Page Last modified 20 Apr 2016


This report summarises the annual information on ozone monitoring stations and exceedances of ozone threshold values during 1995 transmitted by the Member States in the framework of Council Directive 92/72/EEC on air pollution by ozone. On 6 August 1996 information for the calendar year 1995 had been received from all 15 Member States. All information has been submitted in computer readable form.

An evaluation of the exceedances and annual statistics for 1995 is presented.

The following conclusions are reached:

  • Ozone monitoring data for the year 1995 have been received from 858 stations within the 15 EU Member States. The quality and quantity of the information supplied by the Member States for 1995 is strongly improved compared to 1994.
  • Spatial coverage and documentation on monitoring data quality need improvement. Depending on the local situation, the ozone monitoring stations are characterized as rural, urban, street or other (e.g. industrial). The present subset of rural stations is not representative for the land area of the EU: the subset is estimated to cover only 40-50%. The geographical coverage of the rural stations is rather adequate in North West Europe but in other regions gaps are noted. The subset of urban stations is insufficient to estimate the exposure of the population living in cities with more than 25 000 inhabitants: the urban stations cover at most 30% of the urban population.
  • The threshold value set for the protection of human health is exceeded substantially and in all Member States. The subset of urban stations is assumed to give representative values for the exposure of an urban population of c. 58 million people. 78% of this population is exposed to ozone levels exceeding the threshold during at least one day; 9% is exposed to exceedances during more than 50 days. On the average the EU city population is exposed to concentrations above the threshold during 1-2 consecutive days. Maximum episode lengths of 5-8 days have been reported.
  • The threshold value of daily average concentrations set for the protection of vegetation is exceeded substantially (by up to a factor 3), widely (in all reporting Member States) and frequently (several Member States report exceedances during more than 150 days at some of their stations). In less than 1% of the area for which the subset of rural stations report representative values, this threshold value is not exceeded; exceedances during more than 150 days are estimated for more than 27% of the area.

The threshold value of hourly average concentrations is exceeded largely and widely (reported by 14 Member States) on a limited number of days: in 13% of the mapped area exceedances during more than 5 days are reported.

  • The threshold value for providing information to the population has been exceeded in allmost all EU Member States during a limited number of days. Exceedance of the threshold value for warning of the population has been reported from one station.

A limited presentation of the percentile values observed in the period 1989-1995 is given for four Member States for which this information was available. No significant trend in percentile values has been observed in this seven year period.

European Environment Agency (EEA)
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