Fomin A, Hafner C
Institute of Landscape and Plant Ecology, Department of Plant Ecology and Ecotoxicology, University of Hohenheim, D-70593 Stuttgart, Germany.
Mutat Res. 1998 May 11;414(1-3):139-48. doi: 10.1016/s1383-5718(98)00049-7.
A 4-year study was conducted to investigate the suitability of the Tradescantia-micronucleus bioassay (Trad-MCN) to detect genotoxicity of emissions from municipal waste incinerators. The genotoxic potential of emissions was assessed in three ways: (i) direct fumigation of Tradescantia with diluted incinerator emissions, (ii) exposure of Tradescantia to smoke condensates and (iii) in situ monitoring of genotoxicity of emissions near a municipal incinerator. The results of direct fumigation with smoke emissions varied over the course of the study. In 1992, significantly higher micronuclei frequencies (MCN) were always observed in treated plants than in control plants, regardless of length of fumigation period. Furthermore, MCN frequencies were significantly higher in plants fumigated for 24 h than those fumigated for 8 h, and MCN frequencies were also higher in plants fumigated in chamber 1 (low dilution, high stack gas concentration) than those in chamber 2 (P<0.05). MCN frequencies were substantially lower in 1993 and 1994, and in only 1 out of the 5 fumigation experiments were MCN frequencies significantly higher in treated plants than in controls. This drop in MCN frequencies was possibly due to the installation of better pollution control devices in the incinerator in 1993. Exposure to smoke condensates induced significant increases in MCN frequencies in most exposure trials. A drop in MCN frequencies over the course of the 4-year study was also attributed to the installation of new smoke scrubbing devices. This was further confirmed by the chemical analysis of the condensate, which showed a significant reduction in organic pollutants after the installation of the new devices. The results of in situ monitoring of genotoxicity near a municipal waste incinerator showed that MCN frequencies of Tradescantia depended on the distance from the incinerator, and the direction of wind. Because exposure periods of 6 h were insufficient to elicit significant responses, periods of 10 to 24 h are recommended for in situ monitoring.
开展了一项为期4年的研究，以调查紫露草微核生物测定法（Trad-MCN）检测城市垃圾焚烧炉排放物遗传毒性的适用性。通过三种方式评估排放物的遗传毒性潜力：（i）用稀释的焚烧炉排放物直接熏蒸紫露草，（ii）使紫露草暴露于烟雾冷凝物中，以及（iii）在城市垃圾焚烧炉附近对排放物的遗传毒性进行现场监测。在研究过程中，用烟雾排放物直接熏蒸的结果有所不同。1992年，无论熏蒸期长短，处理过的植株中总是观察到微核频率（MCN）显著高于对照植株。此外，熏蒸24小时的植株中的MCN频率显著高于熏蒸8小时的植株，并且在1号试验箱（低稀释度、高烟囱气体浓度）中熏蒸的植株中的MCN频率也高于2号试验箱中的植株（P<0.05）。1993年和1994年MCN频率大幅降低，在5次熏蒸试验中只有1次处理过的植株中的MCN频率显著高于对照植株。MCN频率的这种下降可能是由于1993年焚烧炉中安装了更好的污染控制装置。在大多数暴露试验中，暴露于烟雾冷凝物会导致MCN频率显著增加。在为期4年的研究过程中MCN频率的下降也归因于新的烟雾洗涤装置的安装。冷凝物的化学分析进一步证实了这一点，该分析表明安装新装置后有机污染物显著减少。在城市垃圾焚烧炉附近对遗传毒性进行现场监测的结果表明，紫露草的MCN频率取决于与焚烧炉的距离以及风向。由于6小时的暴露期不足以引发显著反应，因此建议现场监测的暴露期为10至24小时。
