1. Institute of Occupational Health Sciences IST, rue du Bugnon 19, CH-1005 Lausannehttp://www.iurst.ch Challenges in exposure assessment to Diesel soot M.P. Guillemin Institute of Occupational Health Sciences Lausanne - Switzerland

2. Director of the Institute of Occupational Health Sciences in Lausanne, Switzerland Chemist and occupational hygienist most interested by the exposure assessment strategies Committed to the development of our knowledge in the area of complex mixtures and not well specified hazards Michel Guillemin

3. Introduction What is Diesel exhaust ? Health effects Mechanisms Exposure assessment Fine dust Carbon Further developments Conclusion Outline

4. Gas phase Usual gases found after the burning of fuels Particulate phase A core of « elemental carbon » coated with organic compounds and inorganic compounds What is diesel exhaust ?

5. Acute and temporary effects irritation chest tightness wheeze Chronic effects alteration of the lung function response of the immune system inflammation reaction cancer Effect on the workers’ lung

6. Health effects Animal

7. 0 10 20 30 40 50 60 70 80 90 020406080100120 Exposure (mg/m 3 years) Risk (%) Quartz PVC Coal Risk of pneumoconiosis in relation to cumulative exposure Mechanisms of action - pneumoconiosis

8. Clearance half-time for ultrafine particles and other dusts 0 200 400 600 800 1000 05101520 Dust concentration [mg/m ] 3 Clearance half-time (days) Quartz Ultrafine TiO 2 Diesel TiO PVC Mechanisms of action - clearance 2

9. 0.50.7511.251.51.752 Railroad workers Equipment operators Truck drivers Bus workers Pooled relative risk estimates and heterogeneity- adjusted 95% confidence intervals Health effects

10. Particle Macrophage Cytokines Growth factors Proteases Inflammation Cell injury Cell proliferation Hyperplasia Fibrosis Nongenotoxic Pathway Diesel exhaust-induced carcinogenesis

11. Organic Chemicals Detoxification Excretion Activation DNA Adducts DNA Repair Mutations Initiation Initiated cell Promotion Preneoplastic lesion Progression Malignant tumor Activation of protooncogenes Inactivation of tumor supressor genes Genotoxic Pathway Diesel exhaust-induced carcinogenesis

12. Gases and «total dust» Respirable particles Respirable particles and nicotine Total carbon First attempts in measuring exposure

13. Elemental carbon Small particles counting Particles identification and counting Dinitro-Polynuclear Aromatic Hydrocarbons... Potential Surrogate of Diesel Exhaust Particulates

14. Real Occupational Health problem Potential problem in Public Health Need of a multidisciplinary approach Political awareness and financial support Conclusions