Provincial and district centers, having the maximum rate of increase in sulphurdioxide concentration in December of 1999 compared to the previous Decmber are; Bursa (İnegöl) with 1089%, Ankara with 134%, Niğde (Bor) with 121%, Kırşehir with 104% and Kütahya with 91%. For the same period provincial and district centers, having the maximum rate of decrease in SO₂ concentration compared to the previous December are; Yozgat with 70%, Sinop with 63%, Isparta with 62%, İzmir (Bergama) with 52% and Samsun with 44%.

Provincial and district centers, having the maximum rate of increase in particulate matter concentration in December of 1999 compared to the previous December are; Kırıkkale with 144%, Ankara with 124%, Kütahya with 114%, Manisa with 100% and Elazığ with 78%. For the same period, provincial and district centers, having the maximum rate of decrease in PM compared to the previous December are; Samsun and Yozgat with 38%, Afyon with 30%, Nevşehir with 25%, Edirne with 23%, Aydın and Bilecik (City Center) with 15%.

According to the SO2 concentrations, obtained from the measurement stations in Ankara and İstanbul provincial centers, and İzmir (Bergama), İzmir (Ödemiş) district centers, in December of 1999, Target Limit Value (TLV) was exceeded in all stations except Demetevler in Ankara and exceded in Bakırköy, Eminönü and Eyüp mesurement stations in İstanbul, on the other hand TLV was not exceeded in İzmir (Bergama) and İzmir (Ödemiş). Short Term Limit Value (STL) was exceeded in Cebeci in Ankara but was not exceeded in İstanbul and district centers of İzmir. First Warning Level Limit Value (1. WLL) was not exceeded in the measurement stations in Ankara, İstanbul and district centers of İzmir.

For the same period, according to the particulate matter concentrations, obtained from the measurement stations, TLV was excedded in all of the measurement stations in Ankara and in the mesaurement stations of Bakırköy, Eyüp, Fatih, Maltepe and Zeytinburnu in İstanbul. STL was exceeded in the measurement stations of Bahçelievler, Balgat, Cebeci, Demetevler, İncirli, Yenidoğan in Ankara and Eyüp in İstanbul. 1^st WLL was not exceeded in any measurement stations except Balgat in Ankara and İstanbul.

Since the sulphurdioxide and particulate matter concentrations could not be measured in İzmir in December of 1999, no evaluation could be done.

DETAILED DATA OF THE PROVINCIAL AND DISTRICT CENTERS CAN BE OBTAINED FROM THE TABLES
GIVEN BELOW.

TABLE 1.

Provincial and district centers by the average concentration of sulphurdioxide (SO₂) and particulate matter (smoke), the days exceeding the Target Limit and Short Term Limit Values in December of 1999