“三门六科”水质基准最少毒性数据需求原则

Discussion of Minimum "3 Phyla and 6 Families" Toxicity Data Requirements for Deriving Water Quality Criteria

MTDR(最少毒性数据需求)是水质基准推算中数据应用的重要原则.以重金属Pb2+、Cd2+、Cu2+、Zn2+、Hg2+、Cr6+为例,在广泛搜集物种毒性数据的基础上,通过数据比较分析,初步研究了我国水生生物基准的MTDR.结果表明:Hg2+、Pb2+和Cu2+基于"三门六科"推导的急性基准值与基于美国"三门八科"MTDR的推算结果相近,分别相差20.5%、25.2%和33.3%;Cd2+、Zn2+和Cr6+的计算结果差别较为明显,表明相对于美国"三门八科"MTDR,在我国生物毒性数据缺乏的情况下,"三门六科"MTDR对于部分污染物基本可行,但仍具有一定的不确定性."三门六科"包括鲤科、除鲤科外的另一科鱼类(冷水鱼优先)、两栖类、浮游甲壳类、昆虫类和环节动物类.

The Minimum Toxicity Data Requirement （MTDR） is an important data principle in deriving water quality criteria. The MTDRs of water quality criteria in China were preliminarily studied with acute toxicity data of six heavy metals, Pb2＋ , Cd2 ＋ , Cu2 ＋ , Zn2＋ , Hg2＋ and Cr6＋ , through data screening and analysis. The results showed that the derived criteria values for Hg2＋ , Pb2＋ and Cu2＋ using the MTDRs of ＂3 Phyla and 6 Families＂ were similar with the predicted values based on the MTDRs of ＂3 Phyla and 8 Families＂ suggested by the US EPA. The differences were 20. 5% , 25.2% and 33.3% , respectively. In contrast, the differences in the derived values for the other metals, Cd2＋ , Zn2＋ and Cr6＋ were significant using the two different MTDRs. Therefore, ＂3 Phyla and 6 Families＂ is basically feasible for some pollutants in China when lacking toxicity data, although there are some uncertainties. The six families of aquatic organisms are fish species of Cyprinidae, another family of fish （ cold water fish recommended） , amphibians, planktonic crustaceans, insects and annelid.