6th International Symposium on Ultrafine Particles

Air Quality and Climate Brussels, Belgium May 10 and 11, 2017 

 See photo impression  (2 pages) and Proceedings


Seventy experts from more than 12 different European countries participated in the 6th symposium on ultrafine particles (UFP) to discuss aerosol related health effects indoors and outdoors, urban air pollution on different scales, engineered nanoparticles in ambient air, airborne aerosol measurements, emission reduction, and abatement strategies in 11 sessions. The symposium was completed by a panel discussion on emissions and abatement strategies for ultrafine particles. UFP especially from vehicle exhaust are associated with cardiovascular morbidity and mortality by multiple mechanisms. Also cognitive decline could be associated with particulate air pollution but it was pointed out how rare and demanding useful epidemiological studies are. The initial response of lung cells on combustion aerosols include oxidative stress, inflammation and apoptosis. For lung cells the overall biological response-strength differs considerably for different aerosol sources and is not well correlated with the deposited particle mass. The health risk of the use of fuel additives, the estimation of the toxicity with integrated dose monitoring techniques and the relationship of indoor to outdoor ultrafine particle levels were described, as well as the challenges for science and regulation. The potential release and atmospheric fate of engineered nanoparticles bares still significant uncertainties.

Ultrafine particle number concentrations observed near and downwind of big airports like Amsterdam or Frankfurt reach very high peak values. A pattern between the mortality risk and the distance to the airport was not clearly visible but it cannot be excluded that the UFP contribution of air traffic can lead to an excess mortality risk or impact on morbidity. UFP have a significant climate impact. New particle formation generates half of the cloud condensation nuclei in the Earth atmosphere with highly oxidized organic compounds from the biosphere having a substantial influence on particle formation and growths. Airborne measurements of UFP showed their global distribution and the importance of vertical mixing for their concentration variations especially in urban areas. READ MORE

Ultrafine particles

Ultrafine particles, (UFP), are the smallest constituents of airborne particulate matter and are considered to be causing serious health problems and environmental effects. They may nucleate as a result of combustion processes or result from photochemical reactions of volatile precursor gases, thus showing a clear link to gaseous pollution. Recently, direct emission of man-made nanoparticles, e.g. from the incineration or degradation of synthetic nanomaterials, has attracted considerable attention.


Apart from the specific role of UFP in air quality, they play also a key role in atmospheric processes such as cloud formation and precipitation and, in fact,in climate. The relation between UFP and human health and that of UFP and climate are both areas of active research and cross-links between these fields are found nowadays. The new subtitle of the conference series: "air quality and climate” reflects this development.


Size and composition

Present policies to decrease exposure to particulate matter make use of the mass-based metrics PM10/PM2.5, which do not properly represent all risks for human health. EFCA is, therefore, in favour of the development of a fraction-by-fraction approach, both with respect to size and chemical composition.

It already recommended European policymakers the introduction of Black Carbon Particles as additional metric in the Air Quality Directive.Click here to read more