman suffering from severe allergic asthma and severe chronic urticaria with concomitant angioedema is presented in the article. She had a life-threatening episode of bronchospasm and larynx edema after exposure to house dust recorded in her medical history. The patient did not respond to standard therapy. The improvement in asthma control and remission of chronic urticaria and angioedema was achieved after introducing the therapy with omalizumab. PMID:24683397

Korczy?ska, Paulina; Tworek, Damian; Kuna, Piotr

2014-01-01

230

OUTREACH TO MANUFACTURERS OF LEAD TEST KITS  

EPA Science Inventory

Lead test kits offer a potentially rapid, inexpensive, and simple to use technique for the analysis of low levels of lead in paint, soil, and house dust. n order to assess the feasibility of homeowners and contractors using test kits as an indicator of the need for or success of ...

231

Blood lead levels among rural Thai children exposed to lead-acid batteries from solar energy conversion systems.  

PubMed

We evaluate blood lead levels among Thai children to determine if exposure to lead-acid batteries is associated with elevated blood lead levels (EBLL). We screened 254 children aged 1-14 years old from 2 rural Thai villages for blood lead levels. We also screened 18 of 92 houses in these 2 villages for the presence of environmental lead. The overall prevalence of EBLL (> or = 10 microg/dl) was 43.3% and the mean lead level among study subjects was 9.8 +/- 5.1 microg/dl. The blood lead levels significantly decreased with increasing age. Fifty point eight percent of children who lived in a house with vented lead-acid batteries had EBLL while 23.3% of children who lived in a house without vented lead-acid batteries had EBLL. Multiple logistic regression analysis revealed a significant positive association between the presence of vented lead-acid batteries and EBLL, after adjusting for other variables. Forty-two point nine percent of house floor dust samples collected near the batteries had elevated lead levels, 7.1% of house floor dust samples collected from other areas in the house had elevated lead levels and 0% of the house floor dust samples collected in houses without vented lead-acid batteries had elevated lead levels. In the sampled houses with vented lead-acid batteries, lead contamination was found in the drinking-water kept in household containers, but not in the tap water or other village sources of water. Improper care and placement of vented lead-acid batteries can result in lead contamination in the home environment causing EBLL in exposed children. PMID:24450246

Swaddiwudhipong, Witaya; Tontiwattanasap, Worawit; Khunyotying, Wanlee; Sanreun, Cherd

2013-11-01

232

1 http://www.e1.greatlakes.com/fr/products/jsp/firemaster_550.jsp. 2 Stapleton et al.2008.Alternate and New Brominated Flame Retardants Detected in US House Dust.  

E-print Network

on Brominated Flame Retardants,Victoria,BC,Canada. 3 Andersson,P.L.; Oberg,K.; Orn,U.,2006.Chemical,Furniture Flame Retardancy Partnership:Environmental Profiles of Chemical Flame Retardant Alternatives for Low.2008.Alternate and New Brominated Flame Retardants Detected in US House Dust. 10th Annual Workshop

233

Monoclonal antibodies to recombinant Der p 2, a major house dust mite allergen: specificity, epitope analysis and development of two-site capture ELISA  

PubMed Central

House dust mite allergens have been well established as sensitizing agents that are important in the induction of allergic diseases. In order to analyze epitopes of the allergen and to develop a quantitative method of the allergen exposure, monoclonal antibodies against a recombinant Der p 2 (rDer p 2), one of the major allergens of Dermatophagoides pteronyssinus, were produced. Four monoclonal antibodies produced were species-specific and did not cross-react to the D. farinae crude extract. Two of the monoclonal antibodies were found to be IgG1 and the others were IgM. For the analysis of epitopes, a Der p 2 cDNA encoding 126 amino acids (aa) was dissected into three fragments with several overlapping peptides, A (aa residues 1-49), B (44-93), and C fragment (84-126). Three monoclonal antibodies showed reactivities to the recombinant B fragment and to the full-length rDer p 2, but one monoclonal antibody reacted only with the full-length rDer p 2. Two-site capture ELISA was developed using two different monoclonal antibodies for quantitating Der p 2 in house dust. The sensitivity limit was 4 ng/ml with rDer p 2 and 8 µg/ml with the D. pteronyssinus crude extract. The result suggested that the assay using monoclonal antibodies against rDer p 2 could be useful for the environmental studies and for the standardization of mite allergen extracts. PMID:10507224

Lee, Sang-Mi; Park, Gab-Man; Lee, In-Yong; Ree, Han-Il; Kim, Kyung-Sup; Oh, Sang-Hwan; Park, Jung-Won; Hong, Chein-Soo

1999-01-01

234

ELEVATED LEAD LEVELS IN URBAN HOUSE SPARROWS: A THREAT TO SHARP-SHINNED HAWKS AND MERLINS?  

Microsoft Academic Search

ABSTRAGT.--In urban environments, lead (Pb) has been recognized as a health threat to humans as well as wildlife. Although this hazard has waned since the banning of leaded gasoline and paint in the 1970s, soil and atmospheric Pb concentrations have remained higher in disturbed habitats than in exurban habitats. Our study evaluated the threat of Pb exposure to Sharp-shinned Hawks

RICHARD B. CHANDLER; ALLAN M. STRONG; CARLIN C. KAUFMAN

235

Evaluation of dioxin-like activities in settled house dust from Vietnamese E-waste recycling sites: relevance of polychlorinated/brominated dibenzo-p-dioxin/furans and dioxin-like PCBs.  

PubMed

Few studies have investigated the human exposure to the ensemble of dioxin-related compounds (DRCs) released from uncontrolled e-waste recycling, especially from a toxic effect standpoint. This study evaluated the TCDD toxic equivalents (TEQs) in persistent extracts of settled house dust from two Vietnamese e-waste recycling sites (EWRSs) using the Dioxin-Responsive Chemically Activated LUciferase gene eXpression assay (DR-CALUX), combined with chemical analysis of PCDD/Fs, DL-PCBs, PBDD/Fs, and monobromo PCDD/Fs to determine their TEQ contribution. The CALUX-TEQ levels in house dust ranged from 370 to 1000 pg g(-1) in the EWRSs, approximately 3.5-fold higher than in the urban control site. In EWRS house dust, the concentrations of the unregulated PBDFs were 7.7-63 ng g(-1), an order of magnitude higher than those of regulated DRCs (PCDD/Fs and DL-PCBs), and PBDFs were also principal CALUX-TEQ contributors (4.2-22%), comparable to PCDD/Fs (8.1-29%). The CALUX-TEQ contribution of DRCs varied, possibly depending on thermal processing activities (higher PCDD/F-TEQs) and PBDE content in the waste (higher PBDF-TEQs). However, the percentage of unknown dioxin-like activities was high in all dust samples, indicating large contribution from unidentified DRCs and/or synergy among contaminants. Estimates of TEQ intake from dust ingestion suggest that children in the EWRSs may be adversely affected by DRCs from dust. PMID:21058701

Tue, Nguyen M; Suzuki, Go; Takahashi, Shin; Isobe, Tomohiko; Trang, Pham T K; Viet, Pham H; Tanabe, Shinsuke

2010-12-01

236

Encasing lead hazards and adding energy efficiency in low-income housing  

SciTech Connect

Field research has confirmed that the lower the incremental (marginal) cost of producing an outcome, the more likely that production will occur. In residential building rehabilitation the economic truth suggests that energy efficiency is likely to become part of the scope of work of a project when the additional cost of conservation measures are relatively small, i.e., comparing gut rehab to moderate rehab, replacement of a furnace with an energy efficient model, and low-cost solutions to address lead poisoning hazards. Energy efficiency must fit into the overall needs and opportunities of a building retrofit. If little is being done to the building, then few measures can be expected to be justified. If much must be done, however, the opportunities for conservation are likely to be great. An example of this is the composite wall system described, therein, that was developed to address the problem of lead poisoning hazards on wall surfaces while adding a tight, well-insulated, and strong interior surface to perimeter walls at the lowest possible cost.

Cavallo, J.D. [Argonne National Lab., IL (United States); Wendt, R. [Oak Ridge National Lab., TN (United States)

1997-03-01

237

Retagging Identifies Dendritic Cell-specific Intercellular Adhesion Molecule-3 (ICAM3)-grabbing Non-integrin (DC-SIGN) Protein as a Novel Receptor for a Major Allergen from House Dust Mite*  

PubMed Central

Dendritic cells (DCs) have been shown to play a key role in the initiation and maintenance of immune responses to microbial pathogens as well as to allergens, but the exact mechanisms of their involvement in allergic responses and Th2 cell differentiation have remained elusive. Using retagging, we identified DC-SIGN as a novel receptor involved in the initial recognition and uptake of the major house dust mite and dog allergens Der p 1 and Can f 1, respectively. To confirm this, we used gene silencing to specifically inhibit DC-SIGN expression by DCs followed by allergen uptake studies. Binding and uptake of Der p 1 and Can f 1 allergens was assessed by ELISA and flow cytometry. Intriguingly, our data showed that silencing DC-SIGN on DCs promotes a Th2 phenotype in DC/T cell co-cultures. These findings should lead to better understanding of the molecular basis of allergen-induced Th2 cell polarization and in doing so paves the way for the rational design of novel intervention strategies by targeting allergen receptors on innate immune cells or their carbohydrate counterstructures on allergens. PMID:22205703

Emara, Mohamed; Royer, Pierre-Joseph; Mahdavi, Jafar; Shakib, Farouk; Ghaemmaghami, Amir M.

2012-01-01

238

Comparison of home lead dust reduction techniques on hard surfaces: the New Jersey assessment of cleaning techniques trial.  

PubMed

High efficiency particulate air filter (HEPA) vacuums, which collect particles > 0.3 micro m, and trisodium phosphate (TSP), a detergent claimed to selectively remove lead, have been included in the HUD Guidelines for the Evaluation and Control of Lead Based Paint Hazards in Housing without systematic validation of their effectiveness. At the time the study was initiated, both HEPA vacuums and TSP were relatively expensive, they were not readily found in urban retail centers, and there were environmental concerns about the use and disposal of high-phosphate detergents. A randomized, controlled trial was conducted in urban high-risk homes in northern New Jersey to determine whether a more readily available and less expensive low-phosphate, non-TSP detergent and non-HEPA vacuum could perform as well as TSP and a HEPA vacuum in a cleaning protocol. Homes were randomized to one of three cleaning methods: TSP/HEPA vacuum, TSP/non-HEPA vacuum, or non-TSP/non-HEPA vacuum. Change in log-transformed lead loading was used in mixed models to compare the efficacy of the three cleaning techniques separately for uncarpeted floors, window sills, and window troughs. After we adjusted for baseline lead loading, the non-HEPA vacuum produced larger reductions on hard floors [19%; 95% confidence interval (CI), 3-38%], but the HEPA vacuum produced larger reductions on window sills (22%; 95% CI, 11-32%) and larger reductions on window troughs (16%; 95% CI, -4 to 33%). The non-TSP produced larger reductions on window troughs (21%; 95% CI, -2 to 50%), but TSP produced larger reductions on hard floors (5%; 95% CI, -12 to 19%) and window sills (8%; 95% CI, -5 to 20%). TSP/HEPA produced larger reductions on window sills (28%; 95% CI, 18-37%) and larger reductions on window troughs (2%; 95% CI, -24 to 23%), whereas the non-TSP/non-HEPA method produced larger reductions on hard floors (13%; 95% CI, -5 to 34%). Because neither vacuum nor detergent produced consistent results across surface types, the use of low-phosphate detergents and non-HEPA vacuums in a temporary control measure is supported. PMID:12204823

Rich, David Q; Rhoads, George G; Yiin, Lih-Ming; Zhang, Junfeng; Bai, Zhipeng; Adgate, John L; Ashley, Peter J; Lioy, Paul J

2002-09-01

239

The distribution of lead between sea salt, dust, and lead-rich aerosols in the mid South Pacific Easterlies at American Samoa  

SciTech Connect

Aerosols in the South Pacific Easterlies have been sampled at American Samoa with a cascade impactor and analyzed for Pb, Ba, K, Ca, Sr, and Rb by isotope dilution mass spectrometry using ultraclean procedures. Some 84% of the Pb was found in fine ({le}0.5 {mu}m) aerosols which were collected on the backup filter with an efficiency of only 33%. Sea salt and eroded terrestrial material (dust) containing 6% and < 1% respectively, of the Pb (sea salt indexed by the metals K, Ca, Sr, and Rb and dust indexed by Ba) were collected on early stages of the impactor, although 65% of the dust, because of its larger size, was lost to surfaces of the rain shelter before reaching the impactor. The remaining 10% of the Pb was associated with plant leaf waxes of continental origin which produced Pb and Ba peaks on stage 4 (0.5 {mu}m) of the impactor.

Rosman, K.J.R.; Patterson, C.C.; Settle, D.M. (California Inst. of Tech., Pasadena (United States))

1990-03-20

240

Hyposensitization in asthmatics with mPEG modified and unmodified house dust mite extract. II. Effect evaluated by challenges with allergen and histamine.  

PubMed

In a 2-year study, 46 asthmatics with verified allergy to the house dust mite D. pteronyssinus (Dp) were included either as controls (Ctls) or receiving hyposensitization (HS) with unmodified or monomethoxypolyethylene glycol (mPEG) modified Dp-extract. Patients were monitored by annual challenges with histamine in bronchi, and Dp allergen in bronchi, nose and conjunctiva. mPEG-modified extract was not inferior to unmodified Dp-extract; both were to some extent able to improve tolerance to Dp and histamine in bronchi and to Dp in nose and eyes. During the 1st year, the bronchial sensitivity to Dp decreased significantly in the HS groups but not in the Ctls. During the 2nd year, improvement was more pronounced in the Ctl group. The relative increase in Dp or histamine tolerance did not differ significantly between groups after either 1 or 2 years; the only exception was conjunctival sensitivity, which in the Ctl group was unchanged, and a 10-fold increase in tolerance in the HS groups. No direct benefit was seen on late-phase bronchial reactions. In patients with improved pulmonary symptoms a tendency was seen towards reduced sensitivity to histamine and Dp. Variation within groups was extensive. PMID:2817306

Mosbech, H; Dreborg, S; Frřlund, L; Ljungstedt-Pĺhlman, I; Svendsen, U G; Sřborg, M; Taudorf, E; Weeke, B

1989-09-01

241

A pilot study of the effect of mechanical ventilation and heat exchange on house-dust mites and Der p 1 in New Zealand homes.  

PubMed

We have examined the effect of reducing relative humidity (RH), with inbuilt mechanical ventilation and heat-exchange (MVHE) units, on house-dust-mite (HDM) counts and allergen levels, in a pilot study of 10 Wellington dwellings. Recent international prevalence studies in adults and children have confirmed a high prevalence of asthma in New Zealand. Sensitivity to HDM is common among the general population, and HDM is the major allergen associated with asthma. Recent studies of allergen levels have confirmed high concentrations of Der p 1 in the domestic environment. While humidity was significantly reduced in those dwellings fitted with ventilation units, no systematic effect on mites or Der p 1 was observed during the study period. When the reductions in humidity were examined in the context of the time spent below the critical equilibrium humidity (CEH), the intervention led to RH values below the CEH for only 39% of the total of 24-h periods for which measurements were made. Reducing RH by means of MVHE in New Zealand domestic dwellings does not lower humidity sufficiently, or long enough, to have any measurable effect on HDM populations. PMID:9722224

Crane, J; Ellis, I; Siebers, R; Grimmet, D; Lewis, S; Fitzharris, P

1998-08-01

242

Resident CD11b+Ly6C? Lung Dendritic Cells Are Responsible for Allergic Airway Sensitization to House Dust Mite in Mice  

PubMed Central

Conventional dendritic cells (DCs) are considered to be the prime initiators of airway allergy. Yet, it remains unclear whether specific DC subsets are preferentially involved in allergic airway sensitization. Here, we systematically assessed the respective pro-allergic potential of individually sorted lung DC subsets isolated from house dust mite antigen (HDM)-treated donor mice, following transfer to naďve recipients. Transfer of lung CD11c+CD11b+ DCs, but not CD11c+CD11b?CD103+ DCs, was sufficient to prime airway allergy. The CD11c+CD11b+ DC subpopulation was composed of CD11c+CD11b+Ly6C+ inflammatory monocyte-derived cells, whose numbers increase in the lungs following HDM exposure, and of CD11c+CD11b+Ly6C? DCs, which remain stable. Counterintuitively, only CD11c+CD11b+Ly6C? DCs, and not CD11c+CD11b+Ly6C+ DCs, were able to convey antigen to the lymph nodes and induce adaptive T cell responses and subsequent airway allergy. Our results thus support that lung resident non-inflammatory CD11c+CD11b+Ly6C? DCs are the essential inducers of allergic airway sensitization to the common aeroallergen HDM in mice. PMID:23300898

Marichal, Thomas; Toussaint, Marie; Cataldo, Didier; Drion, Pierre-Vincent; Lekeux, Pierre

2012-01-01

243

Monocyte-derived dendritic cells induce a house dust mite-specific Th2 allergic inflammation in the lung of humanized SCID mice: involvement of CCR7.  

PubMed

In rodents, airway dendritic cells (DCs) capture inhaled Ag, undergo maturation, and migrate to the draining mediastinal lymph nodes (MLN) to initiate the Ag-specific T cell response. However, the role of human DCs in the pathogenesis of the Th2 cell-mediated disease asthma remains to be clarified. Here, by using SCID mice engrafted with T cells from either house dust mite (HDM)-allergic patients or healthy donors, we show that DCs pulsed with Der p 1, one of the major allergens of HDM, and injected intratracheally into naive animals migrated into the MLN. In the MLN, Der p 1-pulsed DCs from allergic patients induced the proliferation of IL-4-producing CD4(+) T cells, whereas those from healthy donors induced IFN-gamma-secreting cells. In reconstituted human PBMC-reconstituted SCID mice primed with pulsed DCs from allergic patients, repeated exposure to aerosols of HDM induced 1) a strong pulmonary inflammatory reaction rich in T cells and eosinophils, 2) an increase in IL-4 and IL-5 production in the lung lavage fluid, and 3) increased IgE production compared with that in mice primed with unpulsed DCs. All these effects were reduced following in vivo neutralization of the CCR7 ligand secondary lymphoid tissue chemokine. These data in human PBMC-reconstituted SCID mice show that monocyte-derived DCs might play a key role in the pathogenesis of the pulmonary allergic response by inducing Th2 effector function following migration to the MLN. PMID:12133980

Hammad, Hamida; Lambrecht, Bart N; Pochard, Pierre; Gosset, Philippe; Marquillies, Philippe; Tonnel, André-Bernard; Pestel, Joël

2002-08-01

244

Crystallization and preliminary X-ray analysis of Der f 2, a potent allergen derived from the house dust mite (Dermatophagoides farinae)  

NASA Technical Reports Server (NTRS)

Although a number of allergens have been identified and isolated, the underlying molecular basis for the potent immune response is poorly understood. House dust mites (Dermatophagoides sp.) are ubiquitous contributors to atopy in developed countries. The rhinitis, dermatitis and asthma associated with allergic reactions to these arthropods are frequently caused by relatively small (125-129 amino acids) mite proteins of unknown biological function. Der f 2, a major allergen from the mite D. farinae, has been recombinantly expressed, characterized and crystallized. The crystals belong to the tetragonal space group I4(1)22, with unit-cell parameters a = b = 95.2, c = 103.3 A. An essentially complete (97.2%) data set has been collected to 2.4 A at a synchrotron source. Attempts to solve the crystal structure of Der f 2 by molecular replacement using the NMR coordinates for either Der f 2 or Der p 2 (the homologous protein from D. pteronyssinus) failed, but preliminary searches using the crystalline Der p 2 atomic coordinates appear to be promising.

Roeber, Dana; Achari, Aniruddha; Takai, Toshiro; Okumura, Yasushi; Scott, David L.

2003-01-01

245

High Dose Allergen Stimulation of T Cells from House Dust Mite-Allergic Subjects Induces Expansion of IFN-?+ T Cells, Apoptosis of CD4+IL4+ T Cells and T Cell Anergy  

Microsoft Academic Search

Background: During clinically effective allergen-specific immunotherapy a shift in cytokine dominance from IL-4, IL-5 predominant to IFN-? predominant has been observed. As antigen concentration influences Th cell priming, this study aimed to determine the effect of different allergen concentrations on human house dust mite (HDM)-specific T cell production of IL-4 and IFN-?, proliferation and apoptosis. Methods: HDM-allergic donor PBMC were

Leanne M. Gardner; Robyn E. O’Hehir; Jennifer M. Rolland

2004-01-01

246

Dust to Dust  

NSDL National Science Digital Library

The dust around us is composed of bits of detritus of all manner of things, but it is mostly bits of human skin. This radio broadcast explores the universe through tiny dust particles and discovers what it can tell us about our past as well as our future. The broadcast discusses dust from ice cores that reveal the climate record and the cosmic dust that Earth is gathering every day. There is also explanation of the microscopic composition of the dust around us and the damage dust can do to museum exhibits, especially when the dust interacts with the moisture in the atmosphere. The broadcast is 28 minutes in length.

247

Severity of Allergic Airway Disease Due to House Dust Mite Allergen Is Not Increased after Clinical Recovery of Lung Infection with Chlamydia pneumoniae in Mice  

PubMed Central

Chlamydia pneumoniae is associated with chronic inflammatory lung diseases like bronchial asthma and chronic obstructive pulmonary disease. The existence of a causal link between allergic airway disease and C. pneumoniae is controversial. A mouse model was used to address the question of whether preceding C. pneumoniae lung infection and recovery modifies the outcome of experimental allergic asthma after subsequent sensitization with house dust mite (HDM) allergen. After intranasal infection, BALB/c mice suffered from pneumonia characterized by an increased clinical score, reduction of body weight, histopathology, and a bacterial load in the lungs. After 4 weeks, when infection had almost resolved clinically, HDM allergen sensitization was performed for another 4 weeks. Subsequently, mice were subjected to a methacholine hyperresponsiveness test and sacrificed for further analyses. As expected, after 8 weeks, C. pneumoniae-specific antibodies were detectable only in infected mice and the titer was significantly higher in the C. pneumoniae/HDM allergen-treated group than in the C. pneumoniae/NaCl group. Intriguingly, airway hyperresponsiveness and eosinophilia in bronchoalveolar lavage fluid were significantly lower in the C. pneumoniae/HDM allergen-treated group than in the mock/HDM allergen-treated group. We did observe a relationship between experimental asthma and chlamydial infection. Our results demonstrate an influence of sensitization to HDM allergen on the development of a humoral antibacterial response. However, our model demonstrates no increase in the severity of experimental asthma to HDM allergen as a physiological allergen after clinically resolved severe chlamydial lung infection. Our results rather suggest that allergic airway disease and concomitant cellular changes in mice are decreased following C. pneumoniae lung infection in this setting. PMID:23817611

Dutow, Pavel; Lingner, Sandra; Laudeley, Robert; Glage, Silke; Hoymann, Heinz-Gerd; Dittrich, Anna-Maria; Fehlhaber, Beate; Müller, Meike; Braun, Armin

2013-01-01

248

Absence of Toll-IL-1 receptor 8/single immunoglobulin IL-1 receptor-related molecule reduces house dust mite-induced allergic airway inflammation in mice.  

PubMed

Allergic asthma is a chronic inflammatory disease predominately associated with the activation of CD4(+) T helper Type 2 (Th2) cells. Innate pattern recognition receptors are widely acknowledged to shape the adaptive immune response. For example, the activation of airway epithelial Toll-like receptor-4 (TLR4) is necessary for the generation of house dust mite (HDM)-specific Th2 responses and the development of asthma in mice. Here we sought to determine whether the absence of Toll-interleukin-1 receptor (TIR)-8, a negative regulator of TLR4 signaling that is highly expressed in airway epithelial cells, would exacerbate HDM-induced asthma in a murine model. We found that Th2 but not Th1 or Th17 cytokine expression was significantly reduced in the lung and draining lymph nodes in HDM-sensitized/challenged TIR8 gene-deleted mice. Mucus-producing goblet cells, HDM-specific IgG1, and airway hyperreactivity were also significantly reduced in HDM-exposed, TIR8-deficient mice. Consistent with the attenuated Th2 response, eotaxin-2/CCL24 expression and airway and peribronchial eosinophils were significantly reduced in the absence of TIR8. In contrast, IL-17A-responsive chemokines and neutrophil numbers were unaffected. Similar findings were obtained for cockroach allergen. HDM sensitization alone up-regulated the expression of IL-1F5, a putative TIR8 ligand and inducer of IL-4. Of note, innate IL-4, IL-5, IL-13, and IL-33 cytokine expression was reduced during HDM sensitization in the absence of TIR8, as was the recruitment of conventional dendritic cells and basophils to the draining lymph nodes. Our findings suggest that TIR8 enhances the development of HDM-induced innate and adaptive Th2, but not Th1 or Th17 type immunity. PMID:23614768

Barry, Jessica; Loh, Zhixuan; Collison, Adam; Mazzone, Stuart; Lalwani, Amit; Zhang, Vivian; Davidson, Sophia; Wybacz, Elisha; Garlanda, Cecilia; Mantovani, Alberto; Mattes, Joerg; Foster, Paul S; Phipps, Simon

2013-09-01

249

Hyposensitization in asthmatics with mPEG-modified and unmodified house dust mite extract. IV. Occurrence and prediction of side effects.  

PubMed

A double-blind study on hyposensitization (HS) with two extracts prepared from the house dust mite Dermatophagoides pteronyssinus (Dp) was performed on a group of asthmatics with bronchial sensitivity to Dp. In 18 patients, aluminium-hydroxide was added to the Dp-extract to give a depot effect (Dp-group). Nineteen patients were treated with a similar extract in which allergenicity had been reduced by coupling to monomethoxypolyethylene glycol (mPEG-Dp-group). This extract had previously been shown to have less effect on clinical symptoms and skin sensitivity compared to the Dp-extract. In the Dp- and mPEG-Dp-groups, 778 and 675 injections were administered. Fifteen and 12 patients in the Dp- and mPEG-Dp-groups had systemic reactions (P greater than 0.05). The frequency of injections giving systemic reactions was reduced in the mPEG-Dp-group: 5.1% compared to 9.0% in the Dp-group (P less than 0.01). In the mPEG-Dp-group, reactions were mild to moderate, mainly late-occurring asthma and urticaria, whereas two episodes of anaphylaxis and four of severe asthma occurred in the Dp-group. The reduction in side effects seems promising, but a further dose increase in the mPEG-Dp-group would be necessary to compare the side effects of doses with equal therapeutic effectiveness. High frequency of late local reactions made dose increase impossible with the present slightly modified extract. The systemic side effects occurred more frequently in patients highly skin test-sensitive to Dp prior to treatment. All patients skin test-positive to less than or equal to 100 BU had systemic reactions. Systemic side effects could not be predicted from the size of previous local reactions. PMID:2316824

Mosbech, H; Dirksen, A; Dreborg, S; Frřlund, L; Heinig, J H; Svendsen, U G; Sřborg, M; Taudorf, E; Weeke, B

1990-02-01

250

Hyposensitization in asthmatics with mPEG modified and unmodified house dust mite extract. I. Clinical effect evaluated by diary cards and a retrospective assessment.  

PubMed

Forty-six asthmatics with verified allergy to the house dust mite, D. pteronyssinus (Dp), participated in a double-blind study comparing the effect of 2 years' hyposensitization with two different Dp extracts. Two groups received either monomethoxypolyethylene glycol modified (mPEG) Dp extract or the corresponding non-modified extract, and a third group acted as controls receiving no injections. Medicine consumption, symptom scores, and peak expiratory flow (PEF) were recorded daily from September to December prior to and after 6 and 18 months of treatment. Changes were calculated choosing changes greater than or equal to 10% as relevant. In addition, patients were asked to give their direct assessment of the clinical effect at the end of the study. After 6 months, there was an improvement in symptoms + medication in 11/14 of Dp-treated, 6/17 of the mPEG-Dp group (P greater than 0.05) and 3/15 of openly treated controls. Few patients had changed in PEF. During the second year, several Dp-treated relapsed and some controls improved. At the end of the study the same improvement rate was seen in all groups. Similarly, the retrospective questionnaire data did not disclose any significant differences between groups after 2 years. In conclusion, hyposensitization with unmodified Dp extract seemed to have a favourable short-term effect on bronchial symptoms + medication in the majority of patients. When mainly on maintenance dose, the beneficial effect was reduced. The mPEG modification of the extract had reduced not only allergenicity but also the clinical effect of equal doses. Changes in medicine and symptom scores only partly correlated to retrospective assessment, thus stressing the problems in this kind of evaluation. PMID:2817305

Mosbech, H; Dreborg, S; Frřlund, L; Ljungstedt-Pĺhlman, I; Svendsen, U G; Sřborg, M; Taudorf, E; Weeke, B

1989-09-01

251

In Vivo and In Vitro Studies of Th17 Response to Specific Immunotherapy in House Dust Mite-Induced Allergic Rhinitis Patients  

PubMed Central

T helper (Th)17 cells have been implicated in the development of allergic rhinitis (AR), but their response to specific immunotherapy (SIT) remains unclear. We investigated the impact of SIT on Th17 response and Th1/Th2 changes in AR patients. Blood samples from AR patients (n?=?20) who were monosensitized to house dust mite (HDM) were collected before the initiation of SIT (SIT-untreated) and after the end of 2-year SIT (SIT-treated) treatment. Twenty healthy volunteers were recruited as controls. In vitro HDM stimulation in peripheral blood mononuclear cells (PBMCs) was also performed. Expression levels of Th17 associated genes were determined in both PBMCs and plasma by PCR and ELISA, while Th17/Th1/Th2/IL10 producing cell proportions were evaluated in PBMCs by flow cytometry. The SIT effect was evaluated by assessing clinical symptoms. mRNA levels of Th17 specific genes (IL17 and RORC) were increased in SIT-untreated AR versus controls, and decreased following SIT treatment. SIT can change the production of Th17 associated genes (reduction of IL17, IL6, and IL23, but increase of IL27) in plasma from AR patients. Th2/Th1 ratio and proportions of Th17 cells were suppressed while IL10 producing CD4+ T cells were elevated after SIT. In vitro HDM challenge presents concordant patterns with in vivo findings: 1) increase of Th2 and Th17 response in AR patients; 2) suppression of IL10 producing CD4+ T cells in SIT-untreated AR but elevation in SIT-treated AR patients. Most importantly, a positive correlation between IL17 mRNA/protein levels and clinical symptom scores was observed. SIT significantly inhibits Th17 mediated inflammation in AR and IL17 may be a useful biomarker for both AR severity and SIT therapeutic effect. Trial Registration Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12613000445774 PMID:24647473

Chen, De Hua; Lin, Zhi Bin; Wang, De Yun; Li, Tian Ying

2014-01-01

252

Severity of allergic airway disease due to house dust mite allergen is not increased after clinical recovery of lung infection with Chlamydia pneumoniae in mice.  

PubMed

Chlamydia pneumoniae is associated with chronic inflammatory lung diseases like bronchial asthma and chronic obstructive pulmonary disease. The existence of a causal link between allergic airway disease and C. pneumoniae is controversial. A mouse model was used to address the question of whether preceding C. pneumoniae lung infection and recovery modifies the outcome of experimental allergic asthma after subsequent sensitization with house dust mite (HDM) allergen. After intranasal infection, BALB/c mice suffered from pneumonia characterized by an increased clinical score, reduction of body weight, histopathology, and a bacterial load in the lungs. After 4 weeks, when infection had almost resolved clinically, HDM allergen sensitization was performed for another 4 weeks. Subsequently, mice were subjected to a methacholine hyperresponsiveness test and sacrificed for further analyses. As expected, after 8 weeks, C. pneumoniae-specific antibodies were detectable only in infected mice and the titer was significantly higher in the C. pneumoniae/HDM allergen-treated group than in the C. pneumoniae/NaCl group. Intriguingly, airway hyperresponsiveness and eosinophilia in bronchoalveolar lavage fluid were significantly lower in the C. pneumoniae/HDM allergen-treated group than in the mock/HDM allergen-treated group. We did observe a relationship between experimental asthma and chlamydial infection. Our results demonstrate an influence of sensitization to HDM allergen on the development of a humoral antibacterial response. However, our model demonstrates no increase in the severity of experimental asthma to HDM allergen as a physiological allergen after clinically resolved severe chlamydial lung infection. Our results rather suggest that allergic airway disease and concomitant cellular changes in mice are decreased following C. pneumoniae lung infection in this setting. PMID:23817611

Dutow, Pavel; Lingner, Sandra; Laudeley, Robert; Glage, Silke; Hoymann, Heinz-Gerd; Dittrich, Anna-Maria; Fehlhaber, Beate; Müller, Meike; Braun, Armin; Klos, Andreas

2013-09-01

253

Improved tRNA prediction in the American house dust mite reveals widespread occurrence of extremely short minimal tRNAs in acariform mites  

PubMed Central

Background Atypical tRNAs are functional minimal tRNAs, lacking either the D- or T-arm. They are significantly shorter than typical cloverleaf tRNAs. Widespread occurrence of atypical tRNAs was first demonstrated for secernentean nematodes and later in various arachnids. Evidence started to accumulate that tRNAs of certain acariform mites are even shorter than the minimal tRNAs of nematodes, raising the possibility that tRNAs lacking both D- and T-arms might exist in these organisms. The presence of cloverleaf tRNAs in acariform mites, particularly in the house dust mite genus Dermatophagoides, is still disputed. Results Mitochondrial tRNAs of Dermatophagoides farinae are minimal, atypical tRNAs lacking either the T- or D-arm. The size (49-62, 54.4 ± 2.86 nt) is significantly (p = 0.019) smaller than in Caenorhabditis elegans (53-63, 56.3 ± 2.30 nt), a model minimal tRNA taxon. The shortest tRNA (49 nt) in Dermatophagoides is approaching the length of the shortest known tRNAs (45-49 nt) described in other acariform mites. The D-arm is absent in these tRNAs, and the inferred T-stem is small (2-3 bp) and thermodynamically unstable, suggesting that it may not exist in reality. The discriminator nucleotide is probably not encoded and is added postranscriptionally in many Dermatophagoides tRNAs. Conclusions Mitochondrial tRNAs of acariform mites are largely atypical, non-cloverleaf tRNAs. Among them, the shortest known tRNAs with no D-arm and a short and unstable T-arm can be inferred. While our study confirmed seven tRNAs in Dermatophagoides by limited EST data, further experimental evidence is needed to demonstrate extremely small and unusual tRNAs in acariform mites. PMID:20003349

2009-01-01

254

The effect of two months of treatment with inhaled budesonide on bronchial responsiveness to histamine and house-dust mite antigen in asthmatic children.  

PubMed

We studied the effect of 2 months of treatment with budesonide (BUD) (Pulmicort), an inhaled corticosteroid, on the bronchial hyperresponsiveness to house-dust mite antigen (BHR-HDM) and to histamine (BHR-H). We also investigated whether BUD started 20 to 24 h after the development of a late asthmatic reaction (LAR) would influence the antigen-induced increase in nonspecific bronchial hyperresponsiveness to BHR-H. Thirty-one children with mild asthma who were atopic to HDM were randomized double blind into two parallel groups. Fifteen patients inhaled 0.2 mg BUD three times a day. Sixteen inhaled placebo in a similar way. Treatment began 20 to 24 h after antigen exposure and continued for 2 months. BHR-H and BHR-HDM were measured prior to and at the end of treatment. BHR-H was also determined 3 days after each antigen provocation. In the children receiving BUD, mean BHR-H and mean BHR-HDM were decreased approximately twofold after 2 months. No increase in BHR-H was observed after 3 days in the BUD group, irrespective of whether a LAR occurred. In patients in whom BUD treatment was withheld after the second antigen provocation, the protective effect of BHR-H was abolished. We conclude that 2 months of treatment with an inhaled corticosteroid causes a decrease in BHR-H and BHR-HDM. When an inhaled corticosteroid is administered 20 to 24 h after antigen provocation, It may protect against the antigen-induced increase in BHR-H. After treatment is discontinued, the protective effect wears off rapidly. PMID:2389909

De Baets, F M; Goeteyn, M; Kerrebijn, K F

1990-09-01

255

The effects of inhaled corticosteroids on intrinsic responsiveness and histology of airways from infant monkeys exposed to house dust mite allergen and ozone  

SciTech Connect

Inhaled corticosteroids (ICS) are recommended to treat infants with asthma, some with intermittent asthma. We previously showed that exposing infant monkeys to allergen/ozone resulted in asthma-like characteristics of their airways. We evaluated the effects of ICS on histology and intrinsic responsiveness of allergen/ozone-exposed and normal infant primate airways. Infant monkeys were exposed by inhalation to (1) filtered air and saline, (2) house dust mite allergen (HDMA) + ozone and saline, (3) filtered air and ICS (budesonide) or (4) HDMA + ozone and ICS. Allergen/ozone exposures started at 1 month and ICS at 3 months of age. At 6 months of age, methacholine-induced changes in luminal area of airways in proximal and distal lung slices were determined using videomicrometry, followed by histology of the same slices. Proximal airway responsiveness was increased by allergen/ozone and by ICS. Eosinophil profiles were increased by allergen/ozone in both proximal and distal airways, an effect that was decreased by ICS in distal airways. In both allergen/ozone- and air-exposed monkeys, ICS increased the number of alveolar attachments in distal airways, decreased mucin in proximal airways and decreased epithelial volume in both airways. ICS increased smooth muscle in air-exposed animals while decreasing it in allergen/ozone-exposed animals in both airways. In proximal airways, there was a small but significant positive correlation between smooth muscle and airway responsiveness, as well as between alveolar attachments and responsiveness. ICS change morphology and function in normal airways as well as allergen/ozone-exposed airways, suggesting that they should be reserved for infants with active symptoms.

Joad, Jesse P. [Department of Pediatrics, School of Medicine, University of California at Davis, Davis, CA 95616 (United States)], E-mail: jesse.joad@ucdmc.ucdavis.edu; Kott, Kayleen S.; Bric, John M. [Department of Pediatrics, School of Medicine, University of California at Davis, Davis, CA 95616 (United States); Schelegle, Edward S. [Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California at Davis, Davis, CA 95616 (United States); Gershwin, Laurel J. [Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California at Davis, Davis, CA 95616 (United States); Plopper, Charles G. [Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California at Davis, Davis, CA 95616 (United States); Peake, Janice L.; Pinkerton, Kent E. [Department of Pediatrics, School of Medicine, University of California at Davis, Davis, CA 95616 (United States)

2008-01-15

256

Differences in respiratory syncytial virus and influenza infection in a house-dust-mite-induced asthma mouse model: consequences for steroid sensitivity.  

PubMed

A significant number of clinical asthma exacerbations are triggered by viral infection. We aimed to characterize the effect of virus infection in an HDM (house dust mite) mouse model of asthma and assess the effect of oral corticosteroids. HDM alone significantly increased eosinophils, lymphocytes, neutrophils, macrophages and a number of cytokines in BAL (bronchoalveolar lavage), all of which were sensitive to treatment with prednisolone (with the exception of neutrophils). Virus infection also induced cell infiltration and cytokines. RSV (respiratory syncytial virus) infection in HDM-treated animals further increased all cell types in BAL (except eosinophils, which declined), but induced no further increase in HDM-elicited cytokines. However, while HDM-elicited TNF-? (tumour necrosis factor-?), IFN-? (interferon-?), IL (interleukin)-2, IL-5 and IL-10 were sensitive to prednisolone treatment, concomitant infection with RSV blocked the sensitivity towards steroid. In contrast, influenza infection in HDM- challenged animals resulted in increased BAL lymphocytes, neutrophils, IFN-?, IL-1?, IL-4, IL-5, IL-10 and IL-12, but all were attenuated by prednisolone treatment. HDM also increased eNO (exhaled NO), which was further increased by concomitant virus infection. This increase was only partially attenuated by prednisolone. RSV infection alone increased BAL mucin. However, BAL mucin was increased in HDM animals with virus infection. Chronic HDM challenge in mice elicits a broad inflammatory response that shares many characteristics with clinical asthma. Concomitant influenza or RSV infection elicits differing inflammatory profiles that differ in their sensitivity towards steroids. This model may be suitable for the assessment of novel pharmacological interventions for asthmatic exacerbation. PMID:23789621

Mori, Hiroki; Parker, Nicole S; Rodrigues, Deborah; Hulland, Kathryn; Chappell, Deborah; Hincks, Jennifer S; Bright, Helen; Evans, Steven M; Lamb, David J

2013-12-01

257

Lead  

MedlinePLUS

... Childhood Lead Poisoning Data, Statistics, and Surveillance Partners Policy Resources Prevention Tips Publications Tools and Training Calendar of Events Ten Great Public Health Achievements 2001--2010 Â Lead in Drinking Water Healthy Homes A Healthy Homes approach is a ...

258

Identification of trace metal pollution in urban dust from kindergartens using magnetic, geochemical and lead isotopic analyses  

NASA Astrophysics Data System (ADS)

In the present study, magnetic measurements were combined with geochemical analysis and stable Pb isotopic ratios to reveal the distribution and origination of trace metal pollutants in kindergarten dusts from a typical urban environment of Wuhan, central China. The geoaccumulation index (Igeo) of magnetic properties was more prominent than those of individual metals. The magnetic susceptibility (MS) and trace metals (Zn, Pb, and Cu) in this study together with published results from other Chinese cities formed a liner relationship, suggesting that metal contaminants in Chinese urban areas had similar MS to metal ratios, which could be used as an indicator for identification of pollution sources between Chinese cities and the other Asian cities. Stable Pb isotopic ratios (1.1125-1.1734 for 206Pb/207Pb and 2.4457-2.4679 for 208Pb/207Pb) in the urban dusts from Wuhan were characterized by higher 208Pb component in comparison with those from other Chinese cities. This result combined with principal component analysis (PCA) indicated that metal pollutants in the dusts were derived from industrial activities and coal combustion, whereas the traffic emissions were no longer a predominant pollution source in urban environment. Our study demonstrated that environmental magnetic methods could not only reveal the overall situation of trace metal contamination, but also prove evidence in the identification of pollution sources.

Zhu, Zongmin; Sun, Guangyi; Bi, Xiangyang; Li, Zhonggen; Yu, Genhua

2013-10-01

259

Assessing remedial effectiveness through the blood lead:soil\\/dust lead relationship at the Bunker Hill Superfund Site in the Silver Valley of Idaho  

Microsoft Academic Search

The 21 square mile Bunker Hill Superfund Site in northern Idaho includes several thousand acres of contaminated hillsides and floodplain, a 365-acre abandoned lead\\/zinc smelter and is home to more than 7000 people in 5 residential communities. Childhood lead poisoning was epidemic in the 1970s with >75% of children exceeding 40 ?g\\/dl blood lead. Health response activities have been ongoing

Ian von Lindern; Susan Spalinger; Varduhi Petroysan; Margrit von Braun

2003-01-01

260

Lead Poisoning  

MedlinePLUS

Lead is a metal that occurs naturally in the earth's crust. Lead can be found in all parts of our ... from human activities such as mining and manufacturing. Lead used to be in paint; older houses may ...

261

Effect of inhaled dust mite allergen on regional particle deposition and mucociliary clearance in allergic asthmatics**  

EPA Science Inventory

Background Acute exacerbations in allergic asthmatics may lead to impaired ability to clear mucus from the airways, a key factor in asthma morbidity. Objective The purpose of this study was to determine the effect of inhaled house dust mite challenge on the regional deposition of...

262

Development and field trial of a household surface lead loading rate sampling device in a lead-contaminated community of southern Thailand.  

PubMed

A new dust-collecting device was developed to assess surface lead loading rates in houses in communities contaminated with lead oxide dust used for caulking in nearby boat-repair yards. The device consists of two small glass sheets with total area of 1,200 cm(2) placed in two plastic trays suspended from the ceiling in the house for 3 months before wiping and sending the dust specimen for determination of lead content using flame atomic absorption spectrophotometry. After a pilot trial in four households, further data were collected from 43 matched pairs of boat-caulkers' and neighboring control households. All devices were retained in the house for 3 months without any complaint. Static measurements of lead dust levels were also assessed in all households. The values significantly discriminated high from low lead exposure households (p = 0.015) and provided good correlations with floor lead loading (Spearman rank correlation coefficient, r = 0.39 to 0.62) and dust lead content (r = 0.53 to 0.64). This sampling method is an alternative to others which consume more household space or require a longer collection period. PMID:19415518

Untimanon, Orrapan; Geater, Alan; Chongsuvivatwong, Virasakdi; Thoumsang, Somkiat; Verkasalo, Pia K; Saetia, Wiyada

2010-05-01

263

40 CFR 745.226 - Certification of individuals and firms engaged in lead-based paint activities: target housing and...  

...in a related field (e.g., lead, asbestos, environmental remediation work, or...in a related field (e.g., lead, asbestos, environmental remediation work, or...in a related field (e.g., lead, asbestos, environmental remediation work or...

2014-07-01

264

75 FR 13127 - Lead-Based Paint Renovation, Repair and Painting Activities in Target Housing and Child Occupied...  

Federal Register 2010, 2011, 2012, 2013

...exposures that cause serious lead poisonings, especially...susceptible to the hazards of lead. Under section 404 of...human health and the environment as the Federal program...human health and the environment as the Federal program...and Painting Program/Lead-Safe Renovator...

2010-03-18

265

Bioaccessibility, release kinetics, and molecular speciation of arsenic and lead in geo-dusts from the Iron King Mine Federal Superfund site in Humboldt, Arizona.  

PubMed

Mine tailings contain multiple toxic metal(loid)s that pose a threat to human health via inhalation and ingestion. The goals of this research include understanding the speciation and molecular environment of these toxic metal(loid)s (arsenic and lead) as well as the impacts particle size and residence time have on their bioaccessibilty in simulated gastric and lung fluid. Additionally, future work will include smaller size fractions (PM10 and PM2.5) of surface mine tailings, with the goal of increasing our understanding of multi-metal release from contaminated geo-dusts in simulated bio-fluids. This research is important to environmental human health risk assessment as it increases the accuracy of exposure estimations to toxic metal(loid)s. PMID:24552959

Menka, Nazune; Root, Rob; Chorover, Jon

2014-01-01

266

EVALUATION OF PORTABLE X-RAY FLUORESCENCE SPECTROMETER FOR MEASUREMENT OF LEAD IN PAINT, SOIL AND DUST  

EPA Science Inventory

Three widely used commercially available portable X-ray fluorescence spectrometers were evaluated for precision and accuracy of measurement of lead in paint. ncluded were two direct reading instruments and one spectrum analyzer. est materials were prepared by spiking oil-based an...

267

House dust mite and cockroach exposure are strong risk factors for positive allergy skin test responses in the Childhood Asthma Management Program  

Microsoft Academic Search

Background: Children with asthma have a high prevalence of environmental allergies, especially to indoor allergens. The relationships of exposure to indoor allergens (dust mites, cat, dog, cockroach, and molds) and other host factors to allergy sensitization have not been evaluated simultaneously in a large cohort. Objectives: We studied 1041 children aged 5 to 12 years with mild-to-moderate asthma to determine

Karen Huss; N. Franklin Adkinson; Peyton A. Eggleston; Christopher Dawson; Mark L. Van Natta; Robert G. Hamilton

2001-01-01

268

Lead intake and blood lead in two-year-old U.K. urban children.  

PubMed

A comprehensive study of a group of 2-year-old urban children (n = 97), designed to provide quantitative information simultaneously for lead intakes via all identified pathways, has been carried out in Birmingham (U.K.). Results showed that for children whose blood levels and exposure to environmental lead were within the normal range for the U.K., blood lead concentration was significantly related to a combination of house dust lead loading and an overall rate of touching objects, to water lead concentration and to the parents' smoking habits. On the basis of assumptions used by the Royal Commission on Environmental Pollution (RCEP), the estimated average total uptake of lead was 36 micrograms day-1; of this, 97% was from ingestion from dust, food and water and only 3% from inhalation. PMID:2305239

Davies, D J; Thornton, I; Watt, J M; Culbard, E B; Harvey, P G; Delves, H T; Sherlock, J C; Smart, G A; Thomas, J F; Quinn, M J

1990-01-01

269

Measurement of nicotine in household dust  

SciTech Connect

An analytical method of measuring nicotine in house dust was optimized and associations among three secondhand smoking exposure markers were evaluated, i.e., nicotine concentrations of both house dust and indoor air, and the self-reported number of cigarettes smoked daily in a household. We obtained seven house dust samples from self-reported nonsmoking homes and 30 samples from smoking homes along with the information on indoor air nicotine concentrations and the number of cigarettes smoked daily from an asthma cohort study conducted by the Johns Hopkins Center for Childhood Asthma in the Urban Environment. House dust nicotine was analyzed by isotope dilution gas chromatography-mass spectrometry (GC/MS). Using our optimized method, the median concentration of nicotine in the dust of self-reported nonsmoking homes was 11.7 ng/mg while that of smoking homes was 43.4 ng/mg. We found a substantially positive association (r=0.67, P<0.0001) between house dust nicotine concentrations and the numbers of cigarettes smoked daily. Optimized analytical methods showed a feasibility to detect nicotine in house dust. Our results indicated that the measurement of nicotine in house dust can be used potentially as a marker of longer term SHS exposure.

Kim, Sungroul [Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Institute for Global Tobacco Control, 627 N. Washington Street, 2nd Floor Baltimore, MD 21205 (United States); Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 (United States)], E-mail: srkim@jhsph.edu; Aung, Ther; Berkeley, Emily [Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 (United States); Diette, Gregory B. [Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 (United States); Department of Medicine, Johns Hopkins University School of Medicine (United States); Breysse, Patrick N. [Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 (United States)

2008-11-15

270

Manufacturing improvements in the processing of lead-acid battery plates and reduction in plate dusting with an active-material additive  

NASA Astrophysics Data System (ADS)

Present-day plate processing offers ample opportunity for improvement within lead-acid battery plants. An inorganic, glass micro-fiber, active-material additive has been found to improve plate processing and lower cost in many of the various operations. This additive allows paste batches to be made with higher moisture contents that improve grid filling and paste texture through higher malleability and reduced resistance to flow. The additive also acts as a bulking agent to extend the plate yield of paste batches, which results in lower cost of active material per plate. Energy consumption and operation throughput in plate making is improved by lower flash-dryer temperatures on the pasting line and by a substantial reduction in curing time. Plates made with the additive have decreased paste pellet friability, which reduces battery assembly scrap. The additive also lowers plate surface dusting that results from handling and thus offers the battery manufacturer the opportunity of lowering lead-in-air emissions within the battery plant. Plates made with the additive have been found to have higher surface area and increased active-material utilization, which can enhance battery performance.

Ferreira, A.; Jordan, J.; Wertz, J.; Zguris, G.

271

Exposure to Beta-(1,3)-D-Glucan in House Dust at Age 7-10 Is Associated with Airway Hyperresponsiveness and Atopic Asthma by Age 11-14  

PubMed Central

Background Mould exposure has been linked to childhood asthma and bronchial hyper-responsiveness. Few studies have assessed beta-(1,3)-d-glucan (beta-glucan), a significant fungal cell wall constituent, in relation to asthma in adolescence. Objective To determine whether house dust-derived beta-glucan exposure at age 7–10 is associated with the development and persistence of atopic and non-atopic asthma, and bronchial hyper-responsiveness (BHR) by age 11–14. Methods Dust samples were collected from the 1995 Study of Asthma, Genes, and Environment (SAGE) birth cohort. This cohort was derived from Manitoba provincial healthcare administrative records of children high and low risk for asthma. Samples were collected from the homes of 422 children at age 7–10 and analyzed using beta-glucan and endotoxin-specific Limulus Amoebocyte Lysate assays. Asthma, atopy, and BHR status of each child were also assessed at ages 7–10 and 11–14. Results At age 7–10, beta-glucan dust levels in the home were associated with persistent atopic asthma at age 11–14 (OR 1.79 for each unit increase in levels, 95% CI 1.14–2.81), independent of endotoxin exposure, and Alternaria or Cladosporium sensitization. The likelihood of BHR almost doubled with unit increases in dust beta-glucan in asthmatic children. In children without asthma, exposure to high beta-glucan levels at age 7–10 also elevated risk for BHR in adolescence (OR 1.74, 95% CI 1.05–2.89). New-onset atopic asthma was twice more likely following high beta-glucan exposure in children without asthma but the association did not reach statistical significance. No associations were evident with concurrent asthma phenotype at age 7–10 or non-atopic asthma at age 11–14. Conclusion These findings implicate home beta-glucan exposure at school-age as a risk factor for persistent atopic asthma and new-onset BHR. The higher prevalence of BHR in urban adolescents may be propagated by this home exposure. PMID:24905346

Maheswaran, Dharini; Zeng, Yiye; Chan-Yeung, Moira; Scott, James; Osornio-Vargas, Alvaro; Becker, Allan B.; Kozyrskyj, Anita L.

2014-01-01

272

Galaxy formation by dust  

NASA Technical Reports Server (NTRS)

It has been known since the early 1940's that radiation can cause an instability in the interstellar medium. Absorbing dust particles in an isotropic radiation field shadow each other by a solid angle which is inversely proportional to the square of the distance between the two particles, leading to an inverse-square attractive force - mock gravity. The effect is largest in an optically thin medium. Recently Hogan and White (HW, hereafter) proposed that if the pre-galactic universe contained suitable sources of radiation and dust, instability in the dust distribution caused by mock gravity may have led to the formation of galaxies and galaxy clusters. In their picture of a well-coupled dust-gas medium, HW show that mock gravity begins to dominate gravitational instability when the perturbation becomes optically thin, provided that the radiation field at the time is strong enough. The recent rocket observation of the microwave background at submillimeter wavelengths by Matsumoto et al. might be from pre-galactic stars, the consequence of the absorption of ultraviolet radiation by dust, and infrared reemission which is subsequently redshifted. HW's analysis omits radiative drag, incomplete collisional coupling of gas and dust, finite dust albedo, and finite matter pressure. These effects could be important. In a preliminary calculation including them, the authors have confirmed that mock gravitational instability is effective if there is a strong ultraviolet radiation at the time, but any galaxies that form would be substantially enriched in heavy elements because the contraction of the dust is more rapid than that of the gas. Moreover, since the dust moves with supersonic velocity through the gas soon after the perturbation becomes optically thin, the sputtering of dust particles by gas is significant, so the dust could disappear before the instability develops significantly. They conclude that the mock gravity by dust is not important in galaxy formations.

Wang, Boqi; Field, Goerge B.

1989-01-01

273

PROBLEMS WITH THE US PROGRAM APPROACH TO URBAN HOUSING: CAN EUROPE LEAD AMERICA TO A POLICY SOLUTION IN 2002 AND BEYOND?  

Microsoft Academic Search

The history of housing and urban development in America over the past fifty years offers important lessons for the United States and Europe in 2002 and beyond. From 1950 on, housing and urban development was a series of piece-meal programs. These programs were input-oriented, and often the goal of providing adequate housing for inner city residents was displaced or minimized.

George E. OConnell

2002-01-01

274

Dust dynamics and processing in shocks  

Microsoft Academic Search

The processing of dust in shocks in the interstellar medium can lead to changes in the dust to gas mass ratio and also to a radical evolution of the dust size distribution. Here we focus on the important results of numerical models that simulate the impact of shocks on the interstellar dust size distribution in molecular clouds and in the

V. Guillet; A. Jones; G. Pineau Des Foręts

2009-01-01

275

H. R. 870: This Act may be cited as the Lead Battery Recycling Incentives Act, introduced in the House of Representatives, One Hundred Second Congress, First Session, February 6, 1991  

SciTech Connect

According to the EPA, 138,000 tons of lead were discarded in batteries in 1986 (65% of total lead discarded). There was a 64% increase between 1970 and 1986, and the EPA projects a further increase of 31% by the year 2000. H.R.870 was introduced into the US House of Representatives on February 6, 1991 to amend the Solid Waste Disposal Act to provide management standards and recycling requirements for spent lead-acid batteries.

Not Available

1991-01-01

276

Atmospheric Dust  

NSDL National Science Digital Library

Atmospheric dust storms are common in many of the world's semi-arid and arid regions and can impact local, regional, and even global weather, agriculture, public health, transportation, industry, and ocean health. This module takes a multifaceted approach to studying atmospheric dust storms. The first chapter examines the impacts of dust storms, the physical processes involved in their life cycle, their source regions, and their climatology. The second chapter explores satellite products (notably dust RGBs) and dust models used for dust detection and monitoring, and presents a process for forecasting dust storms. The third and final chapter of the module examines the major types of dust storms: those that are synoptically forced, such as pre- and post-frontal dust storms and those induced by large-scale trade winds; and those caused by mesoscale systems such as downslope winds, gap flow, convection, and inversion downburst storms.

Comet

2012-03-06

277

Migration of Contaminated Soil and Airborne Particulates to Indoor Dust  

PubMed Central

We have developed a modeling and measurement framework for assessing transport of contaminated soils and airborne particulates into a residence, their subsequent distribution indoors via resuspension and deposition processes, and removal by cleaning and building exhalation of suspended particles. The model explicitly accounts for the formation of house dust as a mixture of organic matter (OM) such as shed skin cells and organic fibers, soil tracked-in on footwear, and particulate matter (PM) derived from the infiltration of outdoor air. We derived formulas for use with measurements of inorganic contaminants, crustal tracers, OM, and PM to quantify selected transport parameters. Application of the model to residences in the U.S. Midwest indicates that As in ambient air can account for nearly 60% of the As input to floor dust, with soil track-in representing the remainder. Historic data on Pb contamination in Sacramento, CA, was used to reconstruct sources of Pb in indoor dust, showing that airborne Pb was likely the dominant source in the early 1980s. However, as airborne Pb levels declined due to the phase out of leaded gasoline, soil resuspension and track-in eventually became the primary sources of Pb in house dust. PMID:19924944

Layton, David W.; Beamer, Paloma I.

2009-01-01

278

Selecting baghouse dust collectors  

SciTech Connect

A thorough analysis of the dust to be captured and determination of specific application requirements are necessary when designing a baghouse collection system. Independent consultants specializing in pollution control equipment and manufacturers with experience in several types of collectors are possible sources of assistance. These experts typically have testing facilities to analyze the dust characteristics. This final article of a two-part series on baghouse design and selection concentrates on application considerations created by the type of dust handled, selecting the best filtration media, selecting the best filtration media, and determining the air-to-cloth (A/C) ratio. The first article discussed bag sizing and cleaning methods and housing and hopper designs.

Moore, S.; Rubak, J.; Jolin, M. [Farr Co., El Segundo, CA (United States)]|[Farr Co., Laval, Quebec (Canada)

1997-04-01

279

Cosmic dust  

NASA Technical Reports Server (NTRS)

Dust is a ubiquitous component of our galaxy and the solar system. The collection and analysis of extraterrestrial dust particles is important to exobiology because it provides information about the sources of biogenically significant elements and compounds that accumulated in distant regions of the solar nebula and that were later accreted on the planets. The topics discussed include the following: general properties of interplanetary dust; the carbonaceous component of interplanetary dust particles; and the presence of an interstellar component.

Brownlee, Donald E.; Sandford, Scott A.

1992-01-01

280

Lead exposure assessment from study near a lead-acid battery factory in China.  

PubMed

The production of lead-acid battery in China covered about one-third of the world total output and there are more than 2000 lead-acid battery factories. They may cause the major environment lead pollution. Blood lead levels of several hundreds of residents were over 100 ?g/L due to the waste discharges from a lead-acid battery factory in Heyuan, Guangdong province. This study aimed to find out the environmental lead sources, the human lead exposure pathways, and the amplitudes from a lead-acid battery factory. The study results showed that lead levels in soil, dust, tree leaves and human blood declined with the distances increased from the production site. Twenty nine of 32 participants had blood lead levels of over 100 ?g/L with an exceptional high value of 639 ?g/L for one child. This result suggested that the lead-acid battery production from this factory has caused the elevated lead levels in its neighboring environment and residents. Dust intake was the dominant exposure pathway for humans (over 90%). The lead levels found in adult and toddler (6.19 and 50.1 ?g/kg/d, respectively) in the polluted area were far higher than the provisional tolerable weekly intake (PTWI) of 25 ?g/kg body weight (translated into 3.5 ?g/kg/d), which was established by the joint FAO/WHO Expert Committee. Blood lead levels within the family members were strongly correlated with the house dust lead levels. Our results in this study suggested that further studies in this area should be performed to assess human exposure and relevant human health risks from living close to lead-acid battery factories. PMID:22578522

Chen, Laiguo; Xu, Zhencheng; Liu, Ming; Huang, Yumei; Fan, Ruifang; Su, Yanhua; Hu, Guocheng; Peng, Xiaowu; Peng, Xiaochun

2012-07-01

281

NHEXAS PHASE I REGION 5 STUDY--STANDARD OPERATING PROCEDURE--ANALYSIS OF DUST AND SOIL FOR LEAD, CADMIUM, AND CHROMIUM (RTI/ACS-AP-209-120)  

EPA Science Inventory

This protocol describes methodology and quality control measures used in the analysis of dust wipes, wet wipes, soil, and the rug/mat for metals. The samples were extracted with a 10% or greater concentration of ultra-pure nitric acid and diluted to a final concentration of 2% or...

282

Dust World  

NSDL National Science Digital Library

The increasing importance of understanding dust and its role in the Earth system is driving new research and an analysis of past data. This website offers research on the impact of dust forcings on the Earth system from dust storms. Analysis of dust from a whole Earth perspective incorporates connections and interconnections of dust in the atmospheres as well as how to mitigate the increase and severity of dust storms. This resource is sponsored by the Earth System Science Education Alliance (ESSEA), a NASA, NSF and NOAA-supported program implemented by the Institute for Global Environmental Strategies (IGES) to improve the quality of geoscience instruction for pre-service and in-service K-12 teachers.

2011-02-23

283

Interplanetary Dust  

NASA Astrophysics Data System (ADS)

The birth of a solar system is enshrouded in gas and dust. A collapsing rotating cloud increases in density until a critical point is reached and a YOUNG STELLAR OBJECT begins its rapid accretion at the center, still surrounded by a disk of gas and dust (figure 1). As stars evolve through a T-Tauri phase, much of this primordial dust cloud is removed by strong stellar winds and radiation forces...

Sykes, M.; Murdin, P.

2000-11-01

284

An immunogenetic analysis of the T-cell recognition of the major house dust mite allergen Der p 2: identification of high- and low-responder HLA-DQ alleles and localization of T-cell epitopes.  

PubMed Central

Cellular reactivity to Der p 2, a major allergen of the house dust mite (HDM) Dermatophagoides pteronyssinus, was studied in a group of 41 symptomatic HDM sensitive patients, using fresh peripheral blood mononuclear cells (PBMC) and assays of proliferation. Sixty per cent of the patients responded to Der p2, with reactivities being greater in patients with asthma as one of their clinical manifestations and also in those who had skin-test reactivity to a number of allergens. HLA-DR and -DQ serotyping was undertaken in 39 of the patients and the magnitude of T-cell proliferative responses to Der p 2 were found to be positively associated with DQ7 and negatively associated with DQ2. T-cell determinants within the Der p 2 molecule were identified by assays using a series of overlapping peptides (15- to 19-mers) spanning the entire protein. Fifty-nine per cent of the 41 HDM-sensitive patients responded to one or more of the peptides. All of the peptides were antigenic for at least one of the individuals, indicating the heterogeneity of the human repertoire reactive with Der p 2. There was a substantial variability in the number and location of epitopes recognized by T cells from the different allergic patients, the mean number per patient being 2.3 +/- 1.3 (SD). The most frequently recognized peptide was that spanning residues 111-129, being stimulatory in 66.7%, the other peptides were each recognized by between 8 to 25% of individuals. There was no correlation between the epitope recognized and the presence of particular HLA-DQ antigens. PMID:7490115

O'Brien, R M; Thomas, W R; Nicholson, I; Lamb, J R; Tait, B D

1995-01-01

285

Paraoccupational exposures to lead and tin carried by electric-cable splicers  

SciTech Connect

To test the hypothesis that electric-cable splicers contaminate their homes with lead and tin, nine splicers were matched with nine of their neighbors. House dust samples were collected in two areas within each home: a laundry room/dirty clothes area, and a composite sample from other areas in the house. Samples were analyzed by energy dispersive X-ray fluorescence for lead and tin (tin is a tracer to the occupational source of lead). The difference in the geometric mean lead concentrations in the laundry areas between the splicers' and neighbors' homes (1021 ppm and 390 ppm) was statistically significant (p < 0.025). The difference in concentrations from the other areas of the house (585 ppm and 329 ppm) was also significant (p < 0.05). Tin concentrations in house dust were very different between the two groups (p < 0.0005), suggesting that electric-cable splicers were contaminating their homes with lead and tin from work. Recommendations are included to prevent paraoccupational lead exposures by eliminating the pathways into the home. Another recommendation suggests that blood-lead levels be screened in children under the age of seven who live with electric-cable splicers.

Rinehart, R.D.; Yanagisawa, Y. (Harvard School of Public Health, Boston, MA (United States))

1993-10-01

286

Dust removal  

Microsoft Academic Search

This report, presented on December 3, 1936, discusses dust removal installations. Four types of equipment which were used for this purpose were: (1) gravity separators, (2) centrifugal separators, (3) electrostatic separators, (4) molecular and frictional force separators. In use of the first three methods, dust particles left the steam of gas, while the filters operating in the fourth method depended

Geister

1947-01-01

287

Lead Poisoning Prevention Tips  

MedlinePLUS

... sources of lead. Regularly wash children’s hands and toys. Hands and toys can become contaminated from household dust or exterior ... not shown to be lead free; remove recalled toys and toy jewelry immediately from children. use only ...

288

Andromeda's Dust  

NASA Astrophysics Data System (ADS)

Spitzer Space Telescope and Herschel Space Observatory imaging of M31 is used, with a physical dust model, to construct maps of dust surface density, dust-to-gas ratio, starlight heating intensity, and polycyclic aromatic hydrocarbon (PAH) abundance, out to R ? 25 kpc. The global dust mass is M d = 5.4 × 107 M ?, the global dust/H mass ratio is M d/M H = 0.0081, and the global PAH abundance is langq PAHrang = 0.039. The dust surface density has an inner ring at R = 5.6 kpc, a maximum at R = 11.2 kpc, and an outer ring at R ? 15.1 kpc. The dust/gas ratio varies from M d/M H ? 0.026 at the center to ~0.0027 at R ? 25 kpc. From the dust/gas ratio, we estimate the interstellar medium metallicity to vary by a factor ~10, from Z/Z ? ? 3 at R = 0 to ~0.3 at R = 25 kpc. The dust heating rate parameter langUrang peaks at the center, with langUrang ? 35, declining to langUrang ? 0.25 at R = 20 kpc. Within the central kiloparsec, the starlight heating intensity inferred from the dust modeling is close to what is estimated from the stars in the bulge. The PAH abundance reaches a peak q PAH ? 0.045 at R ? 11.2 kpc. When allowance is made for the different spectrum of the bulge stars, q PAH for the dust in the central kiloparsec is similar to the overall value of q PAH in the disk. The silicate-graphite-PAH dust model used here is generally able to reproduce the observed dust spectral energy distribution across M31, but overpredicts 500 ?m emission at R ? 2-6 kpc, suggesting that at R = 2-6 kpc, the dust opacity varies more steeply with frequency (with ? ? 2.3 between 200 and 600 ?m) than in the model.

Draine, B. T.; Aniano, G.; Krause, Oliver; Groves, Brent; Sandstrom, Karin; Braun, Robert; Leroy, Adam; Klaas, Ulrich; Linz, Hendrik; Rix, Hans-Walter; Schinnerer, Eva; Schmiedeke, Anika; Walter, Fabian

2014-01-01

289

Self-organization of Dust Forming Media  

NASA Astrophysics Data System (ADS)

Multi-dimensional, time-dependent simulations of the dust formation process around late type stars have confirmed the existence of a thermal/radiative instability in dust forming gases. This instability may lead to a clumpy rather than a smooth dust distribution, i. e. a self-organization of irradiated, dust forming matter. The models combine time-dependent dust formation theory with detailed, frequency-dependent radiative transfer calculations by means of a Monte Carlo method, which has been carefully adapted to the special case of clumpy media and tested against deterministic codes. The models show that dust formation behind already existing dust clouds, which shield the stellar radition, is strongly favoured. In the shadow of these clouds, the temperature decreases by several hundered Kelvin which faciliates subsequent dust formation and results in radially aligned dust structures. Theses structures are similar to those revealed by high resolution observations of planetary nebulae and star formation regions.

Woitke, Peter

290

Streptomycetes in house dust: associations with housing characteristics and endotoxin  

EPA Science Inventory

In addition to mold, indoor bioaerosols also contain bacterial components that may have implications for human health. Endotoxin is a cell wall component in Gram-negative bacteria present at varying levels indoors that has been found to have respiratory health implications. Stre...

291

Occupational Exposure to Lead  

MedlinePLUS

... stirring up lead-containing dust with dry sweeping; wet cleaning is safer. If you wear a respirator at work, make sure it fits well. What about lead in my home? Lead is present in lead-based paint and in lead-contaminated soil and water. The older the home, the greater ...

292

Optical characteristics of desert dust  

NASA Astrophysics Data System (ADS)

We have been conducting research aimed at enabling prediction of desert optical environments from meteorological and satellite observations. To this end we have been collecting aerosol size distributions, visibility and meteorological data continuously for the past year at 2 sites in the Mojave Desert of California. Optical properties of dust are calculated from these data for a great variety of meteorological conditions. The concentration of dust particles is strongly dependent on wind speed for speeds greater than a threshold (7 m/s at Edwards and 15 m/s at China Lake). For individual wind episodes there is a clear relationship between wind speed and dust mass. However, that relationship changes from event to event leading to noisy summary plots; thus, indicating that other factors, such as dust sources, also influence dust loading. The HYPACT program is used to map out the sources, concentration and flow of dust. HYPACT is a pollution transport program that uses RAMS meteorological code output for input. HYPACT can calculate concentration forward in time from an assumed emission source or backward in time from an observation site. This facilitates the location of dust sources and the calculation of dust concentrations along air streams. Once dust concentrations are known and assuming the particle size distributions are the same as at the measurement sites knowledge of IR extinction is no longer confined to just the measurement sites.

Walker, Philip L.; Blomshield, Fred

2002-08-01

293

Dust Catchers  

NSDL National Science Digital Library

In this activity related to indoor air pollution, learners build take-home dust catchers with wax paper and petroleum jelly. After a set monitoring period, learners conduct representative particle counts using a comparison grid. Learners will also graph the results. This activity can be enhanced by sharing the "Health Hazards of Lunar Dust" Podcast with learners (see related resource link). This resource includes background information, variation ideas and a handout for learners in both English and Spanish.

Moreno, Nancy P.; Tharp, Barbara Z.; Dresden, Judith

2007-01-01

294

From Dust to Protoplanets  

NASA Astrophysics Data System (ADS)

To date, most simulations of planetary accretion have considered a single stage of growth such as dust coagulation, planetesimal formation, or oligarchic growth. However, these stages are likely to take place concurrently in different regions of a protoplanetary disk, and even at the same location in a disk. This can lead to interactions and feedbacks between the various growth stages, altering the outcome. Here I will present results of new simulations that model growth from micrometer-size dust grains up to planetary embryos throughout a protoplanetary disk, including potentially important physical processes such as radial drift,bouncing and fragmentation during collisions, and pebble accretion onto large bodies. I will also discuss the implications for giant-planet formation, dust retention in protoplanetary disks, and meteorite parent body ages and compositions.

Chambers, John E.

2014-11-01

295

Historic Houses.  

ERIC Educational Resources Information Center

Reviews some of the efforts of the Society for the Preservation of New England Antiquities (SPNEA) to preserve, conserve, and interpret historic houses to the public. Examines the history and some of the specific preservation problems concerning the Beauport Cottage, the Sayward-Wheeler House, and the Gropius House. (MJP)

Curtis, Nancy

1997-01-01

296

Does Housing Mobility Policy Improve Health?  

Microsoft Academic Search

This article summarizes the empirical evidence for the effect of housing mobility policies on health outcomes. Our focus derived from our interest in housing policies that might help reduce health disparities and our finding that, excluding policies concerned with the physical characteristics of housing (e.g., exposure to lead), only housing mobility has been evaluated for its effects on health.We reviewed

Theresa L. Osypuk; Rebecca E. Werbel; Ellen R. Meara; David M. Cutler; Lisa F. Berkman

2004-01-01

297

Lead isotopes as a supplementary tool in the routine evaluation of household lead hazards.  

PubMed Central

The advent of magnetic sector inductively coupled plasma-mass spectrometry (ICP-MS) allows rapid, accurate, and precise measurement of lead isotopes in environmental and biological samples at a lower cost than traditional methods. This may increase the feasibility of including lead isotope measurements as a routine tool to identify household sources of lead exposure to children. Here, we present three household case studies to illustrate how lead hazard evaluations by an environmental specialist could be supplemented with routine lead isotope analyses of potential lead sources and blood. Sampling for lead isotopes was undertaken following the U.S. Department of Housing and Urban Development regulatory guidelines for the evaluation of lead hazards in housing, and with the consideration of minimizing the additional costs associated with lead isotope measurements. The range of isotopic ratios within a single residence was large enough to allow the characterization of different lead sources, particularly when both major (e.g., (207)Pb/(206)Pb) and minor (e.g., (206)Pb/(204)Pb) isotope ratios were considered. These cases illustrate the utility of the lead isotope method to identify main source(s) of lead exposure to the child; discard unlikely sources of exposure to the child; point to sources of lead to dust; and substantiate or refine the environmental assessment based exclusively on lead concentrations and loadings. Thus, a more effective evaluation of household lead hazards would likely benefit from considering a) lead concentrations and loadings in and around the household environment; b) all isotopic ratios of potential lead sources within that environment; and c) information about behavioral habits, as well as an evaluation of viable pathways of exposure to the child. PMID:11102302

Gwiazda, R H; Smith, D R

2000-01-01

298

Housing and child health.  

PubMed

The connection between housing and health is well established. Physical, chemical, and biological aspects of the child's home, such as cleanliness, moisture, pests, noise, accessibility, injury risks, and other forms of housing environmental quality, all have the potential to influence multiple aspects of the health and development of children. Basic sanitation, reduced household crowding, other improvements in housing and expanded, and improved housing regulations have led to advances in children's health. For example, lead poisoning prevention policies have profoundly reduced childhood lead exposure in the United States. This and many other successes highlight the health benefits for families, particularly children, by targeting interventions that reduce or eliminate harmful exposures in the home. Additionally, parental mental health problems, food insecurity, domestic violence, and the presence of guns in children's homes all are largely experienced by children in their homes, which are not as yet considered part of the Healthy Homes agenda. There is a large movement and now a regulatory structure being put in place for healthy housing, which is becoming closely wedded with environmental health, public health, and the practice of pediatrics. The importance of homes in children's lives, history of healthy homes, asthma, and exposures to lead, carbon monoxide, secondhand/thirdhand smoke, radon, allergy triggers is discussed, as well as how changes in ambient temperature, increased humidity, poor ventilation, water quality, infectious diseases, housing structure, guns, electronic media, family structure, and domestic violence all affect children's health. PMID:23953987

Weitzman, Michael; Baten, Ahmareen; Rosenthal, David G; Hoshino, Risa; Tohn, Ellen; Jacobs, David E

2013-09-01

299

Mite and Booklouse Fauna From Vacuumed Dust Samples From Beijing  

PubMed Central

A significant-source of allergens come from house dust that contain particles derived from arthropods, molds, and pet dander. This study evaluated mite and booklouse fauna from vacuumed dust samples in Beijing China (a temperate zone). Our survey was carried out in Beijing in the homes of mite allergic patients who visited our Allergy Department. In total, 38 homes were selected for the collection of dust samples by vacuuming, from December 2008 to January 2010. The flotation method was used to isolate mites from house dust. Permanent slides were prepared for mite specimens and mites were identified and counted under a microscope. In total, 1,798 separate mite and insect specimens were found in 345 dust samples taken from 38 homes. A total of 95 individual Dermatophagoides (D) siboney were detected in 35 dust samples from 19 homes (representing 5.3% of all mite and insect species found in house dust); in addition, this mite was found to co-exist with D. farinae (Hughes, 1961) in 33 dust samples. Our results demonstrated the presence D. siboney that co-existed with D. farinae in house dust in Beijing China (a temperate zone). PMID:24843802

Sun, Jin-Lu; Shen, Lian; Chen, Jun; Yu, Jin-Miao

2014-01-01

300

Dust bands in the asteroid belt  

NASA Technical Reports Server (NTRS)

This paper describes the original IRAS observations leading to the discovery of the three dust bands in the asteroid belt and the analysis of data. Special attention is given to an analytical model of the dust band torus and to theories concerning the origin of the dust bands, with special attention given to the collisional equilibrium (asteroid family), the nonequilibrium (random collision), and the comet hypotheses of dust-band origin. It is noted that neither the equilibrium nor nonequilibrium models, as currently formulated, present a complete picture of the IRAS dust-band observations.

Sykes, Mark V.; Greenberg, Richard; Dermott, Stanley F.; Nicholson, Philip D.; Burns, Joseph A.

1989-01-01

301

Lead poisoning.  

PubMed Central

Lead poisoning is the most common disease of environmental origin in the United States today. Adult lead poisoning results primarily from exposure by inhalation in the workplace. Pediatric lead poisoning results principally from the ingestion of lead from environmental media, including paint chips, dust, soil, drinking water, ceramics, and medications. Lead is toxic to many organ systems, among them developing erythrocytes, the kidneys, and the nervous system. Lead-induced toxicity to the central nervous system causes delayed development, diminished intelligence, and altered behavior. In young children, this effect has been demonstrated convincingly to occur at blood lead levels between 10 and 20 micrograms per dl. The Centers for Disease Control and Prevention has recommended that a blood lead level of 10 micrograms per dl or higher be considered evidence of increased lead absorption, and the National Academy of Sciences has concurred in that recommendation. Unresolved issues in need of further study include the frequency of screening young children for lead, the question of whether women should be offered screening for lead before conceiving a pregnancy, the role of x-ray fluorescence analysis in assessing lead in bone, and the appropriate legislative response of the United States government to lead-based paint abatement. PMID:7941534

Landrigan, P J; Todd, A C

1994-01-01

302

Where Is Lead Found? Paint in many homes built before 1978 may contain lead.  

E-print Network

Where Is Lead Found? · Paint in many homes built before 1978 may contain lead. · Soil surrounding a home may have lead from exterior paint dust or from leaded gasoline in cars. · Household dust can contain lead from deteriorating lead- based paint or from soil containing lead that is tracked

Liskiewicz, Maciej

303

Animal House  

NSDL National Science Digital Library

The goal of this activity is to design, build and test a house or toy for an animal. Learners will research a particular animal and design a house or toy that will encourage that animal's specific behaviors. Each house or toy must fit into the animal's cage, support the animal's size and weight, and be constructed of non-toxic materials. Safety note: adult supervision recommended for cutting cardboard boxes.

Museum Of Science, Boston

2005-01-01

304

Newton to Einstein — dust to dust  

NASA Astrophysics Data System (ADS)

We investigate the relation between the standard Newtonian equations for a pressureless fluid (dust) and the Einstein equations in a double expansion in small scales and small metric perturbations. We find that parts of the Einstein equations can be rewritten as a closed system of two coupled differential equations for the scalar and transverse vector metric perturbations in Poisson gauge. It is then shown that this system is equivalent to the Newtonian system of continuity and Euler equations. Brustein and Riotto (2011) conjectured the equivalence of these systems in the special case where vector perturbations were neglected. We show that this approach does not lead to the Euler equation but to a physically different one with large deviations already in the 1-loop power spectrum. We show that it is also possible to consistently set to zero the vector perturbations which strongly constrains the allowed initial conditions, in particular excluding Gaussian ones such that inclusion of vector perturbations is inevitable in the cosmological context. In addition we derive nonlinear equations for the gravitational slip and tensor perturbations, thereby extending Newtonian gravity of a dust fluid to account for nonlinear light propagation effects and dust-induced gravitational waves.

Kopp, Michael; Uhlemann, Cora; Haugg, Thomas

2014-03-01

305

Determination of numbers of lead-exposed American children as a function of lead source: Integrated summary of a report to the US Congress on childhood lead poisoning  

SciTech Connect

In 1986, the U.S. Congress (Section 118(f), Superfund Amendments and Reauthorization Act (SARA)) directed the Agency for Toxic Substances and Disease Registry to provide to it a quantitative assessment of the contributions of various sources of lead to childhood exposure. We provided both a quantitative response to the mandate and a critique of low-level lead sources for U.S. population segments. We also present here an integrated assessment of major and low-level lead sources. Significant sources of lead in childhood exposure include lead in paint, dust, soil, and drinking water. Approximately 6 million U.S. children less than 7 years old reside in the oldest housing, with highest exposure risk due to leaded paint. About 2 million in deteriorated units are at particularly high risk for exposure with ca. 1.2 million children in oldest, deteriorated housing estimated to have blood lead (PbB) levels above 15 micrograms/dl. Soil and dust lead are potential sources of exposure for 6-12 million children. Residential tap water lead is a measurable source for ca. 3.8 million children, of whom the U.S. EPA estimates ca. 240,000 have water-specific exposures at toxic levels. Leaded gasoline combustion mainly in past years has produced, and will continue to produce into the 1990s, significant numbers of exposed children with toxicologically elevated PbBs. For 1990, 1.25 million children will have their PbBs fall below 15 micrograms/dl. Food lead can cause significant exposure in certain cases.36 references.

Mushak, P.; Crocetti, A.F. (Univ. of North Carolina, Chapel Hill (USA))

1989-12-01

306

Environmental health disparities in housing.  

PubMed

The physical infrastructure and housing make human interaction possible and provide shelter. How well that infrastructure performs and which groups it serves have important implications for social equity and health. Populations in inadequate housing are more likely to have environmental diseases and injuries. Substantial disparities in housing have remained largely unchanged. Approximately 2.6 million (7.5%) non-Hispanic Blacks and 5.9 million Whites (2.8%) live in substandard housing. Segregation, lack of housing mobility, and homelessness are all associated with adverse health outcomes. Yet the experience with childhood lead poisoning in the United States has shown that housing-related disparities can be reduced. Effective interventions should be implemented to reduce environmental health disparities related to housing. PMID:21551378

Jacobs, David E

2011-12-01

307

Environmental Health Disparities in Housing  

PubMed Central

The physical infrastructure and housing make human interaction possible and provide shelter. How well that infrastructure performs and which groups it serves have important implications for social equity and health. Populations in inadequate housing are more likely to have environmental diseases and injuries. Substantial disparities in housing have remained largely unchanged. Approximately 2.6 million (7.5%) non-Hispanic Blacks and 5.9 million Whites (2.8%) live in substandard housing. Segregation, lack of housing mobility, and homelessness are all associated with adverse health outcomes. Yet the experience with childhood lead poisoning in the United States has shown that housing-related disparities can be reduced. Effective interventions should be implemented to reduce environmental health disparities related to housing. PMID:21551378

2011-01-01

308

Comet Gas and Dust Dynamics Modeling  

NASA Technical Reports Server (NTRS)

This software models the gas and dust dynamics of comet coma (the head region of a comet) in order to support the Microwave Instrument for Rosetta Orbiter (MIRO) project. MIRO will study the evolution of the comet 67P/Churyumov-Gerasimenko's coma system. The instrument will measure surface temperature, gas-production rates and relative abundances, and velocity and excitation temperatures of each species along with their spatial temporal variability. This software will use these measurements to improve the understanding of coma dynamics. The modeling tool solves the equation of motion of a dust particle, the energy balance equation of the dust particle, the continuity equation for the dust and gas flow, and the dust and gas mixture energy equation. By solving these equations numerically, the software calculates the temperature and velocity of gas and dust as a function of time for a given initial gas and dust production rate, and a dust characteristic parameter that measures the ability of a dust particle to adjust its velocity to the local gas velocity. The software is written in a modular manner, thereby allowing the addition of more dynamics equations as needed. All of the numerical algorithms are added in-house and no third-party libraries are used.

Von Allmen, Paul A.; Lee, Seungwon

2010-01-01

309

Using state and metropolitan area house price cycles to interpret the U. S. housing market  

Microsoft Academic Search

This brief examines the numerous house price cycles in states and metropolitan areas since the 1970s, drawing lessons that may be informative for analyzing and projecting national patterns. It finds that house sales volumes, new home construction, and mortgage delinquencies have provided leading indicators when a statewide house price boom was nearing an end, but that house prices have rarely

Yolanda K. Kodrzycki; Nelson Gerew

2006-01-01

310

Manufacturing improvements in the processing of lead-acid battery plates and reduction in plate dusting with an active-material additive  

Microsoft Academic Search

Present-day plate processing offers ample opportunity for improvement within lead-acid battery plants. An inorganic, glass micro-fiber, active-material additive has been found to improve plate processing and lower cost in many of the various operations. This additive allows paste batches to be made with higher moisture contents that improve grid filling and paste texture through higher malleability and reduced resistance to

A Ferreira; J Jordan; J Wertz; G Zguris

2004-01-01

311

Clay Houses  

ERIC Educational Resources Information Center

In this article, the author describes a project designed for fourth-graders that involves making clay relief sculptures of houses. Knowing the clay houses will become a family heirloom makes this lesson even more worth the time. It takes three classes to plan and form the clay, and another two to underglaze and glaze the final products.

Pedro, Cathy

2011-01-01

312

Associations of phthalate concentrations in floor dust and multi-surface dust with the interior materials in Japanese dwellings.  

PubMed

Phthalates are widely used as plasticizers in numerous products. However, there has been some concern about the various effects they may have on human health. Thus, household phthalate levels are an important public health issue. While many studies have assessed phthalate levels in house dust, the association of these levels with building characteristics has scarcely been examined. The present study investigated phthalate levels in house dust samples collected from the living areas of homes, and examined associations between these phthalate levels and the interior materials. Dust was collected from two portions of the living area: floor dust from the entire floor surface, and multi-surface dust from objects more than 35 cm above the floor. The levels of seven phthalates were measured using gas chromatography/mass spectrometry in selective ion monitoring mode. Phthalate levels were higher in multi-surface dust than in floor dust. Among floor dust samples, those from dwellings with compressed wooden flooring had significantly higher levels of di-iso-butyl phthalate compared to those with other floor materials, while polyvinyl chloride (PVC) flooring was associated with higher di-2-ethylhexyl phthalate (DEHP) levels. Among multi-surface dust samples, higher levels of DEHP and di-iso-nonyl phthalate (DINP) were found in samples from homes with PVC wallpaper than without. The number of PVC interior materials was significantly positively correlated with the levels of DEHP and DINP in multi-surface dust. The phthalate levels in multi-surface dust were associated with the interior surface materials, and those in floor dust were directly related to the flooring materials. Our findings show that when using house dust as an exposure assessment, it is very important to note where the samples were collected from. The present report provides useful information about the association between phthalates and dust inside dwellings, which will assist with establishing public health provisions. PMID:24012901

Ait Bamai, Yu; Araki, Atsuko; Kawai, Toshio; Tsuboi, Tazuru; Saito, Ikue; Yoshioka, Eiji; Kanazawa, Ayako; Tajima, Shuji; Shi, Cong; Tamakoshi, Akiko; Kishi, Reiko

2014-01-15

313

ANALYSIS OF SOIL AND DUST SAMPLES FOR POLYCHLORINATED BIPHENYLS BY ENZYME LINKED IMMUNOSORBENT ASSAY (ELISA)  

EPA Science Inventory

An inhibition enzyme-linked immunosorbent assay (ELISA) was used to determine polychlorinated biphenyls (PCBs) in house dust and soil. Soil and house dust samples were analyzed for PCB by both gas chromatography/electron capture detection (GC/ECD) and ELISA methods. A correlati...

314

DEVELOPMENT OF A HIGH VOLUME SURFACE SAMPLER FOR PESTICIDES IN FLOOR DUST  

EPA Science Inventory

A high volume surface sampler (HVS2) for the collection of house dust and the semivolatile organics (including pesticides) in house dust has been designed and tested. The sampler consists of an intake nozzle, cyclone, and filter. The position of the nozzle is regulated by the sta...

315

The retrieval of optical properties from terrestrial dust devil vortices  

NASA Astrophysics Data System (ADS)

The retrieval of the optical properties of desert aerosols in suspension within terrestrial dust devils is presented with possible future application for martian dust devils. The transmission of light through dust devil vortices was measured in situ to obtain the wavelength-dependent attenuation by the aerosols. A Monte Carlo model was applied to each dust devil with the retrieved optical properties corresponding to the set of parameters which lead to the best model representation of the observed transmission spectra. The retrieved optical properties agree well with single scattering theory and are consistent with previous studies of dust aerosols. The enhanced absorption observed for dust devils with a higher tangential wind speed, and in comparison to atmospheric aerosol studies, suggests that larger dust particles are lofted and suspended around dust devil vortices. This analysis has shown that the imaginary refractive indices (and thus the optical properties of the suspended dust) are generally overestimated when these larger dust grains entrained by dust devils are neglected. This will lead to an overestimation of the amount of solar radiation absorbed by the small particles that remain in suspension after the dust devil terminates. It is also demonstrated that a 10% uncertainty in the particle size distribution of the dust entrained in the dust devils can result in a 50% increase in the predicted amount of incident solar radiation absorbed by the dust particles once the dust devil has terminated. The method used here provides the capability to retrieve the optical properties of the dust entrained in martian dust devils by taking advantage of transits over surface spacecraft which are capable of making optical measurements at ultraviolet and visible wavelengths. Our results suggest that we would observed higher absorption at all wavelengths for dust particles entrained in dust devil vortices compared to the ubiquitous dust haze.

Mason, Jonathon P.; Patel, Manish R.; Lewis, Stephen R.

2014-03-01

316

Interactive Soil Dust Aerosol Model in the GISS GCM. Part 1; Sensitivity of the Soil Dust Cycle to Radiative Properties of Soil Dust Aerosols  

NASA Technical Reports Server (NTRS)

The sensitivity of the soil dust aerosol cycle to the radiative forcing by soil dust aerosols is studied. Four experiments with the NASA/GISS atmospheric general circulation model, which includes a soil dust aerosol model, are compared, all using a prescribed climatological sea surface temperature as lower boundary condition. In one experiment, dust is included as dynamic tracer only (without interacting with radiation), whereas dust interacts with radiation in the other simulations. Although the single scattering albedo of dust particles is prescribed to be globally uniform in the experiments with radiatively active dust, a different single scattering albedo is used in those experiments to estimate whether regional variations in dust optical properties, corresponding to variations in mineralogical composition among different source regions, are important for the soil dust cycle and the climate state. On a global scale, the radiative forcing by dust generally causes a reduction in the atmospheric dust load corresponding to a decreased dust source flux. That is, there is a negative feedback in the climate system due to the radiative effect of dust. The dust source flux and its changes were analyzed in more detail for the main dust source regions. This analysis shows that the reduction varies both with the season and with the single scattering albedo of the dust particles. By examining the correlation with the surface wind, it was found that the dust emission from the Saharan/Sahelian source region and from the Arabian peninsula, along with the sensitivity of the emission to the single scattering albedo of dust particles, are related to large scale circulation patterns, in particular to the trade winds during Northern Hemisphere winter and to the Indian monsoon circulation during summer. In the other regions, such relations to the large scale circulation were not found. There, the dependence of dust deflation to radiative forcing by dust particles is probably dominated by physical processes with short time scales. The experiments show that dust radiative forcing can lead to significant changes both in the soil dust cycle and in the climate state. To estimate dust concentration and radiative forcing by dust more accurately, dust size distributions and dust single scattering albedo in the model should be a function of the source region, because dust concentration and climate response to dust radiative forcing are sensitive to dust radiative parameters.

Perlwitz, Jan; Tegen, Ina; Miller, Ron L.

2000-01-01

317

Housing Policy  

NSDL National Science Digital Library

Understanding the variegated terrain of local and state housing policies is key for urban planners, geographers, and others with an interest in the built environment and public policy. This site was created by the Center for Housing Policy (the research affiliate of the National Housing Conference) in order to provide information for "expanding the availability of homes for working families and others in your community." The site was launched in 2008, and includes sections such as Toolbox, Building a Strategy, and Forum. The Getting Started area provides answers to basic questions such as "What is 'affordable housing'?" and "What is 'subsidized housing'?" Moving on, the Toolbox area includes documents and summaries on specific policy tools designed for a variety of reasons, from meeting the housing needs of older adults to improving residential energy efficiency. Visitors won't want to miss the Building a Strategy area. Here they will find information about how to create a successful housing strategy that will provide residential units for a range of community members.

2012-04-20

318

NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR EXTRACTION OF SOIL AND HOUSE DUST SAMPLES FOR GC/MS ANALYSIS OF PESTICIDE AND PAH (BCO-L-28.0)  

EPA Science Inventory

The purpose of this SOP is to describe procedures for extracting and preparing a dust or soil sample for gas chromatography mass spectrometry (GC/MS) analysis of pesticides and polyaromatic hydrocarbons (PAHs). This procedure was followed to ensure consistent data retrieval durin...

319

NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR EXTRACTION OF SOIL/HOUSE DUST FOR GC/MS ANALYSIS OF PESTICIDES (BCO-L-14.0)  

EPA Science Inventory

The purpose of this SOP is to describe procedures for extracting and preparing dust or soil samples for gas chromatography/mass spectrometry (GC/MS) analysis of pesticides. This procedure was followed to ensure consistent data retrieval during the Arizona NHEXAS project and the "...

320

BIOAVAILABILITY AND BIOLOGICAL RESPONSE OF PBDES ADMINISTERED TO RATS IN HOUSEHOLD DUST  

EPA Science Inventory

Abstract Household dust has recently been implicated as a source of PBDE exposure. This study investigated the bioavailability of PBDEs in house dust administered through the diet as compared to PBDEs in oil via the diet. PBDEs in household dust were just as bioavailabl...

321

PBDEs in indoor dust in South-Central China: characteristics and implications.  

PubMed

Dust samples were collected randomly from 76 houses, 12 offices, 43 outdoor sites, two televisions and two computers in South-Central China. The indoor dust samples were analyzed for the concentrations, congener profiles, and possible sources of polybrominated diphenyl ethers (PBDEs) and compared to similar data obtained for outdoor dusts. The concentrations of Sigma(10)PBDEs (the sum of BDE28, 47, 66, 85, 99, 100, 153, 154, 183, and 209) were 186.6-9654 ng g(-1) (mean=2662 ng g(-1)) and 1737-4408 ng g(-1) (mean=3179 ng g(-1)) for house dust and office dust, respectively. No significant differences were found among the congener profiles of PBDEs in house dust from three different cities. The dominant congener in all dust samples was BDE209, accounting for an average of 96.2%, 99.0% and 97.4% of Sigma(10)PBDEs for house dust, office dust and outdoor dust, respectively. Unlike previous studies, this study found that BDE183 was present in high proportion to Sigma(9)PBDEs (BDE209 excluded) in both indoor and outdoor dusts, in addition to the usually dominant congeners, BDE47 and 99. Sigma(10)PBDEs concentrations in house dust were higher than those in outdoor dust for most comparison samples. Combined with the significantly higher Sigma(10)PBDEs concentrations in television and computer dusts, PBDE-containing products used indoors, including television and computers, were important potential emission sources for PBDEs in indoor dusts. Further studies are required to detail the source of the high levels of BDE183 in Chinese indoor dusts. PMID:19875146

Huang, Yumei; Chen, Laiguo; Peng, Xiaochun; Xu, Zhencheng; Ye, Zhixiang

2010-01-01

322

Performance of dust allergen carpet samplers in controlled laboratory studies.  

PubMed

Allergens and other pollutants in house dust are collected using a variety of dust samplers that are assumed to operate similarly. This factorial design study compared sampler performance under controlled environmental conditions. House dust with known particle sizes (212-90, 90-45, and <45??m) and allergen concentrations were sampled from new carpet squares with varying denier, pile height and pile densities. Dust mass and allergen recovery for total dust mites (Der p 1 and Der f 1), cat (Fel d 1) and cockroach allergen (Bla g 1) were assessed using the Eureka Mighty Mite (EURK), the High Volume Small Surface Sampler (HVS), or the American Industrial Hygiene Association (AIHA) method. Allergen concentrations were quantified using enzyme-linked immunosorbent assays, and dust mass results were corrected for carpet fiber shedding. Samplers were compared by exploring mass collection efficiency (CE=fiber corrected dust mass/applied dust mass) and concentration ratio (CR=allergen concentration in collected sample/allergen concentration in test dust). Test dust allergen concentrations varied by particle size fraction due to varying laboratory performance over time. The EURK and HVS samplers had CEs of 41-63% in the small and medium particle size fractions, and collected less than 20% of the available dust from the large size fraction. The AIHA CE ranged from 10% to 17% in the medium and small particle size fractions, but collected little dust in the largest particle size fraction. The AIHA and HVS samplers were more likely to acquire more representative and less variable allergen CRs compared with the EURK method. Health studies that use allergen concentration as an exposure metric need to consider the implications of sampler performance when interpreting links to health outcomes and development of health-based standards for allergens in house dust. PMID:23281430

Adgate, John L; Banerjee, Sudipto; Wang, Mei; McKenzie, Lisa M; Hwang, Jooyeon; Ja Cho, Sook; Ramachandran, Gurumurthy

2013-07-01

323

Building Houses  

NSDL National Science Digital Library

Build a house you can fit inside, using cardboard tubes. Variations of this activity include building for a toy (easier) or building a house the right size for a stuffed animal or a garage for a toy car. Also included is an option to build houses inspired by those around the world (harder). This activity focuses on the understanding of sizes and shapes: Can I fit in this if I stand up? if I sit? Do we have enough cardboard tubes to make a triangular roof? This activity is available as a webpage and a downloadable pdf. Students should have the ability to use scissors and tape well.

2010-01-01

324

NHEXAS PHASE I REGION 5 STUDY--STANDARD OPERATING PROCEDURE--DUST SAMPLING WORKPLAN (RTI/ACS-AP-209-020)  

EPA Science Inventory

This procedure describes the work plan for collecting house dust samples. Wipe samples were collected to determine the concentrations (ug/g) and loadings (ug/cm2) of trace metals in house dust. The selection of the surfaces from which dust was collected was based upon the availab...

325

Theory of charged dust clouds: Equilibrium  

SciTech Connect

Gravitational equilibria of low density dust clouds imbedded in plasma background are studied. These are a new class of astrophysical objects, in which the electric field in quasineutral plasma balances the self-gravity of the dust. Heuristic arguments based on the total potential energy of a uniform dust ball are given for the existence of stable equilibrium and the mass limit for the maximum dust mass M{sub AS}, which can be supported against its self-gravity. The gravitational collapse is initiated by the destabilization of the fundamental radial mode as the mass of the dust cloud M{sub D}{yields}M{sub AS}. The physics of the mass limit is similar to the Chandrasekhar's mass limit for compact objects. One parameter family of spherically symmetric, static solutions of radius R ({approx_equal}0.1 AU) and the total mass of the dust cloud M{sub D} ({approx_equal}10{sup 19} g), for given central dust density, are constructed. A finite flux of photoelectrons is shown to decrease R and M{sub D}. Two-dimensional rotating dust disk equilibrium, characterized by a sharp and diffuse boundary, is also constructed. These dust equilibria (spherical clouds, rotating disks), which are predicted to be within the interstellar clouds, could be relevant for planet formation, as they provide locations where a significant quantity of dust can be stably trapped. The accretion and coagulation interaction between these trapped dust grains may lead to planet formation.

Avinash, K. [Department of Physics and Astrophysics, University of Delhi, Delhi - 7 (India)

2007-01-15

326

Arctic house  

E-print Network

Currently available housing in the Arctic is limited to solutions that have been adapted from designs for less severe climates. This thesis has developed a new manner of residential construction designed specifically for ...

Turkel, Joel A. (Joel Abram), 1969-

1999-01-01

327

Recycling of electric-arc-furnace dust  

Microsoft Academic Search

Electric arc furnace (EAF) dust is one of the largest solid waste streams produced by steel mills, and is classified as a waste under the Resource Conservation and Recovery Act (RCRA) by the U.S. Environmental Protection Agency (EPA). Successful recycle of the valuable metals (iron, zinc, and lead) present in the dust will result in resource conservation while simultaneously reducing

Sresty

1990-01-01

328

Partnership for Advancing Technologies in Housing (PATH)  

NSF Publications Database

... Technology Systems Interactions and Whole House Approaches PATH?s mission is to advance technology ... technology arena. Far reaching exploratory research that can lead to breakthrough technologies and ...

329

5. View of living room of Lucas House, looking through ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. View of living room of Lucas House, looking through archway into dining room. Archway at right leads to bedrooms and bathroom. Doorway in background leads to kitchen. Looking northeast. - Lucas House, 470 Petersburg Road, Hebron, Boone County, KY

330

China Dust and Sand  

... article title:  Dust and Sand Sweep Over Northeast China     View Larger Image ... these views of the dust and sand that swept over northeast China on March 10, 2004. Information on the height of the dust and an ...

2013-04-16

331

Dust agglomeration  

NASA Technical Reports Server (NTRS)

John Marshall, an investigator at Ames Research Center and a principal investigator in the microgravity fluid physics program, is studying the adhesion and cohesion of particles in order to shed light on how granular systems behave. These systems include everything from giant dust clouds that form planets to tiny compressed pellets, such as the ones you swallow as tablets. This knowledge should help us control the grains, dust, and powders that we encounter or use on a daily basis. Marshall investigated electrostatic charge in microgravity on the first and second U.S. Microgravity Laboratory shuttle missions to see how grains aggregate, or stick together. With gravity's effects eliminated on orbit, Marshall found that the grains of sand that behaved ever so freely on Earth now behaved like flour. They would just glom together in clumps and were quite difficult to disperse. That led to an understanding of the prevalence of the electrostatic forces. The granules wanted to aggregate as little chains, like little hairs, and stack end to end. Some of the chains had 20 or 30 grains. This phenomenon indicated that another force, what Marshall believes to be an electrostatic dipole, was at work.(The diagram on the right emphasizes the aggregating particles in the photo on the left, taken during the USML-2 mission in 1995.)

2000-01-01

332

Interstellar Dust: Contributed Papers  

NASA Technical Reports Server (NTRS)

A coherent picture of the dust composition and its physical characteristics in the various phases of the interstellar medium was the central theme. Topics addressed included: dust in diffuse interstellar medium; overidentified infrared emission features; dust in dense clouds; dust in galaxies; optical properties of dust grains; interstellar dust models; interstellar dust and the solar system; dust formation and destruction; UV, visible, and IR observations of interstellar extinction; and quantum-statistical calculations of IR emission from highly vibrationally excited polycyclic aromatic hydrocarbon (PAH) molecules.

Tielens, Alexander G. G. M. (editor); Allamandola, Louis J. (editor)

1989-01-01

333

Lunar Dust 101  

NASA Technical Reports Server (NTRS)

Largely due to rock and soil samples returned during the Apollo program, much has been learned about the composition and properties of lunar regolith. Although, for the most part, the mineral composition resembles terrestrial minerals, the characteristics of the lunar environment have led to very different weathering processes. These result in substantial differences in the particle shapes, particle size distributions, and surface chemistry. These differences lead to non-intuitive adhesion, abrasion, and possible health properties that will pose challenges to future lunar missions. An overview of lunar dust composition and properties will be given with a particular emphasis on possible health effects.

Gaier, James R.

2008-01-01

334

X-ray fluorescence measurements of lead burden in subjects with low-level community lead exposure.  

PubMed

A k-x-ray fluorescence (K-XRF) instrument that can measure in vivo bone lead at low levels was used on a population of 34 adults with no known history of excessive lead exposure. A questionnaire that gathered information relevant to occupational and environmental lead exposure was administered prior to the measurement. A 30-min measurement that produced an average estimated uncertainty of 6 mcg lead/g bone mineral was taken at the mid-tibial diaphysis for each subject. Eighteen subjects had bone lead levels below the measurement uncertainty. The remainder had bone lead levels ranging up to 21 mcg lead/g bone mineral. Bone lead levels were greater among older subjects. Among young adult subjects, bone lead levels greater than the measurement uncertainty were confined entirely to subjects who had grown up in housing that was estimated to have been build prior to 1955. Such a childhood environment is at high risk of fostering exposure to biologically absorbable lead through ingestion of lead paint-contaminated dust and lead pipe-contaminated water. We conclude that the K-XRF technique has the potential to distinguish between low levels of lead burden in epidemiologic studies. PMID:2270952

Hu, H; Milder, F L; Burger, D E

1990-01-01

335

Analytical evaluation of the Tsytovich-Angelis dust-dust collision functions arising from the kinetic theory of dusty plasmas  

SciTech Connect

An efficient analytical calculation approach is presented for the Tsytovich-Angelis dust-dust collision functions consisting of the kinetic theory of dusty plasmas. This method is based on the use of binomial expansion theorem for the analytical representation of the dust-dust collision functions. The analytical calculation offers the advantage that leads to a mathematical expression, which allows the direct calculation of the dust-dust collision functions. The proposed algorithm is implemented numerically using a computer program, and its convergence properties are investigated.

Mamedov, B. A. [Department of Physics, Faculty of Arts and Sciences, Gaziosmanpasa University, Tokat 60100 (Turkey)

2010-11-15

336

Housing Market Segmentation  

Microsoft Academic Search

Housing submarkets are typically defined as geographic areas where the price per unit of housing quantity (defined using some index of housing characteristics) is constant. This paper defines housing markets as geographic areas where (1) the price of housing (per unit of service) is constant and (2) individual housing characteristics are available for purchase. We examine housing market segmentation within

Allen C. Goodman; Thomas G. Thibodeau

1998-01-01

337

Dust Measurements in Tokamaks  

SciTech Connect

Dust production and accumulation impose safety and operational concerns for ITER. Diagnostics to monitor dust levels in the plasma as well as in-vessel dust inventory are currently being tested in a few tokamaks. Dust accumulation in ITER is likely to occur in hidden areas, e.g. between tiles and under divertor baffles. A novel electrostatic dust detector for monitoring dust in these regions has been developed and tested at PPPL. In DIII-D tokamak dust diagnostics include Mie scattering from Nd:YAG lasers, visible imaging, and spectroscopy. Laser scattering resolves size of particles between 0.16-1.6 {micro}m in diameter; the total dust content in the edge plasmas and trends in the dust production rates within this size range have been established. Individual dust particles are observed by visible imaging using fast-framing cameras, detecting dust particles of a few microns in diameter and larger. Dust velocities and trajectories can be determined in 2D with a single camera or 3D using multiple cameras, but determination of particle size is problematic. In order to calibrate diagnostics and benchmark dust dynamics modeling, pre-characterized carbon dust has been injected into the lower divertor of DIII-D. Injected dust is seen by cameras, and spectroscopic diagnostics observe an increase of carbon atomic, C2 dimer, and thermal continuum emissions from the injected dust. The latter observation can be used in the design of novel dust survey diagnostics.

Rudakov, D; Yu, J; Boedo, J; Hollmann, E; Krasheninnikov, S; Moyer, R; Muller, S; Yu, A; Rosenberg, M; Smirnov, R; West, W; Boivin, R; Bray, B; Brooks, N; Hyatt, A; Wong, C; Fenstermacher, M; Groth, M; Lasnier, C; McLean, A; Stangeby, P; Ratynskaia, S; Roquemore, A; Skinner, C; Solomon, W M

2008-04-23

338

Housing Tips for International Students Oncampus Housing  

E-print Network

Life website www.fau.edu/housing or at housing@fau.edu (Boca) and JupiterHousing@fau.edu (Jupiter housing at FAU is available on the Boca Raton Campus and the MacArthur (Jupiter) Campus. Oncampus housing involved with the university, make friends, and have the full university life experience. You must apply

Fernandez, Eduardo

339

PORTABLE TECHNOLOGIES FOR MEASURING LEADING IN DUST  

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) Environmental Technology Verification (ETV) program evaluates the performance of innovative air, water, pollution prevention and monitoring technologies that have the potential to improve human health and the environment. This techn...

340

Affordable housing  

SciTech Connect

This book is designed to assist in implementing a housing affordability program by supporting the use of energy efficient mortgages. The information contained in this book can be applied to many aspects of real estate programs which utility companies have developed. Included are: planning material and worksheets; support material that includes presentation scripts, overheads, slides; and fact sheets.

Not Available

1989-01-01

341

Dust feed mechanism  

DOEpatents

The invention is a dust feed device for delivery of a uniform supply of dust for long periods of time to an aerosolizing means for production of a dust suspension. The device utilizes at least two tandem containers having spiral brushes within the containers which transport the dust from a supply to the aerosolizer means.

Milliman, Edward M. (Benton City, WA)

1984-01-01

342

Lead atmospheric deposition rates and isotopic trends in Asian dust during the last 9.5 kyr recorded in an ombrotrophic peat bog on the eastern Qinghai-Tibetan Plateau  

NASA Astrophysics Data System (ADS)

A full understanding of the atmospheric Pb cycle in Asia during the Holocene is key to palaeoclimate studies of past atmospheric circulation patterns, as well as to assess the impact of increasing industrial activities in this region. However, long-term records of atmospheric Pb isotopic trends in Asia are still sparse. Consequently, we study changes in the concentrations, fluxes and isotopic signature of deposited Pb contained in a 14C-dated peat core from the eastern Qinghai-Tibetan Plateau, dating back to 9.5 kyr BP, and present the first peat record of the changing isotopic composition of atmospheric Pb in dust in Asia during this time. Lead concentrations and fluxes vary between 2.96-21.58 ?g g-1 and 0.06-3.52 mg m-2 y-1, respectively, with an average Pb baseline of 6.80 ± 4.18 ?g g-1. These values agree with other Pb studies of lake and peat archives in China but are one order of magnitude larger than early and mid-Holocene values measured in Europe. Lead isotopic variability throughout the core is small, varying between 206Pb/207Pb = 1.190-1.197, 206Pb/204Pb = 18.648-18.786, 207Pb/204Pb = 15.666-15.694 and 208Pb/204Pb = 38.890-39.090. The application of Bayesian trans-dimensional changepoint modelling to the Pb dataset enabled the identification of eight significant changes in the isotopic composition of the deposited Pb. Such changes mark different phases of atmospheric Pb deposition, and hence variations in atmospheric circulation patterns and environmental conditions. Temporal variations in the potential natural and/or anthropogenic Pb sources are assessed based on the 206Pb, 207Pb, 208Pb and 204Pb isotopic composition and the 1/[Pb] ratio of the peat samples. Our results suggest that Pb deposition throughout the Holocene was governed by local deposition and long-range input from natural dust sources in northwestern (Taklamakan desert and Qaidam basin) and northern China (Badain Jaran and Tengger deserts). Input from the northern sources seems to have been particularly important between 3.1-2.7 kyr BP and 1.7-0.9 kyr BP, suggesting a possible strengthening of the East Asian winter monsoon, in agreement with previous reconstructions in Asia. Based on the Pb/Sc and isotopic composition profiles we do not note any evidence for anthropogenic Pb derived from the thriving mining or smelting activities in northern and eastern China in the last few millennia, suggesting that atmospheric deposition to this region of the eastern Tibetan Plateau was dominated by natural Pb fluxes. These can serve as a true Asian "background" value against which anthropogenic impacts can be quantified. Our results confirm that the combination of radiogenic isotopes (Pb) and trace elements in peat bogs enables observational reconstructions of changes in past regional atmospheric circulation. Such records will enable more refined interpretations of marine and terrestrial palaeorecords in Asia and the Pacific and consequently provide further constraints for changes in ocean and atmospheric circulation and for the testing of palaeoclimate models of circulation patterns.

Ferrat, Marion; Weiss, Dominik J.; Dong, Shuofei; Large, David J.; Spiro, Baruch; Sun, Youbin; Gallagher, Kerry

2012-04-01

343

Martian Dust Simulator  

NASA Technical Reports Server (NTRS)

The Martian Dust Simulator (MDS) was designed to investigate the contamination effects of Martian soil and rock on the performance and function of flight-like microvalves and flight-like filters located within the Sample Analysis at Mars (SAM) instrument suite. The SAM instrument suite, which houses over fifty percent of the science payload, is located on-board the Mars exploration rover. The mission objective of the Mars Science Laboratory Rover is to determine the past, present, and future habitability of Mars. It will serve as a robot geologist, traveling the Mars surface for a period of one Martian year (equivalent to two earth years). The microvalves were designed as a conduit to control the flow of Martian gas to the science instruments. If exposed to particle sizes greater than half a micron, both the science instruments and science equipment, including forty-seven microvalves, could experience performance degradation. As a result, filters were used at various gas inlets to protect flight hardware from particulate degradation. Additionally, the filters serve as the only interface between the Martian environment and the mechanisms within SAM. The MDS operates at 7 Torr (0.135 psi) with a gas flow rate of 0 to 20 m/s. Iron (III) Oxide was the only dust particle specimen used, although several others were initially considered (i.e. JSC-Mars-1, Corundum Powder (Al2O3), Hydrated Sulfate, and Belville (Basalt)). The overarching goal of the MDS is to demonstrate that the Mars exploration program is adequately designed and prepared for the Martian mission environment.

Zuray, Monica; Houston, Karrie; Lorentson, Chris

2008-01-01

344

Dust and gas in active galaxies  

E-print Network

There are strong evidences which favour the existence of dust in active galaxies. Understanding the way in which dust interacts with the radiation and influences the physical conditions of the gas is crucial if we want to learn about the nature of the central active nucleus and about the physical conditions of the ISM in such galaxies. Not taking into account such effects may lead us towards misleading interpretations. Many intriguing questions concerns to the nature and the existence of dust in active galaxies: for instance, under which conditions does the very hard ionizing continuum of an AGN allows the survival of dust grains? Is the composition and size distribution of the dust the same as in our local interstellar medium? How is dust distributed compared to the gas which is at least in part highly ionized by the central AGN? Does dust also exist in radio galaxies at very high redshifts? The work developed in this thesis tries to find answers to some of these questions, through a detailed theoretical and observational research of the mechanisms which control the interaction of dust with the radiation and with the ions. The observable effects of the dust on the emission line spectrum are also analyzed in detail. The final goal has been to give clues about more general questions: origin of the emitting gas, ionization mechanisms, geometry, connection between low and high redshift active galaxies or the validity of the unification scenario. This thesis tries, in summary, to provide a clearer understanding of active galaxies in general.

M. Villar-Martin

1996-05-21

345

Dynamics of urban and rural housing stocks in China  

Microsoft Academic Search

The massive migration flows from rural to urban areas in China, combined with an expected decline in the total population over the next decades, leads to two important challenges for China's housing: the growth of its urban housing stock and the shrinkage of rural housing. The rural and urban housing systems in China were analyzed using a dynamic material flow

Mingming Hu; Hĺvard Bergsdal; Ester van der Voet; Gjalt Huppes; Daniel B. Müller

2010-01-01

346

Smart Houses  

NASA Technical Reports Server (NTRS)

GWS takes plans for a new home and subjects them to intensive computerized analysis that does 10,000 calculations relative to expected heat loss and heat gain, then provides specifications designed specifically for each structure as to heating, cooling, ventilation and insulation. As construction progresses, GWS inspects the work of the electrical, plumbing and insulation contractors and installs its own Smart House Radiant Barrier. On completion of the home, GWS technicians use a machine that creates a vacuum in the house and enables computer calculation of the air exchanged, a measure of energy efficiency. Key factor is the radiant barrier, borrowed from the Apollo program. This is an adaptation of a highly effective aluminized heat shield as a radiation barrier holding in or keeping out heat, cold air and water vapor.

1987-01-01

347

Interactive dust-radiation modeling: A step to improve weather forecasts  

Microsoft Academic Search

Inclusion of mineral dust radiative effects could lead to a significant improvement in the radiation balance of numerical weather prediction models with subsequent improvements in the weather forecast itself. In this study the radiative effects of mineral dust have been fully incorporated into a regional atmospheric dust model. Dust affects the radiative fluxes at the surface and the top of

Carlos Pérez; Slobodan Nickovic; Goran Pejanovic; José María Baldasano; Emin Özsoy

2006-01-01

348

Freedom House  

NSDL National Science Digital Library

Founded in 1941, Freedom House was organized by prominent Americans who were concerned with mounting threats to peace and democracy. Today, as in previous decades, their mission includes promoting "the growth of freedom by encouraging U.S. policymakers, international institutions, and the governments of established democracies to adopt policies that advance human rights and democracy around the world." First-time visitors may wish to begin by looking to the right-hand side of the homepage to the "Around the World" section. Here visitors can learn about the work that the Freedom House organization is doing in other parts of the world, and more importantly, they can read their in-house reports on democratic movements in different countries. Moving along, the left-hand side of the page includes links to their other publications, which include the "Nations In Transit" series. This particular series takes a long view on political reform in the former Communist states of Europe and Eurasia. To really get a full appreciation of the site's contents and scope requires several visits, but it should have no problem holding the attention of public policy types and scholars.

349

Metal concentrations and distribution in the household, stairs and entryway dust of some Egyptian homes  

NASA Astrophysics Data System (ADS)

Household, stairs and entryway dust samples were collected from 16 houses distributed across Greater Cairo by using vacuum cleaner and sweeping methods during summer season of 2009. Lead (Pb), nickel (Ni), cadmium (Cd), aluminum (Al), iron (Fe), zinc (Zn), cobalt (Co), chromium (Cr) and copper (Cu) were measured in different dust particle sizes: <38 ?m, >38-45 ?m and >45-63 ?m. The highest average concentrations of Pb, Ni, Cd, Co, Cu, and Cr in different particle sizes were found in entryway followed by household and stairs. Al, Fe and Zn concentrations followed the pattern of entryway > stairs > household. Pb, Ni, Cd, Zn, Co and Cr were found in significantly (p < 0.01) higher concentrations in dust of the small particle size (<38 ?m), whereas Al, Fe and Cu were detected in significantly (p < 0.01) higher concentrations in dust of the large particle size (>45-63 ?m). The average concentrations of the individual metals in dust of the small particle size (<38 ?m) were 268, 196.4 and 254.49 ?g gm-1 for Pb, 49.6, 43.5 and 46.66 ?g gm-1 for Ni, 2.86, 2.15 and 2.71 ?g gm-1 for Cd, 4340, 3796 and 2602 ?g gm-1 for Al, 2860, 2200 and 2004 ?g gm-1 for Fe, 209.25, 152.3 and 103.26 ?g gm-1 for Zn, 4.1, 2.88 and 1.96 ?g gm-1 for Co, 85.99, 74.06 and 83.17 ?g gm-1 for Cr and 168.2, 156.5 and 122.02 ?g gm-1 for Cu in entryway, stairs and household, respectively. The mean concentrations of Cu and Pb in the entryway, stairs and household dust exceeded the maximum permissible limit 100 ?g gm-1 for Cu and Pb in soil. The highest concentrations of Pb, Cd, Co and Ni were found in urban areas, Al and Fe in the residential areas, and Cu, Zn and Cr in the residential near to industrial area. Significant positive correlation (p < 0.001) were found between the metal concentrations in household and entryway dust, indicating that the metals in household dust may be derived from outdoor sources in addition to dust generated within the house itself. The contribution of anthropogenic sources, especially traffic emission, to metal levels in household, entryway and stairs dust was reflected by the high values of enrichment factors for Pb, Cd, Zn and Cu and Ni and Cr in fine dust particle compared to the average crustal composition. Insignificant positive correlation coefficients were found between the concentrations of Pb and other metals in household dust. However, the correlation coefficients between the concentrations of Cd, Ni, Cr, Cu, Zn and Fe were statistically significant.

Hassan, Salwa Kamal Mohamed

2012-07-01

350

The discrete heat source approach to dust cloud combustion  

NASA Astrophysics Data System (ADS)

In the present paper, combustion of dust clouds from the discrete point heat source method has been addressed. Time-place temperature profile generated by single particle burning has been obtained to study the dust combustion. The summation of the temperature profiles of burned and burning particles predict the temperature in the preheating zone so that the ignition time of layer in flame front can be determined. Consequently the flame propagating speed was obtained based on the dust concentration corresponding to particles spacing and particle diameter. This method has been validated with aluminum dust cloud combustion. Decrease in the dust concentration leads to the lean limit of dust combustion. Increase in particles diameter or reduction in the dust concentration causes higher lean limit and also reduction in the flame propagating speed. Adding the ignition energy as igniter to this system, provides the path to study the effects of ignition energy in the dust combustion.

Bidabadi, Mehdi; Zadsirjan, Saeedreza; Mostafavi, Seyed Alireza

2014-06-01

351

Assessing the human health risk for aluminium, zinc and lead in outdoor dusts collected in recreational sites used by children at an industrial area in the western part of the Bassin Minier de Provence, France  

NASA Astrophysics Data System (ADS)

The Western part of the “Bassin Minier de Provence”, a former coal mining area, is still occupied by old polluting industries such as a coal-fired power plant and an alumina factory. In 2011 a preliminary outdoor dust survey was carried out in the area as the first step to an exposure and health risk assessment study. Dust samples were taken at 19 sites distributed across the study area, depending on the location of recreational areas used by children to play outdoors. Pseudo-total concentrations of Al, Zn and Pb were determined by ICP-MS and bioaccessible concentrations were estimated using the Unified BARGE Method. Exposure was calculated according to a scenario evaluation approach for dust ingestion and dermal contact routes. Estimation of health risk for exposure to Al, Zn and Pb in outdoor dust was based on the summation of individual risks for the oral and dermal routes. Results show that Al occurs in very high concentrations but mainly innon-bioaccessible forms, especially near the alumina plant. Zinc and Pb occur in low-average levels but mainly in bioaccessible forms. The estimated potential risk decreases according to Pb ? Al > Zn and is lower for the ingestion route. The preliminary results presented in this study indicate that, for Al and Zn, the outdoor dusts of the BMP represent an acceptable risk to children's health. However, the estimated hazard quotients suggest that there is some health risk associated to environmental Pb.

Reis, A. P.; Patinha, C.; Noack, Y.; Robert, S.; Dias, A. C.; Ferreira da Silva, E.

2014-11-01

352

Dust and Ocean Plants  

NASA Technical Reports Server (NTRS)

Adding iron to the diet of marine plant life has been shown in shipboard experiments to boost the amount of carbon-absorbing phytoplankton in certain parts of the world's oceans. A new study promises to give scientists their first global picture of the extent of these unique 'iron-limited' ocean regions, an important step in understanding how the ocean's biology controls the flow of carbon between the atmosphere and the ocean. The new study by researchers at NASA's Goddard Space Flight Center and the Department of Energy's Oak Ridge National Laboratory was presented at the American Geophysical Union's annual meeting in San Francisco on Friday, Dec. 15, 2000. Oceanic phytoplankton remove nearly as much carbon from the atmosphere each year as all land-based plants. Identifying the location and size of nutrient-limited areas in the open ocean has challenged oceanographers for nearly a century. The study pinpointed iron-limited regions by seeing which phytoplankton-rich areas of the world's oceans were also areas that received iron from wind-blown dust. In this map, areas with high levels of chlorophyll from phytoplankton and high levels of dust deposition (high correlation coefficients) are indicated in dark brown. Dust deposition was calculated by a 3-year modelled climatology for the years 1996-1998. The chlorophyll measurements are from 1998 observations from the SeaWiFS (Sea-viewing Wide Field-of-view Sensor) instrument on the OrbView-2 satellite. 'Global, satellite-based analyses such as this gives us insight into where iron deposition may be limiting ocean biological activity,' says lead author David Erickson of Oak Ridge National Laboratory's Computer Science and Mathematics Division. 'With this information we will be able to infer how the ocean productivity/iron deposition relationship might shift in response to climate change.' Map Source: David Erickson, Oak Ridge National Laboratory's Computer Science and Mathematics Division

2002-01-01

353

Model houses and housing ideology in Australia  

Microsoft Academic Search

This paper explores the meaning of the house through an interpretation of model house advertisements and display houses in Australia over the past 20 years. The advertising discourse is analysed as a set of cultural constructs, which, being market sensitive, reflect changing social structures, values and ideologies. Over this period the house structure has been transformed. The informal ‘family’ area

Kim Dovey

1992-01-01

354

Lead Poisoning  

MedlinePLUS

... should hire either a risk assessor or a sampling technician. They will take samples of dust throughout ... the problem. Alternatively, you can buy a dust sampling kit and carefully do the sampling yourself, send ...

355

40 CFR 63.1544 - Standards for fugitive dust sources.  

Code of Federal Regulations, 2010 CFR

...HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission...Hazardous Air Pollutants for Primary Lead Smelting § 63.1544 Standards for fugitive dust sources. (a) Each owner or operator of a primary lead smelter shall...

2010-07-01

356

40 CFR 63.1544 - Standards for fugitive dust sources.  

Code of Federal Regulations, 2011 CFR

...HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission...Hazardous Air Pollutants for Primary Lead Smelting § 63.1544 Standards for fugitive dust sources. (a) Each owner or operator of a primary lead smelter shall...

2011-07-01

357

Lead Poisoning in Children.  

ERIC Educational Resources Information Center

This publication is a guide to help social and health workers plan a preventive campaign against lead poisoning, a cause of mental retardation other neurological handicaps, and death among children. The main victims are 1- to 6-year-olds living in areas where deteriorating housing prevails. Among the causes of lead poisoning are: ingestion of…

Lin-Fu, Jane S.

358

Dust Storms Threaten Snowpacks  

NSDL National Science Digital Library

This National Public Radio story follows Thomas Painter, a scientist with the National Snow and Ice Data Center at the University of Colorado, as he researches the effects of dust on the Colorado Rockies snow pack. The story discusses how dust acts as a catalyst to melting snow, where the dust comes from, and explains some of the environmental and economic repercussions of widespread premature melting. The site also features links to other NPR dust- and drought-related articles.

Harris, Richard; Npr

359

Written In Dust  

NSDL National Science Digital Library

This news article from Lamont-Doherty Earth Observatory highlights the research that uses interplanetary dust from seafloor sediment to study the Earth's climate and geology thousands of years ago. The article gives a description of this project and other related studies with interplanetary dust. Also included is a photograph of a piece of this dust.

2009-02-12

360

Fugitive Dust: Nonpoint Sources  

Microsoft Academic Search

Fugitive dust is a relatively new term for an old problem. Simply put, fugitive dust is a type of nonpoint source air pollution — small airborne particles that do not originate from a specific point such as a gravel quarry or grain mill. Fugitive dust originates in small quantities over large areas. Significant sources include unpaved roads, agricultural cropland and

John H. Ferguson; H. Willard Downs; Donald L. Pfost

361

1. EXTERIOR VIEW OF NEW FAN HOUSE AND HILLMAN FAN ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. EXTERIOR VIEW OF NEW FAN HOUSE AND HILLMAN FAN HOUSE LOOKING NORTHWEST The building on the left, the New Fan House, houses a Corliss steam engine which powered a Buffalo Forge Company single inlet Duplex Conoidal centrifugal exhausted fan through a metal updraft chimney. Part of the brick airway leading to the Baltimore shaft is visible to its right rear. The Hillman Fan House, on the right, houses the 1883 double inlet Guibal fan. The south entry, the curve of the fan housing, and brick updraft chimney are visible in this view. - Dorrance Colliery Fan Complex, South side of Susquehanna River at Route 115 & Riechard Street, Wilkes-Barre, Luzerne County, PA

362

Characterization of Jovian plasma-embedded dust particles  

NASA Astrophysics Data System (ADS)

As the data from space missions and laboratories improve, a research domain combining plasmas and charged dust is gaining in prominence. Our solar system provides many natural laboratories such as planetary rings, comet comae and tails, ejecta clouds around moons and asteroids, and Earth's noctilucent clouds for which to closely study plasma-embedded cosmic dust. One natural laboratory to study electromagnetically controlled cosmic dust has been provided by the Jovian dust streams and the data from the instruments which were on board the Galileo spacecraft. Given the prodigious quantity of dust poured into the Jovian magnetosphere by Io and its volcanoes resulting in the dust streams, the possibility of dusty plasma conditions exist. This paper characterizes the main parameters for those interested in studying dust embedded in a plasma with a focus on the Jupiter environment. I show how to distinguish between dust-in-plasma and dusty-plasma and how the Havnes parameter P can be used to support or negate the possibility of collective behavior of the dusty plasma. The result of applying these tools to the Jovian dust streams reveals mostly dust-in-plasma behavior. In the orbits displaying the highest dust stream fluxes, portions of orbits E4, G7, G8, C21 satisfy the minimum requirements for a dusty plasma. However, the P parameter demonstrates that these mild dusty plasma conditions do not lead to collective behavior of the dust stream particles.

Graps, Amara L.

2006-08-01

363

Deflagration to detonation transition fueled by dust layers  

NASA Astrophysics Data System (ADS)

The roles which dust layers play in severe dust explosions were investigated in a 70 m long and 30 cm inside diameter horizontal Flame Acceleration Tube (FAT) with one end closed and the other end open to the atmosphere. A variety of dusts such as corn dust, cornstarch, Mira Gel starch, wheat dust, and wood flour were layered on the bottom half of the FAT. To initiate the combustion process, a detonation tube filled with a stoichiometric H2/O2 mixture at room temperature and 1 atm pressure was used to ignite a short presuspended dust cloud with a dust concentration of 500 600 g/m3. Combustion waves generated by this dust cloud travel toward the open end of the FAT and are continuously fueled by the dust/air mixtures. Flame propagation processes in the FAT were closely monitored by a variety of measuring instruments at different locations. The study demonstrates that stable quasi-detonation were reached in some runs, but self-sustained Chapman-Jouguet detonations were not observed possibly due to the limitation of the tube length. Attempts were made to determine the structure of dust detonations fueled by a dust layer. Preliminary evidence indicates that for Mira Gel starch the leading shock is essentially a triple shock configuration which involves a Mach stem and for wheat and wood dusts there possibly exists a multi-headed spin structure.

Li, Y.-C.; Harbaugh, A. S.; Alexander, C. G.; Kauffman, C. W.; Sichel, M.

1995-12-01

364

Renovate Right: Important Lead Hazard Information for Families, Child Care Providers and Schools  

ERIC Educational Resources Information Center

Lead can affect children's brains and developing nervous systems, causing reduced IQ, learning disabilities, and behavioral problems. Lead is also harmful to adults. Lead in dust is the most common way people are exposed to lead. People can also get lead in their bodies from lead in soil or paint chips. Lead dust is often invisible. Lead-based…

US Environmental Protection Agency, 2008

2008-01-01

365

Living on the Lunar Surface: Determining the Health Effects of Exposure to Respirable Lunar Dusts  

NASA Astrophysics Data System (ADS)

NASA formed the Lunar Airborne Dust Toxicity Advisory Group (LADTAG) to determine the toxicological effects of lunar dust. This interdisciplinary group is comprised of leading experts in space toxicology, lunar geology, space medicine and biomedical research.

Khan-Mayberry, N. N.

2008-07-01

366

Cosmic Dust VI  

NASA Astrophysics Data System (ADS)

This special issue is primarily devoted to the 6th meeting on Cosmic Dust (COSMIC DUST VI), which was held at CPS (Center for Planetary Science) in Kobe, Japan, on August 5-9, 2013. This meeting was coordinated in an order where a friendly and welcoming atmosphere persuaded the participants of the meeting to develop human relations and interactions among themselves. This has been our interdisciplinary approach to answering the question of where dust comes from and where dust goes. We briefly review some of the exciting papers presented at the meeting and provide perspectives for the development of cosmic dust research.

Kimura, Hiroshi; Kolokolova, Ludmilla; Li, Aigen; Inoue, Akio K.; Jäger, Cornelia

2014-10-01

367

Dust and Planetary Rings  

NASA Astrophysics Data System (ADS)

ABSTRACT Space is not empty it has comic radiations (CMBR), dust etc. Cosmic dust is that type of dust which is composed of particles in space which vary from few molecules to 0.1micro metres in size. This type of dust is made up of heavier atoms born in the heart of stars and supernova. Mainly it contains dust grains and when these dust grains starts compacting then it turns to dense clouds, planetary ring dust and circumstellar dust. Dust grains are mainly silicate particles. Dust plays a major role in our solar system, for example in zodiacal light, Saturn's B ring spokes, planetary rings at Jovian planets and comets. Observations and measurements of cosmic dust in different regions of universe provide an important insight into the Universe's recycling processes. Astronomers consider dust in its most recycled state. Cosmic dust have radiative properties by which they can be detected. Cosmic dusts are classified as intergalactic dusts, interstellar dusts and planetary rings. A planetary ring is a ring of cosmic dust and other small particles orbiting around a planet in flat disc shape. All of the Jovian planets in our solar system have rings. But the most notable one is the Saturn's ring which is the brightest one. In March 2008 a report suggested that the Saturn's moon Rhea may have its own tenuous ring system. The ring swirling around Saturn consists of chunks of ice and dust. Most rings were thought to be unstable and to dissipate over course of tens or hundreds of millions of years but it now appears that Saturn's rings might be older than that. The dust particles in the ring collide with each other and are subjected to forces other than gravity of its own planet. Such collisions and extra forces tend to spread out the rings. Pluto is not known to have any ring system but some Astronomers believe that New Horizons probe might find a ring system when it visits in 2015.It is also predicted that Phobos, a moon of Mars will break up and form into a planetary ring. Many theories are present regarding the formation of rings for example when moons collide, when moon breaks up and due to dust formation in supernova. But the most important question is, that how they maintain their orbit and why they are present there.

Siddiqui, Muddassir

368

Pesticide loadings of select organophosphate and pyrethroid pesticides in urban public housing.  

EPA Science Inventory

We investigated the magnitude and distribution of pyrethroid and organophosphate pesticide loadings within public housing dwellings in Boston, Massachusetts and compared the results using various sampling methods. We collected dust matrices from living room and kitchen in 42 apar...

369

Mental health and housing.  

PubMed

With the present trend away from the designing of individual buildings and towards the systematic planning of whole residential communities, it should be possible to take mental health requirements into account at the planning stage. At present, sociologists are all too seldom consulted on matters of residential planning. When discussing the relationship between housing and mental health one cannot restrict oneself only to the external aspects of the house, but rather one must also consider the opportunities available for the members of the family to satisfy their own needs, both within the home and in its immediate surroundings. Factors which may affect residential requirements include geographical location, type and standard of dwelling and time and continuity of occupation. A move between two districts or groups representing different housing norms and values may lead to withdrawal symptoms in the individual. This may arise equally well from the remoteness of the country districts as from the conflicting pressures brought on by the abundance of contacts available in the large towns. Town life tends to heighten susceptibility to neuroses and personality conflicts. The character of a residential area may affect the mental health of its occupants. Faris & Dunham (4), in studying the incidence of various types of mental illness with an urban population, observed that schizophrenia was most common among people who were in some way isolated from social involvement. The striving for spaciousness in residential areas and the creation of a "summer city" or "garden city" image or a "family-centred way of life" may lead to unexpected problems and have a variety of social consequences. Mental health difficulties have been noted, for example, among housewives in "dormitory" towns or suburbs (11). The institutions required by a community may be grouped into four categories, representing the basic needs of its members. These are (1) economic institutions, (2) social and political organizations, (3) leisure-time clubs and (4) societies and institutions for promoting social integration, including educational, advisory and assistance bodies. The study of satiation processes offers an interesting approach to the relationship between housing and mental health. Man requires new stimuli to motivate him. Boredom and satiation serve to induce passivity and may provoke destructive behaviour and escapism. Finland has the highest percentage of dwellings constructed in the immediate post-war period of any country in Europe, and in respect of the functions of housing many aspects are still apparent which are detrimental to mental health. PMID:1273551

Kari-Koskinen, O; Karvonen, P

1976-01-01

370

Dust Mitigation Vehicle  

NASA Technical Reports Server (NTRS)

A document describes the development and demonstration of an apparatus, called a dust mitigation vehicle, for reducing the amount of free dust on the surface of the Moon. The dust mitigation vehicle would be used to pave surfaces on the Moon to prevent the dust from levitating or adhering to surfaces. The basic principle of operation of these apparatuses is to use a lens or a dish mirror to concentrate solar thermal radiation onto a small spot to heat lunar regolith. In the case of the prototype dust mitigation vehicle, a Fresnel lens was used to heat a surface layer of regolith sufficiently to sinter or melt dust grains into a solid mass. The prototype vehicle has demonstrated paving rates up to 1.8 square meters per day. The proposed flight design of the dust mitigation vehicle is also described.

Cardiff, Eric H.

2011-01-01

371

Housing policy in China  

E-print Network

In the last three decades, the People's Republic of China (PRC) has managed to replace its welfare-based urban housing system with a market-based housing provision scheme. With such significant housing policy changes, the ...

Gao, Lu, S.M. Massachusetts Institute of Technology

2011-01-01

372

Use of a field portable X-Ray fluorescence analyzer to determine the concentration of lead and other metals in soil samples.  

PubMed

Field portable methods are often needed in risk characterization, assessment and management to rapidly determine metal concentrations in environmental samples. Examples are for determining: "hot spots" of soil contamination, whether dust wipe lead levels meet housing occupancy standards, and worker respiratory protection levels. For over 30 years portable X-Ray Fluorescence (XRF) analyzers have been available for the in situ, non-destructive, measurement of lead in paint. Recent advances made possible their use for analysis of airborne dust filter samples, soil, and dust wipes. Research at the University of Cincinnati with the NITON 700 Series XRF instrument (40 millicurie Cadmium 109 source, L X-Rays) demonstrated its proficiency on air sample filters (NIOSH Method No. 7702, "Lead by Field Portable XRF; limit of detection 6 microg per sample; working range 17-1,500 microg/m3 air). Research with lead dust wipe samples from housing has also shown promising results. This XRF instrument was used in 1997 in Poland on copper smelter area soil samples with the cooperation of the Wroclaw Medical Academy and the Foundation for the Children from the Copper Basin (Legnica). Geometric mean soil lead concentrations were 200 ppm with the portable XRF, 201 ppm with laboratory-based XRF (Kevex) and 190 ppm using atomic absorption (AA). Correlations of field portable XRF and AA results were excellent for samples sieved to less than 125 micrometers with R-squared values of 0.997, 0.957, and 0.976 for lead, copper and zinc respectively. Similarly, correlations were excellent for soil sieved to less than 250 micrometers, where R-squared values were 0. 924, 0.973, and 0.937 for lead, copper and zinc, respectively. The field portable XRF instrument appears to be useful for the determination of soil pollution by these metals in industrial regions. PMID:10384212

Clark, S; Menrath, W; Chen, M; Roda, S; Succop, P

1999-01-01

373

Pilot study of sources of lead exposure in Moscow, Russia  

Microsoft Academic Search

This preliminary investigation of sources of lead exposure in Moscow, Russia, by Russian and US collaborators measured lead in paint, interior dust, and drinking water in seven day-care centres, and in petrol, soil and canned food. Some paint samples exceeded US regulatory standards for lead in paint on surfaces (0.5%). Dust lead loadings were -2 and below the guidance levels

Anna O. Orlova; Desmond I. Bannon; Mark R. Farfel; Valerie M. Thomas; Lev V. Aleschukin; Valery V. Kudashov; James P. Shines; Georgy I. Kruchkov

1995-01-01

374

Factors associated with elevated blood lead concentrations in children in Karachi, Pakistan.  

PubMed Central

OBJECTIVES: To confirm whether blood lead concentrations in Karachi were as high as reported in 1989 and to identify which types of exposure to lead contribute most to elevated blood lead concentrations in children in Karachi. METHODS: A total of 430 children aged 36-60 months were selected through a geographically stratified design from the city centre, two suburbs, a rural community and an island situated within the harbour at Karachi. Blood samples were collected from children and a pretested questionnaire was administered to assess the effect of various types of exposure. Cooked food, drinking-water and house dust samples were collected from households. FINDINGS: About 80% of children had blood lead concentrations 10 g/dl, with an overall mean of 15.6 g/dl. At the 5% level of significance, houses nearer to the main intersection in the city centre, application of surma to children's eyes, father's exposure to lead at workplace, parents' illiteracy and child's habit of hand- to-mouth activity were among variables associated with elevated lead concentrations in blood. CONCLUSION: These findings are of public health concern, as most children in Karachi are likely to suffer some degree of intellectual impairment as a result of environmental lead exposure. We believe that there is enough evidence of the continuing problem of lead in petrol to prompt the petroleum industry to take action. The evidence also shows the need for appropriate interventions in reducing the burden due to other factors associated with this toxic element. PMID:12471396

Rahbar, Mohammad Hossein; White, Franklin; Agboatwalla, Mubina; Hozhabri, Siroos; Luby, Stephen

2002-01-01

375

Student Housing.  

ERIC Educational Resources Information Center

Traditional dormitories are out of step with the concepts of higher education that make the 4 years of college a cultural and social experience as well as a period for gathering information on academic topics. These experiences are not served well in twin-bed rooms lined along both sides of corridors that lead only to stairwells or gang bathrooms.…

Educational Facilities Labs., Inc., New York, NY.

376

The impact of cosmic dust on supernova cosmology  

Microsoft Academic Search

Extinction by intergalactic grey dust introduces a magnitude redshift-dependent offset in the standard-candle relation of supernova Type Ia. This leads to overestimated luminosity distances compared to a dust-free universe. Quantifying the amplitude of this systematic effect is crucial for an accurate determination of the dark energy parameters. In this paper, we model the grey dust extinction in terms of the

Pier Stefano Corasaniti

2006-01-01

377

Blair House: The President's Guest House  

NSDL National Science Digital Library

The Blair House has been the next-door neighbor of the White House in Washington, DC since 1824 and it is the President's official guest house. The house is named after Francis Preston Blair, who served in President Andrew Jackson's "Kitchen Cabinet" and he was the consummate political insider during the administrations of Martin Van Buren and Abraham Lincoln. Today, the house also serves as a home for the president-elect in the days before the inauguration. This marvelous website from CSPAN provides visitors with video clips of the house, and it's quite a tour. There are ten short profiles that include views of the principal suite, the drawing room, and the Lincoln Room. The site also has interviews with people who have spent time getting to know the Blair House, including Ambassador Nancy Brinker and Deputy Chief of Protocol Raymond P. Martinez.

378

Infrared Extinction Spectra of Mineral Dust Aerosol  

NASA Astrophysics Data System (ADS)

Mineral dust aerosol affects the atmosphere by absorbing and scattering radiation and plays an important role in the Earth's radiative budget. The effect of atmospheric dust on climate is studied by various remote sensing techniques that use measurements from narrow band IR channels of satellites to determine key atmospheric properties. Therefore, it is essential to take radiative effects of mineral dust aerosol into account to correctly process remote sensing data. As aerosols are transported through the atmosphere they undergo aging and heterogeneous chemistry. This leads to changes in their optical properties and their effects on climate. In this study we carried out spectral simulations using both Mie theory and solutions derived in the Rayleigh regime for authentic dust samples and several processed components of mineral dust. Simulations of the extinction based on Mie theory shows that it does not accurately reproduce the peak position and band shape of the prominent IR resonance features. Errors in the simulated peak position and the line shape associated with Mie theory can adversely affect determination of mineral composition based on IR satellite data. Analytic solutions for various shapes derived from Rayleigh theory offer a better fit to the major band features of the spectra, therefore the accuracy of modeling atmospheric dust properties can be improved by using these analytic solutions. It is also important to take aging of mineral dust into account. We investigated the effect of chemical processing on the optical properties. It was shown that interactions of components of mineral dust (calcite, quartz and kaolinite) with humic and organic acids cause a shift of the IR resonance bands of these minerals. It may indicate changes in shape of the particles as well as changes in hygroscopicity and, as the result, the water content in these samples. Therefore, care should be taken when modeling optical properties of aged mineral dust.

Kleiber, P.; Laskina, O.; Alexander, J. M.; Young, M.; Grassian, V. H.

2012-12-01

379

A New Pyrometallurgical Process for Producing Antimony White from By-Product of Lead Smelting  

NASA Astrophysics Data System (ADS)

Antimonial dust is a by-product of lead smelting and an important material for extracting antimony. A new pyrometallurgical process for producing antimony white from the antimonial dust is reported. The process mainly consists of three steps, which are reduction smelting, alkaline refining, and blowing oxidation. First, the reduction smelting of antimonial dust is carried out in an oxygen-rich bottom blow furnace to enrich antimony and lead in the crude alloy. The antimony and lead contents in the slag can thus be reduced to 2.8 wt.% and 0.1 wt.%, respectively. Second, the conventional method of alkaline refining is adopted to remove arsenic from the crude alloy, and arsenic content in the low-arsenic alloy could be decreased to 0.009 wt.%. Finally, the low-arsenic alloy is oxidized in a special oxidizing pan at 650°C by blowing compressed air or oxygen-rich air on the surface, during which qualified antimony white can be produced and collected in a bag house. The oxygen concentration and antimony content in the bottom alloy have a significant impact on production efficiency and product quality during blowing oxidation.

Liu, Weifeng; Yang, Tianzu; Zhang, Duchao; Chen, Lin; Liu, Yunfeng

2014-09-01

380

A New Pyrometallurgical Process for Producing Antimony White from By-Product of Lead Smelting  

NASA Astrophysics Data System (ADS)

Antimonial dust is a by-product of lead smelting and an important material for extracting antimony. A new pyrometallurgical process for producing antimony white from the antimonial dust is reported. The process mainly consists of three steps, which are reduction smelting, alkaline refining, and blowing oxidation. First, the reduction smelting of antimonial dust is carried out in an oxygen-rich bottom blow furnace to enrich antimony and lead in the crude alloy. The antimony and lead contents in the slag can thus be reduced to 2.8 wt.% and 0.1 wt.%, respectively. Second, the conventional method of alkaline refining is adopted to remove arsenic from the crude alloy, and arsenic content in the low-arsenic alloy could be decreased to 0.009 wt.%. Finally, the low-arsenic alloy is oxidized in a special oxidizing pan at 650°C by blowing compressed air or oxygen-rich air on the surface, during which qualified antimony white can be produced and collected in a bag house. The oxygen concentration and antimony content in the bottom alloy have a significant impact on production efficiency and product quality during blowing oxidation.

Liu, Weifeng; Yang, Tianzu; Zhang, Duchao; Chen, Lin; Liu, Yunfeng

2014-06-01

381

Dust in the Universe  

NSDL National Science Digital Library

Space is seeming less and less like empty space as new discoveries and reexaminations fill in the gaps. And, ingenuity and technology are allowing for examination of the far reaches of the Milky Way and beyond. Even dust is getting its due, but not the dust we're familiar with. This article describes how astronomers worldwide are studying the dust in space with the Spitzer Space Telescope and also describes the technology behind the telescope's design.

2004-10-01

382

Interstellar Dust Models  

NASA Technical Reports Server (NTRS)

A viable interstellar dust model - characterized by the composition, morphology, and size distribution of the dust grains and by the abundance of the different elements locked up in the dust - should fit all observational constraints arising primarily from the interactions of the dust with incident radiation or the ambient gas. As a minimum, these should include the average interstellar extinction, the infrared emission from the diffuse interstellar medium (ISM), and the observed interstellar abundances of the various refractory elements. The last constraint has been largely ignored, resulting in dust models that require more elements to be in the dust phase than available in the ISM. In this talk I will describe the most recent advances towards the construction of a comprehensive dust model made by Zubko, Dwek, and Arendt, who, for the first time, included the interstellar abundances as explicit constraints in the construction of interstellar dust models. The results showed the existence of many distinct models that satisfy the basic set of observational constraints, including bare spherical silicate and graphite particles, PAHs, as well as spherical composite particles containing silicate, organic refractories, water ice, and voids. Recently, a new interstellar dust constituent has emerged, consisting of metallic needles. These needles constitute a very small fraction of the interstellar dust abundance, and their existence is primarily manifested in the 4 to 8 micron wavelength region, where they dominate the interstellar extinction. Preliminary studies show that these models may be distinguished by their X-ray halos, which are produced primarily by small angle scattering off large dust particles along the line of sight to bright X-ray sources, and probe dust properties largely inaccessible at other wavelengths.

Dwek, Eli

2004-01-01

383

Self-contained dust collector with quick release adapter duct  

SciTech Connect

The patent describes a self-containing dust collector comprising: a support frame; a housing mounted on the frame having partition means dividing the housing into a dirty air chamber having a dirty air inlet and a clean air chamber having a clean air outlet. A partition means has an aperture connecting the dirty air chamber in air flow communication with the clean air chamber; a filter means operatively mounts across the aperture; means for circulating dirty air through the dirty air inlet, into the dirty air chamber, through the filter means into the clean air chamber and the clean air outlet; a hopper mounted on the frame in dust receiving relation to the filter means has a first opening constituting a dust discharge port; and a dust storage receptacle spaced from the dust discharge port. It has a wall means defining a second opening constituting a dust receiving port. The improvement comprises a quick release adapter duct movable to either an open nonduct forming position or a closed duct forming position relative to the storage receptacle.

Revell, A.E.

1987-07-14

384

The dissolution of natural and artificial dusts in glutamic acid  

NASA Astrophysics Data System (ADS)

This article describes the characteristics of natural dusts, industrial dusts, and artificial dusts, such as mineral phases, chemical components, morphological observation and size. Quartz and calcite are the main phases of natural dusts and industrial dusts with high SiO2 and CaO and low K2O and Na2O in the chemical composition. The dissolution and electrochemical action of dusts in glutamic acid liquor at the simulated human body temperature (37 °C) in 32 h was investigated. The potential harm that the dust could lead to in body glutamic acid acidic environment, namely biological activity, is of great importance for revealing the human toxicological mechanism. The changes of pH values and electric conductivity of suspension of those dusts were similar, increased slowly in the first 8 h, and then the pH values increased rapidly. The total amount of dissolved ions of K, Ca, Na, and Mg was 35.4 to 429 mg/kg, particularly Ca was maximal of 20 to 334 mg/kg. The total amount of dissolved ions of Fe, Zn, Mn, Pb, and Ba was 0.18 to 5.59 mg/kg and in Al and Si was 3.0 to 21.7 mg/kg. The relative solubility order of dusts in glutamic acid is wollastonite > serpentine > sepiolite, the cement plant industrial dusts > natural dusts > power plant industrial dusts. The wollastonite and cement plant industrial dusts have the highest solubility, which also have high content of CaO; this shows that there are a poorer corrosion-resisting ability and lower bio-resistibility. Sepiolite and power plant industrial dusts have lowest solubility, which also have high content of SiO2; this shows that there are a higher corrosion-resisting ability and stronger bio-resistibility.

Ling, Zhang; Faqin, Dong; Xiaochun, He

2014-08-01

385

Zodiacal emission. III - Dust near the asteroid belt  

NASA Technical Reports Server (NTRS)

Properties of the zodiacal dust bands are derived from fits to Infrared Astronomical Satellite profiles of the ecliptic. Three observations lead to the conclusion that the dust-band material is spread over a range of heliocentric distances between the asteroid belt and the sun: parallax, color temperature, and wavelength dependence of the band latitudes. The orientations of the midplanes of the bands are found to be typical of asteroids. A model of 'migrating bands', wherein dust is produced near the asteroid belt and spirals into the sun under the influence of Poynting-Robertson drag, is used to explain the range of heliocentric distances of dust-band material.

Reach, William T.

1992-01-01

386

Modeling Agglomeration of Dust Particles in Plasma  

SciTech Connect

The charge on an aggregate immersed in a plasma environment distributes itself over the aggregate's surface; this can be approximated theoretically by assuming a multipole distribution. The dipole-dipole (or higher order) charge interactions between fractal aggregates lead to rotations of the grains as they interact. Other properties of the dust grains also influence the agglomeration process, such as the monomer shape (spherical or ellipsoidal) or the presence of magnetic material. Finally, the plasma and grain properties also determine the morphology of the resultant aggregates. Porous and fluffy aggregates are more strongly coupled to the gas, leading to reduced collisional velocities, and greater collisional cross sections. These factors in turn can determine the growth rate of the aggregates and evolution of the dust cloud. This paper gives an overview of the numerical and experimental methods used to study dust agglomeration at CASPER and highlights some recent results.

Matthews, Lorin S.; Land, Victor; Ma Qianyu; Perry, Jonathan D.; Hyde, Truell W. [Center for Astrophysics, Space Physics, and Engineering Research Baylor University, One Bear Place 97310, Waco, Texas 76798-7310 (United States)

2011-11-29

387

Can dust coagulation trigger streaming instability?  

NASA Astrophysics Data System (ADS)

Context. Streaming instability can be a very efficient way of overcoming growth and drift barriers to planetesimal formation. However, it was shown that strong clumping, which leads to planetesimal formation, requires a considerable number of large grains. State-of-the-art streaming instability models do not take into account realistic size distributions resulting from the collisional evolution of dust. Aims: We investigate whether a sufficient quantity of large aggregates can be produced by sticking and what the interplay of dust coagulation and planetesimal formation is. Methods: We develop a semi-analytical prescription of planetesimal formation by streaming instability and implement it in our dust coagulation code based on the Monte Carlo algorithm with the representative particles approach. Results: We find that planetesimal formation by streaming instability may preferentially work outside the snow line, where sticky icy aggregates are present. The efficiency of the process depends strongly on local dust abundance and radial pressure gradient, and requires a super-solar metallicity. If planetesimal formation is possible, the dust coagulation and settling typically need ~100 orbits to produce sufficiently large and settled grains and planetesimal formation lasts another ~1000 orbits. We present a simple analytical model that computes the amount of dust that can be turned into planetesimals given the parameters of the disk model.

Dr??kowska, J.; Dullemond, C. P.

2014-12-01

388

Dust Coagulation in Protoplanetary Accretion Disks  

NASA Technical Reports Server (NTRS)

The time evolution of dust particles in circumstellar disk-like structures around protostars and young stellar objects is discussed. In particular, we consider the coagulation of grains due to collisional aggregation. The coagulation of the particles is calculated by solving numerically the non-linear Smoluchowski equation. The different physical processes leading to relative velocities between the grains are investigated. The relative velocities may be induced by Brownian motion, turbulence and drift motion. Starting from different regimes which can be identified during the grain growth we also discuss the evolution of dust opacities. These opacities are important for both the derivation of the circumstellar dust mass from submillimeter/millimeter continuum observations and the dynamical behavior of the disks. We present results of our numerical studies of the coagulation of dust grains in a turbulent protoplanetary accretion disk described by a time-dependent one-dimensional (radial) alpha-model. For several periods and disk radii, mass distributions of coagulated grains have been calculated. From these mass spectra, we determined the corresponding Rosseland mean dust opacities. The influence of grain opacity changes due to dust coagulation on the dynamical evolution of a protostellar disk is considered. Significant changes in the thermal structure of the protoplanetary nebula are observed. A 'gap' in the accretion disk forms at the very frontier of the coagulation, i.e., behind the sublimation boundary in the region between 1 and 5 AU.

Schmitt, W.; Henning, Th.; Mucha, R.

1996-01-01