Acute-to-chronic ratios of aquatic phototoxicity of polycyclic aromatic hydrocarbons and the prediction of chronic phototoxicity using the phototoxic target lipid model.

This article focuses on evaluating acute-to-chronic ratios (ACRs) of phototoxicity caused by polycyclic aromatic hydrocarbons (PAHs) in aquatic species and testing the extension of the phototoxic target lipid model (PTLM) to predict chronic phototoxicity. Acute and chronic bioassays were conducted on eight aquatic species exposed to three PAHs (anthracene, fluoranthene, and pyrene) under ultraviolet radiation (UVR) and non-UVR conditions, generating new toxicity data. Results showed generally higher ACRs under UVR, though no statistically significant difference was found across species; a global ACR of 11.6 was derived by combining new and literature data. Using the PTLM with this global ACR, predicted chronic phototoxic effect concentrations were mostly within a factor of 10 of observed values, demonstrating the model's capability to predict chronic phototoxicity of PAHs despite variability among species and chemicals.