Objective Exposure to particulate matter (PM) has been linked to negative health effects. Traditionally attributed to PM<10µm and<2.5µm, negative health effects may be enhanced with decreasing particle size, suggesting that ultrafine particles (UFP, PM<0.1µm) might be responsible for what has previously been attributed to larger size fractions of PM.According to their origin, UFP can be primary (directly emitted to the atmosphere) or secondary (formed in the atmosphere from precursor gaseous pollutants). In central European cities, UFP particle concentrations (N) are mainly affected by road traffic emissions, as evidenced by the parallel variation of N and Black Carbon (BC, traffic tracer) concentrations. However, in European regions with high insolation, the maximum N is observed at midday (when BC is low) due to photochemical nucleation. A methodology developed by Rodriguez et al. (2007) allows the quantification of the primary (N1) and the secondary (N2) contribution to total N. Depending on origin and size, UFP may differently affect human health but no study has yet tackled this key issue. Moreover, there are currently no legal ambient standards for UFP. The main objectives of Health1UP2 (Differentiated health impacts of primary and secondary ultrafine particles) are (i) to uncover the differences in N1 and N2 in the cities of London (UK), Barcelona (Spain), Zurich (Switzerland) and Helsinki (Finland), based on long time-series of size-segregated UFP and BC data, and (ii) to determine the health impacts (mortality and hospital admissions as outcomes) of the exposure to differentiated N1 and N2 in different size-ranges in these cities.This research requires an international collaboration, since different meteorological conditions, pollutant emissions and other parameters influence divergently on N1 and N2. The results of this work will serve as indication to the corresponding authorities of which pollutants should be included in future EU legislation about air quality. Fields of science medical and health scienceshealth sciencespublic healthsocial sciencessociologydemographymortalitynatural sciencesearth and related environmental sciencesatmospheric sciencesmeteorologysolar radiationengineering and technologyenvironmental engineeringair pollution engineering Programme(s) H2020-EU.1.3. - EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions Main Programme H2020-EU.1.3.2. - Nurturing excellence by means of cross-border and cross-sector mobility Topic(s) MSCA-IF-2016 - Individual Fellowships Call for proposal H2020-MSCA-IF-2016 See other projects for this call Funding Scheme MSCA-IF-EF-ST - Standard EF Coordinator KING'S COLLEGE LONDON Net EU contribution € 183 454,80 Address Strand WC2R 2LS London United Kingdom See on map Region London Inner London — West Westminster Activity type Higher or Secondary Education Establishments Links Contact the organisation Opens in new window Website Opens in new window Participation in EU R&I programmes Opens in new window HORIZON collaboration network Opens in new window Other funding € 0,00