GC/MS and MS/MS studies of diesel exhaust mutagenicity and emissions from chemically-defined fuels (original) (raw)
Related papers
Atmospheric Environment, 2015
This paper investigates the effects of emissions including carcinogenic polycyclic aromatic 23 hydrocarbons (cPAH) of a conventional diesel engine without a particle filter. Experiments were carried 24 on during extended idle and during a loaded operation immediately following the extended idle. Extended 25 low-load operation of diesel engines due to idling and creep at border crossings, loading areas and in 26 severe congestion has been known to deteriorate the combustion and catalytic device performance and to 27 increase the emissions of particulate matter (PM). A conventional diesel engine was coupled to a 28 dynamometer and operated on diesel fuel and neat biodiesel alternately at idle speed and 2% of rated 29 power and at 30% and 100% load at intermediate speed. Exhaust was sampled on fiber filters, from which 30 the content of elemental and organic carbon and polycyclic aromatic hydrocarbons (PAH), including 31 cPAH and benzo[a]pyrene (B[a]P) have been determined. The emissions of cPAH and B[a]P have 32 increased 4-6 times on diesel fuel and by 4-21% on biodiesel during extended idling relative to a short 33 idle and 8-12 times on diesel fuel and 2-20 times during subsequent operation at full load relative to 34 Vojtisek et al., Atmospheric Environment 109 (2015) 9-18 -author's draft -page 2 stabilized operation at full load. The total "excess" cPAH emissions after the transition to full load were 35 on the same order of magnitude as the total "excess" cPAH during extended idling. The absolute levels of 36 PAH, cPAH and B[a]P emissions under all operating conditions were lower on biodiesel compared to 37 diesel fuel. Genotoxicity of organic extracts of particles was analysed by acellular assay with calf thymus 38 DNA (CT-DNA) and was consistently higher for diesel than for biodiesel. The exhaust generated during 39 extended idle and subsequent full load exhibited the highest genotoxicity for both fuels. These two 40 regimes are characterized by significant formation of cPAH as well as other DNA reactive reactive 41 compounds substantially contributing to the total genotoxicity. Oxidative DNA damage by all tested 42 extracts was negligible. 43 44 Abbreviations 45 B[a]P, benzo[a]pyrene; cPAH, carcinogenic PAH: benzo[a]anthracene, chrysene, benzo[b]fluoranthene, 46 benzo[k]fluoranthene, benzo[a]pyrene, dibenzo[a,h]anthracene, indeno[1,2,3-cd]pyrene; CT-DNA, calf 47 77 Extended idling or low-load operation of diesel engines is typical for border crossings, loading 78 and unloading areas, heavily congested sections of urban streets and roadways, and, where not prohibited 79 by legislation or excessive fuel costs, during layovers. Under such conditions, diesel engines operate at 80 very high excess air ratio. The combustion chamber surfaces are gradually cooled, the combustion 81 efficiency decreases, and the relatively low exhaust gas temperatures (around 100 °C) effectively inhibit 82 the functionality of virtually all catalyst surfaces. The resulting elevated emissions of volatile and semi-83 volatile organic compounds are expected to be, of all pollutants, of highest concern, and are targeted in 84 this study. Oyana and Lwebuga-Mukasa (2004) have found a cluster of excessively high prevailence of 85 asthma within close proximity of truck waiting area of the U.S.-Canada border crossing in Buffalo, NY.
The effect of fuel composition on the mutagenicity of diesel engine exhaust
Mutation Research Letters, 1995
The effect of fuel composition on the mutagenicity of diesel engine emission was investigated. To this end, a fuel matrix comprising fuels with different contents of aromatic and naphthenic compounds was used. Extracts of the organic phase of raw exhausts obtained with different fuels were tested for mutagenicity in bacterial reversion assays. The results obtained demonstrate that the mutagenicity of diesel exhaust is largely dependent on the aromatic content of the fuel. In fact, mutagenicity was greatly reduced when the aromatic content of the fuel was lowered by hydrogen treatment. Conversely, mutagenicity was enhanced when the fuel was enriched with fractions of di-or triaromatic compounds. The addition of di-and trinaphthenic compounds only produced borderline mutagenicity. No clear relationship was observed between sulfur content of the fuel and mutagenicity of the exhaust. Assays in bacterial strains with different sensitivity to nitroaromatic compounds suggest a low contribution of the highly mutagenic dinitropyrenes to the responses observed, and a relatively greater contribution of 1-nitropyrene or other nitroaromatics processed by the same bacterial nitroreductase. * Corresponding author. Tel. + +39 6 4990 ext. 840; Fax + +39 6 4440140. diesel engine exhausts are mutagenic and carcinogenic to laboratory animals and possibly to humans (IARC, 1989). Due to the growing impact of vehicle emissions on human health, especially in urban, densely populated areas, the development of control measures to contain human exposure to motor vehicle pollutants is urgently required. To this end, both the hardware control of emissions, e.g. through the use of advanced engine technology including catalysts, proper engine design, inspection and maintenance, and the 0165-7992/95/$09.50 © 1995 Elsevier Science B.V. All rights reserved SSDI 0165-7992(94)00083-2
Combustion of diesel fuel from a toxicological perspective
International Archives of Occupational and Environmental Health, 1992
Since the use of diesel engines is still increasing, the contribution of their incomplete combustion products to air pollution is becoming ever more important The presence of irritating and genotoxic substances in both the gas phase and the particulate phase constituents is considered to have significant health implications The quantity of soot particles and the particle-associated organics emitted from the tail pipe of a dieselpowered vehicle depend primarily on the engine type and combustion conditions but also on fuel properties. The quantity of soot particles in the emissions is determined by the balance between the rate of formation and subsequent oxidation Organics are adsorbed onto carbon cores in the cylinder, in the exhaust system, in the atmosphere and even on the filter during sample collection Diesel fuel contains polycyclic aromatic hydrocarbons (PA Hs) and some alkyl derivatives Both groups of compounds may survive the combustion process PA Hs are formed by the combustion of crankcase oil or may be resuspended from engine and/or exhaust deposits The conversion of parent PA Hs to oxygenated and nitrated PA Hs in the combustion chamber or in the exhaust system is related to the vast amount of excess combustion air that is supplied to the engine and the high combustion temperature Whether the occurrence of these derivatives is characteristic for the composition of diesel engine exhaust remains to be ascertained After the emission of the particles, their properties may change because of atmospheric processes such as aging and resuspension The particle-associated organics may also be subject to (photo)chemical conversions or the components may change during sampling and analysis Measurement of emissions of incomplete combustion products as determined on a chassis dynamometer provides knowledge of the chemical composition of the particleassociated organics This knowledge is useful as a basis for a toxicological evaluation of the health hazards of diesel engine emissions.
Chemical Research in Toxicology, 1996
The emission of diesel exhaust particulates is associated with potentially severe biological effects, e.g., cancer. The aim of the present study was to apply multivariate statistical methods to identify factors that affect the biological potency of these exhausts. Ten diesel fuels were analyzed regarding physical and chemical characteristics. Particulate exhaust emissions were sampled after combustion of these fuels on two makes of heavy duty diesel engines. Particle extracts were chemically analyzed and tested for mutagenicity in the Ames test. Also, the potency of the extracts to competitively inhibit the binding of 2,3,7,8-tetrachlorodibenzo-pdioxin (TCDD) to the Ah receptor was assessed. Relationships between fuel characteristics and biological effects of the extracts were studied, using partial least squares regression (PLS). The most influential chemical fuel parameters included the contents of sulfur, certain polycyclic aromatic compounds (PAC), and naphthenes. Density and flash point were positively correlated with genotoxic potency. Cetane number and upper distillation curve points were negatively correlated with both mutagenicity and Ah receptor affinity. Between 61% and 70% of the biological response data could be explained by the measured chemical and physical factors of the fuels. By PLS modeling of extract data versus the biological response data, 66% of the genotoxicity could be explained, by 41% of the chemical variation. The most important variables, associated with both mutagenicity and Ah receptor affinity, included 1-nitropyrene, particle bound nitrate, indeno[1,2,3-cd]pyrene, and emitted mass of particles. S9-requiring mutagenicity was highly correlated with certain PAC, whereas S9-independent mutagenicity was better correlated with nitrates and 1-nitropyrene. The emission of sulfates also showed a correlation both with the emission of particles and with the biological effects. The results indicate that fuels with biologically less hazardous potentials should have high cetane number and contain less PAC and sulfur. The results also indicate that engine factors affect the formation and emission of nitrated PAC.
Polycyclic Aromatic Hydrocarbons in the Particles Emitted from the Diesel and Gasoline Engines
Polish Journal of Environmental Studies, 2017
Polycyclic aromatic hydrocarbons (PAHs) are contaminants widespread in the environment and vehicular emissions have long been recognized as the most important anthropogenic sources of PAHs in urban air Polycyclic aromatic hydrocarbons (PAHs) emitted in the exhaust gases of diesel and petrol engines using different fuels were quantified. Size fractionated chemical analysis of particles in vehicle emissions were carried out by sampling with an electrical low pressure multi-stage impactor ELPI. The mean concentrations of total PAHs adsorbed onto the particulate matter in the rage of 0.03-0.25 μm emitted from the exhaust gases were 48.3, 128.2 and 83.0 ng•m-3 , respectively from three kinds of diesel fuels. Results indicated that PAHs present in the last two fraction (0.17-0.25 μm) have the highest contribution in the total content of these compounds. In the collected fractions of particulate matter emitted in gasoline engine exhaust 12 compounds were identified in the 0.25 µm fraction and 9 PAHs in the 0.17 µm fraction.
Analytical Chemistry, 2006
The presence of nitro-polycyclic aromatic hydrocarbons (NPAHs) in diesel fuel emissions has been studied for a number of years predominantly because of their contribution to the overall health and environmental risks associated with these emissions. Electron monochromator-mass spectrometry (EM-MS) is a highly selective and sensitive method for detection of NPAHs in complex matrixes, such as diesel emissions. Here, EM-MS was used to compare the levels of NPAHs in fuel emissions from conventional (petroleum) diesel, ultra-low sulfur/low-aromatic content diesel, Fischer-Tropsch synthetic diesel, and conventional diesel/synthetic diesel blend. The largest quantities of NPAHs were detected in the conventional diesel fuel emissions, while the ultra-low sulfur diesel and synthetic diesel fuel demonstrated a more than 50% reduction of NPAH quantities when compared to the conventional diesel fuel emissions. The emissions from the blend of conventional diesel with 30% synthetic diesel fuel also demonstrated a more than 30% reduction of the NPAH content when compared to the conventional diesel fuel emissions. In addition, a correlation was made between the aromatic content of the different fuel types and NPAH quantities and between the nitrogen oxides emissions from the different fuel types and NPAH quantities. The EM-MS system demonstrated high selectivity and sensitivity for detection of the NPAHs in the emissions with minimal sample cleanup required.
Toxic Effects of Polycyclic Aromatic Hydrocarbons in a Water Medium from Diesel Combustion
Anais do XX Congresso Brasileiro de Engenharia Química, 2015
Most energy consumed on the planet derives from petroleum, coal and natural gas and the air pollution caused by such combustion is largely solved in water resources. The reaction produces highly toxic polycyclic aromatic hydrocarbons (PAHs). Current analysis evaluates the toxic effects of gas emissions from the combustion of diesel S10, S50 and B2 in a stationary engine. Methodology comprises the absorption of combustion gases in de-ionized water, with a fixed bed column. Absorption water is used for acute toxicity assays on Mysidopsis juniae, following norms by ABNT 15308. PAHs are quantified by fluorometry. Results showed an average concentration of 34.65 mg.L-1 of total PAH in the collected water sample. A 100% mortality of Mysidacea occurred in all dilutions in the three toxicity assays, except control, with a survival rate of 100% in both cases.
Atmosphere
Emissions of PAH, nitro-PAHs, and oxy-PAHs from a diesel engine fueled with diesel-biodiesel-ethanol blends need to be controlled and reduced, as they are unregulated emissions harmful to the environment and human health. The objective of this work was to investigate the effect of ethanol concentration on diesel engine emissions when fueled with diesel–biodiesel–ethanol blends. Ethanol was added with biodiesel–diesel blends. Diesel B7 and two ternary blends, B7E3 and B7E10, with 3% and 10% ethanol, were tested and studied in a diesel engine to determine engine performance characteristics and particulate matter emissions and to quantify polycyclic aromatic compounds (PACs) associated with PM1.0 and PM2.5. Under the same engine conditions, 18 PAHs, 27 nitro-PAHs, and 6 quinones (oxy-PAHs) were determined by GC–MS in real samples obtained from the engine. The mean concentrations of PACs found in the B7, B7E3, and B7E10 blends for PM1.0 ranged from 0.1 µg m−3 (coronene) to 118.1 µg m−3 ...
Issue 2, 2018
In the present investigation, an attempt for the reduction of six hazardous air Pollutants (HAPs) from diesel exhaust by different blends of diesel and biodiesel has been made. The synthesis of biodiesel has been done from Jetrofa, Linseed Castor and Karanja oils which are commonly used in the Indian market. Blending of diesel with biodiesel was done in different ratios (20 to 40 %) for the estimation of carcinogenic HAPs from the exhaust of a Honda engine (EBK 2010AC Model). The order of HAPs emission from engine exhaust by using diverse blends were Diesel>Jatropha-diesel>Linseed-diesel>Castor-diesel> Karanja-diesel. The maximum reduction of HAPs was established in the following ratio 40% (Biodiesel):60% (Diesel). B(a)P and Chrysene were the two individual aromatic hydrocarbons (AHCs) found in higher concentration in almost all blending fuels, ranging between 50 ng/µl to 101.1 ng/µl. The emission of almost all AHCs reduces by Blending of Diesel with Biodiesel. This was ...
Environmental Science & Technology, 2013
A dx.doi.org/10.1021/es400518d | Environ. Sci. Technol. XXXX, XXX, XXX−XXX cal00 | ACSJCA | JCA10.0.1465/W Unicode | research.3f (R3.5.i1:3915 | 2.0 alpha 39) 2012/12/04 10:21:00 | PROD-JCA1 | rq_1359745 | 5/14/2013 13:14:53 | 9 65 Moreover, a reduction of emissions of carbon monoxide (CO), 66 total hydrocarbons (HC), and nitrogen oxides (NO X ) was 67 shown following combustion of a 30% blend with DF in a 68 heavy duty engine. 7 Combustion of blends in three different 69 light duty vehicles yielded decreased CO, HC, and particulate 70 matter (PM) emissions and reduced aldehydes, 1,3-butadiene, 71 benzene, particle-bound polycyclic aromatic hydrocarbons 72 (PAHs), and bacterial mutagenicity of the exhaust. 5 In this 73 study, we compared the emissions of 100% HVO with those of 74 DF and two biodiesel fuels. 75 The introduction of new fuels requires comprehensive 76 investigation of possible hazards. This should involve ecological 77 concerns and possible human health effects. The analyses of 78 CO, HC, NO X , and PM are required by emission standards in 79 the European Union, the U.S.A., and many other countries. 80 Obviously the investigation of regulated exhaust components 81 does not cover all suspected health effects of diesel engine 82 emissions (DEE). Since studies on emissions and their 83 biological effects after combustion of biofuels for diesel engines 84 revealed unexpected results indicating increased health 85 hazards, 8,9 an intensified research on the possible hazards for 86 human health is needed. 10 87 Increased particle exposures are associated with acute and 88 chronic respiratory diseases. These particle exposures are partly 89 ascribed to DEE. 11−15 Moreover, epidemiologic data point to 90 adverse circulatory effects by particulate air pollution. 16 DEE 91 can also contribute to acute, adverse cardiovascular effects 92 according to a controlled inhalation study with healthy 93 volunteers and patients suffering from coronary heart disease. 17 94 Long-term occupational DEE exposures were associated with 95 an elevated lung cancer risk in a pooled analysis of 11 96 population-based European and Canadian case-control studies 97 covering exposures from the 1950s to the 1980. 18 Whereas 98 most previous studies showed moderate increased lung cancer 99 risks, a recent "nested case control study" revealed dose-100 dependent increased odd ratios up to 7.30 (95% confidence 101 interval (CI) = 1.46−36.57) for DEE exposed "non-metal 102 miners" which were exposed toward 304 μg/m 3 -y or more. 19 103 This investigation was based on a cohort study which included 104 12 315 workers exposed to DEE at eight US nonmetal mining 105 facilities. Hazard ratios for lung cancer mortality up to 5.01 106 (95% CI = 1.97−12.76) were seen in this cohort. 20 These 107 results prompted the International Agency for Research on 108 Cancer (IARC) to change the classification of DEE from 109 "probably carcinogenic to humans" (group 2A) into "carcino-110 genic to humans" (group 1) in June 2012. 21 Further evidence 111 for the association of increased lung cancer mortality with DEE 112 exposure was added by a recent retrospective cohort study on 113 trucking industry workers using cumulative elemental carbon 114 (EC) as a surrogate of exposure to engine exhaust from diesel 115 vehicles, traffic, and loading dock operations. 22 116 Carcinogenicity of DEE from combustion of common DF is 117 ascribed to chronic inflammatory effects of diesel particulate 118 matter and to PAHs which are adherent to the particles. 1,23 119 Corresponding to the genotoxicity of many PAHs, extracts of 120 diesel particulate matter induced strong mutagenicity in the 121 bacterial reverse mutation assay. 24,25 A small part of PAHs react 122 with nitrogen oxides (NO X ) out of the gaseous phase of DEE 123 forming nitrated PAHs (nPAHs). Compared to their parent 124 PAHs, most of the resulting compounds are much stronger 125 mutagens and directly mutagenic. 26,27 157 184 Regulated Emissions. CO, HC, and NO X were 185 determined with a commercial gas analyzer and sampled each 186 second. A mean was determined from the values sampled in the 187 last minute of each operating point. The hot and filtered 188 exhaust gas was passed to the HC analyzer via a pipe, which was 189 heated to 190°C. HC were analyzed by a gas analyzer (RS 55-Environmental Science & Technology Article dx.