NOx and NH3 emissions have not decreased significantly in Western Europe except for NOx in Germany and the United Kingdom but NOx has been reduced in many CEE countries (Czech Environmental Institute and Ministry of the Environment 1996, EEA 2001b, GRID-Budapest 1999, GRID-Warsaw 1998, Interstate Statistical Committee 1999, OECD 1999a, UNECE/EMEP/MSC 1998).