Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1021/acs.est.6b06163
Title (Primary) Toxic mixtures in time-the sequence makes the poison
Author Ashauer, R.; O'Connor, I.; Escher, B.I.
Source Titel Environmental Science & Technology
Year 2017
Department ZELLTOX
Volume 51
Issue 5
Page From 3084
Page To 3092
Language englisch
Supplements https://pubs.acs.org/doi/suppl/10.1021/acs.est.6b06163
UFZ wide themes RU3;
Abstract “The dose makes the poison”. This principle assumes that once a chemical is cleared out of the organism (toxicokinetic recovery), it no longer has any effect. However, it overlooks the other process of re-establishing homeostasis, toxicodynamic recovery, which can be fast or slow depending on the chemical. Therefore, when organisms are exposed to two toxicants in sequence, the toxicity can differ if their order is reversed. We test this hypothesis with the freshwater crustacean Gammarus pulex and four toxicants that act on different targets (diazinon, propiconazole, 4,6-dinitro-o-cresol, 4-nitrobenzyl chloride). We found clearly different toxicity when the exposure order of two toxicants was reversed, while maintaining the same dose. Slow toxicodynamic recovery caused carry-over toxicity in subsequent exposures, thereby resulting in a sequence effect–but only when toxicodynamic recovery was slow relative to the interval between exposures. This suggests that carry-over toxicity is a useful proxy for organism fitness and that risk assessment methods should be revised as they currently could underestimate risk. We provide the first evidence that carry-over toxicity occurs among chemicals acting on different targets and when exposure is several days apart. It is therefore not only the dose that makes the poison but also the exposure sequence.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=18888
Ashauer, R., O'Connor, I., Escher, B.I. (2017):
Toxic mixtures in time-the sequence makes the poison
Environ. Sci. Technol. 51 (5), 3084 - 3092 10.1021/acs.est.6b06163