Introduction of a new combustion technology of oil shale - circulating fluidized bed (CFB) process hi the Estonian and Baltic Power Plants (Narva PPs) - is all efficient way to reduce the emissions of SO2 from electric energy production in Estonia. In 2004-2005, the exploitation of CFB boilers in. the renovated power unit No 8 at the Estonian PP showed that the mean concentration of SO2 in e:exhaust gases was 3-24 mg Nm(-3), whereas old-fashioned pulverized oil shale combustion (PC) boilers would have yielded 19203000 in Nm(-3). After the renovation of the other power unit (No 11) ill the Baltic PP the total SO2 emission from Narva PPs will decrease from 5.7-7.9 t per 1000 t burned oil shale (in 2000-2001) to 4 t (about 38,000 t year(-1)) and in the renovated power units to 0.74 t. Compared to PC, CFB yields twice less emissions of NOx (about 150 mg Nm(-3) as NO2). The modelling (AEROPOL model, developed in Tartu Observatory) indicated that air pollution levels in the surroundings of Narva PPs and transboundary air pollution (to Finland and Russia) would be reduced about 10 times as compared with the period 2000-2003.