12 44. Turning to particulate pollution in the Megalopolis region, the Government supplies data on average annual TSP concentrations between 1995 and 2005 that show that although the daily limits were exceeded in a number of years this has not occurred since 2004 and that the long-term exposure limits have never been exceeded. 45. The Government maintains that nitrogen oxide (NOx) pollution in both the Kozani-Ptolemaida and Megalopolis regions is very low, which is the result of the very low calorific value of lignite, resulting in even lower combustion temperatures. The daily limits for these and nitrogen dioxide (NO2) concentrations laid down in European regulations have rarely if ever been exceeded and emissions are currently well within European standards. In support of this, the Government supplies graphs showing average annual nitroden dioxide (NO2) concentrations from 1997 to 2006. 46. It supplies figures on trends in annual average sulphur dioxide (SO2) concentrations from 1985 to 2006 that also show that the daily limits laid down in European regulations have rarely if ever been exceeded and that emissions are currently well within European standards. 47. The Government states that it is pursuing a coherent and progressive emissions reduction strategy that reflects a firm national commitment to reduce polluting emissions. This has already lead to a significant improvement in air quality and will continue to do so in the future. In support of this, it refers to the implementation of the IPPC directive and the adaptation of equipment to "best available techniques" (see below), as well as the application of Directive 2001/80/EC and presentation of the national emissions reduction plan concerning existing combustion plants, which establishes emission ceilings for SO2, NOx and particulates to be achieved in 2008 and 2016. 48. The Government denies that there are gaps in the air quality measuring system. Since the early 1980s – and even earlier in the case of SO2 and NO2 – air quality has been measured systematically in the regions concerned. There are nine air quality monitoring stations in the prefectures of Kozani and Florina (western Macedonia) and three in the Arcadia prefecture (Megalopolis). These measure, as the case may be, concentrations of SO2, NOx, NO2 and particulates, as well as meteorological parameters, such as wind force and direction and humidity. The results are notified at regular intervals to the competent agencies. The Government points out that it is these measurements that have served as the basis for the aforementioned studies by independent researchers.