Fewer summer ozone peaks in 2012, but levels still harmful

The information comes from a European Environment Agency (EEA) report on ground-level ozone levels in summer 2012. The pollutant can cause respiratory problems and other severe illnesses, also damaging crops and the wider environment. A new report published today by the World Health Organization suggests that ozone exposure may be more harmful than previously thought.

During summer 2012, the percentage of sites exceeding the ‘alert threshold’ was the lowest on record, indicating peak episodes were shorter and maximum ozone concentrations were lower. Nonetheless, the ‘long-term objective’ (LTO) to protect human health was exceeded in all EU Member States apart from Estonia, and it is likely many of them will not meet other targets phased in recently.

The lower levels seen during the summer last year were in part due to weather conditions. Ground-level ozone production depends on weather conditions such as sunshine and temperature, and is a result of chemical reactions between other pollutants in the air. These substances are emitted by industry, traffic, farming practices and from other sources.

Ozone pollution can travel great distances, meaning that it is both a local air quality issue and also a global, cross-border problem. This edition of the European Environment Agency (EEA) annual report on summer ozone levels covers the period from April to September 2012. It is based on data from 2 107 monitoring sites across Europe.

Main findings

• Monitoring stations report when the ‘information threshold’ is exceeded. This is a one-hour average ozone concentration of 180 μg/m³. During summer 2012, the information threshold was exceeded at approximately 28 % of all operational stations, one of the lowest percentages since 1997.

• The ‘alert threshold’, a one-hour average ozone concentration of 240 μg/m³ was exceeded on 25 occasions – the lowest number on record. This occurred in only seven EU Member States (Belgium, France, Germany, Greece, Italy, Portugal and Spain).

• As in previous years, the LTO for the protection of human health (maximum daily eight-hour mean concentration of 120 μg/m³) was exceeded in all EU Member States except Estonia. This level was exceeded at least once at approximately 85 % of all operational stations.
• The EU also has a target for protecting human health, stating that the LTO should not be exceeded on more than 25 days per year. This threshold was exceeded in 17 EU Member States (Austria, Bulgaria, Cyprus, the Czech Republic, France, Germany, Greece, Hungary, Italy, Luxembourg, Malta, Poland, Portugal, Romania, Slovakia, Slovenia and Spain) and five other countries submitting data to the EEA (Albania, Croatia, the former Yugoslav Republic of Macedonia, Serbia and Switzerland). As in previous years, the most widespread concentrations occurred in the Mediterranean area.

Additional information

• Official summer ozone statistics 2012
• European Commission press release 31/01/13: Newly found health effects of air pollution call for stronger EU air policies
• World Health Organization: Review of evidence on health aspects of air pollution