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search.filters.applied.f.access: openAccess Ă— End date: 2021 Ă— DDC: 570 Ă— Has files: Yes Ă— Type: Article Ă— WGL Institute: TROPOS Ă—

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    Airborne bacterial emission fluxes from manure-fertilized agricultural soil
    (Oxford : Wiley-Blackwell, 2020) Thiel, Nadine; MĂĽnch, Steffen; Behrens, Wiebke; Junker, Vera; Faust, Matthias; Biniasch, Oliver; Kabelitz, Tina; Siller, Paul; Boedeker, Christian; Schumann, Peter; Roesler, Uwe; Amon, Thomas; Schepanski, Kerstin; Funk, Roger; NĂĽbel, Ulrich
    This is the first study to quantify the dependence on wind velocity of airborne bacterial emission fluxes from soil. It demonstrates that manure bacteria get aerosolized from fertilized soil more easily than soil bacteria, and it applies bacterial genomic sequencing for the first time to trace environmental faecal contamination back to its source in the chicken barn. We report quantitative, airborne emission fluxes of bacteria during and following the fertilization of agricultural soil with manure from broiler chickens. During the fertilization process, the concentration of airborne bacteria culturable on blood agar medium increased more than 600 000-fold, and 1 m3 of air carried 2.9 Ă— 105 viable enterococci, i.e. indicators of faecal contamination which had been undetectable in background air samples. Trajectory modelling suggested that atmospheric residence times and dispersion pathways were dependent on the time of day at which fertilization was performed. Measurements in a wind tunnel indicated that airborne bacterial emission fluxes from freshly fertilized soil under local climatic conditions on average were 100-fold higher than a previous estimate of average emissions from land. Faecal bacteria collected from soil and dust up to seven weeks after fertilization could be traced to their origins in the poultry barn by genomic sequencing. Comparative analyses of 16S rRNA gene sequences from manure, soil and dust showed that manure bacteria got aerosolized preferably, likely due to their attachment to low-density manure particles. Our data show that fertilization with manure may cause substantial increases of bacterial emissions from agricultural land. After mechanical incorporation of manure into soil, however, the associated risk of airborne infection is low.
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    A new method to measure real-world respiratory tract deposition of inhaled ambient black carbon
    (Amsterdam [u.a.] : Elsevier Science, 2019) Madueño, Leizel; Kecorius, Simonas; Löndahl, Jakob; Müller, Thomas; Pfeifer, Sascha; Haudek, Andrea; Mardoñez, Valeria; Wiedensohler, Alfred
    In this study, we present the development of a mobile system to measure real-world total respiratory tract deposition of inhaled ambient black carbon (BC). Such information can be used to supplement the existing knowledge on air pollution-related health effects, especially in the regions where the use of standard methods and intricate instrumentation is limited. The study is divided in two parts. Firstly, we present the design of portable system and methodology to evaluate the exhaled air BC content. We demonstrate that under real-world conditions, the proposed system exhibit negligible particle losses, and can additionally be used to determine the minute ventilation. Secondly, exemplary experimental data from the system is presented. A feasibility study was conducted in the city of La Paz, Bolivia. In a pilot experiment, we found that the cumulative total respiratory tract deposition dose over 1-h commuting trip would result in approximately 2.6 μg of BC. This is up to 5 times lower than the values obtained from conjectural approach (e.g. using physical parameters from previously reported worksheets). Measured total respiratory tract deposited BC fraction varied from 39% to 48% during walking and commuting inside a micro-bus, respectively. To the best of our knowledge, no studies focusing on experimental determination of real-world deposition dose of BC have been performed in developing regions. This can be especially important because the BC mass concentration is significant and determines a large fraction of particle mass concentration. In this work, we propose a potential method, recommendations, as well as the limitations in establishing an easy and relatively cheap way to estimate the respiratory tract deposition of BC. In this study we present a novel method to measure real-world respiratory tract deposition dose of Black Carbon. Results from a pilot study in La Paz, Bolivia, are presented. © 2019 The Authors
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    Investigation of atmospheric conditions fostering the spreading of legionnaires’ disease in outbreaks related to cooling towers
    (Berlin ; Heidelberg : Springer, 2019) Villanueva, Diego; Schepanski, Kerstin
    Legionnaires’ disease (LD) is a severe lung infection caused by the bacteria Legionella pneumophila which is usually associated with water managing installations like cooling towers. Several outbreaks of LD have been linked to individual sources of bioaerosol in the past. However, the transmission pathways as well as the influence of meteorological factors in the spreading of such bioaerosols remain unclear. Using the meteorological data near 12 LD outbreaks in Europe for the period 2000–2016, the correlation between key meteorological factors and the occurrence of LD was assessed. Temperature, humidity, atmospheric pressure, wind speed, precipitation, cloud cover and, for the first time, fog occurrence were included as potential risk factors. It was found that the occurrence of fog was related to four of the LD outbreaks, suggesting that the presence of fog droplets and/or the thermal inversions associated with fog may play a role in the disease spreading. This finding can contribute to outbreak investigations and to the prevention of future outbreaks. © 2019, The Author(s).