基于物种敏感性分布的微囊藻毒素与氮污染水体生态风险评估  

Aquatic ecological risk assessment of microcystins and nitrogen pollution based on species sensitivity distribution

作　　者：陈瑾[1,2] 刘奕梅[3] 张建英[1,2] 

机构地区：[1]浙江大学环境科学研究所,杭州310058 [2]浙江省有机污染过程与控制重点实验室,杭州310058 [3]杭州市环境监测中心站,杭州310007

出　　处：《应用生态学报》2014年第4期1171-1180,共10页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(21177106);杭州市科技局项目(20130533B05)资助

摘　　要：应用物种敏感性分布（SSD）方法，可正向和反向评估物种的生态风险及确定保护物种的污染物浓度阈值，为水体生态风险管理提供依据．本文通过采集淡水生物毒性数据，构建SSD方程，在95％物种保护基础上评估微囊藻毒素、氨氮和亚硝态氮对淡水生物的生态风险浓度阈值（HC，）和复合生态风险，以及不同暴露浓度下的潜在影响比例（PAF）．结果表明：微囊藻毒素对淡水生物的HC，值为19．22μg·L-1，其水生态风险高于氨氮（HC，6583．94μg·L-1）和亚硝态氮（HC，334．33μg·L-1）．不同类别生物对微囊藻毒素和氨氮、亚硝态氮的敏感性随暴露浓度不同存在差异．当微囊藻毒素与亚硝态氮的浓度低于临界浓度125．04、2989．40μg·L“时，甲壳类对微囊藻毒素敏感性高于鱼类，对亚硝态氮敏感性则低于鱼类，而高于临界值其物种敏感性呈相反效应，但氨氮所引起的物种敏感性差异不显著．在代表性水体中，复合生态风险高于单一污染风险，微囊藻毒素、氨氮、亚硝态氮对全部物种的复合潜在影响比例msPAF为2．6％～5．6％，且太湖和红枫湖已超过HC5生态风险阈值．Abstract： Species sensitivity distributions （SSDs） used to evaluate the ecological risk and determine protection of aquatic species and ecological quality. methods in both forward and reverse modes were the contaminant concentration threshold for the In this study, the existing toxicity data of fresh- water organisms were fitted to SSD functions to estimate the hazardous concentrations for 5% of the species （ HC5 ） for microcystins, ammonia and nitrite, and the ecological risk of their mixtures. The potentially affected fractions （PAFs） of various concentrations of microcystins, ammonia and nitrite were also calculated. Results showed that microcystins exhibited a higher ecological risk than am- monia and nitrite. The HC5 value for microcystins exposure was 19.22 txg ＂ L-1 whereas the HC5 values for ammonia and nitrite exposure were 6583.94 Ixg ~ L-1 and 334.33 tzg . L-1 , ＇respectively. The sensitivity of freshwater organisms varied with exposed concentrations of microcystins, ammonia and nitrite. Crustaceans were more sensitive than fishes to microcystins, and less sensitive than fi- shes to nitrite when the concentrations of microcystins and nitrite were below 125.04 Ixg ＂ L-1 and 2989.40 Ixg ~ L-1 , respectively, and vice versa when exposed to higher concentrations of micro- cystins and nitrite. No significant difference was observed for the sensitivities of fishes and crustace- ans exposed to ammonia. In studies with selected lakes in China, our results showed that the eco- logical risk in both Tai and Hongfeng lakes exceeded the permissible HC5 threshold, and the multi- ple substance potentially affected fractions （msPAFs） of microcystins, ammonia and nitrite were 2.6%-5.6%, indicating that the ecological individual contaminant being investigated. risk of their mixtures was more threatening than each individual contaminant being investigated.

关 键 词：富营养化水体 微囊藻毒素 氨氮 亚硝态氮 物种敏感性分布 水生态风险 

分 类 号：X52[环境科学与工程—环境工程] X824