Airborne particles have numerous effects on humans, the environment, climate and anthropogenic constructions. Examples are • short-term and long-term health effects for humans leading to higher morbidity and mortality rates, • ecosystem effects through acid deposition and nitrification causing ‘waldsterben’, • climate effects via direct and indirect radiative forcing leading mainly to cooling and • corrosive effects by enhanced degradation of anthropogenic constructions. Hence, these effects also lead to significant economic losses. Both, our wish to protect and preserve our lives and the environment, and to save money and be more competitive worldwide drive the research into airborne particles. In recent years, as described in the introduction, it became obvious that especially fine particles, particles less than 2.5 µm in diameter are linked to most of the abovementioned effects which enhanced corresponding research and technological developments. Section 2 describes and summarises both, the existing devices to determine and characterise airborne particles as well as the current shortcomings leading to further needs in developments. The focus in this area will be online measurement methods for particle sizes from the nanometer up to 10s’ of micrometre giving multiparameter information. This may be size and chemical composition or size and morphology. Another focus in this area will be the miniaturisation and development of low cost devices to facilitate the determination and characterisation indoors, on personal level as well as multi-location monitoring in any environment of interest. These developments will enable improved exposure assessments for humans as well as other living and dead matter in the environment. Exposure assessments in general also include the determination of sources leading to harmful exposure levels. Source identification and quantification is still a major issue in ambient air quality since no simple straight forward methods exist. Section 3 gives examples on how source apportionment can be conducted and summarises the current knowledge. The latter has certainly to be improved to enable source related and hence cost effective abatement measures. Besides improved data availability by the new devices, validation of current source apportionment methods including comprehensive evaluation of source receptor models and chemical transport models (dispersion models) results are needed and should be pursued. Human exposure at workplaces, especially towards product nanoparticles and nanomaterials, is another focus in exposure research. This is dealt with in section 4 where both, measurement strategies to determine workplace exposure as well as results of exposure related field measurements, are presented and discussed. One major problem in assessing exposure and ensuring workplace safety at ‘nano’ related workplaces is that not enough data for a generalisation is available. Hence two approaches are currently pursued. One building on new measurement devices and exposure related measurements and the other using detailed studies of handling and processing of nanomaterials to assess possible release by the process and hence possible exposure. Another major issue for workplace exposure assessment is the discrimination of background particles, composed of other particles than those produced in the plant. This is still an issue and future work has to be put into the harmonisation of approaches for different types of exposure settings and processes. The release of fine dust into the environment and its detection and characterisation has to be assessed in view of possible health effects. This is the topic of section 5 which also is the topic with the highest uncertainties. It is known and was shown in the introduction that airborne particles, especially fine dust lead to health effects. Current investigations mainly base on mass concentrations as an exposure metric. Other, alternative metrics such as ultrafine particle number concentration, surface area concentrations, black carbon or the potential to form reactive oxygen species are currently also discussed to be of relevance and some investigations are ongoing, studying the correlation of these metrics to health effects. This certainly will be one focus in the future. It may well be that one metric will correlate better to some health endpoints than to others and that another metric is more closely linked to the other health endpoints. The major aim of the research area “airborne particles and health” is to advance our knowledge on release, exposure, dose and health effect and the interactions inbetween to reduce the adverse health impacts and improve our quality of life.