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Particulate Matter (particulate + matter)
Kinds of Particulate Matter Terms modified by Particulate Matter Selected AbstractsDevelopment of Cu and Zn Isotope MC-ICP-MS Measurements: Application to Suspended Particulate Matter and Sediments from the Scheldt EstuaryGEOSTANDARDS & GEOANALYTICAL RESEARCH, Issue 2 2008Jérôme C.J. Petit isotopes de Cu et Zn; interférences spectrales et non spectrales; fractionnement de masse instrumental; MC-ICP-MS; sédiments The present study evaluates several critical issues related to precision and accuracy of Cu and Zn isotopic measurements with application to estuarine particulate materials. Calibration of reference materials (such as the IRMM 3702 Zn) against the JMC Zn and NIST Cu reference materials were performed in wet and/or dry plasma modes (Aridus I and DSN-100) on a Nu Plasma MC-ICP-MS. Different mass bias correction methods were compared. More than 100 analyses of certified reference materials suggested that the sample-calibrator bracketing correction and the empirical external normalisation methods provide the most reliable corrections, with long term external precisions of 0.06 and 0.07, (2SD), respectively. Investigation of the effect of variable analyte to spike concentration ratios on Zn and Cu isotopic determinations indicated that the accuracy of Cu measurements in dry plasma is very sensitive to the relative Cu and Zn concentrations, with deviations of ,65Cu from ,0.4, (Cu/Zn = 4) to +0.4, (Cu/Zn = 0.2). A quantitative assessment (with instrumental mass bias corrections) of spectral and non-spectral interferences (Ti, Cr, Co, Fe, Ca, Mg, Na) was performed. Titanium and Cr were the most severe interfering constituents, contributing to inaccuracies of ,5.1, and +0.60, on ,68/64Zn, respectively (for 500 ,g l,1 Cu and Zn standard solutions spiked with 1000 ,g l,1 of Ti or Cr). Preliminary isotopic results were obtained on contrasting sediment matrices from the Scheldt estuary. Significant isotopic fractionation of zinc (from 0.21, to 1.13, for ,66Zn) and copper (from ,0.38, to 0.23, for ,65Cu), suggest a control by physical mixing of continental and marine water masses, characterized by distinct Cu and Zn isotopic signatures. These results provide a stepping-stone to further evaluate the use of Cu and Zn isotopes as biogeochemical tracers in estuarine environments. L'étude présentée ici porte sur l'évaluation critique d'un certain nombre de paramètres contrôlant la précision et la justesse des mesures des isotopes de Cu et Zn, dans le cadre d'une application à du matériel particulaire estuarien. Une calibration de matériaux de référence (tels que le Zn IRMM 3702) par rapport aux matériaux de référence JMC Zn et NIST Cu a été effectuée avec des plasmas humides et secs (avec Aridus I et DSN-100) sur un MC-ICP-MS Nu. Différentes méthodes de correction de biais de masse ont été comparées. Plus de 100 analyses de matériaux de référence certifiés ont montré que la correction par l'intercalation d'un calibrateur entre chaque échantillon et la calibration externe empirique fournissaient les corrections les plus fiables, avec des précisions externes sur le long terme de 0.06 et 0.07, (2SD) respectivement. Les effets de la variation des rapports de concentrations entre analyte et spike sur les mesures des rapports isotopiques de Cu et Zn ont montré que la justesse des mesures pour Cu en plasma sec est très tributaire des concentrations relatives de Cu et Zn, avec des déviations de ,65Cu allant de ,0.4, (Cu/Zn = 4) à+0.4, (Cu/Zn = 0.2). Une estimation quantitative des interférences spectrales et non spectrales (Ti, Cr, Co, Fe, Ca, Mg, Na) a été faite. Ti et Cr se sont révélés être les constituants interférents les plus importants pouvant entraîner des erreurs de ,5.1, et +0.60, sur ,68/64Zn respectivement (pour des solutions standards à 500 ,g l,1 de Cu et Zn dopées avec 1000 ,g l,1 de Ti ou Cr). Des données isotopiques préliminaires ont été obtenues sur des matrices sédimentaires très différentes provenant de l'estuaire de Scheldt. Les fractionnements significatifs du zinc (de 0.21,à 1.13, pour ,66Zn) et du cuivre (de ,0.38,à 0.23, pour ,65Cu) suggèrent un contrôle par un processus physique de mélange entre des masses d'eaux continentales et marines ayant des signatures isotopiques de Cu et Zn distinctes. Ces résultats constituent un tremplin vers une utilisation future des isotopes de Cu et Zn comme traceurs biogéochimiques des environnements estuariens. [source] Particulate Matter in the Ross Sea: a Spreading ModelMARINE ECOLOGY, Issue 2002Sergio Tucci Abstract. Within the framework of the C.L.I.M.A. Project, a part of the Italian Research Program in Antarctica, the Total Particulate Matter (TPM) was used as a natural marker to characterise the water masses. The dynamics of TPM was estimated by using a numerical model capable of following the evolution of the basin during the ice absence in summer. The first numerical simulation, with horizontally constant initial conditions and the absence of TPM source areas, merely reveals how TPM passive dispersion is strongly influenced by the Ross Ice Shelf and bathymetry. The second simulation, with TPM concentration horizontally variable and vertically decreasing layers, shows a dynamic evolution of TPM that is in agreement with experimental data. On the surface, in correspondence with the shelf-break, an out-flowing flux with particulate matter contribution coming from Ross Ice Shelf is recognised. The TPM concentration may be linked to the ice melting due to the Antarctic Surface Water, with production of Shallow Ice Shelf Water. The numerical model produces, near the Drygalski area, two cells with high concentration. This numerical evolution is confirmed by the 1990 data (Spezie et al, 1993) that clearly show these two areas and their correlations with the Drygalski contributions (the inner area) and with the thermo-haline front (the external one). This condition is evident in the 1994-1995 data too (Bu-dillon et al, 1999). In this case the authors observed that the Circumpolar Deep Water penetrates onto the shelf at about 174°E; then, modifying its properties, it follows a southward path for about 200 km. The Antarctic Shelf Front (ASF) separates CDW from the colder shelf water with a high concentration of suspended matter. At the 300-meter level, the diffusion of the particulate matter directed under the RIS, towards the continental shelf, seems to be an important feature. Very high TPM values are also present in the deep water in the area off the Drygalski Glacier; this evolution agrees with the ,400 m data collected during the 1990,1991 cruise (Spezie et al., 1993). [source] Temporal Variations of Nutrients, Chlorophyll a and Particulate Matter in Three Coastal Lagoons of Amvrakikos Gulf (Ionian Sea, Greece)MARINE ECOLOGY, Issue 3 2001Konstantinos A. Kormas Abstract. The temporal variations of nutrients, chlorophyll a (chl a), suspended particulate matter (SPM) and particulate organic carbon (POC) were measured over 12 months in three shallow coastal brackish water lagoons of the Amvrakikos Gulf, Ionian Sea. Two of the lagoons, Tsoukalio and Rodia, are interconnected but separated from Logarou by a narrow strip of land. Logarou has a better water exchange with the sea as indicated by the higher salinity and dissolved oxygen concentrations and the smaller variation of the above-mentioned parameters. Nitrate concentrations were largely the same in the three lagoons and higher than in the Amvrakikos Gulf. Phosphate concentrations in Logarou exceeded by far those of Tsoukalio/Rodia; the increased phosphate levels recorded in January caused an extended phytoplankton bloom with chl a concentrations higher than in the other two lagoons. Chl a in Tsoukalio was positively correlated with nitrate whereas in the most shallow lagoon, Logarou, it showed a positive correlation with light winds (force 4 and lower), probably caused by resuspension from the sediment. Increased phytoplankton biomass in Logarou coupled with the better water exchange may be related to the higher fish production in this lagoon. [source] A Sampling Approach for Evaluating Particle Loss During Continuous Field Measurement of Particulate MatterPARTICLE & PARTICLE SYSTEMS CHARACTERIZATION, Issue 2 2005Christopher A. Noble Abstract A method for evaluating sample bias in field measurements is presented. Experiments were performed in the field and laboratory to quantify the bias as a function of particle size for the scanning mobility particle sizer and the aerodynamic particle sizer. Sources of bias and sample loss considered in this work were sampling line loss, instrumental differences and inlet efficiencies. Measurement of the bias and sample loss allow for correction of the data acquired in the field, so as to obtain more representative samples of atmospheric concentrations. Substantial losses of fine and ultrafine particle count were observed, with sampling line losses ranging from 10,50,%, dependent on particle size. Only minor line losses were observed for coarse particles (approximately 5,%) because the sampling line was oriented vertically. Please note: corrected DOI, in print wrong DOI (10.1002/ppsc.200400939) [source] Variations of chemical compositions in coarse aerosols and fine aerosols in two successive episodesENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2006Chung-Yih Kuo Abstract Particulate matter with diameters less than 2.5 ,m (PM2.5) and ranging between 10 to 2.5 ,m (PM10-2.5) were simultaneously collected at four air-quality monitoring stations in the Taichung area of central Taiwan during the period of February 12 to 22, 2004. Two different types of PM10 episodes, a nonlocal dust-storm episode and a local episode, were observed in the present study. High concentrations of coarse aerosols occurred during the dust-storm episode, whereas high concentrations of fine aerosols were present during the local episode. Relatively high levels of Na+, Mg2+, Ca2+, and Cl, in coarse aerosols were observed during the dust-storm episode. Very high concentrations of secondary aerosols (NH+4, SO2,4, and NO,3) in fine aerosols were observed during the local episode. The nitrate ion demonstrated the greatest increase in the ratios of ionic species to PM2.5 and ionic species to PM10-2.5 during the local episode. Significantly high ratios (0.444) of NO,3 to NO2 in fine aerosols were present during the local episode, indicating that the relatively high formation rate of NO,3 was one of the important factors leading to the increase of the NO,3 to PM2.5 ratio during the local episode. Results also showed that an abundant quantity of fine ammonium nitrate was formed during the local episode, and chloride depletion probably was the major pathway to form coarse NaNO3 during this episode. [source] Analysis of the effects of ultrafine particulate matter while accounting for human exposureENVIRONMETRICS, Issue 2 2009B. J. REICH Abstract Particulate matter (PM) has been associated with mortality in several epidemiological studies. The US EPA currently regulates PM10 and PM2.5 (mass concentration of particles with diameter less than 10 and 2.5 µm, respectively), but it is not clear which size of particles are most responsible for adverse heath outcomes. A current hypothesis is that ultrafine particles with diameter less than 0.1 µm are particularly harmful because their small size allows them to deeply penetrate the lungs. This paper investigates the association between exposure to particles of varying diameter and daily mortality. We propose a new dynamic factor analysis model to relate the ambient concentrations of several sizes of particles with diameters ranging from 0.01 to 0.40 µm with mortality. We introduce a Bayesian model that converts ambient concentrations into simulated personal exposure using the EPA's Stochastic Human Exposure and Dose Simulator, and relates simulated exposure with mortality. Using new data from Fresno, CA, we find that the 4-day lag of particles with diameter between 0.02 and 0.08 µm is associated with mortality. This is consistent with the small particles hypothesis. Copyright © 2008 John Wiley & Sons, Ltd. [source] Analyzing weather effects on airborne particulate matter with HGLMENVIRONMETRICS, Issue 7 2003Yoon Dong Lee Abstract Particulate matter is one of the six constituent air pollutants regulated by the United States Environmental Protection Agency. In analyzing such data, Bayesian hierarchical models have often been used. In this article we propose the use of hierarchical generalized linear models, which use likelihood inference and have well developed model-checking procedures. Comparisons are made between analyses from hierarchical generalized linear models and Daniels et al.'s (2001) Bayesian models. Model-checking procedure indicates that Daniels et al.'s model can be improved by use of the log-transformation of wind speed and precipitation covariates. Copyright © 2003 John Wiley & Sons, Ltd. [source] Assessing sources of variability in measurement of ambient particulate matterENVIRONMETRICS, Issue 6 2001Michael J. Daniels Abstract Particulate matter (PM), a component of ambient air pollution, has been the subject of United States Environmental Protection Agency regulation in part due to many epidemiological studies examining its connection with health. Better understanding the PM measurement process and its dependence on location, time, and other factors is important for both modifying regulations and better understanding its effects on health. In light of this, in this paper, we will explore sources of variability in measuring PM including spatial, temporal and meteorological effects. In addition, we will assess the degree to which there is heterogeneity in the variability of the micro-scale processes, which may suggest important unmeasured processes, and the degree to which there is unexplained heterogeneity in space and time. We use Bayesian hierarchical models and restrict attention to the greater Pittsburgh (USA) area in 1996. The analyses indicated no spatial dependence after accounting for other sources of variability and also indicated heterogeneity in the variability of the micro-scale processes over time and space. Weather and temporal effects were very important and there was substantial heterogeneity in these effects across sites. Copyright © 2001 John Wiley & Sons, Ltd. [source] Characterization of combustion-derived individual fine particulates by computer-controlled scanning electron microscopyAICHE JOURNAL, Issue 11 2009Lian Zhang Abstract Particulate matter (PM) emission from the combustion of solid fuels potentially poses a severe threat to the environment. In this article, a novel approach was developed to examine the properties of individual particles in PM. With this method, PM emitted from combustion was first size-segregated. Subsequently, each size was characterized by computer-controlled scanning electron microscopy (CCSEM) for both bulk property and single particle analysis. Combustion of bituminous coal, dried sewage sludge (DSS) and their mixture were conducted at 1200°C in a laboratory-scale drop tube furnace. Three individual sizes smaller than 2.5 ,m were investigated. The results indicate that a prior size-segregation can greatly minimize the particle size contrast and phase contrast on the backscattered images during CCSEM analysis. Consequently, high accuracy can be achieved for quantifying the sub-micron particles and their inherent volatile metals. Regarding the PM properties as attained, concentrations of volatile metals including Na, K, and Zn have a negative relationship with particle size; they are enriched in the smallest particles around 0.11 ,m as studied here. Strong interactions can occur during the cofiring of coal and DSS, leading to the distinct properties of PM emitted from cofiring. The method developed here and results attained from it are helpful for management of the risks relating to PM emission during coal-fired boilers. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source] Variations of nitrate and sulfate in the atmosphere on days of high and low particulate mattersENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2005Chung-Yih Kuo Abstract Particulate matters with aerodynamicdiameter less than 10 ,m (PM10) were collected with high-volume samplers for four periods of consecutive samplings. Each period included a high PM10 (defined as PM10 ,110 ,g/m3) episode. The concentrations of all ionic species of high PM10 day (HPD) samples were higher than those of low PM10 (defined as PM10 < 110,g/m3) d (LPD) samples. Using the ionic concentrations of HPD samples at each station divided by those of LPD samples at respective stations, the results showed thatNO increased most from LPD to HPD among the eight ionic species examined. A high mean value (3.15) of NO/elemental carbon (EC) ratio of HPD divided by that of LPD indicates that concentration variations due to chemical formation and nonchemical factors apparently were higher than those of the concentration variations due to nonchemical factors alone. The NO/SO ratio of HPD divided by that of LPD ranged from 1.62 to 3.92 for the four periods. The results indicate that more nitrate than sulfate had formed during high PM10 episodes. Multiple linear regression analysis showed that the percentage of NH associated with nitrate and sulfate decreased and the percentage that could be explained by Ca2+ and Na+ increased on HPD. The reactions of HNO3 and H2SO4 with sea salt particles and with aqueous carbonates on soil particles during HPD were considered the main causes leading to these variations. [source] Evaluation of the SWEEP model during high winds on the Columbia Plateau ,EARTH SURFACE PROCESSES AND LANDFORMS, Issue 11 2009G. Feng Abstract A standalone version of the Wind Erosion Prediction System (WEPS) erosion submodel, the Single-event Wind Erosion Evaluation Program (SWEEP), was released in 2007. A limited number of studies exist that have evaluated SWEEP in simulating soil loss subject to different tillage systems under high winds. The objective of this study was to test SWEEP under contrasting tillage systems employed during the summer fallow phase of a winter wheat,summer fallow rotation within eastern Washington. Soil and PM10 (particulate matter ,10 µm in diameter) loss and soil and crop residue characteristics were measured in adjacent fields managed using conventional and undercutter tillage during summer fallow in 2005 and 2006. While differences in soil surface conditions resulted in measured differences in soil and PM10 loss between the tillage treatments, SWEEP failed to simulate any difference in soil or PM10 loss between conventional and undercutter tillage. In fact, the model simulated zero erosion for all high wind events observed over the two years. The reason for the lack of simulated erosion is complex owing to the number of parameters and interaction of these parameters on erosion processes. A possible reason might be overestimation of the threshold friction velocity in SWEEP since friction velocity must exceed the threshold to initiate erosion. Although many input parameters are involved in the estimation of threshold velocity, internal empirical coefficients and equations may affect the simulation. Calibration methods might be useful in adjusting the internal coefficients and empirical equations. Additionally, the lack of uncertainty analysis is an important gap in providing reliable output from this model. Published in 2009 by John Wiley & Sons, Ltd. [source] Windblown dust influenced by conventional and undercutter tillage within the Columbia Plateau, USA,EARTH SURFACE PROCESSES AND LANDFORMS, Issue 10 2009B. S. Sharratt Abstract Exceedance of the US Environmental Protection Agency national ambient air quality standard for PM10 (particulate matter ,10 µm in aerodynamic diameter) within the Columbia Plateau region of the Pacific Northwest US is largely caused by wind erosion of agricultural lands managed in a winter wheat,summer fallow rotation. Land management practices, therefore, are sought that will reduce erosion and PM10 emissions during the summer fallow phase of the rotation. Horizontal soil flux and PM10 concentrations above adjacent field plots (>2 ha), with plots subject to conventional or undercutter tillage during summer fallow, were measured using creep and saltation/suspension collectors and PM10 samplers installed at various heights above the soil surface. After wheat harvest in 2004 and 2005, the plots were either disked (conventional) or undercut with wide sweeps (undercutter) the following spring and then periodically rodweeded prior to sowing wheat in late summer. Soil erosion from the fallow plots was measured during six sampling periods over two years; erosion or PM10 loss was not observed during two periods due to the presence of a crust on the soil surface. For the remaining sampling periods, total surface soil loss from conventional and undercutter tillage ranged from 3 to 40 g m,2 and 1 to 27 g m,2 while PM10 loss from conventional and undercutter tillage ranged from 0·2 to 5·0 g m,2 and 0·1 to 3·3 g m,2, respectively. Undercutter tillage resulted in a 15% to 65% reduction in soil loss and 30% to 70% reduction in PM10 loss as compared with conventional tillage at our field sites. Therefore, based on our results at two sites over two years, undercutter tillage appears to be an effective management practice to reduce dust emissions from agricultural land subject to a winter wheat,summer fallow rotation within the Columbia Plateau. Copyright © 2009 John Wiley & Sons, Ltd. [source] The factors influencing the abrasion efficiency of saltating grains on a clay-crusted playaEARTH SURFACE PROCESSES AND LANDFORMS, Issue 5 2001Christopher A. Houser Abstract The entrainment and subsequent transport of PM10 (particulate matter <10,µm) has become an important and challenging focus of research for both scientific and practical applications. Arid and semi-arid environments are important sources for the atmospheric loading of PM10, although the emission of this material is often limited by surface crusts. It has been suggested that the primary mechanisms through which PM10 is released from a crusted surface are abrasion by saltating grains or disturbance by agricultural and recreational activities. To examine the importance of saltation abrasion in the emission of PM10, a series of field wind tunnel tests were conducted on a clay-crusted surface near Desert Wells, Arizona. In a previous part of this study it was found that the emission rate varies linearly with the saltation transport rate, although there can be considerable variation in this relationship. This paper more closely examines the source of the variability in the abrasion efficiency, the amount of PM10 emitted by a given quantity of saltating grains. The abrasion efficiency was found to vary with the susceptibility of the surface to abrasion, the ability of the sand to abrade that surface and the availability of material with a caliper size <10,µm within the crust. Specifically, the results of the study show that the abrasion efficiency is related to the crust strength, the amount of surface disturbance and the velocity of the saltating grains. It is concluded that the spatial and temporal variability of these controls on the abrasion efficiency imposes severe contextual limitations on experimentally derived models, and can make theoretical models too complex and impractical to be of use. Copyright© 2001 John Wiley & Sons, Ltd. [source] Tissue-specific metabolic activation and mutagenicity of 3-nitrobenzanthrone in MutaÔMouse,ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 8 2008Guosheng Chen Abstract 3-Nitrobenzanthrone (3-NBA) is a mutagen and suspected human carcinogen detected in diesel exhaust, airborne particulate matter, and urban soil. We investigated the tissue specific mutagenicity of 3-NBA at the lacZ locus of transgenic MutaÔMouse following acute single dose or 28-day repeated-dose oral administration. In the acute high dose (50 mg/kg) exposure, increased lacZ mutant frequency was observed in bone marrow and colonic epithelium, but not in liver and bladder. In the repeated-dose study, a dose-dependent increase in lacZ mutant frequency was observed in bone marrow and liver (2- and 4-fold increase above control), but not in lung or intestinal epithelium. In addition, a concentration-dependent increase in mutant frequency (8.5-fold above control) was observed for MutaÔMouse FE1 lung epithelial cells exposed in vitro. 1-Nitropyrene reductase, 3-NBA reductase, and acetyltransferase activities were measured in a variety of MutaÔMouse specimens in an effort to link metabolic activation and mutagenicity. High 3-NBA nitroreductase activities were observed in lung, liver, colon and bladder, and detectable N -acetyltransferase activities were found in all tissues except bone marrow. The relatively high 3-NBA nitroreductase activity in MutaÔMouse tissues, as compared with those in Salmonella TA98 and TA100, suggests that 3-NBA is readily reduced and activated in vivo. High 3-NBA nitroreductase levels in liver and colon are consistent with the elevated lacZ mutant frequency values, and previously noted inductions of hepatic DNA adducts. Despite an absence of induced lacZ mutations, the highest 3-NBA reductase activity was detected in lung. Further studies are warranted, especially following inhalation or intratracheal exposures. Environ. Mol. Mutagen., 2008. Published 2008 Wiley-Liss, Inc. [source] A preliminary characterization of the mutagenicity of atmospheric particulate matter collected during sugar cane harvesting using the Salmonella/microsome microsuspension assayENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 4 2008Gisela de Aragão Umbuzeiro Abstract During sugar cane harvesting season, which occurs from May to November of each year, the crops are burnt, cut, and transported to the mills. There are reports showing that mutagenic activity and PAH content increase during harvesting season in some areas of São Paulo State in comparison with nonharvesting periods. The objective of this work was to preliminarily characterize the mutagenic activity of the total organic extracts as well as corresponding organic fractions of airborne particulate matter (PM) collected twice from two cities, Araraquara (ARQ) and Piracicaba (PRB), during sugar cane harvesting season using the Salmonella/microsome microssuspension assay. One sample collected in São Paulo metropolitan area was also included. The mutagenicity of the total extracts ranged from 55 to 320 revertants per cubic meter without the addition of S9 and from not detected to 57 revertants per cubic meter in the presence of S9 in areas with sugar cane plantations. Of the three fractions analyzed, the most polar ones (nitro and oxy) were the most potent. A comparison of the response of TA98 with YG1041 and the increased potencies without S9 indicated that nitro compounds are causing the observed effect. More studies are necessary to verify the sources of the mutagenic activity such as burning of vegetal biomass and combustion of heavy duty vehicles used to transport the sugar cane to the mills. The Salmonella/microsome assay can be an important tool to monitor the atmosphere for mutagenicity during sugar cane harvesting season. Environ. Mol. Mutagen. 2008. © 2008 Wiley-Liss, Inc. [source] Genotoxicity and physicochemical characteristics of traffic-related ambient particulate matterENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 2 2005Theo M. de Kok Abstract Exposure to ambient particulate matter (PM) has been linked to several adverse health effects. Since vehicular traffic is a PM source of growing importance, we sampled total suspended particulate (TSP), PM10, and PM2.5 at six urban locations with pronounced differences in traffic intensity. The mutagenicity, DNA-adduct formation, and induction of oxidative DNA damage by the samples were studied as genotoxicological parameters, in relation to polycyclic aromatic hydrocarbon (PAH) levels, elemental composition, and radical-generating capacity (RGC) as chemical characteristics. We found pronounced differences in the genotoxicity and chemical characteristics of PM from the various locations, although we could not establish a correlation between traffic intensity and any of these characteristics for any of the PM size fractions. Therefore, the differences between locations may be due to local sources of PM, other than traffic. The concentration of total (carcinogenic) PAHs correlated positively with RGC, direct and S9-mediated mutagenicity, as well as the induction of DNA adducts and oxidative DNA damage. The interaction between total PAHs and transition metals correlated positively with DNA-adduct formation, particularly from the PM2.5 fraction. RGC was not associated with one specific PM size fraction, but mutagenicity and DNA reactivity after metabolic activation were relatively high in PM10 and PM2.5, when compared with TSP. We conclude that the toxicological characteristics of urban PM samples show pronounced differences, even when PM concentrations at the sample sites are comparable. This implies that emission reduction strategies that take chemical and toxicological characteristics of PM into account may be useful for reducing the health risks associated with PM exposure. Environ. Mol. Mutagen., 2005. © 2005 Wiley-Liss, Inc. [source] Effect of artificial mixtures of environmental polycyclic aromatic hydrocarbons present in coal tar, urban dust, and diesel exhaust particulates on MCF-7 cells in cultureENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 2 2004Brinda Mahadevan Abstract Human exposure to polycyclic aromatic hydrocarbons (PAHs) occurs through complex mixtures. The National Institute of Standards and Technology has established standard reference materials (SRMs) for selected PAH mixtures that are composed of carcinogenic, noncarcinogenic, and weakly carcinogenic compounds, such as those derived from coal tar (SRM 1597), atmospheric particulate matter (SRM 1649), and diesel particulate matter (SRM 1650). To study the effects of PAHs with different carcinogenic potential in complex mixtures, and to investigate the metabolic activation of noncarcinogenic and weakly carcinogenic PAHs to DNA-binding derivatives, artificial mixtures (1597H, 1649H, and 1650H) were prepared in the laboratory. These artificial mixtures contained the same relative ratios of noncarcinogenic and weakly carcinogenic PAHs present in SRM 1597, SRM 1649, and SRM 1650. The human mammary carcinoma-derived cell line MCF-7 was treated with these artificial mixtures and analyzed for PAH-DNA adduct formation and the induction of cytochrome P450 (CYP) enzymes. We found that the artificial mixtures formed lower but detectable levels of DNA adducts 24 and 48 hr after treatment than benzo[a]pyrene. Induction of CYP enzyme activity was measured by the ethoxyresorufin- O -deethylase assay, and the expression of CYP1A1 and CYP1B1 was confirmed by immunoblots. Both noncarcinogenic and weakly carcinogenic PAHs present in the artificial mixtures have the ability to induce CYP1A1 and CYP1B1 in MCF-7 cells and contribute to DNA binding. Therefore, it is necessary to take into account the noncarcinogenic and weakly carcinogenic PAHs present in environmental mixtures in assessing the potential risk associated with human exposure. Environ. Mol. Mutagen. 44:99,107, 2004. © 2004 Wiley-Liss, Inc. [source] Use of a high-throughput umu -microplate test system for rapid detection of genotoxicity produced by mutagenic carcinogens and airborne particulate matterENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 1 2004Yoshimitsu Oda Abstract In the present study, we developed a rapid umu -microplate test system that uses the nitroreductase- and O -acetyltransferase-overproducing Salmonella typhimurium strain NM3009 and the O -acetyltransferase-overproducing S. typhimurium strain NM2009 to detect genotoxic activity in small volume samples. The assay was used to test the genotoxicity of several standard mutagens and environmental samples. Exponentially growing cultures of NM3009, NM2009, and the parental strain TA1535/pSK1002 were incubated in 96-well microplates with test chemicals both in the presence and in the absence of rat liver S9. The relative ,-galactosidase activities were then determined colorimetrically using either chlorophenol red-,- D -galactopyranoside (CPRG) or O -nitrophenyl-,- D -galactopyranoside (ONPG) as a measure of umuC gene induction activity. The sensitivities of NM3009 without S9 mix and NM2009 with S9 mix to nitroarenes and aromatic amines were up to 24- to 75-fold higher than those of the parent strain. Induction of umuC gene expression was detected more readily with CPRG than ONPG. The umu -microplate assay also detected genotoxicity in organic extracts of particulate matter from air samples collected in Osaka City, Japan. The pattern of the responses suggested that the genotoxic activity of the particulate extract was due primarily to nitrated polycyclic aromatic hydrocarbons. Our results indicate that the umu -microplate assay may be a useful way of carrying out rapid screens for genotoxicity in small-volume environmental samples. Environ. Mol. Mutagen. 43:10,19, 2004. © 2004 Wiley-Liss, Inc. [source] Detection of microbial biomass by intact polar membrane lipid analysis in the water column and surface sediments of the Black SeaENVIRONMENTAL MICROBIOLOGY, Issue 10 2009Florence Schubotz Summary The stratified water column of the Black Sea produces a vertical succession of redox zones, stimulating microbial activity at the interfaces. Our study of intact polar membrane lipids (IPLs) in suspended particulate matter and sediments highlights their potential as biomarkers for assessing the taxonomic composition of live microbial biomass. Intact polar membrane lipids in oxic waters above the chemocline represent contributions of bacterial and eukaryotic photosynthetic algae, while anoxygenic phototrophic bacteria and sulfate-reducing bacteria comprise a substantial amount of microbial biomass in deeper suboxic and anoxic layers. Intact polar membrane lipids such as betaine lipids and glycosidic ceramides suggest unspecified anaerobic bacteria in the anoxic zone. Distributions of polar head groups and core lipids show planktonic archaea below the oxic zone; methanotrophic archaea are only a minor fraction of archaeal biomass in the anoxic zone, contrasting previous observations based on the apolar derivatives of archaeal lipids. Sediments contain algal and bacterial IPLs from the water column, but transport to the sediment is selective; bacterial and archaeal IPLs are also produced within the sediments. Intact polar membrane lipid distributions in the Black Sea are stratified in accordance with geochemical profiles and provide information on vertical successions of major microbial groups contributing to suspended biomass. This study vastly extends our knowledge of the distribution of complex microbial lipids in the ocean. [source] Gradients of coastal fish farm effluents and their effect on coral reef microbesENVIRONMENTAL MICROBIOLOGY, Issue 9 2008Melissa Garren Summary Coastal milkfish (Chanos chanos) farming may be a source of organic matter enrichment for coral reefs in Bolinao, Republic of the Philippines. Interactions among microbial communities associated with the water column, corals and milkfish feces can provide insight into the ecosystem's response to enrichment. Samples were collected at sites along a transect that extended from suspended milkfish pens into the coral reef. Water was characterized by steep gradients in the concentrations of dissolved organic carbon (70,160 ,M), total dissolved nitrogen (7,40 ,M), chlorophyll a (0.25,10 ,g l,1), particulate matter (106,832 ,g l,1), bacteria (5 × 105,1 × 106 cells ml,1) and viruses (1,7 × 107 ml,1) that correlated with distance from the fish cages. Particle-attached bacteria, which were observed by scanning laser confocal microscopy, increased across the gradient from < 0.1% to 5.6% of total bacteria at the fish pens. Analyses of 16S rRNA genes by denaturing gradient gel electrophoresis and environmental clone libraries revealed distinct microbial communities for each sample type. Coral libraries had the greatest number of phyla represented (range: 6,8) while fish feces contained the lowest number (3). Coral libraries also had the greatest number of ,novel' sequences (defined as < 93% similar to any sequence in the NCBI nt database; 29% compared with 3% and 5% in the feces and seawater libraries respectively). Despite the differences in microbial community composition, some 16S rRNA sequences co-occurred across sample types including Acinetobacter sp. and Ralstonia sp. Such patterns raise the question of whether bacteria might be transported from the fish pens to corals or if microenvironments at the fish pens and on the corals select for the same phylotypes. Understanding the underlying mechanisms of effluent,coral interactions will help predict the ability of coral reef ecosystems to resist and rebound from organic matter enrichment. [source] Comparison of air quality management strategies of PM10, SO2, and NOx by an industrial source complex model in BeijingENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 1 2007Gaoxiang Ying Abstract The primary air pollutants in the Beijing urban area are fine particulate matter (PM10), sulfur dioxide (SO2), and nitrogen oxides (NOx). Using suitable emission factors for point, area, and line sources from 20 categories of industrial, commercial, domestic and traffic, total yearly mean emissions were estimated at 103.3 kton of PM10, 209.9 kton of SO2, and 225.4 kton of NOx in 1999. To abate this elevated air pollution, three air quality management schemes are adopted. After the implementation, the annual mean ground-level concentrations of air pollutants are predicted by an industrial source complex short term (ISCST3) dispersion model and compared by the geographic information system (GIS). The ISCST3 dispersion model is used by inputting emission inventory and meteorological data with 1 h temporal and 1 km × 1 km spatial resolution. The model validity is verified by its agreement with monitoring data from Beijing's Environmental Protection Bureau. Results indicate that the levels of PM10, SO2, and NOx in Beijing are improved gradually because of the adoption of these three control schemes. The predicted annual mean concentrations decreased from 90.63 to 67.28 ,g/m3 for PM10, 57.94 to 31.77 ,g/m3 for SO2, and 119.97 to 73.83 ,g/m3 for NOx, respectively. © 2007 American Institute of Chemical Engineers Environ Prog 26:33,42, 2007. [source] Cytotoxicity and oxidative stress caused by chemicals adsorbed on particulate matter,ENVIRONMENTAL TOXICOLOGY, Issue 5 2006Andrea Müller Abstract Air particulate matter (PM) and bound chemicals are potential mediators for adverse health effects. The cytotoxicity and changes in energy-providing processes caused by chemical compounds bound to PM of different size fractions were investigated in Tetrahymena pyriformis. The PM samplings were carried out using a high volume cascade impactor (6 size fractions between 10 ,m and less than 0.49 ,m) at three points of La Plata, Argentina: in an industrial area, a traffic-influenced urban area, and a control area. Extracts from respirable particles below 1 ,m initiated the highest cytotoxic effects, demonstrating their higher risk. In contrast, an increase on oxygen consumption was observed especially in tests of extracts from particles less than 1 ,m from urban and industrial areas. The increase on oxygen consumption could be caused by decoupling processes in the respiratory chain. Otherwise the ATP concentration was increased too, even though to a lower extent. The observed imbalance between oxygen consumption and ATP concentration in exposed T. pyriformis cells may be due to oxidative stress, caused by chemical compounds bound to the particles. Owing to the complexity of effects related to PM and their associated chemical compounds, various physiological parameters necessarily need to be investigated to obtain more information about their possible involvement in human relevant pathogenic processes. As shown here, effects on cell proliferation and on energy-providing processes are suitable indicators for the different impact of PM and adsorbed chemicals from various sampling locations. © 2006 Wiley Periodicals, Inc. Environ Toxicol 21: 457,463, 2006. [source] Pulmonary responses of acute exposure to ultrafine iron particles in healthy adult ratsENVIRONMENTAL TOXICOLOGY, Issue 4 2003Ya-Mei Zhou Abstract As critical constituents of ambient particulate matter, transition metals such as iron may play an important role in health outcomes associated with air pollution. The purpose of this study was to determine the respiratory effects of inhaled ultrafine iron particles in rats. Sprague Dawley rats 10,12 weeks of age were exposed by inhalation to iron particles (57 and 90 ,g/m3, respectively) or filtered air (FA) for 6 h/day for 3 days. The median diameter of particles generated was 72 nm. Exposure to iron particles at a concentration of 90 ,g/m3 resulted in a significant decrease in total antioxidant power along with a significant induction in ferritin expression, GST activity, and IL-1, levels in lungs compared with lungs of the FA control or of animals exposed to iron particles at 57 ,g/m3. NF,B,DNA binding activity was elevated 1.3-fold compared with that of control animals following exposure to 90 ,g/m3 of iron, but this change was not statistically significant. We concluded that inhalation of iron particles leads to oxidative stress associated with a proinflammatory response in a dose-dependent manner. The activation of NF,B may be involved in iron-induced respiratory responses, but further studies are merited. © 2003 Wiley Periodicals, Inc. Environ Toxicol 18: 227,235, 2003. [source] Polychlorinated naphthalenes and other dioxin-like compounds in Elbe River sedimentsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2008Werner Brack Abstract Contamination of Elbe River (Germany) sediments with dioxin-like toxicants was investigated following the 500-year flood (flood that statistically occurs once in 500 years) of 2002. It was hypothesized that large amounts of particulate matter from river beds and associated dioxin-like toxicants were mobilized and transported during this flood event. The investigation focused on polychlorinated naphthalenes (PCNs) that have not been determined previously in the Elbe River. The in vitro H4IIE- luc assay was used as an overall measure for toxicants capable of binding to the aryl hydrocarbon receptor (AhR). The assay was combined with congener-specific instrumental analyses and fractionation to quantify PCN contributions to total AhR-mediated activity relative to polychlorinated dibenzo- p -dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs). Penta- to octachloron-aphthalene concentrations of 30 ng/kg dry weight up to 13 ,g/kg dry weight were found in Elbe River sediments downstream of Bitterfeld. Concentrations of penta- to octachloronaphthalenes, however, were only approximately 3 ,g/kg dry weight at a site in the vicinity of Bitterfeld, where a level of approximately 3 mg/kg dry weight was reported before the flood. Also, the congener pattern of PCNs at this site changed after the flood, and PCN patterns reported previously for Bitterfeld and assigned to chlor-alkali electrolysis with graphite electrodes could now be observed at the sites from downstream of Bitterfeld and Magdeburg. Whereas PCDD/Fs dominated the dioxin-like activity in the middle and lower Elbe River, PCNs contributed as much as 10% of the total AhR-mediated activity. The contribution of PCBs was less significant (maximum, 0.2%). Thus, in Elbe River sediments, PCNs should be considered as relevant contaminants and be included in future monitoring and risk assessment programs. [source] Bioconcentration of persistent organic pollutants in four species of marine phytoplanktonENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2005Antje Gerofke Abstract The uptake of polychlorinated biphenyls (PCBs) was studied in four species of marine algae. A novel experimental system to establish and maintain constant dissolved concentrations of PCBs was employed. Headspace sampling was used to verify that the freely dissolved concentrations remained constant with time. The headspace analysis also allowed sorption to dissolved organic carbon (DOC) to be quantified for all but the most lipophilic PCB congeners. Equilibration with the dissolved phase was rapid for three of the four algae species (<1 d for the majority of congeners). Organic carbon,normalized algae/water partition coefficients (KAlgW) were similar for three of the four species, but were lower by a factor of 10 to 20 for Phaeodactylum tricornutum. The KAlgW values of the first three species were similar to the octanol/water partition coefficient (KOW) for those PCB congeners for which DOC sorption could be quantified. These KAlgW values also agreed well with organic carbon,normalized bioconcentration factors for PCBs in suspended particulate matter (BCFSPM) sampled in Baltic Sea surface water during the summer. [source] Partitioning of copper at concentrations below the marine water quality criteria,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2001Anthony J. Paulson Abstract Partitioning of Cu between the aqueous and particulate phases and among their components was examined in six ambient Puget Sound, Washington State, USA, samples (6,10 nM Cu). Most of the particulate Cu (4,12% of the total Cu) was associated with particulate organic matter, and resulted in distribution coefficients (Kd) ranging between 104,55 and 105,1. For the dissolved phase, the portion of Cu extracted by C18 -packed cartridges averaged 44% (+ 11%). Radioactive 64Cu was added to these samples to total stable Cu concentrations (17,33 nM). After 24 h of equilibration, the portion of 64Cu associated with the particulate matter in five of the six samples (Kd between 1047 and 1053) was an average of 70% higher than that of natural Cu in the ambient samples. In contrast, only 19 ± 7% of the 64Cu was extracted by C18 -packed cartridges. The partitioning of natural Cu and 64Cu onto particles was not significantly different when the equilibria were based on dissolved Cu passing through the C18 cartridges. Further research is warranted on utilizing the hydrophilic component of the dissolved phase as a parameter on which water quality criteria are based. [source] Cytotoxicity of settling particulate matter and sediments of the Neckar River (Germany) during a winter floodENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2000Henner Hollert Abstract To investigate the cytotoxic and genotoxic potentials of settling particulate matter (SPM) carried by the Neckar River, a well-studied model for a lock-regulated river in central Europe, during a flood, acute cytotoxicity was investigated using the fibroblast-like fish cell line RTG-2 with the neutral red retention, the succinic acid dehydrogenase (MTT), and the lactatedehydro-genase (LDH) release assays as well as microscopic inspection as endpoints. Genotoxicity of water, pore water, sediments, and SPM were assessed using the Ames test. Different extraction methods (Soxhlet extraction with solvents of variable polarity as well as a fluid/fluid extraction according to pH) in addition to a supplementation of biotests with S9 fractions from the liver of ,-naphthoflavone/phenobarbital-induced rats allowed a further characterization of the biological damage. Both sediments and SPM extracts caused cytotoxic effects in RTG-2 cells. Cytotoxicity was found to increase significantly with polarity of extracting solvents (NR50 = effective concentration for 50% cell death in the neutral red test: 80 [65], 100 [70], 180 [220], and 225 [270] mg/ml for ethanol, acetone, dichloromethane, and n -hexane extracts, respectively, if measured with [without] S9 supplementation). Following extraction according to pH, cytotoxicity could be attributed mainly to neutral substances (NR50: 80 and 218 mg dry SPM/ml test medium for the neutral and the acid fractions, respectively), whereas the slightly acid and basic fractions already showed little or no cytotoxicity. Samples taken during the period of flood rise showed the highest cytotoxic activities. Cytotoxicity was significantly enhanced by the addition of S9 preparations. In contrast, no genotoxic activity was found in native surface waters, pore waters, and SPM. [source] An evaluation of European air pollution regulations for particulate matter monitored from a heterogeneous networkENVIRONMETRICS, Issue 8 2009Sujit K. Sahu Abstract Statistical methods are needed for evaluating many aspects of air pollution regulations increasingly adopted by many different governments in the European Union. The atmospheric particulate matter (PM) is an important air pollutant for which regulations have been issued recently. A challenging task here is to evaluate the regulations based on data monitored on a heterogeneous network where PM has been observed at a number of sites and a surrogate has been observed at some other sites. This paper develops a hierarchical Bayesian joint space,time model for the PM measurements and its surrogate between which the exact relationship is unknown, and applies the methods to analyse spatio -temporal data obtained from a number of sites in Northern Italy. The model is implemented using MCMC techniques and methods are developed to meet the regulatory demands. These enablefull inference with regard to process unknowns, calibration, validation, predictions in time and space and evaluation of regulatory standards. Copyright © 2008 John Wiley & Sons, Ltd. [source] Erratum: Analysis of the effects of ultrafine particulate matter while accounting for human exposureENVIRONMETRICS, Issue 6 2009Brian J. Reich Volume 20, Issue 2, Pages 131,146 (March 2009) DOI: 10.1002/env.915 On page 144 of the above paper, under Discussion, the first sentence of the third paragraph should read, "The dynamic factor model proposed in Section 3 could be adapted to model a single pollutant that is repeatedly measured at multiple locations, as in Lopes et al. (2008).". The additional reference is: Lopes, H., Salazar, E. and Gamerman, D. 2008. Spatial dynamic factor analysis. Bayesian Analysis3: 759,792. [source] Analysis of the effects of ultrafine particulate matter while accounting for human exposureENVIRONMETRICS, Issue 2 2009B. J. REICH Abstract Particulate matter (PM) has been associated with mortality in several epidemiological studies. The US EPA currently regulates PM10 and PM2.5 (mass concentration of particles with diameter less than 10 and 2.5 µm, respectively), but it is not clear which size of particles are most responsible for adverse heath outcomes. A current hypothesis is that ultrafine particles with diameter less than 0.1 µm are particularly harmful because their small size allows them to deeply penetrate the lungs. This paper investigates the association between exposure to particles of varying diameter and daily mortality. We propose a new dynamic factor analysis model to relate the ambient concentrations of several sizes of particles with diameters ranging from 0.01 to 0.40 µm with mortality. We introduce a Bayesian model that converts ambient concentrations into simulated personal exposure using the EPA's Stochastic Human Exposure and Dose Simulator, and relates simulated exposure with mortality. Using new data from Fresno, CA, we find that the 4-day lag of particles with diameter between 0.02 and 0.08 µm is associated with mortality. This is consistent with the small particles hypothesis. Copyright © 2008 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||||||||