Hidekichi Yoshino* and Kohei Urano**

*Kanagawa Environmental Research Center, Divsion of Environmental Engineering
**Yokohama National University, Laboratory of Safety and Environmental Engineering

+ Correspondence should be addressed to Hidekichi Yoshino:
Kanagawa Environmental Research Center, Divsion of Environmental Engineering
(842 Nakaharashimojyuku, Hiratsuka-shi, Kanagawa, 254 Japan)

Abstract

Genotoxicity of fly ash samples from 23 plants and bottom ash samples from 10 plants were estimated by Ames mutagenicity after using the extraction method reported in the previous paper. Mutagenicity was clearly observed in 8 fly ash samples, especially in TA98+S9 which shows mutagenicity of the frame shift type. Low level mutagenicity was detected in 3 bottom ash samples. Considering the information for the plants, high mutagenicity of the fly ash was estimated for the stoker type incinerator, which was operated in shorter residence time of gas. In the test at a stoker type incinerator operated in various feed volumes of waste and air flow rates, mutagenicity was increased with increases of CO concentration in flue gas and ignition loss of the fly ash. Namely, mutagens in the fly ash may be produced in incomplete incineration. The mutagenicity of fly ash was lost after heating it at 400*C[Celsius degeree] for 30 minutes, and some of the mutagens were decomposed by treatments with 2N HCl or 2N NaOH.

Key words: municipal waste, mutagenicity, Ames test, ash, HCl treatment