Evaluation of the health impact of nanoparticles emitted from combustion sources: Comprehensive characterization of the physicochemical properties of nanoparticle emissions from wood combustion compliances, car- and ship diesel-engines as well as investigation of their toxicological effects on human lung cells and macrophages.

Combustion emissions cause health effects. The HICE-Aerosol and Health project team studies the physicochemical properties as well as biological and toxicological effects on lung cells of combustion particle emissions. The chemical composition and physical parameters thoroughly characterized. Human lung cells are exposed to the diluted combustion exhaust fumes at the air-liquid interface (ALI), allowing a realistic lung-cell exposure by simulation of the lung situation. After exposure, cellular responses of the exposed lung cells are studied by multi-omics molecular biological analyses on transcriptomic, proteomic and metabolomic level. Emissions of wood combustion (log wood, pellet heater), ship diesel engines and car gasoline engines are addressed. Special field deployable ALI-exposition systems in a mobile S2-biological laboratory were set up and applied. Human alveolar epithelial cells (A549, BEAS2B and primary cells) as well as murine macrophages were ALI-exposed to diluted emissions. The cellular effects were then comprehensively characterized (viability, cyto-toxicology, multi-omics effects monitoring) and put in context with the chemical and physical aerosol data. The following order of overall cellular response-strength was observed: A relatively mild cellular effect is observed for the diluted wood combustion emissions. Interestingly the effects-strength for log-wood and pellet burner emissions are similar, although PM-concentrations are much higher for the log-wood heater. Similar mild biological effects are observed for the gasoline car emissions. The ship diesel engine emissions induced the most intense biological responses. A surprising result in this context is, that heavy fuel oil (HFO)-emissions showed lower biological effect strengths than the supposedly cleaner diesel fuel emissions (DF). The HFO-emission contain high concentrations of known toxicants (transition metals, polycyclic aromatics). This result was recently confirmed by experiments with murine RAW macrophages. Detailed analyses of the activated cellular response pathways, such as pro-inflammatory responses, xenobiotic metabolism, phagocytosis and oxidative stress were performed. The data is suggesting a large difference in relative toxicity for different combustion sources.