Environ Toxicol Chem. 2013 Dec;32(12):2870-3. doi: 10.1002/etc.2386.
Ameliorating acidic soils is a common practice and may affect the bioavailability of an ionizable organic pollutant to organisms. The toxicity of the weak base carbendazim to the earthworm (Eisenia fetida) was studied in an acidic soil (pH-H₂O, 4.6) and in the ameliorated soil (pH-H₂O, 7.5). The results indicated that the median lethal concentration of carbendazim for E. fetida decreased from 21.8 mg/kg in acidic soil to 7.35 mg/kg in the ameliorated soil. To understand why the amelioration increased carbendazim toxicity to the earthworm, the authors measured the carbendazim concentrations in the soil porewater. The authors found increased carbendazim concentrations in porewater, resulting in increased toxicity of carbendazim to earthworms. The increased pore concentrations result from decreased adsorption because of the effects of pH and calcium ions.
改良酸性土壤是一种常见的做法，可能会影响可电离有机污染物对生物体的生物利用度。本研究采用弱碱性杀菌剂多菌灵为模型污染物，在酸性土壤（pH-H₂O，4.6）和改良土壤（pH-H₂O，7.5）中研究了其对蚯蚓（赤子爱胜蚓）的毒性。结果表明，多菌灵对赤子爱胜蚓的半致死浓度从酸性土壤中的 21.8mg/kg 降低到改良土壤中的 7.35mg/kg。为了了解为什么改良会增加多菌灵对蚯蚓的毒性，作者测量了土壤孔隙水中的多菌灵浓度。作者发现土壤孔隙水中的多菌灵浓度增加，导致多菌灵对蚯蚓的毒性增加。由于 pH 值和钙离子的影响，吸附减少，导致孔隙浓度增加。
