Levels of damaging fine particulate matter, caused mainly by vehicle emissions, have exceeded EU limits on 41 days already this year in Brussels. The official EU quota for days on which limits can be exceeded is 35 days in a year. Brussels is rated one of the poorest performing cities in Europe in the fight against fine particulate pollution. Emergency plans launched two years ago to deal with the problem have been condemned as ineffective. More aggressive measures have been called for, such as temporarily or permanently barring more polluting vehicles from parts of the city.