The Challenge of the Epidemiologic Evidence for Excess Mortality and Morbidity Associated with Atmospheric Aerosols; M. Lippman. A Mechanistic Approach to Assessing the Lung Cancer Risk of Diesel Exhaust and Carbon Black; R. McClellan. Measurement of Highly Concentrated Fine Aerosols; W. Szymanski. Lung Morphometry and Particle Transport and Deposition: Overview of Existing Models; W. Hofmann. The Behaviour of Aerosols in the Human Nasal and Oral Airways, Including the Ultrafine Size Region; D. Swift. A Deposition Model for Fibres in the Deep Parts of the Lung Based on Similarities of Bead Beds and Human Lungs; J. Marijnissen, et al. Deposition of Hygroscopic Aerosol Particles in the Lungs; G. Ferron, B. Busch. The Influence of Charge on the Deposition Behavior of Aerosol Particles with Emphasis on Singly Charged Nanometer Sized Particles; B. Cohen, et al. Effects of Ultrafine Particles in the Lung and Potential Relevance to Environmental Particles; G. Oberdorster. Atmospheric Particulate Pollutants and Environmental Health, Physico-Chemical Standpoint; K. Spurny. Flow-Induced Mixing at Low Reynolds Number in an Expanding and Contracting Alveolus Model; Y. Otani, et al. The Influence of Normal and Pathological Inhomogeneities of the Lung Tissue son Particle Transport and Deposition; D. Orlicki, L. Gradon. Methods for Predicting Total Size Dependent Particle Collection Efficiencies with More than One Mechanism Acting; J. Gentry, N.C. Liu. The Retention of Inhaled Particles in the Human Respiratory System. Cytotoxic Effects; L. Gradon, A. Podgorski. Quantitative Fit Testing Techniques for Respirators Protecting the Human Respiratory System Against Environmental Aerosols; K. Willeke, D.-H. Han. Aerosol Delivery to the Respiratory Tract in Experimental Animals; M. Dahlback, et al. Experimental Investigation of Deposition and Fate of Particles: Animal Models and Interspecies Difference; R. Wolff. Pollen Grains, their Role in Allergy; G. Peltre. Atmosphere at Altitude, Another Approach; R. Roos. Panel Discussion.