摘要:

AbstractDDT is a persistent and toxic nonionic organic chemical commonly present as a contaminant in aquatic sediments. As a result of effluent discharges by a chemical company manufacturing DDT on the Redstone Army Arsenal near Huntsville, Alabama, the water column, sediment, and biota of the Huntsville Spring Branch‐Indian Creek stream system (HSB‐IC) became heavily contaminated with DDT and its metabolites, DDE and DDD. Because DDT appeared to be the primary contaminant in the system, an investigation was begun to evaluate equilibrium partitioning theory (EqP) as a basis for predicting the free pore‐water concentrations in and toxicity of DDT‐contaminated sediments from the system. In 10‐d laboratory, flow‐through, water‐only exposures with the amphipodHyalella azteca, LC50 values of 0.07 (0.06‐0.28), 1.66 (1.55‐1.78), and 0.19 (0.16‐0.41) μg/L were determined forp,p′‐DDT, DDE, and DDD, respectively. Bulk sediment toxicity assays also were conducted withHyalella aztecaand pore waters analyzed for thep,p′‐ ando,p′‐isomers of DDT, DDE, and DDD. Measured and EqP‐predicted pore‐water chemical concentrations generally agreed within one order of magnitude. Predicted or measuredHyalella azteca10‐d pore‐water LC50 values for DDT and DDD also were similar to water‐only LC50 values forHyalella azteca.These data demonstrate an effect‐based EqP prediction of the toxicity of field‐collected sediments contaminated by a nonionic organic compound and the potential utility of the EqP app

ISSN:0730-7268    

DOI:10.1002/etc.5620130121

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractThe joint toxicity of some ethyleneamines toSelenastrum capricornutum Daphria magna, andPoecilia reticulatahave been determined as a contribution to the environmental risk assessment of wastewater discharges A few combinations showed antagonistic or synergistic effects, but the majority of combinations were additive at the lethal level Thus additivity appears to be a reasonable assumption for risk assessment purposes of wastewater discharges The design of tests and the bio metrical approach using models describing isobolograms to evaluate test results are described in detail This method and subse quent statistical evaluation procedure were found to be very suitable to determine additivity in aquatic toxicity tests

ISSN:0730-7268    

DOI:10.1002/etc.5620130122

出版商:Wiley Periodicals, Inc.    

年代:1994

数据来源: WILEY