Journal
ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY
Volume 25, Issue 2, Pages 623-629Publisher
WILEY
DOI: 10.1897/05-370R.1
Keywords
mixture toxicity; concentration addition; independent action; esfenvalerate; chlorpyrifos
Categories
Ask authors/readers for more resources
The joint toxicity of esfenvalerate and chlorpyrifos to the fathead minnow (Pimephales promelas) and the aquatic midge larvae (Chironomus tentans) was determined using comparisons to independent action (IA) and concentration addition (CA) models. Equipotent mixtures of the two insecticides were used for initial testing of both species. A secondary study evaluating the effects of low-level chlorpyrifos on esfenvalerate toxicity also was performed. For fathead minnows, the equipotent mixture and the low-level chlorpyrifos exposure resulted in toxicity greater than that predicted by either model. In both studies, however, the observed concentrations causing 50% effect (EC50) were within a factor of two of the values predicted by the CA model. For midges, the observed EC50s were similar to the values predicted by the CA model, whereas the IA model slightly underpredicted toxicity. The observance of toxicity that was not predicted by either of the conceptual models tested likely results from a toxicokinetic interaction occurring between the toxicants.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available