The areas affected are: Greater London, West Midlands, Greater Manchester, West Yorkshire, Teesside, the Potteries, Hull, Southampton, Glasgow, East, South East, East Midlands, Merseyside, Yorkshire & Humberside, West Midlands and the North East.
European legislation sets limits on air pollution and the NOx limits should have been achieved by 1 January 2010. However, the EU rules offer some flexibility and extensions have been agreed with Member States who presented a credible and workable plan for meeting air quality standards within five years of the original deadline, ie by January 2015.
The UK has not presented any such plan for the zones in question.
Today's announcement follows a judgement by the UK Supreme Court last year in which it declared that air pollution limits are regularly exceeded in the 16 UK zones.
The Court also noted the air quality improvement plans estimate that London compliance with EU standards will only be achieved by 2025, fifteen years after the original deadline and in 2020 for the remaining 15 zones.
In the Commission's opinion the UK is in breach of its obligations under the Directive, and a letter of formal notice has been sent.
The UK has two months to respond.
In a separate move, the Commission has also asked Belgium to act on air pollution over its failure to protect the health of its citizens from fine dust (PM10) pollution. In particular, those living and working in Brussels, Ghent port zone, Antwerp (including the port zone), Flanders and Liege have been exposed to unhealthy levels of PM 10 since 2005.
These tiny particles originate in emissions from industry, traffic and domestic heating, and they can cause asthma, cardiovascular problems, lung cancer and premature death.