The European Community's air pollutant emission inventory report released by the European Environment Agency finds that in 2007 sulphur oxides emissions were down by 72% from 1990 levels. The downward emission trend of three main pollutants which cause ground-level ozone continued in 2007: carbon monoxide fell by 57%, non-methane volatile organic compounds were down by 47% and nitrogen oxides have dropped 36%. EU-27 emissions of all four pollutants were lower in 2007 than in 2006. In 2007 the top polluting sources in the EU-27 were fuel combustion in households, passenger cars, heavy duty vehicles, and in power plants. The largest member states are generally responsible for the most air pollution. France, Germany, Italy, Poland, Spain and the United Kingdom contributed the most to EU-27 emissions in 2007.