Title; Table of Contents; Preface and Summary
POLLUTION BY OZONE IN EUROPE
in 1997 and Summer 1998
Topic Report no. 03/1999 part I - European Topic Centre on Air Quality
Frank de Leeuw, Rob Sluyter and Tim de Paus
This report was prepared under the supervision of:
Gabriel Kielland, Project Manager European Environment Agency
|Table of contents|
EXCEEDANCE OF OZONE THRESHOLD VALUES IN EUROPE IN 1997.
2.2 Data handling
4.1 Geographic coverage of monitoring stations
4.2 Annual statistics, 1997
4.3 Exceedances of thresholds in 1997
4.3.1 Exceedances of the threshold value for protection of human health
4.3.2 Exceedances of the threshold values for information and warning of the population
4.3.3 Exceedances of the daily threshold value for protection of vegetation
4.3.4 Exceedance of the hourly threshold value for protection of vegetation
4.5 Preliminary review of exceedances of the revised guidelines of WHO
4.6 Data reported for 1994-1997
INFORMATION DOCUMENT CONCERNING AIR POLLUTION BY OZONE
Overview of the situation in the European Union during the
1998 summer season (April-August)
3.1 Geographical distribution
3.2 Comparison with earlier years
This report is based upon data submitted to the European Commission under the Directive
92/72/EEC on air pollution by ozone. The Commission has requested the European Environment
Agency (EEA) to assist in this annual reporting by EU Member States since 1995. The
voluntary submission to the EEA of information on ozone levels by other European countries
made it possible to present an ozone assessment on a wider European scale. The data
collection in Phare countries was greatly facilitated by the Phare Topic Link on Air
Quality working as part of the European Topic Centre on Air Quality. Two separate reports,
one covering the year 1997, the other covering summer 1998, were originally produced by
the European Topic Centre on Air Quality and presented to the Member States in their
meeting of November 1998. The separate reports are available in electronic form on the EEA homepage on the Internet.
In this topic report, the annual 1997 and summer 1998 reports are reproduced in their original form as presented to the Commission. The differences in available data, the set of threshold values, the number of stations, the location of stations and the status of the information (based on validated 1997 data and non-validated 1998 data) justifies such an approach.
A major asset of this report is the timeliness of its delivery. The assessment of ozone episodes in 1998 was based upon data measured only two months earlier, while the normal production time from field measurements to validated assessment reports is rarely less than eighteen months. This timely reporting has only been possible with the support of the individual contact points within each Member State and the efficient communication established.
The harmful effects of tropospheric ozone on human health and well-being as well as damage to ecosystems is now being recognised as a major concern throughout the European Union. The European Community has taken steps to address the problem through Directive 92/72/EEC on ambient ozone, Directive 96/62/EEC on ambient air quality assessment and management (the Framework Directive), and development of an ozone daughter Directive, as well as the decision to develop a Community strategy for the reduction of ozone pollution. The measures necessary to abate pollution remain however a responsibility of each Member States and require political decisions with cost implications and consequences for the development of activities in the society. In this political process objective and reliable information on the extent and severity of the problem is essential.
It is the intention of EEA to continue a yearly reporting and assessment of the ground level ozone situation in Europe in close co-operation with the European Commission.
This report summarises the annual information on ozone monitoring stations and exceedances of ozone threshold values during 1997 and gives a first evaluation of the observed exceedances of the thresholds during Summer 1998 (April-August). According to the Council Directive 92/72/EEC on air pollution by ozone, EU Member States have to provide information on ozone levels (statistical parameters, number and duration of exceedances of specified threshold values) on an annual basis before 1 July of the next year. Additionally, exceedances of the threshold values for population information and warning, as set in the Directive, must be reported to the Commission within one month after occurrence.
The analysis for the year 1997 presented in this report is based on information made available before 12 August 1998. By then, information for the calendar year 1997 was received from all Member States and, on a voluntary basis, from 5 other European countries (Switzerland, Czech Republic, Latvia, Norway and Poland). Information on the situation in Slovakia was received one month later; unfortunately too late to include fully in this report. All information has been submitted in computer readable form.
For the summer 1998-period, all 15 EU Member States provided information on the observed exceedances in time (the deadline for transmitting data was set at 20 September 1998), or indicated that no exceedances were observed. It is greatly appreciated by the Commission that Member States were able to transmit August exceedance data before the formal deadline as set in the Directive. Some countries submitted files which were not formatted according to the prescribed Commission requirements. These files by exception were converted at the European Topic Centre on Air Quality (ETC-AQ) for further processing.
From an evaluation of the exceedances and annual statistics, the following conclusions are drawn:
- In 1997 the threshold value set for the protection of human health (110 µg/m3
for 8-hourly average concentrations) was exceeded substantially and in all reporting
countries: the total number of exceedances reported for stations within in the EU
approached 20,000; on the average, this threshold was exceeded per station on more than 23
days per year.
- In 1997 the threshold value of daily average concentrations set for the protection of
vegetation (65 µg/m3) was exceeded substantially (by up to a factor 3), widely
(in all reporting countries) and frequently: at 52 stations located in 10 different
countries exceedances have been reported during more than 200 days.
- The threshold value of hourly average concentrations set for the protection of
vegetation (200 µg/m3) was exceeded largely and widely (reported by 10 EU
Member States and in three out of the six other European countries) on a limited number of
days (in total 909 exceedance days were counted at EU monitoring stations).
- In 1997 the threshold value for providing information to the population (180 µg/m3
for hourly values) was exceeded in 15 countries of which 12 EU Member States during a
limited number of days: in EU Member States a total of 2336 exceedance days was counted.
During Summer 1998 this threshold was exceeded in all Member States with the exception of
Ireland, Finland, Denmark and Sweden. The number of days on which at least one exceedance
was observed ranged from 7 in Belgium to 74 in Spain. 61 % of all stations reported one or
more exceedance. On average 3.9 exceedances occurred this year at stations which recorded
at least one exceedance; the average exceedance duration was 2.7 hours. The average
maximum hourly concentration during an exceedance of the threshold this year was 201 µg/m3.
- Exceedance of the threshold value for warning of the population was reported in 1997
from one station (on 18 June 1997, 13.00 an hourly ozone concentration of 383 µg/m3
was measured at Lykovrissi, Athens, Greece). The threshold was exceeded on three days
during summer 1998 in the Athens conurbation (2 and 3 July 1998 at 2 stations, 29 July
1998 at 1 station) and at 1 station on 7 August 1998 in France.
- Ozone monitoring data for the year 1997 were received from 984 stations within the EU
and from 100 stations in other countries; during Summer 1998 a comparable number of
stations was operational.
- Spatial coverage and documentation on monitoring data quality need improvement.
Depending on the local situation, the ozone monitoring stations are characterised 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 about
40-50% of the area. The geographical coverage of the rural stations is rather adequate in
North West Europe but in other regions gaps are noted.
- A limited presentation of the percentile values observed in the period 1989-1997 is given for four Member States for which this information was available. Based on the reported data no firm conclusion concerning a trend in percentile values can be given.
THE INFORMATION PRESENTED IN PART II, INFORMATION
DOCUMENT CONCERNING AIR POLLUTION BY OZONE, IS PARTLY BASED ON
NON-VALIDATED MONITORING DATA AND HENCE SHOULD BE
REGARDED AS PRELIMINARY