We demonstrate that there is great variation in the size range and chemical composition of metalliferous particulate matter (PM) present within petrochemical complex chimney stacks. Cascade impactor PM samples from seven size ranges (17, 14, 5, 2.5, 1.3, 0.67, and 0.33 mu m) were collected from inside stacks within the San Roque complex which includes the largest oil refinery in Spain. SEM analysis demonstrates the PM to be mostly carbonaceous and aluminous fly ash and abundant fine metalliferous particles. The metals with the most extreme concentrations averaged over all size ranges were Ni (up to 3295 mu g m(-3)), Cr (962 mu g m(-3)), V (638 mu g m(-3)), Zn (225 mu g m(-3)), Mo (91 mu g m(-3)), La (865 mu g m(-3)), and Co (94 mu g m(-3)). Most metal PM are strongly concentrated into the finest fraction (200 mu g m(-3) in PM(0.67-1.3)). Cr and Ni in a relatively coarse PM size range (0.7-14 mu m). Our unique database, directly sampled from chimney stacks, confirms that oil refinery complexes such as San Roque are a potent source of a variety of fine, deeply inhalable metalliferous atmospheric PM emissions ; This study was supported by the Department of the Environment and the Department of Innovation, Science and Enterprise (project RNM2007-02729) of the Autonomous Government of Andalusia, and Projects GRACCIE-CSD2007 of the Spanish Ministry of Science and Innovation. The authors are indebted to Juan Contreras, Francisca Godoy and Antonio Lozano of the Department of Air Quality in the Environmental Office of Andalusia Government for their collaboration with this study. Thanks are due to Wes Gibbons for his revision of the manuscript.
This study is the first to investigate the mineral composition of the atmospheric particulate matter deposited at Rio Tinto, Spain, an historical mining district of world-class importance, with emphasis on metal-bearing particles and their environmental implications. The dustfall is composed of quartz, feldspars, phyllosilicates (mica, chlorite and/or kaolinite) and a variety of accessory heavy minerals, the most common being primary sulfides (pyrite, chalcopyrite with minor galena, sphalerite and bornite) and their oxidation products (notably goethite, hematite and jarosite). This mineral assemblage suggests a local source of wind-blown dust and it is consistent with the large deposition levels of sulfide-related elements (As, Bi, Cd, Cu, Pb, Sb and Zn) registered at the sampling site adjacent to the mine waste dumps. However, the generation of potentially harmful dust particles is not restricted to mine wastes. Anthropogenic metallic compounds arising from a nearby hazardous waste disposal centre can make a relevant additional contribution to the metal deposition, particularly for Fe, Ni, Cr and Mn. Atmospheric fallout is a major mechanism for metal input to soils and plants around or near the mining area. ; This study was supported by grants from the Spanish Ministry of Science and Innovation (Projects CRACCIE-CSD2007-0067 and CGL2008-06270-C02-02/CLI) and the Department of the Environment, and the Department of Innovation, Science and Enterprise (Projects RNM2007-02729 and RNM2009-5163M) of the Andalusia Autonomous Government. Karen Hudson-Edwards and an anonymous reviewer are thanked for their constructive comments and suggestions.
An analysis of chemical composition data of particulate matter samples (TSP, PM10 and PM2.5) collected from 2002 to 2008 in the North Atlantic free troposphere at the Izana Global Atmospheric Watch (GAW) observatory (Tenerife, Canary Islands) shows that desert dust is very frequently mixed with particulate pollutants in the Saharan Air Layer (SAL). The study of this data set with Median Concentrations At Receptor (MCAR) plots allowed the identification of the potential source regions of the dust and particulate pollutants. Areas located at the south of the southern slope of the Atlas mountains emerge as the most frequent source of the soil desert dust advected to the northern edge of the SAL in summer. Industrial emissions occurring in Northern Algeria, Eastern Algeria, Tunisia and the Atlantic coast of Morocco appear as the most important source of the nitrate, ammonium and a fraction of sulphate (at least 60% of the sulphate <10 mu m transported from some regions) observed in the SAL. These emissions are mostly linked to crude oil refineries, phosphate-based fertilizer industry and power plants. Although desert dust emissions appear as the most frequent source of the phosphorous observed in the SAL, high P concentrations are observed when the SAL is affected by emissions from open mines of phosphate and phosphate based fertilizer industry. The results also show that a significant fraction of the sulphate (up to 90% of sulphate <10 mu m transported from some regions) observed in the SAL may be influenced by soil emissions of evaporite minerals in well defined regions where dry saline lakes (chotts) are present. These interpretations of the MCAR plots are consistent with the results obtained with the Positive Matrix Factorization PMF2) receptor modelling. The results of this study show that North African industrial pollutants may be mixed with desert dust and exported to the North Atlantic in the Saharan Air Layer. ; This study has been carried out within the Global Atmospheric Watch Program (financed by AEMET), and in the framework of the research projects GRACCIE (CSD2007-00067; Ministry of Science and Innovation of Spain), CARIATI (CGL2008-06294/CLI; Ministry of Science and Innovation of Spain), AER-REG (P07-RNM-03125; Department of Innovation, Science and Enterprise of the Government of Andalusia) and REDMAAS (CGL2010-11095-E; Ministry of Science and Innovation of Spain). We thank NOAA Air Resources Laboratory for the facilities (software and data) for determining back-trajectories, NOAA Earth System Research Laboratory for providing meteorological tools, NASA Goddard Earth Sciences Data and Information Service Centre (Giovanni service) for providing Aerosol Index data and Google Earth (TM), Google map (TM) and Panoramio (TM). We distinguish the excellent work performed by the staff in charge of the aerosol sampling: Fernando de Ory, Carlos Torres, Virgilio Varreno, Candida Hernandez, Julian Perez, Daniel Martin, Ruben Del Campo, Cesar Lopez, Marco Hernandez, Damian Exposito, Antonio Hernandez and Jose Hernandez.
Black carbon (BC) has been simulated for south-west Spain with the air quality model CAMx driven by the MM5 meteorological model, with a spatial resolution of 2 km × 2 km and a temporal resolution of 1 h. The simulation results were evaluated against hourly equivalent black carbon (EBC) concentrations obtained in the cities of Seville and Huelva for a winter period (January 2013) and a summer period (June 2013). A large seasonal variability was observed in PM2.5 EBC concentration in the two cities, with higher concentrations in wintertime; summertime EBC concentrations were typically less than half those of the wintertime. The model captured the large diurnal, seasonal and day to day variability in these urban areas, mean biases ranged between −0.14 and 0.07 μg m−3 in winter and between 0.01 and 0.29 μg m−3 in summer while hourly PM2.5 EBC observations ranged between 0.03 μg m−3 to 10.9 μg m−3. The diurnal variation in EBC concentrations was bimodal, with a morning and evening peak. However, the EBC evening peak was much smaller in summer than in winter. The modelling analysis demonstrates that the seasonal and day to day variability in EBC concentration in these urban areas is primarily driven by the variation in meteorological conditions. An evaluation of the role of regional versus local contributions to EBC concentrations indicates that in the medium size city of Seville, local on-road sources are dominant, whereas in the small size city of Huelva, local as well as regional sources produce a similar contribution. Considering the large diesel share of the vehicle fleet in Spain (currently ∼ 56%), we conclude that continued reduction of BC from diesel on-road sources in these urban areas is indeed a priority, and we suggest that targeted mitigation strategies, for example reducing the heaviest emitters in wintertime, would yield the greatest benefits. ; The authors gratefully acknowledge funding from the Department of Innovation, Science and Enterprise of the Government of Andalusia through the research projects SIMAND (P07-RNM-02729) and (2011RNM-7800) and from the Department of Environment, Andalusian Regional Government (project: 199/2011/C/00). In addition, we thank the Spanish Ministry of Economy and Competitiveness for funding through the project POLLINDUST (CGL2011-26259). We would also like to thank the Government of Andalusia for providing data from their Air Quality Network and from their Atmospheric Emissions Inventory and AEMET for providing meteorological data. We also thank Dr. Fantine Ngan for providing the GEOS-Chem data.
A long-term series (2001–2008) of chemical analysis of atmospheric particulate matter (PM10 and PM2.5) collected in the city of Huelva (SW Spain) is considered in this study. The impact of emission plumes from one of the largest Cu-smelters in the world on air quality in the city of Huelva is evidenced by the high daily and hourly levels of As, other potentially toxic elements (e.g. Cu, Zn, Cd, Se, Bi, and Pb) in particulate matter, as well as the high levels of some gaseous pollutants (NO2 and SO2). Mean arsenic levels in the PM10 fraction were higher than the target value set by European Directive 2004/ 107/EC (6 ngAs m 3) for 1st January 2013. Hourly peak concentrations of As and other metals and elements (Zn, Cu, P and Se) analyzed by PIXE can reach maximum hourly levels as high as 326 ngAs m 3, 506 ngZn m 3, 345 ngCu m 3, 778 ngP m 3 and 12 ngSe m 3. The contribution of Cu-smelter emissions to ambient PM is quantified on an annual basis in 2.0–6.7 mg m 3 and 1.8–4.2 mg m 3 for PM10 and PM2.5, respectively. High resolution outputs of the HYSPLIT dispersion model show the geographical distribution of the As ambient levels into the emission plume, suggesting that the working regime of the Cu-smelter factory and the sea breeze circulation are the main factors controlling the impact of the Cu-smelter on the air quality of the city. The results of this work improve our understanding of the behaviour of industrial emission plumes and their impact on air quality of a city, where the population might be exposed to very high ambient concentrations of toxic metals during a few hours. ; This work was developed within the framework of project CGL2005-05693-C03-01 and was funded by the Spanish Ministry of Science and Innovation, and Project CS2007-0067 GRACCIE by the Spanish Ministry of Science and Innovation. Also, we would like to thank the Autonomous Government of Andalusia for financing this work (Projects 2007-RNM 02729 and RNM-03125). We would like to thank the NOAA Air Resources Laboratory (ARL) for providing the HYSPLIT transport and dispersion model. Thanks also go to the NASA/Goddard Space Flight Center, Laboratory for Atmospheres, Greenbelt (MD, USA), the Atmospheric Modeling and Weather Forecasting Group from the University of Athens and NASA's SeaWIFS Project for the valuable information supplied by the TOMS and SKIRON aerosol maps and satellite images.
In many large cities of Europe standard air quality limit values of particulate matter (PM) are exceeded. Emissions from road traffic and biomass burning are frequently reported to be the major causes. As a consequence of these exceedances a large number of air quality plans, most of them focusing on traffic emissions reductions, have been implemented in the last decade. In spite of this implementation, a number of cities did not record a decrease of PM levels. Thus, is the efficiency of air quality plans overestimated? Do the road traffic emissions contribute less than expected to ambient air PM levels in urban areas? Or do we need a more specific metric to evaluate the impact of the above emissions on the levels of urban aerosols? This study shows the results of the interpretation of the 2009 variability of levels of PM, Black Carbon (BC), aerosol number concentration (N) and a number of gaseous pollutants in seven selected urban areas covering road traffic, urban background, urban-industrial, and urban-shipping environments from southern, central and northern Europe. The results showed that variations of PM and N levels do not always reflect the variation of the impact of road traffic emissions on urban aerosols. However, BC levels vary proportionally with those of traffic related gaseous pollutants, such as CO, NO2 and NO. Due to this high correlation, one may suppose that monitoring the levels of these gaseous pollutants would be enough to extrapolate exposure to traffic-derived BC levels. However, the BC/CO, BC/NO2 and BC/NO ratios vary widely among the cities studied, as a function of distance to traffic emissions, vehicle fleet composition and the influence of other emission sources such as biomass burning. Thus, levels of BC should be measured at air quality monitoring sites. During morning traffic rush hours, a narrow variation in the N/BC ratio was evidenced, but a wide variation of this ratio was determined for the noon period. Although in central and northern Europe N and BC levels tend to vary simultaneously, not only during the traffic rush hours but also during the whole day, in urban background stations in southern Europe maximum N levels coinciding with minimum BC levels are recorded at midday in all seasons. These N maxima recorded in southern European urban background environments are attributed to midday nucleation episodes occurring when gaseous pollutants are diluted and maximum insolation and O3 levels occur. The occurrence of SO2 peaks may also contribute to the occurrence of midday nucleation bursts in specific industrial or shipping-influenced areas, although at several central European sites similar levels of SO2 are recorded without yielding nucleation episodes. Accordingly, it is clearly evidenced that N variability in different European urban environments is not equally influenced by the same emission sources and atmospheric processes. We conclude that N variability does not always reflect the impact of road traffic on air quality, whereas BC is a more consistent tracer of such an influence. However, N should be measured since ultrafine particles (<100 nm) may have large impacts on human health. The combination of PM10 and BC monitoring in urban areas potentially constitutes a useful approach for air quality monitoring. BC is mostly governed by vehicle exhaust emissions, while PM10 concentrations at these sites are also governed by non-exhaust particulate emissions resuspended by traffic, by midday atmospheric dilution and by other non-traffic emissions. ; This work was funded by the Spanish Ministry of Science and Innovation (VAMOS CGL2010-19464/CLI; DAURE CGL2007-30502-E/CLI, GRACCIE-CSD2007-00067), Department of Inovation, Science and Enterprise of the Andalusian Autonomous Government (AER-REG-P07-RNM-03125), the Ministry of the Environment and Rural and Marine Affairs, and the 7th FP from the EC project SAPUSS (Marie Curie intra-European Fellowship). The authors acknowledge the Departament de Territori i Sostenibilitat from Generalitat de Catalunya, Gobierno de Canarias and Junta de Andalucia (Spain), DEFRA (UK) and the Swiss Federal Office for the Environment (FOEN) for providing the data.
