Health Relevance of Aerosols from Biomass Combustion in Comparison to Diesel Soot Indicated by Cytotoxicity Tests

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1 Health Relevance of Aerosols from Biomass Combustion in Comparison to Diesel Soot Indicated by Cytotoxicity Tests Norbert Klippel, Thomas Nussbaumer, Michael Oser, Zurich (Switzerland),

2 How do different combustion particles influence human health?

3 Particle deposition in respitatory tract [Health Phys. 12, 173] [Huch et al., 2003]

4 1.E+8 Comparison: PM10 emissions of different sources number concentration per size interval, dn/dlogd [particles/cm 3 ] 1.E+7 1.E+6 1.E+5 1.E+4 1.E+3 1.E+2 1.E+1 1.E+0 1.E-1 Diesel 100mg/m 3 GT oil full load <1µg/m 3 Diesel engines wood fire oil household burners coal power plant with ESP gas turbine with oil fuel gas turbine with gas fuel Ambient air data from EMPA Switzerland Alstom data particle diameter D [µm] wood fire 100 mg/m g/m 3 coal + ESP <50mg/m 3 ambient 50µg/m 3 Klippel et al., Schmatloch et al., ETH Nanoparticle Conf. Zurich

5 PM10 Emissions of Different Sources Main specific emitters in particle mass: badly maintained wood fires, old furnaces, open fires with wet wood and/or contaminants old generation Diesel engines Main specific emitters in particle number, i. e. submicron particles all types of wood furnaces all Diesel engines without particle filter Do they also cause similar health effects?

6 Chemistry of particles from wood firing K, Ca, Na, Cl, S.. [Baltensperger 1985] KCl, K 2 SO 4,CaCO 3 K <0.41 [Kaufmann/Nussbaumer 1998] [Oser et al. 2000] incomplete combustion 5.13 Aerodynamic Diameter [µm] 7.59 OC Ca > [mg/nm3] (13% O 2 )

7 Wood combustion and Diesel engines Chemistry of emitted particles is different: Diesel: mainly unburned carbon (soot) Wood: mainly salts of K, Ca, Cl, SO 4 <5% organic material in modern automatic furnaces high content of unburned material (organic carbon, soot) under bad combustion conditions only What is the impact on health?

8 Health effects of Diesel and Wood Ultra fine particles penetrate into lung Influence on lung tissue can be very different due to chemistry Toxicity of different substances can be investigated by cell culture tests first estimate on toxic reactions inside lung Both wood and Diesel particles applied to culture of lung cells of Chinese hamster (V79 standard cells)

9 Samples generated for health study Particles sampled after: A. Diesel engine (Euro III passenger car) B. Automatic wood furnace: 1. Standard operation eval. in present study 2. Low-Particle-concept (50% lower particle emission) 3. Non-optimal operation (higher emissions)

10 View of particle sampling after wood furnace filter for particle sampling

11 Particle filters after sampling Diesel particles particles from automatic wood furnace 0.5 g particle mass 2 g particle mass

12 Sample preparation grinding in a mixer add liquid cell medium ultrasonic treatment (10 min.) filter sample particle and filter fibre mixture sample in cell medium particles partly dipersed mixing for 24h at 37 C particles and filter fibres completely dispersed separation with syringe filter fibres in syringe particles in cell medium

13 Investigation of cell cultures

14 Toxicity test results: Diesel particles Cell survival [%] Diesel, test series V2, filter 106 Diesel, test series V4, filter 106 Diesel, test series V4, filter Extraction solution concentration [%]

15 Toxicity test results: Particles from automatic wood furnace Cell survival [%] wood particles V2 wood particles V4 wood (filter 25) V Extraction solution concentration [%]

16 Control test with empty filter material Cell survival [%] empty filter V2 empty filter V Extraction solution concentration [%]

17 Cell survival [%] Comparison between Diesel and wood particle toxicity wood V2 wood V4 wood (filter 25) V4 wood (filter 25) V4 Diesel V2 Diesel (filter 103) V4 Diesel (filter 106) V Particle concentration in cell medium [mg/ml].

18 Conclusions In very high concentrations both particle types are toxic Toxicity of Diesel particles is significantly higher at the same particle concentration: up to 100% of cells dead at 3mg/ml at this concentration, toxicity for wood particles is at detection limit of present study Ultra fine particles from automatic wood furnaces are less toxic than Diesel soot

19 Outlook Lower toxicity shown for wood combustion particles, consisting mainly of salts Direct cell tests with K salts in progress for comparison and better quantification What is the impact of unburned carbons, which result from bad combustion conditions? To which extend can health impact further be reduced by low particle firing concept? Next tests with already generated samples

20 Acknowledgements Swiss Federal Office of Energy (BFE), Berne Swiss Agency for the Environment, Forests and Landscape (BUWAL), Berne Swiss Federal Institute of Material Testing and Sciences (EMPA), Dept. Combustion Engines, Dübendorf RCC Cytotest Cell Research GmbH, Darmstadt (Germany)