title: Ozone levels in European and USA cities are increasing more than at rural sites, while peak values are decreasing.
abstract: Ground-level ozone (O3) levels are usually lower in urban centers than nearby rural sites. To compare trends in O3 levels during the period 1990-2010, we obtained monitoring data from paired urban and rural sites from the European Environment Agency and the US Environmental Protection Agency. Ozone peaks decreased at both station types, with no significant differences between urban and rural stations. Ozone annual averages increased at both urban and rural sites, with a faster rate of increase for urban centers. The overall trend was for convergence between urban and rural O3 data. Ozone levels exceeded the criteria established for the protection of human and vegetation health at both urban and rural sites.
authors.affiliation: IPSP-CNR, Florence, Italy. Electronic address: elena.paoletti@cnr.it.
authors.forename: Elena
authors.initials: E
authors.lastname: Paoletti
authors.affiliation: ENEA, Rome, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: De Marco
authors.affiliation: National Centre for Atmospheric Science, School of Geography, Earth & Environmental Sciences, University of Birmingham, B15 2TT, United Kingdom.
authors.forename: David C S
authors.initials: DC
authors.lastname: Beddows
authors.affiliation: National Centre for Atmospheric Science, School of Geography, Earth & Environmental Sciences, University of Birmingham, B15 2TT, United Kingdom.
authors.forename: Roy M
authors.initials: RM
authors.lastname: Harrison
authors.affiliation: Dept Plant, Soil Insect Sciences, Univ. Massachusetts, Amherst, USA.
authors.forename: William J
authors.initials: WJ
authors.lastname: Manning
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data*; D002947:Cities / Q000706:statistics & numerical data*; D004784:Environmental Monitoring; D006801:Humans; D010126:Ozone / Q000032:analysis*; D014481:United States
chemical_list: D000393:Air Pollutants; D010126:Ozone
keywords: Air quality; Protection of human health; Protection of vegetation; Tropospheric ozone; Urban air pollution