Chairs: Christof Asbach (asbach@iuta.de), David Green (david.c.green@kcl.ac.uk), Andreas Held (andreas.held@uni-bayreuth.de)

Low-cost sensors for particulate matter have gained increased popularity over the last few years. While their accuracy may not be comparable to that of established aerosol measurement techniques, they offer a large variety of new possibilities. Among others, these include citizen science projects on air quality, surveillance of workplace and indoor exposure concentrations or the use of these sensors to control HVAC systems.

The aim of the special session is to provide an overview on both the characterization of the sensors as well as their application in different fields.

Chairs: Ulas Im (ulas@envs.au.dk), Risto Makkonen (risto.makkonen@helsinki.fi), Annica Ekman, (annica@misu.su.se)

Description: Earth System models (ESMs) are global climate models, explicitly representing biogeochemical processes that interact with the physical climate and so alter its response to climate forcing from natural and anthropogenic emissions of greenhouse gases and aerosols. Aerosols reflect incoming solar radiation (a direct cooling effect) and alter cloud properties (an indirect cooling effect), as well as absorbing radiation (e.g. black carbon), contributing to the warming of the atmosphere. Therefore they are key players in chemistry-climate feedbacks. ESMs provide valuable insight into climate variability and change, and the role of human activities and possible mitigation actions on future climate change.

Chairs: Francis Pope (F.Pope@bham.ac.uk), Johan Boman (johan.boman@chem.gu.se), Örjan Gustavsson (Orjan.Gustafsson@aces.su.se)

Worldwide it is recognized that air pollution, especially particulate matter, is causing alarming degradation of the human health and to the environment. This is especially true in low and middle income countries (LMIC) where emissions are high and societal focus is easily turned to more day to day concerns like employment and getting food for the family. But air quality is considered one of the most important obstacles impeding the development of a livable and productive municipality. Concerted efforts are now urgently required to limit exposure to pollutants by the local and national authorities. How can aerosol science contribute to a positive development? What is the current status of knowledge and what’s needed for the future? Can good air quality act as a driver of sustainability, build local capacity and help achieve the Sustainable Development Goals? Where can aerosol science help? Can low cost measurements provide reliable data? How does PM composition and emissions in LMICs differ to more well studied regions? Does aerosol chemistry differ in LMICs due to different PM and gas phase composition? Welcome to discuss these and other related question in this special session.

Chairs: Helena Thörn Helena.Thorn@astrazeneca.com and Ulrika Tehler Ulrika.Tehler@astrazeneca.com

This session aims to address the topic of pulmonary delivery to animals and humans. Aerosol characterization and precise drug delivery for pre-clinical and clinical investigations is needed throughout the development of an inhaled medicine. Some of the challenges of conducting in vivo inhalation studies is the generation of a well-defined and reproducible aerosol that delivers an ideal size distribution and composition of the aerosol to the lungs. In addition, the translation from the pre-clinical to the clinical phase is dependent on robust in vivo data and predictive in silico models. The key challenge is to understand, deliver and control, as well as model, the aerosol facilitating the generation of reliable data throughout the various phases of the drug development process.

Chairs: María Cruz Minguillón (mariacruz.minguillon@idaea.csic.es) and André Prévot (andre.prevot@psi.ch)

The widespread use of high time resolution instrumentation for the measurement of organic and black/brown carbon over long time periods (> 1 year) has resulted in an increased application of source apportionment techniques to interpret these data. This special session focuses on advanced and innovative approaches including positive matrix factorization / multi-linear engine and similar techniques to improve these insights. This session was initiated by members of the COST project CA16109 COLOSSAL (Chemical On-Line Composition and Source Apportionment of fine aerosol), which is focusing on the analysis of long-term data in Europe using aerosol chemical speciation monitors (Time-of-Flight and quadrupole) for the organic and non-refractory inorganic aerosol and the Aethalometer for black and brown carbon. Any international contributions using the above-mentioned or alternative on-line instrumentation for carbonaceous aerosol source apportionment and chemical characterization are encouraged to contribute, as are approaches towards real-time source apportionment.

Chairs: Claudia Mohr (claudia.Mohr@aces.su.se) and Thomas Mentel (t.mentel@fz-juelich.de)

Exchange between the gas and particle phase is a constitutive element of the dynamic system that is atmospheric organic aerosols. In both phases organic compounds can undergo oxidation reactions that change their vapor pressure and thus partitioning behavior. Organic compounds can be of both biogenic and anthropogenic origin. Emissions from the biosphere couple tree emissions to cloud formation and climate via secondary particle formation; anthropogenic emissions are important players in air pollution.

Therefore, to understand organic aerosol components, their fate in the atmosphere, and ultimately air quality and climate effects, techniques are required to quantitatively probe the same molecules in the gas- and particulate phase.

In this session we want get an overview of state-of-the-art techniques to measure partitioning, direct atmospheric observations of partitioning, as well as of concepts to implement partitioning in models.

Chairs: Johan Mellqvist ( johan.mellqvist@chalmers.se), Michael Vojtisek (michal.vojtisek@fs.cvut.cz), Ismael Ortega (ismael.ortega@onera.fr)

This session will focus on emissions from aircraft (commercial or other) and ship traffic. These sources of combustion aerosol particles are of interest from a fundamental aspect but are also subjected for a transition due to climate mitigation and new emission regulations. Thus, the session is expected to reach across several “traditional” disciplines. Papers are invited on a variety of topics, including but not limited to characterization and quantification of primary emissions, measurement techniques, secondary aerosols and effects on air quality/environment/health, and evaluation of the effects of new technologies, fuels and emissions reduction measures.

Chairs: Lidia Morawska ( l.morawska@qut.edu.au) and Giorgio Buonanno (buonanno@unicas.it)

Ultrafine particles (UFP) present a scientific challenge and potential health issue. They present a legislative challenge, since there are no standard measurement methods and their spatial distribution is very inhomogeneous. Based on research to date, there is a reasonably scientific understanding of the particle concentration levels, size distributions associated with various sources, and their spatial heterogeneity in the urban environments. However, despite the progress made, there has been very limited progress in understanding the risk to human health posed by UFP, and therefore whether the particles should be controlled. Part of the reason relates to the challenges in epidemiological studies on the impact of UFP, and lack of consistency.

The cross-disciplinary Special Session will attempt to build a bridge between UFP science, epidemiology and control, by addressing the following broad questions:

• Can we offer a recommendation on ‘normal’ versus ‘abnormal’ UFP concentrations? What do we know about opportunities to reduce the UFP levels?
• There are no accepted standard methods to measure UFP: is this likely to change and/or is there a way around it?
• What are restricting epidemiological studies and can one match these with toxicological and clinical study findings? Is it possible to design an epidemiological study accounting for all relevant UFP characteristics in both indoor and outdoor microenvironments?
• What key evidence can already be used to recommend exposure limits? Which concentration-response functions should be used to inform policy makers and regulators