Clean air is essential to human health and sustaining the environment. Major improvements in air quality have been achieved in the European Union (EU) over the past three decades, thanks to joint efforts by the EU and national, regional and local authorities in the Member States to reduce the adverse impacts of air pollution. However, around 300 000 premature deaths a year (compared with up to 1 million a year in the early 1990s) and a significant number of noncommunicable diseases such as asthma, cardiovascular problems and lung cancer, are still attributed to air pollution (and especially to particulate matter, nitrogen dioxide and ozone); Air pollution continues to be the number one environmental cause of early death in the EU. It disproportionally affects vulnerable groups such as children, elderly people and persons with pre-existing conditions, as well as socioeconomically disadvantaged groups. There is also increasing evidence that air pollution may be associated with changes of the nervous system, such as dementia.

In addition, air pollution threatens the environment through acidification, eutrophication, and ozone damage, causing damage to forests, ecosystems and crops. Eutrophication from deposition of nitrogen exceeds critical loads in two thirds of ecosystem areas across the EU, with significant impact on biodiversity. 6 This pollution pressure can aggravate situations of nitrogen surplus via water pollution.