Deadline : extended until Wednesday, January 26, 2022

Notification of acceptance: Monday January 31, 2022


The following must be included in your submission:

• A title that clearly described the session.
• A 300-word description of your proposal. The content should reflect the conference theme.
• Full Contact details of the session organizer(s) – name, address, affiliation, email id, postal address and phone number.

For additional information please contact us at

Special Sessions

Special Session 01

Optical Particle Sensors. The effect of Aerosol Composition on Calibration

Organized by: Vasileios Papapostolou

South Coast Air Quality Management District, Diamond Bar, California, United States of America

Special Session 02

Integrated interdisciplinary approaches to quantify human health risk from outdoor air pollution

Organized by: Paola Crippa

University of Notre Dame, Notre Dame, Indiana, United States of America

Special Session 03

Urban impacts and the role of aerosols on extreme precipitation events

Organized by: Paola Crippa

University of Notre Dame, Notre Dame, Indiana, United States of America

Special Session 04

Metrology for mitigating adverse health effects from airborne particulate pollutants: The EMPIR AeroTox project

Organized by: Konstantina Vasilatou

Federal Institute of Metrology Metas, Bern, Switzerland


Aerosol composition (i.e., density, refractive index, shape, hygroscopicity, and particle size distribution) has significant effects on consumer-grade optical particle sensor (OPS) response, and studies show up to an order of magnitude difference in OPS signal between particles of different composition. OPS response is inherently dependent on aerosol composition since particle mass is inferred from a light scattering signal, and assumptions of composition made at the time of OPS factory calibration rarely correspond to those at the location and time of OPS deployment by the end-user. Existing efforts to compensate OPS response for aerosol composition include: laboratory/field calibration of OPS using aerosols representative of the composition expected at the location and time of deployment; development of calibration factors that specifically account for particle refractive index and particle size distribution from laboratory experiments; development of approximate scattering response functions for different aerosol types from laboratory experiments; and the use of theoretical models to predict OPS response to different aerosol compositions. While important, all such efforts share a common challenge in that the aerosol composition must be known or created a priori to OPS deployment, which is an impractical requirement for most users, applications, times, and locations. 

In this session, we will discuss efforts to apply machine learning to historical ambient air monitoring reference data (of climate, gas, particles, speciation), use data collected by only the consumer-grade OPS sensor system itself (of climate and particles) to predict when an event is occurring or there is an aerosol composition change or, use an array of particle sensors (multiple laser wavelengths, or combining both a nephelometric and OPC measurement technique) along with an array of gas sensors (CO, NO2, O3) with machine learning to determine if certain classes of aerosol composition have distinct “fingerprints” from other classes of aerosol composition.


The World Health Organization has set the aspirational goal of reducing the number of deaths from air pollution by two thirds by 2030 to achieve the sustainable development target of clean air quality in cities. The United Nations have also stressed the urgent need to recognize access to clean breathing air as a fundamental human right and to take action for sustainable plans and management practices to protect human health in response to challenges brought on by urbanization.

This session will focus on new interdisciplinary approaches to understand and improve the interactions between outdoor air quality, public knowledge, behavior and policy to reduce population exposure to outdoor air pollution and improve public health at the urban and regional scale. The session will include studies aimed at producing new data and methods on both the air quality and epidemiological side to improve assessment of the impacts of air pollution on exposure and health. Innovative approaches are needed to characterize air pollutants’ variability at fine spatio-temporal scales, such as new statistics-based data assimilation and machine learning techniques to incorporate observational datasets from traditional ground-based and citizen science networks, and from satellites, into high-resolution regional chemical transport model simulations and urban dispersion models. Similarly, new epidemiological studies aimed at improving knowledge on the physiological response to outdoor air pollution exposure and its variation by demographic factors are needed. Research case studies focused on integrating advances in either air pollution or health response characterization (or both) and on reducing the uncertainty in the associated health risk will be presented. Finally, as marginalized communities are often disproportionately affected by air pollution, and at times also comparatively under-monitored, the session will present studies seeking to investigate gaps in pollution, demographic, and health data for risk assessments in previously overlooked populations.


Over the past thirty years, extreme precipitation events have increased in frequency and intensity in many regions of the world as a result of the warmer climate. However, other potential drivers of change such as land use and land cover change (LULCC) in the form of urban expansion and changes in the intensity and spatial variability of aerosol and aerosol precursors are also important at local to regional scales. Understanding such mechanisms is thus critical to ensure societal preparedness to extreme events, particularly in a warming climate. 

This session will focus on improving understanding of land-atmosphere coupling and the response of cloud and precipitation characteristics, particularly of extreme events, to LULCC and aerosol concentration/spatial distributions associated with urbanization.

We will present studies quantifying recent changes in extreme precipitation events at the regional/urban scale from observations and model simulations to improve understanding of the mechanisms by which urban areas impact hydroclimates and to identify key controls in dictating the occurrence and characteristics of extreme precipitation and their spatial variability. Research studies addressing key challenges in the observational capabilities as well as statistical approaches to capture/explain the urban signature in precipitation properties will be discussed. Modeling studies analyzing the sensitivity to physical and chemical drivers, including aerosols, in contemporary and future climate scenarios will be also included.


Atmospheric particulate pollution has been linked to a broad spectrum of adverse health effects including respiratory problems, cardiovascular diseases, cancer and dementia. These effects depend not only on physical, but also on chemical properties of airborne particulate matter (PM) though to date it has proven difficult to disentangle the relative contribution of PM constituents to the reported population-level health effects.

To address this issue, the joint European research project AeroTox (2018-2022) [1] was initiated. The project has used ‘tailored’ reference aerosols generated in the laboratory, combined with high-resolution optical imaging of exposed cells and state-of-the-art cell analysis methods to study the cytotoxic effects of airborne PM in vitro. The goal is to help inform which PM metrics are associated with the induction of toxic mechanisms so that they can then be linked to specific health effects.

We propose  to organise a special session, where partners of the AeroTox Consortium will present  the progress achieved in the fields of aerosol generation and characterisation, in vitro cytotoxicity and high-resolution imaging of exposed cells and tissues.

Apart from presenting new research findings, the Consortium will seek to gather feedback from the aerosol and public health communities for the preparation of a follow-up EU research proposal.

[1] 18HLT02 AeroTox,


To date, the global SARS-CoV-2 pandemic COVID-19 has resulted in more than 350 million confirmed cases and more than 5.5 million deaths (WHO, 2021). The financial cost of the COVID-19 pandemic associated with lost production and reduced health is estimated at more than $ 20 trillion. One of the biggest oversights of public health authorities in the initial stages of the pandemic was the inability to realize the importance of airborne transmission of the virus despite repeated efforts by the international aerosol community to underscore this avenue of transmission. According to the Centers for Disease Control (CDC) of the US, we now know that over 90% of Covid19 infections occur through airborne transmission.

In this special session, we invite aerosol scientists to submit abstracts for platform and poster presentations on the theme of “”COVID-19 aerosol transmission and indoor air removal””.  Topics of interest include (but are not limited to) Covid19 aerosol dynamics in indoor environments, evaluation of mitigation strategies including face masks, ventilation, and air purification, and case studies exploring the role of factors such as relative humidity and temperature on Covid19 virus survival and transmission.


Accurate aerosol metrology i.e. dimensional quantification and chemical analysis, is a prerequisite for enforcing regulations, protecting human health, and supporting research on climate change and atmospheric processes.

However, air pollution is a complex metrology challenge that currently lacks traceable measurement and characterization of aerosols in the environment.

To address this, contribution in this proposed session will provide methodological improvements, including calibration guides and reference materials, for the calibration of particle size spectrometers, pollen monitoring instruments and the chemical characterization of ambient aerosols. Suitable contributions are also validation of current developments in the AEROMET II project using field campaigns and the development of portable instruments and software for the measurement of ambient aerosol particle concentrations under variable environmental conditions. Finally, the session also responds to current challenges regarding aerosol instruments used by non-experts. The overall focus will be on the traceable measurement and characterization of aerosols in the environment targeting at new traceable characterization techniques.


This special session is dedicated to the atmospheric emissions of aerosols from agricultural and livestock activities. In Europe, significant progress has been made over the past 20 years in reducing the emission of anthropogenic pollutants. Despite this, NH3 emissions from agriculture decreased by only 5% from 2005 to 2013, while from 2013 onwards, emissions increased slightly again (+ 3% from 2013 to 2016). Due to its relevant role in acids neutralisation, reactive nitrogen contributes to the formation of atmospheric aerosols participating in gas-to-particle conversion processes. Previous studies showed that during the winter months, the concentration of secondary inorganic aerosols (mainly ammonium nitrate and ammonium sulphate) can account for 40% – 50% of the total PM2.5 mass, with contributions of up to 75% at measurement sites located in agricultural areas.

In agricultural and livestock activities, reducing ammonia and carbon emissions is linked to the correct and efficient management of reactive nitrogen. Possible actions to reduce atmospheric aerosol emissions include: proper management of reactive nitrogen within the production cycle, efficient feeding and housing systems, proper management (storage, treatment and application) of manure, and efficient fertiliser management. The application of modelling techniques can help in this respect. Different modelling approaches can be adopted depending on the scale and focus of the analysis.

This special session aims at collecting relevant contributions on the topic of aerosol emissions into the atmosphere from agricultural and livestock activities, and on the link with new particles formation. Participants are welcome to submit contributions concerning the study of sources, datasets and evolution of aerosol emissions related to agricultural and livestock activities.


It is well established that global population exposure to outdoor and indoor air pollution leads to millions of premature deaths from respiratory, cardiovascular and other diseases every year. Epidemiological evidence associates the health effects of air pollution to the inhalation of particulate matter, which acts as carrier for a mixture of toxic substances, including metals and organic species. Mounting evidence suggests that the adverse health effects are related to the induction of oxidative stress following the formation of reactive oxygen species (ROS) in the lung and throughout the body. Oxidative potential (OP) has been proposed as a metric for characterizing the potential of pollutants to cause oxidative stress and health outcomes. OP can be quantified using a variety of acellular and cellular assays as well as model simulation. Establishing the relationships between aerosol sources and chemical composition, exposure pathways, biochemical mechanisms, and health outcomes is key for risk assessment of air pollutants and effective air quality management. This session provides a platform for international experts from academia, government, and industry to share their research on the role of OP in the adverse health effects of air pollutants. Submission topics could include: OP of indoor and outdoor aerosols, application of acellular and cellular OP assays, OP and its relation to aerosol chemical and physical characteristics and emission sources, and biological and epidemiological aspects of OP.