Toxicological properties of emission particles from heavy duty engines powered by conventional and bio-based diesel fuels and compressed natural gas

• Published in: Particle and fibre toxicology 2012-09, Vol.9 (1), p.37-37
• Main Authors: Jalava, Pasi I, Aakko-Saksa, Päivi, Murtonen, Timo, Happo, Mikko S, Markkanen, Ari, Yli-Pirilä, Pasi, Hakulinen, Pasi, Hillamo, Risto, Mäki-Paakkanen, Jorma, Salonen, Raimo O, Jokiniemi, Jorma, Hirvonen, Maija-Riitta
• Format: Article
• Language: English
• Subjects: Air Pollutants - chemistry; Air Pollutants - toxicity; Air pollution; Analysis; Animals; Apoptosis - drug effects; Biodiesel; Biodiesel fuels; Biofuels; Biomass energy; Buses; Cell Cycle - drug effects; Cell Line; Cell Membrane Permeability - drug effects; Cell Survival - drug effects; Compressed natural gas; Cytokines - metabolism; Diesel engines; Diesel fuels; Diesel motor; Diesel motor exhaust gas; Emissions; Emissions control; Environmental aspects; Evaluation; Exhaust emissions; Fatty Acids, Monounsaturated; Gas industry; Health aspects; Hydrogenation; Hydrotreated vegetable oil; In vitro toxicology; Internal combustion engines; Macrophages - drug effects; Macrophages - metabolism; Mice; Natural gas; Natural Gas - toxicity; Oxidative stress; Particulate matter; Particulate Matter - chemistry; Particulate Matter - toxicity; Plant Oils - toxicity; Rapeseed Oil; Reactive Oxygen Species - metabolism; Renewable energy; Renewable fuels; Risk factors; Vegetable oils; Vehicle Emissions - analysis; Vehicle Emissions - toxicity
• ISSN: 1743-8977; 1743-8977
• DOI: 10.1186/1743-8977-9-37

One of the major areas for increasing the use of renewable energy is in traffic fuels e.g. bio-based fuels in diesel engines especially in commuter traffic. Exhaust emissions from fossil diesel fuelled engines are known to cause adverse effects on human health, but there is very limited information available on how the new renewable fuels may change the harmfulness of the emissions, especially particles (PM). We evaluated the PM emissions from a heavy-duty EURO IV diesel engine powered by three different fuels; the toxicological properties of the emitted PM were investigated. Conventional diesel fuel (EN590) and two biodiesels were used - rapeseed methyl ester (RME, EN14214) and hydrotreated vegetable oil (HVO) either as such or as 30% blends with EN590. EN590 and 100% HVO were also operated with or without an oxidative catalyst (DOC + POC). A bus powered by compressed natural gas (CNG) was included for comparison with the liquid fuels. However, the results from CNG powered bus cannot be directly compared to the other situations in this study. High volume PM samples were collected on PTFE filters from a constant volume dilution tunnel. The PM mass emission with HVO was smaller and with RME larger than that with EN590, but both biofuels produced lower PAH contents in emission PM. The DOC + POC catalyst greatly reduced the PM emission and PAH content in PM with both HVO and EN590. Dose-dependent TNFα and MIP-2 responses to all PM samples were mostly at the low or moderate level after 24-hour exposure in a mouse macrophage cell line RAW 264.7. Emission PM from situations with the smallest mass emissions (HVO + cat and CNG) displayed the strongest potency in MIP-2 production. The catalyst slightly decreased the PM-induced TNFα responses and somewhat increased the MIP-2 responses with HVO fuel. Emission PM with EN590 and with 30% HVO blended in EN590 induced the strongest genotoxic responses, which were significantly greater than those with EN590 + cat or 100% HVO. The emission PM sample from the CNG bus possessed the weakest genotoxic potency but had the strongest oxidative potency of all the fuel and catalyst combinations. The use of 100% HVO fuel had slightly weaker and 100% RME somewhat stronger emission PM induced ROS production, when compared to EN590. The harmfulness of the exhaust emissions from vehicle engines cannot be determined merely on basis of the emitted PM mass. The study conditions and the engine type significantly affect the toxicity of the e