OCR Text |
Show particles. From the result of the Ames test, it was found that dichloromethane ext r act s 0 f the sam pIe s vY' ere m uta g e n i c to sol m 0 nell a t y him uri u m T A 9 8 when P.S. \\:as incinerated at deficient nxygen supply, lower than 0.105 KL/min.as sho'W'n in Table 3. The mutagenicity of particulates and PUF extracts caused significantly higher potence of revertants to S. Typhimurium T A98 in the presence of S9 mixture than that observed in its absence. This indicates that the emitted gas from P. S. incineration at deficient oxygen supplies contain not only direct- acting mutagens but also indirect mutagens, which are usually activated by the mixed-function oxygenases in the microsomes (contained in the S9 mixture) of animal liver to become ultimate mutagens. Three types of the mutagenicity pattern are observed as : (1) the mutagenicity increased with the stage-two temperature, (2) the mutagenicity occurred the maximum at 1000 - 1100°C of stage-t'W·o temperature and (3)The mutagenicity decreased with the stage-two temperature. When P. S. was pyrolysed from 900°C to 1200°C, the mutagenicity was increased as the stage-two temperature increased, as sho'W'n in figure 12 .. the maximum mutagenicity of particulates and PUF extracts occured at 1200°C and were 6184 and 1292 Revs/plate,respectively. It shows that the higher the stage -two temperature was controlled from P. S. pyrolysis, the more mutagenic product formed. the reasoning is that the nitrogen molecular may particpate the reaction when the stage-two temperature increased, and form acridine compounds and carbazole compounds. When oxygen supply was at 0.0525 NL/min, the maXImum mutagenicity of particules extracts was shifted to occure at 1100°C, and was 8224 Revs./plate. The mutagenicity of the PUF extracts was increased as the stage-two temperature increased,as shown in Figure 13. The maximum mutagenicity was 1856 Revs/plate at 1200°C. When oxygen supply was increased to 0.105 NL/min. the trend of mutagenicity related with the stage-two temperature was similar to that of oxygen supply of 0.0525 ~L Imino But the maximum mutagenicity was much lower than that of 0.0525 ~L/min and was 1712 and 1232 Revs./plate,repectively. From the regression analysis, when the oxygen supplies were controlled at 0.0525 ~l/min and - 21 - |