An integrated assessment model for fine particulate matter in Europe

Exposure to fine particles in the ambient air is recognized as a significan t threat to human health. Two pathways contribute to the particle burden in the atmosphere: Fine particles originate from primary emissions, and secon dary organic and inorganic particles are formed from the gas phase from the emissions of 'conventional' pollutants such as SO2, NOx, VOC and NH3. Both types of particulate matter can be transported over long distances in the atmosphere. An integrated assessment model for particulate matter developed at IIASA ad dresses the relative importance of the different types of particulates, dis tinguishing primary and secondary particles and two size fractions. The mod el projects these emissions into the future and seeks cost-effective strate gies for reducing health risks to population. The model integrates the cont rol of primary emissions of fine particles with strategies to reduce the pr ecursor emissions for the secondary aerosols. Preliminary results addressin g the PM2.5 fraction of both primary and secondary particulate matter indic ate that in Europe the exposure to particulates will be significantly reduc ed as a side effect of the emission controls for conventional air pollutant s (SO2, NOx NH3).