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Sample records for house dust lead

  1. Exterior surface dust lead, interior house dust lead and childhood lead exposure in an urban environment

    SciTech Connect

    Bornschein, R.L.; Succop, P.A.; Krafft, K.M.; Clark, C.S.; Peace, B.; Hammond, P.B.

    1986-01-01

    The impact of urban lead exposure is being examined in a prospective study of several hundred children followed from birth to five years of age. A wide range of social, behavioral, biological and environmental factors are being assessed at approximately one year intervals beginning at birth. Previous analyses on this cohort have indicated a strong relationship between hand lead and hand-to-mouth activity and suggests that this is an important mechanism of inadvertent ingestion of lead in infants and young children. The present analyses was undertaken to examine the joint influence of lead in exterior surface dust and interior lead-containing painted surfaces on lead levels in house dust. In addition the joint influence of exterior and interior surface dust lead on children's hand lead content and blood lead concentration was examined. At 18 months of age 38% of the observed variation in blood lead was accounted for by hand lead and dust lead. Interior paint lead and exterior surface dust lead accounted for 52% of the observed variation in interior surface dust lead concentration. Exterior surface dust lead, obtained from exterior surface scrapings, indirectly influenced blood lead through its impact on interior house dust lead and children's hand lead content, but had no observable direct impact on blood lead. 13 references, 4 figures, 3 tables.

  2. Lead in Chinese villager house dust

    NASA Astrophysics Data System (ADS)

    Bi, Xiangyang; Liu, Jinling; Han, Zhixuan

    2016-04-01

    House dust has been recognized as an important contributor to children's blood Pb. Here we conducted a comprehensive study to investigate geographical variation of Pb in Chinese villager house dust. The concentrations of Pb in 477 house dust samples collected from twenty eight areas throughout China varied from 12 to 2510 mg/kg, with geometric mean and median concentration of 54 mg/kg and 42 mg/kg, respectively. The median Pb concentrations in different geographical areas ranged from 16 (Zhangjiakou, Hebei) to 195 mg/kg (Loudi, Hunan). The influences of outdoor soil Pb concentrations, dates of construction, house decorative materials, heating types, and site specific pollution on Pb concentrations in house dust were evaluated. No correlations were found between the house dust Pb concentrations and the age of houses, as well as house decorative materials. Whereas outdoor soil, coal combustion, and site specific pollution may be potential Pb sources. The results of scanning electron microscopy (SEM) showed that Pb bearing particles appeared as cylindrical, flaky and irregular aggregates with the particle size ranging from about 10 to 800 μm. The energy dispersive X-ray microanalysis (EDX) suggested that Pb in the dust particles may be associated with calcium compounds. But 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 order 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.

  3. The influence of soil remediation on lead in house dust.

    PubMed

    von Lindern, Ian H; Spalinger, Susan M; Bero, Bridget N; Petrosyan, Varduhi; von Braun, Margrit C

    2003-02-15

    Lead in house dust has long been recognized as a principal source of excess lead absorption among children at the Bunker Hill Superfund Site (BHSS) in northern Idaho. House dust lead concentration from homeowner's vacuum cleaner bags has been monitored since the epidemic of childhood lead poisoning in 1974. Geometric mean house dust lead concentrations decreased from >10000 mg/kg in 1974 to approximately 4000 mg/kg in 1975, in response to air pollution control initiatives at the defective primary lead smelter. After smelter closure, 1983 mean dust lead concentrations were near 3000 mg/kg and were most dependent on soil sources. Following emergency soil removals from public areas and roadsides and fugitive dust control efforts in the mid-1980s, house dust lead decreased by approximately 40-60% to 1200-1500 mg/kg. In 1992, a cleanup goal of 500 mg/kg dust lead community average, with no individual home exceeding 1000 mg/kg, was adopted. This goal was to be achieved by a combination of contaminated soil removals and fugitive dust control efforts throughout the 21 square mile BHSS. Continual reductions in house dust lead concentrations have been noted throughout the residential area soil cleanup. Geometric mean house dust lead concentrations averaged approximately 500-600 mg/kg from 1996 to 1999 and dropped below 500 mg/kg in 2000. Analysis of these data indicates that approximately 20% of the variance in dust lead concentrations is attributed to yard, neighborhood, and community soil lead concentrations. Since 1996, dust lead concentrations and dust and lead loading rates have also been measured by dust mats placed at entryways into the homes. Neighborhood soil lead concentrations, household hygiene, the number of adults living in the home, and the number of hours a child spends outdoors in summer explain approximately 26% of the variance in mat dust lead loading rates. It is estimated that post-remedial house dust lead concentrations will stabilize at 400-500 mg

  4. Northern Idaho house dust and soil lead levels compared to the Bunker Hill Superfund Site.

    PubMed

    Spalinger, Susan M; von Braun, Margrit C; Petrosyan, Varduhi; von Lindern, Ian H

    2007-07-01

    House dust has been identified as a major exposure medium for lead (Pb) in children. High levels of Pb in soil and house dust have been recorded at the Bunker Hill Superfund Site (BHSS) in northern Idaho, an historic mining and smelting district. Soil and dust remediation at the site was required; however, regional background soil and dust Pb levels had not been well characterized. The objective of this survey was to determine background house dust Pb levels and to compare those levels with concentrations, and dust and Pb loading rates measured at the BHSS. Soil and house dust samples were collected in five towns demographically similar to the BHSS but unaffected by the mining industry. The background concentrations and loading rates were significantly lower than those observed at the site. House age was a significant factor affecting background soil and house dust Pb concentrations and loading rates. PMID:17171279

  5. Canadian House Dust Study: Lead Bioaccessibility and Speciation

    SciTech Connect

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

    2011-12-31

    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.

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

    SciTech Connect

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

    1985-10-01

    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 cmS) 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 <177 m 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 >80% of the lead applied. House dusts of different particle sizes <246 m 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 digestion/decantations for analysis of dust and paint; and three wipes with handwipes with one digestion/decantation for the analysis of six handwipes together.

  7. Lead and Other Heavy Metals in Dust Fall from Single-Family Housing Demolition

    PubMed Central

    Cali, Salvatore; Welch, Alison; Catalin, Bogdan; Dixon, Sherry L.; Evens, Anne; Mucha, Amy P.; Vahl, Nicole; Erdal, Serap; Bartlett, John

    2013-01-01

    Objective We measured lead and other heavy metals in dust during older housing demolition and effectiveness of dust suppression. Methods We used American Public Housing Association Method 502 and U.S. Environmental Protection Agency Methods SW3050B and SW6020 at 97 single-family housing demolition events with intermittent (or no) use of water to suppress dust at perimeter, non-perimeter, and locations without demolition, with nested mixed modeling and tobit modeling with left censoring. Results The geometric mean (GM) lead dust fall during demolition was 6.01 micrograms of lead per square foot per hour (μg Pb/ft2/hour). GM lead dust fall was 14.18 μg Pb/ft2/hour without dust suppression, but declined to 5.48 μg Pb/ft2/hour (p=0.057) when buildings and debris were wetted. Significant predictors included distance, wind direction, and main street location. At 400 feet, lead dust fall was not significantly different from background. GM lead concentration at demolition (2,406 parts per million [ppm]) was significantly greater than background (GM=579 ppm, p=0.05). Arsenic, chromium, copper, iron, and manganese demolition dust fall was significantly higher than background (p<0.001). Demolition of approximately 400 old housing units elsewhere with more dust suppression was only 0.25 μg Pb/ft2/hour. Conclusions Lead dust suppression is feasible and important in single-family housing demolition where distances between houses are smaller and community exposures are higher. Neighbor notification should be expanded to at least 400 feet away from single-family housing demolition, not just adjacent properties. Further research is needed on effects of distance, potential water contamination, occupational exposures, and water application. PMID:24179257

  8. The contribution of lead-contaminated house dust and residential soil to children`s blood lead levels

    SciTech Connect

    Lanphear, B.P.; Matte, T.D.; Rogers, J.

    1998-10-01

    In 1992, the US Congress passed the Residential Lead-Based Paint Hazard Reduction Act, which requires the promulgation of health-based dust lead and soil lead standards for residential dwellings to prevent undue lead exposure in children. Unfortunately, the levels of lead in house dust and soil that are associated with elevated blood lead levels among US children remain poorly defined. This pooled analysis was done to estimate the contributions of lead-contaminated house dust and soil to children`s blood lead levels. The results of this pooled analysis, the most comprehensive existing epidemiologic analysis of childhood lead exposure, confirm that lead-contaminated house dust is the major source of lead exposure for children. These analyses further demonstrate that a strong relationship between interior dust lead loading and children`s blood lead levels persists at dust lead levels considerably below the US Department of Housing and urban Development`s current post-abatement standards and the Environmental Protection Agency`s guidance levels. Finally, these analyses demonstrate that a child`s age, race, mouthing behaviors, and study-site specific factors influence the predicted blood lead level at a given level of exposure. These data can be used to estimate the potential health impact of alternative health-based lead standards for residential sources of lead exposure.

  9. Dust Weight and Asthma Prevalence in the National Survey of Lead and Allergens in Housing (NSLAH)

    PubMed Central

    Elliott, Leslie; Arbes, Samuel J.; Harvey, Eric S.; Lee, Robert C.; Salo, Päivi M.; Cohn, Richard D.; London, Stephanie J.; Zeldin, Darryl C.

    2007-01-01

    Background Settled dust has been used in studies to assess exposures to allergens and other biologically active components, but it has not been considered in the aggregate in relation to respiratory health outcomes in the general population. Objective We addressed whether total house dust weight, an index of total dust exposure, was associated with respiratory health outcomes in the National Survey of Lead and Allergens in Housing (1998–1999) (NSLAH). Methods NSLAH was a cross-sectional survey designed to represent permanently occupied housing units in the United States. In each household, a questionnaire was administered and settled dust was vacuumed from five locations. Linear regression models were used to identify predictors of dust weight; logistic regression models were used to examine the relationship between dust weight and asthma and wheeze. Results Dust weight samples were available for 829 households, and survey information was available for 2,456 participants (children and adults). Lower income, older homes, household pets, having a smoker in the house, and less frequent cleaning predicted higher dust weight levels in U.S. households. Higher levels of dust weight were associated with greater odds of current asthma and wheeze. The strongest associations were seen for wheeze [adjusted odds ratio (OR) = 1.99; 95% confidence interval (CI), 1.21–3.28 for bedroom bed dust; OR = 2.81; 95% CI, 1.52–5.21 for upholstery dust). These associations persisted when adjusting for allergen and endotoxin exposures. Conclusions Dust weight, an index of total dust exposure in the home, may contribute to respiratory outcomes independently of the exposure to specific components. PMID:17384767

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

    PubMed

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

    2006-02-01

    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

  11. Lead in Chinese villager house dust: Geographical variation and influencing factors.

    PubMed

    Bi, Xiangyang; Liu, Jinling; Han, Zhixuan; Yang, Wenlin

    2015-12-01

    House dust has been recognized as an important contributor to Pb exposure of children. Here we conducted a comprehensive study to investigate geographical variation of Pb in Chinese villager house dust. The influences of outdoor soil Pb concentrations, dates of construction, house decoration materials, heating types, and site specific pollution on Pb concentrations in house dust were evaluated. The concentrations of Pb in 477 house dust samples collected from twenty eight areas throughout China varied from 12 to 2510 mg/kg, with a median concentration of 42 mg/kg. The median Pb concentrations in different geographical areas ranged from 16 (Zhangjiakou, Hebei) to 195 mg/kg (Loudi, Hunan). No correlations were found between the house dust Pb concentrations and the age of houses, as well as house decoration materials. Whereas outdoor soil, coal combustion, and site specific pollution may be potential Pb sources. Principal component analysis (PCA) confirmed that elemental compositions of the house dust were controlled by both anthropogenic and geogenic sources. Using scanning electron microscopy (SEM), the Pb bearing particles in the house dust were also studied. PMID:26381088

  12. House-Dust Allergy

    PubMed Central

    Johnson, C. A.

    1982-01-01

    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

  13. House dust as possible route of environmental exposure to cadmium and lead in the adult general population

    SciTech Connect

    Hogervorst, Janneke; Plusquin, Michelle; Vangronsveld, Jaco; Nawrot, Tim; Cuypers, Ann; Van Hecke, Etienne; Roels, Harry A.; Carleer, Robert; Staessen, Jan A. . E-mail: jan.staessen@med.kuleuven.be

    2007-01-15

    Contaminated soil particles and food are established routes of exposure. We investigated the relations between biomarkers of exposure to cadmium and lead, and the metal loading rates in house dust in the adult residents of an area with a soil cadmium concentration of >=3mg/kg (n=268) and a reference area (n=205). We determined the metal concentrations in house dust allowed to settle for 3 months in Petri dishes placed in the participants' bedrooms. The continuously distributed vegetable index was the first principal component derived from the metal concentrations in six different vegetables. The biomarkers of exposure (blood cadmium 9.2 vs. 6.2nmol/L; 24-h urinary cadmium 10.5 vs. 7.0nmol; blood lead 0.31 vs. 0.24{mu}mol/L), the loading rates of cadmium and lead in house dust (0.29 vs. 0.12 and 7.52 vs. 3.62ng/cm{sup 2}/92 days), and the vegetable indexes (0.31 vs. -0.44 and 0.13 vs. -0.29 standardized units) were significantly higher in the contaminated area. A two-fold increase in the metal loading rate in house dust was associated with increases (P<0.001) in blood cadmium (+2.3%), 24-h urinary cadmium (+3.0%), and blood lead (+2.0%), independent of the vegetable index and other covariates. The estimated effect sizes on the biomarkers of internal exposure were three times greater for house dust than vegetables. In conclusion, in the adult population, house dust is potentially an important route of exposure to heavy metals in areas with contaminated soils, and should be incorporated in the assessment of health risks.

  14. Lead Speciation in Indoor Dust: A Case Study to Assess Old Paint Contribution in a Canadian Urban House

    SciTech Connect

    S Beauchemin; L MacLean; P Rasmussen

    2011-12-31

    Residents in older homes may experience increased lead (Pb) exposures due to release of lead from interior paints manufactured in past decades, especially pre-1960s. The objective of the study was to determine the speciation of Pb in settled dust from an urban home built during WWII. X-ray absorption near-edge structure (XANES) and micro-X-ray diffraction (XRD) analyses were performed on samples of paint (380-2,920 mg Pb kg{sup -1}) and dust (200-1,000 mg Pb kg{sup -1}) collected prior to renovation. All dust samples exhibited a Pb XANES signature similar to that of Pb found in paint. Bulk XANES and micro-XRD identified Pb species commonly found as white paint pigments (Pb oxide, Pb sulfate, and Pb carbonate) as well as rutile, a titanium-based pigment, in the <150 m house dust samples. In the dust fraction <36 {mu}m, half of the Pb was associated with the Fe-oxyhydroxides, suggesting additional contribution of outdoor sources to Pb in the finer dust. These results confirm that old paints still contribute to Pb in the settled dust for this 65-year-old home. The Pb speciation also provided a clearer understanding of the Pb bioaccessibility: Pb carbonate > Pb oxide > Pb sulfate. This study underscores the importance of taking precautions to minimize exposures to Pb in house dust, especially in homes where old paint is exposed due to renovations or deterioration of painted surfaces.

  15. Lead speciation in indoor dust: a case study to assess old paint contribution in a Canadian urban house

    SciTech Connect

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

    2012-10-23

    Residents in older homes may experience increased lead (Pb) exposures due to release of lead from interior paints manufactured in past decades, especially pre-1960s. The objective of the study was to determine the speciation of Pb in settled dust from an urban home built during WWII. X-ray absorption near-edge structure (XANES) and micro-X-ray diffraction (XRD) analyses were performed on samples of paint (380-2,920 mg Pb kg{sup -1}) and dust (200-1,000 mg Pb kg{sup -1}) collected prior to renovation. All dust samples exhibited a Pb XANES signature similar to that of Pb found in paint. Bulk XANES and micro-XRD identified Pb species commonly found as white paint pigments (Pb oxide, Pb sulfate, and Pb carbonate) as well as rutile, a titanium-based pigment, in the <150 {micro}m house dust samples. In the dust fraction <36 {micro}m, half of the Pb was associated with the Fe-oxyhydroxides, suggesting additional contribution of outdoor sources to Pb in the finer dust. These results confirm that old paints still contribute to Pb in the settled dust for this 65-year-old home. The Pb speciation also provided a clearer understanding of the Pb bioaccessibility: Pb carbonate > Pb oxide > Pb sulfate. This study underscores the importance of taking precautions to minimize exposures to Pb in house dust, especially in homes where old paint is exposed due to renovations or deterioration of painted surfaces.

  16. Garden soil and house dust as exposure media for lead uptake in the mining village of Stratoni, Greece.

    PubMed

    Argyraki, Ariadne

    2014-08-01

    The relationships between two exposure media, garden soil and house dust, were studied for Pb uptake in Stratoni village in northern Greece, an industrial area of mining and processing of sulphide ore. Lead data for the two media were assessed in terms of total and bioaccessible content, measurement and geochemical variability, and mineralogical composition. It was found that total Pb was enriched in house dust samples by a factor of 2 on average. Total Pb concentration in soil samples had a maximum of 2,040 mg/kg and reached a maximum of 7,000 mg/kg in house dust samples. The estimated variability due to measurement uncertainty was dominated by the sampling process, and the proportion of sampling variance was greater for soil samples, indicating a higher degree of Pb heterogeneity in soil on the given spatial scale of sampling strata. Although the same general spatial trend was observed for both sampling media with decreasing Pb concentration by increasing distance from the ore-processing plant, Pb in dust samples displayed the highest concentrations within a 300-600-m zone from the ore-processing facility. The significant differences which were observed in Pb speciation between the studied media were explained by differences in mineralogical composition of outdoor soil and indoor dust. Lead-enriched Fe and Mn oxides predominated in soil samples while fine galena grains (<10-20 μm diameter) were the major Pb-bearing phase in dust samples. The integrated exposure uptake biokinetic model was used to predict the risk of elevated blood lead levels in children of Stratoni. Model prediction indicated an average probability of 61 % for blood-Pb to exceed 10 μg/dl. The results underline the importance of house dust in risk assessment and highlight the effect of outdoor and indoor conditions on the fate of Pb in the particular environment of Stratoni. PMID:24292695

  17. Factors affecting lead, cadmium, and arsenic levels in house dust in a smelter town in eastern Germany

    SciTech Connect

    Meyer, I.; Heinrich, J. . Inst. fuer Epidemiologie); Lippold, U. )

    1999-07-01

    Hettstedt, a city in eastern Germany with a long history of mining and smelting of nonferrous ores, has several industrial sources of heavy metals. The indoor exposure to metals of children (5 to 14 years old) in the Hettstedt area was assessed by measuring the levels of lead, cadmium, and arsenic contamination in sedimented house dust. Factors which influence the dust loading rate and the surface loading rates of these contaminants in house dust were investigated. The geometric mean of the dust loading rate was 8.9 mg/m[sup 2] day. The geometric means of surface loading rates were 1.14, 0.024, and 0.023 [micro]g/m[sup 2] day for lead, cadmium, and arsenic, respectively. Factors that were significantly associated with surface loading rates included the city area of residence, automobile traffic near home, parent with occupational exposure to heavy metals, type of heating, housing characteristics, whether child's home is damp, number of persons living in the child's home,and parents' education. The most significant of these factors was the city area of residence, which reflects the distance from the metal sources; this factor accounted for about half of the variances explained by the regression models.

  18. Lead Speciation in House Dust from Canadian Urban Homes Using EXAFS Micro-XRF and Micro-XRD

    SciTech Connect

    L MacLean; S Beauchemin; P Rasmussen

    2011-12-31

    X-ray absorption fine-structure (XAFS) spectroscopy, micro-X-ray fluorescence ({mu}XRF), and micro-X-ray diffraction ({mu}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{sup -1}). Linear combination fitting of the XAFS data, supported by {mu}XRF and {mu}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.

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

    PubMed

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

    2011-07-01

    X-ray absorption fine-structure (XAFS) spectroscopy, micro-X-ray fluorescence (μXRF), and micro-X-ray diffraction (μXRD) 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 μXRF and μXRD, 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

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

    PubMed

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

    2014-06-01

    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

  1. Long-term exposure to house dust mite leads to suppression of allergic airway disease despite persistent lung inflammation

    PubMed Central

    Bracken, Sonali J.; Adami, Alexander J.; Szczepanek, Steven M.; Ehsan, Mohsin; Natarajan, Prabitha; Guernsey, Linda A.; Shahriari, Neda; Rafti, Ektor; Matson, Adam P.; Schramm, Craig M.; Thrall, Roger S.

    2015-01-01

    Background Allergic asthma is a major cause of worldwide morbidity and results from inadequate immune regulation in response to innocuous, environmental antigens. The need exists to understand the mechanisms that promote non-reactivity to human-relevant allergens such as house dust mite (HDM) in order to develop curative therapies for asthma. The aim of our study was to compare the effects of short-, intermediate- and long-term HDM administration in a murine asthma model and determine the ability of long-term HDM exposure to suppress allergic inflammation. Methods C57BL/6 mice were intranasally instilled with HDM for short-term (2 weeks), intermediate-term (5 weeks) and long-term (11 weeks) periods to induce allergic airway disease (AAD). Severity of AAD was compared across all stages of the model via both immunologic and pulmonary parameters. Results Short- and intermediate-term HDM exposure stimulated development of AAD that included eosinophilia in the bronchoalveolar lavage fluid (BAL), pronounced airway hyper-reactivity (AHR), and evidence of lung inflammation. Long-term HDM exposure promoted suppression of AAD, with loss of BAL eosinophilia and AHR despite persistent mononuclear inflammation in the lungs. Suppression of AAD with long-term HDM exposure was associated with an increase in both Foxp3+ regulatory T cells and IL-10+ alveolar macrophages at the site of inflammation. Conclusions This model recapitulates key features of human asthma and may facilitate investigation into the mechanisms that promote immunological tolerance against clinically relevant aeroallergens. PMID:25924733

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

    PubMed

    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

    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 CD8α+ 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

  3. Polyfluoroalkyl chemicals in house dust

    SciTech Connect

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

    2009-07-15

    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.

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

    PubMed Central

    Lambert, Timothy W; Lane, Stephanie

    2004-01-01

    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

  5. Lead loadings in household dust in Delhi, India.

    PubMed

    Kumar, A; Scott Clark, C

    2009-10-01

    Lead in household dust is dangerous to children who ingest lead from playing close to the ground, and having frequent hand-to-mouth contact. Although there have been several investigations of lead levels in India in air, blood and new paint, the literature is sparse on the levels of lead in household dust. This study analyzed 99 samples of dust taken from bare floors and 49 samples of dust taken from windowsills in a cross-section of Delhi, India houses for lead loadings. The arithmetic mean of lead loading for floor samples and windowsill dust samples was found to be 36.24 microg/ft(2) and 129.5 microg/ft(2), respectively. The geometric mean of dust lead loading for floor and interior windowsill samples was found to be 19.7 microg/ft(2) and 75.5 microg/ft(2), respectively. Comparing the results with US geometric mean dust lead levels from a national cross-section of US housing, which in 2000 were 1.1 microg/ft(2) and 9.4 microg/ft(2) on floors and windowsills, respectively as reported by Jacobs et al. (2002) suggests that the lead content of the dust in Delhi homes is much higher than that in the national data in the US and that the levels pose a hazard to children. Practical Implications The present study is first of its kind in this part of the world. In the context of ongoing efforts to eliminate lead from paints worldwide this research will help the scientists and policy makers in assessing the Children's exposure to lead in developing country as well. Since more than one half of the housing units tested had at least one dust lead sample exceeding US health-based standards, health care providers and public health officials need to give attention to possible lead poisoning in Delhi children. Routine blood lead screening of children should follow recommended public health practice for children at risk. Additional larger-scale studies are needed in Delhi and elsewhere to determine how representative these findings are and to attempt to delineate the sources of

  6. Chemical speciation of lead dust associated with primary lead smelting.

    PubMed Central

    Spear, T M; Svee, W; Vincent, J H; Stanisich, N

    1998-01-01

    The research presented in this article assessed geochemical factors relating to dust produced during primary lead smelting. Bulk dust samples and size-selective airborne dust samples were collected from four areas of a primary lead smelter and analyzed by X-ray diffraction and sequential chemical extraction. X-ray diffraction showed that the smelter dusts were composed primarily of sulfides, oxides, sulfates, and silicates of metal ores, with galena being the primary dust component. Sequential extraction revealed the solubility of lead compounds at less than 7% in the exchangeable and mildly acidic steps for the bulk dusts collected from four smelter areas. The later steps of the extraction procedure were more effective in dissolving the lead compounds associated with the bulk dust samples, with 43%, 26%, and 8% of the total lead, in the ore storage, sinter, and blast/dross smelter areas, respectively, being extracted in the residual step. Sequential extraction of coarse airborne dust samples from the ore storage and sinter plant showed that 1.2% and 4.1% of the total lead, respectively, was exchangeable. The finer particle size fractions from these areas of the smelter showed higher percentages of exchangeable lead. Of the course airborne dust from the blast/dross furnace processes, 65% of the total lead was exchangeable. However, the largest percentage of lead from these areas was associated with the finer particle-size fractions. If lead bioavailability is related to its solubility as determined through sequential extraction, the health hazards associated with lead exposure may be appreciably enhanced in the blast and dross furnace processes. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:9721256

  7. House dust mite allergy: environment evaluation and disease prevention

    PubMed Central

    Yu, Sheng-Jie; Liao, En-Chih

    2014-01-01

    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

  8. Screening housing to prevent lead toxicity in children.

    PubMed Central

    Lanphear, Bruce P.; Hornung, Richard; Ho, Mona

    2005-01-01

    OBJECTIVE: Screening children to identify those with blood lead levels > or = 10 microg/dl fails to protect children from lead-associated cognitive deficits and behavioral problems. To broaden our efforts at primary prevention, screening criteria are needed to identify lead-contaminated housing before children are unduly exposed. The purpose of this study was to identify and validate housing characteristics associated with children having elevated blood lead levels (> or = 10 microg/dl). METHODS: Two existing studies were used to examine housing characteristics linked with undue lead exposure: a cross-sectional study of 205 children aged 12 to 31 months, and a random sample from a longitudinal study of 276 children followed from 6 to 24 months of age. Logistic regression analysis was conducted to examine the association of children's blood lead levels > or = 10 microg/dl. RESULTS: The mean age of the 481 children was 17.8 months; 99 (20.6%) had a blood lead concentration of 10 microg/dl or higher. The following characteristics were associated with blood lead concentration > or = 10 microg/dl: floor lead loading > 15 microg/ft2 (odds ratio [OR]=2.2; 95% confidence interval [CI] 1.3, 3.8); rental housing (OR=3.2; 95% CI 1.3, 7.6); poor housing condition (OR=2.1; CI 1.2, 3.6); African American race (OR=3.3; CI 1.9, 6.1); paint chip ingestion (OR=5.8; CI 1.3, 26.5); and soil ingestion (OR=2.2; CI 1.1, 4.2). Housing characteristics including rental status, lead-contaminated floor dust, and housing condition had a range of sensitivity from 47% to 92%; specificity from 28% to 76%; a positive predictive value from 25% to 34%; and a negative predictive value of 85% to 93%. CONCLUSIONS: Housing characteristics and floor dust lead levels can be used to screen housing to identify lead hazards prior to occupancy, before purchasing a home, or after renovation to prevent children's exposure to lead hazards. PMID:16134573

  9. 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...

  10. Bioaccessibility of Fipronil Sorbed to Soil and House Dust

    EPA Science Inventory

    Fipronil is a phenylpyrazole insecticide with uses ranging from soil treatment, to the control of household pests and ectoparasites on pets. Soils and house dusts readily sorb fipronil and when these soils and dusts are ingested, the fipronil may become bioaccessible for uptake ...

  11. Residential dust lead loading immediately after intervention in the HUD lead hazard control grant program.

    PubMed

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

    2004-11-01

    At the conclusion of most lead hazard control interventions in federally assisted housing built before 1978, a certified clearance examiner must verify that the lead hazard control work was completed as specified and that the area is safe for residents, a process referred to as clearance. This study explores the experience of 14 grantees participating in the Evaluation of the HUD Lead-Based Paint Hazard Control Grant Program in passing clearance. The study also considers how preintervention lead levels (interior dust and paint), building condition/characteristics, and the scope of work influenced initial clearance dust lead loadings and clearance rates. At the initial clearance inspection, 80% of the 2682 dwellings achieved grantee-specific clearance standards on windowsills, window troughs (500 microg/ft2 and 800 microg/ft2, respectively), and floors (80, 100, or 200 microg/ft2 depending on state/local regulations at the dates of clearance in the mid-1990s), with individual grantee success rates ranging from 63 to 100%. Dwellings that failed initial clearance required an average of 1.13 retests to clear. The high level of success at clearance demonstrates that following methods for work site containment, lead hazard control, and cleaning similar to those recommended in the HUD Guidelines for the Evaluation and Control of Lead-Based Paint in Housing is effective. The most common lead hazard control intervention was window abatement accompanied by the repair or abatement of all other deteriorated lead-based paint (56% of dwellings). An additional 5% of dwellings were fully abated, 29% had lower intensity interventions. Interventions including window replacement are recommended to reduce dust lead loading on windowsills and troughs at clearance, but lower level interventions such as full paint stabilization are just as good at reducing floor dust lead loadings. Whatever lead hazard control activities are selected, the condition of the surfaces of interest should be

  12. House dust in seven Danish offices

    NASA Astrophysics Data System (ADS)

    Mølhave, L.; Schneider, T.; Kjærgaard, S. K.; Larsen, L.; Norn, S.; Jørgensen, O.

    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 μg 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

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

    SciTech Connect

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

    1985-10-01

    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.

  14. Condition and type of housing as an indicator of potential environmental lead exposure and pediatric blood lead levels

    SciTech Connect

    Clark, C.S.; Bornschein, R.L.; Succop, P.; Que Hee, S.S.; Hammond, P.B.; Peace, B.

    1985-10-01

    Environmental evaluations in a prospective behavior study of children with blood lead levels up to about 50 g/dl were performed by an intensive environmental survey and by exterior visual evaluations of housing quality. Serial blood lead values for infants in the study were compared to exterior housing type and quality, which itself was also compared with results of the intensive environmental evaluation. Five housing condition and type categories were defined: public housing; private housing (satisfactory, deteriorated, and dilapidated); and rehabilitated private housing. In this interim report on the first subset of available data, the housing categories were found to differ in paint and environment dust lead levels, with public and rehabilitated housing having lowest values. Blood lead concentrations of children differed across housing categories as early as 6 months of age, with children residing in public housing having lowest levels, followed by those in rehabilitated housing. The spread in mean blood lead concentrations among the housing quality categories increased with increasing age of the children. Housing category accounted for over one-half of the blood lead variability in 18-month-old children.

  15. 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...

  16. Estimating outdoor and indoor dust lead levels from accidental bridge repair containment releases

    SciTech Connect

    Cohen, J.T.; Conway, R.F.

    1999-07-01

    A 1998 New York City Department of Transportation (NYCDOT) environmental impact statement (EIS) evaluated the proposed removal of deteriorated lead paint from NYCDOT-owned bridges. The EIS health risk assessment quantified the potential impact of particulate releases on blood lead levels among members of the public living and working near affected bridges. The risk assessment consisted of a fate and transport component and an exposure-dose component. The fate and transport component, modeled using the EPA's Industrial Source Complex (ISC3) model, calculated the impact of paint removal activities on ambient air lead concentrations and dust lead deposition rates. The exposure-dose component, modeled using EPA's Integrated Exposure Uptake Biokinetic (IEUBK) model, the Bowers et al. Adult Lead model, and the O'Flaherty lead model, calculated the impact of additional lead in air, street dust, interior house dust, and soil on blood lead levels, a conventional measure of body lead burden. The analysis was complicated because the ISC3 model provides a dust lead deposition rate ({micro}g/m{sup 2}-day), while the IEUBK, Bowers et al., and O'Flaherty models demand as input specification of dust lead concentrations ({micro}g lead per g dust). This paper describes a model developed for the EIS that quantifies long term average dust lead concentrations associated with typical bridge containment releases, and short term dust lead concentration spikes following worst case release events associated with bridge repair containment structure failures. The model reflects the influence of both lead and other debris associated with bridge repair activities, the contribution of background debris to street dust, and the impact of rainfall on removal of both lead and other material from the street dust reservoir.

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

    SciTech Connect

    Gulson, Brian; Anderson, Phil; Taylor, Alan

    2013-10-15

    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

  18. Sublingual Immunotherapy for Asthmatic Children Sensitized to House Dust Mite

    PubMed Central

    Liao, Wei; Hu, Qi; Shen, Lei-Lei; Hu, Ying; Tao, Hai-feng; Li, Hui-fan; Fan, Wen-ting

    2015-01-01

    Abstract The house dust mite is one of the most common allergens worldwide. There is good evidence that house dust mite subcutaneous immunotherapy is efficacious and has long-term benefit in children. However, the evidence of the benefit of house dust mite sublingual immunotherapy (SLIT) is less convincing. The purpose of this meta-analysis was to evaluate that efficacy and safety of dust mite SLIT in children with asthma. Medical Literature Analysis and Retrieval System Online, ISI Web of Knowledge, and Cochrane Central Register of Controlled Trials databases until February 2014 were searched. The primary outcome was mean change in asthma symptom score. Secondary outcomes included mean change in serum immunoglobulin G4 (sIgG4), specific Dermatophagoides pteronyssinus, immunoglobulin E (IgE) levels, and medication score. Safety was also assessed. We found that SLIT significantly decreased asthma symptom score (P = 0.007) and increased sIgG4 levels (P = 0.011) greater than control in children (<18 years of age) with asthma. There was no difference between SLIT and control groups in specific D pteronyssinus IgE levels (P = 0.076) and medication score (P = 0.408). The safety profile was similar between groups. Our study indicates that dust mite SLIT therapy was effective in reducing asthma symptoms and in increasing sIgG4 but did not significantly reduce medication scores or specific D pteronyssinus IgE levels. Our findings are not enough to support the use of dust mite SLIT in children with asthma.

  19. Genotoxicity of organic extracts of house dust from Shanxi, China.

    PubMed

    Naufal, Ziad; Zhou, Guo-dong; McDonald, Thomas; Li, Zhiwen; Li, Zhu; Donnelly, K C

    2007-12-01

    Indoor combustion of solid fuel such as coal may generate respirable particles containing polycyclic aromatic hydrocarbons (PAH) that may adhere to settled dust. Dust might therefore present a major source of PAH exposure in humans. This study evaluated the in vitro and in vivo genotoxicity of PAH mixtures extracted from house dust samples. Four dust samples (E1-4) were collected from houses in Shanxi, China, where coal is heavily used for heating and cooking. For comparison, a coal sample was also collected from one of the houses and included in the analyses. The samples were extracted with methylene chloride:acetone (95:5 v/v), dried, and redissolved in appropriate solvents for assessment in genotoxicity assays. Samples were evaluated for their ability to induce point mutations in bacteria and DNA adducts in vivo. DNA adduct levels were analyzed by nuclease P1-enhanced 32P-postlabeling. PAH were quantified using gas chromatography/mass spectrometry. Based on chemical analysis, sample E1 had the highest concentration by sampling area of benzo[a]pyrene (BaP) (181 microg/m2) and total PAH (10100 microg/m2). However, based on the microbial genotoxicity assay, sample E3, with the highest carcinogenic PAH/total PAH ratio (26%), produced the greatest number of revertants. In mice, administration of the extract of coal induced more adducts (9.81 adducts per 10(9) nucleotides) than dust extracts. The results of this study confirm the presence of genotoxic chemicals in residential dust. Inhalation of respirable particles containing similar mixtures of PAH represents a cancer risk for humans. PMID:18049997

  20. Innate Immune Responses in House Dust Mite Allergy

    PubMed Central

    Jacquet, Alain

    2013-01-01

    Sensitizations to house dust mites (HDM) trigger strong exacerbated allergen-induced inflammation of the skin and airways mucosa from atopic subjects resulting in atopic dermatitis as well as allergic rhinitis and asthma. Initially, the Th2-biased HDM allergic response was considered to be mediated only by allergen B- and T-cell epitopes to promote allergen-specific IgE production as well as IL-4, IL-5, and IL-13 to recruit inflammatory cells. But this general molecular model of HDM allergenicity must be revisited as a growing literature suggests that stimulations of innate immune activation pathways by HDM allergens offer new answers to the following question: what makes an HDM allergen an allergen? Indeed, HDM is a carrier not only for allergenic proteins but also microbial adjuvant compounds, both of which are able to stimulate innate signaling pathways leading to allergy. This paper will describe the multiple ways used by HDM allergens together with microbial compounds to control the initiation of the allergic response through engagement of innate immunity. PMID:23724247

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

    PubMed

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

    2009-01-01

    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

  2. Associations between brominated flame retardants in house dust and hormone levels in men.

    PubMed

    Johnson, Paula I; Stapleton, Heather M; Mukherjee, Bhramar; Hauser, Russ; Meeker, John D

    2013-02-15

    Brominated flame retardants (BFRs) are used in the manufacture of a variety of materials and consumer products in order to meet fire safety standards. BFRs may persist in the environment and have been detected in wildlife, humans and indoor dust and air. Some BFRs have demonstrated endocrine and reproductive effects in animals, but human studies are limited. In this exploratory study, we measured serum hormone levels and flame retardant concentrations [31 polybrominated diphenyl ether (PBDE) congeners and 6 alternate flame retardants] in house dust from men recruited through a US infertility clinic. PBDE congeners in dust were grouped by commercial mixtures (i.e. penta-, octa- and deca-BDE). In multivariable linear regression models adjusted by age and body mass index (BMI), significant positive associations were found between house dust concentrations of pentaBDEs and serum levels of free T4, total T3, estradiol, and sex hormone binding globulin (SHBG), along with an inverse association with follicle stimulating hormone (FSH). There were also positive associations of octaBDE concentrations with serum free T4, thyroid stimulating hormone (TSH), luteinizing hormone (LH) and testosterone and an inverse association of decaBDE concentrations with testosterone. Hexabromocyclododecane (HBCD) was associated with decreased SHBG and increased free androgen index. Dust concentrations of bis-tribromophenoxyethane (BTBPE) and tetrabromo-diethylhexylphthalate (TBPH) were positively associated with total T3. These findings are consistent with our previous report of associations between PBDEs (BDE 47, 99 and 100) in house dust and hormone levels in men, and further suggest that exposure to contaminants in indoor dust may be leading to endocrine disruption in men. PMID:23333513

  3. Application of Synchrotron Microprobe Methods to Solid-Phase Speciation of Metals and Metalloids in House Dust

    SciTech Connect

    S Walker; H Jamieson; P Rasmussen

    2011-12-31

    Determination of the source and form of metals in house dust is important to those working to understand human and particularly childhood exposure to metals in residential environments. We report the development of a synchrotron microprobe technique for characterization of multiple metal hosts in house dust. We have applied X-ray fluorescence for chemical characterization and X-ray diffraction for crystal structure identification using microfocused synchrotron X-rays at a less than 10 {micro}m spot size. The technique has been evaluated by application to archived house dust samples containing elevated concentrations of Pb, Zn, and Ba in bedroom dust, and Pb and As in living room dust. The technique was also applied to a sample of soil from the corresponding garden to identify linkages between indoor and outdoor sources of metals. Paint pigments including white lead (hydrocerussite) and lithopone (wurtzite and barite) are the primary source of Pb, Zn, and Ba in bedroom dust, probably related to renovation activity in the home at the time of sampling. The much lower Pb content in the living room dust shows a relationship to the exterior soil and no specific evidence of Pb and Zn from the bedroom paint pigments. The technique was also successful at confirming the presence of chromated copper arsenate treated wood as a source of As in the living room dust. The results of the study have confirmed the utility of this approach in identifying specific metal forms within the dust.

  4. Non-targeted screening of house dust samples using accurate mass TOFMS

    EPA Science Inventory

    House dust exists as an environmental repository of chemicals to which we are exposed in our homes. A growing number of studies have targeted select persistent organic and inorganic pollutants found in house dust. Many have concluded that dust exists as an important human expos...

  5. 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...

  6. Pheromonal Communication in the European House Dust Mite, Dermatophagoides pteronyssinus

    PubMed Central

    Steidle, Johannes L.M.; Barcari, Elena; Hradecky, Marc; Trefz, Simone; Tolasch, Till; Gantert, Cornelia; Schulz, Stefan

    2014-01-01

    Despite the sanitary importance of the European house dust mite Dermatophagoides pteronyssinus (Trouessart, 1897), the pheromonal communication in this species has not been sufficiently studied. Headspace analysis using solid phase micro extraction (SPME) revealed that nerol, neryl formate, pentadecane, (6Z,9Z)-6,9-heptadecadiene, and (Z)-8-heptadecene are released by both sexes whereas neryl propionate was released by males only. Tritonymphs did not produce any detectable volatiles. In olfactometer experiments, pentadecane and neryl propionate were attractive to both sexes as well as to tritonymphs. (Z)-8-heptadecene was only attractive to male mites. Therefore it is discussed that pentadecane and neryl propionate are aggregation pheromones and (Z)-8-heptadecene is a sexual pheromone of the European house dust mite D. pteronyssinus. To study the potential use of pheromones in dust mite control, long-range olfactometer experiments were conducted showing that mites can be attracted to neryl propionate over distances of at least 50 cm. This indicates that mite pheromones might be useable to monitor the presence or absence of mites in the context of control strategies. PMID:26462831

  7. An aerobiological perspective of dust in cage-housed and floor-housed poultry operations

    PubMed Central

    Just, Natasha; Duchaine, Caroline; Singh, Baljit

    2009-01-01

    The Canadian poultry production industry contributes nearly $10 billion to the Canadian economy and employs nearly 50,000 workers. However, modern poultry facilities are highly contaminated with airborne dust. Although there are many bioaerosols in the poultry barn environment, endotoxin is typically attributed with the negative respiratory symptoms observed in workers. These adverse respiratory symptoms have a higher prevalence in poultry workers compared to workers from other animal confinement buildings. Workers in cage-housed operations compared to floor-housed facilities report a higher prevalence of some respiratory symptoms. We review the current state of knowledge on airborne dust in poultry barns and respiratory dysfunction in poultry workers while highlighting the areas that need further investigation. Our review focuses on the aerobiological pathway of poultry dust including the source and aerosolization of dust and worker exposure and response. Further understanding of the source and aerosolization of dust in poultry operations will aid in the development of management practices to reduce worker exposure and response. PMID:19515256

  8. Lead and zinc dust depositions from ore trains characterised using lead isotopic compositions.

    PubMed

    Kristensen, L J; Taylor, M P; Morrison, A L

    2015-03-01

    This study investigates an unusual source of environmental lead contamination - the emission and deposition of lead and zinc concentrates along train lines into and out of Australia's oldest silver-lead-zinc mine at Broken Hill, Australia. Transport of lead and zinc ore concentrates from the Broken Hill mines has occurred for more than 125 years, during which time the majority was moved in uncovered rail wagons. A significant amount of ore was lost to the adjoining environments, resulting in soil immediately adjacent to train lines elevated with concentrations of lead (695 mg kg(-1)) and zinc (2230 mg kg(-1)). Concentrations of lead and zinc decreased away from the train line and also with depth shown in soil profiles. Lead isotopic compositions demonstrated the soil lead contained Broken Hill ore in increasing percentages closer to the train line, with up to 97% apportioned to the mined Broken Hill ore body. SEM examination showed ceiling dusts collected from houses along the train line were composed of unweathered galena particles, characteristic of the concentrate transported in the rail wagons. The loss of ore from the uncovered wagons has significantly extended the environmental footprint of contamination from local mining operations over an area extending hundreds of kilometres along each of the three train lines. PMID:25627173

  9. Lead poisoning

    MedlinePlus

    ... swallows a lead object or breathes in lead dust, some of the poison can stay in the ... a health problem. Lead is everywhere, including dirt, dust, new toys, and old house paint. Unfortunately, you ...

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

    PubMed Central

    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

    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

  11. Associations between bacterial communities of house dust and infant gut

    SciTech Connect

    Konya, T.; Koster, B.; Maughan, H.; Escobar, M.; Azad, M.B.; Guttman, D.S.; Sears, M.R.; Becker, A.B.; Brook, J.R.; Takaro, T.K.; Kozyrskyj, A.L.; Scott, J.A.

    2014-05-01

    The human gut is host to a diverse and abundant community of bacteria that influence health and disease susceptibility. This community develops in infancy, and its composition is strongly influenced by environmental factors, notably perinatal anthropogenic exposures such as delivery mode (Cesarean vs. vaginal) and feeding method (breast vs. formula); however, the built environment as a possible source of exposure has not been considered. Here we report on a preliminary investigation of the associations between bacteria in house dust and the nascent fecal microbiota from 20 subjects from the Canadian Healthy Infant Longitudinal Development (CHILD) Study using high-throughput sequence analysis of portions of the 16S rRNA gene. Despite significant differences between the dust and fecal microbiota revealed by Nonmetric Multidimensional Scaling (NMDS) analysis, permutation analysis confirmed that 14 bacterial OTUs representing the classes Actinobacteria (3), Bacilli (3), Clostridia (6) and Gammaproteobacteria (2) co-occurred at a significantly higher frequency in matched dust–stool pairs than in randomly permuted pairs, indicating an association between these dust and stool communities. These associations could indicate a role for the indoor environment in shaping the nascent gut microbiota, but future studies will be needed to confirm that our findings do not solely reflect a reverse pathway. Although pet ownership was strongly associated with the presence of certain genera in the dust for dogs (Agrococcus, Carnobacterium, Exiguobacterium, Herbaspirillum, Leifsonia and Neisseria) and cats (Escherichia), no clear patterns were observed in the NMDS-resolved stool community profiles as a function of pet ownership.

  12. Shellfish and House Dust Mite Allergies: Is the Link Tropomyosin?

    PubMed

    Wong, Lydia; Huang, Chiung Hui; Lee, Bee Wah

    2016-03-01

    Crustacean shellfish allergy is an important cause of food allergy and anaphylaxis in Asia. The major allergen in shellfish allergy is tropomyosin, a pan-allergen that is also found in house dust mites and cockroaches. Tropomyosins from house dust mites (HDMs) have a high sequence homology to shellfish tropomyosins, and cross-reactivity between HDM and shrimp tropomyosins has been demonstrated. Exposure to inhaled tropomyosins from house dust mites has been postulated to be the primary sensitizer for shellfish allergy, in a reaction analogous to the oral allergy (inhalant-food) syndrome. This notion is supported by indirect data from the effects of HDM immunotherapy on shellfish allergy, and strong correlations of shellfish and HDM sensitization. HDM immunotherapy has been reported to induce both shrimp allergy in non-allergic patients and shrimp tolerance in shrimp-allergic patients. Epidemiological surveys have also demonstrated a strong correlation between shellfish and HDM sensitization in both hospital-based and community-based studies. Unexposed populations have also been shown to develop sensitization-shellfish sensitization in orthodox Jews with no history of shellfish consumption was associated with HDM sensitization. Reciprocally, HDM sensitization in an Icelandic population living in a HDM-free environment was associated with shrimp sensitization. In vitro IgE inhibition studies on sera in shrimp-allergic Spanish patients indicate that mites are the primary sensitizer in shrimp-allergic patients living in humid and warm climates. Current data supports the hypothesis that tropomyosin is the link between HDM and shellfish allergies. The role of tropomyosin in HDM and shellfish allergies is a fertile field for investigation as it may provide novel immunotherapeutic strategies for shellfish allergy. PMID:26739402

  13. House dust mite control measures in the treatment of asthma

    PubMed Central

    Vallance, Gillian; McSharry, Charles; Wood, Stuart; Thomson, Neil C

    2006-01-01

    Sensitization to the house dust mite (Dermataphagoides pteronyssinus) (HDM) is the most common risk factor associated with the development of asthma in adults and children. The effectiveness of HDM control measures in the treatment of asthma is not yet proven. The strategies for control for avoidance depend on our understanding of the biology of the HDM. The evidence suggests a favorable effect of transferring allergic asthmatic children to naturally low dust mite environments, such as at altitude or in hospital, but little to suggest that this can be replicated in general practice by simple practical measures such as mattress covers. However, a recent multi-allergen reduction approach has suggested benefits may be achievable. HDM densities tend to be high in warm, humid conditions in the home, which may be modified by external factors, such as ventilation. However, ventilation control to reduce indoor humidity has had inconsistent effects on dust mite levels and asthma. The challenge is to further refine the interventions in large placebo-controlled trials such that clinical outcomes may be more easily demonstrated. PMID:18360647

  14. Impact of soil and dust lead on children's blood lead on Children's blood lead in contaminated areas of Sweden

    SciTech Connect

    Berglund, M.; Lind, B.; Soerensen, S.; Vahter, M.

    2000-04-01

    The impact of lead in soil and dust on blood lead concentrations in young children and the risk of health effects were investigated in an urban and a mining areas of Sweden. Blood, soil, and indoor dust, as well as information on lead-exposure factors, were collected. The blood lead concentrations (total range = 9--77 {micro}g/l) the authors measured indicated a low risk for lead-induced health effects. Lead in soil and in dust had little effect on blood lead concentrations, given the present conditions and present concentration range--especially in the mining area. Urban children had significantly higher blood lead concentrations that children in the mining area, despite higher concentrations of lead in soil in the mining area. In the urban children, blood lead concentrations were influenced by parental smoking and lead in dust at day-care centers.

  15. Orchestrating house dust mite-associated allergy in the lung

    PubMed Central

    Gregory, Lisa G.; Lloyd, Clare M.

    2012-01-01

    House dust mites (HDM; Dermatophagoides sp.) are one of the commonest aeroallergens worldwide and up to 85% of asthmatics are typically HDM allergic. Allergenicity is associated both with the mites themselves and with ligands derived from mite-associated bacterial and fungal products. Murine models of allergic airways disease for asthma research have recently switched from the use of surrogate allergen ovalbumin together with adjuvant to use of the HDM extract. This has accelerated understanding of how adaptive and innate immunity generate downstream pathology. We review the myriad ways in which HDM allergic responses are orchestrated. Understanding the molecular pathways that elicit HDM-associated pathology is likely to reveal novel targets for therapeutic intervention. PMID:21783420

  16. Modeling responses to respiratory house dust mite exposure.

    PubMed

    Cates, Elizabeth C; Fattouh, Ramzi; Johnson, Jill R; Llop-Guevara, Alba; Jordana, Manel

    2007-01-01

    House dust mite (HDM) is the most pervasive indoor aeroallergen source worldwide. Allergens derived from HDM are associated with sensitization and allergic asthma. Allergic asthma is an immunologically driven disease characterized by a Th2-polarized immune response, eosinophilic inflammation, airway hyperreactivity, and remodeling. Animal models of asthma utilizing ovalbumin (OVA) exposure have afforded us considerable insight with respect to the mediators and cell types involved in allergic airway inflammation. However, OVA preparations and HDM are two vastly different materials. This chapter is specifically concerned with modeling responses to HDM exposure in mice. These studies have furnished new information and unlocked new lines of inquiry regarding biological responses to common aeroallergens. The complexity of HDM as an allergen source, with its plethora of protein and nonprotein immunogenic components, may influence the mechanisms underlying sensitization, inflammation and remodeling. Here, we will discuss this issue, along with giving critical thought to the use of experimental models. PMID:17684332

  17. Dust-bathing behavior of laying hens in enriched colony housing systems and an aviary system.

    PubMed

    Louton, H; Bergmann, S; Reese, S; Erhard, M H; Rauch, E

    2016-07-01

    The dust-bathing behavior of Lohmann Selected Leghorn hens was compared in 4 enriched colony housing systems and in an aviary system. The enriched colony housing systems differed especially in the alignment and division of the functional areas dust bath, nest, and perches. Forty-eight-hour video recordings were performed at 3 time-points during the laying period, and focal animal sampling and behavior sampling methods were used to analyze the dust-bathing behavior. Focal animal data included the relative fractions of dust-bathing hens overall, of hens bathing in the dust-bath area, and of those bathing on the wire floor throughout the day. Behavior data included the number of dust-bathing bouts within a predefined time range, the duration of 1 bout, the number of and reasons for interruptions, and the number of and reasons for the termination of dust-bathing bouts. Results showed that the average duration of dust bathing varied between the 4 enriched colony housing systems compared with the aviary system. The duration of dust-bathing bouts was shorter than reported under natural conditions. A positive correlation between dust-bathing activity and size of the dust-bath area was observed. Frequently, dust baths were interrupted and terminated by disturbing influences such as pecking by other hens. This was especially observed in the enriched colony housing systems. In none of the observed systems, neither in the enriched colony housing nor in the aviary system, were all of the observed dust baths terminated "normally." Dust bathing behavior on the wire mesh rather than in the provided dust-bath area generally was observed at different frequencies in all enriched colony housing systems during all observation periods, but never in the aviary system. The size and design of the dust-bath area influenced the prevalence of dust-bathing behavior in that small and subdivided dust-bath areas reduced the number of dust-bathing bouts but increased the incidence of sham dust

  18. Dust-bathing behavior of laying hens in enriched colony housing systems and an aviary system

    PubMed Central

    Louton, H.; Bergmann, S.; Reese, S.; Erhard, M. H.; Rauch, E.

    2016-01-01

    The dust-bathing behavior of Lohmann Selected Leghorn hens was compared in 4 enriched colony housing systems and in an aviary system. The enriched colony housing systems differed especially in the alignment and division of the functional areas dust bath, nest, and perches. Forty-eight-hour video recordings were performed at 3 time-points during the laying period, and focal animal sampling and behavior sampling methods were used to analyze the dust-bathing behavior. Focal animal data included the relative fractions of dust-bathing hens overall, of hens bathing in the dust-bath area, and of those bathing on the wire floor throughout the day. Behavior data included the number of dust-bathing bouts within a predefined time range, the duration of 1 bout, the number of and reasons for interruptions, and the number of and reasons for the termination of dust-bathing bouts. Results showed that the average duration of dust bathing varied between the 4 enriched colony housing systems compared with the aviary system. The duration of dust-bathing bouts was shorter than reported under natural conditions. A positive correlation between dust-bathing activity and size of the dust-bath area was observed. Frequently, dust baths were interrupted and terminated by disturbing influences such as pecking by other hens. This was especially observed in the enriched colony housing systems. In none of the observed systems, neither in the enriched colony housing nor in the aviary system, were all of the observed dust baths terminated “normally.” Dust bathing behavior on the wire mesh rather than in the provided dust-bath area generally was observed at different frequencies in all enriched colony housing systems during all observation periods, but never in the aviary system. The size and design of the dust-bath area influenced the prevalence of dust-bathing behavior in that small and subdivided dust-bath areas reduced the number of dust-bathing bouts but increased the incidence of sham dust

  19. [The contamination of vegetable foods by lead containing street dust].

    PubMed

    Auermann, E; Börtitz, S

    1977-01-01

    To assess the contamination of fruit and vegetables by lead-containing road dust, products displayed in the open air and in retail shops, respectively, were analysed for lead content. The lead exposure within the range of the retail shop was characterized by an aerosol with 0.2-2.5 microgram/m3 and a sedimentable lead dust of 2.13-6.55 mg/m2-30 d. The lead content of the products displayed in the open air was some 0.5 to 6-fold higher. This difference was statistically significant. 92-100% of the lead dust could be removed from the products by washing with water. Increased lead contents were also found on fruit stored in a cellar (0.66 and 0.42 p.p.m., respectively) near a parking place. In consideration of the proportion of these foods in the diet consumed, no health hazard to the population can be deduced from these data; but in single cases, a temporary rise of the blood-lead level may occur. Covering fruit and vegetables presented in the open air with thin-sheet plastics or selling such products in plastics bags will prevent contamination. PMID:609359

  20. 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

  1. 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

  2. Sequential digestion for measuring leachable and total lead in the same sample of dust or paint chips by ICP-MS.

    PubMed

    Le Bot, Barbara; Arcelin, Claire; Briand, Emmanuel; Glorennec, Philippe

    2011-01-01

    House lead exposure is generally assessed using total lead, except in France, where acid-leachable lead is used for routine regulatory purposes. In order to allow an international comparison of French lead dust contamination, a sequential digestion protocol is developed to determine both leachable and total lead on the same sample with a two-step digestion stage: firstly, hydrochloric acid is added to the sample at 37°C to solubilize leachable lead; then nitric acid is added to an aliquot at 95°C to solubilize residual (i.e., non-leachable) lead. Both sample fractions are analyzed with inductively coupled plasma mass spectrometry (ICP-MS). The sum of the two fractions allows to determine total lead. This new protocol has been tested with wiped dust (n = 111) and paint chip (n = 46) samples collected in houses (n = 16). The leachability of lead ranged from 63 to 100% in dust and from 4 to 100% in paint. These findings confirm the strong variability of lead leachability in houses samples and thus the importance of considering it for lead poisoning prevention. This double determination of leachable and total lead for each wiped dust or paint sample appears to be a reproducible, simple, low-cost protocol and thus a useful tool for international comparison of house dust lead contamination. PMID:21104496

  3. Removal of lead contaminated dusts from hard surfaces.

    PubMed

    Lewis, Roger D; Condoor, Sridhar; Batek, Joe; Ong, Kee Hean; Backer, Denis; Sterling, David; Siria, Jeff; Chen, John J; Ashley, Peter

    2006-01-15

    Government guidelines have widely recommended trisodium phosphate (TSP) or "lead-specific" cleaning detergents for removal of lead-contaminated dust (LCD) from hard surfaces, such as floors and window areas. The purpose of this study was to determine if low-phosphate, non-lead-specific cleaners could be used to efficiently remove LCD from 3 types of surfaces (vinyl flooring, wood, and wallpaper). Laboratory methods were developed and validated for simulating the doping, embedding, and sponge cleaning of the 3 surface types with 4 categories of cleaners: lead-specific detergents, nonionic cleaners, anionic cleaners, and trisodium phosphate (TSP). Vinyl flooring and wood were worn using artificial means. Materials were ashed, followed by ultrasound extraction, and anodic stripping voltammetry (ASV). One-way analysis of variance approach was used to evaluate the surface and detergent effects. Surface type was found to be a significant factor in removal of lead (p < 0.001). Vinyl flooring cleaned better than wallpaper by over 14% and wood cleaned better than wallpaper by 13%. There was no difference between the cleaning action of vinyl flooring and wood. No evidence was found to support the use of TSP or lead-specific detergents over all-purpose cleaning detergents for removal of lead-contaminated dusts. No-phosphate, non-lead-specific detergents are effective in sponge cleaning of lead-contaminated hard surfaces and childhood lead prevention programs should consider recommending all-purpose household detergents for removal of lead-contaminated dust after appropriate vacuuming. PMID:16468407

  4. METHODOLOGY FOR DETERMINATION OF POLYCYCLIC AROMATIC HYDROCARBONS AND OTHER SEMIVOLATILE ORGANIC COMPOUNDS IN HOUSE DUST

    EPA Science Inventory

    Analytical methods were validated to determine polycyclic aromatic hydrocarbons (PAH) and other semivolatile organic compounds in house dust. e also examined the storage stability of three potential markers (solanesol, nicotine, and continine) for particulate-phase environmental ...

  5. DEVELOPMENT OF ANALYTICAL METHODS FOR SPECIFIC LAWN- APPLIED PESTICIDES IN HOUSE DUST

    EPA Science Inventory

    Many pesticides have been developed for residential outdoor application, particularly for lawn care. Residues from these applications may be tracked into the home, where they become incorporated with house dust and persist for long periods of time. Consequently, potential human...

  6. Utilizing Pyrosequencing and Quantitative pCR to Characterize Fungal Populations among House Dust Samples

    EPA Science Inventory

    Molecular techniques are an alternative to 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,...

  7. Microchemical investigations of dust emitted by a lead smelter

    SciTech Connect

    Sobanska, S.; Ricq, N.; Laboudigue, A.; Guillermo, R.; Bremard, C.; Laureyns, J.; Merlin, J.C.; Wignacourt, J.P.

    1999-05-01

    Dusts emitted by an important pyrometallurgical lead smelter have been sampled within the pipes of the grilling and furnace working units before and after the filtering systems, respectively. Particle size distribution, elementary analyses, and X-ray powder diffraction analysis indicate PbS, PbSO{sub 4}, PbSO{sub 4}{center_dot}PbO, Pb, ZnS small particles less than 5 {micro}m in size to contribute mainly to the current atmospheric pollution. Although at least 90% of dust are retained on the filters, the amounts of the respirable smaller particles are significantly larger in the current emission. The average chemical speciation was found to be analogous for the dust samples collected before and after the filters. The scanning electron microscopy associated with energy-dispersive X-ray analysis and Raman microspectrometry established the morphology and chemical composition at the level of individual particles. A lot of minor compounds were found as small heterogeneous individual particles in the heterogeneous particles of grilling dust. Among the homogeneous particles of furnace dust, amorphous C, {beta}-PbO, PbO-PbCl{sub 2}, FeO, CdS, CdSO{sub 4} were often detected as homogeneous mixtures with the major compounds within the particles.

  8. Concentration and determinants of molds and allergens in indoor air and house dust of French dwellings.

    PubMed

    Dallongeville, Arnaud; Le Cann, Pierre; Zmirou-Navier, Denis; Chevrier, Cécile; Costet, Nathalie; Annesi-Maesano, Isabella; Blanchard, Olivier

    2015-12-01

    Molds and allergens are common indoor biocontaminants. The aims of this study were to assess the concentrations of common molds in indoor air and floor dust and the concentrations of house dust mite, cat and dog allergens in mattress dust in French dwellings, and to assess predictors of these concentrations. A sample of 150 houses in Brittany (western France) was investigated. Airborne Cladosporium and Penicillium were detected in more than 90% of the dwellings, Aspergillus in 46% and Alternaria in only 6% of the housings. Regarding floor dust samples, Cladosporium and Penicillium were detected in 92 and 80% of the housings respectively, Aspergillus in 49% and Alternaria in 14%. House dust mite allergens Der p1 and Der f1 were detected in 90% and 77% of the mattress dust samples respectively and Can f1 and Fel d1 in 37% and 89% of the homes. Airborne and dustborne mold concentrations, although not statistically correlated (except for Aspergillus) shared most of their predictors. Multivariate linear models for mold levels, explaining up to 62% of the variability, showed an influence of the season, of the age of the dwelling, of aeration habits, presence of pets, smoking, signals of dampness, temperature and relative humidity. Allergens in the dust of the mattress were strongly related to the presence of pets and cleaning practices of bedsheets, these factors accounting for 60% of the variability. This study highlights ubiquitous contamination by molds and underlines complex interaction between outdoor and indoor sources and factors. PMID:26094801

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

    EPA Science Inventory

    An efficient and reliable analytical method was developed for the sensitive and selective quantification 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...

  10. DISTRIBUTION OF PESTICIDES AND POLYCYCLIC AROMATIC HYDROCARBONS IN HOUSE DUST AS A FUNCTION OF PARTICLE SIZE

    EPA Science Inventory

    House dust is a repository for environmental pollutants that may accumulate indoors from both internal and external sources over long periods of time. Dust and tracked-in soil accumulate most efficiently in carpets, and the pollutants associated with it may present an exposure...

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

    ERIC Educational Resources Information Center

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

    2009-01-01

    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…

  12. Do new wipe materials outperform traditional lead dust cleaning methods?

    PubMed

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

    2012-01-01

    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 μm, 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

  13. Hierarchy and molecular properties of house dust mite allergens.

    PubMed

    Thomas, Wayne R

    2015-10-01

    The allergenic load of house dust mite allergy is largely constituted by a few proteins with a hierarchical pattern of allergenicity. The serodominant specificities are the group 1&2 and the group 23 faecal allergens. The collective IgE binding to the group 1&2 allergens can measure unequivocal HDM sensitisation better than HDM extracts although discrepancies have been found in regions with complex acarofauna suggesting a need to investigate the specificity with allergen components. The group 4, 5, 7&21 allergens that each induce responses in about 40% of subjects are mid-tier allergens accounting for most of the remaining IgE binding. Their titres are proportional to the concomitant responses to Der p1&2. Group 2 allergen variants have different antibody binding. Body proteins only occasionally induce sensitisation although a higher prevalence of binding by atopic dermatitis patients provides a new avenue of research. A broad spectrum of IgE binding has been associated with diverse symptoms but not with the severity of asthma which is associated with low IgG antibody. Some allergens such as the group 14 large lipid binding proteins and the recently described proteins Der f 24-33, need further investigation but with the cognoscence that other denominated allergens have been found to be minor sensitisers by comparative quantitative analyses. Scabies is a confounder for diagnosis with extracts, inducing cross-reactive antibodies with Der p 4&20 as is seafood allergy with cross reactivity to Der p 10 a minor HDM allergen. The HDM genome sequence can now be used to verify allelic and paralogous variations. PMID:26433526

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

    PubMed Central

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

    2003-01-01

    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

  15. [Use of dust and air as indicators of environmental pollution in areas adjacent to a source of stationary lead emission].

    PubMed

    Quiterio, S L; da Silva, C R; Vaitsman, D S; Martinhon, P T; Moreira, M F; Araújo, U C; Mattos, R C; Santos, L S

    2001-01-01

    This study measured lead concentrations in both the outdoor air and household dust from houses located around a lead-acid battery repair shop. Such installations are one of the largest sources of lead exposure, since outdated technology is still used, coupled with the lack of strict air-quality control programs. Measurements of the air lead concentration around the repair shop were carried out at 6 points, approximately 25 and 500 m from the shop. Over 50% of the air samples exceeded the limit of 1.5 microg Pb.m-3 (range 0.03 - 183.3 microg Pb.m-3). House dust samples were collected from 6 places in houses located at approximately 25, 50, and 500 m from the repair shop, and the concentration of 1,500 microg Pb.m-2 for lead in house dust was exceeded in 44% of the samples, with results varying from 2.2 to 54,338.9 microg Pb.m-2. PMID:11395788

  16. CHILDHOOD BLOOD LEAD LEVELS NOT AFFECTED BY HOUSING COMPLIANCE STATUS

    EPA Science Inventory

    In a secondary analysis of data from the Childhood Lead Poisoning Prevention Program of Philadelphia (July 1, 1999 through September 1, 2004), the authors evaluated the effect of housing compliance status and time to achieve compliance on changes in children's blood lead levels. ...

  17. Human Exposure Assessment: Development of methods to assess the bioaccessibility of organic contaminants sorbed to soils and house dusts

    EPA Science Inventory

    Research task- Are physicochemical properties of soil and house dust predictive of the bioaccessibility of sorbed organic compoundsGoalIdentify dust and soil characteristics that influence the bioaccessibility of organic compounds and provide chemical specific data on the fractio...

  18. Molecular mechanisms of dust-induced toxicity in human corneal epithelial cells: Water and organic extract of office and house dust.

    PubMed

    Xiang, Ping; Liu, Rong-Yan; Sun, Hong-Jie; Han, Yong-He; He, Rui-Wen; Cui, Xin-Yi; Ma, Lena Q

    2016-01-01

    Human corneal epithelial (HCE) cells are continually exposed to dust in the air, which may cause corneal epithelium damage. Both water and organic soluble contaminants in dust may contribute to cytotoxicity in HCE cells, however, the associated toxicity mechanisms are not fully elucidated. In this study, indoor dust from residential houses and commercial offices in Nanjing, China was collected and the effects of organic and water soluble fraction of dust on primary HCE cells were examined. The concentrations of heavy metals in the dust and dust extracts were determined by ICP-MS and PAHs by GC-MS, with office dust having greater concentrations of heavy metals and PAHs than house dust. Based on LC50, organic extract was more toxic than water extract, and office dust was more toxic than house dust. Accordingly, the organic extracts induced more ROS, malondialdehyde, and 8-Hydroxydeoxyguanosine and higher expression of inflammatory mediators (IL-1β, IL-6, and IL-8), and AhR inducible genes (CYP1A1, and CYP1B1) than water extracts (p<0.05). Extracts of office dust presented greater suppression of superoxide dismutase and catalase activity than those of house dust. In addition, exposure to dust extracts activated NF-κB signal pathway except water extract of house dust. The results suggested that both water and organic soluble fractions of dust caused cytotoxicity, oxidative damage, inflammatory response, and activation of AhR inducible genes, with organic extracts having higher potential to induce adverse effects on primary HCE cells. The results based on primary HCE cells demonstrated the importance of reducing contaminants in indoor dust to reduce their adverse impacts on human eyes. PMID:27131017

  19. Investigating a novel flame retardant known as V6: measurements in baby products, house dust, and car dust.

    PubMed

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

    2013-05-01

    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, 3 mL). 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 1110 ng/g with a median of 12.5 ng/g, and <5 ng/g to 6160 ng/g in the car dust with a median of 103.0 ng/g. Concentrations in car dust were significantly higher than in 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

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

    PubMed Central

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

    2013-01-01

    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

  1. 12. CONCRETE STAIRWAY LEADING TO A LANDING BUILT TO HOUSE ...

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

    12. CONCRETE STAIRWAY LEADING TO A LANDING BUILT TO HOUSE THE MACHINERY AND COUNTERWEIGHT FOR THE DRUM GATE WHICH WAS NEVER INSTALLED, INSIDE THE RIGHT (WEST) BUTTRESS. CAMERA FACING NORTH. - Salinas Dam, Salinas River near Pozo Road, Santa Margarita, San Luis Obispo County, CA

  2. FIELD DEMONSTRATION OF LEAD PAINT ABATEMENT TECHNOLOGIES IN RESIDENTIAL HOUSING

    EPA Science Inventory

    This study was conducted to demonstrate lead-based paint (LBP) removal from architectural wood components in CO2 unoccupied residential housing using four technologies: granular carbon dioxide (CO2 blasting), pelletized CO2 blasting, encapsulant paint remover, and wet abrasive bl...

  3. Lead concentration in Hong Kong roadside dust after reduction of lead level in petrol

    SciTech Connect

    Chan, G.Y.; Chui, V.W.; Wong, M.H. )

    1989-06-01

    Samples of roadside dust were collected from 30 sites in Hong Kong. The total concentrations of 10 metals in the samples were analyzed, and the correlation coefficients among the metal contents and the annual average daily traffic (AADT) in 1986 were determined. Pb was found to have a significant correlation (P less than 0.01) with AADT. No correlation was found between Al, Ba, Cd, Cr, Cu, Fe, Mn, Ni, and Zn with respect to AADT. A general decrease in the level of Pb in roadside dust in the past few years has been observed since the reduction in the level of lead in petrol.

  4. A survey of spatially distributed exterior dust lead loadings in New York City

    SciTech Connect

    Caravanos, Jack; Weiss, Arlene L.; Blaise, Marc J.; Jaeger, Rudolph J. . E-mail: jaegerr@envmed.com

    2006-02-15

    This work documents ambient lead dust deposition values (lead loading) for the boroughs of New York City in 2003-2004. Currently, no regulatory standards exist for exterior concentrations of lead in settled dust. This is in contrast to the clearance and risk assessment standards that exist for interior residential dust. The reported potential for neurobehavioral toxicity and adverse cognitive development in children due to lead exposure prompts public health concerns about undocumented lead sources. Such sources may include settled dust of outdoor origin. Dust sampling throughout the five boroughs of NYC was done from the top horizontal portion of pedestrian traffic control signals (PTCS) at selected street intersections along main thoroughfares. The data (n=214 samples) show that lead in dust varies within each borough with Brooklyn having the highest median concentration (730{mu}g/ft{sup 2}), followed in descending order by Staten Island (452{mu}g/ft{sup 2}), the Bronx (382{mu}g/ft{sup 2}), Queens (198{mu}g/ft{sup 2}) and finally, Manhattan (175{mu}g/ft{sup 2}). When compared to the HUD/EPA indoor lead in dust standard of 40{mu}g/ft{sup 2}, our data show that this value is exceeded in 86% of the samples taken. An effort was made to determine the source of the lead in the dust atop of the PTCS. The lead in the dust and the yellow signage paint (which contains lead) were compared using isotopic ratio analysis. Results showed that the lead-based paint chip samples from intact signage did not isotopically match the dust wipe samples taken from the same surface. We know that exterior dust containing lead contributes to interior dust lead loading. Therefore, settled leaded dust in the outdoor environment poses a risk for lead exposure to children living in urban areas, namely, areas with elevated childhood blood lead levels and background lead dust levels from a variety of unidentified sources.

  5. Phthalates in dormitory and house dust of northern Chinese cities: Occurrence, human exposure, and risk assessment.

    PubMed

    Li, Hai-Ling; Song, Wei-Wei; Zhang, Zi-Feng; Ma, Wan-Li; Gao, Chong-Jing; Li, Jia; Huo, Chun-Yan; Mohammed, Mohammed O A; Liu, Li-Yan; Kannan, Kurunthachalam; Li, Yi-Fan

    2016-09-15

    Phthalates are widely used chemicals in household products, which severely affect human health. However, there were limited studies emphasized on young adults' exposure to phthalates in dormitories. In this study, seven phthalates were extracted from indoor dust that collected in university dormitories in Harbin, Shenyang, and Baoding, in the north of China. Dust samples were also collected in houses in Harbin for comparison. The total concentrations of phthalates in dormitory dust in Harbin and Shenyang samples were significantly higher than those in Baoding samples. The total geometric mean concentration of phthalates in dormitory dust in Harbin was lower than in house dust. Di-(2-ethylhexyl) phthalate (DEHP) was the most abundant phthalate in both dormitory and house dust. The daily intakes of the total phthalates, carcinogenic risk (CR) of DEHP, hazard index (HI) of di-isobutyl phthalate (DiBP), dibutyl phthalate (DBP), and DEHP were estimated, the median values for all students in dormitories were lower than adults who live in the houses. Monte Carlo simulation was applied to predict the human exposure risk of phthalates. HI of DiBP, DBP, and DEHP was predicted according to the reference doses (RfD) provided by the United States Environmental Protection Agency (U.S.EPA) and the reference doses for anti-androgenicity (RfD AA) developed by Kortenkamp and Faust. The results indicated that the risks of some students had exceeded the limitation, however, the measured results were not exceeded the limitation. Risk quotients (RQ) of DEHP were predicted based on China specific No Significant Risk Level (NSRL) and Maximum Allowable Dose Level (MADL). The predicted results of CR and RQ of DEHP suggested that DEHP could pose a health risk through intake of indoor dust. PMID:27186877

  6. Prevalence of Lead Hazards and Soil Arsenic in U.S. Housing.

    PubMed

    Dewalt, F Gary; Cox, David C; O'Haver, Robert; Salatino, Brendon; Holmes, Duncan; Ashley, Peter J; Pinzer, Eugene A; Friedman, Warren; Marker, David; Viet, Susan M; Fraser, Alexa

    2015-12-01

    The American Healthy Homes Survey, June 2005-March 2006, measured levels of lead and arsenic in homes nationwide. Based on a three-stage cluster sample of 1,131 housing units, key statistically weighted estimates of the prevalence of lead-based paint (LBP) and LBP hazards associated with paint, dust, and soil, and arsenic in dust and soil, were as follows: 37.1 million homes (35%) had some LBP; 23.2 million (22%) had one or more LBP hazards; 93% of the homes with LBP were built before 1978. The highest prevalence of LBP and LBP hazards was in the Northeast and Midwest. Over three million homes with children under six years of age had LBP hazards, including 1.1 million low-income households (< $30,000/yr.). Less than 5% of homes had detectable levels of arsenic in dust (≥ 5 μg/ft2). Arsenic in soil (for homes with yard soil) averaged 6.6 parts per million (ppm). Many homes had soil arsenic levels of 20 ppm or greater, including 16% of homes with wooden structures in the yard and 8% of homes without such structures. PMID:26738315

  7. The relative allergenicity of Stachybotrys chartarum compared to 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. The authors compared the ability of the fungus Stachybotrys chartarum (SCE) and house dust mite (HDM) extracts to i...

  8. 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...

  9. 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 ...

  10. Primary Prevention of Lead Poisoning: Protecting Children From Unsafe Housing

    PubMed Central

    Lucht, James A.; Sylvaria, Alyssa J.; Cigna, Jessica; Vanderslice, Robert; Vivier, Patrick M.

    2014-01-01

    Objectives. We examined the effects of changes in Rhode Island’s Lead Hazard Mitigation Law in 2005 on children’s blood lead levels. Methods. We used 2005 to 2009 data from Rhode Island’s Lead Elimination Surveillance System; city tax assessor records in Central Falls, Pawtucket, Providence, and Woonsocket, Rhode Island; and records of conformance to the state’s lead hazard mitigation law, to assess the extent to which legislation changes resulted in minimizing children’s exposure to lead. Results. During the 5-year study, the proportion of properties that complied with the new law increased for properties that housed young children. However, the majority of rental properties did not comply with the law. Children’s lead levels declined by approximately 1 microgram per deciliter on average in properties that did comply, demonstrating that the law could have a protective effect for children. Conclusions. Legislation changes increased the proportion of properties that were certified as nonhazardous, leading to decreased blood lead levels for children living in these properties. However, legislation cannot be a highly effective primary prevention strategy if it does not cover all properties where children live and is not strictly enforced. PMID:24922160

  11. Provenance of dust to Antarctica: A lead isotopic perspective

    NASA Astrophysics Data System (ADS)

    Gili, Stefania; Gaiero, Diego M.; Goldstein, Steven L.; Chemale, Farid, Jr.; Koester, Edinei; Jweda, Jason; Vallelonga, Paul; Kaplan, Michael R.

    2016-03-01

    Antarctic ice preserves an ~800 kyr record of dust activity in the Southern Hemisphere. Major efforts have been dedicated to elucidate the origin of this material in order to gain greater insight into the atmospheric dust cycle. On the basis of Pb isotopes in Antarctic dust samples and potential sources, this contribution demonstrates for the first time that Patagonia is the main contributor of dust to Antarctica during interglacial periods as well as glacials, although the potential importance of Tierra del Fuego remains unclear because of its geochemical similarities to Patagonia. An important new finding is that the Puna-Altiplano sector of the continent is a second important dust source to eastern Antarctica during both glacials and interglacials, being more prominent during interglacials. The data indicate South America is the primary dust source to Antarctica during both glacials and interglacials.

  12. Brominated, chlorinated and phosphate organic contaminants in house dust from Portugal.

    PubMed

    Coelho, Sónia D; Sousa, Ana C A; Isobe, Tomohiko; Kim, Joon-Woo; Kunisue, Tatsuya; Nogueira, António J A; Tanabe, Shinsuke

    2016-11-01

    House dust is an important matrix to evaluate the human exposure to a large number of contaminants including organochlorine compounds and flame retardants. In this study, we measured the levels of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDDs), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), decabromodiphenyl ethane (DBDPE), polychlorinated biphenyls (PCBs) and several organophosphorus flames retardants (PFRs) in 28 house dust samples collected between 2010 and 2011 in two Portuguese cities, Aveiro and Coimbra. Among the measured compounds, PFRs, particularly tris(2-ethylhexyl) phosphate (TEHP), triphenyl phosphate (TPHP), 2-ethylhexyl diphenyl phosphate (EHDPP) and tris(methylphenyl) phosphate (TMPP), were the dominant group (median: 3200ngg(-1)). PBDE levels were the second highest (median: 340ngg(-1)) with great predominance of BDE 209 (median 270ngg(-1)), followed by HBCDDs (median: 150ngg(-1)), DBDPE (54ngg(-1)), PCBs (median: 6.3ngg(-1)) and BTBPE (median: 1.2ngg(-1)). Estimated daily intakes (EDIs) via dust ingestion showed a higher intake of PFRs (median: 4.6ngkg-bw(-1)day); however for all contaminants the EDIs were much lower than the established reference dose (RfD) values. Therefore, the studied population is exposed to non-hazardous levels of the target compounds when considering the exposure through house dust ingestion. PMID:27351149

  13. Is house dust the missing exposure pathway for PBDEs? An analysis of the urban fate and human exposure to PBDEs.

    PubMed

    Jones-Otazo, Heather A; Clarke, John P; Diamond, Miriam L; Archbold, Josephine A; Ferguson, Glenn; Harner, Tom; Richardson, G Mark; Ryan, John Jake; Wilford, Bryony

    2005-07-15

    Polybrominated diphenyl ether (PBDE) body burdens in North America are 20 times that of Europeans and some "high accumulation" individuals have burdens up to 1-2 orders of magnitude higher than median values, the reasons for which are not known. We estimated emissions and fate of sigma PBDEs (minus BDE-209) in a 470 km2 area of Toronto, Canada, using the Multi-media Urban Model (MUM-Fate). Using a combination of measured and modeled concentrations for indoor and outdoor air, soil, and dust plus measured concentrations in food, we estimated exposure to sigma PBDEs via soil, dust, and dietary ingestion and indoor and outdoor inhalation pathways. Fate calculations indicate that 57-85% of PBDE emissions to the outdoor environment originate from within Toronto and that the dominant removal process is advection by air to downwind locations. Inadvertent ingestion of house dust is the largest contributor to exposure of toddlers through to adults and is thus the main exposure pathway for all life stages other than the infant, including the nursing mother, who transfers PBDEs to her infant via human milk. The next major exposure pathway is dietary ingestion of animal and dairy products. Infant consumption of human milk is the largest contributor to lifetime exposure. Inadvertent ingestion of dust is the main exposure pathway for a scenario of occupational exposure in a computer recycling facility and a fish eater. Ingestion of dust can lead to almost 100-fold higher exposure than "average" for a toddler with a high dust intake rate living in a home in which PBDE concentrations are elevated. PMID:16082939

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

    PubMed

    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

    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

  15. Distribution of pesticides and polycyclic aromatic hydrocarbons in house dust as a function of particle size.

    PubMed Central

    Lewis, R G; Fortune, C R; Willis, R D; Camann, D E; Antley, J T

    1999-01-01

    House dust is a repository for environmental pollutants that may accumulate indoors from both internal and external sources over long periods of time. Dust and tracked-in soil accumulate most efficiently in carpets, and the pollutants associated with dust and soil may present an exposure risk to infants and toddlers, who spend significant portions of their time in contact with or in close proximity to the floor and who engage in frequent mouthing activities. The availability of carpet dust for exposure by transfer to the skin or by suspension into the air depends on particle size. In this study, a large sample of residential house dust was obtained from a commercial cleaning service whose clients were homeowners residing in the Raleigh-Durham-Chapel Hill (Research Triangle) area of North Carolina. The composite dust was separated into seven size fractions ranging from < 4 to 500 microm in diameter, and each fraction was analyzed for 28 pesticides and 10 polycyclic aromatic hydrocarbons (PAHs). Over 20% of the fractionated dust sample consisted of particles < 25 microm in diameter. Fourteen pesticides and all 10 of the target PAHs were detected in one or more of the seven size-fractionated samples. Sample concentrations reported range from 0.02 to 22 microg/g; the synthetic pyrethroids cis- and trans-permethrin were the most abundant pesticide residue. The concentrations of nearly all of the target analytes increased gradually with decreasing particle size for the larger particles, then increased dramatically for the two smallest particle sizes (4-25 microm and < 4 microm). Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:10464072

  16. Continuous exposure to house dust mite elicits chronic airway inflammation and structural remodeling.

    PubMed

    Johnson, Jill R; Wiley, Ryan E; Fattouh, Ramzi; Swirski, Filip K; Gajewska, Beata U; Coyle, Anthony J; Gutierrez-Ramos, José-Carlos; Ellis, Russ; Inman, Mark D; Jordana, Manel

    2004-02-01

    It is now fully appreciated that asthma is a disease of a chronic nature resulting from intermittent or continued aeroallergen exposure leading to airway inflammation. To investigate responses to continuous antigen exposure, mice were exposed to either house dust mite extract (HDM) or ovalbumin intranasally for five consecutive days, followed by 2 days of rest, for up to seven consecutive weeks. Continuous exposure to HDM, unlike ovalbumin, elicited severe and persistent eosinophilic airway inflammation. Flow cytometric analysis demonstrated an accumulation of CD4+ lymphocytes in the lung with elevated expression of inducible costimulator a marker of T cell activation, and of T1/ST2, a marker of helper T Type 2 effector cells. We also detected increased and sustained production of helper T cell Type 2-associated cytokines by splenocytes of HDM-exposed mice on in vitro HDM recall. Histologic analysis of the lung showed evidence of airway remodeling in mice exposed to HDM, with goblet cell hyperplasia, collagen deposition, and peribronchial accumulation of contractile tissue. In addition, HDM-exposed mice demonstrated severe airway hyperreactivity to methacholine. Finally, these responses were studied for up to 9 weeks after cessation of HDM exposure. We observed that whereas airway inflammation resolved fully, the remodeling changes did not resolve and airway hyperreactivity resolved only partly. PMID:14597485

  17. Identification and prevalence of culturable mesophilic microfungi in house dust from 100 Danish homes. Comparison between airborne and dust-bound fungi.

    PubMed

    Gravesen, S

    1978-10-01

    In order to encircle possible allergen sources, fungi from house dust were cultivated and identified. Dust from vacuum cleaners was inoculated on Petri dishes containing V-8 agar with addition of penicillin and streptomycin to eliminate the bacterial flora. The number of genera identified were for the most part consistent with the genera trapped from the air. However, presumably owing to their dispersal biology it was demonstrated that members of Mucorales were much more frequently represented in the samples obtained by this method compared with gravimetric and volumetric measurements. The method is recommended as a simple way to demonstrate and identify the mould contents in house dust and as a tool for the identification of some of the real allergenic sources in house dust. PMID:362974

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

    PubMed Central

    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

    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

  19. Non-PBDE halogenated flame retardants in Canadian indoor house dust: sampling, analysis, and occurrence.

    PubMed

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

    2016-04-01

    An analytical method was developed for the measurement of 18 novel halogenated flame retardants in house dust. Sample preparation was based on ultrasound-assisted solvent extraction and clean up with solid phase extraction (SPE). Sample extracts were analyzed by gas chromatography-mass spectrometry (GC/MS) operated in electron capture negative ion (ECNI) chemical ionization mode. Baseline data from 351 fresh (active) dust samples collected under the Canadian House Dust Study (CHDS) revealed that five out of 18 target chemicals were present with detection frequencies higher than 90 %. Median (range) concentrations for these five compounds were as follows: 104 (<1.5-13,000) ng/g for 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTBB), 8.5 (<1.7-2390) ng/g for 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), 10.2 (<1.7-430) ng/g for hexabromobenzene (HBB), 2.9 (<1.2-1410) ng/g for syn-dechlorane plus (syn-DP) and 5.6 (<1.9-1570) ng/g for anti-dechlorane plus (anti-DP). A comparison of two sampling methods in a subset of 40 homes showed significant positive correlations between samples of "active" dust and samples taken directly from the household vacuum cleaner for all target compounds having median values above their corresponding method detection limits (MDLs). In addition, the method was also applied to the analysis of the targeted compounds in National Institute of Standards and Technology (NIST) standard reference material (SRM 2585, organic contaminants in house dust). Results from the current study could contribute to the potential certification of target chemicals in SRM 2585. PMID:26780041

  20. 42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Efficiency Respirators and Combination Gas Masks § 84.1146 Lead fume test for dust, fume, and mist... oxygen-gas flame on molten lead. (e) Samples of the test suspension will be taken during each test...

  1. 42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Efficiency Respirators and Combination Gas Masks § 84.1146 Lead fume test for dust, fume, and mist... oxygen-gas flame on molten lead. (e) Samples of the test suspension will be taken during each test...

  2. 42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Efficiency Respirators and Combination Gas Masks § 84.1146 Lead fume test for dust, fume, and mist... oxygen-gas flame on molten lead. (e) Samples of the test suspension will be taken during each test...

  3. 42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Efficiency Respirators and Combination Gas Masks § 84.1146 Lead fume test for dust, fume, and mist... oxygen-gas flame on molten lead. (e) Samples of the test suspension will be taken during each test...

  4. Sensitization to house-dust mite and mite fauna in selected children's homes in Kütahya, Turkey.

    PubMed

    Akdemir, Cihangir; Yilmaz, Sema

    2009-01-01

    The aim of this study was to determine the relationship between the house-dust mite allergy and prevalence of house-dust mites in dwellings of children who were tested for specific IgE against Dermatophagoides pteronyssinus (D. pteronyssinus) and D. farinae on the suspicion of allergic rhinitis, dermatitis and asthma. All dust specimens collected from children's houses were investigated under a light microscope. House-dust mites were found in 31.7% of houses of children with a specific IgE, while the rate was 27.5% in houses of those without a specific IgE. Overall, house dust specimens collected from a total of 92 houses were examined, and mites were found in 27 (29.3%) of them. Both Der p and Der f were found in 38 (92.7%), while mixed allergy (D. pteronyssinus + D. farinae) was found in 3 (7.3%). Der p allergy (100%) was found in all of the allergic children, while no child was found with specific IgE for Der f allergy, except in mixed allergies. PMID:19817266

  5. First National Survey of Lead and Allergens in Housing: survey design and methods for the allergen and endotoxin components.

    PubMed Central

    Vojta, Patrick J; Friedman, Warren; Marker, David A; Clickner, Robert; Rogers, John W; Viet, Susan M; Muilenberg, Michael L; Thorne, Peter S; Arbes, Samuel J; Zeldin, Darryl C

    2002-01-01

    From July 1998 to August 1999, the U.S. Department of Housing and Urban Development and the National Institute of Environmental Health Sciences conducted the first National Survey of Lead and Allergens in Housing. The purpose of the survey was to assess children's potential household exposure to lead, allergens, and bacterial endotoxins. We surveyed a sample of 831 homes, representing 96 million permanently occupied, noninstitutional housing units that permit resident children. We administered questionnaires to household members, made home observations, and took environmental samples. This article provides general background information on the survey, an overview of the survey design, and a description of the data collection and laboratory methods pertaining to the allergen and endotoxin components. We collected dust samples from a bed, the bedroom floor, a sofa or chair, the living room floor, the kitchen floor, and a basement floor and analyzed them for cockroach allergen Bla g 1, the dust mite allergens Der f 1 and Der p 1, the cat allergen Fel d 1, the dog allergen Can f 1, the rodent allergens Rat n 1 and mouse urinary protein, allergens of the fungus Alternaria alternata, and endotoxin. This article provides the essential context for subsequent reports that will describe the prevalence of allergens and endotoxin in U.S. households, their distribution by various housing characteristics, and their associations with allergic diseases such as asthma and rhinitis. PMID:12003758

  6. New house dust collection system and its use in a study of asthma in dust mite sensitive children in Raleigh, North Carolina

    SciTech Connect

    Lindstrom, A.B.; Beck, M.A.; Henry, M.M.; Barnes, D.M.; Henderson, F.W.

    1993-01-01

    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 dust samples from all potentially relevant domestic substrates, with the primary sampling objective being the retrieval at least 100 mg of sample material. During the winter of 1991-92, dust samples were collected from six different microenvironments in the homes of 49 dust mite sensitive children living in the Raleigh, NC metropolitan area. In addition to the standard antigen immunoassay, the performance of the HDVI was assessed by conducting side by side comparison tests using two alternative antigen collection systems. Microenvironmental antigen concentrations were found to be lognormally distributed within the test homes and within each microenvironment. With the relatively large quantity of sample material collected and the ease with which the HDVI was able to collect samples from a wide variety of substrates, the new unit was determined to be well suited for surface dust and dust mite antigen collection studies.

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    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 μm (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.

  8. Dermatophytes, related keratinophilic and opportunistic fungi in indoor dust of houses and hospitals.

    PubMed

    Singh, I; Mishra, A; Kushwaha, Rks

    2009-01-01

    Dermatophytes, related keratinophilic and opportunistic fungi were isolated from indoor dust samples of 46 hospitals and 47 houses in Kanpur. A total of 19 fungi represented by 11 genera were isolated by the hair-baiting technique from 230 and 235 samples from hospitals and houses respectively. The isolated fungi are Acremonium implicatum (Indian Type Culture Collection) ITCC 5266, A. strictum (Germplasm Centre for Keratinophilic Fungi) GPCK 1137, Aphanoascus fulvescens GPCK 1081, Arthroderma simii GPCK 1275, Chrysosporium queenslandicum ITCC 5270, C. indicum ITCC 5269, C. pannicola GPCK 1022, C. tropicum GPCK 1269, Ctenomyces serratus ITCC 5267, Gymnoascus reessii ITCC 5265, Malbranchea fulva GPCK 1075, Malbranchea pulchella ITCC 5268, Micosporum gypseum GPCK 1038 , Microsporum cookei GPCK 2001, M. fulvum GPCK 2002, Paecilomyces lilacinum GPCK 1080, Penicillium expansum GPCK 1082, Trichophyton mentagrophytes GPCK 2003 and T. terrestre GPCK 2004. In hospitals, the minimum frequency was of Ctenomyces serratus ITCC 5267 while the maximum frequency was of Arthroderma simii GPCK 1275. In houses, Chrysosporium queenslandicum ITCC 5270 and C. tropicum GPCK 1269 were with minimum and maximum frequencies respectively. This makes the first report of these fungi with keratinolytic ability in the indoor dust of hospitals and houses. PMID:19584506

  9. Comparison of techniques to reduce residential lead dust on carpet and upholstery: the new jersey assessment of cleaning techniques trial.

    PubMed

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

    2002-12-01

    High-efficiency particulate air (HEPA) filtered vacuum cleaners are recommended by the U.S. Department of Housing and Urban Development for cleaning lead-contaminated house dust. We performed a randomized field study to determine whether a conventional (non-HEPA) vacuum cleaner could achieve cleaning results comparable with those of a HEPA vacuum cleaner. We compared the lead loading reductions of these two vacuum cleaners in a total of 127 New Jersey homes of lead-exposed children. We used wet towelettes and a vacuum sampler to collect lead dust from carpets and upholstery before and after vacuum cleaning. The vacuum sampling data showed that the HEPA and non-HEPA vacuum cleaners resulted in 54.7% (p = 0.006) and 36.4% (p = 0.020) reductions in lead loading, respectively, when used on soiled carpets, although the overall difference in lead loading reduction between the two vacuum cleaners was not statistically significant (p = 0.293). The wipe sampling data did not show any significant lead loading reduction for either of the vacuum cleaners, suggesting that both vacuum cleaners fail to clean the surfaces of carpet effectively, considering that wipe sampling media simulate surface contact. On upholstery, the wipe sampling data showed a significant reduction in lead loading for the non-HEPA vacuum cleaner (22.2%, p = 0.047). Even with the significant reduction, the postcleaning lead loadings on upholstery were similar to those on carpets. The similar lead loading results for carpets and upholstery indicate that soiled upholstery may be as important a source of childhood lead exposure as carpets. PMID:12460803

  10. Comparison of techniques to reduce residential lead dust on carpet and upholstery: the new jersey assessment of cleaning techniques trial.

    PubMed Central

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

    2002-01-01

    High-efficiency particulate air (HEPA) filtered vacuum cleaners are recommended by the U.S. Department of Housing and Urban Development for cleaning lead-contaminated house dust. We performed a randomized field study to determine whether a conventional (non-HEPA) vacuum cleaner could achieve cleaning results comparable with those of a HEPA vacuum cleaner. We compared the lead loading reductions of these two vacuum cleaners in a total of 127 New Jersey homes of lead-exposed children. We used wet towelettes and a vacuum sampler to collect lead dust from carpets and upholstery before and after vacuum cleaning. The vacuum sampling data showed that the HEPA and non-HEPA vacuum cleaners resulted in 54.7% (p = 0.006) and 36.4% (p = 0.020) reductions in lead loading, respectively, when used on soiled carpets, although the overall difference in lead loading reduction between the two vacuum cleaners was not statistically significant (p = 0.293). The wipe sampling data did not show any significant lead loading reduction for either of the vacuum cleaners, suggesting that both vacuum cleaners fail to clean the surfaces of carpet effectively, considering that wipe sampling media simulate surface contact. On upholstery, the wipe sampling data showed a significant reduction in lead loading for the non-HEPA vacuum cleaner (22.2%, p = 0.047). Even with the significant reduction, the postcleaning lead loadings on upholstery were similar to those on carpets. The similar lead loading results for carpets and upholstery indicate that soiled upholstery may be as important a source of childhood lead exposure as carpets. PMID:12460803

  11. Effect on quality of life of the mixed house dust mite/weed pollen extract immunotherapy

    PubMed Central

    Li, Lisha

    2016-01-01

    Background Although many patients with allergic rhinitis have symptoms due to sensitization to more than one kind of allergens, and mixed allergen extracts are widely used for immunotherapy, there are few published trials. Objective Our study aimed to evaluate the effect of multiple-allergen immunotherapy on improving the symptoms and quality of life of allergic rhinitis patients. Methods We performed a 1-year single-center observation study of subcutaneous immunotherapy using house dust mite extract (n = 12), weed pollen extract (n = 21), or mixed house dust mite/weed pollen extract (n = 11) in 44 allergic rhinitis patients. All the allergens responsible for the symptom of each patient were included in his immunotherapy. Symptom score, medication score, and quality of life of the patients were evaluated before and after 1-year immunotherapy. Quality of life was evaluated with the Rhinoconjunctivitis Quality of Life Questionnaire. Results In all 3 groups receiving subcutaneous immunotherapy, significant improvement of symptom score, medication score, and quality of life was found vs. baseline at 1 year, irrespective of the allergen used. In the weed pollen season, the changes of quality of life questionnaire score after 1-year treatment were not significantly different between the weed pollen group (1.55 ± 1.24) and the mixed house dust mite/weed pollen group (1.14 ± 1.01). The same happened in the nonpollen seasons, during which dust mite immunotherapy (1.23 ± 1.63) and mixed immunotherapy (0.60 ± 0.47) did not show significantly different effect on the quality of life. Conclusion The multiple-allergen immunotherapy might be effective in polysensitized allergic rhinitis patients, and could improve their quality of life. Our result did not show significant difference between the effects of multiple-allergen immunotherapy and mono-allergen immunotherapy. PMID:27489789

  12. Peanut allergen in house dust of eating area and bed--a risk factor for peanut sensitization?

    PubMed

    Trendelenburg, V; Ahrens, B; Wehrmann, A-K; Kalb, B; Niggemann, B; Beyer, K

    2013-11-01

    It has been hypothesized that high environmental exposure to peanut allergens may be a potent risk factor for cutaneous sensitization. Therefore, we wanted to investigate whether peanut proteins are detectable in house dust of different household areas. Peanut levels of dust samples were measured with ELISA. Overall, peanut was detectable in 19 of 21 households in the eating area and/or in bed. The frequency of peanut consumption correlated with peanut levels. Forty-eight hours after intentional peanut consumption, peanut levels were highly increased. Nevertheless, further research is required to prove whether peanut allergen in house dust can cause sensitization via skin. PMID:24351066

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

    NASA Astrophysics Data System (ADS)

    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

    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 μg g-1, respectively, and maximal concentrations 9950 and 2150 μg 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.

  14. A study on the prevalence of house dust mites in Al-Arish city, North Sinai Governorate, Egypt.

    PubMed

    El-Sherbiny, Gihad T; El-Sherbini, Eman T; Saled, Nagla Mostafa K; Haridy, Fouad M; Morsy, Ayman T A

    2010-04-01

    Free living mites comprise a huge and various groups of tiny arthropods in the class Arachida, mainly of the Pyroglyphidae family. Exposure to allergens derived from house dust mite (HDM) feces is a postulated risk factor for allergic sensitization, asthma development and asthma morbidity. However, practical and effective method to mitigate these allergens in low-income, urban home environments remains elusive. It well known that (HDM) physiology is greatly affected by hydrothermal microclimatic condition. El Arish has subtropical climate and warm humid summer, such situation are favourable to proliferate house dust mites. As no valid data are available for house dust mites fauna of El Arish, this study was carried out to determine the prevalence and contamination rates of homes in El Arish city. Samples of house dust collected in 2008 from 50 houses in El Arish city were subjected to acarological examination. Acri were found in (34.6 %) of the samples collected from these homes. Results indicated that dust mites were present in all humid environments. Also, hypersensitivity to dust mites was common among patients with asthma. PMID:20503586

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

    PubMed Central

    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

    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

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

    PubMed

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

    2001-08-01

    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

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

    PubMed Central

    2010-01-01

    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 μg/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 μg/g, n = 12]). T-PAH in SHD from apartments with CT parking lots (median 129 μg/g) was 25 times higher than that in SHD from apartments with parking lots with other pavement surface types (median 5.1 μg/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

  18. Coal-tar-based parking lot sealcoat: An unrecognized source of PAH to settled house dust

    USGS Publications Warehouse

    Mahler, B.J.; Van Metre, P.C.; Wilson, J.T.; Musgrove, M.; Burbank, T.L.; Ennis, T.E.; Bashara, T.J.

    2010-01-01

    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 coaltar-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. ?? 2010 American Chemical Society.

  19. How to minimize iron loss while decontaminating converter dust from lead.

    PubMed

    Moussavi, Mohsen; Fathikalajahi, Jamshid; Khalili, Fariba

    2011-12-01

    The purpose of this work was to decontaminate a converter flue dust from lead while minimizing the iron loss from the dust matrix. A physicochemical method based on a leaching cascade was applied to remove lead impurities with HCl. Finally, the lead-rich wastes generated at the end of the operations were further treated in order to meet the standards of waste disposal sites. The results show that lead could be removed from the dust with efficiencies of better than 90%. However, some iron was lost in these operations. It was noticed that under optimum conditions 8.5 g of iron would be lost as leachate per each gram of removed lead. It was also noticed that the lead-treated dust was more concentrated in iron and had less calcium. A number of parameters that could affect the amount of iron loss, such as acid dose, exposure time and temperature, were identified and the extent of the effects are presented. It was concluded that the lead content in the flue dust could practically be lowered to any level. It was also concluded that the difference between the solubility of lead chloride in cold and hot water, as well as the affinity of certain ligands such as Cl- and OH- to form stable complexes with lead ions, played a key role in this study. The lead-containing complexes in the leachate were identified to be predominantly PbCl3- and PbCl+. PMID:22439558

  20. Evaluation of HEPA vacuum cleaning and dry steam cleaning in reducing levels of polycyclic aromatic hydrocarbons and house dust mite allergens in carpets

    PubMed Central

    Yu, Chang Ho; Yiin, Lih-Ming; Fan, Zhi-Hua (Tina); Rhoads, George G.

    2014-01-01

    Dry steam cleaning, which has gained recent attention as an effective method to reduce house dust mite (HDM) allergen concentration and loading in carpets, was evaluated in this study for its efficacy in lowering levels of polycyclic aromatic hydrocarbons (PAHs) as well as HDM allergens. Fifty urban homes with wail-to-wall carpets, mostly low-income and with known lead contamination, were studied in 2003 and 2004. Two carpet-cleaning interventions were compared: Repeated HEPA (High Efficiency Particulate Air filtered) vacuuming alone and repeated HEPA vacuuming supplemented with dry steam cleaning. Vacuum samples were collected to measure carpet loading of dust and contaminants immediately before and after cleaning. Paired comparisons were conducted to evaluate the effectiveness of the cleaning protocols in reducing the levels of PAHs and HDM allergens in carpets. The results indicated that both cleaning methods substantially reduced the loading of PAHs and HDM allergens as well as dust in carpets (p < 0.0001). The reductions in loading of dust (64.4%), PAHs (69.1%), and HDM allergens (85.5%), by dry steam cleaning plus repetitive HEPA vacuuming were larger than the reductions by regular HEPA vacuuming alone: dust (55.5%), PAHs (58.6%), and HDM allergens (80.8%), although the difference was statistically significant only for dust and PAHs. We conclude that intensive HEPA vacuum cleaning substantially reduced the loading of PAHs and HDM allergens in carpets in these urban homes and that dry steam cleaning added modestly to cleaning effectiveness. PMID:19137159

  1. Evaluation of HEPA vacuum cleaning and dry steam cleaning in reducing levels of polycyclic aromatic hydrocarbons and house dust mite allergens in carpets.

    PubMed

    Yu, Chang Ho; Yiin, Lih-Ming; Tina Fan, Zhi-Hua; Rhoads, George G

    2009-01-01

    Dry steam cleaning, which has gained recent attention as an effective method to reduce house dust mite (HDM) allergen concentration and loading in carpets, was evaluated in this study for its efficacy in lowering levels of polycyclic aromatic hydrocarbons (PAHs) as well as HDM allergens. Fifty urban homes with wall-to-wall carpets, mostly low-income and with known lead contamination, were studied in 2003 and 2004. Two carpet-cleaning interventions were compared: Repeated HEPA (High Efficiency Particulate Air filtered) vacuuming alone and repeated HEPA vacuuming supplemented with dry steam cleaning. Vacuum samples were collected to measure carpet loading of dust and contaminants immediately before and after cleaning. Paired comparisons were conducted to evaluate the effectiveness of the cleaning protocols in reducing the levels of PAHs and HDM allergens in carpets. The results indicated that both cleaning methods substantially reduced the loading of PAHs and HDM allergens as well as dust in carpets (p < 0.0001). The reductions in loading of dust (64.4%), PAHs (69.1%), and HDM allergens (85.5%), by dry steam cleaning plus repetitive HEPA vacuuming were larger than the reductions by regular HEPA vacuuming alone: dust (55.5%), PAHs (58.6%), and HDM allergens (80.8%), although the difference was statistically significant only for dust and PAHs. We conclude that intensive HEPA vacuum cleaning substantially reduced the loading of PAHs and HDM allergens in carpets in these urban homes and that dry steam cleaning added modestly to cleaning effectiveness. PMID:19137159

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

    PubMed

    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

    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

  3. Beta(1-->3)-glucan in house dust of German homes: housing characteristics, occupant behavior, and relations with endotoxins, allergens, and molds.

    PubMed Central

    Gehring, U; Douwes, J; Doekes, G; Koch, A; Bischof, W; Fahlbusch, B; Richter, K; Wichmann, H E; Heinrich, J

    2001-01-01

    beta(1-->3)-Glucans are potent proinflammatory agents that have been suggested to play a role in indoor-related respiratory health effects. The aim of this study was to assess whether beta(1-->3)-glucan concentrations in house dust are correlated with levels of endotoxins, allergens, and culturable mold spore counts in house dust. Further, the associations of beta(1-->3)-glucan with housing characteristics and occupant behavior were assessed. beta(1-->3)-Glucan was measured in settled house dust from living room floors of 395 homes of two German cities, Erfurt and Hamburg, with a specific enzyme immunoassay. Concentrations ranged from below the limit of detection to 19,013 microg/m(2) (22,588 microg/g dust). Concentrations per square meter were found to be correlated with endotoxins, mite and cat allergens, and culturable mold spores. Correlations were weaker when concentrations were expressed per gram of dust, indicating that variance in concentrations of all factors is largely determined by the amount of dust sampled. Associations between beta(1-->3)-glucan, housing characteristics, and occupant behavior were found for concentrations per square meter but not for concentrations per gram of dust. The following characteristics were associated with a significant increase in beta(1-->3)-glucan levels: carpets in the living room [means ratio (MR) = 1.9-2.1], keeping a dog inside (MR = 1.4), use of the home by four or more persons (MR = 1.4), use of the living room for > 180 hr/week (MR = 2.1), lower frequency of vacuum cleaning (MR = 1.6-3.0) and dust cleaning (MR = 1.2 and 1.4, respectively), and presence of mold spots during the past 12 months (MR = 1.4). We conclude that that the amount of dust sampled can be used as a proxy for hygiene and that beta(1-->3)-glucan concentrations per square meter are related to the amount of dust sampled. PMID:11266323

  4. Evaluation of new sensitizations in asthmatic children monosensitized to house dust mite by specific immunotherapy.

    PubMed

    Harmanci, Koray; Razi, Cem H; Toyran, Muge; Kanmaz, Gozde; Cengizlier, Mehmet R

    2010-03-01

    Specific immunotherapy (SIT) is one of the treatment modalities recomended for the management of asthma and allergic rhinitis by international guidelines. A potential benefit of immunotherapy (IT) is to prevent the development of sensitisation to new allergens. There is stil no conclusion on this subject. One hundred twenty-two children 8-18 years old with intermittent asthma, with or without allergic rhinitis, all of whom were monosensitised to house dust mite (HDM) were selected. Sixty two of these children accepted to receive SIT with HDM extract for 4 years and the remaining 60 did not accept SIT and were treated with asthma medications only. This second group of children served as the control group. At the end of the 4-year study period, 36 of the 53 patients (67.9%) in the SIT group showed no new sensitizations, compared to 38 of 52 (73.0%) in the control group (p = 0.141). The most frequent new sensitizations at the end of the study were pollens, grasses and olive polen, followed by animal dander, alternaria and cockroach. In conclusion, SIT may not prevent the onset of new sensitizations in asthmatic children monosensitized to house dust mites. Further investigation is required to clarify the immunologic mechanisms and other factors by which SIT reduces or not the development of new sensitizations in monosensitized children. PMID:20527510

  5. Endotoxin and House Dust Mite Allergen Levels on Synthetic and Buckwheat Pillows

    PubMed Central

    Nam, Hae-Seon; Park, Choon-Sik; Crane, Julian

    2004-01-01

    Pillows are known to contain significant levels of indoor allergens and endotoxin, that are of importance to house dust mite sensitized asthmatics. Buckwheat pillows are commonly used in Korea. We studied the levels of the house dust mite allergen, Der f 1, and endotoxin on new synthetic and buckwheat pillows and their accumulation over three months. Endotoxin levels were significantly higher on new buckwheat pillows compared to synthetic pillows; geometric mean levels (95% CI) were 60,950 EU/g (30,270-122,700) and 4,887 EU/g (2,570-9,311) respectively (p<0.001). No Der f 1 was detected on the new pillows. After three months Der f 1 levels were similar on buckwheat and synthetic pillows, geometric mean levels (95% CI) were 1.16 µg/g (0.02-8.13) and 1.08 µg/g (0.19-1.68) respectively. These results indicate that buckwheat pillows are a source of very high endotoxin levels that may be of relevance to asthma severity of atopic asthmatics. PMID:15308838

  6. Effects of five insect growth regulators on laboratory populations of the North American house-dust mite, Dermatophagoides farinae.

    PubMed

    Downing, A S; Wright, C G; Farrier, M H

    1990-08-01

    The potential of insect growth regulators (methoprene, hydroprene, fenoxycarb, diflubenzuron and triflumuron) to control populations of the North American house-dust mite Dermatophagoides farinae (Hughes) was assessed in laboratory bioassays. Methoprene was most effective at suppressing population growth, especially at concentrations of 1.0% (10,000 ppm) and 5.0% (5000 ppm) active ingredient. Hydroprene, structurally related to methoprene, also suppressed house-dust mite populations but not as consistently as methoprene. Fenoxycarb may be effective at controlling house-dust mites but at greater concentrations than were tested. Diflubenzuron and triflumuron, two chitin-synthesis inhibitors, failed to suppress mite numbers and may, in fact, stimulate reproduction in some cases. Almost all concentration of the insect growth regulators were shown to be ineffective when assayed 90 days after treatment. PMID:2226070

  7. Exposure assessment to airborne endotoxin, dust, ammonia, hydrogen sulfide and carbon dioxide in open style swine houses.

    PubMed

    Chang, C W; Chung, H; Huang, C F; Su, H J

    2001-08-01

    Information is limited for the exposure levels of airborne hazardous substances in swine feed buildings that are not completely enclosed. Open-style breeding, growing and finishing swine houses in six farms in subtropical Taiwan were studied for the airborne concentrations of endotoxin, dust, ammonia, hydrogen sulfide and carbon dioxide. The air in the farrowing and nursery stalls as partially enclosed was also simultaneously evaluated. Three selected gases and airborne dusts were quantified respectively by using Drager diffusion tubes and a filter-weighing method. Endotoxin was analyzed by the Limulus amoebocyte lysate assay. Average concentration of airborne total endotoxin among piggeries was between 36.8 and 298 EU/m(3), while that for respirable endotoxin was 14.1-129 EU/m(3). Mean concentration of total dust was between 0.15 and 0.34 mg/m(3), with average level of respirable dust of 0.14 mg/m(3). The respective concentrations of NH3, CO2 and H2S were less than 5 ppm, 600-895 ppm and less than 0.2 ppm. Airborne concentrations of total dust and endotoxin in the nursery house were higher than in the other types of swine houses. The finishing house presented the highest exposure risk to NH3, CO2 and H2S. Employees working in the finishing stalls were also exposed to the highest airborne levels of respirable endotoxin and dust. On the other hand, the air of the breeding units was the least contaminated in terms of airborne endotoxin, dust, NH3, CO2 and H2S. The airborne concentrations of substances measured in the present study were all lower than most of published studies conducted in mainly enclosed swine buildings. Distinct characteristics, including maintaining swine houses in an open status and frequent spraying water inside the stalls, significantly reduce accumulation of gases and airborne particulates. PMID:11513795

  8. Inhaled house dust programs pulmonary dendritic cells to promote type 2 T-cell responses by an indirect mechanism.

    PubMed

    Moran, Timothy P; Nakano, Keiko; Whitehead, Gregory S; Thomas, Seddon Y; Cook, Donald N; Nakano, Hideki

    2015-11-15

    The induction of allergen-specific T helper 2 (Th2) cells by lung dendritic cells (DCs) is a critical step in allergic asthma development. Airway delivery of purified allergens or microbial products can promote Th2 priming by lung DCs, but how environmentally relevant quantities and combinations of these factors affect lung DC function is unclear. Here, we investigated the ability of house dust extract (HDE), which contains a mixture of environmental adjuvants, to prime Th2 responses against an innocuous inhaled antigen. Inhalational exposure to HDE conditioned lung conventional DCs, but not monocyte-derived DCs, to induce antigen-specific Th2 differentiation. Conditioning of DCs by HDE was independent of Toll-like receptor 4 signaling, indicating that environmental endotoxin is dispensable for programming DCs to induce Th2 responses. DCs directly treated with HDE underwent maturation but were poor stimulators of Th2 differentiation. In contrast, DCs treated with bronchoalveolar lavage fluid (BALF) from HDE-exposed mice induced robust Th2 differentiation. DC conditioning by BALF was independent of the proallergic cytokines IL-25, IL-33, and thymic stromal lymphopoietin. BALF treatment of DCs resulted in upregulation of CD80 but low expression of CD40, CD86, and IL-12p40, which was associated with Th2 induction. These findings support a model whereby environmental adjuvants in house dust indirectly program DCs to prime Th2 responses by triggering the release of endogenous soluble factor(s) by airway cells. Identifying these factors could lead to novel therapeutic targets for allergic asthma. PMID:26386119

  9. Comparison of Lead Species in Household Dust Wipes, Soil, and Airborne Particulate Matter in El Paso, Texas, by X-Ray Absorption Spectroscopy

    NASA Astrophysics Data System (ADS)

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

    2006-12-01

    Understanding the interplay of indoor and outdoor sources of lead in an urban setting is one foundation in establishing risk for lead exposure in children in our cities. A household may be the source for lead contamination due to the deterioration of interior lead-based paint, or a sink if lead particles are tracked or blown into the home from such potential ambient sources as yard soil or urban street dust. In addressing this issue, X-Ray Absorption Spectroscopy (XAS) presents the opportunity to directly and quantitatively speciate lead at low concentrations in bulk samples. We performed XAS analyses on dust wipes from window sills or floors from 8 houses that exceeded Federal standards for lead in dust. We entered these data into a Principal Components Analysis (PCA) that also included El Paso environmental samples: lead-based paints, soils, and airborne particulate matter. A simple two-component mixing system accounted for more than 95% of the variance of this data set. Paint and lead oxide appear to be the principal components, with all the samples falling in a compositional range from pure paint to 75% paint, 25% lead oxide. Note that several different lead compounds are possible constituents of a given lead-based paint. The paints spread from one end out along perhaps a fifth of the range of the compositional axis, followed closely, but not overlapped, by the soil samples, which covered the remainder of the compositional range. Two of the dust wipes plotted within the paint range, and the remaining 6 dust wipes plotted randomly through the soil range. Samples of airborne particulate matter plotted in both the paint and soil ranges. These observations suggest that the lead on most of the dust wipes originated outside the house, probably from deteriorated exterior lead-based paint deposited in adjacent yards. This paint mixed with lead oxide present in the soil and entered the houses by the airborne route. The probable source of the oxide in the soil is former

  10. COST ESTIMATES OF USING THREE LEAD-BASED PAINT ABATEMENT TECHNOLOGIES ON RESIDENTIAL HOUSING

    EPA Science Inventory

    Elevated blood lead levels in children of the US due to exposure to flaking lead-based paint continues to be an important health concern. Approximately 57M housing units, which represent 75% of all privately owned and occupied housing built before 1980 in the US are contaminated ...

  11. The impact of drinking water, indoor dust and paint on blood lead levels of children aged 1–5 years in Montréal (Québec, Canada)

    PubMed Central

    Levallois, Patrick; St-Laurent, Julie; Gauvin, Denis; Courteau, Marilène; Prévost, Michèle; Campagna, Céline; Lemieux, France; Nour, Shokoufeh; D'Amour, Monique; Rasmussen, Pat E

    2014-01-01

    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 μg/dL) and water lead when the mean water concentration was >3.3 μg/L: adjusted OR=4.7 (95% CI: 2.1–10.2). Windowsill dust loading >14.1 μg/ft2 was also associated with BLL ≥1.78 μg/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

  12. A Controlled Challenge Study on Di(2-ethylhexyl) Phthalate (DEHP) in House Dust and the Immune Response in Human Nasal Mucosa of Allergic Subjects

    PubMed Central

    Deutschle, Tom; Reiter, Rudolf; Butte, Werner; Heinzow, Birger; Keck, Tilman; Riechelmann, Herbert

    2008-01-01

    Background Few studies have yet addressed the effects of di(2-ethylhexyl) phthalate (DEHP) in house dust on human nasal mucosa. Objectives We investigated the effects of house dust containing DEHP on nasal mucosa of healthy and house dust mite (HDM)–allergic subjects in a short-term exposure setting. Methods We challenged 16 healthy and 16 HDM-allergic subjects for 3 hr with house dust at a concentration of 300 μg/m3 containing either low (0.41 mg/g) or high (2.09 mg/g) levels of DEHP. Exposure to filtered air served as control. After exposure, we measured proteins and performed a DNA microarray analysis. Results Nasal exposure to house dust with low or high DEHP had no effect on symptom scores. Healthy subjects had almost no response to inhaled dust, but HDM-allergic subjects showed varied responses: DEHPlow house dust increased eosinophil cationic protein, granulocyte-colony–stimulating factor (G-CSF), interleukin (IL)-5, and IL-6, whereas DEHPhigh house dust decreased G-CSF and IL-6. Furthermore, in healthy subjects, DEHP concentration resulted in 10 differentially expressed genes, whereas 16 genes were differentially expressed in HDM-allergic subjects, among them anti-Müllerian hormone, which was significantly up-regulated after exposure to DEHPhigh house dust compared with exposure to DEHPlow house dust, and fibroblast growth factor 9, IL-6, and transforming growth factor-β1, which were down-regulated. Conclusions Short-term exposure to house dust with high concentrations of DEHP has attenuating effects on human nasal immune response in HDM-allergic subjects, concerning both gene expression and cytokines. PMID:19057701

  13. Adhesion molecules in atopic dermatitis: patch tests elicited by house dust mite.

    PubMed

    Jung, K; Linse, F; Pals, S T; Heller, R; Moths, C; Neumann, C

    1997-10-01

    Different T-helper subsets, which are characterized by the secretion of distinct cytokines (Th1, Th2), have been found in house dust mite-exposed skin of sensitized individuals and in nickel-specific T lymphocytes from nickel contact allergic and non-allergic individuals. In order to evaluate the role which adhesion molecules may play in the homing of different T-cell subsets into allergen-exposed skin of atopic and normal individuals, we compared the expression pattern of adhesion molecules in patch test reactions to house dust mite antigen (D.pt.), nickel sulfate (Ni) and the irritant anthralin. Biopsies were taken at various time points after application of these agents and studied by immuncytochemistry. To exclude an endogenous difference in adhesion molecule expression in atopic and non-atopic skin, sequential biopsies from Ni patch tests of 2 normal individuals were also included in this study. The expression of E-selectin, P-selectin, CD31, VCAM-1 and ICAM-1 on endothelial cells and other cells in the skin was quantified by microscopic evaluation. Skin homing T cells were also quantified using antibodies to CD3, CD4, CD8, UCHL-1, L-selectin and the cutaneous lymphocyte antigen (CLA). Independent of the eliciting substance, all lesions showed an upregulation of all adhesion molecules tested, with the exception of CD62. The appearance of E-selectin and an increase in ICAM-1 and VCAM-1 expression were first observed at 12 h after application of the various agents. In parallel, the number of CLA+ and L-selectin+ lymphocytes increased steadily. No principle differences could be established between the various types of skin reactions in atopic individuals, nor did the skin of patients with AD differ from normal controls. Our results provide evidence that differential expression of adhesion molecules does not play a major part in observed differential homing of Th1 and Th2-cell subsets into patch test sites provoked by house dust mite and nickel sulfate in atopic

  14. Low-flow, long-term air sampling under normal domestic activity to measure house dust mite and cockroach allergens.

    PubMed

    Park, Jung Won; Kim, Cheol Woo; Kang, Dae Bong; Lee, In Young; Choi, Soo Young; Yong, Tai-Soon; Shin, Dong Cheon; Kim, Kyu Earn; Hong, Chein-Soo

    2002-01-01

    Successful applications of air sampling for the quantification of exposure to indoor allergens have been reported, but its efficiency is still controversial. We evaluated whether the low-flow, long-term air sampling in normal domestic activity conditions can quantify the exposure of house dust mites (HDM) and cockroaches (CR) allergens or not. Airborne Der f 1 and Bla g 1 were captured with a personal air sampler in 25 bedrooms during normal domestic activity. Quantification of the major allergens in the reservoir dust and the extraction of the air sampler filters were done with two-site ELISA kits. Airborne Der f 1 was measured above the threshold level of detection in 15 houses (60%). Detection rate of airborne Der f 1 was significantly higher in those houses where D. farinae was microscopically found in the reservoir dusts (76.5% vs. 25%, chi 2 = 6.0, p = 0.014). Airborne Der f 1 was more frequently detected in the houses with higher Der f 1 (> or = 10 micrograms/g dust) in bedding reservoir dust than the other group (91% vs. 35.7%, chi 2 = 7.819, p = 0.005), and the median value of airborne Der f 1 was also significantly higher in that group (14.0 pg/m3 vs. below detection limit, p = 0.002). Airborne Der f 1 was significantly correlated with Der f 1 in bedding reservoir dust (r = 0.591, p < 0.01). Airborne Bla g 1 was measured with ELISA in 16 houses (64%), and it was more frequently detected in the houses where the CRs were captured by adhesive traps (91% vs. 57%, chi 2 = 3,484, p = 0.06). The median concentration of Bla g 1 in the filter was also higher in the houses with captured CRs (0.12 vs. 0.05 mU/m3, p = 0.06), but the level of Bla g 1 did not correlate with that of the bedding dusts or the floor dusts of kitchen. These results suggested that airborne HDM or CR allergens could be measured by low-flow, long-term air sampling, and that it might be one of appropriate modalities for evaluating personal exposure to HDM and CR allergens. PMID:12926189

  15. Air Quality in Alternative Housing Systems May Have an Impact on Laying Hen Welfare. Part I—Dust

    PubMed Central

    David, Bruce; Oppermann Moe, Randi; Michel, Virginie; Lund, Vonne; Mejdell, Cecilie

    2015-01-01

    The new legislation for laying hens in the European Union put a ban on conventional cages. Production systems must now provide the hens with access to a nest, a perch, and material for dust bathing. These requirements will improve the behavioral aspects of animal welfare. However, when hens are kept with access to litter, it is a concern that polluted air may become an increased threat to health and therefore also a welfare problem. This article reviews the literature regarding the health and welfare effects birds experience when exposed to barn dust. Dust is composed of inorganic and organic compounds, from the birds themselves as well as from feed, litter, and building materials. Dust may be a vector for microorganisms and toxins. In general, studies indicate that housing systems where laying hens have access to litter as aviaries and floor systems consistently have higher concentrations of suspended dust than caged hens with little (furnished cages) or no access to litter (conventional cages). The higher dust levels in aviaries and floor housing are also caused by increased bird activity in the non-cage systems. There are gaps in both the basic and applied knowledge of how birds react to dust and aerosol contaminants, i.e., what levels they find aversive and/or impair health. Nevertheless, high dust levels may compromise the health and welfare of both birds and their caretakers and the poor air quality often found in new poultry housing systems needs to be addressed. It is necessary to develop prophylactic measures and to refine the production systems in order to achieve the full welfare benefits of the cage ban. PMID:26479370

  16. AMCase is a crucial regulator of type 2 immune responses to inhaled house dust mites

    PubMed Central

    Kim, Lark Kyun; Morita, Rimpei; Kobayashi, Yasushi; Eisenbarth, Stephanie C.; Lee, Chun Geun; Elias, Jack; Eynon, Elizabeth E.; Flavell, Richard A.

    2015-01-01

    Chitinases are enzymes that cleave chitin, a component of the exoskeleton of many organisms including the house dust mite (HDM). Here we show that knockin mice expressing an enzymatically inactive acidic mammalian chitinase (AMCase), the dominant true chitinase in mouse lung, showed enhanced type 2 immune responses to inhaled HDM. We found that uncleaved chitin promoted the release of IL-33, whereas cleaved chitin could be phagocytosed and could induce the activation of caspase-1 and subsequent activation of caspase-7; this results in the resolution of type 2 immune responses, probably by promoting the inactivation of IL-33. These data suggest that AMCase is a crucial regulator of type 2 immune responses to inhaled chitin-containing aeroallergens. PMID:26038565

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

    SciTech Connect

    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.

    2012-07-11

    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.

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

    PubMed Central

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

    2014-01-01

    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

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

    PubMed Central

    2011-01-01

    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

  20. Gene silencing by RNA interference in the house dust mite, Dermatophagoides pteronyssinus.

    PubMed

    Marr, Edward J; Sargison, Neil D; Nisbet, Alasdair J; Burgess, Stewart T G

    2015-12-01

    This is the first report of gene silencing by RNA interference (RNAi) in the European house dust mite, Dermatophagoides pteronyssinus, Trouessart, 1897. Using a non-invasive immersion method first developed for the honey bee mite, Varroa destructor, a significant reduction in the expression of D. pteronyssinus glutathione-S-transferase mu-class 1 enzyme (DpGST-mu1) was achieved following overnight immersion in double stranded RNA encoding DpGST-mu1. Although no detrimental phenotypic changes were observed following silencing, this technique can now be used to address fundamental physiological questions and assess the potential therapeutic benefit in silencing D. pteronyssinus target genes in selected domestic situations of high human-mite interface. PMID:26212476

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

    PubMed Central

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

    2009-01-01

    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

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

    SciTech Connect

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

    1983-11-01

    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.

  3. Dustborne Alternaria alternata antigens in U.S. homes: Results from the National Survey of Lead and Allergens in Housing

    PubMed Central

    Salo, Päivi M.; Yin, Ming; Arbes, Samuel J.; Cohn, Richard D.; Sever, Michelle; Muilenberg, Michael; Burge, Harriet A.; London, Stephanie J.; Zeldin, Darryl C.

    2005-01-01

    Background: Alternaria alternata is one of the most common fungi associated with allergic disease. However, Alternaria exposure in indoor environments is not well characterized. Objective: The primary goals of this study were to examine the prevalence of Alternaria exposure and identify independent predictors of Alternaria antigen concentrations in U.S. homes. Methods: Data for this cross-sectional study were obtained from the National Survey of Lead and Allergens in Housing. A nationally representative sample of 831 housing units in 75 different locations throughout the U.S. completed the survey. Information on housing and household characteristics was obtained by questionnaire and environmental assessments. Concentrations of Alternaria antigens in dust collected from various indoor sites were assessed with a polyclonal anti-Alternaria antibody assay. Results: Alternaria antigens were detected in most (95-99%) of the dust samples. The geometric mean concentration, reflecting the average Alternaria concentration in homes, was 4.88 μg/g (SE=0.13 μg/g). In the multivariable linear regression analysis, the age of the housing unit, geographic region, urbanization, poverty, family race, observed mold and moisture problems, use of dehumidifier, and presence of cats and dogs were independent predictors of Alternaria antigen concentrations. Less frequent cleaning and smoking indoors also contributed to higher Alternaria antigen levels in homes. Conclusion: Exposure to Alternaria alternata antigens in U.S. homes is common. Antigen levels in homes are not only influenced by regional factors but also by residential characteristics. Preventing mold and moisture problems, avoiding smoking indoors, and regular household cleaning may help reduce exposure to Alternaria antigens indoors. PMID:16159634

  4. House Dust Concentrations of Organophosphate Flame Retardants in Relation to Hormone Levels and Semen Quality Parameters

    PubMed Central

    Meeker, John D.; Stapleton, Heather M.

    2010-01-01

    Background Organophosphate (OP) compounds, such as tris(1,3-dichloro-2-propyl) phosphate (TDCPP) and triphenyl phosphate (TPP), are commonly used as additive flame retardants and plasticizers in a wide range of materials. Although widespread human exposure to OP flame retardants is likely, there is a lack of human and animal data on potential health effects. Objective We explored relationships of TDCPP and TPP concentrations in house dust with hormone levels and semen quality parameters. Methods We analyzed house dust from 50 men recruited through a U.S. infertility clinic for TDCPP and TPP. Relationships with reproductive and thyroid hormone levels, as well as semen quality parameters, were assessed using crude and multivariable linear regression. Results TDCPP and TPP were detected in 96% and 98% of samples, respectively, with widely varying concentrations up to 1.8 mg/g. In models adjusted for age and body mass index, an interquartile range (IQR) increase in TDCPP was associated with a 3% [95% confidence interval (CI), −5% to −1%) decline in free thyroxine and a 17% (95% CI, 4–32%) increase in prolactin. There was a suggestive inverse association between TDCPP and free androgen index that became less evident in adjusted models. In the adjusted models, an IQR increase in TPP was associated with a 10% (95% CI, 2–19%) increase in prolactin and a 19% (95% CI, −30% to −5%) decrease in sperm concentration. Conclusion OP flame retardants may be associated with altered hormone levels and decreased semen quality in men. More research on sources and levels of human exposure to OP flame retardants and associated health outcomes are needed. PMID:20194068

  5. Optimization of a Der p 2-based prophylactic DNA vaccine against house dust mite allergy.

    PubMed

    Pulsawat, Pinya; Pitakpolrat, Patrawadee; Prompetchara, Eakachai; Kaewamatawong, Theerayuth; Techakriengkrai, Navapon; Sirivichayakul, Sunee; Buranapraditkun, Supranee; Hannaman, Drew; Ruxrungtham, Kiat; Jacquet, Alain

    2013-03-01

    DNA vaccines encoding allergens are promising immunotherapeutics to prevent or to treat allergy through induction of allergen-specific Th1 responses. Despite anti-allergy effects observed in small rodents, DNA-based vaccines are weak immunogens in primates and humans and particularly when administered by conventional injection. The goal of the present study was to improve the immunogenicity of a prophylactic vaccine encoding the major house dust mite allergen Der p 2. In this context, we evaluated the influence of different DNA backbones including notably intron and CpG enriched sequence, the DNA dose, the in vivo delivery by electroporation as well as the heterologous prime boost regimen on the vaccine efficiency. We found that a minimal allergen expression level threshold must be reached to induce the production of specific antibodies but beyond this limit, the intensity of the immune response was independent on the DNA dose and allergen expression. The in vivo DNA delivery by electroporation drastically enhanced the production of specific antibodies but not the IFNg secretion. Vaccination of naïve mice with DNA encoding Der p 2 delivered by electroporation even at very low dose (2μg) prevented the development of house dust mite allergy through Th1-skewed immune response characterized by the drastic reduction of allergen-specific IgE, IL-5 and lung inflammation together with the induction of strong specific IgG2a titers and IFNg secretion. CpG cassette in the DNA backbone does not play a critical role in the efficient prophylaxis. Finally, comparable protective immune responses were observed when using heterologous DNA prime/protein boost or homologous DNA prime/boost. Taken together, these data suggest that the potent Th1 response induced by DNA-based vaccine encoding allergens through electroporation provides the rationale for the evaluation of DNA encoding Der p 2 into HDM allergy clinical trials. PMID:23396105

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

    PubMed

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

    2014-02-01

    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

  7. IN-HOUSE CORROSION RESEARCH EMPHASIZING LEAD, COPPER AND IRON

    EPA Science Inventory

    Lead and copper are directly regulated via the "Lead and Copper Rule;" however, water suppliers must balance all water treatment processes in order to simultaneously comply with all regulations. Specific research needs for copper and lead chemistry still exist, as applications o...

  8. 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...

  9. Use of fluorinated polybrominated diphenyl ethers and simplified cleanup for the analysis of polybrominated diphenyl ethers in house dust

    EPA Science Inventory

    A simple, cost-effective method is described for the analysis of polybrominated diphenyl ethers (PBDEs) in house dust using pressurized fluid extraction, cleanup with modified silica solid phase extraction tubes, and fluorinated internal standards. There are 14 PBDE congeners inc...

  10. No Concentration Decrease of House Dust Mite Allergens With Rising Altitude in Alpine Regions

    PubMed Central

    Grafetstätter, Carina; Prossegger, Johanna; Braunschmid, Herbert; Sanovic, Renata; Hahne, Penelope; Pichler, Christina; Thalhamer, Josef

    2016-01-01

    Purpose Several studies over the past 4 decades have indicated a significant reduction in house dust mite (HDM) and HDM allergen concentration in areas higher than 1,500 m above sea level. These have served as basis of allergen avoidance therapies for HDM allergy and asthma. However, modern construction techniques used in the insulation, heating, and glazing of buildings as well as global warming have changed the environmental parameters for HDM living conditions. The present study revisits the paradigm of decreasing HDM allergen concentrations with increasing altitude in the alpine region of Germany and Austria. Methods A total of 122 dust samples from different abodes (hotels, privates and mountain huts) at different altitudes (400-2,600 m) were taken, and concentrations of HDM allergens were analyzed. Humidity and temperature conditions, and numerous indoor environmental parameters such as fine dust, type of flooring, age of building, and frequency of cleaning were determined. Results HDM allergen concentrations did not significantly change with increasing altitude or relative humidity. At the level of indoor parameters, correlations could be found for different flooring types and the concentration of HDM allergens. Conclusions In contrast to the widespread view of the relationship between altitude and HDM allergen concentrations, clinically relevant concentrations of HDM allergens could be detected in high-lying alpine regions in Austria and Germany. These results indicate that improvement in conditions of asthmatic patients sensitized against HDMs during a stay at high altitude can no longer be ascribed to decreased levels of HDM allergens, instead, other mechanisms may trigger the beneficial effect. PMID:27126724

  11. Recovery of Zinc and Lead from Electric-Furnace Steelmaking Dust at Berzelius

    NASA Astrophysics Data System (ADS)

    Maczek, Helmut; Kola, Rolf

    1980-01-01

    The Waelz unit at the Berzelius Metallhütten GmbH plant in Duisburg, West Germany, was originally built to recover zinc and lead values in zinc retort residues and slags from lead shaft furnaces. The process has also proved suitable for recovering zinc and lead from steelmaking dusts. The metallurgical characteristics and information on operating costs encountered in the three decades over which this Waelz plant has been in operation at Berzelius are described and discussed.

  12. Polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD) and "novel" brominated flame retardants in house dust in Germany.

    PubMed

    Fromme, H; Hilger, B; Kopp, E; Miserok, M; Völkel, W

    2014-03-01

    Brominated flame retardants (BFRs) are used in a wide variety of products such as electronic devices, upholstery and carpets and in insulation boards. The study presented here aimed to quantify the amounts of BFRs in house dust in Germany. For this purpose 20 residences' dust samples were collected from vacuum cleaner bags and analysed with LC-MS/MS and simultaneously with GC/MS. Using GC/MS, the median (95th percentile) concentrations of PBDEs (sum of tetra- to hepta-congeners), BDE 209, Σ-HBCD (sum of three congeners), and decabromodiphenylethane (DBDPE) were 42ng/g (230ng/g), 950ng/g (3426ng/g), 335ng/g (1545ng/g), and 146ng/g (1059ng/g), respectively. Using LC-MS/MS some "novel" flame retardants were found in median concentrations of 343ng/g (bis(2-ethyl-1-hexyl)tetrabromophthalate, TBPH), and 28ng/g (tetrabromobisphenol A, TBBPA). Whilst 1,2-bis-(2,4,6-tribromophenoxy)ethane (BTBPE) and 2-ethyl-1-hexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) could not be detected. Based on these measurements an exposure assessment for the sum of tetra- to heptabrominated congeners, BDE 209, and Σ-HBCD resulted in a "high" daily intake for toddlers (based on 95th percentiles) of 1.2ng/kg b.w., 0.69ng/kg b.w., and 8.9ng/kg b.w., respectively. For TBPH the "high" intake was calculated at 4.1ng/kg b.w. and for DBDPE at 5.3ng/kg b.w. A clear tendency was observed to apply "novel" BFRs in Germany. Moreover, the results suggest that the recent exposure to PBDEs and HBCD via house dust in Germany is well below the levels that are associated with health effects. For the "novel" brominated flame retardants such an assessment is not possible due to limited toxicological information. PMID:24368294

  13. Lead exposure in young children from dust and soil in the United Kingdom

    SciTech Connect

    Thornton, I.; Watt, J.M. ); Davies, D.J.A.; Quinn, M.J. )

    1990-11-01

    A survey of metals in United Kingdom dusts and soils has confirmed widespread lead contamination with a geometric mean value for lead in surface (0-5 cm) garden soils of 266 {mu}g/g and in housedusts of 561 {mu}g/g (excluding old mining areas). A subsequent detailed survey of 97 householders in Birmingham with 2-year-old children showed dust lead loading in the home environment to be an important predictor of blood lead concentrations in young children, when both variables fell within the normal range for the UK. The total estimated lead uptake by the young child was 36 {mu}g/day of which 1 {mu}g was by inhalation and 35 {mu}g by ingestion.

  14. Asthma, Airway Symptoms and Rhinitis in Office Workers in Malaysia: Associations with House Dust Mite (HDM) Allergy, Cat Allergy and Levels of House Dust Mite Allergens in Office Dust

    PubMed Central

    Lim, Fang Lee; Hashim, Zailina; Than, Leslie Thian Lung; Md Said, Salmiah; Hisham Hashim, Jamal; Norbäck, Dan

    2015-01-01

    A prevalence study was conducted among office workers in Malaysia (N= 695). The aim of this study was to examine associations between asthma, airway symptoms, rhinitis and house dust mites (HDM) and cat allergy and HDM levels in office dust. Medical data was collected by a questionnaire. Skin prick tests were performed for HDM allergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae) and cat allergen Felis domesticus. Indoor temperature and relative air humidity (RH) were measured in the offices and vacuumed dust samples were analyzed for HDM allergens. The prevalence of D. pteronyssinus, D. farinae and cat allergy were 50.3%, 49.0% and 25.5% respectively. Totally 9.6% had doctor-diagnosed asthma, 15.5% had current wheeze and 53.0% had current rhinitis. The Der p 1 (from D. pteronyssinus) and Der f 1 (from D. farinae) allergens levels in dust were 556 ng/g and 658 ng/g respectively. Statistical analysis was conducted by multilevel logistic regression, adjusting for age, gender, current smoking, HDM or cat allergy, home dampness and recent indoor painting at home. Office workers with HDM allergy had more wheeze (p= 0.035), any airway symptoms (p= 0.032), doctor-diagnosed asthma (p= 0.005), current asthma (p= 0.007), current rhinitis (p= 0.021) and rhinoconjuctivitis (p< 0.001). Cat allergy was associated with wheeze (p= 0.021), wheeze when not having a cold (p= 0.033), any airway symptoms (p= 0.034), doctor-diagnosed asthma (p= 0.010), current asthma (p= 0.020) and nasal allergy medication (p= 0.042). Der f 1 level in dust was associated with daytime breathlessness (p= 0.033) especially among those with HDM allergy. Der f 1 levels were correlated with indoor temperature (p< 0.001) and inversely correlated with RH (p< 0.001). In conclusion, HDM and cat allergies were common and independently associated with asthma, airway symptoms and rhinitis. Der f 1 allergen can be a risk factor for daytime breathlessness. PMID:25923543

  15. Human exposure to per- and polyfluoroalkyl substances (PFASs) via house dust in Korea: Implication to exposure pathway.

    PubMed

    Tian, Zhexi; Kim, Seung-Kyu; Shoeib, Mahiba; Oh, Jeong-Eun; Park, Jong-Eun

    2016-05-15

    A wide range of per- and polyfluoroalkyl substances (PFASs), including fluorotelomer alcohols (FTOHs), perfluorooctane sulfonamidoethanols (FOSEs), perfluoroalkyl carboxylic acids (PFCAs), and perfluoroalkane sulfonic acids (PFSAs), were measured in fifteen house dust and two nonresidential indoor dust of Korea. Total concentrations of PFASs in house dust ranged from 29.9 to 97.6 ng g(-1), with a dominance of perfluorooctane sulfonic acid (PFOS), followed by 8:2 FTOH, N-Ethyl perfluorooctane sulfonamidoethanol (EtFOSE), perfluoroctanoic acid (PFOA). In a typical exposure scenario, the estimated daily intakes (EDIs) of total PFASs via house dust ingestion were 2.83 ng d(-1) for toddlers and 1.13 ng d(-1) for adults, which were within the range of the mean EDIs reported from several countries. For PFOA and PFOS exposure via house dust ingestion, indirect exposure (via precursors) was a minor contributor, accounting for 5% and 12%, respectively. An aggregated exposure (hereafter, overall-EDIs) of PFOA and PFOS occurring via all pathways, estimated using data compiled from the literature, were 53.6 and 14.8 ng d(-1) for toddlers, and 20.5 and 40.6 ng d(-1) for adults, respectively, in a typical scenario. These overall-EDIs corresponded to 82% (PFOA) and 92% (PFOS) of a pharmacokinetic model-based EDIs estimated from adults' serum data. Direct dietary exposure was a major contributor (>89% of overall-EDI) to PFOS in both toddlers and adults, and PFOA in toddlers. As for PFOA exposure of adults, however direct exposure via tap water drinking (37%) and indirect exposure via inhalation (22%) were as important as direct dietary exposure (41%). House dust-ingested exposure (direct+indirect) was responsible for 5% (PFOS in toddlers) and <1% (PFOS in adults, and PFOA in both toddlers and adults) of the overall-EDIs. In conclusion, house-dust ingestion was a minor contributor in this study, but should not be ignored for toddlers' PFOS exposure due to its significance in the

  16. Mice housed on coal dust-contaminated sand: A model to evaluate the impacts of coal mining on health.

    PubMed

    Caballero-Gallardo, Karina; Olivero-Verbel, Jesus

    2016-03-01

    Coal dust is the most important air pollutant in coal mining in regards to producing deleterious health effects. It permeates the surrounding environment threatening public health. The aim of this study was to evaluate the toxic effects associated with exposure to sand contaminated with coal dust particles below 38 μm in diameter, obtained from a mineral sample collected in the largest coal mine in South America, La Loma, Cesar, Colombia. Sterilized sand was spiked with coal dust to obtain concentrations ranging from zero to 4% coal dust. To model natural exposure, mice were housed for eight weeks in boxes containing this mixture as bedding after which, they were euthanized and blood and tissue samples were collected. Real time PCR analysis revealed an increase in Cyp1A1 mRNA for living on sand with coal dust concentrations greater than 2% compared to mice living on sand without coal dust. Unexpectedly, for mice on coal dust-polluted sand, Sod1, Scd1 and Nqo1 hepatic mRNA were downregulated. The Comet assay in peripheral blood cells and the micronucleus test in blood smears, showed a significant potential genotoxic effect only at the highest coal dust concentration. Histopathological analysis revealed vascular congestion and peribronchial inflammation in the lungs. A dose-response relationship for the presence of hepatic steatosis, vacuolization and nuclei enlargements was observed in the exposed animals. The data suggest living on a soil polluted with coal dust induces molecular, cellular and histopathological changes in mice. Accordingly, the proposed model can be used to identify deleterious effects of exposure to coal dust deposited in soils that may pose health risks for surrounding wildlife populations. PMID:26774687

  17. [Distribution characteristic and bioaccessibility of lead in kindergarten dust of Wuhan City].

    PubMed

    Sun, Guang-Yi; Bi, Xiang-Yang; Li, Zhong-Gen; Chen, Yu-Peng

    2011-11-01

    The characteristics of lead pollution and the associated health risk of children for the dust samples from 69 representative kindergartens in different type districts of Wuhan were investigated. Total lead concentration and bioaccessibility according to physiologically based extraction test (PBET) were determined. Results showed that the levels of lead concentration in dust ranged from 36.3 to 1 523 mg x kg(-1) with an average value of 169 mg x kg(-1), lower than published data from other areas. The great spatial variation of Pb in dust indicated that specific sites have been seriously contaminated by Pb. The bioaccessibilities of Pb in dusts were 35% +/- 15% at gastric phases and 7.6% +/- 5.8% at intestinal phases. According to the predicted model with the Integration Exposure Uptake Biokinetic Model (IEUBK), the geometric mean blood lead of children (0-6 years) was 2.73 microg x dL(-1), of which over 10 microg x dL(-1) was less than 0.001% and exceeded 5 microg x dL(-1) was 3.32%. PMID:22295628

  18. Estimating Children’s Soil/Dust Ingestion Rates through Retrospective Analyses of Blood Lead Biomonitoring from the Bunker Hill Superfund Site in Idaho

    PubMed Central

    von Lindern, Ian; Spalinger, Susan; Stifelman, Marc L.; Stanek, Lindsay Wichers; Bartrem, Casey

    2016-01-01

    Background: Soil/dust ingestion rates are important variables in assessing children’s health risks in contaminated environments. Current estimates are based largely on soil tracer methodology, which is limited by analytical uncertainty, small sample size, and short study duration. Objectives: The objective was to estimate site-specific soil/dust ingestion rates through reevaluation of the lead absorption dose–response relationship using new bioavailability data from the Bunker Hill Mining and Metallurgical Complex Superfund Site (BHSS) in Idaho, USA. Methods: The U.S. Environmental Protection Agency (EPA) in vitro bioavailability methodology was applied to archived BHSS soil and dust samples. Using age-specific biokinetic slope factors, we related bioavailable lead from these sources to children’s blood lead levels (BLLs) monitored during cleanup from 1988 through 2002. Quantitative regression analyses and exposure assessment guidance were used to develop candidate soil/dust source partition scenarios estimating lead intake, allowing estimation of age-specific soil/dust ingestion rates. These ingestion rate and bioavailability estimates were simultaneously applied to the U.S. EPA Integrated Exposure Uptake Biokinetic Model for Lead in Children to determine those combinations best approximating observed BLLs. Results: Absolute soil and house dust bioavailability averaged 33% (SD ± 4%) and 28% (SD ± 6%), respectively. Estimated BHSS age-specific soil/dust ingestion rates are 86–94 mg/day for 6-month- to 2-year-old children and 51–67 mg/day for 2- to 9-year-old children. Conclusions: Soil/dust ingestion rate estimates for 1- to 9-year-old children at the BHSS are lower than those commonly used in human health risk assessment. A substantial component of children’s exposure comes from sources beyond the immediate home environment. Citation: von Lindern I, Spalinger S, Stifelman ML, Stanek LW, Bartrem C. 2016. Estimating children’s soil/dust ingestion

  19. House dust and storage mite contamination of dry dog food stored in open bags and sealed boxes in 10 domestic households.

    PubMed

    Gill, Christina; McEwan, Neil; McGarry, John; Nuttall, Tim

    2011-04-01

    Dry pet food is a potential source of exposure to house dust and storage mite allergens in canine atopic dermatitis. This study evaluated contamination of house dust and dry dog food stored in paper bags, sealable plastic bags and sealable plastic boxes in 10 households for 90 days using Acarex(®) tests for guanine, a Der p 1 ELISA and mite flotation. Acarex(®) tests were negative in all the food samples but positive in all the house dust samples. The Der p 1 levels and mite numbers significantly increased in food from paper bags (P = 0.0073 and P = 0.02, respectively), but not plastic bags or boxes. Mite numbers and Der p 1 levels were 10-1000 times higher in house dust than the corresponding food samples (P < 0.0001). There were significant correlations between Der p 1 in house dust and food from the paper (P < 0.0001) and plastic bags (P = 0.003), and mite numbers in house dust and food from the paper bags (P = 0.0007). Bedding and carpets were significantly associated with Der p 1 levels in house dust (P = 0.015 and P = 0.01, respectively), and food from the paper (both P = 0.02) and plastic bags (P = 0.03 and P = 0.04, respectively). Mites were identified in six of 10 paper bag, three of 10 plastic bag, one of 10 plastic box and nine of 10 house dust samples. These comprised Dermatophagoides (54%), Tyrophagus (10%; all from food) and unidentified mites (36%). Storage of food in sealable plastic boxes largely prevented contamination for 3 months. Exposure to mites and mite proteins in all the stored food, however, appeared to be trivial compared with house dust. PMID:21106038

  20. Mobilization and distribution of lead originating from roof dust and wet deposition in a roof runoff system.

    PubMed

    Yu, Jianghua; Yu, Haixia; Huang, Xiaogu

    2015-12-01

    In this research, the mobilization and distribution of lead originating in roof dust and wet deposition were investigated within a roof dust-rooftop-runoff system. The results indicated that lead from roof dust and wet deposition showed different transport dynamics in runoff system and that this process was significantly influenced by the rainfall intensity. Lead present in the roof dust could be easily washed off into the runoff, and nearly 60 % of the total lead content was present in particulate form. Most of the lead from the roof dust was transported during the late period of rainfall; however, the lead concentration was higher for several minutes at the rainfall beginning. Even though some of the lead from wet deposition, simulated with a standard isotope substance, was adsorbed onto adhered roof dust and/or retained on rooftop in runoff system, most of it (50-82 %) remained as dissolved lead in the runoff for rainfall events of varying intensity. Regarding the distribution of lead in the runoff system, the results indicated that it could be carried in the runoff in dissolved and particulate form, be adsorbed to adhered roof dust, or remain on the rooftop because of adsorption to the roof material. Lead from the different sources showed different distribution patterns that were also related to the rainfall intensity. Higher rainfall intensity resulted in a higher proportion of lead in the runoff and a lower proportion of lead remaining on the rooftop. PMID:26289339

  1. 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...

  2. Origin and patterns of distribution of trace elements in street dust: Unleaded petrol and urban lead

    NASA Astrophysics Data System (ADS)

    Miguel, Eduardo de; Llamas, Juan F.; Chacón, Enrique; Berg, Torunn; Larssen, Steinar; Røyset, Oddvar; Vadset, Marit

    The elemental composition, patterns of distribution and possible sources of street dust are not common to all urban environments, but vary according to the peculiarities of each city. The common features and dissimilarities in the origin and nature of street dust were investigated through a series of studies in two widely different cities, Madrid (Spain) and Oslo (Norway), between 1990 and 1994. The most comprehensive sampling campaign was carried out in the Norwegian capital during the summer of 1994. An area of 14 km 2, covering most of downtown Oslo and some residential districts to the north of the city, was divided into 1 km2 mapping units, and 16 sampling increments of approximately 150 g were collected from streets and roads in each of them. The fraction below 100 μm was acid-digested and analysed by ICP-MS. Statistical analyses of the results suggest that chemical elements in street dust can be classified into three groups: "urban" elements (Ba, Cd, Co, Cu, Mg, Pb, Sb, Ti, Zn), "natural" elements (Al, Ga, La, Mn, Na, Sr, Th, Y) and elements of a mixed origin or which have undergone geochemical changes from their original sources (Ca, Cs, Fe, Mo, Ni, Rb, Sr, U). Soil resuspension and/or mobilisation appears to be the most important source of "natural" elements, while "urban" elements originate primarily from traffic and from the weathering and corrosion of building materials. The data for Pb seem to prove that the gradual shift from leaded to unleaded petrol as fuel for automobiles has resulted in an almost proportional reduction in the concentration of Pb in dust particles under 100 μm. This fact and the spatial distribution of Pb in the city strongly suggest that lead sources other than traffic (i.e. lead accumulated in urban soil over the years) may contribute as much lead, if not more, to urban street dust.

  3. Characterizing the Peroxisome Proliferator-Activated Receptor (PPARγ) Ligand Binding Potential of Several Major Flame Retardants, Their Metabolites, and Chemical Mixtures in House Dust

    PubMed Central

    Fang, Mingliang; Webster, Thomas F.; Ferguson, P. Lee

    2014-01-01

    Background: Accumulating evidence has shown that some environmental contaminants can alter adipogenesis and act as obesogens. Many of these contaminants act via the activation of the peroxisome proliferator-activated receptor γ (PPARγ) nuclear receptor. Objectives: Our goal was to determine the PPARγ ligand binding potency of several major flame retardants, including polybrominated diphenyl ethers (PBDEs), halogenated phenols and bisphenols, and their metabolites. Ligand binding activity of indoor dust and its bioactivated extracts were also investigated. Methods: We used a commercially available fluorescence polarization ligand binding assay to investigate the binding potency of flame retardants and dust extracts to human PPARγ ligand-binding domain. Rosiglitazone was used as a positive control. Results: Most of the tested compounds exhibited dose-dependent binding to PPARγ. Mono(2-ethylhexyl) tetrabromophthalate, halogenated bisphenols and phenols, and hydroxylated PBDEs were found to be potent PPARγ ligands. The most potent compound was 3-OH-BDE-47, with an IC50 (concentration required to reduce effect by 50%) of 0.24 μM. The extent of halogenation and the position of the hydroxyl group strongly affected binding. In the dust samples, 21 of the 24 samples tested showed significant binding potency at a concentration of 3 mg dust equivalent (DEQ)/mL. A 3–16% increase in PPARγ binding potency was observed following bioactivation of the dust using rat hepatic S9 fractions. Conclusion: Our results suggest that several flame retardants are potential PPARγ ligands and that metabolism may lead to increased binding affinity. The PPARγ binding activity of house dust extracts at levels comparable to human exposure warrants further studies into agonistic or antagonistic activities and their potential health effects. Citation: Fang M, Webster TF, Ferguson PL, Stapleton HM. 2015. Characterizing the peroxisome proliferator-activated receptor (PPARγ) ligand binding

  4. CO2 sequestration using accelerated gas-solid carbonation of pre-treated EAF steel-making bag house dust.

    PubMed

    El-Naas, Muftah H; El Gamal, Maisa; Hameedi, Suhaib; Mohamed, Abdel-Mohsen O

    2015-06-01

    Mineral CO2 sequestration is a promising process for the reduction of carbon dioxide emissions to the atmosphere. In this paper, alkaline calcium-rich dust particles collected from bag filters of electric arc furnaces (EAF) for steel making were utilized as a viable raw material for mineral CO2 sequestration. The dust particles were pre-treated through hydration, drying and screening. The pre-treated particles were then subjected to direct gas-solid carbonation reaction in a fluidized-bed reactor. The carbonated products were characterized to determine the overall sequestration capacity and the mineralogical structures. Leaching tests were also performed to measure the extracted minerals from the carbonated dust and evaluate the carbonation process on dust stabilization. The experimental results indicated that CO2 could be sequestered using the pre-treated bag house dust. The maximum sequestration of CO2 was 0.657 kg/kg of dust, based on the total calcium content. The highest degree of carbonation achieved was 42.5% and the carbonation efficiency was 69% at room temperature. PMID:25846002

  5. The effects of a newsletter on bedding control on house dust mite allergen concentrations in childcare centers in Korea

    PubMed Central

    Kim, Jeonghoon; Jeong, Kyoung Yong; Kwon, Ho-Jang; Yang, Heasuk; Yum, Hye Yung; Lee, Seon Ah; Kim, Chae-Bong; Kim, Hyunjung; Lim, Wan Ryung; Hong, Soyoung; Kim, Kyoosang

    2015-01-01

    Objectives Bedding in childcare centers (CCCs) can hold house dust mite (HDM) allergens. This study examined whether HDM allergen levels can be reduced through the distribution of an educational newsletter on bedding control to parents of CCC children in Korea. Methods All 38 CCCs were measured for Der 1 (sum of Der f 1 and Der p 1) concentrations on classroom floors and bedding before the intervention. Educational newsletters on children’s bedding control were sent to 21 CCCs by mail, and teachers were asked to distribute the newsletters to the parents of the children (intervention group). The remaining 17 CCCs were not sent newsletters (control group). The measurement of Der 1 concentrations in 38 CCCs was repeated after the intervention. Dust samples were collected with a vacuum cleaner and analyzed using enzyme-linked immunosorbent assay methods. Results The Der 1 concentrations on the bedding were significantly higher than those on the floors in 38 CCCs at baseline (p<0.05). Although changes of the Der 1 concentrations for the control group (n=17) were not significant, Der 1 concentrations for the intervention group (n=21) decreased significantly from 2077.9 ng/g dust to 963.5 ng/g dust on the floors and from 3683.9 ng/g dust to 610.4 ng/g dust on bedding (p<0.05). Conclusions The distribution of educational newsletters on bedding control to parents may be an effective means of controlling HDMs in CCCs. PMID:26602559

  6. House dust mite Der p 1 downregulates defenses of the lung by inactivating elastase inhibitors.

    PubMed

    Brown, Alan; Farmer, Kinley; MacDonald, Louise; Kalsheker, Noor; Pritchard, Dave; Haslett, Chris; Lamb, Jonathan; Sallenave, J-M

    2003-09-01

    House dust mites (HDM) are the most common source of aeroallergens and in genetic susceptible individuals can cause symptoms ranging from atopic dermatitis to bronchial asthma. Der p 1, a major target of the human immune responses to HDM, through its enzymatic properties can modulate the adaptive immune system by the cleavage of CD23 and CD25. The consequences of this would be to promote allergic inflammatory responses. Furthermore, by disrupting epithelial tight junctions Der p 1 facilitates the transport of allergen across the epithelium. Here, we report that Der p 1 has additional effects on the innate defense mechanisms of the lung, by inactivating in vitro and ex vivo the elastase inhibitors human (h) alpha1-proteinase inhibitor (h-A1-Pi), mouse (m-), (but not human [h])-SLPI and h-elafin. We confirm that Der p 1 contain both cysteine and serine proteinases, and extend this finding to demonstrate for the first time that h-elafin is particularly sensitive to the biological activity of the latter. Because these elastase inhibitors have antimicrobial, as well as antielastase activity, our results suggest that inactivation of these innate components of the lung defense system by Der p 1 may increase the susceptibility of patients with allergic inflammation to infection. PMID:12689923

  7. Inhaled house dust mite induces pulmonary T helper 2 cytokine production

    PubMed Central

    Gregory, L. G.; Causton, B.; Murdoch, J. R.; Mathie, S. A.; O’Donnell, V.; Thomas, C. P.; Priest, F. M.; Quint, D. J.; Lloyd, C. M.

    2012-01-01

    Background Inhaled house dust mite (HDM) results in T-helper (TH) 2 type pathology in unsensitized mice, in conjunction with airway hyperreactivity and airway remodelling. However, the pulmonary cytokine and chemokine profile has not been reported. Methods We have performed a time course analysis of the characteristic molecular mediators and cellular influx in the bronchoalveolar lavage (BAL) and lung in order to define the pulmonary inflammatory response to inhaled HDM extract. Mice were exposed five times a week to soluble HDM extract for 3 weeks. Lung function was measured in groups of mice at intervals following the final HDM challenge. Recruitment of inflammatory cells and inflammatory mediator production was then assessed in BAL and lungs of individual mice. Results We found that Th2 cytokines were significantly increased in BAL and lung after HDM challenge from as early as 2 h post-final challenge. The levels of cytokines and chemokines correlated with the influx of eosinophils and Th2 cells to the different compartments of the lung. However, the production of key cytokines such as IL-4, IL-5 and IL-13 preceded the increase in airways resistance. Conclusion Inhaled HDM challenge induces a classical Th2 inflammatory mediator profile in the BAL and lung. These data are important for studies determining the efficacy of novel treatment strategies for allergic airways disease. PMID:19545261

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

    PubMed Central

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

    2011-01-01

    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

  9. Acaricidal activity of DHEMH, derived from patchouli oil, against house dust mite, Dermatophagoides farinae.

    PubMed

    Wu, Hai-Qiang; Li, Li; Li, Jing; He, Zhen-Dan; Liu, Zhi-Gang; Zeng, Qing-Qian; Wang, Yu-Sheng

    2012-01-01

    This study characterized the acaricidal activity of constituents of patchouli oil extracted from (Pogostemon cablin (Blanco) BENTH) against the house dust mite, Dermatophagoides farinae. A new compound, 2-(1,3-dihydroxy-but-2-enylidene)-6-methyl-3-oxo-heptanoic acid (DHEMH), was isolated from patchouli oil and characterized by (1)H-NMR, (13)C-NMR, LC-MS and elemental analysis (EA). This active component was identified as the hydrolysate of pogostone. Fifteen other constituents found in patchouli oil were also identified by GC-MS, including patchouli alcohol and pogostone. LD(50) studies carried out over 24 h using contact toxicity tests identified DHEMH as the most toxic compound to D. farinae (2.04 μg/cm(2)), followed by patchouli oil (6.11 μg/cm(2)), benzyl benzoate (BP) (9.31 μg/cm(2)) and dibutyl phthalate (DBP) (58.52 μg/cm(2)). In vapor phase toxicity tests, all of these compounds were more effective in closed than open containers, indicating that the most efficient mode of delivery for these compounds is the vapor phase. These results indicate that DHEMH and patchouli oil merit further study as potential agents for the control of D. farinae. PMID:22293476

  10. Induction of vascular remodeling in the lung by chronic house dust mite exposure.

    PubMed

    Rydell-Törmänen, Kristina; Johnson, Jill R; Fattouh, Ramzi; Jordana, Manel; Erjefält, Jonas S

    2008-07-01

    Structural changes to the lung are associated with chronic asthma. In addition to alterations to the airway wall, asthma is associated with vascular modifications, although this aspect of remodeling is poorly understood. We sought to evaluate the character and kinetics of vascular remodeling in response to chronic aeroallergen exposure. Because many ovalbumin-driven models used to investigate allergic airway disease do so in the absence of persistent airway inflammation, we used a protocol of chronic respiratory exposure to house dust mite extract (HDME), which has been shown to induce persistent airway inflammation consistent with that seen in humans with asthma. Mice were exposed to HDME intranasally for 7 or 20 consecutive weeks, and resolution of the inflammatory and remodeling response to allergen was investigated 4 weeks after the end of a 7-week exposure protocol. Measures of vascular remodeling, including total collagen deposition, procollagen I production, endothelial and smooth muscle cell proliferation, smooth muscle area, and presence of myofibroblasts, were investigated histologically in lung vessels of different sizes and locations. We observed an increase in total collagen content, which did not resolve upon cessation of allergen exposure. Other parameters were significantly increased after 7 and/or 20 weeks of allergen exposure but returned to baseline after allergen withdrawal. We conclude that respiratory HDME exposure induces airway remodeling and pulmonary vascular remodeling, and, in accordance with airway remodeling, some components of these structural changes may be irreversible. PMID:18314535

  11. 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

    ... 24 Housing and Urban Development 4 2012-04-01 2012-04-01 false Do lead-based paint poisoning prevention requirements apply to affordable housing activities under NAHASDA? 1000.40 Section 1000.40 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND...

  12. Polycyclic aromatic hydrocarbons in house dust and track-in soil in an eight-home study

    SciTech Connect

    Chuang, J.C.; Callahan, P.J.; Katona, V.; Gordon, S.M.; Lewis, R.G.; Wilson, N.K.

    1994-12-31

    The analytical method to determine polycyclic aromatic hydrocarbons (PAH) in house dust and soil samples was validated. The method consists of sonication with 10 mL of hexane (C6) for two 30-minute extractions, and analysis of the C6 extract by gas chromatography/mass spectrometry (GC/MS). An eight-home pilot field study was conducted in Columbus, Ohio before and after the 1992/1993 heating season to obtain concentration profiles of PAH in house dust and track-in soil, and to determine whether track-in of outdoor soil residues is an important source of PAH in house dust. A total of 19 PAH, ranging from 2-ring naphthalene to 7-ring coronene, was monitored. The sum of the concentrations of all target PAH in the house dust samples evaluated in this study raged from 41 to 580 ppm and from 25 to 310 ppm in the samples collected during october 1992 and April 1993. Higher concentrations were observed in entryway soil samples and the sums of the concentrations of target PAH ranged from 68 to 4,000 ppm and 58 to 5,500 ppm in samples collected before (October 1992) and after (April 1993) the winter heating season, respectively. The sum of the concentrations of PAH in the pathway soil samples varied from 3.0 to 1,200 ppm in samples collected before the heating season. The sum of the concentrations of PAH ranged from 0.58 to 610 ppm and from 0.63 to 63 ppm in pathway soil and foundation soil samples collected after the heating season, respectively.

  13. Exposure assessment of organophosphorus and organobromine flame retardants via indoor dust from elementary schools and domestic houses.

    PubMed

    Mizouchi, Shigekazu; Ichiba, Masayoshi; Takigami, Hidetaka; Kajiwara, Natsuko; Takamuku, Toshiyuki; Miyajima, Toru; Kodama, Hiroki; Someya, Takashi; Ueno, Daisuke

    2015-03-01

    To assess the exposure of flame retardants (FRs) for school-children, organophosphorus flame retardants and plasticizers (PFRs) and organobromine flame retardants (BFRs) were determined in the indoor dust samples collected from elementary schools and domestic houses in Japan in 2009 and 2010. PFRs were detected in all the dust samples analyzed and the highest concentration of total PFRs was thousand-fold higher than that of BFRs. Among the PFRs, tris(butoxyethyl)phosphate (TBOEP) showed the highest concentration with a median (med.) of 270,000 ng g(-1) dry weight (3700-5,500,000 ng g(-1) dry weight), followed by tris(methylphenyl)phosphate (TMPPs)>triphenyl phosphate (TPHP)=tris(1,3-dichloro-2-propyl)phosphate (TDCIPP)=tris(2-chloroisopropyl)phosphate (TCIPP)=tris(2chloroethyl)phosphate (TCEP)>ethylhexyl diphenyl phosphate (EHDPP). Significantly higher concentrations of TBOEP, tri-n-butyl phosphate (TNBP), TPHP, TMPPs, and total-PFRs were found in dust samples from elementary schools than from domestic houses. It might be due to that higher concentrations of TBOEP (as leveling agent) were detected from the floor polisher/wax products collected in those elementary schools. On the other hand, significantly higher concentrations of TCEP, TCIPPs, and total chloroalkyl-PFRs were found in domestic houses than in elementary schools. Exposure assessments of PFRs via indoor dust from elementary schools and domestic houses were conducted by calculating the hazard quotient (HQ). Among PFRs, HQs for TBOEP exceeded 1 (higher than reference dose: RfD) and its highest value was 1.9. To reduce the intake of TBOEP by school-children, it is recommended that the use of floor polisher/wax containing TBOEP be reduced in schools. PMID:25532762

  14. Depression of alveolar macrophage hydrogen peroxide and superoxide anion release by mineral dusts: Correlation with antimony, lead, and arsenic contents

    SciTech Connect

    Gulyas, H.; Labedzka, M.; Gercken, G. )

    1990-04-01

    Activated rabbit alveolar macrophages were incubated with airborne dusts from four West German sites (1 to 200 micrograms/10(6) cells) and waste incinerator fly ash fractions (50 to 500 micrograms/10(6) cells). Quartz dust DQ 12 (5 to 200 micrograms/10(6) cells) and Fe2O3 (0.05 to 50 micrograms/10(6) cells) were used as control dusts. The zymosan-stimulated hydrogen peroxide and superoxide anion release of the macrophages were not affected significantly by Fe2O3. All other investigated dusts decreased the two cell functions which were correlated negatively with surfaces, particle numbers, and antimony, lead, and arsenic contents of the dusts. The influence of heavy metal antagonisms and dust surfaces on dust toxicity against alveolar macrophages is discussed.

  15. Depression of alveolar macrophage hydrogen peroxide and superoxide anion release by mineral dusts: correlation with antimony, lead, and arsenic contents.

    PubMed

    Gulyas, H; Labedzka, M; Gercken, G

    1990-04-01

    Activated rabbit alveolar macrophages were incubated with airborne dusts from four West German sites (1 to 200 micrograms/10(6) cells) and waste incinerator fly ash fractions (50 to 500 micrograms/10(6) cells). Quartz dust DQ 12 (5 to 200 micrograms/10(6) cells) and Fe2O3 (0.05 to 50 micrograms/10(6) cells) were used as control dusts. The zymosan-stimulated hydrogen peroxide and superoxide anion release of the macrophages were not affected significantly by Fe2O3. All other investigated dusts decreased the two cell functions which were correlated negatively with surfaces, particle numbers, and antimony, lead, and arsenic contents of the dusts. The influence of heavy metal antagonisms and dust surfaces on dust toxicity against alveolar macrophages is discussed. PMID:2159400

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

    PubMed Central

    2012-01-01

    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

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

    PubMed

    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

    2014-01-14

    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

  18. Indoor Pollutant Hexabromocyclododecane Has a Modest Immunomodulatory Effect on House Dust Mite Induced Allergic Asthma in Mice.

    PubMed

    Canbaz, Derya; Logiantara, Adrian; Hamers, Timo; van Ree, Ronald; van Rijt, Leonie S

    2016-01-01

    Hexabromocyclododecane (HBCD) has been recognized as an indoor pollutant. HBCD is added as a flame retardant to many consumer products and leaches from the products into house dust. HBCD might be potentially hazardous to the airways because of inhalation of house dust. Sensitization to house dust mite (HDM) is a risk factor for the development of allergic asthma. In this study, we examined whether HBCD can affect the immune response to HDM allergens. Bone-marrow-derived dendritic cells (BMDCs) were exposed simultaneously to HBCD and HDM in vitro. HBCD enhanced oxidative stress in HDM-pulsed BMDCs, which was accompanied by a higher production of Interleukin (IL)-6 and -10. Adoptive transfer of HDM/HBCD-exposed BMDCs into naı̈ve mice resulted in enhanced levels of IL-17A after inhalational challenge with HDM. Direct mucosal exposure to HBCD during HDM inhalation enhanced IL-4 or IL-17A production, depending on the HDM extract used, but did not aggravate the eosinophilic airway inflammation or airway hyper-reactivity. Our results indicate that exposure to HBCD can have a mild immune-modulating effect by enhancing the inflammatory cytokine production in response to inhaled HDM in mice. PMID:26633745

  19. The contribution of housing renovation to children’s blood lead levels: a cohort study

    PubMed Central

    2013-01-01

    Background Routine renovation of older housing is a risk factor for childhood lead poisoning, but the contribution to children’s blood lead levels is poorly defined for children with lower exposure levels. Methods We examined a prospective cohort of 276 children followed from 6 to 24 months of age. We conducted surveys of renovation activities and residential lead hazards and obtained blood lead level (B-Pb) every six months. We analyzed B-Pb in a repeated measures design using a mixed effects linear model. Results Parent reported interior renovation ranged from 11 to 25% of housing units at the four, 6-month periods. In multivariable analysis, children whose housing underwent interior renovation had a 12% higher mean B-Pb by two years of age compared with children whose housing units were not renovated (p < 0.01). The time between renovation and the child blood lead sample was associated with higher B-Pb (p-value for trend <0.01); compared to children in non-renovated housing, children whose housing units underwent renovation in the prior month had a 17% higher mean B-Pb at two years of age, whereas children whose housing renovation occurred in the prior 2–6 months had an 8% higher mean B-Pb. We also found an association between higher paint lead loading, measured using an X-ray fluorescence (XRF) based paint lead index, and child B-Pb (p = 0.02); for every 10 mg/cm2 increase in paint lead loading index there was a 7.5% higher mean childhood B-Pb. Conclusions In an analysis of data collected before the recent changes to Environmental Protection Agency’s Lead, Renovation, Repair and Painting Rule, routine interior housing renovation was associated with a modest increase in children’s B-Pb. These results are important for the provision of clinical advice, for housing and public health professionals, and for policymakers. PMID:23981571

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

    SciTech Connect

    Sterling, D.A.; Roegner, K.C.; Lewis, R.D.; Luke, D.A. . Div. of Environmental and Occupational Health); Wilder, L.C. . Div. of Health Assessment and Consultation); Burchette, S.M. )

    1999-08-01

    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.

  1. Comparison of Living and Bedrooms in Terms of House Dust Mites in the Province of Erzincan, Turkey.

    PubMed

    Zeytun, Erhan; Doğan, Salih; Özçiçek, Fatih; Ünver, Edhem; Dilkaraoğlu, Sibel

    2016-01-01

    The most important factors in development of symptoms such as allergic asthma, rhinitis, conjunctivitis, and dermatitis in atopic persons are the allergens of house dust mites. The objective of this study was to compare living rooms and bedrooms, and woolen and spring mattresses in terms of the number and species of mites in houses in the province of Erzincan, Turkey. In total, 74 dust samples were collected from living rooms and bedrooms of 37 randomly selected houses from various districts of the city. All examined houses were positive for house dust mites. In total, 5,210 mites were isolated, 1,058 from the living rooms and 4,152 from the bedrooms, and the differences were statistically significant (P < 0.05). Of 4,152 mites detected in bedrooms, 1,330 (32%) were isolated from 31 spring mattresses and 2,822 (68%) from 6 woolen mattresses (P < 0.001). The study identified 14 families, 17 genera, and 16 species belonging to Astigmata, Prostigmata, and Oribatida. Of these, Dermatophagoides pteronyssinus (Trouessart) was the dominant species: living rooms, 63.3%; bedrooms, 74.4%; woolen mattresses, 84.6%; and spring mattresses, 52.8%. This was followed by Lepidoglyphus destructor (Schrank) (9.8%), Dermatophagoides farinae Hughes (5.1%), Tyrophagus putrescentiae (Schrank) (4.3%), and Acarus siro L. (2.5%) in living rooms; L. destructor (11.2%), Euroglyphus maynei (Cooreman) (4.2%), D. farinae (3.8%), and T. putrescentiae (1.0%) in bedrooms; L. destructor (11.8%), D. farinae (2.1%), E. maynei (0.3%), and T. putrescentiae (0.2%) in woolen mattresses; and E. maynei (12.5%), L. destructor (9.9%), D. farinae (7.5%), and T. putrescentiae (2.7%) in spring mattresses. PMID:26586534

  2. 40 CFR 745.227 - Work practice standards for conducting lead-based paint activities: target housing and child...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... lead-based paint activities: target housing and child-occupied facilities. 745.227 Section 745.227... practice standards for conducting lead-based paint activities: target housing and child-occupied facilities... section are found in the following: The U.S. Department of Housing and Urban Development (HUD)...

  3. 40 CFR 745.227 - Work practice standards for conducting lead-based paint activities: target housing and child...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... lead-based paint activities: target housing and child-occupied facilities. 745.227 Section 745.227... practice standards for conducting lead-based paint activities: target housing and child-occupied facilities... section are found in the following: The U.S. Department of Housing and Urban Development (HUD)...

  4. 40 CFR 745.227 - Work practice standards for conducting lead-based paint activities: target housing and child...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... lead-based paint activities: target housing and child-occupied facilities. 745.227 Section 745.227... practice standards for conducting lead-based paint activities: target housing and child-occupied facilities... section are found in the following: The U.S. Department of Housing and Urban Development (HUD)...

  5. 40 CFR 745.227 - Work practice standards for conducting lead-based paint activities: target housing and child...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... lead-based paint activities: target housing and child-occupied facilities. 745.227 Section 745.227... practice standards for conducting lead-based paint activities: target housing and child-occupied facilities... section are found in the following: The U.S. Department of Housing and Urban Development (HUD)...

  6. Effectiveness of vacuum cleaning and wet cleaning in reducing house-dust mites, fungi and mite allergen in a cotton carpet: a case study.

    PubMed

    Wassenaar, D P

    1988-02-01

    In order to evaluate the effect of continuous, thorough vacuuming on house dust organisms and mite allergen, a cotton carpet was vacuumed every other day, six times in total. Seven weeks later, the carpet was cleaned by means of spray extraction. Samples were taken before and after this wet cleaning. In total 1150 g of dust was collected, containing approximately 174,000 arthropods (dead and alive) and 9000 X 10(6) fungal spores. In the course of the experiment, the amount of dust collected at each vacuuming decreased. The number of extracted house dust mites did not decrease significantly, but that of the predator mite Cheyletus did. The number of extracted fungal spores showed a significant decrease (from 142 to 16 X 10(6) spores/m2 per minute vacuuming), as did the extracted mite allergen per m2. After 7 weeks the number of mite eggs and complete house dust mites had increased enormously. After cleaning by spray extraction another increase in the number of complete mites and mite eggs was found, while the amount of mite allergen was diminished. The population growth of the house dust mite between the 6th and the 7th vacuuming is probably due to the decrease of their most important predator, Cheyletus. After the wet cleaning a number of extra eggs hatched, probably due to the high humidity in the carpet. The procedures used in this study to combat house dust mites may have an adverse effect in the long run. PMID:3378462

  7. Using paired soil and house dust samples in an in vitro assay to assess the post ingestion bioaccessibility of sorbed fipronil.

    PubMed

    Starr, James M; Li, Weiwei; Graham, Stephen E; Bradham, Karen D; Stout Ii, Daniel M; Williams, Alan; Sylva, Jason

    2016-07-15

    For children, ingestion of soils and house dusts can be an important exposure pathway for regulated organic compounds. Following ingestion, the extent to which compounds desorb and become bioaccessible is a critical determinant of systemic adsorption. We characterized the physicochemical properties of 37 soil and house dust pairs collected during a national survey of United States homes. For each sample, we measured the bioaccessibility of fipronil, a phenylpyrazole insecticide using an in vitro, three- compartment digestive system, then modeled the physicochemical predictors of fipronil bioaccessibility. The properties of the soils and dusts were not correlated and percent carbon was the only significant predictor of bioaccessibility for both soils (p<0.001) and dusts (p<0.001). The carbon content of the soils (3.1±2.4%) was lower than that of the dusts (18.6±6.9%) Due to the lower carbon content, soil sorbed fipronil was more bioaccessible than dust sorbed fipronil. However, the slope of the bioaccessibility carbon regression line was steeper for the soils than for the house dusts. This suggested that, for soils having carbon percentages greater than those in this study, fipronil bioaccessibility may be less than that of house dusts having equal carbon content. PMID:27017400

  8. NHEXAS PHASE I MARYLAND STUDY--STANDARD OPERATING PROCEDURE FOR EXTRACTION OF NEUTRAL PESTICIDES AND PAHS FROM HOUSE DUST AND SOIL (L11)

    EPA Science Inventory

    The purpose of this SOP is to describe the procedures to be used for the extraction of pesticides and polynuclear aromatic hydrocarbons (PAHs) from house dust and soil. This procedure also describes the splitting of dust and soil samples for metal extractions for shipment to Emo...

  9. Hexavalent chromium in house dust — A comparison between an area with historic contamination from chromate production and background locations

    PubMed Central

    Stern, Alan H.; Yu, Chang Ho; Black, Kathleen; Lin, Lin; Lioy, Paul J.; Gochfeld, Michael; Fan, Zhi-Hua (Tina)

    2014-01-01

    In contrast to Cr+ 3, Cr+ 6 is carcinogenic and allergenic. Although Cr+ 6 can occur naturally, it is thought that most soil Cr+ 6 is anthropogenic, however, the extent of Cr+ 6 in the background environment is unknown. Cr+ 6-containing chromite ore processing residue (COPR) from chromate manufacture was deposited in numerous locations in Jersey City (JC), New Jersey. In the 1990’s, significantly elevated concentrations of total Cr (Cr+ 6+Cr+ 3) were found in house dust near COPR sites. We undertook a follow-up study to determine ongoing COPR exposure. We compared Cr+6 in house dust in JC to selected background communities with no known sources of Cr+ 6. Samples were collected from living areas, basements and window wells. Cr+6 was detected in dust from all JC and background houses. In the JC homes, the mean (±SD) Cr+ 6 concentration for all samples was 3.9±7.0 μg/g (range: non-detect–90.4 μg/g), and the mean Cr+ 6 loading was 5.8±15.7 μg/m2 (range: non-detect–196.4 μg/m2). In background homes, the mean Cr+ 6 concentrations of all samples was 4.6±7.8 μ μg/g, (range, 0.05–56.6 μg/g). The mean loading was 10.0±27.9 μg/m2 (range, 0.22–169.3 μg/m2). There was no significant difference between Cr+ 6 dust concentrations in Jersey City and background locations. Stratification by sample location within houses and sampling method gave similar results. Samples exceeding 20 μg/g were obtained only from single wood surfaces in different homes. Lower concentrations in window well samples suggests transport from outside is not the major source of indoor Cr+ 6. Landscaping and groundcover may influence indoor Cr+6. There appears to be a widespread low level background of Cr+ 6 that is not elevated in Jersey City homes despite its historic COPR contamination. It is possible that house dust, in general, is a source of Cr+ 6 exposure with potential implications for persistence of chromium allergic contact dermatitis. PMID:20692023

  10. 40 CFR 745.226 - Certification of individuals and firms engaged in lead-based paint activities: target housing and...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Lead-Based Paint Activities § 745.226 Certification of individuals and firms engaged in lead-based paint activities: target housing... engaged in lead-based paint activities: target housing and child-occupied facilities. 745.226 Section...

  11. 40 CFR 745.226 - Certification of individuals and firms engaged in lead-based paint activities: target housing and...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Lead-Based Paint Activities § 745.226 Certification of individuals and firms engaged in lead-based paint activities: target housing... engaged in lead-based paint activities: target housing and child-occupied facilities. 745.226 Section...

  12. 40 CFR 745.226 - Certification of individuals and firms engaged in lead-based paint activities: target housing and...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Lead-Based Paint Activities § 745.226 Certification of individuals and firms engaged in lead-based paint activities: target housing... engaged in lead-based paint activities: target housing and child-occupied facilities. 745.226 Section...

  13. 40 CFR 745.226 - Certification of individuals and firms engaged in lead-based paint activities: target housing and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Lead-Based Paint Activities § 745.226 Certification of individuals and firms engaged in lead-based paint activities: target housing... engaged in lead-based paint activities: target housing and child-occupied facilities. 745.226 Section...

  14. Acetaminophen Attenuates House Dust Mite-Induced Allergic Airway Disease in Mice.

    PubMed

    Smith, Gregory J; Thrall, Roger S; Cloutier, Michelle M; Manautou, Jose E; Morris, John B

    2016-09-01

    Epidemiologic evidence suggests that N-acetyl-para-aminophenol (APAP) may play a role in the pathogenesis of asthma, likely through pro-oxidant mechanisms. However, no studies have investigated the direct effects of APAP on the development of allergic inflammation. To determine the likelihood of a causal relationship between APAP and asthma pathogenesis, we explored the effects of APAP on inflammatory responses in a murine house dust mite (HDM) model of allergic airway disease. We hypothesized that APAP would enhance the development of HDM-induced allergic inflammation. The HDM model consisted of once daily intranasal instillations for up to 2 weeks with APAP or vehicle administration 1 hour prior to HDM during either week 1 or 2. Primary assessment of inflammation included bronchoalveolar lavage (BAL), cytokine expression in lung tissue, and histopathology. Contrary to our hypothesis, the effects of HDM treatment were substantially diminished in APAP-treated groups compared with controls. APAP-treated groups had markedly reduced airway inflammation: including decreased inflammatory cells in the BAL fluid, lower cytokine expression in lung tissue, and less perivascular and peribronchiolar immune cell infiltration. The anti-inflammatory effect of APAP was not abrogated by an inhibitor of cytochrome P450 (P450) metabolism, suggesting that the effect was due to the parent compound or a non-P450 generated metabolite. Taken together, our studies do not support the biologic plausibility of the APAP hypothesis that APAP use may contribute to the causation of asthma. Importantly, we suggest the mechanism by which APAP modulates airway inflammation may provide novel therapeutic targets for asthma. PMID:27402277

  15. Effects of astragaloside IV on eosinophil activation induced by house dust mite allergen.

    PubMed

    Gu, Xiaoyan; Jiang, Desheng; Wang, Yuwei; Du, Qiang; Cai, Jiankang

    2012-07-01

    Astragaloside IV (AS-IV) has been noted for its reduction of eosinophilic airway inflammation in a murine model of chronic asthma. To gain a better understanding of the mechanisms involved in this anti-inflammatory phenomenon, the effect of AS-IV on human blood eosinophils was studied in vitro. Eosinophils were isolated from the blood of patients with mild atopic asthma, preincubated with AS-IV for 1 h and stimulated in the presence or absence of the house dust mite allergen Dermatophagoides pteronyssinus (Der p) 1 for 4 h. The survival of the eosinophils at 48 h was investigated using trypan blue and the surface expression of CC chemokine receptor 3 (CCR3) and intercellular adhesion molecule-1 (ICAM-1) by the eosinophils was analyzed using flow cytometry. The secretion of cytokines in the supernatants and the chemotaxis of the eosinophils were measured by ELISA and the transwell system, respectively. Der p 1 was found to prolong the survival of the eosinophils. Similarly, the expression of CCR3 and ICAM-1, secretion of interleukin (IL)-1β, IL-5, tumor necrosis factor (TNF)-α and the granulocyte macrophage colony stimulating factor (GM-CSF) and transmigration of the eosinophils were increased in the presence of Der p 1. However, these inductive effects on the eosinophils were significantly inhibited by AS-IV (50 µg/ml). These findings suggest that AS-IV modulates eosinophil activation and trafficking in response to Der p 1 and may therefore be a useful therapeutic option in eosinophilic asthma. PMID:22505212

  16. Immunoglobulin E to allergen components of house dust mite in Korean children with allergic disease

    PubMed Central

    Kim, Hwan Soo; Kang, Sung Hee; Won, Sulmui; Lee, Eu Kyoung; Chun, Yoon Hong; Kim, Hyun Hee; Kim, Jin Tack

    2015-01-01

    Background House dust mites (HDMs) are important sources of indoor allergens. Seventeen components have been identified from Dermatophagoides pteronyssinus (Der p). Objective Our aim was to define the prevalence of specific IgE to components of Der p in Korea and investigate the clinical features of them in children with allergic disease. Methods We performed a prospective evaluation of 80 HDM sensitized patients with history of allergic rhinitis (AR), atopic dermatitis (AD), asthma and urticaria (UC). Patients underwent ImmunoCAP for total IgE, Der p, Der f, Der p 1, Der p 2, and Der p 10. Results Seventy-nine patients had detectable serum IgE to Der p, 80 patients were sensitized to Der f, 66 patients were sensitized to Der p 1, 63 patients to Der p 2, and 7 patients were sensitized to Der p 10. Der p 1 specific IgE was significantly lower in the UC group compared with the AD and AR group. Total IgE was significantly higher in the Der p 10 sensitized group. Der p 10 serum IgE level was highly correlated with crab and shrimp specific IgE. There was a significant positive correlation between total IgE and specific IgE to Der p and its components and Der f. Conclusion Sensitization to HDM and its components in Korea is similar to previous studies from temperate climate. The determination of Der p 1, Der p 2, and Der p 10 specific IgE helps in obtaining additional information in regards to allergic disease. PMID:26240792

  17. Primary nasal epithelium exposed to house dust mite extract shows activated expression in allergic individuals.

    PubMed

    Vroling, Aram B; Jonker, Martijs J; Luiten, Silvia; Breit, Timo M; Fokkens, Wytske J; van Drunen, Cornelis M

    2008-03-01

    Nasal epithelial cells form the outermost protective layer against environmental factors. However, this defense is not just physical; it has been shown that epithelial cells respond by the production of inflammatory mediators that may affect local immune responses. In this research we set out to characterize potential differences between the responses of nasal epithelium from healthy and allergic individuals to house dust mite (HDM) allergen. These differences will help us to define local mechanisms that could contribute to allergic disease expression. Epithelial cells were cultured from nasal biopsies taken from five healthy and five allergic individuals. These cultures were exposed for 24 hours to culture medium containing HDM allergen, or to culture medium alone. Isolated RNA was used for microarray analysis. Gene-ontology of the response in healthy epithelium revealed mainly up-regulation of chemokines, growth factors, and structural proteins. Moreover, we saw increased expression of two transcription factors (NF-kappaB and AP-1) and their regulatory members. The expression pattern of epithelium from allergic individuals in the absence of the HDM stimulus suggests that it is already in an activated state. Most striking is that, while the already activated NF-kappaB regulatory pathway remained unchanged in allergic epithelium, the AP-1 pathway is down-regulated upon exposure to HDM allergen; this is contrary to what we see in healthy epithelium. Clear differences in the expression pattern exist between epithelial cells isolated from healthy and allergic individuals at baseline and between their responses to allergen exposure; these differences may contribute to the inflammatory response. PMID:17901406

  18. Neonatal Exposure to Pneumococcal Phosphorylcholine Modulates the Development of House Dust Mite Allergy during Adult Life

    PubMed Central

    Patel, Preeyam S.

    2015-01-01

    Currently, ∼20% of the global population suffers from an allergic disorder. Allergies and asthma occur at higher rates in developed and industrialized countries. It is clear that many human atopic diseases are initiated neonatally and herald more severe IgE-mediated disorders, including allergic asthma, which is driven by the priming of Th2 effector T cells. The hygiene hypothesis attempts to link the increased excessively sanitary conditions early in life to a default Th2 response and increasing allergic phenomena. Despite the substantial involvement of IgE Abs in such conditions, little attention has been paid to the effects of early microbial exposure on the B cell repertoire prior to the initiation of these diseases. In this study, we use Ab-binding assays to demonstrate that Streptococcus pneumoniae and house dust mite (HDM) bear similar phosphorylcholine (PC) epitopes. Neonatal C57BL/6 mice immunized with a PC-bearing pneumococcal vaccine expressed increased frequencies of PC-specific B cells in the lungs following sensitizing exposure to HDM as adults. Anti-PC IgM Abs in the lung decreased the interaction of HDM with pulmonary APCs and were affiliated with lowered allergy-associated cell infiltration into the lung, IgE production, development of airway hyperresponsiveness, and Th2 T cell priming. Thus, exposure of neonatal mice to PC-bearing pneumococci significantly reduced the development of HDM-induced allergic disease during adult life. Our findings demonstrate that B cells generated against conserved epitopes expressed by bacteria, encountered early in life, are also protective against the development of allergic disease during adult life. PMID:25957171

  19. Neonatal exposure to pneumococcal phosphorylcholine modulates the development of house dust mite allergy during adult life.

    PubMed

    Patel, Preeyam S; Kearney, John F

    2015-06-15

    Currently, ∼20% of the global population suffers from an allergic disorder. Allergies and asthma occur at higher rates in developed and industrialized countries. It is clear that many human atopic diseases are initiated neonatally and herald more severe IgE-mediated disorders, including allergic asthma, which is driven by the priming of Th2 effector T cells. The hygiene hypothesis attempts to link the increased excessively sanitary conditions early in life to a default Th2 response and increasing allergic phenomena. Despite the substantial involvement of IgE Abs in such conditions, little attention has been paid to the effects of early microbial exposure on the B cell repertoire prior to the initiation of these diseases. In this study, we use Ab-binding assays to demonstrate that Streptococcus pneumoniae and house dust mite (HDM) bear similar phosphorylcholine (PC) epitopes. Neonatal C57BL/6 mice immunized with a PC-bearing pneumococcal vaccine expressed increased frequencies of PC-specific B cells in the lungs following sensitizing exposure to HDM as adults. Anti-PC IgM Abs in the lung decreased the interaction of HDM with pulmonary APCs and were affiliated with lowered allergy-associated cell infiltration into the lung, IgE production, development of airway hyperresponsiveness, and Th2 T cell priming. Thus, exposure of neonatal mice to PC-bearing pneumococci significantly reduced the development of HDM-induced allergic disease during adult life. Our findings demonstrate that B cells generated against conserved epitopes expressed by bacteria, encountered early in life, are also protective against the development of allergic disease during adult life. PMID:25957171

  20. Pim1 kinase activity preserves airway epithelial integrity upon house dust mite exposure.

    PubMed

    de Vries, M; Hesse, L; Jonker, M R; van den Berge, M; van Oosterhout, A J M; Heijink, I H; Nawijn, M C

    2015-12-01

    Most patients with allergic asthma are sensitized to house dust mite (HDM). The allergenicity of HDM largely depends on disruption of the integrity and proinflammatory activation of the airway epithelium. In this study, we hypothesized that Pim1 kinase activity attenuates HDM-induced asthma by preserving airway epithelial integrity. The effects of Pim1 kinase activity on barrier function and release of the proinflammatory mediators IL-1α and CCL20 were studied in vitro in 16HBE and primary bronchial epithelial cells (PBECs). Pim1-proficient and -deficient mice were exposed to a HDM-driven model of allergic asthma, and airway hyperresponsiveness (AHR) was measured upon methacholine challenge. Airway inflammation and proinflammatory mediators in lung tissue and BAL fluid were determined. We observed that inhibition of Pim1 kinase prolongs the HDM-induced loss of barrier function in 16HBE cells and sensitizes PBECs to HDM-induced barrier dysfunction. Additionally, inhibition of Pim1 kinase increased the HDM-induced proinflammatory activity of 16HBE cells as measured by IL-1α secretion. In line herewith, HDM exposure induced an enhanced production of the proinflammatory chemokines CCL17 and CCL20 in Pim1-deficient mice compared with wild-type controls. While we observed a marked increase in eosinophilic and neutrophilic granulocytes as well as mucus cell metaplasia and AHR to methacholine in mice exposed to HDM, these parameters were independent of Pim1 kinase activity. In contrast, levels of the Th2-cytokines IL-5 and IL-10 were significantly augmented in HDM-treated Pim1-deficient mice. Taken together, our study shows that Pim1 kinase activity maintains airway epithelial integrity and protects against HDM-induced proinflammatory activation of the airway epithelium. PMID:26453516

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

    PubMed

    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

    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 FcεR1. 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

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

    PubMed Central

    El-Sayed, Shereen; Abdul-Rahman, Nahla

    2014-01-01

    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. PMID:25276487

  3. Intranasal exposure of mice to house dust mite elicits allergic airway inflammation via a GM-CSF-mediated mechanism.

    PubMed

    Cates, Elizabeth C; Fattouh, Ramzi; Wattie, Jennifer; Inman, Mark D; Goncharova, Susanna; Coyle, Anthony J; Gutierrez-Ramos, José-Carlos; Jordana, Manel

    2004-11-15

    It is now well established that passive exposure to inhaled OVA leads to a state of immunological tolerance. Therefore, to elicit allergic sensitization, researchers have been compelled to devise alternative strategies, such as the systemic delivery of OVA in the context of powerful adjuvants, which are alien to the way humans are exposed and sensitized to allergens. The objectives of these studies were to investigate immune-inflammatory responses to intranasal delivery of a purified house dust mite (HDM) extract and to evaluate the role of GM-CSF in this process. HDM was delivered to BALB/c mice daily for 10 days. After the last exposure, mice were killed, bronchoalveolar lavage was performed, and samples were obtained. Expression/production of Th2-associated molecules in the lymph nodes, lung, and spleen were evaluated by real-time quantitative PCR and ELISA, respectively. Using this exposure protocol, exposure to HDM alone generated Th2 sensitization based on the expression/production of Th2 effector molecules and airway eosinophilic inflammation. Flow cytometric analysis demonstrated expansion and activation of APCs in the lung and an influx of activated Th2 effector cells. Moreover, this inflammation was accompanied by airways hyper-responsiveness and a robust memory-driven immune response. Finally, administration of anti-GM-CSF-neutralizing Abs markedly reduced immune-inflammatory responses in both lung and spleen. Thus, intranasal delivery of HDM results in Th2 sensitization and airway eosinophilic inflammation that appear to be mediated, at least in part, by endogenous GM-CSF production. PMID:15528378

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

    PubMed

    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

    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

  5. 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

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Do lead-based paint poisoning... AMERICAN HOUSING ACTIVITIES General § 1000.40 Do lead-based paint poisoning prevention requirements apply..., subparts A, B, H, J, K, M and R of this title, which implement the Lead-Based Paint Poisoning...

  6. 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

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false Do lead-based paint poisoning... AMERICAN HOUSING ACTIVITIES General § 1000.40 Do lead-based paint poisoning prevention requirements apply..., subparts A, B, H, J, K, M and R of this title, which implement the Lead-Based Paint Poisoning...

  7. 24 CFR 1000.40 - Do lead-based paint poisoning prevention requirements apply to affordable housing activities...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 4 2014-04-01 2014-04-01 false Do lead-based paint poisoning... AMERICAN HOUSING ACTIVITIES General § 1000.40 Do lead-based paint poisoning prevention requirements apply..., subparts A, B, H, J, K, M and R of this title, which implement the Lead-Based Paint Poisoning...

  8. 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

    ... 24 Housing and Urban Development 4 2013-04-01 2013-04-01 false Do lead-based paint poisoning... AMERICAN HOUSING ACTIVITIES General § 1000.40 Do lead-based paint poisoning prevention requirements apply..., subparts A, B, H, J, K, M and R of this title, which implement the Lead-Based Paint Poisoning...

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

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

    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

  10. Isotopically constrained lead sources in fugitive dust from unsurfaced roads in the southeast Missouri mining district

    USGS Publications Warehouse

    Witt, Emitt C.; Pribil, Michael; Hogan, John P; Wronkiewicz, David

    2016-01-01

    The isotopic composition of lead (Pb) in fugitive dust suspended by a vehicle from 13 unsurfaced roads in Missouri was measured to identify the source of Pb within an established long-term mining area. A three end-member model using 207Pb/206Pb and concentration as tracers resulted in fugitive dust samples plotting in the mixing field of well characterized heterogeneous end members. End members selected for this investigation include the 207Pb/206Pb for 1) a Pb-mixture representing mine tailings, 2) aerosol Pb-impacted soils within close proximity to the Buick secondary recycling smelter, and 3) an average of soils, rock cores and drill cuttings representing the background conditions. Aqua regia total concentrations and 207Pb/206Pb of mining area dust suggest that 35.4–84.3% of the source Pb in dust is associated with the mine tailings mixture, 9.1–52.7% is associated with the smelter mixture, and 0–21.6% is associated with background materials. Isotope ratios varied minimally within the operational phases of sequential extraction suggesting that mixing of all three Pb mixtures occurs throughout. Labile forms of Pb were attributed to all three end members. The extractable carbonate phase had as much as 96.6% of the total concentration associated with mine tailings, 51.8% associated with smelter deposition, and 34.2% with background. The next most labile geochemical phase (Fe + Mn Oxides) showed similar results with as much as 85.3% associated with mine tailings, 56.8% associated with smelter deposition, and 4.2% associated with the background soil.

  11. Biosignature for airway inflammation in a house dust mite-challenged murine model of allergic asthma.

    PubMed

    Piyadasa, Hadeesha; Altieri, Anthony; Basu, Sujata; Schwartz, Jacquie; Halayko, Andrew J; Mookherjee, Neeloffer

    2016-01-01

    House dust mite (HDM) challenge is commonly used in murine models of allergic asthma for preclinical pathophysiological studies. However, few studies define objective readouts or biomarkers in this model. In this study we characterized immune responses and defined molecular markers that are specifically altered after HDM challenge. In this murine model, we used repeated HDM challenge for two weeks which induced hallmarks of allergic asthma seen in humans, including airway hyper-responsiveness (AHR) and elevated levels of circulating total and HDM-specific IgE and IgG1. Kinetic studies showed that at least 24 h after last HDM challenge results in significant AHR along with eosinophil infiltration in the lungs. Histologic assessment of lung revealed increased epithelial thickness and goblet cell hyperplasia, in the absence of airway wall collagen deposition, suggesting ongoing tissue repair concomitant with acute allergic lung inflammation. Thus, this model may be suitable to delineate airway inflammation processes that precede airway remodeling and development of fixed airway obstruction. We observed that a panel of cytokines e.g. IFN-γ, IL-1β, IL-4, IL-5, IL-6, KC, TNF-α, IL-13, IL-33, MDC and TARC were elevated in lung tissue and bronchoalveolar fluid, indicating local lung inflammation. However, levels of these cytokines remained unchanged in serum, reflecting lack of systemic inflammation in this model. Based on these findings, we further monitored the expression of 84 selected genes in lung tissues by quantitative real-time PCR array, and identified 31 mRNAs that were significantly up-regulated in lung tissue from HDM-challenged mice. These included genes associated with human asthma (e.g. clca3, ear11, il-13, il-13ra2, il-10, il-21, arg1 and chia1) and leukocyte recruitment in the lungs (e.g. ccl11, ccl12 and ccl24). This study describes a biosignature to enable broad and systematic interrogation of molecular mechanisms and intervention strategies for

  12. Environmental arsenic, cadmium and lead dust emissions from metal mine operations: Implications for environmental management, monitoring and human health

    SciTech Connect

    Taylor, Mark Patrick Mould, Simon Anthony; Kristensen, Louise Jane; Rouillon, Marek

    2014-11-15

    Although blood lead values in children are predominantly falling globally, there are locations where lead exposure remains a persistent problem. One such location is Broken Hill, Australia, where the percentage of blood lead values >10 μg/dL in children aged 1–4 years has risen from 12.6% (2010), to 13% (2011) to 21% (2012). The purpose of this study was to determine the extent of metal contamination in places accessible to children. This study examines contemporary exposure risks from arsenic, cadmium, lead, silver and zinc in surface soil and dust, and in pre- and post-play hand wipes at six playgrounds across Broken Hill over a 5-day period in September 2013. Soil lead (mean 2,450 mg/kg) and zinc (mean 3,710 mg/kg) were the most elevated metals in playgrounds. Surface dust lead concentrations were consistently elevated (mean 27,500 μg/m{sup 2}) with the highest lead in surface dust (59,900 μg/m{sup 2}) and post-play hand wipes (60,900 μg/m{sup 2}) recorded close to existing mining operations. Surface and post-play hand wipe dust values exceeded national guidelines for lead and international benchmarks for arsenic, cadmium and lead. Lead isotopic compositions ({sup 206}Pb/{sup 207}Pb, {sup 208}Pb/{sup 207}Pb) of surface dust wipes from the playgrounds revealed the source of lead contamination to be indistinct from the local Broken Hill ore body. The data suggest frequent, cumulative and ongoing mine-derived dust metal contamination poses a serious risk of harm to children. - Highlights: 1.Playground soils and surface dust in a mining town have high metal concentrations. 2.Elevated levels of As, Cd, Pb and Zn dust are found on playground users′ hands. 3.Pb isotope analysis shows that the source of playground dust is ore body Pb. 4.Surface mine operations must be contained to reduce childhood lead exposure risks. 5.Mine environmental licences need to set trigger values for As, Cd, Pb and Zn dust.

  13. Supercritical fluid extraction of polybrominated diphenyl ethers (PBDEs) from house dust with supercritical 1,1,1,2-tetrafluoroethane (R134a).

    PubMed

    Calvosa, Frank C; Lagalante, Anthony F

    2010-01-15

    The extraction of polybrominated diphenyl ethers (PBDEs) from SRM 2585 (Organic Contaminants in House Dust) was investigated using supercritical fluid R134a as an extraction solvent. Three methods of dust extraction were studied: (1) extraction of dry dust, (2) extraction of dry dust dispersed on Ottawa sand and (3) extraction of dust wet with dichloromethane. For each of the three sample preparation methods, extracts at three temperatures (110, 150, and 200 degrees C) above the critical temperature of R134a were performed. Eight PBDE congeners (BDE-28, -47, -99, 100, -153, -154, -183, and -209) in the SFE extracts were analyzed by liquid chromatography negative-ion atmospheric pressure photoionization tandem mass spectrometry (LC/NI-APPI/MS/MS). The optimum extraction of PBDEs from house dust using supercritical R134a is obtained when the dust is pre-wet with dichloromethane prior to extraction to swell the dust. For all sample preparation methods, higher temperatures afforded higher percent recoveries of the eight PBDE congeners. Only a combination of high-temperature (200 degrees C) and pre-wetting the dust with dichloromethane produced high recovery of the environmentally important, fully brominated PBDE congener, BDE-209. PMID:20006061

  14. Spatiotemporal analysis and human exposure assessment on polycyclic aromatic hydrocarbons in indoor air, settled house dust, and diet: A review.

    PubMed

    Ma, Yuning; Harrad, Stuart

    2015-11-01

    This review summarizes the published literature on the presence of polycyclic aromatic hydrocarbons (PAH) in indoor air, settled house dust, and food, and highlights geographical and temporal trends in indoor PAH contamination. In both indoor air and dust, ΣPAH concentrations in North America have decreased over the past 30 years with a halving time of 6.7±1.9years in indoor air and 5.0±2.3 years in indoor dust. In contrast, indoor PAH concentrations in Asia have remained steady. Concentrations of ΣPAH in indoor air are significantly (p<0.01) higher in Asia than North America. In studies recording both vapor and particulate phases, the global average concentration in indoor air of ΣPAH excluding naphthalene is between 7 and 14,300 ng/m(3). Over a similar period, the average ΣPAH concentration in house dust ranges between 127 to 115,817ng/g. Indoor/outdoor ratios of atmospheric concentrations of ΣPAH have declined globally with a half-life of 6.3±2.3 years. While indoor/outdoor ratios for benzo[a]pyrene toxicity equivalents (BaPeq) declined in North America with a half-life of 12.2±3.2 years, no significant decline was observed when data from all regions were considered. Comparison of the global database, revealed that I/O ratios for ΣPAH (average=4.3±1.3), exceeded significantly those of BaPeq (average=1.7±0.4) in the same samples. The significant decline in global I/O ratios suggests that indoor sources of PAH have been controlled more effectively than outdoor sources. Moreover, the significantly higher I/O ratios for ΣPAH compared to BaPeq, imply that indoor sources of PAH emit proportionally more of the less carcinogenic PAH than outdoor sources. Dietary exposure to PAH ranges from 137 to 55,000 ng/day. Definitive spatiotemporal trends in dietary exposure were precluded due to relatively small number of relevant studies. However, although reported in only one study, PAH concentrations in Chinese diets exceeded those in diet from other parts of the

  15. Metals and metalloids in atmospheric dust: Use of lead isotopic analysis for source apportionment

    NASA Astrophysics Data System (ADS)

    Felix Villar, Omar I.

    Mining activities generate aerosol in a wide range of sizes. Smelting activities produce mainly fine particles (<1 microm). On the other hand, milling, crushing and refining processes, as well tailings management, are significant sources of coarse particles (> 1 microm). The adverse effects of aerosols on human health depend mainly on two key characteristics: size and chemical composition. One of the main objectives of this research is to analyze the size distribution of contaminants in aerosol produced by mining operations. For this purpose, a Micro-Orifice Uniform Deposit Impactor (MOUDI) was utilized. Results from the MOUDI samples show higher concentrations of the toxic elements like lead and arsenic in the fine fraction (<1 microm). Fine particles are more likely to be deposited in the deeper zones of the respiratory system; therefore, they are more dangerous than coarse particles that can be filtered out in the upper respiratory system. Unfortunately, knowing the total concentration of contaminants does not give us enough information to identify the source of contamination. For this reason, lead isotopes have been introduced as fingerprints for source apportionment. Each source of lead has specific isotopic ratios; by knowing these ratios sources can be identified. During this research, lead isotopic ratios were analyzed at different sites and for different aerosol sizes. From these analyses it can be concluded that lead isotopes are a powerful tool to identify sources of lead. Mitigation strategies could be developed if the source of contamination is well defined. Environmental conditions as wind speed, wind direction, relative humidity and precipitation have an important role in the concentration of atmospheric dust. Dry environments with low relative humidity are ideal for the transport of aerosols. Results obtained from this research show the relationship between dust concentrations and meteorological parameters. Dust concentrations are highly correlated

  16. 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

    Koburger, Torsten; Pitts, Deike; Kramer, Axel

    2010-01-01

    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

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

    PubMed Central

    2013-01-01

    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

  18. Environmental arsenic, cadmium and lead dust emissions from metal mine operations: Implications for environmental management, monitoring and human health.

    PubMed

    Taylor, Mark Patrick; Mould, Simon Anthony; Kristensen, Louise Jane; Rouillon, Marek

    2014-11-01

    Although blood lead values in children are predominantly falling globally, there are locations where lead exposure remains a persistent problem. One such location is Broken Hill, Australia, where the percentage of blood lead values >10 μg/dL in children aged 1-4 years has risen from 12.6% (2010), to 13% (2011) to 21% (2012). The purpose of this study was to determine the extent of metal contamination in places accessible to children. This study examines contemporary exposure risks from arsenic, cadmium, lead, silver and zinc in surface soil and dust, and in pre- and post-play hand wipes at six playgrounds across Broken Hill over a 5-day period in September 2013. Soil lead (mean 2,450 mg/kg) and zinc (mean 3,710 mg/kg) were the most elevated metals in playgrounds. Surface dust lead concentrations were consistently elevated (mean 27,500 μg/m(2)) with the highest lead in surface dust (59,900 μg/m(2)) and post-play hand wipes (60,900 μg/m(2)) recorded close to existing mining operations. Surface and post-play hand wipe dust values exceeded national guidelines for lead and international benchmarks for arsenic, cadmium and lead. Lead isotopic compositions ((206)Pb/(207)Pb, (208)Pb/(207)Pb) of surface dust wipes from the playgrounds revealed the source of lead contamination to be indistinct from the local Broken Hill ore body. The data suggest frequent, cumulative and ongoing mine-derived dust metal contamination poses a serious risk of harm to children. PMID:25462679

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

    PubMed

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

    1988-01-01

    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

  20. 77 FR 70179 - Requirements for Lead-Based Paint Hazards in Federally Owned Residential Properties and Housing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-23

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT Requirements for Lead-Based Paint Hazards in Federally Owned Residential Properties...: Requirements for Lead-Based Paint Hazards in Federally Owned Residential Properties and Housing...

  1. Manganese and lead in dust fall accumulation in elementary schools near a ferromanganese alloy plant.

    PubMed

    Menezes-Filho, José Antonio; Souza, Karine O Fraga de; Rodrigues, Juliana L Gomes; Santos, Nathália Ribeiro Dos; Bandeira, Matheus de Jesus; Koin, Ng Lai; Oliveira, Sérgio S do Prado; Godoy, Ana Leonor P Campos; Mergler, Donna

    2016-07-01

    Previous studies have shown elevated airborne manganese (Mn) in villages adjacent to a Mn alloy production plant in Brazil and negative associations between biomarkers of Mn and children's cognition and behavior. Since small Mn particles may be carried for long distances, we measured manganese (Mn) and lead (Pb) dust fall accumulation in 15 elementary schools, located between 1.25 and 6.48km from the plant in the municipality of Simões Filho, Bahia, Brazil. Passive samplers (polyethylene Petri dishes) were set in interior and exterior environments. After 30 days, the samplers' content was solubilized with diluted nitric acid and Mn and Pb levels were analyzed by electrothermal absorption spectrometry. The overall geometric mean and range of Mn and Pb accumulation in dust fall (loading rates) were 1582μg Mn/m(2)/30 days (37-37,967) and 43.2μg Pb/m(2)/30 days (2.9-210.4). A logarithmic decrease in interior and exterior Mn loading rates was observed with distance from the ferro-manganese alloy plant. Multiple regression analyses of log-transformed Mn loading rate within the schools showed a positive association with Mn levels in outdoor dust, a negative association with distance from the plant; as well, wind direction (downwind>upwind) and school location (urban>rural) entered significantly into the model. For the interior school environments, located within a 2-km radius from the plant, loading rate was, on average, 190 times higher than the Mn levels reported by Gulson et al., (2014) in daycare centers in Sydney, Australia, using a similar method. Pb loading rates were not associated with distance from the plant and were lower than the rates observed in the same daycare centers in Sydney. Our findings suggest that a significant portion of the children in this town in Brazil may be exposed to airborne Mn at concentrations that may affect their neurodevelopment. PMID:27107708

  2. Studies on the Occurrence, Identification and Control of House Dust Mites at Rural Houses of Shebin El-Kom Locality, Egypt.

    PubMed

    Heikal, H M

    2015-04-01

    The present study was conducted at Elkom Elakhdar village, Shebin El-Kom, Menoufia Governorate along 2012 year seasons, to calculate and identify the species composition and the occurrence frequency of the extracted dust mites collected from three building ages at rural houses, as well as to determine the toxicity limits of different concentrations of three plant essential oils against two species of the family Pyroglyphidae the main causal of allergy to humans. The obtained results revealed that there were eleven mite species belong to five families (Pyroglyphidae, Chortoglyphidae, Glycyphagidae, Acaridae and Cheyletidae). Of the total collected mites (5276) the highest dominant percentage species was the dust mites: Dermatophagoides farinae (66.1%), followed by D. pteronyssinus (23.3%), while the percentages of the rest species: Chortoglyphus arcuatus, Lepidoglyphus destructor, Glycyphagus domesticus, Gohieria fusca, Tyrophagusputrescentiae, Caloglyphus sp, Cheyletus malaccensis, Blomia sp. and Acarus siro were ranged between 0.16-2.0%. Regarding to the effect of temperature degrees on mite population, high degrees more than 25 degrees C at summer season, decreased the numbers of D. farinae and D. pteronyssinus. Toxicological tests of the three plant essential oils against adult stages of D. farinae and D. pteronyssinus showed that lemon grass oil gave the highest toxicity effect, in comparison with geranium and thyme oils, where mortality percentages were approximately around 100% at 800 ppm concentration on both species. The LC50 of lemon grass were 228.992 and 293.615 ppm against the two species, respectively. From the results of the research, it could be recommend that it is preferable to apply control operation during summer season where the mite population density is the least, moreover, the botanical oil extracts effectively controlled the parasitic dust mites, D. farinae and D. pteronyssinus and can be used in the biological control programs, as well as

  3. Levels of Non-Polybrominated Diphenyl Ether Brominated Flame Retardants in Residential House Dust Samples and Fire Station Dust Samples in California

    PubMed Central

    Brown, F Reber; Whitehead, Todd P; Park, June-Soo; Metayer, Catherine; Petreas, Myrto X

    2014-01-01

    Eleven novel brominated flame retardants (NBFRs) were analyzed in dust samples from California homes as a part of the Northern California Childhood Leukemia Study (NCCLS) and from the living quarters of California fire stations as a part of the Firefighter Occupational Exposure (FOX) study using high resolution gas chromatography/mass spectrometry. The eleven NBFRs, were: α- and β-1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (α- and β-DBE-DBCH), 2-bromoallyl 2,3,6-tribromophenylether (BATE), pentabromotoluene (PBT), pentabromoethylbenzene (PBEB), 2,3-dibromopropyl 2,4,6-tribromophenyl ether (TBP-DBPE), hexabromobenzene (HBB), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), bis(2-ethylhexyl) tetrabromophthalate (BEH-TEBP), and decabromodiphenylethane (DBDPE). Six of the seven NBFRs that are produced in relatively small quantities (i.e., α−, β−DBE-DBCH, BATE, PBEB, PBT, TBP-DBPE) were measured close to or below the limit of quantitation (0.64 ng/g) in both the NCCLS and FOX samples, and the seventh, HBB, was measured at median concentrations of 1.85 ng/g and 9.40 ng/g in the NCCLS and FOX samples, respectively. The remaining four NBFRs, EH-TBB, BEH-TEBP, BTBPE, and DBDPE, are produced in higher quantities, and were detected at median concentrations of 337 ng/g, 186 ng/g, 22.3, ng/g, and 82.8 ng/g, respectively in the NCCLS samples, and at median concentrations of 2687 ng/g, 2076 ng/g, 28.4 ng/g, and 161 ng/g, respectively, in the FOX samples. Concentrations of NBFRs in the NCCLS and FOX dust samples were several times lower than concentrations of PBDEs previously measured in the same samples. Concentrations of NBFRs in the NCCLS and FOX dust samples were generally comparable to concentrations of NBFRs in other studies of house dust from the US and Canada. PMID:25261858

  4. Levels of non-polybrominated diphenyl ether brominated flame retardants in residential house dust samples and fire station dust samples in California.

    PubMed

    Brown, F Reber; Whitehead, Todd P; Park, June-Soo; Metayer, Catherine; Petreas, Myrto X

    2014-11-01

    Eleven novel brominated flame retardants (NBFRs) were analyzed in dust samples from California homes as a part of the Northern California Childhood Leukemia Study (NCCLS) and from the living quarters of California fire stations as a part of the Firefighter Occupational Exposure (FOX) study using high resolution gas chromatography/mass spectrometry. The eleven NBFRs were α- and β-1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (α- and β-DBE-DBCH), 2-bromoallyl 2,3,6-tribromophenylether (BATE), pentabromotoluene (PBT), pentabromoethylbenzene (PBEB), 2,3-dibromopropyl 2,4,6-tribromophenyl ether (TBP-DBPE), hexabromobenzene (HBB), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), bis(2-ethylhexyl) tetrabromophthalate (BEH-TEBP), and decabromodiphenylethane (DBDPE). Six of the seven NBFRs that are produced in relatively small quantities (i.e., α-, β-DBE-DBCH, BATE, PBEB, PBT, TBP-DBPE) were measured close to or below the limit of quantitation (0.64 ng/g) in both the NCCLS and FOX samples, and the seventh, HBB, was measured at median concentrations of 1.85 ng/g and 9.40 ng/g in the NCCLS and FOX samples, respectively. The remaining four NBFRs, EH-TBB, BEH-TEBP, BTBPE, and DBDPE, are produced in higher quantities, and were detected at median concentrations of 337 ng/g, 186 ng/g, 22.3 ng/g, and 82.8 ng/g, respectively in the NCCLS samples, and at median concentrations of 2687 ng/g, 2076 ng/g, 28.4 ng/g, and 161 ng/g, respectively, in the FOX samples. Concentrations of NBFRs in the NCCLS and FOX dust samples were several times lower than concentrations of PBDEs previously measured in the same samples. Concentrations of NBFRs in the NCCLS and FOX dust samples were generally comparable to concentrations of NBFRs in other studies of house dust from the US and Canada. PMID:25261858

  5. Product screening for sources of halogenated flame retardants in Canadian house and office dust.

    PubMed

    Abbasi, Golnoush; Saini, Amandeep; Goosey, Emma; Diamond, Miriam L

    2016-03-01

    Human exposure to halogenated flame retardants (HFRs) such as polybrominated diphenyl ethers (PBDEs) and their replacements, can be related to exposure to indoor dust and direct contact with HFR-containing products. This study aimed to identify electronic products that contributed to HFRs measured in indoor dust and to develop a screening method for identifying HFRs in hard polymer products. Concentrations of 10 PBDEs and 12 halogenated replacements in dust and surface wipe samples of hard polymer casings of electronic products plus Br in the surfaces of those casing measured using X-ray fluorescence (XRF) were analyzed from 35 homes and 10 offices in Toronto (ON, Canada). HFR concentrations in dust and product wipes were positively correlated. Thus, we hypothesize that electronic products with the highest HFR concentrations contribute the most to concentrations in dust, regardless of the volatility of the HFR. Abundant HFRs in dust and product wipes were PBDEs (BDE-47, 99, 100, 153, 154, 183, 209), TDCPP, DBDPE, EH-TBB and BEHTBP. Older CRT TVs had the highest concentration of BDE-209 of all products tested. This was followed by higher concentrations of HFRs in PCs, Audio/Video (A/V) devices, small household appliances (HHAs) and flat screen TVs. The removal of HFRs from polymer surfaces using wipes supports concerns that HFRs could be transferred from these surfaces to hands as a result of direct contact with HFR-containing products. Surface wipe testing shows promise for screening additive HFRs. In comparison, the Br-content obtained using a handheld XRF analyzer did not correspond to concentrations obtained from surface wipe testing. PMID:26747994

  6. Evaluation of errors and limits of the 63-μm house-dust-fraction method, a surrogate to predict hidden moisture damage

    PubMed Central

    Baudisch, Christoph; Assadian, Ojan; Kramer, Axel

    2009-01-01

    Background The aim of this study is to analyze possible random and systematic measurement errors and to detect methodological limits of the previously established method. Findings To examine the distribution of random errors (repeatability standard deviation) of the detection procedure, collective samples were taken from two uncontaminated rooms using a sampling vacuum cleaner, and 10 sub-samples each were examined with 3 parallel cultivation plates (DG18). In this two collective samples of new dust, the total counts of Aspergillus spp. varied moderately by 25 and 29% (both 9 cfu per plate). At an average of 28 cfu/plate, the total number varied only by 13%. For the evaluation of the influence of old dust, old and fresh dust samples were examined. In both cases with old dust, the old dust influenced the results indicating false positive results, where hidden moist was indicated but was not present. To quantify the influence of sand and sieving, 13 sites were sampled in parallel using the 63-μm- and total dust collection approaches. Sieving to 63-μm resulted in a more then 10-fold enrichment, due to the different quantity of inert sand in each total dust sample. Conclusion The major errors during the quantitative evaluation from house dust samples for mould fungi as reference values for assessment resulted from missing filtration, contamination with old dust and the massive influence of soil. If the assessment is guided by indicator genera, the percentage standard deviation lies in a moderate range. PMID:19852825

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

    NASA Astrophysics Data System (ADS)

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

    2012-01-01

    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.

  8. QUANTITATIVE PCR ANALYSIS OF HOUSE DUST CAN REVEAL ABNORMAL MOLD CONDITIONS

    EPA Science Inventory

    Indoor mold populations were measured in the dust of homes in Cleveland and Cincinnati, OH, by quantitative PCR (QPCR) and, in Cincinnati, also by culturing. QPCR assays for 82 species (or groups of species) were used to identify and quantify indoor mold populations in moldy home...

  9. Relationship between chicken cellular immunity and endotoxin levels in dust from chicken housing environments

    PubMed Central

    Roque, Katharine; Shin, Kyung-Min; Jo, Ji-Hoon; Kim, Hyoung-Ah

    2015-01-01

    Hazardous biochemical agents in animal husbandry indoor environments are known to promote the occurrence of various illnesses among workers and animals. The relationship between endotoxin levels in dust collected from chicken farms and various immunological markers was investigated. Peripheral blood was obtained from 20 broiler chickens and 20 laying hens from four different chicken farms in Korea. Concentrations of total or respirable dust in the inside the chicken farm buildings were measured using a polyvinyl chloride membrane filter and mini volume sampler. Endotoxin levels in the dust were determined by the Limulus Amebocyte Lysate Kinetic method. Interferon-γ production by peripheral blood mononuclear cells stimulated with concanavalin A was significantly lower in broilers or layers from the farms with higher endotoxin concentrations than the chickens from the farms with lower endotoxin levels. An opposite pattern was observed for plasma cortisol concentrations with higher cortisol levels found in chickens from the farms with higher endotoxin levels. When peripheral lymphocytes were examined, the percentage of CD3-Ia+ B cells was lower in layers from farms with higher endotoxin levels than those from locations with lower endotoxin levels. Overall, these results suggest a probable negative association between dust endotoxin levels and cell-mediated immunity in chickens. PMID:25549222

  10. Determination of polybrominated diphenyl ethers in house dust using standard addition method and gas chromatography with electron capture and mass spectrometric detection.

    PubMed

    Król, Sylwia; Zabiegała, Bożena; Namieśnik, Jacek

    2012-08-01

    Monitoring of the environmental fate of polybrominated diphenyl ethers (PBDEs) involves determination of their concentration in air, airborne particles and settled dust. This requires the implementation of appropriate analytical tools like measuring instruments, reference materials and analytical procedures. In this study an analytical procedure was developed for determining PBDEs in samples with a complex matrix composition. The efficiencies of three different extraction techniques - Soxhlet extraction (SE), Accelerated Solvent Extraction (ASE) and Ultrasound Assisted Extraction (UAE) - were compared. The study investigated the possibility of using the standard addition method for estimating PBDEs levels. The GC-μECD system was successfully applied as an alternative to low resolution mass spectrometry (LRMS) for determining BDE-209 in dust samples. The developed analytical procedure was then used to analyze dust samples, collected from houses and computer suites in the Tri-city area (Gdansk, Gdynia and Sopot), in order to detect and quantify the presence of polybrominated diphenyl ethers (PBDEs) in the indoor environment. Concentrations of studied congeners (from triBDE to heptaBDE), obtained by chromatographic analysis of dust samples extracts, performed applying two measurement systems (GC-EIMS and GC-μECD) ranged between 331 and 3102 ng g(-1) for house dust and between dust. The highest concentrations were obtained for congeners with four, five and six bromine atoms (BDE-47, BDE-99, BDE-100 and BDE-153). Concentrations of BDE-209 ranged from 384 ng g(-1) (house dust) to 12,553 ng g(-1) (electronic dust). PMID:22749362

  11. Aspergillus, Penicillium and Talaromyces isolated from house dust samples collected around the world

    PubMed Central

    Visagie, C.M.; Hirooka, Y.; Tanney, J.B.; Whitfield, E.; Mwange, K.; Meijer, M.; Amend, A.S.; Seifert, K.A.; Samson, R.A.

    2014-01-01

    As part of a worldwide survey of the indoor mycobiota, dust was collected from nine countries. Analyses of dust samples included the culture-dependent dilution-to-extinction method and the culture-independent 454-pyrosequencing. Of the 7 904 isolates, 2 717 isolates were identified as belonging to Aspergillus, Penicillium and Talaromyces. The aim of this study was to identify isolates to species level and describe the new species found. Secondly, we wanted to create a reliable reference sequence database to be used for next-generation sequencing projects. Isolates represented 59 Aspergillus species, including eight undescribed species, 49 Penicillium species of which seven were undescribed and 18 Talaromyces species including three described here as new. In total, 568 ITS barcodes were generated, and 391 β-tubulin and 507 calmodulin sequences, which serve as alternative identification markers. PMID:25492981

  12. SQ house dust mite (HDM) SLIT-tablet provides clinical improvement in HDM-induced allergic rhinitis.

    PubMed

    Klimek, Ludger; Mosbech, Holger; Zieglmayer, Petra; Rehm, Dorte; Stage, Brian Sonne; Demoly, Pascal

    2016-04-01

    House dust mite (HDM) allergy represents a highly prevalent inhalant allergy, and exposure to HDM allergens results in allergic rhinitis with persistent symptoms that may not be adequately controlled with available allergy pharmacotherapy. Allergy immunotherapy constitutes a complementary treatment option targeting the underlying immunological mechanisms of allergic disease and represents the only treatment with a potential for disease modification and long-term efficacy. As traditional allergy immunotherapy delivered by subcutaneous injection of specific HDM allergens involves a time-consuming treatment regimen and a risk of systemic adverse reactions, sublingually administered allergy immunotherapy (SLIT) has been investigated as a more convenient treatment option with similar levels of efficacy and an improved safety profile that allows for at-home daily administration. In this Drug Profile, we provide a review of the clinical data behind the SQ HDM SLIT-tablet, which was recently approved for the treatment of HDM-induced allergic rhinitis by regulatory authorities in Europe and Japan. PMID:26788764

  13. Molecular, Structural and Immunological Characterization of Der p 18, a Chitinase-Like House Dust Mite Allergen

    PubMed Central

    Resch, Yvonne; Blatt, Katharina; Malkus, Ursula; Fercher, Christian; Swoboda, Ines; Focke-Tejkl, Margit; Chen, Kuan-Wei; Seiberler, Susanne; Mittermann, Irene; Lupinek, Christian; Rodriguez-Dominguez, Azahara; Zieglmayer, Petra; Zieglmayer, René; Keller, Walter; Krzyzanek, Vladislav; Valent, Peter; Valenta, Rudolf; Vrtala, Susanne

    2016-01-01

    Background The house dust mite (HDM) allergen Der p 18 belongs to the glycoside hydrolase family 18 chitinases. The relevance of Der p 18 for house dust mite allergic patients has only been partly investigated. Objective To perform a detailed characterization of Der p 18 on a molecular, structural and immunological level. Methods Der p 18 was expressed in E. coli, purified to homogeneity, tested for chitin-binding activity and its secondary structure was analyzed by circular dichroism. Der p 18-specific IgG antibodies were produced in rabbits to localize the allergen in mites using immunogold electron microscopy and to search for cross-reactive allergens in other allergen sources (i.e. mites, crustacea, mollusca and insects). IgE reactivity of rDer p 18 was tested with sera from clinically well characterized HDM-allergic patients (n = 98) and its allergenic activity was analyzed in basophil activation experiments. Results Recombinant Der p 18 was expressed and purified as a folded, biologically active protein. It shows weak chitin-binding activity and partial cross-reactivity with Der f 18 from D. farinae but not with proteins from the other tested allergen sources. The allergen was mainly localized in the peritrophic matrix of the HDM gut and to a lower extent in fecal pellets. Der p 18 reacted with IgE from 10% of mite allergic patients from Austria and showed allergenic activity when tested for basophil activation in Der p 18-sensitized patients. Conclusion Der p 18 is a rather genus-specific minor allergen with weak chitin-binding activity but exhibits allergenic activity and therefore should be included in diagnostic test panels for HDM allergy. PMID:27548813

  14. 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...

  15. NHEXAS PHASE I REGION 5 STUDY--STANDARD OPERATING PROCEDURE--ANALYSIS OF HOUSE DUST FOR ARSENIC (RTI/ACS-AP-209-121)

    EPA Science Inventory

    The purpose of this protocol is to provide guidelines for the analysis of wipes that were used in Lioy-Wainman-Weisel (LWW) surface samplers to collect house dust for arsenic (As). This method involves the extraction of the analyte from wipe samples using 50% ultra-pure nitric ac...

  16. NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR ANALYSIS OF SOIL OR HOUSE DUST SAMPLES USING CHLORPYRIFOS ELISA SAMPLES (BCO-L-1.0)

    EPA Science Inventory

    This abstract is included for completeness of documentation, but this SOP was not used in the study.

    The purpose of this SOP is to describe the procedures for analyzing both Stage II and Stage III soil and vacuum-cleaner collected house dust samples, and Stage III air samples u...

  17. Using paired soil and house dust samples in an in vitro assay to assess the post ingestion bioaccessibility of sorbed fipronil

    EPA Science Inventory

    For children, ingestion of soils and house dusts can be an important exposure pathway for regulated organic compounds. Following ingestion, the extent to which compounds desorb and become bioaccessible is a critical determinant of systemic adsorption.We characterized the physicoc...

  18. A post-remediation assessment in Jersey City of the association of hexavalent chromium in house dust and urinary chromium in children.

    PubMed

    Black, Kathleen; Gochfeld, Michael; Lioy, Paul J; Fan, Zhi-Hua Tina; Yu, Chang Ho; Jeitner, Chris; Hernandez, Marta; Einstein, Stephanie A; Stern, Alan H

    2015-01-01

    Although all chromite ore processing residue (COPR) sites near residential neighborhoods in Jersey City, New Jersey have undergone remediation, recent studies found widespread, but low levels of hexavalent chromium (Cr(+6)) in house dust both in Jersey City and in communities with no known sources of Cr(+6). This study was designed as a follow-up to determine whether there is an association between current Cr(+6) levels in house dust and urinary chromium concentrations in young children. Dust samples (N=369) were collected from 123 homes. The median Cr(+6) concentration was 3.3 μg/g (mean±SD 5.2±7.5) and the median Cr(+6) loading was 1.1 μg/m(2) (1.9±3.1). These levels were not elevated compared with previously reported levels in background communities (median concentration=3.5 μg/g; median loading=2.8 μg/m(2)). Urinary chromium concentrations were measured in spot urine samples collected from 150 children, ages 3 months to 6 years. The median uncorrected urinary chromium concentration was 0.19 μg/l (0.22±0.16). Current urinary chromium concentrations were significantly lower than those previously reported before and during remediation (t-test; P<0.001). Urinary chromium concentrations were not significantly higher in homes with high (75th or 90th percentile) Cr(+6) dust levels (concentration or loading) compared with other homes. Multiple linear regression was used to examine the relationship between Cr(+6) levels (concentration and loading) in house dust and urinary chromium concentrations (uncorrected and specific gravity corrected). Contrary to pre-remediation studies, we did not find a positive association between Cr(+6) levels in house dust and urinary chromium concentrations. The findings indicate that current Cr(+6) levels in house dust are not positively associated with children's chromium exposure as measured by urinary chromium, and the children's exposure to Cr(+6) in house dust is below the level that could be identified by urine

  19. 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)

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

    2013-07-01

    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.

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

    PubMed

    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

    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

  1. Levels of polybrominated diphenyl ethers in settled house dust from urban dwellings with resident preschool-aged children in Nanjing, China.

    PubMed

    Wang, Bing-Ling; Pang, Shu-tao; Zhang, Xiao-ling; Li, Xi-ling; Sun, Yong-gang; Lu, Xiao-mei; Zhang, Qi

    2015-01-01

    We investigated the levels and possible determinants of polybrominated diphenyl ethers (PBDEs) in the settled house-dust (SHD) of urban dwellings with resident preschool-aged children in Nanjing, China. The possible neurodevelopmental effects of house-dust PBDEs were also explored. SHD was collected from 216 urban houses. Levels of 8 PBDEs were measured by gas chromatography-negative chemical ionization mass spectrometry. The Child Behavior Checklist and the Gesell Development Inventory were used to evaluate the child's development. BDE47, BDE99, BDE153, BDE18, and BDE209 were detected in the SHD of >90 % of houses, of which BDE209 predominated. Most PBDEs were found at significantly greater levels in indoor than in outdoor dust (P < 0.05). Levels of BDE28 and BDE154 in houses with solid-wood floors were significantly greater than those in houses with plywood floors (P < 0.05). BDE154 levels in houses with wallpaper were significantly greater than those without wallpaper (P < 0.05). Greater BDE47 concentrations were found in houses with less natural ventilation time (linear trend P < 0.05). After dichotomization at the geometric mean concentration, BDE209 and total BDEs showed significant risks for depressed behavior problems and lower personal social developmental quotients (DQs); BDE99 and BDE153 indicated a risk for lower personal social DQs. In conclusion, PBDEs (especially BDE209) are ubiquitous in urban SHD in Nanjing residences. Natural ventilation and floor materials potentially influence PBDE levels in SHD. The potential adverse effect of postnatal exposure to PBDEs on the behavior and neurodevelopment of preschool-age children requires follow-up in larger studies. PMID:25034333

  2. Determination of mite allergens in house dust using the enzyme immunoassay.

    PubMed

    Prester, Ljerka; Brcić Karaconji, Irena; Macan, Jelena

    2007-12-01

    The aim of this study was to determine the level of two major mite allergens Dermatophagoides pteronyssinus (Der p 1) and Dermatophagoides farinae (Der f 1) in 30 urban homes in Zagreb, Croatia, using the enzyme immunoassay with two monoclonal antibodies which has been established as the reference method for indoor allergen analysis. Dust samples were taken by vacuuming a carpeted area and collected on cellulose filters. The ranges of Der p 1 and Der f 1 were (0.1-12.5) microg g-1 (median 0.32 microg g-1) and (0.1-31.2) microg g-1 (median 0.35 microg g-1), respectively. Der p 1 and Der f 1 (>2 microg g-1) associated with increased risk of sensitization to mite allergens were found in approximately 16% homes for each allergen. The sum of allergen (Der p 1 + Der f 1) exceeded the lower threshold in 27% of homes. Analytical evaluation of the ELISA assay showed satisfactory results for precision (intra-assay CV <6.9%, inter-assay CV<13.3%), accuracy (91% to 93%), and sensitivity (2 ng mL-1). The ELISA assay for the measurement of dust mite allergens demonstrated very good analytical characteristics for routine laboratory use, and will provide the essential basis for our future studies of various indoor allergens. PMID:18063526

  3. Quantitative PCR analysis of house dust can reveal abnormal mold conditions†

    PubMed Central

    Meklin, Teija; Haugland, Richard A.; Reponen, Tiina; Varma, Manju; Lummus, Zana; Bernstein, David; Wymer, Larry J.; Vesper, Stephen J.

    2007-01-01

    Indoor mold concentrations were measured in the dust of moldy homes (MH) and reference homes (RH) by quantitative PCR (QPCR) assays for 82 species or related groups of species (assay groups). About 70% of the species and groups were never or only rarely detected. The ratios (MH geometric mean : RH geometric mean) for 6 commonly detected species (Aspergillus ochraceus, A. penicillioides, A. unguis, A. versicolor, Eurotium group, and Cladosporium sphaerospermum) were > 1 (Group I). Logistic regression analysis of the sum of the logs of the concentrations of Group I species resulted in a 95% probability for separating MH from RH. These results suggest that it may be possible to evaluate whether a home has an abnormal mold condition by quantifying a limited number of mold species in a dust sample. Also, four common species of Aspergillus were quantified by standard culturing procedures and their concentrations compared to QPCR results. Culturing underestimated the concentrations of these four species by 2 to 3 orders of magnitude compared to QPCR. PMID:15237292

  4. Analysis of the dust emissions from a naturally ventilated turkey house using tracer gas method.

    PubMed

    Mostafa, Ehab; Diekmann, Bernd; Buescher, Wolfgang; Schneider, Till

    2016-06-01

    Particulate matter (PM) emissions are becoming increasingly important in licensing procedures for the construction of new livestock houses or for the modernization of existing ones. Emission predictions require reliable data about emission rates. On this account, it is necessary to obtain information about the emission development and the relevant influencing factors in naturally ventilated turkey houses. The primary objective of the present research was to describe different aspects of PM emissions from a naturally ventilated turkey house. This includes the quantification of PM emissions and descriptions of the relevant influencing factors. Moreover, the tracer gas decay (TGD) method for ventilation rate estimation had to be used. To determine the emission mass flow from livestock buildings, it was necessary to measure the concentration of the target substance in the exhaust air and the airflow volume. The PM concentration measurements were carried out with a light scattering aerosol spectrometer in the exhaust air. The airflow volume was determined using the TGD method. To this purpose, tracer gas was injected into the supply air before the concentration decay was measured in the exhaust air of the building. The main influences on the PM concentration and the PM size distribution were shown to be animal activity and air volume flow. For the turkey barn, the PM emission factor averaged 0.027 g h(-1) animal(-1) over the entire year. If service times were to be included in the calculation, the emission factor 0.021 g h(-1) animal(-1), again averaged over the entire year, is well below the regulatory limit. PMID:27234512

  5. Development and evaluation of monitoring methods for polycyclic aromatic hydrocarbons in house dust and track-in soil. Final report, June 1992-September 1993

    SciTech Connect

    Chuang, J.C.; Callahan, P.J.; Katona, V.; Gordon, S.M.

    1993-09-01

    The analytical methods were developed for the determination of Polycyclic aromatic hydrocarbons (PAH) and Polychlorinated biphenyls (PCBs) in the dust and soil based on sonication with hexane and 10% ether/hexane, respectively, and analysis by gas chromatography/mass spectrometry (GC/MS). Quantitative recoveries of spiked perdeuterated PAH and (13)C labeled PCB were obtained using the above methods. In an eight-home field evaluation, the concentrations of the sum of all target PAH in the house dust ranged from 16 to 550 ppm, from 41 to 580 ppm, and from 25 to 310 ppm in the samples collected during June 1992, October 1992, and April 1993, respectively. The PCB concentrations were lower than PAH concentrations in all samples; the sum of all target PCB varied from 210 to 1900 ppb in house dust, from 30 to 880 ppb in entryway soil, from 16 to 500 ppb in pathway soil, and from 18 to 210 ppb in foundation soil. Higher PCB concentrations were found in house dust samples than in entryway soil samples. Similar PCB concentrations were observed in the pathway soil samples and the foundation soil samples, which were lower than PCB found in entryway soil samples.

  6. House-dust mite allergy: mapping of Dermatophagoides pteronyssinus allergens for dogs by two-dimensional immunoblotting

    PubMed Central

    Marques, Andreia Grilo; Pereira, Luísa Maria Dotti Silva; Goicoa, Ana; Semião-Santos, Saul José; Bento, Ofélia Pereira

    2015-01-01

    Introduction Specific immunotherapy has shown to be very useful for allergy control in dogs, with a common success rate ranging from 65% to 70%. However, this efficacy could probably be improved and the identification of individual allergomes, with the choice of more adequate molecular allergen pools for specific immunotherapy, being the strategy. Aim To map Dermatophagoides pteronyssinus (Der p) allergens for mite-sensitized atopic dogs, for better understanding how individual allergograms may influence the response to house-dust mite immunotherapy. Material and methods To identify the Der p mite allergome for dogs, 20 individuals allergic to dust-mites and sensitized to Der p, were selected. The extract from Der p was submitted to isoelectric focusing (IEF), one-dimensional (1-D) and two-dimensional (2-D) sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Separated proteins were blotted onto polyvinylidene difluoride (PVDF) membranes and immunoblottings were performed with patient sera. Allergen-bound specific IgE was detected. Results Eleven allergens were identified from isoelectric focusing (IEF), as well as from 1-D SDS PAGE. From 2-D SDS-PAGE, 24 spots were identified. Conclusions Several similarities were found between dog and human allergograms and no absolute correlation between sensitization and allergy was observed either. As in humans, different individual allergograms do not seem to implicate different clinical patterns, but may influence the response to specific immunotherapy. The molecular epidemiology approach in veterinary allergy management, by the characterization of individual patients’ allergoms and by choosing the best molecular allergen pool for each patient could also improve the efficacy of allergy immunotherapy. PMID:26015775

  7. House dust mite extracts activate cultured human dermal endothelial cells to express adhesion molecules and secrete cytokines.

    PubMed

    Arlian, Larry G; Elder, B Laurel; Morgan, Marjorie S

    2009-05-01

    The human skin contacts molecules from house dust mites that are ubiquitous in many environments. These mite-derived molecules may penetrate the skin epidermis and dermis and contact microvascular endothelial cells and influence their function. The purpose of this study was to determine the response of normal human dermal microvascular endothelial cells to extracts of the dust mites, Dermatophagoides farinae, D. pteronyssinus, and Euroglyphus maynei with and without endotoxin (lipopolysaccharide). Endothelial cells were stimulated with mite extracts and the expression of surface molecules and the secretion of cytokines were measured in the absence and presence of polymyxin B to bind endotoxin. All three mite extracts stimulated endothelial cells to express intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin and to secrete interleukin (IL)-6, IL-8, monocyte chemoattractant protein (MCP-1), and granulocyte/macrophage colony stimulating factor (GM-CSF). Euroglyphus maynei-induced expression of all the cell surface molecules was not inhibited when the endotoxin activity in the mite extract was inhibited. In contrast, endothelial cells challenged with D. farinae or D. pteronyssinus extract depleted of endotoxin activity expressed only constitutive levels of ICAM-1, VCAM-1, and E-selectin. D. farinae and E. maynei extracts depleted of endotoxin activity still induced secretion of IL-8 and MCP-1 but at reduced levels. Only constitutive amounts of IL-6, G-CSF, and GM-CSF were secreted in response to any of the endotoxin-depleted mite extracts. Extracts of D. farinae, D. pteronyssinus, and E. maynei contain both endotoxins and other molecules that can stimulate expression of cell adhesion molecules and chemokine receptors and the secretion of cytokines by normal human microvascular endothelial cells. PMID:19496432

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

    SciTech Connect

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

    1985-01-01

    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).

  9. 40 CFR 745.226 - Certification of individuals and firms engaged in lead-based paint activities: target housing and...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Certification of individuals and firms engaged in lead-based paint activities: target housing and child-occupied facilities. 745.226 Section 745.226 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT LEAD-BASED PAINT POISONING PREVENTION...

  10. 75 FR 51808 - Lead-Based Paint Renovation, Repair and Painting Activities in Target Housing and Child Occupied...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-23

    ... April 22, 2008, (73 FR 21692), EPA promulgated final TSCA section 402(c)(3) regulations governing... Program are found in R23-24.6-PB-Section 14.0 of the Rhode Island Rules and Regulations For Lead Poisoning... AGENCY Lead-Based Paint Renovation, Repair and Painting Activities in Target Housing and Child...

  11. 75 FR 13127 - Lead-Based Paint Renovation, Repair and Painting Activities in Target Housing and Child Occupied...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-18

    ... Exposure Reduction. In the Federal Register dated April 22, 2008 (73 FR 21692), EPA promulgated final TSCA... AGENCY Lead-Based Paint Renovation, Repair and Painting Activities in Target Housing and Child Occupied... Action Apply to Me? This action is directed to the public in general, to entities offering Lead...

  12. 40 CFR 745.227 - Work practice standards for conducting lead-based paint activities: target housing and child...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT LEAD-BASED... for the Evaluation and Control of Lead-Based Paint Hazards in Housing; the EPA Guidance on Residential... control procedures; and/or (ii) All collected paint chip samples shall be analyzed according to...

  13. Department of Housing and Urban Development, Office of Lead Hazard Control and Healthy Homes

    MedlinePlus

    ... Guidelines, Announcements, and other IPM information Advancing Healthy Housing: A Strategy For Action What is a Healthy Home? Apply for a Grant Healthy Home Rating System File a Housing Discrimination ...

  14. Polybrominated Diphenyl Ethers in Maternal Serum, Breast Milk, Umbilical Cord Serum, and House Dust in a South Korean Birth Panel of Mother-Neonate Pairs.

    PubMed

    Shin, Mi-Yeon; Lee, Sunggyu; Kim, Hai-Joong; Lee, Jeong Jae; Choi, Gyuyeon; Choi, Sooran; Kim, Sungjoo; Kim, Su Young; Park, Jeongim; Moon, Hyo-Bang; Choi, Kyungho; Kim, Sungkyoon

    2016-01-01

    Polybrominated diphenyl ethers (PBDEs) have been used as flame retardants. Although many reports have indicated an association between exposure to PBDEs and developmental neurotoxicity, the relative contributions of different sources of dust PBDE congeners to the levels in various tissues of mother-baby pairs is not well understood. The aims of this study were thus to measure the quantitative relationship between the level of PBDEs in house dust and tissues of mother-neonate pairs, and to investigate the chemical sources of the PBDEs. Forty-one mother-neonate pairs were recruited and provided samples of maternal serum (n = 29), umbilical cord serum (n = 25), breast milk (n = 50), and house dust (n = 41), where PBDEs were determined with high-resolution gas chromatography coupled with high-resolution mass spectrometry. While deca- (e.g., BDE 209, detected 100%), nona- (BDE 206/207, 95.1%), octa- (BDE 183, 100%), penta- (BDE 99/153, 100%, 98%) and tetra-BDEs (BDE 47, 100%) were detected abundantly in dust, penta- (BDE 99, 76%, 92%) and tetra-BDEs (BDE 47, 84%, 98%) were detected abundantly in umbilical cord serum and breast milk, respectively; tetra-BDEs (BDE 47, 86%) were detected more often relative to other congeners in maternal serum. Spearman's pairwise comparison showed that the levels of BDE 47 (ρ = 0.52, p < 0.001) and -99 (ρ = 0.64, p < 0.01) in umbilical cord serum were associated with BDE 209 levels in dust; BDE 47 in maternal serum also showed correlation with BDE 99 in cord serum (ρ = 0.48, p < 0.01) but there was no significant correlation between maternal BDE 47 and dust BDE 209. On the other hand, a comparison of the distribution among congeners suggested probable associations of BDE 47 in maternal serum, breast milk, and umbilical cord serum with BDE 209 in dust; and of BDE 99 in maternal and umbilical cord serum, breast milk, and dust with BDE 209 in dust. Although further studies are needed, a radar chart-based distributional comparison among

  15. Polybrominated Diphenyl Ethers in Maternal Serum, Breast Milk, Umbilical Cord Serum, and House Dust in a South Korean Birth Panel of Mother-Neonate Pairs

    PubMed Central

    Shin, Mi-Yeon; Lee, Sunggyu; Kim, Hai-Joong; Lee, Jeong Jae; Choi, Gyuyeon; Choi, Sooran; Kim, Sungjoo; Kim, Su Young; Park, Jeongim; Moon, Hyo-Bang; Choi, Kyungho; Kim, Sungkyoon

    2016-01-01

    Polybrominated diphenyl ethers (PBDEs) have been used as flame retardants. Although many reports have indicated an association between exposure to PBDEs and developmental neurotoxicity, the relative contributions of different sources of dust PBDE congeners to the levels in various tissues of mother–baby pairs is not well understood. The aims of this study were thus to measure the quantitative relationship between the level of PBDEs in house dust and tissues of mother-neonate pairs, and to investigate the chemical sources of the PBDEs. Forty-one mother-neonate pairs were recruited and provided samples of maternal serum (n = 29), umbilical cord serum (n = 25), breast milk (n = 50), and house dust (n = 41), where PBDEs were determined with high-resolution gas chromatography coupled with high-resolution mass spectrometry. While deca- (e.g., BDE 209, detected 100%), nona- (BDE 206/207, 95.1%), octa- (BDE 183, 100%), penta- (BDE 99/153, 100%, 98%) and tetra-BDEs (BDE 47, 100%) were detected abundantly in dust, penta- (BDE 99, 76%, 92%) and tetra-BDEs (BDE 47, 84%, 98%) were detected abundantly in umbilical cord serum and breast milk, respectively; tetra-BDEs (BDE 47, 86%) were detected more often relative to other congeners in maternal serum. Spearman’s pairwise comparison showed that the levels of BDE 47 (ρ = 0.52, p < 0.001) and −99 (ρ = 0.64, p < 0.01) in umbilical cord serum were associated with BDE 209 levels in dust; BDE 47 in maternal serum also showed correlation with BDE 99 in cord serum (ρ = 0.48, p < 0.01) but there was no significant correlation between maternal BDE 47 and dust BDE 209. On the other hand, a comparison of the distribution among congeners suggested probable associations of BDE 47 in maternal serum, breast milk, and umbilical cord serum with BDE 209 in dust; and of BDE 99 in maternal and umbilical cord serum, breast milk, and dust with BDE 209 in dust. Although further studies are needed, a radar chart-based distributional comparison

  16. Nanoparticle conjugation enhances the immunomodulatory effects of intranasally delivered CpG in house dust mite-allergic mice

    SciTech Connect

    Ballester, Marie; Jeanbart, Laura; de Titta, Alexandre; Nembrini, Chiara; Marsland, Benjamin J.; Hubbell, Jeffrey A.; Swartz, Melody A.

    2015-09-21

    An emerging strategy in preventing and treating airway allergy consists of modulating the immune response induced against allergens in the lungs. CpG oligodeoxynucleotides have been investigated in airway allergy studies, but even if promising, efficacy requires further substantiation. We investigated the effect of pulmonary delivery of nanoparticle (NP)-conjugated CpG on lung immunity and found that NP-CpG led to enhanced recruitment of activated dendritic cells and to Th1 immunity compared to free CpG. We then evaluated if pulmonary delivery of NP-CpG could prevent and treat house dust mite-induced allergy by modulating immunity directly in lungs. When CpG was administered as immunomodulatory therapy prior to allergen sensitization, we found that NP-CpG significantly reduced eosinophilia, IgE levels, mucus production and Th2 cytokines, while free CpG had only a moderate effect on these parameters. In a therapeutic setting where CpG was administered after allergen sensitization, we found that although both free CpG and NP-CpG reduced eosinophilia and IgE levels to the same extent, NP conjugation of CpG significantly enhanced reduction of Th2 cytokines in lungs of allergic mice. Taken together, these data highlight benefits of NP conjugation and the relevance of NP-CpG as allergen-free therapy to modulate lung immunity and treat airway allergy.

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

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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.

  18. Vaccination against IL-33 Inhibits Airway Hyperresponsiveness and Inflammation in a House Dust Mite Model of Asthma

    PubMed Central

    Lei, Ying; Adner, Mikael; Hellman, Lars; Nilsson, Gunnar

    2015-01-01

    In several clinical and experimental studies IL-33 and its receptor have been found to play important roles in the development of asthma and allergic airway inflammation. We evaluated the effects of vaccination against IL-33 in a mouse model of airway inflammation induced by house dust mite (HDM) allergen. Balb/c mice received the IL-33 vaccine subcutaneously, followed by intranasal administration of HDM for up to six weeks. Vaccination against IL-33 induced high titers of specific anti-IL-33 IgG antibodies that inhibited HDM-induced airway hyperresponsiveness (AHR) in the conducting airways and tissue damping. The vaccination also attenuated the HDM-induced elevation in the numbers of eosinophils in bronchoalveolar lavage fluid (BALF) and suppressed the accumulation of inflammatory cells in the airways. Furthermore, the levels of IL-17A, IL-25, IL-33 and TSLP in lung tissue homogenates were reduced by vaccination against IL-33. These observations demonstrate that vaccination against IL-33 inhibits HDM-induced development of AHR, airway inflammation and production of inflammatory cytokines. The results also indicate an important role of IL-33 in the regulation of AHR of the distal lung compartments. Thus, administration of such a vaccine is potentially an effective therapeutic tool for treating allergic asthma. PMID:26214807

  19. Allergic Responses Induced by a Fungal Biopesticide Metarhizium anisopliae and House Dust Mite Are Compared in a Mouse Model.

    PubMed

    Ward, Marsha D W; Chung, Yong Joo; Copeland, Lisa B; Doerfler, Donald L

    2011-01-01

    Biopesticides can be effective in controlling their target pest. However, research regarding allergenicity and asthma development is limited. We compared the ability of fungal biopesticide Metarhizium anisopliae (MACA) and house dust mite (HDM) extracts to induce allergic responses in BALB/c mice. The extracts were administered by intratracheal aspiration at doubling doses (2.5-80 μg protein) 4X over a four-week period. Three days after the last exposure, serum and bronchoalveolar lavage fluid (BALF) were collected. The extracts' relative allergenicity was evaluated based on response robustness (lowest significant dose response compared to control (0 μg)). MACA induced a more robust serum total IgE response than HDM. However, in the antigen-specific IgE assay, a similar dose of both MACA and HDM was required to achieve the same response level. Our data suggest a threshold dose of MACA for allergy induction and that M. anisopliae may be similar to HDM in allergy induction potential. PMID:21785589

  20. Dendritic cells induce Th2-mediated airway inflammatory responses to house dust mite via DNA-dependent protein kinase

    PubMed Central

    Mishra, Amarjit; Brown, Alexandra L.; Yao, Xianglan; Yang, Shutong; Park, Sung-Jun; Liu, Chengyu; Dagur, Pradeep K.; McCoy, J. Philip; Keeran, Karen J.; Nugent, Gayle Z.; Jeffries, Kenneth R.; Qu, Xuan; Yu, Zu-Xi; Levine, Stewart J.; Chung, Jay H.

    2015-01-01

    DNA-dependent protein kinase (DNA-PK) mediates double stranded DNA break repair, V(D)J recombination, and immunoglobulin class switch recombination, as well as innate immune and pro-inflammatory responses. However, there is limited information regarding the role of DNA-PK in adaptive immunity mediated by dendritic cells (DCs), which are the primary antigen-presenting cells in allergic asthma. Here we show that house dust mite induces DNA-PK phosphorylation, which is a marker of DNA-PK activation, in DCs via the generation of intracellular reactive oxygen species. We also demonstrate that pharmacological inhibition of DNA-PK, as well as the specific deletion of DNA-PK in DCs, attenuates the induction of allergic sensitization and Th2 immunity via a mechanism that involves the impaired presentation of mite antigens. Furthermore, pharmacological inhibition of DNA-PK following antigen priming similarly reduces the manifestations of mite-induced airway disease. Collectively, these findings suggest that DNA-PK may be a potential target for treatment of allergic asthma. PMID:25692509

  1. House-dust mite allergen and ozone exposure decreases histamine H3 receptors in the brainstem respiratory nuclei

    SciTech Connect

    Sekizawa, Shin-ichi; Bechtold, Andrea G.; Tham, Rick C.; Kott, Kayleen S.; Hyde, Dallas M.; Joad, Jesse P.; Bonham, Ann C.

    2010-09-15

    Allergic airway diseases in children are a common and a growing health problem. Changes in the central nervous system (CNS) have been implicated in contributing to some of the symptoms. We hypothesized that airway allergic diseases are associated with altered histamine H3 receptor expression in the nucleus tractus solitarius (NTS) and caudal spinal trigeminal nucleus, where lung/airway and nasal sensory afferents terminate, respectively. Immunohistochemistry for histamine H3 receptors was performed on brainstem sections containing the NTS and the caudal spinal trigeminal nucleus from 6- and 12-month-old rhesus monkeys who had been exposed for 5 months to house dust mite allergen (HDMA) + O{sub 3} or to filtered air (FA). While histamine H3 receptors were found exclusively in astrocytes in the caudal spinal trigeminal nucleus, they were localized to both neuronal terminals and processes in the NTS. HDMA + O{sub 3} exposure significantly decreased histamine H3 receptor immunoreactivity in the NTS at 6 months and in the caudal spinal trigeminal nucleus at 12 months of age. In conclusion, exposing young primates to HDMA + O{sub 3} changed histamine H3 receptor expression in CNS pathways involving lung and nasal afferent nerves in an age-related manner. Histamine H3 receptors may be a therapeutic target for allergic asthma and rhinitis in children.

  2. Nanoparticle conjugation enhances the immunomodulatory effects of intranasally delivered CpG in house dust mite-allergic mice.

    PubMed

    Ballester, Marie; Jeanbart, Laura; de Titta, Alexandre; Nembrini, Chiara; Marsland, Benjamin J; Hubbell, Jeffrey A; Swartz, Melody A

    2015-01-01

    An emerging strategy in preventing and treating airway allergy consists of modulating the immune response induced against allergens in the lungs. CpG oligodeoxynucleotides have been investigated in airway allergy studies, but even if promising, efficacy requires further substantiation. We investigated the effect of pulmonary delivery of nanoparticle (NP)-conjugated CpG on lung immunity and found that NP-CpG led to enhanced recruitment of activated dendritic cells and to Th1 immunity compared to free CpG. We then evaluated if pulmonary delivery of NP-CpG could prevent and treat house dust mite-induced allergy by modulating immunity directly in lungs. When CpG was administered as immunomodulatory therapy prior to allergen sensitization, we found that NP-CpG significantly reduced eosinophilia, IgE levels, mucus production and Th2 cytokines, while free CpG had only a moderate effect on these parameters. In a therapeutic setting where CpG was administered after allergen sensitization, we found that although both free CpG and NP-CpG reduced eosinophilia and IgE levels to the same extent, NP conjugation of CpG significantly enhanced reduction of Th2 cytokines in lungs of allergic mice. Taken together, these data highlight benefits of NP conjugation and the relevance of NP-CpG as allergen-free therapy to modulate lung immunity and treat airway allergy. PMID:26387548

  3. T cells are necessary for ILC2 activation in house dust mite-induced allergic airway inflammation in mice.

    PubMed

    Li, Bobby W S; de Bruijn, Marjolein J W; Tindemans, Irma; Lukkes, Melanie; KleinJan, Alex; Hoogsteden, Henk C; Hendriks, Rudi W

    2016-06-01

    Allergic asthma is a chronic inflammation of the airways mediated by an adaptive type 2 immune response. Upon allergen exposure, group 2 innate lymphoid cells (ILC2s) can be rapidly activated and represent an early innate source of IL-5 and IL-13. Here, we used a house dust mite (HDM)-driven asthma mouse model to study the induction of ILC2s in allergic airway inflammation. In BALF, lungs, and lymph nodes, ILC2 activation is critically dependent on prior sensitization with HDM. Importantly, T cells are required for ILC2 induction, whereby T-cell activation precedes ILC2 induction. During HDM-driven allergic airway inflammation the accumulation of ILC2s in BALF is IL-33 independent, although infiltrating ILC2s produce less cytokines in Il33(-/-) mice. Transfer of in vitro polarized OVA-specific OT-II Th2 cells alone or in combination with Th17 cells followed by OVA and HDM challenge is not sufficient to induce ILC2, despite significant eosinophilic inflammation and T-cell activation. In this asthma model, ILC2s are therefore not an early source of Th2 cytokines, but rather contribute to type 2 inflammation in which Th2 cells play a key role. Taken together, ILC2 induction in HDM-mediated allergic airway inflammation in mice critically depends on activation of T cells. PMID:27062360

  4. Der p 11 is a major allergen for house dust mite-allergic patients suffering from atopic dermatitis.

    PubMed

    Banerjee, Srinita; Resch, Yvonne; Chen, Kuan-Wei; Swoboda, Ines; Focke-Tejkl, Margit; Blatt, Katharina; Novak, Natalija; Wickman, Magnus; van Hage, Marianne; Ferrara, Rosetta; Mari, Adriano; Purohit, Ashok; Pauli, Gabrielle; Sibanda, Elopy N; Ndlovu, Portia; Thomas, Wayne R; Krzyzanek, Vladislav; Tacke, Sebastian; Malkus, Ursula; Valent, Peter; Valenta, Rudolf; Vrtala, Susanne

    2015-01-01

    House dust mites (HDMs) belong to the most potent indoor allergen sources worldwide and are associated with allergic manifestations in the respiratory tract and the skin. Here we studied the importance of the high-molecular-weight group 11 allergen from Dermatophagoides pteronyssinus (Der p 11) in HDM allergy. Sequence analysis showed that Der p 11 has high homology to paramyosins from mites, ticks, and other invertebrates. A synthetic gene coding for Der p 11 was expressed in Escherichia coli and rDer p 11 purified to homogeneity as folded, alpha-helical protein as determined by circular dichroism spectroscopy. Using antibodies raised against rDer p 11 and immunogold electron microscopy, the allergen was localized in the muscle beneath the skin of mite bodies but not in feces. IgE reactivity of rDer p 11 was tested with sera from HDM-allergic patients from Europe and Africa in radioallergosorbent test-based dot-blot assays. Interestingly, we found that Der p 11 is a major allergen for patients suffering from atopic dermatitis (AD), whereas it is only a minor allergen for patients suffering from respiratory forms of HDM allergy. Thus, rDer p 11 might be a useful serological marker allergen for the identification of a subgroup of HDM-allergic patients suffering from HDM-associated AD. PMID:24999597

  5. Der p 11 Is a Major Allergen for House Dust Mite-Allergic Patients Suffering from Atopic Dermatitis

    PubMed Central

    Banerjee, Srinita; Resch, Yvonne; Chen, Kuan-Wei; Swoboda, Ines; Focke-Tejkl, Margit; Blatt, Katharina; Novak, Natalija; Wickman, Magnus; van Hage, Marianne; Ferrara, Rosetta; Mari, Adriano; Purohit, Ashok; Pauli, Gabrielle; Sibanda, Elopy N.; Ndlovu, Portia; Thomas, Wayne R.; Krzyzanek, Vladislav; Tacke, Sebastian; Malkus, Ursula; Valent, Peter; Valenta, Rudolf; Vrtala, Susanne

    2015-01-01

    House dust mites (HDMs) belong to the most potent indoor allergen sources worldwide and are associated with allergic manifestations in the respiratory tract and the skin. Here we studied the importance of the high-molecular-weight group 11 allergen from Dermatophagoides pteronyssinus (Der p 11) in HDM allergy. Sequence analysis showed that Der p 11 has high homology to paramyosins from mites, ticks, and other invertebrates. A synthetic gene coding for Der p 11 was expressed in Escherichia coli and rDer p 11 purified to homogeneity as folded, alpha-helical protein as determined by circular dichroism spectroscopy. Using antibodies raised against rDer p 11 and immunogold electron microscopy, the allergen was localized in the muscle beneath the skin of mite bodies but not in feces. IgE reactivity of rDer p 11 was tested with sera from HDM-allergic patients from Europe and Africa in radioallergosorbent test–based dot-blot assays. Interestingly, we found that Der p 11 is a major allergen for patients suffering from atopic dermatitis (AD), whereas it is only a minor allergen for patients suffering from respiratory forms of HDM allergy. Thus, rDer p 11 might be a useful serological marker allergen for the identification of a subgroup of HDM-allergic patients suffering from HDM-associated AD. PMID:24999597

  6. Nanoparticle conjugation enhances the immunomodulatory effects of intranasally delivered CpG in house dust mite-allergic mice

    PubMed Central

    Ballester, Marie; Jeanbart, Laura; de Titta, Alexandre; Nembrini, Chiara; Marsland, Benjamin J.; Hubbell, Jeffrey A.; Swartz, Melody A.

    2015-01-01

    An emerging strategy in preventing and treating airway allergy consists of modulating the immune response induced against allergens in the lungs. CpG oligodeoxynucleotides have been investigated in airway allergy studies, but even if promising, efficacy requires further substantiation. We investigated the effect of pulmonary delivery of nanoparticle (NP)-conjugated CpG on lung immunity and found that NP-CpG led to enhanced recruitment of activated dendritic cells and to Th1 immunity compared to free CpG. We then evaluated if pulmonary delivery of NP-CpG could prevent and treat house dust mite-induced allergy by modulating immunity directly in lungs. When CpG was administered as immunomodulatory therapy prior to allergen sensitization, we found that NP-CpG significantly reduced eosinophilia, IgE levels, mucus production and Th2 cytokines, while free CpG had only a moderate effect on these parameters. In a therapeutic setting where CpG was administered after allergen sensitization, we found that although both free CpG and NP-CpG reduced eosinophilia and IgE levels to the same extent, NP conjugation of CpG significantly enhanced reduction of Th2 cytokines in lungs of allergic mice. Taken together, these data highlight benefits of NP conjugation and the relevance of NP-CpG as allergen-free therapy to modulate lung immunity and treat airway allergy. PMID:26387548

  7. Allergic Responses Induced by a Fungal Biopesticide Metarhizium anisopliae and House Dust Mite Are Compared in a Mouse Model

    PubMed Central

    Ward, Marsha D. W.; Chung, Yong Joo; Copeland, Lisa B.; Doerfler, Donald L.

    2011-01-01

    Biopesticides can be effective in controlling their target pest. However, research regarding allergenicity and asthma development is limited. We compared the ability of fungal biopesticide Metarhizium anisopliae (MACA) and house dust mite (HDM) extracts to induce allergic responses in BALB/c mice. The extracts were administered by intratracheal aspiration at doubling doses (2.5–80 μg protein) 4X over a four-week period. Three days after the last exposure, serum and bronchoalveolar lavage fluid (BALF) were collected. The extracts' relative allergenicity was evaluated based on response robustness (lowest significant dose response compared to control (0 μg)). MACA induced a more robust serum total IgE response than HDM. However, in the antigen-specific IgE assay, a similar dose of both MACA and HDM was required to achieve the same response level. Our data suggest a threshold dose of MACA for allergy induction and that M. anisopliae may be similar to HDM in allergy induction potential. PMID:21785589

  8. Nanoparticle conjugation enhances the immunomodulatory effects of intranasally delivered CpG in house dust mite-allergic mice

    DOE PAGESBeta

    Ballester, Marie; Jeanbart, Laura; de Titta, Alexandre; Nembrini, Chiara; Marsland, Benjamin J.; Hubbell, Jeffrey A.; Swartz, Melody A.

    2015-09-21

    An emerging strategy in preventing and treating airway allergy consists of modulating the immune response induced against allergens in the lungs. CpG oligodeoxynucleotides have been investigated in airway allergy studies, but even if promising, efficacy requires further substantiation. We investigated the effect of pulmonary delivery of nanoparticle (NP)-conjugated CpG on lung immunity and found that NP-CpG led to enhanced recruitment of activated dendritic cells and to Th1 immunity compared to free CpG. We then evaluated if pulmonary delivery of NP-CpG could prevent and treat house dust mite-induced allergy by modulating immunity directly in lungs. When CpG was administered as immunomodulatorymore » therapy prior to allergen sensitization, we found that NP-CpG significantly reduced eosinophilia, IgE levels, mucus production and Th2 cytokines, while free CpG had only a moderate effect on these parameters. In a therapeutic setting where CpG was administered after allergen sensitization, we found that although both free CpG and NP-CpG reduced eosinophilia and IgE levels to the same extent, NP conjugation of CpG significantly enhanced reduction of Th2 cytokines in lungs of allergic mice. Taken together, these data highlight benefits of NP conjugation and the relevance of NP-CpG as allergen-free therapy to modulate lung immunity and treat airway allergy.« less

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

    PubMed

    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

    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-1α. Likewise, GM-CSF administration in vivo resulted in increased levels of IL-33 but not IL-1α. 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

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

    PubMed Central

    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

    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-1α. Likewise, GM-CSF administration in vivo resulted in increased levels of IL-33 but not IL-1α. 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

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

    PubMed

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

    2012-05-01

    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 μg), 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

  12. House dust (1–3)-β-D-glucan and wheezing in infants

    PubMed Central

    Iossifova, Y. Y.; Reponen, T.; Bernstein, D. I.; Levin, L.; Kalra, H.; Campo, P.; Villareal, M.; Lockey, J.; Hershey, G. K. K.; LeMasters, G.

    2007-01-01

    Background (1–3)-β-D-glucan is a fungal cell wall component, suspected to cause respiratory symptoms in adults. However, very little is known on the possible health effects of (1–3)-β-D-glucan during infancy. We examined the association between (1–3)-β-D-glucan exposure and the prevalence of allergen sensitization and wheezing during the first year of life in a birth cohort of 574 infants born to atopic parents. Endotoxin exposure was included as a possible confounder. Methods (1–3)-β-D-glucan and endotoxin exposures were measured in settled dust collected from infants’ primary activity rooms. The primary outcomes at approximately age one included parental reports of recurrent wheezing and allergen sensitization evaluated by skin prick testing to a panel of 15 aeroallergens as well as milk and egg white. Results Exposure to high (1–3)-β-D-glucan concentration (within fourth quartile) was associated with reduced likelihood of both recurrent wheezing [adjusted OR (aOR) = 0.39, 95% CI = 0.16–0.93] and recurrent wheezing combined with allergen sensitization (aOR = 0.13, 95% CI = 0.03–0.61). Similar trends were found between (1–3)-β-D-glucan concentrations and allergen sensitization (aOR = 0.57, 95% CI = 0.30–1.10). In contrast, recurrent wheezing with or without allergen sensitization was positively associated with low (1–3)-β-D-glucan exposure within the first quartile (aOR = 3.04, 95% CI = 1.25–7.38; aOR = 4.89, 95% CI = 1.02–23.57). There were no significant associations between endotoxin exposure and the studied health outcomes. Conclusions This is the first study to report that indoor exposure to high levels of (1–3)-β-D-glucan (concentration >60 μg/g) is associated with decreased risk for recurrent wheezing among infants born to atopic parents. This effect was more pronounced in the subgroup of allergen-sensitized infants. PMID:17441791

  13. Determination of parabens in house dust by pressurised hot water extraction followed by stir bar sorptive extraction and thermal desorption-gas chromatography-mass spectrometry.

    PubMed

    Ramírez, Noelia; Marcé, Rosa Maria; Borrull, Francesc

    2011-09-16

    This study describes the development of a new method for determining p-hydroxybenzoic esters (parabens) in house dust. This optimised method was based on the pressurised hot water extraction (PHWE) of house dust, followed by the acetylation of the extracted parabens, stir bar sorptive extraction (SBSE) with a polydimethylsiloxane stir bar, and finally analysis using thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). The combination of SBSE and PHWE allows the analytes to be preconcentrated and extracted from the aqueous extract in a single step with minimal manipulation of the sample. Furthermore the in situ acetylation of parabens prior to SBSE improved their extraction efficiency and their GC-MS signal. The method showed recoveries of between 40 and 80%, good linearity, repeatability and reproducibility (<10% RSD, at 100 ng g(-1), n=5), low limits of detection (from 1.0 ng g(-1) for propyl paraben to 2.1 ng g(-1) for methyl paraben) and quantification (from 3.3 ng g(-1) for propyl paraben to 8.5 ng g(-1) for methyl paraben). The proposed method was applied to the analysis of house dust samples. All the target parabens were found in the samples. Methyl and propyl parabens were the most abundant, with concentrations up to 2440 ng g(-1) and 910 ng g(-1), respectively. The high levels of parabens found in the samples confirm the importance of determining organic contaminants in indoor environments. PMID:21802088

  14. Tracing dust transport from Middle-East over Delhi in March 2012 using metal and lead isotope composition

    NASA Astrophysics Data System (ADS)

    Kumar, S.; Aggarwal, S. G.; Malherbe, J.; Barre, J. P. G.; Berail, S.; Gupta, P. K.; Donard, O. F. X.

    2016-05-01

    A severe dust-storm which was originated in Middle-East crossed over Delhi during March 20-22, 2012. We have collected these dust-storm (DS) aerosol samples, and analyzed them for selected metals (As, Cd, Cr, Cu, Fe, Ni, Pb, Sb, Se, Sn, Sr, V and Zn) together with after dust-storm (ADS) and winter (WS) samples. High aerosol mass loadings were observed in DS samples (1097-1965 μg/m3). On the contrary, metals derived prominently from the anthropogenic sources were found lower in concentration compared to that of ADS and WS aerosols. We observed significantly high concentrations of Ni and V (which are abundantly found in crude oils of Middle-East origin) in the DS samples than that of ADS and WS samples. Also enrichment factor (EF) of these metals with respect to Fe shows no significant enrichment (<10). Fe (and Sr) concentrations were also 3-5 fold higher in DS samples compared to ADS and WS. These results suggest that Ni and V can be used as tracers for dust aerosols transported from Middle-East region. Lead isotope signatures can tell about the variation in the sources of urban aerosols. Therefore Pb isotope analyses of these samples were performed using MC-ICP-MS. The isotope ratios, 208Pb/206Pb is determined to be (mean ± sd) 2.1315 ± 0.0018, 2.1370 ± 0.0022 and 2.1389 ± 0.0016, whereas 206Pb/207Pb is 1.1311 ± 0.0022, 1.1244 ± 0.0017 and 1.1233 ± 0.0016 in DS, ADS and WS aerosols, respectively. There is a clear distinction in Pb isotope composition between DS and urban (ADS and WS) aerosols. Further, these results suggest that in urban aerosols, Pb is less radiogenic in nature compared to that of in transported dust aerosols collected in New Delhi.

  15. Oncostatin M synergises with house dust mite proteases to induce the production of PGE2 from cultured lung epithelial cells

    PubMed Central

    Knight, Darryl A; Asokananthan, Nithiananthan; Watkins, D Neil; Misso, Neil L A; Thompson, Philip J; Stewart, Geoffrey A

    2000-01-01

    The release of PGE2 and nitric oxide (NO) from the respiratory epithelium may act to dampen inflammation. In other tissues, oncostatin M (OSM), a potent inducer of epithelial antiproteases, has also been shown to interact with IL-1β to stimulate PGE2 release. However, whether OSM interacts with pro-inflammatory cytokines and proteases in the production of anti-inflammatory eicosanoids and NO from airway epithelium is unknown.The effect of OSM and the related cytokine leukaemia inhibitory factor (LIF) on PGE2 and NO production by the respiratory epithelial cell line, A549 in response to pro-inflammatory cytokines as well as protease-rich house dust mite (HDM) fractions and a protease-deficient rye grass pollen extract was examined by immunohistochemistry, cell culture, ELISA and enzyme-immunoassay.Cells treated with a mixture of IL-1β, IFNγ and LPS for 48 h produced a 9 fold increase in PGE2 and a 3 fold increase in NO levels (both P<0.05). Both OSM and LIF were without effect. However, OSM added together with the cytokine mixture synergistically enhanced PGE2 production (22 fold, P<0.05). OSM also synergistically enhanced PGE2 production in response to a cysteine protease-enriched, but not serine protease-enriched HDM fraction (P<0.05). Rye grass extract, neither alone nor in combination with OSM, induced PGE2 or NO production, although it did induce the release of GM-CSF.These observations suggest that OSM is an important co-factor in the release of PGE2 and NO from respiratory epithelial cells and may play a role in defense against exogenous proteases such as those derived from HDM. PMID:11015296

  16. Development of a poly (lactic-co-glycolic acid) particle vaccine to protect against house dust mite induced allergy.

    PubMed

    Joshi, Vijaya B; Adamcakova-Dodd, Andrea; Jing, Xuefang; Wongrakpanich, Amaraporn; Gibson-Corley, Katherine N; Thorne, Peter S; Salem, Aliasger K

    2014-09-01

    Poly(lactic-co-glycolic acid) (PLGA) particles carrying antigen and adjuvant is a promising vaccine system which has been shown to stimulate systemic antigen-specific immune responses. In this study, we investigated the relationship of (i) the sizes of PLGA particle and (ii) the presence of cytosine-phosphate-guanine motifs (CpG), with the extent and type of immune response stimulated against Dermatophagoides pteronyssinus-2 (Der p2) antigen. Different sizes of PLGA particles encapsulating CpG were prepared using a double emulsion solvent evaporation method. Mice were vaccinated with Der p2 and different sizes of empty or CpG-loaded PLGA particles. Vaccinated mice were exposed to daily intranasal instillation of Der p2 for 10 days followed by euthanization to estimate leukocyte accumulation in bronchoalveolar lavage (BAL) fluids, antibody profiles, and airway hyperresponsiveness. PLGA particles showed a size-dependent decrease in the proportion of eosinophils found in BAL fluids. Mice vaccinated with the Der p2 coated on 9-μm-sized empty PLGA particles showed increased levels of IgE and IgG1 antibodies as well as increased airway hyperresponsiveness. All sizes of PLGA particles encapsulating CpG prevented airway hyperresponsiveness after Der p2 exposures. Inflammatory responses to Der p2 exposure were significantly reduced when smaller PLGA particles were used for vaccination. In addition, encapsulating CpG in PLGA particles increased IgG2a secretion. This study shows that the size of PLGA particles used for vaccination plays a major role in the prevention of house dust mite-induced allergy and that incorporation of CpG into the PLGA particles preferentially develops a Th1-type immune response. PMID:24981892

  17. Proteins and endotoxin in house dust mite extracts modulate cytokine secretion and gene expression by dermal fibroblasts.

    PubMed

    Rockwood, Jananie; Morgan, Marjorie S; Arlian, Larry G

    2013-11-01

    House dust mite extracts used for diagnostic tests and immunotherapy contain bioreactive molecules including proteins and endotoxin. These extracts can influence the cytokine secretion and adhesion molecule expression by cells in the skin and lung airways. The aim of this study was to determine the role of proteins and endotoxin in mite extracts in modulating gene expression and cytokine secretion by human dermal fibroblasts. Cultured normal human dermal fibroblasts were stimulated with whole mite extracts, mite extracts boiled to denature proteins, or mite extracts treated with polymyxin B to inactivate lipopolysaccharide. Gene expression and secretion of interleukin-6 (IL-6), IL-8, and monocyte chemoattractant protein-1 (MCP-1) were determined after 6 h of stimulation. Whole Dermatophagoides farinae, D. pteronyssinus and Euroglyphus maynei extracts induced dose-dependent IL-6 and IL-8 secretion. In addition, D. farinae and E. maynei induced secretion of MCP-1. Dermatophagoides farinae and E. maynei also induced parallel cytokine gene expression. Cells stimulated with boiled D. farinae extract showed moderate to marked reductions in IL-6 and IL-8 secretion. In contrast, boiled D. pteronyssinus and E. maynei extracts induced equal or greater cytokine secretions than untreated extracts. The stimulating properties were reduced for all three extracts following treatment with polymyxin B. Our data suggest that both endotoxin and proteins in mite extracts modulate the secretion of cytokines by dermal fibroblasts. The biological activities of D. farinae, D. pteronyssinus, and E. maynei extracts are not equivalent. There appears to be a lipopolysaccharide-binding protein in some mite extracts. PMID:23640713

  18. Immunomodulation of airway epithelium cell activation by mesenchymal stromal cells ameliorates house dust mite-induced airway inflammation in mice.

    PubMed

    Duong, Khang M; Arikkatt, Jaisy; Ullah, M Ashik; Lynch, Jason P; Zhang, Vivian; Atkinson, Kerry; Sly, Peter D; Phipps, Simon

    2015-11-01

    Allergic asthma is underpinned by T helper 2 (Th2) inflammation. Redundancy in Th2 cytokine function and production by innate and adaptive immune cells suggests that strategies aimed at immunomodulation may prove more beneficial. Hence, we sought to determine whether administration of mesenchymal stromal cells (MSCs) to house dust mite (HDM) (Dermatophagoides pteronyssinus)-sensitized mice would suppress the development of Th2 inflammation and airway hyperresponsiveness (AHR) after HDM challenge. We report that the intravenous administration of allogeneic donor MSCs 1 hour before allergen challenge significantly attenuated the features of allergic asthma, including tissue eosinophilia, Th2 cytokine (IL-5 and IL-13) levels in bronchoalveolar lavage fluid, and AHR. The number of infiltrating type 2 innate lymphoid cells was not affected by MSC transfer, suggesting that MSCs may modulate the adaptive arm of Th2 immunity. The effect of MSC administration was long lasting; all features of allergic airway disease were significantly suppressed in response to a second round of HDM challenge 4 weeks after MSC administration. Further, we observed that MSCs decreased the release of epithelial cell-derived alarmins IL-1α and high mobility group box-1 in an IL-1 receptor antagonist-dependent manner. This significantly decreased the expression of the pro-Th2 cytokine IL-25 and reduced the number of activated and antigen-acquiring CD11c(+)CD11b(+) dendritic cells in the lung and mediastinal lymph nodes. Our findings suggest that MSC administration can ameliorate allergic airway inflammation by blunting the amplification of epithelial-derived inflammatory cytokines induced by HDM exposure and may offer long-term protection against Th2-mediated allergic airway inflammation and AHR. PMID:25789608

  19. Effect of high-dose sublingual immunotherapy on respiratory infections in children allergic to house dust mite

    PubMed Central

    Barberi, Salvatore; Verduci, Elvira; D'Auria, Enza; Poli, Piercarlo; Pietra, Benedetta; Incorvaia, Cristoforo; Buttafava, Serena; Frati, Franco; Riva, Enrica

    2015-01-01

    Background Allergic rhinitis is characterized by eosinophil inflammation. Allergic inflammation may induce susceptibility to respiratory infections (RI). House dust mite (HDM) sensitization is very frequent in childhood. Allergen immunotherapy may cure allergy as it restores a physiologic immune and clinical tolerance to allergen and exerts anti-inflammatory activity. Objective This study investigated whether six-month high-dose, such as 300 IR (index of reactivity), HDM-sublingual immunotherapy (SLIT) could affect RI in allergic children. Methods Globally, 40 HDM allergic children (18 males; mean age, 9.3 years) were subdivided in 2 groups: 20 treated by symptomatic drugs (group 1) and 20 by high-dose HDM-SLIT (group 2), since September 2012 to April 2013. The daily maintenance dose of HDM-SLIT was 4 pressures corresponding to 24, 4.8, and 60 µg, respectively of the major allergens Dermatophagoides pteronyssinus (Der p) 1, Der p 2, and Dermatophagoides farinae (Der f) 1. RI was diagnosed when at least 2 symptoms or signs, and fever were present for at least 48 hours. A family pediatrician provided diagnosis on a clinical ground. Results SLIT-treated children had significantly (p = 0.01) less RI episodes (3.5) than control group (5.45). About secondary outcomes, SLIT-treated children had less episodes of pharyngo-tonsillitis (p < 0.05) and bronchitis (p < 0.005), and snoring (p < 0.05) than control group. In addition, SLIT-treated children had less fever (p < 0.01) and took fewer medications, such as antibiotics (p < 0.05) and fever-reducers (p < 0.01), than control group. Conclusion This preliminary study might suggest that also a short course (6 months) of high-dose SLIT, titrated in µg of major allergens, could reduce RI in allergic children. PMID:26240793

  20. A CCL24-dependent pathway augments eosinophilic airway inflammation in house dust mite-challenged Cd163(-/-) mice.

    PubMed

    Dai, C; Yao, X; Gordon, E M; Barochia, A; Cuento, R A; Kaler, M; Meyer, K S; Keeran, K J; Nugent, G Z; Jeffries, K R; Qu, X; Yu, Z-X; Aponte, A; Gucek, M; Dagur, P K; McCoy, J P; Levine, S J

    2016-05-01

    CD163 is a macrophage scavenger receptor with anti-inflammatory and pro-inflammatory functions. Here, we report that alveolar macrophages (AMΦs) from asthmatic subjects had reduced cell-surface expression of CD163, which suggested that CD163 might modulate the pathogenesis of asthma. Consistent with this, house dust mite (HDM)-challenged Cd163(-/-) mice displayed increases in airway eosinophils and mucous cell metaplasia (MCM). The increased airway eosinophils and MCM in HDM-challenged Cd163(-/-) mice were mediated by augmented CCL24 production and could be reversed by administration of a neutralizing anti-CCL24 antibody. A proteomic analysis identified the calcium-dependent binding of CD163 to Dermatophagoides pteronyssinus peptidase 1 (Der p1). Der p1-challenged Cd163(-/-) mice had the same phenotype as HDM-challenged Cd163(-/-) mice with increases in airway eosinophils, MCM and CCL24 production, while Der p1 induced CCL24 secretion by bone marrow-derived macrophages (BMMΦs) from Cd163(-/-) mice, but not BMMΦs from wild-type (WT) mice. Finally, airway eosinophils and bronchoalveolar lavage fluid CCL24 levels were increased in Der p1-challenged WT mice that received adoptively transferred AMΦ's from Cd163(-/-) mice. Thus, we have identified CD163 as a macrophage receptor that binds Der p1. Furthermore, we have shown that HDM-challenged Cd163(-/-) mice have increased eosinophilic airway inflammation and MCM that are mediated by a CCL24-dependent mechanism. PMID:26376364

  1. Retrospective Analysis on the Effects of House Dust Mite Specific Immunotherapy for More Than 3 Years in Atopic Dermatitis

    PubMed Central

    Lee, Jungsoo; Lee, Hemin; Noh, Seongmin; Bae, Byung Gi; Shin, Jung U; Park, Chang Ook

    2016-01-01

    Purpose In extrinsic atopic dermatitis (AD), house dust mites (HDM) play a role in eliciting or aggravating allergic lesions. The nature of skin inflammation in AD has raised a growing interest in allergen-specific immunotherapy (SIT). Thus, we assessed clinical improvement and laboratory parameters for evaluation of the benefit of long-term SIT. Materials and Methods A total of 217 AD patients who were treated with SIT for at least 3 years were retrospectively assessed, by using their investigator global assessment, pruritus scores, loss of sleep (LOS), total serum IgE, and eosinophil counts collected. Patients were additionally classified into subgroups according to age, initial AD severity and mono- or multi-sensitization to include different individual factors in the evaluation of SIT efficacy. Lastly, we compared laboratory data of good responders to SIT with that of poor responders to SIT. Results Improvement after SIT therapy was observed in 192 out of 217 patients (88.4%). Among these patients, 138 (63.5%) achieved excellent, near-complete or complete clinical remission. Significant reduction of pruritus, LOS, and the mean value of total serum IgE were observed (p<0.01). Better outcome was found in patients younger than 12 years of age (p=0.024). Patients with moderate to severe AD showed better treatment outcomes (p=0.036). Patients sensitized only to HDM had the better response to treatment, but SIT was also effective in multi-sensitized groups (p=1.051). No significant differences in baseline laboratory results were observed between good and poor responders (p>0.05). Conclusion We emphasize the usefulness of long-term HDM SIT as a disease-modifying therapy for AD. PMID:26847292

  2. Overexpression of Smad2 Drives House Dust Mite–mediated Airway Remodeling and Airway Hyperresponsiveness via Activin and IL-25

    PubMed Central

    Gregory, Lisa G.; Mathie, Sara A.; Walker, Simone A.; Pegorier, Sophie; Jones, Carla P.; Lloyd, Clare M.

    2010-01-01

    Rationale: Airway hyperreactivity and remodeling are characteristic features of asthma. Interactions between the airway epithelium and environmental allergens are believed to be important in driving development of pathology, particularly because altered epithelial gene expression is common in individuals with asthma. Objectives: To investigate the interactions between a modified airway epithelium and a common aeroallergen in vivo. Methods: We used an adenoviral vector to generate mice overexpressing the transforming growth factor-β signaling molecule, Smad2, in the airway epithelium and exposed them to house dust mite (HDM) extract intranasally. Measurements and Main Results: Smad2 overexpression resulted in enhanced airway hyperreactivity after allergen challenge concomitant with changes in airway remodeling. Subepithelial collagen deposition was increased and smooth muscle hyperplasia was evident resulting in thickening of the airway smooth muscle layer. However, there was no increase in airway inflammation in mice given the Smad2 vector compared with the control vector. Enhanced airway hyperreactivity and remodeling did not correlate with elevated levels of Th2 cytokines, such as IL-13 or IL-4. However, mice overexpressing Smad2 in the airway epithelium showed significantly enhanced levels of IL-25 and activin A after HDM exposure. Blocking activin A with a neutralizing antibody prevented the increase in lung IL-25 and inhibited subsequent collagen deposition and also the enhanced airway hyperreactivity observed in the Smad2 overexpressing HDM-exposed mice. Conclusions: Epithelial overexpression of Smad2 can specifically alter airway hyperreactivity and remodeling in response to an aeroallergen. Moreover, we have identified novel roles for IL-25 and activin A in driving airway hyperreactivity and remodeling. PMID:20339149

  3. PARP is activated in human asthma and its inhibition by olaparib blocks house dust mite-induced disease in mice.

    PubMed

    Ghonim, Mohamed A; Pyakurel, Kusma; Ibba, Salome V; Wang, Jeffrey; Rodriguez, Paulo; Al-Khami, Amir A; Lammi, Matthew R; Kim, Hogyoung; Zea, Arnold H; Davis, Christian; Okpechi, Samuel; Wyczechowska, Dorota; Al-Ghareeb, Kamel; Mansy, Moselhy S; Ochoa, Augusto; Naura, Amarjit S; Boulares, A Hamid

    2015-12-01

    Our laboratory established a role for poly(ADP-ribose)polymerase (PARP) in asthma. To increase the clinical significance of our studies, it is imperative to demonstrate that PARP is actually activated in human asthma, to examine whether a PARP inhibitor approved for human testing such as olaparib blocks already-established chronic asthma traits in response to house dust mite (HDM), a true human allergen, in mice and to examine whether the drug modulates human cluster of differentiation type 4 (CD4(+)) T-cell function. To conduct the study, human lung specimens and peripheral blood mononuclear cells (PBMCs) and a HDM-based mouse asthma model were used. Our results show that PARP is activated in PBMCs and lung tissues of asthmatics. PARP inhibition by olaparib or gene knockout blocked established asthma-like traits in mice chronically exposed to HDM including airway eosinophilia and hyper-responsiveness. These effects were linked to a marked reduction in T helper 2 (Th2) cytokine production without a prominent effect on interferon (IFN)-γ or interleukin (IL)-10. PARP inhibition prevented HDM-induced increase in overall cellularity, weight and CD4(+) T-cell population in spleens of treated mice whereas it increased the T-regulatory cell population. In CD3/CD28-stimulated human CD4 (+)T-cells, olaparib treatment reduced Th2 cytokine production potentially by modulating GATA binding protein-3 (gata-3)/IL-4 expression while moderately affecting T-cell proliferation. PARP inhibition inconsistently increased IL-17 in HDM-exposed mice and CD3/CD28-stimulated CD4(+) T cells without a concomitant increase in factors that can be influenced by IL-17. In the present study, we provide evidence for the first time that PARP-1 is activated in human asthma and that its inhibition is effective in blocking established asthma in mice. PMID:26205779

  4. Lead isotopes combined with a sequential extraction procedure for source apportionment in the dry deposition of Asian dust and non-Asian dust.

    PubMed

    Lee, Pyeong-Koo; Yu, Soonyoung

    2016-03-01

    Lead isotopic compositions were determined in leachates that were generated using sequential extractions of dry deposition samples of Asian dust (AD) and non-Asian dust (NAD) and Chinese desert soils, and used to apportion Pb sources. Results showed significant differences in (206)Pb/(207)Pb and (206)Pb/(204)Pb isotopic compositions in non-residual fractions between the dry deposition samples and the Chinese desert soils while (206)Pb/(207)Pb and (206)Pb/(204)Pb isotopic compositions in residual fraction of the dry deposition of AD and NAD were similar to the mean (206)Pb/(207)Pb and (206)Pb/(204)Pb in residual fraction of the Alashan Plateau soil. These results indicate that the geogenic materials of the dry deposition of AD and NAD were largely influenced by the Alashan Plateau soil, while the secondary sources of the dry deposition were different from those of the Chinese desert soils. In particular, the lead isotopic compositions in non-residual fractions of the dry deposition were homogenous, which implies that the non-residual four fractions (F1 to F4) shared the primary anthropogenic origin. (206)Pb/(207)Pb values and the predominant wind directions in the study area suggested that airborne particulates of heavily industrialized Chinese cities were one of the main Pb sources. Source apportionment calculations showed that the average proportion of anthropogenic Pb in the dry deposition of AD and NAD was 87% and 95% respectively in total Pb extraction, 92% and 97% in non-residual fractions, 15% and 49% in residual fraction. Approximately 81% and 80% of the anthropogenic Pb was contributed by coal combustion in China in the dry deposition of AD and NAD respectively while the remainder was derived from industrial Pb contamination. The research result proposes that sequential extractions with Pb isotope analysis are a useful tool for the discrimination of anthropogenic and geogenic origins in highly contaminated AD and NAD. PMID:26708760

  5. Evaluating the Bioaccessibility of Flame Retardants in House Dust Using an In Vitro Tenax Bead-Assisted Sorptive Physiologically Based Method

    PubMed Central

    2015-01-01

    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

  6. Road dust lead (Pb) in two neighborhoods of urban Atlanta, (GA, USA).

    PubMed

    Deocampo, Daniel M; Reed, Jack; Kalenuik, Alexander P

    2012-06-01

    Road dust continues to be a major potential reservoir of Pb in the urban environment, and an important potential component of child Pb exposure. This study presents ICP-AES analyses of metals in 72 samples of road dust (<250 µm) collected in the urban core of Atlanta, Georgia. In the Downtown area, median Pb concentrations are ~63 mg/kg Pb, with high values of 278 mg/kg. For comparison, median Pb values in a nearby residential neighborhood (also in the urban core) were ~93 mg/kg, with a high of 972 mg/kg. Geospatial variability is high, with significant variation observed over tens to hundreds of meters. Spearman Rank Correlation tests suggest that Pb and other metals (Cu, Ni, V, Zn) are associated with iron and manganese oxide phases in the residential area, as reported in other cities. However, Pb in the Downtown area is not correlated with the others, suggesting a difference in source or transport history. Given these complexities and the expected differences between road dust and soil Pb, future efforts to assess exposure risk should therefore be based on spatially distributed sampling at very high spatial resolution. PMID:22829787

  7. Road Dust Lead (Pb) in Two Neighborhoods of Urban Atlanta, (GA, USA)

    PubMed Central

    Deocampo, Daniel M.; Reed, Jack; Kalenuik, Alexander P.

    2012-01-01

    Road dust continues to be a major potential reservoir of Pb in the urban environment, and an important potential component of child Pb exposure. This study presents ICP-AES analyses of metals in 72 samples of road dust (<250 µm) collected in the urban core of Atlanta, Georgia. In the Downtown area, median Pb concentrations are ~63 mg/kg Pb, with high values of 278 mg/kg. For comparison, median Pb values in a nearby residential neighborhood (also in the urban core) were ~93 mg/kg, with a high of 972 mg/kg. Geospatial variability is high, with significant variation observed over tens to hundreds of meters. Spearman Rank Correlation tests suggest that Pb and other metals (Cu, Ni, V, Zn) are associated with iron and manganese oxide phases in the residential area, as reported in other cities. However, Pb in the Downtown area is not correlated with the others, suggesting a difference in source or transport history. Given these complexities and the expected differences between road dust and soil Pb, future efforts to assess exposure risk should therefore be based on spatially distributed sampling at very high spatial resolution. PMID:22829787

  8. 42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... fume, calculated as lead (Pb), per cubic meter of air. (d) The fume will be generated by impinging an..., which is analyzed and calculated as lead (Pb), shall not exceed 1.5 milligrams of lead for a...

  9. The correlations between heavy metals in residential indoor dust and outdoor street dust in Bahrain

    SciTech Connect

    Madany, I.M. ); Akhter, M.S.; Al Jowder, O.A. )

    1994-01-01

    The lead, zinc, cadmium, chromium, and nickel contents in both indoor house dust and outdoor street dust from 76 sites in Bahrain were determined by ICP-ES. The results showed widespread heavy metal contamination, especially lead, with an overall mean value in house dust for Pb, Zn, Cd, Cr, and Ni of 517, 202, 1.9, 11, and 10, respectively. The mean values in street dust were 742, 67, 1.5, 9.6, and 12 mg/kg, respectively. The major source of metals in street dust was automobile exhaust. The major source of heavy metals indoors was also from automobile dust, i.e., lead and nickel. With respect to zinc, cadmium, and chromium, indoor sources were more important than outdoor sources. The distribution of lead both indoors and outdoors in Bahrain showed high levels of contamination occurring generally in the north and northeastern part where traffic is concentrated. The levels of these toxic metals found in indoor house dust may be a significant source of exposure, especially for children.

  10. No Amount of Lead Is Safe for Kids

    MedlinePlus

    ... for lead hazards in house dust, water and soil are needed. The group also wants to see ... group. The AAP said other sources include contaminated soil and water, and certain toys, hobby materials, dishware, ...

  11. Cost-minimization analysis of sublingual immunotherapy versus subcutaneous immunotherapy for house dust mite respiratory allergic disease in Denmark.

    PubMed

    Rønborg, Steen; Johnsen, Claus R; Theilgaard, Sune; Winther, Anders; Hahn-Pedersen, Julie; Andreasen, Jakob Nørgaard; Olsen, Jens

    2016-08-01

    Objectives Currently, patients with persistent moderate-to-severe house dust mite (HDM) allergic rhinitis despite use of symptom-relieving medication can be offered subcutaneously administered allergy immunotherapy (SQ SCIT; Alutard SQ) as standard care of treatment in Denmark. Recently, a HDM sublingually administered allergy immunotherapy tablet (SQ SLIT-tablet; ACARIZAX) has been developed for at-home treatment. The purpose of this analysis is to compare the costs related to treatment and administration of SQ SLIT-tablet and SQ SCIT. Methods Assuming equal efficacy between ther SQ SLIT-tablet and SQ SCIT, the cost-minimization analysis was the most appropriate for the comparison. According to guidelines and Summary of Product Characteristics, the treatment duration of SQ SLIT-tablet is 3 years and 3-5 years for SQ SCIT. The courses of treatment vary among patients and, therefore, the costs of treatment have been calculated for an average patient with HDM respiratory allergic disease (RAD) receiving either SQ SLIT-tablet or SQ SCIT. All costs associated with allergy immunotherapy were collected, i.e., cost of medication, administration and treatment setting, and discounted according to Danish guidelines. Comprehensive univariate sensitivity analyses were carried out. Results The treatment costs for an average patient with HDM RAD are €3094 for SQ SLIT-tablet and €3799 for SQ SCIT; however, when adding indirect costs to the calculations the total costs of the treatments are €3697 and €6717 for SQ SLIT-tablet and SQ SCIT, respectively. Therefore, if 2500 patients with HDM RAD were treated with SQ SLIT-tablet instead of SQ SCIT, it would elicit a saving to the healthcare system of ∼€1.8 million. The conclusion was robust to any changes in the sensitivity analysis. Conclusion With regards to the cost of treating Danish patients with HDM RAD, it is clearly cost-saving to treat patients with SQ SLIT-tablet compared to SQ SCIT. PMID:26909663

  12. The complete mitochondrial genome of the house dust mite Dermatophagoides pteronyssinus (Trouessart): a novel gene arrangement among arthropods

    PubMed Central

    Dermauw, Wannes; Van Leeuwen, Thomas; Vanholme, Bartel; Tirry, Luc

    2009-01-01

    Background The apparent scarcity of available sequence data has greatly impeded evolutionary studies in Acari (mites and ticks). This subclass encompasses over 48,000 species and forms the largest group within the Arachnida. Although mitochondrial genomes are widely utilised for phylogenetic and population genetic studies, only 20 mitochondrial genomes of Acari have been determined, of which only one belongs to the diverse order of the Sarcoptiformes. In this study, we describe the mitochondrial genome of the European house dust mite Dermatophagoides pteronyssinus, the most important member of this largely neglected group. Results The mitochondrial genome of D. pteronyssinus is a circular DNA molecule of 14,203 bp. It contains the complete set of 37 genes (13 protein coding genes, 2 rRNA genes and 22 tRNA genes), usually present in metazoan mitochondrial genomes. The mitochondrial gene order differs considerably from that of other Acari mitochondrial genomes. Compared to the mitochondrial genome of Limulus polyphemus, considered as the ancestral arthropod pattern, only 11 of the 38 gene boundaries are conserved. The majority strand has a 72.6% AT-content but a GC-skew of 0.194. This skew is the reverse of that normally observed for typical animal mitochondrial genomes. A microsatellite was detected in a large non-coding region (286 bp), which probably functions as the control region. Almost all tRNA genes lack a T-arm, provoking the formation of canonical cloverleaf tRNA-structures, and both rRNA genes are considerably reduced in size. Finally, the genomic sequence was used to perform a phylogenetic study. Both maximum likelihood and Bayesian inference analysis clustered D. pteronyssinus with Steganacarus magnus, forming a sistergroup of the Trombidiformes. Conclusion Although the mitochondrial genome of D. pteronyssinus shares different features with previously characterised Acari mitochondrial genomes, it is unique in many ways. Gene order is extremely rearranged

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

    PubMed Central

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

    2012-01-01

    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

  14. Tracing dust transport from Middle-East over Delhi in March 2012 using metal and lead isotope composition

    NASA Astrophysics Data System (ADS)

    Kumar, S.; Aggarwal, S. G.; Malherbe, J.; Barre, J. P. G.; Berail, S.; Gupta, P. K.; Donard, O. F. X.

    2016-05-01

    A severe dust-storm which was originated in Middle-East crossed over Delhi during March 20-22, 2012. We have collected these dust-storm (DS) aerosol samples, and analyzed them for selected metals (As, Cd, Cr, Cu, Fe, Ni, Pb, Sb, Se, Sn, Sr, V and Zn) together with after dust-storm (ADS) and winter (WS) samples. High aerosol mass loadings were observed in DS samples (1097-1965 μg/m3). On the contrary, metals derived prominently from the anthropogenic sources were found lower in concentration compared to that of ADS and WS aerosols. We observed significantly high concentrations of Ni and V (which are abundantly found in crude oils of Middle-East origin) in the DS samples than that of ADS and WS samples. Also enrichment factor (EF) of these metals with respect to Fe shows no significant enrichment (<10). Fe (and Sr) concentrations were also 3-5 fold higher in DS samples compared to ADS and WS. These results suggest that Ni and V can be used as tracers for dust aerosols transported from Middle-East region. Lead isotope signatures can tell about the variation in the sources of urban aerosols. Therefore Pb isotope analyses of these samples were performed using MC-ICP-MS. The isotope ratios, 208Pb/206Pb is determined to be (mean ± sd) 2.1315 ± 0.0018, 2.1370 ± 0.0022 and 2.1389 ± 0.0016, whereas 206Pb/207Pb is 1.1311 ± 0.0022, 1.1244 ± 0.0017 and 1.1233 ± 0.0016 in DS, ADS and WS aerosols, respectively. There is a clear distinction in Pb isotope composition between DS and urban (ADS and WS) aerosols. Further, these results suggest that in urban aerosols, Pb is less radiogenic in nature compared to that of in transported dust aerosols collected in New Delhi.

  15. Removal of lead by using Raschig rings manufactured with mixture of cement kiln dust, zeolite and bentonite.

    PubMed

    Salem, A; Afshin, H; Behsaz, H

    2012-07-15

    The present investigation is a follow-up of study on manufacturing Raschig ring for removal of lead from aqueous solution. The mixtures were formulated using cement kiln dust, zeolite, and bentonite, normally used as natural adsorbents in the industrial scale, according to mixture design algorithm and response surface method. The pastes were prepared by addition of 28.0wt.% de-ionized water, containing 0.1wt.% carboxymethyl cellulose, with mixed powders. The adsorbents were fabricated by extrusion of the pastes in Raschig ring form and calcination at 500°C after drying in oven. The effects of starting materials on the mechanical behavior of rings were studied from view point of mixture design algorithm to optimize the adsorbent composition. This method demonstrated to yield valuable information on the effects of used materials on mechanical characteristics. The study concluded that the strength, reliability and sorption capacity of ring can be simultaneously optimized by the addition of 47.5wt.% cement kiln dust, 32.5wt.% zeolite, and 20.0wt.% bentonite. In the next part of work, the sorption kinetics was investigated. The kinetic study indicated that the modified model can successfully correlate the sorption data. The equilibrium result showed the possibility of lead immobilization by fabricated rings. PMID:22608209

  16. Lead, mercury, cadmium, chromium, nickel, copper, zinc, calcium, iron, manganese and chromium (VI) levels in Nigeria and United States of America cement dust.

    PubMed

    Ogunbileje, J O; Sadagoparamanujam, V-M; Anetor, J I; Farombi, E O; Akinosun, O M; Okorodudu, A O

    2013-03-01

    This study was aimed at investigating the relative abundance of heavy metals in cement dust from different cement dust factories in order to predict their possible roles in the severity of cement dust toxicity. The concentrations of total mercury (Hg), copper (Cu), chromium (Cr), cadmium (Cd), nickel (Ni), manganese (Mn), lead (Pb), iron (Fe) and chromium (VI) (Cr (VI)) levels in cement dust and clinker samples from Nigeria and cement dust sample from the United States of America (USA) were determined using graphite furnace atomic absorption (GFAAS), while Zn and Ca were measured by flame atomic absorption spectrophotometry (FAAS), and Cr (VI) by colorimetric method. Total Cu, Ni and Mn were significantly higher in cement dust sample from USA (p<0.05), also, both total Cr and Cr (VI) were 5.4-26 folds higher in USA cement dust compared with Nigeria cement dust or clinker (p<0.001). Total Cd was higher in both Nigeria cement dust and clinker (p<0.05 and p<0.001), respectively. Mercury was more in both Nigeria cement dust and clinker (p<0.05), while Pb was only significantly higher in clinker from Nigeria (p<0.001). These results show that cement dust contain mixture of metals that are known human carcinogens and also have been implicated in other debilitating health conditions. Additionally, it revealed that metal content concentrations are factory dependent. This study appears to indicate the need for additional human studies relating the toxicity of these metals and their health impacts on cement factory workers. PMID:23261125

  17. Combining datasets to predict the effects of regulation of environmental lead exposure in housing stock.

    PubMed

    Strauss, W J; Carroll, R J; Bortnick, S M; Menkedick, J R; Schultz, B D

    2001-03-01

    A model for children's blood lead concentrations as a function of environmental lead exposures was developed by combining two nationally representative sources of data that characterize the marginal distributions of blood lead and environmental lead with a third regional dataset that contains joint measures of blood lead and environmental lead. The complicating factor addressed in this article was the fact that methods for assessing environmental lead were different in the national and regional datasets. Relying on an assumption of transportability (that although the marginal distributions of blood lead and environmental lead may be different between the regional dataset and the nation as a whole, the joint relationship between blood lead and environmental lead is the same), the model makes use of a latent variable approach to estimate the joint distribution of blood lead and environmental lead nationwide. PMID:11252599

  18. Addressing Lead-Based Paint Hazards During Renovation, Remodeling, and Rehabilitation in Federally Owned and Assisted Housing. Instructor Manual for Use in HUD-Sponsored Lead-Safe Work Practices Training.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Washington, DC. Office of Pollution Prevention and Toxics.

    This document is the instructor's manual for a U.S. Department of Housing and Urban Development (HUD) training course that reflects the requirements of HUD's Lead Safe Housing Rule and is designed to provide training contractors with information regarding containment, minimization, and cleanup of lead hazards during activities that disturb…

  19. Metal enrichment and lead isotope analysis for source apportionment in the urban dust and rural surface soil.

    PubMed

    Yu, Yang; Li, Yingxia; Li, Ben; Shen, Zhenyao; Stenstrom, Michael K

    2016-09-01

    To understand the metal accumulation in the environment and identify its sources, 29 different metal contents and lead (Pb) isotope ratios were determined for 40 urban dust samples, 36 surface soil samples, and one river sediment sample collected in the municipality of Beijing, China. Results showed that cadmium, copper (Cu), mercury, Pb, antimony (Sb), and zinc demonstrated to be the typical urban contaminants and mostly influenced by the adjacent human activities with higher content to background ratios and SD values. Among the 29 metal elements investigated, Cu and Sb were found to be the most distinct elements that were highly affected by the developing level and congestion status of the cities with much higher contents in dust in more developed and congested cities. There was a relatively wider range of Pb isotope ratios of country surface soil than those of urban dust. The results of source identification based on Pb isotope ratios showed that coal combustion was the first largest Pb source and vehicle exhaust was the second largest source. The sum of them accounted for 74.6% mass proportion of overall Pb pollution on average. The surface soil sample collected at an iron mine had the highest (204)Pb/(206)Pb, (207)Pb/(206)Pb, and (208)Pb/(206)Pb ratios indicating ore had much higher ratios than other sources. The fine particle subsamples had higher (204)Pb/(206)Pb, (207)Pb/(206)Pb, and (208)Pb/(206)Pb ratios than the coarse particle subsamples indicating more anthropogenic sources of coal combustion and vehicle exhaust for fine particles and more background influence for coarse particles. These results help with pinpointing the major Pb sources and applying suitable measures for the target sources. PMID:27376990

  20. Sources of halogenated brominated retardants in house dust in an industrial city in southern China and associated human exposure.

    PubMed

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

    2014-11-01

    Halogenated flame retardants (HFRs) are a class of ubiquitous pollutants in the environment and attract increasing attention. In the present study, HFR concentrations were measured in indoor and outdoor dust in an important industrial city (Dongguan) in southern China, in which their presence and associated human exposure are unknown. The HFRs were dominated by polybrominated diphenyl ethers (PBDEs) and decabromodiphenyl ethane (DBDPE), with mean concentrations of 2365 and 2441 ng/g in the indoor dust, respectively, which were 2-3 order of magnitude higher the concentrations of other HFRs. However elevated tri- to hepta-BDE concentrations (869 ng/g) were found in Houjie Town, a furniture manufacturing center. The mean indoor/outdoor (I/O) ratios of HFR concentrations in the dust were all larger than one (1.55-16.4), suggesting the importance of indoors sources for HFRs in indoor dust in this industrial city. Principal component analysis (PCA) showed that the correlations among the HFRs in the indoor dust probably revealed differences in their commercial applications, while most HFRs in the outdoor dust have similar sources except for phased-out BDE47 and 99. The compositions of lower brominated PBDEs varied among the towns, probably due to their different sources or influence of photo-degradation. Nevertheless, the similar composition of highly brominated congeners indicated little photo-degradation encountered in the ambient environment. The non-cancer risk associated with indoor dust ingestion is low for the general population in Dongguan, but some children in the furniture manufacturing center have significantly high risk of exposure to banned PBDEs. PMID:25282276

  1. Spatial distribution, health risk assessment, and isotopic composition of lead contamination of street dusts in different functional areas of Beijing, China.

    PubMed

    Han, Lanfang; Gao, Bo; Wei, Xin; Xu, Dongyu; Gao, Li

    2016-02-01

    Street dusts from heavy density traffic area (HDTA), tourism area (TA), residential area (RA), and educational area (EA) in Beijing were collected to explore the distribution, health risk assessment, and source of lead (Pb). The average concentration of Pb in TA was the highest among the four areas. Compared with other cities, Pb concentrations in Beijing were generally at moderate or low levels. The average value (14.05) of ecological risk index (RI) indicated that Pb was at "low pollution risk" status. According to the calculation on hazard index (HI), the ingestion of dust particles of children and adults was the major route of exposure to street dusts in four studied areas, followed by dermal contact. The lower values of HI than 1 further suggested that non-carcinogenic risks of Pb in the street dusts were in the low range. Comparing (206)Pb/(207)Pb and (208)Pb/(207)Pb ratios of street dusts with other environmental samples, it was found that atmospheric deposition of coal combustion dust might be the main pathway for anthropogenic Pb input to the street dusts in four functional areas. PMID:26490894

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

    PubMed Central

    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.

    2014-01-01

    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-β1 (TGF-β1), 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-β1, 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-β1 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 α-smooth muscle actin (α-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 α-SMA. Collectively, these findings demonstrate an important requirement for JNK1 in promoting HDM-induced fibrotic airway remodeling. PMID:24610935

  3. DEVELOPMENT AND EVALUATION OF MONITORING METHODS FOR POLYCYCLIC AROMATIC HYDROCARBONS IN HOUSE DUST AND TRACK-IN SOIL

    EPA Science Inventory

    The analytical methods were developed for the determination of PAH and PCBs in the dust and soil based on sonication with hexane and 10% ether/hexane, respectively, and analysis by gas chromatography/mass spectrometry (GC/MS). uantitative recoveries of spiked perdeuterated PAH an...

  4. 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

    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

    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

  5. Effectiveness of house dust mite acaricide tri-n-butyl tin maleate on carpets, fabrics and mattress foam: a standardization of methodology.

    PubMed

    Uehara, Satiko; Franzolin, Marcia Regina; Chiesa, Soledad; Moreira, Débora; Gambale, Walderez; Paula, Claudete Rodrigues

    2006-01-01

    The aim of this study was to determine the effectiveness of the acaricide tri-n-butyl tin maleate, industrially applied to samples of carpets, mattress foam, and fabrics used for furniture upholstery, soft toys and shoe uppers. Approximately 100 adult house dust mites of the species Dermatophagoides pteronyssinus were inoculated into a Petri dish containing the sample (a piece of carpet, mattress foam, or fabric), treated with the acaricide, randomly collected. Mite-maintenance culture medium was added on top of each sample. After one, two, three, seven and 30 days of incubation at 25 degrees C and 75% relative humidity, each dish was examined using a 40X stereoscopic microscope (40X). One hundred percent acaricide effectiveness was obtained in treated materials by the end of the 30th-day postinoculation period, under optimal conditions for mite maintenance. PMID:16847508

  6. The Discovery of Potent, Selective, and Reversible Inhibitors of the House Dust Mite Peptidase Allergen Der p 1: An Innovative Approach to the Treatment of Allergic Asthma

    PubMed Central

    2014-01-01

    Blocking the bioactivity of allergens is conceptually attractive as a small-molecule therapy for allergic diseases but has not been attempted previously. Group 1 allergens of house dust mites (HDM) are meaningful targets in this quest because they are globally prevalent and clinically important triggers of allergic asthma. Group 1 HDM allergens are cysteine peptidases whose proteolytic activity triggers essential steps in the allergy cascade. Using the HDM allergen Der p 1 as an archetype for structure-based drug discovery, we have identified a series of novel, reversible inhibitors. Potency and selectivity were manipulated by optimizing drug interactions with enzyme binding pockets, while variation of terminal groups conferred the physicochemical and pharmacokinetic attributes required for inhaled delivery. Studies in animals challenged with the gamut of HDM allergens showed an attenuation of allergic responses by targeting just a single component, namely, Der p 1. Our findings suggest that these inhibitors may be used as novel therapies for allergic asthma. PMID:25365789

  7. Modification of the late asthmatic reaction by hyposensitization in asthmatic children allergic to house dust mite (Dermatophagoides pteronyssinus) or grass pollen.

    PubMed

    Van Bever, H P; Bosmans, J; De Clerck, L S; Stevens, W J

    1988-07-01

    The frequency and severity of the late asthmatic reaction (LAR) was studied in asthmatic children allergic to house dust mite (HDM) or grass pollen (GP) with and without hyposensitization (HS). The four groups were comparable according to their severity of asthma. All children were allergic to HDM (Dermatophagoides pteronyssinus) or GP according to history, skin testing and specific IgE determination via the RAST. The LAR occurred less frequently (29% versus 73%) (P less than 0.001) and was less severe in children receiving HS. The difference was significant between the children allergic to HDM as well as between children allergic to GP. The immediate asthmatic reaction (IAR) was also less severe in children allergic to HDM who received HS, compared to those who never received HS, (P = 0.033) although the PD20 of the HDM challenge (PD20HDM) was not different between the two groups. In children allergic to GP, there was no difference in PD20 of the GP challenge (PD20GP) or in severity of the IAR, whether the children received HS or not. There was no difference between the PD20HDM in patients who developed a LAR and in patients who did not. There was no relation between the type of asthmatic reaction following the allergen provocation test and the level of circulating immune complexes (CIC) and the level of house dust mite-specific IgG (IgGHDM) or grass pollen-specific IgE (IgGGP) in the different groups, determined before the challenge. There was a decrease in the level of IgG containing CIC (IgGCIC) during the LAR. It is concluded that the LAR occurs less frequently and is less severe in asthmatic children who receive HS. PMID:3414914

  8. Biological activity of recombinant Der p 2, Der p 5 and Der p 7 allergens of the house-dust mite Dermatophagoides pteronyssinus.

    PubMed

    Lynch, N R; Thomas, W R; Garcia, N M; Di Prisco, M C; Puccio, F A; L'opez, R I; Hazell, L A; Shen, H D; Lin, K L; Chua, K Y

    1997-09-01

    Der p 2, Der p 5 and Der p 7 are three allergens of the house-dust mite Dermatophagoides pteronyssinus that have been cloned and expressed in Escherichia coli as fusion proteins with glutathione-S-transferase (GST). We showed that these recombinant allergens produced immediate hypersensitivity skin-test reactions in 70, 60 and 52% respectively of a group of mite-sensitive allergic patients who were strongly positive to whole mite extract (WME). Comparable positivities were found for serum levels of specific IgE antibody against these allergens, as measured by the radioallergosorbant test (RAST). Overall, for the group of allergic patients that we evaluated, the serum IgE antibody concentrations against Der p 2, 5 and 7 were calculated to represent about one third, one quarter and one fifth respectively of the levels measured against the WME. However, for some patients the activity determined against the separate allergens was far higher than that detected against the WME, thus indicating that the concentration of these can be limiting in the WME. We found no significant correlations between the RAST levels against Derp 2 and either Derp 5 or 7, and RAST-inhibition tests indicated a lack of cross-reactivity between Der p 2 and the other two allergens. In contrast, the RAST results revealed the existence of a significant immunological relationship between Der p 5 and 7. Although a certain degree of reactivity against the GST fusion partner was found in the allergic patients studied, this was not a significant influence in determining the positivity against the recombinant allergens. These results confirm the in vivo biological activity of recombinant Der p 2, 5 and 7, and indicate that whilst Der p 2 is undoubtedly a major mite allergen, both Der p 5 and 7 make important contributions toward the overall allergenic activity of house-dust mites. PMID:9303332

  9. Retrofit wall system for insulation and lead encasement in older multi-family housing.

    SciTech Connect

    Wendt, R. L.

    1998-08-11

    This paper presents an approach to modernization or rehabilitation of buildings with uninsulated masonry walls that have lead-based paint hazards or deteriorated plaster walls. The approach provides a solution to lead contamination on the walls, increased energy efficiency and comfort improvements associated with better insulated building envelopes. The system sheaths or replaces damaged or contaminated walls with a tight, well-insulated, durable interior surface. The costs of this system are estimated to be less than those of other insulated wall systems. Modeling of the impact of this system shows significant improvement in energy performance. The energy savings over the life of this durable system contribute to significantly offset the often-times sizeable cost of lead hazard remediation.

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

    SciTech Connect

    Cavallo, J.D.; Wendt, R.

    1997-03-01

    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.

  11. Boltless Seal for Electronic Housings

    NASA Technical Reports Server (NTRS)

    Dawe, R. H.; Evans, J. T.

    1982-01-01

    Spring clips seal housings for electronic circuitry, preventing electromagnetic interference from entering or leaving housings. Clips also keep dust out of housing. Since no bolts are used, housing can be opened quickly; unlike bolts, clips can be used on thin-walled housing. Seal was developed for an X-band array amplifier.

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

    PubMed

    Leclerc, Nathalie; Meux, Eric; Lecuire, Jean Marie

    2002-04-26

    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 mineralogical forms present in these wastes are Fe3O4, ZnO, ZnFe2O4 and PbOHCl. The proposed process consists of a hydrometallurgical treatment of wastes based on selective leaching of zinc and lead. Initially, a leaching is carried out utilizing a chelating agent, nitrilotriacetate anion (NTA3-), as the protonated form HNTA2-. Treatment of five EAFD samples for an hour at room temperature with a molar solution of reagent results in total leaching of the ZnO. In all cases the solubilized iron does not exceed 3 wt.%. The recovery of zinc and lead is performed by precipitation of metallic sulfides with a solution of Na2S4 sodium tetrasulfide 2M. These metallic sulfides can be used as metallurgical raw materials and the chelating reagent can be reused in the process after pH adjustment. The results of the normalized leaching test AFNOR X31-210 conducted on the leaching residues, shows that all the samples meet acceptance thresholds for hazardous wastes landfill. However, the residues contain a considerable amount of zinc as ZnFe2O4. The extraction of the zinc element requires the destruction of the ferrite structure. In this process, ZnFe2O4 is treated by FeCl3.6H2O. The reaction consists in a particle O2-/Cl- exchange allowing the recovery of zinc as ZnCl2 and iron as hematite Fe2O3. The separation of these products is accomplished by simple aqueous leaching. All of the zinc is extracted in a 8h treatment at 150 degrees C with a molar ratio FeCl3.6H2O/ZnFe2O4 equal to 10. Ultimate solid residues, which have been concentrated in iron, can be oriented towards the steel industry. PMID:11900917

  13. Human lead (Pb) exposure via dust from different land use settings of Pakistan: A case study from two urban mountainous cities.

    PubMed

    Eqani, Syed Ali Musstjab Akber Shah; Khalid, Ramsha; Bostan, Nazish; Saqib, Zafeer; Mohmand, Jawad; Rehan, Mohammad; Ali, Nadeem; Katsoyiannis, Ioannis A; Shen, Heqing

    2016-07-01

    The current study aims to determine the dust-borne lead (Pb) levels into outdoor dust, which were collected from the areas nearby the cities/districts of Islamabad and Swat in Pakistan. In general dust samples from all land use settings (industrial, urban and rural) showed significantly higher (p<0.05) Pb-levels (median, ppm) from Islamabad (110, 52, 24) than those of Swat district (75, 37, 21), respectively. Index of Geo-accumulation (Igeo values) indicated that industrial and urban areas of both sites were highly polluted due to severe anthropogenic influence, whereas the rural areas were in most parts unpolluted and where moderately polluted, this was mainly due to geological factors and short and/or long distance atmospheric deposition from surrounding polluted areas. According to the calculated chemical daily intake (mg/kg-day) values, dust ingestion is one of the major routes of human exposure for lead. Hazard Index (HI) values, calculated for both adult and children populations, were above unity in industrial and urban areas, indicating serious health risks especially to the children populations. PMID:27129063

  14. Lead

    MedlinePlus

    ... Lead Share Facebook Twitter Google+ Pinterest Contact Us Lead Poisoning is Preventable If your home was built before ... of the RRP rule. Read more . Learn about Lead Poisoning Prevention Week . Report Uncertified Contractors and Environmental Violations ...

  15. Systemic administration of an Fcgamma-Fc(epsilon)-fusion protein in house dust mite sensitive nonhuman primates.

    PubMed

    Van Scott, Michael R; Mertsching, Elisabeth; Negrou, Ella; Miles, Jeremy; Stallings, Howard W; Graff, Candace; Kehry, Marilyn R

    2008-09-01

    Crosslinking Fc(epsilon)RI and FcgammaRIIB receptors inhibits mast cell and basophil activation, decreasing mediator release. In this study, a fusion protein incorporating human Fcgamma and Fc(epsilon) domains, hGE2, was shown to inhibit degranulation of human mast cells and basophils, and to exhibit efficacy in a nonhuman primate model of allergic asthma. hGE2 increased the provocative concentration of dust mite aeroallergen that induced an early phase asthmatic response. The treatment effect lasted up to 4 weeks and was associated with reduction in the number of circulating basophils and decreased expression of Fc(epsilon)RI on repopulating basophils. Repeat hGE2 dosing induced production of serum antibodies against human Fcgamma and Fc(epsilon) domains and acute anaphylaxis-like reactions. Immune serum induced histamine release from human IgE or hGE2-treated cord blood-derived mast cells and basophils in vitro. These results indicate that repeat administration with hGE2 induced an antibody response to the human molecule that resulted in activation rather than inhibition of allergic responses. PMID:18583194

  16. Lead exposures from varnished floor refinishing.

    PubMed

    Schirmer, Joseph; Havlena, Jeff; Jacobs, David E; Dixon, Sherry; Ikens, Robert

    2012-01-01

    We evaluated the presence of lead in varnish and factors predicting lead exposure from floor refinishing and inexpensive dust suppression control methods. Lead in varnish, settled dust, and air were measured using XRF, laboratory analysis of scrape and wipe samples, and National Institute for Occupational Safety and Health (NIOSH) Method 7300, respectively, during refinishing (n = 35 homes). Data were analyzed using step-wise logistic regression. Compared with federal standards, no lead in varnish samples exceeded 1.0 mg/cm(2), but 52% exceeded 5000 ppm and 70% of settled dust samples after refinishing exceeded 40 μg/ft(2). Refinishing pre-1930 dwellings or stairs predicted high lead dust on floors. Laboratory analysis of lead in varnish was significantly correlated with airborne lead (r = 0.23, p = 0.014). Adding dust collection bags into drum sanders and HEPA vacuums to edgers and buffers reduced mean floor lead dust by 8293 μg Pb/ft(2) (p<0.05) on floors and reduced most airborne lead exposures to less than 50 μg/m(3). Refinishing varnished surfaces in older housing produces high but controllable lead exposures. PMID:22494405

  17. Lead

    MedlinePlus

    ... obvious symptoms, it frequently goes unrecognized. CDC’s Childhood Lead Poisoning Prevention Program is committed to the Healthy People ... Lead Levels Information for Parents Tips for preventing lead poisoning About Us Overview of CDC’s Childhood Lead Poisoning ...

  18. In vitro bioaccessibility of lead in surface dust and implications for human exposure: A comparative study between industrial area and urban district.

    PubMed

    Bi, Xiangyang; Li, Zhonggen; Sun, Guangyi; Liu, Jinling; Han, Zhixuan

    2015-10-30

    In this study, ground surface dust samples from two contrasting areas, a former zinc smelting area in Guizhou Province and a common urban district in Wuhan city, Hubei Province, China, were assessed for in vitro Pb bioaccessibility using a physiologically based extraction test (PBET). Extremely elevated concentrations of Pb (220-6348 mg/kg) and other trace metals were observed in the zinc smelting area. While moderate high metal concentrations (79-1544 mg/kg of Pb) in the urban dusts were attributed to various urban activities, coal combustion and traffic emissions. Lead bioaccessibility in the stomach-phase varied from 17.6 to 76.1% and no significant difference was found between industrial and urban dust samples. Compared with the stomach-phase, Pb bioaccessibility in the more alkaline intestinal-phase was considerably lower (1.2-21.8%). A significantly negative correlation was found between dust Ca concentrations and Pb bioaccessibility in the intestinal-phase, suggesting that Ca plays an important role in reducing the bioaccessible Pb in the intestinal-phase. The estimated Pb exposure based on gastric bioaccessible Pb was 13.9 and 1.8 μg/kg day for children living in the industrial and urban areas, respectively, accounting for 85% and 41% of their corresponding total Pb exposure. PMID:25958267

  19. Savings associated with high-dose hypoallergenic house dust mite immunotherapy in rhinitis and/or asthma patients in Spain

    PubMed Central

    García Robaina, José Carlos; Polanco Sánchez, Carlos; Estella Pérez, Elvira

    2016-01-01

    Objectives To quantify the cost difference between conventional symptomatic treatment of mite allergy and specific subcutaneous immunotherapy (SCIT). Methods Observational, retrospective, and multicenter study was carried out in Spain in 2013. The medical records of 419 patients diagnosed with rhinitis and/or bronchial asthma for mite allergy were retrieved. Mean age was 24.9 years (standard deviation 14.4). The use of symptomatic medication (rescue and daily), diagnostic tests, unscheduled medical care, and sick leave days associated with SCIT treatment versus no-SCIT treatment was compared. Also measured was the SCIT treatment to no-SCIT treatment costs ratio: used resources (symptomatic medication, unscheduled medical care, diagnostic tests, and 3 years SCIT treatment and sick leave days) were quantified in euros. Efficacy (decreased resource usage) of first-year treatment was assumed during the remaining 2 years and also during the 3-year follow-up period. Results After a single year of SCIT, all quantified resources diminished significantly (P<0.05) from baseline. Estimated reduction in cost items included hospital resources (100% in hospitalizations, 82% in visits to the allergist, and 79% in emergency room visits), therapies (56% in rescue medication and 63% in daily medication), diagnostic tests (77%), and sick leave days (94%). Ratio of comparative calculation described as SCIT treatment versus non-SCIT treatment (or conventional symptomatic treatment) is 0.8. Conclusion Direct costs are reduced by 64% and indirect costs by 94%. SCIT of hypoallergenic preparation of dust mite (Acaroid®) allows cost savings versus conventional treatment. Estimated savings for the public National Health System are 5.7 times the cost of immunotherapy. PMID:27366098

  20. Lead poisoning

    MedlinePlus

    ... lead is still found in some modern faucets. Soil contaminated by decades of car exhaust or years ... house paint scrapings. Lead is more common in soil near highways and houses. Hobbies involving soldering, stained ...

  1. Extracellular superoxide dismutase ameliorates house dust mite-induced atopic dermatitis-like skin inflammation and inhibits mast cell activation in mice.

    PubMed

    Lee, Yun Sang; Choi, Jung-Hye; Lee, Ji-Hyun; Lee, Han-Woong; Lee, Weontae; Kim, Woo Taek; Kim, Tae-Yoon

    2016-08-01

    Extracellular superoxide dismutase (EC-SOD) is an enzyme that catalyses the dismutation of superoxide anions. It has multiple functions, such as reactive oxygen species scavenging, anti-angiogenic, anti-inflammatory, antichemotatic and antitumor activities. Recently, we demonstrated that EC-SOD inhibits ovalbumin-induced allergic airway inflammation in mice. However, the anti-allergic effect of EC-SOD on skin tissue and the role of EC-SOD in mast cells, which are important for allergic responses, have not been well studied. In this study, we investigated whether EC-SOD can alleviate atopic dermatitis in mice and inhibit mast cell activation. Treatment with human recombinant EC-SOD ameliorated house dust mite-induced atopic dermatitis in mice. Furthermore, the levels of pro-allergic cytokine gene expression and histamine release increased in EC-SOD KO mast cells and decreased in EC-SOD overexpressing mast cells, suggesting that EC-SOD inhibits mast cell activation. Consistently, a passive cutaneous anaphylaxis experiment showed more blood leakage from EC-SOD KO mouse ear skin, implying that the lack of EC-SOD increases allergic responses. These results suggest that EC-SOD inhibits mast cell activation and atopic dermatitis and that the loss of EC-SOD causes more severe allergic responses, implying that EC-SOD might be a good drug candidate for treatment of allergic disorders, such as atopic dermatitis. PMID:27061078

  2. Enhanced Cysteinyl-Leukotriene Type 1 Receptor Expression in T Cells from House Dust Mite-Allergic Individuals following Stimulation with Der p

    PubMed Central

    Thivierge, Maryse

    2015-01-01

    In order to determine the potential for allergen to modulate T cell expression of the CysLT1 receptor and responsiveness to leukotrienes, peripheral blood mononuclear cells from house dust mite-allergic or nonallergic individuals were incubated with D. pteronyssinus allergen (Der p). Baseline CysLT1 expression was similar in both groups of donors, but Der p significantly enhanced CysLT1 expression in CD4+ and CD8+ T cells of only allergic individuals and induced enhanced responsiveness of CD4+ T cells to LTD4 in terms of calcium mobilisation. This effect was prevented by the CysLT1 antagonist MK571. Der p also induced IL-4 and IL-10 production, and neutralizing antibody to IL-4 prevented both the enhanced CysLT1 expression and the enhanced responsiveness of T cells to LTD4 induced by Der p. In allergic individuals, Der p also induced T cell proliferation and a Th2-biased phenotype. Our data suggest that, in allergen-sensitized individuals, exposure to allergen can enhance T cell expression of CysLT1 receptors through a mechanism involving IL-4 production. This, in turn, would induce CD4+ T cell responsiveness to cysteinyl-leukotrienes and Th2 cell activation. PMID:25918735

  3. 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)

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

    2003-01-01

    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.

  4. Pruni cortex ameliorates skin inflammation possibly through HMGB1-NFκB pathway in house dust mite induced atopic dermatitis NC/Nga transgenic mice

    PubMed Central

    Watanabe, Kenichi; Karuppagounder, Vengadeshprabhu; Arumugam, Somasundaram; Thandavarayan, Rajarajan A.; Pitchaimani, Vigneshwaran; Sreedhar, Remya; Afrin, Rejina; Harima, Meilei; Suzuki, Hiroshi; Suzuki, Kenji; Nakamura, Takashi; Nomoto, Mayumi; Miyashita, Shizuka; Fukumoto, Kyoko; Ueno, Kazuyuki

    2015-01-01

    Pruni cortex, the bark of Prunus jamasakura Siebold ex Koidzumi, has been used in the Japanese systems of medicine for many years for its anti-inflammatory, antioxidant and antitussive properties. In this study, we investigated the effect of pruni cortex on atopic dermatitis NC/Nga mouse model. Atopic dermatitis-like lesion was induced by the application of house dust mite extract to the dorsal skin. After induction of atopic dermatitis, pruni cortex aqueous extract (1 g/kg, p.o.) was administered daily for 2 weeks. We evaluated dermatitis severity, histopathological changes and cellular protein expression by Western blotting for nuclear and cytoplasmic high mobility group box 1, receptor for advanced glycation end products, nuclear factor κB, apoptosis and inflammatory markers in the skin of atopic dermatitis mice. The clinical observation confirmed that the dermatitis score was significantly lower when treated with pruni cortex than in the atopic dermatitis group. Similarly pruni cortex inhibited hypertrophy and infiltration of inflammatory cells as identified by histopathology. In addition, pruni cortex significantly inhibited the protein expression of cytoplasmic high mobility group box 1, receptor for advanced glycation end products, nuclear p-nuclear factor kappa B, apoptosis and inflammatory markers. These results indicate that pruni cortex may have therapeutic potential in the treatment of atopic dermatitis by attenuating high mobility group box 1 and inflammation possibly through the nuclear factor κB pathway. PMID:26060348

  5. Sensitization by subcutaneous route is superior to intraperitoneal route in induction of asthma by house dust mite in a murine mode

    PubMed Central

    Aun, Marcelo Vivolo; Saraiva-Romanholo, Beatriz Mangueira; de Almeida, Francine Maria; Brüggemann, Thayse Regina; Kalil, Jorge; Martins, Milton de Arruda; Arantes-Costa, Fernanda Magalhães; Giavina-Bianchi, Pedro

    2015-01-01

    ABSTRACT Objective To develop a new experimental model of chronic allergic pulmonary disease induced by house dust mite, with marked production of specific immunoglobulin E (IgE), eosinophilic inflammatory infiltrate in the airways and remodeling, comparing two different routes of sensitization. Methods The protocol lasted 30 days. BALB/c mice were divided into six groups and were sensitized subcutaneously or intraperitoneally with saline (negative control), Dermatophagoides pteronyssinus (Der p) 50 or 500mcg in three injections. Subsequently they underwent intranasal challenge with Der p or saline for 7 days and were sacrificed 24 hours after the last challenge. We evaluated the titration of specific IgE anti-Der p, eosinophilic density in peribronchovascular space and airway remodeling. Results Both animals sensitized intraperitoneally and subcutaneously produced specific IgE anti-Der p. Peribronchovascular eosinophilia increased only in mice receiving lower doses of Der p. However, only the group sensitized with Der p 50mcg through subcutaneously route showed significant airway remodeling. Conclusion In this murine model of asthma, both pathways of sensitization led to the production of specific IgE and eosinophilia in the airways. However, only the subcutaneously route was able to induce remodeling. Furthermore, lower doses of Der p used in sensitization were better than higher ones, suggesting immune tolerance. Further studies are required to evaluate the efficacy of this model in the development of bronchial hyperresponsiveness, but it can already be replicated in experiments to create new therapeutic drugs or immunotherapeutic strategies. PMID:26761554

  6. Prostaglandin E2 deficiency uncovers a dominant role for thromboxane A2 in house dust mite-induced allergic pulmonary inflammation.

    PubMed

    Liu, Tao; Laidlaw, Tanya M; Feng, Chunli; Xing, Wei; Shen, Shiliang; Milne, Ginger L; Boyce, Joshua A

    2012-07-31

    Prostaglandin E(2) (PGE(2)) is an abundant lipid inflammatory mediator with potent but incompletely understood anti-inflammatory actions in the lung. Deficient PGE(2) generation in the lung predisposes to airway hyperresponsiveness and aspirin intolerance in asthmatic individuals. PGE(2)-deficient ptges(-/-) mice develop exaggerated pulmonary eosinophilia and pulmonary arteriolar smooth-muscle hyperplasia compared with PGE(2)-sufficient controls when challenged intranasally with a house dust mite extract. We now demonstrate that both pulmonary eosinophilia and vascular remodeling in the setting of PGE(2) deficiency depend on thromboxane A(2) and signaling through the T prostanoid (TP) receptor. Deletion of TP receptors from ptges(-/-) mice reduces inflammation, vascular remodeling, cytokine generation, and airway reactivity to wild-type levels, with contributions from TP receptors localized to both hematopoietic cells and tissue. TP receptor signaling ex vivo is controlled heterologously by E prostanoid (EP)(1) and EP(2) receptor-dependent signaling pathways coupling to protein kinases C and A, respectively. TP-dependent up-regulation of intracellular adhesion molecule-1 expression is essential for the effects of PGE(2) deficiency. Thus, PGE(2) controls the strength of TP receptor signaling as a major bronchoprotective mechanism, carrying implications for the pathobiology and therapy of asthma. PMID:22802632

  7. The Hot-Water Extract of Smilacis Chinae Rhizome Suppresses 2,4-Dinitrochlorobenzene and House Dust Mite-Induced Atopic Dermatitis-Like Skin Lesions in Mice.

    PubMed

    Ki, Nam Yong; Park, Eun-Ji; Sung, In Sung; Ju, Seul A; Kim, Kyoung Un; Kim, Mi Rae; Song, Do Yeon; Lee, Min-Ju; Kim, Hak-Soo; Kang, Boo-Hyon; Chung, Hun-Jong; Choi, Eun-Ju; Yoon, Ki-Hun; Lee, Min Won; Yun, Seongho; Min, Bokkee; Kwon, Suk Hyung; Shin, Hwa-Sup

    2016-04-01

    Smilacis Chinae Rhizome (SCR) has been used as an oriental folk medicine for various biological activities. However, its effect on atopic dermatitis (AD) remains undetermined to date. We assessed the effect of orally administered hot-water extract of SCR on AD-like skin lesions in mice and its underlying mechanisms. AD-like murine model was prepared by repeated alternate application of house dust mite (Dermatophagoides farinae) extract (DFE) and 2,4-dinitrochlorobenzene (DNCB) for 4 weeks, topically to the ears. Daily oral administration of SCR for 3 and 4 weeks significantly reduced inflammatory ear thickening, with the effect being enhanced at the earlier start and longer period of administration. This effect was accompanied by a significant decrease in both Th2 and Th1 serum antibodies (total IgE, DFE-specific IgE, and IgG2a). Histological analysis showed that SCR markedly decreased the epidermal/dermal ear thickening and the dermal infiltration of inflammatory cells. Furthermore, SCR suppressed DFE/DNCB-induced expression of IL-4, IL-13, IL-17, IL-18, TSLP, and IFN-γ genes in the ear tissue. Taken together, our observations demonstrate that chronic oral administration of SCR exerts beneficial effect in mouse AD model, suggesting that SCR has the therapeutic potential as an orally active treatment of AD by modulating both Th1 and Th2 responses. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26840656

  8. Exposure to soil, house dust and decaying plants increases gut microbial diversity and decreases serum immunoglobulin E levels in BALB/c mice.

    PubMed

    Zhou, Dongrui; Zhang, Honglin; Bai, Zhimao; Zhang, Aidi; Bai, Futian; Luo, Xing; Hou, Yue; Ding, Xiao; Sun, Beili; Sun, Xiao; Ma, Ning; Wang, Cuifen; Dai, Xiaoniu; Lu, Zuhong

    2016-05-01

    To assess the impact of sanitation of a living environment on gut microbiota and development of the immune system, we raised BALB/c mice under three distinct environmental conditions: a specific pathogen-free animal room (SPF), a general animal room (XZ) and a farmhouse (JD). All other variables like diet, age, genetic background, physiological status and original gut microbiota were controlled for in the three groups. Using high-throughput sequencing of the 16S rRNA gene, we found that each mouse group had a specific structure of the gut microbial community. Groups JD and XZ harboured a significantly more diverse and richer gut microbiota than did group SPF. Bacteroidetes were significantly more abundant in groups XZ and JD than in group SPF, whereas Firmicutes showed the inverse pattern. Total serum immunoglobulin E (IgE) levels were significantly lower in groups XZ and JD than in group SPF. There were no significant differences in gut microbiota diversity and serum IgE concentration between groups JD and XZ, but we found higher abundance of dominant genera in the gut microflora of group JD. We conclude that exposure to soil, house dust and decaying plant material enhances gut microbial diversity and innate immunity. Our results seem to provide new evidence supporting the hygiene hypothesis. PMID:25958920

  9. Soil is an important pathway of human lead exposure.

    PubMed Central

    Mielke, H W; Reagan, P L

    1998-01-01

    This review shows the equal or greater importance of leaded gasoline-contaminated dust compared to lead-based paint to the child lead problem, and that soil lead, resulting from leaded gasoline and pulverized lead-based paint, is at least or more important than lead-based paint (intact and not pulverized) as a pathway of human lead exposure. Because lead-based paint is a high-dose source, the biologically relevant dosage is similar to lead in soil. Both lead-based paint and soil lead are associated with severe lead poisoning. Leaded gasoline and lead in food, but not lead-based paint, are strongly associated with population blood lead levels in both young children and adults. Soil lead and house dust, but not lead-based paint, are associated with population blood lead levels in children. Most soil lead and house dust are associated with leaded gasoline. Lead-based paint dust is associated with cases of renovation of either exterior or interior environments in which the paint was pulverized. Based upon the limited data to date, abatement of soil lead is more effective than abatement of lead-based paint in reducing blood lead levels of young children. About equal numbers of children under 7 years of age are exposed to soil lead and lead-based paint. Seasonality studies point to soil lead as the main source of population blood lead levels. Soil lead is a greater risk factor than lead-based paint to children engaged in hand-to-mouth and pica behavior. In summary, soil lead is important for addressing the population of children at risk of lead poisoning. When soil lead is acknowledged by regulators and the public health community as an important pathway of human lead exposure, then more effective opportunities for improving primary lead prevention can become a reality. Images Figure 1 PMID:9539015

  10. Lead Sampling Technician Training Course. Trainer Manual.

    ERIC Educational Resources Information Center

    ICF, Inc., Washington, DC.

    This document presents a model curriculum for use by trainers presenting training course in assessing and reporting dust and debris from deteriorated lead-based paint. The course, which was developed by the U.S. Environmental Protection Agency, is intended for use with housing quality standard inspectors, rehabilitation specialists, home…

  11. Serum antibody to Sarcoptes scabiei and house dust mite prior to and during infestation with S. scabiei.

    PubMed

    Arlian, L G; Morgan, M S

    2000-07-01

    In this study, serum antibodies to Sarcoptes scabiei var. canis (SS), Dermatophagoides farinae (DF), and D. pteronyssinus (DP) were determined in 19 healthy, random-source dogs prior to infestation with scabies then again during a primary infestation, cure and challenge infestation with scabies. Prior to scabies infestation, serum of 11 dogs contained faintly detectable amounts of IgE and/or IgG to proteins in SS extract, probably resulting from sensitization to dust mites that share cross-reactive antigenic epitopes with SS. After becoming infested with scabies, the response to SS antigens became stronger with antibodies appearing to more antigens as the scabies infestation progressed. Three of the newly recognized proteins were 170, 155 and 142/133kD and could be used in a diagnostic test since antibodies to them appeared during the primary infestation. In addition, during the primary infestation, 14 of 15 dogs developed IgE to 1-11 new SS proteins in addition to an increase in IgE binding to those proteins recognized prior to infestation. Overall, the strongest antibody responses (IgE and IgG) were exhibited during cure of the first infestation, when dead mites were still present in the stratum corneum. As expected, the antibody response was strong and rapid during challenge when the infestation self-cured. The immunogenic SS proteins identified by serum antibody binding during challenge, when the hosts self-cured, are candidates for inclusion in a vaccine. These candidate proteins are 200, 185, 170, 155, 142/133, 112, 97, 74, 57, 45/42, 32 and 22kD. Some of the proteins in SS that exhibited new or increased antibody binding during the experiment also had IgE and IgG binding to proteins with similar molecular weights in DF and DP extracts. These results illustrate the difficulties involved in understanding and interpreting serum antibody for developing a serological test for the diagnosis of scabies, isolating relevant SS antigens that could be included in a

  12. Lead Toxicity

    MedlinePlus

    ... homes. • Most people, especially children, who suffer from lead poisoning are exposed through lead-contaminated household dust or ... and six if they are at risk of lead poisoning (see: ). Who can I call to get more ...

  13. Modelling and bioinformatics analysis of the dimeric structure of house dust mite allergens from families 5 and 21: Der f 5 could dimerize as Der p 5.

    PubMed

    Khemili, Souad; Kwasigroch, Jean Marc; Hamadouche, Tarik; Gilis, Dimitri

    2012-01-01

    Allergy represents an increasing thread to public health in both developed and emerging countries and the dust mites Dermatophagoides pteronyssinus (Der p), Blomia tropicalis (Blo t), Dermatophagoides farinae (Der f), Lepidoglyphus destructor (Lep d) and Suidasia medanensis (Sui m) strongly contribute to this problem. Their allergens are classified in several families among which families 5 and 21 which are the subject of this work. Indeed, their biological function as well as the mechanism or epitopes by which they are contributing to the allergic response remain unknown and their tridimensional structures have not been resolved experimentally except for Blo t 5 and Der p 5. Blo t 5 is a monomeric three helical bundle, whereas Der p 5 shows a three helical bundle with a kinked N-terminal helix that assembles in an entangled dimeric structure with a large hydrophobic cavity. This cavity could be involved in the binding of hydrophobic ligands, which in turn could be responsible for the shift of the immune response from tolerance to allergic inflammation. We used molecular modelling approaches to bring out if other house dust mite allergens of families 5 and 21 (Der f 5, Sui m 5, Lep d 5, Der p 21 and Der f 21) could dimerize and form a large cavity in the same way as Der p 5. Monomeric models were first performed with MODELLER using the experimental structures of Der p 5 and Blo t 5 as templates. The ClusPro server processed the selected monomers in order to assess their capacity to form dimeric structures with a positive result for Der p 5 and Der f 5 only. The other allergens (Blo t 5, Sui m 5, Lep d 5, Der p 21 and Der f 21) did not present such a propensity. Moreover, we identified mutations that should destabilize and/or prevent the formation of the Der p 5 dimeric structure. The production of these mutated proteins could help us to understand the role of the dimerization process in the allergic response induced by Der p 5, and if Der p 5 and Der f 5 behave

  14. Identification of lead sources in residential environments: Sydney Australia.

    PubMed

    Laidlaw, M A S; Zahran, S; Pingitore, N; Clague, J; Devlin, G; Taylor, M P

    2014-01-01

    Interior and exterior dust, soil and paint were analysed at five brick urban Sydney homes over 15 months to evaluate temporal variations and discriminate sources of lead (Pb) exposure. Exterior dust gauge Pb loading rates (μg/m(2)/28 days), interior vacuum dust Pb concentrations (mg/kg) and interior petri-dish Pb loading rates (μg/m(2)/28 days), were correlated positively with soil Pb concentrations. Exterior dust gauge Pb loading rates and interior vacuum dust Pb concentrations peaked in the summer. Lead isotope and Pb speciation (XAS) were analysed in soil and vacuum dust samples from three of the five houses that had elevated Pb concentrations. Results show that the source of interior dust lead was primarily from soil in two of the three houses and from soil and Pb paint in the third home. IEUBK child blood Pb modelling predicts that children's blood Pb levels could exceed 5 μg/dL in two of the five houses. PMID:24071634

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

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

    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.

  16. Group V secretory phospholipase A2 reveals its role in house dust mite-induced allergic pulmonary inflammation by regulation of dendritic cell function

    PubMed Central

    Giannattasio, Giorgio; Fujioka, Daisuke; Xing, Wei; Katz, Howard R.; Boyce, Joshua A.; Balestrieri, Barbara

    2010-01-01

    We have previously shown that group V secretory phospholipase A2 (sPLA2) regulates phagocytosis of zymosan and Candida albicans by a mechanism that depends on fusion of phagosomes with late endosomes in macrophages. Here we report that group V sPLA2 (Pla2g5)-null mice exposed to an extract of house dust mite Dermatophagoides farinae (Df) had markedly reduced pulmonary inflammation and goblet cell metaplasia compared to wild-type (WT) mice. Pla2g5-null mice had also impaired Th2-type adaptive immune responses to Df compared to WT mice. Pla2g5-null bone marrow-derived dendritic cells (BMDCs) activated by Df had delayed intracellular processing of allergen and impaired allergen-dependent maturation, a pattern recapitulated by the native lung DCs of Df-challenged mice. Adoptively transferred Df-loaded Pla2g5-null BMDCs were less able than Df-loaded WT BMDCs to induce pulmonary inflammation and Th2 polarization in WT mice. However, Pla2g5-null recipients transferred with WT or Pla2g5-null Df-loaded BMDCs exhibited significantly reduced local inflammatory responses to Df, even though the transfer of WT BMDCs still induced an intact Th2 cytokine response in regional lymph nodes. Thus, the expression of group V sPLA2 in APC regulates Ag processing and maturation of dendritic cells, and contributes to pulmonary inflammation and immune response against Df. Furthermore, an additional yet to be identified resident cell type is essential for the development of pulmonary inflammation, likely a cell in which group V sPLA2 is upregulated by Df and whose function is also regulated by group V sPLA2. PMID:20817863

  17. The crucial role of IL-22 and its receptor in thymus and activation regulated chemokine production and T-cell migration by house dust mite extract.

    PubMed

    Jang, Mirim; Kim, Hyemin; Kim, Yejin; Choi, Jiyea; Jeon, Jane; Hwang, Youngil; Kang, Jae Seung; Lee, Wang Jae

    2016-08-01

    House dust mite (HDM) is known as one of the factors that causes atopic dermatitis (AD). Interleukin (IL)-22 and thymus and activation regulated chemokine (TARC) are related to skin inflammatory disease and highly expressed in AD lesions. However, the effects of HDM on IL-22 production in T cells and on TARC production and IL-22Rα receptor expression in keratinocytes are unknown. To identify the role of HDM in keratinocytes and T cells, we investigated IL-22Rα expression and TARC production in the human keratinocyte cell line HaCaT and IL-22 production in T cells treated with HDM extract as well as their roles in HDM-induced skin inflammation. HDM extract not only increased IL-22Rα expression and TARC production in HaCaT but also enhanced IL-22, tumor necrosis factor (TNF)-α and interferon (IFN)-γ production in T cells. The HDM extract-induced IL-22 from T cells significantly increased the production of IL-1α, IL-6 and TARC in HaCaT cells. In addition, we found that TARC produced in HDM extract-treated HaCaT induced T-cell recruitment. These results suggest that there is a direct involvement of HDM extract-induced IL-22 in TARC production and T-cell migration. Taken together, TARC production in HaCaT through the interaction between IL-22 and IL-22Rα facilitates T-cell migration. These data show one of the reasons for inflammation in the skin lesions of AD patients. PMID:26914146

  18. 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

    Joad, Jesse P. Kott, Kayleen S.; Bric, John M.; Schelegle, Edward S.; Gershwin, Laurel J.; Plopper, Charles G.; Peake, Janice L.; Pinkerton, Kent E.

    2008-01-15

    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.

  19. Interleukin-33 from Monocytes Recruited to the Lung Contributes to House Dust Mite-Induced Airway Inflammation in a Mouse Model

    PubMed Central

    Tashiro, Hiroki; Takahashi, Koichiro; Hayashi, Shinichiro; Kato, Go; Kurata, Keigo; Kimura, Shinya; Sueoka-Aragane, Naoko

    2016-01-01

    Background Interleukin-33 (IL-33) activates group 2 innate lymphoid cells (ILC2), resulting in T-helper-2 inflammation in bronchial asthma. Airway epithelial cells were reported as sources of IL-33 during apoptosis and necrosis. However, IL-33 is known to be from sources other than airway epithelial cells such as leukocytes, and the mechanisms of IL-33 production and release are not fully understood. The aim of this study was to clarify the role of IL-33 production by monocytes in airway inflammation. Methods BALB/c mice were sensitized and challenged with a house dust mite (HDM) preparation. Airway inflammation was assessed by quantifying inflammatory cells in bronchoalveolar lavage (BAL) fluid, and IL-25, IL-33, and thymic stromal lymphopoietin (TSLP) levels in lung. Immunohistochemistry for IL-33 in lung sections was also performed. Ly6c, CD11b, and CD11c expression was examined by flow cytometry. Clodronate liposomes were used in the HDM-airway inflammation model to deplete circulating monocytes. Results The IL-33, but not IL-25 or TSLP, level in lung homogenates was markedly increased in HDM mice compared to control mice. IL-33-positive cells in the lungs were identified using immunohistochemistry and were increased in areas surrounding bronchi and vasculature. Furthermore, IL-33 levels were increased in mononuclear cells derived from lungs of HDM mice compared to controls. The expression of Ly6c in mononuclear cells was significantly higher in HDM mice than in controls. Treatment with clodronate liposomes led to inhibition of not only inflammatory cells in BAL fluid, airway hyper reactivity and Th2 cytokines in lung, but also IL-33 in lung. Conclusion IL-33 from monocytes recruited to the lung may contribute to the pathogenesis of HDM-induced airway inflammation. PMID:27310495

  20. House Dust Mite-Derived Chitin Enhances Th2 Cell Response to Inhaled Allergens, Mainly via a TNF-α-Dependent Pathway

    PubMed Central

    Choi, Jun-Pyo; Lee, Sang-Min; Choi, Hyun-Il; Kim, Min-Hye; Jeon, Seong Gyu; Jang, Myoung Ho; Jee, Young-Koo; Yang, Sanghwa; Cho, Young-Joo

    2016-01-01

    Purpose Chitin is a potent adjuvant in the development of immune response to inhaled allergens in the airways. According to other studies, chitin is known as multi-faced adjuvants which can induce Th2 responses. Recently, we found that TNF-α is a key mediator in the development of Th2 cell response to inhaled allergens. Here, we evaluated the immunologic mechanisms in the development of airway hypersensitivity to inhaled allergens, enhanced by house dust mite (HDM)-derived chitin. Methods The role of TNF-α and TLRs was evaluated in an airway hypersensitivity mouse model induced by a sensitization with an allergen (ovalbumin, OVA) and HDM-derived chitin using mice with the null mutation of target genes. Results The present study showed that airway sensitization with HDM-derived chitin plus OVA enhanced OVA-induced airway inflammation v. OVA alone. This phenotype was associated with the increased expression of Th1, Th2, and Th17 cytokines and also with the enhanced production of OVA-specific IgE, IgG1, and IgG2a. As for T cell responses, OVA-specific Th2 cell response, enhanced by chitin, was abolished by the treatment of chitinase, whereas Th1 and Th17 cell responses enhanced by this treatment. Moreover, the null mutation of the TNF-α gene revealed similar effects as the chitinase treatment. In contrast, all the OVA-specific T cell responses, enhanced by chitin, were blocked by the absence of TLR2, but not of TLR1, TLR4, or TLR6. Conclusions In conclusion, these data suggest that HDM-derived chitin may enhance airway hypersensitivity to inhaled allergens, via the TLR2-dependent pathway, and that chitin-induced TNF-α can be a key mediator in the development of Th2 cell response to inhaled allergens. PMID:27126730

  1. In Utero exposure to genistein enhanced intranasal house dust mite allergen-induced respiratory sensitization in young adult B6C3F1 mice.

    PubMed

    Guo, Tai L; Meng, Andrew H

    2016-06-24

    Despite many hypothesized benefits of dietary isoflavone genistein (GEN) deriving from soy-based products, questions surrounding GEN's developmental immunotoxic effects are increasing. To understand how in utero GEN exposure may modulate postnatal respiratory sensitization, we conducted a time course study using a common household allergen (house dust mites: HDM; 10μg/mouse) following intranasal instillation, a physiological route of allergen exposure. GEN was administered to dams by gavage from gestational day 14 to parturition at a physiologically relevant dose (20mg/kg bw). Female and male offspring were sensitized with HDM allergens beginning about one month prior to sacrifice followed by challenges with three weekly doses of HDM extracts, and they were euthanized at day 3 following the final HDM exposure at four different time points (postnatal day (PND) 80, 120, 160, and 200). In utero GEN combined with postnatal HDM exposures (GEN+HDM) increased total IgE production in both young female and male B6C3F1 offspring (e.g., PND 80 in females and PND 120 in males). Increased antigen-specific IgG1, IgG2a and IgG2b levels were also observed at various time points in both female and male offspring. In addition, increases in macrophage number in bronchoalveolar lavage fluid of both female and male GEN+HDM offspring at PND 80 and PND 120, respectively, were observed when compared to the vehicle group. For T cells, an increase over the vehicle in female GEN+HDM offspring was observed at PND 80. Due to similar patterns of increases, it seems likely that GEN+HDM-induced increases in total IgE and macrophages are related. Overall, in utero GEN plus later-life HDM exposures exert increases in total IgE and HDM-specific IgG production as well as macrophage recruitments to the lung in young adult mice. PMID:27113705

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

    PubMed Central

    2009-01-01

    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

  3. Lead Poisoning

    MedlinePlus

    ... Experiments Stories Lessons Topics Games Activities Lessons MENU Lead Poisoning Kids Homepage Topics Pollution Lead Poisoning What is ... you can avoid contact with it! Sources of Lead Poisoning HOUSE PAINTS: Before1950, lead-based paint was used ...

  4. Battery housing

    SciTech Connect

    Skinner, N. G.

    1985-03-19

    The present invention comprises a battery housing suitable for holding a battery which may generate a dangerously high level of internal pressure. The housing includes a receptacle having a vent passage covered by a rupture disc, the rupture disc in turn covered by a diffuser head having a longitudinal bore therein extending from the rupture disc to a blind end, the bore being traversed by at least one lateral passage leading to the exterior of the housing. Upon reaching a predetermined internal pressure level, the rupture disc ruptures and vents the interior of the housing safely to the exterior through the lateral passage.

  5. Quantities of lead producing health effects in humans: sources and bioavailability.

    PubMed Central

    Mahaffey, K R

    1977-01-01

    Levels of lead ingestion and inhalation producing increased body burden of lead and clinical toxicity in adults and children are compared with usual levels of exposure. The magnitude of lead exposure from air, water, and food is estimated. Sources of high level exposure to lead are described; urban street dirt, house dust, and paint are particularly common sources of high concentrations of lead. The bioavailability of different lead compounds is reviewed as well as factors affecting susceptibility to lead. PMID:908307

  6. House dust allergy and immunotherapy

    PubMed Central

    Thomas, Wayne R.

    2012-01-01

    HDM allergy is associated with asthma, allergic rhinitis and atopic dermatitis. In many countries childhood asthma is predominantly found in HDM-allergic children with their probability of developing disease being proportional to their IgE antibody titers and the early development of Th2 responses. While the pathogenesis is complex and increasingly linked to infection the immunologically-based allergen immunotherapy and anti-IgE antibody therapy are highly beneficial. Immunotherapy could be a short-term treatment providing lifelong relief but the current regimens depend on repeated administration of allergen over years. Immunological investigations point to a contribution of responses outside the Th2 pathway and multiple potential but unproven control mechanisms. Over half of the IgE antibodies are directed to the group 1 and 2 allergens with most of remainder to the group 4, 5, 7 and 21 allergens. This hierarchy found in high and low responders provides a platform for introducing defined allergens into immunotherapy and defined reagents for investigation. PMID:22894952

  7. Children and lead: new findings and concerns

    SciTech Connect

    Lin-Fu, J.S.

    1982-09-02

    An editorial dealing with lead in the environment and its health risks to children is presented. Young children are particularly vulnerable to lead exposure. Through hand-to-mouth activities, such as thumb sucking, nail biting, or eating with dirty hands, lead in house dust and garden soil readily enters their bodies. Children with pica are exposed to more lead because they eat such items as paint chips, broken plaster, and dirt. Moreover, intestinal lead absorption is greater in children than in adults. The author recommends a concerted effort to reduce undue lead absorption in children. (JMT)

  8. Group 1 Allergen Genes in Two Species of House Dust Mites, Dermatophagoides farinae and D. pteronyssinus (Acari: Pyroglyphidae): Direct Sequencing, Characterization and Polymorphism

    PubMed Central

    Shafique, Rubaba Hamid; Klimov, Pavel B.; Inam, Muhammad; Chaudhary, Farhana Riaz; OConnor, Barry M.

    2014-01-01

    Group 1 allergens of Dermatophagoides farinae (Der f 1) and D. pteronyssinus (Der p 1) dominate overall allergic responses in house dust mite allergy patients. The need for accurate identification and characterization of representative variants of group 1 allergens in any given geographic locality has been emphasized for development of appropriate allergen extracts. Regional amino acid sequence polymorphism has been described but the extent of this polymorphism is not well understood. Such data are completely absent for the USA and many other countries. Most previous studies used cDNA libraries generated by reverse transcriptase (RT-PCR) and/or primers amplifying shorter fragments of this gene. Using novel species-specific primers and direct PCR, we document group 1 allergen gene sequence polymorphism in populations of D. farinae and D. pteronyssinus from the USA and Pakistan. We report two novel introns (nt pos 87 and 291) in both species, and the absence of intron 3 in Der p 1. Thirteen silent and one novel non-synonymous mutation (Tryptophan W197 to Arginine R197) were detected in D. farinae. The potential medical significance of the latter mutation is discussed. Two haplotypes of the Der f 1 gene were identified, haplotype 1 (63%) was more frequent than haplotype 2 (18%). Polymorphism in Der f 1 displayed geographical localization, since both haplotypes were present in mite populations from Pakistan whereas haplotype 1 was observed only in the USA. In Der p 1, a silent mutation at nt (aa) position 1011(149) and four non-synonymous mutations at positions 589(50), 935(124), 971(136), 1268(215) were observed. These mutations were reported from many other geographic regions, suggesting that polymorphism in the Der p 1 gene is panmictic. The extent of polymorphism in both genes is substantially lower than that reported previously (0.10–0.16% vs 0.31–0.49%), indicating the need for careful evaluation of potential polymerase errors in studies utilizing RT

  9. Dust collector

    SciTech Connect

    Nelson, R.T.

    1986-10-21

    This patent describes a dust collector comprising: (a) a housing having inlet means for receiving air to be cleaned; (b) a plurality of filter units within the housing; (c) a first centrifugal fan arranged for drawing air through the units for removing dust from the air; (d) a plurality of ducts each connected to a corresponding one of the units at one end and to the first fan at the other end to provide passages for air from the units to the first fan, the ducts through a portion of their length being arranged in side-by-side relationship; (e) a second centrifugal fan for providing reverse flow of air through the ducts to the units, the second fan providing a high volume of air at low pressure; (f) a transverse duct connected to the second fan and extending transversely of the portion of the plurality of ducts and adjacent thereto: (g) a plurality of openings providing communication between the transverse duct and each of the plurality of ducts; (i) rotatable means engaging the vanes for sequentially moving the vanes between the first and second positions.

  10. Peeling Lead Paint Turns into Poisonous Dust. Guess Where It Ends Up? A Media Campaign to Prevent Childhood Lead Poisoning in New York City

    ERIC Educational Resources Information Center

    Greene, Danielle; Tehranifar, Parisa; DeMartini, Diana P.; Faciano, Andrew; Nagin, Deborah

    2015-01-01

    Successful public health media campaigns promote messages, increase awareness, engage the public, and encourage behavior change. Between 2004 and 2006, the Lead Poisoning Prevention Program of the New York City Department of Health and Mental Hygiene conducted a media campaign grounded in social learning theory and the social marketing model to…

  11. Peeling lead paint turns into poisonous dust. Guess where it ends up? A media campaign to prevent childhood lead poisoning in New York City.

    PubMed

    Greene, Danielle; Tehranifar, Parisa; DeMartini, Diana P; Faciano, Andrew; Nagin, Deborah

    2015-06-01

    Successful public health media campaigns promote messages, increase awareness, engage the public, and encourage behavior change. Between 2004 and 2006, the Lead Poisoning Prevention Program of the New York City Department of Health and Mental Hygiene conducted a media campaign grounded in social learning theory and the social marketing model to increase parents' awareness of childhood lead poisoning, ways to protect their children, and property owners' legal responsibility to fix peeling lead paint safely, and increase awareness of regulatory changes and encourage enforcement of New York City's Local Law 1 of 2004. Campaign materials were focus group tested and the campaign was refined annually. The campaign ran city-wide and in targeted high-risk neighborhoods. Neighborhoods and media venue (bus, train, kiosk, and store) changed annually, based on population risk factors and venue availability. Exposure to the campaign, campaign-related knowledge, and behavior were assessed using pre- and postcampaign street intercept surveys. Results showed that campaign reached the targeted population, and had an impact on knowledge of lead poisoning prevention measures as evidenced by increased knowledge of lead paint exposures sources in one year and increased knowledge of preventive behaviors in another year; these improvements were observed for both genders and most ethnic, primary language, educational attainment, and age groups in each year. Lessons learned indicate that well-targeted media campaigns, designed with audience participation, can reach parents through various venues, and improve key knowledge areas. Evaluation challenges faced include high levels of knowledge at baseline, competing media messages, and balancing between program needs and evaluation design. PMID:25558876

  12. 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 ...

  13. 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

    Menka, Nazune; Root, Rob; Chorover, Jon

    2014-01-01

    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

  14. 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...

  15. Window replacement and residential lead paint hazard control 12 years later.

    PubMed

    Dixon, Sherry L; Jacobs, David E; Wilson, Jonathan W; Akoto, Judith Y; Nevin, Rick; Scott Clark, C

    2012-02-01

    Window replacement is a key method of reducing childhood lead exposure, but the long-term effectiveness has not been previously evaluated. Windows have the highest levels of interior lead paint and dust compared to other building components. Our objective was to conduct a follow-up study of residential window replacement and lead hazard control 12 years after homes were enrolled in an evaluation of the HUD Lead Hazard Control Grant Program, sampling settled lead dust in housing in four cities (n=189 homes). Previous work evaluated lead hazard controls up to 6 years after intervention using dust lead measurements and two years after intervention using both dust and blood lead data. But the earlier work could not examine the effect of window replacement over the longer time period examined here: 12 years. The individual homes were assigned to one of three categories, based on how many windows had been replaced: all replacement, some replacement, or non-replacement. Windows that were not replaced were repaired. We controlled for covariates such as site, housing condition, presence of lead paint, and season using longitudinal regression modeling. Adjusted floor and sill dust lead geometric mean dust lead loadings declined at least 85% from pre-intervention to 12 years after the intervention for homes with all replacement windows, some windows replaced and no windows replaced. Twelve years after intervention, homes with all replacement windows had 41% lower interior floor dust lead, compared to non-replacement homes (1.4 versus 2.4 μg/ft2, p<0.001), and window sill dust lead was 51% lower (25 versus 52 μg/ft2, p=0.006) while controlling for covariates. Homes with some windows replaced had interior floor and window sill dust lead loadings that were 28% (1.7 versus 2.4 μg/ft2, p=0.19) and 37% (33 versus 52 μg/ft2, p=0.07) lower, respectively, compared to non-replacement homes. The net economic benefit of window replacement compared to window repair (non

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

    PubMed

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

    2010-05-01

    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

  17. 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...

  18. 76 FR 12106 - Lead-Based Paint Renovation, Repair and Painting Activities in Target Housing and Child Occupied...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-04

    .... In the Federal Register dated April 22, 2008 (73 FR 21692), EPA promulgated final TSCA section 402(c... Kansas Department of Health and Environment (KDHE) to operate a lead poisoning prevention program in... other individuals who request it in order to advance the success of the lead poisoning...

  19. Nurse Case Management and Housing Interventions Reduce Allergen Exposures: The Milwaukee Randomized Controlled Trial

    PubMed Central

    Breysse, Jill; Wendt, Jean; Dixon, Sherry; Murphy, Amy; Wilson, Jonathan; Meurer, John; Cohn, Jennifer; Jacobs, David E.

    2011-01-01

    Objective We examined the impact of a combination of home environmental interventions and nurse case management services on total settled dust loadings and on allergen concentrations in the homes of asthmatic children. Methods Using a randomized longitudinal controlled trial study design, we randomly assigned homes of asthmatic children in Milwaukee to either a control (n=64) or an intervention (n=57) group. Control group homes received a visual assessment, education, bed/pillow dust mite encasings, and treatment of lead-based paint hazards. The intervention group received these same services plus nurse case management that included tailored, individual asthma action plans, provision of minor home repairs, home cleaning using special vacuuming and wet washing, and integrated pest management. Dust vacuum samples were collected from measured surface areas of floors in the TV room, kitchen, and child's bedroom at baseline and at three-, six-, and 12-month follow-up visits. Dust loading (mass per surface area) is a means of measuring total dust and the total amount of allergen present. Results For the intervention group, geometric mean dust loadings declined significantly from baseline (39 milligrams per square foot [mg/ft2]) to post-intervention (11 mg/ft2) (p<0.001). Baseline dust loading, treatment group, visit, and season were significant predictors of follow-up dust loadings. Mean post-intervention dust loadings were 72% higher in the control group. The total amount of allergen in settled house dust declined significantly following the intervention because total dust loading declined; the concentration of allergens in settled dust did not change significantly. Conclusion The combination of nurse case management and home environmental interventions promotes collaboration between health and housing professionals and is effective in reducing exposures to allergens in settled dust. PMID:21563716

  20. Identification of sources of lead in children in a primary zinc-lead smelter environment.

    PubMed Central

    Gulson, Brian L; Mizon, Karen J; Davis, Jeff D; Palmer, Jacqueline M; Vimpani, Graham

    2004-01-01

    We compared high-precision lead isotopic ratios in deciduous teeth and environmental samples to evaluate sources of lead in 10 children from six houses in a primary zinc-lead smelter community at North Lake Macquarie, New South Wales, Australia. Teeth were sectioned to allow identification of lead exposure in utero and in early childhood. Blood lead levels in the children ranged from 10 to 42 micro g/dL and remained elevated for a number of years. For most children, only a small contribution to tooth lead can be attributed to gasoline and paint sources. In one child with a blood lead concentration of 19.7 microg/dL, paint could account for about 45% of lead in her blood. Comparison of isotopic ratios of tooth lead levels with those from vacuum cleaner dust, dust-fall accumulation, surface wipes, ceiling (attic) dust, and an estimation of the smelter emissions indicates that from approximately 55 to 100% of lead could be derived from the smelter. For a blood sample from another child, > 90% of lead could be derived from the smelter. We found varying amounts of in utero-derived lead in the teeth. Despite the contaminated environment and high blood lead concentrations in the children, the levels of lead in the teeth are surprisingly low compared with those measured in children from other lead mining and smelting communities. PMID:14698931

  1. Comparison of a wipe method with and without a rinse to recover wall losses in closed face 37-mm cassettes used for sampling lead dust particulates

    PubMed Central

    Ceballos, Diana; King, Bradley; Beaucham, Catherine; Brueck, Scott E.

    2015-01-01

    Closed-face 37-millimeter (mm) polystyrene cassettes are often used for exposure monitoring of metal particulates. Several methods have been proposed to account for the wall loss in air sampling cassettes, including rinsing, wiping, within-cassette dissolution, and an internal capsule fused to the filter that could be digested with the filter. Until internal capsules replace filters, other methods for assessing wall losses may be considered. To determine if rinsing and wiping or wiping alone is adequate to determine wall losses on cassettes, we collected 54 full-shift area air samples at a battery recycling facility. We collected six replicate samples at three locations within the facility for 3 consecutive days. The wall losses of three replicate cassettes from each day-location were analyzed following a rinse and two consecutive wipes. The wall losses of the other three replicates from each day-location were analyzed following two consecutive wipes only. Mixed-cellulose ester membrane filter, rinse, and wipes were analyzed separately following NIOSH Method 7303. We found an average of 29% (range: 8%–54%) recovered lead from the cassette walls for all samples. We also found that rinsing prior to wiping the interior cassette walls did not substantially improve recovery of wall losses compared to wiping alone. A rinse plus one wipe recovered on average 23% (range: 13%–33%) of the lead, while one wipe alone recovered on average 21% (range: 16%–22%). Similarly we determined that a second wipe did not provide substantial additional recovery of lead (average: 4%, range: 0.4%–19%) compared to the first wipe disregarding the rinse (average: 18%, range: 4%–39%). We concluded that when an internal capsule is not used, wall losses of lead dust in air sampling cassettes can be adequately recovered by wiping the internal wall surfaces of the cassette with a single wipe. PMID:26125330

  2. Concentration of lead, cadmium, and iron in sediment dust and total suspended particles before and after initialisation of integral production in iron and steel work plant Zenica.

    PubMed

    Prcanović, Halim; Duraković, Mirnes; Beganović, Sanela

    2012-06-01

    Poor air quality is a common fact for all areas with base industry. The city of Zenica was once the metallurgical centre of Ex-Yugoslavia and is therefore highly polluted at present. Air pollution peaked in 1987 when average concentration of pollutants was extremely high (daily average concentration of SO(2) was 1800 μg m(-3)). With the beginning of the war in 1992, integral production in the steel work plant was shut down, to be re-launched in 2008. Limit values for iron do not exist, but iron has been monitored in Zenica for the past 28 years because of the presence of steel works. Concentrations of cadmium and lead have also been measured because they are very much present in polluted areas with steel works. The concentration of mentioned elements in air deposit and total suspended particles before and after integral production in the steel work plant was re-launched is the subject of this paper. Total suspended particles were measured in two locations using German standard VDI 2463 Blatt 4. Sediment dust was measured in nine locations using Bergerhoff method. The concentration of iron, lead, and cadmium was performed in the chemical laboratory of the Metallurgical Institute "Kemal Kapetanović" Zenica using standard methods. Higher concentrations of these parameters during the period of integral production clearly point to the impact of steel works on Zenica valley. PMID:22728800

  3. The relationship of environmental lead to blood-lead levels in children

    SciTech Connect

    Stark, A.D.; Quah, R.; Meigs, J.W.; DeLouise, E.R.

    1982-04-01

    An in-depth study of the distribution of lead sources in the residential environment of 377 children in New Haven, Connecticut, was carried out. Substantial amounts of lead were present in soil, paint, and house dust throughout New Haven, but not in air or water. Multiple regression modeling indicated that the most important contributors to variation in children's blood-lead levels were soil lead and exterior house paint lead. Using the best five-variable model only 11.7% of the variation in the children's blood-lead levels could be explained. This led to the conclusion that availability of lead in the residential environment did not account for most of the variation observed in the population.

  4. Ionic liquid coated carbon nanospheres as a new adsorbent for fast solid phase extraction of trace copper and lead from sea water, wastewater, street dust and spice samples.

    PubMed

    Tokalıoğlu, Şerife; Yavuz, Emre; Şahan, Halil; Çolak, Süleyman Gökhan; Ocakoğlu, Kasım; Kaçer, Mehmet; Patat, Şaban

    2016-10-01

    In this study a new adsorbent, ionic liquid (1,8-naphthalene monoimide bearing imidazolium salt) coated carbon nanospheres, was synthesized for the first time and it was used for the solid phase extraction of copper and lead from various samples prior to determination by flame atomic absorption spectrometry. The ionic liquid, carbon nanospheres and ionic liquid coated carbon nanospheres were characterized by using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, (1)H NMR and (13)C NMR, Brunauer, Emmett and Teller surface area and zeta potential measurements. Various parameters for method optimization such as pH, adsorption and elution contact times, eluent volume, type and concentration, centrifuge time, sample volume, adsorption capacity and possible interfering ion effects were tested. The optimum pH was 6. The preconcentration factor, detection limits, adsorption capacity and precision (as RSD%) of the method were found to be 300-fold, 0.30µgL(-1), 60mgg(-1) and 1.1% for copper and 300-fold, 1.76µgL(-1); 50.3mgg(-1) and 2.2%, for lead, respectively. The effect of contact time results showed that copper and lead were adsorbed and desorbed from the adsorbent without vortexing. The equilibrium between analyte and adsorbent is reached very quickly. The method was rather selective for matrix ions in high concentrations. The accuracy of the developed method was confirmed by analyzing certified reference materials (LGC6016 Estuarine Water, Reference Material 8704 Buffalo River Sediment, and BCR-482 Lichen) and by spiking sea water, wastewater, street dust and spice samples. PMID:27474302

  5. Measurement of nicotine in household dust

    SciTech Connect

    Kim, Sungroul Aung, Ther; Berkeley, Emily; Diette, Gregory B.; Breysse, Patrick N.

    2008-11-15

    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.

  6. DUST FORMATION IN MACRONOVAE

    SciTech Connect

    Takami, Hajime; Ioka, Kunihito; Nozawa, Takaya E-mail: kunihito.ioka@kek.jp

    2014-07-01

    We examine dust formation in macronovae (as known as kilonovae), which are the bright ejecta of neutron star binary mergers and one of the leading sites of r-process nucleosynthesis. In light of information about the first macronova candidate associated with GRB 130603B, we find that dust grains of r-process elements have difficulty forming because of the low number density of the r-process atoms, while carbon or elements lighter than iron can condense into dust if they are abundant. Dust grains absorb emission from ejecta with an opacity even greater than that of the r-process elements, and re-emit photons at infrared wavelengths. Such dust emission can potentially account for macronovae without r-process nucleosynthesis as an alternative model. This dust scenario predicts a spectrum with fewer features than the r-process model and day-scale optical-to-ultraviolet emission.

  7. The effect of disodium cromoglycate, budesonide, and cyclosporin A on interleukin-4, interleukin-5, and interleukin-13 secretions in Der p I-stimulated T cells from house dust mite-sensitive atopic and nonatopic individuals.

    PubMed

    Oh, Jae-Won; Lee, Ha-Baik; Chung, Yong-Hoon; Choi, Yong

    2002-01-01

    Disodium cromoglycate (DSCG), budesonide, and cyclosporin A (CsA) were the well-known immunomodulators for the allergic and immunologic diseases clinically. In this study, we evaluated the characteristics of inhibition on cytokine synthesis of Der p I-stimulated T cells by the same inhibiting concentrations of DSCG, budesonide, and CsA in house-dust mite antigen (Der p I)-specific atopic and nonatopic healthy individuals. Seven house dust mite allergen specific patients were recruited for this study. Seven healthy volunteers were included on the basis of negative allergic manifestations and low serum immunoglobulin E values. Peripheral blood mononuclear cells (PBMCs) were cultured in the presence of recombinant interleukin (rIL)-2 with or without budesonide, DSCG, CsA, and Der p I for 48 hours. Cells were stained with anti-CD4 fluorescein isothiocyanate-conjugated monoclonal antibody, and then anti-human IL-4 phycoerythrin, IL-5, or IL-13 monoclonal antibody, respectively, was added to both blocked and stained samples. Incubation of PBMC from atopics with each immunomodulator and Der p I resulted in the reduction of IL-4 secretion compared with Der p I alone stimulation. However, IL-4 secretion in PBMC from nonatopics was not reduced with DSCG and Der p I stimulation. IL-4, IL-5, and IL-13 secretions of PBMC from atopics were significantly decreased after incubation with each immunomodulator and Der p I, compared with after incubation with Der p I alone. These results might be considered to show either that DSCG has a selective inhibiting effect on cytokine production in T cells from atopics or is a weak inhibitor of cytokine secretions compared with budesonide and CsA at even strength for the inhibition of lymphocyte proliferation in normal, healthy individuals. PMID:12001789

  8. Vacuum Head Removes Sanding Dust

    NASA Technical Reports Server (NTRS)

    Bengle, C. G.; Holt, J. W.

    1982-01-01

    Vacuum sander prevents sanding dust from entering a work area, since dust particles are drawn off as quickly as they are produced. Tool is useful where dust presents health hazards, interferes with such processes as semiconductor manufacture, or could destroy wet paint or varnish finishes. Could be used to sand such materials as lead paint.

  9. Lead Poisoning

    MedlinePlus

    ... our environment. Much of it comes from human activities such as mining and manufacturing. Lead used to be in paint; older houses may still have lead paint. You could be exposed to lead by Eating food or drinking water that contains lead. Water pipes in older homes ...

  10. Dust Detector

    NASA Technical Reports Server (NTRS)

    Kelley, M. C.

    2001-01-01

    We discuss a recent sounding rocket experiment which found charged dust in the Earth's tropical mesosphere. The dust detector was designed to measure small (5000 - 10000 amu.) charged dust particles, most likely of meteoric origin. A 5 km thick layer of positively charged dust was found at an altitude of 90 km, in the vicinity of an observed sporadic sodium layer and sporadic E layer. The observed dust was positively charged in the bulk of the dust layer, but was negatively charged near the bottom.

  11. Health and environmental outcomes of traditional and modified practices for abatement of residential lead-based paint.

    PubMed Central

    Farfel, M R; Chisolm, J J

    1990-01-01

    We evaluated traditional and modified practices for abating lead-based paint in homes of children with blood-lead concentrations (PbB) greater than 1.4 mumol/L (greater than 29 micrograms/dl). Traditional abatement resulted in acute increases in: 1) lead contaminated house dust (generally 3 to 6-fold over pre-abatement levels, but at abated sites typically 10 to 100-fold); and 2) the PbBs of nearly half of the occupant children. Modified practices represented modest short-term improvement compared to traditional practices but were also inadequate. By six months, it was clear that neither form of abatement resulted in long-term reductions of PbB or house dust lead levels, leaving children at continued risk of excessive exposure to lead and permanent adverse neurobehavioral effects. Windows were found to be high sources of lead contaminated house dust. Recommendations are made for improved abatement practices including more complete abatement of window units and more effective clean-up to remove lead-bearing dust. Thirteen million US children live in lead-painted dwellings. Research is needed to identify abatement strategies that will be practical and well suited to the current understanding of low-level lead toxicity. PMID:2136329

  12. Health and environmental outcomes of traditional and modified practices for abatement of residential lead-based paint

    SciTech Connect

    Farfel, M.R.; Chisolm, J.J. Jr. )

    1990-10-01

    We evaluated traditional and modified practices for abating lead-based paint in homes of children with blood-lead concentrations (PbB) greater than 1.4 mumol/L (greater than 29 micrograms/dl). Traditional abatement resulted in acute increases in: (1) lead contaminated house dust (generally 3 to 6-fold over pre-abatement levels, but at abated sites typically 10 to 100-fold); and (2) the PbBs of nearly half of the occupant children. Modified practices represented modest short-term improvement compared to traditional practices but were also inadequate. By six months, it was clear that neither form of abatement resulted in long-term reductions of PbB or house dust lead levels, leaving children at continued risk of excessive exposure to lead and permanent adverse neurobehavioral effects. Windows were found to be high sources of lead contaminated house dust. Recommendations are made for improved abatement practices including more complete abatement of window units and more effective clean-up to remove lead-bearing dust. Thirteen million US children live in lead-painted dwellings. Research is needed to identify abatement strategies that will be practical and well suited to the current understanding of low-level lead toxicity.

  13. Origin of lead in the United States diet.

    PubMed

    Manton, William I; Angle, Carol R; Krogstrand, Kaye L Stanek

    2005-11-15

    We report 208Pb/207Pb and 206Pb/207Pb ratios for 1001 duplicate diets collected from mothers and children, 1304 samples of house dust and hand wipes, and 64 samples of aerosols that were taken in Omaha, Nebraska, during the period from 1990 to 1997. A plot of 208Pb/207Pb versus 206Pb/ 207Pb for the dust and hand wipes indicates that they contain lead from ores mined in Idaho, Missouri, and Mexico. The absence of lead from Utah suggests that this mixture is not representative of the whole country. The lead in the aerosols has a narrower range of isotope ratios and resembles aerosols collected elsewhere in the United States. Most dietary collections contain a large component of house dust. Some, especially those from infants, are dominated by uranogenic lead with high 206Pb/207Pb ratios. Its source is taken to be calcium-supplemented food where the calcium is derived from limestone. Another source of lead is thorogenic and is ascribed to lead in tin coatings. Agricultural lead, whether from soil (estimated from recently published analyses of sedimentary materials), fertilizer, or agricultural lime, could not be unambiguously identified in the diets. Lead derived from aerosols, if present at all, is insignificant. PMID:16329199

  14. A coordinated relocation strategy for enhancing case management of lead poisoned children: outcomes and costs.

    PubMed

    McLaine, Pat; Shields, Wendy; Farfel, Mark; Chisolm, J Julian; Dixon, Sherry

    2006-01-01

    Controlling residential lead hazards is critical for case management of lead poisoned children. To attain this goal, permanent relocation of the family is sometimes necessary or advisable for many reasons, including poor housing conditions; extensive lead hazards; lack of abatement resources, landlord compliance and local enforcement capacity; and family eviction. During 1996-1998, the Kennedy Krieger Institute implemented a unique capitated program for case management of Baltimore City children with blood lead concentrations (PbB) >19 microg/dL. The Program provided financial, housing, and social work assistance to facilitate relocation as a means of providing safer housing. Nearly half of the Program families relocated with direct assistance, and 28% relocated on their own. The Program evaluation examined the costs and benefits of relocation. Average relocation cost per child was relatively inexpensive (<1,500 dollars). Average relocation time of 5 months (range <2 months to >12 months) was less than the 8-month average time to complete lead hazard control work in 14 city and state programs funded by U.S. HUD. Relocation was associated with (1) a statistically significant decrease in dust lead loadings on floors, windowsills and window troughs that persisted for one year, and (2) statistically significantly greater decreases in children's PbB compared to children who did not relocate from untreated homes. Children relocated to housing that met current Federal residential dust lead standards had statistically significant decreases in blood lead levels. Visual inspection did not consistently identify relocation houses with dust lead levels below current Federal standards, indicating that dust testing should be an essential component of future programs. This will require additional resources for dust testing and possibly cleaning and repairs but is expected to yield additional benefits for children. The findings support recent U.S. CDC case management

  15. Dust control for draglines

    SciTech Connect

    Grad, P.

    2009-09-15

    Monitoring dust levels inside draglines reveals room for improvement in how filtration systems are used and maintained. The Australian firm BMT conducted a field test program to measure airflow parameters, dust fallout rates and dust concentrations, inside and outside the machine house, on four draglines and one shovel. The study involved computational fluid dynamics (CFD) simulations. The article describes how the tests were made and gives results. It was not possible to say which of the two main filtration systems currently used on Australian draglines - Dynavane or Floseps - performs better. It would appear that more frequent maintenance and cleaning would increase the overall filtration performance and systems could be susceptible to repeat clogging in a short time. 2 figs., 1 photos.

  16. Cosmic dust

    NASA Technical Reports Server (NTRS)

    Brownlee, Donald E.; Sandford, Scott A.

    1992-01-01

    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.

  17. Migration of Contaminated Soil and Airborne Particulates to Indoor Dust

    PubMed Central

    Layton, David W.; Beamer, Paloma I.

    2009-01-01

    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

  18. Dust Storm

    Atmospheric Science Data Center

    2013-04-16

    article title:  Massive Dust Storm over Australia     View ... at JPL September 22, 2009 - Massive dust storm over Australia. project:  MISR category:  ... Sep 22, 2009 Images:  Dust Storm location:  Australia and New Zealand ...

  19. Sahara Dust

    Atmospheric Science Data Center

    2013-04-15

    article title:  Casting Light and Shadows on a Saharan Dust Storm     ... (nadir) camera. High-altitude cirrus clouds cast shadows on the underlying ocean and dust layer, which are visible in shades of ... was unable to retrieve elevation data. However, the edges of shadows cast by the cirrus clouds onto the dust (indicated by blue and cyan ...

  20. Lead in the Japanese living environment.

    PubMed

    Yoshinaga, Jun

    2012-11-01

    Lead has long been known to be a neurotoxic heavy metal, particularly in the context of occupational health. However, its adverse effect on the cognitive development of children at lower exposure levels has only recently received attention. Although the exposure level of contemporary Japanese children is among the lowest in the world, it is desirable to reduce exposure as much as reasonably possible due to the absence of a threshold of exposure for adverse effects. In this review, information on lead levels in milieus of our proximate environment, such as the atmosphere, drinking water, soil, house dust, diet and others, of contemporary Japan was compiled with the aim of updating our knowledge on lead distribution. Monitoring data demonstrates that lead concentrations in the atmosphere and lead intake from food consumption have decreased substantially from the 1970s. Lead was hardly detectable in tap water in a recent nation-wide monitoring survey. To the contrary, elevated lead concentrations were detected in surface soil and house dust in one of the studies on daily exposure to lead from all potential sources, and both of these sources were regarded by the authors as significant contributors of lead exposure to general Japanese children. A similar study indicated that diet is the sole major source of lead for Japanese children. A significant difference was present in the estimated dietary lead intake levels in different studies, resulting in significant discrepancies in the current knowledge on lead in our environment. Further studies are warranted to identify the major source(s) of lead exposure in Japanese children in order to establish an effective countermeasure to reduce lead exposure to children. PMID:22528209

  1. NHEXAS PHASE I MARYLAND STUDY--STANDARD OPERATING PROCEDURE FOR SIEVING AND DIVISION OF DUST AND SOIL SAMPLES (L05)

    EPA Science Inventory

    The purpose of this SOP is to describe the procedure for sieving samples of house dust and soil. The procedure is applicable to house dust samples taken using the HVS3 dust sampler, and to soil samples. Keywords: dust; soil.

    The National Human Exposure Assessment Survey (NHE...

  2. Circumstellar dust

    NASA Technical Reports Server (NTRS)

    Dwek, E.

    1986-01-01

    The presence of dust in the general interstellar medium is inferred from the extinction, polarization, and scattering of starlight; the presence of dark nebulae; interstellar depletions; the observed infrared emission around certain stars and various types of interstellar clouds. Interstellar grains are subject to various destruction mechanisms that reduce their size or even completely destroy them. A continuous source of newly formed dust must therefore be present for dust to exist in the various phases of the interstellar medium (ISM). The working group has the following goals: (1) review the evidences for the formation of dust in the various sources; (2) examine the clues to the nature and composition of the dust; (3) review the status of grain formation theories; (4) examine any evidence for the processing of the dust prior to its injection into the interstellar medium; and (5) estimate the relative contribution of the various sources to the interstellar dust population.

  3. Environmental Lead after Hurricane Katrina: Implications for Future Populations

    PubMed Central

    Iqbal, Shahed; Perry, Sara; Arroyave, Whitney; Rice, Janet C.

    2011-01-01

    Background: As a result of Hurricane Katrina, > 100,000 homes were destroyed or damaged and a significant amount of sediment was deposited throughout the city of New Orleans, Louisiana. Researchers have identified the potential for increased lead hazards from environmental lead contamination of soils. Objectives: We assessed the distribution of residential soil and dust lead 2 years poststorm and compared soil lead before and after the storm. Methods: We conducted a cross-sectional study in New Orleans in which households were selected by stratified random sampling. A standard residential questionnaire was administered, and lead testing was performed for both the interior and exterior of homes. Logistic regression was used to identify significant predictors of interior and exterior lead levels in excess of allowable levels. Results: One hundred nine households were enrolled; 61% had at least one lead measurement above federal standards. Of homes with bare soil, 47% had elevated lead and 27% had levels exceeding 1,200 ppm. Housing age was associated with soil lead, and housing age and soil lead were associated with interior lead. Race, income, and ownership status were not significantly associated with either interior or exterior lead levels. The median soil lead level of 560 ppm was significantly higher than the median level of samples collected before Hurricane Katrina. Conclusions: The high prevalence (61%) of lead above recommended levels in soil and dust samples in and around residences raises concern about potential health risks to the New Orleans population, most notably children. Steps should be taken to mitigate the risk of exposure to lead-contaminated soil and dust. Further research is needed to quantify the possible contribution of reconstruction activities to environmental lead levels. PMID:22052045

  4. Lunar Dust Mitigation Screens

    NASA Astrophysics Data System (ADS)

    Knutson, Shawn; Holloway, Nancy

    With plans for the United States to return to the moon, and establish a sustainable human presence on the lunar surface many issues must be successfully overcome. Lunar dust is one of a number of issues with the potential to create a myriad of problems if not adequately addressed. Samples of dust brought back from Apollo missions show it to be soft, yet sharp and abrasive. The dust consists of a variety of morphologies including spherical, angular blocks, shards, and a number of irregular shapes. One of the main issues with lunar dust is its attraction to stick to anything it comes in contact with (i.e. astronauts, equipment, habitats, etc.). Ionized radiation from the sun strikes the moon's surface and creates an electrostatic charge on the dust. Further, the dust harbors van der Waals forces making it especially difficult to separate once it sticks to a surface. During the Apollo missions, it was discovered that trying to brush the lunar dust from spacesuits was not effective, and rubbing it caused degradation of the suit material. Further, when entering the lunar module after moonwalks, the astronauts noted that the dust was so prolific inside the cabin that they inhaled and ingested it, causing at least one of them, Harrison "Jack" Schmidt, to report irritation of the throat and lungs. It is speculated that the dust could also harm an astronaut's nervous and cardiovascular systems, especially during an extended stay. In addition to health issues, the dust can also cause problems by scouring reflective coatings off of thermal blankets, and roughening surfaces of windows and optics. Further, panels on solar cells and photovoltaics can also be compromised due to dust sticking on the surfaces. Lunar dust has the capacity to penetrate seals, interfere with connectors, as well as mechanisms on digging machines, all of which can lead to problems and failure. To address lunar dust issues, development of electrostatic screens to mitigate dust on sur-faces is currently

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

    PubMed

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

    2012-07-01

    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 μg/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 μg/L with an exceptional high value of 639 μg/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 μg/kg/d, respectively) in the polluted area were far higher than the provisional tolerable weekly intake (PTWI) of 25 μg/kg body weight (translated into 3.5 μg/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

  6. Comments on Dust Reverberation

    NASA Astrophysics Data System (ADS)

    Peterson, B.

    2015-09-01

    Dust reverberation is an important technique for studying the inner structure of AGNs and probing the properties of astrophysical dust, and even has some potential as a cosmological probe. We will discuss two recent results that pose a serious limitation to understanding dust reverberation at the present time. First, recent high-cadence monitoring of the UV and optical continuum in two AGNs, NGC 2617 and NGC 5548, have yielded unambiguous lags between variations of the UV continuum and corresponding variations of the continuum at longer wavelengths. In the absence of UV data, this leads to a systematic underestimate of the innermost radius where dust is found. This similarly leads to an underestimate of the size of the broad emission-line region, although it does not affect the AGN black hole mass scale, which calibrates out this effect. Second, broad-band monitoring of continuum variations in the optical through near-IR show that the innermost dust is not necessarily at the 'instantaneous sublimation radius.' The innermost dust can be considerably cooler than expected at the sublimation radius and thus can heat up without sublimating when the central continuum source becomes more luminous (see the poster by Pott).

  7. Multimedia exposures to arsenic and lead for children near an inactive mine tailings and smelter site.

    PubMed

    Loh, Miranda M; Sugeng, Anastasia; Lothrop, Nathan; Klimecki, Walter; Cox, Melissa; Wilkinson, Sarah T; Lu, Zhenqiang; Beamer, Paloma I

    2016-04-01

    Children living near contaminated mining waste areas may have high exposures to metals from the environment. This study investigates whether exposure to arsenic and lead is higher in children in a community near a legacy mine and smelter site in Arizona compared to children in other parts of the United States and the relationship of that exposure to the site. Arsenic and lead were measured in residential soil, house dust, tap water, urine, and toenail samples from 70 children in 34 households up to 7 miles from the site. Soil and house dust were sieved, digested, and analyzed via ICP-MS. Tap water and urine were analyzed without digestion, while toenails were washed, digested and analyzed. Blood lead was analyzed by an independent, certified laboratory. Spearman correlation coefficients were calculated between each environmental media and urine and toenails for arsenic and lead. Geometric mean arsenic (standard deviation) concentrations for each matrix were: 22.1 (2.59) ppm and 12.4 (2.27)ppm for soil and house dust (<63μm), 5.71 (6.55)ppb for tap water, 14.0 (2.01)μg/L for specific gravity-corrected total urinary arsenic, 0.543 (3.22)ppm for toenails. Soil and vacuumed dust lead concentrations were 16.9 (2.03)ppm and 21.6 (1.90) ppm. The majority of blood lead levels were below the limit of quantification. Arsenic and lead concentrations in soil and house dust decreased with distance from the site. Concentrations in soil, house dust, tap water, along with floor dust loading were significantly associated with toenail and urinary arsenic but not lead. Mixed models showed that soil and tap water best predicted urinary arsenic. In our study, despite being present in mine tailings at similar levels, internal lead exposure was not high, but arsenic exposure was of concern, particularly from soil and tap water. Naturally occurring sources may be an additional important contributor to exposures in certain legacy mining areas. PMID:26803211

  8. Protoplanetary Dust

    NASA Astrophysics Data System (ADS)

    Apai, Dániel; Lauretta, Dante S.

    2010-01-01

    Preface; 1. Planet formation and protoplanetary dust Daniel Apai and Dante Lauretta; 2. The origins of protoplanetary dust and the formation of accretion disks Hans-Peter Gail and Peter Hope; 3. Evolution of protoplanetary disk structures Fred Ciesla and Cornelius P. Dullemond; 4. Chemical and isotopic evolution of the solar nebula and protoplanetary disks Dmitry Semenov, Subrata Chakraborty and Mark Thiemens; 5. Laboratory studies of simple dust analogs in astrophysical environments John R. Brucato and Joseph A. Nuth III; 6. Dust composition in protoplanetaty dust Michiel Min and George Flynn; 7. Dust particle size evolution Klaus M. Pontoppidan and Adrian J. Brearly; 8. Thermal processing in protoplanetary nebulae Daniel Apai, Harold C. Connolly Jr. and Dante S. Lauretta; 9. The clearing of protoplanetary disks and of the protosolar nebula Ilaira Pascucci and Shogo Tachibana; 10. Accretion of planetesimals and the formation of rocky planets John E. Chambers, David O'Brien and Andrew M. Davis; Appendixes; Glossary; Index.

  9. Protoplanetary Dust

    NASA Astrophysics Data System (ADS)

    Apai, D.´niel; Lauretta, Dante S.

    2014-02-01

    Preface; 1. Planet formation and protoplanetary dust Daniel Apai and Dante Lauretta; 2. The origins of protoplanetary dust and the formation of accretion disks Hans-Peter Gail and Peter Hope; 3. Evolution of protoplanetary disk structures Fred Ciesla and Cornelius P. Dullemond; 4. Chemical and isotopic evolution of the solar nebula and protoplanetary disks Dmitry Semenov, Subrata Chakraborty and Mark Thiemens; 5. Laboratory studies of simple dust analogs in astrophysical environments John R. Brucato and Joseph A. Nuth III; 6. Dust composition in protoplanetaty dust Michiel Min and George Flynn; 7. Dust particle size evolution Klaus M. Pontoppidan and Adrian J. Brearly; 8. Thermal processing in protoplanetary nebulae Daniel Apai, Harold C. Connolly Jr. and Dante S. Lauretta; 9. The clearing of protoplanetary disks and of the protosolar nebula Ilaira Pascucci and Shogo Tachibana; 10. Accretion of planetesimals and the formation of rocky planets John E. Chambers, David O'Brien and Andrew M. Davis; Appendixes; Glossary; Index.

  10. Evaluation of health and environmental effects of two methods for residential lead paint removal

    SciTech Connect

    Farfel, M.

    1987-01-01

    The primary objective of this prospective study was to compare the effectiveness of traditional lead-paint abatement to the alternative approach outlined in recent, but never tested, Centers for Disease Control (CDC) guidelines which were followed by Baltimore City work crews in a one-year project. Concurrent serial measurements of lead in house-dust (PbD) and children's blood (PbB) were made pre, post, and 6 month post-abatement in 53 dwellings of affected children abated by traditional methods and 18 abated by city crews using methods similar to CDC guidelines. Traditional methods increased exposure to lead in house dust. CDC guidelines represent modest improvement, although they do no adequately reduce the hazard associated with domestic exposure to particulate lead.

  11. Implications of different residential lead standards on children's blood lead levels in France: predictions based on a national cross-sectional survey.

    PubMed

    Oulhote, Youssef; LeTertre, Alain; Etchevers, Anne; Le Bot, Barbara; Lucas, Jean-Paul; Mandin, Corinne; Le Strat, Yann; Lanphear, Bruce; Glorennec, Philippe

    2013-11-01

    Despite the dramatic reductions in children's blood lead levels (BLLs), there is considerable evidence that low-level lead exposure is associated with intellectual deficits and behavioral problems, without apparent threshold. There are limited data, however, about the contribution of residential sources of lead to contemporary children's blood lead levels. The aim of this study is to calculate the contributions of residential sources of lead to assess the potential impact of setting new standards for lead levels in residential dust, soil and water. We enrolled 484 French children aged from 6 months to 6 years, and collected data on social, housing and individual characteristics. Lead concentrations in blood and environmental samples (water, soils, and dusts) were measured using inductively coupled plasma mass spectrometry. Data were analyzed using a multivariate generalized additive model accounting for the sampling design and the sampling weights. We found that exceedingly low concentrations of lead in dust, soil and water were significant predictors of children's BLLs, after adjustment for potential confounding variables. Lead-contaminated floor dust was the main source of lead in blood. BLLs (GM: 14μg/L) increased by 65%, 13%, 25%, and 5% when lead content in floor dust, loose soil, hard soil and water increased from their 25th percentile to their 95th percentile, respectively. We also observed that the steepest increase in BLLs occurred at the lowest levels of lead-contaminated floor dust, which indicates that lead contamination should be kept as low as possible. Impact of different possible standards on children's BLLs was also tabulated and indicated that unless standards are set low, they will only benefit a small proportion of children who have the highest exposures. PMID:23528234

  12. An evaluation of the effectiveness of lead paint hazard reduction when conducted by homeowners and landlords

    SciTech Connect

    Etre, L.A.; Reynolds, S.J.; Burmeister, L.F.; Whitten, P.S.; Gergely, R.

    1999-08-01

    This research project was conducted in collaboration with the Iowa Department of Public Health to evaluate whether property owners who follow recommended procedures for lead-based paint removal/repair can do the work safely and effectively. This study included 29 homes where a lead-based paint hazard had been identified and lead-based paint was removed or repaired (hazard reduction). Exposure evaluation included pre-project surface dust wipe sampling, air monitoring during lead-based paint removal, post-project surface dust wipe sampling, and pre- and post-project blood samples from adult study participants. The comparison of surface dust wipe samples taken before and after lead paint hazard reduction was used to evaluate the effectiveness of lead paint hazard reduction. The lead loadings on window sill surfaces in the work area were significantly lower after completion of the project, and the lead-based paint removal did not contaminate the adjoining living area. The proportion of homes with surface dust lead loading exceeding Department of Housing and Urban Development (HUD) clearance standard was 73% pre-project and 38% post-project. Personal airborne exposures during lead removal activities reinforce the need to respiratory protection and good hygiene. There was no difference in adult pre-/post-blood levels, indicating that participants die remove lead in a safe manner with respect to their own exposures. The results indicate that hazard reduction can be done effectively when recommended procedures for the removal of lead-based paint are followed.

  13. Dust Storm

    Atmospheric Science Data Center

    2013-04-16

    ... contrast strongly with the dust storm that swept across Iraq and Saudi Arabia on May 13, 2004 (bottom panels). These data products from ... as yellowish ripples that obscure a large part of southern Iraq. The dust is easy to discern over the dark waters of the teardrop-shaped ...

  14. Andromeda's dust

    SciTech Connect

    Draine, B. T.; Aniano, G.; Krause, Oliver; Groves, Brent; Sandstrom, Karin; Klaas, Ulrich; Linz, Hendrik; Rix, Hans-Walter; Schinnerer, Eva; Schmiedeke, Anika; Walter, Fabian; Braun, Robert; Leroy, Adam E-mail: ganiano@ias.u-psud.fr

    2014-01-10

    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 {sub d} = 5.4 × 10{sup 7} M {sub ☉}, the global dust/H mass ratio is M {sub d}/M {sub H} = 0.0081, and the global PAH abundance is (q {sub PAH}) = 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 {sub d}/M {sub 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 {sub ☉} ≈ 3 at R = 0 to ∼0.3 at R = 25 kpc. The dust heating rate parameter (U) peaks at the center, with (U) ≈ 35, declining to (U) ≈ 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 {sub PAH} ≈ 0.045 at R ≈ 11.2 kpc. When allowance is made for the different spectrum of the bulge stars, q {sub PAH} for the dust in the central kiloparsec is similar to the overall value of q {sub 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 μm emission at R ≈ 2-6 kpc, suggesting that at R = 2-6 kpc, the dust opacity varies more steeply with frequency (with β ≈ 2.3 between 200 and 600 μm) than in the model.

  15. EVALUATION OF A NEW METHOD OF DUST CONTROL

    PubMed Central

    Harris, M. Coleman; Shure, Norman

    1952-01-01

    Microscopic dust sampling was done to determine the amount of dust in the homes of six patients who were sensitive to house dust and who had allergic disease that was intractable to treatment. One case was subsequently excluded from the study because of extraordinary circumstances. The remaining five cases were studied with repeated dust counts before and after a water-and-oil emulsion was sprayed in the patient's bedroom to immobilize house dust. In all five cases, the patients had dramatic relief of symptoms after the spraying was done. In four out of five, there was concomitant reduction of the amount of dust in the air as determined by microscopic counting of the dust particles on a glycerincoated slide. In the fifth case, relief of symptoms was not accompanied by reduction of dust on slides, but investigation revealed an error in control of exposure of the slides. PMID:14886758

  16. Southeastward Dust Transport during the 16-24 March 2006 Asian Dust Event

    NASA Astrophysics Data System (ADS)

    Tsai, F.; Liu, T.; Hsu, S.; Chen, W.; Tu, J.

    2012-04-01

    Synoptic analyses and regional dust models are applied to analyze the dust measurements obtained during the Asian dust events from 16 to 24 March, 2006, in order to understand the controlling mechanism leading to the dust transport far southeastward of the continent. The southeastward transported dust concentrations measured over Taiwan are traced back to their source areas. By tracing the dust loaded air parcels, the synoptic characteristics of the dust event during generation, transport, and dissipation are inspected and compared with an eastward transported event. It has been found that the synoptic mechanism, rather than the emission intensity, leads to the high dust concentration far southeastward off the continent. Most southeastward moving dust clouds are generated behind the surface front in the descent regions and then transported behind a deep lower-level trough, in which the prevailing northerlies or northwesterlies lead to the southeastward dust transported into the tropics. Without a deep lower-level trough, the dust clouds tend to be transported eastward. Surface lidar observations also show descent of the dust concentrations during their southeastward transport. After moving offshore, the anticyclonic circulation in the leading edge of the surface high circulates the dust parcels ahead of the high-pressure center in a southwestward direction towards the seashore off the Southeast China. With the deceleration of the wind speed, the dust clouds then slowly dissipate over the tropics of the Western Pacific, thus providing nutrients to the marine phytoplanktons.

  17. Differential dust attenuation in CALIFA galaxies

    NASA Astrophysics Data System (ADS)

    Vale Asari, N.; Cid Fernandes, R.; Amorim, A. L.; Lacerda, E. A. D.; Schlickmann, M.; Wild, V.; Kennicutt, R. C.

    2016-06-01

    Dust attenuation has long been treated as a simple parameter in SED fitting. Real galaxies are, however, much more complicated: The measured dust attenuation is not a simple function of the dust optical depth, but depends strongly on galaxy inclination and the relative distribution of stars and dust. We study the nebular and stellar dust attenuation in CALIFA galaxies, and propose some empirical recipes to make the dust treatment more realistic in spectral synthesis codes. By adding optical recombination emission lines, we find better constraints for differential attenuation. Those recipes can be applied to unresolved galaxy spectra, and lead to better recovered star formation rates.

  18. Layers, Boulders, and Dust

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-364, 18 May 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture shows the wall of a trough in the Zephyrus Fossae region, west of the Elysium Rise near 27.9oN, 217.5oW. The trough wall has cut through and exposed layered bedrock, visible near the top of the wall. Talus covers the lower portions of the wall; this debris includes many automobile- and house-sized boulder--most of which are seen as dark dots at the base of the slope. Dust has coated and mantled much of this terrain, including some of the boulders. The dark streak near the center of the picture was formed by landsliding (or avalanching) of some of the dust. Sunlight illuminates the scene from the lower left.

  19. Particulate emission abatement for Krakow boiler houses

    SciTech Connect

    Wysk, R.

    1995-12-31

    Among the many strategies for improving air quality in Krakow, one possible method is to adapt new and improved emission control technology. This project focuses on such a strategy. In order to reduce dust emissions from coal-fueled boilers, a new device called a Core Separator has been introduced in several boiler house applications. This advanced technology has been successfully demonstrated in Poland and several commercial units are now in operation. Particulate emissions from the Core Separator are typically 3 to 5 times lower than those from the best cyclone collectors. It can easily meet the new standard for dust emissions which will be in effect in Poland after 1997. The Core Separator is a completely inertial collector and is based on a unique recirculation method. It can effectively remove dust particles below 10 microns in diameter, the so-called PM-10 emissions. Its performance approaches that of fabric filters, but without the attendant cost and maintenance. It is well-suited to the industrial size boilers located in Krakow. Core Separators are now being marketed and sold by EcoInstal, one of the leading environmental firms in Poland, through a cooperative agreement with LSR Technologies.

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

    SciTech Connect

    Rinehart, R.D.; Yanagisawa, Y. )

    1993-10-01

    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.

  1. Planetary Magnetosphere Probed by Charged Dust Particles

    NASA Astrophysics Data System (ADS)

    Sternovsky, Z.; Horanyi, M.; Gruen, E.; Srama, R.; Auer, S.; Kempf, S.; Krueger, H.

    2010-12-01

    In-situ and remote sensing observations combined with theoretical and numerical modeling greatly advanced our understanding planetary magnetospheres. Dust is an integral component of the Saturnian and Jovian magnetospheres where it can act as a source/sink of plasma particles (dust particles are an effective source for plasma species like O2, OH, etc. through sputtering of ice particles, for example); its distribution is shaped by electrodynamic forces coupled radiation pressure, plasma, and neutral drag, for example. The complex interaction can lead to unusual dust dynamics, including the transport, capture, and ejection of dust grains. The study of the temporal and spatial evolution of fine dust within or outside the magnetosphere thus provides a unique way to combine data from a large number of observations: plasma, plasma wave, dust, and magnetic field measurements. The dust detectors on board the Galileo and Cassini spacecrafts lead to major discoveries, including the jovian dust stream originating from Io or the in-situ sampling and analysis of the plumes of Enceladus. Recent advancement in dust detector technology enables accurate measurement of the dust trajectory and elemental composition that can greatly enhance the understanding of dust magnetorspheric interaction and indentify the source of the dust with high precision. The capabilities of a modern dust detector thus can provide support for the upcoming Europa Jupiter System Mission.

  2. Exozodiacal dust

    NASA Astrophysics Data System (ADS)

    Kuchner, Marc Jason

    Besides the sun, the most luminous feature of the solar system is a cloud of "zodiacal" dust released by asteroids and comets that pervades the region interior to the asteroid belt. Similar clouds of dust around other stars---exozodiacal clouds---may be the best tracers of the habitable zones of extra-solar planetary systems. This thesis discusses three searches for exozodiacal dust: (1) We observed six nearby main-sequence stars with the Keck telescope at 11.6 microns, correcting for atmosphere-induced wavefront aberrations and deconvolving the point spread function via classical speckle analysis. We compare our data to a simple model of the zodiacal dust in our own system based on COBE DIRBE observations and place upper limits on the density of exozodiacal dust in these systems. (2) We observed Sirius, Altair, and Procyon with the NICMOS Coronagraph on the Hubble Space Telescope to look for scattered light from exozodiacal dust and faint companions within 10 AU from these stars. (3) The planned nulling capability of the Keck Interferometer should allow it to probe the region <200 milliarcsecond from a bright star and to suppress on-axis starlight by factors of 10 -3 to reveal faint circumstellar material. We model the response of the Keck Interferometer to hypothetical exozodiacal clouds to derive detection limits that account for the effects of stellar leakage, photon noise, noise from null depth fluctuations, and the fact that the cloud's shape is not known a priori. We also discuss the interaction of dust with planets. We used the COBE DIRBE Sky and Zodi Atlas and the IRAS Sky Survey Atlas to search for dynamical signatures of three different planets in the solar system dust complex: (1) We searched the COBE DIRBE Sky and Zodi Atlas for a wake of dust trailing Mars. We compare the DIRBE images to a model Mars wake based on the empirical model of the Earth's wake as seen by the DIRBE. (2) We searched the COBE DIRRE Sky and Zodi Atlas for Tiojan dust near

  3. 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...

  4. Downflow dust filter

    SciTech Connect

    Richard, K.L.

    1986-09-09

    This patent describes an industrial dust filter apparatus comprising: a housing including upper, intermediate and lower sections, the upper section having a top opening inlet for particulate laden gases and the lower section tapering downwardly to a particulate outlet; a plurality of vertically arranged substantially cylindrical filters supported in substantially parallel relationship to each other in the intermediate section of the housing, the filters being closed at their upper ends and having their exterior filter surfaces exposed to particulate laden gases from the inlet; at least one horizontal duct extending across the housing beneath the filters, closed at one end and opening at its other end to a clean gas outlet through a side wall of the intermediate housing section; means communicating the lower open end of the filters through the upper walls of the duct so that the duct functions as a clean gas plenum; a plurality of verturis, vertically supported in the duct, on aligned with each filter; and means in the duct for pulse firing a jet of air upwardly through the venturis into the interior of the filters to remove particulates from the outer surfaces thereof.

  5. Size-Resolved Dust and Aerosol Contaminants Associated with Copper and Lead Smelting Emissions: Implications for Emissions Management and Human Health

    PubMed Central

    Csavina, Janae; Taylor, Mark P.; Félix, Omar; Rine, Kyle P.; Sáez, A. Eduardo; Betterton, Eric A.

    2014-01-01

    Mining operations, including crushing, grinding, smelting, refining, and tailings management, are a significant source of airborne metal and metalloid contaminants such as As, Pb and other potentially toxic elements. In this work, we show that size-resolved concentrations of As and Pb generally follow a bimodal distribution with the majority of contaminants in the fine size fraction (< 1 μm) around mining activities that include smelting operations at various sites in Australia and Arizona. This evidence suggests that contaminated fine particles (< 1 μm) are the result of vapor condensation and coagulation from smelting operations while coarse particles are most likely the result of windblown dust from contaminated mine tailings and fugitive emissions from crushing and grinding activities. These results on the size distribution of contaminants around mining operations are reported to demonstrate the ubiquitous nature of this phenomenon so that more effective emissions management and practices that minimize health risks associated with metal extraction and processing can be developed. PMID:24995641

  6. Size-resolved dust and aerosol contaminants associated with copper and lead smelting emissions: implications for emission management and human health.

    PubMed

    Csavina, Janae; Taylor, Mark P; Félix, Omar; Rine, Kyle P; Eduardo Sáez, A; Betterton, Eric A

    2014-09-15

    Mining operations, including crushing, grinding, smelting, refining, and tailings management, are a significant source of airborne metal and metalloid contaminants such as As, Pb and other potentially toxic elements. In this work, we show that size-resolved concentrations of As and Pb generally follow a bimodal distribution with the majority of contaminants in the fine size fraction (<1 μm) around mining activities that include smelting operations at various sites in Australia and Arizona. This evidence suggests that contaminated fine particles (<1 μm) are the result of vapor condensation and coagulation from smelting operations while coarse particles are most likely the result of windblown dust from contaminated mine tailings and fugitive emissions from crushing and grinding activities. These results on the size distribution of contaminants around mining operations are reported to demonstrate the ubiquitous nature of this phenomenon so that more effective emission management and practices that minimize health risks associated with metal extraction and processing can be developed. PMID:24995641

  7. PERSONAL AND ENVIRONMENTAL RISK FACTORS SIGNIFICANTLY ASSOCIATED WITH ELEVATED BLOOD LEAD LEVELS IN RURAL THAI CHILDREN.

    PubMed

    Swaddiwudhipong, Witaya; Kavinum, Suporn; Papwijitsil, Ratchadaporn; Tontiwattanasap, Worawit; Khunyotying, Wanlee; Umpan, Jiraporn; BoonthuM, Ratchaneekorn; Kaewnate, Yingyot; Boonmee, Sasis; Thongchub, Winai; Rodsung, Thassanee

    2014-11-01

    A community-based study was conducted to determine personal risk factors and environmental sources of lead exposure for elevated blood lead levels (≥ 10 µg/dl, EBLLs) among rural children living at the Thailand-Myanmar border in Tak Province, northwestern Thailand. Six hundred ninety-five children aged 1-14 years old were screened for BLLs. Environmental specimens for lead measurements included samples of water from the streams, taps, and household containers, house floor dust, and foods. Possible lead release from the cooking ware was determined using the leaching method with acetic acid. The overall prevalence of EBLLs was 47.1% and the geometric mean level of blood lead was 9.16 µg/dl. Personal risk factors significantly associated with EBLLs included being male, younger age, anemia, and low weight-for-age. Significant environmental risk factors were exposure to a lead-acid battery of solar energy system and use of a non-certified metal cooking pot. Some families whose children had high BLLs reported production of lead bullets from the used batteries at home. About one-third of the house dust samples taken near batteries contained lead content above the recommended value, compared with none of those taken from other areas and from the houses with no batteries. The metal pots were safe for cooking rice but might be unsafe for acidic food preparation. Both nutritional intervention and lead exposure prevention programs are essential to reduce EBLLs in this population. PMID:26466436

  8. Home sweet home? A case study of household dust contamination in Hong Kong.

    PubMed

    Tong, S T; Lam, K C

    2000-07-10

    It is well recognized that many heavy metals have chronic effects on humans and as such, they are potential environmental health hazards, particularly to young children (see, for example, Body P, Inglis G, Dolan P, Mulcahy D. Environmental lead: a review. Crit Rev Environ Control 1991;20:299-310). Considerable attention has been paid to the study of metal pollution in city air, roadside dusts and soils. However, there is a lack of concern of the presence of trace metals in house dust in the populous city of Hong Kong, where it has traditionally been assumed that such pollutants are rapidly dispersed by ocean breezes. This research aims at quantifying the concentrations of heavy metals within the home environment in Hong Kong and their relationships with environmental factors. The results of this study seem to suggest that traffic and the age of the building and neighborhood are more important factors than the types of industry and socioeconomic status in affecting household dust contamination. The metal burdens in Kwung Tong, an old area with heavy traffic, are significantly higher than other districts. When a Kruskal-Wallis one-way analysis of variance was performed on the ranked metal concentrations in different housing districts, the Chi-square values are all significant at a probability level of < 0.001. This might be attributable to the fact that there is no highly contaminating industries (such as metal smelters, battery plants and petrochemicals) in Hong Kong. The dust metals may travel from the roads, through the windows and balconies, into the houses, as those homes that do not have their windows opened often had a lower level of contaminants in their house dust (median Cd= 3.6 microg/g; median Cu = 313.2 microg/g; median Pb = 144.6 microg/g; median Mn = 211.6 microg/g; and median Zn = 1,333.7 microg/g). Moreover, those occupants who sweep their floors or dust their furniture on daily bases, or use vacuum cleaners, had a lower level of metals inside their

  9. 2-DUST: Dust radiative transfer code

    NASA Astrophysics Data System (ADS)

    Ueta, Toshiya; Meixner, Margaret

    2016-04-01

    2-DUST is a general-purpose dust radiative transfer code for an axisymmetric system that reveals the global energetics of dust grains in the shell and the 2-D projected morphologies of the shell that are strongly dependent on the mixed effects of the axisymmetric dust distribution and inclination angle. It can be used to model a variety of axisymmetric astronomical dust systems.

  10. Circumstellar dust in symbiotic novae

    NASA Astrophysics Data System (ADS)

    Jurkic, Tomislav; Kotnik-Karuza, Dubravka

    2015-08-01

    Physical properties of the circumstellar dust and associated physical mechanisms play an important role in understanding evolution of symbiotic binaries. We present a model of inner dust regions around the cool Mira component of the two symbiotic novae, RR Tel and HM Sge, based on the long-term near-IR photometry, infrared ISO spectra and mid-IR interferometry. Pulsation properties and long-term variabilities were found from the near-IR light curves. The dust properties were determined using the DUSTY code which solves the radiative transfer. No changes in pulsational parameters were found, but a long-term variations with periods of 20-25 years have been detected which cannot be attributed to orbital motion.Circumstellar silicate dust shell with inner dust shell temperatures between 900 K and 1300 K and of moderate optical depth can explain all the observations. RR Tel showed the presence of an optically thin CS dust envelope and an optically thick dust region outside the line of sight, which was further supported by the detailed modelling using the 2D LELUYA code. Obscuration events in RR Tel were explained by an increase in optical depth caused by the newly condensed dust leading to the formation of a compact dust shell. HM Sge showed permanent obscuration and a presence of a compact dust shell with a variable optical depth. Scattering of the near-IR colours can be understood by a change in sublimation temperature caused by the Mira variability. Presence of large dust grains (up to 4 µm) suggests an increased grain growth in conditions of increased mass loss. The mass loss rates of up to 17·10-6 MSun/yr were significantly higher than in intermediate-period single Miras and in agreement with longer-period O-rich AGB stars.Despite the nova outburst, HM Sge remained enshrouded in dust with no significant dust destruction. The existence of unperturbed dust shell suggests a small influence of the hot component and strong dust shielding from the UV flux. By the use

  11. Dust-Tolerant Intelligent Electrical Connection System

    NASA Technical Reports Server (NTRS)

    Lewis, Mark; Dokos, Adam; Perotti, Jose; Calle, Carlos; Mueller, Robert; Bastin, Gary; Carlson, Jeffrey; Townsend, Ivan, III; Immer, Chirstopher; Medelius, Pedro

    2012-01-01

    Faults in wiring systems are a serious concern for the aerospace and aeronautic (commercial, military, and civilian) industries. Circuit failures and vehicle accidents have occurred and have been attributed to faulty wiring created by open and/or short circuits. Often, such circuit failures occur due to vibration during vehicle launch or operation. Therefore, developing non-intrusive fault-tolerant techniques is necessary to detect circuit faults and automatically route signals through alternate recovery paths while the vehicle or lunar surface systems equipment is in operation. Electrical connector concepts combining dust mitigation strategies and cable diagnostic technologies have significant application for lunar and Martian surface systems, as well as for dusty terrestrial applications. The dust-tolerant intelligent electrical connection system has several novel concepts and unique features. It combines intelligent cable diagnostics (health monitoring) and automatic circuit routing capabilities into a dust-tolerant electrical umbilical. It retrofits a clamshell protective dust cover to an existing connector for reduced gravity operation, and features a universal connector housing with three styles of dust protection: inverted cap, rotating cap, and clamshell. It uses a self-healing membrane as a dust barrier for electrical connectors where required, while also combining lotus leaf technology for applications where a dust-resistant coating providing low surface tension is needed to mitigate Van der Waals forces, thereby disallowing dust particle adhesion to connector surfaces. It also permits using a ruggedized iris mechanism with an embedded electrodynamic dust shield as a dust barrier for electrical connectors where required.

  12. Historic Houses.

    ERIC Educational Resources Information Center

    Curtis, Nancy

    1997-01-01

    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)

  13. Allergies, asthma, and dust

    MedlinePlus

    Allergic rhinitis - dust ... make allergies or asthma worse are called triggers. Dust is a common trigger. When your asthma or allergies become worse due to dust, you are said to have a dust allergy. ...

  14. Newton to Einstein — dust to dust

    SciTech Connect

    Kopp, Michael; Uhlemann, Cora; Haugg, Thomas E-mail: cora.uhlemann@physik.lmu.de

    2014-03-01

    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.

  15. Steelworks dust -- From waste to product

    SciTech Connect

    Strohmeier, G.; Bonestell, J.E.

    1995-07-01

    Scrap-borne zinc and lead are enriched in the electric arc furnace dusts. Its Pb/Zn content of over 20% renders the dumping of this dust impossible in many countries, for both statutory and financial reasons. The Waelz process is the only reliable large-scale method for processing such dusts. 45% of the total electric furnace dusts occurring throughout Europe are being processed in Waelz plants with several operating in the US. The dust is treated in a rotary kiln where it is heated to approximately 1,200 C. Lead and zinc are volatilized under reducing conditions and collected as fine dust from the off-gas by cooling. The Waelz oxide recovered in the off-gas filters contains approximately 55% Zn and up to 10% Pb, and is ideal feedstock for the Imperial Smelting furnace for lead/zinc recovery. The remaining slag is inert and unleachable so that it can be used as a building aggregate.

  16. Addressing Lead-Based Paint Hazards During Renovation, Remodeling, and Rehabilitation in Federally Owned and Assisted Housing. Student Manual for Use in HUD-Sponsored Lead-Safe Work Practices Training.

    ERIC Educational Resources Information Center

    Department of Housing and Urban Development, Washington, DC.

    This student manual comprises the United States Environmental Protection Agency's model renovation training course designed for renovation, remodeling, and painting contractors. It provides information regarding the containment, minimization, and cleanup of lead hazards during activities that disturb lead painted surfaces. Introductory material…

  17. 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

    Mushak, P.; Crocetti, A.F. )

    1989-12-01

    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.

  18. Housing and child health.

    PubMed

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

    2013-09-01

    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

  19. Damping of dust-acoustic waves due to dust-dust interactions in dusty plasmas

    NASA Astrophysics Data System (ADS)

    de Angelis, U.; Shukla, P. K.

    1998-08-01

    The results of a kinetic model are presented which includes dust-dust collisions as a damping mechanism for the low-phase velocity dust-acoustic waves which have been observed [Pieper and Goree, Phys. Rev. Lett. 77 (1976) 3137] in a dusty plasma device. A comparison of our theoretical results with those of observations exhibits a good agreement, and it also leads to quantitative estimates that are close to the predictions of the modified fluid theory, which has introduced a damping rate in an ad hoc manner.

  20. Dust Studies in DIII-D Tokamak

    SciTech Connect

    Rudakov, D L; West, W P; Groth, M; Yu, J H; Boedo, J A; Bray, B D; Brooks, N H; Fenstermacher, M E; Hollmann, E M; Hyatt, A W; Krasheninnikov, S I; Lasnier, C J; Moyer, R A; Pigarov, A Y; Smirnov, R; Solomon, W M; Wong, C C

    2008-04-15

    Studies of submicron dust using Mie scattering from Nd:YAG lasers and video data of micron to sub-millimeter sized dust on DIII-D tokamak have provided the first data of dust sources and transport during tokamak discharges. During normal operation on DIII-D dust observation rates are low, a few events per discharge or less. The net carbon content of the dust corresponds to a carbon atom density a few orders of magnitude below the core impurity density. Statistical analysis of Mie data collected over months of operation reveal correlation of increased dust rate with increased heating power and impulsive wall loading due to edge localized modes (ELMs) and disruptions. Generation of significant amounts of dust by disruptions is confirmed by the camera data. However, dust production by disruptions alone is insufficient to account for estimated in-vessel dust inventory in DIII-D. After an extended entry vent, thousands of dust particles are observed by cameras in the first 2-3 plasma discharges. Individual particles moving at velocities up to {approx}300 m/s, breakup of larger particles into pieces, and collisions of particles with walls are observed. After {approx}70 discharges, dust levels are reduced to a few events per discharge. In order to calibrate diagnostics and benchmark modeling, milligram amounts of micron-sized carbon dust have been injected into DIII-D discharges, leading to the core carbon density increase by a factor of 2-3. Following injection, dust trajectories in the divertor are mostly in the toroidal direction, consistent with the ion drag force. Dust from the injection is observed in the outboard midplane by a fast framing camera. The observed trajectories and velocities of the dust particles are in qualitative agreement with modeling by the 3D DustT code.

  1. Dust Studies in DIII-D Tokamak

    SciTech Connect

    Rudakov, D. L.; Yu, J. H.; Boedo, J. A.; Hollmann, E. M.; Krasheninnikov, S. I.; Moyer, R. A.; Pigarov, A. Yu.; Smirnov, R.; West, W. P.; Bray, B. D.; Brooks, N. H.; Hyatt, A. W.; Wong, C. P. C.; Groth, M.; Fenstermacher, M. E.; Lasnier, C. J.; Solomon, W. M.

    2008-09-07

    Studies of submicron dust using Mie scattering from Nd:YAG lasers and video data of micron to sub-millimeter sized dust on DIII-D tokamak have provided the first data of dust sources and transport during tokamak discharges. During normal operation on DIII-D dust observation rates are low, a few events per discharge or less. The net carbon content of the dust corresponds to a carbon atom density a few orders of magnitude below the core impurity density. Statistical analysis of Mie data collected over months of operation reveal correlation of increased dust rate with increased heating power and impulsive wall loading due to edge localized modes (ELMs) and disruptions. Generation of significant amounts of dust by disruptions is confirmed by the camera data. However, dust production by disruptions alone is insufficient to account for estimated in-vessel dust inventory in DIII-D. After an extended entry vent, thousands of dust particles are observed by cameras in the first 2-3 plasma discharges. Individual particles moving at velocities up to {approx}300 m/s, breakup of larger particles into pieces, and collisions of particles with walls are observed. After {approx}70 discharges, dust levels are reduced to a few events per discharge. In order to calibrate diagnostics and benchmark modeling, milligram amounts of micron-sized carbon dust have been injected into DIII-D discharges, leading to the core carbon density increase by a factor of 2-3. Following injection, dust trajectories in the divertor are mostly in the toroidal direction, consistent with the ion drag force. Dust from the injection is observed in the outboard midplane by a fast framing camera. The observed trajectories and velocities of the dust particles are in qualitative agreement with modeling by the 3D DustT code.

  2. Effect of nonadiabaticity of dust charge variation on dust acoustic waves: generation of dust acoustic shock waves.

    PubMed

    Gupta, M R; Sarkar, S; Ghosh, S; Debnath, M; Khan, M

    2001-04-01

    The effect of nonadiabaticity of dust charge variation arising due to small nonzero values of tau(ch)/tau(d) has been studied where tau(ch) and tau(d) are the dust charging and dust hydrodynamical time scales on the nonlinear propagation of dust acoustic waves. Analytical investigation shows that the propagation of a small amplitude wave is governed by a Korteweg-de Vries (KdV) Burger equation. Notwithstanding the soliton decay, the "soliton mass" is conserved, but the dissipative term leads to the development of a noise tail. Nonadiabaticity generated dissipative effect causes the generation of a dust acoustic shock wave having oscillatory behavior on the downstream side. Numerical investigations reveal that the propagation of a large amplitude dust acoustic shock wave with dust density enhancement may occur only for Mach numbers lying between a minimum and a maximum value whose dependence on the dusty plasma parameters is presented. PMID:11308955

  3. Collection of cometary dust

    NASA Astrophysics Data System (ADS)

    Lell, P.; Igenbergs, E.; Kuczera, H.; Pailer, N.

    Rendezvous Missions to Comets lead to low velocities at the nucleus of the comet. The resulting impact velocity of the cometary dust on a target will range between 10 and 400 m/s. The dust particle which impacts on a target can be collected for a subsequent in-situ analysis. The collection efficiency of a target depends in addition to obvious geometrical conditions upon the surface of the target. The surface characteristics can be divided into two groups: ``dirty'' surfaces, covered with silicate or hydrocarbon compounds (for example vacuum grease), ``clean'' surfaces, like gold (with additional sputtering). This paper deals with the experimental and theoretical investigation of the collection efficiency of ``clean'' targets. Laboratory experiments are described which were conducted at the Technische Universität München, Lehrstuhl für Raumfahrttechnik, and the Max-Planck-Institut für Kernphysik, Heidelberg. In both experiments an electromagnetic accelerator is used to accelerate different types of dust in vacuum to velocities between 10 and 400 m/s. The target is then examined under the microscope and a secondary ion mass spectrometer (which is a model of the laboratory carried on board of the spacecraft for ``in situ'' analysis). The adhesion of the dust grains at the target is evaluated experimentally in an ultracentrifuge.

  4. Comet Gas and Dust Dynamics Modeling

    NASA Technical Reports Server (NTRS)

    Von Allmen, Paul A.; Lee, Seungwon

    2010-01-01

    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.

  5. Litter use by laying hens in a commercial aviary: dust bathing and piling.

    PubMed

    Campbell, D L M; Makagon, M M; Swanson, J C; Siegford, J M

    2016-01-01

    The laying hen industry, including in the United States, is responding to social concerns about hen welfare by implementing alternative housing systems such as the aviary, to provide more space and resources to large groups of hens. Data detailing the behavior of hens in commercial aviaries is needed to determine hens' use of the resources in order to understand their impact on hen welfare. The open litter area of aviaries provides additional space for hens during the day. Litter is also a substrate for dust bathing which is a strongly motivated natural behavior. Hens are often synchronous in their performance of dust bathing, which may lead to overcrowding in the litter area. Additionally, the open litter area can facilitate expression of unusual behavior such as flock piling (defined as the occurrence of densely grouped clusters of hens, resulting from no obvious cause and occurring randomly throughout the day and flock cycle) which may be a welfare concern. Therefore, we conducted observations of hen occupancy of the open litter area and the performance of dust bathing and flock piling across 3 production points (peak lay, mid lay and end of lay) for two flocks of Lohmann White laying hens housed in a commercial aviary. All areas of the open litter area were occupied to the same degree. Hens performed dust bathing throughout the day but showed peak dust bathing activity in the afternoon for Flock 1 (all P < 0.001) and in the late morning for Flock 2 (all P < 0.001). Overall, 174 incidents of piling behavior were observed between the 2 flocks, with piles varying in size, duration, and time of occurrence; however, no smothering was detected. Crowding on the open litter area sometimes occurred during peak periods of synchronous dust bathing and when hens piled. Further research is needed to understand the welfare implications of individual hen use of the open litter area and the causes and welfare implications of hen piling. PMID:26354762

  6. Dust cyclone technology for gins – A literature review

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dust cyclone research leading to more efficient designs has helped the cotton ginning industry to comply with increasingly stringent air quality regulations governing fine particulate emissions. Future changes in regulations may require additional improvements in dust cyclone efficacy. This inter-...

  7. The retrieval of optical properties from terrestrial dust devil vortices

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

    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.

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

    PubMed

    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

    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

  9. Impact of a More Stringent Blood Lead Level Recommendation for Children (Ages 1-5): Vulnerabilities Related to Housing, Food Security, Vitamins, and Environmental Toxicants

    EPA Science Inventory

    The adverse health effects of lead (Pb) exposure in young children are well known. Non-Hispanic black children historically have higher blood Pb levels (BLL) compared to Mexican-Americans and non- Hispanic white children (CDC-MMWR). In the past, BLL tests below 10 µg/dL m...

  10. 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)

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

    2000-01-01

    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.

  11. A multivariate linear regression model for predicting children's blood lead levels based on soil lead levels: A study at four Superfund sites

    SciTech Connect

    Lewin, M.D.; Sarasua, S.; Jones, P.A. . Div. of Health Studies)

    1999-07-01

    For the purpose of examining the association between blood lead levels and household-specific soil lead levels, the authors used a multivariate linear regression model to find a slope factor relating soil lead levels to blood lead levels. They used previously collected data from the Agency for Toxic Substances and Disease Registry's (ATSDR's) multisite lead and cadmium study. The data included in the blood lead measurements of 1,015 children aged 6--71 months, and corresponding household-specific environmental samples. The environmental samples included lead in soil, house dust, interior paint, and tap water. After adjusting for income, education or the parents, presence of a smoker in the household, sex, and dust lead, and using a double log transformation, they found a slope factor of 0.1388 with a 95% confidence interval of 0.09--0.19 for the dose-response relationship between the natural log of the soil lead level and the natural log of the blood lead level. The predicted blood lead level corresponding to a soil lead level of 500 mg/kg was 5.99 [micro]g/kg with a 95% prediction interval of 2.08--17.29. Predicted values and their corresponding prediction intervals varied by covariate level. The model shows that increased soil lead level is associated with elevated blood leads in children, but that predictions based on this regression model are subject to high levels of uncertainty and variability.

  12. Status and Future of Dust Storm Forecasting

    NASA Astrophysics Data System (ADS)

    Westphal, D. L.

    2002-12-01

    In recent years, increased attention has been given to the large amounts of airborne dust derived from the deserts and desertified areas of the world and transported over scales ranging from local to global. This dust can have positive and negative impacts on human activities and the environment, including modifying cloud formation, fertilizing the ocean, degrading air quality, reducing visibility, transporting pathogens, and inducing respiratory problems. The atmospheric radiative forcing by the dust has implications for global climate change and presently is one of the largest unknowns in climate models. These uncertainties have lead to much of the funding for research into the sources, properties, and fate of atmospheric dust. As a result of advances in numerical weather prediction over the past decades and the recent climate research, we are now in a position to produce operational dust storm forecasts. International organizations and national agencies are developing programs for dust forecasting. The approaches and applications of dust detection and forecasting are as varied as the nations that are developing the models. The basic components of a dust forecasting system include atmospheric forcing, dust production, and dust microphysics. The forecasting applications include air and auto traffic safety, shipping, health, national security, climate and weather. This presentation will summarize the methods of dust storm forecasting and illustrate the various applications. The major remaining uncertainties (e.g. sources and initialization) will be discussed as well as approaches for solving those problems.

  13. Rental Housing.

    ERIC Educational Resources Information Center

    American Association of Retired Persons, Washington, DC. Consumer Housing Information Service for Seniors.

    This is one of a series of booklets prepared as a resource for trained Housing Information Volunteers to provide impartial information to older people who have questions of concern about how to find safe, comfortable, affordable housing; how to cut household expenses or use their homes to earn extra income; home maintenance and home improvement;…

  14. Clay Houses

    ERIC Educational Resources Information Center

    Pedro, Cathy

    2011-01-01

    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.

  15. Environmental Health Disparities in Housing

    PubMed Central

    2011-01-01

    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

  16. AMERICAN HOUSING SURVEY

    EPA Science Inventory

    The American Housing Survey (AHS) collects data on the Nation's housing, including apartments, single-family homes, mobile homes, vacant housing units, household characteristics, income, housing and neighborhood quality, housing costs, equipment and fuels, size of housing unit, a...

  17. Possible influence of dust on hurricane genesis

    NASA Astrophysics Data System (ADS)

    Bretl, Sebastian; Reutter, Philipp; Raible, Christoph C.; Ferrachat, Sylvaine; Lohmann, Ulrike

    2014-05-01

    Tropical Cyclones (TCs) belong to the most extreme events in nature. In the past decade, the possible impact of dust on Atlantic hurricanes receives growing interest. As mineral dust is able to absorb incoming solar radiation and therefore warm the surrounding air, the presence of dust can lead to a reduction of sea surface temperature (SST) and an increase in atmospheric stability. Furthermore, resulting baroclinic effects and the dry Saharan easterly jet lead to an enhanced vertical shear of the horizontal winds. SST, stability, moisture and vertical wind shear are known to potentially impact hurricane activity. But how Saharan dust influences these prerequisites for hurricane formation is not yet clear. Some dynamical mechanisms induced by the SAL might even strengthen hurricanes. An adequate framework for investigating the possible impact of dust on hurricanes is comparing high resolution simulations (~0.5°x0.5°, 31 vertical levels) with and without radiatively active dust aerosols. To accomplish this task, we are using the general circulation model ECHAM6 coupled to a modified version of the aerosol model HAM, ECHAM6-HAM-Dust. Instead of the five aerosol species HAM normally contains, the modified version takes only insoluble dust into account, but modifies the scavenging parameters in order to have a similar lifetime of dust as in the full ECHAM6-HAM. All remaining aerosols are prescribed. To evaluate the effects of dust on hurricanes, a TC detection and tracking method is applied on the results. ECHAM6-HAM-Dust was used in two configurations, one with radiatively active dust aerosols and one with dust being not radiatively active. For both set-ups, 10 Monte-Carlo simulations of the year 2005 were performed. A statistical method which identifies controlling parameters of hurricane genesis was applied on North Atlantic developing and non-developing disturbances in all simulations, comparing storms in the two sets of simulations. Hereby, dust can be assigned

  18. 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...

  19. 21. INTERIOR VIEW OF SIXTH FLOOR OF MILL HOUSE, SHOWING ...

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

    21. INTERIOR VIEW OF SIXTH FLOOR OF MILL HOUSE, SHOWING BLOWER AT RIGHT AND DUST CONTROL FILTER SYSTEM AT LEFT, LOOKING SOUTHEAST - Sperry Corn Elevator Complex, Weber Avenue (North side), West of Edison Street, Stockton, San Joaquin County, CA

  20. Contributions of Paint and Soil to Pb in Household Dust Wipes: An XAS Study

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    Speciation of Pb by X-ray absorption spectroscopy (XAS) indicated that Pb compounds associated with lead-based paint accounted for perhaps half of the Pb in 24 household dust wipes collected in El Paso, Texas. Soil-derived, sorbed Pb, likely Pb-humate, was also a major Pb species in many of the dust wipes. Household dust wipes are a standard technique for evaluating health risks of Pb to children, particularly toddlers, in public and private housing. The level of Pb in the wipes does not, however, indicate whether the source of the Pb is the house itself (peeling or powdering interior or exterior paint) or external, from contaminated soil or airborne particulate matter brought into the house by wind or foot traction. Understanding the origin of Pb in household dust is important in remediation: cover the old paint or remove the yard soil. XAS speciation can assist in understanding the source of Pb in household dust. The presence of significant Pb-humate requires a soil source, and suggests the need for soil remediation. Such species of Pb as hydrocerussite, lead sulfate, lead silicate, and lead chromate can be presumed to be components of lead-based paint. These may represent interior and/or exterior paint and thus do not uniquely identify the locus of the Pb source(s). Pb L-III edge XAFS data were collected on beam lines 7-3, 10-2, and 11-2 at SSRL at typical conditions of 3 GeV field and 80-200 mA current, using Si(220) water- or liquid-nitrogen-cooled monochromator crystals. Data were collected at ambient temperature in fluorescence mode using a 13- or 30-element Ge detector with a Se 3 or 6 filter and Soller slits to reduce scattered radiation. This publication was made possible by grant numbers 1RO1-ES11367 and 1 S11 ES013339-01A1 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. Portions of this research were

  1. Nonlinear dust phase-space vortices (holes) in charge-varying dusty plasmas

    SciTech Connect

    Tribeche, Mouloud; Aoutou, Kamel; Zerguini, Taha Houssine

    2005-03-01

    The recent analysis of dust voids [A. A. Mamun and P. K. Shukla, Phys. Plasmas 11, 1757 (2004)] is extended to include self-consistently the dust charge variation. Numerical solutions of highly nonlinear equations are carried out including dust charging and dust trapping. It is found that under certain conditions the effect of dust charge variation can be quite important. In particular, it may be noted that the dust charge variation leads to an additional enlargement of the nonlinear dust voids. The effects of ion/electron temperature, trapping parameter, and dust size on the properties of these nonlinear dust voids are briefly discussed.

  2. Tech House

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The members of the Swain family- Dr. Charles "Bill" Swain, wife Elaine, daughter Carol, 17, son "Chuck", 12, and dog Susie have an interesting assignment. They are active participants in an important NASA research program involving the application of space-age technology to home construction. b' Transplanted Floridians, the Swains now reside in NASA's Tech House, loatedat Langley Research Center, Hampton, Virginia. Their job is to use and help evaluate the variety of advanced technology systems in Tech House. A contemporary three-bedroom home, Tech House incorporates NASA technology, the latest commercial building techniques and other innovations, all designed to reduce energy and water consumption and to provide new levels of comfort, convenience, security and fire safety. Tech House equipment performed well in initial tests, but a house is not a home until it has people. That's where the Swains come in. NASA wants to see how the various systems work under actual living conditions, to confirm the effectiveness of the innovations or to determine necessary modifications for improvement. The Swains are occupying the house for a year, during which NASA engineers are computer monitoring the equipment and assembling a record of day-to-day performance. . Tech House is a laboratory rather than a mass production prototype, but its many benefits may influence home design and construction. In a period of sharply rising utility costs, widespread adoption of Tech House features could provide large-scale savings to homeowners and potentially enormous national benefit in resources conservation. Most innovations are aerospace spinoffs: Some of the equipment is now commercially available; other systems are expected to be in production within a few years. Around 1980, a Tech House-type of home could be built for $45-50,000 (1 976 dollars). It is estimated that the homeowner would save well over $20,000 (again 1976 dollars) in utility costs over the average mortgage span of 20 years.

  3. Dust agglomeration

    NASA Technical Reports Server (NTRS)

    2000-01-01

    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.)

  4. Canyon Dust

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA03682 Canyon Dust

    These dust slides are located on the wall of Thithonium Chasma.

    Image information: VIS instrument. Latitude -4.1N, Longitude 275.7E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  5. Dust Slides

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA03677 Linear Clouds

    Dust slides are common in the dust covered region called Lycus Sulci. A large fracture is also visible in this image.

    Image information: VIS instrument. Latitude 28.1N, Longitude 226.3E. 18 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  6. 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...

  7. Solving the lead dilemma

    SciTech Connect

    Pollack, S. )

    1989-10-01

    This paper discusses the widespread problem of lead poisoning among children. The perils of deleading are addressed and several methods of deleading currently in use are detailed and analyzed. These include the traditional method of burning or sanding off leaded paint, the Baltimore Model involving extensive refabrication of infected dwellings, and encapsulation by which leaded surfaces in the home are covered to prevent the escape of lead dust.

  8. Interstellar Dust: Contributed Papers

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    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.

  9. White House

    MedlinePlus

    ... Check out the most popular infographics and videos Photos View the photo of the day and other galleries Video Gallery ... your questions or your story with President Obama. Photo of the Day Explore the White House Photo ...

  10. House Rules.

    ERIC Educational Resources Information Center

    Hammel, Bette

    2001-01-01

    Discusses the "house" concept architectural design at Albert Lea High School (Minnesota) and how the design addresses the community's 21st Century educational goals. Photos and a floor plan are included. (GR)

  11. Metal dusting of nickel-containing alloys

    SciTech Connect

    Baker, B.A.; Smith, G.D.

    1998-12-31

    Metal dusting is a catastrophic form of carburization which leads to pitting and grooves as the affected metal disintegrates into a mixture of powdery carbon, metallic particles, and possibly oxides and carbides. This high temperature carburization mode is not yet well understood and while relatively infrequent, can be economically disastrous when it does occur in large and complex chemical and petrochemical process streams. References in the literature show that all classes of heat resistant alloys are prone to metal dusting, given the necessary and specific environmental conditions. These same references describe the environments that plague nickel-containing alloys and are used as the basis for postulation on the probable corrosion mechanisms responsible for metal dusting. Using alloy 800 and other nickel-containing alloys and metal dusting atmospheres, an effort is made to examine the steps in the metal dusting process and the temperature ranges over which metal dusting occurs.

  12. Lunar Dust 101

    NASA Technical Reports Server (NTRS)

    Gaier, James R.

    2008-01-01

    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.

  13. National Center for Healthy Housing

    MedlinePlus

    ... Healthy Housing Videos Lead Links Listervs Share NCHH's Flood Cleanup Guide with a Friend Today Several locations ... rains on Saturday, July 30, resulting in flash flood conditions and damage. The town of Ellicott City ...

  14. Dust Measurements in Tokamaks

    SciTech Connect

    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

    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.

  15. 24 CFR 891.325 - Lead-based paint requirements.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 4 2012-04-01 2012-04-01 false Lead-based paint requirements. 891.325 Section 891.325 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED) OFFICE OF THE ASSISTANT SECRETARY FOR HOUSING-FEDERAL HOUSING COMMISSIONER, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT (SECTION...

  16. 24 CFR 200.800 - Lead-based paint.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 2 2013-04-01 2013-04-01 false Lead-based paint. 200.800 Section 200.800 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR HOUSING-FEDERAL HOUSING COMMISSIONER, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT GENERAL INTRODUCTION TO...

  17. Dust feed mechanism

    DOEpatents

    Milliman, Edward M.

    1984-01-01

    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.

  18. Electric Dust Devils and Dust Storms

    NASA Astrophysics Data System (ADS)

    Renno, N. O.; Yana, C.

    2004-12-01

    Electrical fields measurements in terrestrial dust devils show that they maintain tremendous charge separation and that their electric fields exceeds the breakdown potential (~10 kV/m) of the Martian atmosphere (Farrell et al., 2002, 2003; Krauss et al., 2002; Renno et al., 2004). Typical Martian dust devils are be up to 100 times larger and much stronger than the small terrestrial analogues. Martian dust devils have higher dust content and may produce even stronger electrical fields. Indeed, the dust devils observed in the Pathfinder images have about 700 times the dust content of the local background atmosphere (Metzger et al., 1999). Thus, strong charge separations and electric-field breakdown are likely to occur on Martian dust devils and dust storms. Our theory (Renno et al., 2004) and laboratory experiments in a Mars chamber shows that collisions between sand and dust particles produce non-thermal microwave radiation. The non-thermal microwave emission allows not only the indirect detection of electric activity but also the determination of the physical properties of Martian sand and dust by remote sensing. Besides being geologically important, electrically charged Martian dust devils and dust storms are potential hazards to Landers and will be dangerous to future astronauts exploring its surface. Indeed, the design of adequate mechanical and electrical systems for these Landers cannot progress effectively without a better understanding of Martian dust devils and dust storms. Moreover, ancillary phenomena associated with electrically charged vortices can ionize atmospheric gases and might have important implications for atmosphere chemistry and even habitability.

  19. 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)

    Reis, A. P.; Patinha, C.; Noack, Y.; Robert, S.; Dias, A. C.; Ferreira da Silva, E.

    2014-11-01

    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.

  20. Dust Avalanches

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Crater wall dust avalanches in southern Arabia Terra.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

    Image information: VIS instrument. Latitude 10.3, Longitude 24.5 East (335.5 West). 19 meter/pixel resolution.

  1. Inactivation of dust mites, dust mite allergen, and mold from carpet.

    PubMed

    Ong, Kee-Hean; Lewis, Roger D; Dixit, Anupma; MacDonald, Maureen; Yang, Mingan; Qian, Zhengmin

    2014-01-01

    Carpet is known to be a reservoir for biological contaminants, such as dust mites, dust mite allergen, and mold, if it is not kept clean. The accumulation of these contaminants in carpet might trigger allergies or asthma symptoms in both children and adults. The purpose of this study is to compare methods for removal of dust mites, dust mite allergens, and mold from carpet. Carpets were artificially worn to simulate 1 to 2 years of wear in a four-person household. The worn carpets were inoculated together with a common indoor mold (Cladosporium species) and house dust mites and incubated for 6 weeks to allow time for dust mite growth on the carpet. The carpets were randomly assigned to one of the four treatment groups. Available treatment regimens for controlling carpet contaminants were evaluated through a literature review and experimentation. Four moderately low-hazard, nondestructive methods were selected as treatments: vacuuming, steam-vapor, Neem oil (a natural tree extract), and benzalkonium chloride (a quaternary ammonium compound). Steam vapor treatment demonstrated the greatest dust mite population reduction (p < 0.05) when compared to other methods. The two physical methods, steam vapor and vacuuming, have no statistically significant efficacy in inactivating dust mite allergens (p = 0.084), but have higher efficacy when compared to the chemical method on dust mite allergens (p = 0.002). There is no statistically significant difference in the efficacy for reducing mold in carpet (p > 0.05) for both physical and chemical methods. The steam-vapor treatment effectively killed dust mites and denatured dust mite allergen in the laboratory environment. PMID:24467247

  2. Dust particle dynamics in atmospheric dust devils

    NASA Astrophysics Data System (ADS)

    Izvekova, Yulia; Popel, Sergey

    2016-04-01

    Dust particle dynamics is modeled in the Dust Devils (DDs). DD is a strong, well-formed, and relatively long-lived whirlwind, ranging from small (half a meter wide and a few meters tall) to large (more than 100 meters wide and more than 1000 meters tall) in Earth's atmosphere. We develop methods for the description of dust particle charging in DDs, discuss the ionization processes in DDs, and model charged dust particle motion. Our conclusions are consistent with the fact that DD can lift a big amount of dust from the surface of a planet into its atmosphere. On the basis of the model we perform calculations and show that DDs are important mechanism for dust uplift in the atmospheres of Earth and Mars. Influence of DD electric field on dynamics of dust particles is investigated. It is shown that influence of the electric field on dust particles trajectories is significant near the ground. At some altitude (more then a quarter of the height of DD) influence of the electric field on dust particles trajectories is negligible. For the calculation of the dynamics of dust electric field can be approximated by effective dipole located at a half of the height of DD. This work was supported by the Russian Federation Presidential Program for State Support of Young Scientists (project no. MK-6935.2015.2).

  3. A case study of lead contamination cleanup effectiveness at Bunker Hill.

    PubMed

    Sheldrake, Sean; Stifelman, Marc

    2003-02-15

    A review of cleanup effectiveness at Bunker Hill Superfund Site (BHSS) has shown that yard soil cleanup is an effective tool for reducing house dust lead concentrations, thereby reducing children's blood lead levels. This review has also shown that contiguous cleanup of residences has a three-fold greater reduction of children's blood lead levels compared with cleaning only those homes where children currently reside by reducing exposures attributable to neighboring properties. This review underscores the importance of a community-wide, preventative approach to controlling lead contamination in soil and house dust. This review has further characterized the need for careful design, implementation, and perpetual maintenance of a community-wide lead cleanup. Several key areas of importance to maintain large scale mining/smelting remedies in the Bunker Hill area were analyzed and noted for further action, including: infrastructure, institutional controls for homeowner projects (post cleanup), erosion control for undeveloped hillsides with potential to impact the developed valley floor, drainage improvements and flood control, waste piles, and increasing the rate at which cleanup proceeds. Focusing on these areas is crucial to minimizing recontamination at a large scale lead cleanup. PMID:12568767

  4. Environmental chemicals mediated the effect of old housing on adult health problems: US NHANES, 2009-2010.

    PubMed

    Shiue, Ivy; Bramley, Glen

    2015-01-01

    Housing conditions affect occupants continuously, and health interventions have shown a positive association between housing investment or improvement and occupant's health. However, the sources of the housing problems were less understood. Since it was observed that lead dust and chloroanisoles released from housing (materials) as indoor pollutants affected child's health, we now aimed to examine the relationships among built year, environmental chemicals and individual health in adults in a national and population-based setting. Data were retrieved from the US National Health and Nutrition Examination Survey, 2009-2010, including demographics, housing characteristics, self-reported health status, biomarkers and blood and urinary chemical concentrations. Adults aged 20 and above were included for statistical analysis (n = 5,793). Analysis involved chi-square test, t test, and survey-weighted general linear regression and logistic regression modelling. People who resided in older housing built before 1990 tended to report chronic bronchitis, liver problems, stroke, heart failure, diabetes, asthma and emphysema. Higher values in HDL cholesterol, blood lead and blood cadmium and having positive responses of hepatitis A, B, C and E antibodies among occupants were also observed. Furthermore, higher environmental chemical concentrations related to old housing including urinary cadmium, cobalt, platinum, mercury, 2,5-dichlorophenol and 2,4-dichlorophenol concentrations and mono-cyclohexyl phthalate and mono-isobutyl phthalate metabolites were shown in occupants as well. Older housing (≥30 years) seemed to contribute to the amount of environmental chemicals that affected human health. Regular monitoring, upgrading and renovation of housing to remove environmental chemicals and policy to support people in deprived situations against environmental injustice would be needed. PMID:25138559

  5. Housing Projects.

    ERIC Educational Resources Information Center

    Schmalz, Georgann

    1985-01-01

    Building specifications for birdhouses (nesting boxes) are given for 11 species (chickadee, titmouse, nuthatch, Carolina wren, house wren, downy woodpecker, hairy woodpecker, flicker, bluebird, screech owl, and wood duck) including length, width, depth, entrance diameter, and height above the ground. Pointers for construction, materials, and…

  6. Lead exposures in the human environment. Final report

    SciTech Connect

    Elias, R.W.

    1985-01-01

    Humans consume lead by inhaling air, drinking beverages, eating food and ingesting dust. The natural source of this lead is primarily soil. Anthropogenic sources are lead in gasoline, fossil fuels and industrial products and processes. Lead is ubiquitous in the human environment, and pinpointing the primary sources of lead in any particular environmental component is difficult. Nevertheless, our purpose is to describe the total exposure of humans to environmental lead and to determine the sources of lead contributing to this exposure. The total exposure is the total amount of lead consumed by ingestion and inhalation. Excluding lead exposure from choice or circumstance, a baseline level of potential human exposure can be defined for a normal individual eating a typical diet and living in a non-urban community remote from industrial sources of lead in a house without lead-based paints. Beyond this level, additive exposure factors can be determined for other environments (e.g. urban, occupational and smelter communities) and for certain habits and activities (e.g. pica, smoking, drinking and hobbies), with variation for age, sex or socioeconomic status.

  7. [Dust exposure in a pottery plant assessed by using GRIMM dust monitor].

    PubMed

    Woźniak, Helena; Stroszejn-Mrowca, Grazyna; Kita, Natalia

    2002-01-01

    In one of the pottery plants in which pneumoconiosis was the only certified occupational disease (16 cases during the years 1984-1997), the concentrations of dust in inhalable, thoracic and respirable fractions were measured at most characteristic workplaces. The highest concentrations in all the three fractions was found in the slip house; the mean concentrations were as follows: inhalable dust-7231.8 mg/m3; thoracic fraction--4834.9 mg/m3; and respirable fraction 1402.2 mg/m3. High concentrations of all the dust fractions were also observed at the workplace of the intershop transport worker who removed the waste body from cast and throw shops. The largest number of pneumoconiosis (7) cases was found among the workers of the slip house (20 persons employed); this was followed by the intershop transport workers-4 cases (4 persons employed). At the other workplaces (cast shop, throw shop and firing), concentrations of inhalable dust ranged from 1175 to 3232 mg/m3; thoracic from 726 to 2001 mg/m3; and respirable from 146 to 549 mg/m3. The contents of free crystalline silica (SiO2) in the air dust ranged from 3% in firing to 50% in slip house, in the latter mostly in the form of quartz or cristobalite. The main fraction of inhalable dust was the tracheobronchial fraction, ranging from 43.1 to 48.2%, the extrathoracic fraction ranged from 32.8 to 42.3% and respirable fraction from 11.8 to 21.6%. On the basis of the graphic record, such activities as pouring of raw materials into grinding mill and reloading of the waste body were identified at the workplaces of slip making and internship transport as those associated with the highest dust emission. PMID:12577809

  8. Hazards of explosives dusts

    NASA Astrophysics Data System (ADS)

    The Bureau of Mines has investigated the hazards of military explosives dispersed as dust clouds in a 20-L test chamber. For purposes of personnel safety, the spark ignitability of the explosives in the form of unconfined dust layers was also studied. The 20-L data show that most of the explosive dusts were capable of sustaining explosions as dust clouds dispersed in air and some dusts were even capable of sustaining explosions when dispersed in nitrogen. The finest sizes of explosive dusts were less reactive than the larger sizes; this is opposite to the particle size effect observed previously for the pure fuel dusts. The data for the explosive dusts were compared to those for pure fuel dusts.

  9. Skin lead contamination of family members of boat-caulkers in southern Thailand.

    PubMed

    Untimanon, Orrapan; Geater, Alan; Chongsuvivatwong, Virasakdi; Saetia, Wiyada; Utapan, Sutida

    2011-01-01

    Powdered lead oxide (Pb(3)O(4)) is used in the wooden-boat repair industry as a constituent of the caulking material. This study compared skin lead of household members of caulkers' and control homes, and examined the relationship of household member's skin lead with household floor lead loading (FLL) and dust lead content (DLC). FLL and DLC were measured in 67 caulkers' houses and 46 nearby houses with no known lead exposure. In each household, wipe specimens of skin lead were obtained from one selected family member. Hand lead loading (HdLL) and foot lead loading (FtLL) were significantly higher in family members of caulkers than controls (geometric mean 64.4 vs. 36.2 μg m(-2); p = 0.002 and 77.8 vs 43.8 μg m(-2); p = 0.002, respectively). This pattern mirrored FLL and DLC, which were also higher in caulkers' than in control houses (geometric mean 109.9 vs. 40.1 μg m(-2); p<0.001 and 434.8 vs 80.8 μg g(-1); p<0.001, respectively). Multiple linear regression modelling revealed FLL to be a better predictor than DLC for HdLL in all age groups and for FtLL in adult family members. In conclusion, skin lead levels are elevated in family members living in a lead-exposed worker's house and are related to the levels of household lead contamination. PMID:20823635

  10. Dust and Ocean Plants

    NASA Technical Reports Server (NTRS)

    2002-01-01

    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

  11. Evolution of Dust Structures from Room to Cryogenic Temperatures

    SciTech Connect

    Antipov, S. N.; Asinovskii, E. I.; Kirillin, A. V.; Markovets, V. V.; Petrov, O. F.; Fortov, V. E.

    2008-09-07

    In this work dusty plasma of dc glow discharge at the temperatures in the range of 4.2-300 K was experimentally and numerically investigated. As it was shown in the experiments, the deep cooling of discharge tube walls leads to dramatic change of dusty plasma properties. In particular, sufficient increase of dust particle kinetic temperature (by about an order) and dust density (by several orders) was observed at low (cryogenic) temperatures. At 4.2 K, this can lead to the forming of a super dense dust structures with novel properties. Numerical simulations of charging process, dust charge fluctuation and screening of dust particle charge in plasma were made in dependence with the neutral gas temperature and dust density. The main attention was given to proper ion-atom collision analysis that allows us to investigate mechanisms of dust structure transformation observed in the cryogenic experiments.

  12. Metal concentrations and distribution in the household, stairs and entryway dust of some Egyptian homes

    NASA Astrophysics Data System (ADS)

    Hassan, Salwa Kamal Mohamed

    2012-07-01

    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 μm, >38-45 μm and >45-63 μm. 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 μm), whereas Al, Fe and Cu were detected in significantly (p < 0.01) higher concentrations in dust of the large particle size (>45-63 μm). The average concentrations of the individual metals in dust of the small particle size (<38 μm) were 268, 196.4 and 254.49 μg gm-1 for Pb, 49.6, 43.5 and 46.66 μg gm-1 for Ni, 2.86, 2.15 and 2.71 μg gm-1 for Cd, 4340, 3796 and 2602 μg gm-1 for Al, 2860, 2200 and 2004 μg gm-1 for Fe, 209.25, 152.3 and 103.26 μg gm-1 for Zn, 4.1, 2.88 and 1.96 μg gm-1 for Co, 85.99, 74.06 and 83.17 μg gm-1 for Cr and 168.2, 156.5 and 122.02 μg 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 μg 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

  13. In-situ dust detection as a tool to study dust-plasma interactions in the Solar System

    NASA Astrophysics Data System (ADS)

    Srama, R.; Hsu, H. W.; Moragas-Klostermeyer, G.; Postberg, F.; Kempf, S.

    2014-12-01

    The unique results of the Cassini Cosmic Dust Analyzer onboard Cassini revealed the potential of in-situ dust detecti