Atmospheric aerosols are tiny particles (nano- or micro-meter sized) suspended in air. They stem from both natural processes and human activities and are emitted to the atmosphere directly as particles or formed in the atmosphere by chemical reactions and processes.  We inhale aerosols in every breath and aerosols are a key ingredient of indoor as well as outdoor air pollution.  They are known to have adverse health effects. Moreover, aerosols affect visibility, weather and climate via absorption and scattering of light and by acting as seeds for cloud formation.

At Aarhus University several research teams are more or less independently addressing a variety of aspects related to natural and man-made aerosols. In particular:

• Atmospheric chemists clarify fundamental scientific questions related to atmospheric aerosols and are recognized for expertise on thermodynamics of aerosols, cloud formation and analysis of the detailed chemical composition of atmospheric aerosols from different environments. A suite of state of the art instrumentation is available for aerosol characterization and a brand new AU environmental chamber facility for studies of aerosol formation and growth is constructed.
• A team of medical doctors are renowned for epidemiological and toxicological studies of aerosol effects on human health. As an example, they study respiratory diseases and inflammation after exposure to different mixes of aerosols. Newly renovated and outstanding nationwide facilities are available at AU Health for such human exposure studies.  
• Air-quality engineers target the significant source of aerosol precursors (ammonia and sulfur compounds) from livestock production and partake in development of new technologies for abatement of such aerosol precursors. Among other things the team operates state of the art equipment for detection of aerosol precursor molecules in real time.
• Bio-aerosols in the form of micro-organisms are emitted to the atmosphere from soils, vegetation, lakes and oceans but little is known about their fate and impact on atmospheric processes, human health and climate. A team of microbiologists break new ground by investigating ice nucleation abilities of bio-aerosols sampled from ground as well as air-plane.
• Environmental scientists at Department of Environmental Science operate the Danish National Air Quality monitoring network and have the responsibility for managing the national air-quality databases.  The newly inaugurated Villum Research Station at Station Nord, North Greenland will feature a wealth of state of the art aerosol and aerosol precursor instrumentation and is expected to attract aerosol scientists from around the world due to the unique possibilities for studies of aerosols and their impact in the sensitive Arctic ecosystem and climate.
• Finally, economics and social life course epidemiology scientists seek to identify both individual and contextual factors that have an effect on disease. Aerosols and air pollution are important factors in this respect. The group has established an exceptional data infrastructure for register based interdisciplinary research.

It is the aim of this interdisciplinary network to bring together scientist across departments and fields at Aarhus University and jointly establish ongoing collaboration to help answer some of the many research questions within the field of atmospheric aerosols.