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- ItemToxicological Responses of Ī±-Pinene-Derived Secondary Organic Aerosol and Its Molecular Tracers in Human Lung Cell Lines(New York, NY : ACS Publ., 2021) Khan, Faria; Kwapiszewska, Karina; Zhang, Yue; Chen, Yuzhi; Lambe, Andrew T.; KoÅodziejczyk, Agata; Jalal, Nasir; Rudzinski, Krzysztof; MartĆnez-Romero, Alicia; Fry, Rebecca C.; Surratt, Jason D.; Szmigielski, RafalSecondary organic aerosol (SOA) is a major component of airborne fine particulate matter (PM2.5) that contributes to adverse human health effects upon inhalation. Atmospheric ozonolysis of Ī±-pinene, an abundantly emitted monoterpene from terrestrial vegetation, leads to significant global SOA formation; however, its impact on pulmonary pathophysiology remains uncertain. In this study, we quantified an increasing concentration response of three well-established Ī±-pinene SOA tracers (pinic, pinonic, and 3-methyl-1,2,3-butanetricarboxylic acids) and a full mixture of Ī±-pinene SOA in A549 (alveolar epithelial carcinoma) and BEAS-2B (bronchial epithelial normal) lung cell lines. The three aforementioned tracers contributed ā¼57% of the Ī±-pinene SOA mass under our experimental conditions. Cellular proliferation, cell viability, and oxidative stress were assessed as toxicological end points. The three Ī±-pinene SOA molecular tracers had insignificant responses in both cell types when compared with the Ī±-pinene SOA (up to 200 Ī¼g mL-1). BEAS-2B cells exposed to 200 Ī¼g mL-1 of Ī±-pinene SOA decreased cellular proliferation to ā¼70% and 44% at 24- and 48-h post exposure, respectively; no changes in A549 cells were observed. The inhibitory concentration-50 (IC50) in BEAS-2B cells was found to be 912 and 230 Ī¼g mL-1 at 24 and 48 h, respectively. An approximate 4-fold increase in cellular oxidative stress was observed in BEAS-2B cells when compared with untreated cells, suggesting that reactive oxygen species (ROS) buildup resulted in the downstream cytotoxicity following 24 h of exposure to Ī±-pinene SOA. Organic hydroperoxides that were identified in the Ī±-pinene SOA samples likely contributed to the ROS and cytotoxicity. This study identifies the potential components of Ī±-pinene SOA that likely modulate the oxidative stress response within lung cells and highlights the need to carry out chronic exposure studies on Ī±-pinene SOA to elucidate its long-term inhalation exposure effects. Ā© 2021 American Chemical Society.
- ItemAirborne bacterial emission fluxes from manure-fertilized agricultural soil(Oxford : Wiley-Blackwell, 2020) Thiel, Nadine; MĆ¼nch, 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; NĆ¼bel, UlrichThis 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 Ć 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.
- ItemPedestrian exposure to black carbon and PM2.5 emissions in urban hot spots: new findings using mobile measurement techniques and flexible Bayesian regression models(Basingstoke : Nature Publ. Group, 2021) Alas, Honey Dawn; Stƶcker, Almond; Umlauf, Nikolaus; Senaweera, Oshada; Pfeifer, Sascha; Greven, Sonja; Wiedensohler, AlfredBackground Data from extensive mobile measurements (MM) of air pollutants provide spatially resolved information on pedestriansā exposure to particulate matter (black carbon (BC) and PM2.5 mass concentrations). Objective We present a distributional regression model in a Bayesian framework that estimates the effects of spatiotemporal factors on the pollutant concentrations influencing pedestrian exposure. Methods We modeled the mean and variance of the pollutant concentrations obtained from MM in two cities and extended commonly used lognormal models with a lognormal-normal convolution (logNNC) extension for BC to account for instrument measurement error. Results The logNNC extension significantly improved the BC model. From these model results, we found local sources and, hence, local mitigation efforts to improve air quality, have more impact on the ambient levels of BC mass concentrations than on the regulated PM2.5. Significance Firstly, this model (logNNC in bamlss package available in R) could be used for the statistical analysis of MM data from various study areas and pollutants with the potential for predicting pollutant concentrations in urban areas. Secondly, with respect to pedestrian exposure, it is crucial for BC mass concentration to be monitored and regulated in areas dominated by traffic-related air pollution.
- ItemPreventing airborne transmission of SARS-CoV-2 in hospitals and nursing homes(Basel : MDPI AG, 2020) Ahlawat, Ajit; Mishra, Sumit Kumar; Birks, John W.; Costabile, Francesca; Wiedensohler, Alfred[No abstract available]
- ItemLong-term trends of black carbon and particle number concentration in the lower free troposphere in Central Europe(Berlin ; Heidelberg : Springer, 2021) Sun, Jia; Hermann, Markus; Yuan, Ye; Birmili, Wolfram; Collaud Coen, Martine; Weinhold, Kay; MadueƱo, Leizel; Poulain, Laurent; Tuch, Thomas; Ries, Ludwig; Sohmer, Ralf; Couret, Cedric; Frank, Gabriele; Brem, Benjamin Tobias; Gysel-Beer, Martin; Ma, Nan; Wiedensohler, AlfredBackground: The implementation of emission mitigation policies in Europe over the last two decades has generally improved the air quality, which resulted in lower aerosol particle mass, particle number, and black carbon mass concentration. However, little is known whether the decreasing particle concentrations at a lower-altitude level can be observed in the free troposphere (FT), an important layer of the atmosphere, where aerosol particles have a longer lifetime and may affect climate dynamics. In this study, we used data from two high-Alpine observatories, Zugspitze-Schneefernerhaus (ZSF) and Jungfraujoch (JFJ), to assess the long-term trends on size-resolved particle number concentrations (PNCs) and equivalent black carbon (eBC) mass concentration separated for undisturbed lower FT conditions and under the influence of air from the planetary boundary layer (PBL) from 2009 to 2018. Results: The FT and PBL-influenced conditions were segregated for both sites. We found that the FT conditions in cold months were more prevalent than in warm months, while the measured aerosol parameters showed different seasonal patterns for the FT and PBL-influenced conditions. The pollutants in the PBL-influenced condition have a higher chance to be transported to high-altitudes due to the mountainous topography, leading to a higher concentration and more distinct seasonal variation, and vice versa. The long-term trends of the measured aerosol parameters were evaluated and the decreased aerosol concentrations were observed for both FT and PBL-influenced conditions. The observed decreasing trends in eBC concentration in the PBL-influenced condition are well consistent with the reported trends in total BC emission in Germany and Switzerland. The decreased concentrations in the FT condition suggest that the background aerosol concentration in the lower FT over Central Europe has correspondingly decreased. The change of back trajectories in the FT condition at ZSF and JFJ was further evaluated to investigate the other possible drivers for the decreasing trends. Conclusions: The background aerosol concentration in the lower FT over Central Europe has significantly decreased during 2009ā2018. The implementation of emission mitigation policies is the most decisive factor and the decrease of the regional airmass occurrence over Central Europe also has contributed to the decreasing trends. Ā© 2021, The Author(s).
- ItemRespiratory tract deposition of inhaled roadside ultrafine refractory particles in a polluted megacity of South-East Asia(Amsterdam [u.a.] : Elsevier Science, 2019) Kecorius, Simonas; MadueƱo, Leizel; Lƶndahl, Jakob; Vallar, Edgar; Galvez, Maria Cecilia; Idolor, Luisito F.; Gonzaga-Cayetano, Mylene; MĆ¼ller, Thomas; Birmili, Wolfram; Wiedensohler, AlfredRecent studies demonstrate that Black Carbon (BC) pollution in economically developing megacities remain higher than the values, which the World Health Organization considers to be safe. Despite the scientific evidence of the degrees of BC exposure, there is still a lack of understanding on how the severe levels of BC pollution affect human health in these regions. We consider information on the respiratory tract deposition dose (DD) of BC to be essential in understanding the link between personal exposure to air pollutants and corresponding health effects. In this work, we combine data on fine and ultrafine refractory particle number concentrations (BC proxy), and activity patterns to derive the respiratory tract deposited amounts of BC particles for the population of the highly polluted metropolitan area of Manila, Philippines. We calculated the total DD of refractory particles based on three metrics: refractory particle number, surface area, and mass concentrations. The calculated DD of total refractory particle number in Metro Manila was found to be 1.6 to 17 times higher than average values reported from Europe and the U.S. In the case of Manila, ultrafine particles smaller than 100 nm accounted for more than 90% of the total deposited refractory particle dose in terms of particle number. This work is a first attempt to quantitatively evaluate the DD of refractory particles and raise awareness in assessing pollution-related health effects in developing megacities. We demonstrate that the majority of the population may be highly affected by BC pollution, which is known to have negative health outcomes if no actions are taken to mitigate its emission. For the governments of such metropolitan areas, we suggest to revise currently existing environmental legislation, raise public awareness, and to establish supplementary monitoring of black carbon in parallel to already existing PM 10 and PM 2.5 measures. Ā© 2019
- ItemCollocated observations of cloud condensation nuclei, particle size distributions, and chemical composition(London : Nature Publ. Group, 2017) Schmale, Julia; Henning, Silvia; Henzing, Bas; Keskinen, Helmi; Sellegri, Karine; Ovadnevaite, Jurgita; Bougiatioti, Aikaterini; Kalivitis, Nikos; Stavroulas, Iasonas; Jefferson, Anne; Park, Minsu; Schlag, Patrick; Kristensson, Adam; Iwamoto, Yoko; Pringle, Kirsty; Reddington, Carly; Aalto, Pasi; ĆijƤlƤ, Mikko; Baltensperger, Urs; Bialek, Jakub; Birmili, Wolfram; Bukowiecki, Nicolas; Ehn, Mikael; FjƦraa, Ann Mari; Fiebig, Markus; Frank, Gƶran; Frƶhlich, Roman; Frumau, Arnoud; Furuya, Masaki; Hammer, Emanuel; Heikkinen, Liine; Herrmann, Erik; Holzinger, Rupert; Hyono, Hiroyuki; Kanakidou, Maria; Kiendler-Scharr, Astrid; Kinouchi, Kento; Kos, Gerard; Kulmala, Markku; Mihalopoulos, Nikolaos; Motos, Ghislain; Nenes, Athanasios; OāDowd, Colin; Paramonov, Mikhail; PetƤjƤ, Tuukka; Picard, David; Poulain, Laurent; PrĆ©vĆ“t, AndrĆ© Stephan Henry; Slowik, Jay; Sonntag, Andre; Swietlicki, Erik; Svenningsson, Birgitta; Tsurumaru, Hiroshi; Wiedensohler, Alfred; Wittbom, Cerina; Ogren, John A.; Matsuki, Atsushi; Yum, Seong Soo; Myhre, Cathrine Lund; Carslaw, Ken; Stratmann, Frank; Gysel, MartinCloud condensation nuclei (CCN) number concentrations alongside with submicrometer particle number size distributions and particle chemical composition have been measured at atmospheric observatories of the Aerosols, Clouds, and Trace gases Research InfraStructure (ACTRIS) as well as other international sites over multiple years. Here, harmonized data records from 11 observatories are summarized, spanning 98,677 instrument hours for CCN data, 157,880 for particle number size distributions, and 70,817 for chemical composition data. The observatories represent nine different environments, e.g., Arctic, Atlantic, Pacific and Mediterranean maritime, boreal forest, or high alpine atmospheric conditions. This is a unique collection of aerosol particle properties most relevant for studying aerosol-cloud interactions which constitute the largest uncertainty in anthropogenic radiative forcing of the climate. The dataset is appropriate for comprehensive aerosol characterization (e.g., closure studies of CCN), model-measurement intercomparison and satellite retrieval method evaluation, among others. Data have been acquired and processed following international recommendations for quality assurance and have undergone multiple stages of quality assessment.