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Abstract: Particulate matter (PM) pollution in cities has severe impact on morbidity and mortality of their population. In these cities, road dust resuspension contributes largely to PM and airborne heavy metals concentrations. However, the short-term variation of emission through resuspension is not well described in the air quality models, hampering a reliable description of air pollution and related health effects. In this study we experimentally show that the emission strength of resuspension varies widely among road dust components/sources. Our results offer the first experimental evidence of different emission rates for mineral dust, heavy metals and carbon fractions due to traffic-induced resuspension. Also, the same component (or source) recovers differently in a road in Barcelona (Spain) and a road in Utrecht (The Netherlands). This finding has important implications on atmospheric pollution modelling, mostly for mineral dust, heavy metals and carbon species. After rain events, recoveries were generally faster in Barcelona rather than in Utrecht. The largest difference was found for the mineral dust (Al, Si, Ca). Tyre wear particles (organic carbon and zinc) recovered faster than other road dust particles in both cities. The source apportionment of road dust mass provides useful information for air quality management. [Copyright &y& Elsevier]

• Studies on air pollution and children cognitive functions are mainly observational. • We designed a randomized controlled trial using air cleaners with 2123 high school students. • Average levels of PM 2.5 and black carbon after 1.5 h were lower in classrooms with filtered air. • Short-term air filtering in classrooms did not affect attention function in adolescents. The recent evidence of the short-term impact of air pollution on youth cognitive functions is based primarily on observational studies. We conducted a randomized controlled trial to assess whether purifying the air of the classrooms produced short-term changes in attention processes of adolescents. We recruited a total of 2,123 adolescents (13–16 years old) in 33 high schools in Barcelona metropolitan area (Spain). In each school, adolescents from each class were randomly split into two equal-sized groups and assigned to two different classrooms. A set of two air cleaner devices with the same appearance (one recirculating and filtrating the air and the other only recirculating the air) was used. Each one of the devices was placed at random at one of the two classrooms. Students were masked to intervention allocation and had to complete several computerized activities for 1.5 h, including an attention test (Flanker task) to be performed at baseline and at the end of the intervention. The response speed consistency, expressed as hit reaction time standard error (HRT-SE, in ms), was measured as the primary outcome. Analyses were conducted using conditional linear regressions with classroom as strata, adjusted for variables that may differ from one class to another such as temperature, humidity and carbon dioxide concentration. Average levels of PM 2.5 and black carbon throughout the 1.5 h of experiment were 89% and 87%, respectively, lower in the classrooms with air cleaner than in the control classrooms. No differences were found in the median of HRT-SE between classrooms with cleaned air and normal air (percent change: 1.37%, 95% confidence interval: −2.81%, 5.56%). Sensitivity analyses with secondary attention outcomes resulted in similar findings. Cleaning the air of a classroom to reduce exposure to air pollutants for 1.5 h did not have an impact on the attention function of adolescents. Still, in light of previous evidence suggesting an association between air pollution and attention, further experimental studies should explore other short-term timescales of exposure and age ranges. [ABSTRACT FROM AUTHOR]

Abstract: An atmospheric aerosol study was performed in 2008 inside an urban road tunnel, in Lisbon, Portugal. Using a high volume impactor, the aerosol was collected into four size fractions (PM0.5, PM0.5–1, PM1 – 2.5 and PM2.5 – 10) and analysed for particle mass (PM), organic and elemental carbon (OC and EC), polycyclic aromatic hydrocarbons (PAH), soluble inorganic ions and elemental composition. Three main groups of compounds were discriminated in the tunnel aerosol: carbonaceous, soil component and vehicle mechanical wear. Measurements indicate that Cu can be a good tracer for wear emissions of road traffic. Cu levels correlate strongly with Fe, Mn, Sn and Cr, showing a highly linear constant ratio in all size ranges, suggesting a unique origin through sizes. Ratios of Cu with other elements can be used to source apportion the trace elements present in urban atmospheres, mainly on what concerns coarse aerosol particles. [Copyright &y& Elsevier]

Abstract: This work presents a summary of the results obtained from a study of the impact of African dust on levels of atmospheric suspended particulate matter registered among different monitoring sites in the Madrid Air Basin, in the centre of the Iberian Peninsula. African dust outbreaks were identified over the period 2001–2008. Lidar measurements helped to assess the temporal evolution of the dust layers and subsequent impact on the surface boundary layer. Monthly trends were analyzed, revealing a late spring/summer maximum occurrence of episodes. The most common synoptic meteorological situations causing the transport of the African dusty air masses were also identified over the seasons. Time series of particulate matter daily concentrations recorded across Air Quality Network monitoring stations and sampling campaigns were collected and analysed. Our results show the contribution of mineral dust to PM10 (particulate matter lower than 10μm, aerodynamic diameter) during African dust outbreaks to be significantly high at rural and urban sites of the Madrid Air Basin, giving rise to exceedances of the PM10 daily limit value (50μg/m3). This result is especially relevant since European directive 2008/50/EC on air quality, takes into account the potential exceedance of the PM10 daily limit value, due to the transport of natural particles from arid regions. [Copyright &y& Elsevier]

Abstract: Forest fire emissions modify the chemical composition of the atmosphere and the earth''s climate system. The Ayoraburning experiment was designed to assess and quantify fire emissions from Mediterranean shrublands. A number of gaseous pollutants and particulate matter metrics (CO2, CO, CH4, PM2.5) were measured during 3 burning replicates by using real-time monitors. Quantification of carbon emissions released during the experiments showed that 71% was CO2, 26% CO, 3% CH4, and only 0.3% was particulate carbon. Emission factors obtained for CO2, CO and CH4 were 1257 ± 40, 453 ± 28 and 46 ± 12 g kg−1 dry matter, respectively, and combustion efficiencies ranged from 0.46 to 0.99. The experiments allowed the estimation of carbon emission in the different fire phases. Thus, 25% of carbon was sampled in the flaming phase and 75% of C in the smoldering phase. Current natural greenhouse gas (GHG) emission inventories in Mediterranean countries underestimate the actual emissions from forest fires since they do not consider forest shrub understory and shrublands and since they assume that the CO2 emitted is offset by forest re-growth. Our results may be used to improve current forest-fire emission inventories in southern Europe with special emphasis on shrublands. [Copyright &y& Elsevier]

Abstract: The acidification of the aqueous phase induced by the use of an aluminium additive (sulphate), to increase the SO2 trapping efficiency in flue gas desulphurisation (FGD) systems, results in significant differences in the speciation and partitioning of elements between the aqueous and solid phases of gypsum slurries from two Spanish coal-fired power plants (PP1 and PP2). The Al-additive increases the presence of the aqueous Al–Fx complexes in the gypsum slurry from PP2-2007. In the absence of (PP1) or using lower dosages (PP2-2008) of the Al-additive, the predominance of MgF2 and CaF2 in the FGD-gypsum slurries causes their subsequent precipitation, increasing the leachable potential of gypsum waste. This study evaluates the effect of the Al-additive on the fate of a number of elements during FGD by combining a number of experimental and modelling tools. The results suggest the precipitation of CaF2, MgF2, and CaUO4 in the PP1 FGD-gypsum, and Al2O3, AlHO2, KAl3(OH)6(SO4)2 and MgF2 in the PP2 2007 and 2008 FGD-gypsum. When Al-additive is added low amounts of heavy metals are found in the leachates of the FGD-gypsums since these remain mostly in solution of gypsum slurry. The reverse behaviour is found for Se. [Copyright &y& Elsevier]

Abstract: Aim: The aims of this study were to investigate the relationship between pregnant women''s personal exposures to NO x , NO2, PM2.5 concentration and absorbance as a marker for black carbon and their indoor and outdoor concentration levels at their residence, and also to identify predictors of personal exposure and indoor levels using questionnaire and time activity data. Method: We recruited 54 pregnant women in Barcelona who carried a personal PM2.5 sampler for two days and NO x /NO2 passive badges for one week, while indoor and outdoor PM2.5 and NO x /NO2 levels at their residence were simultaneously measured. Time activity and house characteristics were recorded. Gravimetry determinations for PM2.5 concentration and absorbance measurements were carried out on the PM2.5 filter samples. Results: Levels of personal exposure to NO x , PM2.5 and absorbance were slightly higher than indoor and outdoor levels (geometric mean of personal NO x  = 61.9 vs indoor NO x  = 60.6 μg m−3), while for NO2 the indoor levels were slightly higher than the personal ones. Generally, there was a high statistically significant correlation between personal exposure and indoor levels (Spearman''s r between 0.78 and 0.84). Women spent more than 60% of their time indoors at home. Ventilation of the house by opening the windows, the time spent cooking and indicators for traffic intensity were re-occurring statistically significant determinants of the personal and indoor pollutants levels with models for NO x explaining the 55% and 60% of the variability respectively, and models for NO2 explaining the 39% and 16% of the variability respectively. Models for PM2.5 and absorbance explained the least of the variability. Conclusion: Our findings improve the current understanding of the characterization and inter-associations between personal, indoor and outdoor pollution levels among pregnant women. Variability in personal and indoor NO x and to a lesser extent NO2 levels could be explained well, but not the variability in PM2.5 could be explained. [Copyright &y& Elsevier]

This study focuses on the daily and seasonal variability of particle number size distributions and concentrations, performed at the Montseny (MSY) regional background station in the western Mediterranean from October 2010 to June 2011. Particle number concentrations at MSY were shown to be within range of various other sites across Europe reported in literature, but the seasonality of the particle number size distributions revealed significant differences. The Aitken mode is the dominant particle mode at MSY, with arithmetic mean concentrations of 1698 cm³, followed by the accumulation mode (877 cm-3) and the nucleation mode (246 cm-3). Concentrations showed a strong seasonal variability with large increases in particle number concentrations observed from the colder to warmer months. The modality of median size distributions was typically bimodal, except under polluted conditions when the size distribution was unimodal. During the colder months, the daily variation of particle number size distributions are strongly influenced by a diurnal breeze system, whereby the Aitken and accumulation modes vary similarly to PM1 and BC mass concentrations, with nocturnal minima and sharp day-time increases owing to the development of a diurnal mountain breeze. Under clean air conditions, high levels of nucleation and lower Aitken mode concentrations were measured, highlighting the importance of new particle formation as a source of particles in the absence of a significant condensation sink. During the warmer months, nucleation mode concentrations were observed to be relatively elevated both under polluted and clean conditions due to increased photochemical reactions, with enhanced subsequent growth owing to elevated concentrations of condensable organic vapours produced from biogenic volatile organic compounds, indicating that nucleation at MSY does not exclusively occur under clean air conditions. Finally, mixing of air masses between polluted and non-polluted boundary layer air, and brief changes in the air mass being sampled gave rise to unusual particle number size distributions, with specific cases of such behaviour discussed at length. [ABSTRACT FROM AUTHOR]

Aerosol deposition plays an important role in climate and biogeochemical cycles by supplying nutrients to the open ocean, in turn stimulating ocean productivity and carbon sequestration. Aerosol particles also contain elements such as copper (Cu) that are essential in trace amounts for phytoplankton physiology but that can be toxic at high concentrations. Although the toxicity of Cu associated with aerosols has been demonstrated in bioassay experiments, extrapolation of these laboratory results to natural conditions is not straightforward. This study provides observational evidence of the negative effect of aerosols containing high Cu concentrations on marine phytoplankton over a vast region of the western Mediterranean Sea. Direct aerosol measurements were combined with satellite observations, resulting in the detection of significant declines in phytoplankton biomass after atmospheric aerosol events characterized by high Cu concentrations. The declines were more evident during summer, when nanoflagellates predominate in the phytoplankton population and stratification and oligotrophic conditions prevail in the study region. Together with previous findings concerning atmospheric Cu deposition, these results demonstrate that the toxicity of Cu-rich aerosols can involve large areas of the world's oceans. Moreover, they highlight the present vulnerability of oceanic ecosystems to Cu-rich aerosols of anthropogenic origins. Because anthropogenic emissions are increasing, large-scale negative effects on marine ecosystems can be anticipated. [ABSTRACT FROM AUTHOR]

Abstract: In spite of the high air quality and health relevance of PM emissions from road dust resuspension in large cities, very little is known on their temporal variability, severely hampering a reliable description of population exposure by dispersion models. We have experimentally monitored the mobile dust load (only inhalable fraction) in two different European urban environments resulting in the first empirical description of the temporal variation of road dust emission strength. In Central (The Netherlands) and Southern (Spain) European environments the loadings of mobile road dust particles <10 μm were found to be generally constant on a day-to-day scale, except during and in the hours immediately after rain events when the mobility of particles drops dramatically to values close to zero. After the rain event the mobile dust load increases exponentially tending to reach again the maximum value, result of the equilibrium between mobilization/buildup of dust and moistening/resuspension processes. The mobilization/buildup of particles smaller than 10 μm was found to be three times faster in Barcelona than in Utrecht, in relation to higher solar radiation. In Barcelona the recovery of mobile road dust reached 50%, 75%, and 90% of the maximum value after 8, 16 and 27 h, respectively. These values were independent of amounts of rain. In Utrecht the same thresholds were reached after, 28, 55 and 90 h, respectively. Our observations may suggest that, for reducing road dust emissions, light but frequent moistening of roads might be more effective than intensive occasional cleanings. [Copyright &y& Elsevier]

Abstract: In Winter 2009 an intensive experimental campaign (DAURE) was conducted in an urban site (Barcelona) and in an elevated rural background station (Montseny) in the western Mediterranean basin. During this period three main scenarios were identified based on distinct meteorological conditions: A) temperature inversion, B) cloudy days in normal conditions, and C) intense sea breeze. Filter samples of the submicron fraction (PM1) collected during these scenarios were analysed for organic tracer compounds to gain insight into the composition, sources, formation and processing of aerosol organic matter in the region under contrasting conditions. The results were compared to on-line Aerosol Mass Spectrometry (AMS) measurements. Scenario A conditions had the highest pollution concentrations in Barcelona (traffic and secondary aerosol formation) and lowest in Montseny whose sampling station remained above the mixing layer. Under scenario B the biomass burning contribution was highest in Montseny, reflecting nearby biomass burning sources. Under scenario C, the traffic-related contributions were highest in Montseny and lowest in Barcelona in comparison to the other samples, reflecting the enhanced pollution transport to Montseny and greater dilution in Barcelona. In this scenario, secondary organic aerosol was highest in Montseny. Molecular marker data and AMS source apportionment showed strong to moderate correlation for a) dicarboxylic acids and oxygenated organic aerosol, b) levoglucosan and biomass burning organic aerosol and c) Σn-alkanes and hydrocarbon-like organic aerosol. [Copyright &y& Elsevier]

Abstract: Water re-circulation to the scrubber and co-combustion of coal with petroleum coke are the most significant factors that affect the retention capacity for trace elements in a power plant equipped with a forced-oxidation flue gas desulphurisation (FGD) system. The water re-circulation favours the progressive saturation of most elements in the gypsum slurry with the subsequent increase in emission by entraining particles and droplets in the outgoing gas of FGD (OUT-FGD). The co-combustion increases the content of HCl and SO2 in the gaseous stream, which enhances the formation of gaseous chlorides species, especially of Hg, and the formation of condensed species of Cu, Cr, Ni, Na, Cd, and Zn OUT-FGD, respectively. High gaseous retention capacity (83–100%) for S, Cl, F, As, and B is attained by the whole plant with a subsequent reduction in their gaseous emissions below the limits established by the European directive 2001/80/EC for large combustion plants, and also below the Pollutant Release and Transfer Register (PRTR) threshold values. The retention of Se increases from 2007 (75%) to 2008 (97%). The emissions of gaseous Hg and particulate As, Zn, and Ni exceed the PRTR values. Remediation actions for the gaseous and PM emissions are relevant given the role of the filtered water re-circulation increasing the particles emissions OUT-FGD. [Copyright &y& Elsevier]

Abstract: Atmospheric aerosol samples from a boreal forest (Hyytiälä, April 2007), a rural site in Hungary (K-puszta, summer 2008), a polluted rural area in Italy (San Pietro Capofiume, Po Valley, April 2008), a moderately polluted rural site in Germany located on a meadow (Melpitz, May 2008), a natural park in Spain (Montseny, March 2009) and two urban background locations (Zurich, December 2008, and Barcelona, February/March 2009) were collected. Aliphatics, polycyclic aromatic hydrocarbons, carbonyls, sterols, n-alkanols, acids, phenolic compounds and anhydrosugars in aerosols were chemically characterised by gas chromatography–mass spectrometry, along with source attribution based on the carbon preference index (CPI), the ratios between the unresolved and the chromatographically resolved aliphatics, the contribution of wax n-alkanes, n-alkanols and n-alkanoic acids from plants, diagnostic ratios of individual target compounds and source-specific markers to organic carbon ratios. In spite of transboundary pollution episodes, Hyytiälä registered the lowest levels among all locations. CPI values close to 1 for the aliphatic fraction of the Montseny aerosol suggest that the anthropogenic input may be associated with the transport of aged air masses from the surrounding industrial/urban areas, which superimpose the locally originated hydrocarbons with biogenic origin. Aliphatic and aromatic hydrocarbons in samples from San Pietro Capofiume reveal that fossil fuel combustion is a major source influencing the diel pattern of concentrations. This source contributed to 25–45% of the ambient organic carbon (OC) at the Po Valley site. Aerosols from the German meadow presented variable contributions from both biogenic and anthropogenic sources. The highest levels of vegetation wax components and biogenic secondary organic aerosol (SOA) products were observed at K-puszta, while anthropogenic SOA compounds predominated in Barcelona. The primary vehicular emissions in the Spanish city accounted for around 25–30% of the OC in aerosols. Besides the traffic input (10% of OC), residential wood burning was found to be another dominant emission source contributing to the atmospheric aerosol (up to 38% of OC) at the Swiss urban location. It was estimated that around 10% of the OC mass in the urban sites originates from cooking emissions. Aerosols from the urban area of Zurich presented a much higher PAH content, and benzo(a)pyrene equivalent concentrations sometimes exceeding the mandatory limit. [Copyright &y& Elsevier]

A novel on-board system was tested to characterize size-resolved particle number emission patterns under real-world driving conditions, running in a EURO4 diesel vehicle and in a typical urban circuit in Madrid (Spain). Emission profiles were determined as a function of driving conditions. Source apportionment by Positive Matrix Factorization (PMF) was carried out to interpret the real-world driving conditions. Three emission patterns were identified: (F1) cruise conditions, with medium-high speeds, contributing in this circuit with 60% of total particle number and a particle size distribution dominated by particles >52 nm and around 60 nm; (F2) transient conditions, stop-and-go conditions at medium-high speed, contributing with 25% of the particle number and mainly emitting particles in the nucleation mode; and (F3) creep-idle conditions, representing traffic congestion and frequent idling periods, contributing with 14% to the total particle number and with particles in the nucleation mode (<29.4 nm) and around 98 nm. We suggest potential approaches to reduce particle number emissions depending on particle size and driving conditions. Differences between real-world emission patterns and regulatory cycles (NEDC) are also presented, which evidence that detecting particle number emissions <40 nm is only possible under real-world driving conditions. [ABSTRACT FROM AUTHOR]

Abstract: Urban NH3 concentrations were mapped in Barcelona (Spain) by means of passive samplers (dosimeters). Average NH3 levels were 9.5 μg m−3 in summer and 4.4 μg m−3 in winter, higher than those reported in other urban background sites in Europe, this being especially notable in summer. During this season, values were significantly higher at urban background than at traffic sites, probably indicating the impact of emissions from biological sources, such as humans, sewage systems and garbage containers. Thus, the volatilization of NH3 from the aerosol phase seems to be significant enough during summer to dominate over traffic emissions. Conversely, in winter levels were higher at traffic sites, suggesting a contribution from vehicle emissions. Indeed, NH3 levels decreased by 55% with increasing distance (50 m) to the direct emissions from traffic. A significant correlation between NH3 concentrations averaged for the different districts of the city and the number of waste containers per hm2 was also obtained, highlighting the necessity for controlling and reducing the emissions from garbage collection systems. The urban topography of the Barcelona historical city centre, characterised by narrow streets with a high population density, seemed to exert a strong influence on NH3 levels, with levels reaching up to 30 μg m−3 as a consequence of limited dispersion and ventilation conditions. The impact of the sewage system emissions was also detected with an increase of levels when measuring immediately above the source, even though further studies are required to evaluate the relevance of these emissions. [Copyright &y& Elsevier]

An unusual and different speciation of Hg in the outgoing gaseous stream of the flue gas desulfurization (OUT-FGD) system was revealed at two Spanish power plants (PP1 and PP2) equipped with a forced oxidation wet FGD system with water recirculation to the scrubber. At PP1 and PP2, a high proportion of Hg escapes from the electrostatic precipitator in gaseous form, Hg2+ (75-86%) being the species that enters the FGD. At PP1 Hg0 (71%) was the prevalent Hg OUT-FGD species, whereas at PP2 Hg2+ was the prevalent Hg OUT-FGD species in 2007 (66%) and 2008 (87%). The unusual speciation of gaseous Hg OUT-FGD and the different Hg retentions between 2007 and 2008 at PP2 were attributable to the evaporation of HgCl2 particles from the aqueous phase of gypsum slurry in the OUT-FGD gas and the Al additive used at PP2, respectively. The Al additive induced the retention of Hg as HgS in the 2007 FGD gypsum, thus reducing gaseous emissions of Hg in the OUT-FGD gas. [ABSTRACT FROM AUTHOR]

Abstract: The extraction of sulphur produces a hematite-rich waste, known as roasted pyrite ash, which contains significant amounts of environmentally sensitive elements in variable concentrations and modes of occurrence. Whilst the mineralogy of roasted pyrite ash associated with iron or copper mining has been studied, as this is the main source of sulphur worldwide, the mineralogy, and more importantly, the characterization of submicron, ultrafine and nanoparticles, in coal-derived roasted pyrite ash remain to be resolved. In this work we provide essential data on the chemical composition and nanomineralogical assemblage of roasted pyrite ash. XRD, HR-TEM and FE-SEM were used to identify a large variety of minerals of anthropogenic origin. These phases result from highly complex chemical reactions occurring during the processing of coal pyrite of southern Brazil for sulphur extraction and further manufacture of sulphuric acid. Iron-rich submicron, ultrafine and nanoparticles within the ash may contain high proportions of toxic elements such as As, Se, U, among others. A number of elements, such as As, Cr, Cu, Co, La, Mn, Ni, Pb, Sb, Se, Sr, Ti, Zn, and Zr, were found to be present in individual nanoparticles and submicron, ultrafine and nanominerals (e.g. oxides, sulphates, clays) in concentrations of up to 5%. The study of nanominerals in roasted pyrite ash from coal rejects is important to develop an understanding on the nature of this by-product, and to assess the interaction between emitted nanominerals, ultra-fine particles, and atmospheric gases, rain or body fluids, and thus to evaluate the environmental and health impacts of pyrite ash materials. [Copyright &y& Elsevier]

Abstract: Several studies conducted in urban areas have pointed out that road dust resuspension contributes significantly to PM concentration levels. Street washing is one of the methods proposed to reduce resuspended road dust contributions to ambient PM concentrations. As resuspended particles are mainly found in the coarse mode, published studies investigating the effects of street washing have focused on PM10 size fraction. As the PM2.5 mass fraction of particles originating from mechanical abrasion processes may still be significant we conducted a study in order to evaluate the effects of street washing on the mitigation of resuspension of fine particles. The PM2.5 mass concentration data were examined and integrated with the occurrence of street washing activities. In addition, the effect of the meteorological variability, traffic flow and street washing activities, on ambient PM2.5 levels was evaluated by means of a multivariate regression model. The results revealed that traffic flow is the most important factor that controls PM2.5 hourly concentrations while street washing activities did not influence fine particle mass levels. [Copyright &y& Elsevier]

Abstract: Petrographic, mineralogical and geochemical studies have been carried out on beneficiated coal products from mines and preparation plants in the Santa Catarina Basin, southern Brazil, to investigate the range of characteristics exhibited by the materials and the potential impact of their stockpiling and storage on the environment. The coals contain varying proportions of vitrinite and inertinite macerals, and have vitrinite reflectance values ranging from 0.44 to 1.38%. With the exception of one material blended with peat from an external source, they have relatively high percentages of ash (30–58%) and mineral matter (36–66%). The mineral matter consists mainly of clay minerals (kaolinite, illite and illite/smectite), together with 15–25% quartz, up to 10% feldspar, up to 5% calcite and/or dolomite and up to 5% pyrite, and around 1% anatase and/or rutile. Bassanite is also present in low-temperature ash derived from the coals, mainly derived from interaction of Ca and S associated with the organic matter. Jarosite is formed by pyrite oxidation in coals that have been exposed in stockpiles for extended periods. Most of the trace elements in most of the coals have higher concentrations than average values for world coals generally, probably due to the relatively high mineral matter content. A lower-ash product representing a blend of coal and peat has similar to lower concentrations of most elements, but higher concentrations of B, Ba, Be, Cd, Ge and Mn, which may be associated with the peat component. Interaction of relatively fresh coals with water in laboratory tests produces leachates with near-neutral to mildly acid pH values, but leaching of oxidized, jarosite-bearing coal produces a strongly acid leachate, with higher concentrations of Cd, Co, Cu, Ni and Zn. Leachates derived from coals in which the pyrite has been oxidized during storage would thus be expected to have a more adverse environmental impact than leachates derived from coals in which such oxidation has not had an opportunity to develop. [Copyright &y& Elsevier]

Abstract: The mineralogical and geochemical characteristics of the Late Permian Huayingshan coals, partings, roof and floor strata, as well as lutitic rocks from the Longtan Formation, in Sichuan Province, southwestern China, were investigated in this study. The Huayingshan low volatile bituminous coals are characterized by relatively high mineral contents (mainly kaolinite, quartz, pyrite, and calcite). The concentrations of most trace elements are relatively high compared with other Chinese and world coals. The coals and associated strata show similar element affinities: Al, Ti, Li, Ta, Th, Ga, U, Sn, Sc, Cr, Cu, Rb, Co, and Se probably have an aluminosilicate affinity; Zr, Nb, Hf, Y, REEs, and U probably result from the occurrence of heavy minerals such as zircon; S, Fe, W, and Rb mainly have a sulfide affinity; Ca, Sr, and Mn mainly have an carbonate affinity. The high enrichment in the Huayingshan coal of Zr, Nb, Hf, REEs, Ta, Ga, and Th is caused by a geochemical anomaly in the source of this coal''s detrital material (and probably also by input of volcanic ash), which is influenced by the alkaline volcanic magmas of the Emeishan basalt. The Zr/Hf, Zr/Nb, Zr/La and Zr/Th ratios support the volcanic origin of such a geochemical anomaly. [Copyright &y& Elsevier]

Abstract: The abatement capacity of trace inorganic elements was studied in a large Pulverized Coal Combustion (PCC) power plant equipped with a wet limestone Flue Gas Desulphurisation (FGD) system. High proportions of most elements were retained as fly ash as consequence of the efficiency of the electrostatic precipitator (ESP, 99.6% of fly ash) and slag (11%). The most volatile elements, such as S and F are retained by the FGD gypsum, and Cl by the filtered water; whereas the moderately volatile elements, As and B, are retained mainly by fly ash, reaching very high abatement efficiencies for these elements when considering the whole plant (>92%). Selenium and Hg are still retained by the whole system with relatively high proportions (89% and 67%); however a prominently proportion is emitted; Se (11%) and Hg (29%), attaining gaseous/PM rate at the emissions reaching 0.08 and 290, respectively. The gaseous emissions are below the limits according to the European directive 2001/80/EC for large combustion plants and the PRTR threshold values with the exception of Hg emissions and particulate Se, As, Zn, Cu, Ni, and Cr. Remediation actions to prevent and/or reduce the gaseous and PM emissions as well as the determination of leachable potential of trace inorganic pollutants retained in FGD gypsum, especially F in view of its disposal, are of significant relevance. [Copyright &y& Elsevier]

Abstract: Background: The role of Saharan dust outbreaks on the relationship between particulate matter and daily mortality has recently been addressed in studies conducted in Southern Europe, although they have not given consistent results. Methods: We investigated the effects of coarse (PM10–2.5) and fine particulate matter (PM2.5) in Madrid on total mortality during Saharan dust and non-dust days using a case-crossover design. Results: During Saharan dust days, an increase of 10mg/m3 of PM10–2.5 raised total mortality by 2.8% compared with 0.6% during non-dust days (P-value for interaction=0.0165). Conclusion: We found evidence of stronger adverse health effects of PM10–2.5 during Saharan dust outbreaks effects for impacted European populations, but not for PM2.5. Further research is needed to understand mechanisms by which Saharan dust increases risk of mortality. [Copyright &y& Elsevier]

A full-scale field study was carried out at two Spanish coal-fired power plants equipped with electrostatic precipitator (ESP) and wet flue gas desulfurisation (FGD) systems to investigate the distribution of boron in coals, solid by-products, wastewater streams and flue gases. The results were obtained from the simultaneous sampling of solid, liquid and gaseous streams and their subsequent analysis in two different laboratories for purposes of comparison. Although the final aim of this study was to evaluate the partitioning of boron in a (co-)combustion power plant, special attention was paid to the analytical procedure for boron determination. A sample preparation procedure was optimised for coal and combustion by-products to overcome some specific shortcomings of the currently used acid digestion methods. In addition boron mass balances and removal efficiencies in ESP and FGD devices were calculated. Mass balance closures between 83 and 149% were obtained. During coal combustion, 95% of the incoming boron was collected in the fly ashes. The use of petroleum coke as co-combustible produced a decrease in the removal efficiency of the ESP (87%). Nevertheless, more than 90% of the remaining gaseous boron was eliminated via the FGD in the wastewater discharged from the scrubber, thereby causing environmental problems. [Copyright &y& Elsevier]

Abstract: The mobility of inorganic pollutants is of key concern for a range of industrial and engineering applications of fly ash produced during the combustion of lignite in power generation. This paper investigates the role that the geochemical features of lignite, the ash composition and the partitioning of elements during combustion play in determining leaching properties of lignite fired by-products. The work is based on surveys on three lignite-fired power plants in Greece. Calcium-rich ashes show a high abatement potential for SO2 and other gaseous pollutants. For most elements, the concentrations in the parent lignite and the ashes follow the same trend. Relative enrichments in Cd, Co, Cr, Cu, Mo, Ni, Pb, U, V, W, Zn fingerprint the regional and local geological settings of the lignite basins. The total and leachable concentrations of highly volatile elements are strongly influenced by the interaction with ubiquitous free lime. A broad array of elements is highly insoluble in alkaline ash, while a few oxyanionic-forming elements display substantial mobility. Their mode of occurrence in the parent lignite plays a primary role in the leaching of combustion ashes. The outcomes of this study may assist in addressing the impact of co-firing high ash or high Ca alternative fuels on the leaching properties of combustion by-products. [Copyright &y& Elsevier]

Abstract: The enrichment of inorganic trace pollutants in re-circulated water streams was studied at two power plants equipped with wet limestone Flue Gas Desulphurisation (FGD) system from the first re-circulation cycle of water up to the start of sampling campaigns. To elucidate the enrichment of inorganic trace pollutants as result of water re-circulation, a partial and total mass balances were undertaken. A t-Student analysis was performed to ascertain whether the mean contribution of filtered water affected the balance of elements and the enrichment of this water stream. The t-Student revealed the mean contribution of filtered water to total mass balance was statistically significant (p<0.05) for Na, Mg, Cl, B, Mn, Se, Cd, Mo, and U at first plant, and Na, Cl, K, Mg, Hg, Li, B, F, Ni, Zn, Mn, Co Sc, Ge, Se, at the second one. High levels of inorganic trace pollutants in filtered water could be affected by limestone purity, electrostatic precipitator gas temperature, use of additives, fluoride and/or sulphate complexes, and the S/F and S/Cl ratios in the scrubber, which may reduce the gaseous retention efficiencies in FGD and increase the emission of metals by entraining and/or evaporation of droplets as particulate matter from gypsum slurry. [Copyright &y& Elsevier]

Abstract: The primary aim of this study was to quantify the contribution of road dust to airborne particulate matter (PM10) and evaluate the effects of street washing on the mitigation of resuspension. With this purpose an intensive campaign was carried out in a heavily trafficked central road of Madrid (Spain) including PM10 sampling and chemical analysis. PM10 daily levels during dry, unwashed conditions were 2–15% higher than those present during the day after nightly street washing. However, this reduction is lower than the standard deviation of the PM10 measurements. The diurnal variation of PM10 revealed that a reduction in PM10 was noticeable only during the morning hours. The emission sources for the urban area of Madrid were resolved by means of a receptor model, Positive Matrix Factorization, PMF. The results showed that the main sources were vehicle emissions, road dust, secondary aerosol including sulphate and nitrate, and soil. Vehicle emissions and road dust were the major contributor to PM10 particle mass with similar average contributions of 31% and 29% respectively. The effect of street washing was also evaluated by examining the daily variation of the road dust source contribution between days with and without street washing. The mass contribution from the road dust source was ∼2 μg m−3 lower during the days that street washing was implemented with this corresponding to a reduction of 15% of its mass contribution during the days that the road surface was left untreated. [Copyright &y& Elsevier]

Abstract: In summer 2009, emissions of trace gases and aerosols from several wildfires occurring in Portugal were sampled. A portable high-volume sampler was used to collect sequentially, on quartz fibre filters, coarse (PM2.5–10) and fine (PM2.5) smoke particles. Tedlar air sampling bags have been used for complementary chemical characterisation of the gaseous phase. The carbonaceous content (elemental and organic carbon, EC/OC) of particulate matter was analysed by a thermal-optical transmission technique. The levels of almost 50 elements were quantified by inductively coupled plasma-mass spectrometry. The water-soluble ions were obtained by ion chromatography. Emission factors of species that are favoured by the smouldering phase (e.g. CO) were above the values reported in the literature for biomass burning in other ecosystems. The CO emission factors were 231 ± 117 g kg−1 biomass (dry basis) burned. Emissions of compounds that are promoted in fresh plumes and during the flaming phase, such as CO2, were generally lower than those proposed for savannah and tropical forest fires. The CO2 emission factors ranged from about 1000 to 1700 g kg−1. Total hydrocarbons, PM2.5, PM10 and OC presented variable emissions, but in general substantially higher than values reported for wildfires in African and Amazonian biomes. The emission factors obtained in Portugal were as follows (in g kg−1 biomass, dry basis): 6–350 for total hydrocarbons, 0.5–42 for PM2.5, 1–60 for PM10, and 0.2–42 for OC (in PM10). The organic carbon-to-elemental carbon ratios measured in the present study largely exceeded those obtained by other researchers. The aerosol mass was dominated by organic matter (OC/PM2.5 = 50 ± 18%, OC/PM2.5–10 = 36 ± 18%). The metal elements represented, on average, 1.23 and 0.91%, while the measured water-soluble ions accounted for 2.6 and 2.1% of the PM2.5 and PM2.5–10 mass, respectively. Carbonates accounted for 0.15–3.1% (average = 0.83%) of PM2.5–10. The dominant elements were B, Ti, Mn, Cu, Zn, Zr and Ba. [Copyright &y& Elsevier]

African dust (AD) contributions to particulate matter (PM) levels may be reported by Member States to the European Commission during justification of exceedances of the daily limit value (DLV). However, the detection and subsequent quantification of the AD contribution to PM levels is complex, and only two measurement-based methods are available in the literature: the Spanish-Portuguese reference method (SPR), and the Tel Aviv University method (TAU). In the present study, both methods were assessed. The SPR method was more conservative in the detection of episodes (71 days identified as AD by SPR, vs 81 by TAU), as it is less affected by interferences with local dust sources. The mean annual contribution of AD was lower with the TAU method than with SPR (2.7 vs 3.5 ± 1.5 μg/m³). The SPR and TAU AD time series were correlated with daily aluminum levels (a known tracer of AD), as well as with an AD source identified by the Positive Matrix Factorization (PMF) receptor model. Higher r² values were obtained with the SPR method than with TAU in both cases (r² = 0.72 vs 0.56, y = 0.05x vs y = 0.06x with aluminum levels; r² = 0.79 vs 0.43, y = 0.8x vs y - 0.4x with the PMF source). We conclude that the SPR method is more adequate from an EU policy perspective (justification of DLV exceedances) due to the fact that it is more conservative than the TAU method. Based on our results, the TAU method requires adaptation of the thresholds in the algorithm to refine detection of low-impact episodes and avoid misclassification of local events as AD. [ABSTRACT FROM AUTHOR]

Abstract: Phosphogypsum (CaSO4·2H2O), a by-product of phosphate-rock processing, contains high amounts of impurities such P2O5, F, radioactive elements, organic substances, secondary nanominerals, and ultrafine particles (UFP) enriched in metals and metalloids. In this study, we examine phosphogypsum (PG) collected from abandoned fertilizer industry facility in south Brazil (Santa Catarina state). The fragile nature of nanominerals and UFP assemblages from fertilizer industry systems required novel techniques and experimental approaches. The investigation of the geochemistry of complex nanominerals and UFP assemblages was a prerequisite to accurately assess the environmental and human health risks of contaminants and cost-effective chemical and biogeological remediation strategies. Particular emphasis was placed on the study and characterization of the complex mixed nanominerals and UFP containing potentially toxic elements. Nanometer-sized phases in PG were characterized using energy-dispersive X-ray spectrometer (EDS), field-emission scanning electron microscope (FE-SEM), and high-resolution transmission electron microscopy (HR-TEM) images. The chemical composition and possible correlations with morphology of nanominerals and UFP, as well as aspects of nanominerals and UFP, are discussed in the context of human health exposure, as well as in relation to management of the nanominerals and UFP in PG environments. [ABSTRACT FROM AUTHOR]

Abstract: Mineral dust is an important aerosol species in the Earth’s atmosphere and has a major source within North Africa, of which the Sahara forms the major part. Aerosol Time of Flight Mass Spectrometry (ATOFMS) is first used to determine the mixing state of dust particles collected from the land surface in the Saharan region, showing low abundance of species such as nitrate and sulphate internally mixed with the dust mineral matrix. These data are then compared with the ATOFMS single particle mass spectra of Saharan dust particles detected in the marine atmosphere in the vicinity of the Cape Verde islands, which are further compared with those from particles with longer atmospheric residence sampled at a coastal station at Mace Head, Ireland. Saharan dust particles collected near the Cape Verde Islands showed increased internally mixed nitrate but no sulphate, whilst Saharan dust particles collected on the coast of Ireland showed a very high degree of internally mixed secondary species including nitrate, sulphate and methanesulphonate. This uptake of secondary species will change the pH and hygroscopic properties of the aerosol dust and thus can influence the budgets of other reactive gases, as well as influencing the radiative properties of the particles and the availability of metals for dissolution. [Copyright &y& Elsevier]

Measurements of particle number concentration (N), black carbon (BC), and PM10, PM2.5, and PM1 levels and speciation were carried out at an urban background monitoring site in Barcelona. Daily variability of all aerosol monitoring parameters was highly influenced by road traffic emissions and meteorology. The levels of N, BC, PMX, CO, NO, and NO2 increased during traffic rush hours, reflecting exhaust, and non-exhaust traffic emissions and then decreased by the effect of breezes and the reduction of traffic intensity. PM2.5-10 levels did not decrease during the day as a result of dust resuspension by traffic and wind. N showed a second peak, registered in the afternoon and parallel to O3 levels and solar radiation intensity, that may be attributed to photochemical nucleation of precursor gases. An increasing trend was observed for PM1 levels from 1999 to 2006, related to the increase in the traffic flow and the diesel fleet in Barcelona. PM composition was highly influenced by road traffic emissions, with exhaust emissions being an important source of PM1 and dust resuspension processes of PM2.5-10, respectively. [ABSTRACT FROM AUTHOR]

Abstract: In this study, physicochemical characterization of Atmospheric Particulate Matter (PM) was performed in an urban-industrial site background (Bailén, Southern Spain), highly influenced by the impact of emission plumes from ceramic factories. This area is considered one of the towns with the highest PM10 levels and average SO2 concentration in Spain. A three stages methodology was used: 1) real-time measurements of levels of PM10 and gaseous pollutants, and sampling of PM; 2) chemical characterization using ICP-MS, ICP-OES, CI and TOT, and source apportionment analysis (receptor modelling) of PM; and 3) chemical characterization of emission plumes derived from representative factories. High ambient air concentrations were found for most major components and trace elements compared with other industrialized towns in Spain. V and Ni are considered fingerprints of PM derived from the emissions of brick factories in this area, and were shown to be of particular interest. This highlights the high V and Ni concentrations in PM10 (122ngV/m3 and 23.4ngNi/m3), with Ni exceeding the 2013 annual target value for the European Directive 2004/107/EC (20ng/m3). The methodology of this work can be used by Government departments responsible for Environment and Epidemiology in planning control strategies for improving air quality. [Copyright &y& Elsevier]

Abstract: The Zhundong coalfield is a very large coal deposit, currently under exploration, and promises to be an important coal mining resource in Western China. The coal reserves amount to 164Gt. At Xiheishan and Wucaiwan, the coal-bearing units are the Badaowan (Lower Jurassic) and, especially, the Xishanyao formations (Middle Jurassic). These contain from one to 31 coal seams (one to 10 workable coals reaching the rank of high volatile A bituminous) with an accumulated workable coal thickness of 20–87m. These recently explored coal reserves are of a high quality and are characterized by low ash, aluminum, iron, sulfur, and trace element contents. The minerals present in this coal are mainly quartz, kaolinite, siderite, and pyrite. The trace element contents in both Xiheishan and Wucaiwan coals are much lower when compared with the usual concentration ranges present in Chinese coals, with the exception of Ba and Sr. Thus, Ba contents in Xiheishan coal are higher than Swaine''s worldwide concentration range. A large number of elements have mainly aluminosilicate affinity, and occur in clay and other detrital coal minerals. Ca and Mn have mainly carbonate affinity; Fe and S have mainly sulphide affinity in Wuchaiwan coal. In Xiheishan, Fe, Mn and Mg have mainly carbonate affinity (siderite), and probably, B, Co, Ni and S have an organic affinity. Thus, the Zhundong coalfield contains coal with a very high quality and very low levels of impurities. The very low ash yields, S, Fe, and trace element contents may be attributed to the sedimentological setting, with intensive peat bog aggradation in a very shallow lake environment with a low detrital supply. The very low sulfur content, the relatively high Ba-sulfate (barite) content and the high siderite occurrence in Xiheishan coal (in contrast to the pyrite occurrence in Wucaiwan coal) may be attributed to the rapid aggradation of peat with the consequent oxidation and leaching of minerals, elements, and degradation of organic components. Under this scenario, sulfate is trapped by the continuous precipitation and accumulation of barium sulfate (very low soluble). [Copyright &y& Elsevier]

Abstract: Samples of particulate matter were collected during the period from October 2006 through September 2007 in a rural station located 12 km from the city of Colima. A total of 3600 particles were analyzed by SEM-EDS and then classified by their chemical composition and morphology in order of abundance: those rich in C, Fe, Si–Al, Cl–Na, Ca, Ba; and to a lesser abundance, particles rich in heavy metals such as Pb and V–Ni were observed. A factorial analysis was carried out to determine the main elements related with the emission sources such as crustal/farming; fuel-oil; marine; volcanic activity and industry. Trough the seasons, the dominant winds causes the presence of anthropogenic particles in the rural site. The information presented in this study aims to give insight and detailed of the analysis of the morphological characteristics and chemical composition of atmospheric particles at individual level in a rural site from Colima State, Mexico. [Copyright &y& Elsevier]

Source apportionment analyses were carried out by means of receptor modeling techniques to determine the contribution of major fine particulate matter (PM2.5) sources found at six sites in Mexico City. Thirty-six source profiles were determined within Mexico City to establish the fingerprints of particulate matter sources. Additionally, the profiles under the same source category were averaged using cluster analysis and the fingerprints of 10 sources were included. Before application of the chemical mass balance (CMB), several tests were carried out to determine the best combination of source profiles and species used for the fitting. CMB results showed significant spatial variations in source contributions among the six sites that are influenced by local soil types and land use. On average, 24-hr PM2.5 concentrations were dominated by mobile source emissions (45%), followed by secondary inorganic aerosols (16%) and geological material (17%). Industrial emissions representing oil combustion and incineration contributed less than 5%, and their contribution was higher at the industrial areas of Tlalnepantla (11%) and Xalostoc (8%). Other sources such as cooking, biomass burning, and oil fuel combustion were identified at lower levels. A second receptor model (principal component analysis, [PCA]) was subsequently applied to three of the monitoring sites for comparison purposes. Although differences were obtained between source contributions, results evidence the advantages of the combined use of different receptor modeling techniques for source apportionment, given the complementary nature of their results. Further research is needed in this direction to reach a better agreement between the estimated source contributions to the particulate matter mass. [ABSTRACT FROM AUTHOR]

Speciated coarse particulate matter (PM10) data obtained at three air quality monitoring sites in a highly industrialized area in Spain between 2002 and 2007 were analyzed for assessing source contribution of ambient particulate matter (PM). The source apportionment of PM in this area is an especially difficult task. There are industrial mineral dust emissions that need to be separately quantified from the natural sources of mineral PM. On the other hand, the diversity of industrial processes in the area results in a puzzling industrial emissions scenario. To solve this complex problem, a two-step methodology based on the possibilities of the Multilinear Engine was used. Application of positive matrix factorization to the dataset allowed the identification of nine factors relevant to the study area. This preliminary analysis permitted resolving two mineral factors. As a second step, a target rotation was implemented for transforming the mineral factors into experimentally characterized soil resuspension and industrial clay sources. In addition to improving the physical interpretation of these factors, the target rotation reduced the errors arising from the rotational freedom of the solution and the multicollinearity among sources. In this way, the main primary industrial emissions of PM in the zone were identified by this target factor analysis. A marked decrease was observed between 2002 and 2007 for the contributions of industrial sources coinciding with the implementation of mitigation measures in their processes. This study supports the utility of source apportionment methodologies for quantitatively evaluating the effectiveness of the abatement programs for air quality improvement. [ABSTRACT FROM AUTHOR]

Abstract: For more than two decades a number of frameworks for scientific knowledge production are being proposed by science and technology researchers. They all advocate an extended involvement of non-specialists, in particular when it comes to knowledge production applicable to practical societal problems. We look to what extent these new frameworks have taken ground within a particular research community: the ACCENT Network of Excellence which coordinates European atmospheric chemistry and physics research applicable to air pollution and climate change. We did so by stimulating a debate through a “blog”, a survey and in-depth interviews with ACCENT scientists about the interaction between science, policy making and civil society, to which a great deal of ACCENT member contributed in writing or verbally. Most of them had interactions with policy makers and/or the general public, and they generally believe that interactions with spheres other than the scientific are needed. While such interactions give personal insight and satisfaction, they seem to have little impact on the goals and the practice of the scientific work itself. Extended frameworks of science production that go beyond the disciplinary mode seem to emerge at the level of individual scientists, yet they still need to find their way to the level of scientific project management. In this paper we discuss the justifications and barriers to implement a higher degree of extended knowledge integration in applied science projects such as ACCENT. It is felt that the community of atmospheric chemists and physicists is mature for such an implementation and recommendations are given to help and make this happen. [Copyright &y& Elsevier]

The present investigation, carried out as a case study in a typical major city situated in a European coal combustion region (Krakow, Poland), aims at quantifying the impact on the urban air quality of residential heating by coal combustion in comparison with other potential pollution sources such as power plants, industry, and traffic. Emissions were measured for 20 major sources, including small stoves and boilers, and the particulate matter (PM) was analyzed for 52 individual compounds together with outdoor and indoor PM10 collected during typical winter pollution episodes. The data were analyzed using chemical mass balance modeling (CMB) and constrained positive matrix factorization (CMF) yielding source apportionments for PM10 B(a)P, and other regulated air pollutants namely Cd, Ni, As, and Pb. The results are potentially very useful for planning abatement strategies in all areas of the world, where coal combustion in small appliances is significant. During the studied pollution episodes in Krakow, European air quality limits were exceeded with up to a factor 8 for PM10 and up to a factor 200 for B(a)P. The levels of these air pollutants were accompanied by high concentrations of azaarenes, known markers for inefficient coal combustion. The major culprit for the extreme pollution levels was demonstrated to be residential heating by coal combustion in small stoves and boilers (>50% for PM10 and >90% B(a)P), whereas road transport (<10% for PM10 and <3% for B(a)P), and industry (4-15% for PM10 and <6% for B(a)P) played a lesser role. The indoor PM10 and B(a)P concentrations were at high levels similar to those of outdoor concentrations and were found to have the same sources as outdoors. The inorganic secondary aerosol component of PM10 amounted to around 30%, which for a large part may be attributed to the industrial emission of the precursors SO2 and NOx. [ABSTRACT FROM AUTHOR]

Despite the increase of commercial shipping around the world, data are yet relatively scarce on the contribution of these emissions to ambient air particulates. One of the reasons is the complexity in the detection and estimation of shipping contributions to ambient particulates in harbor and urban environments, given the similarity with tracers of other combustion sources. This study aimed to identify specific tracers of shipping emissions in a Mediterranean city with an important harbor (Melilla, Spain). Results showed that, for 24 h PM10 and PM2.5 samples, valid tracers of commercial shipping emissions were ratios of V/Ni = 4-5 and V/EC < 2, whereas V/EC > 8 excluded the influence of shipping emissions. Other ratios (V/ S, La/Ce, Zn/Ni, Pb/Zn, OC/EC) and tracers (Pb, Zn) were also tested but did not correlate with this source. Due to the changing composition of diesel fuels, tracers in the Mediterranean Sea may not be representative in other regions of the world and vice versa. The contribution of shipping emissions to ambient particulate matter (PM) urban background levels was quantified by positive matrix factorization (PMF), resulting in 2% and 4% of mean annual PM10 levels (0.8 μg/m3 primary particles and 1.7 μg/m3 secondary particles, with 20% uncertainty) and 14% of mean annual PM2.5 levels (2.6 μg/m3). [ABSTRACT FROM AUTHOR]

Remodelling works are frequent in harbour areas, given that they must adapt to rapidly changing market requirements. Depending on their nature (construction, demolition, etc.), these works may be carried out during long periods of time and thus exert a significant impact on the air quality at the harbours and their surroundings. The air quality at the Valencia harbour was studied during an enlargement project. Four sampling stations aimed to cover the major dust-emitting activities in the harbour. In addition, a sampling campaign was carried out to collect dust materials at their emission sources (e.g., loading and unloading of clinker and petroleum coke, as well as the enlargement works). Differences obtained between PM levels at the monitoring sites were correlated with the distance between sampling stations and enlargement works and/or harbour operations, as well as with the preferential wind direction. In all cases, the days with the highest PM_10 levels were linked to wind directions coinciding with the location of the enlargement works or the clinker and petroleum coke stocks. Classic source apportionment methodologies (PCA and CMB) were applied to the data, but their interpretation was complex due to the similar chemical signatures of PM originating from direct and fugitive emissions from stocked materials (e.g., clinker), and the enlargement works. To overcome this difficulty, a novel non-statistical approach was used to obtain quantitative estimations of the contributions from sources (petroleum coke and clinker), based on the correlation between specific PM components (e.g., carbonaceous species) and source tracers (e.g., V). Finally, a qualitative test using phenolphthalein was devised to identify the presence of clinker on the filters, which provided positive results. This novel tracer approach is thus recommended for harbour authorities. [Copyright &y& Elsevier]

In this study the purity of the germanium end-products obtained by two different precipitation methods carried out on germanium-bearing solutions was evaluated as a last step of a hydrometallurgy process for the recovery of this valuable element from the Puertollano Integrated Gasification Combined Cycle (IGCC) fly ash. Since H2S is produced as a by-product in the gas cleaning system of the Puertollano IGCC plant, precipitation of germanium as GeS2 was tested by sulfiding the Ge-bearing solutions. The technological and hazardous issues that surround H2S handling conducted to investigate a novel precipitation procedure: precipitation as an organic complex by adding 1,2-dihydroxy benzene pyrocatechol (CAT) and cetyltrimethylammonium bromide (CTAB) to the Ge-bearing solutions. Relatively high purity Ge end-products (90 and 93% hexagonal-GeO2 purity, respectively) were obtained by precipitating Ge from enriched solutions, as GeS2 sulfiding the solutions with H2S, or as organic complex with CAT/CTAB mixtures and subsequent roasting of the precipitates. Both methods showed high efficiency (>99%) to precipitate selectively Ge using a single precipitation stage from germanium-bearing solutions. [Copyright &y& Elsevier]

This work describes the first analytical method specifically developed for the multianalyte determination of several drugs of abuse and their metabolites in air. The methodology is based on pressurized liquid extraction (PLE) of atmospheric particles collected by means of high volume sampler equipped with quartz microfiber filters and subsequent analysis of the extracts by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Up to 17 different com- pounds belonging to five different chemical classes (cocainics, amphetamine-like compounds, opioids, cannabinoids, and lysergic compounds) are determined by means of this methodology. Acquisition is performed in the selected reaction monitoring (SRM) mode recording two transitions per compound (except for amphetamine). Quantitation by the internal standard method is based on the use of surrogated deuterated standards. The method has been validated in terms of linearity, accuracy, repeatability and sensitivity with satisfactory results. Absolute recoveries were above 50% for most investigated compounds. Method precision showed relative standard deviations (RSD) below 13% for all compounds, except for cannabinoids. The method limits of determination ranged from 0.35 pg/m3 (for 2-oxo- 3-hydroxy-LSD) to 22.55 pg/m3 (for 11-nor-9 carboxy THC). Finally, as a part of the method validation, the optimized procedure was applied to the analysis of ambient air samples (fine grain-size parliculates, PM2.5) collected at two urban background sites in Barcelona and Madrid (Spain). Results evidenced the presence of cocaine, benzoilecgonine, tetrahydrocannabinol, ecstasy, amphetamine, methamphetamine, and heroin in some or all of the samples investigated. The highest mean daily levels corresponded to cocaine (850 pg/m3) followed by heroin (143 pg/m3). [ABSTRACT FROM AUTHOR]

• Associations between sources of particle number concentrations and daily deaths. • Time series analysis was carried out for Barcelona, Helsinki, London and Zurich. • Daily photonucleation, fresh traffic, urban, and secondary source contributions. • Inconsistent associations across cities, sources and lags. • Risk increases were stronger for respiratory than for cardiovascular daily mortality. The evidence on the association between ultrafine (UFP) particles and mortality is still inconsistent. Moreover, health effects of specific UFP sources have not been explored. We assessed the impact of UFP sources on daily mortality in Barcelona, Helsinki, London, and Zurich. UFP sources were previously identified and quantified for the four cities: daily contributions of photonucleation, two traffic sources (fresh traffic and urban, with size mode around 30 nm and 70 nm, respectively), and secondary aerosols were obtained from data from an urban background station. Different periods were investigated in each city: Barcelona 2013–2016, Helsinki 2009–2016, London 2010–2016, and Zurich 2011–2014. The associations between total particle number concentrations (PNC) and UFP sources and daily (natural, cardiovascular [CVD], and respiratory) mortality were investigated using city-specific generalized linear models (GLM) with quasi-Poisson regression. We found inconsistent results across cities, sources, and lags for associations with natural, CVD, and respiratory mortality. Increased risk was observed for total PNC and natural mortality in Helsinki (lag 2; 1.3% [0.07%, 2.5%]), CVD mortality in Barcelona (lag 1; 3.7% [0.17%, 7.4%]) and Zurich (lag 0; 3.8% [0.31%, 7.4%]), and respiratory mortality in London (lag 3; 2.6% [0.84%, 4.45%]) and Zurich (lag 1; 9.4% [1.0%, 17.9%]). A similar pattern of associations between health outcomes and total PNC was followed by the fresh traffic source, for which we also found the same associations and lags as for total PNC. The urban source (mostly aged traffic) was associated with respiratory mortality in Zurich (lag 1; 12.5% [1.7%, 24.2%]) and London (lag 3; 2.4% [0.90%, 4.0%]) while the secondary source was associated with respiratory mortality in Zurich (lag 1: 12.0% [0.63%, 24.5%]) and Helsinki (4.7% [0.11%, 9.5%]). Reduced risk for the photonucleation source was observed for respiratory mortality in Barcelona (lag 2, −8.6% [−14.5%, −2.4%]) and for CVD mortality in Helsinki, as this source is present only in clean atmospheres (lag 1, −1.48 [−2.75, −0.21]). We found inconsistent results across cities, sources and lags for associations with natural, CVD, and respiratory mortality. [ABSTRACT FROM AUTHOR]

The physical characterisation of metrics representative of ambient air particle concentration is becoming a topic of great interest for urban air quality monitoring and human exposure assessment. In this article, the influence of sea breeze circulation and primary road traffic emissions on the relationship between the urban aerosol number (N3, particles >3nm), black carbon <10μm (BC), PM1, PM2.5, PM2.5–10 (PMx) concentrations was studied in a coastal city (Santa Cruz de Tenerife, Canary Islands). The daily cycles of sea and mountain breezes (inland during daylight and seaward at night) and road traffic emissions exerted a great, and well differentiated, influence on the BC, N3 and PMx concentrations. In this scenario, the following major aerosol features were observed: (1) fresh vehicle exhaust emissions resulted in high BC and N3 concentrations, in such a way that these two metrics increased when the “road traffic intensity (vehiclesh−1)/wind speed” ratio increased, (2) PM1 and PM2.5 levels were lower during daylight (due to inland entry of relatively clean marine air masses) than at night (due to the seaward drainage airflow resulting in the transport of aged particulate pollutants from the city), (3) although N3 and BC concentrations exhibited a significant correlation during the whole study period, the N3/BC ratio experienced a daily evolution with a maximum during daylight. Thus, high N3 concentrations associated with high N3/BC ratios and high solar irradiance conditions were recorded during the daylight inland breeze period due to an enhancement of processes favouring new particle formation. Data analysis points out that this enhancement in the new particle formation processes is strongly related to the nucleation of photo-oxidized vapours under the relatively low PMx (and consequently low aerosol surface area) concentrations prompted by the inland entry of clean marine air due to the daylight breeze blowing. The results obtained show that, in addition to the vehicle exhaust emissions, new particle formation in coastal urban areas due to photo-oxidation processes may significantly contribute to the ultrafine particle concentration. [Copyright &y& Elsevier]

Abstract: The (co)-firing of low-cost alternative fuels is expected to increase in the forthcoming years in the EU because of the economic and environmental benefits provided by this technology. This study deals with the impact of the different coal/waste fuel ratio of the feed blend on the mineralogy, the chemical composition and especially on the leaching properties of fly ash. Different blends of coal, petroleum coke, sewage sludge, wood pellets, coal tailings and other minor biomass fuels were tested in PCC (pulverised coal combustion) and FBC (fluidized bed combustion) power plants. The co-firing of the studied blends did not drastically modify the mineralogy, bulk composition or the overall leaching of the fly ash obtained. This suggests that the co-firing process using the alternative fuels studied does not entail significant limitations in the re-use or management strategies of fly ash. [Copyright &y& Elsevier]

Co-firing of coal with inexpensive secondary fuels such as petroleum coke is expected to increase in the near future in the EU given that it may provide certain economic and environmental benefits with respect to coal combustion. However, changes in the feed fuel composition of power plants may modify the bulk content and the speciation of a number of elements in fly ash and slag. Consequently, leachability of these byproducts also can be modified. This study is focused on identifying the changes in the environmental quality of co-fired fly ash and slag induced by a modification of the petcoke/coal ratio. Petcoke was found to increase the leachable content of V and Mo and to enhance the mobility of S and As. However, with the exception of these elements,the addition of this secondary fuel did not drastically modify the bulk composition or the overall leachability of the resulting fly ash and slag. [ABSTRACT FROM AUTHOR]

Outdoor levels of fine particles (PM2. 5; particles <2. 5μm) have been associated with cardiovascular health. Persons with existing cardiovascular disease have been suggested to be especially vulnerable. It is unclear, how well outdoor concentrations of PM2. 5 and its constituents measured at a central site reflect personal exposures in Southern European countries. The objective of the study was to assess the relationship between outdoor and personal concentrations of PM2. 5, absorbance and sulphur among post-myocardial infarction patients in Barcelona, Spain. Thirty-eight subjects carried personal PM2. 5 monitors for 24-h once a month (2–6 repeated measurements) between November 2003 and June 2004. PM2. 5 was measured also at a central outdoor monitoring site. Light absorbance (a proxy for elemental carbon) and sulphur content of filter samples were determined as markers of combustion originating and long-range transported PM2. 5, respectively. There were 110, 162 and 88 measurements of PM2. 5, absorbance and sulphur, respectively. Levels of outdoor PM2. 5 (median 17μgm3) were lower than personal PM2. 5 even after excluding days with exposure to environmental tobacco smoke (ETS) (median after exclusion 27μgm3). However, outdoor concentrations of absorbance and sulphur were similar to personal concentrations after exclusion of ETS. When repeated measurements were taken into account, there was a statistically significant association between personal and outdoor absorbance when adjusting for ETS (slope 0. 66, p<0. 001), but for PM2. 5 the association was weaker (slope 0. 51, p=0. 066). Adjustment for ETS had little effect on the respective association of S (slope 0. 69, p<0. 001). Our results suggest that outdoor measurements of absorbance and sulphur can be used to estimate both the daily variation and levels of personal exposures also in Southern European countries, especially when exposure to ETS has been taken into account. For PM2. 5, indoor sources need to be carefully considered. [Copyright &y& Elsevier]