Air pollution can have harmful effects on human health, animals and the environment as a whole. Some air pollutants have natural sources, for example particulate matter from Sahara dust, which is transported to the European continent by long-range transport. Nevertheless, human activities are the main cause of atmospheric pollution. Acid rain has damaged plants and water bodies in Central Europe over the last decades. In 1952 heavy smog over London led to the death of thousands of people.
Over the last years air pollution levels could be significantly reduced. Nevertheless high concentrations of ozone, particulate matter und nitrogen oxides continue to cause problems. Further improvement of air quality will be a main task for the future at national and international level. With the objective of reducing harmful air pollution in Europe, the European Union established common limit values for the most important air pollutants. All Member States are required to take the measures necessary to ensure compliance with the limit values.