title: Past, present and future concentrations of ground-level ozone and potential impacts on ecosystems and human health in northern Europe.
abstract: This review summarizes new information on the current status of ground-level ozone in Europe north of the Alps. There has been a re-distribution in the hourly ozone concentrations in northern Europe during 1990-2015. The highest concentrations during summer daytime hours have decreased while the summer night-time and winter day- and night-time concentrations have increased. The yearly maximum 8-h mean concentrations ([O3]8h,max), a metric used to assess ozone impacts on human health, have decreased significantly during 1990-2015 at four out of eight studied sites in Fennoscandia and northern UK. Also the annual number of days when the yearly [O3]8h,maxexceeded the EU Environmental Quality Standard (EQS) target value of 60ppb has decreased. In contrast, the number of days per year when the yearly [O3]8h,maxexceeded 35ppb has increased significantly at two sites, while it decreased at one far northern site. [O3]8h,maxis predicted not to exceed 60ppb in northern UK and Fennoscandia after 2020. However, the WHO EQS target value of 50ppb will still be exceeded. The AOT40 May-July and AOT40 April-September metrics, used for the protection of vegetation, have decreased significantly at three and four sites, respectively. The EQS for the protection of forests, AOT40 April-September 5000ppbh, is projected to no longer be exceeded for most of northern Europe sometime before the time period 2040-2059. However, if the EQS is based on Phytotoxic Ozone Dose (POD), POD1, it may still be exceeded by 2050. The increasing trend for low and medium range ozone concentrations in combination with a decrease in high concentrations indicate that a new control strategy, with a larger geographical scale than Europe and including methane, is needed for ozone abatement in northern Europe.
authors: Swedish Environmental Research Institute, P.O. Box 53021, SE 40014 Gothenburg, Sweden. Electronic address: pererik.karlsson@ivl.se.
authors: Per Erik
authors: PE
authors: Karlsson
authors: University of Gothenburg, Department of Biological and Environmental Sciences, P.O. Box 461, 40530 Gothenburg, Sweden; University of Gothenburg, Department of Earth Sciences, P.O. Box 460, 40530 Gothenburg, Sweden.
authors: Jenny
authors: J
authors: Klingberg
authors: Swedish Meteorological and Hydrological Institute, SE 60176 Norrköping, Sweden.
authors: Magnuz
authors: M
authors: Engardt
authors: Swedish Meteorological and Hydrological Institute, SE 60176 Norrköping, Sweden.
authors: Camilla
authors: C
authors: Andersson
authors: Swedish Meteorological and Hydrological Institute, SE 60176 Norrköping, Sweden.
authors: Joakim
authors: J
authors: Langner
authors: Swedish Environmental Research Institute, P.O. Box 53021, SE 40014 Gothenburg, Sweden.
authors: Gunilla Pihl
authors: GP
authors: Karlsson
authors: University of Gothenburg, Department of Biological and Environmental Sciences, P.O. Box 461, 40530 Gothenburg, Sweden.
authors: Håkan
authors: H
authors: Pleijel
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D017753:Ecosystem; D004784:Environmental Monitoring; D005060:Europe; D006801:Humans; D010126:Ozone / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D010126:Ozone
keywords: Air quality standards; Climate change; Ground level ozone; Ozone models; Ozone trends