The European Commission says it will get tough on air quality and may penalise members that breach EU rules on pollutants like nitrogen oxide and particle matter.
What is the impact of pollution in the EU?
The Commission estimates that 400,000 people die each year as the result of airborne pollution.
And how are member states doing?
Not so well. Targets introduced for 2005 and 2010 are still being exceeded in 23 of 28 EU countries.
"My patience is running thin" - EU Environment Commissioner
After a meeting with the environment ministers of the nine countries which face legal action because of air quality problems, including the bloc's largest economies Germany and France, EU Environment Commissioner Karmenu Vella said it is time to act.
"The deadlines for meeting the legal obligations have long elapsed and some say we have already waited too long, but we can delay no more. I have made this very clear to ministers this morning," Vella told a news conference.
He added that, while countries had made some suggestions during the meeting, air quality standards would still be breached well beyond 2020 unless new measures were taken.
"In our exchange, there were some positive suggestions but I have to say that, at first sight, these were no substantial enough to change the bigger picture," Vella added. He said members have until next week to improve on their proposals.
What can the EU do about member states that breach the rules?
The Commission can take countries to Europe's top court if they breach EU law. Poland and Bulgaria have already faced legal action over air quality issues.