柳叶湖水域沉积物中PAHs污染特征与潜在生态风险

Pollution Characterization and Potential Ecological Risks of Polycyclic Aromatic Hydrocarbons in Surface Sediments of Liuye Lake and Adjacent Waters

该研究主要考察了柳叶湖及其毗邻水域表层沉积物中PAHs的含量分布,研究结果表明:16种优控PAHs的总含量在199~3 880 ng/g干重,其中荧蒽的平均含量最高(109 ng/g干重)。基于效应区间低值和效应区间中值的结果,沉积物中PAHs的污染将对底栖生物造成一定的影响;同时,通过皮肤接触途径可能对人体造成中度癌症风险,尤其是儿童。组成成分分析结果显示了沉积物中高分子量的4-环和5-环占据主导地位,而诊断比值分析结果暗示柳叶湖及毗邻水域沉积物中PAHs主要来源于生物质或煤的燃烧。因此,为了降低沉积物中PAHs的生态风险,应采取措施以减少秸秆燃烧以及利用更为清洁的能源取代煤。

The concentration distribution of polycyclic aromatic hydrocarbons(PAHs) was investigated for the surface sediments collected from Liuye Lake and adjacent waters. The total concentrations of 16 priority PAHs ranged from 199 ng/g dry weight to 3 880 ng/g dry weight, in which Fla had the highest average concentration of 109 ng/g dry weight. Based on effects range low(ERL) and effects range median(ERM), the PAHs contamination of sediments from Liuye Lake and adjacent waters might have an impact on benthic organisms. Furthermore, the dermal contact with sediments from Liuye Lake and adjacent waters might lead to moderate cancer risk, especially for children. The composition analysis showed that PAHs with4-and 5-rings were dominant in the sediment samples, indicating PAH of high molecular weight were predominant. Diagnostic ratio analysis suggested that PAHs in Liuye Lake and adjacent waters sediment mainly resulted from biomass or coal combustion. In order to lower the ecological risks from PAHs in sediments, more measures should be taken to reduce straw burning and replace coal with cleaner energy.