Leena Rantanen

The Effect of Diesel Fuel Reformulation on the Exhaust Measured by Ames Mutagenicity and DNA AddUcts

In this study we compared two reformulated and one standard European Diesel fuel between particulate soluble organic fraction of PAH, mutagenic activity, and DNA adduct formation. Adducts were analyzed in vitro calf thymus DNA with and without the metabolic activation system and measured by 32 P-postlabeling method. PAH-DNA adduct formation and mutagenicity by Ames test were compared. Both biological tests showed that reformulation decreased genotoxic PAH compounds in diesel particle emission.

Trace Element Determination in Diesel Particulates by Total-Reflection X-Ray Fluorescence Analysis

Abstract. Particulate matter of Diesel emissions collected from diluted exhaust during standard test runs with two Diesel fuels of different sulfur content was analysed by total-reflection X-ray fluorescence (TXRF). The trace elements determined were S, Ca, Cr, Mn, Fe, Ni, Cu, Zn and Pb. Additionally, some filter materials were tested with respect to their applicability for sample collection. Quartz fibre filters were found to be most suitable, both from a technical and a chemical point of view. A clear reduction of total particulate emissions during the whole test was observed when the fuel with very low sulfur content was used. In addition, it was found that the wear metal content of particulate matter emitted by a cold engine was higher than that observed during normal engine working temperature.

DNA Adducts Derived from Diesel Emissions - Assessment of Genotoxic Potency in Vitro and Human Exposure Monitoring

Abstract Diesel particle extracts, which originated from three different diesel fuels, were used to study the activation of polycyclic aromatic hydrocarbons (PAHs). DNA adducts were analyzed in vitro calf thymus, human skin tissue culture and in lymphocytes isolated from diesel exposed workers. Direct-acting mutagens (e.g. nitro-PAHs) measured by Ames test were compared with DNA adducts formed in vitro by nitroreductive xanthine oxide enzyme. PAH-DNA adducts were analyzed by 32P-postlabeling, and when characterizing adducts from skin DNA, a solid-phase micro extraction (SPME) method was developed for sample preparation before HPLC analysis. A good accordance between mutagenicity and DNA adducts showed that the three extracts contain higher amounts of direct-acting PAHs than the PAHs needing S9 activation. Skin DNA adducts demonstrated two-fold differences between the tissue cultures. 32P-postlabeling and HPLC analysis did not confirm the identity of skin DNA adducts with the BPDE-DNA standard. The pilot study on 13 diesd exposed bus garage and waste collection workers showed low levels of PAH exposure (<50 ng/m3) and lymphocyte PAH-DNA adducts less than 2 adducts/108 nucleotides.