Landfills are considered the main option for dumping of municipal solid waste (MSW) all over the world, but these landfills are mostly non-engineered. The decomposition of solid waste in the landfill and rainwater penetration into the decomposing waste produces leachate that contains dissolved organic and inorganic compounds, heavy metals, suspended particles and hazardous substances. Leachate migration in the environment may pose serious health risks to organisms exposed. Hence, the present study explored the cytotoxic potential of landfill leachate collected in different seasons from the Okhla landfill site, Delhi, India. Cytotoxicity of leachate samples was evaluated by cell apoptosis and ultrastructural observations based on Transmission Electron Microscopic (TEM) observations of the cells of root tips of Vicia faba seedlings treated with the leachates collected in summer, winter and monsoon in a time and dose dependent manner. Leachate collected in all the three seasons induced apoptosis in cells of root tips of Vicia faba that increased in a time and dose dependent manner when compared to control. The apoptosis was highest in the samples treated with leachate collected in the summer season, followed by winter and monsoon. It was further confirmed with TEM images that there was induction of apoptotic-like morphological changes in the root cells treated with landfill leachate when compared with the control. The present study indicates that municipal solid waste leachate is very toxic and it should be treated before disposing it to the environment. This study may be useful for the assessment of hazardous and toxic effects of pollutants from solid waste landfill sites.

中文翻译：

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城市垃圾填埋场渗滤液诱导蚕豆根尖细胞毒性：非工程填埋场带来的环境风险

垃圾填埋场被认为是世界各地倾倒城市固体废物 (MSW) 的主要选择，但这些垃圾填埋场大多是非工程化的。垃圾填埋场中固体废物的分解和雨水渗入分解废物中会产生含有溶解的有机和无机化合物、重金属、悬浮颗粒和有害物质的渗滤液。渗滤液在环境中的迁移可能对暴露的生物造成严重的健康风险。因此，本研究探讨了在不同季节从印度德里的 Okhla 垃圾填埋场收集的垃圾渗滤液的细胞毒性潜力。渗滤液样品的细胞毒性通过细胞凋亡和超微结构观察来评估，基于透射电子显微镜 (TEM) 观察，以时间和剂量依赖的方式，对用夏季、冬季和季风收集的渗滤液处理的蚕豆幼苗根尖细胞进行观察。在所有三个季节收集的渗滤液诱导蚕豆根尖细胞凋亡，与对照相比，该细胞以时间和剂量依赖性方式增加。夏季收集的渗滤液处理的样品中细胞凋亡最高，其次是冬季和季风。用 TEM 图像进一步证实，与对照相比，用垃圾渗滤液处理的根细胞中存在凋亡样形态变化的诱导。目前的研究表明，城市固体垃圾渗滤液毒性很大，在将其排放到环境中之前应该对其进行处理。这项研究可能有助于评估来自固体废物填埋场的污染物的有害和毒性影响。