Status Report of Bulgaria

The largest city of Bulgaria – the capital Sofia (1,2 million inhabitants) is located in a broad valley at 550 m a.s.l. (above sea level) and the second largest town is Plovdiv at the Maritza river. Other major towns are located at the Black-sea cost (Varna and Bourgas), and there are a number of smaller towns in mountainous regions. Local circulation systems are therefore significant for the air pollution in Bulgarian cities. Strong temperature inversions during anticyclonic weather conditions in the coldest time of the year lead to accumulation of pollutants in the surface layer and often to exceedances of air quality limits (Batchvarova et al., 1994, Batchvarova and Teneva, 1989 and Teneva et al., 1988).