老化对土壤中芘的生物有效性的影响

Effects of Aging on Bioavailabiltiy of Pyrene

利用蚯蚓作为测试生物,以蚯蚓积累因子作为芘对蚯蚓生物有效性的指标,重点考察了老化(增加污染物和土壤之间的接触时间)对土壤中芘的蚯蚓生物有效性的影响.实验结果表明,未老化土壤中芘的蚯蚓积累因子为0.052～0.452,而土壤老化10 d和120 d后蚯蚓积累因子分别下降到0.036～0.367和0.029～0.126.这说明在老化过程中可能有越来越多的芘进入了蚯蚓不可接触的区域,从而不具备生物有效性.实验结果还说明前10 d内老化过程对芘生物有效性的影响最大,之后老化对芘生物有效性的影响逐渐变弱.

Many field studies have demonstrated that prolonged chemical-soil contact times(aging) may lead to unexpected persistence of these compounds in the environment.This study used earthworms(Eisenia foetida) to assay pyrene bioavailability in the experiment level.Earthworm-soil accumulation factor(ESAF) was used as the prediction of the bioavailability of pollutants to earthworms.Utilizing ESAF,the effects of aging(increasing the contact time between pollutants and soil aggregates) on the bioavailability of pyrene to earthworms in soils were investigated.The results showed that the ESAF value for pyrene aged for 0 day was in the range of 0.052~0.452,and the ESAF value for pyrene aged for 10 and 120 days decreased to 0.036~0.367 and 0.029~0.126,respectively,which suggested that more and more pyrene molecules could had entered into inaccessible domain to earthworms,and then these molecules had no bioavailability for earthworm.Moreover,the effects of aging on bioavailability of pyrene mostly occurred in period of former 10 days.From then on,the effects of aging became gradually weaker.