225,429 research outputs found

    Release of Bet v 1 from birch pollen from 5 European countries. Results from the HIALINE study

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    Exposure to allergens is pivotal in determining sensitization and allergic symptoms in individuals. Pollen grain counts in ambient air have traditionally been assessed to estimate airborne allergen exposure. However, the exact allergen content of ambient air is unknown. We therefore monitored atmospheric concentrations of birch pollen grains and the matched major birch pollen allergen Bet v 1 simultaneously across Europe within the EU-funded project HIALINE (Health Impacts of Airborne Allergen Information Network). Pollen count was assessed with Hirst type pollen traps at 10 l min 1 at sites in France, United Kingdom, Germany, Italy and Finland. Allergen concentrations in ambient air were sampled at 800 l min 1 with a Chemvol high-volume cascade impactor equipped with stages PM > 10 mm, 10 mm > PM > 2.5 mm, and in Germany also 2.5 mm > PM > 0.12 mm. The major birch pollen allergen Bet v 1 was determined with an allergen specific ELISA. Bet v 1 isoform patterns were analyzed by 2D-SDS-PAGE blots and mass spectrometric identification. Basophil activation was tested in an Fc 3R1-humanized rat basophil cell line passively sensitized with serum of a birch pollen symptomatic patient. Compared to 10 previous years, 2009 was a representative birch pollen season for all stations. About 90% of the allergen was found in the PM > 10 mm fraction at all stations. Bet v 1 isoforms pattern did not vary substantially neither during ripening of pollen nor between different geographical locations. The average European allergen release from birch pollen was 3.2 pg Bet v 1/pollen and did not vary much between the European countries. However, in all countries a >10-fold difference in daily allergen release per pollen was measured which could be explained by long-range transport of pollen with a deviating allergen release. Basophil activation by ambient air extracts correlated better with airborne allergen than with pollen concentration. Although Bet v 1 is a mixture of different isoforms, its fingerprint is constant across Europe. Bet v 1 was also exclusively linked to pollen. Pollen from different days varied >10-fold in allergen release. Thus exposure to allergen is inaccurately monitored by only monitoring birch pollen grains. Indeed, a humanized basophil activation test correlated much better with allergen concentrations in ambient air than with pollen count. Monitoring the allergens themselves together with pollen in ambient air might be an improvement in allergen exposure assessmen

    Ozone Contamination in Aircraft Cabins. Appendix B: Overview papers. In-flight measurements

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    The NASA Global Atmospheric Sampling Program ozone measurements were obtained to establish to characteristics of the ambient ozone concentration during routine operations and to determine the attenuation of ambient concentrations of cabin air systems from simultaneous ambient and in cabin measurements. The characteristics of ambient ozone include: (1) maximum concentration; (2) duration of ozone encounters; (3) frequency of ozone during a flight; (4) variability of ozone during a flight; (5) in relation to routes, altitude, and meteorological conditions

    PENGARUH PROGRAM CAR FREE DAY TERHADAP PENURUNAN BEBAN PENCEMAR CO DAN NO2

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    Surabaya is the second largest city after Jakarta, an increasing number of people each year is always followed by an increasing volume of the vehicle so that the air pollution in the city of Surabaya will be increasing as well. Car free day program is one of the mitigation program against air pollution caused by automobiles. Motor vehicles produce gases CO and NO2 gas from fuel combustion processes that can cause air pollution. CO gas also affects the formation of greenhouse gases. This research was intended to analyze the efficiency of car free day program which held at Jln. Jemur Andayani. Efficiency which intended is percentage of CO and NO2 emissions reduction and ambient air concentrations . This CO and NO2 emissions research was using amount of vehicles and emission factor. Meanwhile for the ambient air was using CO meter and Griess Saltzman with impinger for NO2 ambient air. Car free day program reduce the emissions of CO by 60.4% and NO2 reduced by 60.2% . Where as the concentration of CO in the ambient air dropped by 97.3% and NO2 concentrations in ambient air decreased by 83 % . Keywords : ambient , car free day , CO , efficiency , emissions , NO

    Indoor/Ambient Residential Air Toxics Results in Rural Western Montana

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    Indoor and ambient concentrations of 21 Volatile Organic Compounds (including 14 Hazardous Air Pollutants) were measured in the homes of nearly 80 western Montana (Missoula) high school students as part of the ‘Air Toxics Under the Big Sky’ program during the 2004/2005 and 2005/2006 school years. Target analytes were measured using low flow air sampling pumps and sorbent tubes, with analysis of the exposed samples by Thermal Desorption/Gas Chromatography/Mass Spectrometry (TD/GC/MS). The results reported here present the findings of the first indoor/ambient air toxics monitoring program conducted in a semi-rural valley location located in the Northern Rocky Mountain/western Montana region. Of all of the air toxics quantified in this study, toluene was found to be the most abundant compound in both the indoor and ambient environments during each of the two school years. Indoor log-transformed mean concentrations were found to be higher when compared with ambient log-transformed mean concentrations at P \u3c 0.001 for the majority of the compounds, supporting the results of previous studies conducted in urban areas. For the air toxics consistently measured throughout this program, concentrations were approximately six times higher inside the student’s homes compared to those simultaneously measured directly outside their homes. For the majority of the compounds, there were no significant correlations between indoor and ambient concentrations

    Indoor/Ambient Residential Air Toxics Results in Rural Western Montana

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    Indoor and ambient concentrations of 21 volatile organic compounds (including 14 hazardous air pollutants) were measured in the homes of nearly 80 western Montana (Missoula) high school students as part of the ‘Air Toxics Under the Big Sky’ program during the 2004/2005 and 2005/2006 school years. Target analytes were measured using low flow air sampling pumps and sorbent tubes, with analysis of the exposed samples by thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS). The results reported here present the findings of the first indoor/ambient air toxics monitoring program conducted in a semi-rural valley location located in the Northern Rocky Mountain/Western Montana region. Of all of the air toxics quantified in this study, toluene was found to be the most abundant compound in both the indoor and ambient environments during each of the two school years. Indoor log-transformed mean concentrations were found to be higher when compared with ambient log-transformed mean concentrations at P\u3c0.001 for the majority of the compounds, supporting the results of previous studies conducted in urban areas. For the air toxics consistently measured throughout this program, concentrations were approximately six times higher inside the student’s homes compared to those simultaneously measured directly outside their homes. For the majority of the compounds, there were no significant correlations between indoor and ambient concentrations

    Ambient ammonia measurements using laser photo-acoustic spectroscopy

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    Ammonia concentrations reached minimal levels (approximately 0.1 ppb) in early winter, followed by a sudden later winter increase. A direct relationship between ambient ammonia levels and air temperature was inferred from the data (linear correlation coefficient r=0.53). Ammonia concentrations were determined to be directly related to the absolute humidity of the air (r=0.72); a weaker relationship between ammonia concentrations and relative humidity was discovered (r=0.37). The data also indicated that ammonia levels were generally higher within continental air masses than those of maritime origin. Soil parameters such as pH and moisture content were found to have a major bearing on the release of gaseous ammonia from soils in the region

    Ambient air quality monitoring : a comparison between two urban parks in Soweto, South Africa

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    A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science. 14 August 2015Soweto is identified as an air pollution hot spot area which is characteristic of poor air quality where ambient air pollutant concentrations frequently exceed the South African Ambient Air Quality Standards. Urban greening programmes are seen as a way for cities to work towards reducing air pollution, offsetting greenhouse gas emissions and improve ambient air quality. The City of Johannesburg embarked on the Greening Soweto project in 2006 where many degraded open spaces were transformed into urban green parks and 6000 trees were planted. The urban parks and trees are believed to serve several environmental benefits; one of which includes the improvement in local ambient air quality. The aim of this research was to assess and compare the local ambient air quality situation at two different urban park types in close proximity, Thokoza Park (older trees) and Petrus Molefe Eco-Park (young trees), in Soweto and establish whether the air pollutants measured at the urban parks were lower compared to the urban background conditions. Furthermore, this study assessed whether the ambient concentrations of the selected criteria air pollutants were within the South African National Ambient Air Quality Standards. Three ambient air quality monitoring campaigns were conducted during the spring (October) and winter (June and July) seasons of 2013 and 2014 with the use of a mobile air quality monitoring station. The findings of this research suggest that urban trees in Thokoza Park and Petrus Molefe Eco-Park has the greatest potential to improve air quality in Soweto mainly through changes in local meteorological conditions, specifically for temperature and wind fields, rather than direct removal of air pollutants. Differences in the concentrations of the air pollutants at the different sites showed a strong relationship with changes in temperature, wind speed and direction and emission source types. A significant difference in air pollutant concentrations between the two urban park types was only found for particulate matter (PM10 and PM2.5) and CO2. In general, lower air pollutant concentrations were recorded at the urban parks compared to the urban background site, particularly during the spring season. This study also suggests that the urban trees could represent a potential O3 sink during the spring and winter seasons and for NOx during the spring season. Exceedances of the South African Ambient Air Quality Standards at the two urban parks were only observed for PM10 and PM2.5 during the winter season of 2014. PM10 and PM2.5 and NOx were identified to be air pollutants of concern at the urban parks in comparison to other criteria air pollutants assessed in this study. Maximum daily concentrations of 255 μg/m3 for PM10 and 126 μg/m3 for PM2.5 and a maximum hourly concentration of 92 ppb for NOx were recorded at the parks during winter seaso
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