title: Urban NH3 levels and sources in six major Spanish cities.
abstract: A detailed spatial and temporal assessment of urban NH3 levels and potential emission sources was made with passive samplers in six major Spanish cities (Barcelona, Madrid, A Coruña, Huelva, Santa Cruz de Tenerife and Valencia). Measurements were conducted during two different periods (winter-autumn and spring-summer) in each city. Barcelona showed the clearest spatial pattern, with the highest concentrations in the old city centre, an area characterised by a high population density and a dense urban architecture. The variability in NH3 concentrations did not follow a common seasonal pattern across the different cities. The relationship of urban NH3 with SO2 and NOX allowed concluding on the causes responsible for the variations in NH3 levels between measurement periods observed in Barcelona, Huelva and Madrid. However, the factors governing the variations in A Coruña, Valencia and Santa Cruz de Tenerife are still not fully understood. This study identified a broad variability in NH3 concentrations at the city-scale, and it confirms that NH3 sources in Spanish urban environments are vehicular traffic, biological sources (e.g. garbage containers), wastewater treatment plants, solid waste treatment plants and industry. The importance of NH3 monitoring in urban environments relies on its role as a precursor of secondary inorganic species and therefore PMX. Further research should be addressed in order to establish criteria to develop and implement mitigation strategies for cities, and to include urban NH3 sources in the emission inventories.
authors.affiliation: Institute of Environmental Assessment and Water Research (IDÆA-CSIC), Barcelona, Spain. Electronic address: cristina.reche@idaea.csic.es.
authors.forename: Cristina
authors.initials: C
authors.lastname: Reche
authors.affiliation: Institute of Environmental Assessment and Water Research (IDÆA-CSIC), Barcelona, Spain.
authors.forename: Mar
authors.initials: M
authors.lastname: Viana
authors.affiliation: Institute of Environmental Assessment and Water Research (IDÆA-CSIC), Barcelona, Spain.
authors.forename: Angeliki
authors.initials: A
authors.lastname: Karanasiou
authors.affiliation: Institute of Environmental Assessment and Water Research (IDÆA-CSIC), Barcelona, Spain.
authors.forename: Michael
authors.initials: M
authors.lastname: Cusack
authors.affiliation: Institute of Environmental Assessment and Water Research (IDÆA-CSIC), Barcelona, Spain.
authors.forename: Andrés
authors.initials: A
authors.lastname: Alastuey
authors.affiliation: Department of Environment, CIEMAT, Joint Research Unit to CSIC-CIEMAT "Atmospheric Pollution", Madrid, Spain.
authors.forename: Begoña
authors.initials: B
authors.lastname: Artiñano
authors.affiliation: Development and Applications Department, AEMET, Madrid, Spain.
authors.forename: M Aranzazu
authors.initials: MA
authors.lastname: Revuelta
authors.affiliation: Faculty of Sciences, University of A Coruña, A Coruña, Spain.
authors.forename: Purificación
authors.initials: P
authors.lastname: López-Mahía
authors.affiliation: Faculty of Sciences, University of A Coruña, A Coruña, Spain.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Blanco-Heras
authors.affiliation: Izaña Atmospheric Research Centre, AEMET, Joint Research Unit to CSIC 'Studies on Atmospheric Pollution', Santa Cruz de Tenerife, Canary Islands, Spain.
authors.forename: Sergio
authors.initials: S
authors.lastname: Rodríguez
authors.affiliation: Associate Unit CSIC-University of Huelva "Atmospheric Pollution", Centre of Research of Sustainable Chemistry (CIQSO), Campus of Excellence CEIA, University of Huelva, Huelva, Spain.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Sánchez de la Campa
authors.affiliation: Associate Unit CSIC-University of Huelva "Atmospheric Pollution", Centre of Research of Sustainable Chemistry (CIQSO), Campus of Excellence CEIA, University of Huelva, Huelva, Spain.
authors.forename: Rocío
authors.initials: R
authors.lastname: Fernández-Camacho
authors.affiliation: Associate Unit CSIC-University of Huelva "Atmospheric Pollution", Centre of Research of Sustainable Chemistry (CIQSO), Campus of Excellence CEIA, University of Huelva, Huelva, Spain.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: González-Castanedo
authors.affiliation: Fundación Centro de Estudios Ambientales del Mediterráneo (CEAM), Joint Research Unit to CSIC, Parque Tecnologico, Valencia, Spain.
authors.forename: Enrique
authors.initials: E
authors.lastname: Mantilla
authors.affiliation: Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian EH26 0QB, UK.
authors.forename: Y Sim
authors.initials: YS
authors.lastname: Tang
authors.affiliation: Institute of Environmental Assessment and Water Research (IDÆA-CSIC), Barcelona, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Querol
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000641:Ammonia / Q000032:analysis*; D002947:Cities; D004784:Environmental Monitoring; D012621:Seasons; D013030:Spain
chemical_list: D000393:Air Pollutants; D000641:Ammonia
keywords: Ammonia; Reactive nitrogen; SIA; Spain; Urban sources