Cellular Effects of Combustion Generated Nanoparticles

Abstract

Since beginning of 2005 when the latest intensification of the EU norm 96/62/EG becomes effective, a public discussion about limiting values for particulate matter with the size of 10 μm in diameter (PM₁₀) and their possible health risks came up. Short and long term epidemiological studies on PM and associated health effects gave clear evidence that high levels of PM₁₀ can cause increasing cardiovascular or cardiopulmonary mortality. There is further indication that the more dangerous particles in terms of health damage are smaller nano-sized particles (NP) of relative large surface area which are released through combustion processes from vehicles in public and individual traffic in high numbers. In this study the health effects of combustion generated NP were analysed. Therefore samples from commercially purchasable motorbikes as well as samples generated from burning gases in an experimental combustion set up, such as model flames, were tested with regard to their genotoxic and cytotoxic potential with the bacterial SWITCH-Test bioassay. From the measurements it could be concluded that for the two gases tested with increasing C/O ratio the toxic effects, cytotoxic as well as genotoxic, increase, too. The more far away a C/O ratio is from its stoichiometric flame the stronger are the toxic effects. The more impure a combustion process takes place the higher is the amount of toxic particles generated and the greater is their health impact. For all tested motorbikes, regardless if equipped with a two or four stroke engine, all NP samples showed a high toxic potential.