Bioavailability models for predicting acute and chronic toxicity of zinc to algae, daphnids, and fish in natural surface waters
De Schamphelaere, K.A.C.; Lofts, S.; Janssen, C.R. (2005). Bioavailability models for predicting acute and chronic toxicity of zinc to algae, daphnids, and fish in natural surface waters. Environ. Toxicol. Chem. 24(5): 1190-1197. https://dx.doi.org/10.1897/04-229R.1 In: Environmental Toxicology and Chemistry. Setac Press: New York. ISSN 0730-7268; e-ISSN 1552-8618, more |  |
| Keywords | Bioavailability
Chemical elements > Metals > Heavy metals
Chemical elements > Metals > Heavy metals > Zinc
Ligands
Models
Risk analysis
Toxicity
Toxicology > Ecotoxicology
Water > Surface water
Water quality
Algae; Pisces [WoRMS]; Vertebrata [WoRMS]
Fresh water |
| Authors | | Top | - De Schamphelaere, K.A.C., more
- Lofts, S.
- Janssen, C.R., more
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| Abstract | Bioavailability models predicting acute and/or chronic zinc toxicity to a green alga (Pseudokirchneriella subcapitata), a crustacean (Daphnia magna), and a fish (Oncorhynchus mykiss) were evaluated in a series of experiments with spiked natural surface waters. The eight selected freshwater samples had varying levels of bioavailability modifying parameters: pH (5.7-8.4), dissolved organic carbon (DOC, 2.48-22.9 mg/L), Ca (1.5-80 mg/L), Mg (0.79-18 mg/L), and Na (3.8-120 mg/L). In those waters, chronic zinc toxicity (expressed as 10% effective concentrations [EC10]) varied up to 20-fold for the alga (72-h EC10 from 27.3 to 563 μg Zn/L), and approximately sixfold for the crustacean (21-d EC10 from 59.2 to 387 μg Zn/L), and fivefold for the fish (30-d LC10, lethal concentration for 10% of the organisms, from 185 to 902 μg Zn/L). For P. subcapitata a refined bioavailability model was developed by linking an empirical equation, which predicts toxicity expressed as free Zn2+ activity as a function of pH, to the geochemical speciation model WHAM/Model V. This model and previously developed acute and/or chronic biotic ligand models for D. magna and O. mykiss generally predicted most effect concentrations by an error of less than a factor of two. In waters with pH > 8, however, chronic toxicity to D. magna was underestimated by a factor 3 to 4. Based on the results of this validation exercise and earlier research, we determined applicability ranges for pH (6-8) and Ca (5-160 mg/L) in which all three developed models are valid. Within these ranges, all three models may be considered useful tools for taking into account bioavailability in regulatory assessments of zinc. |
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