title: Trends and sources vs air mass origins in a major city in South-western Europe: Implications for air quality management.
abstract: This study presents a 17-years air quality database comprised of different parameters corresponding to the largest city in the south of Spain (Seville) where atmospheric pollution is frequently attributed to traffic emissions and is directly affected by Saharan dust outbreaks. We identify the PM10 contributions from both natural and anthropogenic sources in this area associated to different air mass origins. Hourly, daily and seasonal variation of PM10 and gaseous pollutant concentrations (CO, NO2 and SO2), all of them showing negative trends during the study period, point to the traffic as one of the main sources of air pollution in Seville. Mineral dust, secondary inorganic compounds (SIC) and trace elements showed higher concentrations under North African (NAF) air mass origins than under Atlantic. We observe a decreasing trend in all chemical components of PM10 under both types of air masses, NAF and Atlantic. Principal component analysis using more frequent air masses in the area allows the identification of five PM10 sources: crustal, regional, marine, traffic and industrial. Natural sources play a more relevant role during NAF events (20.6 μg · m(-3)) than in Atlantic episodes (13.8 μg · m(-3)). The contribution of the anthropogenic sources under NAF doubles the one under Atlantic conditions (33.6 μg · m(-3) and 15.8 μg · m(-3), respectively). During Saharan dust outbreaks the frequent accumulation of local anthropogenic pollutants in the lower atmosphere results in poor air quality and an increased risk of mortality. The results are relevant when analysing the impact of anthropogenic emissions on the exposed population in large cities. The increase in potentially toxic elements during Saharan dust outbreaks should also be taken into account when discounting the number of exceedances attributable to non-anthropogenic or natural origins.
authors.affiliation: Associate Unit CSIC-University of Huelva "Atmospheric Pollution", Centre of Research in Sustainable Chemistry-CIQSO, Campus de El Carmen s/n, 21071 Huelva, Spain; Department of Geology, Faculty of Experimental Sciences, University of Huelva, Huelva, Spain. Electronic address: rocio.fernandez@dgeo.uhu.es.
authors.forename: R
authors.initials: R
authors.lastname: Fernández-Camacho
authors.affiliation: Associate Unit CSIC-University of Huelva "Atmospheric Pollution", Centre of Research in Sustainable Chemistry-CIQSO, Campus de El Carmen s/n, 21071 Huelva, Spain; Department of Geology, Faculty of Experimental Sciences, University of Huelva, Huelva, Spain; Agrifood Campus of International Excellence CEIA3, Spain; Campus of International Excellence of the Sea CEIMAR, Spain.
authors.forename: J D
authors.initials: JD
authors.lastname: de la Rosa
authors.affiliation: Associate Unit CSIC-University of Huelva "Atmospheric Pollution", Centre of Research in Sustainable Chemistry-CIQSO, Campus de El Carmen s/n, 21071 Huelva, Spain; Department of Geology, Faculty of Experimental Sciences, University of Huelva, Huelva, Spain.
authors.forename: A M
authors.initials: AM
authors.lastname: Sánchez de la Campa
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data*; D001272:Atmosphere / Q000737:chemistry; D002947:Cities / Q000706:statistics & numerical data; D004784:Environmental Monitoring; D058735:Environmental Policy; D013030:Spain
chemical_list: D000393:Air Pollutants
keywords: Air masses; Saharan dust outbreaks; Source contribution; Traffic; Trend