Health Hazard Evaluation Report HETA 85-165-1605, St. Louis Police Auto Body Shop, St. Louis, Missouri

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carson, G.A.

1985-07-01

Environmental and breathing-zone samples were analyzed for toluene, lead, and total dust at the Saint Louis Police Auto Body Shop, Saint Louis, Missouri in January and February, 1985. The evaluation was requested by the Health Commissioner of the City of Saint Louis to investigate working conditions in the body shop. A prior health department investigation had indicated that there might be health hazards in the shop area. The author concludes that a potential health hazard exists due to overexposure to total dust while performing certain repairs at the facility. Recommendations include installing a supply air ventilation system for the exhaustmore » fans, orienting vehicles in the shop so that technicians are always working upstream of the airflow, and providing respiratory protection when it is not possible to control dust emissions.« less

Dental Technicians' Pneumoconiosis; Illness Behind a Healthy Smile – Case Series of a Reference Center in Turkey

PubMed Central

Alici, Nur Şafak; Beyan, Ayşe Coşkun; Demıral, Yücel; Çimrin, Arif

2018-01-01

Background: Dental laboratories include many hazards and risks. Dental technicians working in an unfavorable work environment in Turkey and other parts of the world may develop pneumoconiosis as a result of exposure to dust, depending on exposure time. In this study, we aimed to investigate the clinical and laboratory findings of dental technicians. Materials and Methods: The study consists of a case series. Between 2013 and 2016, a total of 70 who were working as a dental technician and referred to our clinic with suspicion of occupational disease were evaluated. Comprehensive work-history, physical examination complaints, functional status, chest X-ray, and high-resolution computed lung tomography (HRCT) findings were evaluated. Results: In all, 46 (65.7%) of the 70 dental technicians were diagnosed with pneumoconiosis. About 45 (97.8%) subjects were male and 1 (2.2%) was female. The mean age of starting to work was 15.89 ± 2.79 (11-23) years. The mix dust exposure time was 176.13 ± 73.97 (18-384) months. Small round opacities were most common finding. In 16 patients, high profusion being 2/3 and above were identified, and large opacity was detected in 11 patients. The radiological profusion had a weak negative correlation with FEV 1 and FVC (correlation coefficient − 0.18, P = 0.210 and − 0.058, P = 0704) and moderate negative correlation between radiological profusion and FEV1/FVC (correlation coefficient − 0.377, P = 0.010). In addition, no correlation was observed between the age at start of work and the duration of exposure. Conclusion: The presence of pneumoconiosis continues in dental technicians in Turkey, especially because there is an early childhood apprenticeship culture and almost all workers in this period have the history of sandblasting. PMID:29743783

Chemical characterization of sanding dust and methylene chloride usage in automotive refinishing: implications for occupational and environmental health.

PubMed

Enander, Richard T; Gute, David M; Cohen, Howard J; Brown, Linfield C; Desmaris, Anne Marie C; Missaghian, Richard

2002-01-01

Surface preparation activities conducted during automotive refinishing present several potential human health and environmental risks. This study examines the chemical composition of vehicle sanding dust and the prevalence of methylene chloride use as a basis for evaluating potential chemical exposures in the work environment, fugitive environmental releases, and take-home toxics. This article reports on the findings of (1) a statewide technology and work practices survey of 353 licensed auto body shops and (2) laboratory analyses of sanding dust representing more than 200 vehicles, 10 commercial body filler compounds, and work shirts worn during vehicle sanding while using nonventilated equipment. Survey data revealed that the majority of shops (78%) do not use ventilated sanding equipment, that most workers (55%) take their work clothes and shoes home at the end of the workday, and that 17% of the respondents used a methylene chloride-based paint stripper as an adjunct to mechanical sanding. Laboratory results showed that Pb, As, Cr, Mn, and Ni were present in the sanding dust at every facility tested. Lead concentrations in sanding dust were found to be highest at facilities that performed complete vehicle refinishing (range 770 to 7300 ppm) and at a collision repair shop that used a high-lead content body filler compound (1800 ppm). Hexavalent chromium also was found in two vocational high school paint dust samples at concentrations of 54 and 710 ppm. When total lead and chromium concentrations reached 7300 and 2300 ppm, respectively, facility sanding dust samples failed the U.S. Environmental Protection Agency's Toxicity Characteristic Leaching Procedure for hazardous waste. Metals found in the sanding dust also were present on the work shirts of technicians-ranging from 0.06 (Cd) to 81 (Mg) microg/inch2 of cloth-who sanded on paint without ventilated equipment. Results suggest that sanding dust and methylene chloride paint strippers used in vehicle resurfacing operations pose a potential hazard to human health and the environment.

Food allergens in mattress dust in Norwegian homes - a potentially important source of allergen exposure.

PubMed

Bertelsen, R J; Faeste, C K; Granum, B; Egaas, E; London, S J; Carlsen, K-H; Lødrup Carlsen, K C; Løvik, M

2014-01-01

Sensitization to food allergens and food allergic reactions are mostly caused by ingesting the allergen, but can also occur from exposure via the respiratory tract or the skin. Little is known about exposure to food allergens in the home environment. The objective of this study was firstly to describe the frequency of detection of allergens from fish, egg, milk, and peanut in mattress dust collected from homes of 13-year-old adolescents and secondly to identify home characteristics associated with the presence of food allergen contamination in dust. Food allergens were measured by dot blot analysis in mattress dust from 143 homes in Oslo, Norway. We analysed associations between home characteristics (collected by parental questionnaires and study technicians) and food allergens by multivariate regression models. Fish allergen was detected in 46%, peanut in 41%, milk in 39%, and egg allergen in 22% of the mattress dust samples; only three samples contained none of these allergens. All four food allergens were more frequently detected in mattresses in small dwellings (< 100 m(2)) than larger dwellings (≥ 130 m(2)); 63-71% of the small dwellings (n = 24) had milk, peanut, and fish allergens in the samples compared with 33-44% of the larger dwellings (n = 95). Milk, peanut, and egg allergens were more frequently detected in homes with bedroom and kitchen on the same floor as compared with different floors, with odds ratios of 2.5 (95% confidence interval (CI): 1.1, 5.6) for milk, 2.4 (95% CI: 1.0, 6.1) for peanut, and 3.1 (95% CI: 1.3, 7.5) for egg allergens. Food allergens occurred frequently in beds in Norwegian homes, with dwelling size and proximity of kitchen and bedroom as the most important determinants. Due to the amount of time children spent in the bedroom, mattress dust may be an important source of exposure to food allergens. © 2013 John Wiley & Sons Ltd.

Food Allergens in Mattress Dust in Norwegian Homes - A Potentially Important Source of Allergen Exposure

PubMed Central

Bertelsen, Randi J.; Fæste, Christiane K.; Granum, Berit; Egaas, Eliann; London, Stephanie J.; Carlsen, Kai-Håkon; Carlsen, Karin C. Lødrup; Løvik, Martinus

2014-01-01

Background Sensitization to food allergens and food allergic reactions are mostly caused by ingesting the allergen, but can also occur from exposure via the respiratory tract or the skin. Little is known about exposure to food allergens in the home environment. Objective To describe the frequency of detection of allergens from fish, egg, milk, and peanut in mattress dust collected from homes of 13 year old adolescents, and secondly to identify home characteristics associated with the presence of food allergen contamination in dust. Methods Food allergens were measured by dot blot analysis in mattress dust from 143 homes in Oslo, Norway. We analyzed associations between home characteristics (collected by parental questionnaires and study technicians) and food allergens by multivariate regression models. Results Fish allergen was detected in 46%, peanut in 41%, milk in 39%, and egg allergen in 22% of the mattress dust samples; only three samples contained none of these allergens. All four food allergens were more frequently detected in mattresses in small dwellings (<100m2) than larger dwellings (≥130 m2); 63-71% of the small dwellings (n=24) had milk, peanut, and fish allergens in the samples compared to 33-44% of the larger dwellings (n=95). Milk, peanut, and egg allergens were more frequently detected in homes with bedroom and kitchen on the same floor as compared with different floors; with odds ratios of 2.5 (95% confidence interval (CI): 1.1, 5.6) for milk, 2.4 (95% CI: 1.0, 6.1) for peanut, and 3.1 (95% CI: 1.3, 7.5) for egg allergens. Conclusions and clinical relevance Food allergens occurred frequently in beds in Norwegian homes, with dwelling size and proximity of kitchen and bedroom as the most important determinants. Due to the amount of time children spend in the bedroom, mattress dust may be an important source of exposure to food allergens. PMID:24304208

76 FR 24028 - Proposed Data Collections Submitted for Public Comment and Recommendations

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-29

... Function Testing Course Approval Program, 29 CFR 1910.1043 (OMB No. 0920-0138)--Extension--The National... Administration's Cotton Dust Standard, 29 CFR 1920.1043, for approving courses to train technicians to perform...

Use of electrostatic dust cloth for self-administered home allergen collection

EPA Science Inventory

Abstract Most epidemiologic studies employ a vacuum cleaner used by a trained technician to collect household allergens. This approach is labor intensive, equipment dependent, and impractical if study subjects reside over a wide geographic area. We examined the feasibility of a s...

Identification of potential hazards associated with new residential construction.

PubMed

Methner, M M

2000-02-01

There were several advantages and limitations of this observational study. The most important advantage of this study was the opportunity to observe residential construction workers performing their jobs. By observing work practices, valuable information was gathered about specific trades and their potential exposure to various chemical and physical agents. This information will be useful in guiding subsequent exposure assessments. Probably the greatest limitation of this study was the lack of participation by homebuilders. Ideally, observations of construction processes would have been more objective if the study included the participation of more than one homebuilder. Aside from one worker who was observed to wear safety glasses, leather gloves, and a dust mask, virtually no personal protective equipment (PPE) was observed onsite. Often small contractors do not have the financial resources necessary to procure the appropriate PPE and issue these items to the workers. Based on hazard prevalence, professional judgement, and the degree of hazardous product use, potential exposures that warrant quantitative sampling efforts during Phase 2 of this study are: bulldozer/backhoe operators--noise, vibration, diesel exhaust; concrete workers--naphtha, mineral spirits, Portland cement; asphalt workers--petroleum hydrocarbons, asphalt, mineral spirits; plumbers--methylethyl ketone, acetone, tetrahydrofuran, cyclohexanone; drywall finishers--total and respirable dust, hexane, acetone; painters--ethylene glycol, VOCs; masons--dust (during the preparation of mortar); floor preparation technicians--total and respirable dust; and ceramic tile installers--toluene, naphtha, silica (from grout powder).

Metabolic syndrome and occupation: Any association? Prevalence among auto technicians and school teachers in South West Nigeria.

PubMed

Akintunde, Adeseye A; Oloyede, Taiwo W

2017-11-01

To determine occupational association with metabolic syndrome among auto technicians and school teachers. One hundred and sixty six subjects were selected for this study. Clinical data was obtained while laboratory investigations including plasma glucose and lipid profile were performed. Statistical analysis was done with SPSS 20.0. P<0.05 was taken as statistically significant. School teachers had significantly higher mean total cholesterol and LDL-cholesterol compared to auto technicians. Mean serum triglycerides was significantly higher among auto-technicians compared to school teachers in this study. The prevalence of some conventional cardiovascular risk factors was significantly higher among auto-technicians compared to school teachers: Impaired blood glucose (9.6% vs. 1.2%, p<0.05), hypertriglyceridaemia (18.1% vs. 7.2%, p<0.05) and low HDL-Cholesterol (47.0% vs. 37.3%, p<0.05) respectively. However elevated LDL-cholesterol (56.6% vs. 32.5%, p<0.05) was significantly more common among school teachers compared to auto-technicians. Based on the WHO and the Harmonized criteria, metabolic syndrome was more frequent among auto-technicians compared to school teachers. (8.4% vs. 1.2% and 19.3% vs. 7.2% respectively, p<0.05) CONCLUSION: The prevalence of metabolic syndrome appears to be significantly higher among auto technicians despite their high level of physical activity, exertion and education compared to teachers. This may be related to the increased occupational exposure to organic and inorganic materials from dust particles, oil and oil related matter and particulate matter among auto technicians. Prompt definitive evaluation of this concept and appropriate health education to encourage safety mechanism can reduce this burden of metabolic syndrome among auto technicians in Nigeria. Copyright © 2016 Diabetes India. Published by Elsevier Ltd. All rights reserved.

Finishing Touches for Space Infrared Telescope Facility (SIRTF)

NASA Technical Reports Server (NTRS)

2003-01-01

Technicians put final touches on NASA's Space Infrared Telescope Facility at Lockheed Martin Aeronautics in Sunnyvale, Calif. It will soon be shipped to Cape Canaveral, Florida, where it is scheduled to launch on April 15. The mission will observe the coldest, oldest and most dust-obscured objects in the universe.

[Dental technician's pneumoconiosis; a case report].

PubMed

Karaman Eyüboğlu, Canan; Itil, Oya; Gülşen, Aşkin; Kargi, Aydanur; Cimrin, Arif

2008-01-01

Since 1939, it has been known that, silicosis and extrinsic allergic alveolitis can be seen among dental technicians. The interstitial disease caused by the exposure to complex substances used by dental technicians is classified as a special group called dental technician's pneumoconiosis. A 36-year-old man, who has no smoking history, presented with severe dyspnea. He had worked in different dental laboratories for 22 years, but he did not have respiratory symptoms until five years ago. After that date, he had hospitalized and had been examined for respiratory pathologies for many times. He had came to our clinic, because of the progression of his dyspnea. Diffuse pulmonary parenchymal infiltrates which can be related with pneumoconiosis and chronic type 1 respiratory deficiency had been diagnosed as the result of the examinations. While he has no history of smoking or any other risk factors or diseases in his medical history, the case was accepted as dental technician's pneumoconiosis. The factors related with the pathogenesis of dental technician's pneumoconiosis are; the complex compound of the substances (metal dusts, silica, plaster, wax and resins, chemical liquids, methyl methacrylate) used in this sector and their effects on the lung parenchyma. Extrinsic allergic alveolitis related with methyl methacrylate has been reported. The most important factor to acquire an occupational lung disease is a complex occupational exposure. The insufficient workplace airing and the lack of preventive measures added on this exposure, the risks become much more greater.

Use of Electronic Hand-held Devices for Collection of Savannah River Site Environmental Data - 13329

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marberry, Hugh; Moore, Winston

2013-07-01

Savannah River Nuclear Solutions has begun using Xplore Tablet PC's to collect data in the field for soil samples, groundwater samples, air samples and round sheets at the Savannah River Site (SRS). EPA guidelines for groundwater sampling are incorporated into the application to ensure the sample technician follows the proper protocol. The sample technician is guided through the process for sampling and round sheet data collection by a series of menus and input boxes. Field measurements and well stabilization information are entered into the tablet for uploading into Environmental Restoration Data Management System (ERDMS). The process helps to eliminate inputmore » errors and provides data integrity. A soil sample technician has the ability to collect information about location of sample, field parameter, describe the soil sample, print bottle labels, and print chain of custody for the sample that they have collected. An air sample technician has the ability to provide flow, pressure, hours of operation, print bottle labels and chain of custody for samples they collect. Round sheets are collected using the information provided in the various procedures. The data are collected and uploaded into ERDMS. The equipment used is weather proof and hardened for the field use. Global Positioning System (GPS) capabilities are integrated into the applications to provide the location where samples were collected and to help sample technicians locate wells that are not visited often. (authors)« less

Differential respirable dust related lung function effects between current and former South African coal miners.

PubMed

Naidoo, Rajen N; Robins, Thomas G; Seixas, Noah; Lalloo, Umesh G; Becklake, Margaret

2005-05-01

Dust-related dose-response decrements in lung function among coal miners have been reported in several studies, with varying magnitudes across populations. Few studies have compared differences between current and former coal miners. No studies on dose response relationships with lung function have been conducted in South African coal mines, one of the top three producers of coal internationally. The objectives of this study were (1) to describe the relationship between respirable dust exposure and lung function among current and former South African coal miners and to determine whether differential dust related effects were present between these employment categories; (2) to examine dust related dose response relationships, controlling for potential confounding by smoking and a history of tuberculosis (TB). Six hundred and eighty-four current and 188 ex-miners from three bituminous coal mines in Mpumalanga Province were studied. Interviews assessing work histories, smoking profiles and other risk factors were conducted. Work histories were also obtained from company records. Standardised spirometry was performed by trained technicians. Cumulative respirable dust exposure (CDE) estimates were constructed from company-collected sampling and measurements conducted by the researchers. Regression models examined the associations of CDE with per cent predicted FEV(1) and FVC, controlling for smoking, past history of TB and employment status. A statistically significant decline in FEV(1) of 1.1 and 2.2 ml/mg-year/m(3) was found in representative 40-year-old, 1.7-m tall current and former miners, respectively. Significant differences were found between the highest and medium exposure categories. Ex-miners had a lower mean per cent predicted lung function than current miners for each cumulative exposure category, suggesting a "healthy worker" effect. Past history of TB contributed to 21 and 14% declines in per cent predicted FEV(1) and FVC, respectively. Thus, in this cohort, a dose-related decline in lung function was associated with respirable dust exposure, with a magnitude of effect similar to that seen in other studies and important differences between current and former employees. A "healthy worker" effect may have attenuated the magnitude of this relationship. TB was a significant contributor to lung function loss.

An observational study of the potential for human exposures to pet-borne diazinon residues following lawn applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morgan, Marsha K.; Stout, Daniel M.; Jones, Paul A.

This study examined the potential for pet dogs to be an important pathway for transporting diazinon residues into homes and onto its occupants following residential lawn applications. The primary objectives were to investigate the potential exposures of occupants and their pet dogs to diazinon after an application to turf at their residences and to determine if personal contacts between occupants and their pet dogs resulted in measurable exposures. It was conducted from April to August 2001 before the Agency phased out all residential uses of diazinon in December 2004. Six families and their pet dogs were recruited into the study.more » Monitoring was conducted at pre-, 1, 2, 4, and 8 days post-application of a commercial, granular formulation of diazinon to the lawn by the homeowner. Environmental samples collected included soil, indoor air, carpet dust, and transferable residues from lawns and floors. Samples collected from the pet dogs consisted of paw wipes, fur clippings, and transferable residues from the fur by a technician or child wearing a cotton glove(s). First morning void (FMV) urine samples were collected from each child and his/her parent on each sampling day. Diazinon was analyzed in all samples, except urine, by GC-MS. The metabolite 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMPy) was analyzed in the urine samples by HPLC-MS/MS. Mean airborne residues of diazinon on day 1 post-application were at least six times higher in both the living rooms (235{+-}267 ng/m{sup 3}) and children's bedrooms (179{+-}246 ng/m{sup 3}) than at pre-application. Mean loadings of diazinon in carpet dust samples were at least 20 times greater on days 2, 4, and 8 post-application than mean loadings (0.03{+-}0.04 ng/cm{sup 2}) at pre-application. The pet dogs had over 900 times higher mean loadings of diazinon residues on their paws on day 1 post-application (88.1{+-}100.1 ng/cm{sup 2}) compared to mean loadings (<0.09 ng/cm{sup 2}) at pre-application. The mean diazinon loadings on the fur clippings were at least 14 times higher on days 1, 2, 4, and 8 post-application than mean loadings (0.8{+-}0.4 ng/cm{sup 2}) at pre-application. For transferable residues from dog fur, the mean loadings of diazinon on the technician's cotton glove samples were the lowest before application (0.04{+-}0.08 ng/cm{sup 2}) and the highest on day 1 post-application (10.4{+-}23.9 ng/cm{sup 2}) of diazinon to turf. Urinary IMPy concentrations for the participants ranged from <0.3 to 5.5 ng/mL before application and <0.3-12.5 ng/mL after application of diazinon. The mean urinary IMPy concentrations for children or adults were not statistically different (p>0.05) at pre-application compared to post-application of diazinon to turf. The results showed that the participants and their pet dogs were likely exposed to low levels of diazinon residues from several sources (i.e., air, dust, and soil), through several pathways and routes, after lawn applications at these residences. Lastly, the pet dog appears to be an important pathway for the transfer and translocation of diazinon residues inside the homes and likely exposed occupants through personal contacts (i.e., petting)« less

Certification and Career Success: A LEADS Project

ERIC Educational Resources Information Center

Russ-Eft, Darlene; Dickison, Phil; Levine, Roger

2008-01-01

This study examines the relationship between certification examination test results and Emergency Medical Technician (EMT) career success. The sample was drawn from the Longitudinal Emergency Medical Technician Attributes and Demographics Study (LEADS). LEADS participants were matched with National Registry of Emergency Medical Technician (NREMT)…

A technician works on the Mars Climate Orbiter in SAEF-2

NASA Technical Reports Server (NTRS)

1998-01-01

In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), a technician works on the Mars Climate Orbiter which is scheduled to launch on Dec. 10, 1998, aboard a Boeing Delta II rocket. The Mars Climate Orbiter is heading for Mars where it will primarily support its companion Mars Polar Lander spacecraft, planned for launch on Jan. 3, 1999. After that, the Mars Climate Orbiter's instruments will monitor the Martian atmosphere and image the planet's surface on a daily basis for one Martian year (two Earth years). It will observe the appearance and movement of atmospheric dust and water vapor, as well as characterize seasonal changes on the surface. The detailed images of the surface features will provide important clues to the planet's early climate history and give scientists more information about possible liquid water reserves beneath the surface.

Soils Sampling and Testing Training Guide for Field and Laboratory Technicians on Roadway Construction

DOT National Transportation Integrated Search

1999-12-01

This manual has been developed as a training guide for field and laboratory technicians responsible for sampling and testing of soils used in roadway construction. Soils training and certification will increase the knowledge of laboratory, production...

NHEXAS PHASE I MARYLAND STUDY--STANDARD OPERATING PROCEDURE FOR TRAINING OF FIELD TECHNICIANS (G07)

EPA Science Inventory

The purpose of this SOP is to describe the method used for training field technicians. The SOP outlines the responsibilities of the Field Technician (FT) and the Field Coordination Center Supervisor (FCC-S) before, during, and after sampling at residences, and the training syste...

Examining Career Success of Minority and Women Emergency Medical Technicians (EMTs): A LEADS Project

ERIC Educational Resources Information Center

Russ-Eft, Darlene F.; Dickison, Philip D.; Levine, Roger

2008-01-01

Emergency medical technicians (EMTs) are a critical segment in prehospital medical care. This study examined EMT-paramedic career success focused on minorities and women, as part of the Longitudinal Emergency Medical Technician Attributes and Demographics Study (LEADS). The LEADS data come from a representative sampling of EMTs throughout the…

KSC-02pd0812

NASA Image and Video Library

2002-05-29

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-A, Cape Canaveral Air Force Station, a technician works beneath the Boeing Delta II rocket that will be the launch vehicle for the CONTOUR spacecraft, scheduled to launch July 1. CONTOUR will provide the first detailed look into the heart of a comet -- the nucleus. The spacecraft will fly close to at least two comets, Encke and Schwassmann-Wachmann 3, taking pictures of the nucleus while analyzing the gas and dust that surround these rocky, icy building blocks of the solar system.

Comparison of indoor air sampling and dust collection methods for fungal exposure assessment using quantitative PCR.

PubMed

Cox, Jennie; Indugula, Reshmi; Vesper, Stephen; Zhu, Zheng; Jandarov, Roman; Reponen, Tiina

2017-10-18

Evaluating fungal contamination indoors is complicated because of the many different sampling methods utilized. In this study, fungal contamination was evaluated using five sampling methods and four matrices for results. The five sampling methods were a 48 hour indoor air sample collected with a Button™ inhalable aerosol sampler and four types of dust samples: a vacuumed floor dust sample, newly settled dust collected for four weeks onto two types of electrostatic dust cloths (EDCs) in trays, and a wipe sample of dust from above floor surfaces. The samples were obtained in the bedrooms of asthmatic children (n = 14). Quantitative polymerase chain reaction (qPCR) was used to analyze the dust and air samples for the 36 fungal species that make up the Environmental Relative Moldiness Index (ERMI). The results from the samples were compared by four matrices: total concentration of fungal cells, concentration of fungal species associated with indoor environments, concentration of fungal species associated with outdoor environments, and ERMI values (or ERMI-like values for air samples). The ERMI values for the dust samples and the ERMI-like values for the 48 hour air samples were not significantly different. The total cell concentrations of the 36 species obtained with the four dust collection methods correlated significantly (r = 0.64-0.79, p < 0.05), with the exception of the vacuumed floor dust and newly settled dust. In addition, fungal cell concentrations of indoor associated species correlated well between all four dust sampling methods (r = 0.68-0.86, p < 0.01). No correlation was found between the fungal concentrations in the air and dust samples primarily because of differences in concentrations of Cladosporium cladosporioides Type 1 and Epicoccum nigrum. A representative type of dust sample and a 48 hour air sample might both provide useful information about fungal exposures.

Comparison of coarse coal dust sampling techniques in a laboratory-simulated longwall section.

PubMed

Patts, Justin R; Barone, Teresa L

2017-05-01

Airborne coal dust generated during mining can deposit and accumulate on mine surfaces, presenting a dust explosion hazard. When assessing dust hazard mitigation strategies for airborne dust reduction, sampling is done in high-velocity ventilation air, which is used to purge the mining face and gallery tunnel. In this environment, the sampler inlet velocity should be matched to the air stream velocity (isokinetic sampling) to prevent oversampling of coarse dust at low sampler-to-air velocity ratios. Low velocity ratios are often encountered when using low flow rate, personal sampling pumps commonly used in underground mines. In this study, with a goal of employing mine-ready equipment, a personal sampler was adapted for area sampling of coarse coal dust in high-velocity ventilation air. This was done by adapting an isokinetic nozzle to the inlet of an Institute of Occupational Medicine (Edinburgh, Scotland) sampling cassette (IOM). Collected dust masses were compared for the modified IOM isokinetic sampler (IOM-MOD), the IOM without the isokinetic nozzle, and a conventional dust sampling cassette without the cyclone on the inlet. All samplers were operated at a flow rate typical of personal sampling pumps: 2 L/min. To ensure differences between collected masses that could be attributed to sampler design and were not influenced by artifacts from dust concentration gradients, relatively uniform and repeatable dust concentrations were demonstrated in the sampling zone of the National Institute for Occupational Safety and Health experimental mine gallery. Consistent with isokinetic theory, greater differences between isokinetic and non-isokinetic sampled masses were found for larger dust volume-size distributions and higher ventilation air velocities. Since isokinetic sampling is conventionally used to determine total dust concentration, and isokinetic sampling made a difference in collected masses, the results suggest when sampling for coarse coal dust the IOM-MOD may improve airborne coarse dust assessments over "off-the-shelf" sampling cassettes.

Comparison of coarse coal dust sampling techniques in a laboratory-simulated longwall section

PubMed Central

Patts, Justin R.; Barone, Teresa L.

2017-01-01

Airborne coal dust generated during mining can deposit and accumulate on mine surfaces, presenting a dust explosion hazard. When assessing dust hazard mitigation strategies for airborne dust reduction, sampling is done in high-velocity ventilation air, which is used to purge the mining face and gallery tunnel. In this environment, the sampler inlet velocity should be matched to the air stream velocity (isokinetic sampling) to prevent oversampling of coarse dust at low sampler-to-air velocity ratios. Low velocity ratios are often encountered when using low flow rate, personal sampling pumps commonly used in underground mines. In this study, with a goal of employing mine-ready equipment, a personal sampler was adapted for area sampling of coarse coal dust in high-velocity ventilation air. This was done by adapting an isokinetic nozzle to the inlet of an Institute of Occupational Medicine (Edinburgh, Scotland) sampling cassette (IOM). Collected dust masses were compared for the modified IOM isokinetic sampler (IOM-MOD), the IOM without the isokinetic nozzle, and a conventional dust sampling cassette without the cyclone on the inlet. All samplers were operated at a flow rate typical of personal sampling pumps: 2 L/min. To ensure differences between collected masses that could be attributed to sampler design and were not influenced by artifacts from dust concentration gradients, relatively uniform and repeatable dust concentrations were demonstrated in the sampling zone of the National Institute for Occupational Safety and Health experimental mine gallery. Consistent with isokinetic theory, greater differences between isokinetic and non-isokinetic sampled masses were found for larger dust volume-size distributions and higher ventilation air velocities. Since isokinetic sampling is conventionally used to determine total dust concentration, and isokinetic sampling made a difference in collected masses, the results suggest when sampling for coarse coal dust the IOM-MOD may improve airborne coarse dust assessments over “off-the-shelf” sampling cassettes. PMID:27792474

A Grounded Theory Study of Aircraft Maintenance Technician Decision-Making

NASA Astrophysics Data System (ADS)

Norcross, Robert

Aircraft maintenance technician decision-making and actions have resulted in aircraft system errors causing aircraft incidents and accidents. Aircraft accident investigators and researchers examined the factors that influence aircraft maintenance technician errors and categorized the types of errors in an attempt to prevent similar occurrences. New aircraft technology introduced to improve aviation safety and efficiency incur failures that have no information contained in the aircraft maintenance manuals. According to the Federal Aviation Administration, aircraft maintenance technicians must use only approved aircraft maintenance documents to repair, modify, and service aircraft. This qualitative research used a grounded theory approach to explore the decision-making processes and actions taken by aircraft maintenance technicians when confronted with an aircraft problem not contained in the aircraft maintenance manuals. The target population for the research was Federal Aviation Administration licensed aircraft and power plant mechanics from across the United States. Nonprobability purposeful sampling was used to obtain aircraft maintenance technicians with the experience sought in the study problem. The sample population recruitment yielded 19 participants for eight focus group sessions to obtain opinions, perceptions, and experiences related to the study problem. All data collected was entered into the Atlas ti qualitative analysis software. The emergence of Aircraft Maintenance Technician decision-making themes regarding Aircraft Maintenance Manual content, Aircraft Maintenance Technician experience, and legal implications of not following Aircraft Maintenance Manuals surfaced. Conclusions from this study suggest Aircraft Maintenance Technician decision-making were influenced by experience, gaps in the Aircraft Maintenance Manuals, reliance on others, realizing the impact of decisions concerning aircraft airworthiness, management pressures, and legal concerns related to decision-making. Recommendations included an in-depth systematic review of the Aircraft Maintenance Manuals, development of a Federal Aviation Administration approved standardized Aircraft Maintenance Technician decision-making flow diagram, and implementation of risk based decision-making training. The benefit of this study is to save the airline industry revenue by preventing poor decision-making practices that result in inefficient maintenance actions and aircraft incidents and accidents.

Characterization of atmospheric bioaerosols along the transport pathway of Asian dust during the Dust-Bioaerosol 2016 Campaign

NASA Astrophysics Data System (ADS)

Tang, Kai; Huang, Zhongwei; Huang, Jianping; Maki, Teruya; Zhang, Shuang; Shimizu, Atsushi; Ma, Xiaojun; Shi, Jinsen; Bi, Jianrong; Zhou, Tian; Wang, Guoyin; Zhang, Lei

2018-05-01

Previous studies have shown that bioaerosols are injected into the atmosphere during dust events. These bioaerosols may affect leeward ecosystems, human health, and agricultural productivity and may even induce climate change. However, bioaerosol dynamics have rarely been investigated along the transport pathway of Asian dust, especially in China where dust events affect huge areas and massive numbers of people. Given this situation, the Dust-Bioaerosol (DuBi) Campaign was carried out over northern China, and the effects of dust events on the amount and diversity of bioaerosols were investigated. The results indicate that the number of bacteria showed remarkable increases during the dust events, and the diversity of the bacterial communities also increased significantly, as determined by means of microscopic observations with 4,6-diamidino-2-phenylindole (DAPI) staining and MiSeq sequencing analysis. These results indicate that dust clouds can carry many bacteria of various types into downwind regions and may have potentially important impacts on ecological environments and climate change. The abundances of DAPI-stained bacteria in the dust samples were 1 to 2 orders of magnitude greater than those in the non-dust samples and reached 105-106 particles m-3. Moreover, the concentration ratios of DAPI-stained bacteria to yellow fluorescent particles increased from 5.1 % ± 6.3 % (non-dust samples) to 9.8 % ± 6.3 % (dust samples). A beta diversity analysis of the bacterial communities demonstrated the distinct clustering of separate prokaryotic communities in the dust and non-dust samples. Actinobacteria, Bacteroidetes, and Proteobacteria remained the dominant phyla in all samples. As for Erenhot, the relative abundances of Acidobacteria and Chloroflexi had a remarkable rise in dust events. In contrast, the relative abundances of Acidobacteria and Chloroflexi in non-dust samples of R-DzToUb were greater than those in dust samples. Alphaproteobacteria made the major contribution to the increasing relative abundance of the phylum Proteobacteria in all dust samples. The relative abundance of Firmicutes did not exceed 5 % in all the air samples, even though it is the predominant phylum in the surface sand samples from the Gobi Desert. These results illustrate that the bacterial community contained in dust aerosol samples has a different pattern compared with non-dust aerosol samples, and the relative abundances of airborne bacteria are different from those in the surface sand or soil and differ by location and transmitting vector.

[Geochemical characteristics and sources of atmospheric particulates in Shanghai during dust storm event].

PubMed

Qian, Peng; Zheng, Xiang-min; Zhou, Li-min

2013-05-01

Atmospheric particulates were sampled from three sampling sites of Putuo, Minhang and Qingpu Districts in Shanghai between Oct. , 2009 and Oct. , 2010. In addition, particulate samples were also collected from Nantong, Zhengzhou, Xi'an, and Beijing city where dust storm dust transported along during spring. Element compositions of atmospheric particulates were determined by XRF and ICP-MS. The concentrations of major and trace elements in atmospheric particulates from Putuo, Minhang and Qingpu Districts were similar, indicating their common source. The UCC standardization distribution map showed that the major element composition of dust storm samples was similar to that of loess in northwestern China, indicating that the dust storm dust was mainly derived from Western desert and partly from local area. The REE partition patterns of dust storm dusts among different cities along dust transport route were similar to each other, as well as to those of northern loess, which indicates that the dust storm samples may have the same material source as loess, which mainly comes from crust material. However, the REE partition patterns of non-dust storm particulates were different among the studied cities, and different from those of loess, which suggests that the non-dust storm samples may be mixed with non-crust source material, which is different from dust storm dust and loess. The major element composition and REE partition pattern are effective indicators for source tracing of dust storm dust.

Environmental contamination, product contamination and workers exposure using a robotic system for antineoplastic drug preparation.

PubMed

Sessink, Paul J M; Leclercq, Gisèle M; Wouters, Dominique-Marie; Halbardier, Loïc; Hammad, Chaïma; Kassoul, Nassima

2015-04-01

Environmental contamination, product contamination and technicians exposure were measured following preparation of iv bags with cyclophosphamide using the robotic system CytoCare. Wipe samples were taken inside CytoCare, in the clean room environment, from vials, and prepared iv bags including ports and analysed for contamination with cyclophosphamide. Contamination with cyclophosphamide was also measured in environmental air and on the technicians hands and gloves used for handling the drugs. Exposure of the technicians to cyclophosphamide was measured by analysis of cyclophosphamide in urine. Contamination with cyclophosphamide was mainly observed inside CytoCare, before preparation, after preparation and after daily routine cleaning. Contamination outside CytoCare was incidentally found. All vials with reconstituted cyclophosphamide entering CytoCare were contaminated on the outside but vials with powdered cyclophosphamide were not contaminated on the outside. Contaminated bags entering CytoCare were also contaminated after preparation but non-contaminated bags were not contaminated after preparation. Cyclophosphamide was detected on the ports of all prepared bags. Almost all outer pairs of gloves used for preparation and daily routine cleaning were contaminated with cyclophosphamide. Cyclophosphamide was not found on the inner pairs of gloves and on the hands of the technicians. Cyclophosphamide was not detected in the stationary and personal air samples and in the urine samples of the technicians. CytoCare enables the preparation of cyclophosphamide with low levels of environmental contamination and product contamination and no measurable exposure of the technicians. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Sampling and analysis method for measuring airborne coal dust mass in mixtures with limestone (rock) dust.

PubMed

Barone, T L; Patts, J R; Janisko, S J; Colinet, J F; Patts, L D; Beck, T W; Mischler, S E

2016-01-01

Airborne coal dust mass measurements in underground bituminous coal mines can be challenged by the presence of airborne limestone dust, which is an incombustible dust applied to prevent the propagation of dust explosions. To accurately measure the coal portion of this mixed airborne dust, the National Institute for Occupational Safety and Health (NIOSH) developed a sampling and analysis protocol that used a stainless steel cassette adapted with an isokinetic inlet and the low temperature ashing (LTA) analytical method. The Mine Safety and Health Administration (MSHA) routinely utilizes this LTA method to quantify the incombustible content of bulk dust samples collected from the roof, floor, and ribs of mining entries. The use of the stainless steel cassette with isokinetic inlet allowed NIOSH to adopt the LTA method for the analysis of airborne dust samples. Mixtures of known coal and limestone dust masses were prepared in the laboratory, loaded into the stainless steel cassettes, and analyzed to assess the accuracy of this method. Coal dust mass measurements differed from predicted values by an average of 0.5%, 0.2%, and 0.1% for samples containing 20%, 91%, and 95% limestone dust, respectively. The ability of this method to accurately quantify the laboratory samples confirmed the validity of this method and allowed NIOSH to successfully measure the coal fraction of airborne dust samples collected in an underground coal mine.

Sampling and analysis method for measuring airborne coal dust mass in mixtures with limestone (rock) dust

PubMed Central

Barone, T. L.; Patts, J. R.; Janisko, S. J.; Colinet, J. F.; Patts, L. D.; Beck, T. W.; Mischler, S. E.

2016-01-01

Airborne coal dust mass measurements in underground bituminous coal mines can be challenged by the presence of airborne limestone dust, which is an incombustible dust applied to prevent the propagation of dust explosions. To accurately measure the coal portion of this mixed airborne dust, the National Institute for Occupational Safety and Health (NIOSH) developed a sampling and analysis protocol that used a stainless steel cassette adapted with an isokinetic inlet and the low temperature ashing (LTA) analytical method. The Mine Safety and Health Administration (MSHA) routinely utilizes this LTA method to quantify the incombustible content of bulk dust samples collected from the roof, floor, and ribs of mining entries. The use of the stainless steel cassette with isokinetic inlet allowed NIOSH to adopt the LTA method for the analysis of airborne dust samples. Mixtures of known coal and limestone dust masses were prepared in the laboratory, loaded into the stainless steel cassettes, and analyzed to assess the accuracy of this method. Coal dust mass measurements differed from predicted values by an average of 0.5%, 0.2%, and 0.1% for samples containing 20%, 91%, and 95% limestone dust, respectively. The ability of this method to accurately quantify the laboratory samples confirmed the validity of this method and allowed NIOSH to successfully measure the coal fraction of airborne dust samples collected in an underground coal mine. PMID:26618374

Exposure to microbial components and allergens in population studies: a comparison of two house dust collection methods applied by participants and fieldworkers.

PubMed

Schram-Bijkerk, D; Doekes, G; Boeve, M; Douwes, J; Riedler, J; Ublagger, E; von Mutius, E; Benz, M; Pershagen, G; Wickman, M; Alfvén, T; Braun-Fahrländer, C; Waser, M; Brunekreef, B

2006-12-01

Dust collection by study participants instead of fieldworkers would be a practical and cost-effective alternative in large-scale population studies estimating exposure to indoor allergens and microbial agents. We aimed to compare dust weights and biological agent levels in house dust samples taken by study participants with nylon socks, with those in samples taken by fieldworkers using the sampling nozzle of the Allergology Laboratory Copenhagen (ALK). In homes of 216 children, parents and fieldworkers collected house dust within the same year. Dust samples were analyzed for levels of allergens, endotoxin, (1-->3)-beta-D-glucans and fungal extracellular polysaccharides (EPS). Socks appeared to yield less dust from mattresses at relatively low dust amounts and more dust at high dust amounts than ALK samples. Correlations between the methods ranged from 0.47-0.64 for microbial agents and 0.64-0.87 for mite and pet allergens. Cat allergen levels were two-fold lower and endotoxin levels three-fold higher in socks than in ALK samples. Levels of allergens and microbial agents in sock samples taken by study participants are moderately to highly correlated to levels in ALK samples taken by fieldworkers. Absolute levels may differ, probably because of differences in the method rather than in the person who performed the sampling. Practical Implications Dust collection by participants is a reliable and practical option for allergen and microbial agent exposure assessment. Absolute levels of biological agents are not (always) comparable between studies using different dust collection methods, even when expressed per gram dust, because of potential differences in particle-size constitution of the collected dust.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Que Hee, S.S.; Peace, B.; Clark, C.S.

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 weightmore » 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.« less

Instructor Quality and EMT Certification Examination Results

ERIC Educational Resources Information Center

Russ-Eft, Darlene; Dickison, Phil; Levine, Roger

2007-01-01

The Longitudinal Emergency Medical Technician Attributes and Demographics Study (LEADS) provides a representative sampling of EMTs throughout the United States. This study examines the relationship between instructor quality and National Registry of Emergency Medical Technicians certification examination outcomes. Results show significant…

Creating a performance appraisal template for pharmacy technicians using the method of equal-appearing intervals.

PubMed

Desselle, Shane P; Vaughan, Melissa; Faria, Thomas

2002-01-01

To design a highly quantitative template for the evaluation of community pharmacy technicians' job performance that enables managers to provide sufficient feedback and fairly allocate organizational rewards. Two rounds of interviews with two convenience samples of community pharmacists and pharmacy technicians were conducted. The interview in phase 1 was qualitative, and responses were used to design the second interview protocol. During the phase 2 interviews, a new group of respondents ranked technicians' job responsibilities, identified through the initial interviewees' responses, using scales the researchers had designed using an interval-level scaling technique called equal-appearing intervals. Chain and independent pharmacies. Phase 1-20 pharmacists and 20 technicians from chain and independent pharmacies; phase 2-20 pharmacists and 9 technicians from chain and independent pharmacies. Ratings of the importance of technician practice functions and corresponding responsibilities. Weights were calculated for each practice function. A weighted list of practice functions was developed, and this may serve as a performance evaluation template. Customer service-related activities were judged by pharmacists and technicians alike to be the most important technician functions. Many pharmacies either lack formal performance appraisal systems or fail to implement them properly. Technicians may desire more consistent feedback from pharmacists and value information that may lead to organizational rewards. Using a weighted, behaviorally anchored performance appraisal system may help pharmacists and pharmacy managers meet these demands.

Coping with Work-related Traumatic Situations among Crime Scene Technicians.

PubMed

Pavšič Mrevlje, Tinkara

2016-10-01

Crime scene technicians collect evidence related to crime and are therefore exposed to many traumatic situations. The coping strategies they use are thus very important in the process of facing the psychological consequences of such work. The available literature shows that crime scene technicians are an understudied subgroup of police workers. Our study is therefore the first unfolding insights into technicians' coping strategies, post-traumatic symptomatology and somatic health, based on a sample of 64 male crime scene technicians (85% of all Slovene technicians). Crime scene technicians mainly use avoidance coping strategies. Approach strategies that are more effective in the long-term-i.e. lead to a larger buffering of the effects of traumatic stress-are more frequently used if technicians are familiar with the nature of the task, when they have time to prepare for it, and if they feel that past situations have been positively resolved. Behavioural avoidance strategies were found to be least effective when dealing with traumatic experiences and are also related to more frequent problems of physical health. Results indicate that appropriate trainings for future technicians would facilitate the use of more effective coping strategies and consequently lead to a more effective and satisfied worker. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Uptake and impact of regulated pharmacy technicians in Ontario community pharmacies.

PubMed

Grootendorst, Paul; Shim, Minsup; Tieu, Jimmy

2018-01-01

Since 2010, most provincial Colleges of Pharmacists have licensed pharmacy technicians. The colleges hoped this would give pharmacists time to provide "expanded scope" activities such as medication reviews. Little is known, however, about the uptake and impact of pharmacy technicians on pharmacists' provision of such services. We address these questions using data for Ontario community pharmacies. Data on pharmacists and pharmacy technicians were obtained from the Ontario College of Pharmacists website in September 2016. Their place of employment was used to calculate the number of full-time equivalent (FTE) pharmacists and technicians employed at each community pharmacy. Pharmacy claims data for the 12-month period ending March 31, 2016, were obtained from the Ontario Public Drug Programs (OPDP). These data included number of MedsChecks performed, type of MedsCheck and number of prescriptions dispensed to OPDP beneficiaries. Pharmacy technicians were employed in 24% of the pharmacies in our sample. Technician employment rates were highest in Central Fill pharmacies and pharmacies serving long-term care facilities. In general, pharmacies employing 1 or fewer technician full-time equivalents (FTEs) had a slightly higher probability of providing MedsChecks and, of those that did provide Meds Checks Annuals, provided more of them. Pharmacies that hired 3 or more technician FTEs were markedly less likely to provide MedsChecks. Pharmacies differ in their employment of technicians and in the apparent impact of technicians on the provision of MedsChecks. However, these represent associations. Additional research is needed to assess the causal effect of technician employment on the provision of MedsChecks.

Uptake and impact of regulated pharmacy technicians in Ontario community pharmacies

PubMed Central

Grootendorst, Paul; Shim, Minsup

2018-01-01

Background: Since 2010, most provincial Colleges of Pharmacists have licensed pharmacy technicians. The colleges hoped this would give pharmacists time to provide “expanded scope” activities such as medication reviews. Little is known, however, about the uptake and impact of pharmacy technicians on pharmacists’ provision of such services. We address these questions using data for Ontario community pharmacies. Methods: Data on pharmacists and pharmacy technicians were obtained from the Ontario College of Pharmacists website in September 2016. Their place of employment was used to calculate the number of full-time equivalent (FTE) pharmacists and technicians employed at each community pharmacy. Pharmacy claims data for the 12-month period ending March 31, 2016, were obtained from the Ontario Public Drug Programs (OPDP). These data included number of MedsChecks performed, type of MedsCheck and number of prescriptions dispensed to OPDP beneficiaries. Results: Pharmacy technicians were employed in 24% of the pharmacies in our sample. Technician employment rates were highest in Central Fill pharmacies and pharmacies serving long-term care facilities. In general, pharmacies employing 1 or fewer technician full-time equivalents (FTEs) had a slightly higher probability of providing MedsChecks and, of those that did provide Meds Checks Annuals, provided more of them. Pharmacies that hired 3 or more technician FTEs were markedly less likely to provide MedsChecks. Conclusions: Pharmacies differ in their employment of technicians and in the apparent impact of technicians on the provision of MedsChecks. However, these represent associations. Additional research is needed to assess the causal effect of technician employment on the provision of MedsChecks. PMID:29796133

Microbiological and meteorological analysis of two Australian dust storms in April 2009.

PubMed

Lim, Natalie; Munday, Chris I; Allison, Gwen E; O'Loingsigh, Tadhg; De Deckker, Patrick; Tapper, Nigel J

2011-12-15

Dust is an important source of bioaerosols including bacteria. In this study, the microbiology and meteorology of specific dust storms in Australia were investigated. The samples were collected from two dust events in April 2009 that were characterised by intense cold fronts that entrained dust from the highly erodible and drought-stricken Mallee and Riverina regions of Victoria and central NSW. In the first storm, the dust travelled eastward over Canberra and Sydney, and in the second storm, the dust travelled east/southeastward over Canberra and Melbourne. Rain fell on both cities during the second dust storm. Dust and rain samples were collected, cultured, and the composition compared using polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE). Multiple bands were evident on DGGE indicative of a diverse microflora, and identification of several bands confirmed the presence of multiple genera and species representing three phyla. Numerous bands represented Bacillus species, and these were present in multiple dust samples collected from both Canberra and Melbourne. Interestingly, the microflora present in rain samples collected in Canberra during the second dust storm was quite different and the DGGE banding patterns from these samples clustered separately to most dust samples collected at the same time. Identification of several DGGE bands and PCR products from these rain samples indicated the presence of Pseudomonas species. These results indicate that Australian dust and rain have a diverse microflora and highlights the contribution of dust events to the distribution of microbes in the environment. Copyright © 2011 Elsevier B.V. All rights reserved.

Comparisons of the dust/smoke particulate that settled inside the surrounding buildings and outside on the streets of southern New York City after the collapse of the World Trade Center, September 11, 2001.

PubMed

Yiin, Lih-Ming; Millette, James R; Vette, Alan; Ilacqua, Vito; Quan, Chunli; Gorczynski, John; Kendall, Michaela; Chen, Lung Chi; Weisel, Clifford P; Buckley, Brian; Yang, Ill; Lioy, Paul J

2004-05-01

The collapse of the World Trade Center (WTC) on September 11, 2001, generated large amounts of dust and smoke that settled in the surrounding indoor and outdoor environments in southern Manhattan. Sixteen dust samples were collected from undisturbed locations inside two uncleaned buildings that were adjacent to Ground Zero. These samples were analyzed for morphology, metals, and organic compounds, and the results were compared with the previously reported outdoor WTC dust/smoke results. We also analyzed seven additional dust samples provided by residents in the local neighborhoods. The morphologic analyses showed that the indoor WTC dust/smoke samples were similar to the outdoor WTC dust/smoke samples in composition and characteristics but with more than 50% mass in the <53-microm size fraction. This was in contrast to the outdoor samples that contained >50% of mass above >53 microm. Elemental analyses also showed the similarities, but at lower concentrations. Organic compounds present in the outdoor samples were also detected in the indoor samples. Conversely, the resident-provided convenience dust samples were different from either the WTC indoor or outdoor samples in composition and pH, indicating that they were not WTC-affected locations. In summary, the indoor dust/smoke was similar in concentration to the outdoor dust/smoke but had a greater percentage of mass <53 microm in diameter.

The dustfall collector--a simple passive tool for long-term collection of airborne dust: a project under the Danish Mould in Buildings program (DAMIB).

PubMed

Würtz, H; Sigsgaard, T; Valbjørn, O; Doekes, G; Meyer, H W

2005-01-01

A newly developed dustfall device that collects airborne dust by sedimentation has been evaluated in Danish schools. Dust collected over 140 days was compared with airborne dust sampled during single school days and settled floor dust sampled at the end of a school day. Measurements of culturable fungi in air samples corresponded well to those from the dustfall collector in mechanically but not naturally ventilated rooms. Levels of beta(1 --> 3)glucan and culturable fungi in dust from the dustfall collector and settled floor dust did not agree well. Up to 10 times more beta(1 --> 3)glucan per milligram dust was found in the dustfall collectors than in settled floor dust. Only in dust from the dustfall collector was the mass concentration of culturable fungi (cfu/mg) significantly correlated with the degree of dampness. The culturability of fungi in the 140-day dustfall samples tended to be lower than in other types of samples. Nonetheless, the results indicated that the dustfall collector can be used to estimate the median concentration of airborne culturable fungi, provided identical sampling periods are used for all samples. The collector is cost effective and simple to use. Traditional ways of assessing exposure to microorganisms by sampling airborne dust or dust from floors have several disadvantages. In the present paper, a new sampler, the dustfall collector, which collects airborne dust by sedimentation over a period of months, is introduced. Tests of this collector indicate that it can be used to estimate the mean concentration of airborne culturable fungi but not beta(1 --> 3)glucan over a long period and that the method can differentiate between buildings with different levels of water damage.

The Effects of Workload and Working Conditions on Operating Room Nurses and Technicians.

PubMed

Uğurlu, Ziyafet; Karahan, Azize; Ünlü, Hayriye; Abbasoğlu, Aysel; Özhan Elbaş, Nalan; Avcı Işık, Sevcan; Tepe, Aylin

2015-09-01

This study was conducted between August 15 and September 20, 2013, to determine the effects of workload and working conditions on operating room (OR) nurses and technicians. The study sample included 74 OR nurses and technicians working in a private university's six hospitals. The Individual Workload Perception Scale and a questionnaire that collected data on risk and environmental factors were used. The mean age of study participants was 29.3 ± 6.7 years, and 62.2% of the participants were female. More than 90% of the nurses and technicians had experienced spills or splashing of blood or other body fluids; anesthetic gases and radiation had affected 63.5% and 71.6% of nurses and technicians, respectively; 63.5% reported lumbar pain; and 46.6% defined the work environment as very stressful. The average workload scale score was 32.4 ± 6.2 (min = 11, max = 55). OR nurses and technicians are exposed to many occupational risks. © 2015 The Author(s).

A Submillimeter Continuum Survey of Local Dust-obscured Galaxies

NASA Astrophysics Data System (ADS)

Lee, Jong Chul; Hwang, Ho Seong; Lee, Gwang-Ho

2016-12-01

We conduct a 350 μm dust continuum emission survey of 17 dust-obscured galaxies (DOGs) at z = 0.05-0.08 with the Caltech Submillimeter Observatory (CSO). We detect 14 DOGs with S 350 μm = 114-650 mJy and signal-to-noise > 3. By including two additional DOGs with submillimeter data in the literature, we are able to study dust content for a sample of 16 local DOGs, which consist of 12 bump and four power-law types. We determine their physical parameters with a two-component modified blackbody function model. The derived dust temperatures are in the range 57-122 K and 22-35 K for the warm and cold dust components, respectively. The total dust mass and the mass fraction of the warm dust component are 3-34 × 107 M ⊙ and 0.03%-2.52%, respectively. We compare these results with those of other submillimeter-detected infrared luminous galaxies. The bump DOGs, the majority of the DOG sample, show similar distributions of dust temperatures and total dust mass to the comparison sample. The power-law DOGs show a hint of smaller dust masses than other samples, but need to be tested with a larger sample. These findings support that the reason DOGs show heavy dust obscuration is not an overall amount of dust content, but probably the spatial distribution of dust therein.

Effect of ground control mesh on dust sampling and explosion mitigation.

PubMed

Alexander, D W; Chasko, L L

2015-07-01

Researchers from the National Institute for Occupational Safety and Health's Office of Mine Safety and Health Research conducted an assessment of the effects that ground control mesh might have on rock and float coal dust distribution in a coal mine. The increased use of mesh to control roof and rib spall introduces additional elevated surfaces on which rock or coal dust can collect. It is possible to increase the potential for dust explosion propagation if any float coal dust is not adequately inerted. In addition, the mesh may interfere with the collection of representative dust samples when using the pan-and-brush sampling method developed by the U.S. Bureau of Mines and used by the Mine Safety and Health Administration for band sampling. This study estimates the additional coal or rock dust that could accumulate on mesh and develops a means to collect representative dust samples from meshed entries.

Effect of ground control mesh on dust sampling and explosion mitigation

PubMed Central

Alexander, D.W.; Chasko, L.L.

2017-01-01

Researchers from the National Institute for Occupational Safety and Health’s Office of Mine Safety and Health Research conducted an assessment of the effects that ground control mesh might have on rock and float coal dust distribution in a coal mine. The increased use of mesh to control roof and rib spall introduces additional elevated surfaces on which rock or coal dust can collect. It is possible to increase the potential for dust explosion propagation if any float coal dust is not adequately inerted. In addition, the mesh may interfere with the collection of representative dust samples when using the pan-and-brush sampling method developed by the U.S. Bureau of Mines and used by the Mine Safety and Health Administration for band sampling. This study estimates the additional coal or rock dust that could accumulate on mesh and develops a means to collect representative dust samples from meshed entries. PMID:28936000

Metagenomic Analysis of Airborne Bacterial Community and Diversity in Seoul, Korea, during December 2014, Asian Dust Event.

PubMed

Cha, Seho; Srinivasan, Sathiyaraj; Jang, Jun Hyeong; Lee, Dongwook; Lim, Sora; Kim, Kyung Sang; Jheong, Weonhwa; Lee, Dong-Won; Park, Eung-Roh; Chung, Hyun-Mi; Choe, Joonho; Kim, Myung Kyum; Seo, Taegun

2017-01-01

Asian dust or yellow sand events in East Asia are a major issue of environmental contamination and human health, causing increasing concern. A high amount of dust particles, especially called as particulate matter 10 (PM10), is transported by the wind from the arid and semi-arid tracks to the Korean peninsula, bringing a bacterial population that alters the terrestrial and atmospheric microbial communities. In this study, we aimed to explore the bacterial populations of Asian dust samples collected during November-December 2014. The dust samples were collected using the impinger method, and the hypervariable regions of the 16S rRNA gene were amplified using PCR followed by pyrosequencing. Analysis of the sequencing data were performed using Mothur software. The data showed that the number of operational taxonomic units and diversity index during Asian dust events were higher than those during non-Asian dust events. At the phylum level, the proportions of Proteobacteria, Actinobacteria, and Firmicutes were different between Asian dust and non-Asian dust samples. At the genus level, the proportions of the genus Bacillus (6.9%), Arthrobacter (3.6%), Blastocatella (2%), Planomicrobium (1.4%) were increased during Asian dust compared to those in non-Asian dust samples. This study showed that the significant relationship between bacterial populations of Asian dust samples and non-Asian dust samples in Korea, which could significantly affect the microbial population in the environment.

Metagenomic Analysis of Airborne Bacterial Community and Diversity in Seoul, Korea, during December 2014, Asian Dust Event

PubMed Central

Cha, Seho; Srinivasan, Sathiyaraj; Jang, Jun Hyeong; Lee, Dongwook; Lim, Sora; Kim, Kyung Sang; Jheong, Weonhwa; Lee, Dong-Won; Park, Eung-Roh; Chung, Hyun-Mi; Choe, Joonho; Kim, Myung Kyum; Seo, Taegun

2017-01-01

Asian dust or yellow sand events in East Asia are a major issue of environmental contamination and human health, causing increasing concern. A high amount of dust particles, especially called as particulate matter 10 (PM10), is transported by the wind from the arid and semi-arid tracks to the Korean peninsula, bringing a bacterial population that alters the terrestrial and atmospheric microbial communities. In this study, we aimed to explore the bacterial populations of Asian dust samples collected during November–December 2014. The dust samples were collected using the impinger method, and the hypervariable regions of the 16S rRNA gene were amplified using PCR followed by pyrosequencing. Analysis of the sequencing data were performed using Mothur software. The data showed that the number of operational taxonomic units and diversity index during Asian dust events were higher than those during non-Asian dust events. At the phylum level, the proportions of Proteobacteria, Actinobacteria, and Firmicutes were different between Asian dust and non-Asian dust samples. At the genus level, the proportions of the genus Bacillus (6.9%), Arthrobacter (3.6%), Blastocatella (2%), Planomicrobium (1.4%) were increased during Asian dust compared to those in non-Asian dust samples. This study showed that the significant relationship between bacterial populations of Asian dust samples and non-Asian dust samples in Korea, which could significantly affect the microbial population in the environment. PMID:28122054

Lead isotopes and trace metals in dust at Yucca Mountain

USGS Publications Warehouse

Kwak, Loretta; Neymark, Leonid A.; Peterman, Zell E.

2008-01-01

Lead (Pb)-isotope compositions and trace-metal concentrations were determined for samples of dust collected from underground and surface locations at and near the proposed radioactive waste repository at Yucca Mountain, Nevada. Rare earth element concentrations in the dust samples from the underground tunnels are similar to those in wholerock samples of the repository host rocks (Miocene Tiva Canyon Tuff and Topopah Spring Tuff), supporting interpretation that the subsurface dust is mainly composed of rock comminuted during tunnel construction. Other trace metals (arsenic, cadmium, cobalt, chromium, copper, manganese, nickel, lead, antimony, thallium, and zinc) are variably enriched in the subsurface dust samples relative to the average concentrations in the host rocks. Average concentrations of arsenic and lead in dust samples, high concentrations of which can cause corrosion of waste canisters, have enrichment factors from 1.2 to 1.6 and are insignificant relative to the range of concentrations for these metals observed in the host rock samples. Most dust samples from surface sites also are enriched in many of these trace metals relative to average repository host rocks. At least some of these enrichments may be artifacts of sampling. Plotted on a 208Pb/206Pb-207Pb/206Pb graph, Pb-isotope compositions of dust samples from underground sites form a mixing line extending from host-rock Pb-isotope compositions towards compositions of many of the dust samples from surface sites; however, combined Pb concentration and isotope data indicate the presence of a Pbenriched component in the subsurface dust that is not derived from host rock or surface dust and may derive from anthropogenic materials introduced into the underground environment.

Hazardous Materials Technician. Technical Committee on Occupational Curriculum Development.

ERIC Educational Resources Information Center

Northern Montana Coll., Havre. Montana Center for Vocational Education, Research, Curriculum and Personnel Development.

This document describes Montana's postsecondary curriculum to prepare hazardous materials technicians. Basic general education requirements are described. The technical skills and the knowledge associated with each are listed in the following categories: (1) site assessment; (2) sampling materials; (3) handling materials; (4) recording data; (5)…

β-(1,3)-Glucan Exposure Assessment by Passive Airborne Dust Sampling and New Sensitive Immunoassays▿

PubMed Central

Noss, Ilka; Wouters, Inge M.; Bezemer, Gillina; Metwali, Nervana; Sander, Ingrid; Raulf-Heimsoth, Monika; Heederik, Dick J. J.; Thorne, Peter S.; Doekes, Gert

2010-01-01

Associations between house dust-associated β-(1,3)-glucan exposure and airway inflammatory reactions have been reported, while such exposures in early childhood have been suggested to protect against asthma and wheezing. Most epidemiological studies have used reservoir dust samples and an inhibition enzyme immunoassay (EIA) for β-(1,3)-glucan exposure assessment. The objective of this study was to develop inexpensive but highly sensitive enzyme immunoassays to measure airborne β-(1,3)-glucans in low-exposure environments, like homes. Specificities of available anti-β-(1,3)-glucan antibodies were defined by direct and inhibition experiments. Three suitable antibody combinations were selected for sandwich EIAs. β-(1,3)-Glucans in passive airborne dust collected with an electrostatic dust fall collector (EDC) and floor dust from seven homes were measured with the three EIAs. Floor dust samples were additionally analyzed in the inhibition EIA. The sandwich EIAs were sensitive enough for airborne glucan measurement and showed different specificities for commercial glucans, while the β-(1,3)-glucan levels in house dust samples correlated strongly. The feasibility of measuring glucans in airborne dust with the recently introduced EDC method was further investigated by selecting the most suitable of the three EIAs to measure and compare β-(1,3)-glucan levels in the EDC and in floor and actively collected airborne dust samples of the previously performed EDC validation study. The EDC β-(1,3)-glucan levels correlated moderately with β-(1,3)-glucans in actively collected airborne dust and floor dust samples, while the glucan levels in the airborne dust and floor dust samples did not correlate. The combination of the newly developed β-(1,3)-glucan sandwich EIA with EDC sampling now allows assessment in large-scale population studies of exposure to airborne β-(1,3)-glucans in homes or other low-exposure environments. PMID:20038709

77 FR 59667 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Respirable...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-28

... for OMB Review; Comment Request; Respirable Coal Mine Dust Sampling ACTION: Notice. SUMMARY: The... information collection request (ICR) titled, ``Respirable Coal Mine Dust Sampling,'' to the Office of... operator to protect miners from exposure to excessive dust levels. The respirable coal mine dust sampling...

NHEXAS PHASE I ARIZONA STUDY--METALS IN DUST ANALYTICAL RESULTS

EPA Science Inventory

The Metals in Dust data set contains analytical results for measurements of up to 11 metals in 562 dust samples over 388 households. Samples were taken by collecting dust samples from the indoor floor areas in the main room and in the bedroom of the primary resident. In additio...

NHEXAS PHASE I MARYLAND STUDY--METALS IN DUST ANALYTICAL RESULTS

EPA Science Inventory

The Metals in Dust data set contains analytical results for measurements of up to 4 metals in 282 dust samples over 80 households. Samples were obtained by collecting dust samples from the indoor floor areas in the main activity room using a modified vacuum cleaner device that c...

NHEXAS PHASE I MARYLAND STUDY--PESTICIDES IN DUST ANALYTICAL RESULTS

EPA Science Inventory

The Pesticides in Dust data set contains analytical results for measurements of up to 9 pesticides in 126 dust samples over 50 households. Samples were obtained by collecting dust samples from the indoor floor areas in the main activity room using a modified vacuum cleaner devic...

Levels of fungi and mycotoxins in the samples of grain and grain dust collected from five various cereal crops in eastern Poland.

PubMed

Krysińska-Traczyk, Ewa; Perkowski, Juliusz; Dutkiewicz, Jacek

2007-01-01

During combine harvesting of 5 various cereal crops (rye, barley, oats, buckwheat, corn) 24 samples of grain and 24 samples of settled grain dust were collected on farms located in the Lublin province of eastern Poland. The samples were examined for the concentration of total microfungi, Fusarium species, deoxynivalenol (DON), nivalenol (NIV), and ochratoxin A (OTA). Microfungi able to grow on malt agar were present in 79.2% of grain samples and in 91.7% of grain dust samples in the concentrations of 1.0-801.3x10(3) cfu/g and 1.5-12440.0x10(3) cfu/g, respectively. The concentration of microfungi in grain dust samples was significantly greater than in grain samples (p<0.01). Fusarium strains were isolated from 54.2% of grain samples and from 58.3% of grain dust samples in the concentrations of 0.1-375.0x10(3) cfu/g and 4.0-7,700.0x10(3) cfu/g, respectively. They were found in all samples of grain and grain dust from rye, barley and corn, but only in 0-16.7% of samples of grain and grain dust from oats and buckwheat. DON was found in 79.2% of grain samples and in 100% of grain dust samples in the concentrations of 0.001-0.18 microg/g and 0.006-0.283 microg/g, respectively. NIV was detected in 62.5% of grain samples and in 94.4% of grain dust samples in the concentrations of 0.004-0.502 microg/g and 0.005-0.339 microg/g, respectively. OTA was detected in 58.3% of grain samples and in 91.7% of grain dust samples in the concentrations of 0.00039- 0.00195 microg/g and 0.00036-0.00285 microg/g, respectively. The concentrations of DON, total fusariotoxins (DON+NIV) and OTA were significantly greater in grain dust samples than in grain samples (p<0.05, p<0.05, and p<0.001, respectively). The concentration of Fusarium poae in the samples of rye grain and dust was significantly correlated with the concentrations of DON (p<0.05), NIV (p<0.01), and total fusariotoxins (p<0.05). Similarly, the concentration of Fusarium culmorum in the samples of barley grain and dust was significantly correlated with the concentration of total fusariotoxins (p<0.05). A significant correlation was also found between the concentration of total fungi grown on malt agar and the concentration of OTA (p<0.05). In conclusion, although the concentration of DON, NIV and OTA in the samples of grain dust collected from 5 various cereals on farms in eastern Poland was not large, the persistent presence of these mycotoxins in over 90% of examined samples poses a potential health risk of chronic respiratory intoxication for exposed grain farmers.

A SUBMILLIMETER CONTINUUM SURVEY OF LOCAL DUST-OBSCURED GALAXIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Jong Chul; Hwang, Ho Seong; Lee, Gwang-Ho, E-mail: jclee@kasi.re.kr

We conduct a 350 μ m dust continuum emission survey of 17 dust-obscured galaxies (DOGs) at z = 0.05–0.08 with the Caltech Submillimeter Observatory (CSO). We detect 14 DOGs with S{sub 350μm} = 114–650 mJy and signal-to-noise > 3. By including two additional DOGs with submillimeter data in the literature, we are able to study dust content for a sample of 16 local DOGs, which consist of 12 bump and four power-law types. We determine their physical parameters with a two-component modified blackbody function model. The derived dust temperatures are in the range 57–122 K and 22–35 K for themore » warm and cold dust components, respectively. The total dust mass and the mass fraction of the warm dust component are 3–34 × 10{sup 7} M {sub ⊙} and 0.03%–2.52%, respectively. We compare these results with those of other submillimeter-detected infrared luminous galaxies. The bump DOGs, the majority of the DOG sample, show similar distributions of dust temperatures and total dust mass to the comparison sample. The power-law DOGs show a hint of smaller dust masses than other samples, but need to be tested with a larger sample. These findings support that the reason DOGs show heavy dust obscuration is not an overall amount of dust content, but probably the spatial distribution of dust therein.« less

Taking the Pulse of Training Transfer: Instructor Quality and EMT Certification Examination Results

ERIC Educational Resources Information Center

Russ-Eft, Darlene F.; Dickison, Phil; Levine, Roger

2010-01-01

The Longitudinal Emergency Medical Technician Attributes and Demographics Study (LEADS) provides a representative sampling of EMTs throughout the United States. The present study adds to the transfer of training literature by examining the relationship between instructor quality and National Registry of Emergency Medical Technicians certification…

KSC-02pd0822

NASA Image and Video Library

2002-05-30

KENNEDY SPACE CENTER, FLA. -- A thermal technician with Johns Hopkins University Applied Physics Laboratory closes out the blanket around CONTOUR'S Earth-Sun Sensor. The spacecraft will provide the first detailed look into the heart of a comet -- the nucleus. Flying as close as 60 miles (100 kilometers) to at least two comets, the spacecraft will take the sharpest pictures yet of a nucleus while analyzing the gas and dust that surround these rocky, icy building blocks of the solar system. Launch of CONTOUR aboard a Boeing Delta II rocket is scheduled for July 1 from Launch Pad 17-A, Cape Canaveral Air Force Station

KSC-98pc1339

NASA Image and Video Library

1998-10-13

KENNEDY SPACE CENTER, FLA. -- In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), technicians check underneath the Mars Polar Lander during the testing of science instruments. The solar-powered spacecraft is targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999. It is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere

KSC-98pc1609

NASA Image and Video Library

1998-10-29

KENNEDY SPACE CENTER, FLA. -- In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), a KSC technician prepares the Mars Polar Lander for encapsulation inside the backshell, a protective cover. The solar-powered spacecraft, targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999, is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere

KSC-98pc1613

NASA Image and Video Library

1998-10-29

KENNEDY SPACE CENTER, FLA. -- In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), KSC technicians prepare the Mars Polar Lander for encapsulation inside the backshell, a protective cover. The solar-powered spacecraft, targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999, is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere

U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--METALS IN DUST ANALYTICAL RESULTS

EPA Science Inventory

The Metals in Dust data set contains analytical results for measurements of up to 11 metals in 182 dust samples over 91 households. Samples were taken by collecting dust samples from the indoor floor areas in the main room and in the bedroom of the primary resident. In addition...

Airborne desert dust and aeromicrobiology over the Turkish Mediterranean coastline

USGS Publications Warehouse

Griffin, Dale W.; Kubilay, Nilgün; Kocak, Mustafa; Gray, Mike A.; Borden, Timothy C.; Shinn, Eugene A.

2007-01-01

Between 18 March and 27 October 2002, 220 air samples were collected on 209 of 224 calendar days, on top of a coastal atmospheric research tower in Erdemli, Turkey. The volume of air filtered for each sample was 340 liters. Two hundred fifty-seven bacterial and 2598 fungal colony forming units (CFU) were enumerated from the samples using a low-nutrient agar. Ground-based dust measurements demonstrated that the region is routinely impacted by dust generated regionally and from North Africa and that the highest combined percent recovery of total CFU and African dust deposition occurred in the month of April (93.4% of CFU recovery and 91.1% of dust deposition occurred during African dust days versus no African dust present, for that month). A statistically significant correlation was observed (peak regional African dust months of March, April and May; rs=0.576, P=0.000) between an increase in the prevalence of microorganisms recovered from atmospheric samples on dust days (regional and African as determined by ground-based dust measurements), versus that observed on non-dust days. Given the prevalence of atmospherically suspended desert dust and microorganisms observed in this study, and that culture-based studies typically only recover a small fraction (

[Free crystalline silica: a comparison of methods for its determination in total dust].

PubMed

Maciejewska, Aleksandra; Szadkowska-Stańczyk, Irena; Kondratowicz, Grzegorz

2005-01-01

The major objective of the study was to compare and investigate the usefulness of quantitative analyses of free crystalline silica (FCS) in the assessment of dust exposure in samples of total dust of varied composition, using three methods: chemical method in common use in Poland; infrared spectrometry; and x-ray powder diffraction. Mineral composition and FCS contents were investigated in 9 laboratory samples of raw materials, materials, and industrial wastes, containing from about 2 to over 80% of crystalline silica and reduced to particles of size corresponding with that of total dust. Sample components were identified using XRD and FT-IR methods. Ten independent determinations of FCS with each of the three study methods were performed in dust samples. An analysis of linear correlation was applied to investigate interrelationship between mean FCS determinations. In analyzed dust samples, along with silica dust there were numerous minerals interfering with silica during the quantitative analysis. Comparison of mean results of FCS determinations showed that the results obtained using the FT-IR method were by 12-13% lower than those obtained with two other methods. However, the differences observed were within the limits of changeability of results associated with their precision and dependence on reference materials used. Assessment of occupational exposure to dusts containing crystalline silica can be performed on the basis of quantitative analysis of FCS in total dusts using each of the compared methods. The FT-IR method is most appropriate for the FCS determination in samples of small amount of silica or collected at low dust concentrations; the XRD method for the analysis of multicomponent samples; and the chemical method in the case of medium and high FCS contents in samples or high concentrations of dusts in the work environment.

Seasonal Variation and Exposure Risks of Perchlorate in Soil, Indoor Dust, and Outdoor Dust in China.

PubMed

Li, Yiwen; Liao, Ruoying; Gan, Zhiwei; Qu, Bing; Wang, Rong; Chen, Mengqin; Ding, Sanglan; Su, Shijun

2018-04-25

A total of 97 paired soil, outdoor dust, and indoor dust samples were collected in the national scale of China in summer, and the perchlorate levels were compared with those in soil and outdoor dust samples collected in winter in our previous study. The median perchlorate concentrations in the outdoor dust, indoor dust, and soil samples were 8.10, 11.4, and 0.05 mg/kg, respectively, which were significantly lower than those in the winter samples due to the natural factors and human activities. No significant differences in perchlorate concentrations were found between Northern and Southern China in the dust samples, whereas the difference was obtained in the soil samples. In the terms of possible source, the perchlorate levels in the outdoor dust exhibited strong correlation with SO 4 2- (r 2  = 0.458**) and NO 3 - (r 2  = 0.389**), indicating part of perchlorate in outdoor environment was likely from atmospheric oxidative process in summer. The perchlorate, SO 4 2- , and Cl - levels in the indoor dust were significantly related to those in the outdoor dust, suggesting that outdoor contaminants might be an important source for indoor environment. Furthermore, the human exposure to perchlorate was under relatively safe state in China except for special sites or periods with high perchlorate levels. Dust made an unexpected contribution of 41.3% to the total daily perchlorate intake for children, whereas 2.46% for adults in China based on biomonitoring, which deserves more attention.

PERFLUORINATED COMPOUNDS IN ARCHIVED HOUSE-DUST SAMPLES

EPA Science Inventory

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

Exposure to airborne organophosphates originating from hydraulic and turbine oils among aviation technicians and loaders.

PubMed

Solbu, Kasper; Daae, Hanne Line; Thorud, Syvert; Ellingsen, Dag Gunnar; Lundanes, Elsa; Molander, Paal

2010-12-01

This study describes the potential for occupational exposure to organophosphates (OPs) originating from turbine and hydraulic oils, among ground personnel within the aviation industry. The OPs tri-n-butyl phosphate (TnBP), dibutyl phenyl phosphate (DBPP), triphenyl phosphate (TPP) and tricresyl phosphate (TCP) have been emphasized due to their use in such oils. Oil aerosol/vapor and total volatile organic compounds (tVOCs) in air were also determined. In total, 228 and 182 OPs and oil aerosol/vapor samples from technician and loader work tasks during work on 42 and 21 aircrafts, respectively, were collected in pairs. In general, the measured exposure levels were below the limit of quantification (LOQ) for 84%/98% (oil aerosol) and 82%/90% (TCP) of the samples collected during technician/loader work tasks. The air concentration ranges for all samples related to technician work were

Deposition Rates and Characterization of Arabian Mineral Dust

NASA Astrophysics Data System (ADS)

Puthan Purakkal, J.; Stenchikov, G. L.; Engelbrecht, J. P.

2015-12-01

Airborne mineral dust directly and indirectly impacts on global climate, continental and marine biochemistry, human and animal health, agriculture, equipment, and visibility. Annual global dust emissions are poorly known with estimates differing by a factor of at least two. Local dust emission and deposition rates are even less quantified. Dust deposition rate is a key parameter, which helps to constrain the modeled dust budget of the atmosphere. However, dust deposition remains poorly known, due to the limited number of reliable measurements. Simulations and satellite observations suggest that coastal dusts contribute substantially to the total deposition flux into the Red Sea. Starting December 2014, deposition samplers, both the "frisbee" type, and passive samplers for individual particle scanning electron microscopy were deployed at King Abdullah University of Science and Technology (KAUST), along the Red Sea in Saudi Arabia. Sampling periods of one month were adopted. The deposition rates range from 3 g m-2 month-1 for fair weather conditions to 23 g m-2 month-1 for high dust events. The X-ray diffraction (XRD) analyses of deposited dust samples show mineralogical compositions different from any of the parent soils, the former consisting mainly of gypsum, calcite, and smaller amounts of albite, montmorillonite, chlorite, quartz and biotite. The deposited dust samples on the other hand contain more gypsum and less quartz than the previously collected soil samples. This presentation discusses the results from XRD, chemical analysis and SEM-based individual particle analysis of the soils and the deposited dust samples. The monthly dust accumulation rates and their seasonal and spatial variability are compared with the regional model predictions. Data from this study provide an observational basis for validating the regional dust mass balance along the Arabian Red Sea coastal plain.

Respiratory Findings in Dental Laboratory Technicians in Rasht (North of Iran)

PubMed Central

Shakiba, Maryam; Nejad, Azita Tangestani; Massahnia, Sara; Shiari, Ali

2011-01-01

Background There are several occupations that can expose people to some air pollutants. Dental technicians are exposed to inorganic dust and chemical vapors when making dental prosthesis that can put them at risk for respiratory problems. This study was performed to assess respiratory dysfunction in a group of dental technicians Materials and Methods This was a cross-sectional study designed to ascertain the prevalence of respiratory disorders in dental laboratory technicians in Rasht, a city located in north of Iran. A Structured questionnaire was adapted according to the European Community Respiratory Health Survey questionnaire and used to elicit information regarding sociodemographic characteristics and medical status of the study participants. The ventilation status, protective measures and direct exposure to materials in the laboratories were directly observed by the observers and subjects underwent respiratory tests and chest x-ray. Results The mean age of dental technicians was 31.31 yrs (range 18-56 years) and 83% were males with a mean dental work experience of 9.04 years. In 54.8% of cases, the work environment did not have air conditioning system. The most common signs and symptoms were cough (38.1%) and wheezing (16.7%). There was a significant correlation between smoking and respiratory signs. Restrictive airway pattern and air trapping were two prevalent findings which were observed in 85.7% and 33.3% of the subjects. Cigarette smoking had a negative effect on FEV1, FEF25%-75%, and TLC causing a significant reduction in all three parameters (p < 0.05). The most prevalent finding was interstitial opacity which was observed in 10 individuals (23.8%). This finding was not significantly associated with age, gender, cigarette smoking, or daily work hours. However, there was a significant statistical association between work experience and interstitial opacity. Conclusion The prevalence of respiratory dysfunction and chest x-ray findings were high as in several similar studies. In order to reduce the hazards of respiratory disorders in risky occupations and provide dental workers with technical preventive measures, a more comprehensive study should be conducted throughout the country and further evaluations through biopsy and CT-scan need to be performed in suspicious cases when necessary. PMID:25191362

Assessment of exposure to oak wood dust using gallic acid as a chemical marker.

PubMed

Carrieri, Mariella; Scapellato, Maria Luisa; Salamon, Fabiola; Gori, Giampaolo; Trevisan, Andrea; Bartolucci, Giovanni Battista

2016-01-01

The American Conference of Governmental Industrial Hygienists (ACGIH) has classified oak dust as a human carcinogen (A1), based on increased sinus and nasal cancer rates among exposed workers. The aims of this study were to investigate the use of gallic acid (GA) as a chemical marker of occupational exposure to oak dusts, to develop a high-performance liquid chromatography-diode array detector method to quantify GA and to apply the method in the analysis of oak dust samples collected in several factories. A high-performance liquid chromatography method was developed to detect GA in oak wood dust. The method was tested in the field, and GA was extracted from inhalable oak wood dust collected using the Institute of Occupational Medicine inhalable dust sampler in the air of five woodworking plants where only oak wood is used. A total of 57 samples with dust concentrations in the range of 0.27-11.14 mg/m(3) were collected. Five of these samples exceeded the Italian threshold limit value of 5 mg/m(3), and 30 samples exceeded the ACGIH TLV of 1 mg/m(3). The GA concentrations were in the range 0.02-4.18 µg/m(3). The total oak dust sampled was correlated with the GA content with a correlation coefficient (r) of 0.95. The GA in the tannic extracts of oak wood may be considered a good marker for this type of wood, and its concentration in wood dust sampled in the work environment is useful in assessing the true exposure to carcinogenic oak dust.

Comparison of a direct-reading device to gravimetric methods for evaluating organic dust aerosols in an enclosed swine production environment.

PubMed

Taylor, C D; Reynolds, S J

2001-01-01

The production of livestock in enclosed facilities has become an accepted practice, driven by the need for increased efficiency. Exposure to organic dusts, containing various bioactive components, has been identified an important risk factor for the high rate of lung disease found among workers in these environments. Assessment of organic dust exposure requires technical skills and instrumentation not readily available to most agricultural enterprises. Development of a simple, cost-effective method for measuring organic dust levels would be useful in evaluating and controlling exposures in these environments. The objective of this study was to evaluate the usefulness of the direct reading MIE PDM-3 Miniram for estimating organic dust concentrations in enclosed swine production facilities. Responses from the MIE PDM-3 Miniram were compared to gravimetric methods for total and inhalable dust. Total dust determinations were conducted in accordance with the National Institute for Occupational Safety and Health (NIOSH) method 0500. Inhalable particulate mass (IPM) sampling was conducted using SKC brand IOM (Institute of Occupational Medicine) sampling cassettes, which meet the American Conference of Governmental Industrial Hygienists ACGIH criteria for inhalable dust sampling. This study design also allowed for the comparison of traditional total dust method to the IPM method, in collecting organic dusts in an agricultural setting. Fifteen sets of side-by-side samples (Miniram, total dust, and IPM) were collected over a period of six months in a swine confinement building. There were statistically significant differences in the results provided by the three sampling methods. Measurements for inhalable dust exceeded those for total dust in eleven of fifteen samples. The Miniram time-weighted average (TWA) response to the organic dust was always the lower of the three methods. A high degree of correlation was found among all three methods. The Miniram performed well under field conditions of varying temperature and humidity. The Miniram has the potential to predict the inhalable and total dust concentrations, assuming a correction factor for the organic dust being measured is applied.

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 provisions. © 2013. Published by Elsevier B.V. All rights reserved.

Import Auto Technician; Curriculum Guide for the Development of an Import Automobile Technology Program.

ERIC Educational Resources Information Center

East Los Angeles Coll., CA.

In this curriculum guide, courses in a three-phase community college program for training import automobile technicians are provided. Following an introducation to the guide, the background of the development of the program, the program, the instruction, support for instruction, and the import automobile industry are discussed. Sample options for…

NHEXAS PHASE I REGION 5 STUDY--METALS IN DUST ANALYTICAL RESULTS

EPA Science Inventory

This data set includes analytical results for measurements of metals in 1,906 dust samples. Dust samples were collected to assess potential residential sources of dermal and inhalation exposures and to examine relationships between analyte levels in dust and in personal and bioma...

Rapid methods for jugular bleeding of dogs requiring one technician.

PubMed

Frisk, C S; Richardson, M R

1979-06-01

Two methods were used to collect blood from the jugular vein of dogs. In both techniques, only one technician was required. A rope with a slip knot was placed around the base of the neck to assist in restraint and act as a tourniquet for the vein. The technician used one hand to restrain the dog by the muzzle and position the head. The other hand was used for collecting the sample. One of the methods could be accomplished with the dog in its cage. The bleeding techniques were rapid, requiring approximately 1 minute per dog.

In Situ Sampling of Terrestrial Dust Devils and Implications for Mars

NASA Astrophysics Data System (ADS)

Raack, J.; Reiss, D.; Balme, M. R.; Taj-Eddine, K.; Ori, G. G.

2017-09-01

We report on first very detailed in situ samples of the relative dust load and the vertical grain size distribution of terrestrial dust devils sampled during two field campaigns in Morocco and their implications for Mars. Our measurements imply, i.e., a similar internal structure for sampled dust devils, despite their different strenghts and dimensions; an exponential decreasing of particle size with height; and that between 60 and 70% of all lifted particles can go into atmospheric suspension.

Inorganic chemical composition and chemical reactivity of settled dust generated by the World Trade Center building collapse: Chapter 12

USGS Publications Warehouse

Plumlee, Geoffrey S.; Hageman, Philip L.; Lamothe, Paul J.; Ziegler, Thomas L.; Meeker, Gregory P.; Theodorakos, Peter M.; Brownfield, Isabelle; Adams, Monique G.; Swayze, Gregg A.; Hoefen, Todd M.; Taggart, Joseph E.; Clark, Roger N.; Wilson, S.; Sutley, Stephen J.

2009-01-01

Samples of dust deposited around lower Manhattan by the September 11, 2001, World Trade Center (WTC) collapse have inorganic chemical compositions that result in part from the variable chemical contributions of concrete, gypsum wallboard, glass fibers, window glass, and other materials contained in the buildings. The dust deposits were also modified chemically by variable interactions with rain water or water used in street washing and fire fighting. Chemical leach tests using deionized water as the extraction fluid show the dust samples can be quite alkaline, due primarily to reactions with calcium hydroxide in concrete particles. Calcium and sulfate are the most soluble components in the dust, but many other elements are also readily leached, including metals such as Al, Sb, Mo Cr, Cu, and Zn. Indoor dust samples produce leachates with higher pH, alkalinity, and dissolved solids than outdoor dust samples, suggesting most outdoor dust had reacted with water and atmospheric carbon dioxide prior to sample collection. Leach tests using simulated lung fluids as the extracting fluid suggest that the dust might also be quite reactive in fluids lining the respiratory tract, resulting in dissolution of some particles and possible precipitation of new phases such as phosphates, carbonates, and silicates. Results of these chemical characterization studies can be used by health scientists as they continue to track and interpret health effects resulting from the short-term exposure to the initial dust cloud and the longer-term exposure to dusts resuspended during cleanup.

Lunar Atmosphere and Dust Environment Explorer Integration and Test

NASA Technical Reports Server (NTRS)

Wright, Michael R.; McCormick, John L.; Hoffman, Richard G.

2010-01-01

Integration and test (I&T) of the Lunar Atmosphere and Dust Environment Explorer (LADEE) is presented. A collaborative NASA project between Goddard Space Flight Center and Ames Research Center, LADEE's mission is to explore the low lunar orbit environment and exosphere for constituents. Its instruments include two spectrometers, a dust detector, and a laser communication technology demonstration. Although a relatively low-cost spacecraft, LADEE has I&T requirements typical of most planetary probes, such as prelaunch contamination control, sterilization, and instrument calibration. To lead to a successful mission, I&T at the spacecraft, instrument, and observatory level must include step-by-step and end-to-end functional, environmental, and performance testing. Due to its compressed development schedule, LADEE I&T planning requires adjusting test flows and sequences to account for long-lead critical-path items and limited spares. A protoflight test-level strategy is also baselined. However, the program benefits from having two independent but collaborative teams of engineers, managers, and technicians that have a wealth of flight project experience. This paper summarizes the LADEE I&T planning, flow, facilities, and probe-unique processes. Coordination of requirements and approaches to I&T when multiple organizations are involved is discussed. Also presented are cost-effective approaches to I&T that are transferable to most any spaceflight project I&T program.

[Gohieria fusca found in dust of air-conditioner filters].

PubMed

Qiang, Chai; Xiao-Dong, Zhan; Wei, Guo; Chao-Pin, Li

2017-09-25

To investigate the pollution status of Gohieria fusca in the air conditioner-filters of different places in Wuhu City. The dust samples were collected from the filters of air-conditioners in dining rooms, shopping malls, hotels and households between June and September, 2013, and G. fusca was detected in the dust samples. There were 430 dust samples collected and 98 were G. fusca positive with the breeding rate of 22.79%. The difference of breeding rates of G. fusca were statistically significant among the different places ( χ 2 =18.294, P < 0.05). Among 510.5 g dust samples in total, 783 G. fusca mites were detected with an average breeding density of 1.53 mite/g. G. fusca breeds in the dust of air-conditioner filters in Wuhu City gravely.

Wet Dust Deposition Across Texas, USA

NASA Astrophysics Data System (ADS)

Collins, J. D., Jr.; Ponette-González, A.; Gill, T. E.; Glass, G. A.; Weathers, K. C.

2016-12-01

Atmospheric dust deposition is of critical importance in terrestrial biogeochemical cycles, supplying essential limiting nutrients, such as calcium and phosphorus as well as pollutants, such as lead, to ecosystems. Dust particles are delivered to terrestrial ecosystems directly as dry deposition or in precipitation (wet deposition) as a result of rainout (particles incorporated into cloud droplets) and washout (particles that collide with raindrops as they fall). Compared to dry deposition, wet dust deposition (dissolved + particulate) is a poorly understood yet potentially significant pathway for dust input, especially in humid regions. We quantified wet dust deposition to two National Atmospheric Deposition Monitoring (NADP) sites across Texas-one in west (Guadalupe Mountains) and one in east (near Houston) Texas-with contrasting climate/dust regimes and land cover. We focused on 2012 during one of the most severe droughts in Texas since 1895. Dust event days (DEDs) were identified using meteorological data for stations within 150 km of the NADP sites where wet deposition was sampled weekly. DEDs were defined using the following criteria: visibility <10 km, <30% relative humidity, and wind speed >50 km, supplemented with other Saharan dust incursion and dust observations. A total of 34 DEDs (20 sample weeks) were identified for the west and 5 DEDs (4 sample weeks) for the east Texas sites. Bulk elemental composition of washout particles is analyzed using Particle Induced X-ray Emission (PIXE) spectroscopy and X-ray Fluorescence (XRF) spectroscopy. Using these data, we will examine differences in the chemical composition of rainwater and aerosol particles filtered from rain samples for dust versus non-dust event days at each study site. Deposition fluxes for dust and non-dust event weeks are also compared. Quantifying the magnitude of wet dust deposition is necessary to improve evaluation of dust impacts on biogeochemical cycles.

Using dust, gas and stellar mass-selected samples to probe dust sources and sinks in low-metallicity galaxies

NASA Astrophysics Data System (ADS)

De Vis, P.; Gomez, H. L.; Schofield, S. P.; Maddox, S.; Dunne, L.; Baes, M.; Cigan, P.; Clark, C. J. R.; Gomez, E. L.; Lara-López, M.; Owers, M.

2017-10-01

We combine samples of nearby galaxies with Herschel photometry selected on their dust, metal, H I and stellar mass content, and compare these to chemical evolution models in order to discriminate between different dust sources. In a companion paper, we used an H I-selected sample of nearby galaxies to reveal a subsample of very gas-rich (gas fraction >80 per cent) sources with dust masses significantly below predictions from simple chemical evolution models, and well below Md/M* and Md/Mgas scaling relations seen in dust and stellar-selected samples of local galaxies. We use a chemical evolution model to explain these dust-poor, but gas-rich, sources as well as the observed star formation rates (SFRs) and dust-to-gas ratios. We find that (I) a delayed star formation history is required to model the observed SFRs; (II) inflows and outflows are required to model the observed metallicities at low gas fractions; (III) a reduced contribution of dust from supernovae (SNe) is needed to explain the dust-poor sources with high gas fractions. These dust-poor, low stellar mass galaxies require a typical core-collapse SN to produce 0.01-0.16 M⊙ of dust. To match the observed dust masses at lower gas fractions, significant grain growth is required to counteract the reduced contribution from dust in SNe and dust destruction from SN shocks. These findings are statistically robust, though due to intrinsic scatter it is not always possible to find one single model that successfully describes all the data. We also show that the dust-to-metal ratio decreases towards lower metallicity.

The cytotoxic and genetoxic effects of dust and soil samples from E-waste recycling area on L02 cells.

PubMed

Wang, Liulin; Hou, Meiling; An, Jing; Zhong, Yufang; Wang, Xuetong; Wang, Yangjun; Wu, Minghong; Bi, Xinhui; Sheng, Guoying; Fu, Jiamo

2011-10-01

Electrical and electronic waste (E-waste) has now become the fastest growing solid waste around the world. Primitive recycling operations for E-waste have resulted in severe contamination of toxic metals and organic chemicals in the related areas. In this study, six dust and soil samples collected from E-waste recycling workshops and open-burning sites in Longtang were analyzed to investigate their cytotoxicity and genotoxicity on L02 cells. These six samples were: dust No. 1 collected at the gate of the workshop; dust No. 2 collected from air conditioning compressor dismantling site; dust No. 3 collected from where some motors, wires, and aluminium products since the 1980s were dismantled; soil No. 1 collected at the circuit board acid washing site; soil No. 2 collected from a wire open-burning site; soil No. 3 collected near a fiber open-burning site. At the same time, two control soil samples were collected from farmlands approximately 8 km away from the dismantling workshops. The results showed that all of these samples could inhibit cell proliferation and cause cell membrane lesion, among which dust No. 3 and soil No. 2 had the strongest toxicity. Moreover, the comet assay showed that the dust No. 3 had the most significant capability to cause DNA single-strand beaks (SSB), while the road dust (dust No. 1) collected at the gate of the workshop, a relatively farer site, showed the slightest capability to induce DNA SSB. The intracellular reactive oxygen species (ROS) detection showed that ROS level was elevated with the increase of dust and soil samples concentration. Dust No. 3 and soil No. 2 had the highest ROS level, followed by dust No. 2 and 1, soil No. 3 and 1. All of the above results indicated that polluted soil and dust from the E-waste area had cytotoxicity and genotoxicity on L02 cells, the mechanism might involve the increased ROS level and consequent DNA SSB.

Airborne desert dust and aeromicrobiology over the Turkish Mediterranean coastline

NASA Astrophysics Data System (ADS)

Griffin, Dale W.; Kubilay, Nilgün; Koçak, Mustafa; Gray, Mike A.; Borden, Timothy C.; Shinn, Eugene A.

Between 18 March and 27 October 2002, 220 air samples were collected on 209 of 224 calendar days, on top of a coastal atmospheric research tower in Erdemli, Turkey. The volume of air filtered for each sample was 340 liters. Two hundred fifty-seven bacterial and 2598 fungal colony forming units (CFU) were enumerated from the samples using a low-nutrient agar. Ground-based dust measurements demonstrated that the region is routinely impacted by dust generated regionally and from North Africa and that the highest combined percent recovery of total CFU and African dust deposition occurred in the month of April (93.4% of CFU recovery and 91.1% of dust deposition occurred during African dust days versus no African dust present, for that month). A statistically significant correlation was observed (peak regional African dust months of March, April and May; rs=0.576, P=0.000) between an increase in the prevalence of microorganisms recovered from atmospheric samples on dust days (regional and African as determined by ground-based dust measurements), versus that observed on non-dust days. Given the prevalence of atmospherically suspended desert dust and microorganisms observed in this study, and that culture-based studies typically only recover a small fraction (<1.0%) of the actual microbial population in any given environment, dust-borne microorganisms and other associated constituents (organic detritus, toxins, etc.) may play a significant role in the regional human and ecosystem health.

Pharmacy technician self-efficacies: Insight to aid future education, staff development, and workforce planning.

PubMed

Desselle, Shane P; Hoh, Ryan; Holmes, Erin R; Gill, Amanpreet; Zamora, Lemuel

2017-07-15

The roles of pharmacy technicians are increasingly prominent given pharmacy's transition to patient-centered activities and evolving scopes of practice in many U.S. states and throughout the world. The aims of this study were to assess U.S. pharmacy technicians' self-efficacies for and attitudes toward performing current and emerging roles in hospital and in community pharmacy and to identify factors related to pharmacy technician self-efficacies in these roles. A total of 5000 pharmacy technicians from 8 U.S. states were sent an electronic survey eliciting data on current involvement, self-efficacies, and attitudes for practicing in an expansive list of practice activities. The 8 states from which the sample was drawn were selected from a stratified randomized procedure using U.S. Census Bureau geographically defined regions. Pre-notification and response reminders were employed. Data were analyzed descriptively and with univariate, inferential tests, as appropriate, to determine associations with commitment, practice environment, experience level, and other variables. Of the 612 participants who responded, 494 were currently working as a technician and not enrolled in a PharmD program of study. Participants reported various activities in which they were highly engaged. Overall, attitudes toward performing most of the activities and self-efficacies were quite favorable, even for those activities in which technicians were currently less involved. There were some notable differences between technicians practicing in community versus hospital settings. Years of experience, profession commitment, and advanced employee ranking were associated with higher levels of self-efficacy, overall. This initial examination of pharmacy technician self-efficacies identified areas that along with other factors could help employers with further expanding technician practice activities and vocational institutions with considerations for education and development of these key members of the workforce. The results would suggest technicians to be ready for continued evolution in their practice. Copyright © 2017 Elsevier Inc. All rights reserved.

78 FR 25308 - Proposed Collection; Comment Request; Coal Mine Dust Sampling Devices

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-30

...; Coal Mine Dust Sampling Devices AGENCY: Mine Safety and Health Administration, Labor. ACTION: 60-Day.... Background Continuous Personal Dust Monitors (CPDMs) determine the concentration of respirable dust in coal mines. CPDMs must be designed and constructed for coal miners to wear and operate without impeding their...

NHEXAS PHASE I ARIZONA STUDY--PESTICIDES IN DUST ANALYTICAL RESULTS

EPA Science Inventory

The Pesticides in Dust data set contains analytical results for measurements of up to 3 pesticides in 437 dust samples over 278 households. Samples were taken by collecting dust from the indoor floor areas in the main room and in the bedroom of the primary resident. The primary...

75 FR 64411 - Lowering Miners' Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-19

...The Mine Safety and Health Administration (MSHA) proposes to lower miners' exposure to respirable coal mine dust by revising the Agency's existing standards on miners' occupational exposure to respirable coal mine dust. The major provisions of the proposal would lower the existing exposure limit; provide for full-shift sampling; redefine the term ``normal production shift; '' and add reexamination and decertification requirements for persons certified to sample, and maintain and calibrate sampling devices. In addition, the proposed rule would provide for single shift compliance sampling under the mine operator and MSHA's inspector sampling programs, and would establish sampling requirements for use of the Continuous Personal Dust Monitor (CPDM) and expanded requirements for medical surveillance. The proposed rule would significantly improve health protections for this Nation's coal miners by reducing their occupational exposure to respirable coal mine dust and lowering the risk that they will suffer material impairment of health or functional capacity over their working lives.

Sensitization to house dust mites in Reykjavik, Iceland, in the absence of domestic exposure to mites.

PubMed

Hallas, T E; Gislason, D; Björnsdottir, U S; Jörundsdottir, K B; Janson, C; Luczynska, C M; Gislason, T

2004-05-01

House dust mites are common sources of indoor allergens. In Reykjavik, Iceland, 9% of the young adult population had serum-specific IgE to Dermatophagoides pteronyssinus. Sensitization to mites is usually assumed to be due to exposure to house dust mites in the indoor environment. This investigation was carried out to measure the concentrations of house dust mite allergens and to investigate which species of mites were present in beds in Iceland. A total of 197 randomly selected adults were visited at home using the European Community Respiratory Health Survey (ECRHS) II Indoor protocol. Dust samples were collected from mattresses for measurement of house dust mite allergen concentrations and to estimate the number and type of house dust mites. Additional samples from mattresses and floors were collected from the homes of 10 patients with positive skin prick tests (SPT) to D. pteronyssinus. House dust mite allergen concentrations were measured using ELISA and examination of mite species was carried out using microscopy. Climatic parameters were assessed using psychrometer readings in the bedrooms and outdoors. We found two single mite specimens, both D. pteronyssinus, in two dust samples. Mite allergen analyses indicated that two other dust samples had Der f 1 results close to the cut-off of 0.1 microg/g of dust. No samples were positive for Der p 1. In an additional collection of dust from the homes of 10 SPT-positive patients no Dermatophagoides spp. were found. Reykjavik citizens are exposed to extremely low amounts of house dust mite allergens in their homes. Possible alternative sources for sensitization are discussed, such as bird nests, exposure from travelling abroad, or other mites or invertebrates that cross-react with house dust mite allergens. Our findings suggest that exposures other than to house dust mites indoors are possible sources of mite allergen exposure.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caravanos, Jack; Weiss, Arlene L.; School of Medicine, New York University, NY 10016

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 trafficmore » 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.« less

Using 87Sr/86Sr Ratios of Carbonate Minerals in Dust to Quantify Contributions from Desert Playas to the Urban Wasatch Front, Utah, USA

NASA Astrophysics Data System (ADS)

Goodman, M.; Carling, G. T.; Fernandez, D. P.; Rey, K.; Hale, C. A.; Nelson, S.; Hahnenberger, M.

2017-12-01

Desert playas are important dust sources globally, with potential harmful health impacts for nearby urban areas. The Wasatch Front (population >2 million) in western Utah, USA, is located directly downwind of several playas that contribute to poor air quality on dust event days. Additionally, the exposed lakebed of nearby Great Salt Lake is a growing dust source as water levels drop in response to drought and river diversions. To investigate contributions of playa dust to the Wasatch Front, we sampled dust emissions from the exposed lakebed of Great Salt Lake and seven playas in western Utah, including Sevier Dry Lake, and dust deposition at four locations stretching 160 km from south to north along the Wasatch Front, including Provo, Salt Lake City, Ogden, and Logan. The samples were analyzed for mineralogy, bulk chemistry, and 87Sr/86Sr ratios for source apportionment. The mineralogy of playa dust and Wasatch Front dust samples was dominated by quartz, feldspar, chlorite and calcite. Bulk geochemical composition was similar for all playa dust sources, with higher anthropogenic metal concentrations in the Wasatch Front. Strontium isotope (87Sr/86Sr) ratios in the carbonate fraction of the dust samples were variable in the playa dust sources, ranging from 0.7105 in Sevier Dry Lake to 0.7150 in Great Salt Lake, providing a powerful tool for apportioning dust. Based on 87Sr/86Sr mixing models, Great Salt Lake contributed 0% of the dust flux at Provo, 20% of the dust flux at Salt Lake City, and 40% of the dust flux at Ogden and Logan during Fall 2015. Contrastingly, Great Salt Lake dust was less important in Spring of 2016, contributing 0% of the dust flux at Provo and <10% of the dust flux to Salt Lake City and Logan. Two major dust events that occurred on 3 November 2015 and 23 April 2016 had similar wind and climate conditions as understood by HYSPLIT backward trajectories, meaning that seasonal variability in dust emissions is due to playa surface conditions rather than meteorologic conditions. Further sampling and analysis are needed to understand and quantify patterns in seasonal changes in dust emissions and deposition. These findings suggest that 87Sr/86Sr ratios of the carbonate fraction in dust may be useful for evaluating dust emissions from carbonate-rich playas around the world.

Important skills for biomedical services: The perspectives of Malaysian employers and employees.

PubMed

Buntat, Yahya; Saud, Muhammad Sukri; Mokhtar, Mahani; Kamin, Yusri; Feh, Lim Set

2016-10-17

Increase in the occurrence of existing diseases, continual emergence of new or exotic diseases and re-emergence of old diseases have placed increasing demands on biomedical services in Malaysia. Biomedical technicians play an important role in operating biomedical instruments. However, there are no clear specifications about characteristics and traits for these semi-professional employees. Employers in a few studies claimed that biomedical graduates are not ready to enter and face challenges in the job market. Therefore, the purpose of this study is to identify technical and generic skills for a biomedical technician from the perspectives of the biomedical technicians and their employers. A quantitative survey design was employed whereby data were obtained through the administration of an instrument developed by the researchers. The sample consisted of 20 hospital managers and 186 biomedical technicians who are currently working in Malaysian government hospitals. The findings show that there are no difference in the perceptions of hospital managers and biomedical technicians regarding technical and non-technical skills. These findings resulted in a checklist which can be used for institutions to produce future biomedical technician graduates in order to meet job demands. However, future research is needed to validate the findings and explore the variables in depth.

Mars Polar Lander undergoes testing in SAEF-2

NASA Technical Reports Server (NTRS)

1998-01-01

In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), KSC technicians lower the Mars Polar Lander onto a workstand. The spacecraft is undergoing testing of science instruments and basic spacecraft subsystems. The solar-powered spacecraft, targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999, is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The Lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere.

Mars Polar Lander undergoes testing in SAEF-2

NASA Technical Reports Server (NTRS)

1998-01-01

In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), KSC technicians look over the Mars Polar Lander. The spacecraft is undergoing testing of science instruments and basic spacecraft subsystems. Targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999, the solar-powered spacecraft is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The Lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere.

Mars Polar Lander undergoes testing in SAEF-2

NASA Technical Reports Server (NTRS)

1998-01-01

In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), a KSC technician takes part in testing science instruments and basic spacecraft subsystems on the Mars Polar Lander. The solar- powered spacecraft, targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999, is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere.

KSC-98pc1599

NASA Image and Video Library

1998-10-23

In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), KSC technicians begin to lift the Mars Polar Lander to move it to a workstand. The spacecraft is undergoing testing of science instruments and basic spacecraft subsystems. The solar-powered spacecraft, targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999, is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere

KSC-98pc1610

NASA Image and Video Library

1998-10-29

KENNEDY SPACE CENTER, FLA. -- In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), a KSC technician looks over the Mars Polar Lander before its encapsulation inside the backshell, a protective cover. The solar-powered spacecraft, targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999, is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere

KSC-98pc1337

NASA Image and Video Library

1998-10-13

KENNEDY SPACE CENTER, FLA. -- In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), technicians test the science instruments and the basic spacecraft subsystems on the Mars Polar Lander. The solar-powered spacecraft is targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999. It is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere

KSC-98pc1372

NASA Image and Video Library

1998-10-22

KENNEDY SPACE CENTER, FLA. -- In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), a technician checks out the Mars Polar Lander on its workstand. The spacecraft is undergoing testing of science instruments and basic spacecraft subsystems. The solar-powered spacecraft, targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999, is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere

KSC-98pc1600

NASA Image and Video Library

1998-10-23

In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), KSC technicians guide the raised Mars Polar Lander to another site. The spacecraft is undergoing testing of science instruments and basic spacecraft subsystems. The solar-powered spacecraft, targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999, is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere

KSC-98pc1601

NASA Image and Video Library

1998-10-23

In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), KSC technicians lower the Mars Polar Lander onto a workstand. The spacecraft is undergoing testing of science instruments and basic spacecraft subsystems. The solar-powered spacecraft, targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999, is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The Lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere

KSC-98pc1338

NASA Image and Video Library

1998-10-13

KENNEDY SPACE CENTE, FLA. -- In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), a technician tests the science instruments and the basic spacecraft subsystems on the Mars Polar Lander. The solar-powered spacecraft is targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999. It is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere

KSC-98pc1611

NASA Image and Video Library

1998-10-29

KENNEDY SPACE CENTER, FLA. -- In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), KSC technicians maneuver the backshell, a protective covering, to be placed over the Mars Polar Lander, sitting on the workstand. The solar-powered spacecraft, targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999, is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere

KSC-98pc1605

NASA Image and Video Library

1998-10-29

KENNEDY SPACE CENTER, FLA. -- In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), KSC technicians look over the Mars Polar Lander. The spacecraft is undergoing testing of science instruments and basic spacecraft subsystems. Targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999, the solar-powered spacecraft is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The Lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere

KSC-98pc1607

NASA Image and Video Library

1998-10-29

KENNEDY SPACE CENTER, FLA. -- In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), a KSC technician takes part in testing science instruments and basic spacecraft subsystems on the Mars Polar Lander. The solar-powered spacecraft, targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999, is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere

Laboratory Validation and Field Assessment of Petroleum Laboratory Technicians' Dermal Exposure to Crude Oil Using a Wipe Sampling Method.

PubMed

Galea, Karen S; Mueller, Will; Arfaj, Ayman M; Llamas, Jose L; Buick, Jennifer; Todd, David; McGonagle, Carolyn

2018-05-21

Crude oil may cause adverse dermal effects therefore dermal exposure is an exposure route of concern. Galea et al. (2014b) reported on a study comparing recovery (wipe) and interception (cotton glove) dermal sampling methods. The authors concluded that both methods were suitable for assessing dermal exposure to oil-based drilling fluids and crude oil but that glove samplers may overestimate the amount of fluid transferred to the skin. We describe a study which aimed to further evaluate the wipe sampling method to assess dermal exposure to crude oil, with this assessment including extended sample storage periods and sampling efficiency tests being undertaken at environmental conditions to mimic those typical of outdoor conditions in Saudi Arabia. The wipe sampling method was then used to assess the laboratory technicians' actual exposure to crude oil during typical petroleum laboratory tasks. Overall, acceptable storage efficiencies up to 54 days were reported with results suggesting storage stability over time. Sampling efficiencies were also reported to be satisfactory at both ambient and elevated temperature and relative humidity environmental conditions for surrogate skin spiked with known masses of crude oil and left up to 4 h prior to wiping, though there was an indication of reduced sampling efficiency over time. Nineteen petroleum laboratory technicians provided a total of 35 pre- and 35 post-activity paired hand wipe samples. Ninety-three percent of the pre-exposure paired hand wipes were less than the analytical limit of detection (LOD), whereas 46% of the post-activity paired hand wipes were less than the LOD. The geometric mean paired post-activity wipe sample measurement was 3.09 µg cm-2 (range 1.76-35.4 µg cm-2). It was considered that dermal exposure most frequently occurred through direct contact with the crude oil (emission) or via deposition. The findings of this study suggest that the wipe sampling method is satisfactory in quantifying laboratory technicians' dermal exposure to crude oil. It is therefore considered that this wipe sampling method may be suitable to quantify dermal exposure to crude oil for other petroleum workers.

75 FR 17511 - Coal Mine Dust Sampling Devices

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-06

... Part III Department of Labor Mine Safety and Health Adminisration 30 CFR Parts 18, 74, and 75 Coal Mine Dust Sampling Devices; High-Voltage Continuous Mining Machine Standard for Underground Coal Mines...-AB61 Coal Mine Dust Sampling Devices AGENCY: Mine Safety and Health Administration, Labor. ACTION...

RELATIONSHIPS OF METALS IN FLOOR DUST AND ON THE HANDS OF TODDLERS

EPA Science Inventory

Toddlers are characterized by their frequent hand-to-mouth activity and exploratory behavior. This puts them at risk for exposure to environmental contaminants. Wipe samples are traditionally used to collect dust samples in homes. The assumption is that dust samples are indicativ...

Extraction of Thermal Performance Values from Samples in the Lunar Dust Adhesion Bell Jar

NASA Technical Reports Server (NTRS)

Gaier, James R.; Siamidis, John; Larkin, Elizabeth M. G.

2008-01-01

A simulation chamber has been developed to test the performance of thermal control surfaces under dusty lunar conditions. The lunar dust adhesion bell jar (LDAB) is a diffusion pumped vacuum chamber (10(exp -8) Torr) built to test material samples less than about 7 cm in diameter. The LDAB has the following lunar dust simulant processing capabilities: heating and cooling while stirring in order to degas and remove adsorbed water; RF air-plasma for activating the dust and for organic contaminant removal; RF H/He-plasma to simulate solar wind; dust sieving system for controlling particle sizes; and a controlled means of introducing the activated dust to the samples under study. The LDAB is also fitted with an in situ Xe arc lamp solar simulator, and a cold box that can reach 30 K. Samples of thermal control surfaces (2.5 cm diameter) are introduced into the chamber for calorimetric evaluation using thermocouple instrumentation. The object of this paper is to present a thermal model of the samples under test conditions and to outline the procedure to extract the absorptance, emittance, and thermal efficiency from the pristine and sub-monolayer dust covered samples.

Extraction of Thermal Performance Values from Samples in the Lunar Dust Adhesion Bell Jar

NASA Technical Reports Server (NTRS)

Gaier, James R.; Siamidis, John; Larkin, Elizabeth M.G.

2008-01-01

A simulation chamber has been developed to test the performance of thermal control surfaces under dusty lunar conditions. The lunar dust adhesion bell jar (LDAB) is a diffusion pumped vacuum chamber (10-8 Torr) built to test material samples less than about 7 cm in diameter. The LDAB has the following lunar dust stimulant processing capabilities: heating and cooling while stirring in order to degas and remove absorbed water; RF air-plasma for activating the dust and for organic contaminant removal; RF H/He-plasma to simulate solar wind; dust sieving system for controlling particle sizes; and a controlled means of introducing the activated dust to the samples under study. The LDAB is also fitted with an in situ Xe arc lamp solar simulator, and a cold box that can reach 30 K. Samples of thermal control surfaces (2.5 cm diameter) are introduced into the chamber for calorimetric evaluation using thermocouple instrumentation. The object of this paper is to present a thermal model of the samples under test conditions, and to outline the procedure to extract the absorptance, emittance, and thermal efficiency from the pristine and sub-monolayer dust covered samples

Extraction of Thermal Performance Values from Samples in the Lunar Dust Adhesion Bell Jar

NASA Technical Reports Server (NTRS)

Gaier, James R.; Siamidis, John; Larkin, Elizabeth M. G.

2010-01-01

A simulation chamber has been developed to test the performance of thermal control surfaces under dusty lunar conditions. The lunar dust adhesion bell jar (LDAB) is a diffusion pumped vacuum chamber (10(exp -8) Torr) built to test material samples less than about 7 cm in diameter. The LDAB has the following lunar dust simulant processing capabilities: heating and cooling while stirring in order to degas and remove adsorbed water; RF air-plasma for activating the dust and for organic contaminant removal; RF H/He-plasma to simulate solar wind; dust sieving system for controlling particle sizes; and a controlled means of introducing the activated dust to the samples under study. The LDAB is also fitted with an in situ Xe arc lamp solar simulator, and a cold box that can reach 30 K. Samples of thermal control surfaces (2.5 cm diameter) are introduced into the chamber for calorimetric evaluation using thermocouple instrumentation. The object of this paper is to present a thermal model of the samples under test conditions and to outline the procedure to extract the absorptance, emittance, and thermal efficiency from the pristine and sub-monolayer dust covered samples.

Community variability of bacteria in alpine snow (Mont Blanc) containing Saharan dust deposition and their snow colonisation potential.

PubMed

Chuvochina, Maria S; Marie, Dominique; Chevaillier, Servanne; Petit, Jean-Robert; Normand, Philippe; Alekhina, Irina A; Bulat, Sergey A

2011-01-01

Microorganisms uplifted during dust storms survive long-range transport in the atmosphere and could colonize high-altitude snow. Bacterial communities in alpine snow on a Mont Blanc glacier, associated with four depositions of Saharan dust during the period 2006-2009, were studied using 16S rRNA gene sequencing and flow cytometry. Also, sand from the Tunisian Sahara, Saharan dust collected in Grenoble and Mont Blanc snow containing no Saharan dust (one sample of each) were analyzed. The bacterial community composition varied significantly in snow containing four dust depositions over a 3-year period. Out of 61 phylotypes recovered from dusty snow, only three phylotypes were detected in more than one sample. Overall, 15 phylotypes were recognized as potential snow colonizers. For snow samples, these phylotypes belonged to Actinobacteria, Proteobacteria and Cyanobacteria, while for Saharan sand/dust samples they belonged to Actinobacteria, Bacteroidetes, Deinococcus-Thermus and Proteobacteria. Thus, regardless of the time-scale, Saharan dust events can bring different microbiota with no common species set to alpine glaciers. This seems to be defined more by event peculiarities and aeolian transport conditions than by the bacterial load from the original dust source.

Degradation of radiator performance on Mars due to dust

NASA Technical Reports Server (NTRS)

Gaier, James R.; Perez-Davis, Marla E.; Rutledge, Sharon K.; Forkapa, Mark

1992-01-01

An artificial mineral of the approximate elemental composition of Martian soil was manufactured, crushed, and sorted into four different size ranges. Dust particles from three of these size ranges were applied to arc-textured Nb-1 percent Zr and Cu radiator surfaces to assess their effect on radiator performance. Particles larger than 75 microns did not have sufficient adhesive forces to adhere to the samples at angles greater than about 27 deg. Pre-deposited dust layers were largely removed by clear wind velocities greater than 40 m/s, or by dust-laden wind velocities as low as 25 m/s. Smaller dust grains were more difficult to remove. Abrasion was found to be significant only in high velocity winds (89 m/s or greater). Dust-laden winds were found to be more abrasive than clear wind. Initially dusted samples abraded less than initially clear samples in dust laden wind. Smaller dust particles of the simulant proved to be more abrasive than large. This probably indicates that the larger particles were in fact agglomerates.

NHEXAS PHASE I ARIZONA STUDY--METALS-XRF IN DUST ANALYTICAL RESULTS

EPA Science Inventory

The Metals-XRF in Dust data set contains X-ray fluorescence (XRF) analytical results for measurements of up to 27 metals in 384 dust samples over 384 households. Samples were taken by collecting dust from the indoor floor areas in the main room and in the bedroom of the primary ...

U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--PESTICIDES IN DUST ANALYTICAL RESULTS

EPA Science Inventory

The Pesticides in Dust data set contains analytical results for measurements of up to 8 pesticides in 91 dust samples over 91 households. Samples were taken by collecting dust from the indoor floor areas in the main room and in the bedroom of the primary resident. The primary p...

U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--PAHS IN DUST ANALYTICAL RESULTS

EPA Science Inventory

The PAHs in Dust data set contains the analytical results for measurements of up to 21 polynuclear aromatic hydrocarbons (PAHs) in 91 dust samples over 91 households. Samples were taken by collecting dust from the indoor floor areas from the main room and in the bedroom of the p...

Using an Instrumented Drone to Sample Dust Devils

NASA Astrophysics Data System (ADS)

Jackson, Brian; Lorenz, Ralph; Davis, Karan; Lipple, Brock

2017-10-01

Dust devils are low-pressure, small (many to tens of meters) convective vortices powered by surface heating and rendered visible by lofted dust. Dust devils occur in arid climates on Earth, where they degrade air quality and pose a hazard to small aircraft. They also occur ubiquitously on Mars, where they may dominate the supply of atmospheric dust. Since dust contributes significantly to Mars’ atmospheric heat budget, dust devils probably play an important role in its climate. The dust-lifting capacity of a devil likely depends sensitively on its structure, particularly the wind and pressure profiles, but the exact dependencies are poorly constrained. Thus, the exact contribution to Mars’ atmosphere remains unresolved. Moreover, most previous studies of martian dust devils have relied on passive sampling of the profiles via meteorology packages on landed spacecraft, resulting in random encounter geometries which non-trivially skew the retrieved profiles. Analog studies of terrestrial devils have employed more active sampling (instrumented vehicles or manned aircraft) but have been limited to near-surface (few meters) or relatively high altitude (hundreds of meters) sampling. Unmanned aerial vehicles (UAVs) or drones, combined with miniature, digital instrumentation, promise a novel and uniquely powerful platform from which to sample dust devils via (relatively) controlled geometries at a wide variety of altitudes. In this presentation, we will describe a pilot study using an instrumented quadcopter on an active field site in southeastern Oregon, which (to our knowledge) has not previously been surveyed for dust devils. We will present preliminary results from the resulting encounters, including stereo image analysis and encounter footage collected onboard the drone.

Biogenic lipids in particulates from the lower atmosphere over the eastern Atlantic

NASA Technical Reports Server (NTRS)

Simoneit, B. R. T.; Chester, R.; Eglinton, G.

1977-01-01

The occurrence, isolation, and characterization of terrigenous lipids in aeolian dusts from the eastern Atlantic are discussed. It is pointed out that such lipids have also been found in aeolian dust from other oceanic areas. A description is presented of the collection and extraction of samples. The dust samples were extracted with two aliquots of toluene and methanol (3:1) for lipid analysis. The extracts were concentrated on a rotary evaporator. General aeolian dust collection data and sample descriptions are presented in a table. The origin of the samples is discussed.

Assessing airborne aflatoxin B1 during on-farm grain handling activities.

PubMed

Selim, M I; Juchems, A M; Popendorf, W

1998-04-01

The presence of aflatoxin in corn and corn dust during relatively normal years and the increased risk of Aspergillus flavus infestation during drought conditions suggest that airborne agricultural exposures should be of considerable concern. Liquid extraction, thin layer chromatography, and high pressure liquid chromatography were used for the analysis of aflatoxin B1 in grain dust and bulk corn samples. A total of 24 samples of airborne dust were collected from 8 farms during harvest, 22 samples from 9 farms during animal feeding, and 14 sets of Andersen samples from 11 farms during bin cleaning. A total of 14 samples of settled dust and 18 samples of bulk corn were also collected and analyzed. The airborne concentration of aflatoxin B1 found in dust collected during harvest and grain unloading ranged from 0.04 to 92 ng/m3. Higher levels of aflatoxin B1 were found in the airborne dust samples collected from enclosed animal feeding buildings (5-421 ng/m3) and during bin cleaning (124-4849 ng/m3). Aflatoxin B1 up to 5100 ng/g were detected in settled dust collected from an enclosed animal feeding building; however, no apparent correlation was found between the airborne concentration of aflatoxin B1 and its concentration in settled dust or bulk corn. The data demonstrate that farmers and farm workers may be exposed to potentially hazardous concentrations of aflatoxin B1, particularly during bin cleaning and animal feeding in enclosed buildings.

Spectroscopic and x-ray diffraction analyses of asbestos in the World Trade Center dust:

USGS Publications Warehouse

Swayze, Gregg A.; Clark, Roger N.; Sutley, Stephen J.; Hoefen, Todd M.; Plumlee, Geoffrey S.; Meeker, Gregory P.; Brownfield, Isabelle; Livo, Keith E.; Morath, Laurie C.

2009-01-01

On September 17 and 18, 2001, samples of settled dust and airfall debris were collected from 34 sites within a 1-km radius of the WTC collapse site, including a sample from an indoor location unaffected by rainfall, and samples of insulation from two steel beams at Ground Zero. Laboratory spectral and x-ray diffraction analyses of the field samples detected trace levels of serpentine minerals, including chrysotile asbestos, in about two-thirds of the dust samples at concentrations at or below ~1 wt%. One sample of a beam coating material contained up to 20 wt% chrysotile asbestos. Analyses indicate that trace levels of chrysotile were distributed with the dust radially to distances greater than 0.75 km from Ground Zero. The chrysotile content of the dust is variable and may indicate that chrysotile asbestos was not distributed uniformly during the three collapse events.

Estimation of respirable dust exposure among coal miners in South Africa.

PubMed

Naidoo, Rajen; Seixas, Noah; Robins, Thomas

2006-06-01

The use of retrospective occupational hygiene data for epidemiologic studies is useful in determining exposure-outcome relationships, but the potential for exposure misclassification is high. Although dust sampling in the South African coal industry has been a legal requirement for several decades, these historical data are not readily adequate for estimating past exposures. This study describes the respirable coal mine dust levels in three South African coal mines over time. Each of the participating mining operations had well-documented dust sampling information that was used to describe historical trends in dust exposure. Investigator-collected personal dust samples were taken using standardized techniques from the face, backbye (underground jobs not at the coal face), and surface from 50 miners at each mine, repeated over three sampling cycles. Job histories and exposure information was obtained from a sample of 684 current miners and 188 ex-miners. Linear models were developed to estimate the exposure levels associated with work in each mine, exposure zone, and over time using a combination of operator-collected historical data and investigator-collected samples. The estimated levels were then combined with work history information to calculate cumulative exposure metrics for the miner cohort. The mean historical and investigator-collected respirable dust levels were within international norms and South African standards. Silica content of the dust samples was also below the 5% regulatory action level. Mean respirable dust concentrations at the face, based on investigator-collected samples, were 0.9 mg/m(3), 1.3 mg/m(3), and 1.9 mg/m(3) at Mines 1, 2, and 3, respectively. The operator-collected samples showed considerable variability across exposure zones, mines, and time, with the annual means at the face ranging from 0.4 mg/m(3) to 2.9 mg/m(3). Statistically significant findings were found between operator- and investigator-collected dust samples. Model-based arithmetic mean dust estimates at the face were 1.2 mg/m(3), 2.0 mg/m(3), and 0.9 mg/m(3) for Mines 1, 2, and 3, respectively. Using these levels, the mean cumulative exposure for the cohort was 56.8 mg-years/m(3). Current miners had a mean cumulative exposure of 66.5 mg-years/m(3), compared with ex-miners of 26.8 mg-years/m(3). Improvements in dust management or the use of different sampling equipment could account for the significant differences seen between operator- and investigator-collected data. Regression modeling for estimating mean dust levels over time using combined historical and investigator-collected data seems a reasonable method and useful in constructing models to describe cumulative exposures in a cohort of current and ex-miners.

U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--METALS/XRF IN DUST ANALYTICAL RESULTS

EPA Science Inventory

The Metals-XRF in Dust data set contains X-ray fluorescence (XRF) analytical results for measurements of up to 27 metals in 91 dust samples over 91 households. Samples were taken by collecting dust from the indoor floor areas in the main room and in the bedroom of the primary re...

Oil refinery dusts: morphological and size analysis by TEM.

PubMed

Sielicki, Przemysław; Janik, Helena; Guzman, Agnieszka; Broniszewski, Mieczysław; Namieśnik, Jacek

2011-03-01

The objectives of this work were to develop a means of sampling atmospheric dusts on the premises of an oil refinery for electron microscopic study to carry out preliminary morphological analyses and to compare these dusts with those collected at sites beyond the refinery limits. Carbon and collodion membranes were used as a support for collection of dust particles straight on transmission electron microscopy (TEM) grids. Micrographs of the dust particles were taken at magnifications from ×4,000 to ×80,000 with a Tesla BS500 transmission electron microscope. Four parameters were defined on the basis of the micrographs: surface area, Feret diameter, circumference, and shape coefficient. The micrographs and literature data were used to classify the atmospheric dusts into six groups: particles with an irregular shape and rounded edges; particles with an irregular shape and sharp edges; soot and its aggregates; spherical particles; singly occurring, ultrafine dust particles; and particles not allocated to any of the previous five groups. The types of dusts found in all the samples were similar, although differences did exist between the various morphological parameters. Dust particles with the largest Feret diameter were present in sample 3 (mean, 0.739 μm)-these were collected near the refinery's effluent treatment plant. The particles with the smallest diameter were found in the sample that had been intended to be a reference sample for the remaining results (mean, 0.326 μm). The dust particles collected in the refinery had larger mean Feret diameters, even 100% larger, than those collected beyond it. Particles with diameters from 0.1 to 0.2 μm made up the most numerous group in all the samples collected in the refinery.

Trace-metal concentrations in African dust: effects of long-distance transport and implications for human health

USGS Publications Warehouse

Garrison, Virginia; Lamothe, Paul; Morman, Suzette; Plumlee, Geoffrey S.; Gilkes, Robert; Prakongkep, Nattaporn

2010-01-01

The Sahara and Sahel lose billions of tons of eroded mineral soils annually to the Americas and Caribbean, Europe and Asia via atmospheric transport. African dust was collected from a dust source region (Mali, West Africa) and from downwind sites in the Caribbean [Trinidad-Tobago (TT) and U.S. Virgin Islands (VI)] and analysed for 32 trace-elements. Elemental composition of African dust samples was similar to that of average upper continental crust (UCC), with some enrichment or depletion of specific trace-elements. Pb enrichment was observed only in dust and dry deposition samples from the source region and was most likely from local use of leaded gasoline. Dust particles transported long-distances (VI and TT) exhibited increased enrichment of Mo and minor depletion of other elements relative to source region samples. This suggests that processes occurring during long-distance transport of dust produce enrichment/depletion of specific elements. Bioaccessibility of trace-metals in samples was tested in simulated human fluids (gastric and lung) and was found to be greater in downwind than source region samples, for some metals (e.g., As). The large surface to volume ratio of the dust particles (<2.5 µm) at downwind sites may be a factor.

An automatic collector to monitor insoluble atmospheric deposition: application for mineral dust deposition

NASA Astrophysics Data System (ADS)

Laurent, B.; Losno, R.; Chevaillier, S.; Vincent, J.; Roullet, P.; Bon Nguyen, E.; Ouboulmane, N.; Triquet, S.; Fornier, M.; Raimbault, P.; Bergametti, G.

2015-07-01

Deposition is one of the key terms of the mineral dust cycle. However, dust deposition remains poorly constrained in transport models simulating the atmospheric dust cycle. This is mainly due to the limited number of relevant deposition measurements. This paper aims to present an automatic collector (CARAGA), specially developed to sample the total (dry and wet) atmospheric deposition of insoluble dust in remote areas. The autonomy of the CARAGA can range from 25 days to almost 1 year depending on the programmed sampling frequency (from 1 day to 2 weeks respectively). This collector is used to sample atmospheric deposition of Saharan dust on the Frioul islands in the Gulf of Lions in the Western Mediterranean. To quantify the mineral dust mass in deposition samples, a weighing and ignition protocol is applied. Almost 2 years of continuous deposition measurements performed on a weekly sampling basis on Frioul Island are presented and discussed with air mass trajectories and satellite observations of dust. Insoluble mineral deposition measured on Frioul Island was 2.45 g m-2 for February to December 2011 and 3.16 g m-2 for January to October 2012. Nine major mineral deposition events, measured during periods with significant MODIS aerosol optical depths, were associated with air masses coming from the southern Mediterranean Basin and North Africa.

Design and preliminary validation of a mobile application-based expert system to facilitate repair of medical equipment in resource-limited health settings.

PubMed

Wong, Alison L; Lacob, Kelly M; Wilson, Madeline G; Zwolski, Stacie M; Acharya, Soumyadipta

2018-01-01

One of the greatest barriers to safe surgery is the availability of functional biomedical equipment. Biomedical technicians play a major role in ensuring that equipment is functional. Following in-field observations and an online survey, a mobile application was developed to aid technicians in troubleshooting biomedical equipment. It was hypothesized that this application could be used to aid technicians in equipment repair, as modeled by repair of a pulse oximeter. To identify specific barriers to equipment repair and maintenance for biomedical technicians, an online survey was conducted to determine current practices and challenges. These findings were used to guide the development of a mobile application system that guides technicians through maintenance and repair tasks. A convenience sample of technicians in Ethiopia tested the application using a broken pulse oximeter task and following this completed usability and content validity surveys. Fifty-three technicians from 13 countries responded to the initial survey. The results of the survey showed that technicians find equipment manuals most useful, but these are not easily accessible. Many do not know how to or are uncomfortable reaching out to human resources. Thirty-three technicians completed the broken pulse oximeter task using the application. All were able to appropriately identify and repair the equipment, and post-task surveys of usability and content validity demonstrated highly positive scores (Agree to Strongly Agree) on both scales. This research demonstrates the need for improved access to resources for technicians and shows that a mobile application can be used to address a gap in the access to knowledge and resources in low- and middle-income countries. Further research will include prospective studies to determine the impact of an application on the availability of functional equipment in a hospital and the effect on the provision and safety of surgical care.

Systematic on-site monitoring of compliance dust samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grayson, R.L.; Gandy, J.R.

1996-12-31

Maintaining compliance with U.S. respirable coal mine dust standards can be difficult on high-productivity longwall panels. Comprehensive and systematic analysis of compliance dust sample data, coupled with access to the U.S. Bureau of Mines (USBM) DUSTPRO, can yield important information for use in maintaining compliance. The objective of this study was to develop and apply a customized software for the collection, storage, modification, and analysis of respirable dust data while providing for flexible export of data and linking with the USBM`s expert advisory system on dust control. An executable, IBM-compatible software was created and customized for use by the personmore » in charge of collecting, submitting, analyzing, and monitoring respirable dust compliance samples. Both descriptive statistics and multiple regression analysis were incorporated. The software allows ASCH files to be exported and directly links with DUSTPRO. After development and validation of the software, longwall compliance data from two different mines was analyzed to evaluate the value of the software. Data included variables on respirable dust concentration, tons produced, the existence of roof/floor rock (dummy variable), and the sampling cycle (dummy variables). Because of confidentiality, specific data will not be presented, only the equations and ANOVA tables. The final regression models explained 83.8% and 61.1% of the variation in the data for the two panels. Important correlations among variables within sampling cycles showed the value of using dummy variables for sampling cycles. The software proved flexible and fast for its intended use. The insights obtained from use improved the systematic monitoring of respirable dust compliance data, especially for pinpointing the most effective dust control methods during specific sampling cycles.« less

Water uptake of clay and desert dust aerosol particles at sub- and supersaturated water vapor conditions.

PubMed

Herich, Hanna; Tritscher, Torsten; Wiacek, Aldona; Gysel, Martin; Weingartner, Ernest; Lohmann, Ulrike; Baltensperger, Urs; Cziczo, Daniel J

2009-09-28

Airborne mineral dust particles serve as cloud condensation nuclei (CCN), thereby influencing the formation and properties of warm clouds. It is therefore of atmospheric interest how dust aerosols with different mineralogy behave when exposed to high relative humidity (RH) or supersaturation (SS) with respect to liquid water. In this study the subsaturated hygroscopic growth and the supersaturated cloud condensation nucleus activity of pure clays and real desert dust aerosols were determined using a hygroscopicity tandem differential mobility analyzer (HTDMA) and a cloud condensation nuclei counter (CCNC), respectively. Five different illite, montmorillonite and kaolinite clay samples as well as three desert dust samples (Saharan dust (SD), Chinese dust (CD) and Arizona test dust (ATD)) were investigated. Aerosols were generated both with a wet and a dry disperser. The water uptake was parameterized via the hygroscopicity parameter kappa. The hygroscopicity of dry generated dust aerosols was found to be negligible when compared to processed atmospheric aerosols, with CCNC derived kappa values between 0.00 and 0.02 (the latter corresponds to a particle consisting of 96.7% by volume insoluble material and approximately 3.3% ammonium sulfate). Pure clay aerosols were generally found to be less hygroscopic than natural desert dust particles. The illite and montmorillonite samples had kappa approximately 0.003. The kaolinite samples were less hygroscopic and had kappa=0.001. SD (kappa=0.023) was found to be the most hygroscopic dry-generated desert dust followed by CD (kappa=0.007) and ATD (kappa=0.003). Wet-generated dust showed an increased water uptake when compared to dry-generated samples. This is considered to be an artifact introduced by redistribution of soluble material between the particles. Thus, the generation method is critically important when presenting such data. These results indicate any atmospheric processing of a fresh mineral dust particle which leads to the addition of more than approximately 3% soluble material will significantly enhance its hygroscopicity and CCN activity.

U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--STANDARD OPERATING PROCEDURE FOR FIELD COLLECTION AND POST-FIELD SAMPLE HANDLING OF INDOOR FLOOR DUST SAMPLES (UA-F-7.1)

EPA Science Inventory

The purpose of this SOP is to establish a uniform procedure for the collection of indoor floor dust samples in the field. This procedure was followed to ensure consistent data retrieval of dust samples during the Arizona NHEXAS project and the Border study. Keywords: field; vacu...

Evaluation of Dust Exposure among the Workers in Agricultural Industries in North-East India.

PubMed

Dewangan, Krishna N; Patil, Mahesh R

2015-11-01

This study aims to quantify dust exposure among the workers in four different industrial settings: rice mills, flour mills, oil mills, and tea factories and to compare the obtained data with the permissible exposure limit (PEL) of Indian Union Ministry of Labour as well as to compare the dust exposure across activities and seasons. RespiCon(TM) particle sampler was used for collecting dust concentration in the breathing zone of the workers. In total, 149 workers participated in the study and 204 samples were collected. Samples were collected in the vicinity of different processing operations. Samples in the rice mills were collected for two consecutive years in two seasons; however samples from other industries were collected for 1 year. The results indicate that geometric mean (GM) of dust exposure was significantly (P < 0.0001) different among industrial settings. Respirable dust were 8.22, 5.76, 2.98, and 6.34mg m(-3) and total dust exposure were 81.05, 111.02, 56.68, and 39.85mg m(-3) in the rice mills, oil mills, flour mills, and tea factories, respectively. Considerable variations in dust exposure were observed in different activities in the rice and oil mills; however variation was relatively less in the flour mills and tea factories. In the rice mills, dust concentration was higher in winter than those obtained in autumn and it is significantly different (P < 0.05) for inhalable dust and total dust. Positive correlation was obtained in thoracic dust (r (2) = 0.94) and inhalable dust (r (2) = 0.97) with total dust and thoracic dust with inhalable dust (r (2) = 0.89). The results show that majority of the workers are exposed to higher level of respirable dust as compared to the PEL, while total dust exposure to all the workers were higher than the PEL; thus, immediate reduction of dust exposure among the workers is necessary for preventing respiratory system impairment. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Size-segregated sugar composition of transported dust aerosols from Middle-East over Delhi during March 2012

NASA Astrophysics Data System (ADS)

Kumar, S.; Aggarwal, S. G.; Fu, P. Q.; Kang, M.; Sarangi, B.; Sinha, D.; Kotnala, R. K.

2017-06-01

During March 20-22, 2012 Delhi experienced a massive dust-storm which originated in Middle-East. Size segregated sampling of these dust aerosols was performed using a nine staged Andersen sampler (5 sets of samples were collected including before dust-storm (BDS)), dust-storm day 1 to 3 (DS1 to DS3) and after dust storm (ADS). Sugars (mono and disaccharides, sugar-alcohols and anhydro-sugars) were determined using GC-MS technique. It was observed that on the onset of dust-storm, total suspended particulate matter (TSPM, sum of all stages) concentration in DS1 sample increased by > 2.5 folds compared to that of BDS samples. Interestingly, fine particulate matter (sum of stages with cutoff size < 2.1 μm) loading in DS1 also increased by > 2.5 folds as compared to that of BDS samples. Sugars analyzed in DS1 coarse mode (sum of stages with cutoff size > 2.1 μm) samples showed a considerable increase ( 1.7-2.8 folds) compared to that of other samples. It was further observed that mono-saccharides, disaccharides and sugar-alcohols concentrations were enhanced in giant (> 9.0 μm) particles in DS1 samples as compared to other samples. On the other hand, anhydro-sugars comprised 13-27% of sugars in coarse mode particles and were mostly found in fine mode constituting 66-85% of sugars in all the sample types. Trehalose showed an enhanced ( 2-4 folds) concentration in DS1 aerosol samples in both coarse (62.80 ng/m3) and fine (8.57 ng/m3) mode. This increase in Trehalose content in both coarse and fine mode suggests their origin to the transported desert dust and supports their candidature as an organic tracer for desert dust entrainments. Further, levoglucosan to mannosan (L/M) ratios which have been used to predict the type of biomass burning influences on aerosols are found to be size dependent in these samples. These ratios are higher for fine mode particles, hence should be used with caution while interpreting the sources using this tool.

ELECTROMECHANICAL TECHNOLOGY. A FIELD STUDY OF ELECTROMECHANICAL TECHNICIAN OCCUPATIONS, PART I. A POST-HIGH SCHOOL TECHNICAL CURRICULUM, PART II. (TITLE SUPPLIED)

ERIC Educational Resources Information Center

RONEY, MAURICE W.

A FIELD STUDY OF THE ELECTOMECHANICAL TECHNICIAN OCCUPATION WAS CONDUCTED IN TWO STAGES. IN THE FIRST PHASE, PERSONAL INTERVIEWS WERE CONDUCTED IN 26 INDUSTRIAL ORGANIZATIONS SELECTED BY SIZE, PRINCIPAL ACTIVITY, AND GEOPGRAPHICAL DISTRIBUTION. IN THE SECOND PHASE, A BRIEF QUESTIONNAIRE WAS USED TO OBTAIN A BROAD SAMPLE OF THE QUANTITATIVE NEED…

Collegiate Aviation Maintenance Training Programs Certified under 14CFR Part 147 that Are Members of the Aviation Technician Education Council

ERIC Educational Resources Information Center

Hunt, Terry Lile

2010-01-01

Scope and method of study: The purpose of this study was to construct a descriptive analysis of aviation maintenance training programs that confer the Bachelor of Science degree and who are members of the Aviation Technician Education Council. The sample was comprised of the 11 educational programs within the population that met these criteria.…

Silica dust exposure: Effect of filter size to compliance determination

NASA Astrophysics Data System (ADS)

Amran, Suhaily; Latif, Mohd Talib; Khan, Md Firoz; Leman, Abdul Mutalib; Goh, Eric; Jaafar, Shoffian Amin

2016-11-01

Monitoring of respirable dust was performed using a set of integrated sampling system consisting of sampling pump attached with filter media and separating device such as cyclone or special cassette. Based on selected method, filter sizes are either 25 mm or 37 mm poly vinyl chloride (PVC) filter. The aim of this study was to compare performance of two types of filter during personal respirable dust sampling for silica dust under field condition. The comparison strategy focused on the final compliance judgment based on both dataset. Eight hour parallel sampling of personal respirable dust exposure was performed among 30 crusher operators at six quarries. Each crusher operator was attached with parallel set of integrated sampling train containing either 25 mm or 37 mm PVC filter. Each set consisted of standard flow SKC sampler, attached with SKC GS3 cyclone and 2 pieces cassette loaded with 5.0 µm of PVC filter. Samples were analyzed by gravimetric technique. Personal respirable dust exposure between the two types of filters indicated significant positive correlation (p < 0.05) with moderate relationship (r2 = 0.6431). Personal exposure based on 25 mm PVC filter indicated 0.1% non-compliance to overall data while 37 mm PVC filter indicated similar findings at 0.4 %. Both data showed similar arithmetic mean(AM) and geometric mean(GM). In overall we concluded that personal respirable dust exposure either based on 25mm or 37mm PVC filter will give similar compliance determination. Both filters are reliable to be used in respirable dust monitoring for silica dust related exposure.

Effect of soil texture and chemical properties on laboratory-generated dust emissions from SW North America

NASA Astrophysics Data System (ADS)

Mockford, T.; Zobeck, T. M.; Lee, J. A.; Gill, T. E.; Dominguez, M. A.; Peinado, P.

2012-12-01

Understanding the controls of mineral dust emissions and their particle size distributions during wind-erosion events is critical as dust particles play a significant impact in shaping the earth's climate. It has been suggested that emission rates and particle size distributions are independent of soil chemistry and soil texture. In this study, 45 samples of wind-erodible surface soils from the Southern High Plains and Chihuahuan Desert regions of Texas, New Mexico, Colorado and Chihuahua were analyzed by the Lubbock Dust Generation, Analysis and Sampling System (LDGASS) and a Beckman-Coulter particle multisizer. The LDGASS created dust emissions in a controlled laboratory setting using a rotating arm which allows particle collisions. The emitted dust was transferred to a chamber where particulate matter concentration was recorded using a DataRam and MiniVol filter and dust particle size distribution was recorded using a GRIMM particle analyzer. Particle size analysis was also determined from samples deposited on the Mini-Vol filters using a Beckman-Coulter particle multisizer. Soil textures of source samples ranged from sands and sandy loams to clays and silts. Initial results suggest that total dust emissions increased with increasing soil clay and silt content and decreased with increasing sand content. Particle size distribution analysis showed a similar relationship; soils with high silt content produced the widest range of dust particle sizes and the smallest dust particles. Sand grains seem to produce the largest dust particles. Chemical control of dust emissions by calcium carbonate content will also be discussed.

Seasonal provenance changes in present-day Saharan dust collected in and off Mauritania

NASA Astrophysics Data System (ADS)

Friese, Carmen A.; van Hateren, Johannes A.; Vogt, Christoph; Fischer, Gerhard; Stuut, Jan-Berend W.

2017-08-01

Saharan dust has a crucial influence on the earth climate system and its emission, transport and deposition are intimately related to, e.g., wind speed, precipitation, temperature and vegetation cover. The alteration in the physical and chemical properties of Saharan dust due to environmental changes is often used to reconstruct the climate of the past. However, to better interpret possible climate changes the dust source regions need to be known. By analysing the mineralogical composition of transported or deposited dust, potential dust source areas can be inferred. Summer dust transport off northwest Africa occurs in the Saharan air layer (SAL). In continental dust source areas, dust is also transported in the SAL; however, the predominant dust input occurs from nearby dust sources with the low-level trade winds. Hence, the source regions and related mineralogical tracers differ with season and sampling location. To test this, dust collected in traps onshore and in oceanic sediment traps off Mauritania during 2013 to 2015 was analysed. Meteorological data, particle-size distributions, back-trajectory and mineralogical analyses were compared to derive the dust provenance and dispersal. For the onshore dust samples, the source regions varied according to the seasonal changes in trade-wind direction. Gibbsite and dolomite indicated a Western Saharan and local source during summer, while chlorite, serpentine and rutile indicated a source in Mauritania and Mali during winter. In contrast, for the samples that were collected offshore, dust sources varied according to the seasonal change in the dust transporting air layer. In summer, dust was transported in the SAL from Mauritania, Mali and Libya as indicated by ferroglaucophane and zeolite. In winter, dust was transported with the trades from Western Sahara as indicated by, e.g., fluellite.

Stardust@home: A Massively Distributed Public Search for Interstellar Dust in the Stardust Interstellar Dust Collector

NASA Technical Reports Server (NTRS)

Westphal, Andrew J.; Butterworth, Anna L.; Snead, Christopher J.; Craig, Nahide; Anderson, David; Jones, Steven M.; Brownlee, Donald E.; Farnsworth, Richard; Zolensky, Michael E.

2005-01-01

In January 2006, the Stardust mission will return the first samples from a solid solar system body beyond the Moon. Stardust was in the news in January 2004, when it encountered comet Wild2 and captured a sample of cometary dust. But Stardust carries an equally important payload: the first samples of contemporary interstellar dust ever collected. Although it is known that interstellar (IS) dust penetrates into the inner solar system [2, 3], to date not even a single contemporary interstellar dust particle has been captured and analyzed in the laboratory. Stardust uses aerogel collectors to capture dust samples. Identification of interstellar dust impacts in the Stardust Interstellar Dust Collector probably cannot be automated, but will require the expertise of the human eye. However, the labor required for visual scanning of the entire collector would exceed the resources of any reasonably-sized research group. We are developing a project to recruit the public in the search for interstellar dust, based in part on the wildly popular SETI@home project, which has five million subscribers. We call the project Stardust@home. Using sophisticated chemical separation techniques, certain types of refractory ancient IS particles (so-called presolar grains) have been isolated from primitive meteorites (e.g., [4] ). Recently, presolar grains have been identified in Interplanetary Dust Particles[6]. Because these grains are not isolated chemically, but are recognized only by their unusual isotopic compositions, they are probably less biased than presolar grains isolated from meteorites. However, it is entirely possible that the typical interstellar dust particle is isotopically solar in composition. The Stardust collection of interstellar dust will be the first truly unbiased one.

[Management of cases of active pulmonary tuberculosis in diagnostic radiology departments in Italy: proposal of a checklist and role of radiology technicians].

PubMed

Giorgini, Giulia; Mesto, Anna; Soardo, Vincenzo

2013-01-01

Tuberculosis (TB) affects more than two billion people worldwide. In hospitals, the presence of suspect cases of infectious TB should be reported as quickly as possible. An anonymous questionnaire was administered to a sample of radiology technicians employed by several local health departments in Italy. The questionnaire contained questions regarding workplace characteristics, knowledge about precautions for preventing disease transmission, degree of collaboration between health professionals and departments regarding communicable diseases. Study results point to the presence of structural and organizational weaknesses as well as inadequate communication between healthcare workers and units. Eighty percent of surveyed technicians stated that patients with suspected TB may arrive in diagnostic radiology wards devoid of surgical mask. The authors suggest the adoption of a checklist to aid healthcare professionals and specifically X-Ray technicians in adopting a behavioral model for the management of patients with infectious TB.

Atmospheric microbiology in the northern Caribbean during African dust events

USGS Publications Warehouse

Griffin, Dale W.; Kellogg, C.A.; Garrison, V.H.; Lisle, J.T.; Borden, T.C.; Shinn, E.A.

2003-01-01

Between July 2000 and August 2001 forty-three air samples were collected in the northern Caribbean: Twenty-six in the US Virgin Islands, and 17 samples aboard ship during two 1-week cruises. Samples were collected during African dust events and non-dust conditions and screened for the presence of culturable bacteria and fungi. A total of 3,652 liters of air were collected during non-dust conditions, with 19 bacteria and 28 fungi being recovered. During dust conditions a total of 2,369 liters of air were screened resulting in the recovery of 171 bacteria and 76 fungi. A statistically significant difference was found between the two data sets. These results support previous African dust research and further demonstrate that dust particles can serve as a vessel for the global dispersion of bacteria and fungi. Dustborne microorganisms may play a significant role in the ecology and health of downwind ecosystems.

30 CFR 70.209 - Respirable dust samples; transmission by operator.

Code of Federal Regulations, 2010 CFR

2010-07-01

... operator shall not open or tamper with the seal of any filter cassette or alter the weight of any filter... accordance with § 70.202 (Certified person; sampling) shall properly complete the dust data card that is.... Respirable dust samples with data cards not properly completed will be voided by MSHA. (d) All respirable...

30 CFR 70.209 - Respirable dust samples; transmission by operator.

Code of Federal Regulations, 2011 CFR

2011-07-01

... operator shall not open or tamper with the seal of any filter cassette or alter the weight of any filter... accordance with § 70.202 (Certified person; sampling) shall properly complete the dust data card that is.... Respirable dust samples with data cards not properly completed will be voided by MSHA. (d) All respirable...

Geochemical evidence for diversity of dust sources in the southwestern United States

USGS Publications Warehouse

Reheis, M.C.; Budahn, J.R.; Lamothe, P.J.

2002-01-01

Several potential dust sources, including generic sources of sparsely vegetated alluvium, playa deposits, and anthropogenic emissions, as well as the area around Owens Lake, California, affect the composition of modern dust in the southwestern United States. A comparison of geochemical analyses of modern and old (a few thousand years) dust with samples of potential local sources suggests that dusts reflect four primary sources: (1) alluvial sediments (represented by Hf, K, Rb, Zr, and rare-earth elements, (2) playas, most of which produce calcareous dust (Sr, associated with Ca), (3) the area of Owens (dry) Lake, a human-induced playa (As, Ba, Li, Pb, Sb, and Sr), and (4) anthropogenic and/or volcanic emissions (As, Cr, Ni, and Sb). A comparison of dust and source samples with previous analyses shows that Owens (dry) Lake and mining wastes from the adjacent Cerro Gordo mining district are the primary sources of As, Ba, Li, and Pb in dusts from Owens Valley. Decreases in dust contents of As, Ba, and Sb with distance from Owens Valley suggest that dust from southern Owens Valley is being transported at least 400 km to the east. Samples of old dust that accumulated before European settlement are distinctly lower in As, Ba, and Sb abundances relative to modern dust, likely due to modern transport of dust from Owens Valley. Thus, southern Owens Valley appears to be an important, geochemically distinct, point source for regional dust in the southwestern United States. Copyright ?? 2002 Elsevier Science Ltd.

Dust: a metric for use in residential and building exposure assessment and source characterization.

PubMed Central

Lioy, Paul J; Freeman, Natalie C G; Millette, James R

2002-01-01

In this review, we examine house dust and residential soil and their use for identifying sources and the quantifying levels of toxicants for the estimation of exposure. We answer critical questions that focus on the selection of samples or sampling strategies for collection and discuss areas of uncertainty and gaps in knowledge. We discuss the evolution of dust sampling with a special emphasis on work conducted after the publication of the 1992 review by McArthur [Appl Occup Environ Hyg 7(9):599-606 (1992)]. The approaches to sampling dust examined include surface wipe sampling, vacuum sampling, and other sampling approaches, including attic sampling. The metrics of presentation of results for toxicants in dust surface loading (micrograms per square centimeter) or surface concentration (micrograms per gram) are discussed. We evaluate these metrics in terms of how the information can be used in source characterization and in exposure characterization. We discuss the types of companion information on source use and household or personal activity patterns required to assess the significance of the dust exposure. The status and needs for wipe samplers, surface samplers, and vacuum samplers are summarized with some discussion on the strengths and weaknesses of each type of sampler. We also discuss needs for research and development and the current status of standardization. Case studies are provided to illustrate the use of house dust and residential soil in source characterization, forensic analyses, or human exposure assessment. PMID:12361921

Dust: a metric for use in residential and building exposure assessment and source characterization.

PubMed

Lioy, Paul J; Freeman, Natalie C G; Millette, James R

2002-10-01

In this review, we examine house dust and residential soil and their use for identifying sources and the quantifying levels of toxicants for the estimation of exposure. We answer critical questions that focus on the selection of samples or sampling strategies for collection and discuss areas of uncertainty and gaps in knowledge. We discuss the evolution of dust sampling with a special emphasis on work conducted after the publication of the 1992 review by McArthur [Appl Occup Environ Hyg 7(9):599-606 (1992)]. The approaches to sampling dust examined include surface wipe sampling, vacuum sampling, and other sampling approaches, including attic sampling. The metrics of presentation of results for toxicants in dust surface loading (micrograms per square centimeter) or surface concentration (micrograms per gram) are discussed. We evaluate these metrics in terms of how the information can be used in source characterization and in exposure characterization. We discuss the types of companion information on source use and household or personal activity patterns required to assess the significance of the dust exposure. The status and needs for wipe samplers, surface samplers, and vacuum samplers are summarized with some discussion on the strengths and weaknesses of each type of sampler. We also discuss needs for research and development and the current status of standardization. Case studies are provided to illustrate the use of house dust and residential soil in source characterization, forensic analyses, or human exposure assessment.

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.

Saharan dust - A carrier of persistent organic pollutants, metals and microbes to the Caribbean?

USGS Publications Warehouse

Garrison, V.H.; Foreman, W.T.; Genualdi, S.; Griffin, Dale W.; Kellogg, C.A.; Majewski, M.S.; Mohammed, A.; Ramsubhag, A.; Shinn, E.A.; Simonich, S.L.; Smith, G.W.

2006-01-01

An international team of scientists from government agencies and universities in the United States, U.S. Virgin Islands (USVI), Trinidad & Tobago, the Republic of Cape Verde, and the Republic of Mali (West Africa) is working together to elucidate the role Saharan dust may play in the degradation of Caribbean ecosystems. The first step has been to identify and quantify the persistent organic pollutants (POPs), trace metals, and viable microorganisms in the atmosphere in dust source areas of West Africa, and in dust episodes at downwind sites in the eastern Atlantic (Cape Verde) and the Caribbean (USVI and Trinidad & Tobago). Preliminary findings show that air samples from Mali contain a greater number of pesticides, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) and in higher concentrations than the Caribbean sites. Overall, POP concentrations were similar in USVI and Trinidad samples. Trace metal concentrations were found to be similar to crustal composition with slight enrichment of lead in Mali. To date, hundreds of cultureable micro-organisms have been identified from Mali, Cape Verde, USVI, and Trinidad air samples. The sea fan pathogen, Aspergillus sydowii, has been identified in soil from Mali and in air samples from dust events in the Caribbean. We have shown that air samples from a dust-source region contain orders of magnitude more cultureable micro-organisms per volume than air samples from dust events in the Caribbean, which in turn contain 3-to 4-fold more cultureable microbes than during non-dust conditions.

Dust emissions of organic soils observed in the field and laboratory

NASA Astrophysics Data System (ADS)

Zobeck, T. M.; Baddock, M. C.; Guo, Z.; Van Pelt, R.; Acosta-Martinez, V.; Tatarko, J.

2011-12-01

According to the U.S. Soil Taxonomy, Histosols (also known as organic soils) are soils that are dominated by organic matter (>20% organic matter) in half or more of the upper 80 cm. These soils, when intensively cropped, are subject to wind erosion resulting in loss in crop productivity and degradation of soil, air, and water quality. Estimating wind erosion on Histosols has been determined by USDA-Natural Resources Conservation Service as a critical need for the Wind Erosion Prediction System (WEPS) model. WEPS has been developed to simulate wind erosion on agricultural land in the US, including soils with organic soil material surfaces. However, additional field measurements are needed to calibrate and validate estimates of wind erosion of organic soils using WEPS. In this study, we used a field portable wind tunnel to generate suspended sediment (dust) from agricultural surfaces for soils with a range of organic contents. The soils were tilled and rolled to provide a consolidated, friable surface. Dust emissions and saltation were measured using an isokinetic vertical slot sampler aspirated by a regulated suction source. Suspended dust was collected on filters of the dust slot sampler and sampled at a frequency of once every six seconds in the suction duct using a GRIMM optical particle size analyzer. In addition, bulk samples of airborne dust were collected using a sampler specifically designed to collect larger dust samples. The larger dust samples were analyzed for physical, chemical, and microbiological properties. In addition, bulk samples of the soils were tested in a laboratory wind tunnel similar to the field wind tunnel and a laboratory dust generator to compare field and laboratory results. For the field wind tunnel study, there were no differences between the highest and lowest organic content soils in terms of their steady state emission rate under an added abrader flux, but the soil with the mid-range of organic matter had less emission by one third. In the laboratory wind tunnel, samples with the same ratio of erodible to non-erodible aggregates as the field soils were abraded and dust emissions were observed with the same sampling system as used in the field wind tunnel. In the dust generator, 5 gm samples < 8 mm diameter of each organic soil were rotated in a 50 cm long tube and the dust generated was observed with the GRIMM during a 20 minute run. Comparisons of the field dust emission rates with the laboratory results will be presented.

A survey of cyclic and linear siloxanes in indoor dust and their implications for human exposures in twelve countries.

PubMed

Tran, Tri Manh; Abualnaja, Khalid O; Asimakopoulos, Alexandros G; Covaci, Adrian; Gevao, Bondi; Johnson-Restrepo, Boris; Kumosani, Taha A; Malarvannan, Govindan; Minh, Tu Binh; Moon, Hyo-Bang; Nakata, Haruhiko; Sinha, Ravindra K; Kannan, Kurunthachalam

2015-05-01

Siloxanes are used widely in a variety of consumer products, including cosmetics, personal care products, medical and electrical devices, cookware, and building materials. Nevertheless, little is known on the occurrence of siloxanes in indoor dust. In this survey, five cyclic (D3-D7) and 11 linear (L4-L14) siloxanes were determined in 310 indoor dust samples collected from 12 countries. Dust samples collected from Greece contained the highest concentrations of total cyclic siloxanes (TCSi), ranging from 118 to 25,100ng/g (median: 1380), and total linear siloxanes (TLSi), ranging from 129 to 4990ng/g (median: 772). The median total siloxane (TSi) concentrations in dust samples from 12 countries were in the following decreasing order: Greece (2970ng/g), Kuwait (2400), South Korea (1810), Japan (1500), the USA (1220), China (1070), Romania (538), Colombia (230), Vietnam (206), Saudi Arabia (132), India (116), and Pakistan (68.3). TLSi concentrations as high as 42,800ng/g (Kuwait) and TCSi concentrations as high as 25,000ng/g (Greece) were found in indoor dust samples. Among the 16 siloxanes determined, decamethylcyclopentasiloxane (D5) was found at the highest concentration in dust samples from all countries, except for Japan and South Korea, with a predominance of L11; Kuwait, with L10; and Pakistan and Romania, with L12. The composition profiles of 16 siloxanes in dust samples varied by country. TCSi accounted for a major proportion of TSi concentrations in dust collected from Colombia (90%), India (80%) and Saudi Arabia (70%), whereas TLSi predominated in samples collected from Japan (89%), Kuwait (85%), and South Korea (78%). Based on the measured median TSi concentrations in indoor dust, we estimated human exposure doses through indoor dust ingestion for various age groups. The exposure doses ranged from 0.27 to 11.9ng/kg-bw/d for toddlers and 0.06 to 2.48ng/kg-bw/d for adults. Copyright © 2015 Elsevier Ltd. All rights reserved.

The concentration, source and deposition flux of ammonium and nitrate in atmospheric particles during dust events at a coastal site in northern China

NASA Astrophysics Data System (ADS)

Qi, Jianhua; Liu, Xiaohuan; Yao, Xiaohong; Zhang, Ruifeng; Chen, Xiaojing; Lin, Xuehui; Gao, Huiwang; Liu, Ruhai

2018-01-01

Asian dust has been reported to carry anthropogenic reactive nitrogen during transport from source areas to the oceans. In this study, we attempted to characterize NH4+ and NO3- in atmospheric particles collected at a coastal site in northern China during spring dust events from 2008 to 2011. Based on the mass concentrations of NH4+ and NO3- in each total suspended particle (TSP) sample, the samples can be classified into increasing or decreasing types. In Category 1, the concentrations of NH4+ and NO3- were 20-440 % higher in dust day samples relative to samples collected immediately before or after a dust event. These concentrations decreased by 10-75 % in the dust day samples in Categories 2 and 3. Back trajectory analysis suggested that multiple factors, such as the transport distance prior to the reception site, the mixing layer depth on the transport route and the residence time across highly polluted regions, might affect the concentrations of NH4+ and NO3-. NH4+ in the dust day samples was likely either in the form of ammonium salts existing separately to dust aerosols or as the residual of incomplete reactions between ammonium salts and carbonate salts. NO3- in the dust day samples was attributed to various formation processes during the long-range transport. The positive matrix factorization (PMF) receptor model results showed that the contribution of soil dust increased from 23 to 36 % on dust days, with decreasing contributions from local anthropogenic inputs and associated secondary aerosols. The estimated deposition flux of NNH4++NO3- varied greatly from event to event; e.g., the dry deposition flux of NNH4++NO3- increased by 9-285 % in Category 1 but decreased by 46-73 % in Category 2. In Category 3, the average dry deposition fluxes of particulate nitrate and ammonium decreased by 46 % and increased by 10 %, respectively, leading to 11-48 % decrease in the fluxes of NNH4++NO3-.

In Situ Sampling of Relative Dust Devil Particle Loads and Their Vertical Grain Size Distributions.

PubMed

Raack, Jan; Reiss, Dennis; Balme, Matthew R; Taj-Eddine, Kamal; Ori, Gian Gabriele

2017-04-19

During a field campaign in the Sahara Desert in southern Morocco, spring 2012, we sampled the vertical grain size distribution of two active dust devils that exhibited different dimensions and intensities. With these in situ samples of grains in the vortices, it was possible to derive detailed vertical grain size distributions and measurements of the lifted relative particle load. Measurements of the two dust devils show that the majority of all lifted particles were only lifted within the first meter (∼46.5% and ∼61% of all particles; ∼76.5 wt % and ∼89 wt % of the relative particle load). Furthermore, ∼69% and ∼82% of all lifted sand grains occurred in the first meter of the dust devils, indicating the occurrence of "sand skirts." Both sampled dust devils were relatively small (∼15 m and ∼4-5 m in diameter) compared to dust devils in surrounding regions; nevertheless, measurements show that ∼58.5% to 73.5% of all lifted particles were small enough to go into suspension (<31 μm, depending on the used grain size classification). This relatively high amount represents only ∼0.05 to 0.15 wt % of the lifted particle load. Larger dust devils probably entrain larger amounts of fine-grained material into the atmosphere, which can have an influence on the climate. Furthermore, our results indicate that the composition of the surface, on which the dust devils evolved, also had an influence on the particle load composition of the dust devil vortices. The internal particle load structure of both sampled dust devils was comparable related to their vertical grain size distribution and relative particle load, although both dust devils differed in their dimensions and intensities. A general trend of decreasing grain sizes with height was also detected. Key Words: Mars-Dust devils-Planetary science-Desert soils-Atmosphere-Grain sizes. Astrobiology 17, xxx-xxx.

TRW RECOMMENDATIONS FOR THE SAMPLING AND ANALYSIS OF INDOOR RESIDENTIAL DUST FOR THE IEUBK MODEL

EPA Science Inventory

The purpose of this guidance document is to recommend methods for collecting and analyzing residential dust lead data specifically for use in the IEUBK model. A discussion of other dust sampling methods is also included.

Characterizing Mineral Dust from the Arabian Coast of the Red Sea

NASA Astrophysics Data System (ADS)

Puthan Purakkal, J.; Stenchikov, G. L.; Engelbrecht, J. P.

2014-12-01

The Arabian Peninsula is one of the Earth's major sources of atmospheric dust. Along with profound negative effects on human activity and natural processes in this region, dust is an important nutrient source for the oligothrophic northern Red Sea. From preliminary observations it is estimated that some 18-20 major dust storms per year deposit about 6 Mt of mineral dust into the Red Sea. To better understand the optical properties, health, and ecological impacts of dust, we study the mineralogical, chemical and morphological properties of surface soil samples collected at prevbiously identified potential dust sources along the Arabian coast of the Red Sea. Many of these dust sources lie within a narrow coastal region and because of their proximity to the Red Sea, are important contributors to the dust/nutrient balance, during both dusty and fair weather conditions. Bulk samples were collected from the top 10 mm of soils from three sites along the Arabian coast of the Red Sea. The soil samples were sieved to separate the < 38μm particle fractions for chemical and mineralogical analysis. X-ray diffractometry (XRD) was applied to measure the mineral content of the dust. The chemical composition of individual particles was analyzed using scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). From the XRD analysis of the sieved samples from An Masayat (23.3322 N, 38.9481 E), Buthna (23.2960 N, 38.9384 E) and Rabugh pipeline Road (23.292 N, 38.91 E), it was found that the dust was composed largely of hematite, goethite, calcite, dolomite, quartz, chlorite, muscovite, amphibole, epidote and plagioclase. Our results are being compared to, and show similarities to those of Engelbrecht et al. , collected at 15 Middle East sites. Both the mineralogical content and chemical composition of samples bear the signatures of the regional geology. Engelbrecht, J. P., McDonald, E. V., Gillies, J. A., Jayanty, R. K. M., Casuccio, G., and Gertler, A. W., 2009, Characterizing mineral dusts and other aerosols from the Middle East - Part 2: Grab samples and re-suspensions: Inhalation Toxicology, v. 21, p. 327-336.

Morphology, Spatial Distribution, and Concentration of Flame Retardants in Consumer Products and Environmental Dusts using Scanning Electron Microscopy and Raman Micro-spectroscopy

PubMed Central

WAGNER, JEFF; GHOSAL, SUTAPA; WHITEHEAD, TODD; METAYER, CATHERINE

2013-01-01

We characterized flame retardant (FR) morphologies and spatial distributions in 7 consumer products and 7 environmental dusts to determine their implications for transfer mechanisms, human exposure, and the reproducibility of gas chromatography-mass spectrometry (GC-MS) dust measurements. We characterized individual particles using scanning electron microscopy / energy dispersive x-ray spectroscopy (SEM/EDS) and Raman micro-spectroscopy (RMS). Samples were screened for the presence of 3 FR constituents (bromine, phosphorous, non-salt chlorine) and 2 metal synergists (antimony and bismuth). Subsequent analyses of select samples by RMS enabled molecular identification of the FR compounds and matrix materials. The consumer products and dust samples possessed FR elemental weight percents of up to 36% and 31%, respectively. We identified 24 FR-containing particles in the dust samples and classified them into 9 types based on morphology and composition. We observed a broad range of morphologies for these FR-containing particles, suggesting FR transfer to dust via multiple mechanisms. We developed an equation to describe the heterogeneity of FR-containing particles in environmental dust samples. The number of individual FR-containing particles expected in a 1-mg dust sample with a FR concentration of 100 ppm ranged from <1 to >1000 particles. The presence of rare, high-concentration bromine particles was correlated with decabromodiphenyl ether concentrations obtained via GC-MS. When FRs are distributed heterogeneously in highly concentrated dust particles, human exposure to FRs may be characterized by high transient exposures interspersed by periods of low exposure, and GC-MS FR concentrations may exhibit large variability in replicate subsamples. Current limitations of this SEM/EDS technique include potential false negatives for volatile and chlorinated FRs and greater quantitation uncertainty for brominated FR in aluminum-rich matrices. PMID:23739093

Toxicity of Lunar Dust in Lungs Assessed by Examining Biomarkers in Exposed Mice

NASA Technical Reports Server (NTRS)

Lam, C.-W.; James, J. T.; Zeidler-Erdely, P. C.; Castranova, V.; Young, S. H.; Quan, C. L.; Khan-Mayberry, N.; Taylor, L. A.

2009-01-01

NASA plans to build an outpost on the Moon for prolonged human habitation and research. The lunar surface is covered by a layer of soil, of which the finest portion is highly reactive dust. NASA has invited NIOSH to collaboratively investigate the toxicity of lunar dust. Dust samples of respirable sizes were aerodynamically isolated from two lunar soil samples of different maturities (cosmic exposure ages) collected during the Apollo 16 mission. The lunar dust samples, titanium dioxide, or quartz, suspended in normal saline or in Survanta (a bovine lung surfactant), were given to groups of 5 mice (C-57 male) by intrapharyngeal aspiration at 1, 0.3, or 0.1 mg/mouse. The mice were euthanized 7 or 30 days later, and their lungs were lavaged to assess the toxicity biomarkers in bronchioalveolar lavage fluids. The acellular fractions were assayed for total proteins, lactate dehydrogenase activities, and cytokines; the cellular portions were assessed for total cell counts and cell differentials. Results from the high-dose groups showed that lunar dust, suspended in saline, was more toxic than TiO 2, but less toxic than quartz. Lunar dust particles aggregate and settle out rapidly in water or saline, but not in Survanta. Lunar dust suspended in Survanta manifested greater toxicity than lunar dust in saline. The increase in toxicity presumably was due to that Survanta gave a better particle dispersion in the lungs. The two lunar dust samples showed similar toxicity. The overall results showed that lunar dust is more toxic than TiO 2 but less toxic than quartz.

Seasonal and occupational trends of five organophosphate pesticides in house dust.

PubMed

Smith, Marissa N; Workman, Tomomi; McDonald, Katie M; Vredevoogd, Melinda A; Vigoren, Eric M; Griffith, William C; Thompson, Beti; Coronado, Gloria D; Barr, Dana; Faustman, Elaine M

2017-07-01

Since 1998, the University of Washington's Center for Child Environmental Health Risks Research has followed a community-based participatory research strategy in the Lower Yakima Valley of Washington State to assess pesticide exposure among families of Hispanic farmworkers. As a part of this longitudinal study, house dust samples were collected from both farmworker and non-farmworker households, across three agricultural seasons (thinning, harvest and non-spray). The household dust samples were analyzed for five organophosphate pesticides: azinphos-methyl, phosmet, malathion, diazinon, and chlorpyrifos. Organophosphate pesticide levels in house dust were generally reflective of annual use rates and varied by occupational status and agricultural season. Overall, organophosphate pesticide concentrations were higher in the thinning and harvest seasons than in the non-spray season. Azinphos-methyl was found in the highest concentrations across all seasons and occupations. Farmworker house dust had between 5- and 9-fold higher concentrations of azinphos-methyl than non-farmworker house dust. Phosmet was found in 5-7-fold higher concentrations in farmworker house dust relative to non-farmworker house dust. Malathion and chlorpyriphos concentrations in farmworker house dust ranged between 1.8- and 9.8-fold higher than non-farmworker house dust. Diazinon showed a defined seasonal pattern that peaked in the harvest season and did not significantly differ between farmworker and non-farmworker house dust. The observed occupational differences in four out of five of the pesticide residues measured provides evidence supporting an occupational take home pathway, in which workers may bring pesticides home on their skin or clothing. Further, these results demonstrate the ability of dust samples to inform the episodic nature of organophosphate pesticide exposures and the need to collect multiple samples for complete characterization of exposure potential.

CTEPP STANDARD OPERATING PROCEDURE FOR COLLECTION OF FLOOR DUST SAMPLES FOR PERSISTENT ORGANIC POLLUTANTS (SOP-2.19)

EPA Science Inventory

This SOP describes the method for collecting a floor dust sample from carpet. Dust samples will be collected in the room that the child uses most at home and/or at day care using a High Volume Small Surface Sampler (HVS3). In addition, participants will also be asked to donate a ...

Filter forensics: microbiota recovery from residential HVAC filters.

PubMed

Maestre, Juan P; Jennings, Wiley; Wylie, Dennis; Horner, Sharon D; Siegel, Jeffrey; Kinney, Kerry A

2018-01-30

Establishing reliable methods for assessing the microbiome within the built environment is critical for understanding the impact of biological exposures on human health. High-throughput DNA sequencing of dust samples provides valuable insights into the microbiome present in human-occupied spaces. However, the effect that different sampling methods have on the microbial community recovered from dust samples is not well understood across sample types. Heating, ventilation, and air conditioning (HVAC) filters hold promise as long-term, spatially integrated, high volume samplers to characterize the airborne microbiome in homes and other climate-controlled spaces. In this study, the effect that dust recovery method (i.e., cut and elution, swabbing, or vacuuming) has on the microbial community structure, membership, and repeatability inferred by Illumina sequencing was evaluated. The results indicate that vacuum samples captured higher quantities of total, bacterial, and fungal DNA than swab or cut samples. Repeated swab and vacuum samples collected from the same filter were less variable than cut samples with respect to both quantitative DNA recovery and bacterial community structure. Vacuum samples captured substantially greater bacterial diversity than the other methods, whereas fungal diversity was similar across all three methods. Vacuum and swab samples of HVAC filter dust were repeatable and generally superior to cut samples. Nevertheless, the contribution of environmental and human sources to the bacterial and fungal communities recovered via each sampling method was generally consistent across the methods investigated. Dust recovery methodologies have been shown to affect the recovery, repeatability, structure, and membership of microbial communities recovered from dust samples in the built environment. The results of this study are directly applicable to indoor microbiota studies utilizing the filter forensics approach. More broadly, this study provides a better understanding of the microbial community variability attributable to sampling methodology and helps inform interpretation of data collected from other types of dust samples collected from indoor environments.

The relationship between gorgonian coral (Cnidaria: Gorgonacea) diseases and African dust storms

USGS Publications Warehouse

Weir-Brush, J. R.; Garrison, V.H.; Smith, G.W.; Shinn, E.A.

2004-01-01

The number of reports of coral diseases has increased throughout the world in the last 20 years. Aspergillosis, which primarily affects Gorgonia ventalina and G. flabellum, is one of the few diseases to be characterized. This disease is caused by Aspergillus sydowii, a terrestrial fungus with a worldwide distribution. Upon infection, colonies may lose tissue, and ultimately, mortality may occur if the infection is not sequestered. The spores of A. sydowii are <5 ??m, small enough to be easily picked up by winds and dispersed over great distances. Aspergillosis is prevalent in the Caribbean, and it appears that this primarily terrestrial fungus has adapted to a marine environment. It has been proposed that dust storms originating in Africa may be one way in which potential coral pathogens are distributed and deposited into the marine environments of the Caribbean. To test the hypothesis that African dust storms transport and deposit pathogens, we collected air samples from both dust storms and periods of nondust in St. John, U.S. Virgin Islands. Because we focused on fungal pathogens and used A. sydowii as a model, we isolated and cultured fungi on various types of media. Fungi including Aspergillus spp. were isolated from air samples taken from dust events and non-dust events. Twenty-three separate cultures and seven genera were isolated from dust event samples whereas eight cultures from five genera were isolated from non-dust air samples. Three isolates from the Virgin Islands dust event samples morphologically identified as Aspergillus spp. produced signs of aspergillosis in seafans, and the original pathogens were re-isolated from those diseased seafans fulfilling Koch's Postulates. This research supports the hypothesis that African dust storms transport across the Atlantic Ocean and deposit potential coral pathogens in the Caribbean.

An in-depth examination into pharmacy technician worklife through an organizational behavior framework.

PubMed

Desselle, Shane P

2016-01-01

Pharmacy technicians are a vital part of the health care workforce. Little is known about perceptions of their own work environment that would engender more effective recruitment, retention, and management strategies by pharmacists and employers. The purpose of this study was to gain a greater understanding of certified pharmacy technician worklife. Specific objectives included the identification of themes of worklife phenomena to assist with the development of appropriate responses by other pharmacy stakeholders and to ascertain the contribution of various factors engendering or discouraging career commitment of pharmacy technicians. Semi-structured in-depth interviews were carried out with a convenience sample of pharmacy technicians in one U.S. state, who varied by their work settings and level of experience. The interview guide and corresponding participant responses were framed from around an organizational cultural basis rooted in organizational behavior theory. Notes from the interviews were analyzed thematically using directed content analysis. Four primary themes emerged, including: career impetus, job responsibilities, quality of work life, and equitable partnership. The data revealed pharmacy technicians' need for self-actualization and recognition of the value they bring to the organization. The participants identified primary responsibilities that contribute to their sense of worth and those that if not managed adequately potentially detract from their well-being and effectiveness. Findings in regard to rate of pay corroborate previous work on wages as both an intrinsic and extrinsic motivator. Pharmacy technicians seek equity among each other (their peers) and in a mutually beneficial relationship with their employing organization. This study provides the impetus for interventions and further study that should serve to enhance pharmacy technician effectiveness, quality of work life, and longevity in an emerging profession. Copyright © 2015 Elsevier Inc. All rights reserved.

Immersion freezing of internally and externally mixed mineral dust species analyzed by stochastic and deterministic models

NASA Astrophysics Data System (ADS)

Wong, B.; Kilthau, W.; Knopf, D. A.

2017-12-01

Immersion freezing is recognized as the most important ice crystal formation process in mixed-phase cloud environments. It is well established that mineral dust species can act as efficient ice nucleating particles. Previous research has focused on determination of the ice nucleation propensity of individual mineral dust species. In this study, the focus is placed on how different mineral dust species such as illite, kaolinite and feldspar, initiate freezing of water droplets when present in internal and external mixtures. The frozen fraction data for single and multicomponent mineral dust droplet mixtures are recorded under identical cooling rates. Additionally, the time dependence of freezing is explored. Externally and internally mixed mineral dust droplet samples are exposed to constant temperatures (isothermal freezing experiments) and frozen fraction data is recorded based on time intervals. Analyses of single and multicomponent mineral dust droplet samples include different stochastic and deterministic models such as the derivation of the heterogeneous ice nucleation rate coefficient (J­­het), the single contact angle (α) description, the α-PDF model, active sites representation, and the deterministic model. Parameter sets derived from freezing data of single component mineral dust samples are evaluated for prediction of cooling rate dependent and isothermal freezing of multicomponent externally or internally mixed mineral dust samples. The atmospheric implications of our findings are discussed.

Method development for analysis of urban dust using scanning electron microscopy with energy dispersive x-ray spectrometry to detect the possible presence of world trade center dust constituents

USGS Publications Warehouse

Bern, A.M.; Lowers, H.A.; Meeker, G.P.; Rosati, J.A.

2009-01-01

The collapse of the World Trade Center Towers on September 11, 2001, sent dust and debris across much of Manhattan and in the surrounding areas. Indoor and outdoor dust samples were collected and characterized by U.S. Geological Survey (USGS) scientists using scanning electron microscopy with energy-dispersive spectrometry (SEM/EDS). From this characterization, the U.S. Environmental Protection Agency and USGS developed a particulate screening method to determine the presence of residual World Trade Center dust in the indoor environment using slag wool as a primary "signature". The method describes a procedure that includes splitting, ashing, and sieving of collected dust. From one split, a 10 mg/mL dust/ isopropanol suspension was prepared and 10-30 ??L aliquots of the suspension placed on an SEM substrate. Analyses were performed using SEM/EDS manual point counting for slag wool fibers. Poisson regression was used to identify some of the sources of uncertainty, which are directly related to the small number of fibers present on each sample stub. Preliminary results indicate that the procedure is promising for screening urban background dust for the presence of WTC dust. Consistent sample preparation of reference materials and samples must be performed by each laboratory wishing to use this method to obtain meaningful and accurate results. ?? 2009 American Chemical Society.

A DUST-SETTLING CHAMBER FOR SAMPLING-INSTRUMENT COMPARISON STUDIES

EPA Science Inventory

Introduction: Few methods exist that can evenly and reproducibly deposit dusts onto surfaces for surface-sampling methodological studies. A dust-deposition chamber was designed for that purpose.

Methods: A 1-m3 Rochester-type chamber was modified to produce high airborne d...

Mars Polar Lander undergoes testing in SAEF-2

NASA Technical Reports Server (NTRS)

1998-01-01

In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), KSC technicians check underneath the Mars Polar Lander as it sits on a workstand. The spacecraft is undergoing testing of science instruments and basic spacecraft subsystems. The solar-powered spacecraft, targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999, is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere.

KSC-98pc1606

NASA Image and Video Library

1998-10-29

KENNEDY SPACE CENTER, FLA. -- In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), KSC technicians check underneath the Mars Polar Lander as it sits on a workstand. The spacecraft is undergoing testing of science instruments and basic spacecraft subsystems. The solar-powered spacecraft, targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999, is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere

KSC-98pc1235

NASA Image and Video Library

1998-10-03

KENNEDY SPACE CENTER, FLA. -- In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), a technician begins testing on the Mars Polar Lander. The checkout includes a functional test of the science instruments and the basic spacecraft subsystems. The Mars Polar Lander is targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999. The solar-powered spacecraft is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere

Identification of dust storm origin in South -West of Iran.

PubMed

Broomandi, Parya; Dabir, Bahram; Bonakdarpour, Babak; Rashidi, Yousef

2017-01-01

Deserts are the main sources of emitted dust, and are highly responsive to wind erosion. Low content of soil moisture and lack of vegetation cover lead to fine particle's release. One of the semi-arid bare lands in Iran, located in the South-West of Iran in Khoozestan province, was selected to investigate Sand and Dust storm potential. This paper focused on the metrological parameters of the sampling site, their changes and the relationship between these changes and dust storm occurrence, estimation of Reconaissance Drought Index, the Atterberg limits of soil samples and their relation with soil erosion ability, the chemical composition, size distribution of soil and airborne dust samples, and estimation of vertical mass flux by COMSALT through considering the effect of saffman force and interparticle cohesion forces during warm period (April-September) in 2010. The chemical compositions are measured with X-ray fluorescence, Atomic absorption spectrophotometer and X-ray diffraction. The particle size distribution analysis was conducted by using Laser particle size and sieve techniques. There was a strong negative correlation between dust storm occurrence and annual and seasonal rainfall and relative humidity. Positive strong correlation between annual and seasonal maximum temperature and dust storm frequency was seen. Estimation of RDI st in the studied period showed an extremely dry condition. Using the results of particle size distribution and soil consistency, the weak structure of soil was represented. X-ray diffraction analyses of soil and dust samples showed that soil mineralogy was dominated mainly by Quartz and calcite. X-ray fluorescence analyses of samples indicated that the most important major oxide compositions of the soil and airborne dust samples were SiO 2 , Al 2 O 3 , CaO, MgO, Na 2 O, and Fe 2 O 3 , demonstrating similar percentages for soil and dust samples. Estimation of Enrichment Factors for all studied trace elements in soil samples showed Br, Cl, Mo, S, Zn, and Hg with EF values higher than 10. The findings, showed the possible correlation between the degree of anthropogenic soil pollutants, and the remains of Iraq-Iran war. The results expressed sand and dust storm emission potential in this area, was illustrated with measured vertical mass fluxes by COMSALT.

[Comparative studies of personal and steady-state sampling for determining dust exposure in different job groups].

PubMed

Cherneva, P; Lukanova, R

1994-01-01

The variability of the dust concentration in time and space, as well as the change of worker's place during the working process, define the necessity of introducing personal sampling in the hygiene control practice. However, the laboratory equipment with personal devices is still not sufficient. The aim of this work is to assess the dust exposure of the basic professional groups from the ore- and coal production in Bulgaria by personal sampling in comparative studies of the static ambient sampling used up to now. 63 full-shift investigations of the dust factor were performed on professional groups of miners of the polymetal and coal pits by static ambient devices-[Hygitest production] and personal [from firms "Casella", "Strolein" and "Gilian"] devices, after standardized methods. The results are data processed-by means of logarithmic normal distribution of the relation of the respirable dust concentrations, determined personally and by static ambient sampling. The limits of variation of this correlation are from 0.5 to 4.1 at average geometric value -0.95 and standard geometric deviation-1.8 i.e. both types of sampling are intersubstitutional for the examined groups and sites, as in the underground ores the professional risk of respirable dust is underestimated up to 4 times at static ambient sampling.

Stardust Sample Collection at Wild 2 and Its Preliminary Examination

NASA Technical Reports Server (NTRS)

Tsou, P.; Brownlee, D. E.; Hoerz, F.; Newburn, R. L.; Sandford, S. A.; Sekanina, Z.; Zolensky, M. E.

2004-01-01

The primary objective of STARDUST is to collect coma samples from 81P/Wild 2. This was made on January 2, 2004. Before the encounter three significant model predictions existed for the number and size of samples to be captured. Three investigations during the Wild 2 encounter (Dust Flux Monitor, Comet and Interstellar Dust Analyzer and Dynamic Science) made in situ measurements of the dust. Spectacular images were captured of the Wild 2 nucleus and dust jets. This abstract compares the model predictions with the in situ measurements and Wild 2 images and assesses the likely samples to be returned for analysis on January 15, 2006. To give some lead time for sample analysts to prepare for the analyses of the returned samples, the organization of the Preliminary Examination is presented.

Respiratory assessment of refractory ceramic fibers in a heating technician population.

PubMed

Lucas, David; Clamagirand, Vincent; Capellmann, Pascale; Hervé, Agnès; Mauguen, Gilles; Le Mer, Yannik; Jegaden, Dominique

2018-04-01

Refractory ceramic fibers (RCF) have been extensively used for insulation in condensing boilers. The aim of this study was to evaluate the respiratory exposure to these fibers among maintenance heating technicians. We first created a working group (Carsat Brittany and Finistère Occupational Health Services) and carried out a sampling strategy. Atmospheric measurements were done during work tasks, and filters were analyzed by phase contrast microscopy (PCM) and scanning electron microscopy (SEM) in French approved laboratories. Four companies were included for a total of 15 days of work. During those 15 workdays, 12 SEM and 21 PCM samples were taken and analyzed. The phase contrast microscopy and SEM average results were 0.04 and 0.004 fibers/cm 3 , respectively. In conclusion, the study confirms heating technician RCF respiratory exposure during maintenance work for both condensation gas boilers and atmospheric boilers. Collective and individual prevention measures should be implemented along with appropriate medical follow-up.

Comparison of comet 81P/Wild 2 dust with interplanetary dust from comets.

PubMed

Ishii, Hope A; Bradley, John P; Dai, Zu Rong; Chi, Miaofang; Kearsley, Anton T; Burchell, Mark J; Browning, Nigel D; Molster, Frank

2008-01-25

The Stardust mission returned the first sample of a known outer solar system body, comet 81P/Wild 2, to Earth. The sample was expected to resemble chondritic porous interplanetary dust particles because many, and possibly all, such particles are derived from comets. Here, we report that the most abundant and most recognizable silicate materials in chondritic porous interplanetary dust particles appear to be absent from the returned sample, indicating that indigenous outer nebula material is probably rare in 81P/Wild 2. Instead, the sample resembles chondritic meteorites from the asteroid belt, composed mostly of inner solar nebula materials. This surprising finding emphasizes the petrogenetic continuum between comets and asteroids and elevates the astrophysical importance of stratospheric chondritic porous interplanetary dust particles as a precious source of the most cosmically primitive astromaterials.

Reconciling PM10 analyses by different sampling methods for Iron King Mine tailings dust.

PubMed

Li, Xu; Félix, Omar I; Gonzales, Patricia; Sáez, Avelino Eduardo; Ela, Wendell P

2016-03-01

The overall project objective at the Iron King Mine Superfund site is to determine the level and potential risk associated with heavy metal exposure of the proximate population emanating from the site's tailings pile. To provide sufficient size-fractioned dust for multi-discipline research studies, a dust generator was built and is now being used to generate size-fractioned dust samples for toxicity investigations using in vitro cell culture and animal exposure experiments as well as studies on geochemical characterization and bioassay solubilization with simulated lung and gastric fluid extractants. The objective of this study is to provide a robust method for source identification by comparing the tailing sample produced by dust generator and that collected by MOUDI sampler. As and Pb concentrations of the PM10 fraction in the MOUDI sample were much lower than in tailing samples produced by the dust generator, indicating a dilution of Iron King tailing dust by dust from other sources. For source apportionment purposes, single element concentration method was used based on the assumption that the PM10 fraction comes from a background source plus the Iron King tailing source. The method's conclusion that nearly all arsenic and lead in the PM10 dust fraction originated from the tailings substantiates our previous Pb and Sr isotope study conclusion. As and Pb showed a similar mass fraction from Iron King for all sites suggesting that As and Pb have the same major emission source. Further validation of this simple source apportionment method is needed based on other elements and sites.

Where's the dust? Characterizing locations of azinphos-methyl residues in house and vehicle dust among farmworkers with young children.

PubMed

Coronado, Gloria D; Griffith, William C; Vigoren, Eric M; Faustman, Elaine M; Thompson, Beti

2010-12-01

Organophosphate pesticides are commonly used in the United States, and farmworkers are at risk for chronic exposure. Using data from a community randomized trial to interrupt the take-home pathway of pesticide exposure, we examined the association between floor surface type (smooth floor, thin carpet, and thick carpet) and rooms in which dust samples were collected (living room vs. non-living room) and concentrations of azinphos-methyl residues in home environments. We also examined the association between vehicle type (truck, auto, or other) and footwell floor surfaces (carpeted, smooth surface, or no mat) and concentrations of azinphos-methyl in vehicle dust samples. Dust samples were collected from 203 and 179 households and vehicles, respectively. All households had at least one child aged 2-6. Vehicle dust samples were collected from footwells of the vehicle used for commuting to and from work. A total of 183 samples were collected from living rooms, and 20 were collected from other rooms in the home. Forty-two samples were collected from thick carpets, 130 from thin carpets, and 27 from smooth floor surfaces. Thick and thin carpets had a significantly greater dust mass than smooth floor surfaces (6.0 g/m(2) for thick carpets, 7.8 g/m(2) for thin carpets, and 1.5 g/m(2) for smooth surfaces). Of the 179 vehicle samples, 113 were from cars, 34 from trucks, and 32 from other vehicles. Vehicles with no mats had a significantly higher mass of dust (21.3 g) than those with hard mats (9.3 g) but did not differ from vehicles with plush mats (12.0 g). Further research is needed to characterize the environment in which children may be exposed to pesticides.

Where’s the Dust? Characterizing Locations of Azinphos-Methyl Residues in House and Vehicle Dust Among Farmworkers with Young Children

PubMed Central

Coronado, Gloria D.; Griffith, William C.; Vigoren, Eric M.; Faustman, Elaine M.; Thompson, Beti

2010-01-01

Organophosphate pesticides (OPs) are commonly used in the United States, and farm workers are at risk for chronic exposure. Using data from a community randomized trial to interrupt the take-home pathway of pesticide exposure, we examined the association between floor surface type (smooth floor, thin carpet, and thick carpet) and rooms in which dust samples were collected (living room vs. non-living room) and concentrations of azinphos-methyl residues in home environments. We also examined the association between vehicle type (truck, auto, or other) and footwell floor surfaces (carpeted, smooth surface, or no mat) and concentrations of azinphos-methyl in vehicle dust samples. Dust samples were collected from 203 and 179 households and vehicles, respectively. All households had at least one child aged 2–6. Vehicle dust samples were collected from footwells of the vehicle used for commuting to and from work. A total of 183 samples were collected from living rooms, and 20 were collected from other rooms in the home. Forty-two samples were collected from thick carpets, 130 from thin carpets, and 27 from smooth floor surfaces. Thick and thin carpets had a significantly greater dust mass than smooth floor surfaces (6.0 g/m2 for thick carpets, 7.8 g/m2 for thin carpets, and 1.5 g/m2 for smooth surfaces). Of the 179 vehicle samples, 113 were from cars, 34 from trucks, and 32 from other vehicles. Vehicles with no mats had a significantly higher mass of dust (21.3 g) than those with hard mats (9.3 g) but did not differ from vehicles with plush mats (12.0g). Further research is needed to characterize the environment in which children may be exposed to pesticides. PMID:20945243

Characterization of aerosolized bacteria and fungi from desert dust events in Mali, West Africa

USGS Publications Warehouse

Kellogg, C.A.; Griffin, Dale W.; Garrison, V.H.; Peak, K.K.; Royall, N.; Smith, R.R.; Shinn, E.A.

2004-01-01

Millions of metric tons of African desert dust blow across the Atlantic Ocean each year, blanketing the Caribbean and southeastern United States. Previous work in the Caribbean has shown that atmospheric samples collected during dust events contain living microbes, including plant and opportunistic human pathogens. To better understand the potential downwind public health and ecosystem effects of the dust microbes, it is important to characterize the source population. We describe 19 genera of bacteria and 3 genera of fungi isolated from air samples collected in Mali, a known source region for dust storms, and over which large dust storms travel.

Mite and pet allergen exposure in hotels in Uberlândia, Midwestern Brazil.

PubMed

Simplício, E C; Silva, D A O; Braga, I A; Sopelete, M C; Sung, S J; Taketomi, E A

2007-08-01

Mite allergens are involved in airway sensitization and allergic diseases. We evaluated the exposure to house dust-mite (Der p 1 and Der f 1) and pet (Fel d 1 and Can f 1) allergens in hotels in Uberlândia, Midwestern Brazil. A total of 140 dust samples were collected from bedding (n = 98) and carpet (n = 42) of bedrooms in 20 hotels enrolled for this study. Geometric mean (GM) levels of Der f 1 (11.30 microg/g of dust; 95% CI: 8.34-15.30 microg/g) were significantly higher than Der p 1 (0.15 microg/g of dust; 95% CI: 0.13-0.18 microg/g) in bedding dust samples (P < 0.001), regardless of the hotel classes. Der f 1 levels were significantly higher in bedding (11.30 microg/g of dust; 95% CI: 8.34-15.30 microg/g) than carpet (6.32 microg/g of dust; 95% CI: 4.31-9.26 microg/g) dust samples (P < 0.05). High levels of Der f 1 (>10 microg/g of dust) were found in 58%, 76%, and 69% of dust samples from Simple, Economical, and Tourist/Superior hotels, respectively, while GM levels of Fel d 1 (0.11 microg/g of dust; 95% CI: 0.09-0.14 microg/g) and Can f 1 (0.30 microg/g of dust; 95% CI: 0.20-0.44 microg/g) were relatively low. These results indicate that Der f 1 is the predominant allergen in hotels in Uberlândia, especially in bedding dust samples, regardless of the hotel classes and could represent an important risk factor for exacerbation of allergic symptoms in previously mite-sensitized guests. Mites and pets are important sources of indoor allergens. Most people spend the greatest part of their time indoors. Hotels can constitute an important allergen reservoir of the indoor environment and could represent an important risk for exacerbation of allergic symptoms in previously sensitized guests. Thus, hotels should also be included for planning indoor allergen avoidance as part of a global management strategy, especially in patients with respiratory allergy.

Airway toxicity of house dust and its fungal composition.

PubMed

Piecková, Elena; Wilkins, Ken

2004-01-01

House dust is an important source of different toxic metabolites as well as allergens, including those of fungal origin, in the indoor environment. A bio-assay employing 1-day-old chick tracheas was used to characterize airway effects of 2-butanone and dimethylsulphoxide (Me2SO) extracts of 23 dust samples collected from water damaged (13) and control (10) Danish schools. Direct microscopical analysis of samples, followed by cultivation on dichloran 18 % glycerol agar at 25 degrees C for 10 days to establish their mycoflora, was performed. The in vitro ciliostatic potential of the chloroform-extractable endo- and exometabolites of 41 representative fungal isolates was determined. Nine dust extracts in 2-butanone (2 from damp rooms) or 10 (6) in Me(2)SO showed some ciliostatic activity in the 3-days' experiment. Fungal composition of dust from buildings with leakage was almost identical with that from undamaged houses, as well as the fungal colony counts from the damp schools and the control samples. Aspergillus spp. were prevalent in the samples - 31 or 40 % of all fungi, followed by Penicillium spp. and Cladosporium cladosporioides. Alternaria spp., Chaetomium spp., Mucor spp., Mycelia sterilia, Paecilomyces variotii, Rhizopus sp., Ulocladium sp. and yeasts were each isolated in less than 8 % of the fungal content. No Aspergillus flavus isolate (8 in total) was aflatoxigenic,em>in vitro. Alternaria spp., Aspergillus spp., Botrytis cinerea, Penicillium spp., C. cladosporioides, Chaetomium spp. and Ulocladium sp.; in total, 88 % of all fungi tested, produced ciliostatically active metabolites. These toxigenic strains were also present in 4 dust samples from controls and 5 dust samples from water damaged buildings. Extracts of these dust samples were also toxic in bioassay. There were bio-detectable concentrations (10-20 microg of extracts/ml of the organ culture medium) of toxic compounds in house dust. Contribution of fungal metabolites to its toxic effect should be studied further.

Common Warm Dust Temperatures Around Main Sequence Stars

NASA Technical Reports Server (NTRS)

Morales, Farisa; Rieke, George; Werner, Michael; Stapelfeldt, Karl; Bryden, Geoffrey; Su, Kate

2011-01-01

We compare the properties of warm dust emission from a sample of main-sequence A-type stars (B8-A7) to those of dust around solar-type stars (F5-KO) with similar Spitzer Space Telescope Infrared Spectrograph/MIPS data and similar ages. Both samples include stars with sources with infrared spectral energy distributions that show evidence of multiple components. Over the range of stellar types considered, we obtain nearly the same characteristic dust temperatures (∼ 190 K and ∼60 K for the inner and outer dust components, respectively)-slightly above the ice evaporation temperature for the inner belts. The warm inner dust temperature is readily explained if populations of small grains are being released by sublimation of ice from icy planetesimals. Evaporation of low-eccentricity icy bodies at ∼ 150 K can deposit particles into an inner/warm belt, where the small grains are heated to dust Temperatures of -190 K. Alternatively, enhanced collisional processing of an asteroid belt-like system of parent planetesimals just interior to the snow line may account for the observed uniformity in dust temperature. The similarity in temperature of the warmer dust across our B8-KO stellar sample strongly suggests that dust-producing planetesimals are not found at similar radial locations around all stars, but that dust production is favored at a characteristic temperature horizon.

Combustibility Determination for Cotton Gin Dust and Almond Huller Dust.

PubMed

Hughs, Sidney E; Wakelyn, Phillip J

2017-04-26

It has been documented that some dusts generated while processing agricultural products, such as grain and sugar, can constitute combustible dust hazards. After a catastrophic dust explosion in a sugar refinery in 2008, the Occupational Safety and Health Administration (OSHA) initiated action to develop a mandatory standard to comprehensively address the fire and explosion hazards of combustible dusts. Cotton fiber and related materials from cotton ginning, in loose form, can support smoldering combustion if ignited by an outside source. However, dust fires and other more hazardous events, such as dust explosions, are unknown in the cotton ginning industry. Dust material that accumulates inside cotton gins and almond huller plants during normal processing was collected for testing to determine combustibility. Cotton gin dust is composed of greater than 50% inert inorganic mineral dust (ash content), while almond huller dust is composed of at least 7% inert inorganic material. Inorganic mineral dust is not a combustible dust. The collected samples of cotton gin dust and almond huller dust were sieved to a known particle size range for testing to determine combustibility potential. Combustibility testing was conducted on the cotton gin dust and almond huller dust samples using the UN test for combustibility suggested in NFPA 652.. This testing indicated that neither the cotton gin dust nor the almond huller dust should be considered combustible dusts (i.e., not a Division 4.1 flammable hazard per 49 CFR 173.124). Copyright© by the American Society of Agricultural Engineers.

Dust Concentrations and Composition During African Dust Incursions in the Caribbean Region

NASA Astrophysics Data System (ADS)

Mayol-Bracero, O. L.; Santos-Figueroa, G.; Morales-Garcia, F.

2016-12-01

The World Health Organization (WHO) indicates that exposure to PM10 concentrations higher than 50 µg/m³ 24-hour mean in both developed and developing countries could have an adverse impact on public health. Recent studies showed that in the Caribbean region the PM10 concentrations often exceed the WHO guidelines for PM10. These exceedances are largely driven by the presence of African Dust particles that reach the Caribbean region every year during the summer months. These dust particles also influence the Earth's radiative budget directly by scattering solar radiation in the atmosphere and indirectly by affecting cloud formation and, thus, cloud albedo. In order to have a better understanding of the impacts of African Dust on public health and climate, we determine the concentration of dust particles, the carbonaceous fraction (total, elemental and organic carbon: TC, EC, and OC) and water-soluble ions (e.g., Na+, Cl-, Ca+2, NH4+, SO4-2) of aerosol samples in the presence and absence of African Dust. Samples were collected using a Hi-Vol and Stacked-Filter Units for the sampling of total suspended particles (TSP) at two stations in Puerto Rico: a marine site located at Cabezas de San Juan (CSJ) Nature Reserve, in Fajardo, and an urban site located at the University of Puerto Rico, in San Juan. The presence of African Dust was supported with Saharan Air Layer (SAL) imagery and with the results from the air mass backward trajectories calculated with the NOAA Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT). Preliminary results showed that the total mass concentration of aerosols obtained at the urban site is about two times that at the marine site for SFU samples during African Dust incursions. The average dust concentration obtained at CSJ for Hi Vol samples was 22 µg/m³ during the summer 2015. African Dust concentrations, TC, EC, OC, and ionic speciation results for the marine and urban sites will be presented at the conference.

The Importance of Primary Martian Surface and Airfall Dust Sample Return for Toxicological Hazard Evaluations for Human Exploration

NASA Technical Reports Server (NTRS)

Harrington, A. D.; McCubbin, F. M.

2018-01-01

Manned missions to the Moon highlight a major hazard for future human exploration of the Moon and beyond: surface dust. Not only did the dust cause mechanical and structural integrity issues with the suits, the dust 'storm' generated upon reentrance into the crew cabin caused "lunar hay fever" and "almost blindness" . It was further reported that the allergic response to the dust worsened with each exposure. Due to the prevalence of these high exposures, the Human Research Roadmap developed by NASA identifies the Risk of Adverse Health and Performance Effects of Celestial Dust Exposure as an area of concern. Extended human exploration will further increase the probability of inadvertent and repeated exposures to celestial dusts. Going forward, hazard assessments of celestial dusts will be determined through sample return efforts prior to astronaut deployment.

Determination of crystalline silica in respirable dust upon occupational exposure for Egyptian workers

PubMed Central

MOHAMED, Sabrein H.; EL-ANSARY, Aida L.; EL-AZIZ, Eman M. Abd

2017-01-01

Crystalline free silica is considered as a lung carcinogen and the occupational exposure to its dust is a health hazard to workers employed in industries that involve ores of mineral dust. In Egypt, thousands of people work under conditions of silica dust exposure exceeding the occupational exposure limit, as a result the monitoring of this occupational exposure to crystalline silica dust is required by government legislation. The assessment of the later is a multi-phase process, depend on workplace measurements, quantitative analyses of samples, and comparison of results with the permissible limits. This study aims to investigate occupational exposure to crystalline silica dust at 22 factories in Egypt with different industrial activities like stone cutting, glass making, ceramic, and sand blasting. Dust samples were collected from work sites at the breathing zone using a personal sampling pump and a size-selective cyclone and analyzed using FTIR. The sampling period was 60–120 min. The results show that the exposure at each of the industrial sectors is very much higher than the current national and international limits, and that lead to a great risk of lung cancer and mortality to workers. PMID:29199263

Spatial Distribution of Elemental Concentrations in Street Dust of Hanoi, Vietnam.

PubMed

Phi, Thai Ha; Chinh, Pham Minh; Hung, Nguyen The; Ly, Luong Thi Mai; Thai, Phong K

2017-02-01

Street dust samples were collected at 163 locations across four different zones of Hanoi, Vietnam, covering different traffic and population densities. Samples were sieved into three fractions of different particle sizes and analyzed for elemental concentrations (K, Ca, Mn, Fe, Zn, Pb) using an X-ray fluorescence (XRF) instrument. The metal concentrations in street dust were compared among different sampling zones and with samples from background to evaluate the degree of pollution. The smallest size particle fraction (diameter <75 μm) contained higher concentrations of metals than the coarser ones (diameters = 75-180 and >180 μm). While concentrations of metals like Ca and Fe are spatially similar, concentrations of Pb and Zn in street dust varied between different zones, with the highest concentrations observed in dust from the downtown area, and lowest levels in the new suburb areas. Overall, compared to studies from cities in other countries, the mean concentration of Pb in street dust in Hanoi was relatively low, suggesting a lower risk to human health due to inhalation or ingestion of Pb-containing dust particles than in cities where Pb concentrations were several times higher.

Toxicity of Lunar Dust in Lungs Assessed by Examining Biomarkers in Exposed Mice

NASA Technical Reports Server (NTRS)

Lam, C.-W.; James, J. T.; Zeidler-Erdely, P. C.; Castranova, V.; Young, S. H.; Quan, C. L.; Khan-Mayberry, N.; Taylor, L. A.

2010-01-01

NASA is contemplating to build an outpost on the Moon for prolonged human habitation and research. The lunar surface is covered by a layer of soil, of which the finest portion is highly reactive dust. Dust samples of respirable sizes were aerodynamically isolated from two lunar soil samples of different maturities (cosmic exposure ages) collected during the Apollo 16 mission. The lunar dust samples, TiO2, or quartz, suspended in normal saline were given to groups of 5 C57 male mice by intrapharyngeal aspiration at 0. 1, 0.3, or 1.0 mg/mouse. Because lunar dust aggregates rapidly in aqueous media, some tests were conducted with dusts suspended in Survanta/saline (1:1). The mice were euthanized 7 or 30 days later, and their lungs were lavaged to assess the presence of toxicity biomarkers in bronchioalveolar lavage fluids. The overall results showed that the two lunar dust samples were similar in toxicity, they were more toxic than T102 , but less toxic than quartz. This preliminary study is a part of the large study to obtain data for setting exposure limits for astronauts living on the Moon

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

EPA Science Inventory

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

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...

30 CFR 90.202 - Certified person; sampling.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Certified person; sampling. 90.202 Section 90... Sampling Procedures § 90.202 Certified person; sampling. (a) The respirable dust sampling required by this... on sampling of respirable coal mine dust. (c) A person may be temporarily certified by MSHA to take...

30 CFR 71.202 - Certified person; sampling.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Certified person; sampling. 71.202 Section 71... Sampling Procedures § 71.202 Certified person; sampling. (a) The respirable dust sampling required by this... on sampling of respirable coal mine dust. (c) A person may be temporarily certified by MSHA to take...

30 CFR 71.202 - Certified person; sampling.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Certified person; sampling. 71.202 Section 71... Sampling Procedures § 71.202 Certified person; sampling. (a) The respirable dust sampling required by this... on sampling of respirable coal mine dust. (c) A person may be temporarily certified by MSHA to take...

30 CFR 90.202 - Certified person; sampling.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Certified person; sampling. 90.202 Section 90... Sampling Procedures § 90.202 Certified person; sampling. (a) The respirable dust sampling required by this... on sampling of respirable coal mine dust. (c) A person may be temporarily certified by MSHA to take...

Final Reports of the Stardust ISPE: Seven Probable Interstellar Dust Particles

NASA Technical Reports Server (NTRS)

Allen, Carlton; Sans Tresseras, Juan-Angel; Westphal, Andrew J.; Stroud, Rhonda M.; Bechtel, Hans A.; Brenker, Frank E.; Butterworth, Anna L.; Flynn, George J.; Frank, David R.; Gainsforth, Zack;

Health-hazard evaluation report HETA 83-391-1683, Continental Coffee Products Company, Houston, Texas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arnold, S.J.; Markel, H.L.; Morawetz, J.S.

1986-04-01

The International Chemical Workers Union requested an evaluation be made of the health status of employees at the Continental Coffee Products Company, Houston, Texas with particular attention given to potential exposure to pesticide residues on imported coffee beans. Analysis of air samples revealed the following concentration ranges: 29 personal respirable-dust samples ranging from 0.03 to 2.03 milligrams/cubic meter (mg/m3); 27 of 28 personal total dust samples, 0.09 to 2.65 mg/m3; four area respirable-dust samples, 0.11 to 0.53 mg/m3; and four area total dust samples, 0.16 to 2.39 mg/m3. Pesticide exposures were significantly below acceptable daily intakes. The authors conclude thatmore » it would not be expected that employees would be exposed to pesticide levels posing an appreciable threat to health. Recommendations were made to increase the use of local exhaust ventilation; to improve work practices to reduce generation of dust and accumulation; increase ventilation in the basement re-mix operation; and train employees toward the understanding of potential hazards and their role in controlling dust.« less

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 TCEP in the dust samples, suggesting that the use of V6 is a significant source of TCEP in the indoor environment. PMID:23565680

Trans boundary transport of pollutants by atmospheric mineral dust.

PubMed

Erel, Yigal; Dayan, Uri; Rabi, Reut; Rudich, Yinon; Stein, Mordechai

2006-05-01

The transport of anthropogenic pollution by desert dust in the Eastern Mediterranean region was studied by analyzing major and trace element composition, organic species, and Pb isotope ratios in suspended dust samples collected in Jerusalem, Israel. Dust storms in this region are associated with four distinct synoptic conditions (Red Sea Trough (RS), Eastern High (EH), Sharav Cyclone (SC), and Cold Depression (Cyprus low, CD)) that carry dust mostly from North African (SC, CD, EH) and Arabian and Syrian (RS, EH) deserts. Substantial contamination of dust particles by Pb, Cu, Zn, and Ni is observed, while other elements (Na, Ca, Mg, Mn, Sr, Rb, REE, U, and Th) display natural concentrations. Sequential extraction of the abovementioned elements from the dust samples shows that the carbonate and sorbed fractions contain most of the pollution, yet the Al-silicate fraction is also contaminated, implying that soils and sediments in the source terrains of the dust are already polluted. We identified the pollutant sources by using Pb isotopes. It appears that before the beginning of the dust storm, the pollutants in the collected samples are dominated by local sources but with the arrival of dust from North Africa, the proportion of foreign pollutants increases. Organic pollutants exhibit behavior similar and complementary to that of the inorganic tracers, attesting to the importance of anthropogenic-pollutant addition en route of the dust from its remote sources. Pollution of suspended dust is observed under all synoptic conditions, yet it appears that easterly winds carry higher proportions of local pollution and westerly winds carry pollution emitted in the Cairo basin. Therefore, pollution transport by mineral dust should be accounted for in environmental models and in assessing the health-related effects of mineral dust.

Concentrations of polychlorinated biphenyls in soil and indoor dust associated with electricity generation facilities in Lagos, Nigeria.

PubMed

Folarin, Bilikis Temitope; Abdallah, Mohamed Abou-Elwafa; Oluseyi, Temilola; Olayinka, Kehinde; Harrad, Stuart

2018-09-01

Concentrations of 7 indicator polychlorinated biphenyls (PCBs) were measured in dust and soil samples from 12 power stations collected over the two major seasons of the Nigerian climate. Median ƩPCB 7 concentrations in soil ranged from 2 ng/g for power station A to 220 ng/g for power station I; while those in dust ranged from 21 ng/g for power station L to 2200 ng/g for power station I. For individual congeners, median PCB concentrations ranged from 3.8 ng/g for PCB 101 to 52 ng/g for PCB 180 in dust, and <0.07 ng/g for PCB 28 to 5.9 ng/g for PCB 153 in soil. The type of power station activity exerted a significant influence on concentrations of ΣPCB 7 in dust and soil (generation > transmission > distribution). Congener patterns in dust and soil samples were compared using principal component analysis (PCA) with those in transformer oil samples from 3 of the power stations studied and with common PCB mixtures (Aroclors). This revealed congener patterns in soil were more closely related to that in the transformer oil than dust. Congener patterns in most samples were similar to Aroclor 1260. Concentrations of PCBs in soil samples close to the transformers significantly exceeded those in soil sampled further away. Copyright © 2018 Elsevier Ltd. All rights reserved.

Radiographic outcomes among South African coal miners.

PubMed

Naidoo, Rajen N; Robins, Thomas G; Solomon, A; White, Neil; Franzblau, Alfred

2004-10-01

This study, the first to document the prevalence of pneumoconiosis among a living South African coal mining cohort, describes dose-response relationships between coal workers' pneumoconiosis and respirable dust exposure, and relationships between pneumoconiosis and both lung function deterioration and respiratory symptoms. A total of 684 current miners and 188 ex-miners from three bituminous-coal mines in Mpumalanga, South Africa, was studied. Chest radiographs were read according to the International Labour Organization (ILO) classification by two experienced readers, one an accredited National Institute for Occupational Safety and Health (NIOSH) "B" reader. Interviews were conducted to assess symptoms, work histories (also obtained from company records), smoking, and other risk factors. Spirometry was performed by trained technicians. Cumulative respirable dust exposure (CDE) estimates were constructed from historical company-collected sampling and researcher-collected personal dust measurements. kappa-Statistics compared the radiographic outcomes predicted by the two readers. An average profusion score was used in the analysis for the outcomes of interest. Because of possible confounding by employment status, most analyses were stratified on current and ex-miner status. The overall prevalence of pneumoconiosis was low (2%-4%). The degree of agreement between the two readers for profusion was moderate to high (kappa=0.58). A significant association (P<0.001) and trend (P<0.001) was seen for pneumoconiosis with increasing categories of CDE among current miners only. A significant (P<0.0001) additional 58 mg-years/m3 CDE was seen among those with pneumoconiosis compared to those without. CDE contributed to a statistically significant 0.19% and 0.11% greater decline in the percent predicted 1-second forced expiration volume (FEV1) and forced vital capacity (FVC), respectively, among current miners with pneumoconiosis than among those without. Logistic regression models showed no significant relationships between pneumoconiosis and symptoms. The overall prevalence of pneumoconiosis, although significantly associated with CDE, was low. The presence of pneumoconiosis is associated with meaningful health effects, including deterioration in lung function. Intervention measures that control exposure are indicated, to reduce these functional effects.

Determination of polychlorinated biphenyls and polychlorinated dibenzo-p-dioxins and dibenzofurans by pressurized liquid extraction and gas chromatography coupled to mass spectrometry in street dust samples.

PubMed

Klees, Marcel; Hiester, Ernst; Bruckmann, Peter; Schmidt, Torsten C

2013-07-26

Owing to massive pollution with polychlorinated biphenyls in the harbour area of Dortmund (Germany), several dust samples were taken from surfaces at industrial sites and analyzed by the North-Rhine Westphalian State Agency for Nature, Environment, and Consumer Protection (LANUV NRW). This report describes and validates a rapid approach to screening for the presence of polychlorinated biphenyls (PCBs) in street dust. Samples were collected by using a natural bristle brush and stainless steel scoops. Mass recovery of fine-particle sea sand (a dust surrogate) on asphalt and concrete surfaces was used as a criterion for the effectiveness of sampling. Better recoveries of sea sand were achieved on concrete than on asphalt surfaces. Furthermore, temperature optimization for a pressurized liquid extraction (PLE) method used to extract PCBs and polychlorinated dibenzodioxins and polychlorinated furans (PCDD/Fs) from street dust samples was developed and compared with Soxhlet extraction for the analysis of PCBs in real street dust samples. Toluene was used as the extraction solvent in both cases. During this study, a combination of toluene and PLE achieved better extraction efficiencies than Soxhlet extraction. Finally, the performance of the PLE method was evaluated by analysing NIST Standard Reference Material 1649a for PCB and PCDD/F concentrations. This demonstrated that the accuracy of the PLE method for the determination of both substance classes was satisfactory. In addition, concentrations of PCBs and PCDD/Fs in street dust samples from industrial sites are reported. Copyright © 2013. Published by Elsevier B.V.

Polycyclic Aromatic Hydrocarbons in Residential Dust: Sources of Variability

PubMed Central

Metayer, Catherine; Petreas, Myrto; Does, Monique; Buffler, Patricia A.; Rappaport, Stephen M.

2013-01-01

Background: There is interest in using residential dust to estimate human exposure to environmental contaminants. Objectives: We aimed to characterize the sources of variability for polycyclic aromatic hydrocarbons (PAHs) in residential dust and provide guidance for investigators who plan to use residential dust to assess exposure to PAHs. Methods: We collected repeat dust samples from 293 households in the Northern California Childhood Leukemia Study during two sampling rounds (from 2001 through 2007 and during 2010) using household vacuum cleaners, and measured 12 PAHs using gas chromatography–mass spectrometry. We used a random- and a mixed-effects model for each PAH to apportion observed variance into four components and to identify sources of variability. Results: Median concentrations for individual PAHs ranged from 10 to 190 ng/g of dust. For each PAH, total variance was apportioned into regional variability (1–9%), intraregional between-household variability (24–48%), within-household variability over time (41–57%), and within-sample analytical variability (2–33%). Regional differences in PAH dust levels were associated with estimated ambient air concentrations of PAH. Intraregional differences between households were associated with the residential construction date and the smoking habits of residents. For some PAHs, a decreasing time trend explained a modest fraction of the within-household variability; however, most of the within-household variability was unaccounted for by our mixed-effects models. Within-household differences between sampling rounds were largest when the interval between dust sample collections was at least 6 years in duration. Conclusions: Our findings indicate that it may be feasible to use residential dust for retrospective assessment of PAH exposures in studies of health effects. PMID:23461863

Relating Optical Properties of Dusts to their Mineralogical and Physical Interrelationships

NASA Astrophysics Data System (ADS)

Engelbrecht, J. P.; Moosmuller, H.; Jayanty, R. K. M.; Casuccio, G.; Pincock, S. L.

2015-12-01

The purpose of the project was to provide information on the mineralogical, chemical and physical interrelationships of re-suspended mineral dust samples collected as grab samples from global dust sources. Surface soil samples were collected from about 65 desert sites, including the southwestern USA (12), Mali (3), Chad (3), Morocco (1), Canary Islands (8), Cape Verde (1), Djibouti (1), Afghanistan (3), Iraq (6), Kuwait (5), Qatar (1), UAE (1), Serbia (3), China (5), Namibia (3), Botswana (4), Australia (3), and Chile (1). The < 38 μm sieved fraction of each sample was re-suspended in an entrainment chamber, from which the airborne mineral dust could be monitored, sampled and analyzed. Instruments integrated into the entrainment facility included two PM10 and two PM2.5 filter samplers, a beta attenuation gauge for the continuous measurement of PM10 and PM2.5particulate mass fractions, an aerodynamic particle size (APS) analyzer, and a three wavelength (405, 532, 781nm) photoacoustic resonator with integrating reciprocal nephelometer for monitoring absorption and scattering coefficients during the dust re-suspension process. Filter sample media included Teflon® membrane and quartz fiber filters for chemical analysis (71 species), and Nuclepore® filters for individual particle analysis by Scanning Electron Microscopy (SEM). The < 38 μm sieved fractions were also analyzed by X-ray diffraction for their mineral content while the > 38 μm, < 125 μm soil fractions were mineralogically characterized by optical microscopy. We will be presenting results on the optical measurements, also showing the relationship between single scattering albedo (SSA) at three different wavelengths, and chemical as well as mineralogical content and interdependencies of the entrained dust samples. Examples showing the relationships between the single scattering albedos of airborne dusts, and iron (Fe) in hematite, goethite, and clay minerals (montmorillonite, illite, palygorskite), will be discussed. Our goal is to establish a database of the optical, mineralogical, and chemical properties of dust samples collected at multiple global dust sources. These data can be for applications in climate modeling, remote sensing, visibility, health (medical geology), ocean fertilization, and damage to equipment.

Verbal abuse and mobbing in pre-hospital care services in Chile.

PubMed

Campo, Varinia Rodríguez; Klijn, Tatiana Paravic

2018-01-08

to determine the perception of verbal abuse and mobbing and the associated factors of paramedic technicians (nursing assistants) and professionals (nurses, midwives, kinesiologists) in the pre-hospital care areas of three regions in the south of Chile. descriptive and correlational study was performed within the professional community and a two-stage sample of the paramedic technician population in three regions. The questionnaire "workplace violence in the health sector" (spanish version) was applied after signing the informed consent. 51.4% of professionals and 46.6% of paramedic technicians consider they have been verbally abused during last year. 17.6% of paramedic technicians and 13.5% of professionals perceived mobbing. A low percentage of these events are reported. In only one case of mobbing, the aggressor was legally penalized. No significant differences were found between the job categories and the studied regions. A high percentage of participants in each group perceived verbal abuse and non-minor percentage perceived mobbing, but most of these events are not reported.

Evaluation of a Dust Control for a Small Slab-Riding Dowel Drill for Concrete Pavement

PubMed Central

Echt, Alan; Mead, Kenneth

2016-01-01

Purpose To assess the effectiveness of local exhaust ventilation to control respirable crystalline silica exposures to acceptable levels during concrete dowel drilling. Approach Personal breathing zone samples for respirable dust and crystalline silica were collected while laborers drilled holes 3.5 cm diameter by 36 cm deep in a concrete slab using a single-drill slab-riding dowel drill equipped with local exhaust ventilation. Data were collected on air flow, weather, and productivity. Results All respirable dust samples were below the 90 µg detection limit which, when combined with the largest sample volume, resulted in a minimum detectable concentration of 0.31 mg m−3. This occurred in a 32-min sample collected when 27 holes were drilled. Quartz was only detected in one air sample; 0.09 mg m−3 of quartz was found on an 8-min sample collected during a drill maintenance task. The minimum detectable concentration for quartz in personal air samples collected while drilling was performed was 0.02 mg m−3. The average number of holes drilled during each drilling sample was 23. Over the course of the 2-day study, air flow measured at the dust collector decreased from 2.2 to 1.7 m3 s−1. Conclusions The dust control performed well under the conditions of this test. The initial duct velocity with a clean filter was sufficient to prevent settling, but gradually fell below the recommended value to prevent dust from settling in the duct. The practice of raising the drill between each hole may have prevented the dust from settling in the duct. A slightly higher flow rate and an improved duct design would prevent settling without regard to the position of the drill. PMID:26826033

Alternative Flame Retardant, 2,4,6-Tris(2,4,6-tribromophenoxy)-1,3,5-triazine, in an E-waste Recycling Facility and House Dust in North America.

PubMed

Guo, Jiehong; Stubbings, William A; Romanak, Kevin; Nguyen, Linh V; Jantunen, Liisa; Melymuk, Lisa; Arrandale, Victoria; Diamond, Miriam L; Venier, Marta

2018-03-20

A high molecular weight compound, 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine (TTBP-TAZ), was detected during the analysis of brominated flame retardants in dust samples collected from an electrical and electronic waste (e-waste) recycling facility in Ontario, Canada. Gas chromatography coupled with both high-resolution and low-resolution mass spectrometry (MS) was used to determine TTBP-TAZ's chemical structure and concentrations. To date, TTBP-TAZ has only been detected in plastic casings of electrical and electronic equipment and house dust from The Netherlands. Here we report on the concentrations of TTBP-TAZ in selected samples from North America: e-waste dust ( n = 7) and air ( n = 4), residential dust ( n = 30), and selected outdoor air ( n = 146), precipitation ( n = 19), sediment ( n = 11) and water ( n = 2) samples from the Great Lakes environment. TTBP-TAZ was detected in all the e-waste dust and air samples, and in 70% of residential dust samples. The median concentrations of TTBP-TAZ in these three types of samples were 5540 ng/g, 5.75 ng/m 3 and 6.76 ng/g, respectively. The flame retardants 2,4,6-tribromophenol, tris(2,3-dibromopropyl) isocyanurate, and 3,3',5,5'-tetrabromobisphenol A bis(2,3-dibromopropyl) ether, BDE-47 and BDE-209 were also measured for comparison. None of these other flame retardants concentrations was significantly correlated with those of TTBP-TAZ in any of the sample types suggesting different sources. TTBP-TAZ was not detected in any of the outdoor environmental samples, which may relate to its application history and physicochemical properties. This is the first report of TTBP-TAZ in North America.

Evaluation of a Dust Control for a Small Slab-Riding Dowel Drill for Concrete Pavement.

PubMed

Echt, Alan; Mead, Kenneth

2016-05-01

To assess the effectiveness of local exhaust ventilation to control respirable crystalline silica exposures to acceptable levels during concrete dowel drilling. Personal breathing zone samples for respirable dust and crystalline silica were collected while laborers drilled holes 3.5 cm diameter by 36 cm deep in a concrete slab using a single-drill slab-riding dowel drill equipped with local exhaust ventilation. Data were collected on air flow, weather, and productivity. All respirable dust samples were below the 90 µg detection limit which, when combined with the largest sample volume, resulted in a minimum detectable concentration of 0.31 mg m(-3). This occurred in a 32-min sample collected when 27 holes were drilled. Quartz was only detected in one air sample; 0.09 mg m(-3) of quartz was found on an 8-min sample collected during a drill maintenance task. The minimum detectable concentration for quartz in personal air samples collected while drilling was performed was 0.02 mg m(-3). The average number of holes drilled during each drilling sample was 23. Over the course of the 2-day study, air flow measured at the dust collector decreased from 2.2 to 1.7 m(3) s(-1). The dust control performed well under the conditions of this test. The initial duct velocity with a clean filter was sufficient to prevent settling, but gradually fell below the recommended value to prevent dust from settling in the duct. The practice of raising the drill between each hole may have prevented the dust from settling in the duct. A slightly higher flow rate and an improved duct design would prevent settling without regard to the position of the drill. Published by Oxford University Press on behalf of the British Occupational Hygiene Society 2016.

78 FR 45566 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Coal Mine...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-29

... for OMB Review; Comment Request; Coal Mine Dust Sampling Devices ACTION: Notice. SUMMARY: The... information collection request (ICR) titled, ``Coal Mine Dust Sampling Devices,'' to the Office of Management...) determine the concentration of respirable dust in coal mines. CPDMs must be designed and constructed for...

30 CFR 90.209 - Respirable dust samples; transmission by operator.

Code of Federal Regulations, 2010 CFR

2010-07-01

... designated by the District Manager. (b) The operator shall not open or tamper with the seal of any filter... properly complete the dust data card that is provided by the manufacturer for each filter cassette. The... include that person's certification number. Respirable dust samples with data cards not properly completed...

30 CFR 90.209 - Respirable dust samples; transmission by operator.

Code of Federal Regulations, 2011 CFR

2011-07-01

... designated by the District Manager. (b) The operator shall not open or tamper with the seal of any filter... properly complete the dust data card that is provided by the manufacturer for each filter cassette. The... include that person's certification number. Respirable dust samples with data cards not properly completed...

30 CFR 71.209 - Respirable dust samples; transmission by operator.

Code of Federal Regulations, 2010 CFR

2010-07-01

... designated by the District Manager. (b) The operator shall not open or tamper with the seal of any filter... properly complete the dust data card that is provided by the manufacturer for each filter cassette. The... include that person's certification number. Respirable dust samples with data cards not properly completed...

30 CFR 71.209 - Respirable dust samples; transmission by operator.

Code of Federal Regulations, 2011 CFR

2011-07-01

... designated by the District Manager. (b) The operator shall not open or tamper with the seal of any filter... properly complete the dust data card that is provided by the manufacturer for each filter cassette. The... include that person's certification number. Respirable dust samples with data cards not properly completed...

Size Distributions and Characterization of Native and Ground Samples for Toxicology Studies

NASA Technical Reports Server (NTRS)

McKay, David S.; Cooper, Bonnie L.; Taylor, Larry A.

2010-01-01

This slide presentation shows charts and graphs that review the particle size distribution and characterization of natural and ground samples for toxicology studies. There are graphs which show the volume distribution versus the number distribution for natural occurring dust, jet mill ground dust, and ball mill ground dust.

Level and distribution of employee exposures to total and respirable wood dust in two Canadian sawmills.

PubMed

Teschke, K; Hertzman, C; Morrison, B

1994-03-01

Personal respirable (N = 230) and total (N = 237) dust measurements were made in two coastal British Columbia sawmills using a sampling strategy that randomly selected workers from all jobs in the mills over two seasons. Information about job title, department, season, weather conditions, location of the job relative to wood-cutting machines, and control measures also was collected at the time of sampling. Only 16 respirable wood dust samples were above the detection limit of 0.08 mg/m3; all 16 had levels < or = 0.20 mg/m3. Total wood dust concentrations were also low (36% less than the detection limit), with a mean of 0.51 mg/m3, and ranging from < 0.08 to 52 mg/m3. Measurements of exposure taken close to chippers, planers, and multiple saws had the highest total wood dust levels. Sawmill department and booth enclosures also were associated with wood dust concentrations, while local exhaust ventilation and weather conditions were not. Wood dust levels in this study were generally lower than in other studies of this industry, but most sawmill investigations report mean wood dust concentrations lower than those measured in the furniture and cabinetmaking industries, where concerns about wood dust exposures initially were raised.

Formation of iron nanoparticles and increase in iron reactivity in mineral dust during simulated cloud processing.

PubMed

Shi, Zongbo; Krom, Michael D; Bonneville, Steeve; Baker, Alex R; Jickells, Timothy D; Benning, Liane G

2009-09-01

The formation of iron (Fe) nanoperticles and increase in Fe reactivity in mineral dust during simulated cloud processing was investigated using high-resolution microscopy and chemical extraction methods. Cloud processing of dust was experimentally simulated via an alternation of acidic (pH 2) and circumneutral conditions (pH 5-6) over periods of 24 h each on presieved (<20 microm) Saharan soil and goethite suspensions. Microscopic analyses of the processed soil and goethite samples reveal the neo-formation of Fe-rich nanoparticle aggregates, which were not found initially. Similar Fe-rich nanoparticles were also observed in wet-deposited Saharen dusts from the western Mediterranean but not in dry-deposited dust from the eastern Mediterranean. Sequential Fe extraction of the soil samples indicated an increase in the proportion of chemically reactive Fe extractable by an ascorbate solution after simulated cloud processing. In addition, the sequential extractions on the Mediterranean dust samples revealed a higher content of reactive Fe in the wet-deposited dust compared to that of the dry-deposited dust These results suggestthat large variations of pH commonly reported in aerosol and cloud waters can trigger neo-formation of nanosize Fe particles and an increase in Fe reactivity in the dust

Identifying transfer mechanisms and sources of decabromodiphenyl ether (BDE 209) in indoor environments using environmental forensic microscopy

PubMed Central

Webster, Thomas F.; Harrad, Stuart; Millette, James R.; Holbrook, R. David; Davis, Jeffrey M.; Stapleton, Heather M.; Allen, Joseph G.; McClean, Michael D.; Ibarra, Catalina; Abdallah, Mohamed Abou-Elwafa; Covaci, Adrian

2009-01-01

Although the presence of polybrominated diphenyl ethers (PBDEs) in house dust has been linked to consumer products, the mechanism of transfer remains poorly understood. We conjecture that volatilized PBDEs will be associated with dust particles containing organic matter and will be homogeneously distributed in house dust. In contrast, PBDEs arising from weathering or abrasion of polymers should remain bound to particles of the original polymer matrix and will be heterogeneously distributed within the dust. We used scanning electron microscopy and other tools of environmental forensic microscopy to investigate PBDEs in dust, examining U.S.A. and U.K. dust samples with extremely high levels of BDE 209 (260–2600 µg/g), a non-volatile compound at room temperature. We found that the bromine in these samples was concentrated in widely scattered, highly contaminated particles. In the house dust samples from Boston (U.S.), bromine was associated with a polymer/organic matrix. These results suggest that the BDE 209 was transferred to dust via physical processes such as abrasion or weathering. In conjunction with more traditional tools of environmental chemistry, such as gas chromatography-mass spectrometry (GC/MS), environmental forensic microscopy provides novel insights into the origins of BDE 209 in dust and their mechanisms of transfer from products. PMID:19534115

Composition and Source Identification of Chemical Species in Dust from Selected Indoor Environments in Ile-Ife, Nigeria

NASA Astrophysics Data System (ADS)

Ogundele, Lasun T.; Olasinde, Roseline T.; Owoade, Oyediran K.; Olise, Felix S.

2018-05-01

This study presents the elemental compositions and concentrations of indoor dust and identifies the major sources in some selected indoor environments in Ile-Ife, Nigeria. The dust samples were collected from 16 indoor environments comprising offices, churches, residential and staff quarters using a cyclonic high power vacuum cleaner. The dust samples were analyzed for elemental concentrations using x-ray fluorescences. The data sets were analyzed for the possible sources and their contributions using Principal Component Factor Analysis (PCFA). The result showed that dust samples contained several elements: K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Ga, As, Rb, Sr, Se, Zr, V, and Sc. The PCFA identified three factors with the percentage variance of 92, 77, 71 and 68%, for the office, church, residential, and staff quarters, respectively, for the combined elemental data of each of the site classes. The identified sources were track-in-soil, road and windblown soil dust, paint debris, household dust from personal care materials, cooking, and cleaning activities. The unintentional track-in-soil due to mobility of the occupants, structural materials, and outdoor air was the major sources contributing to the indoor dust.

The effects of dust on Colorado mountain snow cover albedo and compositional links to dust-source areas

NASA Astrophysics Data System (ADS)

Goldstein, H. L.; Reynolds, R. L.; Landry, C.; Derry, J. E.; Kokaly, R. F.; Breit, G. N.

2016-12-01

Dust deposited on mountain snow cover (DOS) changes snow albedo, enhances absorption of solar radiation, and effectively increases rates of snow melt, leading to earlier-than-normal runoff and overall smaller late-season water supplies for tens of millions of people and industries in the American West. Visible-spectrum reflectance of DOS samples is on the order of 0.2 (80% absorption), in stark contrast to the high reflectivity of pure snow which approaches 1.0. Samples of DOS were collected from 12 high-elevation Colorado mountain sites near the end of spring from 2013 through 2016 prior to complete snow melt, when most dust layers had merged into one layer. These samples were analyzed to measure dust properties that affect snow albedo and to link DOS to dust-source areas. Dust mass loadings to snow during water year 2014 varied from 5 to 30 g/m2. Median particle sizes centered around 20 micrometers with more than 80% of the dust <63 micrometers. Dark minerals, carbonaceous matter, and iron oxides, including nano-sized hematite and goethite, together diminished reflectance according to their variable concentrations. Documenting variations in dust-particle masses, sizes, and compositions helps determine their influences on snow-melt and may be useful for modeling snow-melt effects from future dust. Furthermore, variations in dust components and particle sizes lead to new ways to recognize sources of dust by comparison with properties of fine-grained sediments in dust-source areas. Much of the DOS in the San Juan Mountains, Colorado can be linked to southern Colorado Plateau source areas by compositional similarities and satellite imagery. Understanding dust properties that affect snow albedo and recognizing the sources of dust deposited on snow cover may guide mitigation of dust emission that affects water resources of the Colorado River basin.

Morphology, spatial distribution, and concentration of flame retardants in consumer products and environmental dusts using scanning electron microscopy and Raman micro-spectroscopy.

PubMed

Wagner, Jeff; Ghosal, Sutapa; Whitehead, Todd; Metayer, Catherine

2013-09-01

We characterized flame retardant (FR) morphologies and spatial distributions in 7 consumer products and 7 environmental dusts to determine their implications for transfer mechanisms, human exposure, and the reproducibility of gas chromatography-mass spectrometry (GC-MS) dust measurements. We characterized individual particles using scanning electron microscopy/energy dispersive x-ray spectroscopy (SEM/EDS) and Raman micro-spectroscopy (RMS). Samples were screened for the presence of 3 FR constituents (bromine, phosphorous, non-salt chlorine) and 2 metal synergists (antimony and bismuth). Subsequent analyses of select samples by RMS enabled molecular identification of the FR compounds and matrix materials. The consumer products and dust samples possessed FR elemental weight percents of up to 36% and 31%, respectively. We identified 24 FR-containing particles in the dust samples and classified them into 9 types based on morphology and composition. We observed a broad range of morphologies for these FR-containing particles, suggesting FR transfer to dust via multiple mechanisms. We developed an equation to describe the heterogeneity of FR-containing particles in environmental dust samples. The number of individual FR-containing particles expected in a 1-mg dust sample with a FR concentration of 100ppm ranged from <1 to >1000 particles. The presence of rare, high-concentration bromine particles was correlated with decabromodiphenyl ether concentrations obtained via GC-MS. When FRs are distributed heterogeneously in highly concentrated dust particles, human exposure to FRs may be characterized by high transient exposures interspersed by periods of low exposure, and GC-MS FR concentrations may exhibit large variability in replicate subsamples. Current limitations of this SEM/EDS technique include potential false negatives for volatile and chlorinated FRs and greater quantitation uncertainty for brominated FR in aluminum-rich matrices. Copyright © 2013 Elsevier Ltd. All rights reserved.

Introducing a checking technician allows pharmacists to spend more time on patient-focused activities.

PubMed

Napier, Patti; Norris, Pauline; Braund, Rhiannon

2018-04-01

Internationally there is an increasing focus on the clinical and cognitive services that pharmacists can provide. Lack of time has been identified as a barrier to pharmacists increasing their clinical activities. Within the pharmacy workplace there are many tasks that can only be performed by a pharmacist. The final accuracy check of a dispensed prescription is currently the sole responsibility of pharmacists in New Zealand. This takes up a significant amount of time during a pharmacist's work day. The introduction of a checking technician role has been suggested to allow pharmacists more time to do more patient focused work. To investigate the amount of time pharmacy staff spend on specific activities and to establish whether the introduction of a checking technician into twelve pilot sites increased the amount of time that the pharmacists could spend on patient focused activities. This study utilised a self-reported work sampling technique in twelve pilot sites, selected from both the hospital and community settings. Work sampling using an electronic device was conducted at two time-points (before the implementation of a Pharmacy Accuracy Checking Technician (PACT) role and when the PACT was in place). Data was collected at 10 min intervals for the period of five days, a working week. Tasks were grouped into patient focused, dispensing and personal activities. The introduction of the PACT into the pilot sites saw a mean increase of 19% in pharmacists' patient focused activities and a mean 20% decrease in dispensing activities. The introduction of a checking technician role into New Zealand pharmacies demonstrated the potential to provide pharmacists with more time to spend on patient focused activities. Copyright © 2017 Elsevier Inc. All rights reserved.

Herschel-ATLAS: the surprising diversity of dust-selected galaxies in the local submillimetre Universe

NASA Astrophysics Data System (ADS)

Clark, C. J. R.; Dunne, L.; Gomez, H. L.; Maddox, S.; De Vis, P.; Smith, M. W. L.; Eales, S. A.; Baes, M.; Bendo, G. J.; Bourne, N.; Driver, S. P.; Dye, S.; Furlanetto, C.; Grootes, M. W.; Ivison, R. J.; Schofield, S. P.; Robotham, A. S. G.; Rowlands, K.; Valiante, E.; Vlahakis, C.; van der Werf, P.; Wright, A. H.; de Zotti, G.

2015-09-01

We present the properties of the first 250 μm blind sample of nearby galaxies (15 < D < 46 Mpc) containing 42 objects from the Herschel Astrophysical Terahertz Large Area Survey. Herschel's sensitivity probes the faint end of the dust luminosity function for the first time, spanning a range of stellar mass (7.4 < M⋆ < 11.3 log10 M⊙), star formation activity (-11.8 < SSFR < -8.9 log10 yr-1), gas fraction (3-96 per cent), and colour (0.6 < FUV-KS < 7.0 mag). The median cold dust temperature is 14.6 K, colder than in the Herschel Reference Survey (18.5 K) and Planck Early Release Compact Source Catalogue (17.7 K). The mean dust-to-stellar mass ratio in our sample is higher than these surveys by factors of 3.7 and 1.8, with a dust mass volume density of (3.7 ± 0.7) × 105 M⊙ Mpc-3. Counter-intuitively, we find that the more dust rich a galaxy, the lower its UV attenuation. Over half of our dust-selected sample are very blue in FUV-KS colour, with irregular and/or highly flocculent morphology; these galaxies account for only 6 per cent of the sample's stellar mass but contain over 35 per cent of the dust mass. They are the most actively star-forming galaxies in the sample, with the highest gas fractions and lowest UV attenuation. They also appear to be in an early stage of converting their gas into stars, providing valuable insights into the chemical evolution of young galaxies.

Study of road dust magnetic phases as the main carrier of potentially harmful trace elements.

PubMed

Bourliva, Anna; Papadopoulou, Lambrini; Aidona, Elina

2016-05-15

Mineralogical and morphological characteristics and heavy metal content of different fractions (bulk, non-magnetic fraction-NMF and magnetic fraction-MF) of road dusts from the city of Thessaloniki (Northern Greece) were investigated. Main emphasis was given on the magnetic phases extracted from these dusts. High magnetic susceptibility values were presented, whereas the MFs content of road dust samples ranged in 2.2-14.7 wt.%. Thermomagnetic analyses indicated that the dominating magnetic carrier in all road dust samples was magnetite, while the presence of hematite and iron sulphides in the investigated samples cannot be excluded. SEM/EDX analyses identified two groups of ferrimagnetic particles: spherules with various surface morphologies and textures and angular/aggregate particles with elevated heavy metal contents, especially Cr. The road dusts (bulk samples) were dominated by calcium, while the mean concentrations of trace elements decreased in the order Zn > Mn > Cu > Pb > Cr > Ni > V > Sn > As > Sb > Co > Mo > W > Cd. MFs exhibited significantly higher concentrations of trace elements compared to NMFs indicating that these potentially harmful elements (PHEs) are preferentially enriched in the MFs and highly associated with the ferrimagnetic particles. Hazard Index (HI) obtained for both adults and children through exposure to bulk dust samples were lower or close to the safe level (=1). On the contrary, the HIs for the magnetic phases indicated that both children and adults are experiencing potential health risk since HI for Cr was significantly higher than safe level. Cancer risk due to road dust exposure is low. Copyright © 2016 Elsevier B.V. All rights reserved.

Polycyclic aromatic hydrocarbons (PAHs) in indoor dust samples from Cities of Jeddah and Kuwait: Levels, sources and non-dietary human exposure.

PubMed

Ali, Nadeem; Ismail, Iqbal Mohammad Ibrahim; Khoder, Mamdouh; Shamy, Magdy; Alghamdi, Mansour; Costa, Max; Ali, Lulwa Naseer; Wang, Wei; Eqani, Syed Ali Musstjab Akber Shah

2016-12-15

This study reports levels and profiles of polycyclic aromatic hydrocarbons (PAHs) in dust samples collected from three different microenvironments (cars, air conditioner (AC) filters and household floor dust) of Jeddah, Saudi Arabia (KSA) and Kuwait. To the best of our knowledge, this is first study reporting PAHs in indoor microenvironments of KSA, which makes these findings important. Benzo(b)fluoranthene (BbF), benzo(a)pyrene (BaP), phenanthrene (Phe), and pyrene (Pyr) were found to be the major chemicals in dust samples from all selected microenvironments. ΣPAHs occurred at median concentrations (ng/g) of 3450, 2200, and 2650 in Saudi AC filter, car and household floor dust, respectively. The median levels (ng/g) of ΣPAHs in Kuwaiti car (950) and household floor (1675) dust samples were lower than Saudi dust. The PAHs profile in Saudi dust was dominated by high molecular weight (HMW) (4-5 ring) PAHs while in Kuwaiti dust 3 ring PAHs have marked contribution. BaP equivalent, a marker for carcinogenic PAHs, was high in Saudi household floor and AC filter dust with median levels (ng/g) of 370 and 455, respectively. Different exposure scenarios, using 5th percentile, median, mean, and 95th percentile levels, were estimated for adults and toddlers. For Saudi and Kuwaiti toddlers worst exposure scenario of ΣPAHs was calculated at 175 and 85ng/kg body weight/day (ng/kgbw/d), respectively. For Saudi toddlers, the calculated worst exposure scenarios for carcinogenic BaP (27.7) and BbF (29.3ng/kgbw/d) was 2-4 times higher than Kuwaiti toddlers. This study is based on small number of samples which necessitate more detailed studies for better understanding of dynamics of PAHs in the indoor environments of this region. Nevertheless, our finding supports the ongoing exposure of organic pollutants to population that accumulates indoor. Copyright © 2016. Published by Elsevier B.V.

Sulfate and nitrate in Asian dust particles observed in desert, coastal and marine air

NASA Astrophysics Data System (ADS)

Zhang, D.; Wu, F.; Junji, C.

2016-12-01

Sulfate and nitrate in dust particles are believed to be two key species which can largely alter the physical and chemical properties of the particles in the atmosphere, in particular under humid conditions. Their occurrence in the particles has usually been considered to be the consequence of particles' aging during their long-distance travel in the air although they are present in some crustal minerals. Our observations at two deserts in China during dust episodes revealed that there were soil-derived sulfate and background-like nitrate in atmospheric dust samples. Sulfate in dust samples was proportional to samples' mass and comprised at steady mass percentages in differently sized samples. In contrast, nitrate concentration was approximately stable and independent from dust loading. Our observations at inland and coastal areas of China during dust episodes revealed that sulfate and nitrate were hardly produced on the surface of dust particles that were originated from the deserts areas in northwestern China. This is because the dust particles were in the postfrontal air, where the temperature was low and the relative humidity was small due to the adiabatic properties of the air mass. There are a number studies reporting that sulfate and nitrate had been efficiently produced on mineral particles in inland areas of China. However, those mineral particles were more likely from the local areas rather than from the desert areas. Our observations in the coastal areas of Japan, which is located in the downstream areas of the Asian continent and surrounded by sea areas revealed that dust particles appearing there frequently contained sulfate and nitrate, indicating sulfate and nitrate had been efficiently produced on the surface of the particles when the particles traveled in the marine air between China and Japan.

Online Characterisation of Mineral Dust Aerosol by Single Particle Mass Spectrometry: Mineralogical Signatures of Potential Source Areas in North Africa.

NASA Astrophysics Data System (ADS)

Marsden, N. A.; Allan, J. D.; Flynn, M.; Ullrich, R.; Moehler, O.; Coe, H.

2017-12-01

The mineralogy of individual dust particles is important for atmospheric processes because mineralogy influences optical properties, their potential to act as ice nucleating particles (INP) and geochemical cycling of elements to the ocean. Bulk mineralogy of transported mineral dust has been shown to be a reflection of the source area and size fractionation during transport. Online characterisation of single particle mineralogy is highly desirable as the composition of individual particles can be reported at a temporal resolution that is relevant to atmospheric processes. Single particle mass spectrometry (SPMS) has indentified and characterised the composition of ambient dust particles but is hampered by matrix effects that result in a non-quantatative measurement of composition. The work presented describes a comparison of mass spectral characteristics of sub 2.5μm particle fractions generated from; i) nominally pure samples from the clay mineral society (CMS), ii) soil samples collected from potential source areas in North Africa and iii) ambient measurement of transported African dust made at the Cape Verde Islands. Using a novel approach to analyse the mass spectra, the distinct characteristics of the various dust samples are obtained from the online measurements. Using this technique it was observed that dust generated from sources on the North West Margin of the Sahara Desert have distinct characteristics of illite in contrast to the kaolinitic characteristics of dust generated from sources in the Sahel. These methods offer great potential for describing the hourly variation in the source and mineralogy of transported mineral dust and the online differentiation of mineral phase in multi-mineralic dust samples.

Daily intake of polybrominated diphenyl ethers via dust and diet from an e-waste recycling area in China.

PubMed

Jiang, Hong; Lin, Zhenkun; Wu, Yuanyuan; Chen, Xiangping; Hu, Yabing; Li, Yanyan; Huang, Changjiang; Dong, Qiaoxiang

2014-07-15

This study was designed to estimate the human risk to polybrominated diphenyl ethers (PBDEs) exposure via two main exposure routes (dust and diet) in an e-waste recycling area in southern China. A total of 134 dust samples and 129 food samples were analyzed by gas chromatography/mass spectrometry (GC/MS). The mean concentration of ΣPBDE in in-house dust (38,685ng/g dw) was higher than that in out-house dust (24,595ng/g). For food samples, the highest concentration of ΣPBDE was found in fish and shellfish (2755ng/kg ww), followed in descending order by eggs (2423ng/kg), cereals (2239ng/kg) and meat (1799ng/kg). The estimated total daily dietary intake of PBDEs was 1671ng/day for adults and 952ng/day for children. The present study indicated that dust intake was the dominant PBDE exposure route for children, and the dietary intake was the dominant PBDE exposure route for adults. Our findings revealed high PBDE concentrations in dust and food samples collected at the center of e-waste recycling area, raising significant health concerns for residents in this particular region, especially for children. Copyright © 2014 Elsevier B.V. All rights reserved.

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...

Evaluation of coral pathogen growth rates after exposure to atmospheric African dust samples

USGS Publications Warehouse

Lisle, John T.; Garrison, Virginia H.; Gray, Michael A.

2014-01-01

Laboratory experiments were conducted to assess if exposure to atmospheric African dust stimulates or inhibits the growth of four putative bacterial coral pathogens. Atmospheric dust was collected from a dust-source region (Mali, West Africa) and from Saharan Air Layer masses over downwind sites in the Caribbean [Trinidad and Tobago and St. Croix, U.S. Virgin Islands (USVI)]. Extracts of dust samples were used to dose laboratory-grown cultures of four putative coral pathogens: Aurantimonas coralicida (white plague type II), Serratia marcescens (white pox), Vibrio coralliilyticus, and V. shiloi (bacteria-induced bleaching). Growth of A. coralicida and V. shiloi was slightly stimulated by dust extracts from Mali and USVI, respectively, but unaffected by extracts from the other dust sources. Lag time to the start of log-growth phase was significantly shortened for A. coralicida when dosed with dust extracts from Mali and USVI. Growth of S. marcescens and V. coralliilyticus was neither stimulated nor inhibited by any of the dust extracts. This study demonstrates that constituents from atmospheric dust can alter growth of recognized coral disease pathogens under laboratory conditions.

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

PubMed Central

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

2009-01-01

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

Variations in the structure of airborne bacterial communities in Tsogt-Ovoo of Gobi desert area during dust events.

PubMed

Maki, Teruya; Kurosaki, Yasunori; Onishi, Kazunari; Lee, Kevin C; Pointing, Stephen B; Jugder, Dulam; Yamanaka, Norikazu; Hasegawa, Hiroshi; Shinoda, Masato

2017-01-01

Asian dust events transport the airborne bacteria in Chinese desert regions as well as mineral particles and influence downwind area varying biological ecosystems and climate changes. However, the airborne bacterial dynamics were rarely investigated in the Gobi desert area, where dust events are highly frequent. In this study, air samplings were sequentially performed at a 2-m high above the ground at the sampling site located in desert area (Tsogt-Ovoo of Gobi desert; Mongolia 44.2304°N, 105.1700°E). During the dust event days, the bacterial cells and mineral particles increased to more than tenfold of concentrations. MiSeq sequencing targeting 16S ribosomal DNA revealed that the airborne bacteria in desert area mainly belonged to the classes Acidobacteria , Actinobacteria , Bacteroidetes , Chloroflexi , Bacilli , Alpha-proteobacteria , Beta-proteobacteria , and Gamma-proteobacteria. The bacterial community structures were different between dust events and non-dust events. The air samples collected at the dust events indicated high abundance rates of Alpha-proteobacteria , which were reported to dominate on the leaf surfaces of plants or in the saline lake environments. After the dust events, the members of Firmicutes ( Bacilli ) and Bacteroidetes , which are known to form endospore and attach with coarse particles, respectively, increased their relative abundances in the air samples. Presumably, the bacterial compositions and diversities in atmosphere significantly vary during dust events, which carry some particles from grassland (phyllo-sphere), dry lake, and sand surfaces, as well as some bacterial populations such as Firmicutes and Bacteroidetes maintain in the atmosphere for longer time.

Temporal Variability of Pesticide Concentrations in Homes and Implications for Attenuation Bias in Epidemiologic Studies

PubMed Central

Ward, Mary H.; Bell, Erin M.; Whitehead, Todd P.; Gunier, Robert B.; Friesen, Melissa C.; Nuckols, John R.

2013-01-01

Background: Residential pesticide exposure has been linked to adverse health outcomes in adults and children. High-quality exposure estimates are critical for confirming these associations. Past epidemiologic studies have used one measurement of pesticide concentrations in carpet dust to characterize an individual’s average long-term exposure. If concentrations vary over time, this approach could substantially misclassify exposure and attenuate risk estimates. Objectives: We assessed the repeatability of pesticide concentrations in carpet dust samples and the potential attenuation bias in epidemiologic studies relying on one sample. Methods: We collected repeated carpet dust samples (median = 3; range, 1–7) from 21 homes in Fresno County, California, during 2003–2005. Dust was analyzed for 13 pesticides using gas chromatography–mass spectrometry. We used mixed-effects models to estimate between- and within-home variance. For each pesticide, we computed intraclass correlation coefficients (ICCs) and the estimated attenuation of regression coefficients in a hypothetical case–control study collecting a single dust sample. Results: The median ICC was 0.73 (range, 0.37–0.95), demonstrating higher between-home than within-home variability for most pesticides. The expected magnitude of attenuation bias associated with using a single dust sample was estimated to be ≤ 30% for 7 of the 13 compounds evaluated. Conclusions: For several pesticides studied, use of one dust sample to represent an exposure period of approximately 2 years would not be expected to substantially attenuate odds ratios. Further study is needed to determine if our findings hold for longer exposure periods and for other pesticides. PMID:23462689

Determining the spatial variability of personal sampler inlet locations.

PubMed

Vinson, Robert; Volkwein, Jon; McWilliams, Linda

2007-09-01

This article examines the spatial variability of dust concentrations within a coal miner's breathing zone and the impact of sampling location at the cap lamp, nose, and lapel. Tests were conducted in the National Institute for Safety and Health Pittsburgh Research Laboratory full-scale, continuous miner gallery using three prototype personal dust monitors (PDM). The dust masses detected by the PDMs were used to calculate the percentage difference of dust mass between the cap lamp and the nose and between the lapel and the nose. The calculated percentage differences of the masses ranged from plus 12% to minus 25%. Breathing zone tests were also conducted in four underground coal mines using the torso of a mannequin to simulate a miner. Coal mine dust was sampled with multi-cyclone sampling cans mounted directly in front of the mannequin near the cap lamp, nose, and lapel. These four coal mine tests found that the spatial variability of dust levels and imprecision of the current personal sampler is a greater influence than the sampler location within the breathing zone. However, a one-sample t-test of this data did find that the overall mean value of the cap lamp/nose ratio was not significantly different than 1 (p-value = 0.21). However, when applied to the overall mean value of the lapel/nose ratio there was a significant difference from 1 (p-value < .0001). This finding is important because the lapel has always been the sampling location for coal mine dust samples. But these results suggest that the cap location is slightly more indicative of what is breathed through the nose area.

Evaluation of Laser-Induced Breakdown Spectroscopy (LIBS) for Measurement of Silica on Filter Samples of Coal Dust

PubMed Central

Stipe, Christopher B.; Miller, Arthur L.; Brown, Jonathan; Guevara, Edward; Cauda, Emanuele

2015-01-01

Airborne silica dust (quartz) is common in coal mines and represents a respiratory hazard that can lead to silicosis, a potentially fatal lung disease. With an eye toward developing a portable monitoring device for rapid analysis of silica dust, laser-induced breakdown spectroscopy (LIBS) was used to quantify quartz in coal dust samples collected on filter media. Pure silica (Min-U-Sil™ 5), Georgia kaolin, and Pittsburgh-4 and Illinois-6 coal dusts were deposited separately and at multiple mass loadings onto 37-mm polyvinylchloride (PVC) filters. LIBS-generated silicon emission was monitored at 288.16 nm, and non-silica contributions to that signal from kaolinite were removed by simultaneously detecting aluminum. Measurements of the four samples were used to calculate limits of detection (LOD) for silicon and aluminum of approximately 0.08 µg/cm2 and 0.05 µg/cm2, respectively (corresponding to 0.16 µg/cm2 and 0.20 µg/cm2 for silica and kaolinite, respectively). Relative errors of prediction are around 10%. Results demonstrate that LIBS can dependably quantify silica on filter samples of coal dust and confirm that accurate quantification can be achieved for very lightly loaded samples, which supports the potential application of LIBS for rapid, in-field monitoring. PMID:23146184

Evaluation of laser-induced breakdown spectroscopy (LIBS) for measurement of silica on filter samples of coal dust.

PubMed

Stipe, Christopher B; Miller, Arthur L; Brown, Jonathan; Guevara, Edward; Cauda, Emanuele

2012-11-01

Airborne silica dust (quartz) is common in coal mines and represents a respiratory hazard that can lead to silicosis, a potentially fatal lung disease. With an eye toward developing a portable monitoring device for rapid analysis of silica dust, laser-induced breakdown spectroscopy (LIBS) was used to quantify quartz in coal dust samples collected on filter media. Pure silica (Min-U-Sil™ 5), Georgia kaolin, and Pittsburgh-4 and Illinois-6 coal dusts were deposited separately and at multiple mass loadings onto 37-mm polyvinylchloride (PVC) filters. LIBS-generated silicon emission was monitored at 288.16 nm, and non-silica contributions to that signal from kaolinite were removed by simultaneously detecting aluminum. Measurements of the four samples were used to calculate limits of detection (LOD) for silicon and aluminum of approximately 0.08 μg/cm(2) and 0.05 μg/cm(2), respectively (corresponding to 0.16 μg/cm(2) and 0.20 μg/cm(2) for silica and kaolinite, respectively). Relative errors of prediction are around 10%. Results demonstrate that LIBS can dependably quantify silica on filter samples of coal dust and confirm that accurate quantification can be achieved for very lightly loaded samples, which supports the potential application of LIBS for rapid, in-field monitoring.

Associations between PBDEs in Office Air, Dust, and Surface Wipes

PubMed Central

Watkins, Deborah J.; McClean, Michael D.; Fraser, Alicia J.; Weinberg, Janice; Stapleton, Heather M.; Webster, Thomas F.

2013-01-01

Increased use of flame-retardants in office furniture may increase exposure to PBDEs in the office environment. However, partitioning of PBDEs within the office environment is not well understood. Our objectives were to examine relationships between concurrent measures of PBDEs in office air, floor dust, and surface wipes. We collected air, dust, and surface wipe samples from 31 offices in Boston, MA. Correlation and linear regression were used to evaluate associations between variables. Geometric mean (GM) concentrations of individual BDE congeners in air and congener specific octanol-air partition coefficients (Koa) were used to predict GM concentrations in dust and surface wipes and compared to the measured concentrations. GM concentrations of PentaBDEs in office air, dust, and surface wipes were 472 pg/m3, 2411 ng/g, and 77 pg/cm2, respectively. BDE209 was detected in 100% of dust samples (GM=4202 ng/g), 93% of surface wipes (GM=125 pg/cm2), and 39% of air samples. PentaBDEs in dust and air were moderately correlated with each other (r=0.60, p=0.0003), as well as with PentaBDEs in surface wipes (r=0.51, p=0.003 for both dust and air). BDE209 in dust was correlated with BDE209 in surface wipes (r=0.69, p=0.007). Building (three categories) and PentaBDEs in dust were independent predictors of PentaBDEs in both air and surface wipes, together explaining 50% (p=0.0009) and 48% (p=0.001) of the variation respectively. Predicted and measured concentrations of individual BDE congeners were highly correlated in dust (r=0.98, p<0.0001) and surface wipes (r=0.94, p=002). BDE209 provided an interesting test of this equilibrium partitioning model as it is a low volatility compound. Associations between PentaBDEs in multiple sampling media suggest that collecting dust or surface wipes may be a convenient method of characterizing exposure in the indoor environment. The volatility of individual congeners, as well as physical characteristics of the indoor environment, influence relationships between PBDEs in air, dust, and surface wipes. PMID:23797055

Water uptake of clay and desert dust aerosol particles at sub- and supersaturated water vapor conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herich, Hanna; Tritscher, Torsten; Wiacek, Aldona

2009-11-01

Airborne mineral dust particles serve as cloud condensation nuclei (CCN), thereby influencing the formation and properties of warm clouds. It is therefore of particular interest how dust aerosols with different mineralogy behave when exposed to high relative humidity (RH) or supersaturation with respect to liquid water similar to atmospheric conditions. In this study the sub-saturated hygroscopic growth and the supersaturated cloud condensation nucleus activity of pure clays and real desert dust aerosols was determined using a hygroscopicity tandem differential mobility analyzer (HTDMA) and a cloud condensation nuclei counter (CCNC), respectively. Five different illite, montmorillonite and kaolinite clay samples as wellmore » as three desert dust samples (Saharan dust (SD), Chinese dust (CD) and Arizona test dust (ATD)) were used. Aerosols were generated both with a wet and a dry disperser and the water uptake was parameterized via the hygroscopicity parameter, κ. The hygroscopicity of dry generated dust aerosols was found to be negligible when compared to processed atmospheric aerosols, with CCNC derived κ values between 0.00 and 0.02. The latter value can be idealized as a particle consisting of 96.7% (by volume) insoluble material and ~3.3% ammonium sulfate. Pure clay aerosols were found to be generally less hygroscopic than real desert dust particles. All illite and montmorillonite samples had κ~0.003, kaolinites were least hygroscopic and had κ=0.001. SD (κ=0.023) was found to be the most hygroscopic dry-generated desert dust followed by CD (κ=0.007) and ATD (κ=0.003). Wet-generated dust showed an increased water uptake when compared to dry-generated samples. This is considered to be an artifact introduced by redistribution of soluble material between the particles while immersed in an aqueous medium during atomization, thus indicating that specification of the generation method is critically important when presenting such data. Any atmospheric processing of fresh mineral dust which leads to the addition of more than ~3% soluble material is expected to significantly enhance hygroscopicity and CCN activity.« less

Permissible Exposure Level for Lunar Dusts: Gaps are Closing

NASA Technical Reports Server (NTRS)

James, John T.; Lam, Chiu-Wing; Scully Robert; Santana, Patricia; Cooper, Bonnie; McKay, David; Zeidler-Erdely, Patti C.; Castranova, Vincent

2010-01-01

Space faring nations plan to return human explorers to the moon within the next decade. Experience during the Apollo flights suggests that lunar dust will invariably get into the habitat where the finest portion (less than 5 micrometers) could be inhaled by the crew before it is cleared from the atmosphere. NASA is developing a database from which a 6-month, episodic exposure standard for lunar dust can be set. Three kinds of moon dust were prepared from a parent sample of Apollo 14 regolith #14003,96. Our goal was to prepare each type of dust sample with a mean diameter less than 2 m, which is suitable for instillation into the lungs of rats. The three samples were prepared as follows: separation from the parent sample using a fluidized bed, grinding using a jet mill grinder, or grinding with a ball-mill grinder. Grinding simulated restoration of surface activation of dust expected to occur at the surface of the moon on native lunar dust. We used two grinding methods because they seemed to produce different modes of activation. The effects of grinding were preserved by maintaining the dust in ultra-pure nitrogen until immediately before it was placed in suspension for administration to rats. The dust was suspended in physiological saline with 10% Survanta, a lung surfactant. Rats were given intratrachael instillations of the dust suspension at three doses. In addition to the three moon dusts (A, C and E), we instilled the same amount of a negative control (TiO2, B) and a highly-toxic, positive control (quartz, D). These additional mineral dusts were selected because they have well-established and very different permissible exposure levels (PELs). Our goal was to determine where lunar dusts fit between these extremes, and then estimate a PEL for each lunar dust. We evaluated many indices of toxicity to the lung. The figure shows the changes in lactate dehydrogenase (LDH), a marker of cell death, for the five dusts. Benchmark dose software (Version 2.1.2) from the Environmental Protection Agency was used to estimate the 10% effect levels (BMD(sub 10)) using five models. The best-fitting model was used to estimate the optimal BMD(sub 10) (table)

Prevalence of high frequency hearing loss consistent with noise exposure among people working with sound systems and general population in Brazil: A cross-sectional study

PubMed Central

El Dib, Regina P; Silva, Edina MK; Morais, José F; Trevisani, Virgínia FM

2008-01-01

Background Music is ever present in our daily lives, establishing a link between humans and the arts through the senses and pleasure. Sound technicians are the link between musicians and audiences or consumers. Recently, general concern has arisen regarding occurrences of hearing loss induced by noise from excessively amplified sound-producing activities within leisure and professional environments. Sound technicians' activities expose them to the risk of hearing loss, and consequently put at risk their quality of life, the quality of the musical product and consumers' hearing. The aim of this study was to measure the prevalence of high frequency hearing loss consistent with noise exposure among sound technicians in Brazil and compare this with a control group without occupational noise exposure. Methods This was a cross-sectional study comparing 177 participants in two groups: 82 sound technicians and 95 controls (non-sound technicians). A questionnaire on music listening habits and associated complaints was applied, and data were gathered regarding the professionals' numbers of working hours per day and both groups' hearing complaint and presence of tinnitus. The participants' ear canals were visually inspected using an otoscope. Hearing assessments were performed (tonal and speech audiometry) using a portable digital AD 229 E audiometer funded by FAPESP. Results There was no statistically significant difference between the sound technicians and controls regarding age and gender. Thus, the study sample was homogenous and would be unlikely to lead to bias in the results. A statistically significant difference in hearing loss was observed between the groups: 50% among the sound technicians and 10.5% among the controls. The difference could be addressed to high sound levels. Conclusion The sound technicians presented a higher prevalence of high frequency hearing loss consistent with noise exposure than did the general population, although the possibility of residual confounding due to unmeasured factors such as socioeconomic status cannot be ruled out. PMID:18462490

Preliminary assessment of an economical fugitive road dust sampler for the collection of bulk samples for geochemical analysis.

PubMed

Witt, Emitt C; Wronkiewicz, David J; Shi, Honglan

2013-01-01

Fugitive road dust collection for chemical analysis and interpretation has been limited by the quantity and representativeness of samples. Traditional methods of fugitive dust collection generally focus on point-collections that limit data interpretation to a small area or require the investigator to make gross assumptions about the origin of the sample collected. These collection methods often produce a limited quantity of sample that may hinder efforts to characterize the samples by multiple geochemical techniques, preserve a reference archive, and provide a spatially integrated characterization of the road dust health hazard. To achieve a "better sampling" for fugitive road dust studies, a cyclonic fugitive dust (CFD) sampler was constructed and tested. Through repeated and identical sample collection routes at two collection heights (50.8 and 88.9 cm above the road surface), the products of the CFD sampler were characterized using particle size and chemical analysis. The average particle size collected by the cyclone was 17.9 μm, whereas particles collected by a secondary filter were 0.625 μm. No significant difference was observed between the two sample heights tested and duplicates collected at the same height; however, greater sample quantity was achieved at 50.8 cm above the road surface than at 88.9 cm. The cyclone effectively removed 94% of the particles >1 μm, which substantially reduced the loading on the secondary filter used to collect the finer particles; therefore, suction is maintained for longer periods of time, allowing for an average sample collection rate of about 2 g mi. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Angiographic core laboratory reproducibility analyses: implications for planning clinical trials using coronary angiography and left ventriculography end-points.

PubMed

Steigen, Terje K; Claudio, Cheryl; Abbott, David; Schulzer, Michael; Burton, Jeff; Tymchak, Wayne; Buller, Christopher E; John Mancini, G B

2008-06-01

To assess reproducibility of core laboratory performance and impact on sample size calculations. Little information exists about overall reproducibility of core laboratories in contradistinction to performance of individual technicians. Also, qualitative parameters are being adjudicated increasingly as either primary or secondary end-points. The comparative impact of using diverse indexes on sample sizes has not been previously reported. We compared initial and repeat assessments of five quantitative parameters [e.g., minimum lumen diameter (MLD), ejection fraction (EF), etc.] and six qualitative parameters [e.g., TIMI myocardial perfusion grade (TMPG) or thrombus grade (TTG), etc.], as performed by differing technicians and separated by a year or more. Sample sizes were calculated from these results. TMPG and TTG were also adjudicated by a second core laboratory. MLD and EF were the most reproducible, yielding the smallest sample size calculations, whereas percent diameter stenosis and centerline wall motion require substantially larger trials. Of the qualitative parameters, all except TIMI flow grade gave reproducibility characteristics yielding sample sizes of many 100's of patients. Reproducibility of TMPG and TTG was only moderately good both within and between core laboratories, underscoring an intrinsic difficulty in assessing these. Core laboratories can be shown to provide reproducibility performance that is comparable to performance commonly ascribed to individual technicians. The differences in reproducibility yield huge differences in sample size when comparing quantitative and qualitative parameters. TMPG and TTG are intrinsically difficult to assess and conclusions based on these parameters should arise only from very large trials.

The episodic influx of tin-rich cosmic dust particles during the last ice age

NASA Astrophysics Data System (ADS)

LaViolette, Paul A.

2015-12-01

This paper presents evidence of the first detection of interstellar dust in ice age polar ice. Neutron activation analysis (NAA) results are reported for 15 elements found in dust filtered from eight samples of Camp Century Greenland ice dating from 40 to 78 kyrs BP. High concentrations of Sn, Sb, Au, Ag, Ir, and Ni were found to be present in three out of these eight samples. One compositionally anomalous dust sample from an ice core depth of 1230.5 m (age ∼49 kyrs BP, near the beginning of D/O stadial No. 13) was found to contain tin with an average weight percent of 49% as determined by energy dispersive X-ray analysis (EDS). This sample was also found to contain high concentrations of Pb with an average weight abundance of 8.4% and matching the Sn:Pb ratio observed in interstellar spectra. Dust particles in this sample generally have a platy morphology and range from submicron size up to a size as large as 120 μm, a particle consisting almost entirely of SnO2 and being the largest monomineralic extraterrestrial dust particle so far discovered. One porous aggregate tin-bearing particle was found to contain nanometer sized chondrules indicating an extraterrestrial origin. The extraterrestrial origin for the tin is also indicated by the presence of isotopic anomalies in the 114Sn, 115Sn and 117Sn isotopes. Follow up isotopic measurements of this tin-rich dust need to be performed to improve confidence in the anomalies reported here. High abundances of the low melting point elements Ag, Au, and Sb are also present in this tin-rich sample along with elevated abundances of the siderophiles Ir, Ni, Fe, and Co, the latter being present in chondritic proportions and indicating that about 9% of the dust has a C1 chondrite component. Measurements indicate that about 97% of this dust is of extraterrestrial origin with a 3% residual being composed of terrestrial windblown dust. EDS analysis of another tin-rich Camp Century ice core dust sample dating to ∼130 kyrs BP was found to contain tin-rich particles with a similar platy morphology and to have Sn and Pb weight abundances averaging 39% and 7.5% respectively, again approximating the interstellar Sn:Pb ratio. The relative absence of cosmic microspheres and the unmelted appearance of the tin-rich particles in both of these samples suggests that these particles entered the Earth's atmosphere at low velocity, implicating a gradual accumulation of dust from a dispersed state in the near Earth space environment. The unusual enhancement of Sn and Pb could be explained if these dust particles were originally present in the solar system's interstellar environment in a superconducting native metal state and were preferentially concentrated through Meissner effect forces by the passage of cosmic ray driven hydromagnetic shocks which may also have transported them into the solar system. The 49 kyrs BP event is estimated to have lasted over 6 years and to have deposited dust onto the Earth at a rate 104-105 times higher than present rates. This had a significant cooling effect on climate and resulted in a transient 33 fold increase in snow accumulation. Future discovery of these events in ice cores at other locations should void any lingering thoughts that this heavy metal enhancement may be due to sample contamination.

Human exposure to brominated flame retardants through dust in different indoor environments: Identifying the sources of concentration differences in hair from men and women.

PubMed

Li, Junqi; Dong, Zheng; Wang, Ying; Bao, Junsong; Yan, Yijun; Liu, Anming; Jin, Jun

2018-08-01

Brominated flame retardants (BFRs) can accumulate in humans and are associated with adverse health effects. The study was conducted to determine the differences in Polybrominated diphenyl ethers (PBDEs) and alternative brominated flame retardant (Alt-BFR) concentrations between men and women. We analyzed hair samples from 14 male and 20 female university students, paired dust samples from their dormitories (10 for males and 8 for females), and six dust samples from university teaching buildings. The total PBDE concentrations in hair from females were significantly (three times) higher (p = 0.012) than that from males (means 372 and 109 ng/g, respectively). The mean total PBDE concentrations in classroom and dormitory dust were 36100 and 2012 ng/g, respectively. The PBDE patterns were different in the male and female hair samples, as were the patterns in the classroom and dormitory dust. There are no reports concerning human exposure to BFRs through dust that was assessed considering academic and residential environments simultaneously. The differences between BFR exposure for males and females and the differences between BFR concentrations in hair samples from males and females were consistent for 71.4% of the compounds. However, using only dormitory dust in the calculations gave consistent differences only for 28.6% of the compounds, suggesting that the BFR concentration differences in hair were mainly because females spent much more time than males in classrooms. Copyright © 2018 Elsevier Ltd. All rights reserved.

[Health risk assessment of heavy metals in atmospheric dust of Qingdao City].

PubMed

Zhang, Chun-Rong; Wu, Zheng-Long; Yao, Chun-Hui; Gao, Zong-Jun

2014-07-01

Based on the 89 atmospheric dust samples and soil samples that were collected around Qingdao, we tested and analyzed the contents of Cd, Cr, Cu, Hg, Ni, Pb, Zn. Based on these analysis results, the risk of heavy metals in atmospheric dusts to human health were assessed by using the US EPA Health Risk Assessment Model. Analysis showed that the average contents of Cd, Cr, Cu, Hg, Pb, Zn in the atmospheric dust of Shinan, Shibei and Laoshan districts were the highest. Therefore, the air pollution of these districts was more serious than the districts of Licang, Chengyang and Huangdao. Comparing the average contents of heavy metals in atmospheric dust with those in soil, we found that only the content of Hg in atmospheric dust collected from the districts of Shinan, Shibei and Laoshan was lower than that in the corresponding soil. All the contents of other heavy metals in atmospheric dust were higher than those in corresponding soil. As a whole, the heavy metals in atmospheric dust of Qingdao City showed slight difference and were less harmful to human health. However, it was harmful in some samples to human health if the contents of Cr and Pb in atmospheric dusts of Shinan, Laoshan and Chengyang districts were always kept at such high densities. Besides, the accumulation of heavy metals in atmospheric dust through various approaches and categories may obviously increase the risk of damaging human health.

Treated and untreated rock dust: Quartz content and physical characterization.

PubMed

Soo, Jhy-Charm; Lee, Taekhee; Chisholm, William P; Farcas, Daniel; Schwegler-Berry, Diane; Harper, Martin

2016-11-01

Rock dusting is used to prevent secondary explosions in coal mines, but inhalation of rock dusts can be hazardous if the crystalline silica (e.g., quartz) content in the respirable fraction is high. The objective of this study is to assess the quartz content and physical characteristics of four selected rock dusts, consisting of limestone or marble in both treated (such as treatment with stearic acid or stearates) and untreated forms. Four selected rock dusts (an untreated and treated limestone and an untreated and treated marble) were aerosolized in an aerosol chamber. Respirable size-selective sampling was conducted along with particle size-segregated sampling using a Micro-Orifice Uniform Deposit Impactor. Fourier Transform Infrared spectroscopy and scanning electron microscopy with energy-dispersive X-ray (SEM-EDX) analyses were used to determine quartz mass and particle morphology, respectively. Quartz percentage in the respirable dust fraction of untreated and treated forms of the limestone dust was significantly higher than in bulk samples, but since the bulk percentage was low the enrichment factor would not have resulted in any major change to conclusions regarding the contribution of respirable rock dust to the overall airborne quartz concentration. The quartz percentage in the marble dust (untreated and treated) was very low and the respirable fractions showed no enrichment. The spectra from SEM-EDX analysis for all materials were predominantly from calcium carbonate, clay, and gypsum particles. No free quartz particles were observed. The four rock dusts used in this study are representative of those presented for use in rock dusting, but the conclusions may not be applicable to all available materials.

Efficiency of wipe sampling on hard surfaces for pesticides and PCB residues in dust.

PubMed

Cettier, Joane; Bayle, Marie-Laure; Béranger, Rémi; Billoir, Elise; Nuckols, John R; Combourieu, Bruno; Fervers, Béatrice

2015-02-01

Pesticides and polychlorinated biphenyls (PCBs) are commonly found in house dust and have been described as a valuable matrix to assess indoor pesticide and PCB contamination. The aim of this study was to assess the efficiency and precision of cellulose wipe for collecting 48 pesticides, eight PCBs, and one synergist at environmental concentrations. First, the efficiency and repeatability of wipe collection were determined for pesticide and PCB residues that were directly spiked onto three types of household floors (tile, laminate, and hardwood). Second, synthetic dust was used to assess the capacity of the wipe to collect dust. Third, we assessed the efficiency and repeatability of wipe collection of pesticides and PCB residues that was spiked onto synthetic dust and then applied to tile. In the first experiment, the overall collection efficiency was highest on tile (38%) and laminate (40%) compared to hardwood (34%), p<0.001. The second experiment confirmed that cellulose wipes can efficiently collect dust (82% collection efficiency). The third experiment showed that the overall collection efficiency was higher in the presence of dust (72% vs. 38% without dust, p<0.001). Furthermore, the mean repeatability also improved when compounds were spiked onto dust (<30% for the majority of compounds). To our knowledge, this is the first study to assess the efficiency of wipes as a sampling method using a large number of compounds at environmental concentrations and synthetic dust. Cellulose wipes appear to be efficient to sample the pesticides and PCBs that adsorb onto dust on smooth and hard surfaces. Copyright © 2014 Elsevier B.V. All rights reserved.

Dental technician pneumoconiosis mimicking lung cancer.

PubMed

Uyar, Meral; Sokucu, Oral; Sanli, Maruf; Filiz, Ayten; Ali Ikidag, Mehmet; Feridun Isik, Ahmet; Bakir, Kemal

2015-09-01

A 47-year-old man was referred for assessment of bilateral lymph node enlargement identified on a routine chest radiograph. Positron emission tomography showed high standardized uptake values (SUVmax: 20.5) in right supraclavicular, right intercostal, and multiple mediastinal lymph nodes. Biopsy samples obtained from the right upper and left lower paratracheal nodes by mediastinoscopy revealed granulomatous inflammation. Clinical and laboratory findings indicated a diagnosis of dental technician pneumoconiosis. The patient is alive and well 3 years after diagnosis. This case highlights the importance of obtaining an occupational history.

Granulometry, microbial composition and biological activity of dusts collected in French dairy farms.

PubMed

Pfister, Hugo; Morzadec, Claudie; Le Cann, Pierre; Madec, Laurent; Lecureur, Valérie; Chouvet, Martine; Jouneau, Stéphane; Vernhet, Laurent

2017-10-01

Dairy working increases the prevalence of lower airway respiratory diseases, especially COPD and asthma. Epidemiological studies have reported that chronic inhalation of organic dusts released during specific daily tasks could represent a major risk factor for development of these pathologies in dairy workers. Knowledge on size, nature and biological activity of such organic dusts remain however limited. To compare size distribution, microbial composition and cellular effects of dusts liberated by the spreading of straw bedding in five French dairy farms located in Brittany. Mechanized distribution of straw bedding generated a cloud of inhalable dusts in the five dairy farms' barns. Thoracic particles having a 3-7.5µm size constituted 58.9-68.3% of these dusts. Analyses of thoracic dusts by next generation sequencing showed that the microbial dust composition differed between the five French farms, although Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria represent more than 97.5% of the bacterial phyla detected in each sample. Several bacteria genera comprising of human pathogenic species, such as Pseudomonas, Staphylococcus, Thermoactinomyces or Saccharopolyspora were identified. Cladosporium and Alternaria fungal genera, which are potent environmental determinants of respiratory symptoms, were detected in dusts collected in the five farms and their levels reached 15.5-51.1% and 9-24.7% of assignable fungal sequences in each sample, respectively. Finally, all dust samples significantly and strongly increased the expression of the pro-inflammatory TNF-α, IL-1β, IL-6 and IL-8 cytokines at both mRNA and protein levels in human monocyte-derived macrophages. Their effects were dose-dependent and detectable from 1µg/ml. The intensity of the macrophage responses however differed according to the samples. Our results strengthen the hypothesis that organic dusts released during the distribution of straw bedding are mainly constituted of thoracic particles which are small enough to deposit on lower bronchial epithelium of dairy farmers and induce inflammation. Copyright © 2017 Elsevier Inc. All rights reserved.

Multidisciplinary studies of the dust storm that affected Sydney in September 2009

NASA Astrophysics Data System (ADS)

De Deckker, P.

2012-04-01

A major dust storm transgressed over southeastern Australia in September 2009 and continued as far as northern Queensland [to the north], New Zealand and New Caledonia [to the east] . We analysed samples of the dust for organic compounds, its microbiological composition, pollen, trace and rare earth elements as well as Sr and Nd isotopes. Grain size analysis was also performed on some of the samples. We also obtained information on the meteorological conditions that led to the large dust plume and its pathway. Our geochemical fingerprinting allowed us to determine the origin of the dust, and this was confirmed by meteorological observations and satellite imagery. As the pathway of the dust plume went over the city of Canberra, located to the southwest of Sydney, we were able to collect samples of dust that fell with rain, and the surprise was that the geochemical composition of the dust varied with time [and dust fall], identifying that as the dust plume transgressed over the landscape, it picked up additional material that was compositionally different from its point of origin. We also compared our data with those obtained from another major dust event that affected Canberra in October 2002, and a number of important differences are noted, particularly with respect of the microbiological composition of the dust, and its chemical composition. Collaborators on this project are: Chris Munday and Gwen Allison [microbiology]: Research School of Biology, ANU; Jochen Brocks and Janet Hope [organic chemistry] and Marc Norman [inorganic geochemistry]: Research School of Earth Sciences, ANU; Tadhg O'Loingsigh and Nigel Tapper [meteorology, satellite imagery] and Sander van der Kaars [palynology]: Geography and Environmental Science, Monash University; and J.-B. Stuut [grain size analysis], NIOZ.

Diploma Training for Chemical Technicians in Australia

NASA Astrophysics Data System (ADS)

Lampard, Mark G.

1999-07-01

We describe aspects of the present and past training of chemical technicians in Australia, with particular reference to that for senior technicians, technical officers, and those anticipating a career in laboratory management (i.e., diploma courses). We refer to the present study pathways for beginning science technicians leading to a full-time (or part-time equivalent) diploma course offered either by the State Departments of Technical and Further Education (TAFE) or by the universities. Credit for appropriate diploma subjects towards a university science degree is available. We emphasize the national unified nature of training according to the Australian Qualifications Framework (AQF), which sets syllabi for subjects in conjunction with the Australian Standards Framework (ASF) levels that depend on such factors as breadth, depth, and complexity of skills and knowledge, range of activities undertaken, degree to which tasks are routine or complex, level of judgment required, and level of autonomy and responsibility for others. Recognition of the two-year diploma with suitable chemical laboratory or technology experience is through the Royal Australian Chemical Institute (RACI), and the letters AT (Associate Technician) RACI denote the new grade of membership of the RACI, the equivalent of the ACS in America. Sample structures for a Certificate IV and Diploma of Chemical Laboratory Technology are given.

Fluorescence detection of protein content in house dust: the possible role of keratin.

PubMed

Voloshina, O V; Shirshin, E A; Lademann, J; Fadeev, V V; Darvin, M E

2017-03-01

We propose a fluorescence method for protein content assessment in fine house dust, which can be used as an indicator of the hygienic state of occupied rooms. The results of the measurements performed with 30 house dust samples, including ultrafiltration experiments, strongly suggest that the fluorescence emission of house dust extracts excited at 350 nm is mainly due to protein fragments, which are presumably keratin hydrolysates. This suggestion is supported by several facts: (i) Spectral band shapes for all the samples under investigation are close and correspond to that of keratin; (ii) fluorescence intensity correlates with the total protein content as provided by Lowry assay; (iii) treatment of the samples with proteinase K, which induces keratin hydrolysis, results in fluorescence enhancement without changing fluorescence band shape; and (iv) Raman spectra of keratin and fine house dust samples exhibit a very similar structure. Based on the obtained results and literature data, we propose a hypothesis that keratin is a major substrate for fluorescence species in fine house dust, which are responsible for emission at 350-nm excitation. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Allergens in Urban Schools and Homes of Children with Asthma

PubMed Central

Permaul, Perdita; Hoffman, Elaine B.; Fu, Chunxia; Sheehan, William J.; Baxi, Sachin N.; Gaffin, Jonathan M.; Lane, Jeffrey P.; Bailey, Ann; King, Eva; Chapman, Martin D.; Gold, Diane R.; Phipatanakul, Wanda

2012-01-01

Background Most studies of indoor allergens have focused on the home environment. However, schools may be an important site of allergen exposure for children with asthma. We compared school allergen exposure to home exposure in a cohort of children with asthma. Correlations between settled dust and airborne allergen levels in classrooms were examined. Methods Settled dust and airborne samples from 12 inner-city schools were analyzed for indoor allergens using multiplex array technology (MARIA). School samples were linked to students with asthma enrolled in the School Inner-City Asthma Study (SICAS). Settled dust samples from students’ bedrooms were analyzed similarly. Results From schools, 229 settled dust and 197 airborne samples were obtained. From homes, 118 settled dust samples were obtained. Linear mixed regression models of log-transformed variables showed significantly higher settled dust levels of mouse, cat and dog allergens in schools than homes (545% higher for Mus m 1, estimated absolute difference 0.55 μg/g, p<0.0001; 198% higher for Fel d 1, estimated absolute difference 0.13 μg/g, p=0.0033; and 144% higher for Can f 1, estimated absolute difference 0.05 μg/g, p=0.0008). Airborne and settled dust Mus m 1 levels in classrooms were moderately correlated (r=0.48; p< 0.0001). There were undetectable to very low levels of cockroach and dust mite allergens in both homes and schools. Conclusions Mouse allergen levels in schools were substantial. In general, cat and dog allergen levels were low, but detectable, and were higher in schools. Aerosolization of mouse allergen in classrooms may be a significant exposure for students. Further studies are needed to evaluate the effect of indoor allergen exposure in schools on asthma morbidity in students with asthma. PMID:22672325

Measurements of cloud condensation nuclei activity and droplet activation kinetics of wet processed regional dust samples and minerals

NASA Astrophysics Data System (ADS)

Kumar, P.; Sokolik, I. N.; Nenes, A.

2011-04-01

This study reports laboratory measurements of particle size distributions, cloud condensation nuclei (CCN) activity, and droplet activation kinetics of wet generated aerosols from clays, calcite, quartz, and desert soil samples from Northern Africa, East Asia/China, and Northern America. The dependence of critical supersaturation, sc, on particle dry diameter, Ddry, is used to characterize particle-water interactions and assess the ability of Frenkel-Halsey-Hill adsorption activation theory (FHH-AT) and Köhler theory (KT) to describe the CCN activity of the considered samples. Regional dust samples produce unimodal size distributions with particle sizes as small as 40 nm, CCN activation consistent with KT, and exhibit hygroscopicity similar to inorganic salts. Clays and minerals produce a bimodal size distribution; the CCN activity of the smaller mode is consistent with KT, while the larger mode is less hydrophilic, follows activation by FHH-AT, and displays almost identical CCN activity to dry generated dust. Ion Chromatography (IC) analysis performed on regional dust samples indicates a soluble fraction that cannot explain the CCN activity of dry or wet generated dust. A mass balance and hygroscopicity closure suggests that the small amount of ions (of low solubility compounds like calcite) present in the dry dust dissolve in the aqueous suspension during the wet generation process and give rise to the observed small hygroscopic mode. Overall these results identify an artifact that may question the atmospheric relevance of dust CCN activity studies using the wet generation method. Based on a threshold droplet growth analysis, wet generated mineral aerosols display similar activation kinetics compared to ammonium sulfate calibration aerosol. Finally, a unified CCN activity framework that accounts for concurrent effects of solute and adsorption is developed to describe the CCN activity of aged or hygroscopic dusts.

Cytotoxic and Inflammatory Potential of Air Samples from Occupational Settings with Exposure to Organic Dust

PubMed Central

Viegas, Susana; Caetano, Liliana Aranha; Korkalainen, Merja; Faria, Tiago; Pacífico, Cátia; Carolino, Elisabete; Quintal Gomes, Anita; Viegas, Carla

2017-01-01

Organic dust and related microbial exposures are the main inducers of several respiratory symptoms. Occupational exposure to organic dust is very common and has been reported in diverse settings. In vitro tests using relevant cell cultures can be very useful for characterizing the toxicity of complex mixtures present in the air of occupational environments such as organic dust. In this study, the cell viability and the inflammatory response, as measured by the production of pro-inflammatory cytokines tumor necrosis factor-α (TNFα) and interleukin-1 β (IL-1β), were determined in human macrophages derived from THP-1 monocytic cells. These cells were exposed to air samples from five occupational settings known to possess high levels of contamination of organic dust: poultry and swine feed industries, waste sorting, poultry production and slaughterhouses. Additionally, fungi and particle contamination of those settings was studied to better characterize the organic dust composition. All air samples collected from the assessed workplaces caused both cytotoxic and pro-inflammatory effects. The highest responses were observed in the feed industry, particularly in swine feed production. This study emphasizes the importance of measuring the organic dust/mixture effects in occupational settings and suggests that differences in the organic dust content may result in differences in health effects for exposed workers. PMID:29051440

Physical and Chemical Characteristics of Desert Dust Deposited on Mt. Elbrus, Caucasus as Documented in Snow Pit and Shallow Core Records

NASA Astrophysics Data System (ADS)

Kutuzov, S.; Shahgedanova, M.; Mikhalenko, V.; Ginot, P.; Lavrentiev, I.; Popov, G.

2013-12-01

We present a study of dust deposition events and its physical and chemical characteristics in Caucasus Mountains as documented by snow and firn pack at Mt Elbrus. Dust samples were collected from the shallow ice cores and snow pits in 2009-2013 at the western Elbrus plateau (5150 m a.s.l.). Particle size distribution and chemical analysis (major ions, trace elements) were completed for each sample using Coulter Counter Multisizer III, scanning electron microscopy (SEM), IC and ICPMS analysis. It was shown that desert dust deposition occurred in Caucasus 4-8 times a year and originates from the Northern Sahara and the deserts of the Middle East. Analysis of volumetric particle size distributions showed that the modal values ranged between 2 μm and 4 μm although most samples were characterised by modal values of 2.0-2.8 μm with an average of 2.6 μm. These values are lower than those obtained from the ice cores in central and southern Asia following the deposition of long-travelled dust and are closer to those reported for the European Alps and the polar ice cores. All samples containing dust have a single mode which is usually interpreted as a single source region. They do not reveal any significant differences between the Saharan and the Middle Eastern sources. The annual average dust mass concentrations were 10-15 mg kg-1 which is higher than the average concentrations reported for other mountain regions and this was strongly affected by dust deposition events. The deposition of dust resulted in elevated concentrations of most ions, especially Ca2+, Mg2+, K+, and sulphates. Dust originated from multiple sources in the Middle East including Mesopotamia or passing over the Middle East was characterised by the elevated concentrations of nitrates and ammonia which is related to a high atmospheric loads of ammonium emitted by agricultural sources and high concentrations of ammonium in dust originating from this region. By contrast, samples of the Saharan dust showed low concentrations consistent with the low ammonium loads in the source region. . The research leading to these results has received funding from the European Union Seventh Framework Programme FP7-PEOPLE-2010-IIF under grant agreement PIIF-GA-2010-275071 Russian Foundation for Basic Research (grants 11-05-00304 and 13-05-10069).

Using thermal infrared (TIR) data to characterize dust sources, dust fall and the linkage to climate in the Middle East

NASA Astrophysics Data System (ADS)

Mohammad, R.; Ramsey, M.; Scheidt, S. P.

2010-12-01

Prior to mineral dust deposition affecting albedo, aerosols can have direct and indirect effects on local to regional scale climate by changing both the shortwave and longwave radiative forcing. In addition, mineral dust causes health hazards, such as respiratory-related illnesses and deaths, loss of agricultural soil, and safety hazards to aviation and motorists due to reduced visibility. Previous work utilized satellite and ground-based TIR data to describe the direct longwave radiative effect of the Saharan Air Layer (SAL) over the Atlantic Ocean originating from dust storms in the Western Sahara. TIR emission spectroscopy was used to identify the spectral absorption features of that dust. The current research focuses on Kuwait and utilizes a comprehensive set of spatial, analytical and geological tools to characterize dust emissions and its radiative effects. Surface mineral composition maps for the Kuwait region were created using ASTER images and GIS datasets in order to identify the possible sources of wind-blown dust. Backward trajectory analysis using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model suggests the dust source areas were located in Iraq, Syria, Jordan and Saudi Arabia. Samples collected from two dust storms (May and July 2010) were analyzed for their mineral composition and to validate the dust source areas identified by the modeling and remote sensing analysis. These air fall dust samples were collected in glass containers on a 13 meter high rooftop in the suburb of Rumaithiya in Kuwait. Additional samples will be collected to expand the analysis and their chemical compositions will be characterized by a combination of laboratory X-ray fluorescence (XRF), Scanning Electron Microscopy (SEM) and TIR emission spectroscopy. The overarching objective of this ongoing research is to both characterize the effects of mineral dust on climate as well as establish a predictive tool that can identify dust storm sources and potentially aid in establishing a more accurate prediction and warning system in the Middle East region.

Terrestrial in situ sampling of dust devils (relative particle loads and vertical grain size distributions) as an equivalent for martian dust devils.

NASA Astrophysics Data System (ADS)

Raack, J.; Dennis, R.; Balme, M. R.; Taj-Eddine, K.; Ori, G. G.

2017-12-01

Dust devils are small vertical convective vortices which occur on Earth and Mars [1] but their internal structure is almost unknown. Here we report on in situ samples of two active dust devils in the Sahara Desert in southern Morocco [2]. For the sampling we used a 4 m high aluminium pipe with sampling areas made of removable adhesive tape. We took samples between 0.1-4 m with a sampling interval of 0.5 m and between 0.5-2 m with an interval of 0.25 m, respectively. The maximum diameter of all particles of the different sampling heights were then measured using an optical microscope to gain vertical grain size distributions and relative particle loads. Our measurements imply that both dust devils have a general comparable internal structure despite their different strengths and dimensions which indicates that the dust devils probably represents the surficial grain size distribution they move over. The particle sizes within the dust devils decrease nearly exponential with height which is comparable to results by [3]. Furthermore, our results show that about 80-90 % of the total particle load were lifted only within the first meter, which is a direct evidence for the existence of a sand skirt. If we assume that grains with a diameter <31 μm can go into suspension [4], our results show that only less than 0.1 wt% can be entrained into the atmosphere. Although this amount seems very low, these values represent between 60 and 70 % of all lifted particles due to the small grain sizes and their low weight. On Mars, the amount of lifted particles will be general higher as the dust coverage is larger [5], although the atmosphere can only suspend smaller grain sizes ( <20 μm) [6] compared to Earth. During our field campaign we observed numerous larger dust devils each day which were up to several hundred meters tall and had diameters of several tens of meters. This implies a much higher input of fine grained material into the atmosphere (which will have an influence on the climate, weather, and human health [7]) compared to the relative small dust devils sampled during our field campaign. [1] Thomas and Gierasch (1985) Science 230 [2] Raack et al. (2017) Astrobiology [3] Oke et al. (2007) J. Arid Environ. 71 [4] Balme and Greeley (2006) Rev. Geophys. 44 [5] Christensen (1986) JGR 91 [6] Newman et al. (2002) JGR 107 [7] Gillette and Sinclair (1990) Atmos. Environ. 24

Comet coma sample return instrument

NASA Technical Reports Server (NTRS)

Albee, A. L.; Brownlee, Don E.; Burnett, Donald S.; Tsou, Peter; Uesugi, K. T.

1994-01-01

The sample collection technology and instrument concept for the Sample of Comet Coma Earth Return Mission (SOCCER) are described. The scientific goals of this Flyby Sample Return are to return to coma dust and volatile samples from a known comet source, which will permit accurate elemental and isotopic measurements for thousands of individual solid particles and volatiles, detailed analysis of the dust structure, morphology, and mineralogy of the intact samples, and identification of the biogenic elements or compounds in the solid and volatile samples. Having these intact samples, morphologic, petrographic, and phase structural features can be determined. Information on dust particle size, shape, and density can be ascertained by analyzing penetration holes and tracks in the capture medium. Time and spatial data of dust capture will provide understanding of the flux dynamics of the coma and the jets. Additional information will include the identification of cosmic ray tracks in the cometary grains, which can provide a particle's process history and perhaps even the age of the comet. The measurements will be made with the same equipment used for studying micrometeorites for decades past; hence, the results can be directly compared without extrapolation or modification. The data will provide a powerful and direct technique for comparing the cometary samples with all known types of meteorites and interplanetary dust. This sample collection system will provide the first sample return from a specifically identified primitive body and will allow, for the first time, a direct method of matching meteoritic materials captured on Earth with known parent bodies.

Characterization of the bacterial and fungal microbiome in indoor dust and outdoor air samples: a pilot study.

PubMed

Hanson, Blake; Zhou, Yanjiao; Bautista, Eddy J; Urch, Bruce; Speck, Mary; Silverman, Frances; Muilenberg, Michael; Phipatanakul, Wanda; Weinstock, George; Sodergren, Erica; Gold, Diane R; Sordillo, Joanne E

2016-06-15

Environmental microbes have been associated with both protective and adverse health effects in children and adults. Epidemiological studies often rely on broad biomarkers of microbial exposure (i.e. endotoxin, 1 → 3-beta-d-glucan), but fail to identify the taxonomic composition of the microbial community. Our aim was to characterize the bacterial and fungal microbiome in different types of environmental samples collected in studies of human health effects. We determined the composition of microbial communities present in home, school and outdoor air samples by amplifying and sequencing regions of rRNA genes from bacteria (16S) and fungi (18S and ITS). Samples for this pilot study included indoor settled dust (from both a Boston area birth cohort study on Home Allergens and Asthma (HAA) (n = 12) and a study of school exposures and asthma symptoms (SICAS) (n = 1)), as well as fine and coarse concentrated outdoor ambient particulate (CAP) samples (n = 9). Sequencing of amplified 16S, 18S, and ITS regions was performed on the Roche-454 Life Sciences Titanium pyrosequencing platform. Indoor dust samples were dominated by Gram-positive bacteria (Firmicutes and Actinobacteria); the most abundant bacterial genera were those related to human flora (Streptococcus, Staphylococcus, Corynebacterium and Lactobacillus). Outdoor CAPs were dominated by Gram-negative Proteobacteria from water and soil sources, in particular the genera Acidovorax, and Brevundimonas (which were present at very low levels or entirely absent in indoor dust). Phylum-level fungal distributions identified by 18S or ITS regions showed very similar findings: a predominance of Ascomycota in indoor dust and Basidiomycota in outdoor CAPs. ITS sequencing of fungal genera in indoor dust showed significant proportions of Aureobasidium and Leptosphaerulina along with some contribution from Cryptococcus, Epicoccum, Aspergillus and the human commensal Malassezia. ITS sequencing detected more than 70 fungal genera in indoor dust not observed by culture. Microbiome sequencing is feasible for different types of archived environmental samples (indoor dust, and low biomass air particulate samples), and offers the potential to study how whole communities of microbes (including unculturable taxa) influence human health.

Characterization of the bacterial and fungal microbiome in indoor dust and outdoor air samples: a pilot study†

PubMed Central

Hanson, Blake; Zhou, Yanjiao; Bautista, Eddy J.; Urch, Bruce; Speck, Mary; Silverman, Frances; Muilenberg, Michael; Phipatanakul, Wanda; Weinstock, George; Sodergren, Erica; Gold, Diane R.; Sordillo, Joanne E.

2016-01-01

Environmental microbes have been associated with both protective and adverse health effects in children and adults. Epidemiological studies often rely on broad biomarkers of microbial exposure (i.e. endotoxin, 1→3, Beta-D glucan), but fail to identify the taxonomic composition of the microbial community. Our aim was to characterize the bacterial and fungal microbiome in different types of environmental samples collected in studies of human health effects. We determined the composition of microbial communities present in home, school and outdoor air samples by amplifying and sequencing regions of rRNA genes from bacteria (16S) and fungi (18S and ITS). Samples for this pilot study included indoor settled dust (from both a Boston area birth cohort study on Home Allergens and Asthma (HAA)(n=12) and a study of school exposures and asthma symptoms (SICAS) (n=1)), as well as fine and coarse concentrated outdoor ambient particulate (CAP) samples (n=9). Sequencing of amplified 16S, 18S, and ITS regions was performed on the Roche-454 Life Sciences Titanium pyrosequencing platform. Indoor dust samples were dominated by gram-positive bacteria (Firmicutes and Actinobacteria); the most abundant bacterial genera were those related to human flora (Streptococcus, Staphylococcus, Corynebacterium and Lactobacillus). Outdoor CAPs were dominated by gram-negative Proteobacteria from water and soil sources, in particular the genera Acidovorax, and Brevundimonas (which were present at very low levels or entirely absent in indoor dust). Phylum-level fungal distributions identified by 18S or ITS regions showed very similar findings: a predominance of Ascomycota in indoor dust and Basidiomycota in outdoor CAPs. ITS sequencing of fungal genera in indoor dust showed significant proportions of Aureobasidium and Leptosphaerulina along with some contribution from Cryptococcus, Epicoccum, Aspergillus and the human commensal Malassezia. ITS sequencing detected an additional 70 fungal genera in indoor dust not observed by culture. Microbiome sequencing is feasible for different types of archived environmental samples (indoor dust, and low biomass air particulate samples), and offers the potential to study how whole communities of microbes (including unculturable taxa) influence human health. PMID:27213188

Collection and analysis of samples for polycyclic aromatic hydrocarbons in dust and other solids related to sealed and unsealed pavement from 10 cities across the United States, 2005-07

USGS Publications Warehouse

Van Metre, Peter C.; Mahler, Barbara J.; Wilson, Jennifer T.; Burbank, Teresa L.

2008-01-01

Parking lots and driveways are dominant features of the modern urban landscape, and in the United States, sealcoat is widely used on these surfaces. One of the most widely used types of sealcoat contains refined coal tar; coal-tar-based sealcoat products have a mean polycyclic aromatic hydrocarbon (PAH) concentration of about 5 percent. A previous study reported that parking lots in Austin, Texas, treated with coal-tar sealcoat were a major source of PAH compounds in streams. This report presents methods for and data from the analysis of concentrations of PAH compounds in dust from sealed and unsealed pavement from nine U.S. cities, and concentrations of PAH compounds in other related solid materials (sealcoat surface scrapings, nearby street dust, and nearby soil) from three of those same cities and a 10th city. Dust samples were collected by sweeping dust from areas of several square meters with a soft nylon brush into a dustpan. Some samples were from individual lots or driveways, and some samples consisted of approximately equal amounts of material from three lots. Samples were sieved to remove coarse sand and gravel and analyzed by gas chromatography/mass spectrometry. Concentrations of PAHs vary greatly among samples with total PAH (sigmaPAH), the sum of 12 unsubstituted parent PAHs, ranging from nondetection for all 12 PAHs (several samples from Portland, Oregon, and Seattle, Washington; sigmaPAH of less than 36,000 micrograms per kilogram) to 19,000,000 micrograms per kilogram for a sealcoat scraping sample (Milwaukee, Wisconsin). The largest PAH concentrations in dust are from a driveway sample from suburban Chicago, Illinois (sigmaPAH of 9,600,000 micrograms per kilogram).

Asian Dust Particles Induce Macrophage Inflammatory Responses via Mitogen-Activated Protein Kinase Activation and Reactive Oxygen Species Production

PubMed Central

Higashisaka, Kazuma; Fujimura, Maho; Taira, Mayu; Yoshida, Tokuyuki; Tsunoda, Shin-ichi; Baba, Takashi; Yamaguchi, Nobuyasu; Nabeshi, Hiromi; Yoshikawa, Tomoaki; Nasu, Masao; Tsutsumi, Yasuo

2014-01-01

Asian dust is a springtime meteorological phenomenon that originates in the deserts of China and Mongolia. The dust is carried by prevailing winds across East Asia where it causes serious health problems. Most of the information available on the impact of Asian dust on human health is based on epidemiological investigations, so from a biological standpoint little is known of its effects. To clarify the effects of Asian dust on human health, it is essential to assess inflammatory responses to the dust and to evaluate the involvement of these responses in the pathogenesis or aggravation of disease. Here, we investigated the induction of inflammatory responses by Asian dust particles in macrophages. Treatment with Asian dust particles induced greater production of inflammatory cytokines interleukin-6 and tumor necrosis factor-α (TNF-α) compared with treatment with soil dust. Furthermore, a soil dust sample containing only particles ≤10 μm in diameter provoked a greater inflammatory response than soil dust samples containing particles >10 μm. In addition, Asian dust particles-induced TNF-α production was dependent on endocytosis, the production of reactive oxygen species, and the activation of nuclear factor-κB and mitogen-activated protein kinases. Together, these results suggest that Asian dust particles induce inflammatory disease through the activation of macrophages. PMID:24987712

On The Origins Of Cosmic Dust And The Evolution Of Nearby Galaxies With The Herschel Space Observatory

NASA Astrophysics Data System (ADS)

Clark, Christopher Jonathan Redfern

2015-04-01

Using multiwavelength observations, centred around the unique far-infrared and submillimetre window provided by the Herschel Space Observatory, this thesis investigates the origins and evolution of cosmic dust in the local Universe - by examining individual sources of dust in our own galaxy, and by studying dust in nearby galaxies. I search Herschel observations of the remnants of Kepler’s (SN1604) and Tycho’s (SN1572) supernovæ, both Type-Ia explosions, for evidence of dust creation by these events. Being the only Type-Ia supernovæ known to have occurred in our Galaxy within the past 1,000 years, these remnants are the only ones both close enough to resolve, and young enough that they are dominated by their ejecta dynamics. There is no indication of any recently manufactured dust associated with either supernova remnant. It therefore appears that Type-Ia supernovæ do not contribute significantly to the dust budgets of galaxies. The Crab Nebula, the result of a Type-II supernova (SN1054), is also investigated using Herschel and multiwavelength data. After accounting for other sources of emission, a temperature of Td = 63.1 K and mass of Md = 0.21 M⊙ is derived for the Crab Nebula’s dust component. I create a map of the distribution of dust in the Crab Nebula, the first of its kind, by means of a resolved component separation, revealing that the dust is located in the dense filamentary ejecta. We can be confident that this dust will survive in the long term, and be injected into the galactic dust budget. This is the first detection of manufactured supernova dust for which this can be said. Next I use the Herschel-ATLAS to assemble HAPLESS: the Herschel- ATLAS Phase-1 Limited Extent Spatial Sample - a blind, volume-limited, dust- selected sample of nearby galaxies. The majority of this sample is made up of curious very blue galaxies. Often irregular and/or flocculent in morphology, with extremely blue UV-NIR colours, these galaxies appear to be prominent in the local dusty universe. In the absence of reliable photometry for the HAPLESS galaxies, I describe the function and testing of a purpose-built photometric pipeline - CAAPR: Chris’ Adequate Aperture Photometry Routine. The photometry conducted with CAAPR exhibits flux greater by factors of, on average, 1.6 in the FUV and 1.4 in r-band, relative to the previously-available photometry. In comparison to other surveys of dust in local galaxies, the HAPLESS systems show a strong propensity towards very late morphological types and extremely blue FUV-Ks colours. The dust in the HAPLESS galaxies appears to be very cold, with a median temperature of 14.6 K. They are also exceptionally dust rich, with a median dust mass of 5.3 × 106 M(_{\\odot}) , and a median Md/M(_{\\star}) of 4.4×10-3 - greater by a factor of 1.8-3.7 than that seen in other local surveys. The curious very blue HAPLESS galaxies, whilst accounting for only 6% of the stellar mass in our sample, contain over 35% of the dust mass. I show that the more dust-rich a galaxy (as defined by Md/M(_{\\star})), the smaller the fraction of its UV luminosity that suffers dust absorption - this effect is observed to be particularly dramatic in the case of the curious very blue objects. Either the emissivity or geometry of the dust in these systems must be highly unusual. HAPLESS suggests a dust mass volume density of the local universe of (3.7 ± 0.7) × 105 M(_{\\odot}) Mpc-3; the largest value reported to date. The HAPLESS 250 μm luminosity function is in good agreement with surveys of far larger volumes, suggesting that we do not sample an over-dense region of space. The HAPLESS galaxies are extraordinarily gas rich; the median HAPLESS gas fraction is 0.52, and 19% of the sample have gas fractions >0.8. The median HAPLESS gas-to-dust ratio is ≍260, 2-3 times larger than in other local surveys. The very blue galaxies of the sample are found to be particularly gas rich; a chemical and dust evolution model indicates that they are at an early stage of converting their gas into stars. A dust-selected survey such as H-ATLAS is a particularly efficient way of identifying young systems of this kind, which should therefore provide valuable insights into the chemical evolution of young galaxies.

Elemental properties of coal slag and measured airborne exposures at two coal slag processing facilities

PubMed Central

Mugford, Christopher; Boylstein, Randy; Gibbs, Jenna L

2017-01-01

In 1974, the National Institute for Occupational Safety and Health recommended a ban on the use of silica sand abrasives containing >1% silica due to the risk of silicosis. This gave rise to substitutes including coal slag. An Occupational Safety and Health Administration investigation in 2010 uncovered a case cluster of suspected pneumoconiosis in four former workers at a coal slag processing facility in Illinois, possibly attributable to occupational exposure to coal slag dust. This article presents the results from a National Institute for Occupational Safety and Health industrial hygiene survey at the same coal slag processing facility and a second facility. The industrial hygiene survey consisted of the collection of: a) bulk samples of unprocessed coal slag, finished granule product, and settled dust for metals and silica; b) full-shift area air samples for dust, metals, and crystalline silica; and c) full-shift personal air samples for dust, metals, and crystalline silica. Bulk samples consisted mainly of iron, manganese, titanium, and vanadium. Some samples had detectable levels of arsenic, beryllium, cadmium, and cobalt. Unprocessed coal slags from Illinois and Kentucky contained 0.43–0.48% (4,300–4,800 mg/kg) silica. Full-shift area air samples identified elevated total dust levels in the screen (2–38 mg/m3) and bag house (21 mg/m3) areas. Full-shift area air samples identified beryllium, chromium, cobalt, copper, iron, nickel, manganese, and vanadium. Overall, personal air samples for total and respirable dust (0.1–6.6 mg/m3 total; and 0.1–0.4 mg/m3 respirable) were lower than area air samples. All full-shift personal air samples for metals and silica were below published occupational exposure limits. All bulk samples of finished product granules contained less than 1% silica, supporting the claim coal slag may present less risk for silicosis than silica sand. We note that the results presented here are solely from two coal slag processing facilities, and more in-depth air monitoring is needed to better characterize occupational exposure to coal slag dust, metals, and silica at similar facilities. PMID:27808662

Elemental properties of coal slag and measured airborne exposures at two coal slag processing facilities.

PubMed

Mugford, Christopher; Boylstein, Randy; Gibbs, Jenna L

2017-05-01

In 1974, the National Institute for Occupational Safety and Health recommended a ban on the use of silica sand abrasives containing >1% silica due to the risk of silicosis. This gave rise to substitutes including coal slag. An Occupational Safety and Health Administration investigation in 2010 uncovered a case cluster of suspected pneumoconiosis in four former workers at a coal slag processing facility in Illinois, possibly attributable to occupational exposure to coal slag dust. This article presents the results from a National Institute for Occupational Safety and Health industrial hygiene survey at the same coal slag processing facility and a second facility. The industrial hygiene survey consisted of the collection of: (a) bulk samples of unprocessed coal slag, finished granule product, and settled dust for metals and silica; (b) full-shift area air samples for dust, metals, and crystalline silica; and (c) full-shift personal air samples for dust, metals, and crystalline silica. Bulk samples consisted mainly of iron, manganese, titanium, and vanadium. Some samples had detectable levels of arsenic, beryllium, cadmium, and cobalt. Unprocessed coal slags from Illinois and Kentucky contained 0.43-0.48% (4,300-4,800 mg/kg) silica. Full-shift area air samples identified elevated total dust levels in the screen (2-38 mg/m 3 ) and bag house (21 mg/m 3 ) areas. Full-shift area air samples identified beryllium, chromium, cobalt, copper, iron, nickel, manganese, and vanadium. Overall, personal air samples for total and respirable dust (0.1-6.6 mg/m 3 total; and 0.1-0.4 mg/m 3 respirable) were lower than area air samples. All full-shift personal air samples for metals and silica were below published occupational exposure limits. All bulk samples of finished product granules contained less than 1% silica, supporting the claim coal slag may present less risk for silicosis than silica sand. We note that the results presented here are solely from two coal slag processing facilities, and more in-depth air monitoring is needed to better characterize occupational exposure to coal slag dust, metals, and silica at similar facilities.

Undisturbed dust as a metric of long-term indoor insecticide exposure: Residential DDT contamination from indoor residual spraying and its association with serum levels in the VHEMBE cohort.

PubMed

Gaspar, Fraser W; Chevrier, Jonathan; Bornman, Riana; Crause, Madelein; Obida, Muvhulawa; Barr, Dana Boyd; Bradman, Asa; Bouwman, Henk; Eskenazi, Brenda

2015-12-01

Although approximately 123 million people may be exposed to high levels of insecticides through the use of indoor residual spraying (IRS) for malaria control, few studies exist on indoor insecticide contamination due to IRS and its relationship with human exposure. In the present study, we developed a sampling method to collect undisturbed dust from 50 homes in Limpopo, South Africa, a region where dichlorodiphenyltrichloroethane (DDT) has been used in IRS programs to prevent malaria for ~70years. We quantified DDT and its degradation products, dichlorodiphenyldichloroethylene (DDE), and dichlorodiphenyldichloroethane (DDD) in dust samples to determine dust loading levels and compared these levels to paired serum concentrations of p,p'-DDT and p,p'-DDE in women residents. p,p'-DDT and p,p'-DDE had the highest detection frequencies in both dust (58% and 34% detection, respectively) and serum samples (98% and 100% detection, respectively). Significantly higher detection frequencies for o,p'-DDT, p,p'-DDE, and p,p'-DDD were observed in dust samples collected in buildings that had been previously sprayed for malaria control. We also observed a significant, positive association between dust loading and serum concentrations of p,p'-DDT and p,p'-DDE (Spearman's rho=0.68 and 0.54, respectively). Despite the low detection frequency in dust, our results indicate that undisturbed dust may be a good metric to quantify long-term home exposure to DDT-related compounds and that contamination of the home environment may be an important determinant/source of DDT and DDE exposure. Copyright © 2015 Elsevier Ltd. All rights reserved.

Scattering Properties of Large Irregular Cosmic Dust Particles at Visible Wavelengths

DOE Office of Scientific and Technical Information (OSTI.GOV)

Escobar-Cerezo, J.; Palmer, C.; Muñoz, O.

The effect of internal inhomogeneities and surface roughness on the scattering behavior of large cosmic dust particles is studied by comparing model simulations with laboratory measurements. The present work shows the results of an attempt to model a dust sample measured in the laboratory with simulations performed by a ray-optics model code. We consider this dust sample as a good analogue for interplanetary and interstellar dust as it shares its refractive index with known materials in these media. Several sensitivity tests have been performed for both structural cases (internal inclusions and surface roughness). Three different samples have been selected tomore » mimic inclusion/coating inhomogeneities: two measured scattering matrices of hematite and white clay, and a simulated matrix for water ice. These three matrices are selected to cover a wide range of imaginary refractive indices. The selection of these materials also seeks to study astrophysical environments of interest such as Mars, where hematite and clays have been detected, and comets. Based on the results of the sensitivity tests shown in this work, we perform calculations for a size distribution of a silicate-type host particle model with inclusions and surface roughness to reproduce the experimental measurements of a dust sample. The model fits the measurements quite well, proving that surface roughness and internal structure play a role in the scattering pattern of irregular cosmic dust particles.« less

Infrared Luminosities and Dust Properties of z ≈ 2 Dust-obscured Galaxies

NASA Astrophysics Data System (ADS)

Bussmann, R. S.; Dey, Arjun; Borys, C.; Desai, V.; Jannuzi, B. T.; Le Floc'h, E.; Melbourne, J.; Sheth, K.; Soifer, B. T.

2009-11-01

We present SHARC-II 350 μm imaging of twelve 24 μm bright (F 24 μm > 0.8 mJy) Dust-Obscured Galaxies (DOGs) and Combined Array for Research in Millimeter-wave Astronomy (CARMA) 1 mm imaging of a subset of two DOGs. These objects are selected from the Boötes field of the NOAO Deep Wide-Field Survey. Detections of four DOGs at 350 μm imply infrared (IR) luminosities which are consistent to within a factor of 2 of expectations based on a warm-dust spectral energy distribution (SED) scaled to the observed 24 μm flux density. The 350 μm upper limits for the 8 non-detected DOGs are consistent with both Mrk 231 and M82 (warm-dust SEDs), but exclude cold dust (Arp 220) SEDs. The two DOGs targeted at 1 mm were not detected in our CARMA observations, placing strong constraints on the dust temperature: T dust > 35-60 K. Assuming these dust properties apply to the entire sample, we find dust masses of ≈3 × 108 M sun. In comparison to other dusty z ~ 2 galaxy populations such as submillimeter galaxies (SMGs) and other Spitzer-selected high-redshift sources, this sample of DOGs has higher IR luminosities (2 × 1013 L sun versus 6 × 1012 L sun for the other galaxy populations) that are driven by warmer dust temperatures (>35-60 K versus ~30 K) and lower inferred dust masses (3 × 108 M sun versus 3 × 109 M sun). Wide-field Herschel and Submillimeter Common-User Bolometer Array-2 surveys should be able to detect hundreds of these power-law-dominated DOGs. We use the existing Hubble Space Telescope and Spitzer/InfraRed Array Camera data to estimate stellar masses of these sources and find that the stellar to gas mass ratio may be higher in our 24 μm bright sample of DOGs than in SMGs and other Spitzer-selected sources. Although much larger sample sizes are needed to provide a definitive conclusion, the data are consistent with an evolutionary trend in which the formation of massive galaxies at z ~ 2 involves a submillimeter bright, cold-dust, and star-formation-dominated phase followed by a 24 μm bright, warm-dust and AGN-dominated phase.

The Herschel Virgo Cluster Survey. XIII. Dust in early-type galaxies

NASA Astrophysics Data System (ADS)

di Serego Alighieri, S.; Bianchi, S.; Pappalardo, C.; Zibetti, S.; Auld, R.; Baes, M.; Bendo, G.; Corbelli, E.; Davies, J. I.; Davis, T.; De Looze, I.; Fritz, J.; Gavazzi, G.; Giovanardi, C.; Grossi, M.; Hunt, L. K.; Magrini, L.; Pierini, D.; Xilouris, E. M.

2013-04-01

Aims: We study the dust content of a large optical input sample of 910 early-type galaxies (ETG) in the Virgo cluster, also extending to the dwarf ETG, and examine the results in relation to those on the other cold ISM components. Methods: We have searched for far-infrared emission in all galaxies in the input sample using the 250 μm image of the Herschel Virgo Cluster Survey (HeViCS). This image covers a large fraction of the cluster with an area of ~55 square degrees. For the detected ETG we measured fluxes in five bands from 100 to 500 μm, and estimated the dust mass and temperature with modified black-body fits. Results: Dust is detected above the completeness limit of 25.4 mJy at 250 μm in 46 ETG, 43 of which are in the optically complete part of the input sample. In addition, dust is present at fainter levels in another six ETG. We detect dust in the four ETG with synchrotron emission, including M 87. Dust appears to be much more concentrated than stars and more luminous ETG have higher dust temperatures. Considering only the optically complete input sample and correcting for the contamination by background galaxies, dust detection rates down to the 25.4 mJy limit are 17% for ellipticals, about 40% for lenticulars (S0 + S0a), and around 3% for dwarf ETG. Dust mass does not correlate clearly with stellar mass and is often much greater than expected for a passive galaxy in a closed-box model. The dust-to-stars mass ratio anticorrelates with galaxy luminosity, and for some dwarf ETG reaches values as high as for dusty late-type galaxies. In the Virgo cluster slow rotators appear more likely to contain dust than fast ones. Comparing the dust results with those on Hi there are only eight ETG detected both in dust and in Hi in the HeViCS area; 39 have dust but only an upper limit on Hi, and eight have Hi but only an upper limit on dust. The locations of these galaxies in the cluster are different, with the dusty ETG concentrated in the densest regions, while the Hi rich ETG are at the periphery. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Table A.1 is available in electronic form at http://www.aanda.org

Wood Dust Sampling: Field Evaluation of Personal Samplers When Large Particles Are Present

PubMed Central

Lee, Taekhee; Harper, Martin; Slaven, James E.; Lee, Kiyoung; Rando, Roy J.; Maples, Elizabeth H.

2011-01-01

Recent recommendations for wood dust sampling include sampling according to the inhalable convention of International Organization for Standardization (ISO) 7708 (1995) Air quality—particle size fraction definitions for health-related sampling. However, a specific sampling device is not mandated, and while several samplers have laboratory performance approaching theoretical for an ‘inhalable’ sampler, the best choice of sampler for wood dust is not clear. A side-by-side field study was considered the most practical test of samplers as laboratory performance tests consider overall performance based on a wider range of particle sizes than are commonly encountered in the wood products industry. Seven companies in the wood products industry of the Southeast USA (MS, KY, AL, and WV) participated in this study. The products included hardwood flooring, engineered hardwood flooring, door skins, shutter blinds, kitchen cabinets, plywood, and veneer. The samplers selected were 37-mm closed-face cassette with ACCU-CAP™, Button, CIP10-I, GSP, and Institute of Occupational Medicine. Approximately 30 of each possible pairwise combination of samplers were collected as personal sample sets. Paired samplers of the same type were used to calculate environmental variance that was then used to determine the number of pairs of samples necessary to detect any difference at a specified level of confidence. Total valid sample number was 888 (444 valid pairs). The mass concentration of wood dust ranged from 0.02 to 195 mg m−3. Geometric mean (geometric standard deviation) and arithmetic mean (standard deviation) of wood dust were 0.98 mg m−3 (3.06) and 2.12 mg m−3 (7.74), respectively. One percent of the samples exceeded 15 mg m−3, 6% exceeded 5 mg m−3, and 48% exceeded 1 mg m−3. The number of collected pairs is generally appropriate to detect a 35% difference when outliers (negative mass loadings) are removed. Statistical evaluation of the nonsimilar sampler pair results produced a finding of no significant difference between any pairing of sampler type. A practical consideration for sampling in the USA is that the ACCU-CAP™ is similar to the sampler currently used by the Occupational Safety and Health Administration for purposes of demonstrating compliance with its permissible exposure limit for wood dust, which is the same as for Particles Not Otherwise Regulated, also known as inert dust or nuisance dust (Method PV2121). PMID:21036895

30 CFR 90.210 - Respirable dust samples; report to operator.

Code of Federal Regulations, 2010 CFR

2010-07-01

... MINE SAFETY AND HEALTH MANDATORY HEALTH STANDARDS-COAL MINERS WHO HAVE EVIDENCE OF THE DEVELOPMENT OF PNEUMOCONIOSIS Sampling Procedures § 90.210 Respirable dust samples; report to operator. (a) The Secretary shall... for voiding any samples; and, (7) The Social Security Number of the part 90 miner. (b) Upon receipt...

Determining Source Strength of Semivolatile Organic Compounds using Measured Concentrations in Indoor Dust

PubMed Central

Shin, Hyeong-Moo; McKone, Thomas E.; Nishioka, Marcia G.; Fallin, M. Daniele; Croen, Lisa A.; Hertz-Picciotto, Irva; Newschaffer, Craig J.; Bennett, Deborah H.

2014-01-01

Consumer products and building materials emit a number of semivolatile organic compounds (SVOCs) in the indoor environment. Because indoor SVOCs accumulate in dust, we explore the use of dust to determine source strength and report here on analysis of dust samples collected in 30 U.S. homes for six phthalates, four personal care product ingredients, and five flame retardants. We then use a fugacity-based indoor mass-balance model to estimate the whole house emission rates of SVOCs that would account for the measured dust concentrations. Di-2-ethylhexyl phthalate (DEHP) and di-iso-nonyl phthalate (DiNP) were the most abundant compounds in these dust samples. On the other hand, the estimated emission rate of diethyl phthalate (DEP) is the largest among phthalates, although its dust concentration is over two orders of magnitude smaller than DEHP and DiNP. The magnitude of the estimated emission rate that corresponds to the measured dust concentration is found to be inversely correlated with the vapor pressure of the compound, indicating that dust concentrations alone cannot be used to determine which compounds have the greatest emission rates. The combined dust-assay modeling approach shows promise for estimating indoor emission rates for SVOCs. PMID:24118221

Pulmonary Toxicity Studies of Lunar Dusts in Rodents

NASA Technical Reports Server (NTRS)

Lam, Chiu-wing; James, John T.; Taylor, Larry

2008-01-01

NASA will build an outpost on the lunar surface for long-duration human habitation and research. The surface of the Moon is covered by a layer of fine, reactive dust, and the living quarters in the lunar outpost are expected to be contaminated by lunar dust. NASA established the Lunar Airborne Dust Toxicity Advisory Group (LADTAG) to evaluate the risk of exposure to the dust and to establish safe exposure limits for astronauts working in the lunar habitat. Because the toxicity of lunar dust is not known, LADTAG has recommended investigating its toxicity in the lungs of laboratory animals. After receiving this recommendation, NASA directed the JSC Toxicology Laboratory to determine the pulmonary toxicity of lunar dust in exposed rodents. The rodent pulmonary toxicity studies proposed here are the same as those proposed by the LADTAG. Studies of the pulmonary toxicity of a dust are generally done first in rodents by intratracheal instillation (ITI). This toxicity screening test is then followed by an inhalation study, which requires much more of the test dust and is labor intensive. We succeeded in completing an ITI study on JSC-1 lunar dust simulant in mice (Lam et al., Inhalation Toxicology 14:901-916, 2002, and Inhalation Toxicology 14: 917-928, 2002), and have conducted a pilot ITI study to examine the acute toxicity of an Apollo lunar (highland) dust sample. Preliminary results obtained by examining lung lavage fluid from dust-treated mice show that lunar dust was somewhat toxic (more toxic than TiO2, but less than quartz dust). More extensive studies have been planned to further examine lung lavage fluid for biomarkers of toxicity and lung tissues for histopathological lesions in rodents exposed to aged and activated lunar dust samples. In these studies, reference dusts (TiO2 and quartz) of known toxicities and have industrial exposure limits will be studied in parallel so the relative toxicity of lunar dust can be determined. The ITI results will also be useful for choosing an exposure concentration for the animal inhalation study on a selected lunar dust sample, which is included as a part of this proposal. The animal inhalation exposure will be conducted with lunar dust simulant prior to the study with the lunar dust. The simulant exposure will ensure that the study techniques used with actual lunar dust will be successful. The results of ITI and inhalation studies will reveal the toxicological risk of exposures and are essential for setting exposure limits on lunar dust for astronauts living in the lunar habitat.

The effect of ozonization on furniture dust: microbial content and immunotoxicity in vitro.

PubMed

Huttunen, Kati; Kauhanen, Eeva; Meklin, Teija; Vepsäläinen, Asko; Hirvonen, Maija-Riitta; Hyvärinen, Anne; Nevalainen, Aino

2010-05-01

Moisture and mold problems in buildings contaminate also the furniture and other movable property. If cleaning of the contaminated furniture is neglected, it may continue to cause problems to the occupants even after the moisture-damage repairs. The aim of this study was to determine the effectiveness of high-efficiency ozone treatment in cleaning of the furniture from moisture-damaged buildings. In addition, the effectiveness of two cleaning methods was compared. Samples were vacuumed from the padded areas before and after the treatment. The microbial flora and concentrations in the dust sample were determined by quantitative cultivation and QPCR-methods. The immunotoxic potential of the dust samples was analyzed by measuring effects on cell viability and production of inflammatory mediators in vitro. Concentrations of viable microbes decreased significantly in most of the samples after cleaning. Cleaning with combined steam wash and ozonisation was more effective method than ozonising alone, but the difference was not statistically significant. Detection of fungal species with PCR showed a slight but nonsignificant decrease in concentrations after the cleaning. The immunotoxic potential of the collected dust decreased significantly in most of the samples. However, in a small subgroup of samples, increased concentrations of microbes and immunotoxicological activity were detected. This study shows that a transportable cleaning unit with high-efficiency ozonising is in most cases effective in decreasing the concentrations of viable microbes and immunotoxicological activity of the furniture dust. However, the method does not destroy or remove all fungal material present in the dust, as detected with QPCR analysis, and in some cases the cleaning procedure may increase the microbial concentrations and immunotoxicity of the dust. Copyright 2010 Elsevier B.V. All rights reserved.

Application of a Permethrin Immunosorbent Assay Method to Residential Soil and Dust Samples

EPA Science Inventory

A low-cost, high throughput bioanalytical screening method was developed for monitoring cis/trans-permethrin in dust and soil samples. The method consisted of a simple sample preparation procedure [sonication with dichloromethane followed by a solvent exchange into methanol:wate...

Occurrence of indoor allergens in Saudi Arabia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sorensen, H.; Gravesen, S.; Lind, P.

1985-06-01

Investigations on indoor airborne allergens in Saudi Arabia were performed by mold cultures and dust analyses by counter-current immunoelectrophoresis. Twenty fungal genera were isolated, with Aspergillus as the most often encountered. Most of the dust-bound fungi found are ubiquitous and common. Antibodies against Dermatophagoides pteronyssinus, cat- cow- and rat dander, and Cynodon dactylon pollen were used in the dust analyses. Animal antigens were found in five of the ten dust samples. House dust mites were extraordinarily rare. Pollen of Cynodon dactylon (Bermuda grass) was present in nearly all the samples, and in a concurrent clinical study this antigen was foundmore » to be the most common cause of perennial rhinitis.« less

Analysis of "Midnight" Tracks in the Stardust Interstellar Dust Collector: Possible Discovery of a Contemporary Interstellar Dust Grain

NASA Technical Reports Server (NTRS)

Westphal, A. J.; Allen, C.; Bajit, S.; Bastien, R.; Bechtel, H.; Bleuet, P.; Borg, J.; Brenker, F.; Bridges, J.; Brownlee, D. E.;

Physical and chemical properties of deposited airborne particulates over the Arabian Red Sea coastal plain

NASA Astrophysics Data System (ADS)

Engelbrecht, Johann P.; Stenchikov, Georgiy; Jish Prakash, P.; Lersch, Traci; Anisimov, Anatolii; Shevchenko, Illia

2017-09-01

Mineral dust is the most abundant aerosol, having a profound impact on the global energy budget. This research continues our previous studies performed on surface soils in the Arabian Peninsula, focusing on the mineralogical, physical and chemical composition of dust deposits from the atmosphere at the Arabian Red Sea coast. For this purpose, aerosols deposited from the atmosphere are collected during 2015 at six sites on the campus of the King Abdullah University of Science and Technology (KAUST) situated on the Red Sea coastal plain of Saudi Arabia and subjected to the same chemical and mineralogical analysis we conducted on soil samples. Frisbee deposition samplers with foam inserts were used to collect dust and other deposits, for the period December 2014 to December 2015. The average deposition rate measured at KAUST for this period was 14 g m-2 per month, with lowest values in winter and increased deposition rates in August to October. The particle size distributions provide assessments of < 10 and < 2.5 µm dust deposition rates, and it is suggested that these represent proxies for PM10 (coarse) and PM2. 5 (fine) particle size fractions in the dust deposits.X-ray diffraction (XRD) analysis of a subset of samples confirms variable amounts of quartz, feldspars, micas, and halite, with lesser amounts of gypsum, calcite, dolomite, hematite, and amphibole. Freeze-dried samples were re-suspended onto the Teflon® filters for elemental analysis by X-ray fluorescence (XRF), while splits from each sample were analyzed for water-soluble cations and anions by ion chromatography. The dust deposits along the Red Sea coast are considered to be a mixture of dust emissions from local soils and soils imported from distal dust sources. Airborne mineral concentrations are greatest at or close to dust sources, compared to those through medium- and long-range transport. It is not possible to identify the exact origin of deposition samples from the mineralogical and chemical results alone. These aerosol data are the first of their kind from the Red Sea region. They will help assess their potential nutrient input into the Red Sea, as well the impact on human health, industry, and solar panel efficiency. These data will also support dust modeling in this important dust belt source area by better quantifying dust mass balance and optical properties of airborne dust particles.

Verbal abuse and mobbing in pre-hospital care services in Chile

PubMed Central

Campo, Varinia Rodríguez; Klijn, Tatiana Paravic

2018-01-01

ABSTRACT Objective: to determine the perception of verbal abuse and mobbing and the associated factors of paramedic technicians (nursing assistants) and professionals (nurses, midwives, kinesiologists) in the pre-hospital care areas of three regions in the south of Chile. Methods: descriptive and correlational study was performed within the professional community and a two-stage sample of the paramedic technician population in three regions. The questionnaire “workplace violence in the health sector” (spanish version) was applied after signing the informed consent. Results: 51.4% of professionals and 46.6% of paramedic technicians consider they have been verbally abused during last year. 17.6% of paramedic technicians and 13.5% of professionals perceived mobbing. A low percentage of these events are reported. In only one case of mobbing, the aggressor was legally penalized. No significant differences were found between the job categories and the studied regions. Conclusions: A high percentage of participants in each group perceived verbal abuse and non-minor percentage perceived mobbing, but most of these events are not reported. PMID:29319741

Reduction of airborne radioactive dust by means of a charged water spray.

PubMed

Bigu, J; Grenier, M G

1989-07-01

An electrostatic precipitator based on charged water spray technology has been used in an underground uranium mine to control long-lived radioactive dust and short-lived aerosol concentration in a mine gallery where dust from a rock breaking/ore transportation operation was discharged. Two main sampling stations were established: one upstream of the dust precipitator and one downstream. In addition, dust samplers were placed at different locations between the dust discharge and the end of the mine gallery. Long-lived radioactive dust was measured using cascade impactors and nylon cyclone dust samplers, and measurement of the radioactivity on the samples was carried out by conventional methods. Radon and thoron progeny were estimated using standard techniques. Experiments were conducted under a variety of airflow conditions. A maximum radioactive dust reduction of about 40% (approximately 20% caused by gravitational settling) at a ventilation rate of 0.61 m3/sec was obtained as a result of the combined action of water scrubbing and electrostatic precipitation by the charged water spray electrostatic precipitator. This represents the optimum efficiency attained within the range of ventilation rates investigated. The dust reduction efficiency of the charged water spray decreased with increasing ventilation rate, i.e., decreasing air residence time, and hence, reduced dust cloud/charged water droplets mixing time.

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.

Reducing uncertainty in dust monitoring to detect aeolian sediment transport responses to land cover change

NASA Astrophysics Data System (ADS)

Webb, N.; Chappell, A.; Van Zee, J.; Toledo, D.; Duniway, M.; Billings, B.; Tedela, N.

2017-12-01

Anthropogenic land use and land cover change (LULCC) influence global rates of wind erosion and dust emission, yet our understanding of the magnitude of the responses remains poor. Field measurements and monitoring provide essential data to resolve aeolian sediment transport patterns and assess the impacts of human land use and management intensity. Data collected in the field are also required for dust model calibration and testing, as models have become the primary tool for assessing LULCC-dust cycle interactions. However, there is considerable uncertainty in estimates of dust emission due to the spatial variability of sediment transport. Field sampling designs are currently rudimentary and considerable opportunities are available to reduce the uncertainty. Establishing the minimum detectable change is critical for measuring spatial and temporal patterns of sediment transport, detecting potential impacts of LULCC and land management, and for quantifying the uncertainty of dust model estimates. Here, we evaluate the effectiveness of common sampling designs (e.g., simple random sampling, systematic sampling) used to measure and monitor aeolian sediment transport rates. Using data from the US National Wind Erosion Research Network across diverse rangeland and cropland cover types, we demonstrate how only large changes in sediment mass flux (of the order 200% to 800%) can be detected when small sample sizes are used, crude sampling designs are implemented, or when the spatial variation is large. We then show how statistical rigour and the straightforward application of a sampling design can reduce the uncertainty and detect change in sediment transport over time and between land use and land cover types.

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...

Measurement of macrocyclic trichothecene in floor dust of water-damaged buildings using gas chromatography/tandem mass spectrometry—dust matrix effects

PubMed Central

Saito, Rena; Park, Ju-Hyeong; LeBouf, Ryan; Green, Brett J.; Park, Yeonmi

2017-01-01

Gas chromatography-tandem mass spectrometry (GC-MS/MS) was used to detect fungal secondary metabolites. Detection of verrucarol, the hydrolysis product of Stachybotrys chartarum macrocyclic trichothecene (MCT), was confounded by matrix effects associated with heterogeneous indoor environmental samples. In this study, we examined the role of dust matrix effects associated with GC-MS/ MS to better quantify verrucarol in dust as a measure of total MCT. The efficiency of the internal standard (ISTD, 1,12-dodecanediol), and application of a matrix-matched standard correction method in measuring MCT in floor dust of water-damaged buildings was additionally examined. Compared to verrucarol, ISTD had substantially higher matrix effects in the dust extracts. The results of the ISTD evaluation showed that without ISTD adjustment, there was a 280% ion enhancement in the dust extracts compared to neat solvent. The recovery of verrucarol was 94% when the matrix-matched standard curve without the ISTD was used. Using traditional calibration curves with ISTD adjustment, none of the 21 dust samples collected from water damaged buildings were detectable. In contrast, when the matrix-matched calibration curves without ISTD adjustment were used, 38% of samples were detectable. The study results suggest that floor dust of water-damaged buildings may contain MCT. However, the measured levels of MCT in dust using the GC-MS/MS method could be significantly under- or overestimated, depending on the matrix effects, the inappropriate ISTD, or combination of the two. Our study further shows that the routine application of matrix-matched calibration may prove useful in obtaining accurate measurements of MCT in dust derived from damp indoor environments, while no isotopically labeled verrucarol is available. PMID:26853932

Measurement of macrocyclic trichothecene in floor dust of water-damaged buildings using gas chromatography/tandem mass spectrometry-dust matrix effects.

PubMed

Saito, Rena; Park, Ju-Hyeong; LeBouf, Ryan; Green, Brett J; Park, Yeonmi

2016-01-01

Gas chromatography-tandem mass spectrometry (GC-MS/MS) was used to detect fungal secondary metabolites. Detection of verrucarol, the hydrolysis product of Stachybotrys chartarum macrocyclic trichothecene (MCT), was confounded by matrix effects associated with heterogeneous indoor environmental samples. In this study, we examined the role of dust matrix effects associated with GC-MS/MS to better quantify verrucarol in dust as a measure of total MCT. The efficiency of the internal standard (ISTD, 1,12-dodecanediol), and application of a matrix-matched standard correction method in measuring MCT in floor dust of water-damaged buildings was additionally examined. Compared to verrucarol, ISTD had substantially higher matrix effects in the dust extracts. The results of the ISTD evaluation showed that without ISTD adjustment, there was a 280% ion enhancement in the dust extracts compared to neat solvent. The recovery of verrucarol was 94% when the matrix-matched standard curve without the ISTD was used. Using traditional calibration curves with ISTD adjustment, none of the 21 dust samples collected from water damaged buildings were detectable. In contrast, when the matrix-matched calibration curves without ISTD adjustment were used, 38% of samples were detectable. The study results suggest that floor dust of water-damaged buildings may contain MCT. However, the measured levels of MCT in dust using the GC-MS/MS method could be significantly under- or overestimated, depending on the matrix effects, the inappropriate ISTD, or combination of the two. Our study further shows that the routine application of matrix-matched calibration may prove useful in obtaining accurate measurements of MCT in dust derived from damp indoor environments, while no isotopically labeled verrucarol is available.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 Asmore » 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.« less

Environmental Sequencing of Biotic Components of Dust in the Chihuahuan Desert

NASA Astrophysics Data System (ADS)

Walsh, E.; Gill, T. E.; Rivas, J. A., Jr.; Leung, M. Y.; Mohl, J.

2015-12-01

A growing number of studies mark the role of wind in dispersing biota. Most of these approaches have used traditional methods to assess taxonomic diversity. Here we used next generation sequencing to characterize microbiota in dust collected from the Chihuahuan Desert. Atmospheric dust was collected during events during 2011-2014 using dry deposition collectors placed at two sites in El Paso Co., TX. In parallel experiments, we rehydrated subsamples of dust and conducted PCR amplifications using conserved primers for 16S and 18S ribosomal genes. Sequenced reads were de-multiplexed, quality filtered, and processed using QIIME. Taxonomy was assigned based on pairwise identity using BLAST for microbial eukaryotes. All samples were rarefied to a set number of sequences per sample prior to downstream analyses. Bioinformatic analysis of four of the dust samples yielded a diversity of biota, including zooplankton, bacteria, fungi, algae, and protists, but fungi predominate (>90% of both 10K and 3K reads). In our rehydrations of dust samples from the U.S. southwest nematodes, gastrotrichs, tardigrades, monogonont and bdelloid rotifers, branchiopods and numerous ciliates have been recovered. Variability in genetic diversity among samples is based, in part, on the source and extent of the particular dust event. We anticipate the same patterns will be seen in the complete data set. These preliminary results indicate that wind is a major transporter of not only fungi, bacteria and other unicellular organisms but may also be important in shaping the distribution patterns of multi-cellular organisms such as those that inhabit aquatic environments in the arid southwestern US.

30 CFR 71.209 - Respirable dust samples; transmission by operator.

Code of Federal Regulations, 2012 CFR

2012-07-01

... operator. 71.209 Section 71.209 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY HEALTH STANDARDS-SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Sampling Procedures § 71.209 Respirable dust samples; transmission by...

30 CFR 71.209 - Respirable dust samples; transmission by operator.

Code of Federal Regulations, 2013 CFR

2013-07-01

... operator. 71.209 Section 71.209 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY HEALTH STANDARDS-SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Sampling Procedures § 71.209 Respirable dust samples; transmission by...

30 CFR 71.209 - Respirable dust samples; transmission by operator.

Code of Federal Regulations, 2014 CFR

2014-07-01

... operator. 71.209 Section 71.209 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY HEALTH STANDARDS-SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Sampling Procedures § 71.209 Respirable dust samples; transmission by...

Characterisation of bio-aerosols during dust storm period in N-NW India

NASA Astrophysics Data System (ADS)

Yadav, Sudesh; Chauhan, M. S.; Sharma, Anupam

Bio-investigations for pollen and spores were performed on dry free-fall dust and PM 10 aerosol samples, collected from three different locations separated by a distance of 600 km, situated in dust storm hit region of N-NW India. Presence of pollen of trees namely Prosopis ( Prosopis juliflora and Prosopis cinearia), Acacia, Syzygium, Pinus, Cedrus, Holoptelea and shrubs namely Ziziphus, Ricinus, Ephedra and members of Fabaceae, Oleaceae families was recorded but with varying proportions in the samples of different locations. Poaceae, Chenopodiaceae/Amaranthaceae, Caryophyllaceae, Brassicaceae and Cyperaceae (sedges) were some of the herb pollen identified in the samples. Among the fungal spores Nigrospora was seen in almost all samples. Nigrospora is a well known allergen and causes health problems. The concentration of trees and shrubs increases in the windward direction just as the climate changes from hot arid to semiarid. The higher frequency of grasses (Poaceae) or herbs could either be a result of the presence of these herbs in the sampling area and hence the higher production of pollen/spores or due to the resuspension from the exposed surface by the high-intensity winds. But we cannot ascertain the exact process at this stage. The overall similarity in the pollen and spore assemblage in our dust samples indicates a common connection or source(s) to the dust in this region. Presence of the pollen of the species of Himalayan origin in our entire samples strongly point towards a Himalayan connection, could be direct or indirect, to the bioaerosols and hence dust in N-NW India. In order to understand the transport path and processes involved therein, present study needs further extension with more number of samples and with reference to meteorological parameters.

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. © 2010 The Authors. Journal compilation © 2010 ESVD and ACVD.

SPARCLE: Space Plasma Alleviation of Regolith Concentrations in the Lunar Environment

NASA Astrophysics Data System (ADS)

Clark, P. E.; Keller, J. W.; Curtis, S. A.; Nuth, J. A.; Stubbs, T. J.; Farrell, W. M.

2006-05-01

The return of robotic devices and humans to the Moon will occur in the near future. Based on our previous experience, surface dust is a major problem requiring a solution: During Apollo landings, extensive locally- induced stirring of the regolith caused dust to be suspended long enough to come into contact with conducting surfaces. Dust behaved like abrasive Velcro: it adhered to everything and attempts to remove it by simply brushing did not remove fines (<10) and resulted in severe abrasion. Lunar fines, because of their electrostatic charging, were relatively difficult to collect in sample bags along with other size range particles. Within hours, seals were broken, samples contaminated, and portions of the samples, especially fines, lost. Because of this difficulty, details on lunar dust are relatively sparse. Obviously, the strategies initially implemented to deal with lunar dust failed. A major technological challenge will be developing a dust mitigation strategy. A currently proposed strategy based increased magnetic susceptibility in lunar fines may not work uniformly well for fines of non-mare, or non-lunar, composition. Based on dust behavior already observed on previous missions, we believe the successful strategy will deal with dust dynamics resulting from interaction between mechanical and electrostatic forces. We are planning test and develop an electrostatically-based device to modulate the electrical potential of conducting surfaces, hence to self clean exposed surfaces while collecting dust samples. It would scan a surface constantly to control its potential, and a plate of the opposite potential. As a first step, an experimental low mass, power, and volume device with complimentary electron and ion guns with specially designed self-cleaning nozzles are being designed for to test our concept and develop a working charging and discharging strategy in the lunar environment. Meanwhile, a laboratory simulation will act as a feasibility study for a laboratory breadboard self-cleaning device based on the use of combined electron or ion beams. The compact device would act as plasma dust sweeper.

Lab Analysis of Dust Wipe Samples

EPA Pesticide Factsheets

Dust wipe samples collected on residential properties near the fenceline of KCBX North and South Terminals in Chicago, which store and handle pet coke, were analyzed for polycyclic aromatic hydrocarbons (PAHs) and trace metals and minerals.

Exposures to quartz, diesel, dust, and welding fumes during heavy and highway construction.

PubMed

Woskie, Susan R; Kalil, Andrew; Bello, Dhimiter; Virji, M Abbas

2002-01-01

Personal samples for exposure to dust, diesel exhaust, quartz, and welding fume were collected on heavy and highway construction workers. The respirable, thoracic, and inhalable fractions of dust and quartz exposures were estimated from 260 personal impactor samples. Respirable quartz exposures exceeded the National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit (REL) in 7-31% of cases for the trades sampled. More than 50% of the samples in the installation of drop ceilings and wall tiles and concrete finish operations exceeded the NIOSH REL for quartz. Thoracic exposures to quartz and dust exceeded respirable exposures by a factor of 4.5 and 2.8, respectively. Inhalable exposures to quartz and dust exceeded respirable exposures by a factor of 25.6 and 9.3, respectively. These findings are important due to the identification of quartz as a carcinogen by the National Toxicology Program and the International Agency for Research on Cancer. Fourteen percent of the personal samples for EC (n = 261), collected as a marker for diesel exhaust, exceeded the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) for diesel exhaust. Seventeen of the 22 (77%) samples taken during a partially enclosed welding operation reached or exceeded the ACGIH TLV of 5 mg/m3 for welding fume.

Limited production of sulfate and nitrate on front-associated dust storm particles moving from desert to distant populated areas in northwestern China

NASA Astrophysics Data System (ADS)

Wu, Feng; Zhang, Daizhou; Cao, Junji; Guo, Xiao; Xia, Yao; Zhang, Ting; Lu, Hui; Cheng, Yan

2017-12-01

Sulfate and nitrate compounds can greatly increase the hygroscopicity of mineral particles in the atmosphere and consequently alter the particles' physical and chemical properties. Their uptake on long-distance-transported Asian dust particles within mainland China has been reported to be substantial in previous studies, but the production was very inefficient in other studies. We compared these two salts in particles collected from a synoptic-scale, mid-latitude, cyclone-induced dust storm plume at the Tengger Desert (38.79° N, 105.38° E) and in particles collected in a postfrontal dust plume at an urban site in Xi'an (34.22° N, 108.87° E) when a front-associated dust storm from the Tengger Desert arrived there approximately 700 km downwind. The results showed that the sulfate concentration was not considerably different at the two sites, while the nitrate concentration was slightly larger at the urban site than that at the desert site. The estimated nitrate production rate was 4-5 ng µg-1 of mineral dust per day, which was much less than that in polluted urban air. The adiabatic process of the dust-loading air was suggested to be the reason for the absence of sulfate formation, and the uptake of background HNO3 was suggested to be the reason for the small nitrate production. According to our investigation of the published literature, the significant sulfate and nitrate in dust-storm-associated samples within the continental atmosphere reported in previous studies cannot be confirmed as actually produced on desert dust particles; the contribution from locally emitted and urban mineral particles or from soil-derived sulfate was likely substantial because the weather conditions in those studies indicated that the collection of the samples was started before dust arrival, or the air from which the samples were collected was a mixture of desert dust and locally emitted mineral particles. These results suggest that the production of nitrate and sulfate on dust particles following cold fronts is likely limited when the particles move from the desert to populated areas within the continent. For an accurate quantification of sulfate and nitrate formed on long-distance-transported desert dust particles at downwind populated areas in eastern China, dust collection efforts are indispensable to minimize any possible influence by locally emitted particles or at least to ensure that the samples are collected after dust arrival.

Particle atlas of World Trade Center dust

USGS Publications Warehouse

Lowers, Heather; Meeker, Gregory P.

2005-01-01

The United States Environmental Protection Agency (EPA) has begun a reassessment of the presence of World Trade Center (WTC) dust in residences, public buildings, and office spaces in New York City, New York. Background dust samples collected from residences, public buildings, and office spaces will be analyzed by multiple laboratories for the presence of WTC dust. Other laboratories are currently studying WTC dust for other purposes, such as health effects studies. To assist in inter-laboratory consistency for identification of WTC dust components, this particle atlas of phases in WTC dust has been compiled.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amblard, A.; Riguccini, L.; Temi, P.

We compute the properties of a sample of 221 local, early-type galaxies with a spectral energy distribution (SED) modeling software, CIGALEMC. Concentrating on the star-forming (SF) activity and dust contents, we derive parameters such as the specific star formation rate (sSFR), the dust luminosity, dust mass, and temperature. In our sample, 52% is composed of elliptical (E) galaxies and 48% of lenticular (S0) galaxies. We find a larger proportion of S0 galaxies among galaxies with a large sSFR and large specific dust emission. The stronger activity of S0 galaxies is confirmed by larger dust masses. We investigate the relative proportionmore » of active galactic nuclei (AGNs) and SF galaxies in our sample using spectroscopic Sloan Digital Sky Survey data and near-infrared selection techniques, and find a larger proportion of AGN-dominated galaxies in the S0 sample than the E one. This could corroborate a scenario where blue galaxies evolve into red ellipticals by passing through an S0 AGN active period while quenching its star formation. Finally, we find a good agreement comparing our estimates with color indicators.« less

Microbes and Microstructure: Dust's Role in the Snowpack Evolution

NASA Astrophysics Data System (ADS)

Lieblappen, R.; Courville, Z.; Fegyveresi, J. M.; Barbato, R.; Thurston, A.

2017-12-01

Dust is a primary vehicle for transporting microbial communities to polar and alpine snowpacks both through wind distribution (dry deposition) and snowfall events (wet deposition). The resulting microbial community diversity in the snowpack may then resemble the source material properties rather than its new habitat. Dust also has a strong influence on the microstructural properties of snow, resulting in changes to radiative and mechanical properties. As local reductions in snowpack albedo lead to enhanced melting and a heterogeneous snow surface, the microbial communities are also impacted. Here we study the impact of the changing microstructure in the snowpack, its influence on microbial function, and the fate of dust particles within the snow matrix. We seek to quantify the changes in respiration and water availability with the onset of melt. Polar samples were collected from the McMurdo Ice Shelf, Antarctica in February, 2017, while alpine samples were collected from Silverton, CO from October to May, 2017 as part of the Colorado Dust on Snow (CDOS) network. At each site, coincident meteorological data provides temperature, wind, and radiative measurements. Samples were collected immediately following dust deposition events and after subsequent snowpack evolution. We used x-ray micro-computed tomography to quantify the microstructural evolution of the snow, while also imaging the microstructural distribution of the dust within the snow. The dust was then collected and analyzed for chemical and microbial activity.

Dust fallout in Kuwait city: deposition and characterization.

PubMed

Al-Awadhi, Jasem M; Alshuaibi, Arafat A

2013-09-01

Dust fallouts in Kuwait city was monitored on monthly basis during the period from March 2011 to February 2012 at 10 locations. The results of this study reveal that: (1) monthly dust deposition rates ranged from 0.002 to 0.32 kg/m(2) with average deposition rate of 0.053 kg/m(2) and annual average deposition rate of 0.59 kg/m(2), ranking the first out of 56 dust deposition rates observed throughout the world; (2) on average, about 55.9% of the settled dust have fine to very fine sand fraction sizes, while silt and clay comprise an average of 37.4 and 1.4% of the total sample, respectively; (3) the concentrations for Zn and Mo out of 15 other elements analyzed from the dust were up to 11 times higher than their soil background values in Kuwait, while Pb and Ni were about seven times higher; (4) Mo, Ni, Pb and Zn show maximum enrichment relative to the upper continental crustal component (Mn); (5) Sr, Zr and Zn show highest concretions among all collected samples; and (6) quartz and calcite were the dominant minerals in the dust samples. The distribution of the heavy metals in dust seems to be controlled mainly by the land uses and the volume of traffic emissions. Copyright © 2013 Elsevier B.V. All rights reserved.

Cometary Dust: The Diversity of Primitive Matter

NASA Technical Reports Server (NTRS)

Wooden, D. H.; Ishiiii, H. A.; Zolensky, M. E.

2017-01-01

The connections between comet dust and primitive chondrites from asteroids has strengthened considerably over the past decade. Understanding the importance of the connections between Stardust samples and chondrites requires geochemistry lingo as well as a perspective of other cometary dust samples besides Stardust. We present the principal findings of an extensive review prepared for by us for the June 2016 "Cometary Science After Rosetta" meeting at The Royal Society, London.

Elemental Concentrations in Roadside Dust Along Two National Highways in Northern Vietnam and the Health-Risk Implication.

PubMed

Phi, Thai Ha; Chinh, Pham Minh; Cuong, Doan Danh; Ly, Luong Thi Mai; Van Thinh, Nguyen; Thai, Phong K

2018-01-01

There is a need to assess the risk of exposure to metals via roadside dust in Vietnam where many people live along the road/highways and are constantly exposed to roadside dust. In this study, we collected dust samples at 55 locations along two major Highways in north-east Vietnam, which passed through different land use areas. Samples were sieved into three different particle sizes and analyzed for concentrations of eight metals using a X-ray fluorescence instrument. The concentrations and environmental indices (EF, I geo ) of metals were used to evaluate the degree of pollution in the samples. Among different land uses, industrial areas could be highly polluted with heavy metals in roadside dust, followed by commerce and power plants. Additionally, the traffic density probably played an important role; higher concentrations were observed in samples from Highway No. 5 where traffic is several times higher than Highway No. 18. According to the risk assessment, Cr poses the highest noncarcinogenic risk even though the health hazard index values of assessed heavy metals in this study were within the acceptable range. Our assessment also found that the risk of exposure to heavy metals through roadside dust is much higher for children than for adults.

Alpha Air Sample Counting Efficiency Versus Dust Loading: Evaluation of a Large Data Set

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hogue, M. G.; Gause-Lott, S. M.; Owensby, B. N.

Dust loading on air sample filters is known to cause a loss of efficiency for direct counting of alpha activity on the filters, but the amount of dust loading and the correction factor needed to account for attenuated alpha particles is difficult to assess. In this paper, correction factors are developed by statistical analysis of a large database of air sample results for a uranium and plutonium processing facility at the Savannah River Site. As is typically the case, dust-loading data is not directly available, but sample volume is found to be a reasonable proxy measure; the amount of dustmore » loading is inferred by a combination of the derived correction factors and a Monte Carlo model. The technique compares the distribution of activity ratios [beta/(beta + alpha)] by volume and applies a range of correction factors on the raw alpha count rate. The best-fit results with this method are compared with MCNP modeling of activity uniformly deposited in the dust and analytical laboratory results of digested filters. Finally, a linear fit is proposed to evenly-deposited alpha activity collected on filters with dust loading over a range of about 2 mg cm -2 to 1,000 mg cm -2.« less

Alpha Air Sample Counting Efficiency Versus Dust Loading: Evaluation of a Large Data Set

DOE PAGES

Hogue, M. G.; Gause-Lott, S. M.; Owensby, B. N.; ...

2018-03-03

Dust loading on air sample filters is known to cause a loss of efficiency for direct counting of alpha activity on the filters, but the amount of dust loading and the correction factor needed to account for attenuated alpha particles is difficult to assess. In this paper, correction factors are developed by statistical analysis of a large database of air sample results for a uranium and plutonium processing facility at the Savannah River Site. As is typically the case, dust-loading data is not directly available, but sample volume is found to be a reasonable proxy measure; the amount of dustmore » loading is inferred by a combination of the derived correction factors and a Monte Carlo model. The technique compares the distribution of activity ratios [beta/(beta + alpha)] by volume and applies a range of correction factors on the raw alpha count rate. The best-fit results with this method are compared with MCNP modeling of activity uniformly deposited in the dust and analytical laboratory results of digested filters. Finally, a linear fit is proposed to evenly-deposited alpha activity collected on filters with dust loading over a range of about 2 mg cm -2 to 1,000 mg cm -2.« less

Sorption of Organophosphorus Flame-Retardants on Settled ...

EPA Pesticide Factsheets

Dust is an important sink for indoor air pollutants, such as organophosphorus flame-retardants (OPFRs) that are used as additives in industrial and consumer products including electrical and electronic products, furniture, plastics, textile, and building/construction materials. This research investigated the sorption of OPFRs, tris(2-chloroethyl) phosphate (TCEP), tris(1-chlor-2-propyl) phosphate (TCPP), and tris(1,3-dichloro-2-propyl) phosphate (TDCPP) on settled Arizona Test Dust (ATD) using a dual small chamber system. During the test, seven free film release paper dust trays covered with ATD were placed in the sink test chamber. Constant gas phase OPFRs from the source chamber were dosed into the test chamber. The dust evenly spread on each dust tray was removed from the test chamber at different exposure times to determine the amount of OPFRs absorbed by the dust. The ATD has been characterized for a nominal particle size and surface area. The mass of dust on each of seven dust trays was weighed before the dust was placed inside the sink chamber. OPFRs concentrations at the inlet and faceplate of the test chamber were monitored by collecting polyurethane foam (PUF) samples. The OPFR exposed dust and PUF samples were extracted by 1:1 ethyl acetate/methylene chloride and analyzed on GC/MS. The data were used to calculate the OPFR sorption concentration on the dust through dust/air partition. Settled dust can adsorb OPFR from air. The sorption concentration wa

Resilient microorganisms in dust samples of the International Space Station-survival of the adaptation specialists.

PubMed

Mora, Maximilian; Perras, Alexandra; Alekhova, Tatiana A; Wink, Lisa; Krause, Robert; Aleksandrova, Alina; Novozhilova, Tatiana; Moissl-Eichinger, Christine

2016-12-20

The International Space Station (ISS) represents a unique biotope for the human crew but also for introduced microorganisms. Microbes experience selective pressures such as microgravity, desiccation, poor nutrient-availability due to cleaning, and an increased radiation level. We hypothesized that the microbial community inside the ISS is modified by adapting to these stresses. For this reason, we analyzed 8-12 years old dust samples from Russian ISS modules with major focus on the long-time surviving portion of the microbial community. We consequently assessed the cultivable microbiota of these samples in order to analyze their extremotolerant potential against desiccation, heat-shock, and clinically relevant antibiotics. In addition, we studied the bacterial and archaeal communities from the stored Russian dust samples via molecular methods (next-generation sequencing, NGS) and compared our new data with previously derived information from the US American ISS dust microbiome. We cultivated and identified in total 85 bacterial, non-pathogenic isolates (17 different species) and 1 fungal isolate from the 8-12 year old dust samples collected in the Russian segment of the ISS. Most of these isolates exhibited robust resistance against heat-shock and clinically relevant antibiotics. Microbial 16S rRNA gene and archaeal 16S rRNA gene targeting Next Generation Sequencing showed signatures of human-associated microorganisms (Corynebacterium, Staphylococcus, Coprococcus etc.), but also specifically adapted extremotolerant microorganisms. Besides bacteria, the detection of archaeal signatures in higher abundance was striking. Our findings reveal (i) the occurrence of living, hardy microorganisms in archived Russian ISS dust samples, (ii) a profound resistance capacity of ISS microorganisms against environmental stresses, and (iii) the presence of archaeal signatures on board. In addition, we found indications that the microbial community in the Russian segment dust samples was different to recently reported US American ISS microbiota.

Four Interstellar Dust Candidates from the Stardust Interstellar Dust Collector

NASA Technical Reports Server (NTRS)

Westphal, A. J.; Allen, C.; Bajt, S.; Bechtel, H. A.; Borg, J.; Brenker, F.; Bridges, J.; Brownlee, D. E.; Burchell, M.; Burghammer, M.;

30 CFR 74.5 - Tests of coal mine dust personal sampler units.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Tests of coal mine dust personal sampler units. 74.5 Section 74.5 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH COAL MINE DUST SAMPLING DEVICES Approval Requirements for Coal Mine Dust...

30 CFR 74.5 - Tests of coal mine dust personal sampler units.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Tests of coal mine dust personal sampler units. 74.5 Section 74.5 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH COAL MINE DUST SAMPLING DEVICES Approval Requirements for Coal Mine Dust...

30 CFR 74.5 - Tests of coal mine dust personal sampler units.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tests of coal mine dust personal sampler units. 74.5 Section 74.5 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH COAL MINE DUST SAMPLING DEVICES Approval Requirements for Coal Mine Dust...

30 CFR 74.5 - Tests of coal mine dust personal sampler units.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Tests of coal mine dust personal sampler units. 74.5 Section 74.5 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH COAL MINE DUST SAMPLING DEVICES Approval Requirements for Coal Mine Dust...

Composition of aeolian dust in natural traps on isolated surfaces of the central Mojave Desert - Insights to mixing, sources, and nutrient inputs

USGS Publications Warehouse

Reynolds, R.L.; Reheis, M.; Yount, J.; Lamothe, P.

2006-01-01

The recognition and characterization of aeolian dust in soil contribute to a better understanding of landscape and ecosystem dynamics of drylands. Results of this study show that recently deposited dust, sampled in isolated, mostly high-ground settings, is chemically and mineralogically similar on varied geologic substrates over a large area (15 000 km2) in the Mojave Desert. The silt-plus-clay fraction (fines) on these isolated surfaces is closely alike in magnetic-mineral composition, in contrast to greatly dissimilar magnetic compositions of rock surfaces of vastly different lithologies, on which the fines have accumulated. The fines, thus, are predominantly deposited dust. The amounts of potential nutrients in the sampled dust are much more uniform than might be provided by direct, local weathering of bedrock or by dust locally derived from nearby weathered products. The compositional similarity of the dust on these surfaces is interpreted to result from mixing of fines in the atmosphere as well as in fluvial, alluvial, and lacustrine depositional settings prior to dust emission.

Measurement of nicotine in household dust

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Sungroul; Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205; Aung, Ther

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 dilutionmore » 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.« less

Exposure to dust-bound PAHs and associated carcinogenic risk in primitive and traditional cooking practices in Pakistan.

PubMed

Kamal, Atif; Malik, Riffat Naseem; Martellini, Tania; Cincinelli, Alessandra

2015-08-01

The aim of this study was to determine the abundance and distribution of polycyclic aromatic hydrocarbons (PAHs) in dust samples collected from the selected professional cooking workplaces (WCs) and residential household cooking areas (WRs), where traditional and primitive cooking practices are still prevelent. Another aim of this study was to investigate the carcinogenic risk for Pakistani human exposure to dust-bound PAHs via the routes of inhalation, ingestion, and dermal contact. Generally, the concentration of individual congeners of PAHs in surface dust samples of WC sites was higher than those measured in WR sites (p < 0.05). The benzo(a)pyrene (B(a)P), a very high carcinogenic compound, was present in the dust samples from WC sites in the highest mean concentration (630 ng g(-1) dry weight (d.w.)). The BaP mean concentration in WC workplaces was almost eight times higher than the mean value found in WR exposure sites. Moreover, the average concentration of ∑PAHs, combustion origin PAHs (∑COMB) and sum total of 7-carcinogenic PAHs (∑7-carcinogens) were also significantly higher in WC dusts samples than that in WR workplaces. Principal component analysis (PCA) and diagnostic ratios suggested coal/wood combustion as major PAH emission sources in both exposure sites. The average incremental lifetime cancer risk (ILCR) suggested a moderate to potential high cancer risk for adults and children exposed to dust-bound PAHs in both exposure sites, in particular via both dermal and ingestion contact pathways.

Trace metals in fugitive dust from unsurfaced roads in the Viburnum Trend resource mining District of Missouri--implementation of a direct-suspension sampling methodology.

PubMed

Witt, Emitt C; Wronkiewicz, David J; Pavlowsky, Robert T; Shi, Honglan

2013-09-01

Fugitive dust from 18 unsurfaced roadways in Missouri were sampled using a novel cyclonic fugitive dust collector that was designed to obtain suspended bulk samples for analysis. The samples were analyzed for trace metals, Fe and Al, particle sizes, and mineralogy to characterize the similarities and differences between roadways. Thirteen roads were located in the Viburnum Trend (VT) mining district, where there has been a history of contaminant metal loading of local soils; while the remaining five roads were located southwest of the VT district in a similar rural setting, but without any mining or industrial process that might contribute to trace metal enrichment. Comparison of these two groups shows that trace metal concentration is higher for dusts collected in the VT district. Lead is the dominant trace metal found in VT district dusts representing on average 79% of the total trace metal concentration, and was found moderately to strongly enriched relative to unsurfaced roads in the non-VT area. Fugitive road dust concentrations calculated for the VT area substantially exceed the 2008 Federal ambient air standard of 0.15μgm(-3) for Pb. The pattern of trace metal contamination in fugitive dust from VT district roads is similar to trace metal concentrations patterns observed for soils measured more than 40years ago indicating that Pb contamination in the region is persistent as a long-term soil contaminant. Published by Elsevier Ltd.

Mineral magnetism of atmospheric dust over southwest coast of India: Impact of anthropogenic activities and implications to public health

NASA Astrophysics Data System (ADS)

Warrier, Anish Kumar; Shankar, R.; Manjunatha, B. R.; Harshavardhana, B. G.

2014-03-01

We have used rock magnetic techniques in this study to assess atmospheric pollution at five stations in and around Mangalore city on the southwestern coast of India. Samples of dust were collected from two suburban areas (Thokkottu and Pumpwell located respectively ~ 10 km and 3 km from the city center), the city center itself (Milagres) and industrial/port areas (Panambur and Mangalore Refinery and Petrochemicals Limited (MRPL)). Low-frequency magnetic susceptibility (χlf), frequency-dependent susceptibility (χfd), susceptibility of anhysteretic remanent magnetization (χARM) and isothermal remanent magnetization (IRM 20 to 1000 mT) were determined on 23 dust samples and inter-parametric ratios calculated. Results show that samples from suburban areas (particularly Thokkottu) are characterized by low χlf (< 314.1 × 10- 8 m3 kg- 1) and up to 6% χfd, suggesting low levels of pollution and the presence of pedogenic magnetite possibly derived from soils by wind erosion. However, the average χlf of Milagres, Panambur and MRPL dust samples is high by factors of 9.2, 3.3 and 2.6 compared to that of the Thokkottu sample. The Milagres sample contains magnetically "soft" minerals like magnetite, possibly indicating its derivation from motor vehicle exhaust. In contrast, the Panambur dust sample is characterized by magnetically "hard" minerals such as hematite and goethite as it has an 8-fold higher HIRM value compared to the Thokkottu sample. This magnetic signature is perhaps the result of dust particles derived from the grinding of hematite-rich iron ore by the Kudremukh Iron Ore Company Limited (KIOCL) at Panambur and its storage and export through the nearby New Mangalore Port. However, the dust sample from MRPL has magnetically "soft" minerals like magnetite. This magnetic mineral may have originated from petroleum refining processes at MRPL. Particulate pollution from industrial activities and motor vehicle exhaust is a threat to human health and is known to cause cardiovascular and respiratory ailments. Therefore, the pollution levels brought out by this study warrant a comprehensive epidemiological study in the area of study.

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

Compositions of modern dust and surface sediments in the Desert Southwest, United States

USGS Publications Warehouse

Reheis, M.C.; Budahn, J.R.; Lamothe, P.J.; Reynolds, R.L.

2009-01-01

Modern dusts across southwestern United States deserts are compositionally similar to dust-rich Av soil horizons (depths of 0-0.5 cm and 1-4 cm at 35 sites) for common crustal elements but distinctly different for some trace elements. Chemical compositions and magnetic properties of the soil samples are similar among sites relative to dust sources, geographic areas, and lithologic substrates. Exceptions are Li, U, and W, enriched in Owens Valley, California, and Mg and Sr, enriched in soils formed on calcareous fan gravel in southeast Nevada. The Av horizons are dominated by dust and reflect limited mixing with substrate sediments. Modern dust samples are also similar across the region, except that Owens Valley dusts are higher in Mg, Ba, and Li and dusts both there and at sites to the north on volcanic substrates are higher in Sb and W. Thus, dust and Av horizons consist of contributions from many different sources that are well mixed before deposition. Modern dusts contain significantly greater amounts of As, Cd, Cr, Cu, Ni, Pb, and Sb than do Av horizons, which record dust additions over hundreds to thousands of years. These results suggest that modern dust compositions are influenced by anthropogenic sources and emissions from Owens (dry) Lake after its artificial desiccation in 1926. Both modern dusts and Av horizons are enriched in As, Ba, Cu, Li, Sb, Th, U, and W relative to average crustal composition, which we interpret to indicate that the geologic sources of dust in the southwestern United States are geochemically distinctive.

Rock-forming metals and Pb in modern Alaskan snow

USGS Publications Warehouse

Hinkley, Todd K.

1993-01-01

Metal concentrations in annual and subannual increments of snowpack from the accumulation zone of a south central Alaska glacier indicate that the deposition of Pb with and upon snow is decoupled from that of rock dusts. Rock dusts accumulate, apparently as dry deposition, on the topmost, exposed surfaces of snowpacks in spring and summer, whereas Pb does not. Pb concentration is elevated throughout the latest one third of an annual snowpack, whereas that of rock dusts is not. For whole-year snowpacks, there is a generally sympathetic relationship among concentration of Pb, concentration of rock dust, degree of dominance of rock dusts over ocean solutes, and ferromagnesian character of the rock dusts; however, the fractional abundance of Pb in whole year samples may decrease when rock dust masses become large and/or when rock dusts dominate most strongly over salts. The metal suite chosen to characterize rock dusts and to distinguish them from ocean solutes gives detailed information about rock type of dust source areas and about the nature of the degraded rock products that are taken up, transported, and deposited by the atmosphere. Rock dusts are present at concentrations of only about 300 nanograms (ng) of dust per gram of snow in the Alaskan snowpacks. Concentrations of Pb in the Alaska snow samples are moderate, ranging from 0.1 to 0.3 ng Pb/g snow. This contrasts with larger Pb concentrations of 0.4 to 0.9 ng Pb/g snow in whole-year snowpack samples from the Sierra Nevada, California; with similar to smaller concentrations from north and south Greenland of about 0.04 ng Pb/g snow or less, and about 0.2 ng Pb/g snow or less, respectively, and with much smaller concentrations from Antarctica, now believed to range from a minimum of about 0.001 to a maximum of 0.005 (or 0.01) ng Pb/g snow.

Recently Deglaciated High-Altitude Soils of the Himalaya: Diverse Environments, Heterogenous Bacterial Communities and Long-Range Dust Inputs from the Upper Troposphere

PubMed Central

Stres, Blaz; Sul, Woo Jun; Murovec, Bostjan; Tiedje, James M.

2013-01-01

Background The Himalaya with its altitude and geographical position forms a barrier to atmospheric transport, which produces much aqueous-particle monsoon precipitation and makes it the largest continuous ice-covered area outside polar regions. There is a paucity of data on high-altitude microbial communities, their native environments and responses to environmental-spatial variables relative to seasonal and deglaciation events. Methodology/Principal Findings Soils were sampled along altitude transects from 5000 m to 6000 m to determine environmental, spatial and seasonal factors structuring bacterial communities characterized by 16 S rRNA gene deep sequencing. Dust traps and fresh-snow samples were used to assess dust abundance and viability, community structure and abundance of dust associated microbial communities. Significantly different habitats among the altitude-transect samples corresponded to both phylogenetically distant and closely-related communities at distances as short as 50 m showing high community spatial divergence. High within-group variability that was related to an order of magnitude higher dust deposition obscured seasonal and temporal rearrangements in microbial communities. Although dust particle and associated cell deposition rates were highly correlated, seasonal dust communities of bacteria were distinct and differed significantly from recipient soil communities. Analysis of closest relatives to dust OTUs, HYSPLIT back-calculation of airmass trajectories and small dust particle size (4–12 µm) suggested that the deposited dust and microbes came from distant continental, lacustrine and marine sources, e.g. Sahara, India, Caspian Sea and Tibetan plateau. Cyanobacteria represented less than 0.5% of microbial communities suggesting that the microbial communities benefitted from (co)deposited carbon which was reflected in the psychrotolerant nature of dust-particle associated bacteria. Conclusions/Significance The spatial, environmental and temporal complexity of the high-altitude soils of the Himalaya generates ongoing disturbance and colonization events that subject heterogeneous microniches to stochastic colonization by far away dust associated microbes and result in the observed spatially divergent bacterial communities. PMID:24086740

High exposure to respirable dust and quartz in a labour-intensive coal mine in Tanzania.

PubMed

Mamuya, Simon H D; Bråtveit, Magne; Mwaiselage, Julius; Mashalla, Yohana J S; Moen, Bente E

2006-03-01

Labour-intensive mines are numerous in several developing countries, but dust exposure in such mines has not been adequately characterized. The aim of this study was to identify and quantify the determinants of respirable dust and quartz exposure among underground coal mine workers in Tanzania. Personal respirable dust samples (n = 134) were collected from 90 underground workers in June-August 2003 and July-August 2004. The development team had higher exposure to respirable dust and quartz (geometric means 1.80 and 0.073 mg m(-3), respectively) than the mining team (0.47 and 0.013 mg m(-3)), the underground transport team (0.14 and 0.006 mg m(-3)) and the underground maintenance team (0.58 and 0.016 mg m(-3)). The percentages of samples above the threshold limit values (TLVs) of 0.9 mg m(-3) for respirable bituminous coal dust and 0.05 mg m(-3) for respirable quartz, respectively, were higher in the development team (55 and 47%) than in the mining team (20 and 9%). No sample for the underground transport team exceeded the TLV. Drilling in the development was the work task associated with the highest exposure to respirable dust and quartz (17.37 and 0.611 mg m(-3), respectively). Exposure models were constructed using multiple regression model analysis, with log-transformed data on either respirable dust or quartz as the dependent variable and tasks performed as the independent variables. The models for the development section showed that blasting and pneumatic drilling times were major determinants of respirable dust and quartz, explaining 45.2 and 40.7% of the variance, respectively. In the mining team, only blasting significantly determined respirable dust. Immediate actions for improvements are suggested to include implementing effective dust control together with improved training and education programmes for the workers. Dust and quartz in this underground mine should be controlled by giving priority to workers performing drilling and blasting in the development sections of the mine.

Dust Mites Population in Indoor Houses of Suspected Allergic Patients of South Assam, India

PubMed Central

Sharma, Dhruba; Dutta, B. K.; Singh, A. B.

2011-01-01

Background. In the present study, quality and quantity of indoor dust mites was evaluated at the residence of 150 atopic allergic patients from four different districts of South Assam. Methods. Suspected patients with case history of allergic disease were selected for indoor survey. Dust samples (500 mg) were collected from the selected patient's house and were analyzed using standard methods. Results. About 60% of the selected patients were found suffering from respiratory disorders and rest 40% from skin allergy. The dominant mites recorded from indoor dust samples were Dermatophagoides followed by Blomia, Acarus, and Cheyletus while Caloglyphus was recorded in least number. The distribution of mites on the basis of housing pattern indicates that RCC type of buildings supports maximum dust mite's population followed by Assam type (semi-RCC) buildings, and the lowest count was observed in wooden houses. Environmental factors like temperature, rainfall, and relative humidity are found to determine the indoor mite's population. Severity of allergic attack in some of the typical cases was found to be proportional to the allergen load of mites in the dust samples. Conclusions. The economic status, housing pattern, and local environmental factors determine the diversity and abundance of dust mites in indoor environment. PMID:23724231

Imaging-based dust sensors: equipment and methods

NASA Astrophysics Data System (ADS)

Bonifazi, Giuseppe; Greco, Sonia

2004-05-01

Dust detection and control in real time, represent one of the most challenging problem in all those environments where fine and ultrafine airborne particulate solids products are present. The presence of such products can be linked to several factors, often directly related and influenced by the working-production actions performed. Independently from the causes generating dust, airborne contaminants are an occupational problem of increasing interest as they are related to a wide number of diseases. In particular, airborne dusts are well known to be associated with several classical occupational lung diseases, such as the pneumoconiosis, especially at high levels of exposure. Nowadays there is also an increasing interest in other dust related diseases, from the most serious as cancer and asthma, to those related with allergies or irritation and other illnesses, also occurring at lower levels of exposure. Among the different critical factors influencing health risk for airborne dust exposure, mainly four have to be considered, that is: i) nature of the dust resulting from working in terms of presence of specific poisoning material, i.e. free silica, and morphological and morphometrical attributes of particulates constituting airborne dust; ii) size of the particles, iii) duration of exposure time and, finally, iv) airborne dust concentration in the breathing zone where the worker performs his activity. A correct dust detection is not easy, especially if some of the previous mentioned factors, have to be detected and quantified in real time in order to define specific "on-line" control actions aimed to reduce the level of the exposure to dust of the workers, as for example: i) modification of aspirating devices operating condition, change of filtering cleaning sequence, etc. . The more severe are the environmental conditions, in terms of dust presence (in quantity and quality) more difficult is to utilize efficient sampling devices. Detection devices, in fact, tend to become "blind" to dust as dust presence increases, on the other hand severe dust production conditions is exactly the case where control strategies have to be applied to realize safer conditions for the workers. In this paper the possibility to utilize a new logic to perform an "on-line" airborne dust sampling and analysis utilizing imaging is described with particular reference to dusts flowing in a duct after the caption and before their abatement by classical mechanical filtering. The study was particularly addressed to define, design and implement a logic able to extract those parameters affecting airborne dust behavior with respect to its efficient abatement. All dust sampling was performed directly in an industrial plant where tests were carried out in a controlled environment.

Antibiotics in dust originating from a pig-fattening farm: a new source of health hazard for farmers?

PubMed

Hamscher, Gerd; Pawelzick, Heike Theresia; Sczesny, Silke; Nau, Heinz; Hartung, Jörg

2003-10-01

Pig-house dust originates from feed, bedding, feces, and the animals themselves. If the animals receive drugs such as antibiotics, residues of these substances may occur in manure, in the air, or on surfaces of the respective animal house. In a retrospective study, we investigated dust samples collected during two decades from the same piggery for the occurrence of various antibiotics. In 90% of these samples, we detected up to five different antibiotics, including tylosin, various tetracyclines, sulfamethazine, and chloramphenicol, in total amounts up to 12.5 mg/kg dust. High dust exposure in animal confinement buildings is believed to be a respiratory health hazard because of the high content of microorganisms, endotoxins, and allergens. Further risks may arise from the inhalation of dust contaminated with a cocktail of antibiotics. Apart from that, our data provide first evidence for a new route of entry for veterinary drugs in the environment.

'Nuisance Dust' - a Case for Recalibration?

NASA Astrophysics Data System (ADS)

Datson, Hugh; Marker, Brian

2013-04-01

This paper considers the case for a review and recalibration of limit values and acceptability criteria for 'nuisance dust', a widely encountered but poorly defined and regulated aspect of particulate matter pollution. Specific dust fractions such as PM10 and asbestiforms are well characterised and have limit values enshrined in legislation. National, and international, limit values for acceptable concentrations of PM10 and other fractions of particulate matter have been defined and agreed. In the United Kingdom (UK), these apply to both public and workplace exposures. By contrast, there is no standard definition or universal criteria against which acceptable levels for 'nuisance dust' can be assessed. This has implications for land-use planning and resource utilisation. Without meaningful limit values, inappropriate development might take place too near to residential dwellings or land containing economically important mineral resources may be effectively sterilised. Furthermore, the expression 'nuisance dust' is unhelpful in that 'nuisance' has a specific meaning in environmental law whilst 'nuisance dust' is often taken to mean 'generally visible particulate matter'. As such, it is associated with the social and broader environmental impacts of particulate matter. PM10 concentrations are usually expressed as a mass concentration over time. These can be determined using a range of techniques. While results from different instruments are generally comparable, data obtained from alternative methods for measuring 'nuisance dust' are rarely interchangeable. In the UK, many of the methods typically used are derived from approaches developed under the HMIP (Her Majesty's Inspectorate of Pollution) regime in the 1960s onwards. Typical methods for 'nuisance dust' sampling focus on measurement of dust mass (from the weight of dust collected in an open container over time) or dust soiling (from loss of reflectance and or obscuration of a surface discoloured by dust over time). 'Custom and practice' acceptance criteria for dust samples obtained by mass or soiling techniques have been developed and are widely applied even though they were not necessarily calibrated thoroughly and have not been reviewed recently. Furthermore, as sampling techniques have evolved, criteria developed for one method have been adapted for another. Criteria and limit values have sometimes been based on an insufficient knowledge of sampler characteristics. Ideally, limit values should be calibrated for the locality to take differences in dust density and visibility into account. Work is needed on the definition of criteria and limit values, and sampling practices for coarse dust fractions, followed by discussion of good practices for securing effective monitoring that is proportionate and fit for purpose. With social changes and the evolution of environmental controls since the 1960s, the public perception of 'nuisance dust' has changed and needs to be addressed by reviewing existing thresholds in relation to the range of monitoring devices currently in use.

Comparison of pesticides and other compounds in carpet dust samples collected from used vacuum cleaner bags and from a high-volume surface sampler.

PubMed Central

Colt, J S

1998-01-01

Epidemiologic studies of the association between residential pesticide use and cancer risk require an assessment of past pesticide exposures. Pesticide levels in carpet dust are believed to reflect long-term pesticide use. Recent epidemiologic studies have found collection of dust samples using the high-volume surface sampler (HVS3) to be expensive and cumbersome. We compared the levels of pesticides and other compounds in dust obtained from subjects' personal used vacuum cleaner bags to that collected by the HVS3 to see if this simpler method could replace the HVS3 in epidemiologic research. We visited the homes of 15 subjects, took the used bags from their vacuums, and collected carpet dust samples with the HVS3. The samples were analyzed for 42 target compounds: 26 pesticides, 10 polycyclic aromatic hydrocarbons (PAHs), and six polychlorinated biphenyl (PCB) congeners using GC/MS in selected ion monitoring mode. The two methods agreed in detecting the presence of the target compounds between 80% and 100% of the time. Neither sampling method was consistently more sensitive. The median target compound concentrations were similar, and a paired t-test showed no significant differences. For many compounds, the concentrations of compounds in the HVS3 samples were higher than those in the used bag samples at the upper end of the concentration ranges. However, the Spearman rank correlation coefficients were 0.85 or higher for most compounds, indicating that homes would be ranked similarly using both methods. Overall, there appears to be no clear difference in the quality of the pesticide, PAH, or PCB concentration data for the two dust collection methods. Images Figure 1 PMID:9799187

A comparison of two laboratories for the measurement of wood dust using button sampler and diffuse reflection infrared Fourier-transform spectroscopy (DRIFTS).

PubMed

Chirila, Madalina M; Sarkisian, Khachatur; Andrew, Michael E; Kwon, Cheol-Woong; Rando, Roy J; Harper, Martin

2015-04-01

The current measurement method for occupational exposure to wood dust is by gravimetric analysis and is thus non-specific. In this work, diffuse reflection infrared Fourier transform spectroscopy (DRIFTS) for the analysis of only the wood component of dust was further evaluated by analysis of the same samples between two laboratories. Field samples were collected from six wood product factories using 25-mm glass fiber filters with the Button aerosol sampler. Gravimetric mass was determined in one laboratory by weighing the filters before and after aerosol collection. Diffuse reflection mid-infrared spectra were obtained from the wood dust on the filter which is placed on a motorized stage inside the spectrometer. The metric used for the DRIFTS analysis was the intensity of the carbonyl band in cellulose and hemicellulose at ~1735 cm(-1). Calibration curves were constructed separately in both laboratories using the same sets of prepared filters from the inhalable sampling fraction of red oak, southern yellow pine, and western red cedar in the range of 0.125-4 mg of wood dust. Using the same procedure in both laboratories to build the calibration curve and analyze the field samples, 62.3% of the samples measured within 25% of the average result with a mean difference between the laboratories of 18.5%. Some observations are included as to how the calibration and analysis can be improved. In particular, determining the wood type on each sample to allow matching to the most appropriate calibration increases the apparent proportion of wood dust in the sample and this likely provides more realistic DRIFTS results. Published by Oxford University Press on behalf of the British Occupational Hygiene Society 2014.

The Life Cycle of Dust in the Universe: Observations, Theory, and Laboratory Experiments

NASA Astrophysics Data System (ADS)

Kemper, Ciska; Andersen, Anja; Baes, Maarten; Gomez, Haley; Watson, Darach

This meeting addresses the life cycle of dust in the Universe, which covers the formation, evolution and destruction of dust in a range of environments, ranging from the smallest to the largest scales. Bringing together observational and theoretical astrophysicists as well as meteoriticists and experimentalists allows for a cross-disciplinary dialogue. The meeting follows a successful tradition of astrophysical dust meetings, starting in Albany in 1972, with the latest edition "Cosmic Dust: Near and Far" organized by Th. Henning taking place in Heidelberg in 2008. Since that meeting, the field of dust astrophysics has made major leaps forward with the host of data arriving from such missions as the infrared space telescopes Spitzer and Herschel, and the sample return mission, Stardust, which took dust samples from comet Wild-2. The largest telescope on Earth, ALMA, has also recently come online, allowing for investigations into the origin of dust in the Universe, making this is excellent time to review the status of the field of dust astrophysics. The meeting aims to create an environment in which all aspects of the life cycle of dust are discussed, from an astrophysical, chemical and mineralogical perspective, and its effect on a range of environments. Observational insights, theoretical models and experimental approaches all contribute to our view of the life cycle of dust, and the meeting addresses new developments and future projects in all these areas.

NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR FIELD COLLECTION OF INDOOR FLOOR SAMPLES AND POST FIELD SAMPLE HANDLING (UA-F-7.1)

EPA Science Inventory

The purpose of this SOP is to establish a uniform procedure for the collection of indoor floor dust samples in the field. This procedure was followed to ensure consistent data retrieval of dust samples during the Arizona NHEXAS project and the "Border" study. Keywords: field; va...

INFRARED LUMINOSITIES AND DUST PROPERTIES OF z approx 2 DUST-OBSCURED GALAXIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bussmann, R. S.; Dey, Arjun; Jannuzi, B. T.

We present SHARC-II 350 mum imaging of twelve 24 mum bright (F{sub 24m}u{sub m} > 0.8 mJy) Dust-Obscured Galaxies (DOGs) and Combined Array for Research in Millimeter-wave Astronomy (CARMA) 1 mm imaging of a subset of two DOGs. These objects are selected from the Booetes field of the NOAO Deep Wide-Field Survey. Detections of four DOGs at 350 mum imply infrared (IR) luminosities which are consistent to within a factor of 2 of expectations based on a warm-dust spectral energy distribution (SED) scaled to the observed 24 mum flux density. The 350 mum upper limits for the 8 non-detected DOGsmore » are consistent with both Mrk 231 and M82 (warm-dust SEDs), but exclude cold dust (Arp 220) SEDs. The two DOGs targeted at 1 mm were not detected in our CARMA observations, placing strong constraints on the dust temperature: T{sub dust} > 35-60 K. Assuming these dust properties apply to the entire sample, we find dust masses of approx3 x 10{sup 8} M{sub sun}. In comparison to other dusty z approx 2 galaxy populations such as submillimeter galaxies (SMGs) and other Spitzer-selected high-redshift sources, this sample of DOGs has higher IR luminosities (2 x 10{sup 13} L{sub sun} versus 6 x 10{sup 12} L{sub sun} for the other galaxy populations) that are driven by warmer dust temperatures (>35-60 K versus approx30 K) and lower inferred dust masses (3 x 10{sup 8} M{sub sun} versus 3 x 10{sup 9} M{sub sun}). Wide-field Herschel and Submillimeter Common-User Bolometer Array-2 surveys should be able to detect hundreds of these power-law-dominated DOGs. We use the existing Hubble Space Telescope and Spitzer/InfraRed Array Camera data to estimate stellar masses of these sources and find that the stellar to gas mass ratio may be higher in our 24 mum bright sample of DOGs than in SMGs and other Spitzer-selected sources. Although much larger sample sizes are needed to provide a definitive conclusion, the data are consistent with an evolutionary trend in which the formation of massive galaxies at z approx 2 involves a submillimeter bright, cold-dust, and star-formation-dominated phase followed by a 24 mum bright, warm-dust and AGN-dominated phase.« less

Evaluation of take-home organophosphorus pesticide exposure among agricultural workers and their children.

PubMed Central

Curl, Cynthia L; Fenske, Richard A; Kissel, John C; Shirai, Jeffry H; Moate, Thomas F; Griffith, William; Coronado, Gloria; Thompson, Beti

2002-01-01

We analyzed organophosphorus pesticide exposure in 218 farm worker households in agricultural communities in Washington State to investigate the take-home pathway of pesticide exposure and to establish baseline exposure levels for a community intervention project. House dust samples (n = 156) were collected from within the homes, and vehicle dust samples (n = 190) were collected from the vehicles used by the farm workers to commute to and from work. Urine samples were obtained from a farm worker (n = 213) and a young child (n = 211) in each household. Dust samples were analyzed for six pesticides, and urine samples were analyzed for five dialkylphosphate (DAP) metabolites. Azinphosmethyl was detected in higher concentrations (p < 0.0001) than the other pesticides: geometric mean concentrations of azinphosmethyl were 0.53 micro g/g in house dust and 0.75 micro g/g in vehicle dust. Dimethyl DAP metabolite concentrations were higher than diethyl DAP metabolite concentrations in both child and adult urine (p < 0.0001). Geometric mean dimethyl DAP concentrations were 0.13 micro mol/L in adult urine and 0.09 micro mol/L in child urine. Creatinine-adjusted geometric mean dimethyl DAP concentrations were 0.09 micro mol/g in adult urine and 0.14 micro mol/g in child urine. Azinphosmethyl concentrations in house dust and vehicle dust from the same household were significantly associated (r2 = 0.41, p < 0.0001). Dimethyl DAP levels in child and adult urine from the same household were also significantly associated (r2 = 0.18, p < 0.0001), and this association remained when the values were creatinine adjusted. The results of this work support the hypothesis that the take-home exposure pathway contributes to residential pesticide contamination in agricultural homes where young children are present. PMID:12460819

The asteroid-comet continuum from laboratory and space analyses of comet samples and micrometeorites

NASA Astrophysics Data System (ADS)

Engrand, Cecile; Duprat, Jean; Bardin, Noemie; Dartois, Emmanuel; Leroux, Hugues; Quirico, Eric; Benzerara, Karim; Rémusat, Laurent; Dobrică, Elena; Delauche, Lucie; Bradley, John; Ishii, Hope; Hilchenbach, Martin; COSIMA Team

2015-08-01

Comets are probably the best archives of the nascent solar system, 4.5 Gyr ago, and their compositions reveal crucial clues on the structure and dynamics of the early protoplanetary disk. Anhydrous minerals (olivine and pyroxene) have been identified in cometary dust for a few decades. Surprisingly, samples from comet Wild2 returned by the Stardust mission in 2006 also contain high temperature mineral assemblages like chondrules and refractory inclusions, which are typical components of primitive meteorites (carbonaceous chondrites - CCs). A few Stardust samples have also preserved some organic matter of comet Wild 2 that share some similarities with CCs. Interplanetary dust falling on Earth originate from comets and asteroids in proportions to be further constrained. These cosmic dust particles mostly show similarities with CCs, which in turn only represent a few percent of meteorites recovered on Earth. At least two (rare) families of cosmic dust particles have shown strong evidences for a cometary origin: the chondritic porous interplanetary dust particles (CP-IDPs) collected in the terrestrial stratosphere by NASA, and the ultracarbonaceous Antarctic Micrometeorites (UCAMMs) collected from polar snow and ice by French and Japanese teams. The Rosetta mission currently carries dust analyzers capable of measuring dust flux, sizes, physical properties and compositions of dust particles from the Jupiter family comet 67P/Churyumov-Gerasimenko (COSIMA, GIADA, MIDAS), as well as gas analyzers (ROSINA, PTOLEMY, COSAC). A growing number of evidences highlights the existence of a continuum between asteroids and comets, already in the early history of the solar system. We will present the implications of the analyses of samples in the laboratory and in space to a better understanding of the early protoplanetary disk.

Task-shifting of CD4 T cell count monitoring by the touchscreen-based Muse™ Auto CD4/CD4% single-platform system for CD4 T cell numeration: Implication for decentralization in resource-constrained settings.

PubMed

Kouabosso, André; Mossoro-Kpinde, Christian Diamant; Bouassa, Ralph-Sydney Mboumba; Longo, Jean De Dieu; Mbeko Simaleko, Marcel; Grésenguet, Gérard; Bélec, Laurent

2018-04-01

The accuracy of CD4 T cell monitoring by the recently developed flow cytometry-based CD4 T cell counting Muse™ Auto CD4/CD4% Assay analyzer (EMD Millipore Corporation, Merck Life Sciences, KGaA, Darmstadt, Germany) was evaluated in trained lay providers against laboratory technicians. After 2 days of training on the Muse™ Auto CD4/CD4% analyzer, EDTA-blood samples from 6 HIV-positive and 4 HIV-negative individuals were used for CD4 T cell counting in triplicate in parallel by 12 trained lay providers as compared to 10 lab technicians. Mean number of CD4 T cells in absolute number was 829 ± 380 cells/μl by lay providers and 794 ± 409 cells/μl by technicians (P > 0.05); and in percentage 36.2 ± 14.8%CD4 by lay providers and 36.1 ± 15.0%CD4 by laboratory technician (P > 0.05). The unweighted linear regression and Passing-Bablok regression analyses on CD4 T cell results expressed in absolute count revealed moderate correlation between CD4 T cell counts obtained by lay providers and lab technicians. The mean absolute bias measured by Bland-Altman analysis between CD4 T cell/μl obtained by lay providers and lab technicians was -3.41 cells/μl. Intra-assay coefficient of variance (CV) of Muse™ Auto CD4/CD4% in absolute number was 10.1% by lay providers and 8.5% by lab technicians (P > 0.05), and in percentage 5.5% by lay providers and 4.4% by lab technicians (P > 0.05). The inter-assay CV of Muse™ Auto CD4/CD4% in absolute number was 13.4% by lay providers and 10.3% by lab technicians (P > 0.05), and in percentage 7.8% by lay providers and 6.9% by lab technicians (P > 0.05). The study demonstrates the feasibility of CD4 T cell counting using the alternative flow cytometer Muse™ Auto CD4/CD4% analyzer by trained lay providers and therefore the practical possibility of decentralization CD4 T cell counting to health community centers. Copyright © 2018. Published by Elsevier B.V.

Phoenix Magnetic Properties Experiments Using the Surface Stereo Imager and the MECA Microscopy Station

NASA Astrophysics Data System (ADS)

Madsen, M. B.; Drube, L.; Falkenberg, T. V.; Haspang, M. P.; Ellehoj, M.; Leer, K.; Olsen, L. D.; Goetz, W.; Hviid, S. F.; Gunnlaugsson, H. P.; Hecht, M. H.; Parrat, D.; Lemmon, M. T.; Morris, R. V.; Pike, T.; Sykulska, H.; Vijendran, S.; Britt, D.; Staufer, U.; Marshall, J.; Smith, P. H.

2008-12-01

Phoenix carries as part of its scientific payload a series of magnetic properties experiments designed to utilize onboard instruments for the investigation of airborne dust, air-fall samples stirred by the retro-rockets of the lander, and sampled surface and sub-surface material from the northern plains of Mars. One of the aims of these experiments on Phoenix is to investigate any possible differences between airborne dust and soils found on the northern plains from similar samples in the equatorial region of Mars. The magnetic properties experiments are designed to control the pattern of dust attracted to or accumulated on the surfaces to enable interpretation of these patterns in terms of certain magnetic properties of the dust forming the patterns. The Surface Stereo Imager (SSI) provides multi-spectral information about dust accumulated on three iSweep targets on the lander instrument deck. The iSweeps utilize built in permanent magnets and 6 different background colors for the dust compared to only 1 for the MER sweep magnet. Simultaneously these iSweep targets are used as in-situ radiometric calibration targets for the SSI. The visible/near-infrared spectra acquired so far are similar to typical Martian dust and soil spectra. Because of the multiple background colors of the iSweeps the effect of the translucence of thin dust layers can be estimated. High resolution images (4 micrometers/px) acquired by the Optical Microscope (OM) showed subtle differences between different soil samples in particle size distribution, color and morphology. Most samples contain (typically 50 micrometer) large, subrounded particles that are substantially magnetic. The colors of these particles range from red, brown to (almost) black. Based on results from the Mars Exploration Rovers, these dark particles are believed to be enriched in magnetite. Occasionally, also very bright, whitish particles were found on the magnet substrates, likely held by cohesion forces to the magnet surface and/or to other (magnetic) particles.

Cloud condensation nuclei activity and droplet activation kinetics of wet processed regional dust samples and minerals

NASA Astrophysics Data System (ADS)

Kumar, P.; Sokolik, I. N.; Nenes, A.

2011-08-01

This study reports laboratory measurements of particle size distributions, cloud condensation nuclei (CCN) activity, and droplet activation kinetics of wet generated aerosols from clays, calcite, quartz, and desert soil samples from Northern Africa, East Asia/China, and Northern America. The dependence of critical supersaturation, sc, on particle dry diameter, Ddry, is used to characterize particle-water interactions and assess the ability of Frenkel-Halsey-Hill adsorption activation theory (FHH-AT) and Köhler theory (KT) to describe the CCN activity of the considered samples. Wet generated regional dust samples produce unimodal size distributions with particle sizes as small as 40 nm, CCN activation consistent with KT, and exhibit hygroscopicity similar to inorganic salts. Wet generated clays and minerals produce a bimodal size distribution; the CCN activity of the smaller mode is consistent with KT, while the larger mode is less hydrophilic, follows activation by FHH-AT, and displays almost identical CCN activity to dry generated dust. Ion Chromatography (IC) analysis performed on regional dust samples indicates a soluble fraction that cannot explain the CCN activity of dry or wet generated dust. A mass balance and hygroscopicity closure suggests that the small amount of ions (from low solubility compounds like calcite) present in the dry dust dissolve in the aqueous suspension during the wet generation process and give rise to the observed small hygroscopic mode. Overall these results identify an artifact that may question the atmospheric relevance of dust CCN activity studies using the wet generation method. Based on the method of threshold droplet growth analysis, wet generated mineral aerosols display similar activation kinetics compared to ammonium sulfate calibration aerosol. Finally, a unified CCN activity framework that accounts for concurrent effects of solute and adsorption is developed to describe the CCN activity of aged or hygroscopic dusts.

Relationship between presence of cows with milk positive for Mycobacterium avium subsp. paratuberculosis-specific antibody by enzyme-linked immunosorbent assay and viable M. avium subsp. paratuberculosis in dust in cattle barns.

PubMed

Eisenberg, Susanne W F; Chuchaisangrat, Ruj; Nielen, Mirjam; Koets, Ad P

2013-09-01

Paratuberculosis, or Johne's disease, in cattle is caused by Mycobacterium avium subsp. paratuberculosis, which has recently been suspected to be transmitted through dust. This longitudinal study on eight commercial M. avium subsp. paratuberculosis-positive dairy farms studied the relationship between the number of cows with M. avium subsp. paratuberculosis antibody-positive milk and the presence of viable M. avium subsp. paratuberculosis in settled-dust samples, including their temporal relationship. Milk and dust samples were collected in parallel monthly for 2 years. M. avium subsp. paratuberculosis antibodies in milk were measured by enzyme-linked immunosorbent assay (ELISA) and used as a proxy for M. avium subsp. paratuberculosis shedding. Settled-dust samples were collected by using electrostatic dust collectors (EDCs) at six locations in housing for dairy cattle and young stock. The presence of viable M. avium subsp. paratuberculosis was identified by liquid culture and PCR. The results showed a positive relationship (odds ratio [OR], 1.2) between the number of cows with ELISA-positive milk and the odds of having positive EDCs in the same airspace as the adult dairy cattle. Moreover, the total number of lactating cows also showed an OR slightly above 1. This relationship remained the same for settled-dust samples collected up to 2 months before or after the time of milk sampling. The results suggest that removal of adult cows with milk positive for M. avium subsp. paratuberculosis-specific antibody by ELISA might result in a decrease in the presence of viable M. avium subsp. paratuberculosis in dust and therefore in the environment. However, this decrease is likely delayed by several weeks at least. In addition, the data support the notion that M. avium subsp. paratuberculosis exposure of young stock is reduced by separate housing.

Relationship between Presence of Cows with Milk Positive for Mycobacterium avium subsp. paratuberculosis-Specific Antibody by Enzyme-Linked Immunosorbent Assay and Viable M. avium subsp. paratuberculosis in Dust in Cattle Barns

PubMed Central

Chuchaisangrat, Ruj; Nielen, Mirjam; Koets, Ad P.

2013-01-01

Paratuberculosis, or Johne's disease, in cattle is caused by Mycobacterium avium subsp. paratuberculosis, which has recently been suspected to be transmitted through dust. This longitudinal study on eight commercial M. avium subsp. paratuberculosis-positive dairy farms studied the relationship between the number of cows with M. avium subsp. paratuberculosis antibody-positive milk and the presence of viable M. avium subsp. paratuberculosis in settled-dust samples, including their temporal relationship. Milk and dust samples were collected in parallel monthly for 2 years. M. avium subsp. paratuberculosis antibodies in milk were measured by enzyme-linked immunosorbent assay (ELISA) and used as a proxy for M. avium subsp. paratuberculosis shedding. Settled-dust samples were collected by using electrostatic dust collectors (EDCs) at six locations in housing for dairy cattle and young stock. The presence of viable M. avium subsp. paratuberculosis was identified by liquid culture and PCR. The results showed a positive relationship (odds ratio [OR], 1.2) between the number of cows with ELISA-positive milk and the odds of having positive EDCs in the same airspace as the adult dairy cattle. Moreover, the total number of lactating cows also showed an OR slightly above 1. This relationship remained the same for settled-dust samples collected up to 2 months before or after the time of milk sampling. The results suggest that removal of adult cows with milk positive for M. avium subsp. paratuberculosis-specific antibody by ELISA might result in a decrease in the presence of viable M. avium subsp. paratuberculosis in dust and therefore in the environment. However, this decrease is likely delayed by several weeks at least. In addition, the data support the notion that M. avium subsp. paratuberculosis exposure of young stock is reduced by separate housing. PMID:23793639

Optical properties of mineral dust aerosol including analysis of particle size, composition, and shape effects, and the impact of physical and chemical processing

NASA Astrophysics Data System (ADS)

Alexander, Jennifer Mary

Atmospheric mineral dust has a large impact on the earth's radiation balance and climate. The radiative effects of mineral dust depend on factors including, particle size, shape, and composition which can all be extremely complex. Mineral dust particles are typically irregular in shape and can include sharp edges, voids, and fine scale surface roughness. Particle shape can also depend on the type of mineral and can vary as a function of particle size. In addition, atmospheric mineral dust is a complex mixture of different minerals as well as other, possibly organic, components that have been mixed in while these particles are suspended in the atmosphere. Aerosol optical properties are investigated in this work, including studies of the effect of particle size, shape, and composition on the infrared (IR) extinction and visible scattering properties in order to achieve more accurate modeling methods. Studies of particle shape effects on dust optical properties for single component mineral samples of silicate clay and diatomaceous earth are carried out here first. Experimental measurements are modeled using T-matrix theory in a uniform spheroid approximation. Previous efforts to simulate the measured optical properties of silicate clay, using models that assumed particle shape was independent of particle size, have achieved only limited success. However, a model which accounts for a correlation between particle size and shape for the silicate clays offers a large improvement over earlier modeling approaches. Diatomaceous earth is also studied as an example of a single component mineral dust aerosol with extreme particle shapes. A particle shape distribution, determined by fitting the experimental IR extinction data, used as a basis for modeling the visible light scattering properties. While the visible simulations show only modestly good agreement with the scattering data, the fits are generally better than those obtained using more commonly invoked particle shape distributions. The next goal of this work is to investigate if modeling methods developed in the studies of single mineral components can be generalized to predict the optical properties of more authentic aerosol samples which are complex mixtures of different minerals. Samples of Saharan sand, Iowa loess, and Arizona road dust are used here as test cases. T-matrix based simulations of the authentic samples, using measured particle size distributions, empirical mineralogies, and a priori particle shape models for each mineral component are directly compared with the measured IR extinction spectra and visible scattering profiles. This modeling approach offers a significant improvement over more commonly applied models that ignore variations in particle shape with size or mineralogy and include only a moderate range of shape parameters. Mineral dust samples processed with organic acids and humic material are also studied in order to explore how the optical properties of dust can change after being aged in the atmosphere. Processed samples include quartz mixed with humic material, and calcite reacted with acetic and oxalic acid. Clear differences in the light scattering properties are observed for all three processed mineral dust samples when compared to the unprocessed mineral dust or organic salt products. These interactions result in both internal and external mixtures depending on the sample. In addition, the presence of these organic materials can alter the mineral dust particle shape. Overall, however, these results demonstrate the need to account for the effects of atmospheric aging of mineral dust on aerosol optical properties. Particle shape can also affect the aerodynamic properties of mineral dust aerosol. In order to account for these effects, the dynamic shape factor is used to give a measure of particle asphericity. Dynamic shape factors of quartz are measured by mass and mobility selecting particles and measuring their vacuum aerodynamic diameter. From this, dynamic shape factors in both the transition and vacuum regime can be derived. The measured dynamic shape factors of quartz agree quite well with the spheroidal shape distributions derived through studies of the optical properties.

Sr-Nd-Hf isotopic fingerprinting of transatlantic dust derived from North Africa

NASA Astrophysics Data System (ADS)

Zhao, Wancang; Balsam, William; Williams, Earle; Long, Xiaoyong; Ji, Junfeng

2018-03-01

Long-range transport of African dust plays an important role in understanding dust-climate relationships including dust source areas, dust pathways and associated atmospheric and/or oceanic processes. Clay-sized Sr-Nd-Hf isotopic compositions can be used as geochemical fingerprints to constrain dust provenance and the pathways of long-range transported mineral dust. We investigated the clay-sized Sr-Nd-Hf isotopic composition of surface samples along four transects bordering the Sahara Desert. The transects are from Mali, Niger/Benin/Togo, Egypt and Morocco. Our results show that the Mali transect on the West African Craton (WAC) produces lower εNd (εNd-mean = -16.38) and εHf (εHf-mean = -9.59) values than the other three transects. The Egyptian transect exhibits the lowest 87Sr/86Sr ratios (87Sr/86Srmean = 0.709842), the highest εHf (εHf-mean = -0.34) and εNd values of the four transects. Comparison of the clay-sized Sr-Nd-Hf isotopic values from our North African samples to transatlantic African dust collected in Barbados demonstrates that the dust's provenance is primarily the western Sahel and Sahara as well as the central Sahel. Summer emission dust is derived mainly from the western Sahel and Sahara regions. The source of transatlantic dust in spring and autumn is more varied than in the summer and includes dust not only from western areas, but also south central areas. Comparison of the Sr-Nd-Hf isotopic fingerprints between the source and sink of transatlantic dust also suggests that a northwestward shift in dust source occurs from the winter, through the spring and into the summer. The isotopic data we develop here provide another tool for discriminating changes in dust archives resulting from paleoenvironmental evolution of source regions.

CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING DUST AND SOIL SAMPLES FOR ANALYSIS OF NEUTRAL PERSISTENT ORGANIC POLLUTANTS (SOP-5.14)

EPA Science Inventory

This SOP summarizes the method for extracting and preparing a dust or soil sample for analysis of neutral persistent organic pollutants. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/mass spectrometry.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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 Pbmore » 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.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

S Beauchemin; L MacLean; P Rasmussen

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 Pbmore » 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.« less

Respirable dust measured downwind during rock dust application.

PubMed

Harris, M L; Organiscak, J; Klima, S; Perera, I E

2017-05-01

The Pittsburgh Mining Research Division of the U.S. National Institute for Occupational Safety and Health (NIOSH) conducted underground evaluations in an attempt to quantify respirable rock dust generation when using untreated rock dust and rock dust treated with an anticaking additive. Using personal dust monitors, these evaluations measured respirable rock dust levels arising from a flinger-type application of rock dust on rib and roof surfaces. Rock dust with a majority of the respirable component removed was also applied in NIOSH's Bruceton Experimental Mine using a bantam duster. The respirable dust measurements obtained downwind from both of these tests are presented and discussed. This testing did not measure miners' exposure to respirable coal mine dust under acceptable mining practices, but indicates the need for effective continuous administrative controls to be exercised when rock dusting to minimize the measured amount of rock dust in the sampling device.

Field-testing a new directional passive air sampler for fugitive dust in a complex industrial source environment.

PubMed

Ferranti, E J S; Fryer, M; Sweetman, A J; Garcia, M A Solera; Timmis, R J

2014-01-01

Quantifying the sources of fugitive dusts on complex industrial sites is essential for regulation and effective dust management. This study applied two recently-patented Directional Passive Air Samplers (DPAS) to measure the fugitive dust contribution from a Metal Recovery Plant (MRP) located on the periphery of a major steelworks site. The DPAS can collect separate samples for winds from different directions (12 × 30° sectors), and the collected dust may be quantified using several different measurement methods. The DPASs were located up and down-prevailing-wind of the MRP processing area to (i) identify and measure the contribution made by the MRP processing operation; (ii) monitor this contribution during the processing of a particularly dusty material; and (iii) detect any changes to this contribution following new dust-control measures. Sampling took place over a 12-month period and the amount of dust was quantified using photographic, magnetic and mass-loading measurement methods. The DPASs are able to effectively resolve the incoming dust signal from the wider steelworks complex, and also different sources of fugitive dust from the MRP processing area. There was no confirmable increase in the dust contribution from the MRP during the processing of a particularly dusty material, but dust levels significantly reduced following the introduction of new dust-control measures. This research was undertaken in a regulatory context, and the results provide a unique evidence-base for current and future operational or regulatory decisions.

Magnetic Mars Dust Removal Technology

NASA Astrophysics Data System (ADS)

Arias, F. J.; De las Heras, S. A.

2018-04-01

From the recorded data from recent Mars missions, there are substantial evidence that the dust of Mars is strongly magnetic. In this work we propose a novel, reliable, robust, and ad hoc technique for Mars dust removal for Mars Sample Return mission.

The Dust Content and Opacity of Actively Star-Forming Galaxies

NASA Technical Reports Server (NTRS)

Calzetti, Daniela; Armus, Lee; Bohlin, Ralph C.; Kinney, Anne L.; Koornneef, Jan; Storchi-Bergmann, Thaisa

2000-01-01

We present far-infrared (FIR) photometry at 150 and 205 micron(s) of eight low-redshift starburst galaxies obtained with the Infrared Space Observatory (ISO) ISOPHOT. Five of the eight galaxies are detected in both wave bands, and these data are used, in conjunction with IRAS archival photometry, to model the dust emission at lambda approximately greater than 40 microns. The FIR spectral energy distributions (SEDs) are best fitted by a combination of two modified Planck functions, with T approx. 40 - 55 K (warm dust) and T approx. 20-23 K (cool dust) and with a dust emissivity index epsilon = 2. The cool dust can be a major contributor to the FIR emission of starburst galaxies, representing up to 60% of the total flux. This component is heated not only by the general interstellar radiation field, but also by the starburst itself. The cool dust mass is up to approx. 150 times larger than the warm dust mass, bringing the gas-to-dust ratios of the starbursts in our sample close to Milky Way values, once resealed for the appropriate metallicity. The ratio between the total dust FIR emission in the range 1-1000 microns and the IRAS FIR emission in the range 40 - 120 microns is approx. 1.75, with small variations from galaxy to galaxy. This ratio is about 40% larger than previously inferred from data at millimeter wavelengths. Although the galaxies in our sample are generally classified as "UV bright," for four of them the UV energy emerging shortward of 0.2 microns is less than 15% of the FIR energy. On average, about 30% of the bolometric flux is coming out in the UV-to-near-IR wavelength range; the rest is emitted in the FIR. Energy balance calculations show that the FIR emission predicted by the dust reddening of the UV-to-near-IR stellar emission is within a factor of approx. 2 of the observed value in individual galaxies and within 20% when averaged over a large sample. If our sample of local starbursts is representative of high-redshift (z approx. greater than 1), UV - bright star-forming galaxies, these galaxies' FIR emission will be generally undetected in submillimeter surveys, unless: (1) their bolometric luminosity is comparable to or larger than that of ultraluminous FIR galaxies and (2) their FIR SED contains a cool dust component.

Characterizing mineral dusts and other aerosols from the Middle East--Part 2: grab samples and re-suspensions.

PubMed

Engelbrecht, Johann P; McDonald, Eric V; Gillies, John A; Jayanty, R K M Jay; Casuccio, Gary; Gertler, Alan W

2009-02-01

The purpose of the Enhanced Particulate Matter Surveillance Program was to provide scientifically founded information on the chemical and physical properties of dust collected during a period of approximately 1 year in Djibouti, Afghanistan (Bagram, Khowst), Qatar, United Arab Emirates, Iraq (Balad, Baghdad, Tallil, Tikrit, Taji, Al Asad), and Kuwait (northern, central, coastal, and southern regions). To fully understand mineral dusts, their chemical and physical properties, as well as mineralogical inter-relationships, were accurately established. In addition to the ambient samples, bulk soil samples were collected at each of the 15 sites. In each case, approximately 1 kg of soil from the top 10 mm at a previously undisturbed area near the aerosol sampling site was collected. The samples were air-dried and sample splits taken for soil analysis. Further sample splits were sieved to separate the < 38 micro m particle fractions for mineralogical analysis. Examples of major-element and trace-element chemistry, mineralogy, and other physical properties of the 15 grab samples are presented. The purpose of the trace-element analysis was to measure levels of potentially harmful metals while the major-element and ion-chemistry analyses provided an estimate of mineral components. X-ray diffractometry provided a measure of the mineral content of the dust. Scanning electron microscopy with energy dispersive spectroscopy was used to analyze chemical composition of small individual particles. From similarities in the chemistry and mineralogy of re-suspended and ambient sample sets, it is evident that portions of the ambient dust are from local soils.

Mineralogical, Chemical, and Optical Interrelationships of Airborne Mineral Dusts

NASA Astrophysics Data System (ADS)

Engelbrecht, J. P.; Moosmuller, H.; Pincock, S. L.; Jayanty, R. K. M.; Casuccio, G.

2014-12-01

The purpose of the project was to provide information on the mineralogical, chemical and physical interrelationships of re-suspended mineral dust samples collected as grab samples from global dust sources. Surface soil samples were collected from about 65 desert sites, including the southwestern USA (12), Mali (3), Chad (3), Morocco (1), Canary Islands (8), Cape Verde (1), Djibouti (1), Afghanistan (3), Iraq (6), Kuwait (5), Qatar (1), UAE (1), Serbia (3), China (5), Namibia (3), Botswana (4), Australia (3), and Chile (1). The < 38 μm sieved fraction of each sample was re-suspended in an entrainment chamber, from which the airborne mineral dust could be monitored, sampled and analyzed. Instruments integrated into the entrainment facility included two PM10 and two PM2.5 filter samplers, a beta attenuation gauge for the continuous measurement of PM10 and PM2.5 particulate mass fractions, an aerodynamic particle size (APS) analyzer, and a three wavelength (405, 532, 781nm) photoacoustic resonator with integrating reciprocal nephelometer for monitoring absorption and scattering coefficients during the dust re-suspension process. Filter sample media included Teflon® membrane and quartz fiber filters for chemical analysis (71 species), and Nuclepore® filters for individual particle analysis by Scanning Electron Microscopy (SEM). The < 38 μm sieved fractions were also analyzed by X-ray diffraction for their mineral content while the > 38 μm, < 125 μm soil fractions were mineralogically characterized by optical microscopy. We will be presenting results on the optical measurements, also showing the relationship between single scattering albedo (SSA) at three different wavelengths, and chemical as well as mineralogical content and interdependencies of the entrained dust samples. Examples showing the relationships between the single scattering albedos of airborne dusts, and iron (Fe) in hematite, goethite, and clay minerals (montmorillonite, illite, palygorskite), will be discussed. Differences between the clay minerals in samples from Mali and those from other localities are demonstrated. We intend establishing a data base for applications in climate modeling, remote sensing, visibility, health (medical geology), ocean fertilization, and damage to equipment.

Stardust Interstellar Preliminary Examination II: Curating the Interstellar Dust Collector, Picokeystones, and Sources of Impact Tracks

NASA Technical Reports Server (NTRS)

Frank, David R.; Westphal, Andrew J.; Zolensky, Michael E.; Gainsforth, Zack; Butterworth, Anna L.; Bastien, Ronald K.; Allen, Carlton; Anderson, David; Bechtel, Hans A.; Sandford, Scott A.

2013-01-01

We discuss the inherent difficulties that arise during "ground truth" characterization of the Stardust interstellar dust collector. The challenge of identifying contemporary interstellar dust impact tracks in aerogel is described within the context of background spacecraft secondaries and possible interplanetary dust particles and beta-meteoroids. In addition, the extraction of microscopic dust embedded in aerogel is technically challenging. Specifically, we provide a detailed description of the sample preparation techniques developed to address the unique goals and restrictions of the Interstellar Preliminary Exam. These sample preparation requirements and the scarcity of candidate interstellar impact tracks exacerbate the difficulties. We also illustrate the role of initial optical imaging with critically important examples, and summarize the overall processing of the collection to date.

Concentrations and health risk assessment of metal(loid)s in indoor dust from two typical cities of China.

PubMed

Li, Yiwen; Pi, Lu; Hu, Wenli; Chen, Mengqin; Luo, Yan; Li, Zhi; Su, Shijun; Gan, Zhiwei; Ding, Sanglan

2016-05-01

Eleven trace metal(loid)s were determined in the household dust samples from Chengdu and Tianjin, China, and related human exposure and health risk to metal(loid)s via indoor dust intake were evaluated. The trace metal(loid)s were found to be highly concentrated and polluted in the indoor environment of Chengdu and Tianjin, especially for Cu, Zn, Cd, Sb, and Pb, of which the enrichment factors exceeding 5. Metal(loid) levels in the indoor dust samples exhibited no statistical differences between the two cities, with the exception of Sb, which was detected higher in the Chengdu samples. Bioaccessibilities in stomach phase of each element were estimated, Cd, Pb, and Sr exhibited higher bioaccessibility, and Sb showed the lowest bioaccessibility in both Chengdu and Tianjin. Dust ingestion was the main metal(loid) exposure pathway for Chengdu and Tianjin inhabitants, followed by dermal contact, dust inhalation accounted for less than 1 % of the total daily metal(loid) intakes and thus could be negligible. Children suffered more risk when exposure to metal(loid)s via indoor dust intake due to their higher frequency of hand to mouth activities. Risk evaluation indicated that, for most Chengdu and Tianjin inhabitants, there is little non-cancer and carcinogen risk when exposure to indoor dust. However, there is a potential non-cancer and carcinogen risk for children and adults in Chengdu, in the case of highly exposed scenario based on the current study.

The asteroid-comet continuum from laboratory and space analyses of comet samples and micrometeorites

NASA Astrophysics Data System (ADS)

Engrand, Cécile; Duprat, Jean; Bardin, Noémie; Dartois, Emmanuel; Leroux, Hugues; Quirico, Eric; Benzerara, Karim; Remusat, Laurent; Dobrică, Elena; Delauche, Lucie; Bradley, John; Ishii, Hope; Hilchenbach, Martin

2016-10-01

Comets are probably the best archives of the nascent solar system, 4.5 Gyr ago, and their compositions reveal crucial clues on the structure and dynamics of the early protoplanetary disk. Anhydrous minerals (olivine and pyroxene) have been identified in cometary dust for a few decades. Surprisingly, samples from comet Wild2 returned by the Stardust mission in 2006 also contain high temperature mineral assemblages like chondrules and refractory inclusions, which are typical components of primitive meteorites (carbonaceous chondrites - CCs). A few Stardust samples have also preserved some organic matter of comet Wild 2 that share some similarities with CCs. Interplanetary dust falling on Earth originate from comets and asteroids in proportions to be further constrained. These cosmic dust particles mostly show similarities with CCs, which in turn only represent a few percent of meteorites recovered on Earth. At least two (rare) families of cosmic dust particles have shown strong evidences for a cometary origin: the chondritic porous interplanetary dust particles (CP-IDPs) collected in the terrestrial stratosphere by NASA, and the ultracarbonaceous Antarctic Micrometeorites (UCAMMs) collected from polar snow and ice by French and Japanese teams. Analyses of dust particles from the Jupiter family comet 67P/Churyumov-Gerasimenko by the dust analyzers on Rosetta orbiter (COSIMA, GIADA, MIDAS) suggest a relationship to interplanetary dust/micrometeorites. A growing number of evidences highlights the existence of a continuum between asteroids and comets, already in the early history of the solar system.

Knowledge of the nursing team on pressure ulcer prevention.

PubMed

Galvão, Nariani Souza; Serique, Maria Alice Barbosa; Santos, Vera Lúcia Conceição de Gouveia; Nogueira, Paula Cristina

2017-04-01

describe and analyze the nursing team's knowledge about classification, evaluation and measures to prevent pressure ulcers (PU) in patients hospitalized in the ICU of a teaching hospital in the city of Manaus. a descriptive and exploratory study was conducted after approval by a research ethics committee. Data were collected using a validated instrument. The study sample was made up of 40 nursing staff members, of whom 14 were nurses and 26 were nursing technicians/aides. Data were analyzed through descriptive statistics and Student's t-test, with value of p<0.05. the overall mean of hits was 63.4% for technicians/aides and 51.4% for nurses, with statistically significant differences between the groups only for the PU prevention category (p<0.001). a deficit of knowledge on PU prevention was found among nurses and nursing technicians/aides, demanding the training of these professionals.

Evaluation of Diffuse Reflection Infrared Spectrometry for End-of-Shift Measurement of α-quartz in Coal Dust Samples

PubMed Central

Miller, Arthur L.; Murphy, Nathaniel C.; Bayman, Sean J.; Briggs, Zachary P.; Kilpatrick, Andrew D.; Quinn, Courtney A.; Wadas, Mackenzie R.; Cauda, Emanuele G.; Griffiths, Peter R.

2015-01-01

The inhalation of toxic substances is a major threat to the health of miners, and dust containing respirable crystalline silica (α-quartz) is of particular concern, due to the recent rise in cases of coal workers’ pneumoconiosis and silicosis in some U.S. mining regions. Currently, there is no field-portable instrument that can measure airborne α-quartz and give miners timely feedback on their exposure. The U.S. National Institute for Occupational Safety and Health (NIOSH) is therefore conducting studies to investigate technologies capable of end-of-shift or real-time measurement of airborne quartz. The present study focuses on the potential application of Fourier transform infrared (FT-IR) spectrometry conducted in the diffuse reflection (DR) mode as a technique for measuring α-quartz in respirable mine dust. A DR accessory was used to analyze lab-generated respirable samples of Min-U-Sil 5 (which contains more than 90% α-quartz) and coal dust, at mass loadings in the ranges of 100–600 μg and 600–5300 μg, respectively. The dust samples were deposited onto three different types of filters, borosilicate fiberglass, nylon, and polyvinyl chloride (PVC). The reflectance, R, was calculated by the ratio of a blank filter and a filter with deposited mine dust. Results suggest that for coal and pure quartz dusts deposited on 37 mm PVC filters, measurements of −log R correlate linearly with known amounts of quartz on filters, with R2 values of approximately 0.99 and 0.94, respectively, for samples loaded up to ~4000 μg. Additional tests were conducted to measure quartz in coal dusts deposited onto the borosilicate fiberglass and nylon filter media used in the NIOSH-developed Personal Dust Monitor (PDM). The nylon filter was shown to be amenable to DR analysis, but quantification of quartz is more accurate when the filter is “free,” as opposed to being mounted in the PDM filter holder. The borosilicate fiberglass filters were shown to produce excessive interference, making quartz quantification impossible. It was concluded that, while the DR/FT-IR method is potentially useful for on-filter measurement of quartz in dust samples, the use of PVC filters produced the most accurate results. PMID:25636081

Evaluation of Diffuse Reflection Infrared Spectrometry for End-of-Shift Measurement of α-quartz in Coal Dust Samples.

PubMed

Miller, Arthur L; Murphy, Nathaniel C; Bayman, Sean J; Briggs, Zachary P; Kilpatrick, Andrew D; Quinn, Courtney A; Wadas, Mackenzie R; Cauda, Emanuele G; Griffiths, Peter R

2015-01-01

The inhalation of toxic substances is a major threat to the health of miners, and dust containing respirable crystalline silica (α-quartz) is of particular concern, due to the recent rise in cases of coal workers' pneumoconiosis and silicosis in some U.S. mining regions. Currently, there is no field-portable instrument that can measure airborne α-quartz and give miners timely feedback on their exposure. The U.S. National Institute for Occupational Safety and Health (NIOSH) is therefore conducting studies to investigate technologies capable of end-of-shift or real-time measurement of airborne quartz. The present study focuses on the potential application of Fourier transform infrared (FT-IR) spectrometry conducted in the diffuse reflection (DR) mode as a technique for measuring α-quartz in respirable mine dust. A DR accessory was used to analyze lab-generated respirable samples of Min-U-Sil 5 (which contains more than 90% α-quartz) and coal dust, at mass loadings in the ranges of 100-600 μg and 600-5300 μg, respectively. The dust samples were deposited onto three different types of filters, borosilicate fiberglass, nylon, and polyvinyl chloride (PVC). The reflectance, R, was calculated by the ratio of a blank filter and a filter with deposited mine dust. Results suggest that for coal and pure quartz dusts deposited on 37 mm PVC filters, measurements of -log R correlate linearly with known amounts of quartz on filters, with R(2) values of approximately 0.99 and 0.94, respectively, for samples loaded up to ∼4000 μg. Additional tests were conducted to measure quartz in coal dusts deposited onto the borosilicate fiberglass and nylon filter media used in the NIOSH-developed Personal Dust Monitor (PDM). The nylon filter was shown to be amenable to DR analysis, but quantification of quartz is more accurate when the filter is "free," as opposed to being mounted in the PDM filter holder. The borosilicate fiberglass filters were shown to produce excessive interference, making quartz quantification impossible. It was concluded that, while the DR/FT-IR method is potentially useful for on-filter measurement of quartz in dust samples, the use of PVC filters produced the most accurate results.

KSC-2010-1049

NASA Image and Video Library

2010-01-07

CAPE CANAVERAL, Fla. – At the Astrotech Space Operations facility in Titusville, Fla., spacecraft fueling technicians from Kennedy Space Center prepare to sample the monomethylhydrazine propellant that will be loaded aboard the Solar Dynamics Observatory, or SDO. From left are Boeing technicians Richard Gillman and Steve Lay, and SDO technician Brian Kittle. The hydrazine fuel is being sampled for purity before it is loaded aboard the spacecraft. The technicians are dressed in self-contained atmospheric protective ensemble suits, or SCAPE suits, as a safety precaution in the unlikely event that any of the highly toxic chemical should escape from the storage tank. The nitrogen tetroxide oxidizer was loaded earlier in the week which is customarily followed by loading of the fuel. Propellant loading is one of the final processing milestones before the spacecraft is encapsulated in its fairing for launch. SDO is the first mission in NASA's Living With a Star Program and is designed to study the causes of solar variability and its impacts on Earth. The spacecraft's long-term measurements will give solar scientists in-depth information to help characterize the interior of the Sun, the Sun's magnetic field, the hot plasma of the solar corona, and the density of radiation that creates the ionosphere of the planets. The information will be used to create better forecasts of space weather needed to protect the aircraft, satellites and astronauts living and working in space. Liftoff aboard an Atlas V rocket is targeted for Feb. 9 from Launch Complex 41 on Cape Canaveral Air Force Station. For information on SDO, visit http://www.nasa.gov/sdo. Photo credit: NASA/Jack Pfaller

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...

Knowledge and attitudes of health care professionals toward organ donation and transplantation.

PubMed

Alsaied, Osama; Bener, Abdulbari; Al-Mosalamani, Yousuf; Nour, Bakr

2012-11-01

To identify and assess the level of knowledge and attitudes of health care professionals (HCP) in Qatar toward organ donation and transplantation, this cross-sectional study was carried out from October 2007 to February 2008 in the Accident and Emergency Departments and Intensive Care Units of the hospitals of the Hamad Medical Corporation (HMC). A representative sample of 585 HCP working in the hospitals of the HMC was approached and 418 staff gave consent to participate in the study (71.5%). 36.8% were physicians, 48.6% nurses and 14.6% Emergency Medical Service (EMS) technicians. Of the surveyed HCP, 40.7% were males and 59.3% were females. Majority of the staff were in the age group of 30-39 years (58.6%). More than half of the physicians (59.7%) and technicians (57.4%) assumed that organs can be bought and sold in the State of Qatar. Most of the physicians (76.6%) and nurses (75.9%) knew that brain-dead persons are eligible for organ donation, whereas only 57.4% of the EMS technicians thought so. Majority of the HCP supported organ donation; physicians (89.0%), nurses (82.3%) and technicians (70.5%). The attitude of the physicians (24.0%) and nurses (20.2%) to donate a kidney to a family member was very poor compared with the attitude of the technicians (44.3%). Although the HCP support organ donation (83%), more than half of the physicians (51.3%), nurses (61.6%) and technicians (54.1%) wanted to be buried with all their organs intact. The findings, although they give cause for hope, suggest that there is much work yet to be done before organ donation and transplantation can become fully accepted by the medical community in Qatar.

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 bathing on the wire mesh. PMID:27044875

A new method for geochemical characterization of atmospheric mineral dust from polar ice cores: preliminary results from Talos Dome ice core (East Antarctica, Pacific-Ross Sea sector)

NASA Astrophysics Data System (ADS)

Baccolo, Giovanni; Delmonte, Barbara; Clemenza, Massimiliano; Previtali, Ezio; Maggi, Valter

2015-04-01

Assessing the elemental composition of atmospheric dust entrapped in polar ice cores is important for the identification of the potential dust sources and thus for the reconstruction of past atmospheric circulation, at local, regional and global scale. Accurate determination of major and trace elements in the insoluble fraction of dust extracted from ice cores is also useful to better understand some geochemical and biogeochemical mechanisms which are linked with the climate system. The extremely reduced concentration of dust in polar ice (typical Antarctic concentrations during interglacials are in the range of 10 ppb), the limited availability of such samples and the high risk of contamination make these analyses a challenge. A new method based on low background Instrumental Neutron Activation Analysis (INAA) was specifically developed for this kind of samples. The method allows the determination of the concentration of up to 35 elements in extremely reduced dust samples (20-30 μg). These elements span from major to trace and ultra-trace elements. Preliminary results from TALDICE (TALos Dome Ice CorE, East Antarctica, Pacific-Ross Sea Sector) ice core are presented along with results from potential source areas in Victoria Land. A set of 5 samples from Talos Dome, corresponding to the last termination, MIS3, MIS4 and MIS6 were prepared and analyzed by INAA.

Determination of polybrominated diphenyl ethers (PBDEs) in dust samples collected in air conditioning filters of different usage - method development.

PubMed

Śmiełowska, M; Zabiegała, B

2018-06-19

This study presents the results of studies aimed at the development of an analytical procedure for separation, identification, and determination of PBDEs compounds in dust samples collected from automotive cabin air filters and samples collected from filters installed as part of the air purification system in academic facilities. Ultrasound-assisted dispersive solid phase extraction (UA-dSPE) was found to perform better in terms of extract purification than the conventional SPE technique. GC-EIMS was used for final determination of analytes. The concentrations of PBDEs in car filters ranged from < LOD to 688 ng/g while from < LOD to 247 ng/g in dust from air conditioning filters. BDE-47 and BDE-100 were reported the dominating congeners. The estimated exposure to PBDEs via ingestion of dust from car filters varied from 0.00022 to 0.012 ng/day in toddlers and from 0.000036 to 0.0029 ng/day in adults; dust from air conditioning filters: from 0.017 to 0.25 ng/day in toddlers and from 0.0029 to 0.042 ng/day. In addition, an attempt was made at extracting PBDEs from a dust samples using the matrix solid-phase dispersion (MSPD) technique as a promising alternative to conventional SPE separations. Copyright © 2018 Elsevier B.V. All rights reserved.

Assessing the bioavailability and risk from metal-contaminated soils and dusts

EPA Science Inventory

Exposure to contaminated soil and dust is an important pathway in human health risk assessment. Physical and chemical characteristics, as well as biological factors, determine the bioaccessibility/bioavailability of soil and dust contaminants. Within a single sample, contaminat...

A new static sampler for airborne total dust in workplaces.

PubMed

Mark, D; Vincent, J H; Gibson, H; Lynch, G

1985-03-01

This paper describes the development and laboratory testing of a new static dust sampler for airborne total dust in workplaces. Particular attention is paid to designing the sampling head and entry consistent with the concept of inspirability which in turn defines a biologically-relevant aspiration efficiency. The sampling head has a small cylindrical body and a transverse entry slot with thin protruding lips forming an integral part of a weighable capsule containing a 37 mm filter which collects all of the sampled dust (without introducing errors due to external particle blow-off or internal wall losses). A battery-powered sampling pump provides both air suction at 3 L/min and rigid mounting for the sampling head. The sampling head is rotated continuously through 360 degrees at approximately 1.5 rpm by a simple electric drive, connected to the stationary pump through a rotating seal. Wind tunnel testing of the instrument showed it to display an entry efficiency very close to the inspirability curve of Vincent and Armbruster (now recommended by the ACGIH Technical Committee on Air Sampling Procedures for defining inspirable particulate matter (IPM] for particles of aerodynamic diameter up to 90 micron and for windspeeds in the range of one to three m/sec.

What if chondritic porous interplanetary dust particles are not the real McCoy

NASA Astrophysics Data System (ADS)

Rietmeijer, Frans J. M.

To select a target comet for a Comet Nucleus Sample Return Mission (CNSRM) it is necessary to have an experimental data base to evaluate the extent of diversity and similarity of comets. For example, the physical properties (e.g., low density) of chondritic porous (CP) interplanetary dust particles (IDPs) are believed to resemble these properties of cometary dust although it is yet to be demonstrated that the porous structure of CP IDPs is inherent to presolar dust particles stored in comet nuclei. Porous structures of IDPs could conceivably form during sublimation at the surface of active comet nuclei. Porous structures are also obtained during annealing of amorphous Mg-SiO smokes which initially forms porous aggregates of olivine + platey tridymite and which, upon continued annealing, react to fluffy enstatite aggregates. It is therefore uncertain that CP IDPs are entirely composed of unmetamorphosed presolar dust. Conceivably, new minerals and textures may form in situ in nuclei of active comets as a function of their individual thermal history. Unmetamorphosed comet dust is probably structurally amorphous. Thermal annealing of this dust can produce ultra fine-grained minerals and this ultrafine grain size of CP IDPs should be considered in assessments of aqueous alterations that could affect presolar dust in comet nuclei between 200 and 400 K. Devitrification and hydration may occur in situ in ice-dust mixtures and the mantle of active comet nuclei. Devitrification, or uncontrolled crystallization, of amorphous precursor dust can produce a range of chemical compositions of ultrafine-grained minerals and (non-equilibrium) mineral assemblages and textures in dust contained in comet nuclei as a function of period and trajectory of orbit and number of perihelion passages (not considering internal heating). Thus, experimental data on relevant processes and reaction rates between 200 and 400 K are needed in order to evaluate comet selection, penetration depth for sampling device and curation of samples for CNSRM.

What if chondritic porous interplanetary dust particles are not the real McCoy

NASA Technical Reports Server (NTRS)

Rietmeijer, Frans J. M.

1989-01-01

To select a target comet for a Comet Nucleus Sample Return Mission (CNSRM) it is necessary to have an experimental data base to evaluate the extent of diversity and similarity of comets. For example, the physical properties (e.g., low density) of chondritic porous (CP) interplanetary dust particles (IDPs) are believed to resemble these properties of cometary dust although it is yet to be demonstrated that the porous structure of CP IDPs is inherent to presolar dust particles stored in comet nuclei. Porous structures of IDPs could conceivably form during sublimation at the surface of active comet nuclei. Porous structures are also obtained during annealing of amorphous Mg-SiO smokes which initially forms porous aggregates of olivine + platey tridymite and which, upon continued annealing, react to fluffy enstatite aggregates. It is therefore uncertain that CP IDPs are entirely composed of unmetamorphosed presolar dust. Conceivably, new minerals and textures may form in situ in nuclei of active comets as a function of their individual thermal history. Unmetamorphosed comet dust is probably structurally amorphous. Thermal annealing of this dust can produce ultra fine-grained minerals and this ultrafine grain size of CP IDPs should be considered in assessments of aqueous alterations that could affect presolar dust in comet nuclei between 200 and 400 K. Devitrification and hydration may occur in situ in ice-dust mixtures and the mantle of active comet nuclei. Devitrification, or uncontrolled crystallization, of amorphous precursor dust can produce a range of chemical compositions of ultrafine-grained minerals and (non-equilibrium) mineral assemblages and textures in dust contained in comet nuclei as a function of period and trajectory of orbit and number of perihelion passages (not considering internal heating). Thus, experimental data on relevant processes and reaction rates between 200 and 400 K are needed in order to evaluate comet selection, penetration depth for sampling device and curation of samples for CNSRM.

Ice nucleation by soil dust compared to desert dust aerosols

NASA Astrophysics Data System (ADS)

Moehler, O.; Steinke, I.; Ullrich, R.; Höhler, K.; Schiebel, T.; Hoose, C.; Funk, R.

2015-12-01

A minor fraction of atmospheric aerosol particles, so-called ice-nucleating particles (INPs), initiates the formation of the ice phase in tropospheric clouds and thereby markedly influences the Earth's weather and climate systems. Whether an aerosol particle acts as an INP depends on its size, morphology and chemical compositions. The INP fraction of certain aerosol types also strongly depends on the temperature and the relative humidity. Because both desert dust and soil dust aerosols typically comprise a variety of different particles, it is difficult to assess and predict their contribution to the atmospheric INP abundance. This requires both accurate modelling of the sources and atmospheric distribution of atmospheric dust components and detailed investigations of their ice nucleation activities. The latter can be achieved in laboratory experiments and parameterized for use in weather and climate models as a function of temperature and particle surface area, a parameter called ice-nucleation active site (INAS) density. Concerning ice nucleation activity studies, the soil dust is of particular interest because it contains a significant fraction of organics and biological components, both with the potential for contributing to the atmospheric INP abundance at relatively high temperatures compared to mineral components. First laboratory ice nucleation experiments with a few soil dust samples indicated their INP fraction to be comparable or slightly enhanced to that of desert dust. We have used the AIDA (Aerosol Interaction and Dynamics in the Atmosphere) cloud simulation chamber to study the immersion freezing ability of four different arable soil dusts, sampled in Germany, China and Argentina. For temperatures higher than about -20°C, we found the INP fraction of aerosols generated from these samples by a dry dispersion technique to be significantly higher compared to various desert dust aerosols also investigated in AIDA experiments. In this contribution, we will summarize the experimental results, introduce related INP parameterizations for use in weather and climate models, and briefly discuss possible reasons for the discrepancy between the INP fraction of desert and soil dust aerosols.

Composition and sources of atmospheric dusts in snow at 3200 meters in the St. Elias Range, southeastern Alaska, USA

USGS Publications Warehouse

Hinkley, T.K.

1994-01-01

Dusts in snow from the accumulation zone in the St. Elias Range appear from their chemical compositions to have come from terranes of rocks of ferromagnesian composition. These dusts, with respect to their composition and to the moderate degree of variation that occurs through a depositional year, are similar those deposited in Greenland. The high portion of the St. Elias Range is isolated from dominance by any local dust source terranes, because of altitude and the extent of the surrounding glacierized and snow-covered region. In Greenland the altitude is typically lower, but local sources are even less likely to dominate the character of the dusts deposited into the ice record there. The similar compositions and moderate compositional variations of dusts from these two places bear on the question of whether the dusts that are transported over long distances by the atmosphere under modern and glacial-period conditions are uniform and representative of a broad regional or even hemispheric background dust. The dusts in the snow were measured by means of a suite of major, minor, and trace rock-forming metals chosen to give information about rock types, their constituent minerals, degree of degradation (weathering), and energies of atmospheric uptake from source. The variations in amounts of rock dust through the year in the St. Elias Range snowpack have no time-stratigraphic correspondence to the also large variations in concentrations of other species that are not constituents of rock-derived dusts, such the anions chloride, sulfate, and nitrate; the highs and lows of the two types of materials are apparently completely independent. The structure revealed by the moderately fine-scale sampling of the present study (??? 10 increments/y) serves as a background for the interpretation of analysis of ice core samples, in which annual layers may be too compressed to permit analysis of sub-annual samples. ?? 1994.

Composition and sources of atmospheric dusts in snow at 3200 meters in the St. Elias Range, southeastern Alaska, USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hinkley, T.K.

1994-08-01

Dusts in snow from the accumulation zone in the St. Elias Range appear from their chemical compositions to have come from terranes of rocks of ferromagnesian composition. These dusts, with respect to their composition and to the moderate degree of variation that occurs through a depositional year, are similar to those deposited in Greenland. The high portion of the St. Elias Range is isolated from dominance by any local dust source terranes, because of altitude and the extent of the surrounding glacierized and snow-covered region. In Greenland the altitude is typically lower, but local sources are even less likely tomore » dominate the character of the dusts deposited into the ice record there. The similar compositions and moderate compositional variations of dusts from these two places bear on the question of whether the dusts that are transported over long distances by the atmosphere under modern and glacial-period conditions are uniform and representative of a broad regional or even hemispheric background dust. The dusts in the snow were measured by means of a suite of major, minor, and track rock-forming metals chosen to give information about rock types, their constituent minerals, degree of degradation (weathering), and energies of atmospheric uptake from source. The variations in amounts of rock dust through the year in the St. Elias Range snowpack have no time-stratigraphic correspondence to the also-large variations in concentrations of other species that are not constituents of rock-derived dusts, such the anions chloride, sulfate, and nitrate; the highs and lows of the two types of materials are apparently completely independent. The structure revealed by the moderately fine-scale sampling of the present study ([approximately]10 increments/y) serves as a background for the interpretation of analysis of ice core samples, in which annual layers may be too compressed to permit analysis of sub-annual samples.« less

Low-temperature MIR to submillimeter mass absorption coefficient of interstellar dust analogues. II. Mg and Fe-rich amorphous silicates

NASA Astrophysics Data System (ADS)

Demyk, K.; Meny, C.; Leroux, H.; Depecker, C.; Brubach, J.-B.; Roy, P.; Nayral, C.; Ojo, W.-S.; Delpech, F.

2017-10-01

Context. To model the cold dust emission observed in the diffuse interstellar medium, in dense molecular clouds or in cold clumps that could eventually form new stars, it is mandatory to know the physical and spectroscopic properties of this dust and to understand its emission. Aims: This work is a continuation of previous studies aiming at providing astronomers with spectroscopic data of realistic cosmic dust analogues for the interpretation of observations. The aim of the present work is to extend the range of studied analogues to iron-rich silicate dust analogues. Methods: Ferromagnesium amorphous silicate dust analogues were produced by a sol-gel method with a mean composition close to Mg1-xFexSiO3 with x = 0.1, 0.2, 0.3, 0.4. Part of each sample was annealed at 500 °C for two hours in a reducing atmosphere to modify the oxidation state of iron. We have measured the mass absorption coefficient (MAC) of these eight ferromagnesium amorphous silicate dust analogues in the spectral domain 30-1000 μm for grain temperature in the range 10-300 K and at room temperature in the 5-40 μm range. Results: The MAC of ferromagnesium samples behaves in the same way as the MAC of pure Mg-rich amorphous silicate samples. In the 30-300 K range, the MAC increases with increasing grain temperature whereas in the range 10-30 K, we do not see any change of the MAC. The MAC cannot be described by a single power law in λ- β. The MAC of the samples does not show any clear trend with the iron content. However the annealing process has, on average, an effect on the MAC that we explain by the evolution of the structure of the samples induced by the processing. The MAC of all the samples is much higher than the MAC calculated by dust models. Conclusions: The complex behavior of the MAC of amorphous silicates with wavelength and temperature is observed whatever the exact silicate composition (Mg vs. Fe amount). It is a universal characteristic of amorphous materials, and therefore of amorphous cosmic silicates, that should be taken into account in astronomical modeling. The enhanced MAC of the measured samples compared to the MAC calculated for cosmic dust model implies that dust masses are overestimated by the models. The tabulated mass absorption coefficients are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/606/A50

Speciation of Cr(VI) in environmental samples in the vicinity of the ferrochrome smelter.

PubMed

Sedumedi, Hilda N; Mandiwana, Khakhathi L; Ngobeni, Prince; Panichev, Nikolay

2009-12-30

The impact of ferrochrome smelter on the contamination of its environment with toxic hexavalent chromium, Cr(VI), was assessed by analyzing smelter dusts, soil, grass and tree barks. For the separation of Cr(VI) from Cr(III), solid samples were treated with 0.1M Na(2)CO(3) and filtered through hydrophilic PDVF 0.45 microm filter prior to the determination of Cr(VI) by electrothermal atomic absorption spectrometry (ET-AAS). Ferrochrome smelter dust was found to contain significant levels of Cr(VI), viz. 43.5 microg g(-1) (cyclone dust), 2710 microg g(-1) (fine dust), and 7800 microg g(-1) (slimes dust) which exceeded the maximum acceptable risk concentration (20 microg g(-1)). The concentration of Cr(VI) in environmental samples of grass (3.4+/-0.2), soil (7.7+/-0.2), and tree bark (11.8+/-1.2) collected in the vicinity of the chrome smelter were higher as compared with the same kind of samples collected from uncontaminated area. The results of the investigation show that ferrochrome smelter is a source of environmental pollution with contamination factors of Cr(VI) ranging between 10 and 50.

Impact of a pharmacy technician-centered medication reconciliation program on medication discrepancies and implementation of recommendations.

PubMed

Kraus, Sarah K; Sen, Sanchita; Murphy, Michelle; Pontiggia, Laura

2017-01-01

To evaluate the impact of a pharmacy-technician centered medication reconciliation (PTMR) program by identifying and quantifying medication discrepancies and outcomes of pharmacist medication reconciliation recommendations. A retrospective chart review was performed on two-hundred patients admitted to the internal medicine teaching services at Cooper University Hospital in Camden, NJ. Patients were selected using a stratified systematic sample approach and were included if they received a pharmacy technician medication history and a pharmacist medication reconciliation at any point during their hospital admission. Pharmacist identified medication discrepancies were analyzed using descriptive statistics, bivariate analyses. Potential risk factors were identified using multivariate analyses, such as logistic regression and CART. The priority level of significance was set at 0.05. Three-hundred and sixty-five medication discrepancies were identified out of the 200 included patients. The four most common discrepancies were omission (64.7%), non-formulary omission (16.2%), dose discrepancy (10.1%), and frequency discrepancy (4.1%). Twenty-two percent of pharmacist recommendations were implemented by the prescriber within 72 hours. A PTMR program with dedicated pharmacy technicians and pharmacists identifies many medication discrepancies at admission and provides opportunities for pharmacist reconciliation recommendations.

Impact of a pharmacy technician-centered medication reconciliation program on medication discrepancies and implementation of recommendations

PubMed Central

2016-01-01

Objectives: To evaluate the impact of a pharmacy-technician centered medication reconciliation (PTMR) program by identifying and quantifying medication discrepancies and outcomes of pharmacist medication reconciliation recommendations. Methods: A retrospective chart review was performed on two-hundred patients admitted to the internal medicine teaching services at Cooper University Hospital in Camden, NJ. Patients were selected using a stratified systematic sample approach and were included if they received a pharmacy technician medication history and a pharmacist medication reconciliation at any point during their hospital admission. Pharmacist identified medication discrepancies were analyzed using descriptive statistics, bivariate analyses. Potential risk factors were identified using multivariate analyses, such as logistic regression and CART. The priority level of significance was set at 0.05. Results: Three-hundred and sixty-five medication discrepancies were identified out of the 200 included patients. The four most common discrepancies were omission (64.7%), non-formulary omission (16.2%), dose discrepancy (10.1%), and frequency discrepancy (4.1%). Twenty-two percent of pharmacist recommendations were implemented by the prescriber within 72 hours. Conclusion: A PTMR program with dedicated pharmacy technicians and pharmacists identifies many medication discrepancies at admission and provides opportunities for pharmacist reconciliation recommendations. PMID:28690691

Dust studies in DIII-D and TEXTOR

NASA Astrophysics Data System (ADS)

Rudakov, D. L.; Litnovsky, A.; West, W. P.; Yu, J. H.; Boedo, J. A.; Bray, B. D.; Brezinsek, S.; Brooks, N. H.; Fenstermacher, M. E.; Groth, M.; Hollmann, E. M.; Huber, A.; Hyatt, A. W.; Krasheninnikov, S. I.; Lasnier, C. J.; McLean, A. G.; Moyer, R. A.; Pigarov, A. Yu.; Philipps, V.; Pospieszczyk, A.; Smirnov, R. D.; Sharpe, J. P.; Solomon, W. M.; Watkins, J. G.; Wong, C. P. C.

2009-08-01

Studies of naturally occurring and artificially introduced carbon dust are conducted in DIII-D and TEXTOR. In DIII-D, dust does not present operational concerns except immediately after entry vents. Submicrometre sized dust is routinely observed using Mie scattering from a Nd : Yag laser. The source is strongly correlated with the presence of type I edge localized modes (ELMs). Larger size (0.005-1 mm diameter) dust is observed by optical imaging, showing elevated dust levels after entry vents. Inverse dependence of the dust velocity on the inferred dust size is found from the imaging data. Heating of the dust particles by the neutral beam injection (NBI) and acceleration of dust particles by the plasma flows are observed. Energetic plasma disruptions produce significant amounts of dust; on the other hand, large flakes or debris falling into the plasma may induce a disruption. Migration of pre-characterized carbon dust is studied in DIII-D and TEXTOR by introducing micrometre-size particles into plasma discharges. In DIII-D, a sample holder filled with 30-40 mg of dust is inserted in the lower divertor and exposed, via sweeping of the strike points, to the diverted plasma flux of high-power ELMing H-mode discharges. After a brief dwell (~0.1 s) of the outer strike point on the sample holder, part of the dust penetrates into the core plasma, raising the core carbon density by a factor of 2-3 and resulting in a twofold increase in the radiated power. In TEXTOR, instrumented dust holders with 1-45 mg of dust are exposed in the scrape-off-layer 0-2 cm radially outside of the last closed flux surface in discharges heated with 1.4 MW of NBI. Launched in this configuration, the dust perturbed the edge plasma, as evidenced by a moderate increase in the edge carbon content, but did not penetrate into the core plasma.

Asian Dust Observed During the KORUS Air Quality Mission Creates Significant Super-Micron NO3-, NH4+, and SO42- Aerosols.

NASA Astrophysics Data System (ADS)

Heim, E. W.; Dibb, J. E.; Scheuer, E. M.

2017-12-01

The KORUS mission was a collaborative effort between the Korean Institute of Environmental Research and NASA. KORUS provided a comprehensive assessment of air quality in Korea during early 2016. The intensive sampling campaign was timed to assess local photochemistry during increasing solar insolation and biogenic emissions; after the April peak in outflow of pollution and dust from central China. Chinese outflow is well characterized by Silica-Calcium rich dust. Despite the effort to avoid the period with strongest dust outflow, Ca2+ was well represented in all bulk (particle diameters up to 4.5 micron) aerosol filter samples < 3 kilometers altitude (m = 0.640 ug/m3, s = 0.759, n=880). In particular, four flights were heavily impacted by Chinese outflow :(m = 1.607 ug/m3, s = 1.149, n = 152). Back trajectories from the flight tracks of these 4 flights indicate transport from desert regions in north central China. This dust presents a basic surface for the abundant anthropogenic acids (HNO3, H2SO4) to interact with. In combination with abundant anthropogenic NH3 these acids react with CaCO3 contained in the dust in cyclic reactions that form dust cores covered in a shell of acid-base reaction products. The difference between bulk filter measurements and submicron measurements of NH4+, SO42, and NO3- made by AMS indicates substantial super-micron fractions of these anthropogenic ions at times during KORUS-AQ. During the dustiest samples (Ca2+ > 1.5ug/m3) we see marked increases in super-micron concentration of NH4+, SO42-, and NO3-, m = 1.113 ug/m3 , 2.621 ug/m3 , 4.413 ug/m3, with the super-micron contribution to total concentration averaging 47%, 45%, and 81% respectively. In contrast, low dust days (Ca2+ < 0.2ug/m3) the super-micron concentrations averaged 0.262 ug/m3, 0.510 ug/m3, -0.029 ug/m3, respectively and accounted for just 20%, 14%, and 8% of total mass. During the dust events, samples that have trajectories passing over industrial centers in eastern China approached equivalence balance between Ca2++ NH4+ and SO42-+NO3-. In contrast dusty samples that did not pass over these industrial centers during transport to the West Sea and Korea maintained excess cations, dominantly Ca2+. This suggests that dust can act as an important carrier of Chinese pollution to Korea when this saturated dust reaches the peninsula.

78 FR 27442 - Coal Mine Dust Sampling Devices; Correction

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-10

... DEPARTMENT OF LABOR Mine Safety and Health Administration Coal Mine Dust Sampling Devices; Correction AGENCY: Mine Safety and Health Administration, Labor. ACTION: Notice; correction. SUMMARY: On April 30, 2013, Mine Safety and Health Administration (MSHA) published a notice in the Federal Register...

Summary of the development of a signature for detection of residual dust from collapse of the World Trade Center buildings

PubMed Central

Lowers, Heather A; Meeker, Gregory P; Lioy, Paul J; Lippmann, Morton

2014-01-01

The collapse of the World Trade Center (WTC) towers on September 11, 2001, caused lower Manhattan and adjacent areas to be covered in millimeters to centimeters of dust. WTC dust penetrated into indoor spaces, and public health concerns remain regarding exposure to possible residual dust in the affected areas. The goal of the studies outlined in this review was to determine which, if any, components of the bulk WTC dust are sufficiently above typical background dust levels in New York City to develop an analytical method to screen for the component(s). Components of the <150-µm-size fraction of the dust are gypsum, phases compatible with crushed concrete, man-made vitreous fibers (MMVFs), silica, lead, chrysotile asbestos, and other materials. Slag wool was the most common WTC MMVF, whereas soda-lime glass and rock wool were minor to trace constituents. Most background samples also contained gypsum, phases compatible with concrete, and MMVF. However, the proportions of the various MMVF in background samples are typically unlike those characteristic of bulk WTC dust. Results indicate that slag wool can be used as a signature marker to identify areas that contain potential residual WTC dust contamination at concentrations that are less than average background levels for the material. PMID:18478046

EVALUATION OF IMMUNOASSAY METHODS FOR DETERMINATION OF 3,5,6-TRICHLORO-2-PYRIDINOL IN MULTIPLE SAMPLE MEDIA

EPA Science Inventory

Two enzyme-linked immunosorbent assay (ELISA) methods were evaluated for the determination of 3,5,6-trichloro-2-pyridinol (3,5,6-TCP) in multiple sample media (dust, soil, food, and urine). The dust and soil samples were analyzed by the RaPID (TM) commercial immunoassay testing ...

CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING DUST AND SOIL SAMPLES FOR ANALYSIS OF POLAR PERSISTENT ORGANIC POLLUTANTS (SOP-5.15)

EPA Science Inventory

The method for extracting and preparing a dust or soil sample for analysis of polar persistent organic pollutants is summarized in this SOP. It covers the extraction, concentration, and derivatization of samples that are to be analyzed by gas chromatography/mass spectrometry.

Iron oxide minerals in dust-source sediments from the Bodélé Depression, Chad: Implications for radiative properties and Fe bioavailability of dust plumes from the Sahara

USGS Publications Warehouse

Moskowitz, Bruce M; Reynolds, Richard L.; Goldstein, Harland L.; Beroquo, Thelma; Kokaly, Raymond F.; Bristow, Charlie S

2016-01-01

Atmospheric mineral dust can influence climate and biogeochemical cycles. An important component of mineral dust is ferric oxide minerals (hematite and goethite) which have been shown to influence strongly the optical properties of dust plumes and thus affect the radiative forcing of global dust. Here we report on the iron mineralogy of dust-source samples from the Bodélé Depression (Chad, north-central Africa), which is estimated to be Earth’s most prolific dust producer and may be a key contributor to the global radiative budget of the atmosphere as well as to long-range nutrient transport to the Amazon Basin. By using a combination of magnetic property measurements, Mössbauer spectroscopy, reflectance spectroscopy, chemical analysis, and scanning electron microscopy, we document the abundance and relative amounts of goethite, hematite, and magnetite in dust-source samples from the Bodélé Depression. The partition between hematite and goethite is important to know to improve models for the radiative effects of ferric oxide minerals in mineral dust aerosols. The combination of methods shows (1) the dominance of goethite over hematite in the source sediments, (2) the abundance and occurrences of their nanosize components, and (3) the ubiquity of magnetite, albeit in small amounts. Dominant goethite and subordinate hematite together compose about 2% of yellow-reddish dust-source sediments from the Bodélé Depression and contribute strongly to diminution of reflectance in bulk samples. These observations imply that dust plumes from the Bodélé Depression that are derived from goethite-dominated sediments strongly absorb solar radiation. The presence of ubiquitous magnetite (0.002–0.57 wt%) is also noteworthy for its potentially higher solubility relative to ferric oxide and for its small sizes, including PM < 0.1 μm. For all examined samples, the average iron apportionment is estimated at about 33% in ferric oxide minerals, 1.4% in magnetite, and 65% in ferric silicates. Structural iron in clay minerals may account for much of the iron in the ferric silicates. We estimate that the mean ferric oxides flux exported from the Bodélé Depression is 0.9 Tg/yr with greater than 50% exported as ferric oxide nanoparticles (<0.1 μm). The high surface-to-volume ratios of ferric oxide nanoparticles once entrained into dust plumes may facilitate increased atmospheric chemical and physical processing and affect iron solubility and bioavailability to marine and terrestrial ecosystems.

30 CFR 74.11 - Tests of the continuous personal dust monitor.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tests of the continuous personal dust monitor. 74.11 Section 74.11 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH COAL MINE DUST SAMPLING DEVICES Requirements for Continuous Personal Dust Monitors § 74.11 Tests of the continuous personal...

30 CFR 74.11 - Tests of the continuous personal dust monitor.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Tests of the continuous personal dust monitor. 74.11 Section 74.11 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH COAL MINE DUST SAMPLING DEVICES Requirements for Continuous Personal Dust Monitors § 74.11 Tests of the continuous personal...

Levels of polybrominated diphenyl ethers (PBDEs) in dust from personal automobiles in conjunction with studies on the photochemical degradation of decabromodiphenyl ether (BDE-209).

PubMed

Lagalante, Anthony F; Shedden, Courtney S; Greenbacker, Peter W

2011-07-01

The levels of 21 PBDE congeners were detemined in the dust sampled from 66 personal automobiles. The dominant congener in automobile dust was BDE-209 with a median level of 8.12 μg g⁻¹. Personal vehicle dust samples contained the characteristic profile of the PBDE congeners that comprise the PentaBDE and DecaBDE commercial formulations. Levels of PBDEs in personal automobiles are generally reduced in comparison to our previously reported levels in resale vehicles on dealership lots presumably due to a dilution effect introduced by dust or debris that does not originate from the vehicle. Laboratory photochemical studies were conducted on both automobile dust collected from personal vehicles as well as BDE-209 adsorbed to sodium sulfate. No significant degradation occurred in the personal vehicle dust after 56 days of constant UVA irradiation while significant degradation did occur with BDE-209 adsorbed to sodium sulfate. PBDEs from the degradation of BDE-209 were identified and potential degradation pathways elucidated. Human exposure potential to PBDEs from automobile dust ingestion remains a serious concern in the U.S. population. Copyright © 2011 Elsevier Ltd. All rights reserved.

Molecular gas in elliptical galaxies with dust lanes

NASA Technical Reports Server (NTRS)

Wang, Zhong; Kenney, Jeffrey D. P.; Ishizuki, Sumio

1992-01-01

We have searched for CO(1-0) line emission in eight dust lane elliptical and lenticular galaxies using the Nobeyama 45 m telescope. Five of the eight galaxies, including the well-studied elliptical NGC 1052, have CO emission at above the 5-sigma level, with inferred molecular gas masses ranging from 10 exp 8 to a few times 10 exp 9 solar masses. Our selection criterion differs from previous surveys in that it does not depend on the FIR fluxes, and thus is less sensitive to the sizes and distances of the host galaxies or to the degree to which dust is heated. The relatively high detection rate of CO in these ellipticals suggests a close correlation between molecular mass and cold dust. Compared with previously studied samples of FIR selected early-type galaxies, our sample has on average four times more CO emission per unit FIR (40-120 microns) luminosity. If the intrinsic gas-to-dust ratio of these galaxies as similar to that of the Milky Way, then only about 5 percent of the dust mass in dust lane ellipticals radiates substantially at 60 and 100 microns, and the remaining dust must be colder than about 30 K.

Development of Preliminary Remediation Goals for Indoor Dust at the Colonie FUSRAP Site - 12273

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watters, David J.; Opdyke, Clifford P.; Moore, James T.

2012-07-01

The Colonie FUSRAP Site is located in the Town of Colonie, Albany County, New York. The U.S. Army Corps of Engineers is currently addressing environmental contamination associated with the Site under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) process as part of the Formerly Utilized Sites Remedial Action Program (FUSRAP). Soil remediation activities have been substantially completed at the Colonie FUSRAP Site and its vicinity properties under the FUSRAP. A study unrelated to FUSRAP was recently performed by an independent party to establish the distribution of DU contamination in various media in the environs of the Site. Asmore » part of this study, dust samples were collected in residencies and businesses in the immediate vicinity of the Site. These samples were collected in non-living areas such as basement window sills and garages. Many of these samples tested positive for DU. An assessment was performed to establish preliminary remediation goals (PRGs) for indoor dust in non-living areas of residential homes and businesses in the vicinity of the Site. The results of this assessment provide estimates of dose-based, carcinogenic risk-based, and noncarcinogenic-based PRGs derived from a hypothetical exposure scenario with reasonable levels of conservatism. Ultimately, the PRGs will be compared to results of dust sampling and analyses in residences and businesses in proximity of the Site to determine whether a response action is appropriate. This assessment estimates PRGs for DU contaminated dust in non-living areas of residences in the vicinity of the Colonie FUSRAP site based on a reasonably conservative exposure scenario. Estimated PRGs based on residential receptors are considered to be conservatively representative of workers in nearby businesses based on the considerably longer exposure duration of residents relative to workers. This assessment provides reasonably conservative estimates of PRGs for DU contaminated dust in non-living areas within residences in the vicinity of the Site. It should be noted that the PRGs include hypothetical exposures resulting from activities in both the living areas and non-living areas of a residence. The PRGs are derived and presented in terms of DU dust concentration in non-living areas to facilitate comparison to results of a planned Site Investigation that will characterize concentrations of DU in dust in non-living areas. It is important to recognize that the exposure assumptions used to derive these PRGs are based on average dust DU concentrations in non-living areas. It is inappropriate to compare these PRGs to the dust DU concentration in an isolated small area. The ongoing Site Investigation addresses this consideration and is designed to provide reasonable estimates of average dust DU concentrations in non-living areas of vicinity properties. In order to accomplish this, sampling is conducted in accordance with EPA Guidance for the Sampling and Analysis of Lead in Indoor Residential Dust for Use in the Integrated Exposure Uptake Biokinetic (IEUBK) Model, (EPA 2008), which specifically addresses estimating average contaminant concentrations in dust. Four (4) large-area samples are collected from each VP in accordance with this guidance. It is anticipated that the results of the Site Investigation will be used in conjunction with the results of this assessment, and/or subsequent assessments, to establish whether or not a response action is appropriate. (authors)« less

Multilocus Sequence Typing of Cronobacter Strains Isolated from Retail Foods and Environmental Samples.

PubMed

Killer, Jiří; Skřivanová, Eva; Hochel, Igor; Marounek, Milan

2015-06-01

Cronobacter spp. are bacterial pathogens that affect children and immunocompromised adults. In this study, we used multilocus sequence typing (MLST) to determine sequence types (STs) in 11 Cronobacter spp. strains isolated from retail foods, 29 strains from dust samples obtained from vacuum cleaners, and 4 clinical isolates. Using biochemical tests, species-specific polymerase chain reaction, and MLST analysis, 36 strains were identified as Cronobacter sakazakii, and 6 were identified as Cronobacter malonaticus. In addition, one strain that originated from retail food and one from a dust sample from a vacuum cleaner were identified on the basis of MLST analysis as Cronobacter dublinensis and Cronobacter turicensis, respectively. Cronobacter spp. strains isolated from the retail foods were assigned to eight different MLST sequence types, seven of which were newly identified. The strains isolated from the dust samples were assigned to 7 known STs and 14 unknown STs. Three clinical isolates and one household dust isolate were assigned to ST4, which is the predominant ST associated with neonatal meningitis. One clinical isolate was classified based on MLST analysis as Cronobacter malonaticus and belonged to an as-yet-unknown ST. Three strains isolated from the household dust samples were assigned to ST1, which is another clinically significant ST. It can be concluded that Cronobacter spp. strains of different origin are genetically quite variable. The recovery of C. sakazakii strains belonging to ST1 and ST4 from the dust samples suggests the possibility that contamination could occur during food preparation. All of the novel STs and alleles for C. sakazakii, C. malonaticus, C. dublinensis, and C. turicensis determined in this study were deposited in the Cronobacter MLST database available online ( http://pubmlst.org/cronobacter/).

Individual particle analysis in suburban Osaka

NASA Astrophysics Data System (ADS)

Nakata, Makiko; Sano, Itaru; Mukai, Sonoyo

2012-11-01

Higashi-Osaka is urban area located on the east of Osaka city in Japan. We equip various ground measurement devices in Higashi-Osaka campus of Kinki University. The data supplied by the Cimel instrument are analyzed with a standard AERONET (Aerosol Robotics Network) processing system. We set up an SPM sampler attached to our AERONET site. It is found from the simultaneous measurements and analyses that clear atmosphere with few small particles is not too often, usually polluted particles from diesel vehicles and industries are suspended at Higashi-Osaka and the characterization of atmospheric particles varies especially in dust phenomenon. Then we performed detailed analysis of atmospheric particles in dust days. We analyzed atmospheric particles with scanning electron microscope coupled with energy dispersive X-ray analyzer. This instrument can detect contain elements of sample by X-ray emanated from the surface of the sample. In order to investigate change of particle properties before and after dust event, we select three cases as before dust reaches to Higashi-Osaka, peak of dust event and after dust event and after dust passes. The results of analyses for each case indicate that nonspherical particles with large particle size are dominant and the main component becomes silicon derived from soil particles at the peak of dust event and soil particles remain after dust event. It is found that sometimes anthropogenic pollutant is transported to Higashi-Osaka before dust comes and components from anthropogenic source increase before dust event.

Direct detection of Marek's disease virus in poultry dust by loop-mediated isothermal amplification.

PubMed

Woźniakowski, Grzegorz; Samorek-Salamonowicz, Elżbieta

2014-11-01

Marek's disease virus (MDV) is a serious concern for poultry production and represents a unique herpesvirus model. MDV can be shed by doubly infected chickens despite vaccination. The fully infectious MDV particles are produced in the feather follicle epithelium (FFE), and MDV remains infectious for many months in fine skin particles and feather debris. Molecular biology methods including PCR and real-time PCR have been shown to be valuable for the detection of MDV DNA in farm dust. Recently, loop-mediated isothermal amplification (LAMP) was found to be useful in the detection of MDV in feathers and internal organs of infected chickens. LAMP is also less affected by the inhibitors present in DNA samples. Taking into account the advantages of LAMP, direct detection of MDV DNA in poultry dust has been conducted in this research. The detection of MDV DNA was possible in 11 out of the 12 examined dust samples without DNA extraction. The DNA was retrieved from dust samples by dilution and incubation at 95 °C for 5 min. The direct detection of MDV DNA in the dust was possible within 30 min using a water bath and UV light. The results were confirmed by electrophoresis and melting curve analysis of the LAMP products. Our results show that LAMP may be used to test for the presence of virulent MDV in poultry farm dust without DNA extraction.

The uranium-isotopic composition of Saharan dust collected over the central Atlantic Ocean

NASA Astrophysics Data System (ADS)

Aciego, Sarah M.; Aarons, Sarah M.; Sims, Kenneth W. W.

2015-06-01

Uranium isotopic compositions, (234U/238U)activity , are utilized by earth surface disciplines as chronometers and source tracers, including in soil science where aeolian dust is a significant source to the total nutrient pool. However, the (234U/238U)activity composition of dust is under characterized due to material and analytical constraints. Here we present new uranium isotope data measured by high precision MC-ICP-MS on ten airborne dust samples collected on the M55 trans-Atlantic cruise in 2002. Two pairs of samples are presented with different size fractions, coarse (1-30 μm) and fine (<1 μm), and all samples were processed to separate the water soluble component in order to assess the controls on the (234U/238U)activity of mineral aerosols transported from the Sahara across the Atlantic. Our results indicate (234U/238U)activity above one for both the water soluble (1.13-1.17) and the residual solid (1.06-1.18) fractions of the dust; no significant correlation is found between isotopic composition and travel distance. Residual solids indicate a slight dependance of (234U/238U)activity on particle size. Future modeling work that incorporates dust isotopic compositions into mixing or isotopic fractionation models will need to account for the wide variability in dust (234U/238U)activity .

Dust Allergens within Rural Northern Rocky Mountain Residences.

PubMed

Weiler, Emily; Semmens, Erin; Noonan, Curtis; Cady, Carol; Ward, Tony

2015-01-23

To date, few studies have characterized allergens within residences located in rural areas of the northern Rocky Mountain region. In this study, we collected dust samples from 57 homes located throughout western Montana and northern Idaho. Dust samples were collected and later analyzed for dust mite allergens Der f 1 and Der p 1 , Group 2 mite allergens ( Der p 2 and Der f 2 ), domestic feline ( Fel d 1 ), and canine ( Can f 1 ). Indoor temperature and humidity levels were also measured during the sampling program, as were basic characteristics of each home. Dog (96%) and cat (82%) allergens were the most prevalent allergens found in these homes (even when a feline or canine did not reside in the home). Results also revealed the presence of dust mites. Seven percent (7%) of homes tested positive for Der p 1 , 19% of homes were positive for Der f 1 , and 5% of homes were positive for the Group 2 mite allergens. Indoor relative humidity averaged 27.0 ± 7.6% within the homes. Overall, humidity was not significantly associated with dust mite presence, nor was any of the other measured home characteristics. This study provides a descriptive assessment of indoor allergen presence (including dust mites) in rural areas of the northern Rocky Mountains, and provides new information to assist regional patients with reducing allergen exposure using in-home intervention strategies.

Levels of house dust mite allergen in cars.

PubMed

Mason, Howard J; Smith, Ian; Anua, Siti Marwanis; Tagiyeva, Nargiz; Semple, Sean; Devereux, Graham

2015-09-01

This small study investigated house dust mite (HDM) allergen levels in cars and their owners' homes in north-east Scotland. Dust samples from twelve households and cars were collected in a standardised manner. The dust samples were extracted and measured for the Dermatophagoides group 2 allergens (Der p 2 and Der f 2) and total soluble protein. Allergen levels at homes tended to be higher than in the cars, but not significantly. However, they significantly correlated with paired car dust samples expressed either per unit weight of dust or soluble protein (rho=0.657; p=0.02 and 0.769; p=0.003, respectively). This points to house-to-car allergen transfer, with the car allergen levels largely reflecting levels in the owner's home. Car HDM allergen levels were lower than those reported in Brazil and the USA. Twenty-five percent of the houses and none of the cars had allergen levels in dust greater than 2000 ng g(-1). This value is often quoted as a threshold for the risk of sensitisation, although a number of studies report increased risk of sensitisation at lower levels. This small study does not allow for characterisation of the distribution of HDM allergen in vehicles in this geographic area, or of the likely levels in other warmer and more humid areas of the UK. Cars and other vehicles are an under-investigated micro-environment for exposure to allergenic material.

Persistent Organic Pollutants in Dust From Older Homes: Learning From Lead

PubMed Central

Metayer, Catherine; Ward, Mary H.; Colt, Joanne S.; Gunier, Robert B.; Deziel, Nicole C.; Rappaport, Stephen M.; Buffler, Patricia A.

2014-01-01

Objectives. We aimed to (1) evaluate the relation between home age and concentrations of multiple chemical contaminants in settled dust and (2) discuss the feasibility of using lead hazard controls to reduce children’s exposure to persistent organic pollutants. Methods. As part of the California Childhood Leukemia Study, from 2001 to 2007, we used a high-volume small surface sampler and household vacuum cleaners to collect dust samples from 583 homes and analyzed the samples for 94 chemicals with gas chromatography–mass spectrometry and inductively coupled plasma mass spectrometry. We evaluated relations between chemical concentrations in dust and home age with Spearman rank correlation coefficients. Results. Dust concentrations of lead, polychlorinated biphenyls, organochlorine insecticides, and polycyclic aromatic hydrocarbons were correlated with home age (ρ > 0.2; P < .001), whereas concentrations of pyrethroid insecticides and polybrominated diphenyl ethers were not. Conclusions. Dust in older homes contains higher levels of multiple, persistent chemicals than does dust in newer homes. Further development of strategies to reduce chemical exposures for children living in older homes is warranted. PMID:24832145

Major tire fragment contributions to PM{sub 10} non-attainment in Anchorage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Draftz, R.G.; Cowherd, C. Jr.; Grelinger, M.A.

1999-07-01

Anchorage exceeded the 24-hour National Ambient Air Quality Standard for PM{sub 10} a total of thirty-one times in the period from 1987 to 1997. About half of these exceedances were due to natural events. The remaining exceedances could not be linked to natural events. Moreover, these exceedances occurred predominantly at one PM{sub 10} site near one of the major thoroughfares in Anchorage. The apportionment of sources producing these unexplained violations was one of the major goals of a 1996--98 study sponsored and directed by the Air Quality Program of the Municipality of Anchorage. Two suites of PM{sub 10} samples weremore » utilized for source apportionment of exceedances. The first consisted of historical samples selected from sampling periods unaffected by natural events. These samples were carefully selected to avoid the high values during and following volcanic eruptions when there were likely to be considerable accumulations of volcanic ejecta on roads. Dust storms were excluded by simple inspection of data for days that showed that all sites in the Anchorage basin had high PM{sub 10} loadings. The second group of samples were selected from a special springtime road dust tagging experiment used to measure emission and depletion rates of the taggant and accumulated road dust particles, mainly road aggregate wear and anti-skid minerals. Quantitative microscopical analysis of the first suite of historical samples showed that rubber tire concentrations contributed from approximately 12 to 42{micro}g/m{sup 3} of the PM{sub 10} for samples near or exceeding the 24 hour limit. Road dust samples from the road tagging experiment showed that the PM{sub 10}-sized tire fragments were not present in the road dust and therefore, had to have become immediately airborne rather than re-entrained from road dust deposits. Rubber tire fragments are one of the three dominant components that collectively account for more than 95% of the PM{sub 10} non-attainment in Anchorage.« less

Worker exposure to volatile organic compounds in the vehicle repair industry.

PubMed

Wilson, Michael P; Hammond, S Katharine; Nicas, Mark; Hubbard, Alan E

2007-05-01

This study evaluated exposures among vehicle repair technicians to hexane, acetone, toluene, and total volatile organic compounds (VOCs). On randomly selected workdays, we observed a characteristic pattern of solvent use among 36 technicians employed in 10 repair shops, each of which used an aerosol solvent product. We obtained quantitative exposure measurements from a subset of nine technicians (employed in three of these shops) who used an aerosol product containing hexane (25-35%), acetone (45-55%), and toluene (5-10%). The time-weighted average (TWA) exposure concentration for task-length breathing zone (BZ) samples (n = 23) was 36 mg/m(3) for hexane, 50 mg/m(3) for acetone, and 10 mg/m(3) for toluene. The TWA area concentrations (n = 49) obtained contemporaneously with BZ samples ranged from 25% to 35% of the BZ concentrations. The solvent emission rate (grams emitted/task time) was correlated with the total VOC exposure concentration (R(2) = 0.45). The proportions of VOCs in the BZ samples were highly correlated (r = 0.89 to 0.95) and were similar to those of the bulk product. Continuous exposure measurements for total VOCs (n = 1238) during 26 tasks produced a mean BZ VOC "pulse" of 394 mg/m(3) within 1 min following initiation of solvent spraying. The geometric mean air speed was 5.2 meters/min in the work areas (n = 870) and was associated with 0.8 air changes per minute in the BZ. The findings suggest that vehicle repair technicians who use aerosol solvent products experience episodic, inhalation exposures to the VOCs contained in these products, and the proportions of VOCs in the breathing zone are similar to those of the bulk product. Because acetone appears to amplify the severity and duration of the neurotoxic effects of n-hexane, products formulated with both hexane and acetone should be avoided. Further evaluation of exposures to VOCs is needed in this industry, along with information on effective alternatives to aerosol solvent products.

Biological effects of desert dust in respiratory epithelial cells and a murine model.

PubMed

Ghio, Andrew J; Kummarapurugu, Suryanaren T; Tong, Haiyan; Soukup, Joleen M; Dailey, Lisa A; Boykin, Elizabeth; Ian Gilmour, M; Ingram, Peter; Roggli, Victor L; Goldstein, Harland L; Reynolds, Richard L

2014-04-01

As a result of the challenge of recent dust storms to public health, we tested the postulate that desert dust collected in the southwestern United States imparts a biological effect in respiratory epithelial cells and an animal model. Two samples of surface sediment were collected from separate dust sources in northeastern Arizona. Analysis of the PM20 fraction demonstrated that the majority of both dust samples were quartz and clay minerals (total SiO₂ of 52 and 57%). Using respiratory epithelial and monocytic cell lines, the two desert dusts increased oxidant generation, measured by Amplex Red fluorescence, along with carbon black (a control particle), silica, and NIST 1649 (an ambient air pollution particle). Cell oxidant generation was greatest following exposures to silica and the desert dusts. Similarly, changes in RNA for superoxide dismutase-1, heme oxygenase-1, and cyclooxygenase-2 were also greatest after silica and the desert dusts supporting an oxidative stress after cell exposure. Silica, desert dusts, and the ambient air pollution particle NIST 1649 demonstrated a capacity to activate the p38 and ERK1/2 pathways and release pro-inflammatory mediators. Mice, instilled with the same particles, showed the greatest lavage concentrations of pro-inflammatory mediators, neutrophils, and lung injury following silica and desert dusts. We conclude that, comparable to other particles, desert dusts have a capacity to (1) influence oxidative stress and release of pro-inflammatory mediators in respiratory epithelial cells and (2) provoke an inflammatory injury in the lower respiratory tract of an animal model. The biological effects of desert dusts approximated those of silica.

Biological effects of desert dust in respiratory epithelial cells and a murine model

USGS Publications Warehouse

Ghio, Andrew J.; Kummarapurugu, Suryanaren T.; Tong, Haiyan; Soukup, Joleen M.; Dailey, Lisa A.; Boykin, Elizabeth; Gilmour, M. Ian; Ingram, Peter; Roggli, Victor L.; Goldstein, Harland L.; Reynolds, Richard L.

2014-01-01

As a result of the challenge of recent dust storms to public health, we tested the postulate that desert dust collected in the southwestern United States imparts a biological effect in respiratory epithelial cells and an animal model. Two samples of surface sediment were collected from separate dust sources in northeastern Arizona. Analysis of the PM20 fraction demonstrated that the majority of both dust samples were quartz and clay minerals (total SiO2 of 52 and 57%). Using respiratory epithelial and monocytic cell lines, the two desert dusts increased oxidant generation, measured by Amplex Red fluorescence, along with carbon black (a control particle), silica, and NIST 1649 (an ambient air pollution particle). Cell oxidant generation was greatest following exposures to silica and the desert dusts. Similarly, changes in RNA for superoxide dismutase-1, heme oxygenase-1, and cyclooxygenase-2 were also greatest after silica and the desert dusts supporting an oxidative stress after cell exposure. Silica, desert dusts, and the ambient air pollution particle NIST 1649 demonstrated a capacity to activate the p38 and ERK1/2 pathways and release pro-inflammatory mediators. Mice, instilled with the same particles, showed the greatest lavage concentrations of pro-inflammatory mediators, neutrophils, and lung injury following silica and desert dusts. We conclude that, comparable to other particles, desert dusts have a capacity to (1) influence oxidative stress and release of pro-inflammatory mediators in respiratory epithelial cells and (2) provoke an inflammatory injury in the lower respiratory tract of an animal model. The biological effects of desert dusts approximated those of silica.

Dust exposure during small-scale mining in Tanzania: a pilot study.

PubMed

Bratveit, Magne; Moen, Bente E; Mashalla, Yohana J S; Maalim, Hatua

2003-04-01

Small-scale mining in developing countries is generally labour-intensive and carried out with low levels of mechanization. In the Mererani area in the northern part of Tanzania, there are about 15000 underground miners who are constantly subjected to a poor working environment. Gemstones are found at depths down to 500 m. The objectives of this pilot study were to monitor the exposure to dust during work processes, which are typical of small-scale mining in developing countries, and to make a rough estimation of whether there is a risk of chronic pulmonary diseases for the workers. Personal sampling of respirable dust (n = 15) and 'total' dust (n = 5) was carried out during three consecutive days in one mine, which had a total of 50 workers in two shifts. Sampling started immediately before the miners entered the shaft, and lasted until they reappeared at the mine entrance after 5-8 h. The median crystalline silica content and the combustible content of the respirable dust samples were 14.2 and 5.5%, respectively. When drilling, blasting and shovelling were carried out, the exposure measurements showed high median levels of respirable dust (15.5 mg/m(3)), respirable crystalline silica (2.4 mg/m(3)), respirable combustible dust (1.5 mg/m(3)) and 'total' dust (28.4 mg/m(3)). When only shovelling and loading of sacks took place, the median exposures to respirable dust and respirable crystalline silica were 4.3 and 1.1 mg/m(3). This study shows that the exposure to respirable crystalline silica was high during underground small-scale mining. In the absence of personal protective equipment, the miners in the Mererani area are presumably at a high risk of developing chronic silicosis.

Immunoglobulin E-mediated sensitization to pine and beech dust in relation to wood dust exposure levels and respiratory symptoms in the furniture industry.

PubMed

Schlünssen, Vivi; Kespohl, Sabine; Jacobsen, Gitte; Raulf-Heimsoth, Monika; Schaumburg, Inger; Sigsgaard, Torben

2011-03-01

Wood dust exposure may cause Immunoglobulin E (IgE)-mediated allergic diseases. Our objectives were to estimate pine and beech dust sensitization rates among woodworkers and a reference group, explore the association between exposure and sensitization and between sensitization and respiratory symptoms, and finally investigate the impact of proteinogenic specific IgE (sIgE) epitopes on respiratory symptoms. In a Danish study among 52 furniture factories and 2 reference factories, we evaluated the workers' asthma and rhinitis status using questionnaires and blood samples collected from 1506 woodworkers and 195 references. Workers with asthma symptoms (N=298), a random study sample (N=399) and a random rhinitis sample (N=100) were evaluated for IgE-mediated sensitization to pine and beech dust. The prevalence of pine and beech sensitization among current woodworkers was 1.7 and 3.1%, respectively. No differences in sensitization rates were found between woodworkers and references, but the prevalence of wood dust sensitization was dose-dependently associated with the current level of wood dust exposure. No relation was observed between wood dust sensitization per se and respiratory symptoms. Only symptomatic subjects had proteinogenic IgE epitopes to pine. Increased odds ratios for sIgE based on proteinogenic epitopes to beech and respiratory symptoms were found, although they were not statistically significant. Sensitization rates to pine and beech were the same for woodworkers and references but dependent on the current wood dust exposure level. The importance of beech and pine wood sensitization is limited, but may be of clinical significance for a few workers if the IgE epitopes are proteinogenic.

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,...

30 CFR 71.100 - Respirable dust standard.

Code of Federal Regulations, 2010 CFR

2010-07-01

... concentration of respirable dust in the mine atmosphere during each shift to which each miner in the active... shall be measured with an approved sampling device and expressed in terms of an equivalent concentration determined in accordance with § 71.206 (Approved sampling devices; equivalent concentrations). ...

Saharan dust particles in snow samples of Alps and Apennines during an exceptional event of transboundary air pollution.

PubMed

Telloli, Chiara; Chicca, Milvia; Pepi, Salvatore; Vaccaro, Carmela

2017-12-21

Southern European countries are often affected in summer by transboundary air pollution from Saharan dust. However, very few studies deal with Saharan dust pollution at high altitudes in winter. In Italy, the exceptional event occurred on February 19, 2014, colored in red the entire mountain range (Alps and Apennines) and allowed to characterize the particulate matter deposited on snow from a morphological and chemical point of view. Snow samples were collected after this event in four areas in the Alps and one in the Apennines. The particulate matter of the melted snow samples was analyzed by scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDS) and by inductively coupled plasma mass spectrometry (ICP-MS). These analyses confirmed the presence of Saharan dust particle components in all areas with similar percentages, supported also by the positive correlations between Mg-Ca, Al-Ca, Al-Mg, and Al-K in all samples.

Desert Research and Technology Studies Exposure of Lotus Coated Electrodynamic Shield Samples

NASA Technical Reports Server (NTRS)

Rodriquez, Marcello; Peters, Wanda C.; Straka, Sharon A.; Jones, Craig B.

2011-01-01

The Lotus dust mitigation coating and the electrodynamic shield (EDS) are two new technologies currently being developed by NASA as countermeasures for addressing dust accumulation for long-duration human space exploration. These combined technologies were chosen by the Habitation Demonstration Unit (HDU) program for desert dust exposure at the Desert Research and Technologies Studies (D-RaTS) test site in Arizona. Characterization of these samples was performed prior to, during and post D-RaTS exposure.

Geochemical characterization of critical dust source regions in the American West

NASA Astrophysics Data System (ADS)

Aarons, Sarah M.; Blakowski, Molly A.; Aciego, Sarah M.; Stevenson, Emily I.; Sims, Kenneth W. W.; Scott, Sean R.; Aarons, Charles

2017-10-01

The generation, transport, and deposition of mineral dust are detectable in paleoclimate records from land, ocean, and ice, providing valuable insight into earth surface conditions and cycles on a range of timescales. Dust deposited in marine and terrestrial ecosystems can provide critical nutrients to nutrient-limited ecosystems, and variations in dust provenance can indicate changes in dust production, sources and transport pathways as a function of climate variability and land use change. Thus, temporal changes in locations of dust source areas and transport pathways have implications for understanding interactions between mineral dust, global climate, and biogeochemical cycles. This work characterizes dust from areas in the American West known for dust events and/or affected by increasing human settlement and livestock grazing during the last 150 years. Dust generation and uplift from these dust source areas depends on climate and land use practices, and the relative contribution of dust has likely changed since the expansion of industrialization and agriculture into the western United States. We present elemental and isotopic analysis of 28 potential dust source area samples analyzed using Thermal Ionization Mass Spectrometry (TIMS) for 87Sr/86Sr and 143Nd/144Nd composition and Multi-Collector Inductively Coupled Plasma Mass Spectrometer (MC-ICPMS) for 176Hf/177Hf composition, and ICPMS for major and trace element concentrations. We find significant variability in the Sr, Nd, and Hf isotope compositions of potential source areas of dust throughout western North America, ranging from 87Sr/86Sr = 0.703699 to 0.740236, εNd = -26.6 to 2.4, and εHf = -21.7 to -0.1. We also report differences in the trace metal and phosphorus concentrations in the geologic provinces sampled. This research provides an important resource for the geochemical tracing of dust sources and sinks in western North America, and will aid in modeling the biogeochemical impacts of increased dust generation and deposition caused by higher drought frequency and human activity.

Dust deposition in southern Nevada and California, 1984-1989: Relations to climate, source area, and source lithology

NASA Astrophysics Data System (ADS)

Reheis, Marith C.; Kihl, Rolf

1995-05-01

Dust samples collected annually for 5 years from 55 sites in southern Nevada and California provide the first regional source of information on modern rates of dust deposition, grain size, and mineralogical and chemical composition relative to climate and to type and lithology of dust source. The average silt and clay flux (rate of deposition) in southern Nevada and southeastern California ranges from 4.3 to 15.7 g/m2/yr, but in southwestern California the average silt and clay flux is as high as 30 g/m2/yr. The climatic factors that affect dust flux interact with each other and with the factors of source type (playas versus alluvium), source lithology, geographic area, and human disturbance. Average dust flux increases with mean annual temperature but is not correlated to decreases in mean annual precipitation because the regional winds bring dust to relatively wet areas. In contrast, annual dust flux mostly reflects changes in annual precipitation (relative drought) rather than temperature. Although playa and alluvial sources produce about the same amount of dust per unit area, the total volume of dust from the more extensive alluvial sources is much larger. In addition, playa and alluvial sources respond differently to annual changes in precipitation. Most playas produce dust that is richer in soluble salts and carbonate than that from alluvial sources (except carbonate-rich alluvium). Gypsum dust may be produced by the interaction of carbonate dust and anthropogenic or marine sulfates. The dust flux in an arid urbanizing area may be as much as twice that before disturbance but decreases when construction stops. The mineralogic and major-oxide composition of the dust samples indicates that sand and some silt is locally derived and deposited, whereas clay and some silt from different sources can be far-traveled. Dust deposited in the Transverse Ranges of California by the Santa Ana winds appears to be mainly derived from sources to the north and east.

Analysis of Samples Collected from the Surface of Interim Storage Canisters at Calvert Cliffs in June 2017: Revision 01.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bryan, Charles R.; Schindelholz, Eric John

In June 2017, dust and salt samples were collected from the surface of Spent Nuclear Fuel (SNF) dry storage canisters at the Calvert Cliffs Nuclear Power Plant. The samples were delivered to Sandia National laboratories for analysis. Two types of samples were collected: filter-backed Scotch-Brite TM pads were used to collect dry dust samples for characterization of salt and dust morphologies and distributions; and Saltsmart TM test strips were used to collect soluble salts for determining salt surface loadings per unit area. After collection, the samples were sealed into plastic sleeves for shipping. Condensation within the sleeves containing the Scotch-Britemore » TM samples remobilized the salts, rendering them ineffective for the intended purpose, and also led to mold growth, further compromising the samples; for these reasons, the samples were not analyzed. The SaltSmart TM samples were unaffected and were analyzed by ion chromatography for major anions and cations. The results of those analyses are presented here.« less

Long-term airborne contamination studied by attic dust in an industrial area: Ajka, Hungary

NASA Astrophysics Data System (ADS)

Völgyesi, P.; Jordan, G.; Szabo, Cs.

2012-04-01

Heavy industrial activities such as mining, metal industry, coal fired power plants have produced large amount of by-products and wide-spread pollution, particularly in the period of centrally dictated economy after WWII, in Hungary. Several studies suggest that significant amount of these pollutants have been deposited in the urban environment. Nowadays, more than half of the world's population is living in urban areas and people spend almost 80% of their lives indoors in developed countries increasing human health risk due to contamination present in urban dwellings. Attic dust sampling was applied to determine the long-term airborne contamination load in the industrial town of Ajka (Hungary). There has been a high industrial activity in Ajka since the end of the 19th century. In addition to aluminum and alumina industry, coal mining, coal fired power plant and glass industry sites, generated numerous waste heaps which act as multi-contamination sources in the area. In October 2010 the Ajka red mud tailings pond failed and caused an accidental regional contamination of international significance. The major objective of this research was to study and map the spatial distribution of heavy metal contamination in airborne attic dust samples. At 27 sampling sites 30 attic dust samples were collected. Sampling strategy followed a grid-based stratified random sampling design. In each cell a house for attic dust sample collection was selected that was located the closest to a randomly generated point in the grid cell. The project area covers a 8x8 grid of 1x1 km cells with a total area of 64 km2. In order to represent long-term industrial pollution, houses with attics kept intact for at least 30-40 years were selected for sampling. Sampling included the collection of background samples remotely placed from the industrialized urban area. The concentration of the major and toxic elements (Al, Ca, Fe, K, Mg, Mn, Na, P, S, and As, Ba, Cd, Co, Cr, Cu, Li, Mo, Ni, Pb, Se, Sn, Sr, Ti, V, Zn) were measured with ICP-OES and the mercury content was measured with atom absorption spectrometry. Our results show a good spatial correlation of contamination sources and attic dust sampling locations reveal spatial trends as well. Attic dust seems to be an efficient and cheep sampling medium to study long-term airborne contamination and possibly associated human health risk in an industrial area.

Global scale variability of the mineral dust long-wave refractive index: a new dataset of in situ measurements for climate modeling and remote sensing

NASA Astrophysics Data System (ADS)

Di Biagio, Claudia; Formenti, Paola; Balkanski, Yves; Caponi, Lorenzo; Cazaunau, Mathieu; Pangui, Edouard; Journet, Emilie; Nowak, Sophie; Caquineau, Sandrine; Andreae, Meinrat O.; Kandler, Konrad; Saeed, Thuraya; Piketh, Stuart; Seibert, David; Williams, Earle; Doussin, Jean-François

2017-02-01

Modeling the interaction of dust with long-wave (LW) radiation is still a challenge because of the scarcity of information on the complex refractive index of dust from different source regions. In particular, little is known about the variability of the refractive index as a function of the dust mineralogical composition, which depends on the specific emission source, and its size distribution, which is modified during transport. As a consequence, to date, climate models and remote sensing retrievals generally use a spatially invariant and time-constant value for the dust LW refractive index. In this paper, the variability of the mineral dust LW refractive index as a function of its mineralogical composition and size distribution is explored by in situ measurements in a large smog chamber. Mineral dust aerosols were generated from 19 natural soils from 8 regions: northern Africa, the Sahel, eastern Africa and the Middle East, eastern Asia, North and South America, southern Africa, and Australia. Soil samples were selected from a total of 137 available samples in order to represent the diversity of sources from arid and semi-arid areas worldwide and to account for the heterogeneity of the soil composition at the global scale. Aerosol samples generated from soils were re-suspended in the chamber, where their LW extinction spectra (3-15 µm), size distribution, and mineralogical composition were measured. The generated aerosol exhibits a realistic size distribution and mineralogy, including both the sub- and super-micron fractions, and represents in typical atmospheric proportions the main LW-active minerals, such as clays, quartz, and calcite. The complex refractive index of the aerosol is obtained by an optical inversion based upon the measured extinction spectrum and size distribution. Results from the present study show that the imaginary LW refractive index (k) of dust varies greatly both in magnitude and spectral shape from sample to sample, reflecting the differences in particle composition. In the 3-15 µm spectral range, k is between ˜ 0.001 and 0.92. The strength of the dust absorption at ˜ 7 and 11.4 µm depends on the amount of calcite within the samples, while the absorption between 8 and 14 µm is determined by the relative abundance of quartz and clays. The imaginary part (k) is observed to vary both from region to region and for varying sources within the same region. Conversely, for the real part (n), which is in the range 0.84-1.94, values are observed to agree for all dust samples across most of the spectrum within the error bars. This implies that while a constant n can be probably assumed for dust from different sources, a varying k should be used both at the global and the regional scale. A linear relationship between the magnitude of the imaginary refractive index at 7.0, 9.2, and 11.4 µm and the mass concentration of calcite and quartz absorbing at these wavelengths was found. We suggest that this may lead to predictive rules to estimate the LW refractive index of dust in specific bands based on an assumed or predicted mineralogical composition, or conversely, to estimate the dust composition from measurements of the LW extinction at specific wavebands. Based on the results of the present study, we recommend that climate models and remote sensing instruments operating at infrared wavelengths, such as IASI (infrared atmospheric sounder interferometer), use regionally dependent refractive indices rather than generic values. Our observations also suggest that the refractive index of dust in the LW does not change as a result of the loss of coarse particles by gravitational settling, so that constant values of n and k could be assumed close to sources and following transport. The whole dataset of the dust complex refractive indices presented in this paper is made available to the scientific community in the Supplement.

Identifying Dust Sources by Positive Matrix Factorization (PMF)

NASA Astrophysics Data System (ADS)

Engelbrecht, Johann P.

2010-05-01

This presentation is on the source attribution by Positive Matrix Factorization (PMF) of aerosol samples collected in Iraq, a major source of mineral dust in the Middle East. Globally transported mineral dust from North Africa, the Middle East, China, and elsewhere are routinely being sampled at high elevation monitoring sites such as those on the Canary Islands and Hawaii, and many ambient monitoring sites worldwide. Chemical results of these filter samples reflect differences in sources impacting at each site, further complicated by the regional geomorphology and meteorology. Trace elements, isotopes, elemental ratios, and mineralogy are generally being used to pinpoint geological source regions of natural and anthropogenic dusts. A receptor site is seldom impacted by only one source at a time. Dust palls are continually being modified by added dust from soils across which they migrate, also by particle segregation in the dust plume, and precipitation of the coarser particles. The result is that dust is a mixture, with contributions from different sources, each with a different chemical and mineralogical signature. PMF is a non-negative factorization procedure that produces only positive factor scores and loadings, in contrast to classical factor analysis (FA) and Principal Components Analysis (PCA). PMF enables us to resolve factors (chemical signatures) for source types contributing to the ambient chemical data set, and also models the source-type contributions to individual ambient samples. The latter can often be related to specific source regions. PMF was applied separately to two ambient data sets collected in Iraq in 2006, the one on Teflon membrane filters and the other on quartz fiber. Each of the filter types were previously analyzed for different chemical species: Teflon membrane for elements, by XRF and ICP-MS, while quartz fiber filters were analyzed for ions and carbon. [Engelbrecht et al. 2009] A set of 392 Teflon filter samples analyzed for 25 elemental species was modeled by PMF. A five factor solution identified three soil factors, a silicate soil, limestone soil, and a gypsum soil, as well as a salt factor and an anthropogenic metal factor. Similarly, a set of 362 quartz filter samples analyzed for 10 selected chemical species was modeled by PMF. A five factor solution provided a limestone-gypsum soil, diesel combustion, secondary ammonium sulfate, salt and agricultural-burnpit combustion source type. Examples of time series plots of PMF factor contributions for each of six sampling sites (Balad, Baghdad, Tallil, Tikrit, Taji, and Al Asad) will be discussed. Engelbrecht , J. P., McDonald, E. V., Gillies, J. A., Jayanty, R. K. M., Casuccio, G., and Gertler, A. W., 2009, Characterizing mineral dusts and other aerosols from the Middle East - Part 1: Ambient sampling: Inhalation Toxicology, v. 21, p. 297-326.

A method for combined Sr-Nd-Hf isotopic analysis of <10 mg dust samples: implication for ice core science

NASA Astrophysics Data System (ADS)

Ujvari, Gabor; Wegner, Wencke; Klötzli, Urs

2017-04-01

Aeolian mineral dust particles below the size of 10-20 μm often experience longer distance transport in the atmosphere, and thus Aeolian dust is considered an important tracer of large-scale atmospheric circulation. Since ice core dust is purely Aeolian in origin, discrimination of its potential source region(s) can contribute to a better understanding of past dust activity and climatic/environmental causes. Furthermore, ice core dust source information provides critical experimental constraints for model simulations of past atmospheric circulation patterns [1,2]. However, to identify dust sources in past dust archives such as ice cores, the mineralogy and geochemistry of the wind-blown dust material must be characterized. While the amount of dust in marine cores or common terrestrial archives is sufficient for different types of analyses and even for multiple repeat measurements, dust content in ice cores is usually extremely low even for the peak dusty periods such as the Last Glacial Maximum (LGM) (5-8 mg dust/kg ice; [3]). Since the most powerful dust fingerprinting methods, such as REE composition and Sr-Nd-Pb isotopic analyses are destructive there is a clear need to establish sequential separation techniques of Sr, Nd, Pb and other REEs to get the most information out of small (5-10 mg) dust samples recovered from ice cores. Although Hf isotopes have recently been added as a robust tool of aerosol/dust source discrimination (e.g. [4,5,6,7]), precise Hf isotopic measurements of small (<10 mg) dust samples are still challenging due to the small Hf amounts (on the order of 1-10 ng) and often compromised by potential problems arising during ion exchange chemistry. In this pilot study an improved method for chemical separation of Sr, Nd and Hf by Bast et al. [8] was applied, which allows the precise isotope analysis of sub-ng amounts of Hf by MC-ICPMS. This ion exchange chromatography procedure has been combined with established methods of separating and purifying Sr and Nd for subsequent TIMS isotopic measurements. International rock standard BCR-2 (10 mg aliquot) gave 87Sr/86Sr, 143Nd/144Nd and 176Hf/177Hf isotopic ratios of 0.705127±0.000004 (2σ), 0.512625±0.000004 and 0.282853±0.000006, respectively. These data are in good agreement with the certified values (0.705000±0.0000011, 0.512637±0.000013 and 0.282866±0.000011; [9]) demonstrating that the experimental procedures and setup allow for valid 176Lu and 176Yb corrections and results in reliable 176Hf/177Hf (and also 87Sr/86Sr, 143Nd/144Nd) ratios. Along with the standards 50, 10 and 5 mg aliquots of the fine (<10 μm) fractions of three wind-blown loess sediment samples from Central Europe (NUS), China (BEI) and the US (JUD) were processed (all acetic acid treated for carbonate removal, i.e. aluminosilicate fractions were analysed). Sr isotopic compositions varied between the aliquots within a range of ˜0.00007 for the three samples. Comparison of these values with previously obtained 87Sr/86Sr isotopic ratios from the same samples (different acid/sample amounts) reveals that these values are very sensitive to the acetic acid treatment (acid molarity and amount). By contrast, Nd isotopic ratios do not seem to be affected by acid treatment and these signatures are extremely stable both within run (0.000008 variability for the three aliquots, i.e. 0.15 ɛNd unit) and between runs of different laboratories (0.00006, ca 1 ɛNd unit). Hf isotopic compositions varied within 1 (NUS) and 5 ɛHf units (BEI) between the three aliquots, but the BEI sample always gave more positive ɛHf values (mostly below -4.7) than the Central European sample (NUS, above -6.5, mostly around -8). JUD gave two values of -4.9 and -7.9. It should be further studied using other dust samples if the slightly larger dispersion in 176Hf/177Hf for the different aliquots of BEI is a unique feature or not. Nevertheless, the ca. 3-7 ɛHf unit difference between the Central European and Chinese dust sample provides an opportunity to better discriminate last glacial Greenland dust sources [7] in Nd-Hf space. This study was supported by the OMAA 92öu7 project, the OTKA PD-108639 grant and the Bolyai János Research Fellowship (to GÚ). References [1] Biscaye et al., 1997. J. Geophys. Res. 102, 26765-26781; [2] Svensson et al., 2000. J. Geophys. Res. 105, 4637-4656; [3] Ruth et al., 2003. J. Geophys. Res. 108(D3), 4098; [4] Aciego et al., 2009. Chem. Geol. 266, 194-204; [5] Aarons et al., 2013. Chem. Geol. 349(350), 18-26; [6] Zhao et al., 2015. Geophys. Res. Lett. 42, 5661-5669; [7] Újvári et al., 2015. Geophys. Res. Lett. 42, 10399-10408; [8] Bast et al., 2015. J. Anal. Atom. Spectrom. 30, 2323; [9] Jweda et al., 2016. Geostand. Geoanal. Res. 40, 101-105.

[Fauna and biology of the Pyroglyphidae of Poland].

PubMed

Solarz, K

1995-01-01

5 valid species of pyroglyphid mites are actually known in Polish fauna. It should be stressed that the knowledge of their occurrence in house-dust, bird nests and other habitats is still poor. The most common pyroglyphid house-dust mites, Dermatophagoides pteronyssinus, D. farinae and Euroglyphus maynei, were found in samples of dust from houses (Warszawa, Bydgoszcz, Upper Silesia), hospitals (Katowice, Sosnowiec), libraries (Sosnowiec) and port buildings (Gdynia). The both species of the genus Dermatophagoides were also found in house-dust samples in Poznań and Poznań vicinity, whereas E. maynei and D. pteronyssinus--occasionally in stored herbs in Grudziadz. Moreover, Gymnoglyphus longior was reported from house-dust (Tarnowskie Góry, Upper Silesia), debris from a byre in Lesko and from barn litter in Solarnia near Lubliniec, while Hirstia passericola was found in byre debris in Lesko. It seems that D. pteronyssinus and D. farinae are common in house-dust all over the country. The following pyroglyphid mite species--D. pteronyssinus, H. passericola, G. longior--are reported from nests of birds in Poland.

Comparison of Enzyme-Linked Immunosorbent Assay, Surface Plasmon Resonance and Biolayer Interferometry for Screening of Deoxynivalenol in Wheat and Wheat Dust.

PubMed

Sanders, Melanie; McPartlin, Daniel; Moran, Kara; Guo, Yirong; Eeckhout, Mia; O'Kennedy, Richard; De Saeger, Sarah; Maragos, Chris

2016-04-11

A sample preparation method was developed for the screening of deoxynivalenol (DON) in wheat and wheat dust. Extraction was carried out with water and was successful due to the polar character of DON. For detection, an enzyme-linked immunosorbent assay (ELISA) was compared to the sensor-based techniques of surface plasmon resonance (SPR) and biolayer interferometry (BLI) in terms of sensitivity, affinity and matrix effect. The matrix effects from wheat and wheat dust using SPR were too high to further use this screenings method. The preferred ELISA and BLI methods were validated according to the criteria established in Commission Regulation 519/2014/EC and Commission Decision 2002/657/EC. A small survey was executed on 16 wheat lots and their corresponding dust samples using the validated ELISA method. A linear correlation (r = 0.889) was found for the DON concentration in dust versus the DON concentration in wheat (LOD wheat: 233 μg/kg, LOD wheat dust: 458 μg/kg).

Variability in Population Density of House Dust Mites of Bitlis and Muş, Turkey.

PubMed

Aykut, M; Erman, O K; Doğan, S

2016-05-01

This study was conducted to investigate the relationship between the number of house dust mites/g dust and different physical and environmental variables. A total of 1,040 house dust samples were collected from houses in Bitlis and Muş Provinces, Turkey, between May 2010 and February 2012. Overall, 751 (72.2%) of dust samples were mite positive. The number of mites/g dust varied between 20 and 1,840 in mite-positive houses. A significant correlation was detected between mean number of mites and altitude of houses, frequency of monthly vacuum cleaning, number of individuals in the household, and relative humidity. No association was found between the number of mites and temperature, type of heating, existence of allergic diseases, age and structure of houses. A maximum number of mites were detected in summer and a minimum number was detected in autumn. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Antibiotics in dust originating from a pig-fattening farm: a new source of health hazard for farmers?

PubMed Central

Hamscher, Gerd; Pawelzick, Heike Theresia; Sczesny, Silke; Nau, Heinz; Hartung, Jörg

2003-01-01

Pig-house dust originates from feed, bedding, feces, and the animals themselves. If the animals receive drugs such as antibiotics, residues of these substances may occur in manure, in the air, or on surfaces of the respective animal house. In a retrospective study, we investigated dust samples collected during two decades from the same piggery for the occurrence of various antibiotics. In 90% of these samples, we detected up to five different antibiotics, including tylosin, various tetracyclines, sulfamethazine, and chloramphenicol, in total amounts up to 12.5 mg/kg dust. High dust exposure in animal confinement buildings is believed to be a respiratory health hazard because of the high content of microorganisms, endotoxins, and allergens. Further risks may arise from the inhalation of dust contaminated with a cocktail of antibiotics. Apart from that, our data provide first evidence for a new route of entry for veterinary drugs in the environment. PMID:14527837

Hemolytic Uremic Syndrome in Children

MedlinePlus

... in a health care provider's office or a commercial facility. For the test, a nurse or technician ... at a health care provider's office or a commercial facility and sending the sample to a lab ...

Comet composition and density analyzer

NASA Technical Reports Server (NTRS)

Clark, B. C.

1982-01-01

Distinctions between cometary material and other extraterrestrial materials (meteorite suites and stratospherically-captured cosmic dust) are addressed. The technique of X-ray fluorescence (XRF) for analysis of elemental composition is involved. Concomitant with these investigations, the problem of collecting representative samples of comet dust (for rendezvous missions) was solved, and several related techniques such as mineralogic analysis (X-ray diffraction), direct analysis of the nucleus without docking (electron macroprobe), dust flux rate measurement, and test sample preparation were evaluated. An explicit experiment concept based upon X-ray fluorescence analysis of biased and unbiased sample collections was scoped and proposed for a future rendezvous mission with a short-period comet.

Test chamber and forensic microscopy investigation of the transfer of brominated flame retardants into indoor dust via abrasion of source materials.

PubMed

Rauert, C; Harrad, S; Suzuki, G; Takigami, H; Uchida, N; Takata, K

2014-09-15

Brominated flame retardants (BFRs) have been detected in indoor dust in many studies, at concentrations spanning several orders of magnitude. Limited information is available on the pathways via which BFRs migrate from treated products into dust, yet the different mechanisms hypothesized to date may provide an explanation for the range of reported concentrations. In particular, transfer of BFRs to dust via abrasion of particles or fibers from treated products may explain elevated concentrations (up to 210 mg g(-1)) of low volatility BFRs like decabromodiphenyl ether (BDE-209). In this study, an indoor dust sample containing a low concentration of hexabromocyclododecane, or HBCD, (110 ng g(-1) ΣHBCDs) was placed on the floor of an in-house test chamber. A fabric curtain treated with HBCDs was placed on a mesh shelf 3 cm above the chamber floor and abrasion induced using a stirrer bar. This induced abrasion generated fibers of the curtain, which contaminated the dust, and ΣHBCD concentrations in the dust increased to between 4020 and 52 500 ng g(-1) for four different abrasion experiment times. The highly contaminated dust (ΣHBCD at 52 500 ng g(-1)) together with three archived dust samples from various UK microenvironments, were investigated with forensic microscopy techniques. These techniques included Micro X-ray fluorescent spectroscopy, scanning emission microscopy coupled with an energy dispersive X-ray spectrometer, Fourier transform infrared spectroscopy with further BFR analysis on LC-MS/MS. Using these techniques, fibers or particles abraded from a product treated with BFRs were identified in all dust samples, thereby accounting for the elevated concentrations detected in the original dust (3500 to 88 800 ng g(-1) ΣHBCD and 24 000 to 1,438 000 ng g(-1) for BDE-209). This study shows how test chamber experiments alongside forensic microscopy techniques, can provide valuable insights into the pathways via which BFRs contaminate indoor dust. Copyright © 2014 Elsevier B.V. All rights reserved.

The Vertical Dust Profile over Gale Crater

NASA Astrophysics Data System (ADS)

Guzewich, S.; Newman, C. E.; Smith, M. D.; Moores, J.; Smith, C. L.; Moore, C.; Richardson, M. I.; Kass, D. M.; Kleinboehl, A.; Martin-Torres, F. J.; Zorzano, M. P.; Battalio, J. M.

2017-12-01

Regular joint observations of the atmosphere over Gale Crater from the orbiting Mars Reconnaissance Orbiter/Mars Climate Sounder (MCS) and Mars Science Laboratory (MSL) Curiosity rover allow us to create a coarse, but complete, vertical profile of dust mixing ratio from the surface to the upper atmosphere. We split the atmospheric column into three regions: the planetary boundary layer (PBL) within Gale Crater that is directly sampled by MSL (typically extending from the surface to 2-6 km in height), the region of atmosphere sampled by MCS profiles (typically 25-80 km above the surface), and the region of atmosphere between these two layers. Using atmospheric optical depth measurements from the Rover Environmental Monitoring System (REMS) ultraviolet photodiodes (in conjunction with MSL Mast Camera solar imaging), line-of-sight opacity measurements with the MSL Navigation Cameras (NavCam), and an estimate of the PBL depth from the MarsWRF general circulation model, we can directly calculate the dust mixing ratio within the Gale Crater PBL and then solve for the dust mixing ratio in the middle layer above Gale Crater but below the atmosphere sampled by MCS. Each atmospheric layer has a unique seasonal cycle of dust opacity, with Gale Crater's PBL reaching a maximum in dust mixing ratio near Ls = 270° and a minimum near Ls = 90°. The layer above Gale Crater, however, has a seasonal cycle that closely follows the global opacity cycle and reaches a maximum near Ls = 240° and exhibits a local minimum (associated with the "solsticial pauses") near Ls = 270°. Knowing the complete vertical profile also allows us to determine the frequency of high-altitude dust layers above Gale, and whether such layers truly exhibit the maximum dust mixing ratio within the entire vertical column. We find that 20% of MCS profiles contain an "absolute" high-altitude dust layer, i.e., one in which the dust mixing ratio within the high-altitude dust layer is the maximum dust mixing ratio in the vertical column of atmosphere over Gale Crater.

Ice Nucleation Activity of Various Agricultural Soil Dust Aerosol Particles

NASA Astrophysics Data System (ADS)

Schiebel, Thea; Höhler, Kristina; Funk, Roger; Hill, Thomas C. J.; Levin, Ezra J. T.; Nadolny, Jens; Steinke, Isabelle; Suski, Kaitlyn J.; Ullrich, Romy; Wagner, Robert; Weber, Ines; DeMott, Paul J.; Möhler, Ottmar

2016-04-01

Recent investigations at the cloud simulation chamber AIDA (Aerosol Interactions and Dynamics in the Atmosphere) suggest that agricultural soil dust has an ice nucleation ability that is enhanced up to a factor of 10 compared to desert dust, especially at temperatures above -26 °C (Steinke et al., in preparation for submission). This enhancement might be caused by the contribution of very ice-active biological particles. In addition, soil dust aerosol particles often contain a considerably higher amount of organic matter compared to desert dust particles. To test agricultural soil dust as a source of ice nucleating particles, especially for ice formation in warm clouds, we conducted a series of laboratory measurements with different soil dust samples to extend the existing AIDA dataset. The AIDA has a volume of 84 m3 and operates under atmospherically relevant conditions over wide ranges of temperature, pressure and humidity. By controlled adiabatic expansions, the ascent of an air parcel in the troposphere can be simulated. As a supplement to the AIDA facility, we use the INKA (Ice Nucleation Instrument of the KArlsruhe Institute of Technology) continuous flow diffusion chamber based on the design by Rogers (1988) to expose the sampled aerosol particles to a continuously increasing saturation ratio by keeping the aerosol temperature constant. For our experiments, soil dust was dry dispersed into the AIDA vessel. First, fast saturation ratio scans at different temperatures were performed with INKA, sampling soil dust aerosol particles directly from the AIDA vessel. Then, we conducted the AIDA expansion experiment starting at a preset temperature. The combination of these two different methods provides a robust data set on the temperature-dependent ice activity of various agriculture soil dust aerosol particles with a special focus on relatively high temperatures. In addition, to extend the data set, we investigated the role of biological and organic matter in more detail to gain additional information on the trigger of the enhanced ice nucleation activity of soil dust. References Rogers (1988): Development of a continuous flow thermal gradient diffusion chamber for ice nucleation studies Steinke et al. (In preparation for submission): Ice nucleation activity of agricultural soil dust aerosols from Mongolia, Argentina and Germany

UV-to-IR spectral energy distributions of galaxies at z>1: the impact of Herschel data on dust attenuation and star formation determinations

NASA Astrophysics Data System (ADS)

Buat, V.; Heinis, S.; Boquien, M.

2013-11-01

We report on our recent works on the UV-to-IR SED fitting of a sample of distant (z>1) galaxies observed by Herschel in the CDFS as part of the GOODS-Herschel project. Combining stellar and dust emission in galaxies is found powerful to constrain their dust attenuation as well as their star formation activity. We focus on the caracterisation of dust attenuation and on the uncertainties on the derivation of the star formation rates and stellar masses, as a function of the range of wavelengths sampled by the data data and of the assumptions made on the star formation histories

Marine Technician's Handbook, Instructions for Taking Air Samples on Board Ship: Carbon Dioxide Project.

ERIC Educational Resources Information Center

Keeling, Charles D.

This booklet is one of a series intended to provide explicit instructions for the collection of oceanographic data and samples at sea. The methods and procedures described have been used by the Scripps Institution of Oceanography and found reliable and up-to-date. Instructions are given for taking air samples on board ship to determine the…

Determination of Vanadium, Tin and Mercury in Atmospheric Particulate Matter and Cement Dust Samples by Direct Current Plasma Atomic Emission Spectrometry.

ERIC Educational Resources Information Center

Hindy, Kamal T.; And Others

1992-01-01

An atmospheric pollution study applies direct current plasma atomic emission spectrometry (DCP-AES) to samples of total suspended particulate matter collected in two industrial areas and one residential area, and cement dust collected near major cement factories. These samples were analyzed for vanadium, tin, and mercury. The results indicate the…

COMPARISON OF IMMUNOASSAY AND GAS CHROMATOGRAPHY/MASS SPECTROMETRY METHODS FOR MEASURING 3,5,6-TRICHLORO-2PYRIDINOL IN MULTIPLE SAMPLE MEDIA

EPA Science Inventory

Two enzyme-linked immunosorbent assay (ELISA) methods were evaluated for the determination of 3,5,6-trichloro-2-pyridinol (3,5,6-TCP) in multiple sample media (dust, soil, food, and urine). The dust and soil samples were analyzed by a commercial RaPID immunoassay testing kit. ...

Analysis of polycyclic aromatic hydrocarbons extracted from air particulate matter using a temperature programmable injector coupled to GC-C-IRMS.

PubMed

Mikolajczuk, Agnieszka; Przyk, Elzbieta Perez; Geypens, Benny; Berglund, Michael; Taylor, Philip

2010-03-01

Compound specific isotopic analysis (CSIA) can provide information about the origin of analysed compounds - in this case, polycyclic aromatic hydrocarbons (PAHs). In the study, PAHs were extracted from three dust samples: winter and summer filter dust and tunnel dust. The measurement was performed using the method validated in our laboratory using pure, solid compounds and EPA 610 reference assortment. CSIA required an appropriate clean-up method to avoid an unresolved complex in the gas chromatographic analysis usually found in the chromatography of PAHs. Extensive sample clean-up for this particular matrix was found to be necessary to obtain good gas chromatography-combustion-isotope ratio mass spectrometry analysis results. The sample purification method included two steps in which the sample is cleaned up and the aliphatic and aromatic hydrocarbons are separated. The concentration of PAHs in the measured samples was low; so a large volume injection technique (100 microl) was applied. The delta(VPDB)(13)C was measured with a final uncertainty smaller than 1 per thousand. Comparison of the delta(VPDB)(13)C signatures of PAHs extracted from different dust samples was feasible with this method and, doing so, significant differences were observed.

Pharmacy technician involvement in community pharmacy medication therapy management.

PubMed

Lengel, Matthew; Kuhn, Catherine H; Worley, Marcia; Wehr, Allison M; McAuley, James W

To assess the impact of technician involvement on the completion of medication therapy management (MTM) services in a community pharmacy setting and to describe pharmacists' and technicians' perceptions of technician involvement in MTM-related tasks and their satisfaction with the technician's role in MTM. Prospective observational study. In the fall of 2015, pharmacists and selected technicians from 32 grocery store-based community pharmacies were trained to use technicians within MTM services. Completed MTM claims were evaluated at all pharmacies for 3 months before training and 3 months after training. An electronic survey, developed with the use of competencies taught in the training and relevant published literature, was distributed via e-mail to trained employees 3 months after training. The total number of completed MTM claims at the 32 pharmacy sites was higher during the posttraining time period (2687 claims) versus the pretraining period (1735 claims). Of the 182 trained participants, 112 (61.5%) completed the survey. Overall, perceived technician involvement was lower than expected. However, identifying MTM opportunities was the most commonly reported technician MTM task, with 62.5% of technicians and 47.2% of pharmacists reporting technician involvement. Nearly one-half of technicians (42.5%) and pharmacists (44.0%) agreed or strongly agreed they were satisfied with the technician's role in MTM services, and 40.0% of technicians agreed that they were more satisfied with their work in the pharmacy after involvement in MTM. Three months after initial training of technicians in MTM, participation of technicians was lower than expected. However, the technicians involved most often reported identifying MTM opportunities for pharmacists, which may be a focus for future technician trainings. In addition, technician involvement in MTM services may increase satisfaction with many aspects of work for actively involved technicians. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Characterizing Dust from Cutting Corian®, a Solid-Surface Composite Material, in a Laboratory Testing System.

PubMed

Qi, Chaolong; Echt, Alan; Murata, Taichi K

2016-06-01

We conducted a laboratory test to characterize dust from cutting Corian(®), a solid-surface composite material, with a circular saw. Air samples were collected using filters and direct-reading instruments in an automatic laboratory testing system. The average mass concentrations of the total and respirable dusts from the filter samples were 4.78±0.01 and 1.52±0.01mg cm(-3), respectively, suggesting about 31.8% mass of the airborne dust from cutting Corian(®) is respirable. Analysis of the metal elements on the filter samples reveals that aluminum hydroxide is likely the dominant component of the airborne dust from cutting Corian(®), with the total airborne and respirable dusts containing 86.0±6.6 and 82.2±4.1% aluminum hydroxide, respectively. The results from the direct-reading instruments confirm that the airborne dust generated from cutting Corian(®) were mainly from the cutting process with very few particles released from the running circular saw alone. The number-based size distribution of the dusts from cutting Corian(®) had a peak for fine particles at 1.05 µm with an average total concentration of 871.9 particles cm(-3), and another peak for ultrafine particles at 11.8nm with an average total concentration of 1.19×10(6) particles cm(-3) The small size and high concentration of the ultrafine particles suggest additional investigation is needed to study their chemical composition and possible contribution to pulmonary effect. Published by Oxford University Press on behalf of the British Occupational Hygiene Society 2016.

Case Report: Lung Disease in World Trade Center Responders Exposed to Dust and Smoke: Carbon Nanotubes Found in the Lungs of World Trade Center Patients and Dust Samples

PubMed Central

Wu, Maoxin; Gordon, Ronald E.; Herbert, Robin; Padilla, Maria; Moline, Jacqueline; Mendelson, David; Litle, Virginia; Travis, William D.; Gil, Joan

2010-01-01

Context After the collapse of the World Trade Center (WTC) on 11 September 2001, a dense cloud of dust containing high levels of airborne pollutants covered Manhattan and parts of Brooklyn, New York. Between 60,000 and 70,000 responders were exposed. Many reported adverse health effects. Case presentation In this report we describe clinical, pathologic, and mineralogic findings in seven previously healthy responders who were exposed to WTC dust on either 11 September or 12 September 2001, who developed severe respiratory impairment or unexplained radiologic findings and underwent video-assisted thoracoscopic surgical lung biopsy procedures at Mount Sinai Medical Center. WTC dust samples were also examined. We found that three of the seven responders had severe or moderate restrictive disease clinically. Histopathology showed interstitial lung disease consistent with small airways disease, bronchiolocentric parenchymal disease, and nonnecrotizing granulomatous condition. Tissue mineralogic analyses showed variable amounts of sheets of aluminum and magnesium silicates, chrysotile asbestos, calcium phosphate, and calcium sulfate. Small shards of glass containing mostly silica and magnesium were also found. Carbon nanotubes (CNT) of various sizes and lengths were noted. CNT were also identified in four of seven WTC dust samples. Discussion These findings confirm the previously reported association between WTC dust exposure and bronchiolar and interstitial lung disease. Long-term monitoring of responders will be needed to elucidate the full extent of this problem. The finding of CNT in both WTC dust and lung tissues is unexpected and requires further study. PMID:20368128

Characterizing Dust from Cutting Corian®, a Solid-Surface Composite Material, in a Laboratory Testing System

PubMed Central

Qi, Chaolong; Echt, Alan; Murata, Taichi K

2016-01-01

We conducted a laboratory test to characterize dust from cutting Corian®, a solid-surface composite material, with a circular saw. Air samples were collected using filters and direct-reading instruments in an automatic laboratory testing system. The average mass concentrations of the total and respirable dusts from the filter samples were 4.78±0.01 and 1.52±0.01 mg cm−3, respectively, suggesting about 31.8% mass of the airborne dust from cutting Corian® is respirable. Analysis of the metal elements on the filter samples reveals that aluminum hydroxide is likely the dominant component of the airborne dust from cutting Corian®, with the total airborne and respirable dusts containing 86.0%±6.6% and 82.2%±4.1% aluminum hydroxide, respectively. The results from the direct-reading instruments confirm that the airborne dust generated from cutting Corian® were mainly from the cutting process with very few particles released from the running circular saw alone. The number-based size distribution of the dusts from cutting Corian® had a peak for fine particles at 1.05 µm with an average total concentration of 871.9 particles cm−3, and another peak for ultrafine particles at 11.8 nm with an average total concentration of 1.19×106 particles cm−3. The small size and high concentration of the ultrafine particles suggest additional investigation is needed to study their chemical composition and possible contribution to pulmonary effect. PMID:26872962

Heavy metals and polycyclic aromatic hydrocarbons: pollution and ecological risk assessment in street dust of Tehran.

PubMed

Saeedi, Mohsen; Li, Loretta Y; Salmanzadeh, Mahdiyeh

2012-08-15

50 street dust samples from four major streets in eastern and southern Tehran, the capital of Iran, were analyzed for metal pollution (Cu, Cr, Pb, Ni, Cd, Zn, Fe, Mn and Li). Hakanson's method was used to determine the Risk Index (RI) and ecological risks. Amongst these samples, 21 were also analyzed for polycyclic aromatic hydrocarbons (PAHs). Correlation, cluster and principal component analyses identified probable natural and anthropogenic sources of contaminants. The dust had elevated concentrations of Pb, Cd, Cu, Cr, Ni, Zn, Fe and PAHs. Enrichment factors of Cu, Pb, Cd and Zn showed that the dust is extremely enriched in these metals. Multivariate statistical analyses revealed that Cu, Pb, Zn, Fe and PAHs and, to a lesser extent, Cr and Ni have common anthropogenic sources. While Mn and Li were identified to have natural sources, Cd may have different anthropogenic origins. All samples demonstrated high ecological risk. Traffic and related activities, petrogenic and pyrogenic sources are likely to be the main anthropogenic sources of heavy metals and PAHs in Tehran dust. Copyright © 2012 Elsevier B.V. All rights reserved.

Grain dust originating from organic and conventional farming as a potential source of biological agents causing respiratory diseases in farmers.

PubMed

Zukiewicz-Sobczak, Wioletta A; Cholewa, Grażyna; Krasowska, Ewelina; Chmielewska-Badora, Jolanta; Zwoliński, Jacek; Sobczak, Paweł

2013-12-01

Agricultural producers are exposed to a number of different health risks associated with their work environment. The objective of the study was to assess the degree of colonization by fungi in terms of quantity and in terms of variety of species the samples taken from the settled dust from combine threshing of rye cultivation from organic and conventional farms in the Province of Lublin. This paper is a preliminary quantitative assessment of the species of fungi colonizing the samples of settled dust collected during combine threshing from organic and conventional farms in the Province of Lublin. One of the stages of the project was the classification of biosafety BSL (biosafety level) of selected isolates and API ZYM tests to evaluate the potential ability of isolates to cause adverse health effects. To determine the concentration and composition of fungi in collected samples plate dilution method was used with two media: Malt Agar and Potato Dextrose Agar. MOST COMMONLY ISOLATED FUNGI IN SETTLED DUST SAMPLES COLLECTED DURING COMBINE THRESHING FROM ORGANIC FARMS, ON PDA MEDIUM WERE: Alternaria alternata and Aureobasidium pullulans. Cultures on MA medium were dominated by Alternaria alternata, Mycelia sterilia and Fusarium poae. In samples of dust from conventional crops, the predominant species was Alternaria alternata on PDA medium and on MA medium. The obtained results show a potential risk of people involved in agricultural work.

Source diagnostics of polycyclic aromatic hydrocarbons in urban road runoff, dust, rain and canopy throughfall.

PubMed

Zhang, Wei; Zhang, Shucai; Wan, Chao; Yue, Dapan; Ye, Youbin; Wang, Xuejun

2008-06-01

Diagnostic ratios and multivariate analysis were utilized to apportion polycyclic aromatic hydrocarbon (PAH) sources for road runoff, road dust, rain and canopy throughfall based on samples collected in an urban area of Beijing, China. Three sampling sites representing vehicle lane, bicycle lane and branch road were selected. For road runoff and road dust, vehicular emission and coal combustion were identified as major sources, and the source contributions varied among the sampling sites. For rain, three principal components were apportioned representing coal/oil combustion (54%), vehicular emission (34%) and coking (12%). For canopy throughfall, vehicular emission (56%), coal combustion (30%) and oil combustion (14%) were identified as major sources. Overall, the PAH's source for road runoff mainly reflected that for road dust. Despite site-specific sources, the findings at the study area provided a general picture of PAHs sources for the road runoff system in urban area of Beijing.

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

PubMed

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

2013-06-01

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

Ozone reaction characteristics of indoor floor dust examined in the emission cell "FLEC".

PubMed

Vibenholt, Anni; Clausen, Per Axel; Wolkoff, Peder

2014-07-01

Ozone reacts with C-C double bonds in common indoor VOCs and SVOCs contained in indoor dust and may be catalytically degraded on dust surfaces. The reaction between floor dust and ozone was investigated in the FLEC emission cell at different ozone concentrations and relative humidities (0%, 25%, and 50% RH). One gram of dust was spread on a clean stainless steel plate which was placed in the FLEC. Steady state reaction rate (kDust) at 2.2 ppm ozone was determined for four different floor dust samples collected in Danish homes and offices. This high concentration was necessary in order to measure and determine the consumption in the outlet air from the FLEC. Measurements were corrected for FLEC wall effects by subtraction of the steady state reaction rate between ozone and a FLEC on a stainless steel plate without dust (kFLEC). The composition of organic compounds in the dust was analyzed by pressurized liquid extraction and thermal desorption GC-MS before and after ozone exposure. kFLEC was independent of the ozone concentration and the reaction was treated as first order. The same was indicated for kDust since it remained unchanged at 2.2 and 1.6 ppm ozone for one dust sample. However, the measured kDust in the FLEC should be considered an average rate constant due to the FLEC geometry. kDust was in the range 0.039-0.14s(-1) pr. g dust at 50% RH. kDust was 3 times higher at 25% RH than at 50% RH and 6 times higher than at 0% RH. The inhomogeneity of the dust was assessed by experiments in triplicate with a new portion of dust each time. The relative standard deviation of kDust at 50% RH was 6-20%. The major identified compounds before and after ozone exposure included aldehydes, saturated and unsaturated linear alkanoic acids, benzoic acid and their methyl esters, dimethyl esters, phthalates and traces of α-pinene and limonene. Substantial increase of C7-C9 aldehydes was observed after ozone exposure. Copyright © 2014 Elsevier Ltd. All rights reserved.

Lowering SAM Instrument into Curiosity Mars Rover

NASA Image and Video Library

2011-01-18

In this photograph, technicians and engineers inside a clean room at NASA Jet Propulsion Laboratory, Pasadena, Calif., position NASA Sample Analysis at Mars SAM above the mission Mars rover, Curiosity, for installing the instrument.

Installing SAM Instrument into Curiosity Mars Rover

NASA Image and Video Library

2011-01-18

In this photograph, technicians and engineers inside a clean room at NASA Jet Propulsion Laboratory, Pasadena, Calif., position NASA Sample Analysis at Mars SAM above the mission Mars rover, Curiosity, for installing the instrument.

Impact of particle size on distribution and human exposure of flame retardants in indoor dust.

PubMed

He, Rui-Wen; Li, Yun-Zi; Xiang, Ping; Li, Chao; Cui, Xin-Yi; Ma, Lena Q

2018-04-01

The effect of dust particle size on the distribution and bioaccessibility of flame retardants (FRs) in indoor dust remains unclear. In this study, we analyzed 20 FRs (including 6 organophosphate flame retardants (OPFRs), 8 polybrominated diphenyl ethers (PBDEs), 4 novel brominated flame retardants (NBFRs), and 2 dechlorane plus (DPs)) in composite dust samples from offices, public microenvironments (PME), and cars in Nanjing, China. Each composite sample (one per microenvironment) was separated into 6 size fractions (F1-F6: 200-2000µm, 150-200µm, 100-150µm, 63-100µm, 43-63µm, and <43µm). FRs concentrations were the highest in car dust, being 16 and 6 times higher than those in offices and PME. The distribution of FRs in different size fractions was Kow-dependent and affected by surface area (Log Kow=1-4), total organic carbon (Log Kow=4-9), and FR migration pathways into dust (Log Kow>9). Bioaccessibility of FRs was measured by the physiologically-based extraction test, with OPFR bioaccessibility being 1.8-82% while bioaccessible PBDEs, NBFRs, and DPs were under detection limits due to their high hydrophobicity. The OPFR bioaccessibility in 200-2000µm fraction was significantly higher than that of <43µm fraction, but with no difference among the other four fractions. Risk assessment was performed for the most abundant OPFR-tris(2-chloroethyl) phosphate. The average daily dose (ADD) values were the highest for the <43µm fraction for all three types of dust using total concentrations, but no consistent trend was found among the three types of dust if based on bioaccessible concentrations. Our results indicated that dust size impacted human exposure estimation of FRs due to their variability in distribution and bioaccessibility among different fractions. For future risk assessment, size selection for dust sampling should be standardized and bioaccessibility of FRs should not be overlooked. Copyright © 2018 Elsevier Inc. All rights reserved.

Bacterial diversity and composition during rain events with and without Saharan dust influence reaching a high mountain lake in the Alps.

PubMed

Peter, Hannes; Hörtnagl, Paul; Reche, Isabel; Sommaruga, Ruben

2014-12-01

The diversity of airborne microorganisms that potentially reach aquatic ecosystems during rain events is poorly explored. Here, we used a culture-independent approach to characterize bacterial assemblages during rain events with and without Saharan dust influence arriving to a high mountain lake in the Austrian Alps. Bacterial assemblage composition differed significantly between samples with and without Saharan dust influence. Although alpha diversity indices were within the same range in both sample categories, rain events with Atlantic or continental origins were dominated by Betaproteobacteria, whereas those with Saharan dust intrusions were dominated by Gammaproteobacteria. The high diversity and evenness observed in all samples suggests that different sources of bacteria contributed to the airborne assemblage collected at the lake shore. During experiments with bacterial assemblages collected during rain events with Saharan dust influence, cell numbers rapidly increased in sterile lake water from initially ∼3 × 103 cell ml-1 to 3.6-11.1 x105 cells ml-1 within 4-5 days, and initially, rare taxa dominated at the end of the experiment. Our study documents the dispersal of viable bacteria associated to Saharan dust intrusions travelling northwards as far as 47° latitude.

Particle emission from artificial cometary materials

NASA Technical Reports Server (NTRS)

Koelzer, Gabriele; Kochan, Hermann; Thiel, Klaus

1992-01-01

During KOSI (comet simulation) experiments, mineral-ice mixtures are observed in simulated space conditions. Emission of ice-/dust particles from the sample surface is observed by means of different devices. The particle trajectories are recorded with a video system. In the following analysis we extracted the parameters: particle count rate, spatial distribution of starting points on the sample surface, and elevation angle and particle velocity at distances up to 5 cm from the sample surface. Different kinds of detectors are mounted on a frame in front of the sample to register the emitted particles and to collect their dust residues. By means of these instruments the particle count rates, the particle sizes and the composition of the particles can be correlated. The results are related to the gas flux density and the temperature on the sample surface during the insolation period. The particle emission is interpreted in terms of phenomena on the sample surface, e.g., formation of a dust mantle.

Laboratory polarization and permittivity measurements to interpret dust polarimetric observations and in-situ radar studies. Significance for Rosetta mission at 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Levasseur-Regourd, Anny-Chantal; Brouet, Yann; Hadamcik, Edith; Heggy, Essam; Hines, Dean; Lasue, Jérémie; Renard, Jean-Baptiste

2015-08-01

Polarimetric astronomical observations on dust clouds and regolithic surfaces require laboratory simulations on samples to provide information on properties (size distribution, porosity, refractive index) of the scattering media. Similarly, in-situ radar investigations in the solar system require laboratory studies on samples to infer physical properties (e.g. porosity, ice/dust ratio) of sub-surfaces and interiors. Recent developments are illustrated with present studies related to the Rosetta mission, which begun its rendezvous with comet 67P/Churyumov-Gerasimeko (C-G) and landed the Philae module on its nucleus in 2014.We will summarize laboratory simulations with the PROGRA2 suite of instruments that study (in the visible to near IR domain) the polarimetric properties of dust samples in microgravity conditions or on surfaces [1], with emphasis on the interpretation of polarimetric observations of C-G, during its previous perihelion passages from Earth observatories, and currently from HST [2,3]. The presence of large dust particles in the pre-perihelion coma previously inferred from remote observations agrees with Rosetta ground truth [4]. We will also present measurements on the permittivity (in the millimeter to meter domain) of various dust samples, with emphasis on porous samples [5,6]. Results provide constraints on the properties of the subsurface and interior of C-G, as explored by MIRO on Rosetta and CONSERT on Philae.Such studies are relevant for the interpretation of polarimetric observations of other dust clouds (e.g. debris disks, interplanetary dust cloud, clouds in planetary atmospheres) and surfaces (e.g. planets, moons), as well as for those of other radar characterization studies (e.g. Mars, moons, asteroids).[1] Levasseur-Regourd et al. In Polarization of stars and planetary systems, Cambridge UP, in press 2015.[2] Hadamcik et al. A&A 517 2010.[3] Hines and Levasseur-Regourd, PSS submitted 2015.[4] Schulz et al. Nature 518 2015.[5] Heggy et al. 2012, Icarus 221 2012.[6] Brouet et al. A&A submitted 2015.

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.

Molds and mycotoxins in indoor environments--a survey in water-damaged buildings.

PubMed

Bloom, Erica; Nyman, Eva; Must, Aime; Pehrson, Christina; Larsson, Lennart

2009-11-01

Mycotoxins are toxic, secondary metabolites frequently produced by molds in water-damaged indoor environments. We studied the prevalence of selected, potent mycotoxins and levels of fungal biomass in samples collected from water-damaged indoor environments in Sweden during a 1-year period. One hundred samples of building materials, 18 samples of settled dust, and 37 samples of cultured dust were analyzed for: (a) mycoflora by microscopy and culture; (b) fungal chemical marker ergosterol and hydrolysis products of macrocyclic trichothecenes and trichodermin (verrucarol and trichodermol) by gas chromatography-tandem mass spectrometry; and (c) sterigmatocystin, gliotoxin, aflatoxin B(1), and satratoxin G and H by high performance liquid chromatography-tandem mass spectrometry. Sixty-six percent of the analyzed building materials samples, 11% of the settled dust samples, and 51% of the cultured dust samples were positive for at least one of the studied mycotoxins. In addition, except in the case of gliotoxin, mycotoxin-positive building material samples contained 2-6 times more ergosterol than mycotoxin-negative samples. We show that (a) molds growing on a range of different materials indoors in water-damaged buildings generally produce mycotoxins, and (b) mycotoxin-containing particles in mold-contaminated environments may settle on surfaces above floor level. The mass spectrometry methods used in this study are valuable tools in further research to survey mycotoxin exposure and investigate potential links with health effects.

The Vertical Dust Profile Over Gale Crater, Mars

NASA Astrophysics Data System (ADS)

Guzewich, Scott D.; Newman, C. E.; Smith, M. D.; Moores, J. E.; Smith, C. L.; Moore, C.; Richardson, M. I.; Kass, D.; Kleinböhl, A.; Mischna, M.; Martín-Torres, F. J.; Zorzano-Mier, M.-P.; Battalio, M.

2017-12-01

We create a vertically coarse, but complete, profile of dust mixing ratio from the surface to the upper atmosphere over Gale Crater, Mars, using the frequent joint atmospheric observations of the orbiting Mars Climate Sounder (MCS) and the Mars Science Laboratory Curiosity rover. Using these data and an estimate of planetary boundary layer (PBL) depth from the MarsWRF general circulation model, we divide the vertical column into three regions. The first region is the Gale Crater PBL, the second is the MCS-sampled region, and the third is between these first two. We solve for a well-mixed dust mixing ratio within this third (middle) layer of atmosphere to complete the profile. We identify a unique seasonal cycle of dust within each atmospheric layer. Within the Gale PBL, dust mixing ratio maximizes near southern hemisphere summer solstice (Ls = 270°) and minimizes near winter solstice (Ls = 90-100°) with a smooth sinusoidal transition between them. However, the layer above Gale Crater and below the MCS-sampled region more closely follows the global opacity cycle and has a maximum in opacity near Ls = 240° and exhibits a local minimum (associated with the "solsticial pause" in dust storm activity) near Ls = 270°. With knowledge of the complete vertical dust profile, we can also assess the frequency of high-altitude dust layers over Gale. We determine that 36% of MCS profiles near Gale Crater contain an "absolute" high-altitude dust layer wherein the dust mixing ratio is the maximum in the entire vertical column.

Ice nucleation activity of agricultural soil dust aerosols from Mongolia, Argentina, and Germany

NASA Astrophysics Data System (ADS)

Steinke, I.; Funk, R.; Busse, J.; Iturri, A.; Kirchen, S.; Leue, M.; Möhler, O.; Schwartz, T.; Schnaiter, M.; Sierau, B.; Toprak, E.; Ullrich, R.; Ulrich, A.; Hoose, C.; Leisner, T.

2016-11-01

Soil dust particles emitted from agricultural areas contain considerable mass fractions of organic material. Also, soil dust particles may act as carriers for potentially ice-active biological particles. In this work, we present ice nucleation experiments conducted in the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) cloud chamber. We investigated the ice nucleation efficiency of four types of soil dust from different regions of the world. The results are expressed as ice nucleation active surface site (INAS) densities and presented for the immersion freezing and the deposition nucleation mode. For immersion freezing occurring at 254 K, samples from Argentina, China, and Germany show ice nucleation efficiencies which are by a factor of 10 higher than desert dusts. On average, the difference in ice nucleation efficiencies between agricultural and desert dusts becomes significantly smaller at temperatures below 247 K. In the deposition mode the soil dusts showed higher ice nucleation activity than Arizona Test Dust over a temperature range between 232 and 248 K and humidities RHice up to 125%. INAS densities varied between 109 and 1011 m-2 for these thermodynamic conditions. For one soil dust sample (Argentinian Soil), the effect of treatments with heat was investigated. Heat treatments (383 K) did not affect the ice nucleation efficiency observed at 249 K. This finding presumably excludes proteinaceous ice-nucleating entities as the only source of the increased ice nucleation efficiency.

MicroMED: a dust particle counter for the characterization of airborne dust close to the surface of Mars

NASA Astrophysics Data System (ADS)

Cozzolino, Fabio; Esposito, Francesca; Molfese, Cesare; Cortecchia, Fausto; Saggin, Bortolino; D'amato, Francesco

2015-04-01

Monitoring of airborne dust is very important in planetary climatology. Indeed, dust absorbs and scatter solar and thermal radiation, severely affecting atmospheric thermal structure, balance and dynamics (in terms of circulations). Wind-driven blowing of sand and dust is also responsible for shaping planetary surfaces through the formation of sand dunes and ripples, the erosion of rocks, and the creation and transport of soil particles. Dust is permanently present in the atmosphere of Mars and its amount varies with seasons. During regional or global dust storms, more than 80% of the incoming sunlight is absorbed by dust causing an intense atmospheric heating. Airborne dust is therefore a crucial climate component on Mars which impacts atmospheric circulations at all scales. Main dust parameters influencing the atmosphere heating are size distribution, abundance, albedo, single scattering phase function, imaginary part of the index of refraction. Moreover, major improvements of Mars climate models require, in addition to the standard meteorological parameters, quantitative information about dust lifting, transport and removal mechanisms. In this context, two major quantities need to be measured for the dust source to be understood: surface flux and granulometry. While many observations have constrained the size distribution of the dust haze seen from the orbit, it is still not known what the primary airborne dust (e.g. the recently lifted dust) is made of, size-wise. MicroMED has been designed to fill this gap. It will measure the abundance and size distribution of dust, not in the atmospheric column, but close to the surface, where dust is lifted, so to be able to monitor dust injection into the atmosphere. This has never been performed in Mars and other planets exploration. MicroMED is an Optical Particle Counter, analyzing light scattered from single dust particles to measure their size and abundance. A proper fluid-dynamic system, including a pump and a sampling head, allows the sampling of Martian atmosphere with embedded dust. The captured dust grains are detected by an Optical System and then ejected into the atmosphere. MicroMED is a miniaturization of the instrument MEDUSA, developed for the Humboldt payload of the ExoMars mission. An Elegant Breadboard has been developed and tested and successfully demonstrates the instrument performances. The design and performance test results will be discussed.

Health risk assessment of the workers exposed to the heavy metals in e-waste recycling sites of Chandigarh and Ludhiana, Punjab, India.

PubMed

Singh, Manmohit; Thind, Parteek Singh; John, Siby

2018-07-01

Investigations were made to analyze the effects of heavy metals on the adults and children working in informal e-waste recycling sectors of Chandigarh and Ludhiana, Punjab, India. Soil samples of the ground where recycling was being done, dust from the platform where recycling activities were done and dermal samples of workers were collected to estimate the presence of heavy metals (As, Cu, Co, Cd, Cr, Ni, Fe, Zn, Pb, Ba) in them. High concentration of Ba, Cu, Pb and Zn was observed in the soil and dust samples. Cr, Pb and Zn were observed in high concentrations in dermal samples. These heavy metals could cause serious health effects. Therefore, human health risk assessment was also done using carcinogenic (cancer risk potency factor) and non-carcinogenic (health hazard index) health risk assessment. Carcinogenic hazards were not reported in children however, hazard index, for soil and dust contamination for some heavy metals, was found significant (Soil samples: As = 1.69, Cr = 1.38, Cu = 4.5 and Pb = 5.82 and dust samples: Pb = 2.97). Carcinogenic hazards were reported in adults from Cr contamination in soil samples (3.4E-03). Copyright © 2018 Elsevier Ltd. All rights reserved.

30 CFR 90.220 - Status change reports.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH... Procedures § 90.201 Sampling; general and technical requirements. (a) An approved coal mine dust personal sampler unit (CMDPSU) shall be used to take samples of the concentration of respirable coal mine dust in...

PESTICIDES IN DUST SAMPLES FROM HOMES AND SCHOOLS IN YUMA, ARIZONA

EPA Science Inventory

A pilot study was conducted in Yuma, Arizona to investigate children's exposure to pesticides as detected in urine and dust samples. The principle hypothesis of the study is that pesticide levels in young children vary with the distance children live or attend school from agric...

KSC-98pc1082

NASA Image and Video Library

1998-09-14

Technicians carefully maneuver the Mars Climate Orbiter toward its workstand in the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2). The Mars Climate Orbiter is heading for Mars where it will primarily support its companion Mars Polar Lander spacecraft, planned for launch on Jan. 3, 1999. After that, the Mars Climate Orbiter's instruments will monitor the Martian atmosphere and image the planet's surface on a daily basis for one Martian year (two Earth years). It will observe the appearance and movement of atmospheric dust and water vapor, as well as characterize seasonal changes on the surface. The detailed images of the surface features will provide important clues to the planet's early climate history and give scientists more information about possible liquid water reserves beneath the surface. The scheduled launch date for the Mars Climate Orbiter is Dec. 10, 1998, on a Boeing Delta II 7425 rocket

KSC-98pc1083

NASA Image and Video Library

1998-09-14

Technicians lower the Mars Climate Orbiter onto its workstand in the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2). The Mars Climate Orbiter is heading for Mars where it will primarily support its companion Mars Polar Lander spacecraft, planned for launch on Jan. 3, 1999. After that, the Mars Climate Orbiter's instruments will monitor the Martian atmosphere and image the planet's surface on a daily basis for one Martian year (two Earth years). It will observe the appearance and movement of atmospheric dust and water vapor, as well as characterize seasonal changes on the surface. The detailed images of the surface features will provide important clues to the planet's early climate history and give scientists more information about possible liquid water reserves beneath the surface. The scheduled launch date for the Mars Climate Orbiter is Dec. 10, 1998, on a Boeing Delta II 7425 rocket

KSC-98pc1351

NASA Image and Video Library

1998-10-16

KENNEDY SPACE CENTER, FLA. -- In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), a technician works on the Mars Climate Orbiter which is scheduled to launch on Dec. 10, 1998, aboard a Boeing Delta II rocket. The Mars Climate Orbiter is heading for Mars where it will primarily support its companion Mars Polar Lander spacecraft, planned for launch on Jan. 3, 1999. After that, the Mars Climate Orbiter's instruments will monitor the Martian atmosphere and image the planet's surface on a daily basis for one Martian year (two Earth years). It will observe the appearance and movement of atmospheric dust and water vapor, as well as characterize seasonal changes on the surface. The detailed images of the surface features will provide important clues to the planet's early climate history and give scientists more information about possible liquid water reserves beneath the surface

A survey on blood group determination

NASA Astrophysics Data System (ADS)

Radhika, K.; Sowjanya, S. J.; Ramya, T.

2018-04-01

Detection of blood group is an essential factor in critical conditions before performing blood transfer. At presently tests are conducted by lab technicians manually in the laboratory. When the test is done by technicians with large samples it becomes monotonous to do and sometimes it leads to incorrect results and even its time consuming to get the result. The research survey proposal is to reduce the physical work to identify the blood group with a paper-based device. The paper is having a long thermometer with two ends. By using this we can detect the blood type by changing the color of the paper. Chemical reactions between dye, Bromo creosol green, and blood serum proteins, were performed to test the blood sample. The paper becomes teal or brown color, depending on whether the association of antibodies and antigens are present. It gives the result within 30 seconds, which is quicker than traditional detection system. The tested blood sample had a good accuracy rate.

Applicability of the environmental relative moldiness index for quantification of residential mold contamination in an air pollution health effects study.

PubMed

Kamal, Ali; Burke, Janet; Vesper, Stephen; Batterman, Stuart; Vette, Alan; Godwin, Christopher; Chavez-Camarena, Marina; Norris, Gary

2014-01-01

The Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS) investigated the impact of exposure to traffic-related air pollution on the respiratory health of asthmatic children in Detroit, Michigan. Since indoor mold exposure may also contribute to asthma, floor dust samples were collected in participants homes (n = 112) to assess mold contamination using the Environmental Relative Moldiness Index (ERMI). The repeatability of the ERMI over time, as well as ERMI differences between rooms and dust collection methods, was evaluated for insights into the application of the ERMI metric. ERMI values for the standard settled floor dust samples had a mean ± standard deviation of 14.5 ± 7.9, indicating high levels of mold contamination. ERMI values for samples collected from the same home 1 to 7 months apart (n = 52) were consistent and without systematic bias. ERMI values for separate bedroom and living room samples were highly correlated (r = 0.69, n = 66). Vacuum bag dust ERMI values were lower than for floor dust but correlated (r = 0.58, n = 28). These results support the use of the ERMI to evaluate residential mold exposure as a confounder in air pollution health effects studies.

Exposure to phthalates in house dust and associated allergies in children aged 6-12years.

PubMed

Ait Bamai, Yu; Araki, Atsuko; Kawai, Toshio; Tsuboi, Tazuru; Saito, Ikue; Yoshioka, Eiji; Cong, Shi; Kishi, Reiko

2016-11-01

Phthalates are widely used as plasticizers in household products. Several studies have reported an association between phthalate exposure and an increased risk of allergies. The present study estimated phthalate exposure in children aged 6-12years and assessed potential correlations with allergies. House dust samples were collected from floors and multi-surface objects >35cm above the floor. Urine samples were collected from the first morning void of the day. Daily phthalate intake (DI dust and DI) was estimated using both house dust and urinary metabolite concentrations. Exposure to di-2-ethylhexyl phthalate (DEHP) in floor dust was associated with parental-reported rhino-conjunctivitis. After stratification by gender, this trend was found to only occur in boys. Furthermore, urinary mono-isobutyl phthalate was inversely associated with parental-reported wheeze in boys. DI dust of benzyl butyl phthalate (BBzP) and DEHP were significantly correlated with DI_BBzP and DI_DEHP, respectively. These correlations were stronger with floor than with multi-surface dust. Our results suggest that, among Japanese children, house dust from low surfaces, such as living room floors, might play a meaningful role in the indoor environmental exposure pathway for BBzP and DEHP. Copyright © 2016 Elsevier Ltd. All rights reserved.

Measurement of Circumstellar Disk Sizes in the Upper Scorpius OB Association with ALMA

NASA Astrophysics Data System (ADS)

Barenfeld, Scott A.; Carpenter, John M.; Sargent, Anneila I.; Isella, Andrea; Ricci, Luca

2017-12-01

We present detailed modeling of the spatial distributions of gas and dust in 57 circumstellar disks in the Upper Scorpius OB Association observed with ALMA at submillimeter wavelengths. We fit power-law models to the dust surface density and CO J = 3–2 surface brightness to measure the radial extent of dust and gas in these disks. We found that these disks are extremely compact: the 25 highest signal-to-noise disks have a median dust outer radius of 21 au, assuming an {R}-1 dust surface density profile. Our lack of CO detections in the majority of our sample is consistent with these small disk sizes assuming the dust and CO share the same spatial distribution. Of seven disks in our sample with well-constrained dust and CO radii, four appear to be more extended in CO, although this may simply be due to the higher optical depth of the CO. Comparison of the Upper Sco results with recent analyses of disks in Taurus, Ophiuchus, and Lupus suggests that the dust disks in Upper Sco may be approximately three times smaller in size than their younger counterparts, although we caution that a more uniform analysis of the data across all regions is needed. We discuss the implications of these results for disk evolution.

Portable automation of static chamber sample collection for quantifying soil gas flux

USDA-ARS?s Scientific Manuscript database

The collection of soil gas flux using the static chamber method is labor intensive. The number of chambers that can be sampled in a given time period is limited by the spacing between chambers and the availability of trained research technicians. However, the static chamber method can limit spatial ...

The evaluation and quantification of respirable coal and silica dust concentrations: a task-based approach.

PubMed

Grové, T; Van Dyk, T; Franken, A; Du Plessis, J

2014-01-01

Silicosis and coal worker's pneumoconiosis are serious occupational respiratory diseases associated with the coal mining industry and the inhalation of respirable dusts containing crystalline silica. The purpose of this study (funded by the Mine Health and Safety Council of South Africa) was to evaluate the individual contributions of underground coal mining tasks to the respirable dust and respirable silica dust concentrations in an underground section by sampling the respirable dust concentrations at the intake and return of each task. The identified tasks were continuous miner (CM) cutting, construction, transfer of coal, tipping, and roof bolting. The respirable dust-generating hierarchy of the tasks from highest to lowest was: transfer of coal > CM right cutting > CM left cutting > CM face cutting > construction > roof bolting > tipping; and for respirable silica dust: CM left cutting > construction > transfer of coal > CM right cutting. Personal exposure levels were determined by sampling the exposures of workers performing tasks in the section. Respirable dust concentrations and low concentrations of respirable silica dust were found at the intake air side of the section, indicating that air entering the section is already contaminated. The hierarchy for personal respirable dust exposures was as follows, from highest to lowest: CM operator > cable handler > miner > roof bolt operator > shuttle car operator, and for respirable silica dust: shuttle car operator > CM operator > cable handler > roof bolt operator > miner. Dust control methods to lower exposures should include revision of the position of workers with regard to the task performed, positioning of the tasks with regard to the CM cutting, and proper use of the line curtains to direct ventilation appropriately. The correct use of respiratory protection should also be encouraged.

KENNEDY SPACE CENTER, FLA. - After removing its cover, technicians look over the Minus Eighty Lab Freezer for ISS (MELFI), provided as Laboratory Support Equipment by the European Space Agency for the International Space Station. The lab will provide cooling and storage for reagents, samples and perishable materials in four insulated containers called dewars with independently selectable temperatures of -80°C, -26°C, and +4°C. It also will be used to transport samples to and from the station. The MELFI is planned for launch on the ULF-1 mission.

NASA Image and Video Library

2003-09-08

KENNEDY SPACE CENTER, FLA. - After removing its cover, technicians look over the Minus Eighty Lab Freezer for ISS (MELFI), provided as Laboratory Support Equipment by the European Space Agency for the International Space Station. The lab will provide cooling and storage for reagents, samples and perishable materials in four insulated containers called dewars with independently selectable temperatures of -80°C, -26°C, and +4°C. It also will be used to transport samples to and from the station. The MELFI is planned for launch on the ULF-1 mission.

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, technicians remove the cover from the Minus Eighty Lab Freezer for ISS(MELFI) provided as Laboratory Support Equipment by the European Space Agency for the International Space Station. The lab will provide cooling and storage for reagents, samples and perishable materials in four insulated containers called dewars with independently selectable temperatures of -80°C, -26°C, and +4°C. It also will be used to transport samples to and from the station. The MELFI is planned for launch on the ULF-1 mission.

NASA Image and Video Library

2003-09-08

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, technicians remove the cover from the Minus Eighty Lab Freezer for ISS(MELFI) provided as Laboratory Support Equipment by the European Space Agency for the International Space Station. The lab will provide cooling and storage for reagents, samples and perishable materials in four insulated containers called dewars with independently selectable temperatures of -80°C, -26°C, and +4°C. It also will be used to transport samples to and from the station. The MELFI is planned for launch on the ULF-1 mission.

Uneasiness among laboratory technicians.

PubMed

Arluke, A

1999-01-01

Four aspects of animal experimentation cause uneasiness among many animal laboratory technicians. First, if technicians form strong attachments to lab animals, they feel conflict between their nurturing and the experimental manipulations they perform. Most technicians learn to curtail these attachments. Second, the "sacrifice" of lab animals becomes routinized and stripped of special meaning for many technicians, making killing uncomfortably rote. Third, technicians sometimes encounter outsiders who are critical of animal experimentation and ridicule the technicians for doing this work. Most technicians avoid telling outsiders about their work or take an educational approach to deal with these awkward encounters. Finally, most technicians report some ethical uneasiness about certain types of experiments and their clinical value, as well as about the use of certain animals, and they feel they cannot turn to investigators or fellow technicians to pursue such issues.

Organic Matter in Cosmic Dust

PubMed Central

Sandford, Scott A.; Engrand, Cecile; Rotundi, Alessandra

2018-01-01

Organics are observed to be a significant component of cosmic dust in nearly all environments were dust is observed. In many cases only remote telescope observations of these materials are obtainable and our knowledge of the nature of these materials is very basic. However, it is possible to obtain actual samples of extraterrestrial dust in the Earth’s stratosphere, in Antarctic ice and snow, in near-Earth orbit, and via spacecraft missions to asteroids and comets. It is clear that cosmic dust contains a diverse population of organic materials that owe their origins to a variety of chemical processes occurring in many different environments. The presence of isotopic enrichments of D and 15N suggests that many of these organic materials have an interstellar/protosolar heritage. The study of these samples is of considerable importance since they are the best preserved materials of the early Solar System available. PMID:29422977

A New Laboratory For Terahertz Characterization Of Cosmic Analog Dusts

NASA Astrophysics Data System (ADS)

Perera, Thushara; Liu, Lunjun; Breyer, Fiona; Schonert, Ryan; O'Shea, Kyle; Roesner, Rebecca

2016-06-01

Most studies conducted with observatories such as ALMA, SOFIA, PLANCK, and Herschel will benefit from knowledge of (1) the predominant cosmic dust species in various environments and (2) the mm/sub-mm optical properties of cosmic dusts, including the temperature dependent-emissivity and spectral index. We have undertaken two efforts to enable the laboratory study of cosmic analogs dusts in the frequency range 60-2000 GHz. They are: (1) the construction of a novel compact Fourier Transform Spectrometer (FTS) design coupled to a dry 4-K cryostat which houses a cooled sample exchanger (filter wheel) and a bolometer. (2) The production of Mg- and Fe-rich silicate dusts using sol-gel methods; various tests to determine their physical and chemical properties; embedding of samples in LDPE pellets for insertion into the novel FTS. This presentation will focus on the current status of the apparatus and data from its first few months of use.

Biological effects of desert dust in respiratory epithelial cells and a murine model.

EPA Science Inventory

Abstract As a result of the challenge of recent dust storms to public health, we tested the postulate that desert dust collected in the southwestern United States could impact a biological effect in respiratory epithelial cells and an animal model. Two samples of surface sedime...

Elemental properties of copper slag and measured airborne exposures at a copper slag processing facility.

PubMed

Mugford, Christopher; Gibbs, Jenna L; Boylstein, Randy

2017-08-01

In 1974, the National Institute for Occupational Safety and Health recommended a ban on the use of abrasives containing >1% silica, giving rise to abrasive substitutes like copper slag. We present results from a National Institute for Occupational Safety and Health industrial hygiene survey at a copper slag processing facility that consisted of the collection of bulk samples for metals and silica; and full-shift area and personal air samples for dust, metals, and respirable silica. Carcinogens, suspect carcinogens, and other toxic elements were detected in all bulk samples, and area and personal air samples. Area air samples identified several areas with elevated levels of inhalable and respirable dust, and respirable silica: quality control check area (236 mg/m 3 inhalable; 10.3 mg/m 3 respirable; 0.430 mg/m 3 silica), inside the screen house (109 mg/m 3 inhalable; 13.8 mg/m 3 respirable; 0.686 mg/m 3 silica), under the conveyor belt leading to the screen house (19.8 mg/m 3 inhalable), and inside a conveyor access shack (11.4 mg/m 3 inhalable; 1.74 mg/m 3 respirable; 0.067 mg/m 3 silica). Overall, personal dust samples were lower than area dust samples and did not exceed published occupational exposure limits. Silica samples collected from a plant hand and a laborer exceeded the American Conference of Governmental Industrial Hygienist Threshold Limit Value of 0.025 µg/m 3 . All workers involved in copper slag processing (n = 5) approached or exceeded the Occupational Safety and Health Administration permissible exposure limit of 10 µg/m 3 for arsenic (range: 9.12-18.0 µg/m 3 ). Personal total dust levels were moderately correlated with personal arsenic levels (R s = 0.70) and personal respirable dust levels were strongly correlated with respirable silica levels (R s = 0.89). We identified multiple areas with elevated levels of dust, respirable silica, and metals that may have implications for personal exposure at other facilities if preventive measures are not taken. To our knowledge, this is the first attempt to characterize exposures associated with copper slag processing. More in-depth air monitoring and health surveillance is needed to understand occupational exposures and health outcomes in this industry.

Compact Microscope Imaging System with Intelligent Controls

NASA Technical Reports Server (NTRS)

McDowell, Mark

2004-01-01

The figure presents selected views of a compact microscope imaging system (CMIS) that includes a miniature video microscope, a Cartesian robot (a computer- controlled three-dimensional translation stage), and machine-vision and control subsystems. The CMIS was built from commercial off-the-shelf instrumentation, computer hardware and software, and custom machine-vision software. The machine-vision and control subsystems include adaptive neural networks that afford a measure of artificial intelligence. The CMIS can perform several automated tasks with accuracy and repeatability . tasks that, heretofore, have required the full attention of human technicians using relatively bulky conventional microscopes. In addition, the automation and control capabilities of the system inherently include a capability for remote control. Unlike human technicians, the CMIS is not at risk of becoming fatigued or distracted: theoretically, it can perform continuously at the level of the best human technicians. In its capabilities for remote control and for relieving human technicians of tedious routine tasks, the CMIS is expected to be especially useful in biomedical research, materials science, inspection of parts on industrial production lines, and space science. The CMIS can automatically focus on and scan a microscope sample, find areas of interest, record the resulting images, and analyze images from multiple samples simultaneously. Automatic focusing is an iterative process: The translation stage is used to move the microscope along its optical axis in a succession of coarse, medium, and fine steps. A fast Fourier transform (FFT) of the image is computed at each step, and the FFT is analyzed for its spatial-frequency content. The microscope position that results in the greatest dispersal of FFT content toward high spatial frequencies (indicating that the image shows the greatest amount of detail) is deemed to be the focal position.

Biomagnetic monitoring of heavy metals contamination in deposited atmospheric dust, a case study from Isfahan, Iran.

PubMed

Norouzi, Samira; Khademi, Hossein; Cano, Angel Faz; Acosta, Jose A

2016-05-15

Tree leaves are considered as one of the best biogenic dust collectors due to their ability to trap and retain particulate matter on their surfaces. In this study, the magnetic susceptibility (MS) and the concentration of selected heavy metals of plane tree (Platanus orientalis L.) leaves and deposited atmospheric dust, sampled by an indirect and a direct method, respectively, were determined to investigate the relationships between leaf magnetic parameters and the concentration of heavy metals in deposited atmospheric dust. The objective was to develop a biomagnetic method as an alternative to the common ones used for determining atmospheric heavy metal contaminations. Plane tree leaves were monthly sampled on the 19th of May to November, 2012 (T1-T7), for seven months from 21 different sites in the city of Isfahan, central Iran. Deposited atmospheric dust samples were also collected using flat glass surfaces from the same sites on the same dates, except for T1. MS (χlf, χhf) values in washed (WL) and unwashed leaves (UL) as well as Cu, Fe, Mn, Ni, Pb, and Zn concentrations in UL and deposited atmospheric dust samples were determined. The results showed that the MS content with a biogenic source was low with almost no significant change during the sampling period, while an increasing trend was observed in the MS content of UL samples due to the deposition of heavy metals and magnetic particles on leaf surfaces throughout the plant growth. The latter type of MS content could be reduced through washing off by rain. Most heavy metals examined, as well as the Tomlinson pollution load index (PLI) in UL, showed statistically significant correlations with MS values. The correlation between heavy metals content in atmospheric dust deposited on glass surfaces and leaf MS values was significant for Cu, Fe, Pb, and Zn. Moreover, the similarity observed between the spatial distribution maps of leaf MS and deposited atmospheric dust PLI provided convincing evidence regarding the suitability of the biomagnetic approach as a relatively rapid and inexpensive method for identifying highly polluted urban areas with selected heavy metals, especially those subjected to anthropogenic and other traffic related sources. Copyright © 2016 Elsevier Ltd. All rights reserved.

Technical note: Mineralogical, chemical, morphological, and optical interrelationships of mineral dust re-suspensions

NASA Astrophysics Data System (ADS)

Engelbrecht, Johann P.; Moosmüller, Hans; Pincock, Samuel; Jayanty, R. K. M.; Lersch, Traci; Casuccio, Gary

2016-08-01

This paper promotes an understanding of the mineralogical, chemical, and physical interrelationships of re-suspended mineral dusts collected as grab samples from global dust sources. Surface soils were collected from arid regions, including the southwestern USA, Mali, Chad, Morocco, Canary Islands, Cabo Verde, Djibouti, Afghanistan, Iraq, Kuwait, Qatar, UAE, Serbia, China, Namibia, Botswana, Australia, and Chile. The < 38 µm sieved fraction of each sample was re-suspended in a chamber, from which the airborne mineral dust could be extracted, sampled, and analyzed. Instruments integrated into the entrainment facility included two PM10 and two PM2.5 filter samplers, a beta attenuation gauge for the continuous measurement of PM10 and PM2.5 particulate mass fractions, an aerodynamic particle size analyzer, and a three-wavelength (405, 532, 781 nm) photoacoustic instrument with integrating reciprocal nephelometer for monitoring absorption and scattering coefficients during the dust re-suspension process. Filter sampling media included Teflon® membrane and quartz fiber filters for chemical analysis and Nuclepore® filters for individual particle analysis by scanning electron microscopy (SEM). The < 38 µm sieved fractions were also analyzed by X-ray diffraction for their mineral content while the > 75, < 125 µm soil fractions were mineralogically assessed by optical microscopy. Presented here are results of the optical measurements, showing the interdependency of single-scattering albedos (SSA) at three different wavelengths and mineralogical content of the entrained dust samples. To explain the elevated concentrations of iron (Fe) and Fe / Al ratios in the soil re-suspensions, we propose that dust particles are to a large extent composed of nano-sized particles of micas, clays, metal oxides, and ions of potassium (K+), calcium (Ca2+), and sodium (Na+) evenly dispersed as a colloid or adsorbed in amorphous clay-like material. Also shown are differences in SSA of the kaolinite/hematite/goethite samples from Mali and those from colloidal soils elsewhere. Results from this study can be integrated into a database of mineral dust properties, for applications in climate modeling, remote sensing, visibility, health (medical geology), ocean fertilization, and impact on equipment.

Can Transport of Saharan Dust Explain Extensive Clay Deposits in the Amazon Basin? A Test Using Radiogenic Isotopes

NASA Astrophysics Data System (ADS)

Andreae, M. O.; Abouchami, W.; Näthe, K.; Kumar, A.; Galer, S. J.; Jochum, K. P.; Williams, E.; Horbe, A. M.; Rosa, J. W.; Adams, D. K.; Balsam, W. R.

2012-12-01

The Bodélé Depression, located in the Southern Sahara, is a huge source of atmospheric dust and thus an important element in biogeochemical cycles and the radiative budget of Earth's atmosphere. Previous studies have shown that Saharan dust transport across the Atlantic acts as an important source of mineral nutrients to the Amazon rainforest. The Belterra Clay, which outcrops extensively across the Amazon Basin in Brazil, has been proposed to result from dry deposition of African dusts. We have investigated this hypothesis by measuring the radiogenic isotopic composition (Sr, Nd and Pb) of a suite of samples from the Belterra Clay, the Bodélé Depression, dusts deposits collected at various locations along the airmass transport trajectory, as well as loess from the Cape Verde Islands. Radiogenic isotope systems are powerful tracers of provenance and can be used to fingerprint dust sources and atmospheric transport patterns. Our results identify distinct isotopic signatures in the Belterra Clay samples and the African sources. The Belterra Clay display radiogenic Sr and Pb isotope ratios associated with non-radiogenic Nd isotope signatures. In contrast, Bodélé samples and dusts deposits show lower Pb isotope ratios, variable 87Sr/86Sr, and relatively homogeneous Nd isotopic compositions, albeit more radiogenic than those of the Belterra Clay. Our data show unambiguously that the Belterra Clay is not derived from African dust deposition, nor from the Andean chain, as originally suggested by W. Sombroek. Rather, isotopic compositions and Nd model ages are consistent with simple mixing of Archean and younger Proterozoic terranes within the Amazon Basin as a result of weathering and erosion under humid tropical conditions. Whether Saharan dusts contribute to the fertilization in the Amazon Basin cannot be ruled out, however, since the African dust isotopic signature is expected to be entirely overprinted by local sources. Radiogenic isotope data obtained on aerosol filters collected in the US Virgin Islands and Tobago are similar to those of aerosols from Mali, demonstrating that the African dust isotope signal is detectable and transported as far as Central and South America. Thus, while it appears undeniable that Saharan dust reaches the Amazon Basin, its importance for overall soil fertility requires a careful assessment of the dust budget versus bedrock weathering rates for key nutrient elements.

Organophosphorus flame retardants (PFRs) and phthalates in floor and road dust from a manual e-waste dismantling facility and adjacent communities in Thailand.

PubMed

Muenhor, Dudsadee; Moon, Hyo-Bang; Lee, Sunggyu; Goosey, Emma

2018-01-02

This study was undertaken to investigate levels of organophosphorus flame retardants (PFRs) and phthalates in floor and road dust from a manual e-waste dismantling facility and nearby communities in Thailand. Concentrations of Σ10 PFRs and Σ6 phthalates in floor dust from the facility were approximately 36-1,700 and 86,000-790,000 ng g -1 , whereas those from the communities were about 13-9,200 and 44,000-2,700,000 ng g -1 , respectively. The highest content of Σ10 PFRs (9,200 ng g -1 ) and Σ6 phthalates (2,700,000 ng g -1 ) in indoor dust was both detected in the dust sampled from a house with no prevailing winds located 350 m northeast of the facility. Levels of Σ10 PFRs and Σ6 phthalates in road dust from the facility were around 1,100-2,100 and 40,000-670,000 ng g -1 , while those from the residences were about 650-2,000 and 27,000-650,000 ng g -1 , respectively. Concentrations of Σ10 PFRs (2,100 ng g -1 ) and Σ6 phthalates (670,000 ng g -1 ) in road dust were greatest in the dust collected from the facility. For the distributional pattern, TBEP (tris (2-butoxyethyl) phosphate) was the main PFR in residential dust, whereas TPP (triphenyl phosphate) was the major PFR in facility dust. TBEP was also found to be the most prominent PFR in all road dust samples. Furthermore, DEHP (di-2-ethylhexyl phthalate) was the most abundant phthalate congener in both floor and road dust samples. Under realistic high-end scenarios of environmental exposure to DEHP, Thai toddlers (25.29 µg kg -1 bw day -1 ) in the adjacent communities were exposed above the US EPA's (United States Environmental Protection Agency) reference dose (RfD) for this congener (20 µg kg -1 bw day -1 ). Our data reveal that the PFR and phthalate-containing products at the residences are a likely substantial source of PFRs and phthalates to the surrounding indoor environment, and humans can be exposed to PFRs and phthalates in their dwellings via the settled floor dust.

Improved system for floor cleaning in health care facilities.

PubMed Central

Schmidt, E A; Coleman, D L; Mallison, G F

1984-01-01

A new system has been developed for sanitizing floors in hospitals; this system replaces the traditional procedure of daily dusting and wet mopping with a disinfectant-detergent solution and periodic buffing . This new system relies on a sequence of procedures consisting of dust mopping using a chemically treated dust mop, machine buffing of a sprayed-on polymer treatment, and a second dust mopping . The effectiveness of the procedures was evaluated by means of surface sampling for bacterial contamination and air sampling for airborne bacteria and dust. The level of bacterial contamination on the floors was reduced by 93.6% by using the new system, compared with 79.8% by using the conventional process of dust mopping and wet mopping with a disinfectant solution. The levels of airborne bacteria during and after the individual procedures did not vary significantly from the initial level (123.6 CFU/per m3 of air). A survey of representative colonies from air samples revealed staphylococci, gram-positive bacilli, gram-positive diplococci, yeast cells, and infrequent gram-negative rods. The distribution at the conclusion of the sanitizing process was similar to that at the outset. Similarly, the levels of airborne dust measured during and after the individual procedures did not vary significantly from the initial level. When compared with the traditional method of cleaning by wet mopping , the new method was significantly more effective in removal of microbial contamination and required less labor. PMID:6742835

Comparison of Gastric versus Gastrointestinal PBET Extractions for Estimating Oral Bioaccessibility of Metals in House Dust

PubMed Central

Boros, Kristina; Fortin, Danielle; Jayawardene, Innocent; Chénier, Marc; Levesque, Christine; Rasmussen, Pat E.

2017-01-01

Oral bioaccessibility estimates for six metals which are prevalent as contaminants in Canada (zinc, lead, cadmium, copper, nickel, and chromium) are investigated for house dust using the simple gastric phase versus the two-phase physiologically-based extraction technique (PBET). The purpose is to determine whether a complete gastrointestinal (GI) assay yields a more conservative (i.e., higher) estimate of metal bioaccessibility in house dust than the gastric phase alone (G-alone). The study samples include household vacuum dust collected from 33 homes in Montreal, Canada, plus four certified reference materials (NIST 2583, NIST 2584, NIST 2710 and NIST 2710a). Results indicate that percent bioaccessibilities obtained using G-alone are generally greater than or equivalent to those obtained using the complete GI simulation for the six studied metals in house dust. Median bioaccessibilities for G-alone/GI in household vacuum dust samples (n = 33) are 76.9%/19.5% for zinc, 50.4%/6.2% for lead, 70.0%/22.4% for cadmium, 33.9%/30.5% for copper and 28.5%/20.7% for nickel. Bioaccessible chromium is above the detection limit in only four out of 33 samples, for which G-alone results are not significantly different from GI results (p = 0.39). It is concluded that, for the six studied metals, a simple G-alone extraction provides a conservative and cost-effective approach for estimating oral bioaccessibility of metals in house dust. PMID:28106788

A New Method Using Single-Particle Mass Spectrometry Data to Distinguish Mineral Dust and Biological Aerosols

NASA Astrophysics Data System (ADS)

Al-Mashat, H.; Kristensen, L.; Sultana, C. M.; Prather, K. A.

2016-12-01

The ability to distinguish types of particles present within a cloud is important for determining accurate inputs to climate models. The chemical composition of particles within cloud liquid droplets and ice crystals can have a significant impact on the timing, location, and amount of precipitation that falls. Precipitation efficiency is increased by the presence of ice crystals in clouds, and both mineral dust and biological aerosols have been shown to be effective ice nucleating particles (INPs) in the atmosphere. A current challenge in aerosol science is distinguishing mineral dust and biological material in the analysis of real-time, ambient, single-particle mass spectral data. Single-particle mass spectrometers are capable of measuring the size-resolved chemical composition of individual atmospheric particles. However, there is no consistent analytical method for distinguishing dust and biological aerosols. Sampling and characterization of control samples (i.e. of known identity) of mineral dust and bacteria were performed by the Aerosol Time-of-Flight Mass Spectrometer (ATOFMS) as part of the Fifth Ice Nucleation (FIN01) Workshop at the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) facility in Karlsruhe, Germany. Using data collected by the ATOFMS of control samples, a new metric has been developed to classify single particles as dust or biological independent of spectral cluster analysis. This method, involving the use of a ratio of mass spectral peak areas for organic nitrogen and silicates, is easily reproducible and does not rely on extensive knowledge of particle chemistry or the ionization characteristics of mass spectrometers. This represents a step toward rapidly distinguishing particle types responsible for ice nucleation activity during real-time sampling in clouds. The ability to distinguish types of particles present within a cloud is important for determining accurate inputs to climate models. The chemical composition of particles within cloud liquid droplets and ice crystals can have a significant impact on the timing, location, and amount of precipitation that falls. Precipitation efficiency is increased by the presence of ice crystals in clouds, and both mineral dust and biological aerosols have been shown to be effective ice nucleating particles (INPs) in the atmosphere. A current challenge in aerosol science is distinguishing mineral dust and biological material in the analysis of real-time, ambient, single-particle mass spectral data. Single-particle mass spectrometers are capable of measuring the size-resolved chemical composition of individual atmospheric particles. However, there is no consistent analytical method for distinguishing dust and biological aerosols. Sampling and characterization of control samples (i.e. of known identity) of mineral dust and bacteria were performed by the Aerosol Time-of-Flight Mass Spectrometer (ATOFMS) as part of the Fifth Ice Nucleation (FIN01) Workshop at the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) facility in Karlsruhe, Germany. Using data collected by the ATOFMS of control samples, a new metric has been developed to classify single particles as dust or biological independent of spectral cluster analysis. This method, involving the use of a ratio of mass spectral peak areas for organic nitrogen and silicates, is easily reproducible and does not rely on extensive knowledge of particle chemistry or the ionization characteristics of mass spectrometers. This represents a step toward rapidly distinguishing particle types responsible for ice nucleation activity during real-time sampling in clouds.

Reactive organic species on natural dust

NASA Astrophysics Data System (ADS)

Batsaikhan, A.; Schoeler, H.; Williams, J.

2008-05-01

Annually 1000-3000 Tg mineral dust aerosol are emitted into the atmosphere, and transported over the oceans from one continent to the other. During the transport dust particles interact with components in the marine atmosphere and also with seawater as they fall into the ocean. Increased methyl iodide concentrations were observed during a field campaign on the Atlantic Ocean when dust storms occurred. Volatile halogenated organic compounds (VHOC) are photolyzed to produce reactive halogen species which are responsible for ozone depletion. An abiotic production mechanism for VHOC, involving humic-like substance (HULIS), iron and halide, was supposed to produce methyl iodide through the interaction of dust particles with seawater as all necessary ingredients were present. The main goal of this study was to test this hypothesis and to further elucidate the process. For this, simple dust-seawater addition experiments in headspace glasses were conducted in the laboratory, following a purge-and-trap GC-MS analysis of the headspace gas. Dust samples were collected in the source regions in southern Algeria and the Gobi Desert and, as representatives for aeolian dust, samples from Cape Verde Island and Lanzarote Island were used. To exclude the biological contribution, sterilized samples were also employed in this study. As assumed, methyl iodide was produced abiotically and the concentration increased tenfold after addition of Fe (III) within half an hour. Methylene chloride was also produced abiotically along with methyl iodide. In contrast to methyl iodide and methylene chloride, methyl chloride and isoprene were produced biologically, provided the production occurred after at least 24 hours of interaction of only non-sterilized samples with seawater. If the microorganisms responsible for the production of isoprene are common soil organisms found everywhere in the world, this process can be the reason for a hitherto not fully explained increase in atmospheric isoprene concentration during wet seasons, especially when the rain falls practically everyday. The results of this study show the importance of natural dust aerosols for the production and emission of volatile organic compounds to the atmosphere and open interesting questions for further studies.

CV-Dust: Atmospheric aerosol in the Cape Verde region: carbon and soluble fractions of PM10

NASA Astrophysics Data System (ADS)

Pio, C.; Nunes, T.; Cardoso, J.; Caseiro, A.; Custódio, D.; Cerqueira, M.; Patoilo, D.; Almeida, S. M.; Freitas, M. C.

2012-04-01

Every year, billions of tons of eroded mineral soils from the Saharan Desert and the Sahel region, the largest dust source in the world, cross Mediterranean towards Europe, western Asia and the tropical North Atlantic Ocean as far as the Caribbean and South America. Many aspects of the direct and indirect effects of dust on climate are not well understood and the bulk and surface chemistry of the mineral dust particles determines interactions with gaseous and other particle species. The quantification of the magnitude of warming or cooling remains open because of the strong variability of the atmospheric dust burden and the lack of representative data for the spatial and temporal distribution of the dust composition. CV-Dust is a project that aims at provide a detailed data on the size distribution and the size-resolved chemical and mineralogical composition of dust emitted from North Africa using a natural laboratory like Cape Verde. This archipelago is located in an area of massive dust transport from land to ocean, and is thus ideal to set up sampling devices that are able to characterize and quantify dust transported from Africa. Moreover, Cape Verde's future economic prospects depend heavily on the encouragement of tourism, therefore it is essential to elucidate the role of Saharan dust may play in the degradation of Cape Verde air quality. The main objectives of CV-Dust project are: 1) to characterize the chemical and mineralogical composition of dust transported from Africa by setting up an orchestra of aerosol sampling devices in the strategic archipelago of Cape Verde; 2) to identify the sources of particles in Cape Verde by using receptor models; 3) to elucidate the role Saharan dust may play in the degradation of Cape Verde air quality; 4) to model processes governing dust production, transport, interaction with the radiation field and removal from the atmosphere. Here we present part of the data obtained throughout the last year, involving a set of more than 100 PM10 samples, addressing mainly their mass concentrations and the chemical composition of water soluble ions and carbon species (carbonates and organic and elemental carbon). Different PM10 samplers worked simultaneously in order to collect enough mass to make the aerosol characterization through the different methodologies and to collect aerosols in different filter matrixes, which have to be appropriated to the chemical and mineralogical analysis. The sampling site was located at Santiago Island, in the surroundings of Praia City (14° 55' N e 23° 29' W, 98 m at sea level). High concentrations, up to more than 400 μg m-3, are connected to north-east and north-northeast winds, and it was identified several dust events characteristic of "bruma seca", whose duration is on average of two to four days. Backward trajectories analysis confirms that the high concentrations in Cape Verde are associated with air masses passing over the Sahara. During dust events the percentage of inorganic water soluble ions for the total PM10 mass concentration decreased significantly to values lower than 10% in comparison with remainder data that range around 45±10%. Acknowledgement: This work was funded by the Portuguese Science Foundation (FCT) through the project PTDD/AAC-CLI/100331/2008 and FCOMP-01-0124-FEDER-008646 (CV-Dust). J. Cardoso acknowledges the PhD grant SFRH-BD-6105-2009 from FCT.

Herschel-ATLAS: Dusty early-type galaxies

NASA Astrophysics Data System (ADS)

Rowlands, K.; Dunne, L.; Maddox, S.

2015-03-01

Early-type galaxies (ETGs) are thought to be devoid of dust and star-formation, having formed most of their stars at early epochs. We present the detection of the dustiest ETGs in a large-area blind submillimetre survey with Herschel (H-ATLAS, Eales et al. 2010), where the lack of pre-selection in other bands makes it the first unbiased survey for cold dust in ETGs. The parent sample of 1087 H-ATLAS galaxies in this study have a >= 5σ detection at 250μm, a reliable optical counterpart to the submillimetre source (Smith et al. 2011) and a spectroscopic redshift from the GAMA survey (Driver et al. 2011). Additionally, we construct a control sample of 1052 optically selected galaxies undetected at 250μm and matched in stellar mass to the H-ATLAS parent sample to eliminate selection effects. ETGs were selected from both samples via visual classifications using SDSS images. Further details can be found in Rowlands et al. (2012). Physical parameters are derived for each galaxy using the multiwavelength spectral energy distribution (SED) fitting code of da Cunha, Charlot and Elbaz (2008), Smith et al. 2012, using an energy balance argument. We investigate the differences between the dusty ETGs and the general ETG population, and find that the H-ATLAS ETGs are more than an order of magnitude dustier than the control ETGs. The mean dust mass of the 42 H-ATLAS ETGs is 5.5 × 107M⊙ (comparable to the dust mass of spirals in our sample), whereas the dust mass of the 233 control ETGs inferred from stacking at optical positions on the 250μm map is (0.8 - 4.0) × 106M⊙ for 25-15 K dust. The average star-formation rate of the H-ATLAS ETGs is 1.0 dex higher than that of control ETGs, and the mean r-band light-weighted age of the H-ATLAS ETGs is 1.8 Gyr younger than the control ETGs. The rest-frame NUV - r colours of the H-ATLAS ETGs are 1.0 magnitudes bluer than the control ETGs, and some ETGs may be transitioning from the blue cloud to the red sequence. Some H-ATLAS ETGs show signs of morphological disturbance and may have undergone recent rejuvenation of their ISM via gas and dust delivered by mergers. It is found that late-type stars cannot produce enough dust to account for that observed in the H-ATLAS ETGs. This indicates that either an external source of dust from mergers is required, a substantial amount of dust grain growth must occur in the ISM, or dust destruction by hot X-ray gas is less efficient than predicted.

Repeated measurements of mite and pet allergen levels in house dust over a time period of 8 years.

PubMed

Antens, C J M; Oldenwening, M; Wolse, A; Gehring, U; Smit, H A; Aalberse, R C; Kerkhof, M; Gerritsen, J; de Jongste, J C; Brunekreef, B

2006-12-01

Studies of the association between indoor allergen exposure and the development of allergic diseases have often measured allergen exposure at one point in time. We investigated the variability of house dust mite (Der p 1, Der f 1) and cat (Fel d 1) allergen in Dutch homes over a period of 8 years. Data were obtained in the Dutch PIAMA birth cohort study. Dust from the child's mattress, the parents' mattress and the living room floor was collected at four points in time, when the child was 3 months, 4, 6 and 8 years old. Dust samples were analysed for Der p 1, Der f 1 and Fel d 1 by sandwich enzyme immuno assay. Mite allergen concentrations for the child's mattress, the parents' mattress and the living room floor were moderately correlated between time-points. Agreement was better for cat allergen. For Der p 1 and Der f 1 on the child's mattress, the within-home variance was close to or smaller than the between-home variance in most cases. For Fel d 1, the within-home variance was almost always smaller than the between-home variance. Results were similar for allergen levels expressed per gram of dust and allergen levels expressed per square metre of the sampled surface. Variance ratios were smaller when samples were taken at shorter time intervals than at longer time intervals. Over a period of 4 years, mite and cat allergens measured in house dust are sufficiently stable to use single measurements with confidence in epidemiological studies. The within-home variance was larger when samples were taken 8 years apart so that over such long periods, repetition of sampling is recommended.

Organophosphate flame retardants in household dust before and after introduction of new furniture.

PubMed

Keimowitz, A R; Strunsky, N; Wovkulich, K

2016-04-01

Flame retardant compounds originating from household items collect in household dust, a reasonable proxy for human exposure. Contributions of specific items or behaviors to dust are difficult to separate. This study examined standardized college housing before and after the introduction of new, flame retardant couches in order to explore any effect that changing upholstered furniture may have on flame retardant concentrations in dust. Two contradictory hypotheses were posited: (1) that new furniture might increase flame retardant releases immediately after introduction due to initial off-gassing of new materials or (2) that older furniture would release more flame retardants due to mechanical breakdown of polyurethane foam. This study was designed to determine which of these processes dominated. Prior to the introduction of new furniture, TDCIPP was detected in 12/20 samples at a median concentration of 22 μg/g and TCEP was detected in 1/20 samples at a concentration of 16 μg/g. TDCIPP and TCEP were not detected in any samples (N = 29) after the introduction of new couches. TPHP was detected both before (in 11/20 samples) and after (in 5/29 samples) introduction of new couches; the median concentrations before and after were 63 ± 49 and 16 ± 11 μg/g (standard deviation shown). Introduced couches contained TDCIPP (and not TPHP) at ∼1.25% (w/w). These data support the second hypothesis and indicate that removal of older furniture decreases TDCIPP and TCEP concentrations in dust and may potentially reduce total flame retardant concentrations in dust, at least immediately after introduction of the new furniture. Copyright © 2016 Elsevier Ltd. All rights reserved.

Seasonal radiogenic isotopic variability of the African dust outflow to the tropical Atlantic Ocean and across to the Caribbean

NASA Astrophysics Data System (ADS)

Kumar, Ashwini; Abouchami, W.; Galer, S. J. G.; Singh, Satinder Pal; Fomba, K. W.; Prospero, J. M.; Andreae, M. O.

2018-04-01

In order to assess the impact of mineral dust on climate and biogeochemistry, it is paramount to identify the sources of dust emission. In this regard, radiogenic isotopes have recently been used successfully for tracing North African dust provenance and its transport across the tropical Atlantic to the Caribbean. Here we present two time series of radiogenic isotopes (Pb, Sr and Nd) in dusts collected at the Cape Verde Islands and Barbados in order to determine the origin of the dust and examine the seasonality of westerly dust outflow from Northern Africa. Aerosol samples were collected daily during two campaigns - February 2012 (winter) and June-July 2013 (summer) - at the Cape Verde Atmospheric Observatory (CVAO) on the island of São Vicente (16.9°N, 24.9°W). A one-year-long time series of aerosols from Barbados (13.16°N, 59.43°W) - a receptor region in the Caribbean - was sampled at a lower, monthly resolution. Our results resolve a seasonal isotopic signal at Cape Verde shown by daily variations, with a larger radiogenic isotope variability in winter compared to that in summer. This summer signature is also observed over Barbados, indicating similar dust provenance at both locations, despite different sampling years. This constrains the isotope fingerprint of Saharan Air Layer (SAL) dust that is well-mixed during its transport. This result provides unequivocal evidence for a permanent, albeit of variable strength, long-range transport of African dust to the Caribbean and is in full agreement with atmospheric models of North African dust emission and transport across the tropical Atlantic in the SAL. The seasonal isotopic variability is related to changes in the dust source areas - mainly the Sahara and Sahel regions - that are active all-year-round, albeit with variable contributions in summer versus the winter months. Our results provide little support for much dust contributed from the Bodélé Depression in Chad - the "dustiest" place on Earth - reaching Cape Verde and Barbados during the summer, while contributions during the winter months are likely patchy and minor at most. Importantly, a short-term isotopic excursion is resolved in the Cape Verde winter record during a dust outbreak on 06-08 February 2012. This features a highly radiogenic Pb and Sr and unradiogenic Nd signature, marking a clear shift in dust provenance relative to that of normal days. As the dust storm waned, continuous gradual changes are observed, reflecting mixing and progressive dilution with dust typical of normal days. These inferences from radiogenic isotope tracers are corroborated by both satellite images (CALIPSO and MODIS) and back-trajectory analyses. The radiogenic isotope fingerprinting of these presently-active North African dust sources, and especially the Saharan Air Layer, will prove invaluable in studies of past dust emission from Northern Africa, where imagery and back trajectory analysis are unavailable.

Aeolian removal of dust from radiator surfaces on Mars

NASA Technical Reports Server (NTRS)

Gaier, James R.; Perez-Davis, Marla E.; Rutledge, Sharon K.; Hotes, Deborah

1990-01-01

Simulated radiator surfaces made of arc-textured Cu and Nb-1 percent-Zr and ion beam textured graphite and C-C composite were fabricated and their integrated spectral emittance characterized from 300 to 3000 K. A thin layer of aluminum oxide, basalt, or iron (III) oxide dust was then deposited on them, and they were subjected to low pressure winds in the Martian Surface Wind Tunnel. It was found that dust deposited on simulated radiator surfaces may or may not seriously lower their integrated spectral emittance, depending upon the characteristics of the dust. With Al2O3 there is no appreciable degradation of emittance on a dusted sample, with basaltic dust there is a 10 to 20 percent degradation, and with Fe2O3 a 20 to 40 percent degradation. It was also found that very high winds on dusted highly textured surfaces can result in their abrasion. Degradation in emittance due to abrasion was found to vary with radiator material. Arc-textured Cu and Nb-1 percent Zr was found to be more susceptible to emittance degradation than graphite or C-C composite. The most abrasion occurred at low angles, peaking at the 22.5 deg test samples.

Modeling Respiratory Toxicity of Authentic Lunar Dust

NASA Technical Reports Server (NTRS)

Santana, Patricia A.; James, John T.; Lam, Chiu-Wing

2010-01-01

The lunar expeditions of the Apollo operations from the 60 s and early 70 s have generated awareness about lunar dust exposures and their implication towards future lunar explorations. Critical analyses on the reports from the Apollo crew members suggest that lunar dust is a mild respiratory and ocular irritant. Currently, NASA s space toxicology group is functioning with the Lunar Airborne Dust Toxicity Assessment Group (LADTAG) and the National Institute for Occupational Safety and Health (NIOSH) to investigate and examine toxic effects to the respiratory system of rats in order to establish permissible exposure levels (PELs) for human exposure to lunar dust. In collaboration with the space toxicology group, LADTAG and NIOSH the goal of the present research is to analyze dose-response curves from rat exposures seven and twenty-eight days after intrapharyngeal instillations, and model the response using BenchMark Dose Software (BMDS) from the Environmental Protection Agency (EPA). Via this analysis, the relative toxicities of three types of Apollo 14 lunar dust samples and two control dust samples, titanium dioxide (TiO2) and quartz will be determined. This will be executed for several toxicity endpoints such as cell counts and biochemical markers in bronchoaveolar lavage fluid (BALF) harvested from the rats.

Field Measurements and Modeling of Dust Transport and Deposition on a Hawaiian Volcano

NASA Astrophysics Data System (ADS)

Douglas, M.; Stock, J. D.; Cerovski-Darriau, C.; Bishaw, K.; Bedford, D.

2017-12-01

The western slopes of Hawaii's Mauna Kea volcano are mantled by fine-grained soils that record volcanic airfall and eolian deposition. Where exposed, strong winds transport this sediment across west Hawaii, affecting tourism and local communities by decreasing air and water quality. Operations on US Army's Ke'amuku Maneuver Area (KMA) have the potential to increase dust flux from these deposits. To understand regional dust transport and composition, the USGS established 18 ground monitoring sites and sampling locations surrounding KMA. For over three years, each station measured vertical and horizontal dust flux while co-located anemometers measured wind speed and direction. We use these datasets to develop a model for dust supply and transport to assess whether KMA is a net dust sink or source. We find that horizontal dust flux rates are most highly correlated with entrainment threshold wind speeds of 8 m/s. Using a dust model that partitions measured horizontal dust flux into inward- and outward-directed components, we predict that KMA is currently a net dust sink. Geochemical analysis of dust samples illustrates that organics and pedogenic carbonate make up to 70% of their mass. Measured vertical dust deposition rates of 0.005 mm/m2/yr are similar to deposition rates of 0.004 mm/m2/yr predicted from the divergence of dust across KMA's boundary. These rates are low compared to pre-historic rates of 0.2-0.3 mm/yr estimated from radiocarbon dating of buried soils. Therefore, KMA's soils record persistent deposition both over past millennia and at present at rates that imply infrequent, large dust storms. Such events led to soil-mantled topography in an otherwise rocky Pleistocene volcanic landscape. A substantial portion of fine-grained soils in other leeward Hawaiian Island landscapes may have formed from similar eolian deposition, and not direct weathering of parent rock.

Brominated and phosphate flame retardants (FRs) in indoor dust from different microenvironments: Implications for human exposure via dust ingestion and dermal contact.

PubMed

Zheng, Xiaobo; Qiao, Lin; Covaci, Adrian; Sun, Runxia; Guo, Huiying; Zheng, Jing; Luo, Xiaojun; Xie, Qilai; Mai, Bixian

2017-10-01

Indoor dust has been widely used to monitor flame retardants (FRs) in indoor environment, but most studies only focused on floor dust. In the present study, FRs were examined in indoor dust from different locations. Dust from air conditioner (AC) filters, beddings, floor, and windows in bedrooms, and dust from AC filters, printer table surface, computer table surface, floor, and windows in offices were collected, respectively. Polybrominated diphenyl ether congener 209 (BDE 209) and decabromodiphenyl ethane (DBDPE) were the most abundant brominated flame retardants (BFRs), and tris(chloroisopropyl) phosphate (TCIPP), tris(1,3-dichloroisopropyl) phosphate (TDCIPP), and triphenyl phosphate (TPHP) were the most abundant phosphate flame retardants (PFRs). In bedrooms, the AC filter dust had the highest median levels of BDE 209 (536 ng/g) and DBDPE (2720 ng/g), while bed dust had the highest median levels of ΣPFRs (2750 ng/g) among dust samples. In offices, printer table dust had higher median levels of BDE 209 (1330 ng/g), DBDPE (8470 ng/g), and ΣPFRs (11,000 ng/g) than those in other dust samples. The high dust ingestion values of BDE 209, DBDPE, and individual PFR were 0.28, 1.20, and <0.01-0.32 ng/kg bw/day and 7.37, 31.2, and <0.01-4.54 ng/kg bw/day for BDE 209, DBDPE, and individual PFR for adults and toddlers, respectively. The high dermal exposure values of individual PFR during sleeping were <0.01-0.23 and <0.01-0.36 ng/kg bw/day for adults and toddlers, respectively. More human exposure pathways other than dust ingestion should be considered, such as the dermal contact with beddings and furniture. Copyright © 2017 Elsevier Ltd. All rights reserved.

Direct Measurement of Dust Attenuation in z approx. 1.5 Star-Forming Galaxies from 3D-HST: Implications for Dust Geometry and Star Formation Rates

NASA Technical Reports Server (NTRS)

Price, Sedona H.; Kriek, Mariska; Brammer, Gabriel B; Conroy, Charlie; Schreiber, Natascha M. Foerster; Franx, Marijn; Fumagalli, Mattia; Lundren, Britt; Momcheva, Ivelina; Nelson, Erica J.;

Histamine in cereal dusts

PubMed Central

Nicholls, P. J.

1970-01-01

Nicholls, P. J. (1970).Brit. J. industr. Med.,27, 179-180. Histamine in cereal dusts. It has been found that workers exposed to cereal grain dusts may experience acute mild respiratory distress. An attempt has been made to explain this observation by examining the pharmacological activity of aqueous extracts of several cereal dusts from the holds of cargo ships. Histamine, but no other active agent, was found in the samples. It is unlikely that the concentration of histamine in these dusts is sufficient to cause respiratory distress in dockers unloading cereal grain cargoes. PMID:5428638

Acute Meteorite Dust Exposure and Pulmonary Inflammation - Implications for Human Space Exploration

NASA Technical Reports Server (NTRS)

Harrington, A. D.; McCubbin, F. M.; Kaur, J.; Smirnov, A.; Galdanes, K.; Schoonen, M. A. A.; Chen, L. C.; Tsirka, S. E.; Gordon, T.

2017-01-01

The previous manned missions to the Moon represent milestones of human ingenuity, perseverance, and intellectual curiosity. However, one of the major ongoing concerns is the array of hazards associated with lunar surface dust. Not only did the dust cause mechanical and structural integrity issues with the suits, the dust 'storm' generated upon reentrance into the crew cabin caused "lunar hay fever" and "almost blindness [1-3]" (Figure 1). It was further reported that the allergic response to the dust worsened with each exposure [4]. The lack of gravity exacerbated the exposure, requiring the astronauts to wear their helmet within the module in order to avoid breathing the irritating particles [1]. Due to the prevalence of these high exposures, the Human Research Roadmap developed by NASA identifies the Risk of Adverse Health and Performance Effects of Celestial Dust Exposure as an area of concern [5]. Extended human exploration will further increase the probability of inadvertent and repeated exposures to celestial dusts. Going forward, hazard assessments of celestial dusts will be determined through sample return efforts prior to astronaut deployment. Studies on the lunar highland regolith indicate that the dust is not only respirable but also reactive [2, 6-9], and previous studies concluded that it is moderately toxic; generating a greater response than titanium oxide but a lower response than quartz [6]. The presence of reactive oxygen species (ROS) on the surface of the dust has been implicated. However, there is actually little data related to physicochemical characteristics of particulates and pulmonary toxicity, especially as it relates to celestial dust exposure. As a direct response to this deficit, the present study evaluates the role of a particulate's innate geochemical features (e.g., bulk chemistry, internal composition, morphology, size, and reactivity) in generating adverse toxicological responses in vitro and in vivo. This highly interdisciplinary study evaluates the relative toxicity of six meteorite samples representing either basalt or regolith breccia on the surfaces of the Moon, Mars, and Asteroid 4Vesta (Table 1); three potential candidates for future human exploration or colonization. Terrestrial mid-ocean ridge basalt (MORB) is also used for comparison as a control sample.

Pulmonary Inflammatory Responses To Acute Meteorite Dust Exposures - Implications For Human Space Exploration

NASA Technical Reports Server (NTRS)

Harrington, A. D.; McCubbin, F. M.; Kaur, J.; Smirnov, A.; Galdanes, K.; Schoonen, M. A. A.; Chen, L. C.; Tsirka, S. E.; Gordon, T.

2017-01-01

The previous manned missions to the Moon represent milestones of human ingenuity, perseverance, and intellectual curiosity. However, one of the major ongoing concerns is the array of hazards associated with lunar surface dust. Not only did the dust cause mechanical and structural integrity issues with the suits, the dust 'storm' generated upon reentrance into the crew cabin caused "lunar hay fever" and "almost blindness" (Figure 1). It was further reported that the allergic response to the dust worsened with each exposure. The lack of gravity exacerbated the exposure, requiring the astronauts to wear their helmet within the module in order to avoid breathing the irritating particles. Due to the prevalence of these high exposures, the Human Research Roadmap developed by NASA identifies the Risk of Adverse Health and Performance Effects of Celestial Dust Exposure as an area of concern. Extended human exploration will further increase the probability of inadvertent and repeated exposures to celestial dusts. Going forward, hazard assessments of celestial dusts will be determined through sample return efforts prior to astronaut deployment. Studies on the lunar highland regolith indicate that the dust is not only respirable but also reactive, and previous studies concluded that it is moderately toxic; generating a greater response than titanium oxide but a lower response than quartz. The presence of reactive oxygen species (ROS) on the surface of the dust has been implicated. However, there is actually little data related to physicochemical characteristics of particulates and pulmonary toxicity, especially as it relates to celestial dust exposure. As a direct response to this deficit, the present study evaluates the role of a particulate's innate geochemical features (e.g., bulk chemistry, internal composition, morphology, size, and reactivity) in generating adverse toxicological responses in vitro and in vivo. This highly interdisciplinary study evaluates the relative toxicity of six meteorite samples representing either basalt or regolith breccia on the surfaces of the Moon, Mars, and Asteroid 4Vesta; three potential candidates for future human exploration or colonization. Terrestrial mid-ocean ridge basalt (MORB) is also used for comparison as a control sample.

Evaluating levels and health risk of heavy metals in exposed workers from surgical instrument manufacturing industries of Sialkot, Pakistan.

PubMed

Junaid, Muhammad; Hashmi, Muhammad Zaffar; Malik, Riffat Naseem

2016-09-01

The study aimed to monitor heavy metal (chromium, Cr; cadmium, Cd; nickel, Ni; copper, Cu; lead, Pb; iron, Fe; manganese, Mn; and zinc, Zn) footprints in biological matrices (urine, whole blood, saliva, and hair), as well as in indoor industrial dust samples, and their toxic effects on oxidative stress and health risks in exposed workers. Overall, blood, urine, and saliva samples exhibited significantly higher concentrations of toxic metals in exposed workers (Cr; blood 16.30 μg/L, urine 58.15 μg/L, saliva 5.28 μg/L) than the control samples (Cr; blood 5.48 μg/L, urine 4.47 μg/L, saliva 2.46 μg/L). Indoor industrial dust samples also reported to have elevated heavy metal concentrations, as an example, Cr quantified with concentration of 299 mg/kg of dust, i.e., more than twice the level of Cr in household dust (136 mg/kg). Superoxide dismutase (SOD) level presented significant positive correlation (p ≤ 0.01) with Cr, Zn, and Cd (Cr > Zn > Cd) which is an indication of heavy metal's associated raised oxidative stress in exposed workers. Elevated average daily intake (ADI) of heavy metals resulted in cumulative hazard quotient (HQ) range of 2.97-18.88 in workers of different surgical units; this is an alarming situation of health risk implications. Principal component analysis-multiple linear regression (PCA-MLR)-based pie charts represent that polishing and cutting sections exhibited highest metal inputs to the biological and environmental matrices than other sources. Heavy metal concentrations in biological matrices and dust samples showed a significant positive correlation between Cr in dust, urine, and saliva samples. Current study will help to generate comprehensive base line data of heavy metal status in biomatrices and dust from scientifically ignored industrial sector. Our findings can play vital role for health departments and industrial environmental management system (EMS) authorities in policy making and implementation.

Evaluation of a new automated instrument for pretransfusion testing.

PubMed

Morelati, F; Revelli, N; Maffei, L M; Poretti, M; Santoro, C; Parravicini, A; Rebulla, P; Cole, R; Sirchia, G

1998-10-01

A number of automated devices for pretransfusion testing have recently become available. This study evaluated a fully automated device based on column agglutination technology (AutoVue System, Ortho, Raritan, NJ). Some 6747 tests including forward and reverse ABO group, Rh type and phenotype, antibody screen, autocontrol, and crossmatch were performed on random samples from 1069 blood donors, 2063 patients, and 98 newborns and cord blood. Also tested were samples from 168 immunized patients and 53 donors expressing weak or variant A and D antigens. Test results and technician times required for their performance were compared with those obtained by standard methods (manual column agglutination technology, slide, semiautomatic handler). No erroneous conclusions were found in regard to the 5028 ABO group and Rh type or phenotype determinations carried out with the device. The device rejected 1.53 percent of tests for sample inadequacy. Of the remaining 18 tests with discrepant results found with the device and not confirmed with the standard methods, 6 gave such results because of mixed-field reactions, 10 gave negative results with A2 RBCs in reverse ABO grouping, and 2 gave very weak positive reactions in antibody screening and crossmatching. In the samples from immunized patients, the device missed one weak anti-K, whereas standard methods missed five weak antibodies. In addition, 48, 34, and 31 of the 53 weak or variant antigens were detected by the device, the slide method, and the semiautomated handler, respectively. Technician time with the standard methods was 1.6 to 7 times higher than that with the device. The technical performance of the device compared favorably with that of standard methods, with a number of advantages, including in particular the saving of technician time. Sample inadequacy was the most common cause of discrepancy, which suggests that standardization of sample collection can further improve the performance of the device.

Tracking Intercontinental Dust Transport With Radiogenic Isotopes: Hefei, China to California, Spring 2002

NASA Astrophysics Data System (ADS)

Christensen, J. N.; Cliff, S. S.; Vancuren, R. A.; Perry, K. D.; Depaolo, D. J.

2006-12-01

Research over the past decade has highlighted the importance of intercontinental transport and exchange of atmospheric aerosols, including soil-derived dust and industrial pollutants. Far-traveled aerosols can affect air quality, atmospheric radiative forcing and cloud formation and can be an important component in soils. Principal component analysis of elemental data for aerosols collected over California has identified a persistent Asian soil dust component that peaks with Asian dust storm events [1]. Isotopic fingerprinting can provide an additional and potentially more discriminating tool for tracing sources of dust. For example, the naturally variable isotopic compositions of Sr and Nd reflect both the geochemistry of the dust source and its pre- weathering geologic history. Sr and Nd isotopic data and chemical data have been collected for a time series of PM2.5 filter samples from Hefei, China taken from eraly April into early May, 2002. This period encompassed a series of dust storms. The sampling time frame overlapped with the 2002 Intercontinental Transport and Chemical Transformation (ITCT-2K2) experiment along the Pacific coast of North America and inland California. Highs in 87Sr/86Sr in the Hefei time series coincide with peaks in Ca and Si representing peaks in mineral particulate loading resulting from passing dust storms. Mixing diagrams combining isotopic data with chemical data identify several components; a high 87Sr/86Sr component that we identify with mineral dust (loess), and two different low 87Sr/86Sr components (local sources and marine aerosol). Using our measured isotopic composition of the "loess" standard CJ-1 [2] as representative of the pure high 87Sr/86Sr component, we calculate 24 hour average loess particulate concentrations in air which range up to 35 micrograms per cubic meter. Marine aerosol was a major component on at least one of the sampled days. The results for the Hefei samples provide a basis for our isotopic study of California mineral aerosols, including the identification and apportionment of local and far-traveled Asian dust components and their variation in time. [1]VanCuren R.A., Cliff, S.S., Perry, K.D. and Jimenez-Cruz, M. (2005) J. Geophys. Res., 110, D09S90, doi: 10.1029/2004JD004973 [2]Nishikawa, M., Hao, Q. and Morita, M. (2000) Global Environ. Res. 4, 1:103-113.

Properties of Modern Dust Accumulating in the Uinta Mountains, Utah, USA, and Soil Evidence of Long-Term Dust Deposition

NASA Astrophysics Data System (ADS)

Munroe, J. S.

2013-12-01

Modern eolian sediment was collected at four locations in the alpine zone of the Uinta Mountains (Utah, USA) between July 2011 and July 2012. Collectors were a passive design based on the classic marble dust trap, but modified for use in this high-precipitation environment. On average the collectors accumulated 1.5 gm of dust, corresponding to an annual flux of 4.4 g/m2. This result is similar to values measured from snowpack samples in the Wind River (Wyoming) and San Juan (Colorado) Mountains. Dust flux was 3 to 5x higher during the winter compared with summer at the two sites featuring continuous vegetation, but was consistent between the seasons at the two collectors surrounded by a greater area of exposed soil. XRD analysis reveals that dust samples are dominated by quartz, potassium feldspar, plagioclase, and illite. Some samples contain amphibole and chlorite. In contrast, samples of fine sediment collected from the surface of modern snowbanks are dominated by clay with no feldspar or quartz, suggesting that these minerals are derived from the surrounding soil surface, which is snow-covered in the winter. ICP-MS analysis reveals that the geochemistry of the coarse (>63-μm) fraction of the dust resembles that of the underlying bedrock, confirming a local origin for this sediment. In contrast, the fine (<63-μm) fraction of the dust closely matches the fine fraction of the soil A horizon, supporting an eolian origin for the ubiquitous layer of fines that mantles soil profiles throughout the Uinta Mountains. Grain size analysis with laser scattering reveals that modern dust is very well-sorted, with a median size of 8 μm (7.0 Φ). Using the annual dust flux and mean grain size, and taking into account the measured bulk density (0.95 gm/cm3), organic matter content (20%), and silt content (32%) of this loess cap, the extrapolated loess accretion rate is ~18 cm per 10,000 years. Given that prior studies (Bockheim et al., 2000 Catena; Munroe, 2007, Arctic, Antarctic, and Alpine Research) have reported mean loess thickness from 16 to 25 cm throughout the alpine zone, this result suggests that the loess cap is a post-glacial feature.

Spectral- and size-resolved mass absorption efficiency of mineral dust aerosols in the shortwave spectrum: a simulation chamber study

NASA Astrophysics Data System (ADS)

Caponi, Lorenzo; Formenti, Paola; Massabó, Dario; Di Biagio, Claudia; Cazaunau, Mathieu; Pangui, Edouard; Chevaillier, Servanne; Landrot, Gautier; Andreae, Meinrat O.; Kandler, Konrad; Piketh, Stuart; Saeed, Thuraya; Seibert, Dave; Williams, Earle; Balkanski, Yves; Prati, Paolo; Doussin, Jean-François

2017-06-01

This paper presents new laboratory measurements of the mass absorption efficiency (MAE) between 375 and 850 nm for 12 individual samples of mineral dust from different source areas worldwide and in two size classes: PM10. 6 (mass fraction of particles of aerodynamic diameter lower than 10.6 µm) and PM2. 5 (mass fraction of particles of aerodynamic diameter lower than 2.5 µm). The experiments were performed in the CESAM simulation chamber using mineral dust generated from natural parent soils and included optical and gravimetric analyses. The results show that the MAE values are lower for the PM10. 6 mass fraction (range 37-135 × 10-3 m2 g-1 at 375 nm) than for the PM2. 5 (range 95-711 × 10-3 m2 g-1 at 375 nm) and decrease with increasing wavelength as λ-AAE, where the Ångström absorption exponent (AAE) averages between 3.3 and 3.5, regardless of size. The size independence of AAE suggests that, for a given size distribution, the dust composition did not vary with size for this set of samples. Because of its high atmospheric concentration, light absorption by mineral dust can be competitive with black and brown carbon even during atmospheric transport over heavy polluted regions, when dust concentrations are significantly lower than at emission. The AAE values of mineral dust are higher than for black carbon (˜ 1) but in the same range as light-absorbing organic (brown) carbon. As a result, depending on the environment, there can be some ambiguity in apportioning the aerosol absorption optical depth (AAOD) based on spectral dependence, which is relevant to the development of remote sensing of light-absorbing aerosols and their assimilation in climate models. We suggest that the sample-to-sample variability in our dataset of MAE values is related to regional differences in the mineralogical composition of the parent soils. Particularly in the PM2. 5 fraction, we found a strong linear correlation between the dust light-absorption properties and elemental iron rather than the iron oxide fraction, which could ease the application and the validation of climate models that now start to include the representation of the dust composition, as well as for remote sensing of dust absorption in the UV-vis spectral region.

Influence of Air Humidity and Water Particles on Dust Control Using Ultrasonic Atomization

NASA Astrophysics Data System (ADS)

Okawa, Hirokazu; Nishi, Kentaro; Shindo, Dai; Kawamura, Youhei

2012-07-01

The influence of air humidity and water particles on dust control was examined using ultrasonic atomization at 2.4 MHz, an acrylic box (61 L), and four types of ore dust samples: green tuff (4 µm), green tuff (6 µm), kaolin, and silica. It was clearly demonstrated that ultrasonic atomization was effective in raising humidity rapidly. However, at high relative air humidity, the water particles remained stable in the box without changing to water vapor. Ultrasonic atomization was applied to suppress dust dispersion and 40-95% dust reduction was achieved at 83% relative air humidity. Dust dispersion was more effective with ultrasonic atomization than without.

Indoor metallic pollution and children exposure in a mining city.

PubMed

Barbieri, Enio; Fontúrbel, Francisco E; Herbas, Cristian; Barbieri, Flavia L; Gardon, Jacques

2014-07-15

Mining industries are known for causing strong environmental contamination. In most developing countries, the management of mining wastes is not adequate, usually contaminating soil, water and air. This situation is a source of concern for human settlements located near mining centers, especially for vulnerable populations such as children. The aim of this study was to assess the correlations of the metallic concentrations between household dust and children hair, comparing these associations in two different contamination contexts: a mining district and a suburban non-mining area. We collected 113 hair samples from children between 7 and 12 years of age in elementary schools in the mining city of Oruro, Bolivia. We collected 97 indoor dust samples from their households, as well as information about the children's behavior. Analyses of hair and dust samples were conducted to measure As, Cd, Pb, Sb, Sn, Cu and Zn contents. In the mining district, there were significant correlations between non-essential metallic elements (As, Cd, Pb, Sb and Sn) in dust and hair, but not for essential elements (Cu and Zn), which remained after adjusting for children habits. Children who played with dirt had higher dust-hair correlations for Pb, Sb, and Cu (P=0.006; 0.022 and 0.001 respectively) and children who put hands or toys in their mouths had higher dust-hair correlations of Cd (P=0.011). On the contrary, in the suburban area, no significant correlations were found between metallic elements in dust and children hair and neither children behavior nor gender modified this lack of associations. Our results suggest that, in a context of high metallic contamination, indoor dust becomes an important exposure pathway for children, modulated by their playing behavior. Copyright © 2014 Elsevier B.V. All rights reserved.