Document of bibliographic reference 128727

BibliographicReference record

Type

Bibliographic resource

Type of document

Journal article

BibLvlCode

AS

Title

Development and field validation of a biotic ligand model predicting chronic copper toxicity to Daphnia magna

Abstract

In this study, we developed a toxicity model predicting the long-term effects of copper on the reproduction of the cladoceran Daphnia magna that is based on previously reported toxicity tests in 35 exposure media with different water chemistries. First, it was demonstrated that the acute copper hiotic ligand model (BLM) for D. magna could not serve as a reliable basis for predicting chronic copper toxicity. Consequently, BLM constants for chronic exposures were derived by multiple regression analysis of 21-d median effective concentrations (EC50s; expressed as Cu²⁺ activity) versus physicochemistry from a large toxicity dataset and the results of an additional experiment in which the individual effect of sodium on copper toxicity was investigated. The effect of sodium on chronic toxicity (log KNaBl = 2.91) seemed to be similar to its effect on acute toxicity (log K_NaBl = 3.19). However, in contrast to the acute BLM, no significant calcium, magnesium, or combined competition effect was observed, and an increase in proton competition and bioavailability of CuOH and CuCO, complexes was noted. Some indirect evidence was also found for some limited toxicity of complexes of copper with two of three tested types of dissolved organic matter. Because the latter was only a minor effect, this factor was not included in the chronic Cu BLM. The newly developed model performed well in predicting 21-d EC50s and no-observed-effect concentrations in natural water samples: 79% of the toxicity threshold values were predicted within a factor of two of the observed values. It is clear, however, that more research is needed to provide information on the exact mechanisms that have resulted in different BLM constants for chronic exposures (as opposed to acute exposures). It is suggested that the developed model can contribute to the improvement of risk assessment procedures of copper by incorporating bioavailability of copper in these regulatory exercises.

WebOfScience code

https://www.webofscience.com/wos/woscc/full-record/WOS:000221825600002

Bibliographic citation

De Schamphelaere, K.A.C.; Janssen, C.R. (2004). Development and field validation of a biotic ligand model predicting chronic copper toxicity to Daphnia magna. Environ. Toxicol. Chem. 23(6): 1365-1375. https://dx.doi.org/10.1897/02-626

Topic

Fresh water

Is peer reviewed

true