Abstract: BACKGROUND ＆ AIM: To investigate the genotoxicity of bottom ashes of municipal solid waste incineration from Macao and assess their potential risks on eco-environment and human beings. MATERIAL AND METHODS: The micronucleus (MN) assay was employed to detect their genotoxicity on Vicia faba. RESULTS: The leaching solutions of the bottom ashes could induce significantly increasing frequencies of micronuclei in the root tip cells of Vicia faba under the present conditions, compared with the control group. The MN frequency caused by the leaching solutions 0.5％ Na2EDTA was the lowest in the tested groups. CONCLUSION: It is necessary to remove the toxic elements or compounds of the bottom ashes before recycling. The Na2EDTA solution can decrease the bioavailability and the genotoxicity of the heavy metals on Vicia faba, offering a promising chance of chemical remedy.

Key words: municipal solid waste incineration, bottom ash, Vicia faba, micronucleus, genotoxicity