Diesel exhaust: current knowledge of adverse effects and underlying cellular mechanisms

Diesel engine emissions are among the most prevalent anthropogenic pollutants worldwide, and with the growing popularity of diesel-fueled engines in the private transportation sector, they are becoming increasingly widespread in densely populated urban regions. However, a large number of toxicological studies clearly show that diesel engine emissions profoundly affect human health. Thus the interest in the molecular and cellular mechanisms underlying these effects is large, especially concerning the nature of the components of diesel exhaust responsible for the effects and how they could be eliminated from the exhaust. This review describes the fundamental properties of diesel exhaust as well as the human respiratory tract and concludes that adverse health effects of diesel exhaust not only emerge from its chemical composition, but also from the interplay between its physical properties, the physiological and cellular properties, and function of the human respiratory tract. Furthermore, the primary molecular and cellular mechanisms triggered by diesel exhaust exposure, as well as the fundamentals of the methods for toxicological testing of diesel exhaust toxicity, are described. The key aspects of adverse effects induced by diesel exhaust exposure described herein will be important for regulators to support or ban certain technologies or to legitimate incentives for the development of promising new technologies such as catalytic diesel particle filters

Biological effects in lung cells In vitro of exhaust aerosols from a gasoline passenger car with and without particle filter

Exhaust aerosol from gasoline passenger cars is a complex mixture of a particulate fraction as well as volatile compounds. In contrary to the observed adverse effects of diesel exhaust particles the gasoline exhaust has, however, received little attention so far. The aim of this study was to perform a comparison of exhaust composition and biological responses from freshly produced non-filtered exhaust as well as from exhaust filtered with a noncoated gasoline particle filter (GPF). A 3D model of the human epithelial airway barrier was exposed to the exhaust directly at the air-liquid interface and different effects such as cytotoxicity, antioxidative response, pro- inflammation, and activation of the aryl hydrocarbon receptor (AhR) were studied. In addition, genotoxicity was assessed using the Ames test. By an online analysis of the exhaust, it has been shown that the GPF efficiently filters the particle count in both the cold and warm phase when the new European driving cycle (NEDC) was applied. The lung cell tests revealed that the use of the GPF increased the antioxidative glutathionine (GSH) response as well as the pro-inflammatory potential, i.e., IL-8, expression, indicating increased cell stimulation by the volatile compounds alone. The removal of the particulate fraction, however, decreased significantly the AhR activation in comparison to unfiltered exhaust, and the exhaust genotoxicity was reduced as tested by the Ames test. In conclusion, GPF exhaust did not completely reduce the adverse effects of gasoline exhaust in the in vitro test and further experiments with a coated GPF are needed in the future

Effects of an iron-based fuel-borne catalyst and a diesel particle filter on exhaust toxicity in lung cells in vitro

Metal-containing fuel additives catalyzing soot combustion in diesel particle filters are used in a widespread manner, and with the growing popularity of diesel vehicles, their application is expected to increase in the near future. Detailed investigation into how such additives affect exhaust toxicity is therefore necessary and has to be performed before epidemiological evidence points towards adverse effects of their application. The present study investigates how the addition of an iron-based fuel additive (Satacen®3, 40 ppm Fe) to low-sulfur diesel affects the in vitro cytotoxic, oxidative, (pro-)inflammatory, and mutagenic activity of the exhaust of a passenger car operated under constant, low-load conditions by exposing a three-dimensional model of the human airway epithelium to complete exhaust at the air–liquid interface. We could show that the use of the iron catalyst without and with filter technology has positive as well as negative effects on exhaust toxicity compared to exhaust with no additives: it decreases the oxidative and, compared to a non-catalyzed diesel particle filter, the mutagenic potential of diesel exhaust, but increases (pro-)inflammatory effects. The presence of a diesel particle filter also influences the impact of Satacen®3 on exhaust toxicity, and the proper choice of the filter type to be used is of importance with regards to exhaust toxicity

Sécurité et intégration sociale dans l'espace public : champs d'intervention et propositions d'actions : Papier de discussion Colloques urbains 2012 (version complète)

1. Encourager le dialogue intergénérationnel – Promouvoir la cohabitation 2. Instaurer des relations familières dans le quartier – Accroître le bien-être 3. Négocier règles et normes – Encourager un comportement responsable 4. Sécurité grâce à la police de quartier – Rendre visible l'application de la loi 5. Médias, politique et pratique – Réconcilier les discours 6. Dans la course de la société des 24 heures – Les professionnels sont présents 7. Concevoir des espaces – Créer des lieux de vi

Effects of an iron-based fuel-borne catalyst and a diesel particle filter on exhaust toxicity in lung cells in vitro

Metal-containing fuel additives catalyzing soot combustion in diesel particle filters are used in a widespread manner, and with the growing popularity of diesel vehicles, their application is expected to increase in the near future. Detailed investigation into how such additives affect exhaust toxicity is therefore necessary and has to be performed before epidemiological evidence points towards adverse effects of their application. The present study investigates how the addition of an iron-based fuel additive (Satacen®3, 40ppm Fe) to low-sulfur diesel affects the in vitro cytotoxic, oxidative, (pro-)inflammatory, and mutagenic activity of the exhaust of a passenger car operated under constant, low-load conditions by exposing a three-dimensional model of the human airway epithelium to complete exhaust at the air-liquid interface. We could show that the use of the iron catalyst without and with filter technology has positive as well as negative effects on exhaust toxicity compared to exhaust with no additives: it decreases the oxidative and, compared to a non-catalyzed diesel particle filter, the mutagenic potential of diesel exhaust, but increases (pro-)inflammatory effects. The presence of a diesel particle filter also influences the impact of Satacen®3 on exhaust toxicity, and the proper choice of the filter type to be used is of importance with regards to exhaust toxicity. Figure

Test-methods on the test-bench: a comparison of complete exhaust and exhaust particle extracts for genotoxicity/mutagenicity assessment

With the growing number of new exhaust after-treatment systems, fuels and fuel additives for internal combustion engines, efficient and reliable methods for detecting exhaust genotoxicity and mutagenicity are needed to avoid the widespread application of technologies with undesirable effects toward public health. In a commonly used approach, organic extracts of particulates rather than complete exhaust is used for genotoxicity/mutagenicity assessment, which may reduce the reliability of the results. In the present study, we assessed the mutagenicity and the genotoxicity of complete diesel exhaust compared to an organic exhaust particle extract from the same diesel exhaust in a bacterial and a eukaryotic system, that is, a complex human lung cell model. Both, complete exhaust and organic extract were found to act mutagenic/genotoxic, but the amplitudes of the effects differed considerably. Furthermore, our data indicate that the nature of the mutagenicity may not be identical for complete exhaust and particle extracts. Because in addition, differences between the responses of the different biological systems were found, we suggest that a comprehensive assessment of exhaust toxicity is preferably performed with complete exhaust and with biological systems representative for the organisms and organs of interest (i.e., human lungs) and not only with the Ames test