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Effects of low concentration biodiesel blend application on modern passenger cars. Part 1: Feedstock impact on regulated pollutants, fuel consumption and particle emissions
2010
Fontaras, Georgios | Kousoulidou, Marina | Karavalakis, Georgios | Tzamkiozis, Theodoros | Pistikopoulos, Panayotis | Ntziachristos, Leonidas | Bakeas, Evagelos | Stournas, Stamoulis | Samaras, Zissis
Five biodiesels from different feedstocks (rapeseed, soy, sunflower, palm, and used fried oils) blended with diesel at 10% vol. ratio (B10), were tested on a Euro 3 common-rail passenger car. Limited effects (-2% to +4%) were observed on CO2 emissions. CO and HC emissions increased between 10% and 25% on average, except at high speed - high power where emissions were too low to draw conclusions. NOx emissions increased by up to 20% for two out of the five blends, decreased by up to 15% for two other blends, and remained unchanged for one blend. Particulate matter (PM) was reduced for all blends by up to 25% and the reductions were positively correlated with the extent of biodiesel saturation. PM reductions are associated with consistent reductions in non-volatile particle number. A variable behaviour in particle number is observed when volatile particles are also accounted.
Show more [+] Less [-]Historical record of polycyclic aromatic hydrocarbons (PAHs) and spheroidal carbonaceous particles (SCPs) in marine sediment cores from Admiralty Bay, King George Island, Antarctica
2010
Martins, César C. | Bícego, Márcia C. | Rose, N. L. (Neil L) | Taniguchi, Satie | Lourenço, Rafael A. | Figueira, Rubens C.L. | Mahiques, Michel M. | Montone, Rosalinda C.
This paper describes the first results of polycyclic aromatic hydrocarbons (PAHs) and spheroidal carbonaceous particles (SCPs) in sediment cores of Admiralty Bay, Antarctica. These markers were used to assess the local input of anthropogenic materials (particulate and organic compounds) as a result of the influence of human occupation in a sub-Antarctic region and a possible long-range atmospheric transport of combustion products from sources in South America. The highest SCPs and PAHs concentrations were observed during the last 30 years, when three research stations were built in the area and industrial activities in South America increased. The concentrations of SCPs and PAHs were much lower than those of other regions in the northern hemisphere and other reported data for the southern hemisphere. The PAH isomer ratios showed that the major sources of PAHs are fossil fuels/petroleum, biomass combustion and sewage contribution generally close to the Brazilian scientific station. SCPs and PAHs indicate the increase in human activities in a sub-Antarctic region.
Show more [+] Less [-]Air Pollution and its Impact on Lung Function of Children in Delhi, the Capital City of India
2010
Siddique, Shabana | Banerjee, Madhuchanda | Ray, Manas Ranjan | Lahiri, Twisha
Air pollution is a major contributor to several respiratory problems, it affects the whole population in general but children are more susceptible. Exposure to automobile exhaust is associated with increased respiratory symptoms and may impair lung function in children. In view of this, the study was conducted among the children of Delhi, the capital city of India, where ambient air quality was much above the National Ambient Air Quality Standards. The study was conducted in children aged 9-17 years. Pulmonary function test was carried out following the guideline of American Thoracic Society using a portable, electronic spirometer. Air quality data was collected from Central and State Pollution Control Boards. In addition, the level of particulate matter in indoor air was measured by portable laser photometer. Lung function was reduced in 43.5% schoolchildren of the urban area compared with 25.7% of control group. The urban children had increased prevalence of restrictive, obstructive, as well as combined type of lung functions deficits. Besides higher prevalence, the magnitude of lung function deficits was also much more in them. After controlling potential confounders like season, socioeconomic conditions and ETS, PM10 level in ambient air was found to be associated with restrictive (OR = 1.35, 95% CI 1.07-1.58), obstructive (OR = 1.45, 95% CI 1.16-1.82), and combined type of lung function deficits (OR = 1.74, 95% CI 1.37-2.71) in children. Spearman's rank correlation test reaffirmed the association. The study confirms that the level of air pollution is affecting the children.
Show more [+] Less [-]Monitoring Particulate Matter Concentrations with Passive Samplers: Application to the Greater Thessaloniki Area
2010
Assael, Marc J. | Melas, Dimitris | Kakosimos, Konstantinos E.
Modern European cities are characterized by high particulate matter (PM) concentrations. Unfortunately, the number of stations monitoring air pollution, especially PM, is never sufficient for the overall representation of the problem. In the present work, an inexpensive outdoor passive sampler (based on an indoor passive sampler) was developed and assembled in an effort to provide the means to extend current PM monitoring networks. The uncertainty of the sampler was tested in vitro and in vivo. Twenty such outdoor passive samplers were assembled and installed at specific locations in the Greater Thessaloniki Area and measurements of PM were carried out. The results were in good agreement with the official monitoring stations. In addition, they revealed the aggravated air quality in the center of the city and in the west suburbs.
Show more [+] Less [-]Accumulation Capacities of Particulate Matter in an Acrocarpous and a Pleurocarpous Moss Exposed at Three Differently Polluted Sites (Industrial, Urban and Rural)
2010
Fabure, J. | Meyer, C. | Denayer, F. | Gaudry, A. | Gilbert, D. | Bernard, N.
The aim of this study was to compare the capacity of two morphologically different moss species to accumulate elements when exposed to three different types of air pollution (rural, urban and industrial). Transplants of Pseudoscleropodium purum and Ceratodon purpureus were exposed for 6 months, and the concentrations of 18 elements (Al, Ti, V, Cr, Mn, Fe, Co, Cu, Zn, As, Mo, Cd, Sn, Sb, Ba, La, Pb and Bi) in the mosses samples were analysed by inductively coupled plasma-mass spectrometry. On the whole, the metals were accumulated by mosses, and this accumulation was correlated with concentrations in the atmospheric particles. Whereas P. purum is to be preferred for Al, Cu, Zn and Fe monitoring, C. purpureus was most efficient at accumulating Mo, Ti, V, As, Sn, La and Pb. In both species, a phenomenon of saturation was observed during the exposure at the most contaminated site (industrial).
Show more [+] Less [-]Source Apportionment of the Atmospheric Aerosol in Lahore, Pakistan
2010
Suresh, Raja | Biswas, Karabi F. | Husain, Liaquat | Hopke, Philip K.
Samples of airborne particulate matter (PM₂.₅) were collected at a site in Lahore, Pakistan from November 2005 to January 2006. A total of 129 samples were collected using an Andersen Reference Ambient Air Sampler 2.5-400 sampler and analyzed for major ions, trace metals, and organic and elemental carbon concentrations. The data set was then analyzed by positive matrix factorization (PMF) to identify the possible sources of the atmospheric PM collected in this urban area. Six factors reproduced the PM₂.₅ sample compositions with meaningful physical interpretation of the resolved factors. The sources included secondary PM, diesel emissions, biomass burning, coal combustion, two-stroke vehicle exhaust, and industrial sources. Diesel and two-stroke vehicles contributed about 36%, biomass burning about 15%, and coal combustion sources around 13% of the PM₂.₅ mass. Nearly two thirds of the PM₂.₅ mass is carbonaceous material. Secondary particles contributed about 30% of PM₂.₅ mass. The conditional probability function (CPF) was then used to help identify likely locations of the sources present in this area. CPF analysis point to the east and northeast, which are directions of urban and industrial areas located across the border near Amritsar, India as the most probable source for high PM₂.₅ concentration from diesel and two-stroke vehicles exhaust in Lahore. Analysis of those days within three different ranges of PM₂.₅ concentration shows that most of the measured high PM₂.₅ mass concentrations were driven by diesel and two-stroke vehicle emissions including the associated primary sulfate. The use of the potential source contribution function (PSCF) to find the source locations of regionally transported particles is inapplicable in situations when high PM₂.₅ concentrations are dominated by local sources and local meteorology.
Show more [+] Less [-]Levels and Bioaccessibilities of Metals in Dusts from an Arid Environment
2010
Turner, Andrew | Hefzi, Bayan
The elemental composition and bioaccessibility of trace metals have been determined in a variety of geosolids (soils, road dusts and house dusts) from an arid, coastal region (Dhahran, Saudi Arabia). Concentrations of many elements reflected those of the local geology, ascertained by analysis of desert sand. Several trace metals (e.g. Cu, Sb, Zn, Pb, Tl and Sn) were moderately enriched in both road and house dusts, reflecting external and internal (household) anthropogenic sources. For a given trace metal, bioaccessibilities, assessed using a physiologically based extraction test, were broadly similar across the range of geosolids. Median values for a simulated gastric phase ranged from less than 10% (Ba, Cu, Cr, Ni and V) to more than 50% (As, Cd, Sb, Sn and Tl), and for a subsequently simulated intestinal phase from less than 15% (Ba, Cr, Cu, Ni, V and Zn) to more than 50% (As, Cd, Sb, Tl and U). Results suggest that the levels and bioaccessibilities of trace metals in dusts from arid environments are controlled by the dilution of anthropogenic particulates by variable (but significant) proportions of fine, baseline sand.
Show more [+] Less [-]Concentration Distribution and Bioaccessibility of Trace Elements in Nano and Fine Urban Airborne Particulate Matter: Influence of Particle Size
2010
Niu, Jianjun | Rasmussen, Pat E. | Hassan, Nouri M. | Vincent, Renaud
Trace elements, especially those associated with fine particles in airborne particulate matter (PM), may play an important role in PM adverse health effect. The aim of this paper is to characterize elements in a wide particle size range from nano (57-100 nm) to fine (100-1,000 nm) and to coarse (1,000-10,000 nm) fractions of two urban PM samples collected in Ottawa. Size-selective particle sampling was performed using a micro-orifice uniform deposit impactor, and element concentrations were determined in each different size fraction by inductively coupled plasma-mass spectroscopy. A general trend of increasing element concentration with decreasing aerodynamic diameter was observed for elements V, Mn, Ni, Cu, Zn, Se, and Cd, indicating they were predominately concentrated in the nanoparticle size range. Other elements including Fe, Sr, Mo, Sn, Sb, Ba, and Pb were predominately concentrated in the fine-size range. Increased concentration of elements in the nano and fine particle size range is significant due to their ability to penetrate into the deepest alveolar area of the lungs. This was confirmed by the calculation of median concentration diameters, which were less than 800 nm for most of the investigated elements. Particle size distribution and element correlation analysis suggest that the elements concentrated in the nano- and fine-size fractions originated mainly from vehicular combustion and emission. Long-range airborne transport and soil or road dust resuspension may also contribute. Particle size had an important effect on element bioaccessibility for the studied urban PM samples showing a general trend of increasing element bioaccessibility with decreasing particle size. These results emphasize the importance of acquiring information on nano and/or fine PM-bound elements and their bioaccessibilities for accurate element and PM exposure assessment.
Show more [+] Less [-]Nitro-PAHs and PAHs in Atmospheric Particulate Matters and Sea Sediments in Hiroshima Bay Area, Japan
2010
Ozaki, Noriatsu | Takemoto, Nobuya | Kindaichi, Tomonori
Atmospheric and sea sediment concentrations were measured for eight nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) and three unsubstituted PAHs in a suburban area and sea sediments in the Hiroshima Bay watershed area, Japan, from July to December, 2006 (atmospheric particulate matter) and in September and November, 2004 (sea sediments). Atmospheric concentration was higher in winter than summer for both nitro-PAHs and PAHs. Concentrations in sea sediments were less than 10%, and pattern was similar to those of atmospheric particles. Several combustion emission sources were also measured, and the 1-NP/Pyr ratio was compared to environmental values. The ratio of atmospheric and sea sediments were significantly lower than diesel particulate matters. Further, the vehicle emission loading and sea sedimentation loading was evaluated in this watershed area, and from the comparison, the existence of other important sources PAHs were suggested.
Show more [+] Less [-]Seasonal Abundance of Particle-Phase Organic Pollutants in an Urban/Industrial Atmosphere
2010
Di Filippo, Patrizia | Riccardi, Carmela | Pomata, Donatella | Gariazzo, Claudio | Buiarelli, Francesca
Polycyclic aromatic hydrocarbons (PAHs); their derivatives nitro, and methyl-PAHs; n-alkanes; and organic acids were investigated in the aerosol samples collected during two field campaigns conducted at three sampling stations in an industrialized city in southern Italy. The main sources affecting the atmosphere and its toxicity were investigated by means of the diagnostic ratios of: specific particulate-phase PAHs, marker compounds among nitro-PAHs, alkanes, and acids, the dominant wind direction, daily and seasonal abundance of carcinogenic organic substances. The potential importance of the non-regulated pollutants to assess the air quality was confirmed; in fact the carcinogenic organic compounds showed to have scarce correlation with particulate matter (PM) concentration. An exceptionally high variability of toxic compounds at a daily scale was due to meteorological condition causing periods of extremely high pollution levels.
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