With increasing use of municipal solid waste landfills for waste disposal, the leachate generated has become a serious environmental concern. Therefore, it is important to set up simple and accurate methods for monitoring leachate toxicity. In the present study, the physiological and genetic toxicity of the leachate, generated from Xingou Municipal Landfill in China, were investigated with Triticum aestivum (wheat) bioassay. The results indicate that the lower leachate concentrations stimulated the germination, growth and cell division, and did not induce obvious increase in micronucleus (MN) frequency in root tips; while the higher concentrations inhibited the processes, and significantly augmented the MN frequency in a concentration-and time-dependent manner. In addition, pycnotic cells (PNC) and sister chromatid exchange (SCE) occurred in root tips at all leachate concentrations tested, and the frequencies had positive relation with the treatment concentration and time. The results imply that components of leachate from the landfill may be genotoxic in plant cells, and exposure to leachate in the aquatic environment may pose a potential genotoxic risk to organisms. The results also suggest that the wheat bioassay is efficient, simple and reproducible in monitoring genotoxicity of the leachate.

利用全细胞膜片钳技术研究了硫酸镁（Mgs04）对s02衍生物刺激大鼠海马神经元电压门控性钠通道的调节作用。结果表明，Mgs04 对SO2 衍生物增大大鼠海马神经元钠电流的效应具有抑制作用，此作用随着SO2 衍生物浓度的增加而减弱，随着Mgs04 浓度的增加而增强。不同时间加入MgsO4 均会显著抑制SO2衍生物增大钠电流的效应，说明Mgs04不仅对SO2衍生物增大钠电流的效应具有抑制作用，而凡可即时和延效性地抑制此损伤效应的发生。研究结果提示，硫酸镁对SO2 衍生物刺激大鼠海马神经元钠通道具有抑制作用，这可能是MgS04 对SO2 引发的中枢神经系统损伤具有防护和治疗作用的机制之一。图4参14

Recent studies implicate the possible neurotoxicity of SO2, wever, its mechanisms remain unclear. In the present study, we investigated SO2 derivative-induced effect on delayed rectifier potassium channels(IK) and cellular death/apoptosis in primary cultured hippocampal neurons. The results demonstrate that SO2 derivatives (NaHSO3 and Na2SO3, 3:1M/M) effectively augmented IK and promoted the activation of delayed rectifier potassium channels. Also, SO2 derivatives increased neuronal death percentage and contributed to the formation of DNA ladder in concentration-dependent manners. Interestingly, the neuronal death and DNA ladder formation, caused by SO2 derivatives, could be attenuated by the delayed rectifier potassium channel blocker (tetraethylammonium, TEA), but not byt het ransient outward potassium channel blocker(4-aminopyridine, 4-P). It implies that stimulating delayed rectifier potassium channels were involved in SO2 derivative-caused hippocampal neuronal insults, and blocking these channels might be one of the possibly clinical treatment for SO2-caused neuronal dysfunction.

With increasing attention paid to the recycling use of aged refuse as vegetated soil, it is important to check its possible polluting risk and probe the tolerance of plant system to its stress. For this reason, several physiological responses in Zea mays[Gren Open L. Close][Red_L.Red Close] (maize) to the leaching samples of aged refuse in different particlesize [Gren Open (90-30, 30-150, 150-105, 105-90, Gren Close][Red Open(900-300, 300-150, 150-105, 105-90,and 90-0μm Red Close]and [Gren Open 900 Close][Red Open90-oRed Close] lm) were investigated in the present study, including growth, lipid peroxidation, protein oxidation and activities of antioxidant enzymes. The results indicate that the aged refuse affected the growth of maize seedlings, and elevated the levels of lipid peroxidation and protein oxidation in leaf tissues in a time-dependent manner, accompanying by the changes of antioxidant status. Also, above physiological responses varied as a function of particle-size distribution of the aged refuse, and statistical growth inhibition and oxidative stress occurred after the exposure of smaller particle-size samples, which contained higher level trace metals, the characteristic pollutants in the aged refuse. The results implicate that aged refuse might cause environmental stress on plant system, but the polluting risk mainly resulted from smaller particle-size samples. Therefore, the critical point of utilizing aged refuse as vegetated soil focused on analyzing its particle-size distribution, and screening out appropriate particle- size samples.

分析了太原市新沟垃圾填埋场渗滤液的水质特征，并以COD+作为主要指标探讨了垃圾中有机成分，含水率，以及c、H、O、N等元素含量对渗滤液水质的影响。在此基础上，利用植物检测系统考察了渗滤液对种子萌发和幼苗生长的毒性效应。结果表明。太原市新沟垃圾填埋场渗滤液有机污染物浓度高、水质随季节变化较大，垃圾中有机成分、含水率以及c、H、0、N等元素含量影响渗滤液水质，可能改变其污染特性。高浓度渗滤液可抑制植物萌发和幼苗的正常生长，且表现出对染毒浓度和处理时间的双重依赖性；但低浓度渗滤液对植物萌发和幼苗生长过程没有显著影响，甚至在一定浓度条件下可促进植物的生长发育。