土壤甲苯、乙苯和二甲苯对蚯蚓及小麦的毒性效应

以赤子爱胜蚓(Eisenia fetida)和小麦(Triticum aestivum L.)为受试生物,研究了土壤中甲苯、乙苯和二甲苯等苯系物(TEX)的毒性效应.结果表明,3种污染物对赤子爱胜蚓和小麦毒性影响呈明显的剂量-效应关系,甲苯、乙苯和二甲苯对蚯蚓的24hLC50分别为583.6,346.8,192.4mg/kg;48h LC50分别为454.3,167.1,127.2mg/kg.甲苯、乙苯和二甲苯对小麦芽伸长的10%抑制率(IC10)分别为342.2,195.4,45.9mg/kg;对小麦根伸长的10%抑制率(IC10)分别为206.7,134.5,26.3mg/kg.小麦芽长、根长均可用于指示土壤被甲苯、乙苯及二甲苯污染的程度,但小麦种子根长对3种污染物胁迫的响应较芽长更为敏感,根长抑制率与芽长抑制率之间呈明显的相关关系.

Toxic effects of toluene,ethylbenzene and xylene in soils on earthworm Eisenia fetida and wheat Triticum aestivum L.

Soil ecotoxicological effects of toluene, ethylbenzene and xylene (TEX) were investigated using earthworm (Eisenia fetida) and wheat (Triticum aestivum L.). The results showed that there were significantly positive correlations between the lethal or inhibitory effects on Eisenia fetida and Triticum aestivum L. and the tested concentration of the three pollutants. The 24h LC50 values of TEX toxic to Eisenia fetida were 583.6, 346.8 and 192.4mg/kg, and the 48h LC50 values were 454.3, 167.1 and 127.2mg/kg, respectively. The IC10 values based on the toxicity of TEX to shoot elongation of Triticum aestivum L. were 342.2, 195.4 and 45.9mg/kg, and the IC10 values based on the toxicity of TEX to root elongation were 206.7, 134.5 and 26.3mg/kg, respectively. Although both the root and shoot elongation of wheat could indicate the pollution extent of TEX in soil, root elongation was more sensitive than shoot elongation under the pressure of the three pollutants, and there was a significantly positive correlation between these two indexes.