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A new method to measure real-world respiratory tract deposition of inhaled ambient black carbon

2019, MadueƱo, Leizel, Kecorius, Simonas, Lƶndahl, Jakob, MĆ¼ller, Thomas, Pfeifer, Sascha, Haudek, Andrea, MardoƱez, 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 Ī¼g 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. Ā© 2019 The Authors

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Particle number emission rates of aerosol sources in 40 German households and their contributions to ultrafine and fine particle exposure

2020, Zhao, Jiangyue, Birmili, Wolfram, Hussein, Tareq, Wehner, Birgit, Wiedensohler, Alfred

More representative data on source-specific particle number emission rates and associated exposure in European households are needed. In this study, indoor and outdoor particle number size distributions (10ā€“800 nm) were measured in 40 German households under real-use conditions in over 500 days. Particle number emission rates were derived for around 800 reported indoor source events. The highest emission rate was caused by burning candles (5.3 Ć— 1013 hāˆ’1). Data were analyzed by the single-parameter approach (SPA) and the indoor aerosol dynamics model approach (IAM). Due to the consideration of particle deposition, coagulation, and time-dependent ventilation rates, the emission rates of the IAM approach were about twice as high as those of the SPA. Correction factors are proposed to convert the emission rates obtained from the SPA approach into more realistic values. Overall, indoor sources contributed ~ 56% of the daily-integrated particle number exposure in households under study. Burning candles and opening the window leads to seasonal differences in the contributions of indoor sources to residential exposure (70% and 40% in the cold and warm season, respectively). Application of the IAM approach allowed to attribute the contributions of outdoor particles to the penetration through building shell and entry through open windows (26% and 15%, respectively). Ā© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd

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Preventing airborne transmission of SARS-CoV-2 in hospitals and nursing homes

2020, Ahlawat, Ajit, Mishra, Sumit Kumar, Birks, John W., Costabile, Francesca, Wiedensohler, Alfred

[No abstract available]

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From Transfer to Knowledge Co-Production: A Transdisciplinary Research Approach to Reduce Black Carbon Emissions in Metro Manila, Philippines

2020, TƵnisson, Liina, Kunz, Yvonne, Kecorius, Simonas, MadueƱo, Leizel, Tamayo, Everlyn Gayle, Casanova, Dang Marviluz, Zhao, Qi, Schikowski, Tamara, Hornidge, Anna-Katharina, Wiedensohler, Alfred, Macke, Andreas

Air pollution, which kills an estimated 7 million people every year, is one of the greatest environmental health risks of our times. Finding solutions to this threat poses challenges to practitioners and policymakers alike. Increasing awareness on the benefits of transdisciplinary research in solution-oriented sustainable development projects has led to the establishment of the research project ā€œA Transdisciplinary Approach to Mitigate Emissions of Black Carbonā€ (TAME-BC). This paper introduces the TAME-BC research setup that took place with Metro Manila, Philippines, case study. The approach integrates BC measurements with technological, socio-political, and health aspects to improve the scientific state of the art, policymaking, transport sector planning, and clinical studies related to air pollution health effects. The first pillar in the setup presents an (1) air quality assessment through aerosol measurements and instrumentation, complemented by a (2) description and assessment of the current policies, technologies, and practices of the transport sector that is responsible for pollution levels in the Philippines, as well as a (3) BC exposure and associated health impacts assessment. The fourth pillar is intercrossing, fostering (4) knowledge co-creation through stakeholder involvement across scales. We argue that this transdisciplinary approach is useful for research endeavors aiming for emission mitigation in rapidly urbanizing regions beyond Metro Manila.

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Long-term trends of black carbon and particle number concentration in the lower free troposphere in Central Europe

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, Alfred

Background: 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 2009ā€“2018. 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).