Relationship between acute and chronic toxicity for prevalent organic pollutants in Vibrio fischeri based upon chemical mode of action

Chemicals show diverse modes of action (MOAs) in aquatic organisms depending upon acute and chronic toxicity evaluations. In this study, toxicity data for Vibrio fischeri involving 52 compounds for acute and chronic toxicity were used to determine the congruence of acute and chronic toxicity for assessing MOAs. Using toxic ratios, most of the compounds categorised into MOAs that included baseline, less inert or reactive compounds with acute toxicity were also categorised as baseline, less inert or reactive compounds with chronic toxicity. However, significantly different toxic effects were observed with acute and chronic toxicity for the reactive and specific-acting compounds. The acute-chronic toxic ratios were smaller and less variable for the baseline and less inert compounds, but were greater and more variable for the reactive and specific-acting compounds. Baseline and less inert compounds share same MOAs, but reactive and specific-acting compounds have different MOAs between acute and chronic toxicity. Bioconcentration processes cannot reach an equilibrium for highly hydrophilic and ionised compounds with short-term exposure, resulting in lower toxicity compared to long-term exposure. The authors concluded that the pronounced differences for the antibiotics were not only due to the difference in bioconcentration, but also due to a predicted difference in MOAs during acute and chronic exposures.

Authors: Wang XH, Fan LY, Wang S, Wang Y, Yan LC, Zheng SS, Martyniuk CJ, Zhao YH. ;Full Source: Journal of Hazardous Materiel. 2017 Jun 1; 338:458-465. doi: 10.1016/j.jhazmat.2017.05.058. [Epub ahead of print] ;