3rd Year Week 7 MT03

Topic: How should we protect our environment?

NEWS RELEASE Copenhagen, 24 October 2003

Summer 2003 ozone pollution hits high; levels could recur for several more years

Harmful ozone pollution was the worst for almost a decade in large parts of Europe this summer, particularly during the long August heatwave, according to a preliminary assessment by the European Environment Agency. The unusually hot and sunny weather, combined with air pollutants emitted mainly by traffic, industry and vegetation, caused very long lasting and geographically extensive ‘episodes’ with high concentrations of harmful ground-level ozone. And this situation is likely to repeat itself in any future summers with above-average temperatures until measures taken under current legislation result in a much larger cut in emissions of the ‘precursor’ pollutants that cause ground-level ozone towards the year 2010.Emissions of the main precursors – nitrogen oxides and non-methane volatile organic compounds (NMVOCs) – fell by around 30% between 1990 and 2000 in the 15 European Union Member States. EU legislation setting national ceilings, to be met by 2010, on emissions of these and certain other pollutants will bring a further 30% cut.

A summary of the assessment has been sent to EU environment ministers who will discuss the summer ozone episodes at their meeting on Monday (27 October).

In contrast to the stratospheric ozone layer that protects against harmful solar radiation, ground-level ozone can cause serious human health problems and damage to ecosystems, crops and materials. It forms when the precursor pollutants react with sunlight. High temperatures worsen the situation by increasing emissions of NMVOCs from vegetation and man-made sources such as solvents. Out of 31 European countries reporting monitoring results this year, 23 suffered ground-level ozone pollution at concentrations well above an important human health threshold on one or more days between April and August. Beyond this threshold, set at 180 micrograms of ozone per cubic metre of air (180 µg/m3) averaged over one hour, exposure for a short period can have limited, temporary effects on the health of children as well as of adults who are particularly sensitive to ozone. Governments are required by European Union law to inform the public whenever the 180 µg/m3 threshold is breached.

The threshold was exceeded in at least one of the 23 countries on 137 of the 153 days monitored between April and August. Only the Nordic countries, the Baltic States and Ireland reported no exceedances. Breaches of the threshold lasted an average of 3.5 hours, the longest average period since 1995, with a high of 4.2 hours on average recorded in the Slovak Republic. The ozone concentration during the episodes averaged 202 µg/m3 in the 23 countries affected and reached an average of 246 µg/m3 in Romania.The number of hours during spring and summer when ozone concentrations at each monitoring station were above the 180 µg/m3 threshold averaged 31 for the EU, its highest number ever. In France the number was one-third higher than the previous record set nine years ago.The areas with the most exceedances of the threshold were south-west Germany, Switzerland, northern and south-eastern France, Belgium, northern and central Italy and central Spain.These are also among the regions with the highest density of emissions from traffic and industry of the main pollutants contributing to ozone.Under revised EU ozone legislation that took effect in September, the ozone concentration above which brief exposure is considered to pose a health risk for the general population has been tightened from 360µg/m3, averaged over one hour, to 240µg/m3.Governments are required to warn the general public to take precautions whenever the threshold is exceeded. The 360 µg/m3 threshold, which still applied this spring and summer, was breached four times - twice in mid-June, at stations in northern Italy (Varenna) and Romania (Chiciu), and twice in early August at one monitoring station in south-east France (Sausset les Pins). This number of exceedances is in line with previous years, despite this year’s hotter temperatures. The highest ozone concentration was 417 µg/m3, reached at Sausset les Pins during the heatwave that affected much of Europe in the first half of August.The new 240 µg/m3 threshold, which was not yet in force this summer, was exceeded in 15 countries and in around 6% of the episodes where the 180 µg/m3 information threshold was breached.