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Sample records for airborne asian dust

  1. Long-Term Variability of Airborne Asian Dust Observed from TOMS

    NASA Technical Reports Server (NTRS)

    Herman, J. R.; Hsu, N. C.; Seftor, C. J.; Holben, B. N.; Holben, B. N.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    Recent studies suggest that airborne Asian dust may not only play an important role in the regional radiation budget, but also influence the air quality over North America through long-range transport. In this paper, we use satellite data to investigate the long-term variability of airborne Asian dust as well as the daily variation of the dust aerosol distribution. By combining the Total Ozone Mapping Spectrometer (TOMS) aerosol index with National Centers for Environmental Prediction (NCEP) wind data, our analysis shows a strong correlation between the generation of dust storms in the region and the passage of springtime weather fronts. This is consistent with earlier studies performed by other researchers. According to both the Nimbus-7 and Earth-Probe TOMS data the Takla Makan desert, the Gobi desert, and the and region of Inner Mongolia are major sources of the eastward-flowing airborne Asian dust. Heavily populated areas in eastern China (e.g., Beijing) are often on the primary path of the dust storms originating in these desert regions. The increasing desertification north of the Beijing region has served to exacerbate problems stemming from these storms. The time series derived from 20 years of TOMS aerosol index data shows the first significant satellite evidence of the atmospheric effect of increasing desertification, indicating that the amount of dust blown eastward has increased strongly during the past few years including the year 2000.

  2. Changes in the Airborne Bacterial Community in Outdoor Environments following Asian Dust Events

    PubMed Central

    Yamaguchi, Nobuyasu; Park, Jonguk; Kodama, Makiko; Ichijo, Tomoaki; Baba, Takashi; Nasu, Masao

    2014-01-01

    Bacterial abundance and community compositions have been examined in aeolian dust in order to clarify their possible impacts on public health and ecosystems. The influence of transcontinentally transported bacterial cells on microbial communities in the outdoor environments of downwind areas should be determined because the rapid influx of a large amount of bacterial cells can disturb indigenous microbial ecosystems. In the present study, we analyzed bacteria in air samples (approximately 100 m3 d−1) that were collected on both Asian dust days and non-Asian dust days over 2 years (between November 2010 and July 2012). Changes in bacterial abundance and community composition were investigated based on their 16S rRNA gene amount and sequence diversity. Seasonal monitoring revealed that airborne bacterial abundance was more than 10-fold higher on severe dust days, while moderate dust events did not affect airborne bacterial abundance. A comparison of bacterial community compositions revealed that bacteria in Asian dust did not immediately disturb the airborne microbial community in areas 3,000–5,000 km downwind of dust source regions, even when a large amount of bacterial cells were transported by the atmospheric event. However, microbes in aeolian dust may have a greater impact on indigenous microbial communities in downwind areas near the dust source. Continuous temporal and spatial analyses from dust source regions to downwind regions (e.g., from the Gobi desert to China, Korea, Japan, and North America) will assist in estimating the impact of atmospherically transported bacteria on indigenous microbial ecosystems in downwind areas. PMID:24553107

  3. Bioprocess of Kosa bioaerosols: effect of ultraviolet radiation on airborne bacteria within Kosa (Asian dust).

    PubMed

    Kobayashi, Fumihisa; Maki, Teruya; Kakikawa, Makiko; Yamada, Maromu; Puspitasari, Findya; Iwasaka, Yasunobu

    2015-05-01

    Kosa (Asian dust) is a well-known weather phenomenon in which aerosols are carried by the westerly winds from inland China to East Asia. Recently, the frequency of this phenomenon and the extent of damage caused have been increasing. The airborne bacteria within Kosa are called Kosa bioaerosols. Kosa bioaerosols have affected ecosystems, human health and agricultural productivity in downwind areas. In order to develop a new and useful bacterial source and to identify the source region of Kosa bioaerosols, sampling, isolation, identification, measurement of ultraviolet (UV) radiation tolerance and experimental simulation of UV radiation conditions were performed during Kosa bioaerosol transportation. We sampled these bioaerosols using a Cessna 404 airplane and a bioaerosol sampler at an altitude of approximately 2900 m over the Noto Peninsula on March 27, 2010. The bioaerosol particles were isolated and identified as Bacillus sp. BASZHR 1001. The results of the UV irradiation experiment showed that the UV radiation tolerance of Kosa bioaerosol bacteria was very high compared with that of a soil bacterium. Moreover, the UV radiation tolerance of Kosa bioaerosol spores was higher than that of soil bacterial spores. This suggested that Kosa bioaerosols are transported across the atmosphere as living spores. Similarly, by the experimental simulation of UV radiation conditions, the limited source region of this Kosa bioaerosol was found to be southern Russia and there was a possibility of transport from the Kosa source area. PMID:25735592

  4. Bioprocess of Kosa bioaerosols: effect of ultraviolet radiation on airborne bacteria within Kosa (Asian dust).

    PubMed

    Kobayashi, Fumihisa; Maki, Teruya; Kakikawa, Makiko; Yamada, Maromu; Puspitasari, Findya; Iwasaka, Yasunobu

    2015-05-01

    Kosa (Asian dust) is a well-known weather phenomenon in which aerosols are carried by the westerly winds from inland China to East Asia. Recently, the frequency of this phenomenon and the extent of damage caused have been increasing. The airborne bacteria within Kosa are called Kosa bioaerosols. Kosa bioaerosols have affected ecosystems, human health and agricultural productivity in downwind areas. In order to develop a new and useful bacterial source and to identify the source region of Kosa bioaerosols, sampling, isolation, identification, measurement of ultraviolet (UV) radiation tolerance and experimental simulation of UV radiation conditions were performed during Kosa bioaerosol transportation. We sampled these bioaerosols using a Cessna 404 airplane and a bioaerosol sampler at an altitude of approximately 2900 m over the Noto Peninsula on March 27, 2010. The bioaerosol particles were isolated and identified as Bacillus sp. BASZHR 1001. The results of the UV irradiation experiment showed that the UV radiation tolerance of Kosa bioaerosol bacteria was very high compared with that of a soil bacterium. Moreover, the UV radiation tolerance of Kosa bioaerosol spores was higher than that of soil bacterial spores. This suggested that Kosa bioaerosols are transported across the atmosphere as living spores. Similarly, by the experimental simulation of UV radiation conditions, the limited source region of this Kosa bioaerosol was found to be southern Russia and there was a possibility of transport from the Kosa source area.

  5. Investigation of bacterial effects of Asian dust events through comparison with seasonal variability in outdoor airborne bacterial community

    PubMed Central

    Park, Jonguk; Ichijo, Tomoaki; Nasu, Masao; Yamaguchi, Nobuyasu

    2016-01-01

    Atmospheric bacterial dispersion with aeolian dust has been reported to have a potential impact on public health and ecosystems. Asian dust is a major aeolian event that results in an estimated 4 million tons of Asian dust particles falling in Japan annually, 3,000–5,000 km away from their source regions. However, most studies have only investigated the effects of Asian dust during dust seasons. Therefore, in this study, outdoor bacterial abundance and community composition were determined by 16S rRNA quantitative PCR and amplicon sequencing, respectively, and compared on Asian and non-Asian dust days (2013–2015; 44 samples over four seasons). Seasonal variations in bacterial abundance of non-Asian dust days were not observed. Bacterial abundance of individual samples collected on non-Asian dust days changed dynamically relative to Asian dust days, with bacterial abundance occasionally reaching those of Asian dust days. The bacterial community composition on non-Asian dust days was rather stable seasonally, and did not differ from that on Asian dust days. These results indicate that bacteria in Asian dust does not immediately influence indigenous bacterial communities at the phylum/class level in distant downwind areas; accordingly, further studies of bacterial communities in downwind areas closer to the dust source are warranted. PMID:27761018

  6. Variations in the structure of airborne bacterial communities in a downwind area during an Asian dust (Kosa) event.

    PubMed

    Maki, Teruya; Puspitasari, Findya; Hara, Kazutaka; Yamada, Maromu; Kobayashi, Fumihisa; Hasegawa, Hiroshi; Iwasaka, Yasunobu

    2014-08-01

    Asian dust (Kosa) events transport airborne microorganisms that significantly impact biological ecosystems, human health, and ice-cloud formation in downwind areas. However, the composition and population dynamics of airborne bacteria have rarely been investigated in downwind areas during Kosa events. In this study, air samplings were sequentially performed at the top of a 10-m high building within the Kosa event arrival area (Kanazawa City, Japan) from May 1 to May 7, 2011, during a Kosa event. The particle concentrations of bacterial cells and mineral particles were ten-fold higher during the Kosa event than on non-Kosa event days. A 16S ribosomal DNA clone library prepared from the air samples primarily contained sequences from three phyla: Cyanobacteria, Firmicutes, and Alphaproteobacteria. The clones from Cyanobacteria were mainly from a marine type of Synechococcus species that was dominant during the first phase of the Kosa event and was continuously detected throughout the Kosa event. The clones from Alphaproteobacteria were mainly detected at the initial and final periods of the Kosa event, and phylogenetic analysis showed that their sequences clustered with those from a marine bacterial clade (the SAR clade) and Sphingomonas spp. During the middle of the Kosa event, the Firmicutes species Bacillus subtilis and Bacillus pumilus were predominant; these species are known to be predominant in the atmosphere above the Chinese desert, which is the source of the dust during Kosa events. The clones obtained after the Kosa event had finished were mainly from Bacillus megaterium, which is thought to originate from local terrestrial areas. Our results suggest that airborne bacterial communities at the ground level in areas affected by Kosa events change their species compositions during a Kosa event toward those containing terrestrial and pelagic bacteria transported from the Sea of Japan and the continental area of China by the Kosa event. PMID:24815557

  7. Seasonal variations of sugars in atmospheric particulate matter from Gosan, Jeju Island: Significant contributions of airborne pollen and Asian dust in spring

    NASA Astrophysics Data System (ADS)

    Fu, Pingqing; Kawamura, Kimitaka; Kobayashi, Minoru; Simoneit, Bernd R. T.

    2012-08-01

    Sugars are important water-soluble organic constituents of atmospheric particulate matter (PM). In order to better understand the sources and seasonal variations of sugars in aerosols, primary saccharides (fructose, glucose, sucrose, and trehalose) and sugar alcohols (arabitol and mannitol), together with levoglucosan, have been studied in ambient aerosols at Gosan, Jeju Island in the western North Pacific, the downwind region of the Asian outflow, using gas chromatography-mass spectrometry. The results showed that the sugar composition varied seasonally with a total concentration range of 6.8-1760 ng m-3 (mean 246 ng m-3). The total identified sugars had the highest concentration in April, the spring bloom season at Jeju Island, when sucrose contributed up to 80% of the total sugars. The dominance of sucrose was also detected in pollen samples, suggesting that pollen can contribute significantly to sucrose in aerosols during the spring bloom. The seasonal variation of trehalose is consistent with those of non-sea-salt Ca2+ and δ13C of total carbon with elevated levels during the Asian dust storm events. This study indicates that sugar compounds in atmospheric PM over East Asia can be derived from biomass burning, Asian dust, and primary biological aerosols such as fungal spores and pollen. Furthermore, this study supports the idea that sucrose could be used as a tracer for airborne pollen grains, and trehalose as a tracer for Asian dust outflow.

  8. Correlation between Asian Dust and Specific Radioactivities of Fission Products Included in Airborne Samples in Tokushima, Shikoku Island, Japan, Due to the Fukushima Nuclear Accident

    SciTech Connect

    Sakama, M.; Nagano, Y.; Kitade, T.; Shikino, O.; Nakayama, S.

    2014-06-15

    Radioactive fission product {sup 131}I released from the Fukushima Daiichi Nuclear Power Plants (FD-NPP) was first detected on March 23, 2011 in an airborne aerosol sample collected at Tokushima, Shikoku Island, located in western Japan. Two other radioactive fission products, {sup 134}Cs and {sup 137}Cs were also observed in a sample collected from April 2 to 4, 2011. The maximum specific radioactivities observed in this work were about 2.5 to 3.5 mBq×m{sup -3} in a airborne aerosol sample collected on April 6. During the course of the continuous monitoring, we also made our first observation of seasonal Asian Dust and those fission products associated with the FDNPP accident concurrently from May 2 to 5, 2011. We found that the specific radioactivities of {sup 134}Cs and {sup 137}Cs decreased drastically only during the period of Asian Dust. And also, it was found that this trend was very similar to the atmospheric elemental concentration (ng×m{sup -3}) variation of stable cesium ({sup 133}Cs) quantified by elemental analyses using our developed ICP-DRC-MS instrument.

  9. Correlation between Asian Dust and Specific Radioactivities of Fission Products Included in Airborne Samples in Tokushima, Shikoku Island, Japan, Due to the Fukushima Nuclear Accident

    NASA Astrophysics Data System (ADS)

    Sakama, M.; Nagano, Y.; Kitade, T.; Shikino, O.; Nakayama, S.

    2014-06-01

    Radioactive fission product 131I released from the Fukushima Daiichi Nuclear Power Plants (FD-NPP) was first detected on March 23, 2011 in an airborne aerosol sample collected at Tokushima, Shikoku Island, located in western Japan. Two other radioactive fission products, 134Cs and 137Cs were also observed in a sample collected from April 2 to 4, 2011. The maximum specific radioactivities observed in this work were about 2.5 to 3.5 mBq×m-3 in a airborne aerosol sample collected on April 6. During the course of the continuous monitoring, we also made our first observation of seasonal Asian Dust and those fission products associated with the FDNPP accident concurrently from May 2 to 5, 2011. We found that the specific radioactivities of 134Cs and 137Cs decreased drastically only during the period of Asian Dust. And also, it was found that this trend was very similar to the atmospheric elemental concentration (ng×m-3) variation of stable cesium (133Cs) quantified by elemental analyses using our developed ICP-DRC-MS instrument.

  10. An assessment of the surface longwave direct radiative effect of airborne dust in Zhangye, China, during the Asian Monsoon Years field experiment (2008)

    NASA Astrophysics Data System (ADS)

    Hansell, Richard A.; Tsay, Si-Chee; Hsu, N. Christina; Ji, Qiang; Bell, Shaun W.; Holben, Brent N.; Welton, Ellsworth J.; Roush, Ted L.; Zhang, W.; Huang, J.; Li, Zhanqing; Chen, H.

    2012-08-01

    In April-June 2008, NASA Goddard's ground-based mobile laboratories (SMART-COMMIT) were deployed to Zhangye China (39.0°N; 101°W) to support the Asian Monsoon Years field experiment and the East Asian Study of Tropospheric Aerosols and Impact on Regional Climate. One of the primary objectives at Zhangye, a semi-arid region located between the Taklimakan and Gobi Deserts, was to capture and characterize dust aerosols near the source and to quantify their direct radiative effects (DRE). A regional dust optical model was constructed by combining previously measured soil mineralogy data at Zhangye with COMMIT's particle microphysical measurements. During a 2-week period of heightened dust activity, retrieved longwave (LW) aerosol optical thickness (τ) from SMART's Atmospheric Emitted Radiance Interferometer was used in the Fu-Liou radiative transfer model to derive LW instantaneous DRE (DRELW) at the surface, top of atmosphere, and heating rate profiles for cloud-free conditions. Conservatively, surface instantaneous DRELW and LW forcing efficiency range from about 2-20 Wm-2 and 31-35 Wm-2τ-1 (0 ≤ τ ≤ 0.83), respectively. The significance of DRELWrelative to its shortwave counterpart was estimated to be between 51 and 58%, but of opposite sign, partly compensating shortwave surface cooling. Compared to Saharan dust observed during the NAMMA-2006 field experiment at Cape Verde, dust LW forcing efficiency for this study was found to be a factor of two larger stemming from differences in environmental and surface conditions, aerosol absorption, and Zhangye's close proximity to major desert sources. Relative to observed and modeled ranges in surface DRELW for clouds (˜30-80 Wm-2) and greenhouse gases (˜2 Wm-2), this study's upper range in DRELW represents a significant perturbation to the climate system with important implications for better understanding regional changes in surface temperatures and moisture budgets.

  11. Airborne Dust in Space Vehicles and Habitats

    NASA Technical Reports Server (NTRS)

    James, John

    2006-01-01

    Airborne dust, suspended inside a space vehicle or in future celestial habitats, can present a serious threat to crew health if it is not controlled. During the Apollo missions to the moon, lunar dust brought inside the capsule caused eye irritation and breathing difficulty to the crew when they launched from the moon and re-acquired "microgravity." During Shuttle flights reactive and toxic dusts such as lithium hydroxide have created a risk to crew health, and fine particles from combustion events can be especially worrisome. Under nominal spaceflight conditions, airborne dusts and particles tend to be larger than on earth because of the absence of gravity settling. Aboard the ISS, dusts are effectively managed by HEPA filters, although floating dust in newly-arrived modules can be a nuisance. Future missions to the moon and to Mars will present additional challenges because of the possibility that external dust will enter the breathing atmosphere of the habitat and reach the crew's respiratory system. Testing with simulated lunar and Martian dust has shown that these materials are toxic when placed into the lungs of test animals. Defining and evaluating the physical and chemical properties of Martian dusts through robotic missions will challenge our ability to prepare better dust simulants and to determine the risk to crew health from exposure to such dusts.

  12. Asian Dust Storm Outbreaks: A Satellite-Surface Perspective

    NASA Technical Reports Server (NTRS)

    Tsay, Si-Chee

    2006-01-01

    Airborne dusts from northern China contribute a significant part of the air quality problem and, to some extent, regional climatic impact in Asia during springtime. Asian dust typically originates in desert areas far from polluted urban regions. During the transport, dust layers can interact with anthropogenic sulfate and soot aerosols from heavily polluted urban areas. Added to the complex effects of clouds and natural marine aerosols, dust particles reaching the marine environment can have drastically different properties than those from the source. Thus, understanding the unique temporal and spatial variations of Asian dust is of special importance in regional-to-global climate issues (e.g., radiative forcing, hydrological cycle, and primary biological productivity in the mid-Pacific Ocean, etc.), as well as societal concerns (e.g., adverse health effects to humans). The Asian dust and air pollution aerosols can be detected by its colored appearance on current Earth observing satellites (e.g., MODIS, SeaWiFS, TOMS, etc.) and its evolution monitored by satellites and surface network (e.g. AERONET, SKY NET, MPLNET, etc.). Recently, many field campaigns (e.g., ACE-Asia-2001, TRACEP-2001, ADE-2002 & -2003, APEX-2001 & -2003, etc.) were designed and executed to study the compelling variability in spatial and temporal scale of both pollution-derived and naturally occurring aerosols, which often exist in high concentrations over eastern Asia and along the rim of the western Pacific. I will present an overview of the outbreak of Asian dust storms from space and surface observations and to address the climatic effects and societal impacts.

  13. Impacts of Asian dust events on atmospheric fungal communities

    NASA Astrophysics Data System (ADS)

    Jeon, Eun Mi; Kim, Yong Pyo; Jeong, Kweon; Kim, Ik Soo; Eom, Suk Won; Choi, Young Zoo; Ka, Jong-Ok

    2013-12-01

    The composition of atmospheric fungi in Seoul during Asian dust events were assessed by culturing and by molecular methods such as mold specific quantitative PCR (MSQPCR) and internal transcribed spacer cloning (ITS cloning). Culturable fungal concentrations in the air were monitored from May 2008 to July 2011 and 3 pairs of ITS clone libraries, one during Asian dust (AD) day and the other during the adjacent non Asian dust (NAD) day for each pair, were constructed after direct DNA extraction from total suspended particles (TSP) samples. In addition, six aeroallergenic fungi in the atmosphere were also assessed by MSQPCR from October, 2009 to November, 2011. The levels of the airborne culturable fungal concentrations during AD days was significantly higher than that of NAD days (P < 0.005). In addition, the correlation of culturable fungal concentrations with particulate matters equal to or less than 10 μm in aerodynamic diameter (PM10) concentrations was observed to be high (0.775) for the AD days while correlation coefficients of PM10 as well as other particulate parameters with airborne fungal concentrations were significantly negative for the NAD days during intensive monitoring periods (May to June, 2008). It was found that during AD days several airborne allergenic fungal levels measured with MSQPCR increased up to 5-12 times depending on the species. Comparison of AD vs. NAD clones showed significant differences (P < 0.05) in all three cases using libshuff. In addition, high proportions of uncultured soil fungus isolated from semi-arid regions were observed only in AD clone libraries. Thus, it was concluded that AD impacts not only airborne fungal concentrations but also fungal communities.

  14. Airborne Dust Models in Valley Fever Research

    NASA Astrophysics Data System (ADS)

    Sprigg, W. A.; Galgiani, J. N.; Vujadinovic, M.; Pejanovic, G.; Vukovic, A. J.; Prasad, A. K.; Djurdjevic, V.; Nickovic, S.

    2011-12-01

    Dust storms (haboobs) struck Phoenix, Arizona, in 2011 on July 5th and again on July 18th. One potential consequence: an estimated 3,600 new cases of Valley Fever in Maricopa County from the first storm alone. The fungi, Coccidioides immitis, the cause of the respiratory infection, Valley Fever, lives in the dry desert soils of the American southwest and southward through Mexico, Central America and South America. The fungi become part of the dust storm and, a few weeks after inhalation, symptoms of Valley Fever may appear, including pneumonia-like illness, rashes, and severe fatigue. Some fatalities occur. Our airborne dust forecast system predicted the timing and extent of the storm, as it has done with other, often different, dust events. Atmosphere/land surface models can be part of public health services to reduce risk of Valley Fever and exacerbation of other respiratory and cardiovascular illness.

  15. An Assessment of the Surface Longwave Direct Radiative Effect of Airborne Dust in Zhangye China During the Asian Monsoon Year Field Experiment (2008)

    NASA Technical Reports Server (NTRS)

    Hansell, Richard A.; Tsay, Si-Chee; Hsu, N. Christina; Ji, Qiang; Bell, Shaun W.; Holben, Brent N.; Ellsworth, Welton J.; Roush, Ted L.; Zhang, Wu; Huang, J.; Li, Zhanquing; Chen, Hongbin

    2012-01-01

    Tiny suspensions of solid particles or liquid droplets, called aerosols, hover in earth's atmosphere and can be found over just about anywhere including oceans, deserts, vegetated areas, and other global regions. Aerosols come in a variety of sizes, shapes, and compositions which depend on such factors as their origin and how long they have been in the atmosphere (i.e., their residence time). Some of the more common types of aerosols include mineral dust and sea salt which get lifted from the desert and ocean surfaces, respectively by mechanical forces such as strong winds. Depending on their size, aerosols will either fall out gravitationally, as in the case of larger particles, or will remain resident in the atmosphere where they can undergo further change through interactions with other aerosols and cloud particles. Not only do aerosols affect air quality where they pose a health risk, they can also perturb the distribution of radiation in the earth-atmosphere system which can inevitably lead to changes in our climate. One aerosol that has been in the forefront of many recent studies, particularly those examining its radiative effects, is mineral dust. The large spatial coverage of desert source regions and the fact that dust can radiatively interact with such a large part of the electromagnetic spectrum due to its range in particle size, makes it an important aerosol to study. Dust can directly scatter and absorb solar and infrared radiation which can subsequently alter the amount of radiation that would otherwise be present in the absence of dust at any level of the atmosphere like the surface. This is known as radiative forcing. At the surface dust can block incoming solar energy, however at infrared wavelengths, dust acts to partially compensate the solar losses. Evaluating the solar radiative effect of dust aerosols is relatively straightforward due in part to the relatively large signal-to-noise ratio in the measurements. At infrared wavelengths, on the

  16. Airborne dust particle counting techniques.

    PubMed

    Sharma, S G; Prasad, B D

    2006-03-01

    The paper briefly describes an electro-optical system for counting of dust particles, which is based on the scattering phenomena. Utilizing the scattering of light by various size particles present in the environment, various particle counting techniques have been developed in order to measure the scattered intensity of light. Light scatters in all directions but much more in the so-called near forward direction 17( composite function) off axis, at 163( composite function) from the light source in the visible range. On the basis of two techniques, the right angle and forward angle scattering, opto-mechanical systems have been developed which measure scattered intensity and particulate matter. The forward scattering Nephelometer is more sensitive and therefore is more suitable for pollution monitoring than the right angle scattering Nephelometer. Whereas the right angle scattering Nephelometer has the utility in extremely low concentration in ppb level owing to the excellent light trap efficiency in comparison to forward scattering Nephelometer. In this paper measurement techniques and measurement results associated with design and development of a real time particle analyser are also discussed.

  17. Refractive Indices of Asian Dust in Mid-Infrared Region

    NASA Astrophysics Data System (ADS)

    Lee, K.; Park, J.

    2013-12-01

    Optical constants of Asian dust are determined based on mineral compositions of aerosols sampled at Seoul, Korea. Complex refractive index for labradorite (plagioclase) and orthoclase (K-feldspar), which are component minerals of Asian dust, are calculated from the dispersion theory using reflectance data of the Advanced Spaceborne Thermal Emission Reflection Radiometer (ASTER). The optical constants of Asian dust are compared with those of other dust aerosols. Simulated brightness temperatures of satellite measurement using the present optical constants for a typical loading of Asian dust aerosols show spectral features of the Atmospheric Infrared Sounder (AIRS) data for an Asian dust storm. Measured and simulated spectral locations of the maximum brightness temperature are in good agreement. Simulated data show the negative slope in the region of 800-1000 cm-1. Brightness temperature of AIRS near 1233 cm-1 being lower than the maximum near 832 cm-1 can also be simulated using the optical constants of Asian dust.

  18. Abundance and Community Structure of Bacteria on Asian Dust Particles Collected in Beijing, China, during the Asian Dust Season.

    PubMed

    Yamaguchi, Nobuyasu; Baba, Takashi; Ichijo, Tomoaki; Himezawa, Yuka; Enoki, Kanami; Saraya, Makoto; Li, Pin-Fang; Nasu, Masao

    2016-01-01

    Approximately 180 t/km(2) of Asian dust particles are estimated to fall annually on Beijing, China, and there is significant concern about the influence of microbes transported by Asian dust events on human health and downwind ecosystems. In this study, we collected Asian dust particles in Beijing, and analyzed the bacterial communities on these particles by culture-independent methods. Bacterial cells on Asian dust particles were visualized first by laser scanning microscopy, which demonstrated that Asian dust particles carry bacterial cells to Beijing. Bacterial abundance, as determined by quantitative polymerase chain reaction (PCR), was 10(8) to 10(9) cells/g, a value about 10 times higher than that in Asian dust source soils. Inter-seasonal variability of bacterial community structures among Asian dust samples, as compared by terminal restriction fragment length polymorphism (T-RFLP), was low during the Asian dust season. Several viable bacteria, including intestinal bacteria, were found in Asian dust samples by denaturing gradient gel electrophoresis (DGGE). Clone library analysis targeting 16S ribosomal RNA (rRNA) gene sequences demonstrated that bacterial phylogenetic diversity was high in the dust samples, and most of these were environmental bacteria distributed in soil and air. The dominant species in the clone library was Segetibacter aerophilus (Bacteroidetes), which was first isolated from an Asian dust sample collected in Korea. Our results also indicate the possibility of a change in the bacterial community structure during transportation and increases in desiccation-tolerant bacteria such as Firmicutes.

  19. Lunar Airborne Dust Toxicity Hazard Assessments (Invited)

    NASA Astrophysics Data System (ADS)

    Cooper, B. L.; McKay, D. S.; Taylor, L. A.; Wallace, W. T.; James, J.; Riofrio, L.; Gonzalez, C. P.

    2009-12-01

    The Lunar Airborne Dust Toxicity Assessment Group (LADTAG) is developing data to set the permissible limits for human exposure to lunar dust. This standard will guide the design of airlocks and ports for EVA, as well as the requirements for filtering and monitoring the atmosphere in habitable vehicles, rovers and other modules. LADTAG’s recommendation for permissible exposure limits will be delivered to the Constellation Program in late 2010. The current worst-case exposure limit of 0.05 mg/m3, estimated by LADTAG in 2006, reflects the concern that lunar dust may be as toxic as quartz dust. Freshly-ground quartz is known to be more toxic than un-ground quartz dust. Our research has shown that the surfaces of lunar soil grains can be more readily activated by grinding than quartz. Activation was measured by the amount of free radicals generated—activated simulants generate Reactive Oxygen Species (ROS) i.e., production of hydroxyl free radicals. Of the various influences in the lunar environment, micrometeorite bombardment probably creates the most long-lasting reactivity on the surfaces of grains, although solar wind impingement and short-wavelength UV radiation also contribute. The comminution process creates fractured surfaces with unsatisfied bonds. When these grains are inhaled and carried into the lungs, they will react with lung surfactant and cells, potentially causing tissue damage and disease. Tests on lunar simulants have shown that dissolution and leaching of metals can occur when the grains are exposed to water—the primary component of lung fluid. However, simulants may behave differently than actual lunar soils. Rodent toxicity testing will be done using the respirable fraction of actual lunar soils (particles with physical size of less than 2.5 micrometers). We are currently separating the fine material from the coarser material that comprises >95% of the mass of each soil sample. Dry sieving is not practical in this size range, so a new system

  20. Immune Alterations in Rats Exposed to Airborne Lunar Dust

    NASA Technical Reports Server (NTRS)

    Crucian, Brian; Quiriarte, Heather; Nelman, Mayra; Lam, Chiu-wing; James, John T.; Sams, Clarence

    2014-01-01

    The lunar surface is covered by a layer of fine, reactive dust. Very little is known regarding the toxicity of lunar dust on human physiology. This study assessed the toxicity of airborne lunar dust exposure in rats on pulmonary and systemic immune parameters.

  1. SPM and fungal spores in the ambient air of west Korea during the Asian dust (Yellow sand) period

    NASA Astrophysics Data System (ADS)

    Yeo, Hwan-Goo; Kim, Jong-Ho

    The relationship between suspended particulate matter (SPM) and fungal spore was investigated in Seosan, a rural county along the west coast of Korea, in the spring of 2000. SPM concentrations in the air were 199.8 μg m -3 in the first Asian dust period (23-24 March), 249.4 μg m -3 in the second Asian dust period (7-9 April) and 98.9 μg m -3 in the non-Asian dust period (12-16 May), respectively. The majority of the total SPM were composed of coarse particles sized about 5 μm during the two Asian dust periods. Four molds genera grown from airborne fungal spores were identified in colonies grown from SPM samples taken during the Asian dust periods. All the genera found, Fusarium, Aspergillus, Penicillium and Basipetospora, are hyphomycetes in the division Deuteromycota. Morphologically, more diversified mycelia of hyphomycetes were grown on the sample captured from 1.1 to 2.1 μm sized SPM than on the other sized samples gathered in the dust periods. On the other hand, no mold was observed on the sample of 1.1-2.1 μm sized SPM in the non-Asian dust period. From these results, it seems evident that several sorts of fine sized fungal spores were suspended in the atmospheric environment of this study area during Asian dust periods.

  2. Optical constants for Asian dust in midinfrared region

    NASA Astrophysics Data System (ADS)

    Lee, Kwang-Mog; Park, Joong-Hyun

    2014-01-01

    Asian dust aerosols are composed of quartz, plagioclase, K-feldspar, calcite, and phyllosilicates. The optical constants for mixtures of these minerals are important not only to understand the effects of Asian dust on climate but also to retrieve the properties of Asian dust. In this work, the optical constants for labradorite and orthoclase, representative minerals of plagioclase and K-feldspar, respectively, are determined for the spectral range of 500-2000 cm-1 using bidirectional reflectance data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer. Assuming an internal mixture of component minerals, the effective refractive indices for Asian dust are calculated using Bruggeman's rule. The results are proposed as optical constants for Asian dust and differ from those for other dust aerosols, such as the refractive indices for "Saharan dust" derived from aerosol samples collected at Barbados. The imaginary refractive index for Asian dust is larger, indicating more absorptive, than the index for Saharan dust in the range of 1000-1300 cm-1. Using the optical constants derived in this study, the brightness temperatures of satellite measurements are simulated for typical loading scenarios of Asian dust aerosols. The simulated brightness temperatures exhibit a notable decrease with wave number in the region of 800-1000 cm-1. The results also corroborate the spectral features of the Atmospheric Infrared Sounder (AIRS) measurements for an Asian dust storm. AIRS brightness temperatures near 1223 cm-1, lower than the maximum near 830 cm-1, can also be simulated using the derived optical constants for Asian dust.

  3. Airborne Dust, "The Good Guy or the Bad Guy": How Much do We Know?

    NASA Technical Reports Server (NTRS)

    Tsay, Si-Chee

    2010-01-01

    Processes in generating, transporting, and dissipating the airborne dust particles are global phenomena -African dust regularly reaching the Alps; Asian dust seasonally crossing the Pacific into North America, and ultimately the Atlantic into Europe. One of the vital biogeochemical roles dust storms play in Earth's ecosystem is routinely mobilizing mineral dust, as a source of iron, from deserts into oceans for fertilizing the growth of phytoplankton -the basis of the oceanic food chain. Similarly, these dust-laden airs also supply crucial nutrients for the soil of tropical rain forests, the so-called womb of life that hosts 50-90% of the species on Earth. With massive amounts of dust lifted from desert regions and injected into the atmosphere, however, these dust storms often affect daily activities in dramatic ways: pushing grit through windows and doors, forcing people to stay indoors, causing breathing problems, reducing visibility and delaying flights, and by and large creating chaos. Thus, both increasing and decreasing concentrations of doses result in harmful biological effects; so do the airborne dust particles to our Living Earth. Since 1997 NASA has been successfully launching a series of satellites - the Earth Observing System - to intensively study, and gain a better understanding of, the Earth as an integrated system. Through participation in many satellite remote-sensing/retrieval and validation projects over the years, we have gradually developed and refined the SMART (Surface-sensing Measurements for Atmospheric Radiative Transfer) and COMMIT (Chemical, Optical & Microphysical Measurements of In-situ Troposphere) mobile observatories, a suite of surface remote sensing and in-situ instruments that proved to be vital in providing high temporal measurements, which complement the satellite observations. In this talk, we will present SMART-COMMIT which has played key roles, serving as network or supersite, in major international research projects such

  4. Characterization of anthropogenic pollutants in Asian dust

    NASA Astrophysics Data System (ADS)

    Kim, W.; Doh, S.; Yu, Y.

    2008-12-01

    It has well known that the Asian dust storm (ADS) carried anthropogenic pollutants produced in the industrial areas in China to the adjacent East Asian nations including Korea, Japan and Taiwan. In order to characterize such anthropogenic pollutants forced by ADS, detailed electron microscopic observations were carried out on ADS samples collected from the 12 ADS events occurred for the past three years (2004-2006) in Seoul, Korea. In addition, their temporal accumulations were traced using magnetic proxy parameters. As a comparison, companion samples were also collected before- and after- ADS events. We found that anthropogenic signatures in the ADS samples were C, Cr, Pb, S and Zn. Most of these elements were tied with Fe. Therefore the magnetic proxy is highly applicable to trace the quantitative variations in anthropogenic pollutants in ADS. Slightly increasing magnetic concentration parameters reflect increasing amount of anthropogenic pollutants carried by the ADS for the past three years. Connecting with the air- mass trajectories of ADS, the highest magnetic concentration (highest pollution) was observed on the ADS samples from Central China which travelled nearby highly industrialized major cities where foreign multinational enterprises were concentrated.

  5. 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.

  6. Longitudinal study of dust and airborne endotoxin in the home.

    PubMed

    Park, J H; Spiegelman, D L; Burge, H A; Gold, D R; Chew, G L; Milton, D K

    2000-11-01

    To characterize the seasonal variability of endotoxin levels, we measured endotoxin in dust from the bed, bedroom floor, and kitchen floor in 20 homes, and in air from the bedroom in 15 of the homes. All homes were located in the greater Boston, Massachusetts, area and were sampled each month from April 1995 to June 1996. Outdoor air was collected at two locations. We found greater within-home than between-home variance for bedroom floor, kitchen floor, and airborne endotoxin. However, the reverse was true for bed dust endotoxin. Thus, studies using single measurements of dust endotoxin are most likely to reliably distinguish between homes if bed dust is sampled. Dust endotoxin levels were not significantly associated with airborne endotoxin. Airborne endotoxin was significantly (p = 0. 04) and positively associated with absolute humidity in a mixed-effect model adjusting for a random home effect and fixed effect of sampling month and home characteristics. This finding implies that indoor humidity may be an important factor controlling endotoxin exposure. We found a significant (p < 0.05) seasonal effect in kitchen floor dust (spring > fall) and bedroom airborne endotoxin (spring > winter), but not in the other indoor samples. We found significant seasonal pattern in outdoor airborne endotoxin (summer > winter). PMID:11102291

  7. Influence of Asian Dust Particles on Immune Adjuvant Effects and Airway Inflammation in Asthma Model Mice

    PubMed Central

    Kurai, Jun; Watanabe, Masanari; Tomita, Katsuyuki; Yamasaki, Hiroyuki Sano Akira; Shimizu, Eiji

    2014-01-01

    Objective An Asian dust storm (ADS) contains airborne particles that affect conditions such as asthma, but the mechanism of exacerbation is unclear. The objective of this study was to compare immune adjuvant effects and airway inflammation induced by airborne particles collected on ADS days and the original ADS soil (CJ-1 soil) in asthma model mice. Methods Airborne particles were collected on ADS days in western Japan. NC/Nga mice were co-sensitized by intranasal instillation with ADS airborne particles and/or Dermatophagoides farinae (Df), and with CJ-1 soil and/or Df for 5 consecutive days. Df-sensitized mice were stimulated with Df challenge intranasally at 7 days after the last Df sensitization. At 24 hours after challenge, serum allergen specific antibody, differential leukocyte count and inflammatory cytokines in bronchoalveolar lavage fluid (BALF) were measured, and airway inflammation was examined histopathologically. Results Co-sensitization with ADS airborne particles and Df increased the neutrophil and eosinophil counts in BALF. Augmentation of airway inflammation was also observed in peribronchiolar and perivascular lung areas. Df-specific serum IgE was significantly elevated by ADS airborne particles, but not by CJ-1 soil. Levels of interleukin (IL)-5, IL-13, IL-6, and macrophage inflammatory protein-2 were higher in BALF in mice treated with ADS airborne particles. Conclusion These results suggest that substances attached to ADS airborne particles that are not in the original ADS soil may play important roles in immune adjuvant effects and airway inflammation. PMID:25386753

  8. Methods to assess airborne concentrations of cotton dust.

    PubMed

    Corn, M

    1987-01-01

    Assessment of concentrations of airborne cotton dust in the factory is necessary to determine adherence to applicable Permissible Exposure Limits (PELs) on a day-to-day basis, as well as for investigatory studies of an epidemiological nature. The latter are required on an ongoing basis to determine the adequacy of PELs to prevent disease in the exposed population. A strategy of sampling includes considerations of the numbers of samples to be obtained for statistical validity and the locations of samples. Current practice is to obtain more "personal samples" of exposure wherever possible, but with regard to cotton dust, instrumentation is not available for such sampling. In the U.S., the vertical elutriator is the instrument of choice for determining the concentrations of cotton dust in air. Results are expressed as milligrams of airborne particulate (cotton dust) per cubic meter. PMID:3434562

  9. Endotoxins in baled cottons and airborne dusts in textile mills in the People's Republic of China.

    PubMed Central

    Olenchock, S A; Christiani, D C; Mull, J C; Ye, T T; Lu, P L

    1983-01-01

    Bulk cotton samples and airborne vertical elutriated cotton dusts were obtained from textile mills in Shanghai, People's Republic of China. Analysis of endotoxin contents revealed that baled cottons which were grown in different countries varied in endotoxin contamination. The two textile mills, which operated at similar overall airborne dust levels, differed markedly in the levels of airborne endotoxins. The data suggest that the biological activity or "toxicity" of airborne cotton dusts may not be correlated directly with gravimetric dust levels. PMID:6639029

  10. Correlation between acute conjunctivitis and Asian dust on ocular surfaces.

    PubMed

    Ko, Ryota; Hayashi, Masahiko; Hayashi, Hideyuki; Hayashi, Kazue; Kato, Hitoshi; Kurata, Yoshinori; Fuchino, Yuki; Nakamichi, Toshifumi; Migita, Hironori; Yano, Hiroko; Sakata, Tetsuya; Uchio, Eiichi

    2016-01-01

    The aim of this study was to determine the presence of Asian dust particles (ADP) in patients suffering from conjunctivitis and its correlation with clinical scores for conjunctivitis. Forty-five patients from the Fukuoka area who were newly diagnosed acute conjunctivitis were selected. The degrees of inflammatory reaction, itchy sensation, hyperemia, eye discharge, and foreign body sensation were clinically recorded and scored. Eyes were washed with physiological solution. Solid particles collected from the washing solution were observed using a scanning electron microscope. Of the 45 samples, 44 were positive for the elements silicon (Si) and aluminum (Al), which are components of ambient Asian dust. Higher conjunctivitis scores were found in the subgroup in which the Asian dust/whole particle ratio was greater than average. This is the first apparent report on the correlation between amount of ADP exposure at the ocular surface and severity of ocular symptoms. PMID:27142484

  11. Asian dust properties from 10 years of MISR data.

    NASA Astrophysics Data System (ADS)

    Kalashnikova, Olga; Sokolik, Irina; Garay, Michael; Wu, Dong

    2010-05-01

    We use the 10-year aerosol data record from the Multi-angle Imaging SpectroRadiometer (MISR) aboard the Terra satellite to investigate climatological linkages between the dust source activities, mid-range, and long-range transport of Asian dust. The inter-annual and seasonal variability of Asian dust loadings and properties as retrieved by MISR at selected regions along the transport routes was investigated. In particular, we examine the Taklamakan and East and Central Gobi regions (dust sources), South Korea and Japan regions (mid-range transport), and the North Pacific region along the northwestern U.S. coast (long-range transport). To avoid the gridding and averaging effects in Level 3 products, we use the Level 2 MISR data. Within each selected region, the analysis was performed to examine the multi-annual mean and variability of the aerosol optical depth and particle nonsphericity as well as time-lag correlation between the regions, taking into account the effects of MISR sampling and cloud coverage. The results will be presented and interpreted in the context of atmospheric dynamics variability, including variability of meteorological regimes in dust sources and the large-scale atmospheric circulation features controlling the trans-Pacific transport of Asian dust.

  12. Asian dust events of April 1998

    USGS Publications Warehouse

    Husar, R.B.; Tratt, D.M.; Schichtel, B.A.; Falke, S.R.; Li, F.; Jaffe, D.; Gasso, S.; Gill, T.; Laulainen, N.S.; Lu, F.; Reheis, M.C.; Chun, Y.; Westphal, D.; Holben, B.N.; Gueymard, C.; McKendry, I.; Kuring, N.; Feldman, G.C.; McClain, C.; Frouin, R.J.; Merrill, J.; DuBois, D.; Vignola, F.; Murayama, T.; Nickovic, S.; Wilson, W.E.; Sassen, K.; Sugimoto, N.; Malm, W.C.

    2001-01-01

    On April 15 and 19, 1998, two intense dust storms were generated over the Gobi desert by springtime low-pressure systems descending from the northwest. The windblown dust was detected and its evolution followed by its yellow color on SeaWiFS satellite images, routine surface-based monitoring, and through serendipitous observations. The April 15 dust cloud was recirculating, and it was removed by a precipitating weather system over east Asia. The April 19 dust cloud crossed the Pacific Ocean in 5 days, subsided to the surface along the mountain ranges between British Columbia and California, and impacted severely the optical and the concentration environments of the region. In east Asia the dust clouds increased the albedo over the cloudless ocean and land by up to 10-20%, but it reduced the near-UV cloud reflectance, causing a yellow coloration of all surfaces. The yellow colored backscattering by the dust eludes a plausible explanation using simple Mie theory with constant refractive index. Over the West Coast the dust layer has increased the spectrally uniform optical depth to about 0.4, reduced the direct solar radiation by 30-40%, doubled the diffuse radiation, and caused a whitish discoloration of the blue sky. On April 29 the average excess surface-level dust aerosol concentration over the valleys of the West Coast was about 20-50 ??g/m3 with local peaks >100 ??g/m3. The dust mass mean diameter was 2-3 ??m, and the dust chemical fingerprints were evident throughout the West Coast and extended to Minnesota. The April 1998 dust event has impacted the surface aerosol concentration 2-4 times more than any other dust event since 1988. The dust events were observed and interpreted by an ad hoc international web-based virtual community. It would be useful to set up a community-supported web-based infrastructure to monitor the global aerosol pattern for such extreme aerosol events, to alert and to inform the interested communities, and to facilitate collaborative

  13. Asian dust events of April 1998

    NASA Astrophysics Data System (ADS)

    Husar, R. B.; Tratt, D. M.; Schichtel, B. A.; Falke, S. R.; Li, F.; Jaffe, D.; Gassó, S.; Gill, T.; Laulainen, N. S.; Lu, F.; Reheis, M. C.; Chun, Y.; Westphal, D.; Holben, B. N.; Gueymard, C.; McKendry, I.; Kuring, N.; Feldman, G. C.; McClain, C.; Frouin, R. J.; Merrill, J.; Dubois, D.; Vignola, F.; Murayama, T.; Nickovic, S.; Wilson, W. E.; Sassen, K.; Sugimoto, N.; Malm, W. C.

    2001-08-01

    On April 15 and 19, 1998, two intense dust storms were generated over the Gobi desert by springtime low-pressure systems descending from the northwest. The windblown dust was detected and its evolution followed by its yellow color on SeaWiFS satellite images, routine surface-based monitoring, and through serendipitous observations. The April 15 dust cloud was recirculating, and it was removed by a precipitating weather system over east Asia. The April 19 dust cloud crossed the Pacific Ocean in 5 days, subsided to the surface along the mountain ranges between British Columbia and California, and impacted severely the optical and the concentration environments of the region. In east Asia the dust clouds increased the albedo over the cloudless ocean and land by up to 10-20%, but it reduced the near-UV cloud reflectance, causing a yellow coloration of all surfaces. The yellow colored backscattering by the dust eludes a plausible explanation using simple Mie theory with constant refractive index. Over the West Coast the dust layer has increased the spectrally uniform optical depth to about 0.4, reduced the direct solar radiation by 30-40%, doubled the diffuse radiation, and caused a whitish discoloration of the blue sky. On April 29 the average excess surface-level dust aerosol concentration over the valleys of the West Coast was about 20-50 μg/m3 with local peaks >100 μg/m3. The dust mass mean diameter was 2-3 μm, and the dust chemical fingerprints were evident throughout the West Coast and extended to Minnesota. The April 1998 dust event has impacted the surface aerosol concentration 2-4 times more than any other dust event since 1988. The dust events were observed and interpreted by an ad hoc international web-based virtual community. It would be useful to set up a community-supported web-based infrastructure to monitor the global aerosol pattern for such extreme aerosol events, to alert and to inform the interested communities, and to facilitate collaborative

  14. Migration of contaminated soil and airborne particulates to indoor dust.

    PubMed

    Layton, David W; Beamer, Paloma I

    2009-11-01

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

  15. Estimates of Asian dust deposition over the Asian region by using ADAM2 in 2007.

    PubMed

    Park, Soon-Ung; Choe, Anna; Park, Moon-Soo

    2010-05-01

    The Asian Dust Aerosol Model 2 (ADAM2) with the MM5 meteorological model has been employed to estimate the dust concentration, and wet and dry depositions of dust in the Asian region for the year of 2007. It is found that the model simulates quite reasonably the dust (PM(10)) concentrations both in the dust source region (100-110 degrees E and 37-43 degrees N) and the downstream region of Korea. The starting and ending times of most of dust events and their peak concentration occurring times are well simulated. The annual average dust (PM(10)) concentration near the surface is found to be 171microgm(-3) over the dust source area, 39microgm(-3) over the Yellow Sea, 25microgm(-3) over the Korean peninsula and 17microgm(-3) over the East Sea. It is also found that the annual total deposition of dust is about 118.1tkm(-2) (dry deposition, 101.4tkm(-2); wet deposition, 16.7tkm(-2)) in the dust source region, 19.0tkm(-2) (dry deposition, 7.8tkm(-2); wet deposition, 11.2tkm(-2)) in the Yellow Sea, 12.6tkm(-2) (dry deposition, 6.5tkm(-2); wet deposition, 6.1tkm(-2)) in the Korean peninsula and 10.7tkm(-2) (dry deposition, 2.1tkm(-2); wet deposition, 8.6tkm(-2)) in the East Sea. Their ratios of wet deposition to total deposition of dust in the respective regions are 14%, 59%, 48% and 80%. This clearly indicates that the main dust removal mechanism from the atmosphere is dry deposition over the source region whereas wet deposition predominates in the downstream region of the sea. The estimated dust deposition could adversely impact the eco-environmental system in the downstream regions of the dust source region significantly.

  16. Airborne dust transport to the eastern Pacific Ocean off southern California: Evidence from San Clemente Island

    USGS Publications Warehouse

    Muhs, D.R.; Budahn, J.; Reheis, M.; Beann, J.; Skipp, G.; Fisher, E.

    2007-01-01

    Islands are natural dust traps, and San Clemente Island, California, is a good example. Soils on marine terraces cut into Miocene andesite on this island are clay-rich Vertisols or Alfisols with vertic properties. These soils are overlain by silt-rich mantles, 5-20 cm thick, that contrast sharply with the underlying clay-rich subsoils. The silt mantles have a mineralogy that is distinct from the island bedrock. Silt mantles are rich in quartz, which is rare in the island andesite. The clay fraction of the silt mantles is dominated by mica, also absent from local andesite, and contrasts with the subsoils, dominated by smectite. Ternary plots of immobile trace elements (Sc-Th-La and Ta-Nd-Cr) show that the island andesite has a composition intermediate between average upper continental crust and average oceanic crust. In contrast, the silt and, to a lesser extent, clay fractions of the silt mantles have compositions closer to average upper continental crust. The silt mantles have particle size distributions similar to loess and Mojave Desert dust, but are coarser than long-range-transported Asian dust. We infer from these observations that the silt mantles are derived from airborne dust from the North American mainland, probably river valleys in the coastal mountains of southern California and/or the Mojave Desert. Although average winds are from the northwest in coastal California, easterly winds occur numerous times of the year when "Santa Ana" conditions prevail, caused by a high-pressure cell centered over the Great Basin. Examination of satellite imagery shows that easterly Santa Ana winds carry abundant dust to the eastern Pacific Ocean and the California Channel Islands. Airborne dust from mainland North America may be an important component of the offshore sediment budget in the easternmost Pacific Ocean, a finding of potential biogeochemical and climatic significance.

  17. Vertical Resolved Dust Mass Concentration and Backscatter Coefficient Retrieval of Asian Dust Plume Using Quartz Raman Channel in Lidar Measurements

    NASA Astrophysics Data System (ADS)

    Noh, Young M.; Mueller, Detlef; Shin, Sungkyun

    2016-06-01

    In this work, we present a method for estimating vertical resolved mass concentration of dust immersed in Asian dust plume using Raman scattering of quartz (silicon dioxide, silica). During the Asian dust period of March 15, 16, and 21 in 2010, Raman lidar measurements detected the presence of quartz, and successfully showed the vertical profiles of the quartz backscatter coefficient. Since the Raman backscatter coefficient was connected with the Raman backscatter differential cross section and the number density of quartz molecules, the mass concentration of quartz in the atmosphere can be estimated from the quartz backscatter coefficient. The weight percentage from 40 to 70 % for quartz in the Asian dust was estimated from references. The vertical resolved mass concentration of dust was estimated by quartz mass concentration and weight percentage. We also present a retrieval method to obtain dust backscatter coefficient from the mixed Asian dust and pollutant layer. OPAC (Optical Properties of Aerosol and Clouds) simulations were conducted to calculate dust backscatter coefficient. The retrieved dust mass concentration was used as an input parameter for the OPAC calculations. These approaches in the study will be useful for characterizing the quartz dominated in the atmospheric aerosols and estimating vertical resolved mass concentration of dust. It will be especially applicable for optically distinguishing the dust and non-dust aerosols in studies on the mixing state of Asian dust plume. Additionally, the presented method combined with satellite observations is enable qualitative and quantitative monitoring for Asian dust.

  18. Contribution of Asian dust to atmospheric deposition of radioactive cesium ((137)Cs).

    PubMed

    Fukuyama, Taijiro; Fujiwara, Hideshi

    2008-11-01

    Both Asian dust (kosa) transported from the East Asian continent and locally suspended dust near monitoring sites contribute to the observed atmospheric deposition of (137)Cs in Japan. To estimate the relative contribution of these dust phenomena to the total (137)Cs deposition, we monitored weekly deposition of mineral particles and (137)Cs in spring. Deposition of (137)Cs from a single Asian dust event was 62.3 mBq m(-2) and accounted for 67% of the total (137)Cs deposition during the entire monitoring period. Furthermore, we found high (137)Cs specific activity in the Asian dust deposition sample. Although local dust events contributed to (137)Cs deposition, their contribution was considerably smaller than that of Asian dust. We conclude that the primary source of atmospheric (137)Cs in Japan is dust transported from the East Asian continent.

  19. Transport, Evolution and Entrainment of Asian Dust/Pollution into the Pacific Marine Boundary

    NASA Astrophysics Data System (ADS)

    Clarke, A. D.; McNaughton, C. S.; Kapustin, V.; Vetter, O.; Dibb, J. E.; Anderson, B. E.; Browell, E. V.; Carmichael, G.; Landing, B.

    2007-05-01

    Various airborne and ship based studies over the past several years have allowed us to measure Asian dust and pollution aerosol from near its source to locations up to 10,000km downwind where it was entrained into the marine boundary layer (MBL). Dust was found to accumulate up to half of the soluble species such as sulfate and nitrate during passage through pollution regions in Asia before being lofted into the free troposphere near Japan. At times, transport in the free troposphere included regions of subsidence in high pressure regions that brought these "rivers" of dust and pollution down to the top of the MBL. Shipboard measurements and lidar data indicated both clear air entrainment and convective activity, associated with the passage of low pressure systems, facilitated dust transport through the inversion. High temperature volatilization of particles in the MBL up to 900C was used to remove most sulfates, nitrates, carbon and sea-salt to leave only dust measured and sized by an optical particle counter. These shipboard data and concurrent chemical measurements revealed the relation between entrainment of pollution and dust into the MBL associated with passage of high pressure systems. Subsequent passage of low pressure systems also revealed scavenging and removal of aerosol through precipitation to the ocean surface. This process appears to be a common removal pathway for dust over the Pacific and a mechanism for supplying the ocean surface with soluble iron and aluminum to the ocean surface. Measurements in the free troposphere and MBL also captured various aspects of these processes. Airborne missions flown north of Hawaii during the NASA PEM-Tropics and IMPEX missions characterized the vertical structure of subsiding dust and pollution. In-flight mapping of the dust/pollution layers and structure using the NASA Langley DIAL LIDAR show a sloping, subsiding Asian air-mass entraining into the marine boundary layer (MBL). In-situ measurements of the aerosol

  20. Long-term Satellite Observations of Asian Dust Storm: Source, Pathway, and Interannual Variability

    NASA Technical Reports Server (NTRS)

    Hsu, N. Christina

    2008-01-01

    Among the many components that contribute to air pollution, airborne mineral dust plays an important role due to its biogeochemical impact on the ecosystem and its radiative-forcing effect on the climate system. In East Asia, dust storms frequently accompany the cold and dry air masses that occur as part of springtime cold front systems. Outbreaks of Asian dust storms occur often in the arid and semi-arid areas of northwestern China -about 1.6x10(exp 6) square kilometers including the Gobi and Taklimakan deserts- with continuous expanding of spatial coverage. These airborne dust particles, originating in desert areas far from polluted regions, interact with anthropogenic sulfate and soot aerosols emitted from Chinese megacities during their transport over the mainland. Adding the intricate effects of clouds and marine aerosols, dust particles reaching the marine environment can have drastically different properties than those from their sources. Furthermore, these aerosols, once generated over the source regions, can be transported out of the boundary layer into the free troposphere and can travel thousands of kilometers across the Pacific into the United States and beyond. In this paper, we will demonstrate the capability of a new satellite algorithm to retrieve aerosol properties (e.g., optical thickness, single scattering albedo) over bright-reflecting surfaces such as urban areas and deserts. Such retrievals have been difficult to perform using previously available algorithms that use wavelengths from the mid-visible to the near IR because they have trouble separating the aerosol signal from the contribution due to the bright surface reflectance. This new algorithm, called Deep Blue, utilizes blue-wavelength measurements from instruments such as SeaWiFS and MODIS to infer the properties of aerosols, since the surface reflectance over land in the blue part of the spectrum is much lower than for longer wavelength channels. Reasonable agreements have been achieved

  1. Examination of water spray airborne coal dust capture with three wetting agents

    PubMed Central

    Organiscak, J.A.

    2015-01-01

    Water spray applications are one of the principal means of controlling airborne respirable dust in coal mines. Since many coals are hydrophobic and not easily wetted by water, wetting agents can be added to the spray water in an effort to improve coal wetting and assist with dust capture. In order to study wetting agent effects on coal dust capture, laboratory experiments were conducted with three wetting agents used by the coal industry on -325 mesh sized Pocahontas No. 3 coal dust. Significant differences in coal dust sink times were observed among the three wetting agents at water mixture concentrations of 0.05%, 0.1% and 0.2%. The best wetting agent as identified by the coal dust sink test was only tested at the lowest 0.05% water mixture concentration and was found to have a negligible effect on spray airborne dust capture. Water spray airborne dust capture results for all three wetting agents tested at a 0.2% water mixture concentration showed that all three wetting agents exhibit similar but small improvements in dust capture efficiency as compared with water. These results indicate that the coal dust sink test may not be a good predictor for the capture of airborne dust. Additional research is needed to examine if the coal dust sink test is a better predictor of wetting agent dust suppression effects during cutting, loading, conveying and dumping of coal products by comparison to airborne dust capture from sprays. PMID:26251565

  2. Long-range Transport of Asian Dust Storms: A Satellite/Surface Perspective on Societal and Scientific Influence

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Among the many components contributing to air pollution, airborne mineral dust plays an important role due to its biogeochemical impact on the ecosystem and its radiative forcing effect on the weather/climate system. As much as one-third to half of the global dust emissions, estimated about 800 Tg, are introduced annually into Earth's atmosphere from various deserts in China. Asian dust storm outbreaks are believed to have persisted for hundreds and thousands years over the vast territory of north and northwest China, but not until recent decades that many studies reveal the compelling evidence in recognizing the importance of these eolian dust particles for forming Chinese Loess Plateau and for biogeochemical cycling in the North Pacific Ocean to as far as in the Greenland ice-sheets through long-range transport. The Asian dust and air pollution aerosols can be detected by its colored appearance on current Earth observing satellites and its evolution monitored by satellite and surface network. In this paper, we will demonstrate the capability of a new satellite algorithm, called Deep Blue, to retrieve aerosol properties, particularly but not limited to, over bright-reflecting surfaces such as urban areas and deserts. Recently, many field campaigns were designed and executed to study the compelling variability in spatial and temporal scale of both pollution-derived and naturally occurring aerosols, which often exist in high concentrations over eastern Asia and along the rim of the western Pacific. We will provide an overview of the outbreak of Asian dust storms, near source/sink and their evolution along transport pathway, from space and surface observations. The climatic effects and societal impacts of the Asian dusts will be addressed in depth. (to be presented in the International Workshop on Semi-Arid Land Surface-

  3. 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

  4. Numerical simulations of Asian dust events: A Lagrangian Dust Model and its applications

    NASA Astrophysics Data System (ADS)

    Kim, Cheol-Hee; Lee, Hyo-Jung

    2013-11-01

    An uni-modal Lagrangian Dust Model (LDM) was developed to simulate the dust concentrations and source-receptor (SR) relationships for recent Asian dust events that occurred over the Korean Peninsula. The following dust sources were used for the S-R calculation in this study: S-I) Gurbantunggut desert, S-II) Taklamakan desert, S-III) Tibetan Plateau, S-IV) Mu Us Desert, S-V) Manchuria, and S-VI) Nei Mongol and Gobi Desert. The following two 8-day dust simulation periods were selected for two case studies: (Period A) March 15-22, 2011, and (Period B) April 27-May 4, 2011. During two periods there were highly dense dust onsets observed over a wide area in Korea. Meteorological fields were generated using the WRF (Weather Research and Forecasting) meteorological model, and Lagrangian turbulent properties and dust emission were estimated using FLEXPART model and ADAM2 (Asian Dust Aerosol Model 2), respectively. The simulated dust concentrations are compared with point measurements and Eulerian model outputs. Statistical techniques were also employed to determine the accuracy and uncertainty associated with the model results. The results showed that the LDM compared favorably well with observations for some sites; however, for most sites the model overestimated the observations. Analysis of S-R relationships showed that 38-50% of dust particles originated from Nei Mongol and the Gobi Desert, and 16-25% of dust particles originated from Manchuria, accounting for most of the dust particles in Korea. Because there is no nudging or other artificial forcing included in the LDM, higher error indicators (e.g., root mean square error, absolute gross error) were found for some sites. However, the LDM was able to satisfactorily simulate the maximum timing and starting time of dust events for most sites. Compared with the Eulerian model, ADAM2, the results of LDM found pattern correlations (PCs) equal to 0.78-0.83 and indices of agreement (IOAs) greater than 0.6, suggesting that

  5. beta-(1,3)-Glucan exposure assessment by passive airborne dust sampling and new sensitive immunoassays.

    PubMed

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

    2010-02-01

    Associations between house dust-associated beta-(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 beta-(1,3)-glucan exposure assessment. The objective of this study was to develop inexpensive but highly sensitive enzyme immunoassays to measure airborne beta-(1,3)-glucans in low-exposure environments, like homes. Specificities of available anti-beta-(1,3)-glucan antibodies were defined by direct and inhibition experiments. Three suitable antibody combinations were selected for sandwich EIAs. beta-(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 beta-(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 beta-(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 beta-(1,3)-glucan levels correlated moderately with beta-(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 beta-(1,3)-glucan sandwich EIA with EDC sampling now allows assessment in large-scale population studies of exposure to airborne beta-(1,3)-glucans in homes or other low-exposure environments.

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

    PubMed

    Lee, Pyeong-Koo; Yu, Soonyoung

    2016-03-01

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

  7. Microbial immigration across the Mediterranean via airborne dust.

    PubMed

    Rosselli, Riccardo; Fiamma, Maura; Deligios, Massimo; Pintus, Gabriella; Pellizzaro, Grazia; Canu, Annalisa; Duce, Pierpaolo; Squartini, Andrea; Muresu, Rosella; Cappuccinelli, Pietro

    2015-01-01

    Dust particles lifting and discharge from Africa to Europe is a recurring phenomenon linked to air circulation conditions. The possibility that microorganisms are conveyed across distances entails important consequences in terms of biosafety and pathogens spread. Using culture independent DNA-based analyses via next generation sequencing of the 16 S genes from the airborne metagenome, the atmospheric microbial community was characterized and the hypothesis was tested that shifts in species diversity could be recorded in relation to dust discharge. As sampling ground the island of Sardinia was chosen, being an ideal cornerstone within the Mediterranean and a crossroad of wind circulation amidst Europe and Africa. Samples were collected in two opposite coastal sites and in two different weather conditions comparing dust-conveying winds from Africa with a control situation with winds from Europe. A major conserved core microbiome was evidenced but increases in species richness and presence of specific taxa were nevertheless observed in relation to each wind regime. Taxa which can feature strains with clinical implications were also detected. The approach is reported as a recommended model monitoring procedure for early warning alerts in frameworks of biosafety against natural spread of clinical microbiota across countries as well as to prevent bacteriological warfare. PMID:26542754

  8. Microbial immigration across the Mediterranean via airborne dust

    PubMed Central

    Rosselli, Riccardo; Fiamma, Maura; Deligios, Massimo; Pintus, Gabriella; Pellizzaro, Grazia; Canu, Annalisa; Duce, Pierpaolo; Squartini, Andrea; Muresu, Rosella; Cappuccinelli, Pietro

    2015-01-01

    Dust particles lifting and discharge from Africa to Europe is a recurring phenomenon linked to air circulation conditions. The possibility that microorganisms are conveyed across distances entails important consequences in terms of biosafety and pathogens spread. Using culture independent DNA-based analyses via next generation sequencing of the 16 S genes from the airborne metagenome, the atmospheric microbial community was characterized and the hypothesis was tested that shifts in species diversity could be recorded in relation to dust discharge. As sampling ground the island of Sardinia was chosen, being an ideal cornerstone within the Mediterranean and a crossroad of wind circulation amidst Europe and Africa. Samples were collected in two opposite coastal sites and in two different weather conditions comparing dust-conveying winds from Africa with a control situation with winds from Europe. A major conserved core microbiome was evidenced but increases in species richness and presence of specific taxa were nevertheless observed in relation to each wind regime. Taxa which can feature strains with clinical implications were also detected. The approach is reported as a recommended model monitoring procedure for early warning alerts in frameworks of biosafety against natural spread of clinical microbiota across countries as well as to prevent bacteriological warfare. PMID:26542754

  9. Health effects of particulate air pollution and airborne desert dust

    NASA Astrophysics Data System (ADS)

    Lelieveld, J.; Pozzer, A.; Giannadaki, D.; Fnais, M.

    2013-12-01

    Air pollution by fine particulate matter (PM2.5) has increased strongly with industrialization and urbanization. In the past decades this increase has taken place at a particularly high pace in South and East Asia. We estimate the premature mortality and the years of human life lost (YLL) caused by anthropogenic PM2.5 and airborne desert dust (DU2.5) on regional and national scales (Giannadaki et al., 2013; Lelieveld et al., 2013). This is based on high-resolution global model calculations that resolve urban and industrial regions in relatively great detail. We apply an epidemiological health impact function and find that especially in large countries with extensive suburban and rural populations, air pollution-induced mortality rates have been underestimated given that previous studies largely focused on the urban environment. We calculate a global premature mortality by anthropogenic aerosols of 2.2 million/year (YLL ≈ 16 million/year) due to lung cancer and cardiopulmonary disease. High mortality rates by PM2.5 are found in China, India, Bangladesh, Pakistan and Indonesia. Desert dust DU2.5 aerosols add about 0.4 million/year (YLL ≈ 3.6 million/year). Particularly significant mortality rates by DU2.5 occur in Pakistan, China and India. The estimated global mean per capita mortality caused by airborne particulates is about 0.1%/year (about two thirds of that caused by tobacco smoking). We show that the highest premature mortality rates are found in the Southeast Asia and Western Pacific regions (about 25% and 46% of the global rate, respectively) where more than a dozen of the most highly polluted megacities are located. References: Giannadaki, D., A. Pozzer, and J. Lelieveld, Modeled global effects of airborne desert dust on air quality and premature mortality, Atmos. Chem. Phys. Discuss. (submitted), 2013. Lelieveld, J., C. Barlas, D. Giannadaki, and A. Pozzer, Model calculated global, regional and megacity premature mortality due to air pollution by ozone

  10. Atmospheric microbiology in coastal northern California during Asian dust events

    NASA Astrophysics Data System (ADS)

    Warren-Rhodes, K. A.; Griffin, D. W.

    2004-12-01

    Each year, billions of tons of dust are swept from deserts in China and Africa across the globe to the US and Caribbean. Microorganisms are likely hitchhikers aboard this aerosolized dust, with potential human health and ecological impacts. In order to investigate the presence of bacteria and fungi in dust storms from Asia, atmospheric samples for cultivatable microbiological analysis were collected during the NASA Extended- Modis Validation Experiment (EVE), occurring April 21-30, 2004 and coinciding with seasonal Asian dust storm activity. Samples were taken by Twin Otter aircraft along the coast of northern California ( ˜100 km offshore of Monterey to San Francisco). An ˜100 km horizontal leg was flown at ˜100 km altitude, typically in the marine boundary layer, followed by a vertical spiral to the dust layer (as indicated by aerosol extinction monitoring) and a second horizontal leg in the dust layer at higher altitudes (2,100-4,200 m). Air samples were taken via Venturi tube inlets with sterile Millipore filter holders outfitted with 47 mm diameter test filters connected to a vacuum pump system. Total sample time varied and was based on flight conditions and EVE objectives. Typical flow rates were 40 lpm and average sample times were ˜1hr in the marine layer and ˜30 minutes in the dust layer. Control samples for handling and contamination were also obtained. Microbial culture of the filters was conducted using sterile techniques and R2A agar, with filters incubated in the dark at room temperature and monitored for growth over a 2-week period. Fungi and bacterial colonies were further isolated on fresh plates of R2A and Tryptic Soy Broth for the purpose of cataloging/storage. No isolates were obtained from samples of dust layers at altitude. This result may be explained by: i) inadequate sample volumes to detect extremely low bacterial numbers, though sample volumes ranged from 750-2100 liters, ii) light dust layer concentrations during the sampling period

  11. Effect of an electrostatic space charge system on airborne dust and subsequent potential transmission of microorganisms to broiler breeder pullets by airborne dust.

    PubMed

    Richardson, L J; Mitchell, B W; Wilson, J L; Hofacre, C L

    2003-01-01

    High levels of dust and microorganisms are known to be associated with animal confinement rearing facilities. Many of the microorganisms are carried by dust particles, thus providing an excellent vector for horizontal disease transmission between birds. Two environmentally controlled rooms containing female broiler breeder pullets (n = 300) were used to evaluate the effectiveness of an electrostatic space charge system (ESCS) in reducing airborne dust and gram-negative bacteria levels over an 8-wk period (starting when the birds were 10 wk old). The ESCS was used to evaluate the effectiveness of reducing airborne microorganism levels by charging airborne dust particles and causing the particles to be attracted to grounded surfaces (i.e., walls, floor, equipment). The use of the ESCS resulted in a 64% mean reduction in gram-negative bacteria. Airborne dust levels were reduced an average of 37% over a 1-wk period in the experimental room compared with the control room on the basis of samples taken every 10 min. The reductions of airborne dust and bacteria in this study are comparable with earlier results obtained with the ESCS in commercial hatching cabinets and experimental caged layer rooms, suggesting the system could also be applied to other types of enclosed animal housing. PMID:12713167

  12. [Occurrence of molds in airborne dusts in poultry farms].

    PubMed

    Gemeinhardt, H; Wallenstein, G

    1985-01-01

    To reach conclusions in terms of industrial hygiene, mycological samples were taken in modern poultry farms between 1979 and 1981. Sedimentation plates, the Krotow slit collector and the SPG-10 airborne dust sampler were used to determine the mould content of the air. The lowest germ counts were made in cage systems, while somewhat higher numbers were recorded among adult bids kept in the floor systems. Unexpectedly high numbers of mould germs were found in the air of large poultry houses where chickens were reared on relatively fresh litter. The fungus genera Penicillium and Cladosporium and, in one case, the species Scopulariopsis brevicaulis were predominant on old litter in both the floor and the cage system, whereas moulds of the Aspergillus group (Aspergillus candidus and A. versicolor) were additionally existent on fresh straw layers.

  13. Effect of Asian dust storms on mortality in three Asian cities

    NASA Astrophysics Data System (ADS)

    Lee, Hyewon; Honda, Yasushi; Lim, Youn-Hee; Guo, Yue Leon; Hashizume, Masahiro; Kim, Ho

    2014-06-01

    Asian dust storms (ADS) have affected several Asian countries and have been a major concern due to adverse effects on public health. The occurrence of ADS differs in each country based on geographical features and distance from the storms' origin. Many studies have reported significant associations between ADS and morbidity. However, regarding the association between ADS and mortality, only a few studies have found statistically significant ADS effects in Korea, Taiwan and Japan. Accordingly, this study aimed to examine the effects of ADS on daily mortality in three Asian cities (Seoul, South Korea; Taipei, Taiwan; and Kitakyushu, Japan) and to explore the differences in the extent of effects in each city. We performed time-series analyses using a generalized additive model (GAM) with Quasi-Poisson regressions. Deaths due to accidents or external causes were excluded. We used a dummy variable as an indicator of ADS and considered lag effects of ADS. Stratified analyses by disease and age and sensitivity analyses controlling for NO2, SO2, and PM10 were also conducted respectively. Additionally, influenza epidemics were adjusted for considering seasonal patterns, and a meta-analysis was performed. We reported results as excess mortality by percentage due to Asian dust storms. We found significant excess mortality in Seoul and Kitakyushu as follows. In Seoul, ADS showed adverse effects on mortality under 65 years old (lag 2: 4.44%, lag 3: 5%, lag 4: 4.39%). In Kitakyushu, ADS had adverse effects on respiratory mortality (lag 2: 18.82%). Contradictory to results in Seoul and Kitakyushu, ADS seemed to have a protective effect in Taipei: total non-accidental mortality (lag 0: -2.77%, lag 1: -3.24%), mortality over 65 years old (lag 0: -3.35%, lag 1: -3.29%) and respiratory mortality (lag 0: -10.62%, lag 1: -9.67%). Sensitivity analyses showed similar findings as the main results. Our findings suggest that ADS may affect mortality in several Asian cities, and that a dust

  14. Sources, solubility, and acid processing of aerosol iron and phosphorous over the South China Sea: East Asian dust and pollution outflows vs. Southeast Asian biomass burning

    NASA Astrophysics Data System (ADS)

    Hsu, S.-C.; Gong, G.-C.; Shiah, F.-K.; Hung, C.-C.; Kao, S.-J.; Zhang, R.; Chen, W.-N.; Chen, C.-C.; Chou, C. C.-K.; Lin, Y.-C.; Lin, F.-J.; Lin, S.-H.

    2014-08-01

    Iron and phosphorous are essential to marine microorganisms in vast regions in oceans worldwide. Atmospheric inputs are important allochthonous sources of Fe and P. The variability in airborne Fe deposition is hypothesized to serve an important function in previous glacial-interglacial cycles, contributing to the variability in atmospheric CO2 and ultimately the climate. Understanding the mechanisms underlying the mobilization of airborne Fe and P from insoluble to soluble forms is critical to evaluate the biogeochemical effects of these elements. In this study, we present a robust power-law correlation between fractional Fe solubility and non-sea-salt-sulfate / Total-Fe (nss-sulfate / FeT) molar ratio independent of distinct sources of airborne Fe of natural and/or anthropogenic origins over the South China Sea. This area receives Asian dust and pollution outflows and Southeast Asian biomass burning. This correlation is also valid for nitrate and total acids, demonstrating the significance of acid processing in enhancing Fe mobilization. Such correlations are also found for P, yet source dependent. These relationships serve as straightforward parameters that can be directly incorporated into available atmosphere-ocean coupling models that facilitate the assessment of Fe and P fertilization effects. Although biomass burning activity may supply Fe to the bioavailable Fe pool, pyrogenic soils are possibly the main contributors, not the burned plants. This finding warrants a multidisciplinary investigation that integrates atmospheric observations with the resulting biogeochemistry in the South China Sea, which is influenced by atmospheric forcings and nutrient dynamics with monsoons.

  15. Short-cut transport path for Asian dust directly to the Arctic: a case study

    NASA Astrophysics Data System (ADS)

    Huang, Zhongwei; Huang, Jianping; Hayasaka, Tadahiro; Wang, Shanshan; Zhou, Tian; Jin, Hongchun

    2015-11-01

    Asian dust can be transported long distances from the Taklimakan or Gobi desert to North America across the Pacific Ocean, and it has been found to have a significant impact on ecosystems, climate, and human health. Although it is well known that Asian dust is transported all over the globe, there are limited observations reporting Asian dust transported to the Arctic. We report a case study of a large-scale heavy dust storm over East Asia on 19 March 2010, as shown by ground-based and space-borne multi-sensor observations, as well as NCEP/NCAR reanalysis data and HYSPLIT trajectories. Our analysis suggests that Asian dust aerosols were transported from northwest China to the Arctic within 5 days, crossing eastern China, Japan and Siberia before reaching the Arctic. The results indicate that Asian dust can be transported for long distances along a previously unreported transport path. Evidence from other dust events over the past decade (2001-2010) also supports our results, indicating that dust from 25.2% of Asian dust events has potentially been transported directly to the Arctic. The transport of Asian dust to the Arctic is due to cyclones and the enhanced East Asia Trough (EAT), which are very common synoptic systems over East Asia. This suggests that many other large dust events would have generated long-range transport of dust to the Arctic along this path in the past. Thus, Asian dust potentially affects the Arctic climate and ecosystem, making climate change in the Arctic much more complex to be fully understood.

  16. Statistical analysis of the size and elemental composition of airborne coal mine dust

    SciTech Connect

    Lee, C.

    1986-01-01

    The specific purpose of this thesis is to analyze two of the basic characteristics of airborne coal mine dust, size and elemental composition, and to study their ramifications on dust control measures and medical studies of coal workers' pneumoconiosis. A dust-sampling strategy using multi-stage cascade impactors is established for characterization purposes. Analysis of the size data based upon the aerodynamic diameter is performed to examine the two assumptions implicitly made in the current practice for coal mine dust size presentation; lognormality and unimodality in the mass size distribution. The bimodal lognormal model is able to identify the major modal patterns observed in the empirical models. Association of the elemental composition of coal with the rank is tested to be significant. Size dependency and locational variation of elemental composition of airborne coal mine dust are significant. The size dependency is more significant in the immediate return of the continuous miner operation and the elements showing significant locational variability are found to be enriched near the roof bolter operation. The coal seam is the main source of major elements in airborne coal mine dust, while no consistent relationship exists for the trace elements. The significance of the dust in the intake air as a potential source for the elements in airborne coal mine dust is shown. Dust reentrained along the shuttle car route is also found to be a significant dust source. Dust particles in the respirable size range are likely to transport through the working area.

  17. Scavenging of pollutant acid substances by Asian mineral dust particles - article no. L07816

    SciTech Connect

    Matsumoto, J.; Takahashi, K.; Matsumi, Y.; Yabushita, A.; Shimizu, A.; Matsui, I.; Sugimoto, N.

    2006-04-13

    Uptakes of sulfate and nitrate onto Asian dust particles during transport from the Asian continent to the Pacific Ocean were analyzed by using a single-particle time-of-flight mass spectrometer. Observation was conducted at Tsukuba in Japan in the springtime of 2004. Sulfate-rich dust particles made their largest contribution during the 'dust event' in the middle of April 2004. As a result of detailed analysis including backward trajectory calculations, it was confirmed that sulfate components originating from coal combustion in the continent were internally mixed with dust particles. Even in the downstream of the outflow far from the continental coastline, significant contribution of Asian dust to sulfate was observed. Asian dust plays critical roles as the carrier of sulfate over the Pacific Ocean.

  18. Asian dust effect on cause-specific mortality in five cities across South Korea and Japan

    NASA Astrophysics Data System (ADS)

    Kashima, Saori; Yorifuji, Takashi; Bae, Sanghyuk; Honda, Yasushi; Lim, Youn-Hee; Hong, Yun-Chul

    2016-03-01

    Desert dust is considered to be potentially toxic and its toxicity may change during long-range transportation. In Asian countries, the health effects of desert dust in different locations are not well understood. We therefore evaluated the city-combined and city-specific effects of Asian dust events on all-cause and cause-specific mortality in five populous cities in South Korea (Seoul) and Japan (Nagasaki, Matsue, Osaka and Tokyo). We obtained daily mean concentrations of Asian dust using light detection and ranging (lidar) between 2005 and 2011. We then evaluated city-specific and pooled associations of Asian dust with daily mortality for elderly residents (≥65 years old) using time-series analyses. Each 10 μg/m3 increase in the concentration of same-day (lag 0) or previous-day (lag 1) Asian dust was significantly associated with an elevated pooled risk of all-cause mortality (relative risk (RR): 1.003 [95% CI: 1.001-1.005] at lag 0 and 1.001 [95% CI: 1.000-1.003] at lag 1) and cerebrovascular disease (RR: 1.006 [95% CI: 1.000-1.011] at lag 1). This association was especially apparent in Seoul and western Japan (Nagasaki and Matsue). Conversely, no significant associations were observed in Tokyo, which is situated further from the origin of Asian dust and experiences low mean concentrations of Asian dust. Adverse health effects on all-cause and cerebrovascular disease mortality were observed in South Korea and Japan. However, the effects of Asian dust differed across the cities and adverse effects were more apparent in cities closer to Asian dust sources.

  19. Effects of the Asian dust events on daily mortality in Seoul, Korea.

    PubMed

    Kwon, Ho-Jang; Cho, Soo-Hun; Chun, Youngsin; Lagarde, Frederic; Pershagen, Göran

    2002-09-01

    The Korean peninsula has a long history of dust clouds blown by winds from the arid deserts of Mongolia and China in springtime; these are called Asian dust events. Public concern about the possible adverse effects of this dust has increased, because the dust arrives in Korea after having passed over heavily industrialized eastern China. The present study explored the effect of Asian dust events on daily mortality in Seoul, South Korea, during the period 1995-1998. We evaluated the association between daily death counts and the dust events using Poisson regression analysis, adjusted for time trends, weather variables, and the day of the week. Between 1995 and 1998, we identified 28 Asian dust days in Seoul. The estimated percentage increase in the rate of deaths from 3-day moving averages of exposure was 1.7% (95/ confidence interval: -1.6 to 5.3) for all causes, 2.2% (95% confidence interval: -3.5 to 8.3) for deaths of persons aged 65 years and older, and 4.1% (95% confidence interval: -3.8 to 12.6) for cardiovascular and respiratory causes. Our results provide weak evidence that the Asian dust events are associated with risk of death from all causes. However, the association between the dust events and deaths from cardiovascular and respiratory causes was stronger and it suggests that persons with advanced cardiovascular and respiratory disease may be susceptible to the Asian dust events.

  20. Impact of Asian Dust on Global Surface Air Quality and Radiation Budget

    NASA Technical Reports Server (NTRS)

    Chin, Mian; Diehl, Thomas; Yu, Hongbin; Ginoux, Paul

    2006-01-01

    Dust originating from Asian deserts and desertification areas can be transported regionally and globally to affect surface air quality, visibility, and radiation budget not only at immediate downwind locations (e.g., eastern Asia) but also regions far away from the sources (e.g., North America). Deposition of Asian dust to the North Pacific Ocean basin influences the ocean productivity. In this study, we will use the Goddard Chemistry Aerosol Radiation and Transport (GOCART) model, remote sensing data form satellite and from the ground-based network, and in-situ data from aircraft and surface observations to address the following questions: - What are the effects of Asian dust on the surface air quality and visibility over Asia and North America? - What are the seasonal and spatial variations of dust deposition to the North Pacific Ocean? How does the Asian dust affect surface radiation budget?

  1. The effects of transported Asian dust on the composition and concentration of ambient fungi in Taiwan

    NASA Astrophysics Data System (ADS)

    Chao, H. Jasmine; Chan, Chang-Chuan; Rao, Carol Y.; Lee, Chung-Te; Chuang, Ying-Chih; Chiu, Yueh-Hsiu; Hsu, Hsiao-Hsien; Wu, Yi-Hua

    2012-03-01

    This study was conducted to evaluate the effects of transported Asian dust and other environmental parameters on the levels and compositions of ambient fungi in the atmosphere of northern Taiwan. We monitored Asian dust events in Taipei County, Taiwan from January 2003 to June 2004. We used duplicate Burkard portable air samplers to collect ambient fungi before, during, and after dust events. Six transported Asian dust events were monitored during the study period. Elevated concentrations of Aspergillus ( A. niger, specifically), Coelomycetes, Rhinocladiella, Sporothrix and Verticillium were noted ( p < 0.05) during Asian dust periods. Botryosporium and Trichothecium were only recovered during dust event days. Multiple regression analysis showed that fungal levels were positively associated with temperature, wind speed, rainfall, non-methane hydrocarbons and particulates with aerodynamic diameters ≤10 μm (PM10), and negatively correlated with relative humidity and ozone. Our results demonstrated that Asian dust events affected ambient fungal concentrations and compositions in northern Taiwan. Ambient fungi also had complex dynamics with air pollutants and meteorological factors. Future studies should explore the health impacts of ambient fungi during Asian dust events, adjusting for the synergistic/antagonistic effects of weather and air pollutants.

  2. 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

  3. Characterization of microbial community during Asian dust events in Korea.

    PubMed

    Lee, Sunghee; Choi, Bora; Yi, Seung-Muk; Ko, Gwangpyo

    2009-10-01

    An Asian dust event, also sometimes known as a Yellow Sand event, is a seasonal meteorological phenomenon affecting East Asia, typically in the early spring. Because of the significant ecological and health effects of these events on East Asia, and the large amount of dust that is transported from the desert in China to Korea and Japan, these events have been receiving increased attention. It is likely that these storms often provide long-range transport to various microorganisms. However, despite a certain level of attention to the chemical analysis of these storms, microbiological studies of Yellow Sand dust have been scarce. We collected a total of 30 microbiological air samples using a PM(2.5) cyclone sampler in Seoul, Korea from April 2007 to March 2008. Six of these samples were collected during Yellow Sand events, while 24 were from non-Yellow Sand events. Chemical analysis was performed on the samples using a thermal-optical transmittance (TOT) method. Total nucleic acids were also extracted, and the 16S rDNA was amplified by PCR and analyzed by denaturing gradient gel electrophoresis (DGGE). Dendrogram analysis, based on DGGE, indicated that the microbial profiles from the Yellow Sand were distinctive from those of the non-Yellow Sand samples. Microorganisms identified in Yellow Sand samples included Aquabacterium sp., Flavobacteriales bacterium sp., Prevotellaceae bacterium sp., and others, whereas microorganisms in non-Yellow Sand samples included Propionibacterium sp., Bacillus sp., Acinetobacter sp., and others. These results suggest that, as a result of Yellow Sand events, humans in the affected regions are exposed to communities of microorganisms that might cause various adverse health effects. PMID:19631361

  4. A decade of dust: Asian dust and springtime aerosol load in the U.S. Pacific Northwest

    NASA Astrophysics Data System (ADS)

    Fischer, E. V.; Hsu, N. C.; Jaffe, D. A.; Jeong, M.-J.; Gong, S. L.

    2009-02-01

    We integrate SeaWiFS aerosol optical thickness (AOT) over the Taklamakan and Gobi Deserts with U.S. aerosol observations to study surface aerosol variability in the Northwest U.S. in relation to Asian dust emissions. The results indicate that ~50% of the interannual variability in springtime average PM2.5 and PM10 can be explained by changes in Asian dust emissions. On a seasonal timescale, variations in dust emissions appear to be more important in determining the total material crossing the Pacific than the variations in meteorology represented by the PNA or the LRT3 indices. We are able to explain ~80% of the interannual variability using three variables: AOT, a transport index, and regional precipitation. This suggests that a strong source, favorable transport and sufficient residence time are needed for Asian dust to have a maximum seasonal impact in the Northwest. The results contextualize case studies and demonstrate the utility of the Deep Blue algorithm.

  5. Transport of dusts from East Asian and non-East Asian sources to Hong Kong during dust storm related events 1996-2007

    NASA Astrophysics Data System (ADS)

    Lee, Y. C.; Yang, Xun; Wenig, Mark

    2010-09-01

    Over a twelve year period from 1996 to 2007, 76 dust storm related events (as days) in Hong Kong were selected for study, based on Aluminium and Calcium concentrations in PM 10. Four of the 76 events reach episodic levels with exceedances of the Hong Kong air quality standards. The purpose of the study is to identify and characterize dust sources impacting Hong Kong. Global distribution of aerosols in NASA's daily aerosol index images from TOMS and OMI, are compared to plots generated by NRL(US)'s Navy Aerosol Analysis and Prediction System. Possible source areas are assigned by computing air parcel backward trajectories to Hong Kong using the NOAA HYSPLIT model. PM 10 and elemental data are analyzed for crustal mass concentrations and element mass ratios. Our analysis reveals that 73 out of the 76 dust events (96%) involve non-East Asian sources-the Thar, Central/West Asian, Arabian and Sahara deserts (Saharan influence is found in 63 events), which are previously not known to affect Hong Kong. The Gobi desert is the most frequent origin of dust, affecting 68 dust events while the Taklamakan desert impacts only 30 of the dust events. The impact of the Gobi desert in March and December is apparently associated with the northeast monsoon in East Asia. Our results also show a seasonal pattern in dust impact from both East Asian and more remote sources, with a maximum in March. Dust event occurrences are conspicuously absent from summer. Dust transport to Hong Kong is commonly associated with the passage of frontal low-pressure systems. The coarse size fraction of PM 10 concentrations were, as indicated by Al, Ca and Fe concentrations, about 4-8 times higher during dust events. The mean Ca/Al ratios of sources involving the Taklamakan desert are notably higher than those for non-East Asian sources owing to a higher Ca content of most of the East Asian deserts. The Fe/Al ratios follow a similar trend. Contributions from the desert sources are grossly estimated where

  6. On the visibility of airborne volcanic ash and mineral dust

    NASA Astrophysics Data System (ADS)

    Weinzierl, B.; Sauer, D. N.; Minikin, A.; Reitebuch, O.; Dahlkötter, F.; Mayer, B. C.; Emde, C.; Tegen, I.; Gasteiger, J.; Petzold, A.; Veira, A.; Kueppers, U.; Schumann, U.

    2012-12-01

    After the eruption of the Eyjafjalla volcano (Iceland) in April 2010 which caused the most extensive restrictions of the airspace over Europe since the end of World War II, the aviation safety concept of avoiding "visible ash", i.e. volcanic ash that can be seen by the human eye, was recommended. However so far, no clear definition of "visible ash" and no relation between the visibility of an aerosol layer and related aerosol mass concentrations are available. The goal of our study is to assess whether it is possible from the pilot's perspective in flight to detect the presence of volcanic ash and to distinguish between volcanic ash and other aerosol layers just by sight. In our presentation, we focus the comparison with other aerosols on aerosol types impacting aviation: Besides volcanic ash, dust storms are known to be avoided by aircraft. We use in-situ and lidar data as well photographs taken onboard the DLR research aircraft Falcon during the Saharan Mineral Dust Experiments (SAMUM) in 2006 and 2008 and during the Eyjafjalla volcanic eruption in April/May 2010. We complement this analysis with numerical modelling, using idealized radiative transfer simulations with the 3D Monte Carlo radiative transfer code MYSTIC for a variety of selected viewing geometries. Both aerosol types, Saharan mineral dust and volcanic ash, show an enhanced coarse mode (> 1 μm) aerosol concentration, but volcanic ash aerosol additionally contains a significant number of Aitken mode particles (< 150 nm). Volcanic ash is slightly more absorbing than mineral dust, and the spectral behaviour of the refractive index is slightly different. According to our simulations, these differences are not detectable just by human eye. Furthermore, our data show, that it is difficult to define a lower threshold for the visibility of an aerosol layer because the visual detectability depends on many parameters, including the thickness of the aerosol layer, the brightness and color contrast between the

  7. Influence of coal type on water spray suppression of airborne respirable dust

    SciTech Connect

    Organiscak, J.A. ); Leon, M.H. )

    1994-08-01

    A laboratory study was conducted to investigate the water spray capture efficiency of airborne respirable dust generated from nine different bituminous coal seams. Experiments involved grinding a uniform coal sample mass, injecting the dust into a closed steady-state chamber, and measuring the aerosol's decay response when exposed to a hollow cone water spray. The amount of airborne dust generated from these differential coal types varied, but had similar particle size distributions. The spray knockdown efficiency was comparable among coal types, and the size distribution of the dust was uniformly reduced by the water spray. Since water spray capture efficiency remained essentially uniform, the dust concentration at the end of the spray period was a function of the amount of dust generated. Therefore, a particular water spray system used in different coal seams under identical operating conditions (seam height, airflow, water pressure and flow, mining practices, etc.) can be expected to remove airborne dust in a uniform manner. However, dust concentrations will likely vary around identical water spray control systems used in different underground mines because of the diversity in operating conditions and the amount of dust generated from different coal scams. 11 refs., 8 figs., 3 tabs.

  8. Associations Between Subjective Symptoms and Serum Immunoglobulin E Levels During Asian Dust Events

    PubMed Central

    Otani, Shinji; Onishi, Kazunari; Mu, Haosheng; Hosoda, Takenobu; Kurozawa, Youichi; Ikeguchi, Masahide

    2014-01-01

    Asian dust is a seasonal meteorological phenomenon caused by the displacement of atmospheric pollutants from the Mongolian and Chinese deserts. Although the frequency of Asian dust events and atmospheric dust levels have steadily increased in the eastern Asia region, the effects on human health remain poorly understood. In the present study, the impact of Asian dust on human health was determined in terms of allergic reactions. A total of 25 healthy volunteers were tested for a relationship between serum immunoglobulin E (IgE) levels and subjective symptoms during a 3-day Asian dust event recorded in April 2012. They filled daily questionnaires on the severity of nasal, pharyngeal, ocular, respiratory, and skin symptoms by a self-administered visual analog scale. Serum levels of non-specific IgE and 33 allergen-specific IgE molecules were analyzed. Spearman rank-correlation analysis revealed significant positive associations between nasal symptom scores and 2 microbial-specific IgE levels (Penicillium and Cladosporium). Microbes migrate vast distances during Asian dust events by attaching themselves to dust particles. Therefore, some of these symptoms may be associated with type 1 allergic reactions to certain type of microbes. PMID:25075882

  9. Quiescence of Asian dust events in South Korea and Japan during 2012 spring: Dust outbreaks and transports

    NASA Astrophysics Data System (ADS)

    Lee, Yun Gon; Ho, Chang-Hoi; Kim, Joo-Hong; Kim, Jhoon

    2015-08-01

    This study examined the quiescence of Asian dust events in South Korea and Japan during the spring of 2012, presenting a synoptic characterization and suggesting possible causes. Synoptic observation reports from the two countries confirmed that spring 2012 had the lowest number of dust events in 2000-2012. The monthly dust frequency (DF) in March 2012 over the dust source regions, i.e., deserts in northern China and Mongolia, indicated a significant decrease compared to the 12 year (2000-2011) March climatology. The DF in April 2012 was comparable to the 12 year climatology values, but in May 2012 it was slightly lower. The daily Ozone Monitoring Instrument Aerosol Index and the Navy Aerosol Analysis and Prediction System simulations revealed stagnant dust movement in March and May 2012. Anomalous anticyclones north of the source regions decreased the dust outbreaks and enhanced the southeasterly winds, resulting in few dust events over the downwind countries (i.e., South Korea and Japan). By contrast, in April 2012, a strong anomalous cyclone east of Lake Baikal slightly increased the dust outbreaks over northeastern China. However, the major dust outbreaks were not transported downwind because of exceptional dust pathways, i.e., the southeastward pathway of dust transport was unusually blocked by the expansion of an anomalous anticyclonic circulation over the Sea of Okhotsk, with dust being transported northeast.

  10. Dust, Pollution, and Biomass Burning Aerosols in Asian Pacific: A Column Satellite-Surface Perspective

    NASA Technical Reports Server (NTRS)

    Tsay, Si-Chee

    2004-01-01

    Airborne dusts from northern China contribute a significant part of the air quality problem and, to some extent, regional climatic impact in Asia during spring-time. However, with the economical growth in China, increases in the emission of air pollutants generated from industrial and vehicular sources will not only impact the radiation balance, but adverse health effects to humans all year round. In addition, both of these dust and air pollution clouds can transport swiftly across the Pacific reaching North America within a few days, possessing an even larger scale effect. The Asian dust and air pollution aerosols can be detected by its colored appearance on current Earth observing satellites (e.g., MODIS, SeaWiFS, TOMS, etc.) and its evolution monitored by satellites and surface network. Biomass burning has been a regular practice for land clearing and land conversion in many countries, especially those in Africa, South America, and Southeast Asia. However, the unique climatology of Southeast Asia is very different than that of Africa and South America, such that large-scale biomass burning causes smoke to interact extensively with clouds during the peak-burning season of March to April. Significant global sources of greenhouse gases (e.g., CO2, CH4), chemically active gases (e.g., NO, CO, HC, CH3Br), and atmospheric aerosols are produced by biomass burning processes. These gases influence the Earth-atmosphere system, impacting both global climate and tropospheric chemistry. Some aerosols can serve as cloud condensation nuclei, which play an important role in determining cloud lifetime and precipitation, hence, altering the earth's radiation and water budget. Biomass burning also affects the biogeochemical cycling of nitrogen and carbon compounds from the soil to the atmosphere; the hydrological cycle (i.e., run off and evaporation); land surface reflectivity and emissivity; as well as ecosystem biodiversity and stability. Two new initiatives, EAST-AIRE (East

  11. Asian dust transport during the last century recorded in Lake Suigetsu sediments

    NASA Astrophysics Data System (ADS)

    Nagashima, Kana; Suzuki, Yoshiaki; Irino, Tomohisa; Nakagawa, Takeshi; Tada, Ryuji; Hara, Yukari; Yamada, Kazuyoshi; Kurosaki, Yasunori

    2016-03-01

    Asian dust has a significant impact on the natural environment. Its variability on multiple timescales modulates the ocean biogeochemistry and climate. We demonstrate that temporal changes in the deposition flux of Aeolian dust recorded in sediments from Lake Suigetsu, central Japan, during the last century exhibit a continuous decreasing trend and a decadal-scale decrease in 1952-1974. The former decreasing trend can be explained by a decrease in the dust storm frequency at source regions due to the warming of Mongolia in the twentieth century, suggesting future decrease of Asian dust transport with further warming in Mongolia. Decadal-scale decrease of Aeolian dust is explained by weaker westerlies in lower latitudes in central Japan, reflecting a weaker Aleutian Low during the corresponding period. Decadal-scale westerly change probably causes north-south shifts of the dominant dust transport path, which affects subarctic northern Pacific Ocean biogeochemistry by changing the micronutrient iron supply.

  12. Relationship between mortality and fine particles during Asian dust, smog-Asian dust, and smog days in Korea.

    PubMed

    Kim, Hyun-Sun; Kim, Dong-Sik; Kim, Ho; Yi, Seung-Muk

    2012-01-01

    This study examined the association between all-cause/cardiovascular mortality and PM(2.5) as related to Asian dust (AD), smog-AD, smog, and nonevent days and evaluated the differential risks according to specific events for mortality. The daily records of all-cause/cardiovascular mortality and PM(2.5) from March to May 2003-2006 in Seoul, Korea, were used as independent and dependent variables. Differences in the event effects were assessed using a time-series analysis. Both all-cause and cardiovascular mortalities were significantly associated with PM(2.5) during smog-AD and AD days only. Differences in chemical composition emerging during long-range transport to Korea may explain these observations, especially as regards secondary aerosol, metal-sulfate/or nitrate, and metallic components. These results suggest that exposure to PM(2.5) during specific events is differentially associated with human mortality and that changes in the chemical composition of PM(2.5), occurring during long-range transport, represent important factors in such differential effects on health. PMID:22428926

  13. Relationship between mortality and fine particles during Asian dust, smog-Asian dust, and smog days in Korea.

    PubMed

    Kim, Hyun-Sun; Kim, Dong-Sik; Kim, Ho; Yi, Seung-Muk

    2012-01-01

    This study examined the association between all-cause/cardiovascular mortality and PM(2.5) as related to Asian dust (AD), smog-AD, smog, and nonevent days and evaluated the differential risks according to specific events for mortality. The daily records of all-cause/cardiovascular mortality and PM(2.5) from March to May 2003-2006 in Seoul, Korea, were used as independent and dependent variables. Differences in the event effects were assessed using a time-series analysis. Both all-cause and cardiovascular mortalities were significantly associated with PM(2.5) during smog-AD and AD days only. Differences in chemical composition emerging during long-range transport to Korea may explain these observations, especially as regards secondary aerosol, metal-sulfate/or nitrate, and metallic components. These results suggest that exposure to PM(2.5) during specific events is differentially associated with human mortality and that changes in the chemical composition of PM(2.5), occurring during long-range transport, represent important factors in such differential effects on health.

  14. 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 (

  15. Airborne Astronomy Symposium on the Galactic Ecosystem: From Gas to Stars to Dust, volume 73

    NASA Technical Reports Server (NTRS)

    Haas, Michael R. (Editor); Davidson, Jacqueline A. (Editor); Erickson, Edwin F. (Editor)

    1995-01-01

    This symposium was organized to review the science related to NASA's Airborne Astronomy Program on the occasion of the twentieth anniversary of the Kuiper Airborne Observatory (KAO). The theme selected, 'The Galactic Ecosystem: From Gas to Stars to Dust,' was considered to capture the underlying commonality of much of the research discussed. The 8 sessions were as follows: The Interstellar Medium; The Life Cycle of the ISM in Other Galaxies; Star and Planetary System Formation; Our Planetary System: The Solar System; The Enrichment of the Interstellar Medium; The Galactic Center: A Unique Region of the Galactic Ecosystem; Instrumentation for Airborne Astronomy; KAO History and Education; and Missions and the Future of Infrared Astronomy.

  16. Elemental composition of airborne dust in the Shale Shaker House during an offshore drilling operation.

    PubMed

    Hansen, A B; Larsen, E; Hansen, L V; Lyngsaae, M; Kunze, H

    1991-12-01

    During 2 days of an offshore drilling operation in the North Sea, 16 airborne dust samples from the atmosphere of the Shale Shaker House were collected onto filters. During this operation, drilling mud composed of a water slurry of barite (BaSO4) together with minor amounts of additives, among them chrome lignosulphonate and chrome lignite, was circulated between the borehole and the Shale Shaker House. The concentration of airborne dust in the atmosphere was determined and the elemental composition of the particles analysed by both PIXE (proton-induced X-ray emission) and ICP-MS (inductively coupled plasma-mass spectrometry). The total amount of dust collected varied from 0.04 to 1.41 mg m-3 with barium (Ba) as the single most abundant element. The open shale shakers turned out to be the major cause of generation of dust from the solid components of the drilling mud.

  17. Elemental composition of airborne dust in the Shale Shaker House during an offshore drilling operation.

    PubMed

    Hansen, A B; Larsen, E; Hansen, L V; Lyngsaae, M; Kunze, H

    1991-12-01

    During 2 days of an offshore drilling operation in the North Sea, 16 airborne dust samples from the atmosphere of the Shale Shaker House were collected onto filters. During this operation, drilling mud composed of a water slurry of barite (BaSO4) together with minor amounts of additives, among them chrome lignosulphonate and chrome lignite, was circulated between the borehole and the Shale Shaker House. The concentration of airborne dust in the atmosphere was determined and the elemental composition of the particles analysed by both PIXE (proton-induced X-ray emission) and ICP-MS (inductively coupled plasma-mass spectrometry). The total amount of dust collected varied from 0.04 to 1.41 mg m-3 with barium (Ba) as the single most abundant element. The open shale shakers turned out to be the major cause of generation of dust from the solid components of the drilling mud. PMID:1768013

  18. Characterization of Asian dust storm and non-Asian dust storm PM 2.5 aerosol in southern Taiwan

    NASA Astrophysics Data System (ADS)

    Tsai, Ying I.; Chen, Chien-Lung

    High winds that blow sand from the desert regions of central Asia to points east are commonly known as Asian dust storms (ADS). In this paper we study the impact of an ADS on the PM 2.5 aerosol extant in Tainan, a city in southern Taiwan. PM 2.5 aerosol was collected at an urban and a coastal site in Tainan before the ADS (4-12 January 2001), during the ADS (13-16 January 2001), and the following summer (3-12 June 2001). Total PM 2.5 mass was highest at both sites during the ADS despite already moderately high levels of PM 2.5 beforehand, demonstrating that the ADS brought with it a significant amount of PM 2.5 mass. The mass percentage of Ca 2+ in PM 2.5 increased noticeably during the ADS and there was a higher non-sea-salt SO 42-/elemental carbon ratio. This latter change was due to a heightened level of non-sea-salt SO 42-, which has a serious impact on air quality in southern Taiwan, and was likely sourced from sulfur integrated into the ADS aerosol as it passed major cities and industrial districts in China. The percentage water content in PM 2.5 was at its lowest during the ADS. This was despite high levels of hygroscopic sulfate in the ADS aerosol and indicates that sulfate in the ADS may combine with Ca 2+ to form CaSO 4, a major component of ADS dust and one that does not have strong hygroscopic characteristics. Water content was at its highest in summer when winds arrive in Taiwan with elevated sea salt concentrations, having spent several days traversing the South China Sea. Non-ADS urban site aerosols were weakly acidic while coastal site aerosols were weakly alkaline. Urban site acidity was always higher than equivalent to coastal site acidity, due to locally produced acidic aerosols. Acidity peaked during the ADS, however, as a result of additional acidic aerosols transported by the ADS from urban and industrial regions in China.

  19. The Asian Dust and Aerosol Lidar Observation Network (AD-NET): Strategy and Progress

    NASA Astrophysics Data System (ADS)

    Nishizawa, Tomoaki; Sugimoto, Nobuo; Matsui, Ichiro; Shimizu, Atsushi; Higurashi, Akiko; Jin, Yoshitaka

    2016-06-01

    We have operated a ground-based lidar network AD-Net using dual wavelength (532, 1064nm) depolarization Mie lidar continuously and observed movement of Asian dust and air pollution aerosols in East Asia since 2001. This lidar network observation contributed to understanding of the occurrence and transport mechanisms of Asian dust, validation of chemical transport models, data assimilation and epidemiologic studies. To better understand the optical and microphysical properties, externally and internally mixing states, and the movements of Asian dust and airpollution aerosols, we go forward with introducing a multi-wavelength Raman lidar to the AD-Net and developing a multi-wavelength technique of HSRL in order to evaluate optical concentrations of more aerosol components. We will use this evolving AD-Net for validation of Earth-CARE satellite observation and data assimilation to evaluate emissions of air pollution and dust aerosols in East Asia. We go forward with deploying an in-situ instrument polarization optical particle counter (POPC), which can measure size distributions and non-sphericity of aerosols, to several main AD-Net sites and conducting simultaneous observation of POPC and lidar to clarify internally mixed state of Asian dust and air pollution aerosols transported from the Asian continent to Japan.

  20. Using proximate analysis to characterize airborne dust generation from bituminous coals

    SciTech Connect

    Page, S.J.; Organiscak, J.A.

    2005-11-01

    Prolonged exposure to airborne respirable coal dust is responsible for coal workers pneumoconiosis (CWP), commonly called black lung. Health research studies have identified that the prevalence and severity of CWP are directly related to both the amount of dust exposure and the coal rank. The amount of airborne respirable dust (ARD) smaller than 10 micrometers generated from breakage of different coals varies widely. To investigate the cause, researchers for the National Institute for Occupational Safety and Health (NIOSH) have conducted experiments to identify the causes of airborne respirable dust liberation. Laboratory crushing experiments were conducted on a range of low to high volatile bituminous coals from eight mines. The results indicate that the proximate analysis of a coal sample can provide a very good indicator of the potential for a dust problem. For application to the coal mining, processing, and utilization industries, data from 977 US coal seams compiled by the Department of Energy (DoE) has been used to calculate this dust generation potential from an equation based on the NIOSH measured data. A simple procedure for this calculation is provided. 1 fig.

  1. Observed trend in Asian dust days in South Korea and its geo-physiographical implications

    NASA Astrophysics Data System (ADS)

    Yang, Soohyun; Paik, Kyungrock

    2015-04-01

    South Korea has experienced significant socio-economic damages by Asian dust (also called Yellow sand or Yellow dust). Asian dust is a wind-driven natural phenomenon that carries fine sand particles along with surface pollutants from semi-arid areas in northern China, Inner Mongolia, the Gobi Desert, and the Taklimakan Desert to the East Asia. Its occurrence requires three necessary conditions: dry soil in source areas, strong ascending air current to lift sand particles up, and intense wind speed to transport the particles. Accordingly, the drier source areas are, the larger amount of source materials for Asian dust becomes. Further, regional wind speed and direction are key elements that determine the influencing boundary and level of damage. In this study, we investigate number of Asian dust days over South Korea. We utilize monthly data over 50 years (from 1961 to 2013) recorded at 12 stations, operated by the Korean Meteorological Administration, which are evenly distributed over the country. We find that annual number of Asian dust days in South Korea tends to increase until early 2000s and the increasing trend is ceased since then. Interestingly, this transition time (early 2000s) matches the time when the surface wind speed trend has reversed (Kim and Paik, 2015). Hence, we hypothesize that occurrence of Asian dust in South Korea can be largely captured by surface wind, instead of air circulation at high altitude. We also hypothesize that the transition in the trend around early 2000s is associated with expansion of cold air system during winter over the East Asia. Detailed analysis to support these findings will be presented. Reference Kim, JC., & Paik, K. (2015). Recent recovery of surface wind speed after decadal decrease: A focus on South Korea. Climate Dynamics, (Under review).

  2. Effect of Asian dust storms on daily mortality in seven metropolitan cities of Korea

    NASA Astrophysics Data System (ADS)

    Lee, Hyewon; Kim, Ho; Honda, Yasushi; Lim, Youn-Hee; Yi, Seungmuk

    2013-11-01

    The adverse effects of dust storms on health have been a major issue in several countries. A substantial number of studies have found significant associations between dust storms and morbidity such as emergency visits and hospitalizations. However, the results of the studies on the association between dust storms and mortality are inconsistent. In Korea, no study has found statistically significant effect of Asian dust storms on daily mortality. Thus, this study aims to explore the effect of Asian dust storms on daily mortality in Korea during 2001-2009. All analyses were confined to non-accidental mortality. We used generalized additive model with Quasi-Poisson regressions. We considered the lag effect of dust storms up to 7 days and performed subgroup analyses by disease, sex and age. Current day's temperature, relative humidity, barometric pressure, day of the week, season and time trends were controlled for in a basic model. SO2, NO2 and PM10 levels were also added in the further analyses. Meta-analysis was applied for seven metropolitan cities in Korea to estimate the pooled effects of Asian dust storms. We reported results as excessive mortality by percentage due to Asian dust storms. We found significant positive associations between Asian dust storms and mortality at lag 0 (cardiovascular: 2.91%; 95% CI: 0.13, 5.77, male: 2.74%; 95% CI: 0.74, 4.77 and <65 years: 2.52%; 95% CI: 0.06, 5.04), at lag 2 (male 2.4%; 95% CI: 0.43, 4.4 and <65 years: 2.49%; 95% CI: 0.07, 4.97), at lag 3 (total non-accidental: 1.57%; 95% CI: 0.11, 3.06, male: 2.24%; 95% CI: 0.28, 4.25 and <65 years: 2.43%; 95% CI: 0.01, 4.91) and at lag 5 (cardiovascular: 3.7%; 95% CI: 0.93, 6.54 and male: 2.04%, 95 CI: 0.08, 4.04) in the model which adjusted for NO2 additionally. Other models showed similar significant results except the PM10-adjusted model. This is the first study to show the significant relationship between Asian dust storms and mortality in Korea and to present a pooled effect

  3. Health effects of Asian dust events: a review of the literature.

    PubMed

    Hashizume, Masahiro; Ueda, Kayo; Nishiwaki, Yuji; Michikawa, Takehiro; Onozuka, Daisuke

    2010-05-01

    Asian dust, called 'kosa' in Japan, is the long-range transport of atmospheric pollutants originating from the desert areas of China and Mongolia. Although Asian dust has a long history of appearing in Japan, it is only quite recently that there is increasing concern for its possible adverse health effects. We reviewed the epidemiologic evidence of potential health effects of Asian dust events. PubMed was used to search for the following keywords: Asian dust, yellow sand, desert dust, dust storm, sandstorm, mortality, death, morbidity, hospitalization, hospital admission, health, pulmonary and respiratory. The search was limited to the epidemiologic studies published between January 1980 and May 2009. JMEDPlus was used to search for Japanese literature. Seventeen studies were retrieved from PubMed and one study from JMEDPlus. In addition, one study was identified for reviewing from the references of another study. In total, we identified 19 epidemiologic studies (3 for mortality, 13 for hospital visits or admissions and 3 for respiratory functions or symptoms) mainly from Taiwan and Korea. There were many combinations of outcomes and lagged exposures examined, and some suggested possible associations of dust exposure with an increase in mortality and hospital visits and admissions due to cardiovascular and respiratory diseases, whereas the rest of the studies did not show statistically significant associations. The evidence from these studies was limited because exposure assessments were inadequately described and potential confounders were insufficiently controlled. Well-designed epidemiological studies are required to clarify any potential health effects of Asian dust events in Japan. PMID:20508385

  4. Global dispersion of bacterial cells on Asian dust

    PubMed Central

    Yamaguchi, Nobuyasu; Ichijo, Tomoaki; Sakotani, Akiko; Baba, Takashi; Nasu, Masao

    2012-01-01

    The atmospheric dispersion of bacteria over long distances is an important facet of microbial ecology. Certain groups of dispersed bacteria can adapt to their new location and affect established ecosystems. Aeolian dust particles are known to be carriers of microbes but further research is needed to expand our understanding of this field of microbiology. Here we showed the potential of aeolian dust to global migration of bacterial cells. We demonstrated the presence of microbial cells on dust particles directly by bio-imaging. Bacterial abundance on dust particles declined from 105 to less than 103 cells/m3 as the dust event subsided. Taxonomically diverse bacteria were identified by 16S rRNA gene sequencing and some of these bacteria retained growth potential. Our results confirm that bacteria can attach to aeolian dust particles and they have the potential to migrate globally during dust events and thus can contribute to the diversity of downwind ecosystems. PMID:22826803

  5. The role of airborne mineral dusts in human disease

    NASA Astrophysics Data System (ADS)

    Morman, Suzette A.; Plumlee, Geoffrey S.

    2013-06-01

    Exposure to fine particulate matter (PM) is generally acknowledged to increase risk for human morbidity and mortality. However, particulate matter (PM) research has generally examined anthropogenic (industry and combustion by-products) sources with few studies considering contributions from geogenic PM (produced from the Earth by natural processes, e.g., volcanic ash, windborne ash from wildfires, and mineral dusts) or geoanthropogenic PM (produced from natural sources by processes that are modified or enhanced by human activities, e.g., dusts from lakebeds dried by human removal of water, dusts produced from areas that have undergone desertification as a result of human practices). Globally, public health concerns are mounting, related to potential increases in dust emission from climate related changes such as desertification and the associated long range as well as local health effects. Recent epidemiological studies have identified associations between far-traveled dusts from primary sources and increased morbidity and mortality in Europe and Asia. This paper provides an outline of public health research and history as it relates to naturally occurring inorganic mineral dusts. We summarize results of current public health research and describe some of the many challenges related to understanding health effects from exposures to dust aerosols.

  6. Episode simulation of Asian dust storms with an air quality modeling system

    NASA Astrophysics Data System (ADS)

    Ge, Cui; Zhang, Meigen; Han, Zhiwei; Liu, Yanju

    2011-05-01

    A dust deflation module was developed and coupled with the air quality modeling system RAMS-CMAQ to simultaneously treat all the major tropospheric aerosols (i.e., organic and black carbons, sulfate, nitrate, ammonia, soil dust, and sea salt). Then the coupled system was applied to East Asia to simulate Asian dust aerosol generation, transport and dry/wet removal processes during 14-25 March 2002 when two strong dust storms occurred consecutively. To evaluate model performance and to analyze the observed features of dust aerosols over the East Asian region, model results were compared to concentrations of suspended particulate matter of 10 µm or less (PM10; 1-h intervals) at four remote Japanese stations and daily air pollution index (API) values for PM10 at four large Chinese cities. The modeled values were generally in good agreement with observed data, and the model reasonably reproduced two dust storm outbreaks and generally predicted the dust onset and cessation times at each observation site. In addition, hourly averaged values of aerosol optical thickness (AOT) were calculated and compared with observations at four Aerosol Robotic Network (AERONET) stations to assess the model's capability of estimating dust aerosol column burden. Analysis shows that modeled and observed AOT values were generally comparable and that the contribution of dust aerosols to AOT was significant only with regard to their source regions and their transport paths.

  7. The application of performance standards to personal airborne dust samplers.

    PubMed

    Kenny, L C; Lidén, G

    1989-01-01

    This paper summarizes current proposals for the specification and testing of personal sampler performance, and discusses their implications for the precision of dust concentration estimates. A method of specifying the performance of a sampling instrument in terms of the range of masses it would collect from various dust clouds is proposed. Some of the practical difficulties which are likely to arise in the process of testing real samplers with respect to performance standards are discussed.

  8. Regional distribution of monsoon and desert dust signals recorded in Asian glaciers

    NASA Astrophysics Data System (ADS)

    Wake, Cameron P.; Mayewski, Paul A.; Xie, Zichu; Wang, Ping; Li, Zhongqin

    1993-07-01

    Short-term (6 months to 17 years) glaciochemical records have been collected from glacier basins throughout the mountains of central Asia. The spatial distribution of snow chemistry in central Asia is controlled predominantly by the influx of dust from the arid and semi-arid regions in central Asia. The glaciochemical data suggests that glaciers which are removed from large source areas of mineral aerosol, such as those in the Himalaya, the Karakoram, and the southeastern Tibetan Plateau, are the ones most likely to contain longer-term glaciochemical records which detail annual to decadal variation in the strength of the Asian monsoon and long-range transport of Asian dust.

  9. Integrated Study of AD-Net Mie-Lidar Network and Data Assimilated CTM for Asian Dust Epidemiology in Japan

    NASA Astrophysics Data System (ADS)

    Shimizu, Atsushi; Nishizawa, Tomoaki; Sugimoto, Nobuo; Matsui, Ichiro; Kobayashi, Hiroshi; Maki, Takashi; Sekiyama, Thomas T.; Kanatani, Kumiko

    2016-06-01

    Mie-scattering lidar data are going to be incorporated into data assimilation in chemical transport model to represent more reliable / useful horizontal distribution of Asian dust over Japan. The result is utilized in an epidemiology which surveys effect of Asian dust to human health. Wider application of AD-Net is expected in the field of environmental researches.

  10. Geochemical and microbiological fingerprinting of airborne dust that fell in Canberra, Australia, in October 2002

    NASA Astrophysics Data System (ADS)

    de Deckker, Patrick; Abed, Raeid M. M.; de Beer, Dirk; Hinrichs, Kai-Uwe; O'Loingsigh, Tadhg; Schefuß, Enno; Stuut, Jan-Berend W.; Tapper, Nigel J.; van der Kaars, Sander

    2008-12-01

    During the night of 22-23 October 2002, a large amount of airborne dust fell with rain over Canberra, located some 200 km from Australia's east coast, and at an average altitude of 650 m. It is estimated that during that night about 6 g m-2 of aeolian dust fell. We have conducted a vast number of analyses to "fingerprint" some of the dust and used the following techniques: grain size analysis; scanning electron microscope imagery; major, trace, and rare earth elemental, plus Sr and Nd isotopic analyses; organic compound analyses with respective compound-specific isotope analyses; pollen extraction to identify the vegetation sources; and molecular cloning of 16S rRNA genes in order to identify dust bacterial composition. DNA analyses show that most obtained 16S rRNA sequences belong mainly to three groups: Proteobacteria (25%), Bacteriodetes (23%), and gram-positive bacteria (23%). In addition, we investigated the meteorological conditions that led to the dust mobilization and transport using model and satellite data. Grain sizes of the mineral dust show a bimodal distribution typical of proximal dust, rather than what is found over oceans, and the bimodal aspect of size distribution confirms wet deposition by rain droplets. The inorganic geochemistry points to a source along/near the Darling River in NW New South Wales, a region that is characteristically semiarid, and both the organic chemistry and palynoflora of the dust confirm the location of this source area. Meteorological reconstructions of the event again clearly identify the area near Bourke-Cobar as being the source of the dust. This study paves the way for determining the export of Australian airborne dust both in the oceans and other continents.

  11. Iron fertilisation by Asian dust influences North Pacific sardine regime shifts

    NASA Astrophysics Data System (ADS)

    Qiu, Yongsong

    2015-05-01

    Forcing factors and mechanisms underlying multidecadal variability in the production of the world's major fish stocks are one of the great mysteries of the oceans. The Japanese and California sardine are species that exhibit the regime shifts. It is shown in the present work that during two periods of frequent Asian dust events over the last 100 years, sardines on opposite sides of the Pacific Ocean only flourished under a dust-active regime. The earlier such regime that peaked in the 1930s was strong, and it brought synchronous changes in the two species that were linked to the frequency of Asian dust events. However, there is an apparent mismatch in the rise and fall of abundance between the two species in the current dust-active regime. The massive increase in Japanese sardine stock in the 1970s was related to high levels of ocean precipitation and strong winter mixing, whereas the stock collapse since 1988 has been attributed to diminished winter mixing. High levels of ocean precipitation in the western North Pacific effectively cause wet deposition of Asian dust and enhance Japanese sardine stock, whereas it reduces dust flux that can be transported to the eastern North Pacific, delaying the increase of California sardine stock. Analysis further indicates that productivity of Japanese sardine stock is jointly controlled by wet deposition of Asian dust and winter mixing, which supplies macronutrients from depth. California sardine productivity is inversely related to precipitation in the western North Pacific and is positively affected by precipitation off western North America. This indicates that Asian dust influx dominates productivity of the species because of iron-limited ocean productivity in the California sardine ranges. The analysis suggests that dust regime shifts influence shifts in sardine productivity regimes and that iron input from Asian dust during trans-Pacific transport is directly responsible. It appears that in addition to enhancing

  12. Properties and transport of Asian dust from 10 years of MISR data

    NASA Astrophysics Data System (ADS)

    Kalashnikova, O. V.; Sokolik, I. N.; Garay, M. J.; Wu, D. L.

    2009-12-01

    We use the 10-year aerosol data record from the Multi-angle Imaging SpectroRadiometer (MISR) aboard the Terra satellite to investigate climatological linkages between the dust source activities, mid-range, and long-range transport of Asian dust. The inter-annual and seasonal variability of Asian dust loadings and properties as retrieved by MISR at selected regions along the transport routes was investigated. In particular, we examine the Taklamakan and East and Central Gobi regions (dust sources), South Korea and Japan regions (mid-range transport), and the North Pacific region along the northwestern U.S. coast (long-range transport). To avoid the gridding and averaging effects in Level 3 products, we use the Level 2 MISR swath data. Within each selected region, the analysis was performed to examine the multi-annual mean and variability of the aerosol optical depth and particle nonsphericity as well as time-lag correlation between the regions, taking into account the effects of MISR sampling and cloud screening. The results will be presented and interpreted in the context of atmospheric dynamics variability, including variability of meteorological regimes in dust sources and the large-scale atmospheric circulation features controlling the trans-Pacific transport of Asian dust.

  13. Deposition of Asian Dust in the Tahoe Basin and the Impact of Climate Patterns on Deposition

    NASA Astrophysics Data System (ADS)

    Snyder, Jason

    Routine monitoring of fine aerosols in the Lake Tahoe basin began with the Tahoe Regional Planning Association (TRPA) in 1988 (Molenar et. al., 1994). During this time two sites of aerosol impact analysis were chosen based on prior work done by the ARB (Cahill et. al., 1997). These sites included Bliss SP, which is located near Emerald Bay at 200 m Lake Tahoe. Aerosols deposited at the Bliss SP site during each spring from 1988 to 2004, were predominately from sources outside of the Lake Tahoe basin and contained signatures from an "unknown north Sacramento Valley source" (Cahill and Cliff, 2002). The aerosols amounted to about ½ of all fine soil seen at South Lake Tahoe. With a better knowledge regarding the efficiency of the transport of fine aerosol plumes across the Pacific Ocean to North American combined with the presence of Asian dust signatures at other sites including Crater Lake and the Yukon, it was now determined that the source of fine particles to the Lake Tahoe basin was possibly Asian in origin. For this study, aerosols were collected during spring 2006, which coincides with the annual peak of Asian dust transport toward North America. Aerosols were collected at the TERC Tahoe Fish Hatchery, a relatively pollution free site northeast of Tahoe City. Aerosol collections at this site were done on an offshore pier, which reduced the amount of contamination for shore sources of aerosols and pollution such as road dust. The result was the identification of Asian dust signatures in aerosol deposition data for the period of April 28 to May 15, 2006. Such dust plumes were identified using HYSPLIT trajectories. Chemical signatures were also used including the Fe/Ca ratio, which is unique in Asian dust plumes. The particulate matter in these dust plumes produce a regional haze across the Lake Tahoe basin, which could impact incoming solar radiation. Furthermore, deposition of particles from the aerosol plume into the lake not only contributed to suspended

  14. Characterization of Asian Dust Properties Near Source Region During ACE-Asia

    NASA Technical Reports Server (NTRS)

    Tsay, Si-Chee; Hsu, N. Christina; King, Michael D.; Kaufman, Yoram J.; Herman, Jay R.

    2004-01-01

    Asian dust typically originates in desert areas far from polluted urban regions. During transport, dust layers can interact with anthropogenic sulfate and soot aerosols from heavily polluted urban areas. Added to the complex effects of clouds and natural marine aerosols, dust particles reaching the marine environment can have drastically different properties than those from the source. Thus, understanding the unique temporal and spatial variations of Asian aerosols is of special importance in regional-to-global climate issues such as radiative forcing, the hydrological cycle, and primary biological productivity in the mid-Pacific Ocean. During ACE-Asia campaign, we have acquired ground- based (temporal) and satellite (spatial) measurements to infer aerosol physical/optical/radiative properties, column precipitable water amount, and surface reflectivity over this region. The inclusion of flux measurements permits the determination of aerosol radiative flux in addition to measurements of loading and optical depth. At the time of the Terra/MODIS, SeaWiFS, TOMS and other satellite overpasses, these ground-based observations can provide valuable data to compare with satellite retrievals over land. In this paper, we will demonstrate new capability of the Deep Blue algorithm to track the evolution of the Asian dust storm from sources to sinks. Although there are large areas often covered by clouds in the dust season in East Asia, this algorithm is able to distinguish heavy dust from clouds over the entire regions. Examination of the retrieved daily maps of dust plumes over East Asia clearly identifies the sources contributing to the dust loading in the atmosphe. We have compared the satellite retrieved aerosol optical thickness to the ground-based measurements and obtained a reasonable agreement between these two. Our results also indicate that there is a large difference in the retrieved value of spectral single scattering albedo of windblown dust between different

  15. The effect of airborne dust on astronomical polarization measurements

    NASA Astrophysics Data System (ADS)

    Bailey, Jeremy; Ulanowski, Z.; Lucas, P. W.; Hough, J. H.; Hirst, E.; Tamura, M.

    2008-05-01

    In the past, it has generally been assumed that polarization observations made with ground-based telescopes are unaffected by the passage of light through the Earth's atmosphere. Here, we report observations with a new high-sensitivity astronomical polarimeter (PlanetPol) made during a Saharan dust event over the La Palma observatory in 2005 May that show excess linear polarization in the horizontal direction due to the passage of the starlight through the dust. The polarization reached a maximum value of 4.8 × 10-5 at 56° zenith distance and varied over five nights in proportion to the change in dust optical depth. Polarization of transmitted light (dichroism) does not occur for spherical or randomly oriented non-spherical particles. Thus, these results imply that some fraction of the dust grain population aligns with a preferred orientation. We use T-matrix models to demonstrate that the observed polarization direction implies a vertical orientation for the long axis of the particles. We suggest a possible mechanism for vertical orientation resulting from the electric field in the atmosphere. These results will need to be taken into account in the design and use of future instruments for high-sensitivity astronomical polarimetry. The results also indicate possible new approaches to studying aerosol particles and their effects on the Earth's atmosphere.

  16. An improved radiance simulation for hyperspectral infrared remote sensing of Asian dust

    NASA Astrophysics Data System (ADS)

    Han, Hyo-Jin; Sohn, Byung-Ju; Huang, Hung-Lung; Weisz, Elisabeth; Saunders, Roger; Takamura, Tamio

    2012-05-01

    The fast Radiative Transfer for Television Infrared Observation Satellite (TIROS) Operational Vertical Sounder (RTTOV) (Version 9.3) model was used for simulating the effect of East Asian dust on top of atmosphere radiances. The size distribution of Asian dust was retrieved from nine years of sky radiometer measurements at Dunhunag located in the east of Taklimakan desert of China. The default surface emissivity in RTTOV was replaced by the geographically and monthly varying data from University of Wisconsin (UW)/Cooperative Institute for Meteorological Satellite Studies (CIMSS) infrared surface spectral emissivities. For a given size distribution and surface emissivity, the effects of three refractive indices of Optical Properties of Aerosols and Clouds (OPAC) mineral aerosol, dust-like aerosol by Volz, and High Resolution Transmission (HITRAN) quartz were examined. Results indicate that the specification of surface emissivity using geographically and monthly varying UW/CIMSS data significantly improved the performance of the simulation of AIRS brightness temperature (TB) difference (BTD) between window channels, in comparison to the results from the use of default emissivity value of 0.98 in the RTTOV model, i.e., increase of the correlation coefficient from 0.1 to 0.83 for BTD between 8.9 μm and 11 μm, and from 0.31 to 0.61 for BTD between 3.8 μm and 11 μm. On the other hand, the use of Asian dust size distributions contributed to a general reduction of radiance biases over dust-sensitive window bands. A further improvement of the TB simulations has been made by considering the Volz refractive index, suggesting that hyperspectral infrared remote sensing of Asian dust can be improved using the proper optical properties of the dust and surface emissivity.

  17. Investigation of aged Asian dust particles by the combined use of quantitative ED-EPMA and ATR-FTIR imaging

    NASA Astrophysics Data System (ADS)

    Song, Y.-C.; Eom, H.-J.; Jung, H.-J.; Malek, M. A.; Kim, H. K.; Geng, H.; Ro, C.-U.

    2013-03-01

    In our previous works, it was demonstrated that the combined use of quantitative energy-dispersive electron probe X-ray microanalysis (ED-EPMA), which is also known as low-Z particle EPMA, and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) imaging has great potential for a detailed characterization of individual aerosol particles. In this study, extensively chemically modified (aged) individual Asian dust particles collected during an Asian dust storm event on 11 November 2002 in Korea were characterized by the combined use of low-Z particle EPMA and ATR-FTIR imaging. Overall, 109 individual particles were classified into four particle types based on their morphology, elemental concentrations, and molecular species and/or functional groups of individual particles available from the two analytical techniques: Ca-containing (38%), NaNO3-containing (30%), silicate (22%), and miscellaneous particles (10%). Among the 41 Ca-containing particles, 10, 8, and 14 particles contained nitrate, sulfate, and both, respectively, whereas only two particles contained unreacted CaCO3. Airborne amorphous calcium carbonate (ACC) particles were observed in this Asian dust sample for the first time, where their IR peaks for the insufficient symmetric environment of CO32- ions of ACC were clearly differentiated from those of crystalline CaCO3. This paper also reports the first inland field observation of CaCl2 particles probably converted from CaCO3 through the reaction with HCl(g). HCl(g) was likely released from the reaction of sea salt with NOx/HNO3, as all 33 particles of marine origin contained NaNO3 (no genuine sea salt particle was encountered). Some silicate particles with minor amounts of calcium were observed to be mixed with nitrate, sulfate, and water. Among 24 silicate particles, 10 particles are mixed with water, the presence of which could facilitate atmospheric heterogeneous reactions of silicate particles including swelling minerals, such

  18. Airborne fungal and bacterial components in PM1 dust from biofuel plants.

    PubMed

    Madsen, Anne Mette; Schlünssen, Vivi; Olsen, Tina; Sigsgaard, Torben; Avci, Hediye

    2009-10-01

    Fungi grown in pure cultures produce DNA- or RNA-containing particles smaller than spore size (<1.5 microm). High exposures to fungi and bacteria are observed at biofuel plants. Airborne cultivable bacteria are often described to be present in clusters or associated with larger particles with an aerodynamic diameter (d(ae)) of 2-8 microm. In this study, we investigate whether airborne fungal components smaller than spore size are present in bioaerosols in working areas at biofuel plants. Furthermore, we measure the exposure to bacteria and fungal components in airborne particulate matter (PM) with a D(50) of 1 microm (called PM(1) dust). PM(1) was sampled using Triplex cyclones at a working area at 14 Danish biofuel plants. Millipore cassettes were used to sample 'total dust'. The PM(1) particles (29 samples) were analysed for content of 11 different components and the total dust was analysed for cultivable fungi, N-acetyl-beta-D-glucosaminidase (NAGase), and (1 --> 3)-beta-D-glucans. In the 29 PM(1) samples, cultivable fungi were found in six samples and with a median concentration below detection level. Using microscopy, fungal spores were identified in 22 samples. The components NAGase and (1 --> 3)-beta-D-glucans, which are mainly associated with fungi, were present in all PM(1) samples. Thermophilic actinomycetes were present in 23 of the 29 PM(1) samples [average = 739 colony-forming units (CFU) m(-3)]. Cultivable and 'total bacteria' were found in average concentrations of, respectively, 249 CFU m(-3) and 1.8 x 10(5) m(-3). DNA- and RNA-containing particles of different lengths were counted by microscopy and revealed a high concentration of particles with a length of 0.5-1.5 microm and only few particles >1.5 microm. The number of cultivable fungi and beta-glucan in the total dust correlated significantly with the number of DNA/RNA-containing particles with lengths of between 1.0 and 1.5 microm, with DNA/RNA-containing particles >1.5 microm, and with other

  19. SeaWiFS: Asian Dust over the Western United States

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This SeaWiFS image, captured on April 15, 2001, shows dust from the Asian continent over the United States. Atmospheric aerosoles are much easier to see over water than over land, so you can best see the haze offshore. Credit: Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  20. Observation of chemical modification of Asian Dust particles during long-range transport by the combined use of quantitative ED-EPMA and ATR-FT-IR imaging

    NASA Astrophysics Data System (ADS)

    Song, Young-Chul; Eom, Hyo-Jin; Jung, Hae-Jin; Malek, Md Abdul; Kim, HyeKyeong; Ro, Chul-Un

    2012-10-01

    In our previous works, it was demonstrated that the combined use of quantitative energy-dispersive electron probe X-ray microanalysis (ED-EPMA), which is also known as low-Z particle EPMA, and attenuated total reflectance FT-IR (ATR-FT-IR) imaging has great potential for a detailed characterization of individual aerosol particles. In this study, individual Asian Dust particles collected during an Asian Dust storm event on 11 November 2011 in Korea were characterized by the combined use of low-Z particle EPMA and ATR-FT-IR imaging. The combined use of the two single-particle analytical techniques on the same individual particles showed that Asian Dust particles had experienced extensive chemical modification during long-range transport. Overall, 109 individual particles were classified into four particle types based on their morphology, elemental concentrations, and molecular species and/or functional groups of individual particles available from the two analytical techniques: Ca-containing (38%); NaNO3-containing (30%); silicate (22%); and miscellaneous particles (10%). Among the 41 Ca-containing particles, 10, 8, and 14 particles contained nitrate, sulfate, and both, respectively, whereas only two particles contained unreacted CaCO3. Airborne amorphous calcium carbonate (ACC) particles were observed in this Asian Dust sample for the first time, where their IR peaks for the insufficient symmetric environment of CO32- ions of ACC were clearly differentiated from those of crystalline CaCO3. This paper also reports the field observations of CaCl2 particles converted from CaCO3 for the Asian Dust sample collected in the planetary boundary layer. Thirty three particles contained NaNO3, which are the reaction products of sea-salt and NOx/HNO3, whereas no genuine sea-salt particles were encountered, indicating that sea-salt particles are more reactive than CaCO3 particles. Some silicate particles were observed to contain nitrate, sulfate, and water. Among 24 silicate

  1. Comparison of the mixing state of long-range transported Asian and African mineral dust

    NASA Astrophysics Data System (ADS)

    Fitzgerald, Elizabeth; Ault, Andrew P.; Zauscher, Melanie D.; Mayol-Bracero, Olga L.; Prather, Kimberly A.

    2015-08-01

    Mineral dust from arid regions represents the second largest global source of aerosols to the atmosphere. Dust strongly impacts the radiative balance of the earth's atmosphere by directly scattering solar radiation and acting as nuclei for the formation of liquid droplets and ice nuclei within clouds. The climate effects of mineral dust aerosols are poorly understood, however, due to their complex chemical and physical properties, which continuously evolve during atmospheric transport. This work focuses on characterizing atmospheric mineral dust from the two largest global dust sources: the Sahara Desert in Africa and the Gobi and Taklamakan Deserts in Asia. Measurements of individual aerosol particle size and chemical mixing state were made at El Yunque National Forest, Puerto Rico, downwind of the Sahara Desert, and Gosan, South Korea, downwind of the Gobi and Taklamakan Deserts. In general, the chemical characterization of the individual dust particles detected at these two sites reflected the dominant mineralogy of the source regions; aluminosilicate-rich dust was more common at El Yunque (∼91% of El Yunque dust particles vs. ∼69% of Gosan dust particles) and calcium-rich dust was more common at Gosan (∼22% of Gosan dust particles vs. ∼2% of El Yunque dust particles). Furthermore, dust particles from Africa and Asia were subjected to different transport conditions and atmospheric processing; African dust showed evidence of cloud processing, while Asian dust was modified via heterogeneous chemistry and direct condensation of secondary species. A larger fraction of dust detected at El Yunque contained the cloud-processing marker oxalate ion compared to dust detected at Gosan (∼20% vs ∼9%). Additionally, nearly 100% of dust detected at Gosan contained nitrate, showing it was aged via heterogeneous reactions with nitric acid, compared to only ∼60% of African dust. Information on the distinct differences in the chemical composition of mineral dust

  2. Dust aerosol optical properties using ground-based and airborne lidar in the framework of FENNEC

    NASA Astrophysics Data System (ADS)

    Marnas, Fabien; Chazette, Patrick; Flamant, Cyrille; Royer, Philippe; Boytard, Mai-Lan; Genau, Pascal; Doira, Pascal; Bruneau, Didier; Pelon, Jacques; Sanak, Joseph

    2013-04-01

    The FENNEC program aims to improve our knowledge of both the role of the Saharan Heat Low (SHL) on the West African monsoon and the interactions between the African continent and the Mediterranean basin through the Saharan dust transport. The Saharan desert is the major source of mineral dust in the world and may significantly impact the air quality over the Western Europe by increasing the particular matter content. Two lidar systems were operated by the French component of the FENNEC project: an airborne lidar which was flown aboard the French Falcon 20 research aircraft and a ground-based lidar which was located in the southeastern part of Spain, close to Marbella. The presence of dust in the Saharan atmospheric boundary layer has been easily highlighted using the lidars and confirmed by ground-based sunphotometer and observations from both MODIS and SEVIRI spaceborne instruments. The simultaneous use of the sunphotometer-derived Angstrom exponent and the lidar-derived backscatter to extinction ratio is appeared to be a good approach to separate the optical contribution of dust from local aerosols for the coastal site. Over Spain, the dust layer was mainly located above the planetary boundary layer with several kilometers thick. Over the tropical Atlantic Ocean and the Mauritania the airborne lidar shows a high planetary boundary layer (~5 km above the mean sea level) associated to strong aerosol optical thickness (> 0.8 at 532 nm). The airborne lidar data have been inverted using both MODIS and SEVIRI-derived aerosol optical thickness. The differences between dust optical properties close to and remote from the sources will be discussed.

  3. Assessing sources of airborne mineral dust and other aerosols, in Iraq

    NASA Astrophysics Data System (ADS)

    Engelbrecht, Johann P.; Jayanty, R. K. M.

    2013-06-01

    Most airborne particulate matter in Iraq comes from mineral dust sources. This paper describes the statistics and modeling of chemical results, specifically those from Teflon® filter samples collected at Tikrit, Balad, Taji, Baghdad, Tallil and Al Asad, in Iraq, in 2006/2007. Methodologies applied to the analytical results include calculation of correlation coefficients, Principal Components Analysis (PCA), and Positive Matrix Factorization (PMF) modeling. PCA provided a measure of the covariance within the data set, thereby identifying likely point sources and events. These include airborne mineral dusts of silicate and carbonate minerals, gypsum and salts, as well as anthropogenic sources of metallic fumes, possibly from battery smelting operations, and emissions of leaded gasoline vehicles. Five individual PMF factors (source categories) were modeled, four of which being assigned to components of geological dust, and the fifth to gasoline vehicle emissions together with battery smelting operations. The four modeled geological components, dust-siliceous, dust-calcic, dust-gypsum, and evaporate occur in variable ratios for each site and size fraction (TSP, PM10, and PM2.5), and also vary by season. In general, Tikrit and Taji have the largest and Al Asad the smallest percentages of siliceous dust. In contrast, Al Asad has the largest proportion of gypsum, in part representing the gypsiferous soils in that region. Baghdad has the highest proportions of evaporite in both size fractions, ascribed to the highly salinized agricultural soils, following millennia of irrigation along the Tigris River valley. Although dust storms along the Tigris and Euphrates River valleys originate from distal sources, the mineralogy bears signatures of local soils and air pollutants.

  4. Hf-Nd-Sr isotopic fingerprinting of mineral dust from Asian and North African deserts

    NASA Astrophysics Data System (ADS)

    Ji, J.; Zhao, W.; Balsam, W.

    2015-12-01

    Mineral dust accounts for more than 50% of the atmospheric dust loading and plays an important role in the marine and terrestrial geochemical cycles. The deserts in North Africa, Northern China and Southern Mongolia are the major sources of mineral dust and have been studied intensively over past decades, especially with Sr, Nd and recently Hf isotopes which are seen as powerful tools to identify source areas. However, the isotopic compositions of dust are highly dependent on particle size hindering the ability to accurately identify dust provenance. The clay fraction (<2 μm) comprises about half of all mineral dust and has unique minerals phases dominanted by clay minerals. Once the clay-sized particles are deflated to the upper troposphere, they are transported over long distances and are removed from the atmosphere mainly by wet deposition. Thus, the clay-sized isotopic fingerprints from deserts may be ideal targets not only for tracking the provenance tracing of long-distance transported mineral dust, but also to provide an unparalleled window for understanding the global dust cycle, especially eolian dust preserved in deep-sea sediments and ice cores. In this work we investigate multivariate joint radiogenic Sr, Nd, and Hf isotopic compositions obtained from complete dissolution of clay-sized fractions of surface sediments from Asian and North African deserts. Asian dust source samples included the ten Northern China deserts and sandy lands - the Taklimakan, Gurbantunggut, Qaidam, Badaim Jaran, Tengger and Mu Us deserts, and the Hobq, Hulun Buirm, Onqin Daga and Horqin sandy land - and Mongolian Gobi desert. North African dust samples were from four transects in the Sahara and Sahel from Mali, Togo, Egypt and Morocco . Our results on the clay-sized isotopic measurements of these samples describe (1) the general characteristics of dusts from the Asian with ɛNd from -17.3 to 0.98, ɛHf from -5.95 to 3.68 and 87Sr/86Sr from 0.710113 to 0.73306, and North

  5. Resilience of the Asian atmospheric circulation shown by Paleogene dust provenance

    PubMed Central

    Licht, A.; Dupont-Nivet, G.; Pullen, A.; Kapp, P.; Abels, H. A.; Lai, Z.; Guo, Z.; Abell, J.; Giesler, D.

    2016-01-01

    The onset of modern central Asian atmospheric circulation is traditionally linked to the interplay of surface uplift of the Mongolian and Tibetan-Himalayan orogens, retreat of the Paratethys sea from central Asia and Cenozoic global cooling. Although the role of these players has not yet been unravelled, the vast dust deposits of central China support the presence of arid conditions and modern atmospheric pathways for the last 25 million years (Myr). Here, we present provenance data from older (42–33 Myr) dust deposits, at a time when the Tibetan Plateau was less developed, the Paratethys sea still present in central Asia and atmospheric pCO2 much higher. Our results show that dust sources and near-surface atmospheric circulation have changed little since at least 42 Myr. Our findings indicate that the locus of central Asian high pressures and concurrent aridity is a resilient feature only modulated by mountain building, global cooling and sea retreat. PMID:27488503

  6. Resilience of the Asian atmospheric circulation shown by Paleogene dust provenance.

    PubMed

    Licht, A; Dupont-Nivet, G; Pullen, A; Kapp, P; Abels, H A; Lai, Z; Guo, Z; Abell, J; Giesler, D

    2016-01-01

    The onset of modern central Asian atmospheric circulation is traditionally linked to the interplay of surface uplift of the Mongolian and Tibetan-Himalayan orogens, retreat of the Paratethys sea from central Asia and Cenozoic global cooling. Although the role of these players has not yet been unravelled, the vast dust deposits of central China support the presence of arid conditions and modern atmospheric pathways for the last 25 million years (Myr). Here, we present provenance data from older (42-33 Myr) dust deposits, at a time when the Tibetan Plateau was less developed, the Paratethys sea still present in central Asia and atmospheric pCO2 much higher. Our results show that dust sources and near-surface atmospheric circulation have changed little since at least 42 Myr. Our findings indicate that the locus of central Asian high pressures and concurrent aridity is a resilient feature only modulated by mountain building, global cooling and sea retreat. PMID:27488503

  7. Resilience of the Asian atmospheric circulation shown by Paleogene dust provenance

    NASA Astrophysics Data System (ADS)

    Licht, A.; Dupont-Nivet, G.; Pullen, A.; Kapp, P.; Abels, H. A.; Lai, Z.; Guo, Z.; Abell, J.; Giesler, D.

    2016-08-01

    The onset of modern central Asian atmospheric circulation is traditionally linked to the interplay of surface uplift of the Mongolian and Tibetan-Himalayan orogens, retreat of the Paratethys sea from central Asia and Cenozoic global cooling. Although the role of these players has not yet been unravelled, the vast dust deposits of central China support the presence of arid conditions and modern atmospheric pathways for the last 25 million years (Myr). Here, we present provenance data from older (42-33 Myr) dust deposits, at a time when the Tibetan Plateau was less developed, the Paratethys sea still present in central Asia and atmospheric pCO2 much higher. Our results show that dust sources and near-surface atmospheric circulation have changed little since at least 42 Myr. Our findings indicate that the locus of central Asian high pressures and concurrent aridity is a resilient feature only modulated by mountain building, global cooling and sea retreat.

  8. African and Asian dust: from desert soils to coral reefs

    USGS Publications Warehouse

    Garrison, Virginia H.; Shinn, Eugene A.; Foreman, William T.; Griffin, Dale W.; Holmes, Charles W.; Kellogg, Christina A.; Majewski, Michael S.; Richardson, Laurie L.; Ritchie, Kim B.; Smith, Garriet W.

    2003-01-01

    Many hypotheses have been proposed to explain the decline of coral reefs throughout the world, but none adequately accounts for the lack of recovery of reefs or the wide geographical distribution of coral diseases. The processes driving the decline remain elusive. Hundreds of millions of tons of dust transported annually from Africa and Asia to the Americas may be adversely affecting coral reefs and other downwind ecosystems. Viable microorganisms, macro- and micronutrients, trace metals, and an array of organic contaminants carried in the dust air masses and deposited in the oceans and on land may play important roles in the complex changes occurring on coral reefs worldwide.

  9. Radiative feedback of dust aerosols on the East Asian dust storms

    NASA Astrophysics Data System (ADS)

    Wang, Hong; Zhang, Xiaoye; Gong, Sunling; Chen, Yong; Shi, Guangyu; Li, Wei

    2010-12-01

    A new radiative parameterization scheme of dust aerosol has been developed within a mesoscale dust storm (DS) forecasting model to study the direct radiation of dust aerosol by incorporating both online forecasted dust concentrations and the updated dust reflective index. The radiation-induced temperature variations are fed back online to the model dynamics, resulting in two-way interactions between meteorology and dust aerosols. For a typical DS of 16-18 April 2006 in East Asia, the study shows that the strong extinction by dust leads to significant changes in the radiation flux from surface to the top of atmosphere, which tends to decrease the air temperature in the lower dust aerosol layers but to increase the air temperature in the upper dust aerosol layers. Consequently, variations of 3-D temperature fields reduce the cold air in the upper atmosphere, increase the sea level air pressure, decrease surface wind velocity, and eventually weaken the Mongolian cyclones owing to the blocking effects. These changes, in return, have impacts on the emission, transport, and deposition processes of DS. The interactively simulated total dust emission from the ground is reduced by over 50%, and the 72-hour averaged optical depth of dust aerosols declines by about 33% compared to the one-way model without dust direct radiative feedback, which indicates strong negative feedback effects. The findings of this study also suggest that online calculation of dust direct radiative effects in a mesoscale dust prediction model may lead to an improvement in the prediction of meteorological elements such as temperature, wind, and pressure during the dust events owing to its improved calculation accuracy of regional radiation budgets.

  10. Regional prediction of carbon isotopes in soil carbonates for Asian dust source tracer

    NASA Astrophysics Data System (ADS)

    Chen, Bing; Cui, Xinjuan; Wang, Yaqiang

    2016-10-01

    Dust particles emitted from deserts and semi-arid lands in northern China cause particulate pollution that increases the burden of disease particularly for urban population in East Asia. The stable carbon isotopes (δ13C) of carbonates in soils and dust aerosols in northern China were investigated. We found that the δ13C of carbonates in surface soils in northern China showed clearly the negative correlation (R2 = 0.73) with Normalized Difference Vegetation Index (NDVI). Using Moderate Resolution Imaging Spectroradiometer (MODIS) satellite-derived NDVI, we predicted the regional distribution of δ13C of soil carbonates in deserts, sandy lands, and steppe areas. The predictions show the mean δ13C of -0.4 ± 0.7‰ in soil carbonates in Taklimakan Desert and Gobi Deserts, and the isotope values decrease to -3.3 ± 1.1‰ in sandy lands. The increase in vegetation coverage depletes 13C in soil carbonates, thus the steppe areas are predicted by the lowest δ13C levels (-8.1 ± 1.7‰). The measurements of atmospheric dust samples at eight sites showed that the Asian dust sources were well assigned by the 13C mapping in surface soils. Predicting 13C in large geographical areas with fine resolution offers a cost-effective tracer to monitor dust emissions from sandy lands and steppe areas which show an increasing role in Asian dust loading driven by climate change and human activities.

  11. Size-resolved adjoint inversion of Asian dust

    NASA Astrophysics Data System (ADS)

    Yumimoto, K.; Uno, I.; Sugimoto, N.; Shimizu, A.; Hara, Y.; Takemura, T.

    2012-12-01

    We expanded the variational assimilation system of a regional dust model by using size-resolved inversion. Dust emissions and particle-size distributions of a severe dust and sandstorm (DSS) in April 2005 were inversely optimized with optical measurements by the National Institute for Environmental Studies lidar network. The inversion results successfully compensated underestimates by the original model and increased the Ångström exponent around the DSS core by 13-17%, shifting the particle-size distribution to finer. The a posteriori size distribution was distinctly different between eastern and western source regions. In the western regions, dust emissions in the 3.19 and 5.06μm size bins increased considerably, and the peak size shifted from 5.06 to 3.19 μm, whereas in the eastern regions, emissions of finer particles (bins 0.82-2.01 μm) increased. Differences in vegetation and soil type and moisture between eastern and western regions might explain the characteristics of the inverted size distribution.

  12. Size-resolved adjoint inversion of Asian dust

    NASA Astrophysics Data System (ADS)

    Yumimoto, K.; Uno, I.; Sugimoto, N.; Shimizu, A.; Hara, Y.; Takemura, T.

    2012-12-01

    We expanded the variational assimilation system of a regional dust model by using size-resolved inversion. Dust emissions and particle-size distributions of a severe dust and sandstorm (DSS) in April 2005 were inversely optimized with optical measurements by the National Institute for Environmental Studies lidar network. The inversion results successfully compensated underestimates by the original model and increased the Ångström exponent around the DSS core by 13-17%, shifting the particle-size distribution to finer. The a posteriori size distribution was distinctly different between eastern and western source regions. In the western regions, dust emissions in the 3.19 and 5.06 μm size bins increased considerably, and the peak size shifted from 5.06 to 3.19 μm, whereas in the eastern regions, emissions of finer particles (bins 0.82-2.01 μm) increased. Differences in vegetation and soil type and moisture between eastern and western regions might explain the characteristics of the inverted size distribution.

  13. Time-course monitoring of urban bioaerosol bacterial communities and its use in microbial hazard identification during Asian Dust events in Seoul, Korea

    NASA Astrophysics Data System (ADS)

    Park, J.

    2015-12-01

    The microbial communities transported by Asian dust events have attracted much attention as bioaerosols because the transported airborne microbes may strongly influence the downwind ecosystems and potentially human health in East Asia. Bioaerosol study has received relatively little attention and their characterization and risk assessments remain poorly developed. We used high throughput 16S rRNA gene targeted pyrosequencing and real-time quantitative PCR (qPCR) to monitor airborne bacterial communities and assess their potential risk. We monitored microbial communities in bioaerosol in Seoul between 2011 and 2013 using high volume air samplers. Six samples were collected during Asian dust (AD) events and the other 34 samples were urban air collected during non-Asian dust (non-AD) events. According to the qPCR result, the gene copy numbers of 16S rRNA genes were significantly higher during the AD events (P < 0.05) and their abundances were positively correlated with PM10 concentrations and bacterial diversities. The most abundant bacterial members (genus level) in the AD samples were Bacillus, Neisseria and E.coli/Shigella. To identify pathogenic populations, multilocus sequence typing (MLST) and virulence tests were applied using culture methods. 16S rRNA gene sequences of several pathogens were detected and their relative abundances appeared to have increased with increased concentrations of PM10. About 1% of Bacillus isolates were identified as known pathogenic B. cereus, confirming their presence in Asian dust samples. The qPCR detection of bceT gene, which codes for an enterotoxin in B. cereus group, was significantly increased in the AD dust samples over the non-AD samples. The following MLST assessment and virulence test of cultivated Bacillus isolates showed that B. cereus, B. licheniformis and B. mycoides were identified as pathogenic bacteria, and these pathogenic bacteria were usually more abundant during AD events. To assess the possible associations of

  14. Electron Microanalysis of Aerosols Collected at Mauna Loa Observatory During an Asian Dust Storm Event

    NASA Astrophysics Data System (ADS)

    Conny, J. M.; Willis, R. D.; Ortiz-Montalvo, D. L.; Colton, A.

    2014-12-01

    Located in the remote marine free troposphere, the Mauna Loa Observatory (MLO) represents a clean airshed that can be used to study anthropogenic pollution influences and long-range transport of aerosol particles from the Asian mainland. Because of the global nature of Asian dust storms, the radiative properties of these particles transported long-range can significantly impact global climate. It has been proposed that aerosols transported to MLO during upslope wind conditions (typically daytime) are local in origin while aerosols transported during downslope conditions (typically nighttime) represent long-range transport in the free troposphere. Twelve PM10 samples (six daytime/nightime pairs) were collected on polycarbonate filters for 72 hours each between March 15 and April 26, 2011. Bulk samples of dust from local sources (road dust, parking lot, lava fields) were collected as well in order to assess the PM10 contribution from local dusts. On March 19-20 the Korea Meteorological Administration documented a significant dust event over the Korean peninsula. Back-trajectory analyses from MLO coupled with local wind speed and wind direction data suggest that this dust event may have been captured during the MLO sampling campaign. MLO samples were analyzed by computer-controlled scanning electron microscopy (CCSEM) coupled with energy-dispersive X-ray spectrometry (EDX) and particles were sorted into compositionally-distinct particle types which were then compared across the sample set. Concentrations of particle types expected to be associated with Asian dust were observed to peak in one pair of daytime/nighttime samples collected between March 22 and March 28. Manual microscopic characterization of suspected Asian dust particles and local dust particles was carried out using electron backscatter diffraction (EBSD) in conjunction with EDX and focussed ion beam SEM (FIB-SEM) in an effort to characterize differences in physicochemical or radiative properties of

  15. Exposure to airborne microorganisms, dust and endotoxin during processing of peppermint and chamomile herbs on farms.

    PubMed

    Skórska, Czesława; Sitkowska, Jolanta; Krysińska-Traczyk, Ewa; Cholewa, Grazyna; Dutkiewicz, Jacek

    2005-01-01

    The aim of this study was to determine the levels of microorganisms, dust and endotoxin in the air during processing of peppermint (Mentha piperita) and chamomile (Matricaria recutita) by herb farmers, and to examine the species composition of airborne microflora. Air samples were collected on glass fibre filters by use of personal samplers on 13 farms owned by herb cultivating farmers, located in Lublin province (eastern Poland). The concentrations of total viable microorganisms (bacteria + fungi) in the farm air during processing of peppermint herb were large, within a range from 895.1-6,015.8 x 10(3) cfu/m(3) (median 1,055.3 x 10(3) cfu/m(3)). During processing of chamomile herb they were much lower and varied within a range from 0.88-295.6 x 10(3) cfu/m(3) (median 27.3 x 10(3) cfu/m(3)). Gram-negative bacteria distinctly prevailed during processing of peppermint leaves, forming 46.4-88.5 % of the total airborne microflora. During processing of chamomile herb, Gram-negative bacteria were dominant at 3 out of 6 sampling sites forming 54.7-75.3 % of total microflora, whereas at the remaining 3 sites the most common were fungi forming 46.2-99.9 % of the total count. The species Pantoea agglomerans (synonyms: Erwinia herbicola, Enterobacter agglomerans ), having strong allergenic and endotoxic properties, distinctly prevailed among Gram-negative isolates. Among fungi, the most common species was Alternaria alternata. The concentrations of airborne dust and endotoxin determined on the examined herb farms were large. The concentrations of airborne dust during peppermint and chamomile processing ranged from 86.7-958.9 mg/m(3), and from 1.1-499.2 mg/m(3), respectively (medians 552.3 mg/m(3) and 12.3 mg/m(3)). The concentrations of airborne endotoxin determined during peppermint and chamomile processing were within a wide range 1.53-208.33 microg/m(3) and 0.005-2604.19 microg/m(3) respectively (medians 57.3 microg/m(3) and 0.96 microg/m(3)). In conclusion, farmers

  16. The Influence of Asian Dust, Haze, Mist, and Fog on Hospital Visits for Airway Diseases

    PubMed Central

    Park, Jinkyeong; Lim, Myoung Nam; Hong, Yoonki

    2015-01-01

    Background Asian dust is known to have harmful effects on the respiratory system. Respiratory conditions are also influenced by environmental conditions regardless of the presence of pollutants. The same pollutant can have different effects on the airway when the air is dry compared with when it is humid. We investigated hospital visits for chronic obstructive pulmonary disease (COPD) and asthma in relation to the environmental conditions. Methods We conducted a retrospective study using the Korean National Health Insurance Service claims database of patients who visited hospitals in Chuncheon between January 2006 and April 2012. Asian dust, haze, mist, and fog days were determined using reports from the Korea Meteorological Administration. Hospital visits for asthma or COPD on the index days were compared with the comparison days. We used two-way case-crossover techniques with one to two matching. Results The mean hospital visits for asthma and COPD were 59.37 ± 34.01 and 10.04 ± 6.18 per day, respectively. Hospital visits for asthma significantly increased at lag0 and lag1 for Asian dust (relative risk [RR], 1.10; 95% confidence interval [CI], 1.01-1.19; p<0.05) and haze (RR, 1.13; 95% CI, 1.06-1.22; p<0.05), but were significantly lower on misty (RR, 0.89; 95% CI, 0.80-0.99; p<0.05) and foggy (RR, 0.89; 95% CI, 0.84-0.93; p<0.05) days than on control days. The hospital visits for COPD also significantly increased on days with Asian dust (RR, 1.29; 95% CI, 1.05-1.59; p<0.05), and were significantly lower at lag4 for foggy days, compared with days without fog (RR, 0.85; 95% CI, 0.75-0.97; p<0.05). Conclusion Asian dust showed an association with airway diseases and had effects for several days after the exposure. In contrast to Asian dust, mist and fog, which occur in humid air conditions, showed the opposite effects on airway diseases, after adjusting to the pollutants. It would require more research to investigate the effects of various air conditions on

  17. Benzotriazole, benzothiazole, and benzophenone compounds in indoor dust from the United States and East Asian countries.

    PubMed

    Wang, Lei; Asimakopoulos, Alexandros G; Moon, Hyo-Bang; Nakata, Haruhiko; Kannan, Kurunthachalam

    2013-05-01

    Organic corrosion inhibitors (OCIs), including ultraviolet light filters, are widely used in plastics, rubbers, colorants, and coatings to increase the performance of products. Derivatives of benzotriazole (BTR), benzothiazole (BTH), and benzophenone (BP) are high-production volume OCIs that have been detected in the environment and human tissues. However, knowledge of their occurrence in indoor environments, as well as human exposure to them, is still lacking. In this study, BTR, BTH, BP and their 12 derivatives were determined in indoor dust for the first time. All three groups of OCIs were found in all 158 indoor dust samples from the U.S. and three East Asian countries (China, Japan, and Korea). The geometric mean (GM) concentration of the sum of six BTRs (GM CΣBTRs) ranged from 20 to 90 ng/g among the four countries studied, with a maximum CΣBTRs of ∼2000 ng/g found in a dust sample from China. Tolyltriazole was the major derivative of BTR measured in dust. GM CΣBTHs in indoor dust from the four countries ranged from 600 to 2000 ng/g. 2-OH-BTH was the predominant BTH in dust from the U.S., Japan, and Korea. GM CΣBPs in dust ranged from 80 to 600 ng/g, with 2-OH-4-MeO-BP and 2,4-2OH-BP, contributing to the majority of ∑BP concentrations. Based on the concentrations of three types of OCIs in indoor dust, human exposure through dust ingestion was calculated. Daily intake of OCIs through dust ingestion was higher for people in the U.S., Japan, and Korea than in China; the residents in urban China are exposed to higher levels of OCIs via dust ingestion than are those in rural China.

  18. Estimation of aerosol direct forcing by Asian dust using sun/sky radiometer and lidar measurement

    NASA Astrophysics Data System (ADS)

    Won, J. G.; Yoon, S. C.; Holben, B.

    2002-12-01

    Appropriate optical parameters of aerosols are critical part for estimating aerosol direct forcing. We suggest a method of determining aerosol parameters for the radiative transfer model, CRM released by NCAR, from AERONET inversion data set. AERONET inversion provides size distribution and complex refractive indices at 4 wavelengths, 440, 670, 870 and 1020nm. Mie calculation can produce the aerosol optical parameters, such as aerosol optical thickness (AOT), single scattering albedo (SSA), asymmetry factor(g) and by using regression fitting method on log-log plane, the parameters at 19 channels of short wavelength region can be retrieved. With this method, it becomes possible to use ground-base solar radiance measurement data for calculating aerosol direct forcing without assuming the specific aerosol type in advance. We investigated the differences of aerosol forcing by dust and non-dust aerosols. Out of AERONET data collected in Apr. 2001, the properties of Asian dust aerosols were examined, which have the characteristics of bigger AOT, bigger SSA (bigger solar radiance reflection) and less wavelength dependence of SSA and g. This difference makes larger aerosol direct forcing at TOA and less atmospheric absorption. The aerosol profiles measured by lidar are also applied for radiative transfer calculation. The profiles of short wave radiation flux and heating rate by dust were investigated for two Asian dust events, one was elevated dust event and the other was dust event settling into the PBL. Instantaneous heating rate larger than 2K/day was estimated within dust aerosol layer and several differences of radiation flux profiles due to the aerosol profiles were investigated.

  19. Speciation of airborne dust from a nickel refinery roasting operation.

    PubMed

    Andersen, I; Berge, S R; Resmann, F

    1998-04-01

    Earlier work-related lung and nasal cancer studies included estimates of exposures to different nickel species in the refinery. Based on the metallurgy, only insoluble nickel was believed to be present around the roasters but mixed exposure was assumed in most areas, including the tankhouse. Occasional leaching tests of samples from the roaster area have indicated the presence of soluble nickel. This study reports on five parallel sets of dust samples collected from different floors with standard equipment and treated as follows. Two sets were leached with an ammonium citrate buffer at pH 4.4. Undissolved material was treated with HClO4/HNO3, evaporated to dryness and dissolved in HCl, Ni, Cu, Co, Fe, Se, and As were determined in both fractions. Water soluble Ni was found in all samples, ranging from 5-35%. Sulfate in the solutions correlated nearly stoichiometrically to the total metal content. The three remaining sets were investigated by, respectively, differential leaching, X-ray diffraction and scanning electron microscopy. The percentage of soluble nickel found by differential leaching corresponded well with those obtained by the simplified procedure. X-Ray diffraction analysis showed the presence of NiSO4.6H2O as well as oxides of Ni and Cu. This study indicates mixed exposures also in the roaster area. It also clearly indicates that basing exposure on the metallurgy alone can lead to serious misjudgements. The impact of this new information on the interpretation of cancer incidence at this refinery must await the analysis in an ongoing case-reference study. PMID:9684402

  20. Characteristics of Asian dust transport based on synoptic meteorological analysis over Korea.

    PubMed

    Kim, Yoo-Keun; Song, Sang-Keun; Lee, Hwa Woon; Kim, Cheol-Hee; Oh, In-Bo; Moon, Yun-Seob; Shon, Zang-Ho

    2006-03-01

    Classification of synoptic patterns and their correlation with dust events over East Asia were performed by means of cluster analysis. The average linkage and K-means clustering techniques were used to identify two major weather types during Asian dust events (ADEs; total 26 ADEs with 47 dusty days) of six spring seasons from 1996 to 2001. The first weather type mainly influenced neighboring Asian countries and frequently occurred with ADEs (approximately 23% of ADE cases). It mostly occurred under a surface high (low)-pressure system over the west (east) of the Korean peninsula coupled with an upper-level trough and cutoff low passage over the center of the Korean peninsula. It showed strong advection in the middle/ upper troposphere with both a high aerosol index and enhanced coarse particulate matter (PM) loading over Korea. In contrast, the second weather type was mostly associated with long distance or continental-scale transport and occurred less frequently with ADEs (approximately 15%). It appeared with an upper-level trough and a cutoff low vertically connected with a surface low system that was formed by a strong cyclonic vortex over the north of the Korean peninsula. There were weak advection, low aerosol index, and low coarse PM concentration over the Korean peninsula during the second weather type. In addition, it was found to be mostly associated with the trans-Pacific transport of Asian dust to the western coast of North America.

  1. Characteristics of airborne coal mine dust and its implication to coal workers' pneumoconiosis

    SciTech Connect

    Kim, H.

    1989-01-01

    Size selective airborne dust samples were collected using 4-stage cassette impactors at nine different locations in continuous mining sections in each of five coal seams located in the Appalachian bituminous coal field. These coal seams were the Upper Freeport, Pittsburgh, Kittanning, Coalburg, and Pocahontas. Mineralogical analyses were performed by an x-ray powder diffraction photographic technique. The distributions of total and respirable dust concentrations were fit best by a log-normal distribution. The effects of the coal seam and the sampling location on dust levels were significant. The results of the particle size distribution analyses suggest that coal mine dust has a multi-modal distribution. The effects of the coal seam and the sampling locations were significant. The distributions obtained were often affected by such mine-related variables as ventilation rate, relative humidity, and the section dimensions. Nine minerals commonly found in the coal mine dust samples collected from the coal seams studied were illite, calcite, kaolinite, quartz, dolomite, siderite, gypsum, anhydrite, and pyrite in descending order of magnitude. Relative abundance of all mineral species except siderite and gypsum was coal seam specific and suggests that existence of coal seam variability of mineral content. Although mineral content was affected by sampling locations and the sections within a mine, the magnitude was small when compared with that of cal seams. Mineral content also appears to be affected by particle size, although no particular pattern was observed.

  2. Airborne and Grain Dust Fungal Community Compositions Are Shaped Regionally by Plant Genotypes and Farming Practices

    PubMed Central

    Pellissier, Loïc; Oppliger, Anne; Hirzel, Alexandre H.; Savova-Bianchi, Dessislava; Mbayo, Guilain; Mascher, Fabio; Kellenberger, Stefan

    2016-01-01

    Chronic exposure to airborne fungi has been associated with different respiratory symptoms and pathologies in occupational populations, such as grain workers. However, the homogeneity in the fungal species composition of these bioaerosols on a large geographical scale and the different drivers that shape these fungal communities remain unclear. In this study, the diversity of fungi in grain dust and in the aerosols released during harvesting was determined across 96 sites at a geographical scale of 560 km2 along an elevation gradient of 500 m by tag-encoded 454 pyrosequencing of the internal transcribed spacer (ITS) sequences. Associations between the structure of fungal communities in the grain dust and different abiotic (farming system, soil characteristics, and geographic and climatic parameters) and biotic (wheat cultivar and previous crop culture) factors were explored. These analyses revealed a strong relationship between the airborne and grain dust fungal communities and showed the presence of allergenic and mycotoxigenic species in most samples, which highlights the potential contribution of these fungal species to work-related respiratory symptoms of grain workers. The farming system was the major driver of the alpha and beta phylogenetic diversity values of fungal communities. In addition, elevation and soil CaCO3 concentrations shaped the alpha diversity, whereas wheat cultivar, cropping history, and the number of freezing days per year shaped the taxonomic beta diversity of these communities. PMID:26826229

  3. Airborne and Grain Dust Fungal Community Compositions Are Shaped Regionally by Plant Genotypes and Farming Practices.

    PubMed

    Pellissier, Loïc; Oppliger, Anne; Hirzel, Alexandre H; Savova-Bianchi, Dessislava; Mbayo, Guilain; Mascher, Fabio; Kellenberger, Stefan; Niculita-Hirzel, Hélène

    2016-04-01

    Chronic exposure to airborne fungi has been associated with different respiratory symptoms and pathologies in occupational populations, such as grain workers. However, the homogeneity in the fungal species composition of these bioaerosols on a large geographical scale and the different drivers that shape these fungal communities remain unclear. In this study, the diversity of fungi in grain dust and in the aerosols released during harvesting was determined across 96 sites at a geographical scale of 560 km(2) along an elevation gradient of 500 m by tag-encoded 454 pyrosequencing of the internal transcribed spacer (ITS) sequences. Associations between the structure of fungal communities in the grain dust and different abiotic (farming system, soil characteristics, and geographic and climatic parameters) and biotic (wheat cultivar and previous crop culture) factors were explored. These analyses revealed a strong relationship between the airborne and grain dust fungal communities and showed the presence of allergenic and mycotoxigenic species in most samples, which highlights the potential contribution of these fungal species to work-related respiratory symptoms of grain workers. The farming system was the major driver of the alpha and beta phylogenetic diversity values of fungal communities. In addition, elevation and soil CaCO3 concentrations shaped the alpha diversity, whereas wheat cultivar, cropping history, and the number of freezing days per year shaped the taxonomic beta diversity of these communities. PMID:26826229

  4. Analysis of Potentially Toxic Metals in Airborne Cement Dust Around Sagamu, Southwestern Nigeria

    NASA Astrophysics Data System (ADS)

    Gbadebo, A. M.; Bankole, O. D.

    This study analyzed the concentration levels of potentially toxic and harmful elements contained in the airborne cement dust generated in the vicinity and farther away 500 m in the conventional four cardinal directions from the West African Portland Cement Company (WAPCO) factory mill, Sagamu. The results indicated that the concentration range of these toxic elements fall between 40.0 and 280,000 μg g-1 in the cement dust samples. Also, the concentration range of these toxic elements in 1 L of air samples varies between 0.01 μg g-1 and 29.92 μg L-1. The results generally show elevated concentrations of all the elements when compared with USA threshold limit of particulate mental concentration (e.g., Pb (1.5 g m-3); Cd (0.004-0.026 g m-3) in the air. These elements in the airborne cement dusts may pose a great threat to the health of plants, animals and residents in and around the factory and also to workers and visitors to the factory.

  5. Observation of enhanced water vapor in Asian dust layer and its effect on atmospheric radiative heating rates

    NASA Astrophysics Data System (ADS)

    Kim, Sang-Woo; Yoon, Soon-Chang; Jefferson, Anne; Won, Jae-Gwang; Dutton, Ellsworth G.; Ogren, John A.; Anderson, Theodore L.

    2004-09-01

    This study investigates the effect of water vapor associated with mineral dust aerosols on atmospheric radiative heating rates using ground-based lidar, aircraft, radiosonde measurements and a radiation model during Asian dust events in the spring of 2001. We found enhanced levels of water vapor within the dust layer relative to the air above and below the dust layer. The water vapor led to an increase in the net radiative heating rate within the dust layer, changing the heating rate vertical structure. A net cooling was calculated above the dust layer as a result of low aerosol and drier conditions. Our finding suggests that the presence of water vapor within dust layer acts to enhance the temperature of this layer, potentially influencing the static stability of the dust layer. This finding is supported by an increase in the potential temperature at the top and bottom of the dust layer.

  6. 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

  7. Detection of internally mixed Asian dust with air pollution aerosols using a polarization optical particle counter and a polarization-sensitive two-wavelength lidar

    NASA Astrophysics Data System (ADS)

    Sugimoto, Nobuo; Nishizawa, Tomoaki; Shimizu, Atsushi; Matsui, Ichiro; Kobayashi, Hiroshi

    2015-01-01

    East Asia is a unique region where mineral dust (Asian dust) sources are located near urban and industrial areas. Asian dust is often mixed with air pollution aerosols during transportation. It is important to understand the mixing states of Asian dust and other aerosols, because the effects on the environment and human health differ depending on the mixing state. We studied the mixing states of Asian dust using a polarization particle counter (POPC) that measures the forward scattering and the two polarization components of backscattering for single particles and a polarization-sensitive (532 nm) two-wavelength (1064 nm and 532 nm) lidar. We conducted the simultaneous observations using the POPC and the lidar in Seoul from March to December 2013 and captured the characteristics of pure Asian dust and internally mixed polluted Asian dust. POPC measurements indicated that the density of large particles was lower in polluted Asian dust that transported slowly over the polluted areas than in pure Asian dust that transported quickly from the dust source region. Moreover, the backscattering depolarization ratio was smaller for all particle sizes in polluted dust. The optical characteristics measured using the lidar were consistent with the POPC measurements. The backscattering color ratio of polluted dust was comparable to that of pure dust, but the depolarization ratio was lower for polluted dust. In addition, coarse non-spherical particles (Asian dust) almost always existed in the background, and the depolarization ratio had seasonal variation with a lower depolarization ratio in the summer. These results suggest background Asian dust particles are internally mixed in the summer.

  8. Sensory and other neurogenic effects of exposures to airborne office dust

    NASA Astrophysics Data System (ADS)

    Mølhave, L.; Kjærgaard, S. K.; Attermann, J.

    This Danish Office Dust Experiment investigated the response of 24 healthy non-sensitive adult subjects to exposure to normal office dust in the air (7 μg m -3 clean air, 136 and 390 μg m -3 TSP). The dust had no major identifiable specific reactive components. The exposure duration was 5 1/4 h and was arranged in a climate chamber in controlled atmospheric conditions. Measurements were made acutely at exposure onset, subacutely at exposure end and next day (late). As secondary aims the time course and threshold of any observed effect of the exposures, and the characteristics of any hyperresponding subgroup were investigated. In a questionnaire with 36 questions the dust exposures caused increased acute, subacute and late perceptions of reduced air quality, acute and subacute increased odor intensity, acute eye irritation, acute and late heavy head, subacute feeling of perspiration, and subacute general irritation. Cough increased subacutely during exposures. In addition, a performance test showed effects of dust exposures which also affected "Mood Scale" ratings. No effect was seen on an addition test for distraction, and objective measurements of skin humidity. The overall conclusion of the study is that healthy subjects without hypersensitivity reactions seem to respond to airborne house dust. The responses are both subjective sensory reactions and other neurogenic effects even at exposure levels within the range found in normal buildings. Some of the effects appeared acutely and decreased through adaptation while others increased during prolonged exposure and remained for more than 17 h after the exposure ended. The findings may indicate for this type of dust a threshold level for the dose-response relationships below 140 μg m -3.

  9. Long-range transport and vertical structure of Asian dust from CALIPSO and surface measurements during PACDEX

    NASA Astrophysics Data System (ADS)

    Huang, Jianping; Minnis, Patrick; Chen, Bin; Huang, Zhongwei; Liu, Zhaoyan; Zhao, Qingyun; Yi, Yuhong; Ayers, J. Kirk

    2008-12-01

    Knowledge of long-range transport and vertical distribution of Asian dust aerosols in the free troposphere is important for estimating their impact on climate. Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO), surface micropulse lidar (MPL), and standard surface measurements are used to directly observe the long-range transport and vertical distribution of Asian dust aerosols in the free troposphere during the Pacific Dust Experiment (PACDEX). The MPL measurements were made at the Loess Plateau (35.95°N, 104.1°E) near the major dust source regions of the Taklamakan and Gobi deserts. Dust events are more frequent in the Taklamakan, where floating dust dominates, while more intensive, less frequent dust storms are more common in the Gobi region. The vertical distribution of the CALIPSO backscattering/depolarization ratios indicate that nonspherically shaped dust aerosols floated from near the ground to an altitude of approximately 9 km around the source regions. This suggests the possible long-range transport of entrained dust aerosols via upper tropospheric westerly jets. A very distinct large depolarization layer was also identified between 8 and 10 km over eastern China and the western Pacific Ocean corresponding to dust aerosols transported from the Taklamakan and Gobi areas, as confirmed by back trajectory analyses. The combination of these dust sources results in a two-layer or multilayered dust structure over eastern China and the western Pacific Ocean.

  10. Impacts of the East Asian Monsoon on springtime dust concentrations over China

    NASA Astrophysics Data System (ADS)

    Lou, Sijia; Russell, Lynn M.; Yang, Yang; Xu, Li; Lamjiri, Maryam A.; DeFlorio, Michael J.; Miller, Arthur J.; Ghan, Steven J.; Liu, Ying; Singh, Balwinder

    2016-07-01

    We use 150 year preindustrial simulations of the Community Earth System Model to quantify the impacts of the East Asian Monsoon strength on interannual variations of springtime dust concentrations over China. The simulated interannual variations in March-April-May (MAM) dust column concentrations range between 20-40% and 10-60% over eastern and western China, respectively. The dust concentrations over eastern China correlate negatively with the East Asian Monsoon (EAM) index, which represents the strength of monsoon, with a regionally averaged correlation coefficient of -0.64. Relative to the strongest EAM years, MAM dust concentrations in the weakest EAM years are higher over China, with regional relative differences of 55.6%, 29.6%, and 13.9% in the run with emissions calculated interactively and of 33.8%, 10.3%, and 8.2% over eastern, central, and western China, respectively, in the run with prescribed emissions. Both interactive run and prescribed emission run show the similar pattern of climate change between the weakest and strongest EAM years. Strong anomalous northwesterly and westerly winds over the Gobi and Taklamakan deserts during the weakest EAM years result in larger transport fluxes, and thereby increase the dust concentrations over China. These differences in dust concentrations between the weakest and strongest EAM years (weakest-strongest) lead to the change in the net radiative forcing by up to -8 and -3 W m-2 at the surface, compared to -2.4 and +1.2 W m-2 at the top of the atmosphere over eastern and western China, respectively.

  11. East Asian origin of central Greenland last glacial dust: just one possible scenario?

    NASA Astrophysics Data System (ADS)

    Újvári, Gábor; Stevens, Thomas; Svensson, Anders; Klötzli, Urs Stephan; Manning, Christina; Németh, Tibor; Kovács, János

    2016-04-01

    Dust in Greenland ice cores is used to reconstruct the activity of dust emitting regions and atmospheric circulation for the last glacial period. However, the source dust material to Greenland over this period is the subject of considerable uncertainty. Here we use new clay mineral and Sr-Nd isotopic data from eleven loess samples collected around the Northern Hemisphere and compare the 87Sr/86Sr and 143Nd/144Nd isotopic signatures of fine (<10 μm) separates to existing Greenland ice core dust data (GISP2, GRIP; [1]; [2]). Smectite contents and kaolinite/chlorite (K/C) ratios allow exclusion of continental US dust emitting regions as potential sources, because of the very high (>3.6) K/C ratios and extremely high (>~70%) smectite contents. At the same time, Sr-Nd isotopic compositions demonstrate that ice core dust isotopic compositions can be explained by East Asian (Chinese loess) and/or Central/East Central European dust contributions. Central/East Central European loess Sr-Nd isotopic compositions overlap most with ice core dust, while the Sr isotopic signature of Chinese loess is slightly more radiogenic. Nevertheless, an admixture of 90‒10 % from Chinese loess and circum-Pacific volcanic material would also account for the Sr‒Nd isotopic ratios of central Greenland LGM dust. At the same time, sourcing of ice core dust from Alaska, continental US and NE Siberia seems less likely based on Sr and Nd isotopic signatures. The data demonstrate that currently no unique source discrimination for Greenland dust is possible using both published and our new data [3]. Thus, there is a need to identify more diagnostic tracers. Based on initial Hf isotope analyses of fine separates of three loess samples (continental US, Central Europe, China), an apparent dependence of Hf isotopic signatures on the relative proportions of radiogenic clay minerals (primarily illite) was found, as these fine dust fractions are apparently zircon-free. The observed difference between

  12. Effect of ultraviolet on the survival of bacteria airborne in simulated Martian dust clouds.

    PubMed

    Hagen, C A; Hawrylewicz, E J; Anderson, B T; Cephus, M L

    1970-01-01

    A chamber was constructed to create simulated Martian dust storms and thereby study the survival of airborne micro-organisms while exposed to the rigors of the Martian environment, including ultraviolet irradiation. Representative types of sporeforming and non-sporeforming bacteria present in spacecraft assembly areas and indigenous to humans were studied. It was found that daily ultraviolet irradiation of 2 to 9 X 10(7) erg cm-2 was not sufficient to sterilize the dust clouds. The soil particles protected the organisms from ultraviolet irradiation since the numbers of survivors from irradiated environments were similar to those from unirradiated environments. Pending further data of the Martian environment, the contamination and dissemination of Mars with terrestrial micro-organisms is still a distinct possibility.

  13. Airborne Fungal and Bacterial Components in PM1 Dust from Biofuel Plants

    PubMed Central

    Madsen, Anne Mette; Schlünssen, Vivi; Olsen, Tina; Sigsgaard, Torben; Avci, Hediye

    2009-01-01

    Fungi grown in pure cultures produce DNA- or RNA-containing particles smaller than spore size (<1.5 μm). High exposures to fungi and bacteria are observed at biofuel plants. Airborne cultivable bacteria are often described to be present in clusters or associated with larger particles with an aerodynamic diameter (dae) of 2–8 μm. In this study, we investigate whether airborne fungal components smaller than spore size are present in bioaerosols in working areas at biofuel plants. Furthermore, we measure the exposure to bacteria and fungal components in airborne particulate matter (PM) with a D50 of 1 μm (called PM1 dust). PM1 was sampled using Triplex cyclones at a working area at 14 Danish biofuel plants. Millipore cassettes were used to sample ‘total dust’. The PM1 particles (29 samples) were analysed for content of 11 different components and the total dust was analysed for cultivable fungi, N-acetyl-β-D-glucosaminidase (NAGase), and (1 → 3)-β-D-glucans. In the 29 PM1 samples, cultivable fungi were found in six samples and with a median concentration below detection level. Using microscopy, fungal spores were identified in 22 samples. The components NAGase and (1 → 3)-β-D-glucans, which are mainly associated with fungi, were present in all PM1 samples. Thermophilic actinomycetes were present in 23 of the 29 PM1 samples [average = 739 colony-forming units (CFU) m−3]. Cultivable and ‘total bacteria’ were found in average concentrations of, respectively, 249 CFU m−3 and 1.8 × 105 m−3. DNA- and RNA-containing particles of different lengths were counted by microscopy and revealed a high concentration of particles with a length of 0.5–1.5 μm and only few particles >1.5 μm. The number of cultivable fungi and β-glucan in the total dust correlated significantly with the number of DNA/RNA-containing particles with lengths of between 1.0 and 1.5 μm, with DNA/RNA-containing particles >1.5 μm, and with other fungal components in PM1

  14. Provenance of Asian Dust Delivered to the Philippine Sea and Its Transport Pathways: Isotopic and Mineralogical Evidences

    NASA Astrophysics Data System (ADS)

    SEO, I.; Lee, Y. I.; Yoo, C. M.; Kim, H. J.; Hyeong, K.

    2014-12-01

    Most dust studies using deep-sea sediment archives from the North Pacific have focused on understanding the mass flux variation of Asian dust in terms of long-term climate variability, but have not considered specific transport pathways or dust source regions (e.g., central/East Asian deserts versus northern Chinese deserts). To characterize the provenance and transport pathways of eolian dust deposited in the western tropical/subtropical Pacific, and to investigate changes over the late Quaternary, we used the clay mineral assemblage, together with the 143Nd/144Nd and 87Sr/86Sr composition of the inorganic silicate fractions of a deep-sea sediment core retrieved from the Palau-Kyushu Ridge in the Philippine Sea. The analyzed attributes of the core resemble those of dust from the central Asian deserts (CADs; e.g., the Taklimakan Desert) as in the North Central Pacific, but published aerosol data collected near the study site during winter/spring has the mineralogical signature of dust originating from the East Asian deserts (EADs; e.g., the Chinese Loess Plateau and nearby deserts). These data indicate that the relative contribution of EAD dust increases with the northeasterly surface winds associated with the East Asian Winter Monsoon (EAWM) during winter/spring, but the Prevailing Westerlies and Trade Winds that carry dust from the CADs have been the dominant transport agent for the last 600 kyr. The results of this study contradict the prevailing view that direct dust transport by the EAWM winds in spring dominates the annual flux of eolian dust in the northwest Pacific.

  15. Machine vision based particle size and size distribution determination of airborne dust particles of wood and bark pellets

    SciTech Connect

    Igathinathane, C; Pordesimo, L.O.

    2009-08-01

    Dust management strategies in industrial environment, especially of airborne dust, require quantification and measurement of size and size distribution of the particles. Advanced specialized instruments that measure airborne particle size and size distribution apply indirect methods that involve light scattering, acoustic spectroscopy, and laser diffraction. In this research, we propose a simple and direct method of airborne dust particle dimensional measurement and size distribution analysis using machine vision. The method involves development of a user-coded ImageJ plugin that measures particle length and width and analyzes size distribution of particles based on particle length from high-resolution scan images. Test materials were airborne dust from soft pine wood sawdust pellets and ground pine tree bark pellets. Subsamples prepared by dividing the actual dust using 230 mesh (63 m) sieve were analyzed as well. A flatbed document scanner acquired the digital images of the dust particles. Proper sampling, layout of dust particles in singulated arrangement, good contrast smooth background, high resolution images, and accurate algorithm are essential for reliable analysis. A halo effect around grey-scale images ensured correct threshold limits. The measurement algorithm used Feret s diameter for particle length and pixel-march technique for particle width. Particle size distribution was analyzed in a sieveless manner after grouping particles according to their distinct lengths, and several significant dimensions and parameters of particle size distribution were evaluated. Results of the measurement and analysis were presented in textual and graphical formats. The developed plugin was evaluated to have a dimension measurement accuracy in excess of 98.9% and a computer speed of analysis of <8 s/image. Arithmetic mean length of actual wood and bark pellets airborne dust particles were 0.1138 0.0123 and 0.1181 0.0149 mm, respectively. The airborne dust particles of

  16. Evaluating the applicability of a semi-continuous aerosol sampler to measure Asian dust particles.

    PubMed

    Son, Se-Chang; Park, Seung Shik

    2015-03-01

    A Korean prototype semi-continuous aerosol sampler was used to measure Asian dust particles. During two dust-storm periods, concentrations of crustal and trace elements were significantly enriched. Dust storms are one of the most significant natural sources of air pollution in East Asia. The present study aimed to evaluate use of a Korean semi-continuous aerosol sampler (K-SAS) in observation of mineral dust particles during dust storm events. Aerosol slurry samples were collected at 60 min intervals using the K-SAS, which was operated at a sampling flow rate of 16.7 L min(-1) through a PM10 cyclone inlet. The measurements were made during dust storm events at an urban site, Gwangju in Korea, between April 30 and May 5, 2011. The K-SAS uses particle growth technology as a means of collecting atmospheric aerosol particles. Concentrations of 16 elements (Al, Fe, Mn, Ca, K, Cu, Zn, Pb, Cd, Cr, Ti, V, Ni, Co, As, and Se) were determined off-line in the collected slurry samples by inductively coupled plasma-mass spectrometry (ICP-MS). The sampling periods were classified into two types, based on the source regions of the dust storms and the transport pathways of the air masses reaching the sampling site. The first period "A" was associated with dust particles with high Ca content, originating from the Gobi desert regions of northern China and southern Mongolia. The second period "B" was associated with dust particles with low Ca content, originating from northeastern Chinese sandy deserts. The results from the K-SAS indicated noticeable differences in concentrations of crustal and trace elements in the two sampling periods, as a result of differences in the source regions of the dust storms, the air mass transport pathways, and the impact of smoke from forest fires. The concentrations of the crustal (Al, Ca, Ti, Mn, and Fe) and anthropogenic trace elements (Vi, Ni, Cu, Zn, As, Se, and Pb) were enriched significantly during the two dust storm periods. However, the

  17. Evaluating the applicability of a semi-continuous aerosol sampler to measure Asian dust particles.

    PubMed

    Son, Se-Chang; Park, Seung Shik

    2015-03-01

    A Korean prototype semi-continuous aerosol sampler was used to measure Asian dust particles. During two dust-storm periods, concentrations of crustal and trace elements were significantly enriched. Dust storms are one of the most significant natural sources of air pollution in East Asia. The present study aimed to evaluate use of a Korean semi-continuous aerosol sampler (K-SAS) in observation of mineral dust particles during dust storm events. Aerosol slurry samples were collected at 60 min intervals using the K-SAS, which was operated at a sampling flow rate of 16.7 L min(-1) through a PM10 cyclone inlet. The measurements were made during dust storm events at an urban site, Gwangju in Korea, between April 30 and May 5, 2011. The K-SAS uses particle growth technology as a means of collecting atmospheric aerosol particles. Concentrations of 16 elements (Al, Fe, Mn, Ca, K, Cu, Zn, Pb, Cd, Cr, Ti, V, Ni, Co, As, and Se) were determined off-line in the collected slurry samples by inductively coupled plasma-mass spectrometry (ICP-MS). The sampling periods were classified into two types, based on the source regions of the dust storms and the transport pathways of the air masses reaching the sampling site. The first period "A" was associated with dust particles with high Ca content, originating from the Gobi desert regions of northern China and southern Mongolia. The second period "B" was associated with dust particles with low Ca content, originating from northeastern Chinese sandy deserts. The results from the K-SAS indicated noticeable differences in concentrations of crustal and trace elements in the two sampling periods, as a result of differences in the source regions of the dust storms, the air mass transport pathways, and the impact of smoke from forest fires. The concentrations of the crustal (Al, Ca, Ti, Mn, and Fe) and anthropogenic trace elements (Vi, Ni, Cu, Zn, As, Se, and Pb) were enriched significantly during the two dust storm periods. However, the

  18. Asian Dust at Mauna Loa Observatory: Analysis and Modeling of Individual Atmospheric Particles

    NASA Astrophysics Data System (ADS)

    Conny, J. M.; Willis, R. D.; Ortiz-Montalvo, D. L.

    2015-12-01

    Springtime Asian dust storms events, typically originating in the Gobi Desert or Taklamakan Desert, produce particles that can be carried aloft eastward for thousands of miles. As a result, the radiative properties of these particles can significantly affect global climate. Here, we determine the optical properties of particles identified as Asian dust at Mauna Loa Observatory, Hawaii, (MLO) based on the composition and actual shapes of individual particles. Samples of particulate material <10 μm in size were collected at MLO, between March 15 and April 26, 2011. Air mass back trajectories and satellite imagery showed that a subset of the aerosol sampled during this period likely originated from the Asian mainland while most of the aerosol probably did not. Samples were first analyzed by automated scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometry, whereby particles were sorted into compositionally-distinct particle types. Two particle types, identified as dolomite and calcite were determined to have originated from Asia. A third type, anhydrite, also aloft in the free troposphere, was not associated with Asian dust. Individual particles were analyzed compositionally and their shapes modeled spatially using focused ion-beam (FIB) SEM and FIB tomography. Particle 3-D representations were then input to the discrete dipole approximation method to determine their optical properties for 589 nm light. Calculations revealed that the single scattering albedo (SSA) for the Asian dust particles (0.79 to 0.94) straddled the critical SSA for cooling vs. warming (0.86), with the lowest SSA (0.79) attributed to a small amount of soot (1.7 % by volume) attached to a dolomite particle. SSA for the free troposphere anhydrite particles (0.90 to 0.93) was well above the critical SSA. For the three particle types, SSA for the actual-shaped particles was higher than equivalently-sized spheres, cubes, or tetrahedra. For the fraction of backscattered light from

  19. Dielectrophoretic separation of airborne microbes and dust particles using a microfluidic channel for real-time bioaerosol monitoring.

    PubMed

    Moon, Hui-Sung; Nam, Yun-Woo; Park, Jae Chan; Jung, Hyo-Il

    2009-08-01

    Airborne microbes such as fungi, bacteria, and viruses are a threat to public health. Robust and real-time detection systems are necessary to prevent and control such dangerous biological particles in public places and dwellings. For direct and real-time detection of airborne microbes, samples must be collected and typically resuspended in liquid prior to detection; however, environmental particles such as dust are also trapped in such samples. Therefore, the isolation of target bacteria or a selective collection of microbes from unwanted nonbiological particles prior to detection is of great importance. Dielectrophoresis (DEP), the translational motion of charge neutral matter in nonuniform electric fields, is an emerging technique that can rapidly separate biological particles in microfluidics because low voltages produce significant and contactless forces on particles without any modification or labeling. In this paper, we propose a new method for the separation of airborne microbes using DEP with a simple and novel curved electrode design for separating bacteria in a solution containing beads or dust that are taken from an airborne environmental sample. Using this method, we successfully isolated 90% of the airborne bacterium Micrococcus luteus from a mixture of bacteria and dust using a microfluidic device, consisting of novel curved electrodes that attract bacteria and repel or leave dust particles. As there has been little research on analyzing environmental samples using microfluidics and DEP, this work describes a novel strategy for a rapid and direct bioaerosol monitoring system.

  20. Real-time PCR detection of toxigenic Fusarium in airborne and settled grain dust and associations with trichothecene mycotoxins.

    PubMed

    Halstensen, Anne Straumfors; Nordby, Karl-Christian; Eduard, Wijnand; Klemsdal, Sonja Sletner

    2006-12-01

    Inhalation of immunomodulating mycotoxins produced by Fusarium spp. that are commonly found in grain dust may imply health risks for grain farmers. Airborne Fusarium and mycotoxin exposure levels are mainly unknown due to difficulties in identifying Fusarium and mycotoxins in personal aerosol samples. We used a novel real-time PCR method to quantify the fungal trichodiene synthase gene (tri5) and DNA specific to F. langsethiae and F. avenaceum in airborne and settled grain dust, determined the personal inhalant exposure level to toxigenic Fusarium during various activities, and evaluated whether quantitative measurements of Fusarium-DNA could predict trichothecene levels in grain dust. Airborne Fusarium-DNA was detected in personal samples even from short tasks (10-60 min). The median Fusarium-DNA level was significantly higher in settled than in airborne grain dust (p < 0.001), and only the F. langsethiae-DNA levels correlated significantly in settled and airborne dust (r(s) = 0.20, p = 0.003). Both F. langsethiae-DNA and tri5-DNA were associated with HT-2 and T-2 toxins (r(s) = 0.24-0.71, p < 0.05 to p < 00.01) in settled dust, and could thus be suitable as indicators for HT-2 and T-2. The median personal inhalant exposure to specific toxigenic Fusarium spp. was less than 1 genome m(-3), but the exposure ranged from 0-10(5) genomes m(-3). This study is the first to apply real-time PCR on personal samples of inhalable grain dust for the quantification of tri5 and species-specific Fusarium-DNA, which may have potential for risk assessments of inhaled trichothecenes. PMID:17133280

  1. A Southern California Perspective of the April, 1998 Trans-Pacific Asian Dust Event

    NASA Technical Reports Server (NTRS)

    Tratt, David M.; Frouin, Robert J.; Westphal, Douglas L.

    1999-01-01

    The Jet Propulsion Laboratory (JPL) coherent CO2 backscatter lidar has been in almost continuous operation since 1984 and has now accumulated a significant time-series database tracking the long-term and seasonal variability of backscatter from the atmospheric column above the Pasadena, Calif. locale. A particularly noteworthy episode observed by the lidar in 1998 was a particularly extreme instance of incursion by Asian-sourced dust during the closing days of April. Such events are not uncommon during the northern spring, when strong cold fronts and convection over the Asian interior deserts loft crustal material into the mid-troposphere whence it can be transported across the Pacific Ocean, occasionally reaching the continental US. However, the abnormal strength of the initiating storm in this case generated an atypically dense cloud of material which resulted in dramatically reduced visibility along the length of the Western Seaboard. These dust events are now recognized as a potentially significant, non-negligible radiative forcing influence. The progress of the April 1998 dust cloud eastward across the Pacific Ocean was initially observed in satellite imagery and transmitted to the broader atmospheric research community via electronic communications. The use of Internet technology in this way was effective in facilitating a rapid response correlative measurement exercise by numerous atmospheric observation stations throughout the western US and its success has resulted in the subsequent establishment of an ad hoc communications environment, data exchange medium, and mechanism for providing early-warning alert of other significant atmospheric phenomena in the future.

  2. Effects of studded tires on roadside airborne dust pollution in Niigata, Japan

    NASA Astrophysics Data System (ADS)

    Fukuzaki, Norio; Yanaka, Takaaki; Urushiyama, Yoshio

    Two series of dust samples, collected by Andersen impactors (denoted by AN) and low-volume air samplers (denoted by LV), were investigated with respect to roadside airborne dusts collected in two different periods in 1983. These were the periods (i) with studded tires (February and March) and (ii) without studded tires (October). Multi-element determinations of these samples were made by neutron activation analysis and atomic absorption spectrometry. The total concentration of AN in roadside air for period (i) was about three times higher than for the period without studded tires. The lithophilic elements such as Na, Al, K, Ca, Ti, Fe and Th, and component-metal elements of stud tip, W and Ta, produced a significant increase in atmospheric concentration in winter. The contribution of pavement material, one of the most interesting components of airborne particles in this study, was related to total AN and LV by the chemical element balance method. It made up only 16 percent (9.1 μgm -3) of AN in October, compared with 46 percent (70.2 μgm -3) in February. It was also observed that the atmospheric concentrations of pavement debris to total LV decreased with the distance from the road to each sampling site.

  3. Airborne Sunphotometry of African Dust and Marine Boundary Layer Aerosols in PRIDE

    NASA Technical Reports Server (NTRS)

    Livingston, John M.; Redemann, Jens; Russell, Philip; Schmid, Beat; Reid, Jeff; Pilewskie, Peter; Hipskind, R. Stephen (Technical Monitor)

    2000-01-01

    The Puerto Rico Dust Experiment (PRIDE) was conducted during summer 2000 to study the radiative, microphysical and transport properties of Saharan dust in the Caribbean region. During PRIDE, NASA Ames Research Center's six-channel airborne autotracking sunphotometer (AATS-6) was operated aboard a Piper Navajo airplane based at Roosevelt Roads Naval Station on the northeast coast of Puerto Rico. AATS-6 measurements were taken during 21 science flights off the coast of Puerto Rico in the western Caribbean. Data were acquired within and above the Marine Boundary Layer (MBL) and the Saharan Aerosol Layer (SAL) up to 5.5 km altitude tinder a wide range of dust loadings. Aerosol optical depth (AOD) spectra and columnar water vapor (CWV) values have been calculated from the AATS-6 measurements by using sunphotometer calibration data obtained at Mauna Loa Observatory (3A kin ASL) before (May) and after (October) PRIDE. Mid-visible AOD values measured near the surface during PRIDE ranged from 0.07 on the cleanest day to 0.55 on the most turbid day. Values measured above the MBL were as high as 0.35; values above the SAL were as low as 0.01. The fraction of total column AOD due to Saharan dust cannot be determined precisely from AATS-6 AOD data alone due to the uncertainty in the extent of vertical mixing of the dust down through the MBL. However, analyses of ground-based and airborne in-situ aerosol sampling measurements and ground-based aerosol lidar backscatter data should yield accurate characterization of the vertical mixing that will enable calculation of the Saharan dust AOD component from the sunphotometer data. Examples will be presented showing measured AATS-6 AOD spectra, calculated aerosol extinction and water vapor density vertical profiles, and aerosol size distributions retrieved by inversion of the AOD spectra. Near sea-surface AOD spectra acquired by AATS-6 during horizontal flight legs at 30 m ASL are available for validation of AOD derived from coincident

  4. Exposure to airborne microorganisms, dust and endotoxin during processing of valerian roots on farms.

    PubMed

    Skórska, Czesława; Sitkowska, Jolanta; Krysińska-Traczyk, Ewa; Cholewa, Grazyna; Dutkiewicz, Jacek

    2005-01-01

    The aim of this study was to determine the levels of microorganisms, dust and endotoxin in the air during various stages of valerian (Valeriana officinalis) roots processing by herb farmers and to examine the species composition of airborne microflora. Air samples were collected on glass fibre filters by use of personal samplers on 15 farms owned by valerian cultivating farmers, located in Lublin province (eastern Poland). The concentrations of total viable microorganisms (bacteria + fungi) in the air showed a marked variability and were within a range of 0.95-7,966.6 x 10(3) cfu/m (3). Though median was relatively low (10.75 x 10(3) cfu/m (3)), on 4 farms the concentrations exceeded the level of 10(5) cfu/m (3) and on 1 farm the level of 10(6) cfu/m (3). During the processing of valerian roots, distinct changes could be observed in the composition of airborne microflora. In the first stages of processing, the freshly dug and washed roots until shaking in the drying room, the most numerous were Gram-negative bacteria of the family Pseudomonadaceae (mostly Stenotrophomonas maltophilia, Pseudomonas chlororaphis and Pseudomonas fluorescens). After drying, the dominant organisms were thermo-resistant endospore-forming bacilli (Bacillus spp.) and fungi, among which prevailed Aspergillus fumigatus. Altogether, 29 species or genera of bacteria and 19 species or genera of fungi were identified in the farm air during valerian processing, of these, 10 and 12 species or genera respectively were reported as having allergenic and/or immunotoxic properties. The concentrations of airborne dust and endotoxin on the examined farms were very large and ranged from 10.0-776.7 mg/m (3), and from 0.15-24,448.2 microg/m (3), respectively (medians 198.3 mg/m (3) and 40.48 microg/m (3)). In conclusion, farmers cultivating valerian could be exposed during processing of valerian roots to large concentrations of airborne microorganisms, dust and endotoxin posing a risk of work

  5. Shifts in alpine lakes' ecosystems in Japan driven by increasing Asian dusts

    NASA Astrophysics Data System (ADS)

    Tsugeki, N. K.; Tani, Y.; Ueda, S.; Agusa, T.; Toyoda, K.; Kuwae, M.; Oda, H.; Tanabe, S.; Urabe, J.

    2011-12-01

    Recently in East Asia the amount of fossil fuel combustion have increased with economic growth. It has caused a problem of trans-boundary air pollution in the whole of eastern Asia. Furthermore, Asian dust storms contribute episodically to the global aerosol load. However, the effects of increased Asian dusts on aquatic ecosystems are not well understood. If biologically important nutrients such as nitrogen (N) and phosphorus (P) are transported via air dust, the atmospheric deposition of the dust may have serious impacts on recipient aquatic ecosystems because the biological production is limited by these nutrient elements. A previous report using sedimentary records has evaluated that atmospheric P inputs to the alpine lakes in the United States increased fivefold following the increased western settlement to this country during the nineteenth century. Since P is the most deficient nutrient for production in many lakes increase in P loading through atmospheric deposition of anthropogenically-derived dust might greatly affect the lake ecosystems. We examined fossil pigments and zooplankton remains from Pb-dated sediments taken from a high mountain lake of Hourai-Numa, located in the Towada-Hachimantai National Park of Japan, to uncover historical changes in the phyto- and zooplankton community over the past 100 years. Simultaneously, we measured the biogeochemical variables of TOC, TN, TP, δ13C, δ15N, and 206Pb/207Pb, 208Pb/207Pb in the sediments to identify environmental factors causing such changes. As a result, despite little anthropogenic activities in the watersheds, alpine lakes in Japan Islands increased algal and herbivore plankton biomasses by 3-6 folds for recent years depending on terrestrial the surrounded vegetations and landscape conditions. Biological and biogeochemical proxies recorded in the lake sediments indicate that this eutrophication occurred after the 1990s when P deposition increased due to atmospheric loading transported from Asian

  6. Acute Effects of Asian Dust Events on Respiratory Symptoms and Peak Expiratory Flow in Children with Mild Asthma

    PubMed Central

    Yoo, Young; Choung, Ji Tae; Yu, Jinho; Kim, Do Kyun

    2008-01-01

    The aim of this study was to investigate the possible adverse effects of Asian dust events on respiratory health in asthmatic children. Fifty-two children with mild asthma were studied for eight consecutive weeks in the spring of 2004 (March 8 to May 2). During the study period, five Asian dust days were identified; we included a lag period of two days following each of the events. Subjects recorded their respiratory symptom diaries and peak expiratory flow (PEF) twice daily during the study period; and they underwent methacholine bronchial challenge tests. The subjects reported a significantly higher frequency of respiratory symptoms during the Asian dust days than during the control days. They showed significantly more reduced morning and evening PEF values, and more increased PEF variability (10.1%±3.5% vs. 5.5%±2.2%) during the Asian dust days than during the control days. Methacholine PC20 was not significantly different between before and after the study period (geometric mean: 2.82 mg/mL vs. 3.16 mg/mL). These results suggest that the short-term Asian dust events might be associated with increased acute respiratory symptoms and changes in PEF outcomes. However, there might be little long-term influence on airway hyperresponsiveness in children with mild asthma. PMID:18303201

  7. Effects of Asian dust storm events on daily admissions for asthma in Taipei, Taiwan.

    PubMed

    Yang, Chun-Yuh; Tsai, Shang-Shyue; Chang, Chih-Ching; Ho, Shu-Chen

    2005-12-15

    In spring, windblown dust storms originating in the deserts of Mongolia and China make their way to Taipei city. These occurrences are known as Asian dust storm (ADS) events. The objective of this study was to assess the possible associations of ADS on the hospital asthma admissions of residents in Taipei, Taiwan, during the period 1996-2001. We identified 54 dust storm episodes, which were classified as index days. Daily asthma admissions on the index days were compared with admissions on the comparison days. We selected two comparison days for each index day, 7 days before the index days and 7 days after the index days. The effects of dust storms on asthma admissions were prominent 2 days after the event (8%). However, the association was not statistically significant. There may not have been enough power to detect associations resulting from the inadequate sample size of asthma admissions on ADS events days. However, it seems worthwhile to pay more attention to the ADS events and health in the future.

  8. Correlation of Asian dust storm events with daily clinic visits for allergic rhinitis in Taipei, Taiwan.

    PubMed

    Chang, Chih-Ching; Lee, I-Ming; Tsai, Shang-Shyue; Yang, Chun-Yuh

    2006-02-01

    In spring, windblown dust storms originating in the deserts of Mongolia and China head toward Taipei city. These occurrences are known as Asian dust storm (ADS) events. The objective of this study was to assess the possible associations of ADS on the daily clinical visits for allergic rhinitis of residents in Taipei, Taiwan, during the period 1997-2001. Forty-nine dust storms were identified and classified as index days. Daily clinical visits for allergic rhinitis on the index days were compared with clinical visits on the comparison (non-ADS) days. Two non-ADS days for each index day, 7 d before the index day and 7 d after the index day, were selected. The effects of dust storms on clinic visits for allergic rhinitis were prominent 2 d after the event (19%). However, the association was not statistically significant. There may not have been enough power to detect associations resulting from the inadequate sample size of allergic rhinitis visits on ADS days. Further study is needed to clarify this association.

  9. Effects of Asian dust storm events on daily clinical visits for conjunctivitis in Taipei, Taiwan.

    PubMed

    Yang, Chun-Yuh

    2006-09-01

    In spring, windblown dust storms originating in the deserts of Mongolia and China make their way to Taipei city. These occurrences are known as Asian dust storm (ADS) events. The objective of this study was to assess the possible associations of ADS with daily clinic visits for conjunctivitis in residents in Taipei, Taiwan, during the period from 1997-2001. Forty-nine dust storm episodes were classified and classified as index days. Daily clinical visits for conjunctivitis on the index days were compared with clinical visits on the comparison (non-storm) days. Two comparison days for each index day, 7 d before the index days and 7 d after the index days, were selected. The effects of dust storms on clinic visits for conjunctivitis were prominent 4 d after the event. However, the association was not statistically significant. There may not have been enough power to detect associations resulting from the inadequate sample size of conjunctivitis visits on ADS events days. However, it seems worthwhile to pay more attention to the ADS events and health in the future.

  10. The Dust at Altitude Recovery Technology (DART) System was Developed to Recover Plant, Human, and Animal Pathogens in Asian and African Dust Storms over North America

    NASA Astrophysics Data System (ADS)

    Schuerger, A. C.; Tench, B.; Nehr, A.; Emmons, T.; Valbuena, F.; Palaia, J.; Sugars, C.

    2014-12-01

    Dust emanates year-round from Africa and Asia and impacts air quality in North America. Asian dust plumes deliver up to 64 million tonnes of dust over the NW of the USA, and African dust storms deliver over 50 million tonnes of dust over Florida each year. Several recent studies have demonstrated that human and plant pathogens from Asian [1] African [2] aerosols can be transported to N. America in naturally occurring dust storms. What is unknown is whether these 'presumptive pathogens' impact human, plant, or animal health in the USA. In order to initiate a long-term monitoring program of pathogens in Asian and African dust plumes, we have developed a dust collection system called DART (Dust at Altitude Recovery Technology) (figure). The DART dust sampler can be mounted on a F104 Starfighter jet (figure) and a T6 Texan propeller driven airplane (not shown), and was test flown over FL in Dec. 2013 on the F104 and on the T6 in the summer of 2014. The DART system utilizes a high-volume pump to pass air through 6 separate filtration units where both aerosols and microbial cells are captured. The filtration systems exhibit flow rates from 25-142 L/min depending on the pore size and brand of filters used. Flow rates are directly correlated to increased air speed, and are inversely correlated to increased altitude. Filtration units can be turned on and off individually as required for specific science flight objectives. The DART dust sampler has performed nominally up to 7600 m, 0.92 Mach, and 3.5 +G's. During initial test flights in Dec. 2013, 5 of 8 genera of fungi recovered from the lower atmosphere over FL contained plant pathogens including species in the genera: Acremonium, Aspergillus, Cladosporium, Curvularia, and Fusarium. Numbers of recovered fungi, but not bacteria, increased significantly when 5 or 10 µm filters were used in the DART system compared to filter pore sizes ≤ 1.2 µm. Future sampling programs for both Asian and African dust events will be

  11. Deposition of 137Cs in Rokkasho, Japan and its relation to Asian dust.

    PubMed

    Akata, Naofumi; Hasegawa, Hidenao; Kawabata, Hitoshi; Chikuchi, Yuki; Sato, Tadahiro; Ohtsuka, Yoshihito; Kondo, Kunio; Hisamatsu, Shun'ichi

    2007-01-01

    Biweekly atmospheric depositions of (137)Cs were measured in Rokkasho, Aomori, Japan from March 2000 to March 2006 to study recent (137)Cs deposition. Although the deposition level was generally lower than the detectable limit, deposition samples collected in spring occasionally had measurable levels of (137)Cs. The annual (137)Cs deposition from 2001 to 2005 was 0.04-0.69 Bq m(-2) with a mean value of 0.27 Bq m(-2). Depositions of insoluble Al, Fe and Ti were strongly correlated with the (137)Cs deposition, suggesting that suspension of soil particles was the main source of the recent (137)Cs deposition. Asian dust events were coincident with some of the significant (137)Cs depositions in spring. It was found that the ratios of (137)Cs/Al and Fe/Al could be used as indices for discriminating Asian dust from suspension of the local surface soil. Backward trajectory analysis suggested southern Mongolian and northeastern China regions as sources of the significant (137)Cs depositions.

  12. Exacerbation of daily cough and allergic symptoms in adult patients with chronic cough by Asian dust: A hospital-based study in Kanazawa

    NASA Astrophysics Data System (ADS)

    Higashi, Tomomi; Kambayashi, Yasuhiro; Ohkura, Noriyuki; Fujimura, Masaki; Nakanishi, Sayaka; Yoshizaki, Tomokazu; Saijoh, Kiyofumi; Hayakawa, Kazuichi; Kobayashi, Fumihisa; Michigami, Yoshimasa; Hitomi, Yoshiaki; Nakamura, Hiroyuki

    2014-11-01

    The health effects associated with Asian dust have attracted attention due to the rapid increase in the number of Asian dust events in East Asia in recent years. The aim of this study was to investigate the associations between Asian dust and daily cough, as well as allergic symptoms, in adult patients who suffer from chronic cough. We enrolled 86 adult patients from Kanazawa University Hospital, Japan, who were diagnosed with asthma, cough variant asthma, atopic cough or a combination of these conditions. From January to June 2011, subjects recorded their symptoms in a diary every day. Asian dust and non-Asian dust periods were defined according to the dust extinction coefficient, measured using the light detection and ranging (LIDAR). The daily levels of total suspended particulates, polycyclic aromatic hydrocarbons (PAHs) and coexisting factors related to allergies, such as the Japanese cedar pollen count, were measured. McNemar's test showed that there were significantly more cough-positive patients during Asian dust periods than during the non-Asian dust period (p = 0.022). In addition, during Asian dust periods when the daily levels of Japanese cedar pollen, Japanese cypress pollen and PAHs were elevated, there were significantly more patients who experienced itchy eyes than during the non-Asian dust period (p < 0.05). On the other hand, there were no significant differences in the allergic symptoms, including sneezing or a runny nose and nasal congestion. This is the first report to show that Asian dust triggers cough and allergic symptoms in adult patients with chronic cough.

  13. Impacts of Asian Dust and Haze Particles Addition on Phytoplankton in Incubation Experiments in the Yellow Sea of China

    NASA Astrophysics Data System (ADS)

    Gao, H.; Zhang, C.; Liu, Y.; Shi, J.; Yao, X.

    2014-12-01

    Atmospheric deposition (AD) induced by dust events and air pollutants has been considered as an important source of bio-available nutrients such as N, P, Si and trace metals (e.g., Fe, Cu, Pb) to the oceans. The coastal seas of China are severely affected by AD from Asian dust events and haze episodes, especially in spring and winter. In this study, several on-board incubation experiments were performed in the Yellow Sea of China during 2011 - 2014, to explore the responses of micro-, nano- and pico-phytoplankton to various combinations of Asian dust, nutrients and haze particles by measuring the size-fractionated chlorophyll a (Chl a) concentration. In the experiments of Asian dust addition, the concentration of Chl a and the conversion efficiency index of N into Chl a increased by up to ~40 % and ~30 %, respectively, compared to the control, showing enhancement effects on the growth of phytoplankton. The addition of haze particles exhibited more obvious promotions of pico-phytoplankton growth, but more severe inhibitions of micro-phytoplankton growth than other treatments. The incubation experiments conducted in the Yellow Sea also indicated P limitation variations in spring and summer. It was inferred that both Asian dust and haze particles additions had significant impacts on the growth and structure of phytoplankton by modulating the limiting factors.

  14. Dust, Pollution, and Biomass Burning Aerosols in Asian Pacific: A Column Surface/Satellite Perspective

    NASA Technical Reports Server (NTRS)

    Tsay, Si-Chee; Lau, William K. M. (Technical Monitor)

    2002-01-01

    Many recent field experiments are designed to study the compelling variability in spatial and temporal scale of both pollution-derived and naturally occurring aerosols, which often exist in high concentrations over eastern/southeastern Asia and along the rim of the western Pacific. For example, the phase-I of ACE-Asia was conducted from March-May 2001 in the vicinity of the Gobi desert, East Coast of China, Yellow Sea, Korea, and Japan, along the pathway of Kosa (severe events that blanket East Asia with yellow desert dust, peaked in the Spring season). Asian dust typically originates in desert areas far from polluted urban regions. During transport, dust layers can interact with anthropogenic sulfate and soot aerosols from heavily polluted urban areas. Springtime is also the peak season for biomass burning in southeastern Asia. Added to the complex effects of clouds and natural marine aerosols, dust particles reaching the marine environment can have drastically different properties than those from the source. Thus, understanding the unique temporal and spatial variations of Asian aerosols is of special importance in regional-to-global climate issues such as radiative forcing, the hydrological cycle, and primary biological productivity in the mid-Pacific Ocean. During ACE-Asia we have measured continuously aerosol physical/optical/radiative properties, column precipitable water amount, and surface reflectivity over homogeneous areas from surface. The inclusion of flux measurements permits the determination of aerosol radiative flux in addition to measurements of loading and optical depth. At the time of the Terra/MODIS (Moderate Resolution Imaging Spectroradiometer), SeaWiFS (Sea-viewing Wide Field-of-view Sensor), TOMS (Total Ozone Mapping Spectrometer) and other satellite overpasses, these ground-based observations can provide valuable data to compare with satellite retrievals over land. A column satellite-surface perspective of Asian aerosols will be presented

  15. Study on size distribution of total aerosol and water-soluble ions during an Asian dust storm event at Jeju Island, Korea.

    PubMed

    Park, S H; Song, C B; Kim, M C; Kwon, S B; Lee, K W

    2004-01-01

    Soil dust particles transported from loess regions of the Asian continent, called Asian dust, highly influences the air quality of north-eastern Asia and the northern Pacific Ocean. In order to investigate the effects of these dust storms on the chemical composition of atmospheric aerosol particles with different size, measurements of size distributions of total aerosol and major ion species were carried out on Jeju Island, Korea during April 2001. Juju Island was chosen for the study because the levels of emissions of anthropogenic air pollutants are very low. A 5-stage cascade impactor was used to sample size-fractionated aerosol particles. Samples were analyzed for major water-soluble ions using Dionex DX-120 ion chromatograph. The average mass concentration of total aerosol was found to be 24.4 and 108.3 microg m(-3) for non-Asian dust and Asian dust periods, respectively. The total aerosol size distribution, measured during the non-Asian dust period, was bimodal, whereas the coarse particles dominated the size distribution of total aerosol during the Asian dust period. It was found that SO4(2-), NH4+ and K+ were mainly distributed in fine particles, while Cl-, NO3-, Na+, Mg2+ and Ca2+ were in coarse particles. Although SO4(2-) was mainly distributed in fine particles, during the Asian dust period, the concentrations in coarse particles were significantly increased. This indicates heterogeneous oxidation of SO2 on wet surfaces of basic soil dust particles. The NH4+ was found to exist as (NH4)2SO4 in fine particles, with a molar ratio of NH4+ to SO4(2-) of 2.37 and 1.52 for non-Asian dust and Asian dust periods, respectively. Taking into account the proximity of the sampling site to the sea, and the observed chloride depletion, coarse mode nitrate, during the non-Asian dust period, is assumed to originate from the reaction of nitric acid with sodium chloride on the surfaces of sea-salt particles although the chloride depletion was not shown to be large enough to

  16. Distinguishing the Asian dust sources based on cathodoluminescence analysis of single quartz grain

    NASA Astrophysics Data System (ADS)

    Nagashima, K.; Nishido, H.; Kayama, M.; Tada, R.; Isozaki, Y.; Sun, Y.; Igarashi, Y.

    2009-12-01

    Numerous tracers, such as mineralogical component, strontium (87Sr/86Sr) and neodymium (eNd(0)) isotopes (Liu et al., 1994; Biscaye et al.,1997; Bory et al., 2002, 2003; Kanayama et al., 2002, 2005), rare earth element composition (e.g., Svensson et al., 2000), oxygen isotope (Mizota et al., 1992; Hou et al., 2003) and ESR intensity of quartz (Ono et al., 1998; Sun et al., 2007), have been investigated to discriminate source areas of Asian dust. However, these analyses need large volume of samples (mostly more than 10 mg) and the applications to the dust samples are limited. Then, here we developed a provenance-tracing method by using a cathodoluminescence (CL) spectral of “single” quartz grain for applying it to small volume of aeolian dust samples, such as aeolian dust in the ice cores and marine sediments with the location of long distance from the Asian deserts. CL is the emission from a material which is excited by electron beam. Since CL spectroscopy and microscopy provide information on the existence and distribution of defects and trace elements in minerals, CL analyses have potential to characterize dust-source areas. CL spectra of quartz have been demonstrated to show different patterns between the quartz from hydrothermal, plutonic, volcanic and metamorphic origins (e.g., Zinkernagel, 1978; Götze et al., 2001), suggesting the spectra reflect the condition of the quartz formation and the local environment. Then, here we conducted CL spectral analysis of silt size quartz in the surface samples from the major Asian deserts, such as the Taklimakan Desert and Gobi Desert in southern Mongolia (hereafter Mongolian Gobi). CL spectra were measured in the areas of approximately 4 micron square for each quartz grain by a Scanning Electron Microscope-Cathodoluminescence (SEM-CL) at the Okayama University of Science, a SEM (Jeol: JSM-5410) attached with a grating monochromator (Oxford Instruments: Mono CL2), where EDS system can be used in combination with SEM

  17. Deposition of atmospheric (137)Cs in Japan associated with the Asian dust event of March 2002.

    PubMed

    Fujiwara, Hideshi; Fukuyama, Taijiro; Shirato, Yasuhito; Ohkuro, Toshiya; Taniyama, Ichiro; Zhang, Tong-Hui

    2007-10-01

    Considerable deposition of (137)Cs was observed in the northwestern coastal area of Japan in March 2002. Since there were no nuclear explosions or serious nuclear accidents in the early 2000s, transport of previously contaminated dust appears to be the only plausible explanation for this event. In March 2002, there was a massive sandstorm on the East Asian continent, and the dust raised by the storm was transported across the sea to Japan. This dust originated in Mongolia and northeastern China, in an area distant from the Chinese nuclear test site at Lop Nor or any other known possible sources of (137)Cs. Our radioactivity measurements showed (137)Cs enrichment in the surface layer of grassland soils in the area of the sandstorm, which we attributed to accumulation as a result of past nuclear testing. We suggest that the grassland is a potential source of (137)Cs-bearing soil particles. Since the late 1990s, this area has experienced drought conditions, resulting in a considerable reduction of vegetation cover. We attribute the prodigious release of (137)Cs-bearing soil particles into the atmosphere during the sandstorm and the subsequent deposition of (137)Cs in Japan to this change.

  18. Deposition of atmospheric (137)Cs in Japan associated with the Asian dust event of March 2002.

    PubMed

    Fujiwara, Hideshi; Fukuyama, Taijiro; Shirato, Yasuhito; Ohkuro, Toshiya; Taniyama, Ichiro; Zhang, Tong-Hui

    2007-10-01

    Considerable deposition of (137)Cs was observed in the northwestern coastal area of Japan in March 2002. Since there were no nuclear explosions or serious nuclear accidents in the early 2000s, transport of previously contaminated dust appears to be the only plausible explanation for this event. In March 2002, there was a massive sandstorm on the East Asian continent, and the dust raised by the storm was transported across the sea to Japan. This dust originated in Mongolia and northeastern China, in an area distant from the Chinese nuclear test site at Lop Nor or any other known possible sources of (137)Cs. Our radioactivity measurements showed (137)Cs enrichment in the surface layer of grassland soils in the area of the sandstorm, which we attributed to accumulation as a result of past nuclear testing. We suggest that the grassland is a potential source of (137)Cs-bearing soil particles. Since the late 1990s, this area has experienced drought conditions, resulting in a considerable reduction of vegetation cover. We attribute the prodigious release of (137)Cs-bearing soil particles into the atmosphere during the sandstorm and the subsequent deposition of (137)Cs in Japan to this change. PMID:17604085

  19. Airborne Dust Cloud Measurements at the INL National Security Test Range

    SciTech Connect

    Michael L. Abbott; Norm Stanley; Larry Radke; Charles Smeltzer

    2007-09-01

    On July 11, 2007, a surface, high-explosive test (<20,000 lb TNT-equivalent) was carried out at the National Security Test Range (NSTR) on the Idaho National Laboratory (INL) Site. Aircraft-mounted rapid response (1-sec) particulate monitors were used to measure airborne PM-10 concentrations directly in the dust cloud and to develop a PM-10 emission factor that could be used for subsequent tests at the NSTR. The blast produced a mushroom-like dust cloud that rose approximately 2,500–3,000 ft above ground level, which quickly dissipated (within 5 miles of the source). In general, the cloud was smaller and less persistence than expected, or that might occur in other areas, likely due to the coarse sand and subsurface conditions that characterize the immediate NSTR area. Maximum short time-averaged (1-sec) PM-10 concentrations at the center of the cloud immediately after the event reached 421 µg m-3 but were rapidly reduced (by atmospheric dispersion and fallout) to near background levels (~10 µg m-3) after about 15 minutes. This occurred well within the INL Site boundary, about 8 km (5 miles) from the NSTR source. These findings demonstrate that maximum concentrations in ambient air beyond the INL Site boundary (closest is 11.2 km from NSTR) from these types of tests would be well within the 150 µg m-3 24-hour National Ambient Air Quality Standards for PM-10. Aircraft measurements and geostatistical techniques were used to successfully quantify the initial volume (1.64E+9 m3 or 1.64 km3) and mass (250 kg) of the PM-10 dust cloud, and a PM-10 emission factor (20 kg m-3 crater soil volume) was developed for this specific type of event at NSTR. The 250 kg of PM-10 mass estimated from this experiment is almost seven-times higher than the 36 kg estimated for the environmental assessment (DOE-ID 2007) using available Environmental Protection Agency (EPA 1995) emission factors. This experiment demonstrated that advanced aircraft-mounted instruments operated by

  20. Geochemical evidence for airborne dust additions to soils in Channel Islands National Park, California

    USGS Publications Warehouse

    Muhs, D.R.; Budahn, J.R.; Johnson, D.L.; Reheis, M.; Beann, J.; Skipp, G.; Fisher, E.; Jones, J.A.

    2008-01-01

    There is an increasing awareness that dust plays important roles in climate change, biogeochemical cycles, nutrient supply to ecosystems, and soil formation. In Channel Islands National Park, California, soils are clay-rich Vertisols or Alfisols and Mollisols with vertic properties. The soils are overlain by silt-rich mantles that contrast sharply with the underlying clay-rich horizons. Silt mantles contain minerals that are rare or absent in the volcanic rocks that dominate these islands. Immobile trace elements (Sc-Th-La and Ta-Nd-Cr) and rare-earth elements show that the basalt and andesite on the islands have a composition intermediate between upper-continental crust and oceanic crust. In contrast, the silt fractions and, to a lesser extent, clay fractions of the silt mantle have compositions closer to average upper-continental crust and very similar to Mojave Desert dust. Island shelves, exposed during the last glacial period, could have provided a source of eolian sediment for the silt mantles, but this is not supported by mineralogical data. We hypothesize that a more likely source for the silt-rich mantles is airborne dust from mainland California and Baja California, either from the Mojave Desert or from the continental shelf during glacial low stands of sea. Although average winds are from the northwest in coastal California, easterly winds occur numerous times of the year when "Santa Ana" conditions prevail, caused by a high-pressure cell centered over the Great Basin. The eolian silt mantles constitute an important medium of plant growth and provide evidence that abundant eolian silt and clay may be delivered to the eastern Pacific Ocean from inland desert sources. ?? 2007 Geological Society of America.

  1. Separating Dust Mixtures and Other External Aerosol Mixtures Using Airborne High Spectral Resolution Lidar Data

    NASA Astrophysics Data System (ADS)

    Burton, S. P.; Ferrare, R. A.; Vaughan, M.; Hostetler, C. A.; Rogers, R. R.; Hair, J. W.; Cook, A. L.; Harper, D. B.

    2013-12-01

    Knowledge of aerosol type is important for source attribution and for determining the magnitude and assessing the consequences of aerosol radiative forcing. The NASA Langley Research Center airborne High Spectral Resolution Lidar (HSRL-1) has acquired considerable datasets of both aerosol extensive parameters (e.g. aerosol optical depth) and intensive parameters (e.g. aerosol depolarization ratio, lidar ratio) that can be used to infer aerosol type. An aerosol classification methodology has been used extensively to classify HSRL-1 aerosol measurements of different aerosol types including dust, smoke, urban pollution, and marine aerosol. However, atmospheric aerosol is frequently not a single pure type, but instead occurs as a mixture of types, and this mixing affects the optical and radiative properties of the aerosol. Here we present a comprehensive and unified set of rules for characterizing external mixtures using several key aerosol intensive parameters: extinction-to-backscatter ratio (i.e. lidar ratio), backscatter color ratio, and depolarization ratio. Our mixing rules apply not just to the scalar values of aerosol intensive parameters, but to multi-dimensional normal distributions with variance in each measurement dimension. We illustrate the applicability of the mixing rules using examples of HSRL-1 data where mixing occurred between different aerosol types, including advected Saharan dust mixed with the marine boundary layer in the Caribbean Sea and locally generated dust mixed with urban pollution in the Mexico City surroundings. For each of these cases we infer a time-height cross section of mixing ratio along the flight track and we partition aerosol extinction into portions attributed to the two pure types. Since multiple aerosol intensive parameters are measured and included in these calculations, the techniques can also be used for cases without significant depolarization (unlike similar work by earlier researchers), and so a third example of a

  2. Chemistry and mineralogy of clay minerals in Asian and Saharan dusts and the implications for iron availability

    NASA Astrophysics Data System (ADS)

    Jeong, G. Y.; Achterberg, E. P.

    2014-06-01

    Mineral dust supplied to remote ocean regions stimulates phytoplankton growth through delivery of micronutrients, notably iron (Fe). Although attention is usually paid to Fe (hydr)oxides as major sources of available Fe, Fe-bearing clay minerals are typically the dominant phase in mineral dust. The mineralogy and chemistry of clay minerals in dust particles, however, are largely unknown. We conducted microscopic identification and chemical analysis of the clay minerals in Asian and Saharan dust particles. Cross-sectional slices of dust particles were prepared by focused ion beam (FIB) techniques and analyzed by transmission electron microscopy (TEM) combined with energy dispersive X-ray spectroscopy (EDXS). TEM images of FIB slices revealed that clay minerals occurred as either nano-thin platelets or relatively thick plates. The nano-thin platelets included illite, smectite, illite-smectite mixed layers and their nanoscale mixtures (illite-smectite series clay minerals, ISCMs) which could not be resolved with an electron microbeam. EDXS chemical analysis of the clay mineral grains revealed that the average Fe content was 5.8% in nano-thin ISCM platelets assuming 14% H2O, while the Fe content of illite and chlorite was 2.8 and 14.8%, respectively. In addition, TEM and EDXS analyses were performed on clay mineral grains dispersed and loaded on microgrids. The average Fe content of clay mineral grains was 6.7 and 5.4% in Asian and Saharan dusts, respectively. A comparative X-ray diffraction analysis of bulk dusts showed that Saharan dust was more enriched in clay minerals than in Asian dust, while Asian dust was more enriched in chlorite. The average Fe / Si, Al / Si and Fe / Al molar ratios of the clay minerals, compared to previously reported chemistries of mineral dusts and leached solutions, indicated that dissolved Fe originated from clay minerals. Clay minerals, in particular nanocrystalline ISCMs and Fe-rich chlorite are important sources of available Fe in

  3. Chemistry and mineralogy of clay minerals in Asian and Saharan dusts and the implications for iron supply to the oceans

    NASA Astrophysics Data System (ADS)

    Jeong, G. Y.; Achterberg, E. P.

    2014-11-01

    Mineral dust supplied to remote ocean regions stimulates phytoplankton growth through delivery of micronutrients, notably iron (Fe). Although attention is usually paid to Fe (hydr)oxides as major sources of available Fe, Fe-bearing clay minerals are typically the dominant phase in mineral dust. The mineralogy and chemistry of clay minerals in dust particles, however, are largely unknown. We conducted microscopic identification and chemical analysis of the clay minerals in Asian and Saharan dust particles. Cross-sectional slices of dust particles were prepared by focused ion beam (FIB) techniques and analyzed by transmission electron microscopy (TEM) combined with energy dispersive X-ray spectroscopy (EDXS). TEM images of FIB slices revealed that clay minerals occurred as either nano-thin platelets or relatively thick plates. Chemical compositions and lattice fringes of the nano-thin platelets suggested that they included illite, smectite, illite-smectite mixed layers, and their nanoscale mixtures (illite-smectite series clay minerals, ISCMs) which could not be resolved with an electron microbeam. EDXS chemical analysis of the clay mineral grains revealed that the average Fe content was 5.8% in nano-thin ISCM platelets assuming 14% H2O, while the Fe content of illite and chlorite was 2.8 and 14.8%, respectively. In addition, TEM and EDXS analyses were performed on clay mineral grains dispersed and loaded on micro-grids. The average Fe content of clay mineral grains was 6.7 and 5.4% in Asian and Saharan dusts, respectively. A comparative X-ray diffraction analysis of bulk dusts showed that Saharan dust was more enriched in clay minerals than Asian dust, while Asian dust was more enriched in chlorite. Clay minerals, in particular nanocrystalline ISCMs and Fe-rich chlorite, are probably important sources of Fe to remote marine ecosystems. Further detailed analyses of the mineralogy and chemistry of clay minerals in global mineral dusts are required to evaluate the

  4. Variability in the correlation between Asian dust storms and chlorophyll a concentration from the North to Equatorial Pacific.

    PubMed

    Tan, Sai-Chun; Yao, Xiaohong; Gao, Hui-Wang; Shi, Guang-Yu; Yue, Xu

    2013-01-01

    A long-term record of Asian dust storms showed seven high-occurrence-frequency centers in China. The intrusion of Asian dust into the downwind seas, including the China seas, the Sea of Japan, the subarctic North Pacific, the North Pacific subtropical gyre, and the western and eastern Equatorial Pacific, has been shown to add nutrients to ocean ecosystems and enhance their biological activities. To explore the relationship between the transported dust from various sources to the six seas and oceanic biological activities with different nutrient conditions, the correlation between monthly chlorophyll a concentration in each sea and monthly dust storm occurrence frequencies reaching the sea during 1997-2007 was examined in this study. No correlations were observed between dust and chlorophyll a concentration in the <50 m China seas because atmospheric deposition is commonly believed to exert less impact on coastal seas. Significant correlations existed between dust sources and many sea areas, suggesting a link between dust and chlorophyll a concentration in those seas. However, the correlation coefficients were highly variable. In general, the correlation coefficients (0.54-0.63) for the Sea of Japan were highest, except for that between the subarctic Pacific and the Taklimakan Desert, where it was as high as 0.7. For the >50 m China seas and the North Pacific subtropical gyre, the correlation coefficients were in the range 0.32-0.57. The correlation coefficients for the western and eastern Equatorial Pacific were relatively low (<0.36). These correlation coefficients were further interpreted in terms of the geographical distributions of dust sources, the transport pathways, the dust deposition, the nutrient conditions of oceans, and the probability of dust storms reaching the seas.

  5. Variability in the correlation between Asian dust storms and chlorophyll a concentration from the North to Equatorial Pacific.

    PubMed

    Tan, Sai-Chun; Yao, Xiaohong; Gao, Hui-Wang; Shi, Guang-Yu; Yue, Xu

    2013-01-01

    A long-term record of Asian dust storms showed seven high-occurrence-frequency centers in China. The intrusion of Asian dust into the downwind seas, including the China seas, the Sea of Japan, the subarctic North Pacific, the North Pacific subtropical gyre, and the western and eastern Equatorial Pacific, has been shown to add nutrients to ocean ecosystems and enhance their biological activities. To explore the relationship between the transported dust from various sources to the six seas and oceanic biological activities with different nutrient conditions, the correlation between monthly chlorophyll a concentration in each sea and monthly dust storm occurrence frequencies reaching the sea during 1997-2007 was examined in this study. No correlations were observed between dust and chlorophyll a concentration in the <50 m China seas because atmospheric deposition is commonly believed to exert less impact on coastal seas. Significant correlations existed between dust sources and many sea areas, suggesting a link between dust and chlorophyll a concentration in those seas. However, the correlation coefficients were highly variable. In general, the correlation coefficients (0.54-0.63) for the Sea of Japan were highest, except for that between the subarctic Pacific and the Taklimakan Desert, where it was as high as 0.7. For the >50 m China seas and the North Pacific subtropical gyre, the correlation coefficients were in the range 0.32-0.57. The correlation coefficients for the western and eastern Equatorial Pacific were relatively low (<0.36). These correlation coefficients were further interpreted in terms of the geographical distributions of dust sources, the transport pathways, the dust deposition, the nutrient conditions of oceans, and the probability of dust storms reaching the seas. PMID:23460892

  6. Airborne bacteria transported with Sahara dust particles from Northern Africa to the European Alps

    NASA Astrophysics Data System (ADS)

    Lazzaro, A.; Meola, M.

    2015-12-01

    The Sahara Desert is the most important source of aerosols transported across the Mediterranean towards Europe. Airborne microorganisms associated with aerosols may be transported over long distances and act as colonizers of distant habitats. However, little is known on the composition and viability of such microorganisms, due to difficulties related to their detection, collection and isolation. Here we describe an in-depth assessment of the bacterial communities associated with Sahara dust (SD) particles deposited on snow. Two distinct SD events reaching the European Alps in February and May 2014 were preserved as distinct ochre-coloured layers within the snowpack. In June 2014, we collected samples from a snow profile at 3621 m a.s.l. close to the Jungfraujoch (Swiss Alps). SD particles were analyzed by Scanning Electron Microscopy and Energy-Dispersive X-Ray Spectroscopy (SEM-EDX). Backward trajectories were calculated using the NOAA HYSPLIT model. Bacterial communities were charac-terized by MiSeq Illumina sequencing of the 16S rRNA gene. Microbial physiological profiles were assessed by incubation of samples on BIOLOG plates. The SD-layers were generally enriched in illite and kaolinite particles as compared to the adjacent snow layers. The source of SD could be traced back to Algeria. We observed distinct bacterial community structures in the SD-layers as compared to the clean snow layers. While sporulating bacteria were not enriched in the SD-layers, low abundant (<1%) phyla such as Gemmatimonadetes and Deinococcus-Thermus appeared to be specific bioindicators for SD. Both phyla are adapted to arid oligotrophic environments and UV radiation and thus are well suited to survive the harsh conditions of long-distance airborne transport. Our results show that bacteria are viable and metabolically active after the trek to the European Alps.

  7. The threat of Asian dust storms on asthma patients: a population-based study in Taiwan.

    PubMed

    Wang, Chien-Ho; Chen, Chin-Shyan; Lin, Chung-Liang

    2014-01-01

    This study explores the relationship between Asian dust storms (ADSs), asthma hospital admissions and average medical cost discharge. We adopt the hospitalisation data from the Taiwan National Health Insurance research database covering the period from 2000 to 2009. The autoregressive integrated moving average with exogenous variables (ARIMAX) analyses were performed to explore the relationship between ADS and asthma hospital admissions, adjusting for temperature, air pollutants and season dummy. The results show that ADS events do generate a critical influence upon the occurrences of asthma on post-ADS events from days 1 through 3, with an average of 17-20 more hospitalised admissions, and have stronger effects on preschool children, middle-aged people and the elderly. From the perspective of medical expenses, the cost of hospitalised admissions for asthma substantially rises daily, on average, by NT$634,698 to NT$787,407 during ADS event days. This study suggests that government should establish a forecast and alert system and release warnings about dust storms, so that the individuals predisposed to asthma can take precautionary measures to reduce their outdoor exposure. Consequently, personal risk and medical expenditure could be reduced significantly, especially for preschool children, middle-aged people and the elderly with asthma. PMID:25186129

  8. Development of a Forecasting and Data Assimilation System for Asian Dust in the Japan Meteorological Agency (JMA)

    NASA Astrophysics Data System (ADS)

    Yumimoto, K.; Tanaka, T. Y.; Ogi, A.; Sekiyama, T. T.; Maki, T.; Murakami, H.; Kikuchi, M.; Nagao, T. M.

    2015-12-01

    Mineral dust, a major aerosol during springtime in East Asia, impacts various aspects including social activity, human health, climate and the ocean ecosystem. To mitigate the damage of severe dust storms, it is crucial to develop a forecasting and early warning system for Asian dust. Since 2007, the World Meteorological Organization (WMO) has taken the lead with 40 international partners to develop a Sand and Dust Storm Warning Advisory and Assessment System (SDS-WAS). The Japan Meteorological Agency (JMA) launched a numerical forecasting system for Asian dust in 2004, and completed a major renovation of the system in November 2014. In the renovation, we replaced a general circulation model (the JMA98 GCM) and dust emission scheme (based on wind velocity at 10 m) with new ones (the GSMUV GCM and a friction velocity based emission scheme). A 5-year validation exhibits that the renovation achieves better forecasting score (especially in short range forecast). Our group has resolution improvement (up to ~40 km) and implementation of data assimilation with satellite observations in the upcoming updates. A feasibility study on involving observations from Himawari-8 (JMA's new geostationary meteorological satellite) into the system is also conducted for better forecasting skill and toward robust early warning.

  9. On the relations between land-surface Water Use Efficiency and Asian dust storms in the Northeast Asia

    NASA Astrophysics Data System (ADS)

    Park, J.; Kang, S.

    2015-12-01

    Asian dust storm is one of major environmental issures in the Northeast Asia. The dust storm occurrence is typically influenced by both atmospheric (i.e. pressure, wind speed, precipitation, etc.) and land-surface conditions (i.e. vegetation cover and vitality, soil dryness, etc). Severe water stess in arid and semi-arid regions can resulted in reduction of vegetation cover fraction ultimately. Plant physiological change might however precede the vegetation structural change by regulating leaf stomatal resistance. In this study, we tested whether plant physiological index can be used for early indicator of plant recession causing dust storm increase. For the purpose, satellite-based eco-physiological variables such as gross primary production (GPP), evapotranspiration (ET), and water use efficiency (WUE) were prepared and then, compared their spatial and temporal variability with Synop dust storm data for the Northeast Asia. In results, the asian dust storms occurrence decreased in early 2000s but again increased, especially, in eastern mongolia during late 2000s. Our tentative result indicates that this region was appeared consistently low water use efficiency result during the period of late 2000s. In this study, the relations between WUE and dust sorm were interpreted and discussed as a tool for early indicator of land degradation of arid and semi-arid grasslands.

  10. Comparison of Air Impaction and Electrostatic Dust Collector Sampling Methods to Assess Airborne Fungal Contamination in Public Buildings.

    PubMed

    Normand, Anne-Cécile; Ranque, Stéphane; Cassagne, Carole; Gaudart, Jean; Sallah, Kankoé; Charpin, Denis-André; Piarroux, Renaud

    2016-03-01

    Many ailments can be linked to exposure to indoor airborne fungus. However, obtaining a precise measurement of airborne fungal levels is complicated partly due to indoor air fluctuations and non-standardized techniques. Electrostatic dust collector (EDC) sampling devices have been used to measure a wide range of airborne analytes, including endotoxins, allergens, β-glucans, and microbial DNA in various indoor environments. In contrast, viable mold contamination has only been assessed in highly contaminated environments such as farms and archive buildings. This study aimed to assess the use of EDCs, compared with repeated air-impactor measurements, to assess airborne viable fungal flora in moderately contaminated indoor environments. Indoor airborne fungal flora was cultured from EDCs and daily air-impaction samples collected in an office building and a daycare center. The quantitative fungal measurements obtained using a single EDC significantly correlated with the cumulative measurement of nine daily air impactions. Both methods enabled the assessment of fungal exposure, although a few differences were observed between the detected fungal species and the relative quantity of each species. EDCs were also used over a 32-month period to monitor indoor airborne fungal flora in a hospital office building, which enabled us to assess the impact of outdoor events (e.g. ground excavations) on the fungal flora levels on the indoor environment. In conclusion, EDC-based measurements provided a relatively accurate profile of the viable airborne flora present during a sampling period. In particular, EDCs provided a more representative assessment of fungal levels compared with single air-impactor sampling. The EDC technique is also simpler than performing repetitive air-impaction measures over the course of several consecutive days. EDC is a versatile tool for collecting airborne samples and was efficient for measuring mold levels in indoor environments.

  11. Statistical analysis of the size and elemental composition of airborne coal-mine dust. Open File Report (Interim) 1984-86

    SciTech Connect

    Mutmansky, J.M.; Lee, C.

    1987-03-01

    The report was part of an ongoing effort at The Pennsylvania State University to investigate the characteristics of airborne mine dusts and its relationship to coal worker's pneumoconiosis (CWP). The specific purpose of the project was to analyze the size and elemental composition of airborne coal mine dusts and the ramifications of these characteristics. A dust sampling strategy using multi-stage cascade impactors was established for characterization purposes. Analysis of the size distributions of the collected samples was performed based upon the aerodynamic diameter of the dust. Patterns of lognormality and bimodality were found in the data. Elemental analysis was performed by the PIXE method for both major and trace elements. Size dependency and locational variation of the elemental composition of the airborne dust were significant in some cases. Relationships to the mining section activities were also investigated.

  12. The influence of coal physical and mechanical properties and mining energy consumption factor on airborne respirable dust level

    SciTech Connect

    Koziel, A.; Malec, M.; Wardas, E.

    1999-07-01

    The fact that there are not any explicitly defined relationships describing the influence of physical and mechanical properties of coal and of energy consumption factor on dust level prompted Polish and American investigators to carry out a joint research project within the framework of the US-Poland Maria Sklodowska-Curie Joint Fund II. The paper presents methods used to perform tests under laboratory conditions at the Pittsburgh Research Laboratory as well as under real conditions in the course of coal cutting in Polish coal mines. Measuring systems and results of the tests are described. The analysis carried out has provided a basis for determining the influence of specified operational parameters, i.e., coal compression strength R{sub c}, coal cuttability factor A, energy consumption factor of mining E{sub uc}, load of cutting drums as well as of laboratory parameters, i.e., grindability, coal breakage characteristics (product size distribution), moisture content, volatile and fixed carbon content, specific energy of crushing on a level of generated dust (total dust, specific dust and airborne respirable dust). The effect of technical parameters, i.e., face height, airflow velocity in a face, amount and pressure of water in spraying systems of longwall shearers, depth of cut taken by a cutting drum and application of powered cowls on dust level under operating conditions are also presented. Results of the tests made it possible to work out guidelines relating to methods and technology for effective reduction of dust emission on longwall faces.

  13. [Characteristics of atmospheric dust deposited in snow on Urumqi Glacier No.1 of eastern Tian Shan, China: a comparison of measurements during Asian dust period with non-dust period].

    PubMed

    Dong, Zhi-Wen; Li, Zhong-Qin; Wang, Fei-Teng; Zhang, Ming-Jun

    2009-06-15

    Deposition of atmospheric dust was measured in the snow on Glacier No.1 at the headwater of Urumqi River in eastern Tian Shan, central Asia. An analysis of seasonal change of concentration of dust particles in the snow cover suggests that number concentration of dust particle is significantly high from April to June (439 x 10(3)/mL), which may be caused by Asian dust storm in spring. The comparison of mass-size distribution of dust particles between April to August shows an obvious change trend. The distribution of particles changes from single model (3-21 microm) in non-dust period before April, to bio-model (3-21 microm and 20-80 microm) during Asian dust period, and to single model (3-21 microm) after June in non-dust period again. Ca2+ concentration in the snow is also very high from April to June, while NH4+ and SO4(2-), as water-soluble constituents the concentration change is different from each other. Backward trajectory was also employed to examine the transport process of air mass in this region.

  14. Factors Affecting Vegetable Growers’ Exposure to Fungal Bioaerosols and Airborne Dust

    PubMed Central

    Hansen, Vinni M.; Meyling, Nicolai Vitt; Winding, Anne; Eilenberg, Jørgen; Madsen, Anne Mette

    2012-01-01

    We have quantified vegetable growers’ exposure to fungal bioaerosol components including (1→3)-β-d-glucan (β-glucan), total fungal spores, and culturable fungal units. Furthermore, we have evaluated factors that might affect vegetable growers’ exposure to fungal bioaerosols and airborne dust. Investigated environments included greenhouses producing cucumbers and tomatoes, open fields producing cabbage, broccoli, and celery, and packing facilities. Measurements were performed at different times during the growth season and during execution of different work tasks. Bioaerosols were collected with personal and stationary filter samplers. Selected fungal species (Beauveria spp., Trichoderma spp., Penicillium olsonii, and Penicillium brevicompactum) were identified using different polymerase chain reaction-based methods and sequencing. We found that the factors (i) work task, (ii) crop, including growth stage of handled plant material, and (iii) open field versus greenhouse significantly affected the workers’ exposure to bioaerosols. Packing of vegetables and working in open fields caused significantly lower exposure to bioaerosols, e.g. mesophilic fungi and dust, than harvesting in greenhouses and clearing of senescent greenhouse plants. Also removing strings in cucumber greenhouses caused a lower exposure to bioaerosols than harvest of cucumbers while removal of old plants caused the highest exposure. In general, the exposure was higher in greenhouses than in open fields. The exposures to β-glucan during harvest and clearing of senescent greenhouse plants were very high (median values ranging between 50 and 1500 ng m−3) compared to exposures reported from other occupational environments. In conclusion, vegetable growers’ exposure to bioaerosols was related to the environment, in which they worked, the investigated work tasks, and the vegetable crop. PMID:22003240

  15. Airborne dust and aeroallergen concentration in a horse stable under two different management systems.

    PubMed

    Woods, P S; Robinson, N E; Swanson, M C; Reed, C E; Broadstone, R V; Derksen, F J

    1993-05-01

    Airborne dust concentration (ADC) was measured in 2 different horse management systems using an Andersen cascade impactor in the box-stall, and a personal Marple cascade impactor attached to the halter to measure ADC in the breathing zone. The levels of aeroallergens implicated in chronic obstructive pulmonary disease were measured by radioallergosorbent-inhibition immunoassay. A conventional management system (System C) utilising hay feed and straw bedding, and a recommended environment (System R) utilising wood shaving bedding and a complete pelleted diet were studied. In the stall, total and respirable ADC (geometric mean) were significantly higher in System C (2.55 mg/m3; 0.44 mg/m3, respectively) than in System R (0.70 mg/m3; 0.20 mg/m3, respectively). In System C, the total and respirable ADC in the breathing zone (17.51 mg/m3; 9.28 mg/m3) were much higher than in the stall, but values in both regions were similar in System R (0.52 mg/m3; 0.30 mg/m3). Major aeroallergens were significantly higher in System C than in System R: Micropolyspora faeni (1423 ng/m3 and 705 ng/m3), Aspergillus fumigatus (1823 ng/m3 and 748 ng/m3), and mite allergens (1420 ng/m3 and 761 ng/m3). Measurement of ADC with personal samplers indicates that the very high inhalation challenge in the breathing zone is not reflected in measurements of stall air quality. When compared with System C, System R produced only 3% of the respirable dust burden in the breathing zone and a decreased aeroallergen challenge.

  16. Cloud condensation nuclei characteristics of Asian dust particles over the western and central North Pacific

    NASA Astrophysics Data System (ADS)

    Uematsu, M.; Furutani, H.; Kawata, R.; Nakayama, H.

    2015-12-01

    Marine aerosols, such as sea salt particles, and sulfate and organic particles originated from marine biotas, exist in the marine atmosphere. Additionally, continental aerosols, such as dust and anthropogenic substances are transported over the open oceans. Variation of number concentration of cloud condensation nuclei (CCN) depends on the number-size distribution and chemical compositions of aerosols, and affects the lifetime and the reflectivity of clouds over the open oceans. During the R/V Hakuho Maru KH-12-1 cruise from Callao to Tokyo via Honolulu in the Pacific Ocean (23 January - 7 March 2012), aerosol number-size distribution and CCN number concentration were continuously measured, and the marine aerosols for chemical analysis were collected on shipboard. In the marine atmosphere over the Pacific, averaged aerosol total number concentration (TN) was 280 cm-3. Bimodal number-size distributions were observed frequently with peaks at 40-60 nm (Aitken mode) and 160-230 nm (accumulation mode). CCN concentrations were categorized by assuming three types of particles by chemical compositions (i.e., NaCl; a major component of sea salt particles, (NH4)2SO4; a sulfur oxide originated from the marine biotas, and Oxalic acid; a major component among organic carbon (OC) originated from the marine biotas). Activation Rate (AR), which is defined as the ratio of the number concentrations of CCN against TN, varied mainly because of the number-size distribution. Chemical composition was the factor that determined AR values. However, the AR variations caused by changes of the chemical composition were much smaller than those caused changes of the particle size distribution even when Asian dust were observed over the region on 27-29 February. During the long range transport, rapid coagulation among mineral dust, organics and sea salt particles may accelerate the gravitational setting of marine aerosols and supplies the terrestrial substances to the ocean environment.

  17. Asian sand dust enhances ovalbumin-induced eosinophil recruitment in the alveoli and airway of mice

    SciTech Connect

    Hiyoshi, Kyoko; Ichinose, Takamichi; Sadakane, Kaori; Takano, Hirohisa; Nishikawa, Masataka; Mori, Ikuko; Yanagisawa, Rie; Yoshida, Seiichi; Kumagai, Yoshito; Tomura, Shigeo; Shibamoto, Takayuki . E-mail: tshibamoto@ucdavis.edu

    2005-11-15

    Asian sand dust (ASD) containing sulfate (SO{sub 4} {sup 2-}) reportedly causes adverse respiratory health effects but there is no experimental study showing the effect of ASD toward allergic respiratory diseases. The effects of ASD and ASD plus SO{sub 4} {sup 2-} toward allergic lung inflammation induced by ovalbumin (OVA) were investigated in this study. ICR mice were administered intratracheally with saline; ASD alone (sample from Shapotou desert); and ASD plus SO{sub 4} {sup 2-} (ASD-SO{sub 4}); OVA+ASD; OVA+ASD-SO{sub 4}. ASD or ASD-SO{sub 4} alone caused mild nutrophilic inflammation in the bronchi and alveoli. ASD and ASD-SO{sub 4} increased pro-inflammatory mediators, such as Keratinocyte chemoattractant (KC) and macrophage inflammatory protein (MIP)-1 alpha, in bronchoalveolar lavage fluids (BALF). ASD and ASD-SO{sub 4} enhanced eosinophil recruitment induced by OVA in the alveoli and in the submucosa of the airway, which has a goblet cell proliferation in the bronchial epithelium. However, a further increase of eosinophils by addition of SO{sub 4} {sup 2-} was not observed. The two sand dusts synergistically increased interleukin-5 (IL-5) and monocyte chemotactic protein-1 (MCP-1), which were associated with OVA, in BALF. However, the increased levels of IL-5 were lower in the OVA+ASD-SO{sub 4} group than in the OVA+ASD group. ASD caused the adjuvant effects to specific-IgG1 production by OVA, but not to specific-IgE. These results suggest that the enhancement of eosinophil recruitment in the lung is mediated by synergistically increased IL-5 and MCP-1. IgG1 antibodies may play an important role in the enhancement of allergic reaction caused by OVA and sand dust. However, extra sulfate may not contribute to an increase of eosinophils.

  18. Wind barriers suppress fugitive dust and soil-derived airborne particles in arid regions

    SciTech Connect

    Grantz, D.A.; Vaughn, D.L.; Farber, R.J.; Kim, B.; Ashbaugh, L.; Van Curen, T.; Campbell, R.

    1998-07-01

    Areas of abandoned agricultural land in the Antelope Valley, western Mojave (high) desert of California have proven in the previous studies to be recalcitrant to conventional tillage and revegetation strategies designed to suppress wind erosion of soil and transport of sediment and fugitive dust. These areas represented a continuing source of drifting sand and of coarse and respirable suspended particulate matter. The traditional techniques failed because furrows collapsed and the water holding capacity of the overburden was too low to support seed germination and transplant survival. In this study a variety of wind barriers were evaluated for suppression of sediment transport. Airborne particles were measured with an array of coarse particle samplers at heights of 0.2, 1.0, and 2.0 m above the soil surface. Discrete artificial wind barriers, consisting of widely spaced roughness elements were effective in suppressing fugitive emissions. Wind fences established along the leeward edge of an area of blowing sand, perpendicular to the prevailing wind, significantly decreased fugitive emissions. Control was greatest and precision of the measurements was highest under high wind conditions. These techniques provide rapid and effective suppression of fugitive emissions of soil-derived particles under conditions that resist conventional tillage and revegetation techniques. A simple, indirect procedure for determining local wind velocity erosion thresholds requiring only sampling of wind run and suspended particulate mass compared favorably with direct measurement of saltation as a function of wind velocity.

  19. Asian dust event observed in Seoul, Korea, during 29-31 May 2008: analysis of transport and vertical distribution of dust particles from lidar and surface measurements.

    PubMed

    Kim, Sang-Woo; Yoon, Soon-Chang; Kim, Jiyoung; Kang, Jung-Yoon; Sugimoto, Nobuo

    2010-03-01

    In this study, we investigate the transport of dust particles, its vertical distribution, and the associated meteorological conditions during an Asian dust event that was observed in Seoul, Korea on May 29-31, 2008. This study analyzes data from ground-based and space-borne 2-wavelength polarization lidars, particulate mass concentrations, and synoptic weather data. Surface meteorological station observations of dust phenomena, dust transport model, and weather maps consistently show that the dust particles were transported from the source regions (Inner Mongolia, Man-Ju, and Ordos areas) to Korea via the northeastern part of China. Network observations of the PM(10) concentrations in Korea revealed that a majority of the heavy dust particles traveled across South Korea from the northwest to the southeast direction with a horizontal scale of 250-300km and a traveling speed of approximately 40kmh(-1). This extraordinary dust event, in terms of its intensity and timing during the year, occurred due to the blockage of an unusually intensified low-pressure system in the northeastern part of China as well as high-pressure system centered over the Sea of Okhotsk and the Kuril Islands. The low values of the particle depolarization ratio (delta(532)) (dust period indicate the presence of spherical, non-dust, and relatively small particles. The mean delta(532) value was approximately 0.123+/-0.069 between altitudes of ground approximately 2.8km, and 0.161+/-0.049 for near-surface dust layer (ground approximately 1.2km). This value is quite similar to that obtained during the 3-year SNU-Lidar measurements in Seoul (delta(532) approximately 0.136+/-0.027). The value of delta(532) during the 2nd multilayered dust episode ranged between 0.081 and 0.120 for near-surface dust layers, and between 0.076 and 0.114 for elevated dust layers. The CALIPSO measurements of beta(532), delta(532), and CR also revealed the presence of dense dust

  20. Satellite Monitoring of Long-Range Transport of Asian Dust Storms from Sources to Sinks

    NASA Astrophysics Data System (ADS)

    Hsu, N.; Tsay, S.; Jeong, M.; King, M.; Holben, B.

    2007-05-01

    Among the many components that contribute to air pollution, airborne mineral dust plays an important role due to its biogeochemical impact on the ecosystem and its radiative-forcing effect on the climate system. In East Asia, dust storms frequently accompany the cold and dry air masses that occur as part of spring-time cold front systems. China's capital, Beijing, and other large cities are on the primary pathway of these dust storm plumes, and their passage over such popu-lation centers causes flight delays, pushes grit through windows and doors, and forces people indoors. Furthermore, during the spring these anthropogenic and natural air pollutants, once generated over the source regions, can be transported out of the boundary layer into the free troposphere and can travel thousands of kilometers across the Pacific into the United States and beyond. In this paper, we will demonstrate the capability of a new satellite algorithm to retrieve aerosol optical thickness and single scattering albedo over bright-reflecting surfaces such as urban areas and deserts. Such retrievals have been dif-ficult to perform using previously available algorithms that use wavelengths from the mid-visible to the near IR because they have trouble separating the aerosol signal from the contribution due to the bright surface reflectance. The new algorithm, called Deep Blue, utilizes blue-wavelength measurements from instruments such as SeaWiFS and MODIS to infer the properties of aerosols, since the surface reflectance over land in the blue part of the spectrum is much lower than for longer wavelength channels. Deep Blue algorithm has recently been integrated into the MODIS processing stream and began to provide aerosol products over land as part of the opera-tional MYD04 products. In this talk, we will show the comparisons of the MODIS Deep Blue products with data from AERONET sunphotometers on a global ba-sis. The results indicate reasonable agreements between these two. These new

  1. Optimization of the concentration optics of the Martian airborne dust sensor for MetNet space mission

    NASA Astrophysics Data System (ADS)

    Cortés, F.; González, A.; de Castro, A. J.; López, F.

    2012-06-01

    Martian atmosphere contains a significant and rapidly changing load of suspended dust that never drops to zero. The main component of Martian aerosol is micron-sized dust thought to be a product of soil weathering. Although airborne dust plays a key role in Martian climate, the basic physical properties of these aerosols are still poorly known. The scope of Mars MetNet Mission is to deploy several tens of mini atmospheric stations on the Martian surface. MEIGA-MetNet payload is the Spanish contribution in MetNet. Infrared Laboratory of University Carlos III (LIR-UC3M) is in charge of the design and development of a micro-sensor for the characterization of airborne dust. This design must accomplish with a strict budget of mass and power, 45 g and 1 W respectively. The sensor design criteria have been obtained from a physical model specifically developed for optimizing IR local scattering. The model calculates the spectral power density scattered and detected between 1 and 5 μm by a certain particle distribution and sensor configuration. From model calculations a modification based on the insertion of a compound ellipsoidal concentrator (CEC) has appeared as necessary. Its implementation has multiplied up to 100 the scattered optical power detected, significantly enhancing the detection limits of the sensor.

  2. A study of Asian dust plumes using satellite, surface, and aircraft measurements during the INTEX-B field experiment

    NASA Astrophysics Data System (ADS)

    Logan, Timothy; Xi, Baike; Dong, Xiquan; Obrecht, Rebecca; Li, Zhanqing; Cribb, Maureen

    2010-04-01

    Asian dust events occur frequently during the boreal spring season. Their optical properties have been analyzed by using a combination of source region (ground-based and satellite) and remote Pacific Ocean (aircraft) measurements during the Intercontinental Chemical Transport Experiment-Phase B (INTEX-B) field campaign which lasted from 7 April to 15 May 2006. A strong dust event originating from the Gobi Desert and passing over the Xianghe surface site on 17 April 2006 has been extensively analyzed. The surface averaged aerosol optical depth (AOD) values increased from 0.17 (clear sky) to 4.0 (strong dust), and the Angström exponent (α) dropped from 1.26 (clear sky) to below 0.1. Its total downwelling SW flux over the Xianghe site (thousands of kilometers away from the dust source region) is only 46% of the clear-sky value with almost no direct transmission and nearly double the diffuse SW clear-sky value. This event was also captured 6 days later by satellite observations as well as the UND/NASA DC-8 aircraft over the eastern Pacific Ocean. The DC-8 measurements in the remote Pacific region further classified the plumes into dust dominant, pollution dominant, and a mixture of dust and pollution events. HYSPLIT backward trajectories not only verified the origins of each case we selected but also showed (1) two possible origins for the dust: the Gobi and Taklimakan deserts; and (2) pollution: urban areas in eastern China, Japan, and other industrialized cities east of the two deserts. Based on the averaged satellite retrieved AOD data (0.5° × 0.5° grid box), declining AOD values with respect to longitude demonstrated the evolution of the transpacific transport pathway of Asian dust and pollution over the period of the field campaign.

  3. A brief report of gram-negative bacterial endotoxin levels in airborne and settled dusts in animal confinement buildings

    SciTech Connect

    Thedell, T.D.; Mull, J.C.; Olenchock, S.A.

    1980-01-01

    Gram-negative bacterial endotoxins, implicated in adverse worker health responses, were found in settled and airborne dust samples obtained from poultry and swine confinement units. Results of the Limulus amebocyte lysate gel test found endotoxin levels in dust samples ranged from 4.5 to 47.7 micrograms of FDA Klebsiella endotoxin equivalents/gm. Differences in endotoxin levels between dust samples may have been due to variables in time, geographic locations, confined animals, confinement buildings and equipment, and methods of sample collection. Animal confinement workers are potentially exposed to large amounts of gram-negative bacterial endotoxins; however, the respiratory health effects of such exposures to animal confinement workers have yet to be determined.

  4. A case study of Asian dust storm particles: chemical composition, reactivity to SO2 and hygroscopic properties.

    PubMed

    Ma, Qingxin; Liu, Yongchun; Liu, Chang; Ma, Jinzhu; He, Hong

    2012-01-01

    Mineral dust comprises a great fraction of the global aerosol loading, but remains the largest uncertainty in predictions of the future climate due to its complexity in composition and physico-chemical properties. In this work, a case study characterizing Asian dust storm particles was conducted by multiple analysis methods, including SEM-EDS, XPS, FT-IR, BET, TPD/mass and Knudsen cell/mass. The morphology, elemental fraction, source distribution, true uptake coefficient for SO2, and hygroscopic behavior were studied. The major components of Asian dust storm particles are aluminosilicate, SiO2 and CaCO3, with organic compounds and inorganic nitrate coated on the surface. It has a low reactivity towards SO2 with a true uptake coefficient, 5.767 x 10(-6), which limits the conversion of SO2 to sulfate during dust storm periods. The low reactivity also means that the heterogeneous reactions of SO2 in both dry and humid air conditions have little effect on the hygroscopic behavior of the dust particles. PMID:22783615

  5. An Assessment of the Surface Longwave Direct Radiative Effect of Airborne Saharan Dust During the NAMMA Field Campaign

    NASA Technical Reports Server (NTRS)

    Hansell, R. A.; Tsay, S. C.; Ji, Q.; Hsu, N. C.; Jeong, M. J.; Wang, S. H.; Reid, J. S.; Liou, K. N.; Ou, S. C.

    2010-01-01

    In September 2006, NASA Goddard s mobile ground-based laboratories were deployed to Sal Island in Cape Verde (16.73degN, 22.93degW) to support the NASA African Monsoon Multidisciplinary Analysis (NAMMA) field study. The Atmospheric Emitted Radiance Interferometer (AERI), a key instrument for spectrally characterizing the thermal IR, was used to retrieve the dust IR aerosol optical depths (AOTs) in order to examine the diurnal variability of airborne dust with emphasis on three separate dust events. AERI retrievals of dust AOT are compared with those from the coincident/collocated multifilter rotating shadow-band radiometer (MFRSR), micropulse lidar (MPL), and NASA Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) sensors. The retrieved AOTs are then inputted into the Fu-Liou 1D radiative transfer model to evaluate local instantaneous direct longwave radiative effects (DRE(sub LW)) of dust at the surface in cloud-free atmospheres and its sensitivity to dust microphysical parameters. The top-of-atmosphere DRE(sub LW) and longwave heating rate profiles are also evaluated. Instantaneous surface DRE(sub LW) ranges from 2 to 10 W/sq m and exhibits a strong linear dependence with dust AOT yielding a DRE(sub LW) of 16 W/sq m per unit dust AOT. The DRE(sub LW) is estimated to be approx.42% of the diurnally averaged direct shortwave radiative effect at the surface but of opposite sign, partly compensating for the shortwave losses. Certainly nonnegligible, the authors conclude that DRE(sub LW) can significantly impact the atmospheric energetics, representing an important component in the study of regional climate variation.

  6. Roles of surface wind, NDVI and snow cover in the recent changes in Asian dust storm occurrence frequency

    NASA Astrophysics Data System (ADS)

    Lee, Jong-Jae; Kim, Cheol-Hee

    2012-11-01

    This paper describes the recent variations in dust outbreak during the period from 1996 to 2007 over the Asian dust source regions. The Asian dust source regions were divided into four sub-regions; S1, Taklamakan; S2, Gobi; S3, Inner Mongolia-Manchuria; and S4, Loess, and the WMO SYNOP observation and satellite data were employed to analyze the features of recently changed dust outbreak frequencies (DOFs). There was no particular variation in region S1, but the recent spatiotemporal variations in DOFs over S2-S4 were well characterized by a severe and widespread increase in 2001-2002, and significant decreasing in 2003-2004 over the most source regions, with a steadily increasing trend again during 2005-2007. Seasonal features showed that the highest DOFs occurred in March-April before 2002, but was delayed by a month toward April-May during the next five years because of the shift in the month of highest strong wind-speed frequencies (SWFs). A secondary peak of DOF was also found, occurring in October-November since the year 2000. Over all the source regions, the primary controlling factor for explaining the spatiotemporal DOF patterns was the SWF, with a pattern correlation coefficient (PCC) of 0.66-0.76. Other secondary controlling factors varied from region to region. For example, the DOFs observed in region S2-S3 showed relatively greater sensitivity to the snow-cover fraction, and region S4 showed a better correlation with the normalized difference vegetation index (NDVI) than the other regions. Other recent significant changes in DOFs over the Asian dust source regions and their causes are also discussed in this study.

  7. Chemical speciation of size-segregated floor dusts and airborne magnetic particles collected at underground subway stations in Seoul, Korea.

    PubMed

    Jung, Hae-Jin; Kim, BoWha; Malek, Md Abdul; Koo, Yong Sung; Jung, Jong Hoon; Son, Youn-Suk; Kim, Jo-Chun; Kim, HyeKyoung; Ro, Chul-Un

    2012-04-30

    Previous studies have reported the major chemical species of underground subway particles to be Fe-containing species that are generated from wear and friction processes at rail-wheel-brake and catenaries-pantographs interfaces. To examine chemical composition of Fe-containing particles in more details, floor dusts were collected at five sampling locations of an underground subway station. Size-segregated floor dusts were separated into magnetic and non-magnetic fractions using a permanent magnet. Using X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDX), iron metal, which is relatively harmless, was found to be the dominating chemical species in the floor dusts of the <25 μm size fractions with minor fractions of Mg, Al, Si, Ca, S, and C. From SEM analysis, the floor dusts of the <25 μm size fractions collected on railroad ties appeared to be smaller than 10 μm, indicating that their characteristics should somewhat reflect the characteristics of airborne particles in the tunnel and the platform. As most floor dusts are magnetic, PM levels at underground subway stations can be controlled by removing magnetic indoor particles using magnets. In addition, airborne subway particles, most of which were smaller than 10 μm, were collected using permanent magnets at two underground subway stations, namely Jegi and Yangjae stations, in Seoul, Korea. XRD and SEM/EDX analyses showed that most of the magnetic aerosol particles collected at Jegi station was iron metal, whereas those at Yangjae station contained a small amount of Fe mixed with Na, Mg, Al, Si, S, Ca, and C. The difference in composition of the Fe-containing particles between the two subway stations was attributed to the different ballast tracks used. PMID:22381374

  8. Chemical speciation of size-segregated floor dusts and airborne magnetic particles collected at underground subway stations in Seoul, Korea.

    PubMed

    Jung, Hae-Jin; Kim, BoWha; Malek, Md Abdul; Koo, Yong Sung; Jung, Jong Hoon; Son, Youn-Suk; Kim, Jo-Chun; Kim, HyeKyoung; Ro, Chul-Un

    2012-04-30

    Previous studies have reported the major chemical species of underground subway particles to be Fe-containing species that are generated from wear and friction processes at rail-wheel-brake and catenaries-pantographs interfaces. To examine chemical composition of Fe-containing particles in more details, floor dusts were collected at five sampling locations of an underground subway station. Size-segregated floor dusts were separated into magnetic and non-magnetic fractions using a permanent magnet. Using X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDX), iron metal, which is relatively harmless, was found to be the dominating chemical species in the floor dusts of the <25 μm size fractions with minor fractions of Mg, Al, Si, Ca, S, and C. From SEM analysis, the floor dusts of the <25 μm size fractions collected on railroad ties appeared to be smaller than 10 μm, indicating that their characteristics should somewhat reflect the characteristics of airborne particles in the tunnel and the platform. As most floor dusts are magnetic, PM levels at underground subway stations can be controlled by removing magnetic indoor particles using magnets. In addition, airborne subway particles, most of which were smaller than 10 μm, were collected using permanent magnets at two underground subway stations, namely Jegi and Yangjae stations, in Seoul, Korea. XRD and SEM/EDX analyses showed that most of the magnetic aerosol particles collected at Jegi station was iron metal, whereas those at Yangjae station contained a small amount of Fe mixed with Na, Mg, Al, Si, S, Ca, and C. The difference in composition of the Fe-containing particles between the two subway stations was attributed to the different ballast tracks used.

  9. Estimation of Asian Dust Aerosol Effect on Cloud Radiation Forcing Using Fu-Liou Radiative Model and CERES Measurements

    NASA Technical Reports Server (NTRS)

    Su, Jing; Huang, Jianping; Fu, Qiang; Minnis, Patrick; Ge, Jinming; Bi, Jianrong

    2008-01-01

    The impact of Asian dust on cloud radiative forcing during 2003-2006 is studied by using the Earth's Radiant Energy Budget Scanner (CERES) data and the Fu-Liou radiative transfer model. Analysis of satellite data shows that the dust aerosol significantly reduced the cloud cooling effect at TOA. In dust contaminated cloudy regions, the 4-year mean values of the instantaneous shortwave, longwave and net cloud radiative forcing are -138.9, 69.1, and -69.7 Wm(sup -2), which are 57.0, 74.2, and 46.3%, respectively, of the corresponding values in more pristine cloudy regions. The satellite-retrieved cloud properties are significantly different in the dusty regions and can influence the radiative forcing indirectly. The contributions to the cloud radiation forcing by the dust direct, indirect and semi-direct effects are estimated using combined satellite observations and Fu-Liou model simulation. The 4-year mean value of combination of indirect and semi-direct shortwave radiative forcing (SWRF) is 82.2 Wm(sup -2), which is 78.4% of the total dust effect. The direct effect is only 22.7 Wm(sup -2), which is 21.6% of the total effect. Because both first and second indirect effects enhance cloud cooling, the aerosol-induced cloud warming is mainly the result of the semi-direct effect of dust.

  10. An evaluation of effect of airborne dust from a cotton mill on the guinea-pig ileum with reference to byssinosis.

    PubMed

    Cinkotai, F F; Franklin, D W

    1975-08-01

    The effect of airborne dust on the guinea-pig ileum was studied. Tyrode extracts of airborne dust collected freshly in the cardroom of a cotton mill, and extracts of air pollutant samples drawn on the roof of the mill and of the local town hall were all found to induce the guinea-pig ileum to contract when applied in a tissue-bath. However, the force of contraction with air pollutants was rather greater than that with the cardroom dust. Considering the variables involved, the ileum response to the cardroom dust may have been due to ordinary air pollutants which constitute a significant part of the dust. It is concluded that this pharmacological phenomenon is probably not relevant in the context of byssinosis.

  11. Airborne concentrations of metals and total dust during solid catalyst loading and unloading operations at a petroleum refinery.

    PubMed

    Lewis, Ryan C; Gaffney, Shannon H; Le, Matthew H; Unice, Ken M; Paustenbach, Dennis J

    2012-09-01

    Workers handle catalysts extensively at petroleum refineries throughout the world each year; however, little information is available regarding the airborne concentrations and plausible exposures during this type of work. In this paper, we evaluated the airborne concentrations of 15 metals and total dust generated during solid catalyst loading and unloading operations at one of the largest petroleum refineries in the world using historical industrial hygiene samples collected between 1989 and 2006. The total dust and metals, which included aluminum, cadmium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel, platinum, silicon, silver, vanadium, and zinc, were evaluated in relation to the handling of four different types of solid catalysts associated with three major types of catalytic processes. Consideration was given to the known components of the solid catalysts and any metals that were likely deposited onto them during use. A total of 180 analytical results were included in this analysis, representing 13 personal and 54 area samples. Of the long-term personal samples, airborne concentrations of metals ranged from <0.001 to 2.9mg/m(3), and, in all but one case, resulted in concentrations below the current U.S. Occupational Safety and Health Administration's Permissible Exposure Limits and the American Conference of Governmental Industrial Hygienists' Threshold Limit Values. The arithmetic mean total dust concentration resulting from long-term personal samples was 0.31mg/m(3). The data presented here are the most complete set of its kind in the open literature, and are useful for understanding the potential exposures during solid catalyst handling activities at this petroleum refinery and perhaps other modern refineries during the timeframe examined. PMID:22177528

  12. Airborne concentrations of metals and total dust during solid catalyst loading and unloading operations at a petroleum refinery.

    PubMed

    Lewis, Ryan C; Gaffney, Shannon H; Le, Matthew H; Unice, Ken M; Paustenbach, Dennis J

    2012-09-01

    Workers handle catalysts extensively at petroleum refineries throughout the world each year; however, little information is available regarding the airborne concentrations and plausible exposures during this type of work. In this paper, we evaluated the airborne concentrations of 15 metals and total dust generated during solid catalyst loading and unloading operations at one of the largest petroleum refineries in the world using historical industrial hygiene samples collected between 1989 and 2006. The total dust and metals, which included aluminum, cadmium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel, platinum, silicon, silver, vanadium, and zinc, were evaluated in relation to the handling of four different types of solid catalysts associated with three major types of catalytic processes. Consideration was given to the known components of the solid catalysts and any metals that were likely deposited onto them during use. A total of 180 analytical results were included in this analysis, representing 13 personal and 54 area samples. Of the long-term personal samples, airborne concentrations of metals ranged from <0.001 to 2.9mg/m(3), and, in all but one case, resulted in concentrations below the current U.S. Occupational Safety and Health Administration's Permissible Exposure Limits and the American Conference of Governmental Industrial Hygienists' Threshold Limit Values. The arithmetic mean total dust concentration resulting from long-term personal samples was 0.31mg/m(3). The data presented here are the most complete set of its kind in the open literature, and are useful for understanding the potential exposures during solid catalyst handling activities at this petroleum refinery and perhaps other modern refineries during the timeframe examined.

  13. Decreased Pulmonary Function in School Children in Western Japan after Exposures to Asian Desert Dusts and Its Association with Interleukin-8

    PubMed Central

    Watanabe, Masanari; Kurai, Jun; Sano, Hiroyuki; Saito, Rumiko; Kimura, Yutaka; Aiba, Setsuya; Oshimura, Mitsuo; Yamasaki, Akira; Shimizu, Eiji

    2015-01-01

    The objective of the study was to investigate the influence of Asian dust storms (ADS) on pulmonary function of school children and the relationship of this effect with interleukin-8. Morning peak expiratory flow (PEF) was measured daily in 399 children from April to May 2012 and in 384 of these children from March to May 2013. The data were analyzed for an association between ADS events and PEF by linear mixed models. Interleukin-8 transcriptional activity was assessed in THP-G8 cells stimulated by airborne particles collected on ADS days. Seven ADS days were identified: April 23 and 24, 2012; March 8 to 10, 2013; and March 19 and 20, 2013. Changes in PEF after ADS exposure were −8.17 L/min (95% confidence interval, −11.40 to −4.93) in 2012 and −1.17 L/min (−4.07 to 1.74) in 2013, and there was a significant difference between 2012 and 2013. Interleukin-8 transcriptional activity was significantly higher in 2012 at 10.6 ± 2.9-fold compared to 3.7 ± 0.4 in March 8 to 10, 2013, and 2.3 ± 0.2 in March 19 and 20, 2013. The influence of ADS events on pulmonary function of children differs with each ADS event and may be related to interleukin-8 production. PMID:26060816

  14. Decreased pulmonary function in school children in Western Japan after exposures to Asian desert dusts and its association with interleukin-8.

    PubMed

    Watanabe, Masanari; Noma, Hisashi; Kurai, Jun; Sano, Hiroyuki; Saito, Rumiko; Abe, Satoshi; Kimura, Yutaka; Aiba, Setsuya; Oshimura, Mitsuo; Yamasaki, Akira; Shimizu, Eiji

    2015-01-01

    The objective of the study was to investigate the influence of Asian dust storms (ADS) on pulmonary function of school children and the relationship of this effect with interleukin-8. Morning peak expiratory flow (PEF) was measured daily in 399 children from April to May 2012 and in 384 of these children from March to May 2013. The data were analyzed for an association between ADS events and PEF by linear mixed models. Interleukin-8 transcriptional activity was assessed in THP-G8 cells stimulated by airborne particles collected on ADS days. Seven ADS days were identified: April 23 and 24, 2012; March 8 to 10, 2013; and March 19 and 20, 2013. Changes in PEF after ADS exposure were -8.17 L/min (95% confidence interval, -11.40 to -4.93) in 2012 and -1.17 L/min (-4.07 to 1.74) in 2013, and there was a significant difference between 2012 and 2013. Interleukin-8 transcriptional activity was significantly higher in 2012 at 10.6 ± 2.9-fold compared to 3.7 ± 0.4 in March 8 to 10, 2013, and 2.3 ± 0.2 in March 19 and 20, 2013. The influence of ADS events on pulmonary function of children differs with each ADS event and may be related to interleukin-8 production.

  15. Vertical distribution of airborne bacterial communities in an Asian-dust downwind area, Noto Peninsula

    NASA Astrophysics Data System (ADS)

    Maki, Teruya; Hara, Kazutaka; Kobayashi, Fumihisa; Kurosaki, Yasunori; Kakikawa, Makiko; Matsuki, Atsushi; Chen, Bin; Shi, Guangyu; Hasegawa, Hiroshi; Iwasaka, Yasunobu

    2015-10-01

    Bacterial populations transported from ground environments to the atmosphere get dispersed throughout downwind areas and can influence ecosystem dynamics, human health, and climate change. However, the vertical bacterial distribution in the free troposphere was rarely investigated in detail. We collected aerosols at altitudes of 3000 m, 1000 m, and 10 m over the Noto Peninsula, Japan, where the westerly winds carry aerosols from continental and marine areas. During the sampling period on March 10, 2012, the air mass at 3000 m was transported from the Chinese desert region by the westerly winds, and a boundary layer was formed below 2000 m. Pyrosequencing targeting 16S rRNA genes (16S rDNA) revealed that the bacterial community at 3000 m was predominantly composed of terrestrial bacteria, such as Bacillus and Actinobacterium species. In contrast, those at 1000 m and 10 m included marine bacteria belonging to the classes Cyanobacteria and Alphaproteobacteria. The entire 16S rDNA sequences in the clone libraries were identical to those of the terrestrial and marine bacterial species, which originated from the Chinese desert region and the Sea of Japan, respectively. The origins of air masses and meteorological conditions contribute to vertical variations in the bacterial communities in downwind atmosphere.

  16. Dust, Climate, and Human Health

    NASA Technical Reports Server (NTRS)

    Maynard, Nancy G.

    2003-01-01

    Air pollution from both natural and anthropogenic causes is considered to be one of the most serious world-wide environment-related health problems, and is expected to become worse with changes in the global climate. Dust storms from the atmospheric transport of desert soil dust that has been lifted and carried by the winds - often over significant distances - have become an increasingly important emerging air quality issue for many populations. Recent studies have shown that the dust storms can cause significant health impacts from the dust itself as well as the accompanying pollutants, pesticides, metals, salt, plant debris, and other inorganic and organic materials, including viable microorganisms (bacteria, viruses and fungi). For example, thousands of tons of Asian desert sediments, some containing pesticides and herbicides from farming regions, are commonly transported into the Arctic during dust storm events. These chemicals have been identified in animal and human tissues among Arctic indigenous populations. Millions of tons of airborne desert dust are being tracked by satellite imagery, which clearly shows the magnitude as well as the temporal and spatial variability of dust storms across the "dust belt" regions of North Africa, the Middle East, and China. Ths paper summarizes the most recent findings on the effects of airborne desert dust on human health as well as potential climate influences on dust and health.

  17. Dust, Climate, and Human Health

    NASA Technical Reports Server (NTRS)

    Maynard, Nancy G.

    2003-01-01

    Air pollution from both natural and anthropogenic causes is considered to be one of the most serious world-wide environment-related health problems, and is expected to become worse with changes in the global climate. Dust storms from the atmospheric transport of desert soil dust that has been lifted and carried by the winds - often over significant distances - have become an increasingly important emerging air quality issue for many populations. Recent studies have shown that the dust storms can cause significant health impacts from the dust itself as well as the accompanying pollutants, pesticides, metals, salt, plant debris, and other inorganic and organic materials, including viable microorganisms (bacteria, viruses and fungi). For example, thousands of tons of Asian desert sediments, some containing pesticides and herbicides from farming regions, are commonly transported into the Arctic during dust storm events. These chemicals have been identified in animal and human tissues among Arctic indigenous populations. Millions of tons of airborne desert dust are being tracked by satellite imagery, which clearly shows the magnitude as well as the temporal and spatial variability of dust storms across the "dust belt" regions of North Africa, the Middle East, and China. This paper summarizes the most recent findings on the effects of airborne desert dust on human health as well as potential climate influences on dust and health.

  18. Dust, Climate, and Human Health

    NASA Astrophysics Data System (ADS)

    Maynard, N. G.

    2003-12-01

    Air pollution from both natural and anthropogenic causes is considered to be one of the most serious world-wide environment-related health problems, and is expected to become worse with changes in the global climate. Dust storms from the atmospheric transport of desert soil dust that has been lifted and carried by the winds - often over significant distances - have become an increasingly important emerging air quality issue for many populations. Recent studies have shown that the dust storms can cause significant health impacts from the dust itself as well as the accompanying pollutants, pesticides, metals, salt, plant debris, and other inorganic and organic materials, including viable microorganisms (bacteria, viruses and fungi). For example, thousands of tons of Asian desert sediments, some containing pesticides and herbicides from farming regions, are commonly transported into the Arctic during dust storm events. These chemicals have been identified in animal and human tissues among Arctic indigenous populations. Millions of tons of airborne desert dust are being tracked by satellite imagery, which clearly shows the magnitude as well as the temporal and spatial variability of dust storms across the "dust belt" regions of North Africa, the Middle East, and China. This paper summarizes the most recent findings on the effects of airborne desert dust on human health as well as potential climate influences on dust and health

  19. Effects of Asian dust on daily cough occurrence in patients with chronic cough: A panel study

    NASA Astrophysics Data System (ADS)

    Higashi, Tomomi; Kambayashi, Yasuhiro; Ohkura, Noriyuki; Fujimura, Masaki; Nakai, Satoshi; Honda, Yasushi; Saijoh, Kiyofumi; Hayakawa, Kazuichi; Kobayashi, Fumihisa; Michigami, Yoshimasa; Olando, Anyenda Enoch; Hitomi, Yoshiaki; Nakamura, Hiroyuki

    2014-08-01

    Asian dust, known as kosa in Japanese, is a major public health concern. In this panel study, we evaluated the effects of exposure to kosa on daily cough occurrence. The study subjects were 86 patients being treated for asthma, cough variant asthma, or atopic cough in Kanazawa University Hospital from January 2011 to June 2011. Daily mean concentrations of kosa and spherical particles were obtained from light detection and ranging (LIDAR) measurements, and were categorized from Grade 1 (0 μg/m3) to 5 (over 100 μg/m3). The association between kosa and cough was analyzed by logistic regression with a generalized estimating equation. Kosa effects on cough were seen for all Grades with potential time lag effect. Particularly at Lag 0 (the day of exposure), a dose-response relationship was observed: the odds ratios for Grades 2, 3, 4, and 5 above the referent (Grade 1) were 1.111 (95% confidence interval (CI): 0.995-1.239), 1.171 (95% CI: 1.006-1.363), 1.357 (95% CI: 1.029-1.788), and 1.414 (95% CI: 0.983-2.036), respectively. Among the patients without asthma, the association was higher: the odds ratios for Grades 2, 3, 4 and 5 were 1.223 (95% CI: 0.999-1.497), 1.309 (95% CI: 0.987-1.737), 1.738 (95% CI: 1.029-2.935) and 2.403 (95% CI: 1.158-4.985), respectively. These associations remained after adjusting for the concentration of spherical particles or particulate matter with an aerodynamic diameter of less than 2.5 μm (PM2.5). Our findings demonstrate that kosa is an environmental factor which induces cough in a dose-response relationship.

  20. Health impact from climatic extremes: a case study of Asian dust storms in Taiwan

    NASA Astrophysics Data System (ADS)

    Lien, Yi-Jen; Chien, Lung-Chang; Yang, Chiang-Hsin; Yu, Hwa-Lung

    2013-04-01

    Asian dust storm (ADS) originates in the deserts of Mongolia and northern China in every winter and spring seasons, and its impacts on adverse human health were widely investigated and discussed. Recent records show that the frequency and magnitude of ADS are increasing due to changes of environmental and climatic conditions. It is worthwhile to investigate the health impact of these environmental extremes. This study applies a structural spatiotemporal modeling approach to investigate the changes of spatiotemporal variation of a health indicator during and after ADS periods. The health indicator is the daily clinic visits of conjunctivitis in the children population during 2002-2007 among 41 districts across Taipei City and New Taipei City in Taiwan. Results show positively significant effects of children's conjunctivitis clinic visits happened during ADS periods with elevated percentages of relative rate by 1.48% (95% CI = 0.79, 2.17) for preschool children (0~6 years of age) and 9.48% (95% CI = 9.03, 9.93) for schoolchildren (7~14 years of age). The impact even lasted one week after ADS finished by 2.32% (95% CI = 1.98, 2.66) for schoolchildren, but not for preschool children. Moreover, air pollutants NO2 and O3 also contributed significant influence. The spatial pattern of children's conjunctivitis clinic visits demonstrates that stronger spatial vulnerabilities occurred in most populated metropolitan districts in Taipei. Hence, we concluded that ADS may significantly increase the risks of children's conjunctivitis during ADS periods and one week after ADS periods, especially in schoolchildren.

  1. Asian sand dust enhances murine lung inflammation caused by Klebsiella pneumoniae

    SciTech Connect

    He, Miao; Ichinose, Takamichi; Yoshida, Seiichi; Yamamoto, Shoji; Inoue, Ken-ichiro; Takano, Hirohisa; Yanagisawa, Rie; Nishikawa, Masataka; Mori, Ikuko; Sun, Guifan; Shibamoto, Takayuki

    2012-01-15

    Inhaling concomitants from Asian sand dust (ASD) may result in exacerbation of pneumonia by the pathogen. The exacerbating effect of ASD on pneumonia induced by Klebsiella pneumoniae (KP) was investigated in ICR mice. The organic substances adsorbed onto ASD collected from the atmosphere of Iki-island in Japan were excluded by heat treatment at 360 °C for 30 min. ICR mice were instilled intratracheally with ASD at doses of 0.05 mg or 0.2 mg/mouse four times at 2-week intervals (total dose of 0.2 mg or 0.8 mg/mouse) and were administrated with ASD in the presence or absence of KP at the last intratracheal instillation. Pathologically, ASD caused exacerbation of pneumonia by KP as shown by increased inflammatory cells within the bronchiolar and the alveolar compartments. ASD enhanced the neutrophil number dose dependently as well as the expression of cytokines (IL-1β, IL-6, IL-12, IFN-γ, TNF-α) and chemokines (KC, MCP-1, MIP-1α) related to KP in BALF. In an in vitro study using RAW264.7 cells, combined treatment of ASD and KP increased gene expression of IL-1β, IL-6, IFN-β, KC, MCP-1, and MIP-1α. The same treatment tended to increase the protein level of IL-1β, TNF-α and MCP-1 in a culture medium compared to each treatment alone. The combined treatment tended to increase the gene expression of Toll-like receptor 2 (TLR2), and NALP3, ASC and caspase-1 compared with KP alone. These results suggest that the exacerbation of pneumonia by ASD + KP was due to the enhanced production of pro-inflammatory mediators via activation of TLR2 and NALP3 inflammasome pathways in alveolar macrophages.

  2. Spatial vulnerability under extreme events: a case of Asian dust storm's effects on children's respiratory health.

    PubMed

    Yu, Hwa-Lung; Yang, Chiang-Hsing; Chien, Lung-Chang

    2013-04-01

    Asian dust storm (ADS) events have raised concerns regarding their adverse impact on human health. Whether ADS events can result in the heterogeneity of health impacts on children across space and time has not been studied. The goal of this study is to examine the spatial vulnerability impact of ADS events on children's respiratory health geographically and to analyze any patterns related to ADS episodes. From 1998 to 2007, data from both preschool children's and schoolchildren's daily respiratory clinic visits, gathered from patients located in 41 districts of Taipei City and New Taipei City, are analyzed in a Bayesian spatiotemporal model in order to investigate the interaction between spatial effects and ADS episodes. When adjusting for the temporal effect, air pollutants, and temperature, the spatial pattern explicitly varies during defined study periods: non-ADS periods, ADS periods, and post-ADS periods. Compared to non-ADS periods, the relative rate of children's respiratory clinic visits significantly reduced 0.74 to 0.99 times in most districts during ADS periods, while the relative rate rose from 1.01 to 1.11 times in more than half of districts during post-ADS periods, especially in schoolchildren. This spatial vulnerability denotes that the significantly increased relative rate of respiratory clinic visits during post-ADS periods is primarily located in highly urbanized areas for both children's populations. Hence, the results of this study suggest that schoolchildren are particularly more vulnerable to the health impacts of ADS exposure in terms of higher excessive risks over a larger spatial extent than preschool children, especially during post-ADS periods. PMID:23403144

  3. The effects of weather, air pollutants, and Asian dust on hospitalization for asthma in Fukuoka

    PubMed Central

    Nitta, Hiroshi; Odajima, Hiroshi

    2010-01-01

    Objective We assessed the association of fluctuations in ambient temperature, air pollutants, and Asian dust (AD) events with the hospitalization of children for asthma in Fukuoka City. Methods Data on emergency hospitalizations of children under 12 years of age for asthma were collected at Fukuoka National Hospital. We obtained air pollution and meteorological data for Fukuoka from the National Institute for Environmental Studies. Using a time-stratified case-crossover design, we estimated odds ratios (ORs) of hospitalization corresponding to a unit change in weather variables and concentration of air pollutants. We also evaluated the effect of AD events on asthma hospitalization with data stratified by days with or without an AD event. Results There were 3427 hospitalizations and 106 AD events from 2001 to 2007. We found that within-day temperature change rather than ambient temperature was associated with asthma exacerbation. In the multi-pollutant model, the ORs per 1°C within-day drop and rise during the period from the hospitalization day to 3 days previously (lag3) were 1.033 [95% confidence interval (CI) 1.005–1.063] and 1.027 (95% CI 0.995–1.060), rspectively. A 10 μg/m3 increase in suspended particulate matter (SPM) and nitrogen dioxide (NO2) at lag2–lag3 were significantly associated with an increase in asthma hospitalization with ORs of 1.041 (95% CI 1.013–1.070) and 1.112 (95% CI 1.022–1.209), respectively. We did not observe a significant association between asthma hospitalization and AD events. Conclusions This study showed that temperature fluctuation, SPM, and NO2 were associated with an increased risk of hospitalization of children for asthma. PMID:21432566

  4. Sources of polycyclic aromatic hydrocarbons (PAHs) in street dust in a tropical Asian mega-city, Bangkok, Thailand.

    PubMed

    Boonyatumanond, Ruchaya; Murakami, Michio; Wattayakorn, Gullaya; Togo, Ayako; Takada, Hideshige

    2007-10-01

    We collected samples of roadside air, automobile exhaust soot, tires, asphalt, and used engine oil in a tropical Asian mega-city, Bangkok, Thailand, and analyzed them for polycyclic aromatic hydrocarbons (PAHs) and hopanes. The concentrations and compositions of PAHs and hopanes were utilized to identify the sources of PAHs in street dust, in which high concentrations of PAHs were reported in our previous study. Weight-based concentrations of total PAHs had the following order: gasoline-powered vehicle soot (2600+/-2900 microg/g; n=4)>diesel-powered vehicle soot (115+/-245 microg/g; n=7) approximately roadside aerosols (101+/-35 microg/g; n=5) approximately used engine oil (97+/-65 microg/g; n=4) approximately tire wear particles (82+/-41 microg/g; n=5)>asphalt (2.3+/-1.6 microg/g; n=3)>street dust (1.1+/-0.8 microg/g; n=10). In cluster analysis, all the source materials fell into different clusters from that in which street dust fell, indicating that multiple source materials contribute to PAHs in the street dust. Multiple regression analysis of PAH profiles and diagnostics of hopane compositions identified tire debris as the major contributor of PAHs to street dust, followed by diesel vehicle exhaust.

  5. Cold surges and dust events: Establishing the link between the East Asian Winter Monsoon and the Chinese loess record

    NASA Astrophysics Data System (ADS)

    Wyrwoll, Karl-Heinz; Wei, Junhong; Lin, Zhaohui; Shao, Yaping; He, Feng

    2016-10-01

    The Chinese loess/palaeosol succession is one of the most comprehensive and intensively studied archives of Neogene and Quaternary global palaeoclimate events. Its stratigraphic details are widely recognised to indicate close links to the history and function of the East Asian Winter Monsoon (EAWM) - one of the most active components of the Earth's climate system. But the formal meteorological links between the EAWM and dust emission, both in the present day and in the past, have not been established and with it, the veracity of the loess record as an indicator of the EAWM questioned. Here we show that present day major dust events over northern China, while largely occurring during spring, are nevertheless 'conditioned' by the strength of the preceding EAWM. We also demonstrate, for the first time, a close link between the occurrence of dust events and the strength of the EAWM. From these findings, linked to global-scale climate model simulations, we conclude that the Chinese loess succession provides a convincing proxy record of the strength of the East Asian Winter Monsoon.

  6. Characterization of aerosols in East Asia with the Asian Dust and Aerosol Lidar Observation Network (AD-Net)

    NASA Astrophysics Data System (ADS)

    Sugimoto, Nobuo; Nishizawa, Tomoaki; Shimizu, Atsushi; Matsui, Ichiro; Jin, Yoshitaka

    2014-11-01

    Continuous observations of aerosols are being conducted with the Asian Dust and aerosol lidar observation Network (AD-Net). Currently, two-wavelength (1064 nm and 532 nm) polarization-sensitive (532 nm) lidars are operated at 20 stations in East Asia. At the primary stations (6 stations), nitrogen vibrational Raman scattering is also measured to obtain the extinction coefficient at 532 nm. Recently, continuous observations with a three-wavelength (1064 nm, 532 nm and 355 nm) lidar having a high-spectral-resolution receiver at 532 nm and a Raman receiver at 355 nm and polarization-sensitive receivers at 532 nm and 355 nm) was started in Tsukuba. Also, continuous observations with multi-wavelength Raman lidars are being prepared in Fukuoka, Okinawa Hedo, and Toyama. A data analysis method for deriving distributions of aerosol components (weak absorption fine (such as sulfate), weak absorption coarse (sea salt), strong absorption fine (black carbon), non-spherical (dust)) has been developed for these multi-parameter lidars. Major subjects of the current studies with AD-Net include data assimilation of multi-parameter lidars, mixing states of Asian dust with air pollution particulate matter, and validation of EarthCARE ATLID based on the aerosol component analysis method.

  7. TEM analysis of the internal structures and mineralogy of Asian dust particles and the implications for optical modeling

    NASA Astrophysics Data System (ADS)

    Jeong, G. Y.; Nousiainen, T.

    2014-07-01

    Mineral dust interacts with incoming/outgoing electromagnetic radiation in the atmosphere. This interaction depends on the microphysical properties of the dust particles, including size, mineral composition, external morphology, and internal structure. Ideally all of these properties should be accounted for in the remote sensing of dust, the modeling of single-scattering properties, and radiative effect assessment. There have been many reports on the microphysical characterizations of mineral dust, but no investigations of the internal structures of individual dust particles. We explored the interiors of Asian dust particles using the combined application of focused ion beam thin-slice preparation and high-resolution transmission electron microscopy. The results showed that individual dust particles consisted of numerous mineral grains, which were organized into several types of internal structure: single and polycrystalline cores of quartz, feldspars, calcite, and amphibole often with oriented clay coatings; individual clay agglomerates of nano-thin clay platelets showing preferred to random orientations common with coarser mineral inclusions; and platy coarse phyllosilicates (muscovite, biotite, and chlorite). Micron to submicron pores were scattered throughout the interior of particles. Clays in the coatings and agglomerates were dominated by nano-thin platelets of the clay minerals of illite-smectite series including illite, smectite, and their mixed layers with subordinate kaolinite and clay-sized chlorite. Submicron iron oxide grains, dominantly goethite, were distributed throughout the clay agglomerates and coatings. Unlike the common assumptions and simplifications, we found that the analyzed dust particles were irregularly shaped with birefringent, polycrystalline, and polymineralic heterogeneous compositions. Accounting for this structural and mineralogical makeup may improve the remote sensing retrieval of dust and the evaluation of radiation effects

  8. TEM analysis of the internal structures and mineralogy of Asian dust particles and the implications for optical modeling

    NASA Astrophysics Data System (ADS)

    Jeong, G. Y.; Nousiainen, T.

    2014-03-01

    Mineral dust interacts with incoming/outgoing electromagnetic radiation in the atmosphere. This interaction depends on the microphysical properties of the dust particles, including size, mineral composition, external morphology, and internal structure. Ideally all these properties should be accounted for in dust remote sensing, the modeling of single-scattering properties, and radiative effect assessment. There have been many reports on the microphysical characterizations of mineral dust, but no investigations of the internal structures or mineral composition of individual dust particles. We explored the interiors of Asian dust particles using the combined application of focused ion beam thin-slice preparation and high-resolution transmission electron microscopy. The results showed that individual dust particles consisted of numerous mineral grains, which were organized into several types of internal structure: single and polycrystalline cores of quartz, feldspars, calcite, and amphibole often with oriented clay coatings; individual clay agglomerates of nano-thin clay platelets showing preferred to random orientations commonly with coarser mineral inclusions; and platy coarse phyllosilicates (muscovite, biotite, and chlorite). Micron to submicron pores were scattered throughout the interior of particles. Clays in the coatings and agglomerates were dominated by nano-thin platelets of the clay minerals of illite-smectite series including illite, smectite, and their mixed layers with subordinate kaolinite and clay-size chlorite. Submicron iron oxide grains, dominantly goethite, were distributed throughout the clay agglomerates and coatings. Unlike the common assumptions and simplifications, we found that the analyzed dust particles were irregularly shaped with birefringent, polycrystalline, and polymineralic heterogeneous compositions. Accounting for this structural and mineralogical makeup may improve the remote sensing retrieval of dust and the evaluation of

  9. An early South Asian dust storm during March 2012 and its impacts on Indian Himalayan foothills: a case study.

    PubMed

    Srivastava, A K; Soni, V K; Singh, Sachchidanand; Kanawade, V P; Singh, N; Tiwari, S; Attri, S D

    2014-09-15

    The impacts of an early South Asian dust storm that originated over the western part of the Middle East and engulfed northwest parts of India during the third week of March 2012 have been studied at four different stations covering India and Pakistan. The impacts of this dust storm on aerosol optical properties were studied in detail at Delhi, Jodhpur, Lahore and Karachi. The impact could also be traced up to central Himalayan foothills at Manora Peak. During dust events, the aerosol optical depth (AOD) at 500 nm reached a peak value of 0.96, 1.02, 2.17 and 0.49 with a corresponding drop in Ångström exponent (AE for 440-870 nm) to 0.01, -0.02, 0.00 and 0.12 at Delhi, Jodhpur, Lahore and Karachi, respectively. The single scattering albedo (SSA) at 675 nm was relatively lower at Delhi (0.87) and Jodhpur (0.86), with absorption Ångström exponent (AAE) less than 1.0, but a large value of SSA was observed at Lahore (0.98) and Karachi (0.93), with AAE value greater than 1.0 during the event. The study of radiative impact of dust aerosols revealed a significant cooling at the surface and warming in the atmosphere (with corresponding large heating rate) at all the stations during dust event. The effect of this dust storm was also seen at Manora Peak in central Himalayas which showed an enhancement of ~28% in the AOD at 500 nm. The transport of dust during such events can have severe climatic implications over the affected plains and the Himalayas. PMID:24973722

  10. An early South Asian dust storm during March 2012 and its impacts on Indian Himalayan foothills: a case study.

    PubMed

    Srivastava, A K; Soni, V K; Singh, Sachchidanand; Kanawade, V P; Singh, N; Tiwari, S; Attri, S D

    2014-09-15

    The impacts of an early South Asian dust storm that originated over the western part of the Middle East and engulfed northwest parts of India during the third week of March 2012 have been studied at four different stations covering India and Pakistan. The impacts of this dust storm on aerosol optical properties were studied in detail at Delhi, Jodhpur, Lahore and Karachi. The impact could also be traced up to central Himalayan foothills at Manora Peak. During dust events, the aerosol optical depth (AOD) at 500 nm reached a peak value of 0.96, 1.02, 2.17 and 0.49 with a corresponding drop in Ångström exponent (AE for 440-870 nm) to 0.01, -0.02, 0.00 and 0.12 at Delhi, Jodhpur, Lahore and Karachi, respectively. The single scattering albedo (SSA) at 675 nm was relatively lower at Delhi (0.87) and Jodhpur (0.86), with absorption Ångström exponent (AAE) less than 1.0, but a large value of SSA was observed at Lahore (0.98) and Karachi (0.93), with AAE value greater than 1.0 during the event. The study of radiative impact of dust aerosols revealed a significant cooling at the surface and warming in the atmosphere (with corresponding large heating rate) at all the stations during dust event. The effect of this dust storm was also seen at Manora Peak in central Himalayas which showed an enhancement of ~28% in the AOD at 500 nm. The transport of dust during such events can have severe climatic implications over the affected plains and the Himalayas.

  11. Geltape method for measurement of work related surface contamination with cobalt containing dust: correlation between surface contamination and airborne exposure.

    PubMed Central

    Poulsen, O M; Olsen, E; Christensen, J M; Vinzent, P; Petersen, O H

    1995-01-01

    OBJECTIVES--The geltape method is a new method for optical measurement of total amount of dust on surfaces. The objectives were to study the potential applicability of this method to measurements of work related cobalt exposure during painting of plates with cobalt dye. METHODS--Consecutive series of work related geltape prints were taken from surfaces inside and outside the ventilation cabins of two plate painters during two full working days. The amount of dust picked up by the geltapes was measured optically with a field monitor. Also, personal air samples were collected on filters at the different work processes. In the laboratory the contents of cobalt on the geltape prints and the filters were measured with inductive coupled plasma atomic emission spectroscopy. RESULTS--The key results were: (a) when the geltape prints were taken from surfaces inside the cabins the optically measured area of the geltapes covered with total dust (area (%)) correlated well with the chemically measured amount of cobalt present on the geltapes. Linear correlation coefficient (R2) was 0.91 for geltape prints taken on the floor and 0.94 for prints taken on the ceiling; (b) the cumulative airborne cobalt exposure, calculated from data on work related exposure by personal sampling, correlated with the area (%) of geltape prints taken from the ceiling of the cabin (R2 = 0.98); (c) the geltape method could be used to distinguish both between work processes with different levels of cobalt exposure, and between plate painters subjected to significant differences in airborne cobalt exposure. CONCLUSION--The geltape method could produce measures of the work related exposures as well as whole day exposure for cobalt. The geltape results correlated with measurements of personal airborne cobalt exposure. In this industry the profile of exposure is well-defined in time, and it seems reasonable to apply this fast and low cost method in routine exposure surveillance to obtain a more detailed

  12. Asian Dust Storm Events of 2001 and Associated Pollution Observed in New England by the AIRMAP Monitoring Network

    NASA Astrophysics Data System (ADS)

    Debell, L. J.; Vozzella, M. E.; Talbot, R. W.; Dibb, J. E.

    2002-12-01

    The Atmospheric Investigation, Regional Modeling, Analysis and Prediction (AIRMAP) program is operating 4 monitoring sites in New Hampshire, located at Fort Constitution (FC)(43.07oN, 70.71oW, 5m elevation), Thompson Farm (TF) (43.11oN, 70.95oW, 21m elevation), Castle Springs (CS) (43.75oN,71.35oW, 406m elevation) and Mount Washington (MW)(44.267oN, 71.30oW, 1909m elevation). Three chemically distinct, statistically extreme, regional scale dust aerosol events were observed at all four AIRMAP monitoring stations in NH between 4/18/01 and 5/13/01 (UTC). All three events, at all four sites, had days where the 24 hr bulk aerosol samples had Ca2+ concentrations that exceeded at least the 95th percentile of the site-specific, multi-year datasets. NO3- and SO42- were also enhanced above typical levels, ranging from above the 75th to above the 99th percentile. During all three events, mixing ratios of the gas phase pollutants O3 and CO were compared to mixing ratios on either side of the events. During event 1,enhancements above background levels were approximately 130 ppbv for CO and 30 ppbv for O3, very similar to the CO values in apparent Asian dust plumes sampled over Colorado at 6-7 km by aircraft measurements (http://www.cmdl.noaa.gov/info/asiandust.html); enhancements during events 2 and 3 were similar to event 1. The maximum elemental carbon value ever observed at TF, 0.97 μg/m3, occurred during the peak day of event 1. Elemental carbon was not substantially elevated during event 2 and no data were collected during event 3. Elemental ratios, determined by PIXE, on filters from events 1 and 3 were compared pairwise to each other and to published samples attributed to Asian dust storms. The AIRMAP samples collected on the same date at different sites showed good statistical agreement whereas samples collected at the same site on different dates show only moderate correlation. Of 17 published samples of Asian dust storm aerosol, collected well outside of the major

  13. Saharan dust long-range transport across the Atlantic studied by an airborne Doppler wind lidar and the MACC model

    NASA Astrophysics Data System (ADS)

    Chouza, Fernando; Reitebuch, Oliver; Benedetti, Angela; Weinzierl, Bernadett

    2016-09-01

    A huge amount of dust is transported every year from north Africa into the Caribbean region. This paper presents an investigation of this long-range transport process based on airborne Doppler wind lidar (DWL) measurements conducted during the SALTRACE campaign (June-July 2013), as well as an evaluation of the ability of the MACC (Monitoring Atmospheric Composition and Climate) global aerosol model to reproduce it and its associated features. Although both the modeled winds from MACC and the measurements from the DWL show a generally good agreement, some differences, particularly in the African easterly jet (AEJ) intensity, were noted. The observed differences between modeled and measured wind jet speeds are between 5 and 10 m s-1. The vertical aerosol distribution within the Saharan dust plume and the marine boundary layer is investigated during the June-July 2013 period based on the MACC aerosol model results and the CALIOP satellite lidar measurements. While the modeled Saharan dust plume extent shows a good agreement with the measurements, a systematic underestimation of the marine boundary layer extinction is observed. Additionally, three selected case studies covering different aspects of the Saharan dust long-range transport along the west African coast, over the North Atlantic Ocean and the Caribbean are presented. For the first time, DWL measurements are used to investigate the Saharan dust long-range transport. Simultaneous wind and backscatter measurements from the DWL are used, in combination with the MACC model, to analyze different features associated with the long-range transport, including an African easterly wave trough, the AEJ and the intertropical convergence zone.

  14. Investigation of aged aerosols in size-resolved Asian dust storm particles transported from Beijing, China to Incheon, Korea using low-Z particle EPMA

    NASA Astrophysics Data System (ADS)

    Geng, H.; Hwang, H. J.; Liu, X.; Dong, S.; Ro, C.-U.

    2013-10-01

    This is the first study of Asian dust storm (ADS) particles collected in Beijing, China and Incheon, Korea during the same spring ADS event. Using a seven-stage May impactor and a quantitative electron probe X-ray microanalysis (ED-EPMA, also known as low-Z particle EPMA), we examined the composition and morphology of 4200 aerosol particles at stages 1-6 (with a size cut-off of 16, 8, 4, 2, 1, and 0.5 μm in equivalent aerodynamic diameter, respectively) collected during an ADS event on 28-29 April 2005. The results showed that there were large differences in the chemical compositions between particles in sample S1 collected in Beijing immediately after the peak time of the ADS and in samples S2 and S3, which were collected in Incheon approximately 5 h and 24 h later, respectively. In sample S1, mineral dust particles accounted for more than 88% in relative number abundance at stages 1-5, and organic carbon (OC) and reacted NaCl-containing particles accounted for 24% and 32%, respectively, at stage 6. On the other hand, in samples S2 and S3, in addition to approximately 60% mineral dust, many sea salt particles reacted with airborne SO2 and NOx, often mixed with mineral dust, were encountered at stages 1-5, and (C, N, O, S)-rich particles (likely a mixture of water-soluble organic carbon with (NH4)2SO4 and NH4NO3) and K-containing particles were abundantly observed at stage 6. This suggests that the secondary aerosols and the internal mixture of mineral dust with sea spray aerosol increased when the ADS particles passed over the Yellow Sea. In the reacted or aged mineral dust and sea salt particles, nitrate-containing and both nitrate- and sulfate-containing species vastly outnumbered the sulfate-containing species, implying that ambient nitrogen oxides had a greater influence on the atmospheric particles during the ADS episode than SO2. In addition to partially- or totally-reacted CaCO3, reacted or aged Mg-containing aluminosilicates (likely including amesite

  15. Nearly a Decade of CALIPSO Observations of Asian and Saharan Dust Properties Near Source and Transport Regions

    NASA Technical Reports Server (NTRS)

    Omar, Ali H.; Liu, Z.; Tackett, J.; Vaughan, M.; Trepte, C.; Winker, D.; H. Yu,

    2015-01-01

    The lidar on the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) mission, makes robust measurements of dust and has generated a length of record that is significant both seasonally and inter-annually. We exploit this record to determine a multi-year climatology of the properties of Asian and Saharan dust, in particular seasonal optical depths, layer frequencies, and layer heights of dust gridded in accordance with the Level 3 data products protocol, between 2006-2015. The data are screened using standard CALIPSO quality assurance flags, cloud aerosol discrimination (CAD) scores, overlying features and layer properties. To evaluate the effects of transport on the morphology, vertical extent and size of the dust layers, we compare probability distribution functions of the layer integrated volume depolarization ratios, geometric depths and integrated attenuated color ratios near the source to the same distributions in the far field or transport region. CALIPSO is collaboration between NASA and Centre National D'études Spatiales (CNES), was launched in April 2006 to provide vertically resolved measurements of cloud and aerosol distributions. The primary instrument on the CALIPSO satellite is the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), a near-nadir viewing two-wavelength polarization-sensitive instrument. The unique nature of CALIOP measurements make it quite challenging to validate backscatter profiles, aerosol type, and cloud phase, all of which are used to retrieve extinction and optical depth. To evaluate the uncertainty in the lidar ratios, we compare the values computed from dust layers overlying opaque water clouds, considered nominal, with the constant lidar ratio value used in the CALIOP algorithms for dust. We also explore the effects of noise on the CALIOP retrievals at daytime by comparing the distributions of the properties at daytime to the nighttime distributions.

  16. Nearly a Decade of CALIPSO Observations of Asian and Saharan Dust Properties near Source and Transport Regions

    NASA Astrophysics Data System (ADS)

    Omar, A. H.; Tackett, J. L.; Liu, Z.; Vaughan, M. A.; Trepte, C. R.; Winker, D. M.; Yu, H.

    2015-12-01

    The lidar on the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) mission, makes robust measurements of dust and has generated a length of record that is significant both seasonally and inter-annually. We exploit this record to determine a multi-year climatology of the properties of Asian and Saharan dust, in particular seasonal optical depths, layer frequencies, and layer heights of dust gridded in accordance with the Level 3 data products protocol between 2006 and 2015. The data are screened using standard CALIPSO quality assurance flags, cloud aerosol discrimination (CAD) scores, overlying features and layer properties. To evaluate the effects of transport on small-scale phenomena such as morphology, vertical extent and size of the dust layers, we compare probability distribution functions of the layer integrated volume depolarization ratios, geometric depths and integrated attenuated color ratios near the source to the same distributions in the far field or transport region. CALIPSO is collaboration between NASA and Centre National d'Études Spatiales (CNES), was launched in April 2006 to provide vertically resolved measurements of cloud and aerosol distributions. The primary instrument on the CALIPSO satellite is the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), a near-nadir viewing two-wavelength polarization-sensitive instrument. The unique nature of CALIOP measurements make it quite challenging to validate backscatter profiles, aerosol type, and cloud phase, all of which are used to retrieve extinction and optical depth. To evaluate the uncertainty in the lidar ratios, we compare the values computed from dust layers overlying opaque water clouds, considered nominal, with the constant lidar ratio value used in the CALIOP algorithms for dust. We also explore the effects of noise on the CALIOP retrievals at daytime by comparing the distributions of the properties at daytime to the nighttime distributions.

  17. Mortality associated with particulate concentration and Asian dust storms in Metropolitan Taipei

    NASA Astrophysics Data System (ADS)

    Wang, Yu-Chun; Lin, Yu-Kai

    2015-09-01

    This study evaluates mortality risks from all causes, circulatory diseases, and respiratory diseases associated with particulate matter (PM10 and PM2.5) concentrations and Asian dust storms (ADS) from 2000 to 2008 in Metropolitan Taipei. This study uses a distributed lag non-linear model with Poisson distribution to estimate the cumulative 5-day (lags 0-4) relative risks (RRs) and confidence intervals (CIs) of cause-specific mortality associated with daily PM10 and PM2.5 concentrations, as well as ADS, for total (all ages) and elderly (≥65 years) populations based on study periods (ADS frequently inflicted period: 2000-2004; and less inflicted period: 2005-2008). Risks associated with ADS characteristics, including inflicted season (winter and spring), strength (the ratio of stations with Pollutant Standard Index >100 is <0.5 or ≥0.5), and duration (ADS persisted for 1-3 or ≥4 days), were also evaluated. Nonlinear models showed that an increase in PM10 from 10 μg/m3 to 50 μg/m3 was associated with increased all-cause mortality risk with cumulative 5-day RR of 1.10 (95% CI: 1.04, 1.17) for the total population and 1.10 (95% CI: 1.02, 1.18) for elders. Mortality from circulatory diseases for the elderly was related to increased PM2.5 from 5 μg/m3 to 30 μg/m3, with cumulative 5-day RR of 1.21 (95% CI: 1.02, 1.44) from 2005 to 2008. Compared with normal days, the mortality from all causes and circulatory diseases for the elderly population was associated with winter ADS with RRs of 1.05 (95% CI: 1.01, 1.08) and 1.08 (95% CI: 1.01, 1.15), respectively. Moreover, all-cause mortality was associated with shorter and less area-affected ADS with an RR of 1.04 for total and elderly populations from 2000 to 2004. Population health risk differed not only with PM concentration but also with ADS characteristics.

  18. A pervasive and persistent Asian dust event over North America during spring 2010: Lidar and optical depth observations

    NASA Astrophysics Data System (ADS)

    Cottle, P. W.; Strawbridge, K. B.; McKendry, I.; O'Neill, N. T.; Saha, A.

    2012-12-01

    Springtime trans-Pacific transport of crustal dust from Asia to North America was once thought to be a rare occurrence. After years of continuous data collection from multiple, overlapping networks of aerosol monitoring stations, it is now understood to occur to some extent every year. Among the many well-documented cases (significant events include those of 1998, 2001, and 2005), the events of March and April 2010 were extraordinary both in the extent of the dust distribution and in the unique meteorological conditions that caused the dust layers in the free troposphere to linger and be detectable across Canada and the northern United States for over a month. This is interesting in the light of previous events because it provides an opportunity to observe an important part of the global dust cycle in locations and over time spans never before documented. This study focuses on extending previous research by combining data from sunphotometer and lidar networks (i.e. AERONET, CORALNet, and MPLNET) with model results from Hysplit and NAAPS to thoroughly document the distribution of this dust event across North America and show the impacts on fine and coarse mode aerosol optical thickness at multiple locations in China, Canada, and the United States. Aeronet Spectral Deconvolution Algorithm (SDA) retrievals revealed strong increases in coarse mode aerosols at each site coincident with NAAPS global dust model predictions of the progress of the dust cloud. As expected, Hysplit back trajectories performed throughout the free troposphere above these sites showed a large majority of air parcels originating from central Asia on these days. Using these techniques, it was also shown that elevated layers of aerosol reaching the west coast of North America as early as 16 March were actually dust from the same central Asian sources, extending the known duration of the 2010 event by almost a full month. Furthermore, lidar backscatter and depolarization ratios were used to learn

  19. Integrated Analysis of Asian Dust Events from CALIPSO Space Lidar Data in Conjunction with Passive Remote Sensing and Ground-Based Observations

    NASA Astrophysics Data System (ADS)

    Choi, H.; Sokolik, I. N.; Winker, D. M.; Kurosaki, Y.

    2008-05-01

    The vast arid regions of East Asia are active dust sources. Each spring, large amounts of mineral dust are emitted into the atmosphere, affecting the regional air quality, environment and climate. This study presents analyses of Asian dust events by integrating CALIPSO lidar data with A-Train satellite multi-sensor observations (Ozone Monitoring Instrument, OMI, and Moderate-Resolution Imaging Spectroradiometer, MODIS) as well as ground-based observations. We use data from WMO meteorological stations located in China, Mongolia, Korea and Japan that report different present weather types related to dust events. Also, lidar data from Asian network sites were included in the analysis. The focus is on dust events that occurred during the spring seasons of 2006- 2008. The capability of CALIPSO to detect dust was investigated by analyzing the CALIPSO features against independent observations for selected CALPSO overpasses on a case-by-case basis. The changes in the linear depolarization ratio were analyzed in conjunction with T-matrix optical modeling to constrain the particle nonsphericity and size distribution. The dust properties and vertical distribution in different dust sources (the Taklamakan vs. Gobi) were analyzed. The evolution of dust properties during the mid-range transport was also investigated from combined CALIPSO and lidar data.

  20. Vertically-resolved profiles of mass concentrations and particle backscatter coefficients of Asian dust plumes derived from lidar observations of silicon dioxide.

    PubMed

    Noh, Youngmin; Müller, Detlef; Shin, Sung-Kyun; Shin, Dongho; Kim, Young J

    2016-01-01

    This study presents a method to retrieve vertically-resolved profiles of dust mass concentrations by analyzing Raman lidar signals of silicon dioxide (quartz) at 546nm. The observed particle plumes consisted of mixtures of East Asian dust with anthropogenic pollution. Our method for the first time allows for extracting the contribution of the aerosol component "pure dust" contained in the aerosol type "polluted dust". We also propose a method that uses OPAC (Optical Properties of Aerosols and Clouds) and the mass concentrations profiles of dust in order to derive profiles of backscatter coefficients of pure dust in mixed dust/pollution plumes. The mass concentration of silicon dioxide (quartz) in the atmosphere can be estimated from the backscatter coefficient of quartz. The mass concentration of dust is estimated by the weight percentage (38-77%) of mineral quartz in Asian dust. The retrieved dust mass concentrations are classified into water soluble, nucleation, accumulation, mineral-transported and coarse mode according to OPAC. The mass mixing ratio of 0.018, 0.033, 0.747, 0.130 and 0.072, respectively, is used. Dust extinction coefficients at 550nm were calculated by using OPAC and prescribed number concentrations for each of the 5 components. Dust backscatter coefficients were calculated from the dust extinction coefficients on the basis of a lidar ratio of 45±3sr at 532nm. We present results of quartz-Raman measurements carried out on the campus of the Gwangju Institute of Science and Technology (35.10°N, 126.53°E) on 15, 16, and 21 March 2010.

  1. The Effect of Asian Dust Aerosols on Cloud Properties and Radiative Forcing from MODIS and CERES

    NASA Technical Reports Server (NTRS)

    Huang, Jianping; Minnis, Patrick; Lin, Bing; Wang, Tianhe; Yi, Yuhong; Hu, Yongxiang; Sun-Mack, Sunny; Ayers, Kirk

    2005-01-01

    The effects of dust storms on cloud properties and radiative forcing are analyzed over northwestern China from April 2001 to June 2004 using data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) and Clouds and the Earth's Radiant Energy System (CERES) instruments on the Aqua and Terra satellites. On average, ice cloud effective particle diameter, optical depth and ice water path of the cirrus clouds under dust polluted conditions are 11%, 32.8%, and 42% less, respectively, than those derived from ice clouds in dust-free atmospheric environments. The humidity differences are larger in the dusty region than in the dust-free region, and may be caused by removal of moisture by wet dust precipitation. Due to changes in cloud microphysics, the instantaneous net radiative forcing is reduced from -71.2 W/m2 for dust contaminated clouds to -182.7 W/m2 for dust-free clouds. The reduced cooling effects of dusts may lead to a net warming of 1 W/m2, which, if confirmed, would be the strongest aerosol forcing during later winter and early spring dust storm seasons over the studied region.

  2. Vertical Variation of Optical Properties of Mixed Asian Dust/Pollution Plumes According to Pathway of Airmass Transport Over East Asia

    NASA Astrophysics Data System (ADS)

    Shin, Sung-Kyun; Müller, Detlef; Lee, K. H.; Shin, D.; Kim, Y. J.; Noh, Y. M.

    2016-06-01

    We use five years (2009 - 2013) of multiwavelength Raman lidar measurements at Gwangju, Korea (35.10° N, 126.53° E) for the identification of changes of optical properties of East Asian dust in dependence of its transport path over China. Profiles of backscatter and extinction coefficients, lidar ratios, and backscatter-related Ångström exponents (wavelength pair 355/532nm) were measured at Gwangju. Linear particle depolarization ratios were used to identify East Asian dust layers. We used backward trajectory modelling to identify the pathway and the vertical position of dust-laden air masses over China during long-range transport. Most cases of Asian dust events can be described by the emission of dust in desert areas and subsequent transport over highly polluted regions of China. The Asian dust plumes could be categorized into two classes according to the height above ground in which these plumes were transported: (I) the dust layers passed over China at high altitude levels until arrival over Gwangju, and (II) the Asian dust layers were transported near the surface and the lower troposphere over industrialized areas before they arrived over Gwangju. We find that the optical characteristics of these mixed Asian dust layers over Gwangju differ in dependence of their vertical position above ground over China and the change of height above ground during transport. The mean linear particle depolarization ratio was 0.21±0.06 (at 532 nm), the mean lidar ratios were 52±7 sr at 355 nm and 53±8 sr at 532 nm, and the mean Ångström exponent was 0.74±0.31 in case I. In contrast, plumes transported at lower altitudes (case II) showed low depolarization ratios, and higher lidar ratio and Ångström exponents. The mean linear particle depolarization ratio was 0.13 ± 0.04, the mean lidar ratios were 63±9 sr at 355 nm and 62±8 sr at 532 nm, respectively, and the mean Ångström exponent was 0.98±0.51. These numbers show that the optical characteristics of mixed

  3. Evaluation of the Impacts of Marine Salts and Asian Dust on the Forested Yakushima Island Ecosystem, a World Natural Heritage Site in Japan.

    PubMed

    Nakano, Takanori; Yokoo, Yoriko; Okumura, Masao; Jean, Seo-Ryong; Satake, Kenichi

    2012-11-01

    To elucidate the influence of airborne materials on the ecosystem of Japan's Yakushima Island, we determined the elemental compositions and Sr and Nd isotope ratios in streamwater, soils, vegetation, and rocks. Streamwater had high Na and Cl contents, low Ca and HCO(3) contents, and Na/Cl and Mg/Cl ratios close to those of seawater, but it had low pH (5.4 to 7.1), a higher Ca/Cl ratio than seawater, and distinct (87)Sr/(86)Sr ratios that depended on the bedrock type. The proportions of rain-derived cations in streamwater, estimated by assuming that Cl was derived from sea salt aerosols, averaged 81 % for Na, 83 % for Mg, 36 % for K, 32 % for Ca, and 33 % for Sr. The Sr value was comparable to the 28 % estimated by comparing Sr isotope ratios between rain and granite bedrock. The soils are depleted in Ca, Na, P, and Sr compared with the parent materials. At Yotsuse in the northwestern side, plants and the soil pool have (87)Sr/(86)Sr ratios similar to that of rainwater with a high sea salt component. In contrast, the Sr and Nd isotope ratios of soil minerals in the A and B horizons approach those of silicate minerals in northern China's loess soils. The soil Ca and P depletion results largely from chemical weathering of plagioclase and of small amounts of apatite and calcite in granitic rocks. This suggests that Yakushima's ecosystem is affected by large amounts of acidic precipitation with a high sea salt component, which leaches Ca and its proxy (Sr) from bedrock into streams, and by Asian dust-derived apatite, which is an important source of P in base cation-depleted soils.

  4. The bioavailable iron in NEEM ice core related to Asian dust records over the past 110 kyr

    NASA Astrophysics Data System (ADS)

    Xiao, Cunde

    2016-04-01

    The mineral dust can indirectly affect climate by supplying iron and other essential bioavailable elements into ocean. In this study, we present dissolved iron (DFe) and total dissolved iron (TDFe) concentrations in NEEM ice core over the past 110 kyr B.P. The concentrations of bioavailable reactive element Fe have good positive correlation with the concentrations of dust and Ca2+ in NEEM ice core, while show significantly negative relationship with δ18O and CO2 concentration. The ratios of DFe/TDFe are higher in warm periods (Holocene and last interglacial) than in cold period (LGM), indicating the iron-biological pump effect is more significant in warm periods than that in cold periods, this result may provide a new insight for reevaluating the iron hypothesis over glacial/interglacial periods. Our study also shows that the iron flux changes between NEEM ice core and Asian loess records are good consistent with the northern Hemisphere summer insolation. These results emphasize that the variability of Fe flux is most likely driven by solar radiation and dust in northern hemisphere.

  5. Can Asian Dust Trigger Phytoplankton Blooms in the Oligotrophic Northern South China Sea?

    NASA Technical Reports Server (NTRS)

    Wang, Sheng Hsiang; Hsu, Nai-Yung Christina; Tsay, Si-Chee; Lin, Neng-Huei; Sayer, Andrew M.; Huang, Shih-Jen; Lau, William K. M.

    2012-01-01

    Satellite data estimate a high dust deposition flux (approximately 18 g m(exp-2 a(exp-1) into the northern South China Sea (SCS). However, observational evidence concerning any biological response to dust fertilization is sparse. In this study, we combined long-term aerosol and chlorophyll-a (Chl-a) measurements from satellite sensors (MODIS and SeaWiFS) with a 16-year record of dust events from surface PM10 observations to investigate dust transport, flux, and the changes in Chl-a concentration over the northern SCS. Our result revealed that readily identifiable strong dust events over this region, although relatively rare (6 cases since 1994) and accounting for only a small proportion of the total dust deposition (approximately 0.28 g m(exp-2 a(exp-1), do occur and could significantly enhance phytoplankton blooms. Following such events, the Chl-a concentration increased up to 4-fold, and generally doubled the springtime background value (0.15 mg m(exp-3). We suggest these heavy dust events contain readily bioavailable iron and enhance the phytoplankton growth in the oligotrophic northern SCS.

  6. Estimates of Asian dust sources using the adjoint of GEOS-Chem

    NASA Astrophysics Data System (ADS)

    Jeong, J.; Park, R.; Ku, B.

    2011-12-01

    Soil dust aerosols, typically originated from northern China, southern Mongolia, and the Taklamakan desert in spring, have large impacts on human health, local visibility, air quality, and climate in Asia. Large uncertainty, however, exists in estimates of dust emissions in 3-D models. We develop the adjoint of dust modeling in a global chemical transport model, GEOS-Chem, using a four-dimensional variational method and apply it to obtain optimized dust sources over East Asia in April 2001 together with surface PM10 aerosol measurements from the Chinese ambient air pollution index, the Korean Ministry of Environment, and the Acid Deposition Monitoring Network. The optimized dust sources from the assimilation show a large decrease in dust emissions over the Gobi Desert. To evaluate the assimilated results, we compare simulated dust aerosol optical depths (AODs) using the optimized sources with the Total Ozone Mapping Spectrometer aerosol index and the Multi-angle Imaging Spectrometer AOD data. We find that the optimized sources result in much better agreement with the observations, especially in the context of improved the spatial distribution of the simulated AOD compared with the observation over East Asia.

  7. Field Observation of Heterogeneous Formation of Secondary Organic Aerosols on Asian Mineral Dust Surfaces

    NASA Astrophysics Data System (ADS)

    Wang, G.

    2014-12-01

    This study investigated the heterogeneous formation mechanism of secondary organic aerosols (SOA) on dust surfaces by characterizing molecular compositions and size distributions of dicarboxylic acids, keto-carboxylic acids, a-dicarbonyls and inorganic ions in size-segregated aerosols (9-stages) in the urban atmosphere of Xi'an, China during dust storm periods and comparing with those in non-dust storm periods. In the presence of a dust storm, all the above mentioned SOA species in Xi'an are predominantly enriched on coarse particles (>2.1 µm). Oxalic acid well correlated with NO3- (r2=0.72, p<0.01) rather than SO42-. This phenomenon differs greatly from the observed particles during a non-dust storm period, which is characterized by an enrichment of the SOA on fine particles (<2.1 µm) with a strong correlation between C2 and SO42-. We propose a three-step formation pathway to explain these observations as follows. First, nitric acid and nitrogen oxides react with dust to form a liquid film on the surface via water vapor-absorption of calcium nitrate. Second, gaseous Gly and mGly partition into the aqueous-phase. Finally, the aqueous-phase Gly and mGly oxidize into glyoxylic acid (wC2), followed by a further oxidation into C2. To the best of our knowledge, we found for the first time the enrichments of glyoxal (Gly) and methylglyoxal (mGly) on dust surfaces. Our data indicate a more critical role of nitrate than sulfate in the heterogeneous formation process of SOA on dust surfaces. Mass ratio of C2 to wC2 was found to be higher in coarse particles than in fine particles during the dust storm events, which is due to low acidity condition of large particles that is favorable for conversion of wC2 to C2.

  8. Passive airborne dust sampling with the electrostatic dustfall collector: optimization of storage and extraction procedures for endotoxin and glucan measurement.

    PubMed

    Noss, Ilka; Doekes, Gert; Sander, Ingrid; Heederik, Dick J J; Thorne, Peter S; Wouters, Inge M

    2010-08-01

    We recently introduced a passive dust sampling method for airborne endotoxin and glucan exposure assessment-the electrostatic dustfall collector (EDC). In this study, we assessed the effects of different storage and extraction procedures on measured endotoxin and glucan levels, using 12 parallel EDC samples from 10 low exposed indoor environments. Additionally, we compared 2- and 4-week sampling with the prospect of reaching higher dust yields. Endotoxin concentrations were highest after extraction with pyrogen-free water (pf water) + Tween. Phosphate-buffered saline (PBS)-Tween yielded significantly (44%) lower levels, and practically no endotoxin was detected after extraction in pf water without Tween. Glucan levels were highest after extraction in PBS-Tween at 120 degrees C, whereas extracts made in NaOH at room temperature or 120 degrees C were completely negative. Direct extraction from the EDC cloth or sequential extraction after a preceding endotoxin extraction yielded comparable glucan levels. Sample storage at different temperatures before extraction did not affect endotoxin and glucan concentrations. Doubling the sampling duration yielded similar endotoxin and only 50% higher glucan levels. In conclusion, of the tested variables, the extraction medium was the predominant factor affecting endotoxin and glucan yields.

  9. Monitoring airborne dust in a high density coal-fired power station region in North Yorkshire.

    PubMed

    Vallack, H W; Chadwick, M J

    1993-01-01

    Concerns about the levels of dust deposition in the vicinity of coal-fired power stations in North Yorkshire, in particular Drax Power Station, prompted the commissioning of a detailed monitoring study in the area. This paper describes the first two years' work. The first 12-month study concentrated on the village of Barlow close to Drax Power Station, whilst in the second 12-month study, monitoring sites were spread along a transect passing through the power station belt formed by Ferrybridge, Eggborough and Drax Power Stations. Two monitoring sites were common to both 12-month studies, thus giving two years of continuous monitoring. Pairs of wet Frisbee dust deposit gauges (based on inverted Frisbees) were located at each site. Undissolved particulate matter from each gauge was weighed and characterized by microscopic examination of individual particles. The first 12-month study revealed a downward gradient in dust deposition rate and cenosphere content with distance from Drax Power Station. The high cenosphere content at Barlow, especially at the eastern end, suggested that there was a significant contribution from coal-fired power stations. In the second year, the overall pattern of dust deposition rate and cenosphere content across the power station belt suggested that power stations were contributing to higher levels. In particular, relatively high levels were again found at Barlow. Wind direction correlations point to the fly-ash tip next to Drax Power Station as being the source of cenospheres arriving at Barlow. It is concluded that in both years the fly-ash tip Drax Power Station was making a significant contribution to higher than expected dust deposition rates at Barlow, particularly its eastern end. Other villages in the area may also have been affected by dust originating from coal-fired power stations.

  10. Size-differentiated chemical characteristics of Asian paleo dust: records from aeolian deposition on Chinese Loess Plateau.

    PubMed

    Wu, Feng; Chow, Judith C; An, Zhisheng; Watson, John G; Cao, Junji

    2011-02-01

    The Chinese Loess Plateau (CLP) receives and potentially contributes to Asian dust storms that affect particulate matter (PM) concentrations, visibility, and climate. Loess on the CLP has experienced little weathering effect and is regarded as an ideal record to represent geochemical characteristics of Asian paleo dust. Samples were taken from 2-, 9-, and 15-m depths (representing deposition periods from approximately 12,000 to approximately 200,000 yr ago) in the Xi Feng loess profile on the CLP. The samples were resuspended and then sampled through total suspended particulates (TSP), PM10, PM2.5, and PM1 (PM with aerodynamic diameters < approximately 30, 10, 2.5, and 1 microm, respectively) inlets onto filters for mass, elemental, ionic, and carbon analyses using a Desert Research Institute resuspension chamber. The elements Si, Ca, Al, Fe, K, Mg, water-soluble Ca (Ca2+), organic carbon, and carbonate carbon are the major constituents (> 1%) in loess among the four PM fractions (i.e., TSP, PM10, PM2.5, and PM1). Much of Ca is water soluble and corresponds with measures of carbonate, indicating that most of the calcium is in the form of calcium carbonate rather than other calcium minerals. Most of the K is insoluble, indicating that loess can be separated from biomass burning contributions when K+ is measured. The loess has elemental abundances similar to those of the upper continental crust (UCC) for Mg, Fe, Ti, Mn, V, Cr, and Ni, but substantially different ratios for other elements such as Ca, Co, Cu, As, and Pb. These suggest that the use of UCC as a reference to represent pure or paleo Asian dust needs to be further evaluated. The aerosol samples from the source regions have similar ratios to loess for crustal elements, but substantially different ratios for species from anthropogenic sources (e.g., K, P, V, Cr, Cu, Zn, Ni, and Pb), indicating that the aerosol samples from the geological-source-dominated environment are not a "pure" soil product as compared

  11. Effects of two Asian sand dusts transported from the dust source regions of Inner Mongolia and northeast China on murine lung eosinophilia

    SciTech Connect

    He, Miao; Ichinose, Takamichi; Song, Yuan; Yoshida, Yasuhiro; Arashidani, Keiichi; Yoshida, Seiichi; Liu, Boying; Nishikawa, Masataka; Takano, Hirohisa; and others

    2013-11-01

    The quality and quantity of toxic materials adsorbed onto Asian sand dust (ASD) are different based on dust source regions and passage routes. The aggravating effects of two ASDs (ASD1 and ASD2) transported from the source regions of Inner Mongolia and northeast China on lung eosinophilia were compared to clarify the role of toxic materials in ASD. The ASDs contained different amounts of lipopolysaccharides (LPS) and β-glucan (ASD1 < ASD2) and SiO{sub 2} (ASD1 > ASD2). CD-1 mice were instilled intratracheally with ASD1, ASD2 and/or ovalbumin (OVA) four times at 2-week intervals. ASD1 and ASD2 enhanced eosinophil recruitment induced by OVA in the submucosa of the airway, with goblet cell proliferation in the bronchial epithelium. ASD1 and ASD2 synergistically increased OVA-induced eosinophil-relevant cytokines interleukin-5 (IL-5), IL-13 (ASD1 < ASD2) and chemokine eotaxin (ASD1 > ASD2) in bronchoalveolar lavage fluid. ASD2 aggravating effects on lung eosinophilia were greater than ASD1. The role of LPS and β-glucan in ASD2 on the production of pro-inflammatory mediators was assessed using in vitro bone marrow-derived macrophages (BMDMs) from wild type, Toll-like receptor 2-deficient (TLR2 −/−), TLR4 −/−, and MyD88 −/− mice (on Balb/c background). ASD2-stimulated TLR2 −/− BMDMs enhanced IL-6, IL-12, TNF-α, MCP-1 and MIP-1α secretion compared with ASD2-stimulated TLR4 −/− BMDMs. Protein expression from ASD2-stimulated MyD88 −/− BMDM were very low or undetectable. The in vitro results indicate that lung eosinophilia caused by ASD is TLR4 dependent. Therefore, the aggravation of OVA-related lung eosinophilia by ASD may be dependent on toxic substances derived from microbes, such as LPS, rather than SiO{sub 2}. - Highlights: • Asian sand dust (ASD) from the deserts of China causes serious respiratory problems. • The aggravating effects of two ASDs on lung eosinophilia were compared. • The ASDs contained different LPS and β-glucan (ASD1

  12. Investigation of aged aerosols in size-resolved Asian dust storm particles transported from Beijing, China, to Incheon, Korea, using low-Z particle EPMA

    NASA Astrophysics Data System (ADS)

    Geng, H.; Hwang, H.; Liu, X.; Dong, S.; Ro, C.-U.

    2014-04-01

    This is the first study of Asian dust storm (ADS) particles collected in Beijing, China, and Incheon, Korea, during a spring ADS event. Using a seven-stage May impactor and a quantitative electron probe X-ray microanalysis (ED-EPMA, also known as low-Z particle EPMA), we examined the composition and morphology of 4200 aerosol particles at stages 1-6 (with a size cut-off of 16, 8, 4, 2, 1, and 0.5 μm in equivalent aerodynamic diameter, respectively) collected during an ADS event on 28-29 April 2005. The results showed that there were large differences in the chemical compositions between particles in sample S1 collected in Beijing immediately after the peak time of the ADS and in samples S2 and S3, which were collected in Incheon approximately 5 h and 24 h later, respectively. In sample S1, mineral dust particles accounted for more than 88% in relative number abundance at stages 1-5; and organic carbon (OC) and reacted NaCl-containing particles accounted for 24% and 32%, respectively, at stage 6. On the other hand, in samples S2 and S3, in addition to approximately 60% mineral dust, many sea spray aerosol (SSA) particles reacted with airborne SO2 and NOx (accounting for 24% and 14% on average in samples S2 and S3, respectively), often mixed with mineral dust, were encountered at stages 1-5, and (C, N, O, S)-rich particles (likely a mixture of water-soluble organic carbon with (NH4)2SO4 and NH4NO3) were abundantly observed at stage 6 (accounting for 68% and 51% in samples S2 and S3, respectively). This suggests that an accumulation of sea-salt components on individual ADS particles larger than 1 μm in diameter occurred and many secondary aerosols smaller than 1 μm in diameter were formed when the ADS particles passed over the Yellow Sea. In the reacted or aged mineral dust and SSA particles, nitrate-containing and both nitrate- and sulfate-containing species vastly outnumbered the sulfate-containing species, implying that ambient NOx had a greater influence on the

  13. Heavy Metal Content in Airborne Dust of Childhood Leukemia Cluster Areas: Even Small Towns Have Air Pollutants

    NASA Astrophysics Data System (ADS)

    Sheppard, P. R.; Witten, M. L.

    2004-12-01

    Currently in the US, there are at least two ongoing clusters of childhood leukemia, where the incidence rate over the last several years has exceeded the national norm. In Fallon, Nevada, a town of 8,000 people, 16 children have been diagnosed with leukemia since 1995, three of whom have died. In Sierra Vista, Arizona, a town of 38,000 people, 12 children have been diagnosed since 1998, two of whom have died. A possible third cluster of childhood leukemia and other cancers is being monitored in Elk Grove, California, a suburb of Sacramento. For the purpose of characterizing the heavy metal content of airborne dust of these three communities, total suspended particulate samples were collected from each town as well as from nearby towns that could be considered as control comparisons. Sampling was done using portable high-volume blowers and glass- or quartz-fiber filter media. Filters were measured for elemental concentrations using inductively coupled plasma mass spectroscopy. To date, our most notable results are from the Nevada region. Compared to other control towns in the region, Fallon had significantly more tungsten in its airborne dust. Uranium was also higher in dust of Fallon than in other control towns. Uranium is a known health hazard, though it is not necessarily specifically related to childhood leukemia. The role of tungsten in childhood leukemia has not been widely studied. However, other research has identified tungsten exposure as an environmental concern in Fallon. A CDC study of human tissue samples from Fallon has shown high tungsten levels in people of Fallon, and a USGS study of drinking water in Fallon also has shown high tungsten there. Tree-ring research on selected trees has shown high tungsten values in recent rings compared to earlier rings. While these multiple indications of tungsten in the Fallon environment do not directly lead to the conclusion that tungsten causes leukemia, they do combine to suggest that biomedical research on the

  14. Respiratory protection provided by N95 filtering facepiece respirators against airborne dust and microorganisms in agricultural farms.

    PubMed

    Lee, Shu-An; Adhikari, Atin; Grinshpun, Sergey A; McKay, Roy; Shukla, Rakesh; Zeigler, Haoyue Li; Reponen, Tiina

    2005-11-01

    A new system was used to determine the workplace protection factors (WPF) for dust and bioaerosols in agricultural environments. The field study was performed with a subject wearing an N95 filtering facepiece respirator while performing animal feeding, grain harvesting and unloading, and routine investigation of facilities. As expected, the geometric means (GM) of the WPFs increased with increasing particle size ranging from 21 for 0.7-1 microm particles to 270 for 5-10 microm particles (p < 0.001). The WPF for total culturable fungi (GM = 35) was significantly greater than for total culturable bacteria (GM = 9) (p = 0.01). Among the different microorganism groups, the WPFs of Cladosporium, culturable fungi, and total fungi were significantly correlated with the WPFs of particles of the same sizes. As compared with the WPFs for dust particles, the WPFs for bioaerosols were found more frequently below 10, which is a recommended assigned protection factor (APF) for N95 filtering facepiece respirators. More than 50% of the WPFs for microorganisms (mean aerodynamic diameter < 5 microm) were less than the proposed APF of 10. Even lower WPFs were calculated after correcting for dead space and lung deposition. Thus, the APF of 10 for N95 filtering facepiece respirators seems inadequate against microorganisms (mean aerodynamic size < 5 microm). These results provide useful pilot data to establish guidelines for respiratory protection against airborne dust and microorganisms on agricultural farms. The method is a promising tool for further epidemiological and intervention studies in agricultural and other similar occupational and nonoccupational environments. PMID:16234218

  15. Dust storm contributions to airborne particulate matter in Reykjavík, Iceland

    NASA Astrophysics Data System (ADS)

    Thorsteinsson, Throstur; Gísladóttir, Guđrún; Bullard, Joanna; McTainsh, Grant

    2011-10-01

    Episodes of high levels of particulate matter (PM) in Reykjavík occur several times a year. The main sources of daily variation in PM are traffic or highly localized (e.g. construction) sources, however several episodes have been identified where these are not the cause. Examining PM10 (diameter < 10 μm) levels around the time when dust storms are seen on satellite images, and verifying that the weather conditions are favorable for the duration of the high levels of PM (>50-100 μg m-3; 30-min average), demonstrates that dust storms are the source of these increased levels of PM10. Since satellite coverage is sparse, visual confirmation of many such peaks in PM10 cannot be achieved. The level of pollution measured in Reykjavík during dust storms indicates that at least 200 kg s-1 of PM10 sized material is being eroded and transported away from sand plains ˜110 km away - this equates to an emission rate of 35 g m2 h-1. The source regions for dust storms in Iceland are the sandur areas on the southern coast of Iceland, and regions close to the glaciers. With climate warming, and fast retreating glaciers, the potential source regions in Iceland are rapidly increasing.

  16. Swine confinement buildings: effects of airborne particles and settled dust on airway smooth muscles.

    PubMed

    Demanche, Annick; Bonlokke, Jakob; Beaulieu, Marie-Josee; Assayag, Evelyne; Cormier, Yvon

    2009-01-01

    Swine confinement workers are exposed to various contaminants. These agents can cause airway inflammation and bronchoconstriction. This study was undertaken to evaluate if the bronchoconstrictive effects of swine barn air and settled dust are mediated by endotoxin, and if these effects are directly mediated on airway smooth muscles. Mouse tracheas where isolated and mounted isometrically in organ baths. Tracheas, with or without epithelium, were attached to a force transducer and tension was recorded. Concentrated swine building air at 68 EU/ml or settled dust extract at 0.01 g/ml were added for 20 minutes and tracheal smooth muscle contraction was measured. Direct role of LPS was assessed by removing it from air concentrates with an endotoxin affinity resin. Swine barn air and settled dust extract caused contraction of tracheal smooth muscle by 26 and 20%, respectively, of the maximal induced by methacholine. Removal of epithelium did not affect the contractile effects. LPS alone and LPS with peptidoglycans did not induce contraction. However, when endotoxin was removed from swine barn air concentrates, it lost 24% of its contractile effect. Concentrated swine barn air and settled dust have direct effects on airway smooth muscles. This effect is partially due to LPS but a synergy with other components of the environment of swine confinement buildings is required. PMID:20047256

  17. Dust, Elemental Carbon and Other Impurities on Central Asian Glaciers: Origin and Radiative Forcing

    NASA Astrophysics Data System (ADS)

    Schmale, J.; Flanner, M.; Kang, S.; Sprenger, M.; Zhang, Q.; Li, Y.; Guo, J.; Schwikowski, M.

    2015-12-01

    In Central Asia, more than 60 % of the population depends on water stored in glaciers and mountain snow. While temperature, precipitation and dynamic processes are key drivers of glacial change, deposition of light absorbing impurities such as mineral dust and black carbon can lead to accelerated melting through surface albedo reduction. Here, we discuss the origin of deposited mineral dust and black carbon and their impacts on albedo change and radiative forcing (RF). 218 snow samples were taken from 13 snow pits on 4 glaciers, Abramov (Pamir), Suek, Glacier No. 354 and Golubin (Tien Shan), representing deposition between summer 2012 and 2014. They were analyzed for elemental and organic carbon by a thermo-optical method, mineral dust by gravimetry, and iron by ICP-MS. Back trajectory ensembles were released every 6 hours with the Lagranto model for the covered period at all sites. Boundary layer "footprints" were calculated to estimate general source regions and combined with MODIS fire counts for potential fire contributions. Albedo reduction due to black carbon and mineral dust was calculated with the Snow-Ice-Aerosol-Radiative model (SNICAR), and surface spectral irradiances were derived from atmospheric radiative transfer calculations to determine the RF under clear-sky and all sky conditions using local radiation measurements. Dust contributions came from Central Asia, the Arabian Peninsula, the Sahara and partly the Taklimakan. Fire contributions were higher in 2014 and generally came from the West and North. We find that EC exerts roughly 3 times more RF than mineral dust in fresh and relatively fresh snow (~5 W/m2) and up to 6 times more in snow that experienced melting (> 10 W/m2) even though EC concentrations (average per snow pit from 90 to 700 ng/g) were up to two orders of magnitude lower than mineral dust (10 to 140 μg/g).

  18. Overview of Asian Biomass Burning and Dust Aerosols Measured during the Dongsha Experiment in the Spring of 2010

    NASA Astrophysics Data System (ADS)

    Lin, N.; Tsay, S.; Wang, S.; Sheu, G.; Chi, K.; Lee, C.; Wang, J.

    2010-12-01

    launched four times per day during the IOPs. This experiment provides a relatively complete dataset of aerosol chemistry and physical observations conducted in the source/sink region for below marine boundary layer and lower free troposphere of biomass burning/air pollutants in the northern SE Asia. This presentation will give an overview of this experiment and its preliminary results, including a severe and unusual Asian dust event that was observed in Dognsha Island.

  19. Atmospheric circulation feedback on west Asian dust and Indian monsoon rainfall

    NASA Astrophysics Data System (ADS)

    Kaskaoutis, Dimitris; Houssos, Elias; Gautam, Ritesh; Singh, Ramesh; Rashki, Alireza; Dumka, Umesh

    2016-04-01

    Classification of the atmospheric circulation patterns associated with high aerosol loading events over the Ganges valley, via the synergy of Factor and Cluster analysis techniques, has indicated six different synoptic weather patterns, two of which mostly occur during late pre-monsoon and monsoon seasons (May to September). The current study focuses on examining these two specific clusters that are associated with different mean sea level pressure (MSLP), geopotential height at 700 hPa (Z700) and wind fields that seem to affect the aerosol (mostly dust) emissions and precipitation distribution over the Indian sub-continent. Furthermore, the study reveals that enhanced aerosol presence over the Arabian Sea is positively associated with increased rainfall over the Indian landmass. The increased dust over the Arabian Sea and rainfall over India are associated with deepening of the northwestern Indian and Arabian lows that increase thermal convection and convergence of humid air masses into Indian landmass, resulting in larger monsoon precipitation. For this cluster, negative MSLP and Z700 anomalies are observed over the Arabian Peninsula that enhance the dust outflow from Arabia and, concurrently, the southwesterly air flow resulting in increase in monsoon precipitation over India. The daily precipitation over India is found to be positively correlated with the aerosol loading over the Arabian Sea for both weather clusters, thus verifying recent results from satellite observations and model simulations concerning the modulation of the Indian summer monsoon rainfall by the Arabian dust. The present work reveals that in addition to the radiative impacts of dust on modulating the monsoon rainfall, differing weather patterns favor changes in dust emissions, accumulation as well as rainfall distribution over south Asia.

  20. Effects of South Asian dust storm on air quality over the capital city of India

    NASA Astrophysics Data System (ADS)

    Yarragunta, Y.; Srivastava, S.

    2016-05-01

    In the present study, an intense unseasonal dust storm has been analyzed during third week of March 2012 from multi satellite datasets and from surface measurements over National Capital Region (NCR), Delhi. The intrusion of dust over study region has increased the MODIS Aerosol Optical Depth at 550 nm more than 1.0 whereas significant decrease in Angstrom Exponent (α) has been observed . Very high UV aerosol Index (> 2) over study location indicates the presence of UV absorbing aerosols . Fire activities are found to be negligible over the source region confirming the effect of dust storm. Strong southwesterly winds prevailed over northern Arabian Sea which trans ported the dust plume across the oceanic region towards Indian capital region. In-situ measurements of PM 2.5 and PM10, obtained from CPCB observational site over the IGI airport, NCR Delhi, showed abrupt increase on 20, 21 March. Eight hourly average concentration of the particulate matters less than 10 μm (PM10) is found to be ~990 μg/m3 and particulate matters less than 2.5 μm (PM2.5) is found to be ~900 μg/m3 over IGI Airport, NCR Delhi. These values are remarkably higher as compared to the daily National Ambient Air Quality Standards (NAAQS) i.e. 100 μg/m3 and 60 μg/m3 for PM10 and PM2.5 respectively. In addition, Vertical distribution of dust has been examined using CALIPSO observation. The layer of dust is found to be trapped within lower 3 km in altitude. The Potential Source Contribution Function (PSCF) modeling has been carried out to identify the specific source locations.

  1. Satellite Monitoring of Asian Dust Storms from SeaWiFS and MODIS: Source, pathway and Interannual Variability

    NASA Technical Reports Server (NTRS)

    Hsu, N. Christina

    2007-01-01

    Among the many components that contribute to air pollution, airborne mineral dust plays an important role due to its biogeochemical impact on the ecosystem and its radiative-forcing effect on the climate system. In East Asia, dust storms frequently accompany the cold and dry air masses that occur as part of springtime cold front systems. China's capital, Beijing, and other large cities are on the primary pathway of these dust storm plumes, and their passage over such population centers causes flight delays, pushes grit through windows and doors, and forces people indoors. Furthermore, during the spring these anthropogenic and natural air pollutants, once generated over the source regions, can be transported out of the boundary layer into the free troposphere and can travel thousands of kilometers across the Pacific into the United States and beyond. In this paper, we will demonstrate the capability of a new satellite algorithm to retrieve aerosol optical thickness and single scattering albedo over bright-reflecting surfaces such as urban areas and deserts. Such retrievals have been difficult to perform using previously available algorithms that use wavelengths from the mid-visible to the near IR because they have trouble separating the aerosol signal from the contribution due to the bright surface reflectance. The new algorithm, called Deep Blue, utilizes blue-wavelength measurements from instruments such as SeaWiFS and MODIS to infer the properties of aerosols, since the surface reflectance over land in the blue part of the spectrum is much lower than for longer wavelength channels. We have validated the satellite retrieved aerosol optical thickness with data from AERONET sunphotometers over desert and semi-desert regions. The comparisons show reasonable agreements between these two. These new satellite products will allow scientists to determine quantitatively the aerosol properties near sources using high spatial resolution measurements from SeaWiFS and MODIS

  2. Satellite Monitoring of Asian Dust Storms from SeaWiFS and MODIS: Source, Pathway, and Interannual Variability

    NASA Astrophysics Data System (ADS)

    Hsu, N.; Tsay, S.; Jeong, M.; Holben, B.

    2006-12-01

    Among the many components that contribute to air pollution, airborne mineral dust plays an important role due to its biogeochemical impact on the ecosystem and its radiative-forcing effect on the climate system. In East Asia, dust storms frequently accompany the cold and dry air masses that occur as part of spring-time cold front systems. China's capital, Beijing, and other large cities are on the primary pathway of these dust storm plumes, and their passage over such popu-lation centers causes flight delays, pushes grit through windows and doors, and forces people indoors. Furthermore, during the spring these anthropogenic and natural air pollutants, once generated over the source regions, can be transported out of the boundary layer into the free troposphere and can travel thousands of kilometers across the Pacific into the United States and beyond. In this paper, we will demonstrate the capability of a new satellite algorithm to retrieve aerosol optical thickness and single scattering albedo over bright-reflecting surfaces such as urban areas and deserts. Such retrievals have been dif-ficult to perform using previously available algorithms that use wavelengths from the mid-visible to the near IR because they have trouble separating the aerosol signal from the contribution due to the bright surface reflectance. The new algorithm, called Deep Blue, utilizes blue-wavelength measurements from instruments such as SeaWiFS and MODIS to infer the properties of aerosols, since the surface reflectance over land in the blue part of the spectrum is much lower than for longer wavelength channels. We have validated the satellite retrieved aerosol optical thickness with data from AERONET sunphotometers over desert and semi-desert regions. The compari-sons show reasonable agreements between these two. These new satellite prod-ucts will allow scientists to determine quantitatively the aerosol properties near sources using high spatial resolution measurements from SeaWiFS and

  3. Satellite Monitoring of Asian Dust Storms from SeaWiFS and MODIS: Source, Pathway, and Interannual Variability

    NASA Technical Reports Server (NTRS)

    Hsu, N. Christina; Tsay, S.-C.; Bettenhausen, C.; Salustro, C.; Jeong, M. J.

    2010-01-01

    Among the many components that contribute to air pollution, airborne mineral dust plays an important role due to its biogeochernical impact on the ecosystem and its radiative-forcing effect on the climate system. In East Asia, dust storms frequently accompany the cold and dry air masses that occur as part of springtime cold front systems. China's capital, Beijing, and other large cities are on the primary pathway of these dust storm plumes, and their passage over such population centers causes flight delays, pushes grit through windows and doors, and forces people indoors. Furthermore, during the spring these anthropogenic and natural air pollutants, once generated over the source regions, can be transported out of the boundary layer into the free troposphere and can travel thousands of kilometers across the Pacific into the United States and beyond. In this paper, we will demonstrate the capability of a new satellite algorithm to retrieve aerosol optical thickness and single scattering albedo over bright reflecting surfaces such as urban areas and deserts. Such retrievals have been difficult to perform using previously available algorithms that use wavelengths from the mid-visible to the near IR because they have trouble separating the aerosol signal from the contribution due to the bright surface reflectance. The new algorithm, called Deep Blue, utilizes blue-wavelength measurements from instruments such as SeaWiFS and MODIS to infer the properties of aerosols, since the surface reflectance over land in the blue part of the spectrum is much lower than for longer wavelength channels. We have validated the satellite retrieved aerosol optical thickness with data from AERONET sunphotometers over desert and semi-desert regions. The comparisons show reasonable agreements between these two. These new satellite products will allow scientists to determine quantitatively the aerosol properties near sources using high spatial resolution measurements from SeaWiFS and MODIS

  4. Satellite Monitoring of Asian Dust Storms from SeaWiFS and MODIS: Source, Pathway, and Interannual Variability

    NASA Technical Reports Server (NTRS)

    Hsu, N. Christina; Tsay, S.-C.; Bettenhausen, C.; Sayer, A.

    2011-01-01

    Among the many components that contribute to air pollution, airborne mineral dust plays an important role due to its biogeochemical impact on the ecosystem and its radiative-forcing effect on the climate system. In East Asia, dust storms frequently accompany the cold and dry air masses that occur as part of springtime cold front systems. China's capital, Beijing, and other large cities are on the primary pathway of these dust storm plumes, and their passage over such population centers causes flight delays, pushes grit through windows and doors, and forces peop Ie indoors. Furthermore, during the spring these anthropogenic and natural air pollutants, once generated over the source regions, can be tran sported out of the boundary layer into the free troposphere and can travel thousands of kilometers across the Pacific into the United States and beyond. In this paper, we will demonstrate the capability of a new satellite algorithm to retrieve aerosol optical thickness and single scattering albedo over brightreflecting surfaces such as urban areas and deserts. Such retrievals have been difficult to perform using previously available algorithms that use wavelengths from the mid-visible to the near IR because they have trouble separating the aerosol signal from the contribution due to the bright surface reflectance. The new algorithm, called Deep Blue, utilizes blue-wavelength measurements from instruments such as Sea WiFS and MODIS to infer the properties of aerosols, since the surface reflectance over land in the blue part of the spectrum is much lower than for longer wavelength channels. We have validated the satellite retrieved aerosol optical thickness with data from AERONET sunphotometers over desert and semi-desert regions. The comparisons show reasonable agreements between these two. These new satellite products will allow scientists to determine quantitatively the aerosol properties near sources using high spatial resolution measurements from Sea WiFS and

  5. Influence of Asian Desert Dust on Lower Respiratory Tract Symptoms in Patients with Asthma over 4 Years.

    PubMed

    Watanabe, Masanari; Kurai, Jun; Igishi, Tadashi; Yamasaki, Akira; Burioka, Naoto; Takeuchi, Hiromi; Sako, Takanori; Touge, Hirokazu; Nakamoto, Masaki; Hasegawa, Yasuyuki; Chikumi, Hiroki; Matsumoto, Shingo; Yamasaki, Chie; Minato, Sayaka; Ueda, Yutaka; Horasaki, Kazunori; Watanabe, Tetsushi; Shimizu, Eiji

    2012-06-01

    The Asian Dust Storm (ADS) aggravates symptoms and pulmonary dysfunction in adult asthma patients. Our objective was to investigate the association of air pollutants and metals in desert dust with worsening of asthma symptoms during the ADS. A telephone survey was performed to investigate the upper and lower respiratory tract symptoms, ocular symptoms and skin symptoms of asthma patients during the ADS in March between 2007 and 2010. Four surveys were conducted in 46 patients. Two patients noted worsening of lower respiratory tract symptoms in all four surveys, as well as 2 patients in three surveys, 7 patients in two surveys, and 9 patients in one survey. There was no worsening of lower respiratory tract symptoms in 26 patients. In each patient, the influence of the ADS on lower respiratory tract symptoms varied between surveys. In 2010, the level of suspended particulate matter was highest in all four years, but the smallest number of patients noted worsening of lower respiratory tract symptoms. Among pollutants, only the maximum concentration of nitrogen dioxide during the ADS was significantly associated with the worsening of lower respiratory tract symptoms. The influence of the ADS on lower respiratory tract symptoms of adult asthma patients is variable. PMID:24031138

  6. Quantitative estimates of Asian dust input to the western Philippine Sea in the mid-late Quaternary and its potential significance for paleoenvironment

    NASA Astrophysics Data System (ADS)

    Xu, Zhaokai; Li, Tiegang; Clift, Peter D.; Lim, Dhongil; Wan, Shiming; Chen, Hongjin; Tang, Zheng; Jiang, Fuqing; Xiong, Zhifang

    2015-09-01

    We present a new high-resolution multiproxy data set of Sr-Nd isotopes, rare earth element, soluble iron, and total organic carbon data from International Marine Global Change Study Core MD06-3047 located in the western Philippine Sea. We integrate our new data with published clay mineralogy, rare earth element chemistry, thermocline depth, and δ13C differences between benthic and planktonic foraminifera, in order to quantitatively constrain Asian dust input to the basin. We explore the relationship between Philippine Sea and high-latitude Pacific eolian fluxes, as well as its significance for marine productivity and atmospheric CO2 during the mid-late Quaternary. Three different indices indicate that Asian dust contributes between ˜15% and ˜50% to the detrital fraction of the sediments. Eolian dust flux in Core MD06-3047 is similar to that in the polar southern Pacific sediment. Coherent changes for most dust flux maximum/minimum indicate that dust generation in interhemispheric source areas might have a common response to climatic variation over the mid-late Quaternary. Furthermore, we note relatively good coherence between Asian dust input, soluble iron concentration, local marine productivity, and even global atmospheric CO2 concentration over the entire study interval. This suggests that dust-borne iron fertilization of marine phytoplankton might have been a periodic process operating at glacial/interglacial time scales over the past 700 ka. We suggest that strengthening of the biological pump in the Philippine Sea, and elsewhere in the tropical western Pacific during the mid-late Quaternary glacial periods may contribute to the lowering of atmospheric CO2 concentrations during ice ages.

  7. Waveband selection within 400-4000  cm-1 of optical identification of airborne dust in coal mine tunneling face.

    PubMed

    Wang, Wenzheng; Wang, Yanming; Shi, Guoqing

    2016-04-10

    Aimed at the optical evaluation of pollution levels caused by rock dust in an underground coal mine tunneling face, the optimal detection line and optical channel were investigated. The spatial distribution of airborne rock dust under local mining and ventilation conditions was simulated by the computational fluid dynamics method; thus, combined with the scattering and absorption properties of dust particles and gas molecules, the spectral transmission characteristics of a polluted atmosphere, including dust aerosols within 400-4000  cm-1, were obtained. By eliminating the optical background of mine gases, the pure infrared signals of rock dust were further analyzed. Based on the comparison results, the detection line, which is 1.5 m high and 0.3 m away from the right wall, was determined to be the best observation position, and a waveband of 1505-1525  cm-1 was selected to estimate the dust concentration. In addition, a dual-band detection method was presented, which can simultaneously identify the dust distribution and dispersion.

  8. Entrainment of free troposphere Asian dust/pollution into the marine boundary layer North of Hawai`i during INTEX-B

    NASA Astrophysics Data System (ADS)

    McNaughton, C.; Clarke, A.; Kapustin, V.; Dibb, J.; Anderson, B.; Browell, E.; Carmichael, G.

    2006-12-01

    During NASA's INTEX-B experiment (April, 2006), regional and global chemical transport models (CTM's) successfully predicted two Asian dust/pollution outbreaks. The dusty airmasses were transported from Asia to the Pacific Ocean north of Hawai`i via the free troposphere (FT) and reached locations as far south the Mauna Loa atmospheric observatory. Five research flights using the NASA DC-8 were flown in order to characterize the long-range transport of trace gases and aerosols from Asia and in order to calibrate/validate both CTM predictions and satellite retrievals. In-flight mapping of the dust/pollution layers using the NASA Langley DIAL LIDAR show a sloping, subsiding Asian airmass entraining into the marine boundary layer (MBL). Using in-situ measurements of the aerosol size distribution, chemistry, optical properties and the increase in light scattering as a function of relative humidity [f(RH)], we are able to characterize and discriminate between MBL air, FT Asian dust/pollution and an external mixture of the two airmasses during entrainment. After entrainment aerosols are removed via wet deposition ahead of the trailing low pressure front. The entire episode is put further into context using models, satellite observations and data from the Mauna Loa Observatory. We include a discussion of dust-flux to the ocean surface due to wet-deposition, a potentially important source of iron to the oligotrophic waters of the North Pacific Subtropical Gyre.

  9. Transport of mineral dust derived from airborne wind lidar measurements during SALTRACE

    NASA Astrophysics Data System (ADS)

    Chouza, Fernando; Reitebuch, Oliver; Groß, Silke; Rahm, Stephan; Freudenthaler, Volker; Toledano, Carlos; Weinzierl, Bernadett

    2015-04-01

    During the SALTRACE field experiment conducted between the 10 of June and the 15 of July 2013, the transport and properties of Saharan dust were characterized by a 2-µm Doppler wind lidar (DWL) deployed on the DLR Falcon 20 research aircraft. Unlike aerosol lidars, the DLW is able to simultaneously measure wind fields and -by means of an adequate calibration- aerosol optical properties, which is more adequate for aerosol transport studies. The retrieved horizontal and vertical wind speed provide a direct observation of dust long range transport mechanisms across the Atlantic (e.g. by the African easterly jet) from Western Africa to the Caribbean. Vertical wind observations revealed the structure of island induced lee waves in the Cape Verde and Barbados regions. A novel method for the calibration of DWLs based on simultaneous measurements with a ground-based aerosol lidar and sun photometer was developed. After being calibrated, the system is able to retrieve quantitative aerosol backscatter and extinction coefficients, which is usually not obtained from coherent lidars. Results from the validation with a ground-based aerosol lidar in Barbados and the CALIPSO satellite instrument will be discussed.

  10. Particle Size Distribution of Airborne Microorganisms and Pathogens during an Intense African Dust Event in the Eastern Mediterranean

    PubMed Central

    Polymenakou, Paraskevi N.; Mandalakis, Manolis; Stephanou, Euripides G.; Tselepides, Anastasios

    2008-01-01

    Background The distribution of microorganisms, and especially pathogens, over airborne particles of different sizes has been ignored to a large extent, but it could have significant implications regarding the dispersion of these microorganisms across the planet, thus affecting human health. Objectives We examined the microbial quality of the aerosols over the eastern Mediterranean region during an African storm to determine the size distribution of microorganisms in the air. Methods We used a five-stage cascade impactor for bioaerosol collection in a coastal city on the eastern Mediterranean Sea during a north African dust storm. Bacterial communities associated with aerosol particles of six different size ranges were characterized following molecular culture–independent methods, regardless of the cell culturability (analysis of 16S rRNA genes). Results All 16S rDNA clone libraries were diverse, including sequences commonly found in soil and marine ecosystems. Spore-forming bacteria such as Firmicutes dominated large particle sizes (> 3.3 μm), whereas clones affiliated with Actinobacteria (found commonly in soil) and Bacteroidetes (widely distributed in the environment) gradually increased their abundance in aerosol particles of reduced size (< 3.3 μm). A large portion of the clones detected at respiratory particle sizes (< 3.3 μm) were phylogenetic neighbors to human pathogens that have been linked to several diseases. Conclusions The presence of aerosolized bacteria in small size particles may have significant implications to human health via intercontinental transportation of pathogens. PMID:18335093

  11. Natural Airborne Dust and Heavy Metals: A Case Study for Kermanshah, Western Iran (2005–2011)

    PubMed Central

    PIRSAHEB, Meghdad; ZINATIZADEH, Aliakbar; KHOSRAVI, Touba; ATAFAR, Zahra; DEZFULINEZHAD, Saeed

    2014-01-01

    Abstract Background Dust pollution has become a serious environmental problem especially in recent decades. The present study aim was the investigation of the levels of PM10 concentration in Kermanshah, western Iran and also measured five important heavy metals (Pb, Cd, As, Hg and Cr) in some samples during 2005 to 2011. Methods A total 2277 samples were collected from air pollution measurement station belonging to the Department of Environment in Kermanshah. Furthermore, four samples were collected during dusty days to determine the selected heavy metals concentration. The samples were analyzed statistically using the SPSS Ver.16 Results The highest seasonal average concentration in spring was recorded in 2008 with 216.63μg/m3, and the maximum values of 267.79 and 249.09μg/m3 were observed in summer and winter in 2009, respectively. The maximum concentration of 127.1μg/m3 was in autumn in 2010. The metals concentration (Pb, Cd, As, Hg and Cr) of samples were 42.32±5.40, 37.45±9.29, 3.51±2.07, 1.88±1.64 and 0μg/g in July, 2009, respectively. Conclusion According to National Ambient Air Quality of USEPA guidelines, the most days with non-standard, warning, emergency and critical conditions were related to 2009 (120 days) while the least polluted days were recorded in 2006 (16 days). There are concerns about the increasing frequency and intensity trend of dust storms in recent years as a result of special condition in neighboring Western countries which it could endanger public health and environment. All measured heavy metals except mercury was higher than the standard level of WHO and USEPA. PMID:26005656

  12. Influence of the vertical absorption profile of mixed Asian dust plumes on aerosol direct radiative forcing over East Asia

    NASA Astrophysics Data System (ADS)

    Noh, Young Min; Lee, Kwonho; Kim, Kwanchul; Shin, Sung-Kyun; Müller, Detlef; Shin, Dong Ho

    2016-08-01

    We estimate the aerosol direct radiative forcing (ADRF) and heating rate profiles of mixed East Asian dust plumes in the solar wavelength region ranging from 0.25 to 4.0 μm using the Santa Barbara Discrete Ordinate Atmospheric Radiative Transfer (SBDART) code. Vertical profiles of aerosol extinction coefficients and single-scattering albedos (SSA) were derived from measurements with a multi-wavelength Raman lidar system. The data are used as input parameters for our radiative transfer calculations. We considered four cases of radiative forcing in SBDART: 1. dust, 2. pollution, 3. mixed dust plume and the use of vertical profiles of SSA, and 4. mixed dust plumes and the use of column-averaged values of SSA. In our sensitivity study we examined the influence of SSA and aerosol layer height on our results. The ADRF at the surface and in the atmosphere shows a small dependence on the specific shape of the aerosol extinction vertical profile and its light-absorption property for all four cases. In contrast, at the top of the atmosphere (TOA), the ADRF is largely affected by the vertical distribution of the aerosols extinction. This effect increases if the light-absorption capacity (decrease of SSA) of the aerosols increases. We find different radiative effects in situations in which two layers of aerosols had different light-absorption properties. The largest difference was observed at the TOA for an absorbing aerosol layer at high altitude in which we considered in one case the vertical profile of SSA and in another case the column-averaged SSA only. The ADRF at the TOA increases when the light-absorbing aerosol layer is located above 3 km altitude. The differences between height-resolved SSA, which can be obtained from lidar data, and total layer-mean SSA indicates that the use of a layer-mean SSA can be rather misleading as it can induce a large error in the calculation of the ADRF at the TOA, which in turn may cause errors in the vertical profiles of heating rates.

  13. Properties of the size-resolved and individual cloud droplets collected in western Japan during the Asian dust storm event

    NASA Astrophysics Data System (ADS)

    Ma, Chang-Jin; Tohno, Susumu; Kasahara, Mikio; Hayakawa, Shinjiro

    With the point of view of the removal mechanism of Asian dust storm particles, in order to study the physiochemical properties of clouds a field campaign was conducted in western Japan during the Asian dust storm event. The polymeric water absorbent film and collodion film replication techniques were employed in the measurements of size-fractionated precipitation cloud and individual cloud droplets, respectively. In addition, to investigate the source profiles of the elements retained in cloud samples, the original desert sand was collected. Particle-induced X-ray emission was applied for the elemental analysis of size-resolved cloud droplets and desert sand. Also for the quantification analysis of the ultra trace elements in residual particles in individual cloud droplets, the X-ray microprobe system equipped at Super Photon ring-8 GeV (SPring-8) BL-37XU was newly applied. Soil derived components like Si, Ca, and Fe show higher mass concentrations in small droplets (<6.4 μm) than in large droplets (>6.4 μm), while S and Cl dominate at droplet size larger than 20 μm. Three cloud samples have liquid water content ranging from 0.04 to 0.11 g m -3. The number size distribution of droplets collected at cloud base is monomodal with the maximum level around 15 μm. The size distribution of cloud droplets is widespread (up to 60 μm). The droplet residues mainly consisting of crustal components were successively reconstructed as elemental maps by the X-ray fluorescence (XRF) microprobe analytical technique. From these XRF elemental maps, it can be understood that crustal components are significantly distributed on and/or in the residual particles in individual cloud droplets. The plotting of enrichment factors calculated from the elemental composition of original desert sand in China not only indicates the good correlationship between elemental masses in residual particles of cloud base droplets and those of precipitation cloud, but also classify elements into soil

  14. Endotoxin levels in settled airborne dust in European schools: the HITEA school study.

    PubMed

    Jacobs, J H; Krop, E J M; Borras-Santos, A; Zock, J-P; Taubel, M; Hyvarinnen, A; Pekkanen, J; Doekes, G; Heederik, D J J

    2014-04-01

    Indoor exposure to microbial agents is known to influence respiratory health. Besides home exposure, exposure in schools can affect respiratory health. In this study, we measured endotoxin in settled dust in primary schools in three European countries from three different geographical regions with different climates. Our aim was to characterize endotoxin levels in primary schools and evaluate associations with potential determinants. Endotoxin levels were repeatedly assessed in 23 schools in Spain (n = 7), the Netherlands (n = 10), and Finland (n = 6) using electrostatic dustfall collectors. In total, 645 measurements were taken in 237 classrooms. Endotoxin levels differed significantly between countries; Dutch schools had the highest levels, while Finnish schools showed the lowest levels. In each country, differences in endotoxin levels were observed between schools and over the sampling periods. Estimates improved after adjustment for sampling period. Factors affecting endotoxin levels in a school differed per country. In general, endotoxin levels were higher in lower grades and in classrooms with higher occupancy. School endotoxin levels may contribute significantly to total endotoxin exposure in children and teachers. As the correlation between the repeated measurements is reasonable, single endotoxin measurements form a reasonable basis for estimating annual endotoxin levels in schools.

  15. Airborne Fungi in Sahara Dust Aerosols Reaching the Eastern Caribbean: II. Species Identification Using Molecular Techniques

    NASA Astrophysics Data System (ADS)

    de La Mota, A.; Betancourt, C.; Detres, Y.; Armstrong, R.

    2003-12-01

    Fungi samples from filters collected in Castle Bruce, Dominica from March through July 2002, were previously purified and identified to genus level using classic macroscopic and microscopic techniques. A total of 105 isolated colonies were cultured in liquid media and the mycelial mats used for DNA extraction. PCR was used to amplify the ITS region of the rDNA using the ITS1 and ITS4 primers. Both strands of the amplified products were sequenced and the final identification to species level was completed by a GenBank search. Fourteen different species and one fungal endophyte were identified from genders Aspergillus,Penicillium, Fusarium, Cladosporium, Curvularia and Phanerochaete. Some of these species such as A. fumigatus, A. japonicus, P. citrinum and C. cladosporoides are known to cause respiratory disorders in humans. A. fumigatus causes an aggressive pulmonary allergic response that might result in allergic bronchopulmonary aspergillosis. Other species such as F. equiseti and C. brachyspora are plant pathogens affecting economically important crops. Sahara dust is an important source of fungal spores of species that are not common in the Caribbean region.

  16. Airborne Fungi in Sahara Dust Aerosols Reaching the Eastern Caribbean: I. Taxonomic Characterization by Morphological Features

    NASA Astrophysics Data System (ADS)

    Rivera-Denizard, O.; Betancourt, C.; Armstrong, R. A.; Detres, Y.

    2003-12-01

    A wide variety of microorganisms are dispersed into the Caribbean region due to the input of Saharan dust aerosols during the summer months. These microorganisms can cause diseases in plants and animals, and might be responsible for an increase incidence of asthma and respiratory diseases in this region. A PM 2.5 air sampling station was installed in Castle Bruce, Dominica from March through July of 2002. Fourteen filters were obtained by running the air sampler continuously for 24 hour periods. The samples were collected in sterile Teflon filters (47 mm in diameter, 0.2 um pore size), inoculated in Malt Extract Agar (MEA) with lactic acid and incubated at 29° C. Colonies were counted, isolated and cultured on separate Petri dishes. Fungal classification to the genus level used macroscopic features and microscopic evaluation. The Nomarski light microscopy technique was used for identification of reproductive structures. A total of 105 colonies were isolated. Six genera including Aspergillus, Penicillium, Cladosporium, Fusarium, Curvularia,and Nigrospora were identified. The protocol for the molecular characterization to species level is presented as the second part of this work.

  17. Short-term modulation of Indian summer monsoon rainfall by West Asian dust

    SciTech Connect

    Vinoj, V.; Rasch, Philip J.; Wang, Hailong; Yoon, Jin-Ho; Ma, Po-Lun; Landu, Kiranmayi; Singh, Balwinder

    2014-03-16

    The Indian summer monsoon is the result of a complex interplay between radiative heating, dynamics and cloud and aerosol interactions. Despite increased scientific attention, the effect of aerosols on monsoons still remains uncertain. Here we present both observational evidence and numerical modeling results demonstrating a remote aerosol link to Indian summer monsoon rainfall. Rainfall over central India is positively correlated to natural aerosols over the Arabian Sea and West Asia. Simulations using a state-of-the-art global climate model support this remote aerosol link and indicate that dust aerosols induce additional moisture transport and convergence over Central India, producing increased monsoon rainfall. The convergence is driven through solar heating and latent heating within clouds over West Asia that increases surface winds over the Arabian Sea. On the other hand, sea-salt aerosol tends to counteract the effect of dust and reduces rainfall. Our findings highlight the importance of natural aerosols in modulating the strength of the Indian summer monsoon, and motivate additional research in how changes in background aerosols of natural origin may be influencing long-term trends in monsoon precipitation.

  18. Observation of low single scattering albedo of aerosols in the downwind of the East Asian desert and urban areas during the inflow of dust aerosols

    NASA Astrophysics Data System (ADS)

    Khatri, Pradeep; Takamura, Tamio; Shimizu, Atsushi; Sugimoto, Nobuo

    2014-01-01

    We analyzed data observed at Fukue-jima (32.752°N, 128.682°E), the downwind of the East Asian desert and urban areas, during the spring season (March-April) of 2008-2011 aiming to understand the light-absorption capacity of Asian dust aerosols, which is a topic of controversy. We observed the decreasing tendency of single-scattering albedo (SSA) with the decrease of Ångström exponent and the increase of the ratio of dust aerosol optical thickness to total aerosol optical thickness, suggesting the important role of coarse-mode dust aerosols on observed low SSAs. The observational data further indicated that the low SSAs during strong dust events were less likely due to the effect of only strong light-absorbing carbonaceous aerosols, such as black carbon (BC), indicating the association of aerosol size distribution on modulating SSA. Such observational results are justified by numerical calculations showing that aerosol size distribution can be the key factor on modulating SSA even without any change in relative amount of light-absorbing aerosol as well as total aerosol optical thickness. Therefore, the observed low SSAs in the downwind regions during dust events could be partially due to the dominance of coarse-mode aerosols over fine-mode aerosols, which are usual in dust events, along with the effect of mixed light-absorbing aerosols. The study further suggests that such effect of aerosol size distribution on SSA can be one of the important reasons for the low SSAs of dust aerosols in the source region as reported by some studies, if coarse-mode aerosols dominate fine-mode aerosols.

  19. Computationally efficient air quality forecasting tool: implementation of STOPS v1.5 model into CMAQ v5.0.2 for a prediction of Asian dust

    NASA Astrophysics Data System (ADS)

    Jeon, Wonbae; Choi, Yunsoo; Percell, Peter; Souri, Amir Hossein; Song, Chang-Keun; Kim, Soon-Tae; Kim, Jhoon

    2016-10-01

    This study suggests a new modeling framework using a hybrid Eulerian-Lagrangian-based modeling tool (the Screening Trajectory Ozone Prediction System, STOPS) for a prediction of an Asian dust event in Korea. The new version of STOPS (v1.5) has been implemented into the Community Multi-scale Air Quality (CMAQ) model version 5.0.2. The STOPS modeling system is a moving nest (Lagrangian approach) between the source and the receptor inside the host Eulerian CMAQ model. The proposed model generates simulation results that are relatively consistent with those of CMAQ but within a comparatively shorter computational time period. We find that standard CMAQ generally underestimates PM10 concentrations during the simulation period (February 2015) and fails to capture PM10 peaks during Asian dust events (22-24 February 2015). The underestimation in PM10 concentration is very likely due to missing dust emissions in CMAQ rather than incorrectly simulated meteorology, as the model meteorology agrees well with the observations. To improve the underestimated PM10 results from CMAQ, we used the STOPS model with constrained PM concentrations based on aerosol optical depth (AOD) data from the Geostationary Ocean Color Imager (GOCI), reflecting real-time initial and boundary conditions of dust particles near the Korean Peninsula. The simulated PM10 from the STOPS simulations were improved significantly and closely matched the surface observations. With additional verification of the capabilities of the methodology on emission estimations and more STOPS simulations for various time periods, the STOPS model could prove to be a useful tool not just for the predictions of Asian dust but also for other unexpected events such as wildfires and oil spills.

  20. Acute increase of children's conjunctivitis clinic visits by Asian dust storms exposure - a spatiotemporal study in Taipei, Taiwan.

    PubMed

    Chien, Lung-Chang; Lien, Yi-Jen; Yang, Chiang-Hsin; Yu, Hwa-Lung

    2014-01-01

    Adverse health impacts of Asian dust storms (ADS) have been widely investigated and discussed in respiratory disease, but no study has examined the association between ADS events and their impact on eye diseases, especially in children. The impact of ADS events on the incidence of children's conjunctivitis is examined by analyzing the data from children's clinic visits registered in the 41 districts of Taipei area in Taiwan during the period 2002-2007. The structural additive regression modeling approach was used to assess the association between ADS events and clinic visits for conjunctivitis in children with consideration of day-of-the-week effects, temperature, and air quality levels. This study identifies an acute increase in the relative rate for children's conjunctivitis clinic visits during ADS periods with 1.48% (95% CI = 0.79, 2.17) for preschool children (aged <6 years old) and 9.48% (95% CI = 9.03, 9.93) for schoolchildren (aged ≥6 years old), respectively. The relative rates during post-ADS periods were still statistically significant, but much lower than those during ADS periods. The spatial analysis presents geographic heterogeneity of children's conjunctivitis clinic visits where higher relative rates were more likely observed in the most populated districts Compared to previous ADS studies related to respiratory diseases, our results reveals significantly acute impacts on children's conjunctivitis during ADS periods, and much influence on schoolchildren. Vulnerable areas were also identified in high density population.

  1. Asian dust storm elevates children's respiratory health risks: a spatiotemporal analysis of children's clinic visits across Taipei (Taiwan).

    PubMed

    Yu, Hwa-Lung; Chien, Lung-Chang; Yang, Chiang-Hsing

    2012-01-01

    Concerns have been raised about the adverse impact of Asian dust storms (ADS) on human health; however, few studies have examined the effect of these events on children's health. Using databases from the Taiwan National Health Insurance and Taiwan Environmental Protection Agency, this study investigates the documented daily visits of children to respiratory clinics during and after ADS that occurred from 1997 to 2007 among 12 districts across Taipei City by applying a Bayesian structural additive regressive model controlled for spatial and temporal patterns. This study finds that the significantly impact of elevated children's respiratory clinic visits happened after ADS. Five of the seven lagged days had increasing percentages of relative rate, which was consecutively elevated from a 2-day to a 5-day lag by 0.63%∼2.19% for preschool children (i.e., 0∼6 years of age) and 0.72%∼3.17% for school children (i.e., 7∼14 years of age). The spatial pattern of clinic visits indicated that geographical heterogeneity was possibly associated with the clinic's location and accessibility. Moreover, day-of-week effects were elevated on Monday, Friday, and Saturday. We concluded that ADS may significantly increase the risks of respiratory diseases consecutively in the week after exposure, especially in school children. PMID:22848461

  2. Asian dust storm elevates children's respiratory health risks: a spatiotemporal analysis of children's clinic visits across Taipei (Taiwan).

    PubMed

    Yu, Hwa-Lung; Chien, Lung-Chang; Yang, Chiang-Hsing

    2012-01-01

    Concerns have been raised about the adverse impact of Asian dust storms (ADS) on human health; however, few studies have examined the effect of these events on children's health. Using databases from the Taiwan National Health Insurance and Taiwan Environmental Protection Agency, this study investigates the documented daily visits of children to respiratory clinics during and after ADS that occurred from 1997 to 2007 among 12 districts across Taipei City by applying a Bayesian structural additive regressive model controlled for spatial and temporal patterns. This study finds that the significantly impact of elevated children's respiratory clinic visits happened after ADS. Five of the seven lagged days had increasing percentages of relative rate, which was consecutively elevated from a 2-day to a 5-day lag by 0.63%∼2.19% for preschool children (i.e., 0∼6 years of age) and 0.72%∼3.17% for school children (i.e., 7∼14 years of age). The spatial pattern of clinic visits indicated that geographical heterogeneity was possibly associated with the clinic's location and accessibility. Moreover, day-of-week effects were elevated on Monday, Friday, and Saturday. We concluded that ADS may significantly increase the risks of respiratory diseases consecutively in the week after exposure, especially in school children.

  3. Impact of pollution on the optical properties of trans-Pacific East Asian dust from satellite and ground-based measurements

    NASA Astrophysics Data System (ADS)

    Yi, Bingqi; Yang, Ping; Baum, Bryan A.

    2014-05-01

    We investigate changes in the optical properties of a large dust plume originating from East Asian deserts during its transport over the northwestern Pacific Ocean in March 2013. The study makes use of observational products from two sensors in the NASA A-Train satellite constellation, the Moderate Resolution Imaging Spectroradiometer and the Cloud-Aerosol Lidar with Orthogonal Polarization. Forward trajectory clustering analysis and satellite observations show that dust initiating from the Taklimakan and Gobi deserts experienced thorough mixing with industrial pollution aerosols shortly after leaving the source region and were lofted by a strong midlatitude weather system to more than 4 km in height. The dust plume accompanied the weather system and reached the east coast of the North American continent within 7-10 days. The dust aerosols became spectrally absorptive during transport due to mixing with other aerosol types such as soot. Furthermore, a decrease in the depolarization ratio suggests that the complexities in aerosol particle morphologies were reduced during transport over the ocean. More than half of the dust aerosol layers surviving the trans-Pacific transport were polluted and exhibited different optical properties and radiative effects from those of pure dust.

  4. Asian Sand Dust Enhances the Inflammatory Response and Mucin Gene Expression in the Middle Ear

    PubMed Central

    Chang, Jiwon; Go, Yoon Young; Park, Moo Kyun; Chae, Sung-Won; Lee, Seon-Heui; Song, Jae-Jun

    2016-01-01

    Objectives. Asia sand dust (ASD) is known to cause various human diseases including respiratory infection. The aim of this study was to examine the effect of ASD on inflammatory response in human middle ear epithelial cells (HMEECs) in vitro and in vivo. Methods. Cell viability was assessed using the cell counting kit-8 assay. The mRNA levels of various genes including COX-2, TNF-a, MUC 5AC, MUC 5B, TP53, BAX, BCL-2, NOX4, and SOD1 were analyzed using semiquantitative realtime polymerase chain reaction. COX-2 protein levels were determined by western blot analysis. Sprague Dawley rats were used for in vivo investigations of inflammatory reactions in the middle ear epithelium as a result of ASD injection. Results. We observed dose-dependent decrease in HMEEC viability. ASD exposure significantly increased COX-2, TNF-a, MUC5AC, and MUC5B mRNA expression. Also, ASD affected the mRNA levels of apoptosis- and oxidative stress-related genes. Western blot analysis revealed a dose-dependent increase in COX-2 production. Animal studies also demonstrated an ASD-induced inflammatory response in the middle ear epithelium. Conclusion. Environmental ASD exposure can result in the development of otitis media. PMID:27095518

  5. Observation of the simultaneous transport of Asian mineral dust aerosols with anthropogenic pollutants using a POPC during a long-lasting dust event in late spring 2014

    NASA Astrophysics Data System (ADS)

    Pan, Xiaole; Uno, Itsushi; Hara, Yukari; Kuribayashi, Masatoshi; Kobayashi, Hiroshi; Sugimoto, Nobuo; Yamamoto, Shigekazu; Shimohara, Takaaki; Wang, Zifa

    2015-03-01

    We observed a long-lasting dust event from 25 May to 2 June 2014, using a polarization optical particle counter (POPC). The transport of dust plumes over East Asia was verified on the basis of observations of Moderate Resolution Imaging Spectroradiometer, a lidar network, and surface synoptic observation stations. Mixing of dust and anthropogenic pollutants was investigated according to the variation in the depolarization ratio as a function of particle size. The nonsphericity of dust particles varied due to the impact of anthropogenic pollutants on their pathway. In the coarse mode, dust particles always had a clear nonspherical configuration, although large amounts of nitrate were also present. Supermicron particles are occasionally present in a spherical configuration, possibly due to the complex mixing of natural dust and anthropogenic particles. Statistically, ~64% of the total nitrate mass was deemed to be transported from outside of Japan due to a trapping effect in the dust plume.

  6. Vertical mass impact and features of Saharan dust intrusions derived from ground-based remote sensing in synergy with airborne in-situ measurements

    NASA Astrophysics Data System (ADS)

    Córdoba-Jabonero, Carmen; Andrey-Andrés, Javier; Gómez, Laura; Adame, José Antonio; Sorribas, Mar; Navarro-Comas, Mónica; Puentedura, Olga; Cuevas, Emilio; Gil-Ojeda, Manuel

    2016-10-01

    A study of the vertical mass impact of Saharan dust intrusions is presented in this work. Simultaneous ground-based remote-sensing and airborne in-situ measurements performed during the AMISOC-TNF campaign over the Tenerife area (Canary Islands) in summertime from 01 July to 11 August 2013 were used for that purpose. A particular dusty (DD) case, associated to a progressively arriving dust intrusion lasting for two days on 31 July (weak incidence) and 01 August (strong incidence), is especially investigated. AERONET AOD and AEx values were ranging, respectively, from 0.2 to 1.4 and 0.35 to 0.05 along these two days. Vertical particle size distributions within fine and coarse modes (0.16-2.8 μm range) were obtained from aircraft aerosol spectrometer measurements. Extinction profiles and Lidar Ratio (LR) values were derived from MPLNET/Micro Pulse Lidar observations. MAXDOAS measurements were also used to retrieve the height-resolved aerosol extinction for evaluation purposes in comparison to Lidar-derived profiles. The synergy between Lidar observations and airborne measurements is established in terms of the Mass Extinction Efficiency (MEE) to calculate the vertical mass concentration of Saharan dust particles. Both the optical and microphysical profilings show dust particles mostly confined in a layer of 4.3 km thickness from 1.7 to 6 km height. LR ranged between 50 and 55 sr, typical values for Saharan dust particles. In addition, this 2-day dust event mostly affected the Free Troposphere (FT), being less intense in the Boundary Layer (BL). In particular, rather high Total Mass Concentrations (TMC) were found on the stronger DD day (01 August 2013): 124, 70 and 21 μg m-3 were estimated, respectively, at FT and BL altitudes and on the near-surface level. This dust impact was enhanced due to the increase of large particles affecting the FT, but also the BL, likely due to their gravitational settling. However, the use of an assumed averaged MEE value can be

  7. Observation of the April 2001 Asian Dust Event by Robotic Carbon Biomass Profiling Floats in the Subarctic North Pacific

    NASA Astrophysics Data System (ADS)

    Bishop, J. K.; Davis, R. E.

    2001-12-01

    processes and how the pump responds to day-to-day variations of physical forcing. Optical sensors for particulate organic carbon (a WETLabs transmissometer calibrated with MULVFS POC observations) and light scattering have been integrated onto the Sounding Oceanographic Lagrangian Observer (SOLO). Our first two carbon-SOLO observers were deployed April 10 2001 near ocean station PAPA (50N 145W) to explore the 0-1000 m variability of carbon biomass in the high nutrient low-chlorophyll (HNLC) waters of the subarctic north Pacific. Several days later, a cloud of asian dust passed overhead. During our first 150 days of observing each robot has recorded 200+ profiles of T, S, POC and light scattering. Biofouling effects have been small. This paper presents analysis of these first high-frequency observations of the biotic response to the April 2001 asian dust event and storms. We have 'burst' the envelope in a way that would make John proud.

  8. Analysis of Measurements of Saharan Dust by Airborne and Ground-based Remote Sensing Methods during the Puerto Rico Dust Experiment (PRIDE)

    NASA Technical Reports Server (NTRS)

    Reid, Jeffrey S.; Kinney, James E.; Westphal, Douglas L.; Holben, Brent N.; Welton, E. Judd; Tsay, Si-Chee; Eleuterio, Daniel P.; Campbell, James; Christopher, Sundar A.; Jonsson, Haflidi H.

    2003-01-01

    For 26 days in mid-June and July 2000, a research group comprised of U.S. Navy, NASA, and university scientists conducted the Puerto Rico Dust Experiment (PRIDE). In this paper we give a brief overview of mean meteorological conditions during the study. We focus on findings on African dust transported into the Caribbean utilizing Navajo aircraft and AERONET Sun photometer data. During the study midvisible aerosol optical thickness (AOT) in Puerto Rico averaged 0.25, with a maximum less than 0.5 and with clean marine periods of _0.08. Dust AOTs near the coast of Africa (Cape Verde Islands and Dakar) averaged _0.4, 30% less than previous years. By analyzing dust vertical profiles in addition to supplemental meteorology and MPLNET lidar data we found that dust transport cannot be easily categorized into any particular conceptual model. Toward the end of the study period, the vertical distribution of dust was similar to the commonly assumed Saharan Air Layer (SAL) transport. During the early periods of the study, dust had the highest concentrations in the marine and convective boundary layers with only a, weak dust layer in the SAL being present, a state usually associated with wintertime transport patterns. We corroborate the findings of Maring et al. that in most cases, there was an unexpected lack of vertical stratification of dust particle size. We systematically analyze processes which may impact dust vertical distribution and determine and speculate that dust vertical distribution predominately influenced by flow patterns over Africa and differential advection couple with mixing by easterly waves and regional subsidence.

  9. Enhancement of OVA-induced murine lung eosinophilia by co-exposure to contamination levels of LPS in Asian sand dust and heated dust

    PubMed Central

    2014-01-01

    Background A previous study has shown that the aggravation of Asian sand dust (ASD) on ovalbumin (OVA)-induced lung eosinphilia was more severe in lipopolysaccharide (LPS)-rich ASD than in SiO2-rich ASD. Therefore, the effects of different LPS contamination levels in ASD on the aggravation of OVA-induced lung eosinophilia were investigated in the present study. Methods Before beginning the in vivo experiment, we investigated whether the ultra-pure LPS would act only on TLR4 or not using bone marrow-derived macrophages (BMDMs) of wild–type, TLR2-/-, TLR4-/- and MyD88-/- BALB/c mice. ASD collected from the desert was heated to remove toxic organic substances (H-ASD). BALB/c mice were instilled intratracheally with 12 different testing samples prepared with LPS (1 ng and 10 ng), H-ASD, and OVA in a normal saline solution. The lung pathology, cytological profiles in the bronchoalveolar lavage fluid (BALF), the levels of inflammatory cytokines/chemokines in BALF and OVA-specific immunoglobulin in serum were investigated. Results The LPS exhibited no response to the production of TNF-α and IL-6 in BMDMs from TLR4-/-, but did from TLR2-/-. H-ASD aggravated the LPS-induced neutrophilic lung inflammation. In the presence of OVA, LPS increased the level of eosinophils slightly and induced trace levels of Th2 cytokines IL-5 and IL-13 at the levels of 1 ng and 10 ng. In the presence of OVA and H-ASD, LPS induced severe eosinophil infiltration and proliferation of goblet cells in the airways as well as remarkable increases in Th2 cytokines IL-5 and IL-13 in BALF. The mixture containing LPS (1 ng) showed adjuvant activity on OVA-specific IgE and IgG1 production. Conclusions The results suggest that H-ASD with naturally-occurring levels of LPS enhances OVA-induced lung eosinophilia via increases in Th2-mediated cytokines and antigen-specific immunoglobulin. These results indicate that LPS is a strong candidate for being a major aggravating substance in ASD. PMID:24982682

  10. Levoglucosan and Lipid Class Compounds in the Asian Dusts and Marine Aerosols Collected During the ACE-Asia Campaign

    NASA Astrophysics Data System (ADS)

    Kobayashi, M.; Simoneit, B. R.; Kawamura, K.; Mochida, M.; Lee, M.; Lee, G.; Huebert, B. J.

    2002-12-01

    In order to characterize organic aerosols in the Asian Pacific region, we collected filter samples at Gosan (formerly Kosan) and Sapporo sites as well as on mobile platforms (R.V. R.H. Brown and NCAR C-130) in the western North Pacific. The aerosol extracts were analyzed by capillary GC-MS employing a TMS derivatization technique. We identified over 100 organic compounds in the samples. They are categorized into seven different classes in terms of functional groups and sources. First, sugar-type compounds were detected in the aerosols, including levoglucosan, galactosan and mannosan, which are tracers for biomass burning. Second, a homologous series of fatty acids (C12-C30) and fatty alcohols (C12-C30) mainly from plant waxes and marine lipids were present. The third group includes dicarboxylic acids (>C3) and other atmospheric oxidation products. Although oxalic (C2) and malonic (C3) acids were not detected by this method, they are very abundant in the aerosols. The fourth group includes n-alkanes (C18-C35) which usually showed a strong odd/even predominance, suggesting an important contribution from higher plant waxes. The fifth includes polynuclear aromatic hydrocarbons (PAH) ranging from phenanthrene to coronene, all combustion products of petroleum and mainly coal. Saccharides were the sixth group and consisted mainly of a- and b- glucose, sucrose and its alditol, and minor amounts of xylitol, sorbitol and arabitol. These saccharides are tracers for soil dust. Phthalates were detected as the seventh class, with a dominance of dioctyl phthalate. The results suggest that organic aerosols originate primarily from (1) natural emissions of terrestrial plant wax and marine lipids, (2) smoke from biomass burning (mainly non-conifer fuels), (3) soil resuspension due to spring agricultural activity, (4) urban/industrial emissions from fossil fuel use (coal), and (5) secondary reaction products. These compounds are transported by the strong westerly winds and therefore

  11. Reprint of: Effects of Asian dust on daily cough occurrence in patients with chronic cough: A panel study

    NASA Astrophysics Data System (ADS)

    Higashi, Tomomi; Kambayashi, Yasuhiro; Ohkura, Noriyuki; Fujimura, Masaki; Nakai, Satoshi; Honda, Yasushi; Saijoh, Kiyofumi; Hayakawa, Kazuichi; Kobayashi, Fumihisa; Michigami, Yoshimasa; Olando, Anyenda Enoch; Hitomi, Yoshiaki; Nakamura, Hiroyuki

    2014-11-01

    Asian dust, known as kosa in Japanese, is a major public health concern. In this panel study, we evaluated the effects of exposure to kosa on daily cough occurrence. The study subjects were 86 patients being treated for asthma, cough variant asthma, or atopic cough in Kanazawa University Hospital from January 2011 to June 2011. Daily mean concentrations of kosa and spherical particles were obtained from light detection and ranging (LIDAR) measurements, and were categorized from Grade 1 (0 μg/m3) to 5 (over 100 μg/m3). The association between kosa and cough was analyzed by logistic regression with a generalized estimating equation. Kosa effects on cough were seen for all Grades with potential time lag effect. Particularly at Lag 0 (the day of exposure), a dose-response relationship was observed: the odds ratios for Grades 2, 3, 4, and 5 above the referent (Grade 1) were 1.111 (95% confidence interval (CI): 0.995-1.239), 1.171 (95% CI: 1.006-1.363), 1.357 (95% CI: 1.029-1.788), and 1.414 (95% CI: 0.983-2.036), respectively. Among the patients without asthma, the association was higher: the odds ratios for Grades 2, 3, 4 and 5 were 1.223 (95% CI: 0.999-1.497), 1.309 (95% CI: 0.987-1.737), 1.738 (95% CI: 1.029-2.935) and 2.403 (95% CI: 1.158-4.985), respectively. These associations remained after adjusting for the concentration of spherical particles or particulate matter with an aerodynamic diameter of less than 2.5 μm (PM2.5). Our findings demonstrate that kosa is an environmental factor which induces cough in a dose-response relationship.

  12. Asian Dust and Pediatric Emergency Department Visits Due to Bronchial Asthma and Respiratory Diseases in Nagasaki, Japan

    PubMed Central

    Nakamura, Takahiro; Hashizume, Masahiro; Ueda, Kayo; Shimizu, Atsushi; Takeuchi, Ayano; Kubo, Tatsuhiko; Hashimoto, Kunio; Moriuchi, Hiroyuki; Odajima, Hiroshi; Kitajima, Tasuku; Tashiro, Kasumi; Tomimasu, Kunio; Nishiwaki, Yuji

    2016-01-01

    Background The adverse health effects of Asian dust (AD) on the respiratory system of children are unclear. We hypothesized that AD events may lead to increased visits by children to emergency medical centers due to bronchial asthma and respiratory diseases, including bronchial asthma. Methods We used anonymized data on children receiving primary emergency treatment at Nagasaki Municipal Primary Emergency Medical Center, Japan between March 2010 and September 2013. We used Light Detection and Ranging (LIDAR) data to assess AD exposure and performed time-stratified case-crossover analyses to examine the association between AD exposure and emergency department visits. The main analysis was done with data collected from March through May each year. Results The total number of emergency department visits during the study period was 756 for bronchial asthma and 5421 for respiratory diseases, and the number of “AD days” was 47. In school children, AD events at lag day 3 and lag day 4 were associated with increased emergency department visits due to bronchial asthma, with odds ratios of 1.837 (95% confidence interval [CI], 1.212–2.786) and 1.829 (95% CI, 1.179–2.806), respectively. AD events were significantly associated with respiratory diseases among preschool children at lag day 0, lag day 1, and lag day 2, with odds ratios of 1.244 (95% CI, 1.128–1.373), 1.314 (95% CI, 1.189–1.452), and 1.273 (95% CI, 1.152–1.408), respectively. These associations were also significant when the results were adjusted for meteorological variables and other air pollutants. Conclusions The study findings suggested that AD exposure increases emergency department visits by children. PMID:27180931

  13. Airborne manganese as dust vs. fume determining blood levels in workers at a manganese alloy production plant.

    PubMed

    Park, Robert M; Baldwin, Mary; Bouchard, Maryse F; Mergler, Donna

    2014-12-01

    The appropriate exposure metrics for characterizing manganese (Mn) exposure associated with neurobehavioral effects have not been established. Blood levels of Mn (B-Mn) provide a potentially important intermediate marker of Mn airborne exposures. Using data from a study of a population of silicon- and ferro-manganese alloy production workers employed between 1973 and 1991, B-Mn levels were modeled in relation to prior Mn exposure using detailed work histories and estimated respirable Mn concentrations from air-sampling records. Despite wide variation in exposure levels estimated for individual jobs, duration of employment (exposure) was itself a strong predictor of B-Mn levels and strongest when an 80-day half-life was applied to contributions over time (t=6.95, 7.44, respectively; p<10(-5)). Partitioning exposure concentrations based on process origin into two categories: (1) "large" respirable particulate (Mn-LRP) derived mainly from mechanically generated dust, and (2) "small" respirable particulate (Mn-SRP) primarily electric furnace condensation fume, revealed that B-Mn levels largely track the small, fume exposures. With a half-life of 65 days applied in a model with cumulative exposure terms for both Mn-LRP (t=-0.16, p=0.87) and Mn-SRP (t=6.45, p<10(-5)), the contribution of the large-size fraction contribution was negligible. Constructing metrics based on the square root of SRP exposure concentrations produced a better model fit (t=7.87 vs. 7.44, R(2)=0.2333 vs. 0.2157). In a model containing both duration (t=0.79, p=0.43) and (square root) fume (t=2.47, p=0.01) metrics, the duration term was a weak contributor. Furnace-derived, small respirable Mn particulate appears to be the primary contributor to B-Mn levels, with a dose-rate dependence in a population chronically exposed to Mn, with air-concentrations declining in recent years. These observations may reflect the presence of homeostatic control of Mn levels in the blood and other body tissues and be

  14. Fingerprints in the Dust

    NASA Technical Reports Server (NTRS)

    2001-01-01

    These MISR nadir-camera images of eastern China compare a somewhat hazy summer view from July 9, 2000 (left) with a spectacularly dusty spring view from April 7, 2001 (middle). The left-hand and middle images are from Terra orbits 2967 and 6928, respectively, and extend from central Manchuria near the top to portions of North and South Korea at the bottom. They are approximately 380 kilometers in width.

    Asia's desert areas are prone to soil erosion, as underground water tables are lowered by prolonged drought and by industrial and agricultural water use. Heavy winds blowing eastward across the arid and sparsely vegetated surfaces of Mongolia and western China pick up large quantities of yellow dust. Airborne dust clouds from the April 2001 storm blew across the Pacific Ocean and were carried as far as North America. The minerals transported in this manner are believed to provide nutrients for both oceanic and land ecosystems.

    According to the Xinhua News Agency in China, nearly one million tons of Gobi Desert dust blow into Beijing each year. During a similar dust outbreak last year, the Associated Press reported that the visibility in Beijing had been reduced the point where buildings were barely visible across city streets, and airline schedules were significantly disrupted. The dust has also been implicated in adverse health effects such as respiratory discomfort and eye irritation.

    The image on the right is a higher resolution MISR nadir-camera view of a portion of the April 7, 2001 dust cloud. It covers an area roughly 250 kilometers wide by 470 kilometers high. When viewed at full magnification, a number of atmospheric wave features, like the ridges and valleys of a fingerprint, are apparent. These are probably induced by surface topography, which can disturb the wind flow. A few small cumulus clouds are also visible, and are casting shadows on the thick lower dust layer.

    Analyses of images such as these constitute one phase of MISR

  15. Investigation of the chemical mixing state of individual Asian dust particles by the combined use of electron probe X-ray microanalysis and Raman microspectrometry.

    PubMed

    Sobanska, Sophie; Hwang, HeeJin; Choël, Marie; Jung, Hae-Jin; Eom, Hyo-Jin; Kim, HyeKeong; Barbillat, Jacques; Ro, Chul-Un

    2012-04-01

    In this work, quantitative electron probe X-ray microanalysis (EPMA) and Raman microspectrometry (RMS) were applied in combination for the first time to characterize the complex internal structure and physicochemical properties of the same ensemble of Asian dust particles. The analytical methodology to obtain the chemical composition, mixing state, and spatial distribution of chemical species within single particles through the combined use of the two techniques is described. Asian dust aerosol particles collected in Incheon, Korea, during a moderate dust storm event were examined to assess the applicability of the methodology to resolve internal mixtures within single particles. Among 92 individual analyzed particles, EPMA and RMS identified 53% of the particles to be internally mixed with two or more chemical species. Information on the spatial distribution of chemical compounds within internally mixed individual particles can be useful for deciphering the particle aging mechanisms and sources. This study demonstrates that the characterization of individual particles, including chemical speciation and mixing state analysis, can be performed more in detail using EPMA and RMS in combination than with the two single-particle techniques alone. PMID:22380789

  16. China Dust

    Atmospheric Science Data Center

    2013-04-16

    ... SpectroRadiometer (MISR) nadir-camera images of eastern China compare a somewhat hazy summer view from July 9, 2000 (left) with a ... arid and sparsely vegetated surfaces of Mongolia and western China pick up large quantities of yellow dust. Airborne dust clouds from the ...

  17. Stable carbon and nitrogen isotopic compositions of ambient aerosols collected from Okinawa Island in the western North Pacific Rim, an outflow region of Asian dusts and pollutants

    NASA Astrophysics Data System (ADS)

    Kunwar, Bhagawati; Kawamura, Kimitaka; Zhu, Chunmao

    2016-04-01

    Stable carbon (δ13C) and nitrogen (δ15N) isotope ratios were measured for total carbon (TC) and nitrogen (TN), respectively, in aerosol (TSP) samples collected at Cape Hedo, Okinawa, an outflow region of Asian pollutants, during 2009-2010. The averaged δ13C and δ15N ratios are -22.2‰ and +12.5‰, respectively. The δ13C values are similar in both spring (-22.5‰) and winter (-22.5‰), suggesting the similar sources and/or source regions. We found that δ13C from Okinawa aerosols are ca. 2‰ higher than those reported from Chinese megacities probably due to photochemical aging of organic aerosols. A strong correlation (r = 0.81) was found between nss-Ca and TSP, suggesting that springtime aerosols are influenced from Asian dusts. However, carbonates in the Asian dusts were titrated with acidic species such as sulfuric acid and oxalic acid during atmospheric transport although two samples suggested the presence of remaining carbonate. No correlations were found between δ13C and tracer compounds (levoglucosan, elemental carbon, oxalic acid, and Na+). During winter and spring, coal burning is significant source in China. Based on isotopic mass balance, contribution of coal burning origin particles to total aerosol carbon was estimated as ca. 97% in winter, which is probably associated with the high emissions in China. Contribution of NO3- to TN was on average 45% whereas that of NH4+ was 18%. These results suggest that vehicular exhaust is an important source of TN in Okinawa aerosols. Concentration of water-soluble organic nitrogen (WSON) is higher in summer, suggesting that WSON is more emitted from the ocean in warmer season whereas inorganic nitrogen is more emitted in winter and spring from pollution sources in the Asian continent.

  18. A trans-Pacific Asian dust episode and its impacts to air quality in the east coast of U.S.

    NASA Astrophysics Data System (ADS)

    Wu, Yonghua; Han, Zaw; Nazmi, Chowdhury; Gross, Barry; Moshary, Fred

    2015-04-01

    The transport of an intense trans-Pacific Asian dust episode to the Northeast United States (U.S.) is studied using a synergistic suite of observations and models including a ground-based lidar, AERONET-sunphotometer, satellite measurements and global aerosol transport model for New York City (40.821°N, 73.949°W). During the dust intrusion on March 17-19, 2010, the multi-wavelength lidar observations indicate dense dust plumes (∼80% of total column AOD) located between 3 and 9 km altitudes with the lower layer mixing toward the planetary boundary layer (PBL). The column AOD shows a significant increase from 0.08 to 0.38 at 532-nm while the Angstrom exponent indicates a decrease from 1.3 to 0.7. The linear particle depolarization ratio is estimated to be 0.1-0.15 and the single-scattering-albedo shows the dust-like spectral dependence with the value of 0.9-0.95 at 440-nm. The NOAA-NCEP reanalysis and HYSPLIT model indicate that this long-range transport is driven by the strong western jets and travels for 6 days to arrive the U.S. east coast versus the western and northern U.S. Both the NAAPS aerosol transport model and satellite CALIPSO observations for multiple orbits clearly illustrate the dust-dominated aerosol along the transport path. In addition, coincident increase of both particulate matter (PM) and fine soil concentrations indicate the potential impact of transported dust on the air quality that is found to be associated with a large area of sinking air along the U.S. east coast.

  19. Numerical Modeling of 1997-2006 Asian Dust and Mass Budget Analysis in East Asia and West Pacific

    NASA Astrophysics Data System (ADS)

    Liu, M.; Westphal, D. L.

    2006-12-01

    East Asia has two of the Earth's major natural dust sources: the Taklamakan Desert in west China and the Gobi Desert in Mongolia and northwest China. Desertification has increased dust-erodible areas surrounding the deserts so the dust storm frequency has increased in the last few decades. Severe dust storms not only impact East Asia, but also can reach far beyond the continent, as did the dust clouds of April 1998, 2001 and 2005 that drifted over the Pacific Ocean and to North America. The US Navy's operational Coupled Ocean/Atmospheric Mesoscale Prediction System (COAMPS) is used to simulate the dust events for the springs of 1997 through 2006 at a resolution of one quarter of degree with multiple size bins. We use the modeled data to investigate the spatial and temporal dependence of dust emission, transport and deposition, and estimate the impacts of dust on environment. The distribution of dust plumes in area coverage and vertical depth is studied, as is the inter-annual variation of dust patterns from the different deserts of China and Mongolia, and the fluxes across the Pacific. It is found that PM10 is the dominant fraction particles over the continent and near the ocean, while PM2.5 becomes dominant in the boundary outflow along 170E. The details of analyzed model results will be presented at the meeting.

  20. The influence of Asian dust outflow on particle microphysical and optical properties at Mt. Tai in central east China

    NASA Astrophysics Data System (ADS)

    Shen, X. J.; Sun, J. Y.; Zhang, Y. M.; Zhang, X. Y.; Wang, T. T.; Wang, Y. Q.; Zhang, L.; Fan, R. X.; Zhao, Y.; Wang, D. Z.

    2016-10-01

    An in-situ measurement of the particle number size distribution and optical properties (scattering and absorption coefficients) of PM2.5 was conducted at Mt. Tai, a mountain top station in central east China in the spring of 2011. It was found that the particle size distribution, mass concentration, as well as the optical properties have been modified during the dust periods. The mean mass concentration of PM2.5 during the dust periods was nearly twice of that during the non-dust period. The number and volume size distribution showed a higher concentration in the size range of 0.5-2.5 μm during the dust period, which were identified as dust particles. The absorption coefficient increased by ∼40%, while the scattering coefficient did not show much difference. The single scattering albedo of 0.85 during dust period was also comparable with the value of 0.89 during non-dust period. The Mie model was applied to simulate the aerosol optical properties and validated through a closure study for an intensive dust event. This study quantitatively demonstrated that dust particles contributed to nearly 63% of the scattering coefficient, while the remainder was mainly due to anthropogenic particles on dust days. The dust particles took a lower portion to the absorption, about 40%, indicating the anthropogenic particles still played a more dominant role in absorbing. This study also indicated that although there were only a few tens of dust particles during dust period, they could influence in particle optical properties significantly.

  1. Aging of mineral dust during transport from the Sahara into the Cape Verde area - results from airborne measurements during SAMUM

    NASA Astrophysics Data System (ADS)

    Weinzierl, B.; Sauer, D.; Esselborn, M.; Petzold, A.; Veira, A.; Rose, M.; Mund, S.; Wirth, M.; Ansmann, A.; Tesche, M.; Groß, S.; Freudenthaler, V.

    2012-04-01

    The Saharan Mineral Dust Experiment (SAMUM) was conducted to better understand the properties of fresh and aged mineral dust. Within SAMUM, two field missions were performed: SAMUM-1 (summer 2006, Morocco) focused on the chemical, microphysical, optical and radiative properties of fresh dust aerosol in the vertical column over the Sahara, while SAMUM-2 (winter 2008, Cape Verde) concentrated on the properties of aged dust and the mixing of mineral dust with biomass burning aerosol. During both field experiments, the DLR Falcon research aircraft was equipped with an extensive set of aerosol instruments for size, volatility, and absorption measurements, impactor sampling for chemical analyses and with a nadir-looking High Spectral Resolution Lidar (HSRL). In the Cape Verde area, we found a complex stratification with dust covering the altitude range below 2 km and tropical biomass burning layers aloft. We show that the aerosol type of individual aerosol layers can be classified based on depolarization and lidar ratios and, in addition, on in situ measured Ångström exponents of absorption åap. The dust layers had a geometrical depth of 1.3 ± 0.4 km and showed a median åap of 3.95. The median effective diameter Deff was 2.5 μm and the dust layers over Cape Verde yielded clear signals of aging: large particles were depleted due to gravitational settling and the accumulation mode diameter was shifted towards larger sizes as a result of coagulation. The tropical biomass layers had a depth of 2.0 ± 1.1 km and were characterized by a median åap of 1.34. They always contained a certain amount of large dust particles and showed a median Deff of 1.1 μm and a fine mode Deff,fine of 0.33. The dust and biomass burning layers had a median aerosol optical depth (AOD) of 0.23 and 0.09, respectively. The median contributions of the dust and biomass burning layers to the AOD of the total atmospheric column below 10 km were 75 and 37%, respectively. We present the properties of

  2. Ice clouds and Asian dust studied with lidar measurements of particle extinction-to-backscatter ratio, particle depolarization, and water-vapor mixing ratio over Tsukuba.

    PubMed

    Sakai, Tetsu; Nagai, Tomohiro; Nakazato, Masahisa; Mano, Yuzo; Matsumura, Takatsugu

    2003-12-20

    The tropospheric particle extinction-to-backscatter ratio, the depolarization ratio, and the water-vapor mixing ratio were measured by use of a Raman lidar and a polarization lidar during the Asian dust seasons in 2001 and 2002 in Tsukuba, Japan. The apparent (not corrected for multiple-scattering effects) extinction-to-backscatter ratios (Sp) showed a dependence on the relative humidity with respect to ice (RHice) obtained from the lidar-derived water-vapor mixing ratio and radiosonde-derived temperature; they were mostly higher than 30 sr in dry air (RHice < 50%), whereas they were mostly lower than 30 sr in ice-supersaturated air (RHice > or = 100%), where the apparent extinction coefficients were larger than 0.036 km(-1). Both regions showed mean particle depolarization ratios of 20%-22%. Comparisons with theoretical calculations and the previous experiments suggest that the observed dependence of Sp on RHice is attributed to the difference in the predominant particles: nonspherical aerosols (mainly the Asian dust) in dry air and cloud particles in ice-supersaturated air. PMID:14717284

  3. Ice clouds and Asian dust studied with lidar measurements of particle extinction-to-backscatter ratio, particle depolarization, and water-vapor mixing ratio over Tsukuba.

    PubMed

    Sakai, Tetsu; Nagai, Tomohiro; Nakazato, Masahisa; Mano, Yuzo; Matsumura, Takatsugu

    2003-12-20

    The tropospheric particle extinction-to-backscatter ratio, the depolarization ratio, and the water-vapor mixing ratio were measured by use of a Raman lidar and a polarization lidar during the Asian dust seasons in 2001 and 2002 in Tsukuba, Japan. The apparent (not corrected for multiple-scattering effects) extinction-to-backscatter ratios (Sp) showed a dependence on the relative humidity with respect to ice (RHice) obtained from the lidar-derived water-vapor mixing ratio and radiosonde-derived temperature; they were mostly higher than 30 sr in dry air (RHice < 50%), whereas they were mostly lower than 30 sr in ice-supersaturated air (RHice > or = 100%), where the apparent extinction coefficients were larger than 0.036 km(-1). Both regions showed mean particle depolarization ratios of 20%-22%. Comparisons with theoretical calculations and the previous experiments suggest that the observed dependence of Sp on RHice is attributed to the difference in the predominant particles: nonspherical aerosols (mainly the Asian dust) in dry air and cloud particles in ice-supersaturated air.

  4. Improved provenance tracing of Asian dust sources using rare earth elements and selected trace elements for palaeomonsoon studies on the eastern Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Ferrat, Marion; Weiss, Dominik J.; Strekopytov, Stanislav; Dong, Shuofei; Chen, Hongyun; Najorka, Jens; Sun, Youbin; Gupta, Sanjeev; Tada, Ryuji; Sinha, Rajiv

    2011-11-01

    The Asian Monsoon forms an important part of the earth's climate system, yet our understanding of the past interactions between its different sub-systems, the East Asian and Indian monsoons, and between monsoonal winds and other prevailing wind currents such as the Westerly jet, is limited, particularly in central Asia. This in turn affects our ability to develop climate models capable of accurately predicting future changes in atmospheric circulation patterns and monsoon intensities in Asia. Provenance studies of mineral dust deposited in terrestrial settings such as peat bogs can address this problem directly, by offering the possibility to examine past deposition rates and wind direction, and hence reconstruct past atmospheric circulation patterns. However, such studies are challenged by several issues, most importantly the identification of proxies that unambiguously distinguish between the different potential dust sources and that are independent of particle size. In addition, a single analytical method that is suitable for sample preparation of both dust source (i.e. desert sand, soil) and receptor (i.e. dust archive such as peat or soil profiles) material is desirable in order to minimize error propagation derived from the experimental and analytical work. Here, an improved geochemical framework of provenance tracers to study atmospheric circulation patterns and palaeomonsoon variability in central Asia is provided, by combining for the first time mineralogical as well as major and trace elemental (Sc, Y, Th and the rare earth elements) information on Chinese (central Chinese loess plateau, northern Qaidam basin and Taklamakan, Badain Juran and Tengger deserts), Indian (Thar desert) and Tibetan (eastern Qinghai-Tibetan Plateau) dust sources. Quartz, feldspars and clay minerals are the major constituents of all studied sources, with highly variable calcite contents reflected in the CaO concentrations. Chinese and Tibetan dust sources are enriched in middle

  5. Field Observation of Heterogeneous Formation of Dicarboxylic acids, Keto-carboxylic acids, α-Dicarbonyls and Nitrate in Xi'an, China during Asian dust storm periods

    NASA Astrophysics Data System (ADS)

    Wang, G.; Wang, J.; Ren, Y.; Li, J.

    2015-12-01

    To understand the formation mechanism of secondary organic aerosols (SOA) on dust surfaces, this study investigated the concentrations and compositions of dicarboxylic acids (C2-C11), keto-carboxylic acids (C3-C7), α-dicarbonyls and inorganic ions in size-segregated aerosols (9-stages) collected in Xi'an, China during the nondust storm and dust storm periods of 2009 and 2011. During the events the ambient particulate dicarboxylic acids were 932-2240 ng m-3, which are comparable and even higher than those in nondust periods. Molecular compositions of the above SOA are similar to those in nondust periods with oxalic acid being the leading species. In the presence of the dust storms, all the above mentioned SOA species in Xi'an were predominantly enriched on the coarse particles (>2.1μm), and oxalic acid well correlated with NO3- (R2=0.72, p<0.001) rather than SO42-.This phenomenon differs greatly from the SOA in any other nondust period that is characterized by an enrichment of oxalic acid in fine particles and a strong correlation of oxalic acid with SO42-. Our results further demonstrate that NO3- in the dust periods in Xi'an was mostly derived from secondary oxidation, whereas SO42- during the events was largely derived from surface soil of Gobi deserts. We propose a formation pathway to explain these observations, in which nitric acid and/or nitrogen oxides react with dust to produce Ca(NO3)2 and form a liquid phase on the surface of dust aerosols via water vapor-absorption of Ca(NO3)2, followed by a partitioning of the gas-phase water-soluble organic precursors (e.g.,glyoxal and methylglyoxal) into the aqueous-phase and a subsequent oxidation into oxalic acid. To the best of our knowledge, we found for the first time the enrichment of glyoxal and methylglyoxal on dust surface. Our data suggest an important role of nitrate in the heterogeneous formation process of SOA on the surface of Asian dust.

  6. Airborne spectrophotometry of SN 1987A from 1.7 to 12.6 microns - Time history of the dust continuum and line emission

    NASA Technical Reports Server (NTRS)

    Wooden, Diane H.; Rank, David M.; Bregman, Jesse D.; Witteborn, Fred C.; Tielens, A. G. G. M.; Cohen, Martin; Pinto, Philip A.; Axelrod, Timothy S.

    1993-01-01

    Spectrophotometric observations of SN 1987A from the Kuiper Airborne Observatory are presented for five epochs at 60, 260, 415, 615, and 775 days after the explosion. The low-resolution (lambda/Delta lambda = 50-100) spectra of SN 1987A are combined with data from other wavelengths to model the continuum, subtract the continuum from the spectra to determine line strengths and reveal molecular bands, separate the atomic continuum radiation from the dust continuum, and derive constraints on the grain temperatures and optical depths. A scenario for the evolution of SN 1987A and that of the ejecta from which it arises is obtained on the basis of the analysis of the continuum emission.

  7. Elevated Airborne Exposures of Teenagers to Manganese, Chromium, and Iron from Steel Dust and New York City’s Subway System

    PubMed Central

    CHILLRUD, STEVEN N.; EPSTEIN, DAVID; ROSS, JAMES M.; SAX, SONJA N.; PEDERSON, DEE; SPENGLER, JOHN D.; KINNEY, PATRICK L.

    2011-01-01

    There is increasing interest in potential health effects of airborne exposures to hazardous air pollutants at relatively low levels. This study focuses on sources, levels, and exposure pathways of manganese, chromium, and iron among inner-city high school students in New York City (NYC) and the contribution of subways. Samples of fine particulate matter (PM2.5) were collected during winter and summer over 48 h periods in a variety of settings including inside homes, outdoors, and personal samples (i.e., sampling packs carried by subjects). PM2.5 samples were also collected in the NYC subway system. For NYC, personal samples had significantly higher concentrations of iron, manganese, and chromium than did home indoor and ambient samples. The ratios and strong correlations between pairs of elements suggested steel dust as the source of these metals for a large subset of the personal samples. Time–activity data suggested NYC subways as a likely source of these elevated personal metals. In duplicate PM2.5 samples that integrated 8 h of underground subway exposure, iron, manganese, and chromium levels (>2 orders of magnitude above ambient levels) and their ratios were consistent with the elevated personal exposures. Steel dust in the NYC subway system was the dominant source of airborne exposures to iron, manganese, and chromium for many young people enrolled in this study, with the same results expected for other NYC subway riders who do not have occupational exposures to these metals. However, there are currently no known health effects at the exposure levels observed in this study. PMID:14968857

  8. Pool of dust particles over the Asian continent: balloon-borne optical particle counter and ground-based lidar measurements at Dunhuang, China.

    PubMed

    Iwasaka, Y; Shi, G Y; Kim, Y S; Matsuki, A; Trochkine, D; Zhang, D; Yamada, M; Nagatani, T; Nagatani, M; Shen, Z; Shibata, T; Nakata, H

    2004-03-01

    Measurements of aerosols were made in 2001 and 2002 at Dunhuang (40 degrees 00'N, 94 degrees 30'E), China to understand the nature of atmospheric particles over the desert areas in the Asian continent. Balloon-borne measurements with an optical particle counter suggested that particle size and concentration had noticeable peaks in super micron size range not only in the boundary mixing layer but also in the free troposphere. Super-micron particle concentration largely decreased in the mid tropopause (from 5 to 10 km; above sea level, a.s.l.). Lidar measurements made during August 2002 at Dunhuang suggested the possibility that mixing of dust particles occurred from near the ground to about 6 km even under calm weather conditions, and a large depolarization ratio of particulate matter was found in the aerosol layer. The top of the aerosol layer was found at heights of nearly 6 km (a.s.l.). It is strongly suggested that nonspherical dust particles (Kosa particles) frequently diffused in the free atmosphere over the Taklamakan desert through small-scale turbulences and are possible sources of dust particles of weak Kosa events that have been identified in the free troposphere not only in spring but also in summer over Japanese archipelago. Electron microscopic experiments of the particles collected in the free troposphere confirmed that coarse and nonspherical particles observed by the mineral particle were major components of coarse mode (diameter larger than 1 microm) below about 5 km over Dunhuang, China.

  9. Evolution of particulate sulfate and nitrate along the Asian dust pathway: Secondary transformation and primary pollutants via long-range transport

    NASA Astrophysics Data System (ADS)

    Wang, Qiongzhen; Zhuang, Guoshun; Huang, Kan; Liu, Tingna; Lin, Yanfen; Deng, Congrui; Fu, Qingyan; Fu, Joshua S.; Chen, Jiakuan; Zhang, Wenjie; Yiming, Mijiti

    2016-03-01

    Both PM2.5 and TSP over Yulin, a rural site near the Asian dust source region, were collected from 2007 to 2009. Characteristics, sources, and formation mechanisms of sulfate and nitrate were investigated. SO42 - displayed a distinct seasonal variation with the highest average concentration observed in summer when SO42 - accounted for an average of 14.1% and 13.7% of the PM2.5 and PMcoarse mass concentrations, respectively. Ambient temperature and relative humidity were two important factors influencing the formation processes of SO42 - and NO3-. In summer, the high concentrations of SO42 - in PM2.5 were probably from the gas phase oxidation of SO2, while the low concentrations of NO3- in PM2.5 were attributed to the high temperature that was not favorable for the formation of NH4NO3. In spring, autumn, and winter, SO42 - and NO3- were significantly enhanced in those days with high relative humidity, implying that in-cloud/aqueous processing dominated the formations of SO42 - and NO3-. Different from PM2.5 in which NH4+ acted as the dominant neutralizer for acids, alkaline species such as Ca2 + and Mg2 + played an important role in the formation of sulfate and nitrate salts in coarse particles throughout the whole year. During the dust event days, SO42 - in coarse particles significantly increased, while black carbon and NO3- largely decreased, suggesting that the primary mineral dust could be one of the major sources of SO42 -. By comparing the mass ratio of SO42 -/3/S in the dust aerosols of Yulin with different dust source regions (i.e., Taklimakan Desert and Gobi Desert) and the application of air mass backward trajectory analysis, it was found the long-range transported dust from the Taklimakan Desert, which was rich in primary sulfate due to its paleo-ocean characteristics, was a non-negligible source of SO42 - over Yulin. In spring and winter, the prevailing northerlies and northwesterlies promoted chemical interaction between alkaline mineral dust and acid

  10. Column Closure Studies of Lower Tropospheric Aerosol and Water Vapor During ACE-Asia Using Airborne Sunphotometer, Airborne In-Situ and Ship-Based Lidar Measurements

    NASA Technical Reports Server (NTRS)

    Schmid, B.; Hegg, A.; Wang, J.; Bates, D.; Redemann, J.; Russells, P. B.; Livingston, J. M.; Jonsson, H. H.; Welton, E. J.; Seinfield, J. H.

    2003-01-01

    We assess the consistency (closure) between solar beam attenuation by aerosols and water vapor measured by airborne sunphotometry and derived from airborne in-situ, and ship-based lidar measurements during the April 2001 Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia). The airborne data presented here were obtained aboard the Twin Otter aircraft. Comparing aerosol extinction o(550 nm) from four different techniques shows good agreement for the vertical distribution of aerosol layers. However, the level of agreement in absolute magnitude of the derived aerosol extinction varied among the aerosol layers sampled. The sigma(550 nm) computed from airborne in-situ size distribution and composition measurements shows good agreement with airborne sunphotometry in the marine boundary layer but is considerably lower in layers dominated by dust if the particles are assumed to be spherical. The sigma(550 nm) from airborne in-situ scattering and absorption measurements are about approx. 13% lower than those obtained from airborne sunphotometry during 14 vertical profiles. Combining lidar and the airborne sunphotometer measurements reveals the prevalence of dust layers at altitudes up to 10 km with layer aerosol optical depth (from 3.5 to 10 km altitude) of approx. 0.1 to 0.2 (500 nm) and extinction-to-backscatter ratios of 59-71 sr (523 nm). The airborne sunphotometer aboard the Twin Otter reveals a relatively dry atmosphere during ACE- Asia with all water vapor columns less than 1.5 cm and water vapor densities w less than 12 g/cu m. Comparing layer water vapor amounts and w from the airborne sunphotometer to the same quantities measured with aircraft in-situ sensors leads to a high correlation (r(sup 3)=0.96) but the sunphotometer tends to underestimate w by 7%.

  11. Airborne Sunphotometer Measurements of Aerosol Optical Depth and Columnar Water Vapor During the Puerto Rico Dust Experiment, and Comparison with Land, Aircraft, and Satellite Measurements

    NASA Technical Reports Server (NTRS)

    Livingston, John M.; Russell, Philip B.; Reid, Jeffrey; Redemann, Jens; Schmid, Beat; Allen, Duane A.; Torres, Omar; Levy, Robert C.; Remer, Lorraine A.; Holben, Brent N.; Hipskind, R. Stephen (Technical Monitor)

    2002-01-01

    Analyses of aerosol optical depth (AOD) and columnar water vapor (CWV) measurements obtained with the six-channel NASA Ames Airborne Tracking Sunphotometer (AATS-6) mounted on a twin-engine aircraft during the summer 2000 Puerto Rico Dust Experiment are presented. In general, aerosol extinction values calculated from AATS-6 AOD measurements acquired during aircraft profiles up to 5 km ASL reproduce the vertical structure measured by coincident aircraft in-situ measurements of total aerosol number and surface area concentration. Calculations show that the spectral dependence of AOD was small (mean Angstrom wavelength exponents of approximately 0.20) within three atmospheric layers defined as the total column beneath the top of each aircraft profile, the region beneath the trade wind inversion, and the region within the Saharan Air Layer (SAL) above the trade inversion. This spectral behavior is consistent with attenuation of incoming solar radiation by large dust particles or by dust plus sea salt. Values of CWV calculated from profile measurements by AATS-6 at 941.9 nm and from aircraft in-situ measurements by a chilled mirror dewpoint hygrometer agree to within approximately 4% (0.13 g/sq cm). AATS-6 AOD values measured on the ground at Roosevelt Roads Naval Air Station and during low altitude aircraft runs over the adjacent Cabras Island aerosol/radiation ground site agree to within 0.004 to 0.030 with coincident data obtained with an AERONET Sun/sky Cimel radiometer located at Cabras Island. For the same observation times, AERONET retrievals of CWV exceed AATS-6 values by a mean of 0.74 g/sq cm (approximately 21 %) for the 2.9-3.9 g/sq cm measured by AATS-6. Comparison of AATS-6 aerosol extinction values obtained during four aircraft ascents over Cabras Island with corresponding values calculated from coincident aerosol backscatter measurements by a ground-based micro-pulse lidar (MPL-Net) located at Cabras yields a similar vertical structure above the trade

  12. Levels and risk assessment for humans and ecosystems of platinum-group elements in the airborne particles and road dust of some European cities.

    PubMed

    Gómez, B; Palacios, M A; Gómez, M; Sanchez, J L; Morrison, G; Rauch, S; McLeod, C; Ma, R; Caroli, S; Alimonti, A; Petrucci, E; Bocca, B; Schramel, P; Zischka, M; Petterson, C; Wass, U

    2002-11-01

    Traffic is the main source of platinum-group element (PGE) contamination in populated urban areas. There is increasing concern about the hazardous effects of these new pollutants for people and for other living organisms in these areas. Airborne and road dusts, as well as tree bark and grass samples were collected at locations in the European cities of Göteborg (Sweden), Madrid (Spain), Rome (Italy), Munich (Germany), Sheffield and London (UK). Today, in spite of the large number of parameters that can influence the airborne PGE content, the results obtained so far indicate significantly higher PGE levels at traffic sites compared with the rural or non-polluted zones that have been investigated (background levels). The average Pt content in airborne particles found in downtown Madrid, Göteborg and Rome is in the range 7.3-13.1 pg m(-3). The ring roads of these cities have values in the range 4.1-17.7 pg m(-3). In Munich, a lower Pt content was found in airborne particles (4.1 pg m(-3)). The same tendency has been noted for downtown Rh, with contents in the range 2.2-2.8 pg m(-3), and in the range 0.8-3.0 and 0.3 pg m(-3) for motorway margins in Munich. The combined results obtained using a wide-range airborne classifier (WRAC) collector and a PM-10 or virtual impactor show that Pt is associated with particles for a wide range of diameters. The smaller the particle size, the lower the Pt concentration. However, in particles

  13. Potential exposures to airborne and settled surface dust in residential areas of lower Manhattan following the collapse of the World Trade Center--New York City, November 4-December 11, 2001.

    PubMed

    2003-02-21

    Following the terrorist attacks of September 11, 2001, which destroyed the World Trade Center (WTC) in lower Manhattan, the New York City (NYC) Department of Health and Mental Hygiene (DOHMH) and the Agency for Toxic Substances and Disease Registry (ATSDR), with assistance from the U.S. Public Health Service (PHS) Commissioned Corps Readiness Force and the WTC Environmental Assessment Working Group, assessed the composition of outdoor and indoor settled surface and airborne dust in residential areas around the WTC and in comparison areas. This report summarizes the results of the investigation, which found 1) similar levels of airborne total fibers in lower and in upper Manhattan, 2) greater percentage levels of synthetic vitreous fibers (SVF) and mineral components of concrete and building wallboard in settled dust of residential areas in lower Manhattan than in upper Manhattan, and 3) low levels of asbestos in some settled surface dust in lower Manhattan residential areas. Based in part on the results of this investigation, the U.S. Environmental Protection Agency (EPA) is cleaning and sampling residential areas as requested by lower Manhattan residents. In addition, to assess any short- or long-term health effects of smoke, dust, and airborne substances around the WTC site, DOHMH and ATSDR are developing a registry that will track the health of persons who were most highly exposed to these materials.

  14. Coal miners' mortality in relaton to radiological category, lung function and exposure to airborne dust. Final report

    SciTech Connect

    Miller, B.G.; Jacobsen, M.; Steele, R.C.

    1981-06-01

    This report describes mortality among 29,553 British coal miners. They represent 93.5% of 31,611 men who were surveyed radiologically at 24 coal mines in the period 1953 through 1958. The main aim of the work was to consider risks of death attributed to various underlying causes, as recorded on death certificates, in relation to radiological signs of pneumoconiosis, measures of lung function, and exposure to respirable coal mine dust.

  15. Influence of regional biomass burning on the highly elevated organic carbon concentrations observed at Gosan, South Korea during a strong Asian dust period.

    PubMed

    Nguyen, Duc Luong; Kim, Jin Young; Ghim, Young Sung; Shim, Shang-Gyoo

    2015-03-01

    PM2.5 carbonaceous particles were measured at Gosan, South Korea during 29 March-11 April 2002 which includes a pollution period (30 March-01 April) when the highest concentrations of major anthropogenic species (nss-SO4 (2-), NO3 (-), and NH4 (+)) were observed and a strong Asian dust (AD) period (08-10 April) when the highest concentrations of mainly dust-originated trace elements (Al, Ca, Mg, and Fe) were seen. The concentrations of elemental carbon (EC) measured in the pollution period were higher than those measured in the strong AD period, whereas an inverse variation in the concentrations of organic carbon (OC) was observed. Based on the OC/EC ratios, the possible source that mainly contributed to the highly elevated OC concentrations measured in the strong AD period was biomass burning. The influence of the long-range transport of smoke plumes emitted from regional biomass burning sources was evaluated by using MODIS (Moderate Resolution Imaging Spectroradiometer) satellite data for fire locations and the potential source contribution function analysis. The most potential source regions of biomass burning were the Primorsky and Amur regions in Far Eastern Russia and southeastern and southwestern Siberia, Russia. Further discussion on the source characteristics suggested that the high OC concentrations measured in the strong AD period were significantly affected by the smoldering phase of biomass burning. In addition to biomass burning, secondary OC (SOC) formed during atmospheric long-range transport should be also considered as an important source of OC concentration measured at Gosan. Although this study dealt with the episodic case of the concurrent increase of dust and biomass burning particles, understanding the characteristics of heterogeneous mixing aerosol is essential in assessing the radiative forcing of aerosol. PMID:25253054

  16. Occurrence of eight bisphenol analogues in indoor dust from the United States and several Asian countries: implications for human exposure.

    PubMed

    Liao, Chunyang; Liu, Fang; Guo, Ying; Moon, Hyo-Bang; Nakata, Haruhiko; Wu, Qian; Kannan, Kurunthachalam

    2012-08-21

    Bisphenol A has been reported to be a ubiquitous contaminant in indoor dust, and human exposure to this compound is well documented. Information on the occurrence of and human exposure to other bisphenol analogues is limited. In this study, eight bisphenol analogues, namely 2,2-bis(4-hydroxyphenyl)propane (BPA), 4,4'-(hexafluoroisopropylidene)diphenol (BPAF), 4,4'-(1-phenylethylidene)bisphenol (BPAP), 2,2-bis(4-hydroxyphenyl)butane (BPB), 4,4'-dihydroxydiphenylmethane (BPF), 4,4'-(1,4-phenylenediisopropylidene)bisphenol (BPP), 4,4'- sulfonyldiphenol (BPS), and 4,4'-cyclohexylidenebisphenol (BPZ), were determined in indoor dust samples (n = 156) collected from the United States (U.S.), China, Japan, and Korea. Samples were extracted by solid-liquid extraction, purified by automated solid phase extraction methods, and determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The total concentrations of bisphenols (∑BPs; sum of eight bisphenols) in dust were in the range of 0.026-111 μg/g (geometric mean: 2.29 μg/g). BPA, BPS, and BPF were the three major bisphenols, accounting for >98% of the total concentrations. Other bisphenol analogues were rare or not detected, with the exception of BPAF, which was found in 76% of the 41 samples collected in Korea (geometric mean: 0.0039 μg/g). The indoor dust samples from Korea contained the highest concentrations of both individual and total bisphenols. BPA concentrations in dust were compared among three microenvironments (house, office, and laboratory). The estimated median daily intake (EDI) of ∑BPs through dust ingestion in the U.S., China, Japan, and Korea was 12.6, 4.61, 15.8, and 18.6 ng/kg body weight (bw)/day, respectively, for toddlers and 1.72, 0.78, 2.65, and 3.13 ng/kg bw/day, respectively, for adults. This is the first report on the occurrence of bisphenols, other than BPA, in indoor dust.

  17. Perfluoroalkyl compounds in dust from Asian, Australian, European, and North American homes and UK cars, classrooms, and offices.

    PubMed

    Goosey, Emma; Harrad, Stuart

    2011-01-01

    Perfluoroalkyl compounds (PFCs) were measured in dust from Australian, Canadian, French, German, Kazahkstani, Thai, UK, and US homes, and UK cars, classrooms, and offices. Most PFCs were significantly lower in Kazahkstan and Thailand than elsewhere; 2-(N-methylperfluoro-1-octanesulfonamido)-ethanol (MeFOSE) and 2-(N-ethylperfluoro-1-octanesulfonamido)-ethanol (EtFOSE) were significantly lower in Canada than in the UK and the US; perfluoro-1-hexanesulfonate (PFHxS) was significantly lower in Canada than in the UK, and N-ethylperfluoro-1-octanesulfonamide (EtFOSA) was significantly higher in Australia than in the UK. High EtFOSA concentrations in some samples may be consistent with its use as an insecticide. Perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), PFHxS, and MeFOSE were significantly higher in classrooms than in cars, homes, and offices; N-methylperfluoro-1-octanesulfonamide (MeFOSA) was significantly lower in classrooms than in homes and offices, and perfluoro-1-octanesulfonamide (FOSA) was significantly lower in classrooms than in cars, homes, and offices. While homes are usually the most important vector of dust exposure (typically > 60%), offices and classrooms make important contributions. While diet is usually the main exposure pathway for UK adults and children (~1-6 years) for PFOS, PFOA, and PFHxS; dust ingestion can be significant under high dust ingestion scenarios. Even under high-end exposure scenarios for dust and diet, PFOS and PFOA exposures are well within the European Food Safety Authority tolerable daily intakes.

  18. Airborne soil dust and its importance in buffering of atmospheric acidity and critical load assessment, over the semi arid tract of northern India.

    NASA Astrophysics Data System (ADS)

    Sharma, Disha; Kulshrestha, Umesh

    Airborne soil dust and its importance in buffering of atmospheric acidity and critical load assessment, over the semi arid tract of northern India. The Critical Load approach alongwith integrated assessment models has been used in the European nations for policy formations to reduce acidic emissions. This unique approach was applied to assess the of vulnerability of natural systems to the present day atmospheric pollution scenario. The calculated values of critical loads of sulphur ( 225 - 275 eq/ha/yr) and nitrogen (298 - 303 eq/ha/yr), for the soil system in Delhi, were calculated with respect to Anjan grass, Hibiscus and Black siris. The present loads of sulphur (PL(S) = 26.40 eq/ha/yr) and nitrogen (PL(N) = 36.51 eq/ha/yr) were found to be much lower than their critical loads without posing any danger of atmospheric acidic deposition on the soil systems. The study indicated that the system is still protective due to high pH of soil. The nature of buffering capability of calcium derived from soil dust can be considered as a natural tool to combat acidification in the Indian region. The results showed that the pollution status in Delhi is still within the safe limits. However, at the pace at which the city is growing, it is likely that in coming decades, it may exceed these critical values. In order to set deposition limits and avoid adverse effects of acidic deposition this approach can be applied in India too. Such approach is very useful, not only in abating pollution but also in devising means of cost optimal emission abatement strategies.

  19. Airborne Petcoke Dust is a Major Source of Polycyclic Aromatic Hydrocarbons in the Athabasca Oil Sands Region.

    PubMed

    Zhang, Yifeng; Shotyk, William; Zaccone, Claudio; Noernberg, Tommy; Pelletier, Rick; Bicalho, Beatriz; Froese, Duane G; Davies, Lauren; Martin, Jonathan W

    2016-02-16

    Oil sands mining has been linked to increasing atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) in the Athabasca oil sands region (AOSR), but known sources cannot explain the quantity of PAHs in environmental samples. PAHs were measured in living Sphagnum moss (24 sites, n = 68), in sectioned peat cores (4 sites, n = 161), and snow (7 sites, n = 19) from ombrotrophic bogs in the AOSR. Prospective source samples were also analyzed, including petroleum coke (petcoke, from both delayed and fluid coking), fine tailings, oil sands ore, and naturally exposed bitumen. Average PAH concentrations in near-field moss (199 ng/g, n = 11) were significantly higher (p = 0.035) than in far-field moss (118 ng/g, n = 13), and increasing temporal trends were detected in three peat cores collected closest to industrial activity. A chemical mass-balance model estimated that delayed petcoke was the major source of PAHs to living moss, and among three peat core the contribution to PAHs from delayed petcoke increased over time, accounting for 45-95% of PAHs in contemporary layers. Petcoke was also estimated to be a major source of vanadium, nickel, and molybdenum. Scanning electron microscopy with energy-dispersive X-ray spectroscopy confirmed large petcoke particles (>10 μm) in snow at near-field sites. Petcoke dust has not previously been considered in environmental impact assessments of oil sands upgrading, and improved dust control from growing stockpiles may mitigate future risks.

  20. Airborne Petcoke Dust is a Major Source of Polycyclic Aromatic Hydrocarbons in the Athabasca Oil Sands Region.

    PubMed

    Zhang, Yifeng; Shotyk, William; Zaccone, Claudio; Noernberg, Tommy; Pelletier, Rick; Bicalho, Beatriz; Froese, Duane G; Davies, Lauren; Martin, Jonathan W

    2016-02-16

    Oil sands mining has been linked to increasing atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) in the Athabasca oil sands region (AOSR), but known sources cannot explain the quantity of PAHs in environmental samples. PAHs were measured in living Sphagnum moss (24 sites, n = 68), in sectioned peat cores (4 sites, n = 161), and snow (7 sites, n = 19) from ombrotrophic bogs in the AOSR. Prospective source samples were also analyzed, including petroleum coke (petcoke, from both delayed and fluid coking), fine tailings, oil sands ore, and naturally exposed bitumen. Average PAH concentrations in near-field moss (199 ng/g, n = 11) were significantly higher (p = 0.035) than in far-field moss (118 ng/g, n = 13), and increasing temporal trends were detected in three peat cores collected closest to industrial activity. A chemical mass-balance model estimated that delayed petcoke was the major source of PAHs to living moss, and among three peat core the contribution to PAHs from delayed petcoke increased over time, accounting for 45-95% of PAHs in contemporary layers. Petcoke was also estimated to be a major source of vanadium, nickel, and molybdenum. Scanning electron microscopy with energy-dispersive X-ray spectroscopy confirmed large petcoke particles (>10 μm) in snow at near-field sites. Petcoke dust has not previously been considered in environmental impact assessments of oil sands upgrading, and improved dust control from growing stockpiles may mitigate future risks. PMID:26771587

  1. Airborne microorganisms in the African desert dust corridor over the mid-Atlantic ridge, Ocean Drilling Program, Leg 209

    USGS Publications Warehouse

    Griffin, Dale W.; Westphal, Douglas L.; Gray, Michael A.

    2006-01-01

    The objective of this study was to enhance our understanding of the fate and trans-Atlantic transport of dustborne microorganisms from Northern Africa to the Caribbean and Americas, and more specifically to determine if culturable populations could be detected at a mid-ocean site, closer to the source of dust relative to land-based Caribbean sites, during the early summer months of May and June. Between the dates of 22 May and 30 June 2003, daily air samples were collected and evaluated for the presence of culturable bacterial and fungal colony-forming units (CFU). Here we report a statistically significant correlation between daily atmospheric CFU counts at a mid-ocean research site (???15??N, 45??W) and daily desert dust concentrations as determined by the U.S. Navy's Naval Aerosol Analysis and Prediction System (NAAPS) Global Aerosol Model (Honrath et al. (2004). Journal of Geophysical Research, 109; Johnson et al. (2003). Global Biogeochemical Cycles, 17, 1063; Reid et al. (2004). Geophysical Research Letters, 31; Schollaert, Yoder, Westphal, & O'Reilly (2003). Journal of Geophysical Research, 108, 3191). ?? Springer Science+Business Media B.V. 2006.

  2. Occurrence and human exposure of p-hydroxybenzoic acid esters (parabens), bisphenol A diglycidyl ether (BADGE), and their hydrolysis products in indoor dust from the United States and three East Asian countries.

    PubMed

    Wang, Lei; Liao, Chunyang; Liu, Fang; Wu, Qian; Guo, Ying; Moon, Hyo-Bang; Nakata, Haruhiko; Kannan, Kurunthachalam

    2012-11-01

    p-Hydroxybenzoic acid esters (parabens) and bisphenol A diglycidyl ether (BADGE) are widely present in personal care products, food packages, and material coatings. Nevertheless, little is known about the occurrence of these compounds in indoor dust. In this study, we collected 158 indoor dust samples from the U.S., China, Korea, and Japan and determined the concentrations of 11 target chemicals, viz., six parabens and their common hydrolysis product, 4-hydroxybenzoic acid (4-HB), as well as BADGE and its three hydrolysis products (BADGE·H(2)O, BADGE·2H(2)O, and BADGE·HCl·H(2)O). All of the target compounds were found in dust samples from four countries. Concentrations of sum of six parabens in dust were on the order of several hundred to several thousands of nanogram per gram. Geometric mean concentrations of BADGEs in dust ranged from 1300 to 2890 ng/g among four countries. Methyl paraben (MeP), propyl paraben (PrP), BADGE·2H(2)O, and BADGE·HCl·H(2)O were the predominant compounds found in dust samples. This is the first report of BADGE and its hydrolysis products (BADGEs) in indoor dust samples and of parabens in indoor dust from Asian countries. On the basis of the measured concentrations of target chemicals, we estimated the daily intake (EDI) via dust ingestion. The EDIs of parabens via dust ingestion were 5-10 times higher in children than in adults. Among the four countries studied, the EDIs of parabens (5.4 ng/kg-bw/day) and BADGEs (6.5 ng/kg-bw/day) through dust ingestion were the highest for children in Korea and Japan.

  3. Repetitive Immunoassay with a Surface Acoustic Wave Device and a Highly Stable Protein Monolayer for On-Site Monitoring of Airborne Dust Mite Allergens.

    PubMed

    Toma, Koji; Miki, Daisuke; Kishikawa, Chisato; Yoshimura, Naoyuki; Miyajima, Kumiko; Arakawa, Takahiro; Yatsuda, Hiromi; Mitsubayashi, Kohji

    2015-10-20

    This work describes a sensor to be incorporated into the on-site monitoring system of airborne house dust mite (HDM) allergens. A surface acoustic wave (SAW) device was combined with self-assembled monolayers of a highly stable antibody capture protein on the SAW surface that have high resistance to pH change. A sandwich assay was used to measure a HDM allergen, Der f 1 derived from Dermatophagoides farinae. Capture antibodies were cross-linked to a protein G based capture layer (ORLA85) on the sensor surface, thereby only Der f 1 and detection antibodies were regenerated by changing pH, resulting in fast repetition of the measurement. The sensor was characterized through 10 repetitive measurements of Der f 1, which demonstrated high reproducibility of the sensor with the coefficient of variation of 5.6%. The limit of detection (LOD) of the sensor was 6.1 ng·mL(-1), encompassing the standard (20 ng·mL(-1)) set by the World Health Organization. Negligible sensor outputs were observed for five different major allergens including other HDM allergens which tend to have cross-reactivity to Der f 1 and their mixtures with Der f 1. Finally, the sensor lifetime was evaluated by conducting three measurements per day, and the sensor output did not substantially change for 4 days. These characteristics make the SAW immunosensor a promising candidate for incorporation into on-site allergen monitoring systems.

  4. Chemical properties and outflow patterns of anthropogenic and dust particles on Rishiri Island during the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia)

    NASA Astrophysics Data System (ADS)

    Matsumoto, Kiyoshi; Uyama, Yukiko; Hayano, Teruaki; Tanimoto, Hiroshi; Uno, Itsushi; Uematsu, Mitsuo

    2003-12-01

    Investigations of chemical properties and transport mechanisms of continental aerosols are necessary for estimating their influences on global radiative budget and on the global material cycle. Intensive measurements of atmospheric aerosols and the associated species on Rishiri Island, near the northern tip of Japan, were conducted from March to May 2001, in order to understand the chemical properties, source regions, transport pathways, and transport patterns of anthropogenic and mineral aerosols over the east Asian Pacific Rim region during the spring. Mean concentrations of nss-SO42-, NO3-, NH4+, nss-Ca2+ in aerosols were 2.48, 0.64, 0.72, and 0.17 μg m-3, respectively. Elemental carbon and organic carbon in fine particles (d < 2.5 μm) yielded mean concentrations of 0.25 and 0.80 μg m-3, respectively. The concentrations of these species frequently increased to higher values because of outbreaks of continental polluted air masses, whereas under background conditions, they decreased to lower values similar to those observed over the remote ocean. Our results demonstrate that nss-SO42- and NH4+ coexist in fine particles, that NO3- and nss-Ca2+ coexist in coarse particles, and that each set is transported in an alternate manner. Continentally derived NO3- is transported as coarse particle to the east Asian Pacific Rim region. Anthropogenic pollutants and dust particles are not necessarily transported together. It was often found that anthropogenic fine particles containing abundant nss-SO42- appeared first and were then followed by large mineral particles that had absorbed NO3-. Short-term intrusion of the air masses containing abundant particulate carbonaceous compounds, probably due to the influence of biomass burning, also often occurred during the outflow events of continental air masses. Atmospheric behaviors of sulfate, nitrate, and carbonaceous species are different from one another, although they are all derived mainly from combustion processes.

  5. Predictors of airborne endotoxin concentrations in inner city homes.

    PubMed

    Mazique, D; Diette, G B; Breysse, P N; Matsui, E C; McCormack, M C; Curtin-Brosnan, J; Williams, D L; Peng, R D; Hansel, N N

    2011-05-01

    Few studies have assessed in home factors which contribute to airborne endotoxin concentrations. In 85 inner city Baltimore homes, we found no significant correlation between settled dust and airborne endotoxin concentrations. Certain household activities and characteristics, including frequency of dusting, air conditioner use and type of flooring, explained 36-42% of the variability of airborne concentrations. Measurements of both airborne and settled dust endotoxin concentrations may be needed to fully characterize domestic exposure in epidemiologic investigations. PMID:21429483

  6. Difference in Pro-Inflammatory Cytokine Responses Induced in THP1 Cells by Particulate Matter Collected on Days with and without ASIAN Dust Storms

    PubMed Central

    Watanabe, Masanari; Kurai, Jun; Sano, Hiroyuki; Yamasaki, Akira; Shimizu, Eiji

    2015-01-01

    The associations between particulate matter from Asian dust storms (ADS) and health disorders differ among studies, and the underlying mechanisms remain unclear. In this study, ADS and non-ADS particles were tested for their potential to induce pro-inflammatory cytokines associated with adverse respiratory effects. Particulate matter was collected in Japan during four periods in 2013 (2 × ADS periods; 2 × non-ADS). THP1 cells were exposed to this particulate matter, and the levels of various interleukins (ILs), and tumor necrosis factor (TNF)-α were measured. Levels of IL-2 increased significantly following exposure to all particulate matter samples (compared to levels in a solvent control). Increased levels of IL-10 and TNF-α were also observed following exposure to particles collected during three (one ADS and two non-ADS) and two (one ADS and one non-ADS) collection periods, respectively. Thus, the effects of particulate matter on cytokine responses differed according to collection period, and the effects of ADS particles differed for each ADS event. Additionally, the levels of pro-inflammatory cytokines induced by ADS particles were not always higher than those induced by non-ADS particles. PMID:26184251

  7. Difference in Pro-Inflammatory Cytokine Responses Induced in THP1 Cells by Particulate Matter Collected on Days with and without ASIAN Dust Storms.

    PubMed

    Watanabe, Masanari; Kurai, Jun; Sano, Hiroyuki; Yamasaki, Akira; Shimizu, Eiji

    2015-07-01

    The associations between particulate matter from Asian dust storms (ADS) and health disorders differ among studies, and the underlying mechanisms remain unclear. In this study, ADS and non-ADS particles were tested for their potential to induce pro-inflammatory cytokines associated with adverse respiratory effects. Particulate matter was collected in Japan during four periods in 2013 (2 × ADS periods; 2 × non-ADS). THP1 cells were exposed to this particulate matter, and the levels of various interleukins (ILs), and tumor necrosis factor (TNF)-α were measured. Levels of IL-2 increased significantly following exposure to all particulate matter samples (compared to levels in a solvent control). Increased levels of IL-10 and TNF-α were also observed following exposure to particles collected during three (one ADS and two non-ADS) and two (one ADS and one non-ADS) collection periods, respectively. Thus, the effects of particulate matter on cytokine responses differed according to collection period, and the effects of ADS particles differed for each ADS event. Additionally, the levels of pro-inflammatory cytokines induced by ADS particles were not always higher than those induced by non-ADS particles. PMID:26184251

  8. An Automated Method of MFRSR Calibration for Aerosol Optical Depth Analysis with Application to an Asian Dust Outbreak over the United States.

    NASA Astrophysics Data System (ADS)

    Augustine, John A.; Cornwall, Christopher R.; Hodges, Gary B.; Long, Charles N.; Medina, Carlos I.; Deluisi, John J.

    2003-02-01

    Over the past decade, networks of Multifilter Rotating Shadowband Radiometers (MFRSR) and automated sun photometers have been established in the United States to monitor aerosol properties. The MFRSR alternately measures diffuse and global irradiance in six narrow spectral bands and a broadband channel of the solar spectrum, from which the direct normal component for each may be inferred. Its 500-nm channel mimics sun photometer measurements and thus is a source of aerosol optical depth information. Automatic data reduction methods are needed because of the high volume of data produced by the MFRSR. In addition, these instruments are often not calibrated for absolute irradiance and must be periodically calibrated for optical depth analysis using the Langley method. This process involves extrapolation to the signal the MFRSR would measure at the top of the atmosphere (I0). Here, an automated clear-sky identification algorithm is used to screen MFRSR 500-nm measurements for suitable calibration data. The clear-sky MFRSR measurements are subsequently used to construct a set of calibration Langley plots from which a mean I0 is computed. This calibration I0 may be subsequently applied to any MFRSR 500-nm measurement within the calibration period to retrieve aerosol optical depth. This method is tested on a 2-month MFRSR dataset from the Table Mountain NOAA Surface Radiation Budget Network (SURFRAD) station near Boulder, Colorado. The resultant I0 is applied to two Asian dust-related high air pollution episodes that occurred within the calibration period on 13 and 17 April 2001. Computed aerosol optical depths for 17 April range from approximately 0.30 to 0.40, and those for 13 April vary from background levels to >0.30. Errors in these retrievals were estimated to range from ±0.01 to ±0.05, depending on the solar zenith angle. The calculations are compared with independent MFRSR-based aerosol optical depth retrievals at the Pawnee National Grasslands, 85 km to the

  9. A 12-year observation of water-soluble ions in TSP aerosols collected at a remote marine location in the western North Pacific: an outflow region of Asian dust

    NASA Astrophysics Data System (ADS)

    Boreddy, S. K. R.; Kawamura, K.

    2015-06-01

    In order to characterize the long-term trend of remote marine aerosols, a 12-year observation was conducted for water-soluble ions in TSP (total suspended particulate) aerosols collected from 2001 to 2012 in the Asian outflow region at Chichijima Island in the western North Pacific. We found a clear difference in chemical composition between the continentally affected and marine background air masses over the observation site. Asian continental air masses are delivered from late autumn to spring, whereas marine air masses were dominated in summer. Concentrations of non-sea salt (nss-) SO42-, NO3-, NH4+, nss-K+ and nss-Ca2+ are high in winter and spring and low in summer. On the other hand, MSA- (methanesulfonate) exhibits higher concentrations during spring and winter, probably due to springtime dust bloom or due to the direct continental transport of MSA- to the observation site. We could not find any clear decadal trend for Na+, Cl-, Mg2+ and nss-Ca2+ in all seasons, although there exists a clear seasonal trend. However, concentrations of nss-SO42- continuously decreased from 2007 to 2012, probably due to the decreased SO2 emissions in East Asia especially in China. In contrast, nss-K+ and MSA- concentrations continuously increased from 2001 to 2012 during winter and spring seasons, demonstrating that biomass burning and/or terrestrial biological emissions in East Asia are being increasingly transported from the Asian continent to the western North Pacific. This study also demonstrates that Asian dusts can act as an important source of nutrients for phytoplankton and thus sea-to-air emission of dimethyl sulfide over the western North Pacific.

  10. Differences in the effects of Asian dust on pulmonary function between adult patients with asthma and those with asthma–chronic obstructive pulmonary disease overlap syndrome

    PubMed Central

    Watanabe, Masanari; Noma, Hisashi; Kurai, Jun; Sano, Hiroyuki; Ueda, Yasuto; Mikami, Masaaki; Yamamoto, Hiroyuki; Tokuyasu, Hirokazu; Kato, Kazuhiro; Konishi, Tatsuya; Tatsukawa, Toshiyuki; Shimizu, Eiji; Kitano, Hiroya

    2016-01-01

    Background Asian dust (AD) exposure exacerbates pulmonary dysfunction in patients with asthma. Asthma–chronic obstructive pulmonary disease overlap syndrome (ACOS), characterized by coexisting symptoms of asthma and chronic obstructive pulmonary disease, is considered a separate disease entity. Previously, we investigated the effects of AD on pulmonary function in adult patients with asthma. Here, we present the findings of our further research on the differences in the effects of AD exposure on pulmonary function between patients with asthma alone and those with ACOS. Methods Between March and May 2012, we conducted a panel study wherein we monitored daily peak expiratory flow (PEF) values in 231 adult patients with asthma. These patients were divided into 190 patients with asthma alone and 41 patients with ACOS in this study. Daily AD particle levels were measured using light detection and ranging systems. Two heavy AD days (April 23 and 24) were determined according to the Japan Meteorological Agency definition. A linear mixed model was used to estimate the association between PEF and AD exposure. Results Increments in the interquartile range of AD particles (0.018 km−1) led to PEF changes of −0.50 L/min (95% confidence interval, −0.98 to −0.02) in patients with asthma alone and −0.11 L/min (−0.11 to 0.85) in patients with ACOS. The PEF changes after exposure to heavy AD were −2.21 L/min (−4.28 to −0.15) in patients with asthma alone and −2.76 L/min (−6.86 to 1.35) in patients with ACOS. In patients with asthma alone, the highest decrease in PEF values was observed on the heavy AD day, with a subsequent gradual increase over time. Conclusion Our results suggest that the effects of AD exposure on pulmonary function differ between patients with asthma alone and ACOS, with the former exhibiting a greater likelihood of decreased pulmonary function after AD exposure. PMID:26869784

  11. Asians and Asian Americans.

    ERIC Educational Resources Information Center

    San Francisco Unified School District, CA.

    This is a selected bibliography of some good and some outstanding audio-visual educational materials in the library of the Educational Materials Bureau, Audio-Visual Education Section, that may be considered of particular interest in the study of Asians and Asian-Americans. The bibliography is arranged alphabetically within the following subject…

  12. Haul road dust control

    SciTech Connect

    Reed, W.R.; Organiscak, J.A.

    2007-10-15

    A field study was conducted to measure dust from haul trucks at a limestone quarry and a coal preparation plant waste hauling operation. The study found that primarily wind, distance and road treatment conditions notably affected the dust concentrations at locations next to, 50 ft from, and 100 ft away from the unpaved haulage road. Airborne dust measured along the unpaved haul road showed that high concentrations of fugitive dust can be generated with these concentrations rapidly decreasing to nearly background levels within 100 ft of the road. Instantaneous respirable dust measurements illustrated that the trucks generate a real-time dust cloud that has a peak concentration with a time-related decay rate as the dust moves past the sampling locations. The respirable dust concentrations and peak levels were notably diminished as the dust cloud was transported, diluted, and diffused by the wind over the 100 ft distance from the road. Individual truck concentrations and peak levels measured next to the dry road surface test section were quite variable and dependent on wind conditions, particularly wind direction, with respect to reaching the sampling location. The vast majority of the fugitive airborne dust generated from unpaved and untreated haulage roads was non-respirable. 6 figs.

  13. A 12 year observation of water-soluble inorganic ions in TSP aerosols collected at a remote marine location in the western North Pacific: an outflow region of Asian dust

    NASA Astrophysics Data System (ADS)

    Boreddy, S. K. R.; Kawamura, K.

    2015-03-01

    In order to characterize the long term trend of remote marine aerosols, a 12 year observation was conducted for water-soluble inorganic ions in TSP aerosols collected from 2001-2012 in the Asian outflow region at a Chichijima Island in the western North Pacific. We found a clear difference in chemical composition between the continentally affected and marine background air masses over the observation site. Asian continental air masses are delivered from late autumn to spring, whereas marine air masses were dominated in summer. Concentrations of nss-SO42-, NO3-, NH4+, nss-K+ and nss-Ca2+ are high in winter and spring and low in summer. On the other hand, MSA- exhibits higher concentrations during spring and winter, probably due to springtime dust bloom or due to the direct continental transport of MSA- to the observation site. We could not find any clear decadal trend for Na+, Cl-, Mg2+ and nss-Ca2+ in all seasons, although there exists a clear seasonal trend. However, concentrations of nss-SO42- continuously decreased from 2007-2012, probably due to the decreased SO2 emissions in East Asia especially in China. In contrast, nss-K+ and MSA- concentrations continuously increased from 2001-2012 during winter and spring seasons, demonstrating that biomass burning and/or terrestrial biological emissions in East Asia are increasingly more transported from the Asian continent to the western North Pacific.

  14. Pneumoconiosis, lung function and exposure to airborne dust: epidemiological research to compare responses of working coalminers with responses of ex-miners. Part 2. Final report

    SciTech Connect

    Soutar, C.A.; Maclaren, W.; Hurley, F.; Murdoch, R.; Hadden, G.

    1982-03-01

    The relationship between dust exposure and disease for miners was compared with that for ex-miners, in order to determine whether relationships found in other studies on miners alone could be applied to both groups. 17,738 men examined in the 1950s were followed up approximately 22 years later. Sixty one per cent of the survivors were examined, being 40% of the original sample. Records were made of respiratory symptoms, smoking habit, lung spirometry and chest radiograph findings. Radiographs were interpreted according to the International Labour Office Classification of Pneumoconiosis. Lifetime dust exposure was calculated for each subject. The dust/disease relationship was found to be the same for both groups. Ex-miners were found to have more pneumoconiosis and fibrosis and to be in worse health than miners. Pneumoconiosis progression was shown to be related to continued dust exposure; fibrosis progression was related to the presence of dust in the lungs. Dust exposure was shown to cause a mainly restrictive pattern of lung disease in contrast to the obstructive pattern caused by smoking. Colliery-related differences were found in lung disease which it was felt needed further investigation.

  15. Reactive Nitrogen in Asian Continental Outflow over the Western Pacific: Results from the NASA Transport and Chemical Evolution over the Pacific (TRACE-P)Airborne Mission

    NASA Technical Reports Server (NTRS)

    Talbot, R.; Dibb, J.; Scheuer, E.; Seid, G.; Russo, R.; Sandholm, S.; Tan, D.; Blake, D.; Blake, N.; Singh, H.

    2003-01-01

    We present here results for reactive nitrogen species measured aboard the NASA DC-8 aircraft during the Transport and Chemical Evolution over the Pacific TRACE-P) mission. The large-scale distributions total reactive nitrogen (NO(sub y,sum) = NO + NO2 + HNO3 + PAN + C(sub 1)-C(sub 5) alkyl nitrates) and O3 and CO were better defined in the boundary layer with significant degradation of the relationships as altitude increased. Typically, NO(sub y,sum) was enhanced over background levels of approx.260 pptv by 20-to-30-fold. The ratio C2H2/CO had values of 1-4 at altitudes up to 10 km and as far eastward as 150degE, implying significant vertical mixing of air parcels followed by rapid advection across the Pacific. Analysis air parcels originating from five principal Asian source regions showed that HNO3 and PAN dominated NO(sub y,sum). Correlations of NO(sub y,sum) with C2Cl4 (urban tracer) were not well defined in any of the source regions, and they were only slightly better with CH3Cl (biomass tracer). Air parcels over the western Pacific contained a complex mixture of emission sources that are not easily resolvable as shown by analysis of the Shanghai mega-city plume. It contained an intricate mixture of pollution emissions and exhibited the highest mixing ratios of NO(sub y,sum) species observed during TRACE-P. Comparison of tropospheric chemistry between the earlier PEM-West B mission and the recent TRACE-P data showed that in the boundary layer significant increases in the mixing ratios of NO(sub y,sum)species have occurred, but the middle and upper troposphere seems to have been affected minimally by increasing emissions on the Asian continent over the last 7 years.

  16. Reactive nitrogen in Asian continental outflow over the western Pacific: Results from the NASA Transport and Chemical Evolution over the Pacific (TRACE-P) airborne mission

    NASA Astrophysics Data System (ADS)

    Talbot, R.; Dibb, J.; Scheuer, E.; Seid, G.; Russo, R.; Sandholm, S.; Tan, D.; Singh, H.; Blake, D.; Blake, N.; Atlas, E.; Sachse, G.; Jordan, C.; Avery, M.

    2003-10-01

    We present here results for reactive nitrogen species measured aboard the NASA DC-8 aircraft during the Transport and Chemical Evolution over the Pacific (TRACE-P) mission. The large-scale distributions total reactive nitrogen (NOy,sum = NO + NO2 + HNO3 + PAN + C1-C5 alkyl nitrates) and O3 and CO were better defined in the boundary layer with significant degradation of the relationships as altitude increased. Typically, NOy,sum was enhanced over background levels of ˜260 pptv by 20-to-30-fold. The ratio C2H2/CO had values of 1-4 at altitudes up to 10 km and as far eastward as 150°E, implying significant vertical mixing of air parcels followed by rapid advection across the Pacific. Analysis air parcels originating from five principal Asian source regions showed that HNO3 and PAN dominated NOy,sum. Correlations of NOy,sum with C2Cl4 (urban tracer) were not well defined in any of the source regions, and they were only slightly better with CH3Cl (biomass tracer). Air parcels over the western Pacific contained a complex mixture of emission sources that are not easily resolvable as shown by analysis of the Shanghai mega-city plume. It contained an intricate mixture of pollution emissions and exhibited the highest mixing ratios of NOy,sum species observed during TRACE-P. Comparison of tropospheric chemistry between the earlier PEM-West B mission and the recent TRACE-P data showed that in the boundary layer significant increases in the mixing ratios of NOy,sum species have occurred, but the middle and upper troposphere seems to have been affected minimally by increasing emissions on the Asian continent over the last 7 years.

  17. Uranium mill ore dust characterization

    SciTech Connect

    Knuth, R.H.; George, A.C.

    1980-11-01

    Cascade impactor and general air ore dust measurements were taken in a uranium processing mill in order to characterize the airborne activity, the degree of equilibrium, the particle size distribution and the respirable fraction for the /sup 238/U chain nuclides. The sampling locations were selected to limit the possibility of cross contamination by airborne dusts originating in different process areas of the mill. The reliability of the modified impactor and measurement techniques was ascertained by duplicate sampling. The results reveal no significant deviation from secular equilibrium in both airborne and bulk ore samples for the /sup 234/U and /sup 230/Th nuclides. In total airborne dust measurements, the /sup 226/Ra and /sup 210/Pb nuclides were found to be depleted by 20 and 25%, respectively. Bulk ore samples showed depletions of 10% for the /sup 226/Ra and /sup 210/Pb nuclides. Impactor samples show disequilibrium of /sup 226/Ra as high as +-50% for different size fractions. In these samples the /sup 226/Ra ratio was generally found to increase as particle size decreased. Activity median aerodynamic diameters of the airborne dusts ranged from 5 to 30 ..mu..m with a median diameter of 11 ..mu..m. The maximum respirable fraction for the ore dusts, based on the proposed International Commission on Radiological Protection's (ICRP) definition of pulmonary deposition, was < 15% of the total airborne concentration. Ore dust parameters calculated for impactor duplicate samples were found to be in excellent agreement.

  18. WMO Sand and Dust Storm Warning Advisory and Assessment System (SDS-WAS): Research Implementation Status

    NASA Astrophysics Data System (ADS)

    Nickovic, Slobodan; Barrie, Leonard

    2010-05-01

    Assessment System (SDS-WAS) in order to improve the capabilities of countries affected by dust to reduce risks associated with airborne sand and dust. This project is in response to the desire of more than 40 WMO member countries to improve capabilities for more reliable sand and dust storm forecasts. The project has strong crosscutting features: it relies on real-time delivery of products; it integrates research communities (modelling, observation groups, and effects) and communities of practice (e.g. medical, aeronautical, agricultural users). There are two already established SDS-WAS nodes (Asian and North-Africa-Europe-Middle East) that coordinate implementation of the project objectives at regional levels. This presentation will review current status and future steps in the project implementation.

  19. Mammalian airborne allergens.

    PubMed

    Aalberse, Rob C

    2014-01-01

    Historically, horse dandruff was a favorite allergen source material. Today, however, allergic symptoms due to airborne mammalian allergens are mostly a result of indoor exposure, be it at home, at work or even at school. The relevance of mammalian allergens in relation to the allergenic activity of house dust extract is briefly discussed in the historical context of two other proposed sources of house dust allergenic activity: mites and Maillard-type lysine-sugar conjugates. Mammalian proteins involved in allergic reactions to airborne dust are largely found in only 2 protein families: lipocalins and secretoglobins (Fel d 1-like proteins), with a relatively minor contribution of serum albumins, cystatins and latherins. Both the lipocalin and the secretoglobin family are very complex. In some instances this results in a blurred separation between important and less important allergenic family members. The past 50 years have provided us with much detailed information on the genomic organization and protein structure of many of these allergens. However, the complex family relations, combined with the wide range of post-translational enzymatic and non-enzymatic modifications, make a proper qualitative and quantitative description of the important mammalian indoor airborne allergens still a significant proteomic challenge. PMID:24925404

  20. Operational retrieval of Asian sand and dust storm from FY-2C geostationary meteorological satellite and its application to real time forecast in Asia

    NASA Astrophysics Data System (ADS)

    Hu, X. Q.; Lu, N. M.; Niu, T.; Zhang, P.

    2007-06-01

    This paper describes an operational retrieval algorithm for the sand/dust storm (SDS) from FY-2C/S-VISSR (Stretched - Visible and Infrared Spin-Scan Radiometer) developed at the National Satellite Meteorological Center (NSMC) of China. This algorithm, called Dust Retrieval Algorithm based on Geostationary Imager (DRAGI), is based on the optical and radiative physical properties of SDS in mid-infrared and thermal infrared spectral regions as well as the observation of all bands in the geostationary imager, which include the Brightness Temperature Difference (BTD) in split window channels, Infrared Difference Dust Index (IDDI) and the ratio of middle infrared reflectance to visible reflectance. It also combines the visible and water vapor bands observation of the geostationary imager to identify the dust clouds from the surface targets and meteorological clouds. The output product is validated by and related to other dust aerosol observations such as the synoptic weather reports, surface visibility, aerosol optical depth (AOD) and ground-based PM10 observations. Using the SDS-IDDI data and a data assimilation scheme, the dust forecast model CUACE/Dust achieved a substantial improvement to the SDS predictions in spring 2006.

  1. Operational retrieval of Asian sand and dust storm from FY-2C geostationary meteorological satellite and its application to real time forecast in Asia

    NASA Astrophysics Data System (ADS)

    Hu, X. Q.; Lu, N. M.; Niu, T.; Zhang, P.

    2008-03-01

    This paper describes an operational retrieval algorithm for the sand/dust storm (SDS) from FY-2C/S-VISSR (Stretched-Visible and Infrared Spin-Scan Radiometer) developed at the National Satellite Meteorological Center (NSMC) of China. This algorithm, called Dust Retrieval Algorithm based on Geostationary Imager (DRAGI), is based on the optical and radiative physical properties of SDS in mid-infrared and thermal infrared spectral regions as well as the observation of all bands in the geostationary imager, which include the Brightness Temperature Difference (BTD) in split window channels, Infrared Difference Dust Index (IDDI) and the ratio of middle infrared reflectance to visible reflectance. It also combines the visible and water vapor bands observation of the geostationary imager to identify the dust clouds from the surface targets and meteorological clouds. The output product is validated by and related to other dust aerosol observations such as the synoptic weather reports, surface visibility, aerosol optical depth (AOD) and ground-based PM10 observations. Using the SDS-IDD product and a data assimilation scheme, the dust forecast model CUACE/Dust achieved a substantial improvement to the SDS predictions in spring 2006.

  2. [Chemical characteristics in airborne particulate matter (PM10) during a high pollution spring dust storm episode in Beijing, Tianjin and Zhangjiakou, China].

    PubMed

    Liu, Qing-Yang; Liu, Yan-Ju; Zhao, Qiang; Zhang, Ting-Ting; Zhang, Mei-Gen; Wang, Cun-Mei

    2014-08-01

    Atmospheric particulate matter (PM10) was collected at sampling locations of Beijing, Tianjin and Zhangjiakou from April 1st to May 24th, 2012. The mass concentration of PM10 and concentrations of ions, elemental carbon (EC) and organic carbon (OC) in PM10 were determined. The results showed that average mass concentration of PM10 were 233.82 microg x m(-3) for Beijing, 279.64 microg x (-3) for Tianjin and 238.13 microg x m(-3) for Zhangjiakou, respectively. Backward trajectories results confirmed dust storm events occurred from 27th to 29th April. The maximum daily mass concentrations of PM10 were 755.54 microg x m(-3) for Beijing, 831.32 microg x m(-3) for Tianjin and 582.82 microg x m(-3) for Zhangjiakou during the dust storm episodes, respectively. Water-soluble ions (Na+, NH4+, Ca2+, K+, F-, Cl-, NO3-, SO4(2-)), organic carbon (OC) and elemental carbon (EC) were major aerosol components during the dust storm episodes, and their concentrations were higher than non-dust storm days. In addition, dust storm caused increases in NO3-, SO4(2-) and enrichment of secondary organic carbon (SOC) concentration relative to OC, suggesting that chemical reaction processes involving gas-particle conversion occurred during the long-distance transport of aerosol particles. PMID:25338350

  3. [Chemical characteristics in airborne particulate matter (PM10) during a high pollution spring dust storm episode in Beijing, Tianjin and Zhangjiakou, China].

    PubMed

    Liu, Qing-Yang; Liu, Yan-Ju; Zhao, Qiang; Zhang, Ting-Ting; Zhang, Mei-Gen; Wang, Cun-Mei

    2014-08-01

    Atmospheric particulate matter (PM10) was collected at sampling locations of Beijing, Tianjin and Zhangjiakou from April 1st to May 24th, 2012. The mass concentration of PM10 and concentrations of ions, elemental carbon (EC) and organic carbon (OC) in PM10 were determined. The results showed that average mass concentration of PM10 were 233.82 microg x m(-3) for Beijing, 279.64 microg x (-3) for Tianjin and 238.13 microg x m(-3) for Zhangjiakou, respectively. Backward trajectories results confirmed dust storm events occurred from 27th to 29th April. The maximum daily mass concentrations of PM10 were 755.54 microg x m(-3) for Beijing, 831.32 microg x m(-3) for Tianjin and 582.82 microg x m(-3) for Zhangjiakou during the dust storm episodes, respectively. Water-soluble ions (Na+, NH4+, Ca2+, K+, F-, Cl-, NO3-, SO4(2-)), organic carbon (OC) and elemental carbon (EC) were major aerosol components during the dust storm episodes, and their concentrations were higher than non-dust storm days. In addition, dust storm caused increases in NO3-, SO4(2-) and enrichment of secondary organic carbon (SOC) concentration relative to OC, suggesting that chemical reaction processes involving gas-particle conversion occurred during the long-distance transport of aerosol particles.

  4. Measuring airborne components of seismic body vibrations in a Middle-Asian sand-dwelling Insectivora species, the piebald shrew (Diplomesodon pulchellum).

    PubMed

    Volodin, Ilya A; Zaytseva, Alexandra S; Ilchenko, Olga G; Volodina, Elena V; Chebotareva, Anastasia L

    2012-08-15

    Self-produced seismic vibrations have been found for some subterranean rodents but have not been reported for any Insectivora species, although seismic sensitivity has been confirmed for blind sand-dwelling chrysochlorid golden moles. Studying the vocal behaviour of captive piebald shrews, Diplomesodon pulchellum, we documented vibrations, apparently generated by the whole-body wall muscles, from 11 (5 male, 6 female) of 19 animals, placed singly on a drum membrane. The airborne waves of the vibratory drumming were digitally recorded and then analysed spectrographically. The mean frequency of vibration was 160.5 Hz. This frequency matched the periodicity of the deep sinusoidal frequency modulation (159.4 Hz) found in loud screech calls of the same subjects. The body vibration was not related to thermoregulation, hunger-related depletion of energy resources or fear, as it was produced by well-fed, calm animals, at warm ambient temperatures. We hypothesize that in the solitary, nocturnal, digging desert piebald shrew, body vibrations may be used for seismic exploration of substrate density, to avoid energy-costly digging of packed sand for burrowing and foraging. At the same time, the piercing quality of screech calls due to the deep sinusoidal frequency modulation, matching the periodicity of body vibration, may be important for agonistic communication in this species. PMID:22837458

  5. Measuring airborne components of seismic body vibrations in a Middle-Asian sand-dwelling Insectivora species, the piebald shrew (Diplomesodon pulchellum).

    PubMed

    Volodin, Ilya A; Zaytseva, Alexandra S; Ilchenko, Olga G; Volodina, Elena V; Chebotareva, Anastasia L

    2012-08-15

    Self-produced seismic vibrations have been found for some subterranean rodents but have not been reported for any Insectivora species, although seismic sensitivity has been confirmed for blind sand-dwelling chrysochlorid golden moles. Studying the vocal behaviour of captive piebald shrews, Diplomesodon pulchellum, we documented vibrations, apparently generated by the whole-body wall muscles, from 11 (5 male, 6 female) of 19 animals, placed singly on a drum membrane. The airborne waves of the vibratory drumming were digitally recorded and then analysed spectrographically. The mean frequency of vibration was 160.5 Hz. This frequency matched the periodicity of the deep sinusoidal frequency modulation (159.4 Hz) found in loud screech calls of the same subjects. The body vibration was not related to thermoregulation, hunger-related depletion of energy resources or fear, as it was produced by well-fed, calm animals, at warm ambient temperatures. We hypothesize that in the solitary, nocturnal, digging desert piebald shrew, body vibrations may be used for seismic exploration of substrate density, to avoid energy-costly digging of packed sand for burrowing and foraging. At the same time, the piercing quality of screech calls due to the deep sinusoidal frequency modulation, matching the periodicity of body vibration, may be important for agonistic communication in this species.

  6. Integration for Airborne Dust Prediction Systems and Vegetation Phenology to Track Pollen for Asthma Alerts in Public Health Decision Support Systems

    NASA Technical Reports Server (NTRS)

    Luvall, J. C.; Sprigg, W. A.; Nickovic, S.; Huete, A.; Budge, A.; Flowers, L.

    2008-01-01

    The objective of the program is to assess the feasibility of combining a dust transport model with MODIS derived phenology to study pollen transport for integration with a public health decision support system. The use of pollen information has specifically be identified as a critical need by the New Mexico State Health department for inclusion in the Environmental Public Health Tracking (EPHT) program. Material and methods: Pollen can be transported great distances. Local observations of plan phenology may be consistent with the timing and source of pollen collected by pollen sampling instruments. The Dust REgional Atmospheric Model (DREAM) is an integrated modeling system designed to accurately describe the dust cycle in the atmosphere. The dust modules of the entire system incorporate the state of the art parameterization of all the major phases of the atmospheric dust life such as production, diffusion, advection, and removal. These modules also include effects of the particles size distribution on aerosol dispersion. The model was modified to use pollen sources instead of dust. Pollen release was estimated based on satellite-derived phenology of key plan species and vegetation communities. The MODIS surface reflectance product (MOD09) provided information on the start of the plant growing season, growth stage, and pollen release. The resulting deterministic model is useful for predicting and simulating pollen emission and downwind concentration to study details of phenology and meteorology and their dependencies. The proposed linkage in this project provided critical information on the location timing and modeled transport of pollen directly to the EPHT> This information is useful to support the centers for disease control and prevention (CDC)'s National EPHT and the state of New Mexico environmental public health decision support for asthma and allergies alerts.

  7. Measurements of Asian dust optical properties over the Yellow Sea of China by shipboard and ground-based photometers, along with satellite remote sensing: A case study of the passage of a frontal system during April 2006

    NASA Astrophysics Data System (ADS)

    Liu, Yi; Yang, Dongxu; Chen, Wenzhong; Zhang, Hua

    2010-04-01

    Aerosol optical properties were measured by a POM-01 MarkII Sun and sky photometer onboard the Dongfanghong Number 2 Research Ship on the Yellow Sea of China during the passage of a cold front surrounded by airborne dust that originated in Mongolia between 21 and 24 April 2006. The aerosol size distributions in clean marine environment were dominated by an accumulate mode with radius of 0.15 μm and a coarse mode with radius of 4.5 μm. The mean aerosol optical depth (AOD) and Ångström exponent were 0.26 and 1.26, respectively. In the frontal zone the aerosol size distribution was dominated by an accumulate mode with radius of 0.25 μm and two coarse modes with radii of 1.69 and 7.73 μm, and the AOD and Ångström exponent were 2.46 and 0.84, respectively. In the nonfrontal dust conditions, the concentration of coarse modes with radii of 2.5 μm increased to a maximum of 0.3 μm3/μm2, and the mean AOD and Ångström exponent were 0.70 and 0.30, respectively. Aerosol Robotic Network (AERONET) observations combined with shipboard measurements reveal the decreasing concentration of dust aerosol during its transport from continent to Japan. The spatial distribution of dust aerosol was studied using the Aqua/Moderate Resolution Imaging Spectroradiometer (MODIS) and Aura/Ozone Monitoring Instrument (OMI) products. On 22 April, for frontal dust, their AOD and UV aerosol index (UVAI) increased with decreasing distance to the frontal line, peaked with values of 4.36 and 5.21 in the frontal zone, and decreased rapidly with increasing distance off the frontal line. On 23 April, nonfrontal dust showed the lower AOD and UVAI with peak values of 2.0 and 2.7, respectively.

  8. Modeling of dust deposition in central Asia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The deposition of dust particles has a significant influence on the global bio-geochemical cycle. Currently, the lack of spatiotemporal data creates great uncertainty in estimating the global dust budget. To improve our understanding of the fate, transport and cycling of airborne dust, there is a ne...

  9. Assessing exposure risk for dust storm events-associated lung function decrement in asthmatics and implications for control

    NASA Astrophysics Data System (ADS)

    Hsieh, Nan-Hung; Liao, Chung-Min

    2013-04-01

    Asian dust storms (ADS) events are seasonally-based meteorological phenomena that exacerbate chronic respiratory diseases. The purpose of this study was to assess human health risk from airborne dust exposure during ADS events in Taiwan. A probabilistic risk assessment framework was developed based on exposure and experimental data to quantify ADS events induced lung function decrement. The study reanalyzed experimental data from aerosol challenge in asthmatic individuals to construct the dose-response relationship between inhaled dust aerosol dose and decreasing percentage of forced expiratory volume in 1 s (%FEV1). An empirical lung deposition model was used to predict deposition fraction for size specific dust aerosols in pulmonary regions. The toxicokinetic and toxicodynamic models were used to simulate dust aerosols binding kinetics in lung airway in that %FEV1 change was also predicted. The mask respirators were applied to control the inhaled dose under dust aerosols exposure. Our results found that only 2% probability the mild ADS events were likely to cause %FEV1 decrement higher than 5%. There were 50% probability of decreasing %FEV1 exceeding 16.9, 18.9, and 7.1% in north, center, and south Taiwan under severe ADS events, respectively. Our result implicates that the use of activated carbon of mask respirators has the best efficacy for reducing inhaled dust aerosol dose, by which the %FEV1 decrement can be reduced up to less than 1%.

  10. 30 CFR 33.32 - Determination of dust concentration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., EVALUATION, AND APPROVAL OF MINING PRODUCTS DUST COLLECTORS FOR USE IN CONNECTION WITH ROCK DRILLING IN COAL MINES Test Requirements § 33.32 Determination of dust concentration. (a) Concentrations of airborne dust... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Determination of dust concentration....

  11. 30 CFR 33.32 - Determination of dust concentration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Determination of dust concentration. 33.32... MINES Test Requirements § 33.32 Determination of dust concentration. (a) Concentrations of airborne dust... microscopic technique shall be employed in determining concentrations of dust in terms of millions...

  12. 30 CFR 33.32 - Determination of dust concentration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Determination of dust concentration. 33.32... MINES Test Requirements § 33.32 Determination of dust concentration. (a) Concentrations of airborne dust... microscopic technique shall be employed in determining concentrations of dust in terms of millions...

  13. 30 CFR 33.32 - Determination of dust concentration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Determination of dust concentration. 33.32... MINES Test Requirements § 33.32 Determination of dust concentration. (a) Concentrations of airborne dust... microscopic technique shall be employed in determining concentrations of dust in terms of millions...

  14. Towards the Development of a Low Cost Airborne Sensing System to Monitor Dust Particles after Blasting at Open-Pit Mine Sites.

    PubMed

    Alvarado, Miguel; Gonzalez, Felipe; Fletcher, Andrew; Doshi, Ashray

    2015-01-01

    Blasting is an integral part of large-scale open cut mining that often occurs in close proximity to population centers and often results in the emission of particulate material and gases potentially hazardous to health. Current air quality monitoring methods rely on limited numbers of fixed sampling locations to validate a complex fluid environment and collect sufficient data to confirm model effectiveness. This paper describes the development of a methodology to address the need of a more precise approach that is capable of characterizing blasting plumes in near-real time. The integration of the system required the modification and integration of an opto-electrical dust sensor, SHARP GP2Y10, into a small fixed-wing and multi-rotor copter, resulting in the collection of data streamed during flight. The paper also describes the calibration of the optical sensor with an industry grade dust-monitoring device, Dusttrak 8520, demonstrating a high correlation between them, with correlation coefficients (R(2)) greater than 0.9. The laboratory and field tests demonstrate the feasibility of coupling the sensor with the UAVs. However, further work must be done in the areas of sensor selection and calibration as well as flight planning. PMID:26274959

  15. Relations Between Cloud Condensation Nuclei And Aerosol Optical Properties Relevant to Remote Sensing: Airborne Measurements in Biomass Burning, Pollution and Dust Aerosol Over North America

    NASA Astrophysics Data System (ADS)

    Shinozuka, Y.; Clarke, A.; Howell, S.; Kapustin, V.; McNaughton, C.; Zhou, J.; Decarlo, P.; Jimenez, J.; Roberts, G.; Tomlinson, J.; Collins, D.

    2008-12-01

    Remote sensing of the concentration of cloud condensation nuclei (CCN) would help investigate the indirect effect of tropospheric aerosols on clouds and climate. In order to assess its feasibility, this paper evaluates the spectral-based retrieval technique for aerosol number and seeks one for aerosol solubility, using in-situ aircraft measurements of aerosol size distribution, chemical composition, hygroscopicity, CCN activity and optical properties. Our statistical analysis reveals that the CCN concentration over Mexico can be optically determined to a relative error of <20%, smaller than that for the mainland US and the surrounding oceans (~a factor of 2). Mexico's advantage is four-fold. Firstly, many particles originating from the lightly regulated industrial combustion and biomass burning are large enough to significantly affect light extinction, elevating the correlation between extinction and CCN number in absence of substantial dust. Secondly, the generally low ambient humidity near the major aerosol sources limits the error in the estimated response of particle extinction to humidity changes. Thirdly, because many CCN contain black carbon, light absorption also provides a measure of the CCN concentration. Fourthly, the organic fraction of volatile mass of submicron particles (OMF) is anti-correlated with the wavelength dependence of extinction due to preferential anion uptake by coarse dust, which provides a potential tool for remote-sensing OMF and the particle solubility.

  16. Towards the Development of a Low Cost Airborne Sensing System to Monitor Dust Particles after Blasting at Open-Pit Mine Sites

    PubMed Central

    Alvarado, Miguel; Gonzalez, Felipe; Fletcher, Andrew; Doshi, Ashray

    2015-01-01

    Blasting is an integral part of large-scale open cut mining that often occurs in close proximity to population centers and often results in the emission of particulate material and gases potentially hazardous to health. Current air quality monitoring methods rely on limited numbers of fixed sampling locations to validate a complex fluid environment and collect sufficient data to confirm model effectiveness. This paper describes the development of a methodology to address the need of a more precise approach that is capable of characterizing blasting plumes in near-real time. The integration of the system required the modification and integration of an opto-electrical dust sensor, SHARP GP2Y10, into a small fixed-wing and multi-rotor copter, resulting in the collection of data streamed during flight. The paper also describes the calibration of the optical sensor with an industry grade dust-monitoring device, Dusttrak 8520, demonstrating a high correlation between them, with correlation coefficients (R2) greater than 0.9. The laboratory and field tests demonstrate the feasibility of coupling the sensor with the UAVs. However, further work must be done in the areas of sensor selection and calibration as well as flight planning. PMID:26274959

  17. Towards the Development of a Low Cost Airborne Sensing System to Monitor Dust Particles after Blasting at Open-Pit Mine Sites.

    PubMed

    Alvarado, Miguel; Gonzalez, Felipe; Fletcher, Andrew; Doshi, Ashray

    2015-01-01

    Blasting is an integral part of large-scale open cut mining that often occurs in close proximity to population centers and often results in the emission of particulate material and gases potentially hazardous to health. Current air quality monitoring methods rely on limited numbers of fixed sampling locations to validate a complex fluid environment and collect sufficient data to confirm model effectiveness. This paper describes the development of a methodology to address the need of a more precise approach that is capable of characterizing blasting plumes in near-real time. The integration of the system required the modification and integration of an opto-electrical dust sensor, SHARP GP2Y10, into a small fixed-wing and multi-rotor copter, resulting in the collection of data streamed during flight. The paper also describes the calibration of the optical sensor with an industry grade dust-monitoring device, Dusttrak 8520, demonstrating a high correlation between them, with correlation coefficients (R(2)) greater than 0.9. The laboratory and field tests demonstrate the feasibility of coupling the sensor with the UAVs. However, further work must be done in the areas of sensor selection and calibration as well as flight planning.

  18. Airborne Transparencies.

    ERIC Educational Resources Information Center

    Horne, Lois Thommason

    1984-01-01

    Starting from a science project on flight, art students discussed and investigated various means of moving in space. Then they made acetate illustrations which could be used as transparencies. The projection phenomenon made the illustrations look airborne. (CS)

  19. Dynamic Dust Accumulation and Dust Removal Observed on the Mars Exploration Rover Magnets

    NASA Technical Reports Server (NTRS)

    Bertelsen, P.; Bell, J. F., III; Goetz, W.; Gunnlaugsson, H. P.; Herkenhoff, K. E.; Hviid, S. F.; Johnson, J. R.; Kinch, K. M.; Knudsen, J. M.; Madsen, M. B.

    2005-01-01

    The Mars Exploration Rovers each carry a set of Magnetic Properties Experiments designed to investigate the properties of the airborne dust in the Martian atmosphere. It is a preferred interpretation of previous experiments that the airborne dust in the Martian atmosphere is primarily composed by composite silicate particles containing one or more highly magnetic minerals as a minor constituent. The ultimate goal of the magnetic properties experiments on the Mars Exploration Rover mission is to provide some information/ constraints on whether the dust is formed by volcanic, meteoritic, aqueous, or other processes. The first problem is to identify the magnetic mineral(s) in the airborne dust on Mars. While the overall results of the magnetic properties experiments are presented in, this abstract will focus on dust deposition and dust removal on some of the magnets.

  20. In Brief: Agreement signed for NSF participation in IODP; Asian dust storms' intensity, scale grow; Continued use of methyl bromide allowed

    NASA Astrophysics Data System (ADS)

    Jacobs, Judith; Showstack, Randy

    2004-04-01

    The U.S. National Science Foundation on 30 March signed a cooperative agreement with the Joint Oceanographic Institutions (JOI) in Washington, D.C., to lead U.S. participation in the Integrated Ocean Drilling Program (IODP). Large-scale, destructive dust and sand storms that originate in the dry regions of northern China and Mongolia are plaguing the Korean peninsula, Japan and other parts of northeast Asia nearly five times more frequently than in the 1950s, participants in a meeting sponsored by the U.N. Environment Programme (UNEP) learned on 30 March. Twelve countries have received ``critical use exemptions'' to continue using limited amounts of the pesticide methyl bromide in 2005.

  1. Conveyor dust control

    SciTech Connect

    Goldbeck, L.

    1999-11-01

    In the past, three different approaches have been used to control dust arising at conveyor load zones. They are: Dust Containment consists of those mechanical systems employed to keep material inside the transfer point with the main material body. Dust Suppression systems increase the mass of suspended dust particles, allowing them to fall from the air stream. Dust Collection is the mechanical capture and return of airborne material after it becomes airborne from the main material body. Previously, these three approaches have always been seen as separate entities. They were offered by separate organizations competing in the marketplace. The three technologies vied for their individual piece of the rock, at the expense of the other technologies (and often at the expense of overall success). There have been considerable amounts of I`m better selling, as well as finger pointing at the other systems when problems arose. Each system claimed its own technology was the best, providing the most effective, most cost-efficient, most maintenance-free solution to fugitive material.

  2. Desert Dust Layers Over Polluted Marine Boundary Layers: ACE-2 Measurements and ACE-Asia Plans

    NASA Technical Reports Server (NTRS)

    Russell, Philip B.; Schmid, B.; Livingston, J. M.; Redemann, J.; Bergstrom, R. W.; Condon, Estelle P. (Technical Monitor)

    2000-01-01

    Aerosols in ACE-Asia are expected to have some commonalties with those in ACE-2, along with important differences. Among the commonalities are occurrences of desert dust layers over polluted marine boundary layers. Differences include the nature of the dust (yellowish in the East Asia desert outflow, vs. reddish-brown in the Sahara Outflow measured in ACE-2) and the composition of boundary-layer aerosols (e.g., more absorbing, soot and organic aerosol in-the Asian plume, caused by coal and biomass burning, with limited controls). In this paper we present ACE-2 measurements and analyses as a guide to our plans for ACE-2 Asia. The measurements include: (1) Vertical profiles of aerosol optical depth and extinction (380-1558 nm), and of water vapor column and concentration, from the surface through the elevated desert dust, measured by the 14-channel Ames Airborne Tracking Sunphotometer (AATS-14); (2) Comparisons of airborne and shipborne sunphotometer optical depths to satellite-retrieved values, with and without desert dust; (3) Comparisons between airborne Sunphotometer optical depth and extinction spectra and those derived from coincident airborne in situ measurements of aerosol size distribution, scattering and absorption; (4) Comparisons between size distributions measured in situ and retrieved from sunphotometer optical depth spectra; (5) Comparisons between aerosol single scattering albedo values obtained by several techniques, using various combinations of measurements of backscatter, extinction, size distribution, scattering, absorption, and radiative flux. We show how analyses of these data can be used to address questions important to ACE-Asia, such as: (1) How do dust and other absorbing aerosols affect the accuracy of satellite optical depth retrievals? How important are asphericity effects? (2) How important are supermicron dust and seasalt aerosols to overall aerosol optical depth and radiative forcing? How well are these aerosols sampled by aircraft

  3. Radiative Energetics of Mineral Dust Aerosols from Ground-Based Measurements

    NASA Technical Reports Server (NTRS)

    Tsay, Si-Chee; Hansell, Richard A.

    2011-01-01

    Airborne dust aerosols worldwide contribute a significant part to air quality problems and, to some extent, regional climatic issues (e.g., radiative forcing, hydrological cycle, and primary biological productivity in oceans). Evaluating the direct solar radiative effect of dust aerosols is relatively straightforward due in part to the relatively large SIN ratio in broadband irradiance measurements. The longwave (LW) impact, on the other hand, is rather difficult to ascertain since the measured dust signal level (approx.10 W/sq m) is on the same order as the instrumental uncertainties. Although the magnitude of the LW impact is much smaller than that of the shortwave (SW), it can still have a noticeable influence on the energy distribution of Earth-atmosphere system, particularly due to the strong light-absorptive properties commonly found in many terrestrial minerals. The current effort is part of an ongoing research study to perform a global assessment of dust direct aerosol radiative effects (DARE) during major field deployments of key dust source regions worldwide. In this work we present results stemming from two previous field deployments: the 2006 NASA African Monsoon Multidisciplinary Activities and the 2008 Asian Monsoon Years, both utilizing NASA Goddard's mobile ground-based facility. The former study focused on transported Saharan dust at Sal (16.73degN, 22.93degW), Cape Verde along the west coast of Africa while the latter focused on Asian dust at Zhangye (39.082degN, 100.276degE), China near the source between the Taklimakan and Gobi deserts. Due to the compelling variability in spatial and temporal scale of dust properties during field experiments, a deterministic I-D radiative transfer model constrained by local measurements (i.e., spectral photometry/interferometry and lidar for physical/microphysical, mineralogy, and single-scattering properties) is employed to evaluate dust's local instantaneous SW/LW DARE both at the surface and at the top of

  4. Recent Progress in Characterization of Dust over Land Surfaces with Space-borne Passive Remote Sensing

    NASA Technical Reports Server (NTRS)

    Hsu, N. Christina

    2008-01-01

    Among the many components that contribute to air pollution, airborne mineral dust plays an important role due to its biogeochemical impact on the ecosystem and its radiative-forcing effect on the climate system. In East Asia, dust storms frequently accompany the cold and dry air masses that occur as part of springtime cold front systems. Outbreaks of Asian dust storms occur often in the arid and semi-arid areas of northwestern China -about 1.6x10(exp 6) square kilometers including the Gobi and Taklimakan deserts- with continuous expanding of spatial coverage. These airborne dust particles, originating in desert areas far from polluted regions, interact with anthropogenic sulfate and soot aerosols emitted from Chinese mega-cities during their transport over the mainland. Adding the intricate effects of clouds and marine aerosols, dust particles reaching the marine environment can have drastically different properties than those from their sources. Furthermore, these aerosols, once generated over the source regions, can be transported out of the boundary layer into the free troposphere and can travel thousands of kilometers across the Pacific into the United States and beyond. In this paper, we will demonstrate the capability of a new satellite algorithm to retrieve aerosol properties (e.g., optical thickness, single scattering albedo) over bright-reflecting surfaces such as urban areas and deserts. Such retrievals have been difficult to perform using previously available algorithms that use wavelengths from the mid-visible to the near IR because they have trouble separating the aerosol signal from the contribution due to the bright surface reflectance. This new algorithm, called Deep Blue, utilizes blue-wavelength measurements from instruments such as SeaWiFS and MODIS to infer the properties of aerosols, since the surface reflectance over land in the blue part of the spectrum is much lower than for longer wavelength channels. Reasonable agreements have been

  5. Fourth Airborne Geoscience Workshop

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The focus of the workshop was on how the airborne community can assist in achieving the goals of the Global Change Research Program. The many activities that employ airborne platforms and sensors were discussed: platforms and instrument development; airborne oceanography; lidar research; SAR measurements; Doppler radar; laser measurements; cloud physics; airborne experiments; airborne microwave measurements; and airborne data collection.

  6. Improve dust capture on your surface drill

    SciTech Connect

    Page, S.J.; Listak, J.M.; Reed, R.

    2008-09-15

    Researchers have developed a model to describe airborne respirable dust (ARD) generation on surface coal mine drills. By measuring a few basic parameters and using a graph, a drill operator or engineer can estimate the relative severity of drill dust emissions as well as how much of a reduction in ARD can be obtained by changing any given parameter. 4 refs., 2 figs.

  7. Size Distributions and Formation Pathways of Organic and Inorganic Constituents in Spring Aerosols from Okinawa Island in the Western North Pacific Rim: An Outflow Region of Asian Dusts

    NASA Astrophysics Data System (ADS)

    Deshmukh, D. K.; Lazaar, M.; Kawamura, K.; Kunwar, B.; Tachibana, E.; Boreddy, S. K. R.

    2015-12-01

    Size-segregated aerosols (9-stages) were collected at Okinawa Island in the western North Pacific Rim in spring 2008. The samples were analyzed for diacids (C2-C12), ω-oxoacids (ωC2-ωC9), a-dicarbonyls (C2-C3), organic carbon (OC), water-soluble OC (WSOC) and major ions to understand the sources and atmospheric processes in the outflow region of Asian pollutants. The molecular distribution of diacids showed the predominance of oxalic acid (C2) followed by malonic and succinic acids in all the size-segregated aerosols. ω-Oxoacids showed the predominance of glyoxylic acid (ωC2) whereas glyoxal (Gly) was more abundant than methylglyoxal in all the sizes. The abundant presence of sulfate as well as phthalic and adipic acids in Okinawa aerosols suggested a significant contribution of anthropogenic sources in East Asia via long-range atmospheric transport. Diacids (C2-C5), ωC2 and Gly as well as WSOC and OC peaked at 0.65-1.1 µm in fine mode whereas azelaic (C9) and 9-oxononanoic (ωC9) acids peaked at 3.3-4.7 µm in coarse mode. Sulfate and ammonium are enriched in fine mode whereas sodium and chloride are in coarse mode. An important mechanism for the formation of these organic species in Okinawa aerosols is probably gas phase oxidation of VOCs and subsequent in-cloud processing during long-range transport. Their characteristics size distribution implies that fine particles enriched with these organic and inorganic species could act as CCN to develop the cloud cover over the western North Pacific. The major peak of C9 and ωC9 on coarse mode suggest that they are produced by photooxidation of unsaturated fatty acids mainly derived from phytoplankton via heterogeneous reactions on sea spray particles. This study demonstrates that anthropogenic aerosols emitted from East Asia have significant influence on the compositions of organic and inorganic aerosols in the western North Pacific Rim.

  8. Lead atmospheric deposition rates and isotopic trends in Asian dust during the last 9.5 kyr recorded in an ombrotrophic peat bog on the eastern Qinghai-Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Ferrat, Marion; Weiss, Dominik J.; Dong, Shuofei; Large, David J.; Spiro, Baruch; Sun, Youbin; Gallagher, Kerry

    2012-04-01

    A full understanding of the atmospheric Pb cycle in Asia during the Holocene is key to palaeoclimate studies of past atmospheric circulation patterns, as well as to assess the impact of increasing industrial activities in this region. However, long-term records of atmospheric Pb isotopic trends in Asia are still sparse. Consequently, we study changes in the concentrations, fluxes and isotopic signature of deposited Pb contained in a 14C-dated peat core from the eastern Qinghai-Tibetan Plateau, dating back to 9.5 kyr BP, and present the first peat record of the changing isotopic composition of atmospheric Pb in dust in Asia during this time. Lead concentrations and fluxes vary between 2.96-21.58 μg g-1 and 0.06-3.52 mg m-2 y-1, respectively, with an average Pb baseline of 6.80 ± 4.18 μg g-1. These values agree with other Pb studies of lake and peat archives in China but are one order of magnitude larger than early and mid-Holocene values measured in Europe. Lead isotopic variability throughout the core is small, varying between 206Pb/207Pb = 1.190-1.197, 206Pb/204Pb = 18.648-18.786, 207Pb/204Pb = 15.666-15.694 and 208Pb/204Pb = 38.890-39.090. The application of Bayesian trans-dimensional changepoint modelling to the Pb dataset enabled the identification of eight significant changes in the isotopic composition of the deposited Pb. Such changes mark different phases of atmospheric Pb deposition, and hence variations in atmospheric circulation patterns and environmental conditions. Temporal variations in the potential natural and/or anthropogenic Pb sources are assessed based on the 206Pb, 207Pb, 208Pb and 204Pb isotopic composition and the 1/[Pb] ratio of the peat samples. Our results suggest that Pb deposition throughout the Holocene was governed by local deposition and long-range input from natural dust sources in northwestern (Taklamakan desert and Qaidam basin) and northern China (Badain Jaran and Tengger deserts). Input from the northern sources seems to have

  9. Reducing Coal Dust With Water Jets

    NASA Technical Reports Server (NTRS)

    Gangal, M. D.; Lewis, E. V.

    1985-01-01

    Jets also cool and clean cutting equipment. Modular pick-and-bucket miner suffers from disadvantage: Creates large quantities of potentially explosive coal dust. Dust clogs drive chain and other parts and must be removed by hand. Picks and bucket lips become overheated by friction and be resharpened or replaced frequently. Addition of oscillating and rotating water jets to pick-and-bucket machine keeps down dust, cools cutting edges, and flushes machine. Rotating jets wash dust away from drive chain. Oscillating jets cool cutting surfaces. Both types of jet wet airborne coal dust; it precipitates.

  10. Airborne Imagery

    NASA Technical Reports Server (NTRS)

    1983-01-01

    ATM (Airborne Thematic Mapper) was developed for NSTL (National Space Technology Companies) by Daedalus Company. It offers expanded capabilities for timely, accurate and cost effective identification of areas with prospecting potential. A related system is TIMS, Thermal Infrared Multispectral Scanner. Originating from Landsat 4, it is also used for agricultural studies, etc.

  11. Saharan Dust over Senegal

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Airborne African dust regularly reaches northeastern South America and the Caribbean. Westward dust transport from the Sahara across the central Atlantic has been a common occurrence this spring, with major events visible in both satellite images and photographs. Cap Vert, the westernmost point of Senegal, is dimly visible beneath the dust mass (center); the Arquipelago dos Bijagos in Guinea Bissau lies opposite the mouth of the sediment-laden Rio Corubal. This photo (ISS004-E-12080) was taken by the crew of the International Space Station on May 18, 2002, using a digital camera with a 35-mm lens. Image provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

  12. Deciphering the Role of Desert Dust in the Climate Puzzle: The Mediterranean Israeli Dust Experiment (MEIDEX)

    NASA Technical Reports Server (NTRS)

    Levin, Zev; Joseph, Joachim; Mekler, Yuri; Israelevich, Peter; Ganor, Eli; Hilsenrath, Ernest; Janz, Scott

    2002-01-01

    Numerous studies have shown that aerosol particles may be one of the primary agents that can offset the climate warming induced by the increase in the amount of atmospheric greenhouse gases. Desert aerosols are probably the most abundant and massive type of aerosol particles that are present in the atmosphere worldwide. These aerosols are carried over large distances and have various global impacts. They interact with clouds, impact the efficiency of their rain production and change their optical properties. They constitute one of the primary sources of minerals for oceanic life and influence the health of coral reefs. They have direct effects on human health, especially by inducing breathing difficulties in children. It was lately discovered that desert particles carry pathogens from the Sahara desert over the Atlantic Ocean, a fact that may explain the migration of certain types of diseases. Aerosols not only absorb solar radiation but also scatter it, so that their climatic effect is influenced not only by their physical properties and height distribution but also by the reflectivity of the underlying surface. This latter property changes greatly over land and is low over ocean surfaces. Aerosol plumes are emitted from discrete, sporadic sources in the desert areas of the world and are transported worldwide by the atmosphere's wind systems. For example, Saharan dust reaches Mexico City, Florida, Ireland, Switzerland and the Mediterranean region, while Asian dust reaches Alaska, Hawaii and the continental United States. This means that in order to assess its global effects, one must observe dust from space. The Space Shuttle is a unique platform, because it flies over the major deserts of our planet, enabling measurements and remote sensing of the aerosols as they travel from source to sink regions. Such efforts must always be accompanied by in-situ data for validation and calibration, with direct sampling of the airborne particles. MEIDEX is a joint project of

  13. Living on the Lunar Surface: Determining the Health Effects of Exposure to Respirable Lunar Dusts

    NASA Astrophysics Data System (ADS)

    Khan-Mayberry, N. N.

    2008-07-01

    NASA formed the Lunar Airborne Dust Toxicity Advisory Group (LADTAG) to determine the toxicological effects of lunar dust. This interdisciplinary group is comprised of leading experts in space toxicology, lunar geology, space medicine and biomedical research.

  14. Hebes Chasma Dust Avalanches

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Dust avalanches, also called slope streaks, occur on many Martian terrains. The deposition of airborne dust on surfaces causes a bright tone in the THEMIS VIS images. Any movement of the dust downhill, a dust avalanche, will leave behind a streak where the darker, dust-free surface is exposed.

    These dust avalanches are located in Hebes Chasma.

    Image information: VIS instrument. Latitude -1.4, Longitude 286.6 East (73.4 West). 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  15. Dust storm off Western Africa

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The impacts of Saharan dust storms reach far beyond Africa. Wind-swept deserts spill airborne dust particles out over the Atlantic Ocean where they can enter trade winds bound for Central and North America and the Caribbean. This Moderate Resolution Imaging Spectroradiometer (MODIS) image shows a dust storm casting an opaque cloud of cloud across the Canary Islands and the Atlantic Ocean west of Africa on June 30, 2002. In general it takes between 5 and 7 days for such an event to cross the Atlantic. The dust has been shown to introduce foreign bacteria and fungi that have damaged reef ecosystems and have even been hypothesized as a cause of increasing occurrences of respiratory complaints in places like Florida, where the amount of Saharan dust reaching the state has been increasing over the past 25 years.

  16. 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

  17. The improvement of dust model applying modified soil component of dust source over East Asia.

    NASA Astrophysics Data System (ADS)

    Kwon, D. H.; Koo, Y. S.

    2014-12-01

    The East Asia region is the world's most populous area with a rapidly growing economy resulting in large air pollutant emissions. Asian mineral dust from Gobi Desert, Loess Plateau and barren mixed soil in Northern China and Mongolia has a major impact on the air quality in the Seoul Metropolitan Area. These mineral aerosols PM10 (particulate matter less than 10 um in diameter) concentration frequently exceeds the daily ambient air quality standards of 100μgm-3, and the number of exceedance days of daily PM10 reached about 40 times annually. The PM10 prediction by a regional chemical transport model without the dust emission shows an intrinsic tendency to underestimation according to previous studies in this region, especially for the soil originated coarse PM. This is partially due to the uncertainty of fugitive dust emissions. This study is aim to improve dust model(ADAM2 - Asian Dust Aeorosol Model 2) by changing soil component over source regions using Harmonized World Soil Database. ADAM2 has four dust components of the Gobi Desert, sand dsert, Loess Plateau and barren mixed soil. The soil components, however, should be updated as current and detailed soil components. Therfore, we apply updated dust model with CTM(Chemical Transport Model), CMAQ(Community Multi-scale Air Quality Model) to simulate dust concentration over East Asia. It is found that dust concentration with updated dust model is better agreement with observation during dust event periods, compared with standard dust model.

  18. Desert Dust Properties, Modelling, and Monitoring

    NASA Technical Reports Server (NTRS)

    Kaskaoutis, Dimitris G.; Kahn, Ralph A.; Gupta, Pawan; Jayaraman, Achuthan; Bartzokas, Aristides

    2013-01-01

    This paper is just the three-page introduction to a Special Issue of Advances in Meteorology focusing on desert dust. It provides a paragraph each on 13 accepted papers, most relating to the used of satellite data to assess attributes or distribution of airborne desert dust. As guest Associate Editors of this issue, we organized the papers into a systematic whole, beginning with large-scale transport and seasonal behavior, then to regional dust transport, transport history, and climate impacts, first in the Mediterranean region, then India and central Asia, and finally focusing on transport model assessment and the use of lidar as a technique to constrain dust spatial-temporal distribution.

  19. The Continuous Monitoring of Desert Dust using an Infrared-based Dust Detection and Retrieval Method

    NASA Technical Reports Server (NTRS)

    Duda, David P.; Minnis, Patrick; Trepte, Qing; Sun-Mack, Sunny

    2006-01-01

    Airborne dust and sand are significant aerosol sources that can impact the atmospheric and surface radiation budgets. Because airborne dust affects visibility and air quality, it is desirable to monitor the location and concentrations of this aerosol for transportation and public health. Although aerosol retrievals have been derived for many years using visible and near-infrared reflectance measurements from satellites, the detection and quantification of dust from these channels is problematic over bright surfaces, or when dust concentrations are large. In addition, aerosol retrievals from polar orbiting satellites lack the ability to monitor the progression and sources of dust storms. As a complement to current aerosol dust retrieval algorithms, multi-spectral thermal infrared (8-12 micron) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Meteosat-8 Spinning Enhanced Visible and Infrared Imager (SEVIRI) are used in the development of a prototype dust detection method and dust property retrieval that can monitor the progress of Saharan dust fields continuously, both night and day. The dust detection method is incorporated into the processing of CERES (Clouds and the Earth s Radiant Energy System) aerosol retrievals to produce dust property retrievals. Both MODIS (from Terra and Aqua) and SEVERI data are used to develop the method.

  20. 30 CFR 33.4 - Types of dust collectors for which certificates of approval may be granted.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CONNECTION WITH ROCK DRILLING IN COAL MINES General Provisions § 33.4 Types of dust collectors for which... specifically to prevent dissemination of airborne dust generated by drilling into coal-mine rock strata...

  1. 30 CFR 33.4 - Types of dust collectors for which certificates of approval may be granted.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CONNECTION WITH ROCK DRILLING IN COAL MINES General Provisions § 33.4 Types of dust collectors for which... specifically to prevent dissemination of airborne dust generated by drilling into coal-mine rock strata...

  2. 30 CFR 33.4 - Types of dust collectors for which certificates of approval may be granted.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CONNECTION WITH ROCK DRILLING IN COAL MINES General Provisions § 33.4 Types of dust collectors for which... specifically to prevent dissemination of airborne dust generated by drilling into coal-mine rock strata...

  3. 30 CFR 33.4 - Types of dust collectors for which certificates of approval may be granted.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CONNECTION WITH ROCK DRILLING IN COAL MINES General Provisions § 33.4 Types of dust collectors for which... specifically to prevent dissemination of airborne dust generated by drilling into coal-mine rock strata...

  4. Mechanical intervention for reducing dust concentration in traditional rice mills.

    PubMed

    Pranav, Prabhanjan K; Biswas, Mrinmoy

    2016-08-01

    A huge number of workers are employed in traditional rice mills where they are potentially exposed to dust. In this study a dust collection system was developed to capture the airborne dust in the rice mill. The feeding and sieving section of the mill was identified as major dust creating zone. The dust was captured by creating suitable air stream at feeding and sieving sections of the mill and collected in cyclone dust collector. The air stream was created by blower which was selected on the basis to get minimum air speed of 0.5 m/s in the working zones of workers. It was observed that the developed system is successfully collects the significant amount of dust and able to reduce the dust concentration up to 58%. Further, the respirable dust concentration reduced to below 5 mg/m(3) throughout the mill which is within the recommended limit of dust exposure.

  5. Mechanical intervention for reducing dust concentration in traditional rice mills

    PubMed Central

    PRANAV, Prabhanjan K.; BISWAS, Mrinmoy

    2016-01-01

    A huge number of workers are employed in traditional rice mills where they are potentially exposed to dust. In this study a dust collection system was developed to capture the airborne dust in the rice mill. The feeding and sieving section of the mill was identified as major dust creating zone. The dust was captured by creating suitable air stream at feeding and sieving sections of the mill and collected in cyclone dust collector. The air stream was created by blower which was selected on the basis to get minimum air speed of 0.5 m/s in the working zones of workers. It was observed that the developed system is successfully collects the significant amount of dust and able to reduce the dust concentration up to 58%. Further, the respirable dust concentration reduced to below 5 mg/m3 throughout the mill which is within the recommended limit of dust exposure. PMID:26829976

  6. Atmospheric dust and acid rain

    SciTech Connect

    Hedin, L.O.; Likens, G.E.

    1996-12-01

    Why is acid rain still an environmental problem in Europe and North America despite antipollution reforms? The answer really is blowing in the wind: atmospheric dust. These airborne particles can help neutralize the acids falling on forests, but dust levels are unusually low these days. In the air dust particles can neutralize acid rain. What can we do about acid rain and atmospheric dust? Suggestions range from the improbable to the feasible. One reasonable suggestion is to reduce emissions of acidic pollutants to levels that can be buffered by natural quantities of basic compounds in the atmosphere; such a goal would mean continued reductions in sulfur dioxide and nitrogen oxides, perhaps even greater than those prescribed in the 1990 Amendments to the Clean Air Act in the U.S. 5 figs.

  7. Dust Detector

    NASA Technical Reports Server (NTRS)

    Kelley, M. C.

    2001-01-01

    We discuss a recent sounding rocket experiment which found charged dust in the Earth's tropical mesosphere. The dust detector was designed to measure small (5000 - 10000 amu.) charged dust particles, most likely of meteoric origin. A 5 km thick layer of positively charged dust was found at an altitude of 90 km, in the vicinity of an observed sporadic sodium layer and sporadic E layer. The observed dust was positively charged in the bulk of the dust layer, but was negatively charged near the bottom.

  8. The Lunar Environment: Determining the Health Effects of Exposure to Moon Dusts

    NASA Technical Reports Server (NTRS)

    Khan-Mayberry, Noreen

    2007-01-01

    The moon's surface is covered with a thin layer of fine, charged, reactive dust capable of layer of fine, charged, reactive dust capable of capable of entering habitats and vehicle compartments, where it can result in crewmember health problems. NASA formed the Lunar Airborne Dust Toxicity Advisory Group (LADTAG) to study the effects of exposure to Lunar Dust on human health. To date, no scientifically defensible toxicological studies have been performed on lunar dusts, specifically the determination of exposure limits and their affect on human health. The multi-center LADTAG (Lunar Airborne Dust Toxicology center LADTAG (Lunar Airborne Dust Toxicology Advisory Group) was formed in response to the Office of the Chief Health and Medical Office s (OCHMO) request to develop recommendations for defining risk (OCHMO) request to develop recommendations for defining risk defining risk criteria for human lunar dust exposure.

  9. Assessing inhalation exposure from airborne soil contaminants

    SciTech Connect

    Shinn, J.H.

    1998-04-01

    A method of estimation of inhalation exposure to airborne soil contaminants is presented. this method is derived from studies of airborne soil particles with radioactive tags. The concentration of contaminants in air (g/m{sup 3}) can be derived from the product of M, the suspended respirable dust mass concentration (g/m{sup 3}), S, the concentration of contaminant in the soil (g/g), and E{sub f}, an enhancement factor. Typical measurement methods and values of M, and E{sub f} are given along with highlights of experiences with this method.

  10. House dust in seven Danish offices

    NASA Astrophysics Data System (ADS)

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

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

  11. Tikhonravov Crater Dust Avalanches

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Dust avalanches, also called slope streaks, occur on many Martian terrains. The deposition of airborne dust on surfaces causes a bright tone in the THEMIS VIS images. Any movement of the dust downhill, a dust avalanche, will leave behind a streak where the darker, dust-free surface is exposed.

    These dust avalanches are located within a small crater inside Tikhonravov Crater.

    Image information: VIS instrument. Latitude 12.6, Longitude 37.1 East (322.9 West). 36 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  12. Crater Dust Avalanches

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Dust avalanches, also called slope streaks, occur on many Martian terrains. The deposition of airborne dust on surfaces causes a bright tone in the THEMIS VIS images. Any movement of the dust downhill, a dust avalanche, will leave behind a streak where the darker, dust-free surface is exposed.

    These dust avalanches are located in a small canyon within a crater rim northeast of Naktong Vallis.

    Image information: VIS instrument. Latitude 7.1, Longitude 34.7 East (325.3 West). 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  13. Lycus Sulci Dust Avalanches

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Dust avalanches, also called slope streaks, occur on many Martian terrains. The deposition of airborne dust on surfaces causes a bright tone in the THEMIS VIS images. Any movement of the dust downhill, a dust avalanche, will leave behind a streak where the darker, dust-free surface is exposed.

    These dust avalanches occur on the slopes of Lycus Sulci near Olympus Mons.

    Image information: VIS instrument. Latitude 28.1, Longitude 220.4 East (139.6 West). 18 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  14. Crater Dust Avalanches

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Dust avalanches, also called slope streaks, occur on many Martian terrains. The deposition of airborne dust on surfaces causes a bright tone in the THEMIS VIS images. Any movement of the dust downhill, a dust avalanche, will leave behind a streak where the darker, dust-free surface is exposed.

    This region of dust avalanches is located in and around a crater to the west of yesterday's image.

    Image information: VIS instrument. Latitude 14.7, Longitude 32.7 East (327.3 West). 18 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  15. Design and development of a dust dispersion chamber to quantify the dispersibility of rock dust

    PubMed Central

    Perera, Inoka E.; Sapko, Michael J.; Harris, Marcia L.; Zlochower, Isaac A.; Weiss, Eric S.

    2015-01-01

    Dispersible rock dust must be applied to the surfaces of entries in underground coal mines in order to inert the coal dust entrained or made airborne during an explosion and prevent propagating explosions. 30 CFR. 75.2 states that “… [rock dust particles] when wetted and dried will not cohere to form a cake which will not be dispersed into separate particles by a light blast of air …” However, a proper definition or quantification of “light blast of air” is not provided. The National Institute for Occupational Safety and Health (NIOSH) has, consequently, designed a dust dispersion chamber to conduct quantitative laboratory-scale dispersibility experiments as a screening tool for candidate rock dusts. A reproducible pulse of air is injected into the chamber and across a shallow tray of rock dust. The dust dispersed and carried downwind is monitored. The mass loss of the dust tray and the airborne dust measurements determine the relative dispersibility of the dust with respect to a Reference rock dust. This report describes the design and the methodology to evaluate the relative dispersibility of rock dusts with and without anti-caking agents. Further, the results of this study indicate that the dispersibility of rock dusts varies with particle size, type of anti-caking agent used, and with the untapped bulk density. Untreated rock dusts, when wetted and dried forming a cake that was much less dispersible than the reference rock dust used in supporting the 80% total incombustible content rule. PMID:26834390

  16. Cell concentration of bacteria in the Asian continent outflow under different weather conditions observed at southwestern Japan between 2010 and 2013

    NASA Astrophysics Data System (ADS)

    Zhang, D.; Murata, K.

    2013-12-01

    Widespread dispersal of microorganisms in the air is considered to be particularly important for ice cloud formation in elevated levels. However, very few quantitative data on their concentration are available. The purpose of the study is to figure out the manner by which bacteria are transported and gain the bacteria's concentration and viability in the Northern Hemisphere westerly winds at the downstream areas of the Asian continent. Viable and non-viable airborne bacteria were measured with fluorescence microscopy coupled with LIVE/DEAD BacLight Bacterial Viability Kits under various weather conditions at Kumamoto, a coastal city in southwestern Japan. The concentration in thermodynamically different air parcels was in the similar order, hundreds of thousand cells per cubic meter, but different ranges. No correlation was found between the concentration and coarse aerosol particles (diameter>1.0 μm) in prefrontal air and anticyclone air. In contrast, the concentration correlated closely with coarse particles in the postfrontal air and the concentration increased proportionally to coarse particle concentrations by 1 ~ 2 orders in the presence of Asian dust. Bacterial viability was around 70% on average in the different kinds of air parcels. However, the viability in fast-moving postfrontal air was smaller. In summary, air parcels following strong cold fronts in the westerly wind flow constantly and efficiently convey airborne bacteria, characterized by coarse particle-correlated high concentration and low viability, from the Asian continent while the bacteria in slowly-moving anticyclone and prefrontal air, characterized by low concentration and high viability, are more likely a mixture of bacteria from the Asian continent and the local areas.

  17. Modeling for Airborne Contamination

    SciTech Connect

    F.R. Faillace; Y. Yuan

    2000-08-31

    The objective of Modeling for Airborne Contamination (referred to from now on as ''this report'') is to provide a documented methodology, along with supporting information, for estimating the release, transport, and assessment of dose to workers from airborne radioactive contaminants within the Monitored Geologic Repository (MGR) subsurface during the pre-closure period. Specifically, this report provides engineers and scientists with methodologies for estimating how concentrations of contaminants might be distributed in the air and on the drift surfaces if released from waste packages inside the repository. This report also provides dose conversion factors for inhalation, air submersion, and ground exposure pathways used to derive doses to potentially exposed subsurface workers. The scope of this report is limited to radiological contaminants (particulate, volatile and gaseous) resulting from waste package leaks (if any) and surface contamination and their transport processes. Neutron activation of air, dust in the air and the rock walls of the drift during the preclosure time is not considered within the scope of this report. Any neutrons causing such activation are not themselves considered to be ''contaminants'' released from the waste package. This report: (1) Documents mathematical models and model parameters for evaluating airborne contaminant transport within the MGR subsurface; and (2) Provides tables of dose conversion factors for inhalation, air submersion, and ground exposure pathways for important radionuclides. The dose conversion factors for air submersion and ground exposure pathways are further limited to drift diameters of 7.62 m and 5.5 m, corresponding to the main and emplacement drifts, respectively. If the final repository design significantly deviates from these drift dimensions, the results in this report may require revision. The dose conversion factors are further derived by using concrete of sufficient thickness to simulate the drift

  18. Dust Storm

    Atmospheric Science Data Center

    2013-04-16

    article title:  Massive Dust Storm over Australia     View ... at JPL September 22, 2009 - Massive dust storm over Australia. project:  MISR category:  ... Sep 22, 2009 Images:  Dust Storm location:  Australia and New Zealand ...

  19. Airborne Sunphotometry of Aerosol Optical Depth and Columnar Water Vapor During ACE-Asia

    NASA Technical Reports Server (NTRS)

    Redemann, Jens; Schmid, B.; Russell, P. B.; Livingston, J. M.; Eilers, J. A.; Ramirez, S. A.; Kahn, R.; Hipskind, R. Stephen (Technical Monitor)

    2001-01-01

    During the Intensive Field Campaign (IFC) of the Aerosol Characterization Experiment - Asia (ACE-Asia), March-May 2001, the 6-channel NASA Ames Airborne Tracking Sunphotometer (AATS-6) operated during 15 of the 19 research flights aboard the NCAR C- 130, while its 14-channel counterpart (AATS- 14) was flown successfully on all 18 research flights of a Twin Otter aircraft operated by the Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS), Monterey, CA. ACE-Asia was the fourth in a series of aerosol characterization experiments and focused on aerosol outflow from the Asian continent to the Pacific basin. Each ACE was designed to integrate suborbital and satellite measurements and models so as to reduce the uncertainty in calculations of the climate forcing due to aerosols. The Ames Airborne Tracking Sunphotometers measured solar beam transmission at 6 (380-1021 nm, AATS-6) and 14 wavelengths (353-1558 nm, AATS-14) respectively, yielding aerosol optical depth (AOD) spectra and column water vapor (CWV). Vertical differentiation in profiles yielded aerosol extinction and water vapor concentration. The wavelength dependence of AOD and extinction indicates that supermicron dust was often a major component of the aerosol. Frequently this dust-containing aerosol extended to high altitudes. For example, in data flights analyzed to date 34 +/- 13% of full-column AOD(525 nm) was above 3 km. In contrast, only 10 +/- 4% of CWV was above 3 km. In this paper, we will show first sunphotometer-derived results regarding the spatial variation of AOD and CWV, as well as the vertical distribution of aerosol extinction and water vapor concentration. Preliminary comparison studies between our AOD/aerosol extinction data and results from: (1) extinction products derived using in situ measurements and (2) AOD retrievals using the Multi-angle Imaging Spectro-Radiometer (MISR) aboard the TERRA satellite will also be presented.

  20. Profile: Asian Americans

    MedlinePlus

    ... the visibility of Asian Americans, Native Hawaiians and Pacific Islander health issues. Overview (Demographics): This racial group ... White population. Selected Data by Disease/Condition Asian/Pacific Islanders and Asthma . Asian/Pacific Islanders and Cancer . ...

  1. Obesity and Asian Americans

    MedlinePlus

    ... related diseases see: Diabetes – See Diabetes and Asians/Pacific Islanders Heart Disease – See Heart Disease and Asians/Pacific Islanders Stroke – See Stroke and Asians/Pacific Islanders ...

  2. Status and Future of Dust Storm Forecasting

    NASA Astrophysics Data System (ADS)

    Westphal, D. L.

    2002-12-01

    In recent years, increased attention has been given to the large amounts of airborne dust derived from the deserts and desertified areas of the world and transported over scales ranging from local to global. This dust can have positive and negative impacts on human activities and the environment, including modifying cloud formation, fertilizing the ocean, degrading air quality, reducing visibility, transporting pathogens, and inducing respiratory problems. The atmospheric radiative forcing by the dust has implications for global climate change and presently is one of the largest unknowns in climate models. These uncertainties have lead to much of the funding for research into the sources, properties, and fate of atmospheric dust. As a result of advances in numerical weather prediction over the past decades and the recent climate research, we are now in a position to produce operational dust storm forecasts. International organizations and national agencies are developing programs for dust forecasting. The approaches and applications of dust detection and forecasting are as varied as the nations that are developing the models. The basic components of a dust forecasting system include atmospheric forcing, dust production, and dust microphysics. The forecasting applications include air and auto traffic safety, shipping, health, national security, climate and weather. This presentation will summarize the methods of dust storm forecasting and illustrate the various applications. The major remaining uncertainties (e.g. sources and initialization) will be discussed as well as approaches for solving those problems.

  3. Planetary Dust: Cross-Functional Considerations

    NASA Technical Reports Server (NTRS)

    Wagner, Sandra

    2006-01-01

    Apollo astronauts learned first hand how problems with dust impact lunar surface missions. After three days, lunar dust contaminating on EVA suit bearings led to such great difficulty in movement that another EVA would not have been possible. Dust clinging to EVA suits was transported into the Lunar Module. During the return trip to Earth, when microgravity was reestablished, the dust became airborne and floated through the cabin. Crews inhaled the dust and it irritated their eyes. Some mechanical systems aboard the spacecraft were damaged due to dust contamination. Study results obtained by Robotic Martian missions indicate that Martian surface soil is oxidative and reactive. Exposures to the reactive Martian dust will pose an even greater concern to the crew health and the integrity of the mechanical systems. As NASA embarks on planetary surface missions to support its Exploration Vision, the effects of these extraterrestrial dusts must be well understood and systems must be designed to operate reliably and protect the crew in the dusty environments of the Moon and Mars. The AIM Dust Assessment Team was tasked to identify systems that will be affected by the respective dust, how they will be affected, associated risks of dust exposure, requirements that will need to be developed, identified knowledge gaps, and recommended scientific measurements to obtain information needed to develop requirements, and design and manufacture the surface systems that will support crew habitation in the lunar and Martian outposts.

  4. Assessing the Performance of the Photovoltaic Cells on the Effects of Yellow Dust Events and Haze in Seoul, Korea

    NASA Astrophysics Data System (ADS)

    Choi, Jiyeon; Kim, Yong Pyo; Wee, DaeHyun

    2016-04-01

    We analyze the potential effects of the Asian yellow dust Events and haze on the performance of Korean photovoltaic systems. Particulate matters from the Asian yellow dust outbreaks in the deserts of Mongolia and northern China are typically transported to Korea. Haze is an atmospheric phenomenon where dust, smoke and other dry particles obscure the clarity of the sky. Hence, we conjecture that the effects of the Asian yellow dust and haze block the incident solar irradiance. The potential reduction of the solar spectral irradiance due to Asian yellow dust events and haze in Korea is investigated using a clear-sky spectral radiation model, and the performance of photovoltaic systems under reduced irradiance is estimated by using a simple analytic model representing typical photovoltaic cells. Comparison of photovoltaic performance under Asian dust events, haze and that under a clear condition is made to evaluate overall influence of the particulate air pollution, respectively.

  5. Evaluation of a low-cost electrostatic dust fall collector for indoor air endotoxin exposure assessment.

    PubMed

    Noss, Ilka; Wouters, Inge M; Visser, Maaike; Heederik, Dick J J; Thorne, Peter S; Brunekreef, Bert; Doekes, Gert

    2008-09-01

    Exposure to endotoxin in home environments has become a key issue in asthma and allergy research. Most studies have analyzed floor or mattress dust endotoxin, but its validity as a proxy for airborne exposure is unknown, while active airborne dust sampling is not feasible in large-scale population studies because of logistic and financial limitations. We therefore developed and evaluated a simple passive airborne dust collection method for airborne endotoxin exposure assessment. We explored an electrostatic dust fall collector (EDC), consisting of a 42- by 29.6-cm-sized folder with four electrostatic cloths exposed to the air. The EDC was tested during two 14-day periods in seven nonfarm and nine farm homes and in farm stables. In parallel, active airborne dust sampling was performed with Harvard impactors and floor dust collected by vacuuming, using nylon sampling socks. The endotoxin levels could be measured in all EDC cloth extracts. The levels (in EU/m(2)) between EDCs used simultaneously or in different sampling periods in the same home correlated strongly (r > 0.8). EDC endotoxin also correlated moderately to strongly (r = 0.6 to 0.8) with the endotoxin measured by active airborne dust sampling and living room floor dust sampling and-in farm homes-with the endotoxin captured by the EDC in stables. In contrast, endotoxin levels measured by floor dust sampling showed only a poor correlation with the levels measured by active airborne dust sampling. We therefore conclude that measuring endotoxin levels with the EDC is a valid measure of average airborne endotoxin exposure, while reproducibility over time is at least equivalent to that of reservoir dust analyses.

  6. The global transport of dust

    USGS Publications Warehouse

    Griffin, Dale W.; Kellogg, C.A.; Garrison, V.H.; Shinn, E.A.

    2002-01-01

    By some estimates as much as two billion metric tons of dust are lifted into the Earth's atmosphere every year. Most of this dust is stirred up by storms, the more dramatic of which are aptly named dust storms. But more than mere dirt is carried aloft. Drifting with the suspended dust particles are soil pollutants such as herbicides and pesticides and a significant number of microorganisms-bacteria, viruses and fungi. We can gain some appreciation of how much microbial life is actually floating in our atmosphere by performing a quick calculation. There are typically about one million bacteria per gram of soil, but let's be conservative and suppose there are only 10,000 bacteria per gram of airborne sediment. Assuming a modest one billion metric tons of sediment in the atmosphere, these numbers translate into a quintillion (1018) sediment-borne bacteria moving around the planet each year-enough to form a microbial bridge between Earth and Jupiter. Here we consider what we've learned about the airborne transport of sediment across the globe, and review some of the remarkable studies in this reemerging field that had it origins more than 100 years ago.

  7. Protoplanetary Dust

    NASA Astrophysics Data System (ADS)

    Apai, Dániel; Lauretta, Dante S.

    2010-01-01

    Preface; 1. Planet formation and protoplanetary dust Daniel Apai and Dante Lauretta; 2. The origins of protoplanetary dust and the formation of accretion disks Hans-Peter Gail and Peter Hope; 3. Evolution of protoplanetary disk structures Fred Ciesla and Cornelius P. Dullemond; 4. Chemical and isotopic evolution of the solar nebula and protoplanetary disks Dmitry Semenov, Subrata Chakraborty and Mark Thiemens; 5. Laboratory studies of simple dust analogs in astrophysical environments John R. Brucato and Joseph A. Nuth III; 6. Dust composition in protoplanetaty dust Michiel Min and George Flynn; 7. Dust particle size evolution Klaus M. Pontoppidan and Adrian J. Brearly; 8. Thermal processing in protoplanetary nebulae Daniel Apai, Harold C. Connolly Jr. and Dante S. Lauretta; 9. The clearing of protoplanetary disks and of the protosolar nebula Ilaira Pascucci and Shogo Tachibana; 10. Accretion of planetesimals and the formation of rocky planets John E. Chambers, David O'Brien and Andrew M. Davis; Appendixes; Glossary; Index.

  8. Protoplanetary Dust

    NASA Astrophysics Data System (ADS)

    Apai, D.´niel; Lauretta, Dante S.

    2014-02-01

    Preface; 1. Planet formation and protoplanetary dust Daniel Apai and Dante Lauretta; 2. The origins of protoplanetary dust and the formation of accretion disks Hans-Peter Gail and Peter Hope; 3. Evolution of protoplanetary disk structures Fred Ciesla and Cornelius P. Dullemond; 4. Chemical and isotopic evolution of the solar nebula and protoplanetary disks Dmitry Semenov, Subrata Chakraborty and Mark Thiemens; 5. Laboratory studies of simple dust analogs in astrophysical environments John R. Brucato and Joseph A. Nuth III; 6. Dust composition in protoplanetaty dust Michiel Min and George Flynn; 7. Dust particle size evolution Klaus M. Pontoppidan and Adrian J. Brearly; 8. Thermal processing in protoplanetary nebulae Daniel Apai, Harold C. Connolly Jr. and Dante S. Lauretta; 9. The clearing of protoplanetary disks and of the protosolar nebula Ilaira Pascucci and Shogo Tachibana; 10. Accretion of planetesimals and the formation of rocky planets John E. Chambers, David O'Brien and Andrew M. Davis; Appendixes; Glossary; Index.

  9. Coupling Mars' Dust and Water Cycles: Effects on Dust Lifting Vigor, Spatial Extent and Seasonality

    NASA Technical Reports Server (NTRS)

    Kahre, M. A.; Hollingsworth, J. L.; Haberle, R. M.; Montmessin, F.

    2012-01-01

    The dust cycle is an important component of Mars' current climate system. Airborne dust affects the radiative balance of the atmosphere, thus greatly influencing the thermal and dynamical state of the atmosphere. Dust raising events on Mars occur at spatial scales ranging from meters to planet-wide. Although the occurrence and season of large regional and global dust storms are highly variable from one year to the next, there are many features of the dust cycle that occur year after year. Generally, a low-level dust haze is maintained during northern spring and summer, while elevated levels of atmospheric dust occur during northern autumn and winter. During years without global-scale dust storms, two peaks in total dust loading were observed by MGS/TES: one peak occurred before northern winter solstice at Ls 200-240, and one peak occurred after northern winter solstice at L(sub s) 305-340. These maxima in dust loading are thought to be associated with transient eddy activity in the northern hemisphere, which has been observed to maximize pre- and post-solstice. Interactive dust cycle studies with Mars General Circulation Models (MGCMs) have included the lifting, transport, and sedimentation of radiatively active dust. Although the predicted global dust loadings from these simulations capture some aspects of the observed dust cycle, there are marked differences between the simulated and observed dust cycles. Most notably, the maximum dust loading is robustly predicted by models to occur near northern winter solstice and is due to dust lifting associated with down slope flows on the flanks of the Hellas basin. Thus far, models have had difficulty simulating the observed pre- and post- solstice peaks in dust loading. Interactive dust cycle studies typically have not included the formation of water ice clouds or their radiative effects. Water ice clouds can influence the dust cycle by scavenging dust from atmosphere and by interacting with solar and infrared radiation

  10. Remote Sensing of Mineral Dust Sources (Invited)

    NASA Astrophysics Data System (ADS)

    Sprigg, W. A.; Morain, S. A.

    2009-12-01

    Thirty-four percent of Earth's land surface is arid, home to two billion people routinely exposed to airborne dust and increased risk of cardiovascular and respiratory disease. The NASA-supported Public Health Applications in Remote Sensing project has improved the process of simulating and predicting when and where dust storms will occur and the consequent particulate air quality. Partnerships with state public health offices test model products for epidemiological and health surveillance applications. The key to significant improvement in simulations, forecasts and their use has been identifying and monitoring mineral dust sources via satellite based sensors.

  11. Intergalactic Dust

    NASA Astrophysics Data System (ADS)

    Li, A.

    2002-12-01

    We study the composition and sizes of intergalactic dust based on the expulsion of interstellar dust from the galactic disk. Interstellar grains in the Galactic disk are modelled as a mixture of amorphous silicate dust and carbonaceous dust consisting of polycyclic aromatic hydrocarbon (PAH) molecules and larger graphitic grains (Li & Draine 2001) with size distributions like those of the Milky Way dust (Weingartner & Draine 2001). We model their dynamic evolution in terms of the collective effects caused by (1) radiative acceleration, (2) gravitational attraction, (3) gas drag, (4) thermal sputtering, and (5) Lorenz force from the galactic magnetic field (Ferrara et al. 1991). Radiation pressure from the stellar disk exerts an upward force on dust grains and may ultimately expel them out of the entire galaxy. Gravitational force from the stellar, dust and gas disk as well as the dark matter halo exerts a downward force. Thermal sputtering erodes all grains to some degree but more efficiently destroys small grains. This, together with the fact that (1) very small grains (with small radiation pressure efficiencies) are not well coupled to starlight; (2) for large grains the radiative force to the gravitational force is approximately inversely proportional to grain size, acts as a size ``filter'' for dust leaking into the intergalactic space. Since the radiation pressure efficiency and the grain destruction rate are sensitive to dust composition, the relative importance of carbon dust compared to silicate dust expelled into the intergalactic space differs from that in the galactic plane. We derive the size distributions of both silicate and carbonaceous dust finally getting into the intergalactic space and obtain an intergalactic extinction curve. The predicted intergalactic infrared emission spectrum is calculated. References: Ferrara, A., Ferrini, F., Franco, J., & Barsella, B. 1991, ApJ, 381, 137 Li, A., & Draine, B.T. 2001, ApJ, 554, 778 Weingartner, J

  12. Optical dust sensor for the mining industry

    NASA Astrophysics Data System (ADS)

    Sierakowski, Marek W.; Wolinski, Tomasz R.; Domanski, Andrzej W.; Osinska, Katarzyna

    2003-04-01

    One of many hazards in mining industry is presence of airborne dust on underground boards. Hazards caused by dust generated and spread in mines are of the two types: (1) health risk for miners from airborne dust produced from rocks, coal, soluble minerals (pneumoconiosis, toxicity), (2) danger of explosion of carbon dust. Dust particles produced in mines underground range from 0 to about 400 micrometers, have irregular shapes and prevailingly are strongly light absorbing. It is assumed that the most health-risky are particles between 1 μm and 5 μm in size. They are not visible with naked eyes, so their control and measurement need technical equipment. As a standard in polish mines, gravimetric measurement method is used at present. This method works well in post-event evaluation of total health-risk factor, but is not much useful for instantaneous risk warning. In order to recognize and possibly prevent the dust risk as it appears, other methods have to be used, like optical method. Looking towards this demand, an experimental optical dust sensor is demonstrated. The sensor is based on light scattering effect by dust particles, as usual do devices of this type. Originality of this solution lies in construction details of the sensor. Scattering is a complex function of dust kind, size, shape and concentration. Moreover, operating conditions of such a device are cruel -- humidity, elevated temperature, vibrations, and over-all contact with dust -- are harmful for optics. Thus, to achieve reliable indications of the sensor is really a challenge. This paper describes optical construction attempting to overcome difficulties in obtaining dust concentration sensor intended for mining industry and similar applications. First laboratory and operational tests are also reported.

  13. Asian Community Library

    ERIC Educational Resources Information Center

    Yung, Judy

    1978-01-01

    The first Asian Community Library in the U.S. offers a popular collection of print and audiovisual materials in five Asian languages, as well as a special collection in English on Asian Americans and Asian history and culture. Acquisition, cataloging, and political difficulties are also discussed. (Author/JPF)

  14. Human occupancy as a source of indoor airborne bacteria.

    PubMed

    Hospodsky, Denina; Qian, Jing; Nazaroff, William W; Yamamoto, Naomichi; Bibby, Kyle; Rismani-Yazdi, Hamid; Peccia, Jordan

    2012-01-01

    Exposure to specific airborne bacteria indoors is linked to infectious and noninfectious adverse health outcomes. However, the sources and origins of bacteria suspended in indoor air are not well understood. This study presents evidence for elevated concentrations of indoor airborne bacteria due to human occupancy, and investigates the sources of these bacteria. Samples were collected in a university classroom while occupied and when vacant. The total particle mass concentration, bacterial genome concentration, and bacterial phylogenetic populations were characterized in indoor, outdoor, and ventilation duct supply air, as well as in the dust of ventilation system filters and in floor dust. Occupancy increased the total aerosol mass and bacterial genome concentration in indoor air PM(10) and PM(2.5) size fractions, with an increase of nearly two orders of magnitude in airborne bacterial genome concentration in PM(10). On a per mass basis, floor dust was enriched in bacterial genomes compared to airborne particles. Quantitative comparisons between bacterial populations in indoor air and potential sources suggest that resuspended floor dust is an important contributor to bacterial aerosol populations during occupancy. Experiments that controlled for resuspension from the floor implies that direct human shedding may also significantly impact the concentration of indoor airborne particles. The high content of bacteria specific to the skin, nostrils, and hair of humans found in indoor air and in floor dust indicates that floors are an important reservoir of human-associated bacteria, and that the direct particle shedding of desquamated skin cells and their subsequent resuspension strongly influenced the airborne bacteria population structure in this human-occupied environment. Inhalation exposure to microbes shed by other current or previous human occupants may occur in communal indoor environments.

  15. Atmospheric transport of mold spores in clouds of desert dust

    USGS Publications Warehouse

    Shinn, E.A.; Griffin, Dale W.; Seba, D.B.

    2003-01-01

    Fungal spores can be transported globally in clouds of desert dust. Many species of fungi (commonly known as molds) and bacteria--including some that are human pathogens--have characteristics suited to long-range atmospheric transport. Dust from the African desert can affect air quality in Africa, Europe, the Middle East, and the Americas. Asian desert dust can affect air quality in Asia, the Arctic, North America, and Europe. Atmospheric exposure to mold-carrying desert dust may affect human health directly through allergic induction of respiratory stress. In addition, mold spores within these dust clouds may seed downwind ecosystems in both outdoor and indoor environments.

  16. Atmospheric transport of mold spores in clouds of desert dust.

    PubMed

    Shinn, Eugene A; Griffin, Dale W; Seba, Douglas B

    2003-08-01

    Fungal spores can be transported globally in clouds of desert dust. Many species of fungi (commonly known as molds) and bacteria--including some that are human pathogens--have characteristics suited to long-range atmospheric transport. Dust from the African desert can affect air quality in Africa, Europe, the Middle East, and the Americas. Asian desert dust can affect air quality in Asia, the Arctic, North America, and Europe. Atmospheric exposure to mold-carrying desert dust may affect human health directly through allergic induction of respiratory stress. In addition, mold spores within these dust clouds may seed downwind ecosystems in both outdoor and indoor environments.

  17. EXTREME DUST AND SMOKE EVENTS OVER THE U.S. IN 1998

    EPA Science Inventory

    Dust storms and forest fires are major PM events that occur several times a year over different parts of the US. Such events also originate outside the US, e.g., dust from Sahara and the Asian deserts and smoke from forest fires in Central America and Canada. Such dust and smok...

  18. Rocket dust storms and detached dust layers in the Martian atmosphere

    NASA Astrophysics Data System (ADS)

    Spiga, Aymeric; Faure, Julien; Madeleine, Jean-Baptiste; Määttänen, Anni; Forget, François

    2013-04-01

    Airborne dust is the main climatic agent in the Martian environment. Local dust storms play a key role in the dust cycle; yet their life cycle is poorly known. Here we use mesoscale modeling that includes the transport of radiatively active dust to predict the evolution of a local dust storm monitored by OMEGA on board Mars Express. We show that the evolution of this dust storm is governed by deep convective motions. The supply of convective energy is provided by the absorption of incoming sunlight by dust particles, rather than by latent heating as in moist convection on Earth. We propose to use the terminology "rocket dust storm," or conio-cumulonimbus, to describe those storms in which rapid and efficient vertical transport takes place, injecting dust particles at high altitudes in the Martian troposphere (30-50 km). Combined to horizontal transport by large-scale winds, rocket dust storms produce detached layers of dust reminiscent of those observed with Mars Global Surveyor and Mars Reconnaissance Orbiter. Since nighttime sedimentation is less efficient than daytime convective transport, and the detached dust layers can convect during the daytime, these layers can be stable for several days. The peak activity of rocket dust storms is expected in low-latitude regions at clear seasons (late northern winter to late northern summer), which accounts for the high-altitude tropical dust maxima unveiled by Mars Climate Sounder. Dust-driven deep convection has strong implications for the Martian dust cycle, thermal structure, atmospheric dynamics, cloud microphysics, chemistry, and robotic and human exploration.

  19. Interactions Between Mineral Dust, Climate, and Ocean Ecosystems

    NASA Technical Reports Server (NTRS)

    Gasso, Santiago; Grassian, Vicki H.; Miller, Ron L.

    2010-01-01

    Over the past decade, technological improvements in the chemical and physical characterization of dust have provided insights into a number of phenomena that were previously unknown or poorly understood. In addition, models are now incorporating a wider range of physical processes, which will allow us to better quantify the climatic and ecological impacts of dust. For example, some models include the effect of dust on oceanic photosynthesis and thus on atmospheric CO 2 (Friedlingstein et al. 2006). The impact of long-range dust transport, with its multiple forcings and feedbacks, is a relatively new and complex area of research, where input from several disciplines is needed. So far, many of these effects have only been parameterized in models in very simple terms. For example, the representation of dust sources remains a major uncertainty in dust modeling and estimates of the global mass of airborne dust. This is a problem where Earth scientists could make an important contribution, by working with climate scientists to determine the type of environments in which easily erodible soil particles might have accumulated over time. Geologists could also help to identify the predominant mineralogical composition of dust sources, which is crucial for calculating the radiative and chemical effects of dust but is currently known for only a few regions. Understanding how climate and geological processes control source extent and characterizing the mineral content of airborne dust are two of the fascinating challenges in future dust research.

  20. Dust Storm

    Atmospheric Science Data Center

    2013-04-16

    ... April 11, 2004 (top panels) contrast strongly with the dust storm that swept across Iraq and Saudi Arabia on May 13, 2004 (bottom panels). ... Apr 11 and May 13, 2004 Images:  Dust Storm location:  Middle East thumbnail:  ...

  1. The Fate of Saharan Dust Across the Atlantic and Implications for a Central American Dust Barrier

    NASA Technical Reports Server (NTRS)

    Nowottnick, E.; Colarco, P.; da Silva, A.; Hlavka, D.; McGill, M.

    2011-01-01

    Saharan dust was observed over the Caribbean basin during the summer 2007 NASA Tropical Composition, Cloud, and Climate Coupling (TC4) field experiment. Airborne Cloud Physics Lidar (CPL) and satellite observations from MODIS suggest a barrier to dust transport across Central America into the eastern Pacific. We use the NASA GEOS-5 atmospheric transport model with online aerosol tracers to perform simulations of the TC4 time period in order to understand the nature of this barrier. Our simulations are driven by the Modem Era Retrospective-Analysis for Research and Applications (MERRA) meteorological analyses. We evaluate our baseline simulated dust distributions using MODIS and CALIOP satellite and ground-based AERONET sun photometer observations. GEOS-5 reproduces the observed location, magnitude, and timing of major dust events, but our baseline simulation does not develop as strong a barrier to dust transport across Central America as observations suggest. Analysis of the dust transport dynamics and lost processes suggest that while both mechanisms play a role in defining the dust transport barrier, loss processes by wet removal of dust are about twice as important as transport. Sensitivity analyses with our model showed that the dust barrier would not exist without convective scavenging over the Caribbean. The best agreement between our model and the observations was obtained when dust wet removal was parameterized to be more aggressive, treating the dust as we do hydrophilic aerosols.

  2. Improving plant competitiveness through conveyor dust control technologies

    SciTech Connect

    Goldbeck, L.J.

    1997-09-01

    In the past, three different approaches--containment, suppression, and collection--have been used to control dust arising at conveyor load zones. Dust containment consists of those mechanical systems employed to keep material inside the transfer point with the main material body. Dust suppression systems increase the mass of suspended dust particles, allowing them to fall from the airstream. Dust collection is the mechanical capture and return of airborne material after it becomes airborne from the main material body. Previously, these three approaches have always been seen as separate entities, offered by separate organizations competing in the marketplace. Each system claimed its own technology was the best solution, providing the most effective, most cost-efficient, most maintenance-free answer to fugitive material. These three technologies are evaluated.

  3. ACE-Asia Aerosol Optical Depth and Water Vapor Measured by Airborne Sunphotometers and Related to Other Measurements and Calculations

    NASA Technical Reports Server (NTRS)

    Livingston, John M.; Russell, P. B.; Schmid, B.; Redemann, J.; Eilers, J. A.; Ramirez, S. A.; Kahn, R.; Hegg, D.; Pilewskie, P.; Anderson, T.; Hipskind, R. Stephen (Technical Monitor)

    2001-01-01

    In the Spring 2001 phase of the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia), the 6-channel NASA Ames Airborne Tracking Sunphotometer (AATS-6) operated on 15 of the 19 research flights of the NCAR C-130, while its 14-channel counterpart (AATS- 14) flew successfully on all 18 research flights of the CIRPAS Twin Otter. ACE-Asia studied aerosol outflow from the Asian continent to the Pacific basin. It was designed to integrate suborbital and satellite measurements and models so as to reduce the uncertainty in calculations of the climate forcing due to aerosols. AATS-6 and AATS-14 measured solar beam transmission at 6 and 14 wavelengths (380-1021 and 354-1558 nm, respectively), yielding aerosol optical depth (AOD) spectra and column water vapor (CWV). Vertical differentiation in profiles yielded aerosol extinction spectra and water vapor concentration. The wavelength dependence of these AOD and extinction spectra indicates that supermicron dust was often a major component of the ACE-Asia aerosol. Frequently this dust-containing aerosol extended to high altitudes. For example, in AATS- 14 profiles analyzed to date, 36% of full-column AOD at 525 nm was above 3 km. In contrast, only 10% of CWV was above 3 km. Analyses and applications of AATS-6 and AATS-14 data to date include comparisons to (i) extinction products derived using in situ measurements, (ii) extinction profiles derived from lidar measurements, and (iii) AOD retrievals from the Multi-angle Imaging Spectro-Radiometer (MISR) aboard the TERRA satellite. Other planned collaborative studies include comparisons to results from size spectrometers, chemical measurements, other satellite sensors, flux radiometers, and chemical transport models. Early results of these studies will be presented.

  4. Sahara Dust

    Atmospheric Science Data Center

    2013-04-15

    article title:  Casting Light and Shadows on a Saharan Dust Storm   ... CA, for NASA's Science Mission Directorate, Washington, D.C. The Terra spacecraft is managed by NASA's Goddard Space Flight Center, ...

  5. Pb Isotopes as an Indicator of the Asian Contribution to Particulate Air Pollution in Urban California

    SciTech Connect

    Ewing, Stephanie A.; Christensen, John N.; Brown, Shaun T.; Vancuren, Richard A.; Cliff, Steven S.; DePaolo, Donald J.

    2010-10-25

    During the last two decades, expanding industrial activity in east Asia has led to increased production of airborne pollutants that can be transported to North America. Previous efforts to detect this trans-Pacific pollution have relied upon remote sensing and remote sample locations. We tested whether Pb isotope ratios in airborne particles can be used to directly evaluate the Asian contribution to airborne particles of anthropogenic origin in western North America, using a time series of samples from a pair of sites upwind and downwind of the San Francisco Bay Area. Our results for airborne Pb at these sites indicate a median value of 29 Asian origin, based on mixing relations between distinct regional sample groups. This trans-Pacific Pb is present in small quantities but serves as a tracer for airborne particles within the growing Asian industrial plume. We then applied this analysis to archived samples from urban sites in central California. Taken together, our results suggest that the analysis of Pb isotopes can reveal the distribution of airborne particles affected by Asian industrial pollution at urban sites in northern California. Under suitable circumstances, this analysis can improve understanding of the global transport of pollution, independent of transport models.

  6. Pb isotopes as an indicator of the Asian contribution to particulate air pollution in urban California.

    PubMed

    Ewing, Stephanie A; Christensen, John N; Brown, Shaun T; Vancuren, Richard A; Cliff, Steven S; Depaolo, Donald J

    2010-12-01

    During the last two decades, expanding industrial activity in east Asia has led to increased production of airborne pollutants that can be transported to North America. Previous efforts to detect this trans-Pacific pollution have relied upon remote sensing and remote sample locations. We tested whether Pb isotope ratios in airborne particles can be used to directly evaluate the Asian contribution to airborne particles of anthropogenic origin in western North America, using a time series of samples from a pair of sites upwind and downwind of the San Francisco Bay Area. Our results for airborne Pb at these sites indicate a median value of 29% Asian origin, based on mixing relations between distinct regional sample groups. This trans-Pacific Pb is present in small quantities but serves as a tracer for airborne particles within the growing Asian industrial plume. We then applied this analysis to archived samples from urban sites in central California. Taken together, our results suggest that the analysis of Pb isotopes can reveal the distribution of airborne particles affected by Asian industrial pollution at urban sites in northern California. Under suitable circumstances, this analysis can improve understanding of the global transport of pollution, independent of transport models.

  7. Global potential of dust devil occurrence

    NASA Astrophysics Data System (ADS)

    Jemmett-Smith, Bradley; Marsham, John; Knippertz, Peter; Gilkeson, Carl

    2014-05-01

    Mineral dust is a key constituent in the climate system. Airborne mineral dust forms the largest component of the global aerosol budget by mass and subsequently affects climate, weather and biogeochemical processes. There remains large uncertainty in the quantitative estimates of the dust cycle. Dry boundary-layer convection serves as an effective mechanism for dust uplift, typically through a combination of rotating dust devils and non-rotating larger and longer-lived convective plumes. These microscale dry-convective processes occur over length scales of several hundred metres or less. They are difficult to observe and model, and therefore their contribution to the global dust budget is highly uncertain. Using an analytical approach to extrapolate limited observations, Koch and Renno (2006) suggest that dust devils and plumes could contribute as much as 35%. Here, we use a new method for quantifying the potential of dust devil occurrence to provide an alternative perspective on this estimate. Observations have shown that dust devil and convective plume occurrence is favoured in hot arid regions under relatively weak background winds, large ground-to-air temperature gradients and deep dry convection. By applying such known constraints to operational analyses from the European Centre for Medium Range Weather Forecasts (ECMWF), we provide, to the best of the authors' knowledge, the first hourly estimates of dust devil occurrence including an analysis of sensitivity to chosen threshold uplift. The results show the expected diurnal variation and allow an examination of the seasonal cycle and day-to-day variations in the conditions required for dust devil formation. They confirm that desert regions are expected to have by far the highest frequency of dry convective vortices, with winds capable of dust uplift. This approach is used to test the findings of Koch and Renno (2006). Koch J., Renno N. (2006). The role of convective plumes and vortices on the global aerosol

  8. Simulation of South Asian aerosols for regional climate studies

    NASA Astrophysics Data System (ADS)

    Nair, Vijayakumar S.; Solmon, Fabien; Giorgi, Filippo; Mariotti, Laura; Babu, S. Suresh; Moorthy, K. Krishna

    2012-02-01

    Extensive intercomparison of columnar and near-surface aerosols, simulated over the South Asian domain using the aerosol module included in the regional climate model (RegCM4) of the Abdus Salam International Centre for Theoretical Physics (ICTP) have been carried out using ground-based network of Sun/sky Aerosol Robotic Network (AERONET) radiometers, satellite sensors such as Moderate Resolution Imaging Spectroradiometer (MODIS) and Multiangle Imaging Spectroradiometer (MISR), and ground-based black carbon (BC) measurements made at Aerosol Radiative Forcing over India (ARFI) network stations. In general, RegCM4 simulations reproduced the spatial and seasonal characteristics of aerosol optical depth over South Asia reasonably well, particularly over west Asia, where mineral dust is a major contributor to the total aerosol loading. In contrast, RegCM4 simulations drastically underestimated the BC mass concentrations over most of the stations, by a factor of 2 to 5, with a large spatial variability. Seasonally, the discrepancy between the measured and simulated BC tended to be higher during winter and periods when the atmospheric boundary layer is convectively stable (such as nighttime and early mornings), while during summer season and during periods when the boundary layer is convectively unstable (daytime) the discrepancies were much lower, with the noontime values agreeing very closely with the observations. A detailed analysis revealed that the model does not reproduce the nocturnal high in BC, observed at most of the Indian sites especially during winter, because of the excessive vertical transport of aerosols under stable boundary layer conditions. As far as the vertical distribution was concerned, the simulated vertical profiles of BC agreed well with airborne measurements during daytime. This comprehensive validation exercise reveals the strengths and weaknesses of the model in simulating the spatial and temporal heterogeneities of the aerosol fields over

  9. Asian American Studies.

    ERIC Educational Resources Information Center

    Liu, William T.; Yu, Elena S. H.

    The sociodemographic and socioeconomic characteristics of all Asian American communities since 1950 have been greatly influenced by federal immigration legislation, and it is not possible to consider the field of Asian American studies without an understanding of the history of immigration legislation. Asian American research may be divided into…

  10. Teaching Asian American Students.

    ERIC Educational Resources Information Center

    Chiang, Linda H.

    2000-01-01

    Uses data from interviews with parents of Asian American students, observations, and literature reviews to identify cultural and language issues that must be considered in teaching this population. The paper discusses the history of Asian immigrants, attitudes toward education among Asians, the relationship between teaching styles and Asian…

  11. Exposure to airborne allergens: a review of sampling methods.

    PubMed

    Renström, Anne

    2002-10-01

    A number of methods are used to assess exposure to high-molecular weight allergens. In the occupational setting, airborne dust is often collected on filters using pumps, the filters are eluted and allergen content in the eluate analysed using immunoassays. Collecting inhalable dust using person-carried pumps may be considered the gold standard. Other allergen sampling methods are available. Recently, a method that collects nasally inhaled dust on adhesive surfaces within nasal samplers has been developed. Allergen content can be analysed in eluates using sensitive enzyme immunoassays, or allergen-bearing particles can be immunostained using antibodies, and studied under the microscope. Settling airborne dust can be collected in petri dishes, a cheap and simple method that has been utilised in large-scale exposure studies. Collection of reservoir dust from surfaces using vacuum cleaners with a dust collector is commonly used to measure pet or mite allergens in homes. The sampling methods differ in properties and relevance to personal allergen exposure. Since methods for all steps from sampling to analysis differ between laboratories, determining occupational exposure limits for protein allergens is today unfeasible. A general standardisation of methods is needed.

  12. Lofting of dust by very large explosions

    SciTech Connect

    Mason, A.S.; Finnegan, D.L.; Hagan, R.C.; Raymond, R. Jr.; Cocks, G.G.; Zoller, W.H.; Peach, C.L.

    1987-08-01

    One of the goals of the Minor Scale test was to determine the quantity, form, and composition of dust lofted by a large detonation of a conventional high explosive at ground level. The explosive charge was 4427 tonnes of ammonium nitrate-fuel oil (ANFO), whose blast effect is approximately equal to that of an 8 kT nuclear device. The experimental techniques used to determine the amount of dust were (1) use of elements in soil as natural tracers, (2) inclusion of tracer elements in the ANFO charge and the immediate surroundings, (3) airborne collection of the lofted dust on filter media, and (4) analysis of the samples for both tracers and dust. The tracer content of the sample can then relate the dust collected to the total amount lofted and to the location of its origin within the experimental setup. Indium, in the oxide form, was placed within the explosive charge, and tantalum as very fine dust, was placed near the soil surface immediately adjacent to the charge container. The amounts of the tracers and of dust collected by each filter were measured by instrumental neutron activation analysis. A research aircraft equipped with well-characterized high-volume filter samplers was flown through the dust cloud at 10 levels between the top at 4.6 km and the bottom at 1.7 km above ground level. The cloud dust density was distinctly biomodal; its maxima were at 4.1 and 2.9 km. The majority of the indium was associated with the dust in the upper part of the cloud, and the majority of the tantalum was in the lower part. The estimate of the total dust lofted by use of the naturally occurring tracers was 3.0 x 10/sup 9/ g. Samples are being studied by scanning electron microscopy to determine their particle size and composition distributions as functions of location within the cloud.

  13. Asian dustfall in the St. Elias Mountains, Yukon, Canada

    NASA Astrophysics Data System (ADS)

    Zdanowicz, Christian; Hall, Gwendy; Vaive, Judy; Amelin, Yuri; Percival, Jeanne; Girard, Isabelle; Biscaye, Pierre; Bory, Aloys

    2006-07-01

    In April 2001, a major atmospheric dustfall event occurred in the St. Elias Mountains, Yukon Territory, Canada. Field samples were collected and analyzed for particle size, mineralogy, chemical composition and Sr, Nd and Pb isotopes. Dusts found above ˜3000 m had their source in the Gobi desert region of northern China and Inner Mongolia, and were transported to the Yukon following a series of major dust storms that took place in early April. Dusts found below 3000 m had local (Yukon) or mixed source(s). The Asian dusts had a modal volume diameter of ˜4 μm typical of far-traveled mineral aerosols. However larger (>10 μm) particles were also found at ˜5000 m, suggesting a very rapid trans-Pacific transport in the mid-troposphere. We estimate that the April 2001 event deposited from 5500 to 6335 tons of dust over an area of 21,000 km 2 in the southwestern Yukon, most of which probably fell within a week. Our findings are consistent with instrumental observations and model simulations of the April 2001 event. While the dust cloud was reportedly mixed with volatile pollutants from Asia, we found no evidence of metal pollution associated with the dustfall in the Yukon. Our findings contribute to clarify the dynamics and the geochemical impact of Asian dust long-range transport events, and to better estimate eolian fluxes of dustborne elements (e.g., Fe) to the Ocean associated with such events. They may also assist in identifying past Asian dust events in ice cores drilled from the St. Elias Mountains icefields, to develop a long-term record of their frequency, magnitude and source(s).

  14. Exposure to mineral sands dust particles

    NASA Astrophysics Data System (ADS)

    Dias da Cunha, K.; Barros Leite, C. V.; Zays, Z.

    2004-06-01

    The aim of this study is to characterize the airborne particles in a Brazilian region with high concentration of mineral sands (Buena village). In this study proton induced X-ray emission (PIXE), plasma desorption mass spectrometry and alpha spectrometry were used for analyses of airborne particles. The analyses of aerosol samples and lichen samples show that the inhabitants of the Buena village are exposed to airborne particles in the fine fraction of aerosols. The main anthropogenic sources of particles are the mineral sands processing plant and truck traffic, and natural sources as the sea, soil and the swamp. The results from the lichen samples show that at least during the last 15 years the inhabitants of the village have been exposed to monazite particles. The results from aerosols and lichens samples also suggested that the swamp is a source of 226Ra and 210Pb bearing particles besides the monazite dust.

  15. Airborne biological particles and electric fields

    NASA Astrophysics Data System (ADS)

    Benninghoff, William S.; Benninghoff, Anne S.

    1982-01-01

    In November and December 1977 at McMurdo Station in Antarctica we investigated the kinds, numbers, and deposition of airborne particles larger than 2 μm while measuring electric field gradient at 2.5 m above the ground. Elementary collecting devices were used: Staplex Hi-Volume and Roto-rod samplers, Tauber (static sedimentation) traps, petrolatum-coated microscope slides, and snow (melted and filtered). The electric fields were measured by a rotating dipole (Stanford Radioscience Laboratory field mill number 2). During periods of blowing snow and dust the electric field gradient was + 500 to + 2500 V/m, and Tauber traps with grounded covers collected 2 or more times as much snow and dust as the ones with ungrounded covers. During falling snow the electric field gradient was -1000 to -1500 V/m, and the ungrounded traps collected almost twice as much snow and dust as those grounded. These observations suggest that under the prevailing weather conditions in polar regions the probable net effect is deposition of greater quantities of dust, including diaspores and minute organisms, on wet, grounded surfaces. This hypothesis needs examination for its use in explanation of biological distribution patterns.

  16. The thermal infrared radiance properties of dust aerosol over ocean

    NASA Astrophysics Data System (ADS)

    Hao, Zengzhou; Pan, Delu; Tu, Qianguang; Gong, Fang; Chen, Jianyu

    2015-10-01

    Asian dust storms, which can long-range transport to ocean, often occur on spring. The present of Asian dust aerosols over ocean makes some difficult for other studies, such as cloud detection, and also take some advantage for ocean, such as take nutrition into the ocean by dry or wet deposition. Therefore, it is important to study the dust aerosol and retrieve the properties of dust from satellite observations that is mainly from the thermal infrared radiance. In this paper, the thermal infrared radiance properties of dust aerosol over ocean are analyzed from MODIS and MTSAT2 observations and Streamer model simulations. By analyzing some line samples and a series of dust aerosol region, it shows that the dust aerosol brightness temperature at 12μm (BT12) is always greater than BT11 and BT8.5, and BT8.5 is general greater than BT11. The brightness temperature different between 11μm and 12μm (BTD11-12) increases with the dust intensity. And the BTD11-12 will become positive when the atmospheric relative humidity is greater than 70%. The BTD11-12 increases gradually with the surface temperature while the effect on BTD11-12 of dust layer temperature is not evident. Those are caused by the transmission of the dust aerosol is different at the two thermal infrared channels. During daytime, dust infrared brightness temperature at mid-infrared bands should reduce the visual radiance, which takes about 25K or less. In general, BT3.7 is greater than BT11 for dust aerosol. Those results are helpful to monitor or retrieve dust aerosol physical properties over ocean from satellite.

  17. Efficiency of dust sampling inlets in calm air.

    PubMed

    Breslin, J A; Stein, R L

    1975-08-01

    Measurement of airborne dust concentrations usually involves drawing a sample of the dust-laden air into the measuring instrument through an inlet. Even if the surrounding air is calm, theoretical calculations predict that large particles may not be sampled accurately due to the combined effects of gravity and inertia on the particles near the sampling inlet. Tests were conducted to determine the conditions of particle size, inlet radius, and flow rare necessary for accurate dust sampling. A coal-dust aerosol was sampled simultaneously through inlets of different diameters at the same volume flow-rate and collected on filters. The dust was removed from the filters and the particles were counted and sized with a Coulter counter. Results showed that published criteria for inlet conditions for correct sampling are overly restrictive and that respirable-size particles are sampled correctly in the normal range or operation of most dust sampling instruments. PMID:1227283

  18. Rocket dust storms and detached layers in the Martian atmosphere

    NASA Astrophysics Data System (ADS)

    Spiga, A.; Faure, J.; Madeleine, J.; Maattanen, A. E.; Forget, F.

    2012-12-01

    Airborne dust is the main climatic agent in the Martian environment. Local dust storms play a key role in the dust cycle; yet their life cycle is poorly known. Here we use mesoscale modeling with radiatively-active transported dust to predict the evolution of a local dust storm monitored by OMEGA onboard Mars Express. We show that the evolution of this dust storm is governed by deep convective motions. The supply of convective energy is provided by the absorption of incoming sunlight by dust particles, in lieu of latent heating in moist convection on Earth. We propose to use the terminology "rocket dust storm", or conio-cumulonimbus, to describe those storms in which rapid and efficient vertical transport takes place, injecting dust particles at high altitudes in the Martian troposphere (30 to 50 km). Combined to horizontal transport by large-scale winds, rocket dust storms form detached layers of dust reminiscent of those observed with instruments onboard Mars Global Surveyor and Mars Reconnaissance Orbiter. Detached layers are stable over several days owing to nighttime sedimentation being unable to counteract daytime convective transport, and to the resupply of convective energy at sunrise. The peak activity of rocket dust storms is expected in low-latitude regions at clear season, which accounts for the high-altitude tropical dust maximum unveiled by Mars Climate Sounder. Our findings on dust-driven deep convection have strong implications for the Martian dust cycle, thermal structure, atmospheric dynamics, cloud microphysics, chemistry, and robotic and human exploration.ensity-scaled dust optical depth at local times 1400 1600 and 1800 (lat 2.5°S, Ls 135°) hortwave heating rate at local time 1500 and latitude 2.5°S.

  19. Advances in understanding mineral dust and boundary layer processes over the Sahara from Fennec aircraft observations

    NASA Astrophysics Data System (ADS)

    Ryder, C. L.; McQuaid, J. B.; Flamant, C.; Washington, R.; Brindley, H. E.; Highwood, E. J.; Marsham, J. H.; Parker, D. J.; Todd, M. C.; Banks, J. R.; Brooke, J. K.; Engelstaedter, S.; Estellés, V.; Formenti, P.; Garcia-Carreras, L.; Kocha, C.; Marenco, F.; Rosenberg, P.; Sodemann, H.; Allen, C. J. T.; Bourdon, A.; Bart, M.; Cavazos-Guerra, C.; Chevaillier, S.; Crosier, J.; Darbyshire, E.; Dean, A. R.; Dorsey, J. R.; Kent, J.; O'Sullivan, D.; Schepanski, K.; Szpek, K.; Woolley, A.

    2015-01-01

    The Fennec climate program aims to improve understanding of the Saharan climate system through a synergy of observations and modelling. We present a description of the Fennec airborne observations during 2011 and 2012 over the remote Sahara (Mauritania and Mali) and the advances in the understanding of mineral dust and boundary layer processes they have provided. Aircraft instrumentation aboard the UK FAAM BAe146 and French SAFIRE Falcon 20 is described, with specific focus on instrumentation specially developed and relevant to Saharan meteorology and dust. Flight locations, aims and associated meteorology are described. Examples and applications of aircraft measurements from the Fennec flights are presented, highlighting new scientific results delivered using a synergy of different instruments and aircraft. These include: (1) the first airborne measurement of dust particles sized up to 300 microns and associated dust fluxes in the Saharan atmospheric boundary layer (SABL), (2) dust uplift from the breakdown of the nocturnal low-level jet before becoming visible in SEVIRI satellite imagery, (3) vertical profiles of the unique vertical structure of turbulent fluxes in the SABL, (4) in-situ observations of processes in SABL clouds showing dust acting as CCN and IN at -15 °C, (5) dual-aircraft observations of the SABL dynamics, thermodynamics and composition in the Saharan heat low region (SHL), (6) airborne observations of a dust storm associated with a cold-pool (haboob) issued from deep convection over the Atlas, (7) the first airborne chemical composition measurements of dust in the SHL region with differing composition, sources (determined using Lagrangian backward trajectory calculations) and absorption properties between 2011 and 2012, (8) coincident ozone and dust surface area measurements suggest coarser particles provide a route for ozone depletion, (9) discrepancies between airborne coarse mode size distributions and AERONET sunphotometer retrievals under

  20. Mars Airborne Prospecting Spectrometer

    NASA Astrophysics Data System (ADS)

    Steinkraus, J. M.; Wright, M. W.; Rheingans, B. E.; Steinkraus, D. E.; George, W. P.; Aljabri, A.; Hall, J. L.; Scott, D. C.

    2012-06-01

    One novel approach towards addressing the need for innovative instrumentation and investigation approaches is the integration of a suite of four spectrometer systems to form the Mars Airborne Prospecting Spectrometers (MAPS) for prospecting on Mars.

  1. Abrupt Climate Events Recorded in Chinese and Central Asian Loess Sequences

    NASA Astrophysics Data System (ADS)

    Machalett, B.; Oches, E. A.; Haam, E. K.; Lai, Z.; Endlicher, W.

    2013-12-01

    Past climate dynamics associated with the Eurasian continent have been extensively studied. However, the impact of intra-hemispheric-scale climate variability on the entire Eurasian landmass, as well as the self-generated effects of the continent on the global climate system, is still a matter of investigation . While western Atlantic polar and tropical air masses penetrate into the continent and are transformed as they cross Eurasia, the interior regions of Eurasia strongly influence Earth's climate system. Significant cooling and heating of Central and High Asia drive interactions between atmospheric and oceanic processes and regulate teleconnection patterns across the Northern Hemisphere. This paper utilizes high resolution particle size data from the Central Asian loess sequence at Remisowka, Kazakhstan, and the long studied, monsoon-influenced Chinese loess sequence at Xifeng, to reconstruct past atmospheric circulation and aeolian dust dynamics within interior Eurasia since the last interglacial period. The observed dynamics in aeolian dust transport closely mirror d18O and fine dust variations measured in Greenland ice cores, suggesting a correlation with short-term climate oscillations (DO events) recorded therein. An Asian origin of fine aeolian dust preserved in Greenland ice cores has been discussed previously, and recent papers reveal a close link between Asian aeolian dust dynamics and DO events recorded in Greenland ice cores. In this context, data presented here represent the first Central and East Asian aeolian dust records in which DO events are recorded, providing a means to test hypothesized links between short-term climate variability recorded in Greenland and associated climate dynamics at Asian dust source areas. Ultimately, the data extend existing hypotheses, suggesting that the Central and High Asian mountains are a crucial element within the sensitive glacier-desert-dust response system in interior Eurasia and may be considered a pacemaker

  2. Abrupt Climate Events Recorded in Chinese and Central Asian Loess Sequences

    NASA Astrophysics Data System (ADS)

    Machalett, Bjoern; Oches, Eric A.; Haam, Eddie; Lai, Zhongping; Endlicher, Wilfried

    2013-04-01

    Past climate dynamics associated with the Eurasian continent have been extensively studied. However, the impact of intra-hemispheric-scale climate variability on the entire Eurasian landmass, as well as the self-generated effects of the continent on the global climate system, is still a matter of investigation . While western Atlantic polar and tropical air masses penetrate into the continent and are transformed as they cross Eurasia, the interior regions of Eurasia strongly influence Earth's climate system. Significant cooling and heating of Central and High Asia drive interactions between atmospheric and oceanic processes and regulate teleconnection patterns across the Northern Hemisphere. This paper utilizes high resolution particle size data from the Central Asian loess sequence at Remisowka, Kazakhstan, and the long studied, monsoon-influenced Chinese loess sequence at Xifeng, to reconstruct past atmospheric circulation and aeolian dust dynamics within interior Eurasia since the last interglacial period. The observed dynamics in aeolian dust transport closely mirror d18O and fine dust variations measured in Greenland ice cores, suggesting a correlation with short-term climate oscillations (DO events) recorded therein. An Asian origin of fine aeolian dust preserved in Greenland ice cores has been discussed previously, and recent papers reveal a close link between Asian aeolian dust dynamics and DO events recorded in Greenland ice cores. In this context, data presented here represent the first Central and East Asian aeolian dust records in which DO events are recorded, providing a means to test hypothesized links between short-term climate variability recorded in Greenland and associated climate dynamics at Asian dust source areas. Ultimately, the data extend existing hypotheses, suggesting that the Central and High Asian mountains are a crucial element within the sensitive glacier-desert-dust response system in interior Eurasia and may be considered a pacemaker

  3. Physical/chemical and microbiological analyses of dusts at a resource recover plant.

    PubMed

    Duckett, E J; Wagner, J; Welker, R; Rogers, B; Usdin, V

    1980-12-01

    Airborne dusts at a resource recovery pilot plant were sampled and analyzed to determine physical, chemical and microbiological characteristics. The sampling device was a multi-stage impactor equipped with a pre-collector. Dusts are primarily fibrous organic materials, predominantly of nonrespirable size. Microbiological aerosol concentrations are reported and discussed.

  4. 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...

  5. Transport of Alaskan Dust into the Gulf of Alaska and Comparison with Similar High-Latitude Dust Environments

    NASA Technical Reports Server (NTRS)

    Crusium, John; Levy, Rob; Wang, Jun; Campbell, Rob; Schroth, Andrew W.

    2012-01-01

    Transport of Alaskan dust into the Gulf of Alaska and comparison with similar high-latitude dust environments. An airborne flux of the micronutrient iron, derived from dust originating from coastal regions may be an important contributor of iron to the Gulf of Alaska's (GoA) oligotrophic waters. Dust blowing off glacier termini and dry riverbeds is a recurring phenomenon in Alaska, usually occurring in the autumn. Since previous studies assumed that dust originating in the deserts of Asia was the largest source of . airborne iron to the GoA, the budget of aeolian deposition of iron needs to be reassessed. Since late 20 I 0, our group has been monitoring dust activity using satellites over the Copper River Delta (CRD) where the most vigorous dust plumes have been observed. Since 2011, sample aerosol concentration and their composition are being collected at Middleton Island (100km off shore of CRD). This presentation will show a summary of the ongoing dust observations and compare with other similar environments (Patagonia, Iceland) by showing case studies. Common features will be highlighted

  6. Bimodal size distributions of various organic acids and fatty acids in the marine atmosphere: Influence of anthropogenic aerosols, Asian dusts, and sea spray off the coast of East Asia

    NASA Astrophysics Data System (ADS)

    Mochida, Michihiro; Umemoto, Nobuhiko; Kawamura, Kimitaka; Lim, Ho-Jin; Turpin, Barbara J.

    2007-08-01

    Size-segregated (11 stages) marine aerosol samples were collected off the coast of East Asia during the ACE-Asia campaign in 2001 and were analyzed for homologous series of dicarboxylic acids (C2-C12), ω-oxocarboxylic acids (C2-C4), and n-fatty acids (C16-C30), as well as organic carbon (OC), elemental carbon, and major inorganic ions. Concentrations of OC and major diacids and oxoacids in continental polluted air masses showed predominantly submicron maxima. However, during dusty haze events, supermicron maxima were observed, suggesting a size shift due to the secondary accumulation of these components on dust as well as sea salt particles. Supermicron maxima were also found for palmitic acid (C16 fatty acid) and other lower-molecular-weight fatty acids (LFAs, C16-C19) that are emitted from a microlayer of the ocean surface. In contrast, higher-molecular-weight fatty acids (HFAs, C20-C30) were mainly detected in the submicron mode, presumably due to a substantial contribution of biomass burning aerosols. This study demonstrates a high-variability in the size distributions of organic components (i.e., between submicron and supermicron modes) in the coastal regions off East Asia. Such variations in the physical properties of the marine aerosols may be important in relation to their cloud-condensation-nuclei and light extinction activities.

  7. Sensitivities of five alpha continuous air monitors for detection of airborne sup 239 Pu

    SciTech Connect

    McIsaac, C.V.; Amaro, C.R.

    1992-07-01

    Results of measurements of the sensitivities of five alpha continuous air monitors (CAMs) for detection of airborne {sup 239}Pu are presented. Four commercially available alpha CAMs (Kurz model 8311, Merlin Gerin Edgar, RADeCO model 452, and Victoreen model 758) and a prototype alpha CAM currently in use at Argonne National Laboratory- West (ANL-W) were tested sampling natural ambient air and laboratory-generated atmospheres laden with either blank dust or dust containing nCi/g concentrations of {sup 239}Pu. Cumulative alpha spectra were stored at 30 or 60 minute intervals during each sampling and were subsequently analyzed using three different commonly used alpha spectrum analysis algorithms. The effect of airborne dust concentration and sample filter porosity on detector resolution and sensitivity for airborne {sup 239}Pu are described.

  8. Sensitivities of five alpha continuous air monitors for detection of airborne {sup 239}Pu

    SciTech Connect

    McIsaac, C.V.; Amaro, C.R.

    1992-07-01

    Results of measurements of the sensitivities of five alpha continuous air monitors (CAMs) for detection of airborne {sup 239}Pu are presented. Four commercially available alpha CAMs (Kurz model 8311, Merlin Gerin Edgar, RADeCO model 452, and Victoreen model 758) and a prototype alpha CAM currently in use at Argonne National Laboratory- West (ANL-W) were tested sampling natural ambient air and laboratory-generated atmospheres laden with either blank dust or dust containing nCi/g concentrations of {sup 239}Pu. Cumulative alpha spectra were stored at 30 or 60 minute intervals during each sampling and were subsequently analyzed using three different commonly used alpha spectrum analysis algorithms. The effect of airborne dust concentration and sample filter porosity on detector resolution and sensitivity for airborne {sup 239}Pu are described.

  9. Escaping the regulatory dust bowl: fugitive dust and the Clean Air Act

    SciTech Connect

    Probst, G.L.; Becker, R.E. Jr.

    1982-01-01

    The Environmental Protection Agency's (EPA's) regulatory program, as it relates to particulates, is overly complicated. In attempting to accommodate statutory language insensitive to particulate differences, after becoming aware of the varying effects of different-sized particles, EPA has developed an unworkable program. Although agricultural, recreational, transportation, and industrial activities contribute to the airborne dust (or, in the Clean Air Act vernacular, fugitive dust), this article focuses on mining activities. Surface mining inevitably stirs up considerable fugitive dust, and a description of mining activities in arid conditions, and how they fit in with a developing regulatory program, reveals a story of a national program that fails to provide for rational policy and regional flexibility. The article also recommends some regulatory and statutory solutions that could relatively easily correct EPA's fugitive dust program.

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

    PubMed Central

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

    1998-01-01

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

  11. Asian American Cultural Resistance.

    ERIC Educational Resources Information Center

    Libretti, Tim

    1997-01-01

    Explores the encounter of Marxism and Asian American literary theory and imagines an Asian American Marxism. To do so requires theorizing race, class, and gender not as substantive categories of antagonisms but as complementary and coordinated elements of a totality of social relations structuring racial patriarchal capitalism. (SLD)

  12. Asian Resources for Educators.

    ERIC Educational Resources Information Center

    Hansen, C. Bobbie

    1992-01-01

    Cites a number of resources available to teachers to use in teaching about Asian Pacific Rim cultures. Includes addresses, titles, and general information about materials available from the listed sources. Describes some multicultural resources that have been included because of their treatment of Asian Pacific Rim cultures. (DK)

  13. The New Asian Immigrants.

    ERIC Educational Resources Information Center

    Wong, Morrison G.; Hirschman, Charles

    In the early 1960s, Asian immigration to the United States was severely limited. The passage of the Immigration Act of 1965 expanded Asian immigration and ended a policy of racial discrimination and exclusion. Currently, over one third of the total immigrant population to the United States is from Asia, particularly China, Japan, Korea, the…

  14. Asian Open Universities.

    ERIC Educational Resources Information Center

    Hill, John

    1983-01-01

    The appearance of open universities in Asia is of interest to Australian educators, particularly since the Asian institutions differ in some respects from the British model which combined open entry to all and extensively employed the electronic media. The Asian Open Universities have provided access to higher education for many. (SSH)

  15. Emerging Asian Economics.

    ERIC Educational Resources Information Center

    Trezise, Philip H.

    What we can expect in the future from the miracle economies of Japan, South Korea, Taiwan, Singapore, and Hong Kong, whether they pose a threat to the older industrial states of Western Europe and North American, and whether China is to be the next emerging Asian economy are discussed. The amazing economic recovery of these East Asian countries…

  16. Dust Storms in the United States are Associated with Increased Cardiovascular Mortality

    EPA Science Inventory

    Background: Extreme weather events such as dust storms are predicted to become more frequent as the global climate warms through the 21st century. Studies of Asian, Saharan, Arabian, and Australian dust storms have found associations with cardiovascular and total non-accidental...

  17. Dust Storms and Mortality in the United States, 1995-2005

    EPA Science Inventory

    Extreme weather events, such as dust storms, are predicted to become more frequent as the global climate warms through the 21st century. The impact of dust storms on human health has been studied extensively in the context of Asian, Saharan, Arabian, and Australian storms, but t...

  18. Dust Spectroscopy and the Nature of Grains

    NASA Technical Reports Server (NTRS)

    Tielens, A. G. G. M.

    2006-01-01

    Ground-based, air-borne and space-based, infrared spectra of a wide variety of objects have revealed prominent absorption and emission features due to large molecules and small dust grains. Analysis of this data reveals a highly diverse interstellar and circumstellar grain inventory, including both amorphous materials and highly crystalline compounds (silicates and carbon). This diversity points towards a wide range of physical and chemical birthsites as well as a complex processing of these grains in the interstellar medium. In this talk, I will review the dust inventory contrasting and comparing both the interstellar and circumstellar reservoirs. The focus will be on the processes that play a role in the lifecycle of dust in the interstellar medium.

  19. Characterization of dust emission from alluvial sediments using aircraft observations and modeling

    NASA Astrophysics Data System (ADS)

    Schepanski, K.; Flamant, C.; Chaboureau, J.; Kocha, C.; Banks, J.; Brindley, H. E.; Lavaysse, C.; Marnas, F.; Pelon, J.; Tulet, P.

    2013-12-01

    Recent studies using satellite observations show that numerous dust sources are located in the foothills of arid and semi-arid mountain regions such as over North Africa. Alluvial sediments deposited on the valley bottoms and flood plains are very prone to wind erosion and frequently serve as dust source. High surface wind speeds related to the break-down of the nocturnal low-level jet (LLJ) during the morning hours are identified as a frequent driving mechanism for dust uplift. We investigate dust emission from alluvial dust sources located within the upland region in northern Mauritania and discuss the impact of valleys with regard to their role as dust source. Measures for local atmospheric dust burden were retrieved from airborne observations, MSG SEVIR dust AOD fields and MesoNH model simulations, and analyzed in order to provide complementary information on dust source activation and local dust transport at different horizontal scales. Vertical distribution of atmospheric mineral dust was obtained from the LNG backscatter lidar system flying aboard the French Falcon-20 aircraft. Lidar extinction coefficients were compared to topography, aerial photographs, and dust AOD fields to confirm the relevance of alluvial sediments at the valley bottoms as dust source. The observed dust emission event was further evaluated using the regional model MesoNH. A sensitivity study on the impact of the horizontal grid spacing highlights the importance of the spatial resolution on simulated dust loadings. The results further illustrate the importance of an explicit representation of alluvial dust sources in such models to better capture the spatial-temporal distribution of airborne dust concentrations.

  20. 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.

  1. Wind tunnel and field calibration of six aeolian dust samplers

    NASA Astrophysics Data System (ADS)

    Goossens, Dirk; Offer, Zvi Y.

    The efficiency of six aeolian dust samplers was tested via wind tunnel experiments and field measurements. In the wind tunnel, four samplers designed to measure the horizontal dust flux and one sampler designed to measure the vertical dust flux (in the downward direction, i.e., deposition) were calibrated against an isokinetic reference sampler. The horizontal dust flux samplers were: the big spring number eight sampler (BSNE), the modified Wils