Toxicity assessment of polycyclic aromatic hydrocarbons using an air-tight algal toxicity test

Abstract

The existing toxicity data on the effects of polycyclic aromatic hydrocarbons (PAHs) on Pseudokirchneriella subcapitata (green alga) are quite insufficient. These data were derived using different test techniques (e.g. conventional batch test, closed-system test, semi-static test). The relative toxicity relationship for various PAHs is thus difficult to interpret. Consequently, the current toxicity database is insufficient and also inadequate for analyses of the effects of PAHs on P. subcapitata. This study evaluated the toxicity of eleven PAHs using an air-tight test technique. The relative toxicity relationship was determined on a uniform basis, and was different from the relationship based on current available data. P. subcapitata. was found to be more susceptible to PAHs than Daphnia magna, fathead minnow, and Scenedesmus subspicatus. Quantitative structure-activity relationship (QSAR) was established based on the chemical's hydrophobicity with R(2) equal to 0.88. Photo-induced toxicity for various PAHs was also explored by exposing PAHs under UV-photoactivation. Toxicity of anthracene, benzanthrone, and benzo[a]anthracene was found to increase 3.5 to 25 times after UV exposure. Phototoxicity was observed when the HOMO-LUMO gap varied between 6.8 and 8.0 eV.

Chronic toxicity of selected polycyclic aromatic hydrocarbons to algae and crustaceans using passive dosing

“…Generally, literature data show good agreement with the target lipid model up until a log K OW of approximately 5. Above this value, EC50s that are orders of magnitude above the expected solubilities are reported by Chen et al , casting doubt on the reliability of these data. Results obtained from our study fall below the target lipid model prediction at higher log K OW values, consistent with the lack of effects observed (red > symbols in Figure A).…”

Improved Algal Toxicity Test System for Robust Omics-Driven Mode-of-Action Discovery in Chlamydomonas reinhardtii

“…Conventional agitation- and aeration-based exposure vessel systems become highly cumbersome to maintain with increasing experimental scale, and the stability of mid-concentration exposures is difficult in open flask culturing. A variety of solutions has been proposed to address the issue, including tailored complex flasks [68,69,70] and variants of bottle or tube testing [71,72,73,74,75,76,77,78,79]. The lower limit of C. reinhardtii biomass to achieve reproducible data in metabolomics and lipidomics studies has been reported at ca.…”