Michael Strandell

Effect of fuel polycyclic aromatic hydrocarbon content on the emissions of polycyclic aromatic hydrocarbons and other mutagenic substances from a gasoline-fueled automobile

Exhaust emissions from a fuel-injected, Otto engine equipped car driven according to the US Federal Test Procedure (FTP-73) were characterized chemically and by mutagenicity tests. Four fuel qualities of different polycyclic aromatic hydrocarbon (PAH) content were used. Emission variables investigated were regulated pollutants (CO, unburned hydrocarbons, NO/sub x/), particle emissions, emission of particle and gas phase associated polycyclic aromatic hydrocarbons, aldehyde emissions, emissions of benzene, toluene, ethene, and propene, and mutagenicity in particle and gas phases. The amount of formed PAH emitted in the exhaust is approximately constant. In fuels with low PAH contents a large proportion of emitted PAH was formed. Most of the cyclopenta(cd)pyrene and benzo(b and k) fluoranthene, greater than or equal to 80% and greater than or equal to 70%, respectively, is formed in the combustion process. All the exhaust samples, except one, in both the particulate phase and the gas phase, gave significant mutagenic effects on Salmonella typhimurium tester strains TA98 and TA100 with or without a metabolizing system (S9). Generally, the gas phase gave a higher effect compared to the particulate phase. The best correlation between emitted PAH and mutagenicity was found for the particulate phase and TA100+S9.

Fractionation and chemical analysis of gasoline exhaust particulate extracts in connection with biological testing

Abstract Dichloromethane extracts of gasoline vehicle exhaust particulates were fractionated into five fractions according to polarity on a silica gel column. A moderately polar fraction showing high genotoxic activity in the Ames test was further fractionated, using high performance liquid chromatography, on a nitro column, eluted isocratically. Gas chromatography combined with mass spectrometry, flame ionization, and electron capture detection were used for analysis. Also, field desorption mass spectrometry was utilized. Oxygenated derivatives of polycyclic aromatic hydrocarbons, e.g., 9H-fluoren-9-one, alkylfluorenones, and benzofluorenones were the most abundant species in these subfractions. Also, some halogenated aromatic compounds are reported, and quantitative data on nitroarenes are given.

Profile analysis of urban air pollution

Abstract Air pollution data from different traffic environments in Gothenburg were analysed using the SIMCA pattern recognition approach. Differences in traffic composition were reflected primarily by the ‘polycyclic aromatic hydro-carbon (PAH) profile’ of collected particulates. The results support the hypothesis that particle-associated low molecular weight PAH together with benzo(b)naphtho(2,1-d)thiophene (BNT) can be used as tracers for diesel vehicle traffic in city air. It is also indicated that particle-associated higher molecular weight PAH and lead (Pb), together with simple aromatic hydrocarbons in the gas phase, can be used as tracers for gasoline fueled vehicles. The best prediction of mutagenicity was achieved with partial least squares (PLS) regression using individual PAH, BNT, simple aromatics, and lead as predictors. Samples collected during the warmer period (April–October) showed lower levels of PAH and mutagenicity than those collected during the winter (November–March).

Swedish dioxin survey

Abstract The National Environmental Protection Board has received funding from the Swedish government for a broad survey to determine sources and environmental levels of highly toxic organic contaminants, especially dioxins. The funding covers administration, sampling and analyses over a two and a half year period. No plans have yet been made for the time after this period. The survey will include analyses of polychlorinated dibenzo-p-dioxins and dibenzofurans in air, water, sediment, products, combustion emissions, food and biological samples. A few analyses will also include polybrominated equivalents as well as dioxin-like polychlorinated biphenyls (PCB) and polychlorinated naphthalenes. Other substances of interest may come to our attention during the project. Biological test methods such as ethoxyresorfin O-deethylase (EROD) and aryl hydrocarbon hydroxylase (AHH) induction and the Ah receptor test will complement the chemical analyses. The results of analyses will be made available in a database with a direct out-going telephone line.

Emission of mutagenic, irritating and odorous substances from gasoline fueled vehicles with different emission control systems

Abstract The objective of this study was to evaluate the effect of different engine modifications and emission control systems. Both regulated and unregulated emissions were characterized. Unregulated emissions of special interest were mutagenic and carcinogenic compounds as well as odorous and irritating substances. Three consecutive test runs were performed using 8 cars during two different driving cycles. The results support the understanding that reduction of the regulated emissions CO, HC, and NOx, as well as PAH and other organic compounds, may be gained from modification of the engine in combination with a thermal reactor or an oxidation catalyst. However, the same reduction is not necessarily obtained regarding the emission of particles and mutagenic substances. No good indicator of mutagenic activity was found in this study except PAH. It is recommended that measurement of unregulated emissions should be included in studies regarding engine development work. A car equipped with a three-way catalyst was on a low emission level in most cases.