长江上游水体中酞酸酯的污染水平及生态风险评价

CONTAMINATED LEVEL AND RISK ASSESSMENT OF PAES IN THE UPPER REACHES OF THE YANGTZE RIVER

  • 摘要: 为评价酞酸酯类污染物对长江流域水生生态系统的潜在风险, 在长江上游设置了9个采样点, 分析了水样中不同酞酸酯的含量水平, 发现邻苯二甲酸二辛酯(Di-2-ethylhexyl phthalate, DEHP)为其中最主要的单体。通过风险商值法对酞酸酯类污染物的风险进行了初步筛查, 结果表明DEHP和邻苯二甲酸丁苄酯(Butyl benzyl phthalate, BBP)为风险商值较高的单体。安全阈值法评价结果表明, DEHP和BBP的MOS10分别为1.40和1.32×105, 即DEHP的潜在风险最高。进一步采用联合风险概率分布法评价DEHP对水生生物的潜在风险: 以综合毒性数据, 针对不同物种进行的评价结果表明, 长江上游水体中DEHP对5%鱼类和底栖动物造成潜在危害的风险概率分别为99.4%和98.3%; 针对不同毒性终点开展的评价结果表明, DEHP对5%或10%水生生物造成繁殖毒性效应的概率分别为100%和97.8%, 表明繁殖毒性为最敏感的终点指标。上述结果表明, 长江上游水体中DEHP对水生生物存在较高的风险, 特别是繁殖毒性风险尤为显著, 需要长期密切关注。

     

    Abstract: PAEs have been proved to be one of the major organic pollutants. The present study determined the level of PAEs using surface water samples from the upper reaches of the Yangtze River. The results showed that DEHP contributed the most to PAEs pollution, followed by DBP. Risk Quotients of PAEs were used for preliminary screening, and DEHP and BBP were identified as potential risk factors with RQ of 310 and 70.7. The MOS10 of DEHP and BBP were 1.40 and 1.32×105, respectively, indicating that BBP may pose little risk to aquatic organisms. The potential risk of DEHP was further analyzed with joint probabilistic curves. Among different biological groups, fish and zoobenthos were two major groups sensitive to DEHP-induced damage under current concentrations with 99.4% and 98.3% for 5% species of each group. While among the toxicity endpoints, reproduction may be more sensitive than others. The 5% and 10% aquatic species were suffered from reproductive damages by 100% and 97.8%, respectively. Overall, our results indicated that DEHP in the surface water of the upper Yangtze River may pose potential risk to aquatic organisms, especially on their reproduction. Therefore, more concerns should be paid in species protection and environmental management.

     

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