滇池PAHs的沉积记录、来源及其生态风险评估

采用GC/MS方法分析了滇池沉积柱中16种美国EPA优控的多环芳烃(PAHs)的垂直分布状况,并对其来源变化及生态风险进行了分析和评估.研究表明:滇池沉积柱中PAHs的含量范围为558～6418 ng·g-1,并在20世纪90年代初达到峰值,这明显不同于发达国家的同类研究,也与国内沿海地区和偏远湖泊的相关研究有所不同.滇池沉积物中的PAHs主要来自当地的家庭燃煤、木材和生物秸秆等的低温燃烧过程,但工业燃煤和机动车尾气等高温燃烧过程释放的PAHs的相对含量近年来有明显增加的趋势.风险评估结果显示,滇池中上层沉积物中的PAHs可能存在潜在的生态风险,而这些生态风险主要来自低环数的NAP、FLU、PHEN和高环数的BbF、BaP、DBA等.

Sedimentary record, sources and risk assessment of polycyclic aromatic hydrocarbons in Dianchi Lake, Southwest China

Sixteen priority polycyclic aromatic hydrocarbons (PAHs) proposed by US EPA were analyzed using GC/MS method in a sediment core from Dianchi Lake (DC) in Southwest China. Meanwhile, the possible sources and the risk assessment of PAHs in DC were also discussed. The results suggested that total PAHs concentrations in the sediment core ranged from 558 to 6418 ng·g^-1, with the peak value at the early 1990s. The vertical profile of PAHs in the sediment core DC is different from those in developed countries and in coastline and remote lakes in China. PAHs in DC were mainly from the local sources, which were dominated by the low temperature combustion of domestic coal and biomass burning. However, relative abundance of PAHs from high temperature combustion processes, such as combustion of industrial coal and vehicle emission, increased significantly in recent years. Risk assessment suggested that potential ecological risk derived from PAHs could be the probability in the upper sediments, which originated primarily from NAP, FLU, PHEN, BbF, BaP and DBA.