Document of bibliographic reference 7584

BibliographicReference record

Type

Bibliographic resource

Type of document

Journal article

BibLvlCode

AS

Title

A biotic ligand model predicting acute copper toxicity for Daphnia magna: effects of calcium, magnesium, sodium, potassium and pH

Abstract

The extent to which Ca²⁺, Mg²⁺, Na⁺, K⁺ ions and pH independently mitigate acute copper toxicity for the cladoceran Daphnia magna was examined. Higher activities of Ca²⁺, Mg²⁺, and Na⁺ (but not K⁺) linearly increased the 48-h EC50 (as Cu²⁺ activity), supporting the concept of competitive binding of these ions and copper ions to toxic action or transport sites at the organism−water interface (e.g. fish gill, the biotic ligand). The increase of the EC50 (as Cu²⁺ activity) with increasing H⁺, however, seemed to suggest cotoxicity of CuOH⁺ rather than proton competition. Based on the biotic ligand model (BLM) concept, we developed a methodology to estimate stability constants for the binding of Cu²⁺, CuOH⁺, Ca²⁺, Mg²⁺, Na⁺, and H⁺ to the biotic ligand, solely based on toxicity data. Following values were obtained:  log K_CuBL = 8.02, log K_CuOHBL= 7.45, log K_CaBL = 3.47, log K_MgBL = 3.58, log K_NaBL = 3.19, and log K_HBL ∼ 5.4. Further, we calculated that on average 39% of the biotic ligand sites need to be occupied by copper to induce a 50% acute effect for D. magna after 48 h of exposure. Using the estimated constants, a BLM was developed that can predict acute copper toxicity for D. magna as a function of water characteristics. The presented methodology can easily be applied for BLM development for other organisms and metals. After validation with laboratory and natural waters (including DOC), the developed model will support efforts to improve the ecological relevance of presently applied risk assessment procedures.

WebOfScience code

https://www.webofscience.com/wos/woscc/full-record/WOS:000173162600024

Bibliographic citation

De Schamphelaere, K.A.C.; Janssen, C.R. (2002). A biotic ligand model predicting acute copper toxicity for Daphnia magna: effects of calcium, magnesium, sodium, potassium and pH. Environ. Sci. Technol. 36(1): 48-54. https://dx.doi.org/10.1021/es000253s

Topic

Fresh water

Is peer reviewed

true