Harmful ozone levels over Europe
Ozone pollution significantly exceeded EU standards to protect health during the summer of 2013, especially in the Mediterranean and Alpine regions.
Ground-level ozone exceeded legal limits in every EU member state during summer 2013, according to a new report by the European Environment Agency (EEA). Although the number of exceedances is high, they have decreased over recent decades.
EU standards to protect health were significantly exceeded, particularly during July and early August, and the most problematic areas were the Mediterranean and Alpine regions. In some countries up to two-fifths of the population was exposed to levels exceeding limits.
Recent scientific studies have shown that ground-level ozone pollution is also harmful to health at very low levels, well below the limits set in EU air quality standards. Even though the EU limits were exceeded on fewer occasions in 2013 than in many previous years, this does not necessarily mean that public exposure to harmful ozone levels is falling by a corresponding amount. A separate study found that in 2012 almost all inhabitants of cities in the EU were exposed to ozone levels above the World Health Organization (WHO) guideline of 100 μg/m3 as a daily eight-hour mean value, which is stricter than the EU limits.
The EU’s air quality directive includes a long-term objective (LTO) for the protection of human health, which is set at a maximum daily eight-hour mean concentration of 120 μg/m3. This was exceeded at least once in all member states during summer 2013.
The EU target value (TV) for the protection of human health is exceeded when the LTO of 120 μg/m3 has been exceeded at a particular station more than 25 times per calendar year, averaged over three years. More than 25 LTO exceedances occurred at stations in 19 EU member states (Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, France, Germany, Greece, Hungary, Italy, Luxembourg, Malta, Poland, Portugal, Romania, Slovakia, Slovenia and Spain) and in five other reporting countries or territories (Macedonia, Kosovo, Montenegro, Serbia and Switzerland).
Ground-level ozone is a ‘secondary pollutant’, which means it is formed in chemical reactions between other pollutants in the air, primarily nitrogen oxides (NOx) and volatile organic compounds (VOCs). Ozone levels become particularly high in regions where considerable ozone precursor emissions combine with warm and sunny weather during the summer.
Elevated ozone concentrations can cause serious health problems, especially respiratory illnesses and cardiovascular problems, which may lead to premature death. Ozone also damages materials and vegetation, including forest trees and agricultural crops.
Source: EEA, 13 March 2014
Number of days on which ozone concentrations exceeded the LTO for the protection of human health during summer 2013.